FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
WELD BEAD CRUSHING JIG AND METHOD FOR MANUFACTURING
COMPRESSOR;
MITSUBISHI ELECTRIC CORPORATION, A CORPORATION ORGANISED AND
EXISTING UNDER THE LAWS OF JAPAN, WHOSE ADDRESS IS 7-3,
MARUNOUCHI 2-CHOME, CHIYODA-KU, TOKYO 1008310, JAPAN
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION
AND THE MANNER IN WHICH IT IS TO BE PERFORMED

2
DESCRIPTION
Technical Field
[0001]
The present disclosure relates to a weld bead crushing jig for crushing a weld
5 bead and a method for manufacturing a compressor with the weld bead crushing jig.
Background Art
[0002]
As a related-art compressor including a pressure closed vessel obtained by
joining a body portion, a bottom portion, and a lid portion by welding, there has been
10 disclosed a compressor in which a body portion having a circular cylindrical shape
has a butt welded seam joint where marginal edge portions facing each other in a
circumferential direction are joined together (see, for example, Patent Literature 1).
Citation List
Patent Literature
15 [0003]
Patent Literature 1: Japanese Unexamined Patent Application Publication No.
2009-115015
Summary of Invention
Technical Problem
20 [0004]
In the compressor of Patent Literature 1, a weld bead is formed as a bump on
an inner peripheral surface of the body portion, and the weld bead, which is a part
raised from the inner peripheral surface, is removed by so-called chipping. However,
the removal of the weld bead by chipping is curved surface machining, poses a risk of
25 failure to stably form the weld bead into a shape conforming with an inside diameter
shape of the body portion, and takes a lot of trouble with a cutting process.
[0005]
The present disclosure is aimed at solving the aforementioned problems, and
has as an object to provide a weld bead crushing jig for crushing a weld bead and a
30 method for manufacturing a compressor with the weld bead crushing jig, and the weld

3
bead crushing jig and the method allow a weld bead that is a part raised from an inner
peripheral surface to be stably formed into a shape conforming with an inside
diameter shape of a body portion and save the trouble of a cutting process.
Solution to Problem
5 [0006]
A weld bead crushing jig according to an embodiment of the present disclosure
includes: a fixed receiving die having a columnar shape, having a side wall portion
formed by an outward-convex circular-arc-shaped curved surface, configured to be
inserted into a hollow portion of a seamed steel pipe having a circular cylindrical
10 shape, and disposed to face a weld bead formed to be raised from an inner peripheral
surface of the seamed steel pipe; and a movable roller pressing die formed by a
rotating body having a peripheral wall surface portion formed so that a central portion
of the peripheral wall surface portion in an axial direction of an axis of rotation is
concaved in a circular arc shape, the peripheral wall surface portion being disposed
15 to face the side wall portion via the seamed steel pipe, the peripheral wall surface
portion being configured to press the seamed steel pipe and move along a direction
of extension of the seamed steel pipe while rotating.
[0007]
Further, a method for manufacturing a compressor according to an
20 embodiment of the present disclosure includes: rolling by which a rectangular steel
sheet that is to serve as a body portion of a pressure closed vessel is formed into a
roll shape; pipe shrinking by which the steel sheet formed into the roll shape is formed
into a circular cylindrical shape; butt welding by which opposite marginal edge
portions of the steel sheet formed into the circular cylindrical shape are joined
25 together by welding; weld bead crushing by which a weld bead formed to be raised
from an inner peripheral surface of a welded steel pipe is crushed; and pipe
expanding by which a distortion of the steel pipe is reduced by pressing the inner
peripheral surface of the steel pipe. In the weld bead crushing, a fixed receiving die
having a columnar shape and having a side wall portion formed by an outward30 convex circular-arc-shaped curved surface is inserted into a hollow portion of a

4
seamed steel pipe having a circular cylindrical shape and disposed to face a weld
bead formed to be raised from the inner peripheral surface of the steel pipe, a
movable roller pressing die formed by a rotating body has a peripheral wall surface
portion formed so that a central portion of the peripheral wall surface portion in an
5 axial direction of an axis of rotation is concaved in a circular arc shape, the peripheral
wall surface portion is disposed to face the side wall portion via the seamed steel
pipe, and the peripheral wall surface portion presses the seamed steel pipe and
moves along a direction of extension of the seamed steel pipe while rotating.
Advantageous Effects of Invention
10 [0008]
According to an embodiment of the present disclosure, the side wall portion of
the fixed receiving die is disposed to face the weld bead formed to be raised from the
inner peripheral surface of the seamed steel pipe. The peripheral wall surface
portion of the movable roller pressing die is disposed to face the side wall portion via
15 the seamed steel pipe, and the peripheral wall surface portion presses the seamed
steel pipe and moves along the direction of extension of the seamed steel pipe while
rotating. Therefore, the weld bead formed to be raised from the inner peripheral
surface is held between the peripheral wall surface portion and the side wall portion
and pressed along an inside diameter shape of the seamed steel pipe and along the
20 direction of extension of the seamed steel pipe. This makes it possible to provide a
weld bead crushing jig and a method for manufacturing a compressor, and the weld
bead crushing jig and the method allow a weld bead that is a part raised from the
inner peripheral surface to be stably formed into a shape conforming with an inside
diameter shape of a body portion and save the trouble of a cutting process.
25 Brief Description of Drawings
[0009]
[Fig. 1] Fig. 1 is a longitudinal sectional view schematically showing an
example of a compressor according to Embodiment.
[Fig. 2] Fig. 2 is a schematic view illustrating, in a cross-section taken along line
30 A-A in Fig. 1, an example of the internal structure of a compression mechanism unit of

5
the compressor according to Embodiment.
[Fig. 3] Fig. 3 is a flow chart illustrating processing steps of a method for
manufacturing a body portion that forms a pressure closed vessel.
[Fig. 4] Fig. 4 is a perspective view schematically illustrating the external
5 appearance of a yet-to-be-shaped steel sheet that is used in a process of
manufacturing a body portion of a pressure closed vessel in a process of
manufacturing a compressor of Embodiment.
[Fig. 5] Fig. 5 is a schematic view illustrating the structure of the steel sheet
and the structure of a part of a rolling apparatus before rolling in the process of
10 manufacturing a compressor of Embodiment.
[Fig. 6] Fig. 6 is a schematic view illustrating the structure of the steel sheet
and the structure of the part of the rolling apparatus at the start of the rolling in the
process of manufacturing a compressor of Embodiment.
[Fig. 7] Fig. 7 is a schematic view illustrating the structure of the steel sheet
15 and the structure of the part of the rolling apparatus during the rolling in the process of
manufacturing a compressor of Embodiment.
[Fig. 8] Fig. 8 is a schematic view illustrating the structure of the steel sheet
and the structure of the part of the rolling apparatus at the end of the rolling in the
process of manufacturing a compressor of Embodiment.
20 [Fig. 9] Fig. 9 is a schematic view illustrating the steel sheet and the structure
of a part of a pipe shrinking apparatus at the start of pipe shrinking in the process of
manufacturing a compressor of Embodiment.
[Fig. 10] Fig. 10 is a schematic view illustrating the steel sheet and the
structure of the pipe shrinking apparatus during the pipe shrinking in the process of
25 manufacturing a compressor of Embodiment.
[Fig. 11] Fig. 11 is a schematic view illustrating the steel sheet and the structure
of a part of a butt welding apparatus during butt welding in the process of
manufacturing a compressor of Embodiment.
[Fig. 12] Fig. 12 is a schematic view of a cross-section of a seamed steel pipe
30 formed by executing the rolling, the pipe shrinking, and the butt welding on the steel

6
sheet.
[Fig. 13] Fig. 13 is a schematic top view illustrating the structure of a part of a
weld bead crushing jig during weld bead crushing in the process of manufacturing a
compressor of Embodiment.
5 [Fig. 14] Fig. 14 is a schematic top view illustrating the structure of the part of
the weld bead crushing jig during the weld bead crushing in the process of
manufacturing a compressor of Embodiment.
[Fig. 15] Fig. 15 is a schematic top view of the weld bead crushing jig and the
seamed steel pipe before the weld bead crushing.
10 [Fig. 16] Fig. 16 is a schematic side view of the weld bead crushing jig and the
seamed steel pipe before the weld bead crushing.
[Fig. 17] Fig. 17 is a schematic top view of the weld bead crushing jig and the
seamed steel pipe during the weld bead crushing.
[Fig. 18] Fig. 18 is a schematic side view of the weld bead crushing jig and the
15 seamed steel pipe during the weld bead crushing.
[Fig. 19] Fig. 19 is a schematic view illustrating the cross-section structure of
the seamed steel pipe and the cross-section structure of a part of a pipe expanding jig
before primary pipe expanding in the process of manufacturing a compressor of
Embodiment.
20 [Fig. 20] Fig. 20 is a schematic view illustrating the cross-section structure of
the seamed steel pipe and the cross-section structure of the part of the pipe
expanding jig during the primary pipe expanding in the process of manufacturing a
compressor of Embodiment.
[Fig. 21] Fig. 21 is a diagram illustrating the shape of a body portion of a
25 comparative example after pipe expanding.
[Fig. 22] Fig. 22 is a schematic view of a movable roller pressing die of the weld
bead crushing jig.
[Fig. 23] Fig. 23 is a schematic view of a fixed receiving die of the weld bead
crushing jig.
30 [Fig. 24] Fig. 24 is a cross-sectional schematic view illustrating the seamed

7
steel pipe before the weld bead crushing and a seamed steel pipe of the comparative
example after secondary pipe expanding.
[Fig. 25] Fig. 25 is a conceptual diagram of a weld bead crushing jig based on
the configuration of Comparative Example 1.
5 [Fig. 26] Fig. 26 is a cross-sectional conceptual diagram of a seamed steel pipe
subjected to pipe expanding after being subjected to weld bead crushing by the weld
bead crushing jig based on the configuration of Comparative Example 1.
[Fig. 27] Fig. 27 is a conceptual diagram of a weld bead crushing jig based on
the configuration of Comparative Example 2.
10 [Fig. 28] Fig. 28 is a cross-sectional conceptual diagram of a seamed steel pipe
subjected to pipe expanding after being subjected to weld bead crushing by the weld
bead crushing jig based on the configuration of Comparative Example 2.
[Fig. 29] Fig. 29 is a conceptual diagram of a weld bead crushing jig based on
the configuration of Comparative Example 3.
15 [Fig. 30] Fig. 30 is a cross-sectional conceptual diagram of a seamed steel pipe
subjected to pipe expanding after being subjected to weld bead crushing by the weld
bead crushing jig based on the configuration of Comparative Example 3.
[Fig. 31] Fig. 31 is a diagram summarizing a relationship between the radial
shapes of the fixed receiving die and the movable roller pressing die and the outer
20 and inner peripheral surfaces of the seamed steel pipe and the seamed steel pipe of
the comparative example.
[Fig. 32] Fig. 32 is a conceptual diagram of a weld bead crushing jig based on
the configuration of Comparative Example 4.
[Fig. 33] Fig. 33 is a cross-sectional conceptual diagram of a seamed steel pipe
25 subjected to pipe expanding after being subjected to weld bead crushing by the weld
bead crushing jig based on the configuration of Comparative Example 4.
[Fig. 34] Fig. 34 is a conceptual diagram of a weld bead crushing jig based on
the configuration of Comparative Example 5.
[Fig. 35] Fig. 35 is a conceptual diagram of a weld bead crushing jig based on
30 the configuration of Comparative Example 6.

8
[Fig. 36] Fig. 36 is a cross-sectional conceptual diagram of a seamed steel pipe
subjected to pipe expanding after being subjected to weld bead crushing by the weld
bead crushing jig based on the configuration of Comparative Example 6.
[Fig. 37] Fig. 37 is a diagram summarizing a relationship between the widths
5 Wu and Wr of the fixed receiving die and the movable roller pressing die and the
width Ww of an area of welding heat hardening and roll marks on the seamed steel
pipe.
Description of Embodiments
[0010]
10 Embodiment.
Fig. 1 is a longitudinal sectional view schematically illustrating an example of a
compressor 1 according to Embodiment. The configuration of the compressor 1
according to Embodiment is described with reference to Fig. 1. The compressor 1 is
used in a refrigeration cycle apparatus such as an air-conditioning apparatus, and
15 serves as an element that forms a refrigerant circuit of the refrigeration cycle
apparatus.
[0011]
The following drawings including Fig. 1 omit to illustrate the refrigerant circuit or
other constituent elements, such as a radiator, an evaporator, a decompressor, and
20 an oil separator, that constitute the refrigerant circuit. Further, in the following
drawings, a dimensional relationship between each constituent element and the other
and the shape of each constituent element may be different from actual ones.
Further, the following drawings assign identical signs to identical or similar elements
or portions or omit to assign signs. Further, a positional relationship between each
25 constituent element and the other of the compressor 1 in the following description,
such as a positional relationship between constituent elements placed one above the
other, is in principle a positional relationship that holds when the compressor 1 is
installed in an enabled condition. Further, the directive terms (such as "upper",
"lower", "right", "left", "front", and "back") used as appropriate for ease of
30 comprehension are merely so written for convenience of explanation, and are not

9
intended to limit the placement or orientation of an apparatus or a component.
[0012]
[Configuration of Compressor 1]
The compressor 1 is a rolling-piston single-rotary compressor, and is a fluid
5 machine configured to discharge, as high-pressure gas refrigerant, low-pressure gas
refrigerant suctioned into the compressor 1. The compressor 1 has an enclosure
formed by a pressure closed vessel 2, made of iron, that has a cylindrical shape.
The pressure closed vessel 2 is formed by a body portion 2a having a hollow circular
cylindrical shape, a bottom portion 2b having a U-shaped longitudinal section, and a
10 lid portion 2c having an inverted-U-shaped longitudinal section, and outer surfaces of
openings of the bottom portion 2b and the lid portion 2c are fixed to an inner surface
of an opening of the body portion 2a. A joint where the body portion 2a and the
bottom portion 2b are fixed to each other and a joint where the body portion 2a and
the lid portion 2c are fixed to each other are formed, for example, by arc welding or
15 resistance welding. A method for manufacturing a circular cylindrical body that forms
the body portion 2a of the compressor 1 will be described in detail later.
[0013]
An enclosure 3a of a suction muffler 3 is disposed outside the body portion 2a
of the pressure closed vessel 2. Although not illustrated in the following drawings
20 including Fig. 1, the enclosure 3a of the suction muffler 3 is fixed to the body portion
2a of the pressure closed vessel 2 via a supporting part disposed on an outer surface
of the pressure closed vessel 2. An inflow pipe 3b is fixed to a top portion of the
enclosure 3a of the suction muffler 3 and passes through the enclosure 3a. The
inflow pipe 3b is a refrigerant pipe through which low-pressure gas refrigerant or high25 quality two-phase refrigerant flows into the enclosure 3a of the suction muffler 3.
Further, one end of a suction pipe 4 is fixed to and passes through a bottom portion of
the enclosure 3a of the suction muffler 3, and the other end of the suction pipe 4 is
fixed to and passes through a lateral portion of the body portion 2a of the pressure
closed vessel 2.
30 [0014]

10
The suction muffler 3 is a silencer configured to reduce or eliminate noise
generated by refrigerant flowing thereinto through the inflow pipe 3b. Further, the
suction muffler 3 also functions as an accumulator having a refrigerant accumulation
function of accumulating excess refrigerant and a gas-liquid separation function
5 fulfilled by accumulating liquid refrigerant temporarily generated at the time of a
change in operational state. The gas-liquid separation function of the suction muffler
3 makes it possible to prevent liquid compression from occurring in the compressor 1
due to the inflow of a large amount of liquid refrigerant into the pressure closed vessel
2.
10 [0015]
The inflow pipe 4 is a refrigerant pipe through which low-pressure gas
refrigerant is suctioned from the suction muffler 3 into the pressure closed vessel 2.
A fixing part 6 is disposed in a suction hole 5 provided in the body portion 2a of the
pressure closed vessel 2, and the suction pipe 4 is fixed to the body portion 2a of the
15 pressure closed vessel 2 via the fixing part 6 disposed in the suction hole 5.
Although not illustrated in the following drawings including Fig. 1, the suction pipe 4
may be provided with an oil return hole in a lateral portion thereof and configured
such that a lubricant component contained in high-pressure gas refrigerant separated
by the oil separator of the refrigeration cycle apparatus returns into the pressure
20 enclosed vessel 2 via the suction pipe 4.
[0016]
The fixing part 6 has, for example, a connecting pipe 6a and a ring 6b. The
connecting pipe 6a has one end inserted in the suction hole 5 and communicates with
the interior of the pressure closed vessel 2. The suction pipe 4 is inserted in the
25 other end of the connecting pipe 6a. The ring 6b closes a gap between the suction
pipe 4 and the suction hole 5 by being joined to the suction hole 5 and joined to an
outer surface of the connecting pipe 6a and the pressure closed vessel 2. In the
compressor 1, the airtightness of the interior of the pressure closed vessel 2 is
ensured by the fixing part 6.
30 [0017]

11
A discharge pipe 7 is fixed to and passes through an upper surface of the lid
portion 2c of the pressure closed vessel 2. The discharge pipe 7 is a refrigerant pipe
through which high-pressure gas refrigerant is discharged out of the pressure closed
vessel 2. A joint where the discharge pipe 7 and the lid portion 2c are fixed to each
5 other is formed, for example, by brazing or resistance welding.
[0018]
Furthermore, a glass terminal 8 is disposed in the upper surface of the lid
portion 2c of the pressure closed vessel 2. The glass terminal 8 provides an
interface that is connected to an external power source. The external power source
10 is a power supply device configured to supply electric power to the compressor 1, and
as the external power source, a commercial alternating-current power source whose
alternating-current frequency is 50 Hz or 60 Hz or an inverter power source capable
of change in alternating-current frequency is used. Using an inverter power source
capable of change in frequency makes it possible to change the rotation speed of the
15 compressor 1 and therefore allows the compressor 1 to control the amount of highpressure gas refrigerant that is discharged through the discharge pipe 7. In the
following description, the following drawings including Fig. 1 omit to illustrate the
external power source connected to the glass terminal 8.
[0019]
20 The pressure closed vessel 2 accommodates a motor unit 10, a shaft 20, and a
compression mechanism unit 30 inside. The motor unit 10 is disposed at a higher
position than a position in the pressure closed vessel 2 at which the fixing part 6 is
disposed. The shaft 20 is disposed between the motor unit 10 and the compression
mechanism unit 30 in a central part of the pressure closed vessel 2, and is provided
25 to extend in a vertical direction between the motor unit 10 and the compression
mechanism unit 30. The compression mechanism unit 30 is disposed so that the
interior of the compression mechanism unit 30 communicates with the suction pipe 4.
That is, the motor unit 10 is disposed above the compression mechanism unit 30 in
the pressure closed vessel 2. Further, a hollow space in the pressure closed vessel
30 2 is filled with high-pressure gas refrigerant compressed by the compression

12
mechanism unit 30.
[0020]
The motor unit 10 is formed as a motor configured to generate a rotary drive
force in the shaft 20 using electric power supplied from the external power source and
5 transmit the rotary drive force to the compression mechanism unit 30 via the shaft 20.
The motor 10 includes a stator 12 that is hollow circular cylindrical in external
appearance in top view and a circular cylindrical rotor 14 disposed within an inner
surface of the stator 12 so that the rotor 14 can rotate. The stator 12 is fixed to an
inner surface of the body portion 2a of the pressure closed vessel 2 by, for example,
10 shrink fitting, and is connected to the glass terminal 8 via a lead wire 16. In the
motor unit 10, the electric power supplied from the external power source is supplied
via the lead wire 16 to a wound coil constituting the stator 12, thereby allowing the
rotor 14 to rotate within the inner surface of the stator 12. In the compressor 1, for
example, a DC brushless motor is used as the motor unit 10.
15 [0021]
The shaft 20 is fixed to a central part of the rotor 14 and passes through the
rotor 14. The shaft 20 is a rotating shaft configured to fix the rotor 14 on a fixing
surface 20a that is a part of an outer surface of the shaft 20 and transmit a rotary
drive force of the rotor 14 to the compression mechanism unit 30. The shaft 20 is
20 provided to extend upward and downward from the fixing surface 20a, that is, in a
direction toward the lid portion 2c of the pressure closed vessel 2 and a direction
toward the bottom portion 2b of the pressure closed vessel 2.
[0022]
Further, the shaft 20 has an eccentric portion 24 disposed below the fixing
25 surface 20a and disposed in a position in the compression mechanism unit 30
corresponding to that of a cylinder 31. The eccentric portion 24 is surrounded by a
substantially circular cylindrical piston 26 attached so that the piston 26 can rotate
along an outer surface of the eccentric portion 24. When the shaft 20 is brought into
rotation by the motor unit 10, the piston 26 rotates along an inner peripheral surface
30 of the cylinder 31 within the cylinder 31.

13
[0023]
Further, although not illustrated in the following drawings including Fig. 1, the
shaft 20 may have an oil hole provided in a central part thereof. The oil hole extends
upward from a lower end of the shaft 20. Lubricating oil, suctioned from the lower
5 end of the shaft 20, that serves as refrigerating machine oil 40 flows through the oil
hole. Further, the shaft 20 has a plurality of oil feed ports provided in the outer
surface thereof. The plurality of oil feed ports communicate with the aforementioned
oil hole. Lubricating oil is supplied to the compression mechanism unit 30 through
the plurality of oil feed ports.
10 [0024]
Further, although not illustrated in the following drawings including Fig. 1, a
configuration may be set up in which a centrifugal pump is disposed at a lower end
portion of the oil hole of the shaft 20. The aforementioned centrifugal pump is
configured, for example, as a screw centrifugal pump to be able to suck up the
15 refrigerating machine oil 40 accumulated in the bottom portion 2b of the pressure
closed vessel 2. A usable example of the refrigerating machine oil 40 is lubricating
oil such as mineral lubricating oil, alkylbenzene lubricating oil, polyalkylene glycol
lubricating oil, polyvinyl ether lubricating oil, or polyol ester lubricating oil.
[0025]
20 Fig. 2 is a schematic view illustrating, in a cross-section taken along line A-A in
Fig. 1, an example of the internal structure of the compression mechanism unit 30 of
the compressor 1 according to Embodiment. The following describes the structure
of the compression mechanism unit 30 of the compressor 1 with reference to Figs. 1
and 2.
25 [0026]
With the rotary drive force supplied from the motor unit 10, the compression
mechanism unit 30 compresses, into high-pressure gas refrigerant, low-pressure gas
refrigerant suctioned into a low-pressure space of the pressure closed vessel 2
through the suction pipe 4 and discharges the high-pressure refrigerant gas thus
30 compressed to a higher position than the compression mechanism unit 30.

14
[0027]
The compression mechanism unit 30 includes the cylinder 31, which has a
hollow circular cylindrical shape and which has a pair of hollow disk surfaces 31a, an
inner surface 31b provided to extend between inner edge portions of the pair of
5 hollow disk surfaces 31a, and an outer surface 31c provided to extend between outer
edge portions of the pair of hollow disk surfaces 31a. The outer surface 31c of the
cylinder 31 is fixed to the inner surface of the body portion 2a of the pressure closed
vessel 2 by arc welding such as arc spot welding or shrink fitting. The cylinder 31
has a hollow portion 310, formed by a space surrounded by the inner surface 31b of
10 the cylinder 31, in which the eccentric portion 24 and the piston 26 of the shaft 20 are
accommodated. That is, the cylinder 31 is configured such that in the hollow portion
310 of the cylinder 31, the eccentric portion 24 and the piston 26 of the shaft 20 can
eccentrically rotate as the shaft 20 rotates.
[0028]
15 The cylinder 31 has formed therein a suction passage 312 that communicates
between the suction pipe 4 and the hollow portion 310 of the cylinder 31 via the
connecting pipe 6 and through which low-pressure gas refrigerant flows from the
suction pipe 4 into the hollow portion 310 of the cylinder 31. The suction muffler 3 is
connected to the hollow portion 310 via the suction passage 312. Further, the
20 cylinder 31 has provided in the inner surface thereof a discharge passage 314 having
a semicircular shape and extending in a vertical direction. Further, the cylinder 31
has a vane groove 316 formed in a radial direction between the inner surface 31b of
the cylinder 31 and the outer surface 31c of the cylinder 31 in top view.
[0029]
25 A vane 32 is accommodated in the vane groove 316 of the cylinder 31. The
vane 32 is a slide part configured to reciprocate in a radial direction in the vane
groove 316 with an eccentric motion of the piston 26. A distal portion 32a of the
vane 32 disposed in the hollow portion 310 of the cylinder 31 is always pressed into
contact with an outer surface of the piston 26 by a restoring force of an elastic body
30 33, such as a spring, provided in the vane groove 316 or a pressure from a high-

15
pressure portion above the compression mechanism unit 30. As shown in Fig. 2,
during rotary drive of the piston 26, the hollow portion 310 of the cylinder 31 is
partitioned by the vane 32 and the piston 26 into a low-pressure space portion 310a
communicating with the suction passage 312 and a high-pressure space portion 310b
5 communicating with the discharge passage 314. The low-pressure space portion
310a and the high-pressure space portion 310b serve as spaces that constitute the
after-mentioned compression chamber of the compression mechanism unit 30. In
the compression chamber of the compression mechanism unit 30, the low-pressure
space portion 310a is also referred to as "low-pressure chamber", and the high10 pressure space portion 310b as "high-pressure chamber".
[0030]
Further, the cylinder 31 is provided with a vane groove opening 318, bored
through the pair of hollow disk surfaces 31a of the cylinder 31, that communicates
with the vane 316. In the compression mechanism unit 30, the pressure from the
15 high-pressure portion above the compression mechanism unit 30 can be applied to a
proximal portion 32b of the vane 32 via the vane groove opening 318. Further, with
the vane groove opening 318, the compression mechanism unit 30 can restrict the
movement of the vane 32 toward the outer surface of the cylinder 31. Lubricating oil
separated from the high-pressure gas refrigerant is supplied to a clearance between
20 the vane groove 316 and the vane 32 through the vane groove opening 318 and
allows the vane 32 to smoothly reciprocate.
[0031]
Although not illustrated in the following drawings including Fig. 1, the clearance
between the vane groove 316 and the vane 32 is configured such that no friction is
25 produced between the vane groove 316 and the vane 32. Meanwhile, an increase in
size of the clearance between the vane groove 316 and the vane 32 may lead to a
decrease in compression efficiency by causing refrigerant gas compressed in the
hollow portion 310 of the cylinder 31 to leak out of the compression mechanism unit
30 via the clearance and the vane groove opening 318. Accordingly, in the
30 compression mechanism unit 30, the size of the clearance is reduced to such an

16
extent that no friction is produced between the vane groove 316 and the vane 32.
This makes it possible to reduce leakage of compressed refrigerant gas and bring
about improvement in compression efficiency.
[0032]
5 Further, the cylinder 31 has formed therein a plurality of openings 319 located
close to the outer surface 31c of the cylinder 31 and bored through the pair of hollow
disk surfaces 31a. Lubricating oil, separated from the high-pressure gas refrigerant,
that has moved to an upper hollow disk surface 31a of the cylinder 31 by the action of
gravity can return to the bottom portion 2b of the pressure closed vessel 2 through the
10 openings 319. This allows the compressor 1 to prevent depletion of the refrigerating
machine oil 40.
[0033]
An upper bearing 34 is disposed on the upper hollow disk surface 31a of the
cylinder 31, that is, on a hollow disk surface 31a close to the lid portion 2c of the
15 pressure closed vessel 2. A lower bearing 35 is disposed on a lower hollow disk
surface 31a of the cylinder 31, that is, on a hollow disk surface 31a close to the
bottom portion 2b of the pressure closed vessel 2. The shaft 20 passes through the
upper bearing 34, the cylinder 31, and the lower bearing 35. The upper bearing 34
and the lower bearing 35 are sliding bearings configured to support the shaft 20 so
20 that the shaft 20 can slide. The upper bearing 34 and the lower bearing 35 support
the shaft 20 so that the shaft 20 can rotate.
[0034]
The upper bearing 34 is provided in an upper surface portion of the cylinder 31
and closes an upper opening of the hollow portion 310. The lower bearing 35 is
25 provided in a lower surface portion of the cylinder 31 and closes a lower opening of
the hollow portion 310. In this manner, the upper bearing 34, the cylinder 31, and
the lower bearing 35 are stacked in this order, and the airtightness of the interior of
the hollow portion 310 is ensured by closing the upper and lower openings of the
hollow portion 310 with the upper bearing 34 and the lower bearing 35.
30 [0035]

17
The upper bearing 34 is in the shape of a hollow disk in top view. The upper
bearing 34 has a fixed portion 34a fixed to the upper hollow disk surface 31a of the
cylinder 31 and a bearing portion 34b supporting the outer surface of the shaft 20 so
that the outer surface of the shaft 20 can slide. In the longitudinal sectional view of
5 Fig. 1, the upper bearing 34 is illustrated as two L-shaped parts. Further, the upper
bearing 34 is fixed to the upper hollow disk surface 31a of the cylinder 31, for
example, by a bolt.
[0036]
The lower bearing 35 is in the shape of a hollow disk in bottom view. The
10 lower bearing 35 has a fixed portion 35a fixed to the lower hollow disk surface 31a of
the cylinder 31 and a bearing portion 35b supporting the outer surface of the shaft 20
so that the outer surface of the shaft 20 can slide. In the longitudinal sectional view
of Fig. 1, the lower bearing 35 is illustrated as two L-shaped parts. Further, the lower
bearing 35 is fixed to the lower hollow disk surface 31a of the cylinder 31, for
15 example, by a bolt.
[0037]
A silencer configured to eliminate or reduce noise generated during
compression of refrigerant in the compression mechanism unit 30 can be disposed at
an upper surface of the fixed portion 34a of the upper bearing 34. The silencer can
20 be provided with a plurality of openings through which high-pressure gas flowing in
from a discharge port provided in the upper bearing 34 is discharged into the
pressure closed vessel 2.
[0038]
In the compression mechanism unit 30, a closable space surrounded by the
25 piston 26, the cylinder 31, the vane 32, the fixed portion 34a of the upper bearing 34,
and the fixed portion 35a of the lower bearing 35 forms a compression chamber in
which low-pressure gas refrigerant suctioned through the suction pipe 4 is
compressed. The high-pressure gas refrigerant compressed in the compression
chamber is discharged through the discharge port provided in the upper bearing 34.
30 The discharge port provided in the upper bearing 34 is not illustrated in the following

18
drawings including Fig. 1.
[0039]
While the compressor 1 is configured as a longitudinally mounted compressor
in Embodiment, the compressor 1 may alternatively be configured as a transversely
5 mounted compressor. Further, while the compressor 1 is configured as a rollingpiston rotary compressor in Embodiment, the compressor 1 may alternatively be
configured as a swing-vane swing compressor, a screw compressor, and a scroll
compressor. Further, while the compressor 1 is configured as a single-rotary rotary
compressor, the compressor 1 may alternatively be configured as a twin-rotary rotary
10 compressor. Further, while, in Embodiment, the compressor 1 is configured as a
single-stage compressor to have only one compression mechanism unit 30, the
compressor 1 may alternatively be configured as a multistage compressor to
sequentially compress refrigerant through a plurality of compression mechanism units
30.
15 [0040]
[Operation of Compressor 1]
The following describes an operation of the compressor 1 of Embodiment.
Rotation of the shaft 20 by driving of the motor unit 10 causes the eccentric portion 24
and the piston 26, which are accommodated in the cylinder 31, to eccentrically rotate
20 with the shaft 20. The eccentric rotation of the eccentric portion 24 and the piston 26
causes an outer peripheral surface of the piston 26 to move in contact with the inner
surface 31b of the cylinder 31 in the hollow portion 310 of the cylinder 31. In tandem
with the eccentric rotation of the piston 26 of the cylinder 31, the vane 32, which is
disposed in the vane groove 316 of the cylinder 31, makes a piston motion. Low25 pressure gas refrigerant having flowed from the suction pipe 4 into the compression
mechanism unit 30 via the suction passage 312 flows into the compression chamber,
which is a closed space surrounded by the piston 26, the cylinder 31, the vane 32, the
fixed portion 34a of the upper bearing 34, and the fixed portion 35a of the lower
bearing 35. The low-pressure refrigerant having flowed into the compression
30 chamber is compressed into high-pressure gas refrigerant with a decrease in volume

19
of the compression chamber due to the eccentric rotation of the piston 26. The highpressure gas refrigerant is discharged via the discharge portion provided in the upper
bearing 34 into the hollow space in the pressure closed vessel 2 outside the
compression mechanism unit 30. The high-pressure gas refrigerant discharged into
5 the hollow space in the pressure closed vessel 2 passes, for example, through a gap
between the stator 12 and the rotor 14 of the motor 10 and is discharged out of the
pressure closed vessel 2 via the discharge pipe 7.
[0041]
[Method for Manufacturing Compressor 1]
10 The following describes a method and apparatus for manufacturing a
compressor 1 according to Embodiment.
[0042]
Fig. 3 is a flow chart illustrating processing steps of a method for manufacturing
a body portion 2a that forms a pressure closed vessel 2. The body portion 2a of the
15 pressure closed vessel 2 is manufactured by shaping a steel sheet 50. In more
particular, the body portion 2a is manufactured by performing rolling (step S1), pipe
shrinking (step S2), butt welding (step S3), weld bead crushing (step S4), and pipe
expanding (step S5) on a rectangular steel sheet 50. The following describes
processing steps, namely the rolling (step S1), the pipe shrinking (step S2), and the
20 butt welding (step S3), first and then describes the weld bead crushing (step S4),
which is a feature of the present disclosure.
[0043]
Fig. 4 is a perspective view schematically illustrating the external appearance
of a yet-to-be-shaped steel sheet 50 that is used in a process of manufacturing a
25 body portion 2a of a pressure closed vessel 2 in a process of manufacturing a
compressor 1 of Embodiment. As shown in Fig. 3, the body portion 2a is
manufactured by using a rectangular and flat steel sheet 50 having a first sheet
surface portion 52a serving as a front surface and a second sheet surface portion 52b
serving as a back surface. The first sheet surface portion 52a and the second sheet
30 surface portion 52b are a pair of rectangular sheet surface portions 52. The

20
rectangular steel sheet 50 has its short-side edge portions formed by a first marginal
edge portion 54a and a second marginal edge portion 54b. The first marginal edge
portion 54a and the second marginal edge portion 54b are marginal edge portions
located on sides of the steel sheet 50 opposite to each other. Further, the
5 rectangular steel sheet 50 has its long-side edge portions formed by a third marginal
edge portion 56a and a fourth marginal edge portion 56b. The third marginal edge
portion 56a and the fourth marginal edge portion 56b are marginal edge portions
located on sides of the steel sheet 50 opposite to each other. The steel sheet 50 is
made of a steel material such as stainless steel or carbon steel.
10 [0044]
[Rolling (Step S1)]
Fig. 5 is a schematic view illustrating the structure of the steel sheet 50 and the
structure of a part of a rolling apparatus 100 before rolling in the process of
manufacturing a compressor 1 of Embodiment.
15 [0045]
As shown in Fig. 5, the rolling of the steel sheet 50 involves the use of the
rolling apparatus 100, which includes, for example, a first roller 100a, a second roller
100b, and a third roller 100c. In the rolling apparatus 100, the first roller 100a is
larger in diameter than the second roller 100b and the third roller 100c. The steel
20 sheet 50 is placed so that one of the sheet surface portions 52 of the steel sheet 50,
for example, the second sheet surface portion 52b, makes contact with the first roller
100a.
[0046]
Fig. 6 is a schematic view illustrating the structure of the steel sheet 50 and the
25 structure of the part of the rolling apparatus 100 at the start of the rolling in the
process of manufacturing a compressor 1 of Embodiment. In Fig. 6, the arrows
indicate the direction of pressing of the second roller 100b and the third roller 100c
against the steel sheet 50 at the start of the rolling.
[0047]
30 As shown in Fig. 6, at the start of the rolling, the rolling apparatus 100 performs

21
an operation of pressing the steel sheet 50 toward the first roller 100a by pressing the
second roller 100b and the third roller 100c perpendicularly against the first sheet
surface portion 52a of the steel sheet 50. The operation of pressing the second
roller 100b and the third roller 100c against the steel sheet 50 allows the rolling
5 apparatus 100 to hold the steel sheet 50 between the second roller 100b and the first
roller 100a and between the third roller 100c and the first roller 100a.
[0048]
Fig. 7 is a schematic view illustrating the structure of the steel sheet 50 and the
structure of the part of the rolling apparatus 100 during the rolling in the process of
10 manufacturing a compressor 1 of Embodiment. In Fig. 7, the arrows indicate the
directions of rotation of the first roller 100a, the second roller 100b, and the third roller
100c during the rolling of the steel sheet 50.
[0049]
As shown in Fig. 7, during the rolling of the steel sheet 50, the first roller 100a
15 performs an operation of rotating in a direction opposite to the second roller 100b and
the third roller 100c. For example, as shown in Fig. 7, the rolling apparatus 100
performs an operating of rotating the first roller 100a clockwise and performs an
operation of rotating the second roller 100b and the third roller 100c
counterclockwise. The operations of rotating the first roller 100a, the second roller
20 100b, and the third roller 100c allow the rolling apparatus 100 to roll the steel sheet
50 by moving the steel sheet 50 along the first roller 100a in the direction of rotation
of the first roller 100a.
[0050]
Fig. 8 is a schematic view illustrating the structure of the steel sheet 50 and the
25 structure of the part of the rolling apparatus 100 at the end of the rolling in the process
of manufacturing a compressor 1 of Embodiment.
[0051]
As shown in Fig. 8, the operation of rotating the first roller 100a, the second
roller 100b, and the third roller 100c in the rolling apparatus 100 causes the steel
30 sheet 50 to be formed into a roll shape by the third marginal edge portion 56a being

22
rolled into a C shape. After the rolling of the steel sheet 50, the rolling apparatus 100
performs an operation of moving the second roller 100b and the third roller 100c in a
direction away from the steel sheet 50. After the movement of the second roller
100b and the third roller 100c, the rolling apparatus 100 detaches the steel sheet 50
5 from the first roller 100a.
[0052]
As described above in Figs. 5 to 8, the rectangular steel sheet 50 is formed into
a roll shape by the rolling of the steel sheet 50 in the process of manufacturing a
compressor 1 of Embodiment.
10 [0053]
[Pipe Shrinking (Step S2)]
Fig. 9 is a schematic view illustrating the steel sheet 50 and the structure of a
part of a pipe shrinking apparatus 110 at the start of pipe shrinking in the process of
manufacturing a compressor 1 of Embodiment.
15 [0054]
As shown in Fig. 9, the pipe shrinking of the roll-shaped steel sheet 50 involves
the use of the pipe shrinking apparatus 110, which includes, for example, a first pipe
shrinking die 112 having a first groove portion 112a having a semicircular shape and a
second pipe shrinking die 114 having a second groove portion 114a having a
20 semicircular shape. In the pipe shrinking apparatus 110, the first groove portion
112a of the first pipe shrinking die 112 is disposed to face the second groove portion
114a of the second pipe shrinking die 114. At the start of the pipe shrinking, the
steel sheet 50, which was rolled into a roll shape, is held between the first and second
groove portions 112a and 114a of the pipe shrinking apparatus 110.
25 [0055]
Fig. 10 is a schematic view illustrating the steel sheet 50 and the structure of
the pipe shrinking apparatus 110 during the pipe shrinking in the process of
manufacturing a compressor 1 of Embodiment. In Fig. 10, the arrows indicate the
direction of pressing of the second pipe shrinking die 114 during the pipe shrinking of
30 the steel sheet 50.

23
[0056]
As shown in Fig. 10, during the pipe shrinking of the steel sheet 50, the pipe
shrinking apparatus 110 performs an operation of pressing the second pipe shrinking
die 114 toward the first pipe shrinking die 112. The operation of pressing the second
5 pipe shrinking die 114 allows the pipe shrinking apparatus 110 to bring the first and
second marginal edge portions 54a and 54b of the steel sheet 50 into contact with
each other. Further, the operation of pressing the second pipe shrinking die 114
causes the steel sheet 50, which is held between the first groove portion 112a and the
second groove portion 114a, to be formed into a circular cylindrical shape. After the
10 end of the pipe shrinking of the steel sheet 50, the pipe shrinking apparatus 110
performs an operation of moving the second pipe shrinking die 114 in a direction
away from the steel sheet 50. After the movement of the second pipe shrinking die
114, the pipe shrinking apparatus 110 detaches the steel sheet 50 from the first pipe
shrinking die 112.
15 [0057]
As described above in Figs. 9 and 10, the roll-shaped steel sheet 50 is formed
into a circular cylindrical shape by the pipe shrinking of the steel sheet 50 in the
process of manufacturing a compressor 1 of Embodiment. This causes the steel
sheet 50 to be formed into such a shape that ends of the steel sheet 50 facing each
20 other, namely the first marginal edge portion 54a and the second marginal edge
portion 54b, are in contact with each other.
[0058]
[Butt Welding (Step S3)]
Fig. 11 is a schematic view illustrating the steel sheet 50 and the structure of a
25 part of a butt welding apparatus 120 during butt welding in the process of
manufacturing a compressor 1 of Embodiment. In Fig. 11, the arrow indicates the
direction of movement of the butt welding apparatus 120 during the butt welding. As
shown in Fig. 11, the first and second marginal edge portions 54a and 54b of the steel
sheet 50, which was formed into a circular cylindrical shape by the pipe shrinking, are
30 joined together by the butt welding apparatus 120. That is, in the butt welding, the

24
butt welding apparatus 120 forms a welded seam joint between the ends of the steel
sheet 50 brought into contact with each other by the pipe shrinking.
[0059]
The butt welding apparatus 120 can be configured, for example, as a welding
5 apparatus for use in resistance welding such as seam welding or a welding apparatus
for use in arc welding such as TIG welding. The butt welding apparatus 120 includes
a welding torch 122 configured to weld together the first and second marginal edge
portions 54a and 54b of the steel sheet 50. Further, although not illustrated in Fig.
11, the butt welding apparatus 120 includes a welding power source configured to
10 convert, into electric power for use in welding, alternating-current power supplied, for
example, from a commercial alternating-current power source and a welding
transformer configured to amplify, for use in welding, an electric current flowing from
the welding power source and pass the electric current through the welding torch 122.
A welding electrode 124 is attached to a tip 122a of the welding torch 122. The
15 welding electrode 124 can be configured, for example, as a pure-metallic electrode
such as a pure-tungsten electrode or a pure-molybdenum electrode or an alloy
electrode such as a copper-chromium alloy electrode or a copper-alumina alloy
electrode.
[0060]
20 Instead of being joined together by welding, the first and second marginal edge
portions 54a and 54b of the steel sheet 50 may be joined together, for example, by
brazing.
[0061]
A seamed steel pipe 50a that forms the body portion 2a of the circular
25 cylindrical pressure closed vessel 2 is formed by the butt welding of the steel sheet 50
in the process of manufacturing a compressor 1 of Embodiment. That is, the steel
sheet 50 is subjected to the rolling, the pipe shrinking, or other processing so that the
sheet surface portions 52 of the steel sheet 50 are formed into a circular cylindrical
shape and the third and fourth marginal edge portions 56a and 56b, which are
30 marginal edge portions of the steel sheet 50, are formed into a circular shape. Then,

25
the seamed steel pipe 50a is manufactured by the butt welding by which the first and
second marginal edge portions 54a and 54b of the steel sheet 50 facing each other
are joined together, for example, by welding.
[0062]
5 Fig. 12 is a schematic view of a cross-section of the seamed steel pipe 50a
formed by executing the rolling, the pipe shrinking, and the butt welding on the steel
sheet 50. As shown in Fig. 12, a back bead 131 that is a weld bead is formed as a
bump on an inner peripheral surface of the seamed steel pipe 50a. The weld bead
is a raised area of weld marks generated by welding. The back bead 131 is raised
10 from an inner surface 50b of the seamed steel pipe 50a. In the process of
manufacturing a compressor 1 of Embodiment, the seamed steel pipe 50a
manufactured through the foregoing steps is subjected to the next step, namely the
weld bead crushing (step S4).
[0063]
15 [Weld Bead Crushing (Step S4)]
Fig. 13 is a schematic top view illustrating the structure of a part of a weld bead
crushing jig 90 during weld bead crushing in the process of manufacturing a
compressor 1 of Embodiment. Fig. 14 is a schematic top view illustrating the
structure of the part of the weld bead crushing jig 90 during the weld bead crushing in
20 the process of manufacturing a compressor 1 of Embodiment. The weld bead
crushing jig 90, which is used for the weld bead crushing, is described with reference
to Figs. 13 and 14. Although the weld bead crushing can be performed by the weld
bead crushing jig 90 performing a process of removing a bead from the seamed steel
pipe 50a immediately after welding (melting) in the aforementioned butt welding, the
25 bead weld crushing is characterized in being able to be performed by the weld bead
crushing jig 90 performing a process of removing a cooled bead from the seamed
steel pipe 50a after welding and cooling.
[0064]
As shown in Figs. 13 and 14, the weld bead crushing jig 90 includes a fixed
30 receiving die 91 having a semicylindrical shape in top view, a housing 92 to which the

26
fixed receiving die 91 is fixed, and a movable roller pressing die 93 having a
hourglass shape.
[0065]
The fixed receiving die 91 is a columnar part formed so that a D-shaped cross5 section of the fixed receiving die 91 continuously extends. The fixed receiving die 91
is formed by an outward-convex circular-arc-shaped curved surface, and has a side
wall portion 91a facing the movable roller pressing die 93. The side wall portion 91a
forms one side surface of the fixed receiving die 91. The side wall portion 91a has a
circular arc shape in a cross-section perpendicular to the direction of extension of the
10 fixed receiving die 91, which has a columnar shape.
[0066]
The movable roller pressing die 93 is a rotating body having a peripheral wall
surface portion 93a formed so that a central portion of the peripheral wall surface
portion 93a in the axial direction of an axis of rotation RS is concaved in a circular arc
15 shape. In more particular, the movable roller pressing die 93 is shaped so that the
center of a roller in the axial direction is smaller in diameter than both ends of the
roller. The movable roller pressing die 93 has the peripheral wall portion 93a facing
the fixed receiving die 91. The peripheral wall surface portion 93a of the movable
roller pressing die 93 is formed so that a wall surface between both ends of the axis
20 of rotation RS in the axial direction has a circular arc shape concaved in the axial
direction, and the shape is a shape that continues in a circumferential direction with
the axis of rotation RS at the center. The axis of rotation RS of the movable roller
pressing die 93 orthogonally intersects the fixed receiving die 91, which has a
columnar shape.
25 [0067]
In the weld bead crushing jig 90, the side wall portion 91a and a part of the
peripheral wall surface portion 93a face each other. The weld bead crushing jig 90 is
configured such that the peripheral wall portion 93a, which has a concave shape,
fitted onto the side wall portion 91a, which has a convex shape, via the seamed steel
30 pipe 50a. The housing 92 of the weld bead crushing jig 90 is fixed to a weld bead

27
crushing fixture (not illustrated). Therefore, the fixed receiving die 91 is fixed to the
weld bead crushing fixture (not illustrated) via the housing 92.
[0068]
Fig. 15 is a schematic top view of the weld bead crushing jig 90 and the
5 seamed steel pipe 50a before the weld bead crushing. Fig. 16 is a schematic side
view of the weld bead crushing jig 90 and the seamed steel pipe 50a before the weld
bead crushing. In Figs. 15 and 16, the arrows indicate the direction of movement of
the weld bead crushing jig 90 during the weld bead crushing. The following
describes processing in the process of manufacturing a compressor 1 of Embodiment
10 through which to crush a weld bead formed on the seamed steel pipe 50a
manufactured by the rolling, pipe shrinking, and butt welding of the steel sheet 50.
As shown in Figs. 15 and 16, in the weld bead crushing, the fixed receiving die 91
and the housing 92 are inserted into the seamed steel pipe 50a. In this state, the
fixed receiving die 91 faces the inner surface 50b of the seamed steel pipe 50a and
15 the back bead 131 formed on the inner surface 50b. That is, the fixed receiving die
91 is inserted into a hollow portion of the seamed steel pipe 50a formed into a circular
cylindrical shape, and the side wall portion 91a is disposed to face the back bead 131
formed to be raised from the inner peripheral surface of the seamed steel pipe 50a.
In this state, the seamed steel pipe 50a is placed between the fixed receiving die 91
20 and the movable roller pressing die 93. At this point in time, the back bead 131 may
be just molten or may be cooled. In the weld bead crushing jig 90, the insertion of
the fixed receiving die 91 and the housing 92 into the seamed steel pipe 50a causes
the movable roller pressing die 93 to move toward the fixed receiving die 91 as
indicated by the arrows in Figs. 15 and 16.
25 [0069]
Fig. 17 is a schematic top view of the weld bead crushing jig 90 and the
seamed steel pipe 50a during the weld bead crushing. Fig. 18 is a schematic side
view of the weld bead crushing jig 90 and the seamed steel pipe 50a during the weld
bead crushing. As shown in Figs. 17 and 18, in the weld bead crushing jig 90, the
30 seamed steel pipe 50a is held between the movable roller pressing die 93 and the

28
fixed receiving die 91. Then, the weld bead crushing jig 90 presses the seamed
steel pipe 50a with the movable roller pressing die 93 and moves the movable roller
pressing die 93 in the axial direction of the seamed steel pipe 50a. In Figs. 17 and
18, the movable roller pressing die 93 moves from a higher position to a lower
5 position while rotating. That is, the movable roller pressing die 93 is disposed to
face the side wall portion 91a via the seamed steel pipe 50a and, the peripheral wall
portion 93a presses the seamed steel pipe 50a and moves along the direction of
extension of the seamed steel pipe 50a while rotating. The seamed steel pipe 50a
has the back bead 131 crushed by the movable roller pressing die 93 pressing the
10 seamed steel pipe 50a and moving along the direction of extension of the seamed
steel pipe 50a while rotating. While the movable roller pressing die 93 is pressing
the seamed steel pipe 50a and moving along the seamed steel pipe 50a, the fixed
receiving die 91 is fixed to the housing 92 and does not move.
[0070]
15 The steel sheet 50 is subjected to the rolling, the pipe shrinking, or other
processing so that the sheet surface portions 52 of the steel sheet 50 are formed into
a circular cylindrical shape and the third and fourth marginal edge portions 56a and
56b, which are marginal edge portions of the steel sheet 50, are formed into a circular
shape. Then, the seamed steel pipe 50a is manufactured by the butt welding by
20 which the first and second marginal edge portions 54a and 54b of the steel sheet 50
are joined together, for example, by welding. Furthermore, the execution of the weld
bead crushing on the seamed steel pipe 50a causes the back bead 131 formed on
the seamed steel pipe 50a to be crushed, whereby a circular cylindrical body that is to
serve as the body portion 2a of the pressure closed vessel 2 is manufactured.
25 Measures in the weld bead crushing to improve the circularity of the body portion 2a
will be described later.
[0071]
[Pipe Expanding (Step S5)]
Fig. 19 is a schematic view illustrating the cross-section structure of the
30 seamed steel pipe 50a and the cross-section structure of a part of a pipe expanding

29
jig 70 before primary pipe expanding in the process of manufacturing a compressor 1
of Embodiment. Fig. 20 is a schematic view illustrating the cross-section structure of
the seamed steel pipe 50a and the cross-section structure of the part of the pipe
expanding jig 70 during the primary pipe expanding in the process of manufacturing a
5 compressor 1 of Embodiment. Fig. 20 uses a hatched block arrow to indicate the
direction of movement of a rod portion 72 during the primary pipe expending and uses
outline block arrows to indicate the directions of movement of a pipe expanding die
portion 71 entailed by the movement of the rod portion 72.
[0072]
10 The following describes the step of, in the process of manufacturing a
compressor 1 of Embodiment, performing pipe expanding on the seamed steel pipe
50a obtained by executing the rolling, the pipe shrinking, the butt welding, and the
weld bead crushing on the steel sheet 50. The step of performing pipe expanding on
the seamed steel pipe 50a is intended to, by pressing an inner wall surface of the
15 body portion 2a of the pressure closed vessel 2 manufactured by the rolling, pipe
shrinking, and butt welding of the steel sheet 50, reduce a distortion of the body
portion 2a, and is hereinafter referred to as "primary pipe expanding".
[0073]
As shown in Fig. 19, the pipe expanding jig 70 includes the pipe expanding die
20 portion 71, which performs the primary pipe expanding of the seamed steel pipe 50a,
and a casing portion 73 supporting the pipe expanding die portion 71. Further, the
pipe expanding jig 70 includes the rod portion 72, which is disposed in the pipe
expanding die portion 71 and the casing portion 73 so that the rod portion 72 can
reciprocate.
25 [0074]
The pipe expanding die portion 71 has a circular cylindrical shape. The pipe
expanding die portion 71 is divided in a circumferential direction. That is, the pipe
expanding die portion 71 is formed by a plurality of separate component parts being
combined in a circumferential direction. As shown in Fig. 19, the pipe expanding die
30 portion 71 has formed therein a first hollow space portion 76 surrounded by a first

30
inner surface portion 71a of the pipe expanding die portion 71. The first hollow
space portion 76 is configured as a frustum-shaped space such that the first hollow
space portion 76 decreases in opening area with distance from the casing portion 73.
[0075]
5 The casing portion 73 has formed therein a second hollow space portion 77
surrounded by a second inner surface portion 73a of the casing portion 73. The
second hollow space portion 77 allows the first hollow space portion 76 to
communicate with a space outside the casing portion 73. The second hollow space
portion 77 is formed, for example, as a column-shaped space that is larger in opening
10 area than the first hollow space portion 76. Further, although not illustrated in Figs.
19 and 20, the casing portion 73 is fixed to a support to ensure stability during the
primary pipe expanding and reliability of the primary pipe expanding. The casing
portion 73 needs only be shaped to be able to be fixed to the support and can be
configured, for example, to be cubic or circular cylindrical in external appearance.
15 [0076]
As shown in Fig. 19, the rod portion 72 has a frustum-shaped insertion portion
78. That is, the rod portion 72 has a tapered shape. The insertion portion 78 of the
rod portion 72 is accommodated in the first hollow space portion 76 of the pipe
expanding die portion 71 via the second hollow space portion 77 of the casing portion
20 73.
[0077]
The following describes an example of the primary pipe expanding of the
seamed steel pipe 50a. First, the pipe expanding jig 70 is inserted into a hollow of
the seamed steel pipe 50a after the weld bead crushing. Next, the rod portion 72,
25 which is disposed in a central part of the pipe expanding die portion 71, divided into a
plurality of parts in a circumferential direction, which has a circular cylindrical shape,
is pushed in the axial direction, whereby the pipe expanding die portion 71 expands.
Then, the expansion of the pipe expanding die portion 71 causes the seamed steel
pipe 50a to be pressed from inside out by an outer surface 71b of the pipe expanding
30 die portion 71 to a desired inside diameter.

31
[0078]
After the end of the primary pipe expanding, the seamed steel pipe 50a is
subjected to double-end processing. In the double-end processing, peripheral edge
portions of both end portions of the seamed steel pipe 50a after the primary pipe
5 expending are machined by an end face processing apparatus such as a lathe. By
end face processing of both end portions of the seamed steel pipe 50a, the seamed
steel pipe 50a is processed until the length between both end portions of the seamed
steel pipe 50a becomes equal to a desired length or, for example, the length between
both end portions of the body portion 2a of the pressure closed vessel 2 of the
10 compressor 1 thus finished.
[0079]
After the end of the double-end processing, the seamed steel pipe 50a is
subjected to circumferential welding. In the circumferential welding, the bottom
portion 2b is fitted onto one end of the seamed steel pipe 50a after the double-end
15 processing, and the fit between the seamed steel pipe 50a and the bottom portion 2b
is fixed by welding. Instead of being joined together by welding, the seamed steel
pipe 50a and the bottom portion 2b of the pressure closed vessel 2 may be joined
together, for example, by brazing.
[0080]
20 After the end of the double-end processing, the seamed steel pipe 50a is
subjected to suction hole making. In the suction hole making, a suction hole 5 is
bored through the seamed steel pipe 50 by a boring apparatus such as a drill. To
the suction hole 5 formed in the seamed steel pipe 50a, a connecting pipe 6a and a
ring 6b are joined, for example, by welding or brazing. The aforementioned boring of
25 the suction hole 5 through the seamed steel pipe 50a and the aforementioned joining
of the connecting pipe 6a and the ring 6b to the seamed steel pipe 50a, for example,
by welding or brazing create a distortion in the inside diameter of the seamed steel
pipe 50a.
[0081]
30 In the process of manufacturing a compressor 1 of Embodiment, pipe

32
expanding is performed by a pipe expanding jig (not illustrated) to reduce the
aforementioned distortion and make the inside diameter of the body portion 2a of the
pressure closed vessel 2 uniform. The pipe expanding performed by the pipe
expanding jig is hereinafter referred to as "secondary pipe expanding".
5 [0082]
Fig. 21 is a diagram illustrating the shape of a body portion 2a1 of a
comparative example after pipe expanding. In the secondary pipe expanding, the
distortion in the inside diameter of the seamed steel pipe 50a created, for example, by
the suction hole making is corrected by the seamed steel pipe 50a being expanded to
10 a desired inside diameter by a pipe expanding jig 70 of the same structure as that
used in the primary pipe expanding, whereby the body portion 2a is manufactured.
However, at this point in time, the inside diameter shape of the body portion 2a may
not be completely corrected even after the pipe expanding due, for example, to roll
marks produced at the start of the rolling and welding heat hardening caused by the
15 butt welding, with the result that the circularity of the inside diameter of the body
portion 2a may not be improved. For example, as shown in Fig. 21, the body portion
2a1 of the comparative example after the pipe expanding may have a droplet shape.
[0083]
The method for manufacturing a compressor 1 according to Embodiment of the
20 present disclosure is characterized by inhibiting the body portion 2a from having a
droplet shape after the pipe expanding, and the following describes specific measures
in the weld bead crushing as measures to improve the circularity of the body portion
2a.
[0084]
25 [Measures to Improve Circularity of Body Portion 2a]
First, the trial manufacture of a seamed steel pipe 50a is conducted more than
once based on the process of manufacturing a compressor 1 of Embodiment.
Because of the poor circularity, such as the droplet shape of the body portion 2a after
the pipe expanding, in the trial manufacture of a seamed steel pipe 50a, measures
30 are taken at the stage of weld bead crushing as measures to improve the circularity of

33
the body portion 2a after the pipe expanding. As measures to improve the circularity
of the body portion 2a, the fixed receiving die 91 and the movable roller pressing die
93 are configured such that a relationship between the radial shapes of the fixed
receiving die 91 and the movable roller pressing die 93 and the radial shapes of the
5 outer and inner peripheral surfaces of the seamed steel pipe 50a and a seamed steel
pipe 50a1 of the comparative example satisfies the following expressions. The
expressions are Radius Riw < Radius Ru  Radius Rie, Radius Row < Radius Rr 
Radius Roe, and Radius Rr - Radius Ru = t (where t is the wall thickness of a steel
pipe). Further, the fixed receiving die 91 and the movable roller pressing die 93 are
10 configured such that a relationship between the widths Wu and Wr of the fixed
receiving die 91 and the movable roller pressing die 93 and the width Ww of an area
of welding heat hardening and roll marks on the seamed steel pipe 50a satisfies
Width Wu  Width Ww < Width Wr. The dimensions of the seamed steel pipe 50a of
the comparative example are derived at the stage of trial manufacture of the
15 compressor 1 and, with the radial shapes specified based on values obtained by
conducting the trial manufacture of a seamed steel pipe 50a more than once, are
utilized in the actual manufacture of all compressors 1. The following specifically
describes the content of each of the above expressions.
[0085]
20 Fig. 22 is a schematic view of the movable roller pressing die 93 of the weld
bead crushing jig 90. Fig. 23 is a schematic view of the fixed receiving die 91 of the
weld bead crushing jig 90. As shown in Figs. 22 and 23, the bend radius of the
radial shape of the side wall portion 91a of the fixed receiving die 91 in top view is
defined as the radius Ru. Further, the bend radius of the radial shape of the
25 peripheral wall surface portion 93a of the movable roller pressing die 93 in top view is
defined as the radius Rr.
[0086]
Fig. 24 is a cross-sectional schematic view illustrating the seamed steel pipe
50a before the weld bead crushing and the seamed steel pipe 50a1 of the
30 comparative example after secondary pipe expanding. The bend radii of the radial

34
shapes of the inner and outer peripheral surfaces 51 and 53 of the seamed steel pipe
50a before the primary pipe expanding of the seamed steel pipe 50a, that is, before
the weld bead crushing, are defined as the radii Riw and Row, respectively. The
bend radii of the radial shapes of inner and outer peripheral surfaces 51a and 53a of
5 the seamed steel pipe 50a1 of the comparative example after the secondary pipe
expanding are defined as the radii Rie and Roe, respectively.
[0087]
Assume here that the relationship between the radial shapes of the fixed
receiving die 91 and the movable roller pressing die 93 and the radial shapes of the
10 outer and inner peripheral surfaces of the seamed steel pipe 50a and the seamed
steel pipe 50a1 of the comparative example satisfies Radius Riw < Radius Ru 
Radius Rie and Radius Row < Radius Rr  Radius Roe. Assume also that the radial
shapes of the fixed receiving die 91 and the movable roller pressing die 93 satisfies
Radius Rr - Radius Ru = t (where t is the wall thickness of a steel pipe).
15 [0088]
The following describes the width of the weld bead crushing jig 90 in the axial
direction of the axis of rotation RS. As shown in Fig. 22, the width of the movable
roller pressing die 93 in the axial direction of the axis of rotation RS in top view is
defined as the width Wr. The width Wr is a direct distance between both ends
20 portions 93b of the movable roller pressing die 93 in the axial direction of the axis of
rotation RS. As shown in Fig. 23, the width of the fixed receiving die 91 in the axial
direction of the axis of rotation RS in top view is defined as the width Wu. The width
Wu is a direct distance between both ends portions 91b of the side wall portion 91a of
the fixed receiving die 91 in top view. As shown in Fig. 24, the width of an area of a
25 weld heat-hardened zone and roll marks on the seamed steel pipe 50a is defined as
the width Ww. The width WW is a direct distance between both ends portions 50e of
the area of the weld heat-hardened zone and the roll marks in a circumferential
direction of the seamed steel pipe 50a on an outer surface of the seamed steel pipe
50a. The width Ww is specified based on values obtained by conducting the trial
30 manufacture of a seamed steel pipe 50a more than once based on the process of

35
manufacturing a compressor 1 of Embodiment, and is utilized in the manufacture of
all compressors 1.
[0089]
Assume here that the relationship between the widths Wu and Wr of the fixed
5 receiving die 91 and the movable roller pressing die 93 and the width Ww of the area
of welding heat hardening and roll marks on the seamed steel pipe 50a satisfies
Width Wu  Width Ww < Width Wr.
[0090]
The following explains a reason why it is assumed that the relationship
10 between the fixed receiving die 91 and the movable roller pressing die 93 and the
seamed steel pipe 50a and the seamed steel pipe 50a1 of the comparative example
satisfies Radius Riw < Radius Ru  Radius Rie, Radius Row < Radius Rr  Radius
Roe, and Radius Rr - Radius Ru = t (where t is the wall thickness of a steel pipe).
[0091]
15 Fig. 25 is a conceptual diagram of a weld bead crushing jig 90A based on the
configuration of Comparative Example 1. Fig. 26 is a cross-sectional conceptual
diagram of a seamed steel pipe 50a2 subjected to pipe expanding after being
subjected to weld bead crushing by the weld bead crushing jig 90A based on the
configuration of Comparative Example 1. In Comparative Example 1, the weld bead
20 crushing jig 90A is configured such that the radius Rus of the fixed receiving die 91
and the radius Rrs of the movable roller pressing die 93 are smaller than the radii Riw
and Row of the seamed steel pipe 50a before the weld bead crushing. Furthermore,
in Comparative Example 1, the weld bead crushing jig 90A is configured such that the
radius Rus of the fixed receiving die 91 is smaller than the radius Ru and the radius
25 Rrs of the movable roller pressing die 93 is smaller than the radius Rr.
[0092]
In a case where the weld bead crushing jig 90A based on the configuration of
Comparative Example 1 is used in the weld bead crushing, the shape of the seamed
steel pipe 50a2 after the pipe expanding is such that as shown in Fig. 26, a processed
30 portion 56 formed by the weld bead crushing undesirably has a convex shape. In a

36
case where the weld bead crushing jig 90A based on the configuration of
Comparative Example 1 is used in the weld bead crushing, the weld heat-hardened
zone and the roll marks on the seamed steel pipe 50a2 can be corrected, but even
after the pipe expanding, a distortion of the seamed steel pipe 50a based on the weld
5 bead crushing remains uncorrected.
[0093]
Fig. 27 is a conceptual diagram of a weld bead crushing jig 90B based on the
configuration of Comparative Example 2. Fig. 28 is a cross-sectional conceptual
diagram of a seamed steel pipe 50a3 subjected to pipe expanding after being
10 subjected to weld bead crushing by the weld bead crushing jig 90B based on the
configuration of Comparative Example 2. In Comparative Example 2, the weld bead
crushing jig 90B is configured such that the radius Rul of the fixed receiving die 91
and the radius Rrl of the movable roller pressing die 93 are larger than the radii Rie
and Roe of the seamed steel pipe 50a1 after the secondary pipe expanding.
15 Furthermore, in Comparative Example 2, the weld bead crushing jig 90B is configured
such that the radius Rul of the fixed receiving die 91 is larger than the radius Ru and
the radius Rrl of the movable roller pressing die 93 is larger than the radius Rr.
[0094]
In a case where the weld bead crushing jig 90B based on the configuration of
20 Comparative Example 2 is used in the weld bead crushing, the shape of the seamed
steel pipe 50a3 after the pipe expanding is such that as shown in Fig. 28, a processed
portion 57 formed by the weld bead crushing undesirably has a flat shape. In a case
where the weld bead crushing jig 90B based on the configuration of Comparative
Example 2 is used in the weld bead crushing, the weld heat-hardened zone and the
25 roll marks on the seamed steel pipe 50a3 can be corrected, but even after the pipe
expanding, a distortion of the seamed steel pipe 50a based on the weld bead
crushing remains uncorrected.
[0095]
Fig. 29 is a conceptual diagram of a weld bead crushing jig 90C based on the
30 configuration of Comparative Example 3. Fig. 30 is a cross-sectional conceptual

37
diagram of a seamed steel pipe 50a4 subjected to pipe expanding after being
subjected to weld bead crushing by the weld bead crushing jig 90C based on the
configuration of Comparative Example 3. In Comparative Example 3, the weld bead
crushing jig 90C is configured such that the radius Rud of the fixed receiving die 91 is
5 larger than the radius Rrd of the movable roller pressing die 93. For example, the
weld bead crushing jig 90C is configured such that the radius Rud is larger than the
radius Ru and the radius Rrd is smaller than the radius Rr.
[0096]
In a case where the weld bead crushing jig 90C based on the configuration of
10 Comparative Example 3 is used in the weld bead crushing, the shape of the seamed
steel pipe 50a4 after the pipe expanding is such that as shown in Fig. 30, a processed
portion 58 formed by the weld bead crushing undesirably has a mountain shape. In
this state, the seamed steel pipe 50a crushed against the fixed receiving die 91 by the
movable roller pressing die 93 at two points, namely both end portions 93b, remains
15 uncorrected even after the pipe expanding.
[0097]
Fig. 31 is a diagram summarizing a relationship between the radial shapes of
the fixed receiving die 91 and the movable roller pressing die 93 and the outer and
inner peripheral surfaces of the seamed steel pipe 50a and the seamed steel pipe
20 50a1 of the comparative example. For the reason shown in Comparative Examples
1 to 3, the radii Ru and Rr of the weld bead crushing jig 90 need to satisfy the above
expressions for improvement in the inside diameter shape of the seamed steel pipe
50a after the pipe expanding and improvement in the inside diameter circularity of the
seamed steel pipe 50a. That is, the radial shapes of the weld bead crushing jig 90
25 need to satisfy the expressions "Radius Riw < Radius Ru  Radius Rie", "Radius Row
< Radius Rr  Radius Roe", and "Radius Rr - Radius Ru = t (where t is the wall
thickness of a steel pipe)".
[0098]
The following explains a reason why it is assumed that the relationship
30 between the widths Wu and Wr of the fixed receiving die 91 and the movable roller

38
pressing die 93 and the width Ww of the area of welding heat hardening and roll
marks on the seamed steel pipe 50a satisfies Width Wu  Width Ww < Width Wr.
[0099]
Fig. 32 is a conceptual diagram of a weld bead crushing jig 90D based on the
5 configuration of Comparative Example 4. Fig. 33 is a cross-sectional conceptual
diagram of a seamed steel pipe 50a5 subjected to pipe expanding after being
subjected to weld bead crushing by the weld bead crushing jig 90D based on the
configuration of Comparative Example 4. Fig. 32 omits to illustrate the fixed
receiving die 91. In Comparative Example 4, the weld bead crushing jig 90D is
10 configured such that the width Wr of the movable roller pressing die 93 is smaller than
the width Ww of the area of welding heat hardening and roll marks on the seamed
steel pipe 50a.
[0100]
In a case where the weld bead crushing jig 90D based on the configuration of
15 Comparative Example 4 is used in the weld bead crushing, the shape of the seamed
steel pipe 50a5 after the pipe expanding is such that as shown in Fig. 33, a processed
portion 59 formed by the weld bead crushing undesirably has a heart shape. In this
state, the sides of a weld 132 of the seamed steel pipe 50a5 are bulging without
being corrected in the weld bead crushing and remain uncorrected even after the pipe
20 expanding.
[0101]
Fig. 34 is a conceptual diagram of a weld bead crushing jig 90E based on the
configuration of Comparative Example 5. Fig. 34 omits to illustrate the movable
roller pressing die 93. In Comparative Example 5, the weld bead crushing jig 90E is
25 configured such that the width Wu of the fixed receiving die 91 is larger than the width
Ww of the area of welding heat hardening and roll marks on the seamed steel pipe
50a.
[0102]
In a case where the weld bead crushing jig 90E based on the configuration of
30 Comparative Example 5 is used in the weld bead crushing, too, the shape of the

39
seamed steel pipe 50a5 after the pipe expanding is such that as shown in Fig. 33, a
processed portion 59 formed by the weld bead crushing undesirably has a heart
shape. In this state, the sides of a weld 132 of the seamed steel pipe 50a5 are
bulging without being corrected in the weld bead crushing and remain uncorrected
5 even after the pipe expanding.
[0103]
Fig. 35 is a conceptual diagram of a weld bead crushing jig 90F based on the
configuration of Comparative Example 6. Fig. 36 is a cross-sectional conceptual
diagram of a seamed steel pipe 50a6 subjected to pipe expanding after being
10 subjected to weld bead crushing by the weld bead crushing jig 90F based on the
configuration of Comparative Example 6. In Comparative Example 5, the weld bead
crushing jig 90F is configured such that the width Wu of the fixed receiving die 91 is
larger than the width Wr of the movable roller pressing die 93.
[0104]
15 In a case where the weld bead crushing jig 90F based on the configuration of
Comparative Example 6 is used in the weld bead crushing, too, the shape of the
seamed steel pipe 50a6 after the pipe expanding is such that as shown in Fig. 36, a
processed portion 59 formed by the weld bead crushing undesirably has a heart
shape. In this state, the sides of a weld 132 of the seamed steel pipe 50a6 are
20 bulging without being corrected in the weld bead crushing and remain uncorrected
even after the pipe expanding.
[0105]
Fig. 37 is a diagram summarizing a relationship between the widths Wu and Wr
of the fixed receiving die 91 and the movable roller pressing die 93 and the width Ww
25 of the area of welding heat hardening and roll marks on the seamed steel pipe 50a.
For the reason shown in Comparative Examples 4 to 6, the widths Wu and Wr of the
weld bead crushing jig 90 need to satisfy the above expression for improvement in
the inside diameter shape of the seamed steel pipe 50a after the pipe expanding and
improvement in the inside diameter circularity of the seamed steel pipe 50a. That is,
30 the fixed receiving die 91 and the movable roller pressing die 93 of the weld bead

40
crushing jig 90 need to satisfy the expression "Width Wu  Width Ww < Width Wr" in
relation to the seamed steel pipe 50a.
[0106]
The side wall portion 91a of the fixed receiving die 91 is disposed to face the
5 back bead 131 formed to be raised from the inner peripheral surface of the seamed
steel pipe 50a. Further, the peripheral wall surface portion 93a of the movable roller
pressing die 93 is disposed to face the side wall portion 91a via the seamed steel
pipe 50a, and the peripheral wall surface portion 93a presses the seamed steel pipe
50a and moves along the direction of extension of the seamed steel pipe 50a while
10 rotating. Therefore, the back bead 131 formed to be raised from the inner peripheral
surface of the seamed steel pipe 50a is held between the peripheral wall surface
portion 93a and the side wall portion 91a and pressed along the inside diameter
shape of the seamed steel pipe 50a and along the direction of extension of the
seamed steel pipe 50a. Accordingly, the weld bead crushing jig 90, the method for
15 manufacturing a compressor 1 with the weld bead crushing jig 90, and the
compressor 1 allow the weld bead, which is a part raised from the inner peripheral
surface, to be stably formed into a shape conforming with the inside diameter shape
of the body portion 2a and save the trouble of a cutting process.
[0107]
20 Further, for example, a heat-hardened zone near a weld produced by the butt
welding or roll marks produced at the start of the rolling may cause deterioration in
the inside diameter circularity of the body portion 2a. To address this problem, the
peripheral wall surface portion 93a of the movable roller pressing die 93 is disposed
to face the side wall portion 91a via the seamed steel pipe 50a, and the peripheral
25 wall surface portion 93a presses the seamed steel pipe 50 and moves along the
direction of extension of the seamed steel pipe 50a while rotating. This makes it
possible to correct a heat-hardened zone near a weld produced by the butt welding
and roll marks produced at the start of the rolling in the body portion 2a of the
pressure closed vessel 2, making it possible to improve the inside diameter circularity
30 of the body portion 2a.

41
[0108]
Further, in general, the body portion 2a may have a weld bead formed as a
depression toward the inside of the body portion 2a in the butt welding. When thus
configured, the body portion 2a may cause leakage of, for example, refrigerant
5 through a thinned weld and may cause deterioration in weld quality. To address this
problem, the side wall portion 91a of the fixed receiving die 91 is disposed to face the
back bead 131 formed to be raised from the inner peripheral surface of the seamed
steel pipe 50a. Further, the peripheral wall surface portion 93a of the movable roller
pressing die 93 is disposed to face the side wall portion 91a via the seamed steel
10 pipe 50a, and the peripheral wall surface portion 93a presses the seamed steel pipe
50 and moves along the direction of extension of the seamed steel pipe 50a while
rotating. Therefore, the back bead 131 formed to be raised from the inner peripheral
surface of the seamed steel pipe 50a is held between the peripheral wall surface
portion 93a and the side wall portion 91a and pressed along the inside diameter
15 shape of the seamed steel pipe 50a and along the direction of extension of the
seamed steel pipe 50a. Therefore, the body portion 2a does not have a weld
thinned in the butt welding, and can reduce leakage of refrigerant through the weld.
As a result, the weld bead crushing jig 90, the method for manufacturing a
compressor 1 with the weld bead crushing jig 90, and the compressor 1 bring about
20 improvement in weld quality of the body portion 2a.
[0109]
Further, in a possible aspect of the weld bead crushing, the seamed steel pipe
50a may be held for the entire perimeter with a receiving die and a pressing die both
being movable rollers. However, with the receiving die and the pressing die both
25 being movable dies, the weld bead crushing loses stability and may cause the
seamed steel pipe 50a to deform. To address this problem, the peripheral wall
surface portion 93a of the movable roller pressing die 93 is disposed to face the side
wall portion 91a via the seamed steel pipe 50a, and the peripheral wall surface
portion 93a presses the seamed steel pipe 50 and moves along the direction of
30 extension of the seamed steel pipe 50a while rotating. That is, during the weld bead

42
crushing, the fixed receiving die 91 is fixed and the side wall portion 91a does not
change its position. Accordingly, the weld bead crushing jig 90, the method for
manufacturing a compressor 1 with the weld bead crushing jig 90, and the
compressor 1 allow the weld bead, which is a part raised from the inner peripheral
5 surface, to be stably formed into a shape conforming with the inside diameter shape
of the body portion 2a.
[0110]
Further, in the weld bead crushing, the side wall portion 91a is disposed to face
the weld bead 131 with the weld bead 131 cooled. Then, in the weld bead crushing,
10 a bead removing process can be performed on the back bead 131 with the weld bead
131 cooled. Therefore, in the weld bead crushing, it is not necessary to remove the
weld bead immediately after the welding (melting) of the seamed steel pipe 50a. As
a result, the weld bead crushing imposes no restrictions on manufacturing processes
in terms of place or time, as the bead removing process can be performed at a time
15 interval from the welding (melting) of the seamed steel pipe 50a.
[0111]
Further, the relationship between the radial shapes of the fixed receiving die 91
and the movable roller pressing die 93 and the radial shapes of the outer and inner
peripheral surfaces of the seamed steel pipe 50a and the seamed steel pipe 50a1 of
20 the comparative example satisfies Radius Riw < Radius Ru  Radius Rie, Radius
Row < Radius Rr  Radius Roe, and Radius Rr - Radius Ru = t (where t is the wall
thickness of a steel pipe). Further, the relationship between the widths Wu and Wr of
the fixed receiving die 91 and the movable roller pressing die 93 and the width Ww of
the area of welding heat hardening and roll marks on the seamed steel pipe 50a
25 satisfies Width Wu  Width Ww < Width Wr. That is, in the weld bead crushing jig
90, the radial shapes of surfaces of the fixed receiving die 91 and the movable roller
pressing die 93 facing each other and the width shapes of the dies are defined in
conformance with the pipe expanding shape of the seamed steel pipe 50a.
Therefore, the weld bead crushing jig 90, the method for manufacturing a compressor
30 1 with the weld bead crushing jig 90, and the compressor 1 make it possible to further

43
stably correct a heat-hardened zone produced by the butt welding and roll marks
produce by the rolling. Further, the configuration and the method bring about
improvement in inside diameter accuracy of the body portion 2a. This brings about
improvement in assembly of the compressor 1 and, furthermore, improvement in
5 assembly accuracy of the motor unit 10 and the compression mechanism unit 30 of
the compressor 1. This leads to improvement in performance of the compressor 1.
[0112]
The configuration shown in the foregoing embodiment shows an example and
may be combined with another publicly-known technology, and parts of the
10 configuration may be omitted or changed, provided such omissions and changes do
not depart from the scope.
Reference Signs List
[0113]
1: compressor, 2: pressure closed vessel, 2a: body portion, 2a1: body portion,
15 2b: bottom portion, 2c: lid portion, 3: suction muffler, 3a: enclosure, 3b: inflow pipe, 4:
suction pipe, 5: suction hole, 6: fixing part, 6a: connecting pipe, 6b: ring, 7: discharge
pipe, 8: glass terminal, 10: motor unit, 12: stator, 14: rotor, 16: lead wire, 20: shaft,
20a: fixing surface, 24: eccentric portion, 26: piston, 30: compression mechanism
unit, 31: cylinder, 31a: hollow disk surface, 31b: inner surface, 31c: outer surface, 32:
20 vane, 32a: distal portion, 32b: proximal portion, 33: elastic body, 34: upper bearing,
34a: fixed portion, 34b: bearing portion, 35: lower bearing, 35a: fixed portion, 35b:
bearing portion, 40: refrigerating machine oil, 50: steel sheet, 50a: seamed steel pipe,
50a1: seamed steel pipe, 50a2: seamed steel pipe, 50a3: seamed steel pipe, 50a4:
seamed steel pipe, 50a5: seamed steel pipe, 50a6: seamed steel pipe, 50b: inner
25 surface, 50e: both end portions, 51: inner peripheral surface, 51a: inner peripheral
surface, 52: sheet surface portion, 52a: first sheet surface portion, 52b: second sheet
surface portion, 53: outer peripheral surface, 53a: outer peripheral surface, 54a: first
marginal edge portion, 54b: second marginal edge portion, 56: processed portion,
56a: third marginal edge portion, 56b: fourth marginal edge portion, 57: processed
30 portion, 58: processed portion, 59: processed portion, 70: pipe expanding jig, 71: pipe

44
expanding die portion, 71a: first inner surface portion, 71b: outer surface, 72: rod
portion, 73: casing portion, 73a: second inner surface portion, 76: first hollow space
portion, 77: second hollow space portion, 78: inserted portion, 90: weld bead crushing
jig, 90A: weld bead crushing jig, 90B: weld bead crushing jig, 90C: weld bead
5 crushing jig, 90D: weld bead crushing jig, 90E: weld bead crushing jig, 90F: weld
bead crushing jig, 91: fixed receiving die, 91a: side wall portion, 91b: both end
portions, 92: housing, 93: movable roller pressing die, 93a: peripheral wall surface
portion, 93b: both end portions, 100: rolling apparatus, 100a: first roller, 100b: second
roller, 100c: third roller, 110: pipe shrinking apparatus, 112: first pipe shrinking die,
10 112a: first groove, 114: second pipe shrinking die, 114a: second groove, 120: butt
welding apparatus, 122: welding torch, 122a: tip, 124: welding electrode, 131: back
bead, 132: weld, 310: hollow portion, 310a: low-pressure space portion, 310b: highpressure space portion, 312: suction passage, 314: discharge passage, 316: vane
groove, 318: vane groove opening, 319: opening
15

45
We Claim:
[Claim 1]
A weld bead crushing jig comprising:
a fixed receiving die having a columnar shape, having a side wall portion
5 formed by an outward-convex circular-arc-shaped curved surface, configured to be
inserted into a hollow portion of a seamed steel pipe having a circular cylindrical
shape, and disposed to face a weld bead formed to be raised from an inner peripheral
surface of the seamed steel pipe; and
a movable roller pressing die formed by a rotating body having a peripheral
10 wall surface portion formed so that a central portion of the peripheral wall surface
portion in an axial direction of an axis of rotation is concaved in a circular arc shape,
the peripheral wall surface portion being disposed to face the side wall portion via the
seamed steel pipe, the peripheral wall surface portion being configured to press the
seamed steel pipe and move along a direction of extension of the seamed steel pipe
15 while rotating.
[Claim 2]
A method for manufacturing a compressor, the method comprising:
rolling by which a rectangular steel sheet that is to serve as a body portion of a
pressure closed vessel is formed into a roll shape;
20 pipe shrinking by which the steel sheet formed into the roll shape is formed into
a circular cylindrical shape;
butt welding by which opposite marginal edge portions of the steel sheet
formed into the circular cylindrical shape are joined together by welding;
weld bead crushing by which a weld bead formed to be raised from an inner
25 peripheral surface of a welded steel pipe is crushed; and
pipe expanding by which a distortion of the steel pipe is reduced by pressing
the inner peripheral surface of the steel pipe,
wherein
in the weld bead crushing,
30 a fixed receiving die having a columnar shape and having a side wall portion

46
formed by an outward-convex circular-arc-shaped curved surface is inserted into a
hollow portion of a seamed steel pipe having a circular cylindrical shape and the side
wall portion is disposed to face a weld bead formed to be raised from the inner
peripheral surface of the steel pipe,
5 a movable roller pressing die formed by a rotating body has a peripheral wall
surface portion formed so that a central portion of the peripheral wall surface portion
in an axial direction of an axis of rotation is concaved in a circular arc shape,
the peripheral wall surface portion is disposed to face the side wall portion via
the seamed steel pipe, and
10 the peripheral wall surface portion presses the seamed steel pipe and moves
along a direction of extension of the seamed steel pipe while rotating.
[Claim 3]
The method of claim 2, wherein in the weld bead crushing, the side wall portion
is disposed to face the weld bead with the weld bead cooled.