FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
METHOD OF 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 100-8310, JAPAN
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION
AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

2
DESCRIPTION
5 Technical Field
[0001]
The present disclosure relates to a method of manufacturing a compressor by
heat caulking.
Background Art
10 [0002]
A known compressor includes a container forming an outer casing and a
compression mechanism section contained in the container and having a
compression chamber to compress refrigerant. As a way of fixing the compression
mechanism section to the inside of the container, for example, Patent Literature 1
15 discloses a method of manufacturing a compressor by heat caulking. This
compressor manufacturing method includes placing a compression mechanism
section having an outer circumferential surface with multiple prepared holes in a
container and pressing multiple pressing jigs against the heated outer circumferential
surface of the container to form protrusions that are fitted in the prepared holes.
20 Citation List
Patent Literature
[0003]
Patent Literature 1: Japanese Unexamined Patent Application Publication No.
2007-303378
25 Summary of Invention
Technical Problem
[0004]
The compressor manufacturing method disclosed in Patent Literature 1
includes transporting the compression mechanism section loose-fitted in the container
30 to a fixing device, fastening the container to the fixing device, heating the outer
3
circumferential surface of the container, and forming the protrusions with the pressing
jigs. Vibrations during transport may cause the compression mechanism section in
the container to rotate such that the prepared holes are out of phase with portions
against which the pressing jigs are pressed. If the pressing jigs are pressed against
5 the heated outer circumferential surface of the container under such conditions, loads
of the protrusions may be applied to portions of the outer circumferential surface of
the compression mechanism section that are located near the prepared holes,
increasing distortion of the compression mechanism section.
[0005]
10 The present disclosure has been made to solve the above-described problem
and aims at providing a compressor manufacturing method in which when a
compression mechanism section is fixed to a container by heat caulking, a load on
the compression mechanism section is reduced to reduce distortion of the
compression mechanism section and by which the compression mechanism section
15 can be fixed reliably and firmly to the container.
Solution to Problem
[0006]
An embodiment of the present disclosure provides a method of manufacturing
a compressor including a container forming an outer casing and a compression
20 mechanism section that is contained in the container and that has a compression
chamber to compress refrigerant, the container having a connection port and a
plurality of protrusions arranged on an inner wall surface, the compression
mechanism section having a suction port located at a position corresponding to the
connection port and a plurality of fixing grooves circumferentially spaced apart, the
25 suction port and the connection port being connected by a suction pipe extending
through both the suction port and the connection port, the plurality of protrusions
being fitted in and fixed to the plurality of fixing grooves, the method including:
inserting a positioning pin into the suction pipe to position the plurality of fixing
grooves relative to the plurality of protrusions; heating parts of an outer
30 circumferential surface of the container, the parts corresponding to the plurality of
4
fixing grooves; pressing pushing pins against the heated parts of the outer
circumferential surface of the container to form the plurality of protrusions on the inner
surface of the container such that the plurality of protrusions are fitted in the plurality
of fixing grooves; and removing the positioning pin from the suction pipe after
5 formation of the plurality of protrusions.
Advantageous Effects of Invention
[0007]
In the method of manufacturing the compressor according to the embodiment,
if the compression mechanism section is rotated by, for example, vibrations during
10 transport to a heat caulking device, such that the fixing grooves are out of phase, the
fixing grooves can be aligned with the protrusions by inserting the positioning pin into
the suction pipe. Therefore, when the compression mechanism section is fixed to
the container by heat caulking, misalignment of the fixing grooves relative to the
protrusions can be corrected, and a load on the compression mechanism section can
15 be reduced to reduce distortion of the compression mechanism section. Thus, the
compression mechanism section can be fixed reliably and firmly to the container.
Brief Description of Drawings
[0008]
[Fig. 1] Fig. 1 is a longitudinal sectional view illustrating part of an internal
20 structure of a compressor in Embodiment of the present disclosure.
[Fig. 2] Fig. 2 illustrates, in plan view, a section of part A in Fig. 1 and is an
enlarged view of essential part including an upper cylinder to be fixed to a container.
[Fig. 3] Fig. 3 illustrates, in plan view, a section of the part A in Fig. 1 and is an
enlarged view of essential part including the upper cylinder and the container with
25 protrusions pressed in fixing grooves of the upper cylinder.
[Fig. 4] Fig. 4 is a schematic diagram illustrating the protrusions of the
container pressed in the fixing grooves shifted in position.
[Fig. 5] Fig. 5 is a sectional view of part B in Fig. 1 in plan view.
[Fig. 6] Fig. 6 is a sectional view illustrating a suction pipe in Fig. 5 receiving a
30 positioning pin.
5
[Fig. 7] Fig. 7 is a schematic cross-sectional view of the suction pipe receiving
the positioning pin with a reduced outside diameter.
[Fig. 8] Fig. 8 is a schematic cross-sectional view of the suction pipe receiving
the positioning pin with an increased outside diameter.
5 [Fig. 9] Fig. 9 is a schematic longitudinal sectional view of essential part of the
positioning pin with an increased outside diameter.
[Fig. 10] Fig. 10 is a schematic longitudinal sectional view of essential part of
the positioning pin with a reduced outside diameter.
[Fig. 11] Fig. 11 is a schematic diagram illustrating a procedure for fixing the
10 upper cylinder to the container by using a heat caulking device.
[Fig. 12] Fig. 12 is a sectional view of a pallet that is used in a compressor
manufacturing method according to Embodiment of the present disclosure.
[Fig. 13] Fig. 13 is a sectional view of the pallet illustrated in Fig. 12 and having
thereon a workpiece.
15 [Fig. 14] Fig. 14 is a front view of the heat caulking device used in the
compressor manufacturing method according to Embodiment of the present
disclosure.
[Fig. 15] Fig. 15 is a plan view as viewed in the direction of arrows Q in Fig. 14.
[Fig. 16] Fig. 16 is a schematic diagram illustrating a manner of fixing the upper
20 cylinder to the container by using heat caulking mechanisms in the compressor
manufacturing method according to Embodiment of the present disclosure.
[Fig. 17] Fig. 17 is a schematic diagram illustrating a manner of inserting the
positioning pin into the workpiece in the compressor manufacturing method according
to Embodiment of the present disclosure.
25 [Fig. 18] Fig. 18 is a plan view as viewed in the direction of arrow R in Fig. 17.
[Fig. 19] Fig. 19 is a schematic diagram illustrating the suction pipe deformed
due to a load caused by heat caulking.
Description of Embodiment
[0009]
6
Embodiment of the present disclosure will be described below with reference to
the drawings. Note that the same components or equivalents in the figures are
designated by the same reference signs and a description thereof is omitted or
simplified as appropriate. Furthermore, note that, for example, the shapes, sizes,
5 and arrangement of components illustrated in each figure can be appropriately
changed within the scope of the present disclosure.
[0010]
Embodiment
Fig. 1 is a longitudinal sectional view illustrating part of an internal structure of a
10 compressor in Embodiment of the present disclosure. In Embodiment, a method of
manufacturing a twin rotary compressor will be described as an example.
[0011]
As illustrated in Fig. 1, a compressor 100 is a twin rotary compressor including
two cylinders arranged vertically. The compressor 100 includes a compression
15 mechanism section 101 in a container 1 forming an outer casing. The compression
mechanism section 101 includes an upper cylinder 102, a lower cylinder 103, a
spacer 104, a sub-bearing 105, a main bearing 106, and a crankshaft 107, and is
driven by an electric motor (not illustrated) disposed in the container 1.
[0012]
20 The upper cylinder 102 and the lower cylinder 103 each define a compression
chamber. The spacer 104 is disposed between the upper cylinder 102 and the lower
cylinder 103 to separate two compression chambers and seal the compression
chambers. The sub-bearing 105 is located on an upper surface of the upper cylinder
102 to seal the compression chamber of the upper cylinder 102. The main bearing
25 106 is located on a lower surface of the lower cylinder 103 to seal the compression
camber of the lower cylinder 103. The crankshaft 107 extends through the upper
cylinder 102, the lower cylinder 103, the spacer 104, the sub-bearing 105, and the
main bearing 106. The electric motor rotates the crankshaft 107, thus compressing
refrigerant gas in the compression chambers. The refrigerant gas to be compressed
30 is supplied to the compression chamber of the upper cylinder 102 from the outside of
7
the container 1 through a suction pipe 110 connecting a connection port 108 provided
in the container 1 to a suction port 109 provided in the upper cylinder 102. Although
not illustrated in Fig. 1, the refrigerant gas to be compressed is also supplied to the
compression chamber of the lower cylinder 103 from the outside of the container 1
5 through a suction pipe connecting another connection port provided in the container 1
to a suction port provided in the lower cylinder 103.
[0013]
Next, how to fix the upper cylinder 102 to the container 1 will be described.
The upper cylinder 102 to be fixed to the container 1 is loose-fitted in the container 1.
10 The term "loose-fitted" refers to the following state: the outside diameter of the upper
cylinder 102 is smaller than or equal to the inside diameter of the container 1, and the
upper cylinder 102 is fitted in the container 1 such that they are not in contact with
each other even in consideration of the circularities of the upper cylinder 102 and the
container 1. The term "outside diameter" often refers to a mean value of two
15 measured outside diameters intersecting at right angles or three or more measured
outside diameters including the two measured outside diameters intersecting at right
angles. The same applies to the inside diameter. The upper cylinder 102 has an
outer circumferential surface with fixing grooves 120. The upper cylinder 102 is fixed
to the container 1 by fitting protrusions 123, which are formed by pressing parts of the
20 outer circumferential surface of the container 1 that correspond to the fixing grooves
120, into the fixing grooves 120.
[0014]
Fig. 2 illustrates, in plan view, a section of part A in Fig. 1 and is an enlarged
view of essential part including the upper cylinder to be fixed to the container. As
25 illustrated in Fig. 2, the upper cylinder 102 includes a fixing portion 3 to be fixed to an
inner circumferential surface of the container 1. The fixing portion 3, which is part of
the outer circumferential surface of the upper cylinder 102, includes a set of two fixing
grooves 120 and a protrusion 120a interposed between the two fixing grooves 120.
The two fixing grooves 120 are located close to each other. The upper cylinder 102
8
includes three fixing portions 3 circumferentially arranged at a substantially equal
pitch. In other words, six fixing grooves 120 in all are arranged.
[0015]
Fig. 3 illustrates, in plan view, a section of the part A in Fig. 1 and is an
5 enlarged view of essential part including the upper cylinder and the container with
protrusions pressed in the fixing grooves of the upper cylinder. The upper cylinder
102 is fixed to the container 1 by heat caulking. In heat caulking, part of the outer
circumferential surface of the container 1 that corresponds to the fixing grooves 120 is
heated. Then, a caulking punch 122 including two pushing pins 121 is pressed
10 against the part, which corresponds to the fixing grooves 120, of the outer
circumferential surface of the container 1. Each of the pushing pins 121 is a solid
cylinder having a flat end face and has an outside diameter equal to or slightly smaller
than the inside diameter of each fixing groove 120. Two protrusions 123 to be fitted
in the fixing grooves 120 are formed on the inner surface of the container 1, thus
15 forming two caulking points. The two caulking points will be referred to as a caulking
portion. Three caulking portions are formed at substantially the same time for three
areas of the outer circumferential surface of the upper cylinder 102. The caulking
portions may be formed one by one at regular intervals.
[0016]
20 Heat caulking is performed by a heat caulking device. The compressor 100
that is to be subjected to heat caulking and in which the upper cylinder 102 is loosefitted in the container 1 is transported to the heat caulking device. At this time, the
upper cylinder 102 may be rotated about the crankshaft 107 by, for example,
vibrations during transport. Specifically, the fixing grooves 120 arranged in the upper
25 cylinder 102 may be shifted from their positions set before transport.
[0017]
Fig. 4 is a schematic diagram illustrating the protrusions arranged on the
container pressed in the fixing grooves shifted in position. A dashed line represents
a center line X between the two fixing grooves 120. An alternate long and short
30 dashed line represents a center line Y between the two pushing pins 121. In heat
9
caulking under conditions where both the center line X between the two fixing
grooves 120 and the center line Y between the two pushing pins 121 are in the same
straight line, loads on the upper cylinder 102 can be minimized, and the upper
cylinder 102 can be fixed to the container 1. However, as the caulking punch 122 is
5 pressed against the outer circumferential surface of the container 1 under conditions
where the center line X between the two fixing grooves 120 is offset from the center
line Y between the two pushing pins 121 as illustrated in Fig. 4, the protrusions 123
are pressed against parts of the outer circumferential surface of the upper cylinder
102 that are located near the fixing grooves 120, so that loads of the protrusions 123
10 increase distortion of the upper cylinder 102.
[0018]
As described above, to reduce distortion of the upper cylinder 102, the center
line X between the two fixing grooves 120 and the center line Y between the two
pushing pins 121 need to be in the same straight line. After transported to the heat
15 caulking device, the compressor 100 is positioned relative to the caulking punch 122
included in the heat caulking device such that the height, or a circumferential position,
of the container 1 is always kept at a constant level. In other words, the protrusions
123 are always formed at the same level and the same circumferential position on the
container 1. Therefore, the fixing grooves 120 need to be aligned with the
20 protrusions 123 so that the center line X between the two fixing grooves 120 and the
center line Y between the two pushing pins 121 are arranged in the same straight
line.
[0019]
Each set of fixing grooves 120 is circumferentially arranged at a predetermined
25 angle from the suction port 109 in the outer circumferential surface of the upper
cylinder 102. Furthermore, each set of protrusions 123 is circumferentially formed at
a predetermined angle from the connection port 108 of the container 1. The angle
from the suction port 109 to each set of fixing grooves 120 is equal to the angle from
the connection port 108 to the corresponding set of protrusions 123. Therefore, as
30 long as the suction port 109 is aligned with the connection port 108, each set of fixing
10
grooves 120 is aligned with the corresponding set of protrusions 123. The sets of
fixing grooves 120 are circumferentially arranged at intervals of 120 degrees in the
outer circumferential surface of the upper cylinder 102, and the sets of protrusions
123 are circumferentially formed at intervals of 120 degrees in the outer
5 circumferential surface of the container 1. As long as the fixing grooves 120 are
aligned with the protrusions 123 in one of the three areas, the fixing grooves 120 are
spontaneously aligned with the protrusions 123 in the other two areas.
[0020]
Fig. 5 is a sectional view of part B in Fig. 1 in plan view. Fig. 6 is a sectional
10 view illustrating the suction pipe in Fig. 5 receiving a positioning pin. As illustrated in
Figs. 1 and 5, the suction port 109 and the connection port 108 are connected by the
suction pipe 110. The suction pipe 110 is provided such that its axis is directed
toward the center of the compression mechanism section 101. The suction pipe 110
has stiffness lower than that of the upper cylinder 102 and the container 1.
15 Accordingly, the suction pipe 110 may be pulled by the upper cylinder 102 rotated by,
for example, vibrations during transport to the heat caulking device, causing the
suction pipe 110 to be offset from a direction toward the center of the upper cylinder
102. To correct offset of the suction pipe 110, the suction port 109 and the
connection port 108 need to be positioned after transport to the heat caulking device.
20 In Embodiment, as illustrated in Fig. 6, a positioning pin 124 is inserted into the
suction pipe 110 to position the suction port 109 and the connection port 108. Thus,
the axis of the suction port 109 and the axis of the connection port 108 coincide with
each other and pass through the center of the upper cylinder 102. Therefore, the
center line X between the two fixing grooves 120 and the center line Y between the
25 two pushing pins 121 are in the same straight line.
[0021]
Fig. 7 is a schematic cross-sectional view of the suction pipe receiving the
positioning pin with a reduced outside diameter. Fig. 8 is a schematic crosssectional view of the suction pipe receiving the positioning pin with an increased
30 outside diameter. Fig. 9 is a schematic longitudinal sectional view of essential part
11
of the positioning pin with an increased outside diameter. Fig. 10 is a schematic
longitudinal sectional view of the essential part of the positioning pin with a reduced
outside diameter.
[0022]
5 Referring to Fig. 7, the outside diameter of the positioning pin 124 is smaller
than the inside diameter of the suction pipe 110. An outer surface of the positioning
pin 124 is covered with rubber 125 having a thickness of approximately 1.0 mm as
illustrated in Figs. 7 to 10. The positioning pin 124 includes a collet mechanism 4.
As illustrated in Figs. 9 and 10, the collet mechanism 4 includes a piston 126, which is
10 operated by drawing or enclosing compressed air, a wedge 128 operating in
conjunction with operation of the piston 126, and a shaft 127 connecting the piston
126 and the wedge 128. As compressed air is drawn in a state illustrated in Figs. 7
and 9, the piston 126 is operated and the wedge 128 operates in conjunction with
operation of the piston 126, so that the outside diameter of the positioning pin 124 is
15 increased as illustrated in Figs. 8 and 10. As compressed air is enclosed in a state
illustrated in Figs. 8 and 10, the piston 126 is operated and the wedge 128 operates
in conjunction with operation of the piston 126, so that the outside diameter of the
positioning pin 124 is reduced to its original size as illustrated in Figs. 7 and 9.
[0023]
20 As the outside diameter of the positioning pin 124 is increased by the collet
mechanism 4, the rubber 125 comes into contact with an inner surface of the suction
pipe 110, so that the positioning pin 124 is fastened to the suction pipe 110. The
position of the suction pipe 110 is adjusted by a holding force produced by fastening
the positioning pin 124 such that the axis of the suction pipe 110 and the axis of the
25 positioning pin 124 are in the same straight line. Thus, the axis of the suction port
109 and the axis of the connection port 108 are finely adjusted based on the suction
pipe 110 and are in the same straight line directed toward the center of the upper
cylinder 102.
[0024]
12
As described above, to perform heat caulking while minimizing a load on the
upper cylinder 102 in the compressor manufacturing method according to
Embodiment, the upper cylinder 102 is fixed to the container 1 while the positioning
pin 124 is placed in the suction pipe 110 to continuously position the suction port 109
5 and the connection port 108.
[0025]
A procedure for fixing the upper cylinder to the container by using the heat
caulking device will now be described in brief with reference to Fig. 11. Fig. 11 is a
schematic diagram illustrating the procedure for fixing the upper cylinder to the
10 container by using the heat caulking device. The compressor is transported into the
heat caulking device (S101). Then, the positioning pin 124 is inserted into the
suction pipe 110 (S102), and compressed air is drawn from the positioning pin 124 to
activate the collet mechanism 4 (S103). Thus, the suction port 109 and the
connection port 108 are positioned. Then, parts of the outer circumferential surface
15 of the container 1 around the fixing grooves 120 are heated (S104). The caulking
punches 122 including the pushing pins 121 are pressed against the heated parts of
the outer circumferential surface of the container 1 to form the protrusions 123, and
the protrusions 123 are pressed into the fixing grooves 120, thus fixing the upper
cylinder 102 to the container 1 (S105). After completion of pressing the protrusions
20 123, compressed air is enclosed in the positioning pin 124 to return the positioning
pin 124 to the original size (S106). Then, the positioning pin 124 is removed from
the container 1 (S107).
[0026]
A mechanism for increasing or reducing the outside diameter of the positioning
25 pin 124 is not limited to the collet mechanism 4 illustrated. For example, a
mechanism for directly increasing or reducing the outside diameter with compressed
air, a mechanism for increasing or reducing the outside diameter by driving an air
cylinder, or a mechanism for increasing or reducing the outside diameter by driving a
hydraulic cylinder may be used.
30 [0027]
13
If the outside diameter of the positioning pin 124 is equal to or slightly smaller
than the inside diameter of the suction pipe 110, the suction port 109 and the
connection port 108 can be positioned without increasing the outside diameter of the
positioning pin 124 by using, for example, the collet mechanism 4. In such a case,
5 to position the suction port 109 and the connection port 108, the positioning pin 124 is
inserted into the suction pipe 110 and is then moved from side to side such that the
positioning pin 124 is fitted to right and left inner-wall parts of the connection port 108.
Since the upper cylinder 102 is fixed to the container 1 while the positioning pin 124 is
placed in the suction pipe, the circularities of, for example, the suction port 109 and
10 the connection port 108 may deteriorate due to distortion of the container 1 and the
upper cylinder 102 caused by the fixing. As a result, the suction pipe 110 may be
deformed inwardly such that the positioning pin 124 is retained, and it may be difficult
to remove the positioning pin 124.
[0028]
15 Furthermore, the rubber 125 on the outer surface of the positioning pin 124 can
be omitted, and the positioning pin 124 can be expanded to position the suction port
109 and the connection port 108. In such a case, however, when the collet
mechanism 4 expands the positioning pin 124 to perform positioning, the suction pipe
110, the suction port 109, and the connection port 108 may be deformed by a force
20 applied from the positioning pin 124, leading to lower performance and lack of longterm reliability of the compressor 100.
[0029]
The heat caulking device, which positions the compressor 100 to partly heat
the container 1 and form the caulking portions, will now be described with reference
25 to Figs. 12 to 19. Hereinafter, the compressor 100 to be assembled will be referred
to as a workpiece. During assembly of the compressor 100, the workpiece is always
placed on a support called a pallet.
[0030]
Fig. 12 is a sectional view of the pallet used in the compressor manufacturing
30 method according to Embodiment of the present disclosure. Fig. 13 is a sectional
14
view of the pallet illustrated in Fig. 12 and having thereon a workpiece. As illustrated
in Fig. 12, the pallet, 200, includes a pallet base 201, a mount 202, a workpiece
receiving ring 203, and a crankshaft bearing 204 including the collet mechanism.
The mount 202 is disposed on an upper surface of the pallet base 201. The
5 workpiece receiving ring 203 and the crankshaft bearing 204 are arranged on an
upper surface of the mount 202.
[0031]
As illustrated in Fig. 13, the workpiece receiving ring 203 is interposed between
the mount 202 and a workpiece 205 to adjust the height of the workpiece 205 to a
10 predetermined level. For compressors having different heights, the workpiece
receiving ring 203 can be changed from one type of compressor to another such that
the suction pipe 110 is always kept at a constant level relative to a heat caulking
device 210, thus achieving sharing of the device.
[0032]
15 As illustrated in Fig. 13, the workpiece 205 is a twin rotary compressor having
two compression chambers arranged vertically in a direction along the axis of the
workpiece. The container 1 contains the compression mechanism section 101 and
an electric motor 129. The compression mechanism section 101 is provided such
that the upper cylinder 102 is not fixed to the container 1. The electric motor 129
20 includes a stator 129a, which is fixed to the inner wall surface of the container 1 by
shrink fitting through a device (not illustrated) before the workpiece is transported to
the heat caulking device. The outside diameter of the stator 129a is slightly larger
than the inside diameter of the container 1.
[0033]
25 As illustrated in Fig. 13, the crankshaft bearing 204 is configured to fasten or
unfasten the stator 129a by discharging or enclosing compressed air. Therefore, the
stator 129a is fastened to the pallet 200 under conditions where compressed air is
discharged, whereas the stator 129a is unfastened under conditions where
compressed air is enclosed. In other words, the container 1 is fastened to the pallet
30 200 as long as compressed air is discharged.
15
[0034]
As described above, the outer circumferential surface of the upper cylinder 102
has the three fixing portions 3 arranged at an equal pitch of approximately 120
degrees and a total of six fixing grooves 120. Furthermore, the upper cylinder 102
5 has the suction port 109 radially extending between the outer circumferential surface
and an inner circumferential surface of the upper cylinder.
[0035]
For the compressor 100 as a completed product, the upper cylinder 102 is
located in lower part of the compressor, and the electric motor 129 is located in upper
10 part thereof. However, the workpiece 205, which is being assembled and is put into
the heat caulking device, is inverted such that the upper cylinder 102 is located above
the electric motor 129 as illustrated in Fig. 13. A rotor is not yet fixed to the
crankshaft 107, which transmits a driving force produced by the electric motor 129 to
the upper cylinder 102.
15 [0036]
Fig. 14 is a front view of the heat caulking device used in the compressor
manufacturing method according to Embodiment of the present disclosure. Fig. 15
is a plan view as viewed in the direction of arrows Q in Fig. 14. The pallet 200, on
which the workpiece 205 is placed, illustrated in Fig. 13 is transported to lower part
20 211 of the heat caulking device 210 of Fig. 14 and is then lifted to a heat caulking
mechanism 213, which is located in upper part of the heat caulking device 210, by a
lifting mechanism 212. The lifting mechanism 212 is a mechanism that raises the
pallet 200 having thereon the workpiece 205 to the level of the heat caulking
mechanism 213 and adjusts the position of the pallet 200 to position the container 1
25 of the workpiece 205 relative to the pushing pins 121. In other words, the lifting
mechanism 212 adjusts and determines the position of the pallet 200 relative to the
heat caulking mechanism 213. Thus, the workpiece 205 is positioned relative to the
heat caulking mechanism 213, thus determining the positions of the protrusions 123
to be formed by the pushing pins 121.
30 [0037]
16
The lifting mechanism 212 includes four positioning shafts 214 arranged to
surround the pallet 200, four positioning bushes 215 located at positions
corresponding to the positioning shafts 214, and a plate 216. The plate 216
supports a bottom surface of the pallet 200. The positioning shafts 214 and rising
5 pins 217 to raise the pallet 200 from the lower part 211 of the heat caulking device
210 to the heat caulking mechanism 213 are arranged on an upper surface of the
plate 216. The pallet 200 transported to the heat caulking device 210 is disposed
right on the rising pins 217 and is then raised to the heat caulking mechanism 213 by
activation of the lifting mechanism 212. At this time, the lifting mechanism 212
10 raises the plate 216 to raise the rising pins 217, on which the pallet 200 is placed, and
the positioning shafts 214. The lifting mechanism 212 stops raising the plate 216 in
response to contact between the raised positioning shafts 214 and the positioning
bushes 215. The completely raised and positioned workpiece 205 is retained firmly
by a hold-down shaft 220, which is reciprocated by an air cylinder 218 and a guide
15 219, such that the hold-down shaft 220 pushes the top of the workpiece.
[0038]
The length of each positioning shaft 214 is set so that the workpiece 205 on the
pallet 200 is located at a normal level relative to the heat caulking mechanism 213
under conditions where lifting by the lifting mechanism 212 is stopped. The term
20 "normal level" as used herein refers to a level at which the fixing grooves 120 in the
outer circumferential surface of the upper cylinder 102 can be aligned with the
pushing pins 121 of the heat caulking mechanism 213. Thus, the level of the
workpiece 205 relative to the heat caulking mechanism 213 is determined.
[0039]
25 At this time, end faces of the positioning shafts 214 and the positioning bushes
215 are in contact with each other such that the shafts and the bushes surround the
pallet 200. Therefore, if the plate 216 is inclined while being raised, the plate 216
can be held horizontally at completion of lifting. In other words, the pallet 200 and
the workpiece 205 are held horizontally without being inclined relative to the heat
30 caulking mechanism 213. Each of the number of positioning shafts 214 and the
17
number of positioning bushes 215 is not limited to four. The plate 216 can be lifted
as long as each of the number of positioning shafts 214 and the number of positioning
bushes 215 is two or more. To hold the plate 216 horizontally, three or more
positioning shafts 214 and three or more positioning bushes 215 are preferably
5 provided to surround the pallet 200.
[0040]
In heat caulking, if identical pressing forces are simultaneously applied to the
three areas circumferentially arranged on the container 1, the workpiece 205 will not
experience any moment. However, it is difficult to simultaneously apply identical
10 pressing forces because of, for example, variations between workpieces 205 or
variations of control by the heat caulking device 210. In particular, temporal
misalignment may cause the pushing pins 121 to fail to be aligned with the fixing
grooves 120 of the workpiece 205 at the first fixing portion in the three areas. To
avoid such misalignment, as illustrated in Figs. 14 and 15, the heat caulking
15 mechanism 213 includes a solid-cylindrical back-up shaft 221, which receives a
pressing force from the caulking punch 122 on the opposite side of the workpiece 205
from a position at which the workpiece 205 is fixed.
[0041]
The back-up shaft 221 is fixed to a flange 222. The flange 222 is coupled to a
20 caulking flange 223, to which the caulking punch 122 having the pushing pins 121 at
its tip is attached, and four link shafts 224. A servo press 225 to reciprocate the
caulking punch 122 at high speed is fixed to the caulking flange 223.
[0042]
As illustrated in Fig. 15, the heat caulking device 210 includes three heat
25 caulking mechanisms 213. Each heat caulking mechanism 213 includes the
caulking punch 122, the back-up shaft 221, and the four link shafts 224 arranged
around the caulking punch 122 and the back-up shaft 221. The link shafts 224 of the
three heat caulking mechanisms 213 are arranged at different intervals to extent at
different levels because the caulking punches 122 and the back-up shafts 221 of the
30 three heat caulking mechanisms 213 are at the same level. Therefore, the flanges
18
222 of the three heat caulking devices 210 have different sizes and the caulking
flanges 223 thereof have different sizes. Among the three heat caulking
mechanisms 213, for example, the heat caulking mechanism having the innermost
four link shafts 224 arranged at the smallest intervals has the smallest flange 222 and
5 the smallest caulking flange 223.
[0043]
As illustrated in Fig. 14, each of the three heat caulking mechanisms 213 is
configured such that an air cylinder 226 and a guide 227 allow the flange 222 and the
caulking flange 223 to reciprocate together in a direction in which the link shafts 224
10 extend. The heat caulking mechanisms 213 cause the back-up shafts 221, moved
forward in three directions by straight movement of the guides 227 of the air cylinders
226, to come into contact with the lifted workpiece 205. From the viewpoint of
reducing manufacturing time, preferably, the heat caulking mechanisms 213
simultaneously move the three back-up shafts 221 such that the back-up shafts 221
15 simultaneously come into contact with the workpiece 205. The heat caulking
mechanisms 213 may move the three back-up shafts 221 one by one such that the
back-up shafts 221 sequentially come into contact with the workpiece 205. In this
case, since the workpiece 205 is retained firmly while being pushed by the hold-down
shaft 220, the workpiece 205 will not be shifted in position. Each back-up shaft 221
20 may have a flat end face to contact the workpiece 205. If the back-up shaft 221 has
an end face on substantially the same curved plane as the outer circumferential
surface of the container 1, or the workpiece 205, the back-up shaft 221 can reliably
receive a pressing force because the area of contact with the outer circumferential
surface of the container 1 increases.
25 [0044]
Fig. 16 is a schematic diagram illustrating a manner of fixing the upper cylinder
to the container by using the heat caulking mechanisms in the compressor
manufacturing method according to Embodiment of the present disclosure. In an
operation before the workpiece 205 is transported to the heat caulking device 210,
30 the suction pipe 110 is inserted into the connection port 108 and the suction port 109
19
by another device (not illustrated) such that the container 1 and the upper cylinder
102 are connected. As illustrated in Fig. 16, the sets of fixing grooves 120 are
circumferentially arranged at an equal pitch of 120 degrees. Furthermore, the
caulking punches 122 are circumferentially arranged at an equal pitch of 120
5 degrees, and the back-up shafts 221 are also circumferentially arranged at an equal
pitch of 120 degrees.
[0045]
As illustrated in Fig. 16, the caulking punch 122 located adjacent to the suction
port 109 is a first punch 122a, the caulking punch 122 located at a position
10 substantially opposite the suction port 109 is a second punch 122b, and the other
caulking punch 122 is a third punch 122c. The back-up shafts 221 corresponding to
the respective caulking punches 122 are a first back-up 221a, a second back-up
221b, and a third back-up 221c. The positioning pin 124 is disposed between the
first punch 122a and the second back-up 221b.
15 [0046]
Fig. 17 is a schematic diagram illustrating a manner of inserting the positioning
pin into the workpiece in the compressor manufacturing method according to
Embodiment of the present disclosure. Fig. 18 is a plan view as viewed in the
direction of arrow R in Fig. 17. As illustrated in Figs. 17 and 18, the positioning pin
20 124 is attached to a plate 235 having a thickness of approximately 19 mm and a width
of approximately 25 mm, for example. The plate 235 is attached to an air slide table
236 attached to a top plate 2 of the heat caulking device 210. The air slide table 236
causes the positioning pin 124 to slide from side to side in Fig. 17 and be inserted into
the suction pipe 110 of the workpiece 205.
25 [0047]
The positioning pin 124 illustrated in Fig. 17 is inserted into the suction pipe 110
after the back-up shaft 221 comes into contact with the workpiece 205. After the
positioning pin 124 is inserted, the collet mechanism 4 is activated by drawing
compressed air, so that the positioning pin 124 is expanded outwardly in four
30 directions, or upward, downward, rightward, and leftward, such that the state of the
20
pin changes from the state illustrated in Figs. 7 and 9 to the state illustrated in Figs. 8
and 10. The expanded positioning pin 124 is fastened to the inner surface of the
suction pipe 110 with the rubber 125 attached around the positioning pin 124 in
between, so that the axes of the suction port 109 and the connection port 108
5 connected by the suction pipe 110 and the center of the upper cylinder 102 are
arranged in the same straight line. In other words, the axis of each fixing groove 120
and the axis of the corresponding pushing pin 121 are in the same straight line, thus
positioning the workpiece 205.
[0048]
10 Parts of the positioned workpiece 205 that correspond to the fixing portions are
heated by high-frequency heating coils 228, which are illustrated in Fig. 14. Each
high-frequency heating coil 228 is moved downward toward the container 1 of the
workpiece 205 by operating a vertical air cylinder 229 and a vertical guide 230.
Then, the high-frequency heating coil 228 is moved forward toward the container 1 in
15 a radial direction of the container by operating a horizontal air cylinder 231 and a
horizontal guide 232.
[0049]
The high-frequency heating coil 228 is fastened to a holder 233. The highfrequency heating coil 228 includes a protecting mechanism 234, which keeps a
20 predetermined distance between the high-frequency heating coil 228 and the
container 1 for movement in the radial direction of the container 1. The highfrequency heating coil 228 is moved until the protecting mechanism 234 comes into
contact with the container 1. Thus, the high-frequency heating coil 228 is positioned
such that the predetermined distance is kept between the high-frequency heating coil
25 228 and the outer circumferential surface of the container 1. The reason why the
high-frequency heating coil 228 is moved in the radial direction of the container 1 is
as follows. The container 1 has variations in dimension, and it is accordingly difficult
to always keep the predetermined distance between each of the three high-frequency
heating coils 228 and the workpiece 205 only by moving the high-frequency heating
30 coils 228 downward.
21
[0050]
Since the predetermined distance can be kept between each high-frequency
heating coil 228 and the container 1 by the protecting mechanism 234 in contact with
the container 1, the high-frequency heating coil 228 can be positioned relative to the
5 outer circumferential surface of the container 1. Therefore, the high-frequency
heating coil 228 has broad utility because the high-frequency heating coil 228 can
always be positioned at the predetermined distance from the container 1 without
being affected by variations in dimension of the container 1 and can be used for
another container 1 having a different outside diameter. The protecting mechanism
10 234 may be omitted. As long as the outer circumferential surface of the container 1
can be used as a reference, the high-frequency heating coil 228 may be positioned in
a non-contact manner by using, for example, infrared rays.
[0051]
The three heat caulking mechanisms 213 each include the high-frequency
15 heating coil 228. The high-frequency heating coils 228 are simultaneously moved.
When positioned at the predetermined distance from the container 1, the highfrequency heating coils 228 are supplied with power to heat parts of the container 1
using current through the coils. When target areas of the container 1 are heated to a
predetermined temperature, each heat caulking mechanism 213 moves the high20 frequency heating coil 228 away from the container 1. After the container 1 is
heated to the predetermined temperature, the heat caulking mechanism 213 activates
and moves the servo press 225 forward within a period of time during which the
container 1 is still hot. The period of time during which the container 1 is still hot is,
for example, within one second after completion of heating. When the servo press
25 225 is activated to move the caulking punch 122 forward to the container 1, the
pushing pins 121 arranged on the tip of the caulking punch 122 apply a pressing force
to the container 1 to form the protrusions 123, thus performing heat caulking between
the container and the fixing grooves 120 of the upper cylinder 102. After completion
of heat caulking, the servo press 225 is moved backward to move the pushing pins
30 121 of the caulking punch 122 away from the container 1. Thermal shrinkage of the
22
container 1 cooled causes the two fixing grooves 120 to produce a pinching force
toward the middle point between the two fixing grooves 120. The three heat
caulking mechanisms 213 simultaneously perform heat caulking in the abovedescribed manner to produce a pinching force at each of the three areas arranged at
5 an equal pitch, thus completely fixing the upper cylinder 102 to the container 1.
[0052]
Fig. 19 is a schematic diagram illustrating the suction pipe deformed due to a
load caused by heat caulking. After completion of heat caulking, the positioning pin
124 placed for positioning needs to be removed from the suction pipe 110. A load on
10 the upper cylinder 102 during heat caulking is reduced by positioning the upper
cylinder 102 in the above-described manner but is not reduced to zero. Therefore, a
slight load is applied to the upper cylinder 102 during heat caulking, so that the upper
cylinder 102 may be distorted. Distortion of the upper cylinder 102 results in
distortion of, for example, the outside and inside diameters of the upper cylinder 102
15 or the suction port 109. As illustrated in Fig. 19, this distortion results in deformation
of the suction pipe 110, thus applying an inward stress to the positioning pin 124,
which is fastened to the inner surface of the suction pipe 110 by the collet mechanism
4. The inward stress makes it difficult to remove the positioning pin 124 from the
suction pipe 110. However, the positioning pin 124 can be unfastened from the
20 suction pipe 110 by enclosing compressed air in the collet mechanism 4 and thus can
be readily removed from the suction pipe 110.
[0053]
As described above, the compressor manufacturing method according to
Embodiment includes: inserting the positioning pin 124 into the suction pipe 110 to
25 position the fixing grooves 120 relative to the protrusions 123; heating parts of the
outer circumferential surface of the container 1 that correspond to the fixing grooves
120; pressing the pushing pins 121 against the heated parts of the outer
circumferential surface of the container 1 to form the protrusions 123 on the inner
surface of the container such that the protrusions 123 are fitted in the fixing grooves
30 120; and removing the positioning pin 124 from the suction pipe 110 after formation of
23
the protrusions 123. In other words, in the compressor manufacturing method
according to Embodiment, if the compression mechanism section 101 is rotated by,
for example, vibrations during transport to the heat caulking device 210, such that the
fixing grooves 120 are out of phase, the positioning pin 124 is inserted into the
5 suction pipe 110, so that the fixing grooves 120 can be aligned with the protrusions
123. Therefore, misalignment of the fixing grooves 120 relative to the protrusions
123 can be corrected when the compression mechanism section 101 is fixed to the
container 1 by heat caulking. Since distortion of the compression mechanism
section 101 can be reduced by reducing a load on the compression mechanism
10 section 101, the compression mechanism section 101 can be fixed reliably and firmly
to the container 1. The compressor 100, which is manufactured by using the
manufacturing method according to Embodiment, can withstand an excessive force
generated during operation in long-term use. The method according to Embodiment
can provide a high-performance and highly reliable compressor in which any problem,
15 such as an increase in noise and vibration caused by wobbling of parts arranged
inside the compressor, is unlikely to occur.
[0054]
The positioning pin 124 includes the collet mechanism 4, which increases the
outside diameter of the pin or reduces the increased outside diameter to the original
20 size. After insertion into the suction pipe 110, the positioning pin 124 is fastened to
the suction pipe 110 by increasing the outside diameter. After heating of the outer
circumferential surface of the container 1 followed by formation of the protrusions
123, the positioning pin 124 is removed from the suction pipe 110 by reducing the
increased outside diameter. In the compressor manufacturing method according to
25 Embodiment, the fixing grooves 120 can be accurately positioned relative to the
protrusions 123 by increasing the outside diameter of the positioning pin 124, thus
reliably aligning the fixing grooves 120 with the protrusions 123. After heat caulking,
the positioning pin 124 can be readily removed by reducing the increased outside
diameter to the original size.
30 [0055]
24
The collet mechanism 4 includes the piston 126, which is operated by drawing
or enclosing compressed air, and the wedge 128 operating in conjunction with
operation of the piston 126 to increase the outside diameter of the positioning pin 124
or reduce the increased outside diameter to the original size. The positioning pin
5 124 is configured such that as the wedge 128 operates in conjunction with the piston
126 operated by drawing compressed air, the outside diameter is increased, and as
the wedge 128 operates in conjunction with the piston 126 operated by enclosing
compressed air, the increased outside diameter is reduced to the original size. In
the compressor manufacturing method according to Embodiment, therefore, such a
10 simple configuration of the collet mechanism 4 facilitates an operation of increasing
the outside diameter of the positioning pin 124 or reducing the increased outside
diameter to the original size, leading to improved workability in manufacturing
operation.
[0056]
15 Although the present disclosure has been described based on Embodiment,
the present disclosure is not limited to the configuration in Embodiment described
above. For example, the compressor 100 is not limited to the details described
above and may include another component. Furthermore, the compressor 100 is
not limited to the twin rotary compressor. For example, a single rotary compressor
20 or a scroll compressor can be similarly embodied. Briefly, design changes and
variations of applications ordinarily made by those skilled in the art fall within the
scope of the present disclosure without departing from the technical idea of the
present disclosure.
Reference Signs List
25 [0057]
1: container, 2: top plate, 3: fixing portion, 4: collet mechanism, 100:
compressor, 101: compression mechanism section, 102: upper cylinder, 103: lower
cylinder, 104: spacer, 105: sub-bearing, 106: main bearing, 107: crankshaft, 108:
connection port, 109: suction port, 110: suction pipe, 120: fixing grooves, 120a:
30 protrusion, 121: pushing pin, 122: caulking punch, 122a: first punch, 122b: second
25
punch, 122c: third punch, 123: protrusion, 124: positioning pin, 125: rubber, 126:
piston, 127: shaft, 128: wedge, 129: electric motor, 129a: stator, 200: pallet, 201:
pallet base, 202: mount, 203: workpiece receiving ring, 204: crankshaft bearing, 205:
workpiece, 210: heat caulking device, 211: lower part, 212: lifting mechanism, 213:
5 heat caulking mechanism, 214: positioning shaft, 215: positioning bush, 216: plate,
217: rising pin, 218: air cylinder, 219: guide, 220: hold-down shaft, 221: back-up shaft,
221a: first back-up, 221b: second back-up, 221c: third back-up, 222: flange, 223:
caulking flange, 224: link shaft, 225: servo press, 226: air cylinder, 227: guide, 228:
high-frequency heating coil, 229: vertical air cylinder, 230: vertical guide, 231:
10 horizontal air cylinder, 232: horizontal guide, 233: holder, 234: protecting mechanism,
235: plate, 236: air slide table
26
We Claim :
[Claim 1]
A method of manufacturing a compressor including a container forming an
outer casing and a compression mechanism section that is contained in the container
5 and that has a compression chamber to compress refrigerant,
the container having a connection port and a plurality of protrusions arranged
on an inner wall surface,
the compression mechanism section having a suction port located at a position
corresponding to the connection port and a plurality of fixing grooves circumferentially
10 spaced apart,
the suction port and the connection port being connected by a suction pipe
extending through both the suction port and the connection port,
the plurality of protrusions being fitted in and fixed to the plurality of fixing
grooves, the method comprising:
15 inserting a positioning pin into the suction pipe to position the plurality of fixing
grooves relative to the plurality of protrusions;
heating parts of an outer circumferential surface of the container, the parts
corresponding to the plurality of fixing grooves;
pressing pushing pins against the heated parts of the outer circumferential
20 surface of the container to form the plurality of protrusions on the inner surface of the
container such that the plurality of protrusions are fitted in the plurality of fixing
grooves; and
removing the positioning pin from the suction pipe after formation of the
plurality of protrusions.
25 [Claim 2]
The method of manufacturing the compressor of claim 1, wherein the
positioning pin includes a collet mechanism that increases an outside diameter of the
positioning pin or reduces the increased outside diameter to an original size, wherein
after insertion into the suction pipe, the positioning pin is fastened to the suction pipe
30 by increasing the outside diameter, and wherein after heating of the outer
27
circumferential surface of the container followed by formation of the plurality of
protrusions, the positioning pin is removed from the suction pipe by reducing the
increased outside diameter.
[Claim 3]
5 The method of manufacturing the compressor of claim 2,
wherein the collet mechanism includes:
a piston that is operated by drawing or enclosing compressed air; and
a wedge that operates in conjunction with operation of the piston to
increase the outside diameter of the positioning pin or reduce the increased outside
10 diameter to the original size, and
wherein the positioning pin is configured such that as the wedge operates in
conjunction with the piston operated by drawing compressed air, the outside diameter
is increased, and as the wedge operates in conjunction with the piston operated by
enclosing compressed air, the increased outside diameter is reduced to the original
15 size.