FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
MACHINING TOOL AND BURNISHING DEVICE;
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 machining tool used for a burnishing device
that burnishes an inner face of a groove that is formed outward from an inner
peripheral surface of a tubular body and relates to such a burnishing device.
10 Background Art
[0002]
In many cases, a cylinder of a rotary compressor has a tubular shape such that
a through-hole is provided in a middle of the cylinder. The cylinder has a vane
attachment groove extending from an inner peripheral surface of the cylinder in a
15 radial direction. In the vane attachment groove, a vane is disposed such that the
vane is allowed to slide. The vane reciprocates inside the vane attachment groove
while the vane is in contact with an outer surface of an eccentric ring disposed in the
through-hole in the cylinder. To ensure that a rotary compressor including such a
cylinder and such a vane provides improved vane sliding performance and high
20 efficiency, an inner face of the vane attachment groove is required to be machined
with extremely high accuracy in surface smoothness, flatness, degree of
parallelization, groove width, and other factors.
[0003]
An example of a device used to finish an inner face of such a vane attachment
25 groove is a device in Patent Literature 1. Patent Literature 1 discloses a burnishing
device that includes a burnishing shaft having a diameter larger than a width of a
vane attachment groove. In Patent Literature 1, the burnishing device includes a
machining tool that holds the burnishing shaft such that one end of the burnishing
shaft is fixed. The burnishing device causes an inner face of a vane attachment
30 groove to be finely plastically deformed by moving the machining tool such that the
3
burnishing shaft is reciprocated while the burnishing shaft is pressed against the inner
face of the vane attachment groove. In this manner, the burnishing device burnishes
the inner face of the vane attachment groove to reduce protrusions on the inner face.
Citation List
5 Patent Literature
[0004]
Patent Literature 1: Japanese Unexamined Patent Application Publication No.
2015-226971
10 Summary of Invention
Technical Problem
[0005]
In the burnishing device of Patent Literature 1, the burnishing shaft is held by
the machining tool such that one end of the burnishing shaft is fixed, as described
15 above. Thus, during machining, the burnishing shaft may be bent, and a center line
of the vane attachment groove and a central axis of the burnishing shaft may shift
from each other. When in such a state the burnishing shaft moves into the vane
attachment groove, the burnishing shaft is strongly pressed against one side of the
inner face of the vane attachment groove because the burnishing device is not
20 configured to cause the central axis of the burnishing shaft to follow the center line of
the vane attachment groove. Disadvantageously, uneven wear is thus caused on a
surface of the burnishing shaft and a life of the machining tool is shortened.
[0006]
An object of the present disclosure, accomplished to solve the problem
25 described above, is to provide a machining tool and a burnishing device that are
designed to offer a prolonged life of the machining tool by reducing uneven wear on a
burnishing shaft in burnishing an inner face of a groove formed outward from an inner
peripheral surface of a tubular workpiece.
Solution to Problem
30 [0007]
4
A machining tool according to an embodiment of the present disclosure is a
machining tool holding a burnishing shaft used for a burnishing device configured to
burnish an inner face of a groove that is formed outward from an inner peripheral
surface of a tubular workpiece. The machining tool includes a support that supports
both ends of the burnishing shaft without fixing both the ends of the 5 burnishing shaft.
Advantageous Effects of Invention
[0008]
The machining tool according to an embodiment of the present disclosure has
a structure such that both the ends of the burnishing shaft are supported and the
10 machining tool thus can prevent the burnishing shaft from being greatly bent during
machining. Thus, the machining tool prevents localized uneven wear on a surface of
the burnishing shaft and provides a prolonged life of the machining tool.
Brief Description of Drawings
[0009]
15 [Fig. 1] Fig. 1 is a schematic view of a configuration of a burnishing device
according to Embodiment 1 of the present disclosure.
[Fig. 2] Fig. 2 is a schematic perspective view illustrating a tubular workpiece
placed on a workpiece holder in the burnishing device according to Embodiment 1 of
the present disclosure.
20 [Fig. 3] Fig. 3 is a perspective view of a tubular workpiece machined by the
burnishing device according to Embodiment 1 of the present disclosure.
[Fig. 4] Fig. 4 is a schematic cross-sectional view of a machining tool of the
burnishing device according to Embodiment 1 of the present disclosure.
[Fig. 5] Fig. 5 is a schematic perspective view of the machining tool of the
25 burnishing device according to Embodiment 1 of the present disclosure.
[Fig. 6] Fig. 6 is a schematic cross-sectional view illustrating dimensional
relationship of the machining tool of the burnishing device according to Embodiment 1
of the present disclosure.
[Fig. 7] Fig. 7 is a plan view illustrating dimensions of a tubular workpiece
30 machined by the burnishing device according to Embodiment 1 of the present
5
disclosure.
[Fig. 8] Fig. 8 is a schematic perspective view illustrating parts of the burnishing
device according to Embodiment 1 of the present disclosure before a tubular
workpiece is burnished by the burnishing device.
[Fig. 9] Fig. 9 is a schematic plan view illustrating a relationship 5 between a
burnishing shaft of the burnishing device according to Embodiment 1 of the present
disclosure and a vane attachment groove in a tubular workpiece while the burnishing
device is machining the tubular workpiece.
[Fig. 10] Figs. 10 are drawings illustrating a relationship between a position on
10 a vane attachment groove in a radial direction and surface flatness before and after
machining by the burnishing device according to Embodiment 1 of the present
disclosure.
[Fig. 11] Fig. 11 is a drawing illustrating a surface profile of a shaft in some
machining tool that holds the shaft such that one end of the shaft is fixed after the
15 shaft is used at a length of 153.6 m/shaft.
[Fig. 12] Fig. 12 is a drawing illustrating a surface profile of a shaft in the
machining tool according to Embodiment 1 of the present disclosure, which holds the
shaft such that both ends of the shaft are supported after the shaft is used at a length
of 2,304 m/shaft.
20 [Fig. 13] Figs. 13 are drawings illustrating a difference in surface pressure
between presence and absence of uneven wear on a surface of a burnishing shaft.
[Fig. 14] Fig. 14 is a schematic cross-sectional view of a machining tool of a
burnishing device according to Embodiment 2 of the present disclosure.
Description of Embodiments
25 [0010]
Embodiments of the present disclosure will be described below with reference
to the drawings. In the drawings, identical parts are denoted by the same reference
signs.
[0011]
30 Embodiment 1
6
Fig. 1 is a schematic view of a configuration of a burnishing device according to
Embodiment 1 of the present disclosure. Fig. 2 is a schematic perspective view
illustrating a tubular workpiece placed on a workpiece holder in the burnishing device
according to Embodiment 1 of the present disclosure. Fig. 3 is a schematic
perspective view of a tubular workpiece machined by the burnishing 5 device according
to Embodiment 1 of the present disclosure.
With reference to Fig. 1, a configuration of a burnishing device 100 according
to Embodiment 1 will be described. The burnishing device 100 includes a tool
moving unit 10 that burnishes a tubular workpiece that is an object to be machined
10 while moving a machining tool 30 relatively to the tubular workpiece and a workpiece
holder 40 that holds the tubular workpiece. The burnishing described herein refers
to a process of machining that is performed to reduce protrusions on a surface to be
machined by finely plastically deforming the surface to be machined. In this
specification, a description will be given to an example in which, as shown in Fig. 2,
15 the tubular workpiece, which is an object to be machined, is a cylinder 1 of a rotary
compressor and the surface to be machined is a vane attachment groove 5.
[0012]
The tool moving unit 10 includes the machining tool 30, an elevating part 11
that ascends and descends with the machining tool 30 fixed to the elevating part 11,
20 and a slide table 12 that enables the elevating part 11 to move in a vertical direction.
The tool moving unit 10 also includes a ball screw 13 that enables the slide table 12
to move, a drive unit 14 that drives the ball screw 13, a guide 15 that holds the slide
table 12, and a body guide 16 that supports the guide 15. The tool moving unit 10
further includes a slide table 17 that enables the body guide 16 to move in a
25 horizontal direction, a ball screw 18 that enables the slide table 17 to move, a guide
19 that holds the slide table 17, and a drive unit 20 that drives the ball screw 18.
The tool moving unit 10 thus configured enables the machining tool 30 to move in the
vertical direction by rotation of the ball screw 13 and enables the machining tool 30 to
move in a lateral direction shown in Fig. 1 by rotation of the ball screw 18, as shown
30 by arrows in Fig. 1.
7
[0013]
Next, with reference to Figs. 1 and 2, the workpiece holder 40 will be
described.
The workpiece holder 40 includes a stage 41, workpiece support stages 42 that
are disposed on the stage 41 and on which the cylinder 1 is placed, 5 and workpiece
retainers 43 that retain the cylinder 1 on the workpiece support stages 42. In this
example, the workpiece support stages 42 are three in number and the workpiece
retainers 43 are equal in number to the workpiece support stages 42.
[0014]
10 A first dowel pin 44 is attached to one of two workpiece support stages 42a that
are at rear right in Fig. 2 (at right in Fig. 1) and that are of the three workpiece support
stages 42. A second dowel pin 45 is attached to a workpiece support stage 42b that
is different from the two workpiece support stages 42a. The first dowel pin 44 and
the second dowel pin 45 are inserted in a first reference hole 3 and a second
15 reference hole 4 provided in the cylinder 1 to place the cylinder 1 on the workpiece
support stages 42 such that the cylinder 1 is positioned in the horizontal direction.
An upper surface of the cylinder 1 is pressed by the workpiece retainers 43 to prevent
the cylinder 1 from coming off the stages during burnishing.
[0015]
20 In this manner, the cylinder 1 is placed on the stage 41 with a phase angle of
the cylinder 1 fixed by the first dowel pin 44 and the second dowel pin 45. As the
phase angle of the cylinder 1 is fixed, for example, the cylinder 1 is thus readily
transferred to a downstream process such as a process for removing burrs from the
vane attachment groove 5. In other words, the need is thus eliminated for adjusting
25 the phase angle of the cylinder 1 again at a time of placing the cylinder 1 onto a stage
in the downstream process. With a through-hole 2 in the cylinder 1 being gripped by
a transfer chuck (not shown), the cylinder 1 can be readily transferred to the stage in
the downstream process with the current phase angle of the cylinder 1 on the stage
41 being kept unchanged.
30 [0016]
8
As shown in Figs. 2 and 3, the cylinder 1 is cylindrical in shape and has the
through-hole 2 in a middle of the cylinder 1 and the vane attachment groove 5 formed
outward an inner peripheral surface of the cylinder 1 in a radial direction. The vane
attachment groove 5 is a space where a vane slides when the rotary compressor is in
operation. When the vane reciprocates in the vane attachment 5 groove 5 on
condition that an inner face of the vane attachment groove 5 is coarse in surface
quality, protrusions caused by such a coarse face in surface quality are caught by
each other, causing a state unfavorable for use of the cylinder 1 such as a state in
which sliding resistance is increased. Consequently, the inner face of the vane
10 attachment groove 5 is required to be burnished with high accuracy.
[0017]
Next, the machining tool 30 will be described.
Fig. 4 is a schematic cross-sectional view of a machining tool of the burnishing
device according to Embodiment 1 of the present disclosure. Fig. 5 is a schematic
15 perspective view of the machining tool of the burnishing device according to
Embodiment 1 of the present disclosure.
[0018]
The machining tool 30 includes an attachment shaft 32 attached to the
elevating part 11 of the tool moving unit 10 and a support 33 that is fixed to a lower
20 end portion of the attachment shaft 32 and supports a burnishing shaft 31. The
burnishing shaft 31 has a diameter R larger than a groove width A (see Fig. 7
described later) of the vane attachment groove 5 in the cylinder 1, which is an object
to be machined, (R [μm] ≤ A [μm] + ΔA [μm]). The burnishing shaft 31 is made of a
material harder than the cylinder 1.
25 [0019]
The support 33 includes a first support part 34 that supports one end of the
burnishing shaft 31 and a second support part 35 that supports the other end of the
burnishing shaft. The first support part 34 and the second support part 35, which are
separated from each other in an axial direction of the attachment shaft 32, are
30 fastened together by a fastening part 36. The fastening part 36 is made up of bolts
9
36a and nuts 36b in this example. The fastening part 36 may be made up of any
other parts that can fasten the first support part 34 and the second support part 35
together.
[0020]
The first support part 34 has a first insertion hole 37a in which 5 the one end of
the burnishing shaft 31 is inserted. The second support part 35 has a second
insertion hole 37b in which the other end of the burnishing shaft 31 is inserted. The
first insertion hole 37a and the second insertion hole 37b have a common diameter D
that is larger than the diameter R of the burnishing shaft 31 (D [mm] ≤ R [mm] + ΔR
10 [mm]). With the relationship D [mm] ≤ R [mm] + ΔR [mm], the burnishing shaft 31 is
not fixed to the support 33 but is supported by the support 33 with both the ends of
the burnishing shaft 31 being simply inserted in the first insertion hole 37a and the
second insertion hole 37b. Thus, as a clearance ΔR exists between the burnishing
shaft 31 and each of the first insertion hole 37a and the second insertion hole 37b,
15 the burnishing shaft 31 is allowed to move in the horizontal direction within a range of
the clearance.
[0021]
Next, a dimensional relationship between the machining tool 30 and the
cylinder 1 will be described.
20 Fig. 6 is a schematic cross-sectional view illustrating dimensional relationship
of the machining tool of the burnishing device according to Embodiment 1 of the
present disclosure. Fig. 7 is a plan view illustrating dimensions of a tubular
workpiece machined by the burnishing device according to Embodiment 1 of the
present disclosure.
25 A width W of the machining tool 30 is a diameter smaller than a diameter B of
the through-hole 2 in the cylinder 1 (W [mm] ≤ B [mm] − ΔB [mm]). A length L
between the first support part 34 and the second support part 35 of the machining tool
30 is a dimension greater than a thickness E (see Fig. 3) of the cylinder 1 (L [mm] ≤ E
[mm] + ΔE [mm]).
30 [0022]
10
Next, a method of burnishing the inner face of the vane attachment groove 5 in
the cylinder 1 using the machining tool 30 will be described.
[0023]
Fig. 8 is a schematic perspective view illustrating parts of the burnishing device
according to Embodiment 1 of the present disclosure before a tubular 5 workpiece is
burnished by the burnishing device. Fig. 9 is a schematic plan view illustrating a
relationship between a burnishing shaft of the burnishing device according to
Embodiment 1 of the present disclosure and a vane attachment groove in a tubular
workpiece while the burnishing device is machining the tubular workpiece. In Fig. 9,
10 a hollow arrow shows a direction in which the burnishing shaft 31 moves.
[0024]
First, the drive unit 20 is driven to move the slide table 17 and thereby move
the machining tool 30 such that a central axis 30c (see Fig. 6) of the machining tool
30 reaches and coincides with a center 2c (see Fig. 7) of the through-hole 2 in the
15 cylinder 1 as shown in Fig. 8. Subsequently, the drive unit 14 is driven to move the
slide table 12 and move down the elevating part 11 to which the machining tool 30 is
attached. Specifically, the elevating part 11 is moved down to a level at which the
burnishing shaft 31 held by the machining tool 30 faces the inner peripheral surface of
the cylinder 1. Subsequently, the drive unit 20 is driven to move the body guide 16,
20 the guide 15, the elevating part 11, and the machining tool 30 to move the burnishing
shaft 31 into the vane attachment groove 5.
[0025]
A case will be discussed in which, as shown in Fig. 9, a center line 5c of the
vane attachment groove 5 and a central axis 31c of the burnishing shaft 31 are
25 shifted from each other when the burnishing shaft 31 is moved into the vane
attachment groove 5. In this case, the burnishing shaft 31 is strongly pressed
against one side of the inner face of the vane attachment groove 5. Nevertheless,
the clearance ΔR is provided, as described above, between the burnishing shaft 31
and each of the first insertion hole 37a and the second insertion hole 37b in the
30 support 33. As a result, when the burnishing shaft 31 moves into the vane
11
attachment groove 5, the burnishing shaft 31 moves along the vane attachment
groove 5 in the horizontal direction such that the central axis 31c follows the center
line 5c of the vane attachment groove 5.
[0026]
With the central axis 31c of the burnishing shaft 31 following 5 the center line 5c
of the vane attachment groove 5, the burnishing shaft 31 moves into the vane
attachment groove 5 to proceed with machining. A surface of the inner face of the
vane attachment groove 5 is thus pressed, leveled, and finished into a smooth
surface such that the surface of the inner face of the vane attachment groove 5 is
10 uniformly burnished with high accuracy.
[0027]
Figs. 10 are drawings illustrating a relationship between a position on a vane
attachment groove in a radial direction and surface flatness before and after
machining by the burnishing device according to Embodiment 1 of the present
15 disclosure. Fig. 10(a) shows surface flatness [μm] in relation to the position [mm] on
the vane attachment groove 5 in the radial direction before burnishing. Fig. 10(b)
shows surface flatness [μm] in relation to the position [mm] on the vane attachment
groove 5 in the radial direction after burnishing.
The surface flatness of the inner face of the vane attachment groove 5 after
20 burnishing shows that protrusions on the surface are leveled and the surface is
finished into a smooth surface with few protrusions as compared to conditions of the
surface before burnishing.
[0028]
The diameter D of each of the first insertion hole 37a and the second insertion
25 hole 37b in which the burnishing shaft 31 is inserted is a diameter larger than the
diameter R of the burnishing shaft 31 by ΔR, as described above. A size of ΔR is
within an appropriate range. With reference to Fig. 9, a case will be discussed in
which a dimension F is 0.4 mm and the central axis 31c of the burnishing shaft 31
and the center line 5c of the vane attachment groove 5 are shifted from each other by
30 approximately 0.1 mm in the radial direction. The dimension F is a length in a
12
circumferential direction of an edge formed between the through-hole 2 and the vane
attachment groove 5.
[0029]
In this case, when ΔR is greater than or equal to 0.5 mm, the burnishing shaft
31 is very likely to interfere with an inner peripheral surface of 5 the through-hole 2
except for the edge formed between the through-hole 2 and the vane attachment
groove 5, causing a flaw such as a scratch on the tubular workpiece. Thus, an
optimum value of ΔR in this case is set to 0.4 mm ±0.1. The optimum value of ΔR
described herein is a value related to the cylinder 1 of the rotary compressor.
10 Hence, when a groove formed outward from an inner peripheral surface of another
tubular workpiece is machined, a value of ΔR can be appropriately selected
depending on dimensions of the tubular workpiece.
[0030]
The machining tool 30 has a structure such that both ends of the burnishing
15 shaft 31 are supported with a clearance provided between the burnishing shaft 31
and each of the first insertion hole 37a and the second insertion hole 37b and the
machining tool 30 thus can prevent the burnishing shaft 31 from being greatly bent
during machining, unlike some machining tool that holds a shaft such that one end of
the shaft is fixed. Localized uneven wear is thus prevented on a surface of the
20 burnishing shaft 31.
[0031]
As both ends of the burnishing shaft 31 are not fixed, the burnishing shaft 31
can rotate in the circumferential direction during machining. Thus, an entire
circumferential surface of the burnishing shaft 31 can be uniformly pressed against
25 the vane attachment groove 5. As a result, the machining tool 30 is configured to
prevent localized uneven wear on the surface of the burnishing shaft 31 and provide a
substantially prolonged life of the machining tool 30 and burnishing with high
accuracy as compared to a machining tool that holds a shaft such that one end of the
shaft is fixed.
30 [0032]
13
Fig. 11 is a drawing illustrating a surface profile of a shaft in some machining
tool that holds the shaft such that one end of the shaft is fixed after the shaft is used
at a length of 153.6 m/shaft. Fig. 12 is a drawing illustrating a surface profile of a
shaft in the machining tool according to Embodiment 1 of the present disclosure,
which holds the shaft such that both ends of the shaft are supported 5 after the shaft is
used at a length of 2,304 m/shaft. The term 153.6 m/shaft denotes that a cumulative
length machined by a single burnishing shaft is 153.6 m. The term 2,304 m/shaft is
similarly interpreted. A length machined per workpiece is 0.0768 m.
[0033]
10 As shown in Fig. 11, when some machining tool is used, uneven wear is
caused on the surface of the burnishing shaft 31 after the shaft is used at a length of
153.6 m/shaft. However, as shown in Fig. 12, when the machining tool 30 according
to Embodiment 1 is used, uneven wear is not caused on the surface of the burnishing
shaft 31 even after the burnishing shaft 31 is used at a length of 2,304 m/shaft. The
15 prolonged life of the machining tool 30 is thus verified.
[0034]
Figs. 13 are drawings illustrating a difference in surface pressure between
presence and absence of uneven wear on the surface of a burnishing shaft. Fig.
13(a) illustrates a case where uneven wear is absent on the surface of the burnishing
20 shaft 31. Fig. 13(b) illustrates a case where uneven wear is present on the surface
of the burnishing shaft 31. In Figs. 13, arrows show distributions of surface
pressure.
As shown in Fig. 13(a), when uneven wear is absent on the surface of the
burnishing shaft 31, contact between the burnishing shaft 31 and an inner face 5a of
25 the vane attachment groove 5 is contact between a cylindrical column and a plane.
Surface pressure thus increases at a middle of the cylindrical column and a protrusion
reduction amount, which is a plastic deformation quantity during burnishing, increases
accordingly.
[0035]
30 Meanwhile, as shown in Fig. 13(b), when uneven wear is present on the
14
surface of the burnishing shaft 31 and a flat face is formed on the surface of the
burnishing shaft 31, contact between the burnishing shaft 31 and the inner face 5a of
the vane attachment groove 5 is contact between planes. Surface pressure thus
decreases and a protrusion reduction amount, which is a plastic deformation quantity
during burnishing, decrease accordingly. In this manner, uneven 5 wear generated on
the surface of the burnishing shaft 31 reduces machining capacity and thus shortens
the life of the machining tool 30. Thus, the machining tool 30 of Embodiment 1,
which prevents uneven wear, is effective in prolonging the life of the machining tool
30.
10 [0036]
As described above, the machining tool 30 of Embodiment 1 has a structure
such that both ends of the burnishing shaft 31 are supported with a clearance
provided between the burnishing shaft 31 and each of the first insertion hole 37a and
the second insertion hole 37b in the support 33. This configuration prevents the
15 burnishing shaft 31 from being greatly bent during machining and prevents localized
uneven wear on the surface of the burnishing shaft 31. Thus, the machining tool 30
substantially prolongs the life of the machining tool 30. With the ability to prevent the
burnishing shaft 31 from being greatly bent during machining, the machining tool 30 is
configured to burnish the surface of the entire inner face of the vane attachment
20 groove 5 uniformly with high accuracy. As a result, the inner face of the vane
attachment groove 5 can be finished into a smooth surface with few protrusions in
surface quality as shown in Figs. 10.
[0037]
As the burnishing shaft 31 can rotate in the circumferential direction, the entire
25 circumferential surface of the burnishing shaft 31 can be uniformly pressed against
the vane attachment groove 5 during machining. Hence, from this point of view as
well, the machining tool 30 is configured to prevent localized uneven wear on the
surface of the burnishing shaft 31 and provide a substantially prolonged life of the
machining tool 30 and burnishing with high accuracy. The prolonged life of the
30 machining tool 30, in turn, enables the machining tool 30 to process workpieces in
15
large quantities at low cost.
[0038]
In the cylinder 1 in which the inner face of the vane attachment groove 5 is
finished using the burnishing device 100 of Embodiment 1, a friction coefficient of the
inner face of the vane attachment groove 5 is reduced. In the rotary 5 compressor that
includes the cylinder 1 in which the friction coefficient of the inner face of the vane
attachment groove 5 is reduced in this manner, the vane is allowed to slide in the
vane attachment groove 5 without being caught by any protrusion on the inner face of
the vane attachment groove 5 during operation. Thus, a rotary compressor can be
10 obtained that has high vane sliding ability, high efficiency, and high performance.
[0039]
The burnishing device 100 according to Embodiment 1 described above
enables the machining tool 30 to ascend and descend in a direction along the
thickness of the cylinder 1 and move in the horizontal direction. However, the
15 present disclosure is not limited to the above configuration. The burnishing device
100 may be configured in any manner as long as the burnishing device 100 enables
relative motion of the machining tool 30 and the cylinder 1 in a similar manner to that
shown in the above configuration. The burnishing device 100 may be, for example,
configured such that the machining tool 30 is fixed and the cylinder 1 is allowed to
20 move in the thickness direction and in the horizontal direction.
[0040]
Embodiment 2
A burnishing device of Embodiment 2 has a structure in which components of
the machining tool in Embodiment 1 are partly integrated together. Differences
25 between Embodiment 2 and Embodiment 1 will be primarily described below.
Components that are not described in Embodiment 2 are similar to the components in
Embodiment 1.
[0041]
Fig. 14 is a schematic cross-sectional view of a machining tool of a burnishing
30 device according to Embodiment 2 of the present disclosure.
16
A machining tool 50 of Embodiment 2 has a structure in which an attachment
shaft 51 attached to an elevating part 11 of a tool moving unit 10 and a support 52
supporting both ends of a burnishing shaft 31 are integrated together. The support
52 has a first insertion hole 52a and a second insertion hole 52b extending along an
axis of the attachment shaft 51 and having a common axis. The 5 second insertion
hole 52b has an opening port in a lower end surface 52c of the support 52. The
burnishing shaft 31 is inserted through the opening port. To ensure that the
burnishing shaft 31 does not fall through the opening port, a retaining plate 53 is fixed
to the lower end surface 52c of the support 52 with a fastening bolt 54.
10 [0042]
The first insertion hole 52a and the second insertion hole 52b are separated
from each other along the axis of the attachment shaft 51. Both ends of the
burnishing shaft 31 are inserted in and supported by the first insertion hole 52a and
the second insertion hole 52b. A clearance ΔR is provided between the burnishing
15 shaft 31 and each of the first insertion hole 52a and the second insertion hole 52b in a
similar manner to the first insertion hole 37a and the second insertion hole 37b in
Embodiment 1.
[0043]
The machining tool 50 according to Embodiment 2 configured as described
20 above produces effects similar to those of Embodiment 1 as well as effects shown
below because a structure of the support 52 is substantially integration of the first
support part 34 with the second support part 35 in Embodiment 1. The first support
part 34 and the second support part 35 that are separate parts necessitate
adjustment such that the first insertion hole 37a and the second insertion hole 37b
25 have the same axis when the machining tool 30 is assembled. This is because the
burnishing shaft 31 is slanted when the insertion holes have the same axis. As a
result, a vane attachment groove 5 cannot be burnished with high accuracy because
the slanted burnishing shaft 31 moves into the vane attachment groove 5 during
machining.
30 [0044]
17
Meanwhile, the structure of the machining tool 50 of Embodiment 2 is such that
the first insertion hole 52a supporting one end of the burnishing shaft 31 and the
second insertion hole 52b supporting the other end of the burnishing shaft 31 are
provided in a single component and the first insertion hole 52a and the second
insertion hole 52b are ensured to have the same axis. The need 5 is thus eliminated
for adjustment such that the first insertion hole 52a and the second insertion hole 52b
have the same axis when the machining tool 50 is replaced and the machining tool 50
can thus be readily replaced for a short time. In Embodiment 2, the machining tool
50 having the first insertion hole 52a and the second insertion hole 52b, which are
10 ensured to have the same axis, can avoid inconvenience of a slanted burnishing shaft
31 and readily provide burnishing with high accuracy.
[0045]
The structure of the machining tool 50 of Embodiment 2 is such that the
attachment shaft 51 and the support 52 are integrated together. In other words, the
15 structure is such that the attachment shaft 32, the first support part 34, the second
support part 35, and the fastening part 36, which are described in Embodiment 1, are
integrated together. Owing to the components integrated together in this manner,
the machining tool 50 provides increased stiffness compared to a structure of the
separate components. With the machining tool 50 providing increased stiffness, the
20 machining tool 50 can be replaced readily.
[0046]
In Fig. 14, the burnishing shaft 31 is inserted from a lower part of the machining
tool 50. However, the burnishing shaft 31 may be inserted from an upper part of the
machining tool 50. The burnishing shaft 31 may be inserted by any manner as long
25 as the burnishing shaft 31 is allowed to be readily inserted in the first insertion hole
52a and the second insertion hole 52b.
Reference Signs List
[0047]
1 cylinder 2 through-hole 2c center of through-hole 3 first
30 reference hole 4 second reference hole 5 vane attachment groove 5a
18
inner face 5c center line 10 tool moving unit 11 elevating part 12
slide table 13 ball screw 14 drive unit 15 guide 16 body guide 17
slide table 18 ball screw 19 guide 20 drive unit 30 machining tool
30c central axis 31 burnishing shaft 31c central axis 32
attachment shaft 33 support 34 first support part 35 second 5 support part 36
fastening part 36a bolt 36b nut 37a first insertion hole 37b second
insertion hole 40 workpiece holder 41 stage 42 workpiece support
stage 42a workpiece support stage 42b workpiece support stage 43 workpiece
retainer 44 first dowel pin 45 second dowel pin 50 machining tool 51
10 attachment shaft 52 support 52a first insertion hole 52b second insertion hole
52c lower end surface 53 retaining plate 54 fastening bolt
19
We Claim :
[Claim 1]
A machining tool holding a burnishing shaft used for a burnishing device
configured to burnish an inner face of a groove that is formed outward from an inner
peripheral surface of a tubular workpiece, the machining tool comprising 5 a support
that supports both ends of the burnishing shaft without fixing both the ends of the
burnishing shaft.
[Claim 2]
The machining tool of claim 1, wherein the support includes
10 a first support part that supports one end of the burnishing shaft,
a second support part that supports an other end of the burnishing shaft, and
a fastening part that fastens the first support part and the second support part
together.
[Claim 3]
15 The machining tool of claim 2, wherein
the first support part has a first insertion hole in which the one end of the
burnishing shaft is inserted, and
the second support part has a second insertion hole in which the other end of
the burnishing shaft is inserted.
20 [Claim 4]
The machining tool of claim 3, wherein a diameter of each of the first insertion
hole and the second insertion hole is larger than a diameter of the burnishing shaft
such that the machining tool supports the burnishing shaft with a clearance provided
between the burnishing shaft and each of the first insertion hole and the second
25 insertion hole.
[Claim 5]
The machining tool of any one of claims 2 to 4, further comprising an
attachment shaft attached to a tool moving unit of the burnishing device,
wherein the attachment shaft, the first support part, the second support part,
30 and the fastening part are integrated together.
20
[Claim 6]
A burnishing device comprising the machining tool of any one of claims 1 to 5.