U.S. patent application number 16/595678 was filed with the patent office on 2020-04-16 for polishing device.
The applicant listed for this patent is HONDA MOTOR CO., LTD.. Invention is credited to Hideaki Imanishi, Daisuke Nakazono, Naoki Takahashi.
Application Number | 20200114484 16/595678 |
Document ID | / |
Family ID | 70162340 |
Filed Date | 2020-04-16 |
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United States Patent
Application |
20200114484 |
Kind Code |
A1 |
Nakazono; Daisuke ; et
al. |
April 16, 2020 |
POLISHING DEVICE
Abstract
A polishing device is provided with an expandable or
contractible polishing body. The polishing device is further
provided with a polishing mechanism that includes: a pressing force
applying mechanism that applies a pressing force to the polishing
body; and a supporting body that supports the pressing force
applying mechanism. Moreover, the pressing force applying mechanism
is configured to include an advancing or retracting section capable
of advancing or retracting, and a swinging section provided in a
swingable manner to a tip of the advancing or retracting section,
the tip facing the polishing body.
Inventors: |
Nakazono; Daisuke;
(Tochigi-ken, JP) ; Takahashi; Naoki;
(Tochigi-ken, JP) ; Imanishi; Hideaki;
(Tochigi-ken, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HONDA MOTOR CO., LTD. |
Tokyo |
|
JP |
|
|
Family ID: |
70162340 |
Appl. No.: |
16/595678 |
Filed: |
October 8, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B24B 21/08 20130101 |
International
Class: |
B24B 21/08 20060101
B24B021/08 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 15, 2018 |
JP |
2018-194182 |
Claims
1. A polishing device that polishes an object-to-be-polished by an
expandable or contractible polishing body, the polishing device
comprising: a pressing force applying mechanism configured to apply
a pressing force to the polishing body; and a supporting body
configured to support the pressing force applying mechanism, the
pressing force applying mechanism including an advancing or
retracting section configured to advance or retract, and a swinging
section provided in a swingable manner to a tip of the advancing or
retracting section, the tip facing the polishing body, the
polishing device further comprising a control section configured to
control a propelling force applied to the advancing or retracting
section.
2. The polishing device according to claim 1, further comprising an
eccentric rotation unit configured to eccentrically rotate the
supporting body.
3. The polishing device according to claim 1, further comprising a
tension applying unit configured to apply a tension to the
polishing body.
4. The polishing device according to claim 1, wherein the advancing
or retracting section advances or retracts, or the swinging section
swings, according to a shape of the object-to-be-polished.
5. The polishing device according to claim 1, further comprising a
robot configured to hold the supporting body.
6. The polishing device according to claim 1, wherein the advancing
or retracting section is configured from an air cylinder having a
rod.
7. The polishing device according to claim 1, wherein the polishing
body is an endless belt configured to turn, and the polishing
device comprises a driving force applying unit configured to apply,
to the endless belt, a driving force for turning.
8. The polishing device according to claim 1, wherein the polishing
body is a sheet body hooked to the supporting body.
9. The polishing device according to claim 1, wherein the control
section sets the propelling force applied to the advancing or
retracting section at a polishing start point and a polishing end
point for the object-to-be-polished larger than the propelling
force applied to the advancing or retracting section at another
region-to-be-polished.
10. The polishing device according to claim 7, wherein the endless
belt is a stacked body of an inner peripheral belt positioned on an
inner peripheral side and an outer peripheral belt positioned on an
outer peripheral side.
11. The polishing device according to claim 6, wherein the air
cylinder is provided in plurality, and the control section does not
supply or discharge compressed air to or from an air cylinder
outside a region-to-be-polished between a polishing start point and
a polishing end point, among the air cylinders.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based upon and claims the benefit of
priority from Japanese Patent Application No. 2018-194182 filed on
Oct. 15, 2018, the contents of which are incorporated herein by
reference.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present invention relates to a polishing device that
polishes an object-to-be-polished by a polishing body.
Description of the Related Art
[0003] A polishing body for polishing an object-to-be-polished is
usually configured as a disk-shaped rotating body as exemplified in
Japanese Laid-Open Patent Publication No. 2004-009189. However, in
this case, although it is possible for a flat surface to be
polished, it is not easy for an irregular surface where undulations
are present to be uniformly polished.
[0004] Accordingly, providing the polishing body with an elastic
body (a cushion), for example, a sponge, is envisioned. This is
because in this case, the elastic body is crushed when polishing a
projection of the object-to-be-polished, whereas the crushed
elastic body attempts to return to its original shape when
polishing a recess of the object-to-be-polished. Thus, since a
shape following ability is manifested in the polishing body by the
elastic body, it is conceivably made possible for the irregular
surface to be comparatively easily polished.
SUMMARY OF THE INVENTION
[0005] In fact, the shape following ability of the elastic body is
not particularly favorable. Therefore, in the case where, for
example, regarding a region-to-be-polished having a complex shape
of the kind where a projection and a recess are alternately
aligned, it is attempted to polish the projection of the
region-to-be-polished, the elastic body may sometimes be
insufficiently crushed. When such a situation occurs, a polishing
amount with respect to the projection will be larger than a design
value.
[0006] In order to avoid this, often, when the
region-to-be-polished has a complex shape, polishing is performed
manually by an operator. However, this case is troublesome and a
burden for the operator.
[0007] A main object of the present invention is to provide a
polishing device capable of performing automatic and favorable
polishing, even in such a case as when a region-to-be-polished has
a complex shape.
[0008] Due to an embodiment of the present invention, there is
provided a polishing device that polishes an object-to-be-polished
by an expandable or contractible polishing body, the polishing
device comprising: [0009] a pressing force applying mechanism
configured to apply a pressing force to the polishing body; and
[0010] a supporting body configured to support the pressing force
applying mechanism, [0011] the pressing force applying mechanism
including an advancing or retracting section configured to advance
or retract, and a swinging section provided in a swingable manner
to a tip of the advancing or retracting section, the tip facing the
polishing body, [0012] the polishing device further comprising a
control section configured to control a propelling force applied to
the advancing or retracting section.
[0013] In the present invention, when the supporting body
eccentrically rotates so that the polishing body makes sliding
contact with (performs polishing of) the object-to-be-polished, the
advancing or retracting section configuring the pressing force
applying mechanism that applies the pressing force to the polishing
body advances or retracts, or the swinging section swings. Due to
the advancing or retracting section and the swinging section
operating in this way, the polishing body makes sliding contact
with a region-to-be-polished, while suitably expanding/contracting
and applying an appropriate and substantially uniform surface
pressure to the region-to-be-polished. It therefore becomes
possible for automatic and favorable polishing to be
implemented.
[0014] The polishing device is preferably provided with an
eccentric rotation unit configured to eccentrically rotate the
supporting body. When the supporting body is eccentrically rotated,
the pressing force applying mechanism supported by the supporting
body also eccentrically rotates. Therefore, a polishing force
transmitted to the object-to-be-polished via the polishing body
becomes wide-ranging, so a polishable region becomes
wide-ranging.
[0015] In addition, the polishing device is preferably provided
with a tension applying unit configured to apply a tension to the
polishing body. By using the tension applying unit to regulate the
tension applied to the polishing body, the surface pressure on the
region-to-be-polished of the polishing body can be suitably
changed.
[0016] In the pressing force applying mechanism, the advancing or
retracting section advances or retracts, or the swinging section
swings, according to a shape of the region-to-be-polished, for
example. Due to the advancing or retracting section and the
swinging section operating in this way, automatic and favorable
polishing can be implemented, even when the region-to-be-polished
has a complex shape.
[0017] The polishing device preferably comprises a robot configured
to hold the supporting body. In this case, by storing in the robot
(teaching the robot) a locus of movement of a polishing mechanism,
polishing can be continuously and automatically implemented on a
more wide-ranging region-to-be-polished than the polishing body.
Furthermore, as well as it being possible for the polishing
mechanism to be moved following a shape of the
object-to-be-polished even when the object-to-be-polished has a
complex shape, polishing can be performed and completed in a short
time.
[0018] The advancing or retracting section can be configured from
an air cylinder having a rod, for example. In this case, a
configuration of the advancing or retracting section can be
simplified, and compactification and weight-lightening can be
achieved.
[0019] Moreover, the polishing body can be configured from an
endless belt configured to turn. In this case, a driving force
applying unit configured to apply, to the endless belt, a driving
force for turning may be provided. Since an unspecific place of the
endless belt thereby makes sliding contact with the
region-to-be-polished, it can be avoided that a specific place of
the endless belt is worn down early.
[0020] Alternatively, a sheet body hooked to the supporting body
may be adopted as the polishing body. In this case, there is no
specific need to provide a driving force applying unit for turning
the sheet body, so the polishing mechanism can be simplified.
[0021] A polishing start point is a movement start point of the
polishing mechanism, and a polishing end point is a movement end
point of the polishing mechanism. Therefore, at the polishing start
point and the polishing end point, a sliding contact force of the
polishing body when making sliding contact with the
region-to-be-polished is reduced. Accordingly, it is preferable
that by control of the control section, the propelling force
applied to the advancing or retracting section at the polishing
start point and the polishing end point for the
object-to-be-polished is set larger than the propelling force
applied to the advancing or retracting section at another
region-to-be-polished. Due to configuring in this way, a polishing
amount will be sufficient even at the polishing start point and the
polishing end point. As a result, polishing unevenness can be
avoided.
[0022] Due to the present invention, it is arranged that the
pressing force applying mechanism for applying the pressing force
to the polishing body is configured to include the advancing or
retracting section that advances or retracts, and the swinging
section provided in a swingable manner to the tip facing the
polishing body of the advancing or retracting section. The
advancing or retracting section advances or retracts, or the
swinging section swings, whereby the polishing body suitably
expands/contracts. Hence, the polishing body makes sliding contact
with the region-to-be-polished while applying an appropriate and
substantially uniform surface pressure to the
region-to-be-polished. This makes it possible for automatic and
favorable polishing to be implemented.
[0023] The above and other objects, features, and advantages of the
present invention will become more apparent from the following
description when taken in conjunction with the accompanying
drawings, in which preferred embodiments of the present invention
are shown by way of illustrative example.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a schematic overall side view of a polishing
device according to a first embodiment of the present
invention;
[0025] FIG. 2 is a schematic side view of a polishing mechanism
configuring the polishing device;
[0026] FIG. 3 is a schematic plan view of the polishing
mechanism;
[0027] FIG. 4 is a schematic front view of the polishing
mechanism;
[0028] FIG. 5 is a schematic cross-sectional front view of a
pressing force applying mechanism;
[0029] FIG. 6 is a schematic explanatory drawing showing a movement
locus of the polishing mechanism on a workpiece being an
object-to-be-polished;
[0030] FIG. 7 is a schematic plan view showing one example of an
attitude of the pressing force applying mechanism when a recess is
present in a region-to-be-polished;
[0031] FIG. 8 is a schematic plan view showing one example of the
attitude of the pressing force applying mechanism when a projection
is present in the region-to-be-polished;
[0032] FIG. 9 is a schematic plan view of a polishing mechanism
configuring a polishing device according to a second embodiment of
the present invention;
[0033] FIG. 10 is a schematic cross-sectional front view of a
pressing force applying mechanism; and
[0034] FIG. 11 is a schematic plan view of the polishing mechanism
when an advancing or retracting section has advanced.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] Preferred embodiments of a polishing device according to the
present invention will be presented and described in detail below
with reference to the accompanying drawings.
[0036] FIG. 1 is a schematic overall side view of a polishing
device 10 according to a first embodiment. This polishing device 10
comprises: an articulated robot 12; a polishing mechanism 16
provided to a tip arm 14 configuring the articulated robot 12; and
a control section 20 that controls the articulated robot 12 and the
polishing mechanism 16. Note that the reference symbol 22 in FIG. 1
indicates a workpiece being an object-to-be-polished. An automobile
body may be cited as a specific example of the workpiece 22.
[0037] The articulated robot 12 includes a rotatable pedestal 24
and a plurality of shaft sections 26, hence is capable of moving
the polishing mechanism 16 to a certain place of the workpiece 22,
and displacing the polishing mechanism 16 along a
region-to-be-polished of the workpiece 22.
[0038] As shown in FIGS. 2 and 4, the polishing mechanism 16 is
coupled to the tip arm 14 via a coupling plate 30. A gear holding
plate 32 of narrower width and smaller area compared to the
coupling plate 30 is close to the coupling plate 30. This gear
holding plate 32 is provided with a gear train. Specifically, the
gear train includes: a driving gear 38 provided to a driving shaft
for eccentricity 36 of a motor for eccentric rotation 34 (an
eccentric rotation unit); a first driven gear 40 engaged with the
driving gear 38; and a second driven gear 42 engaged with the first
driven gear 40. The second driven gear 42 is provided with a driven
shaft for eccentricity 44.
[0039] The driving shaft for eccentricity 36 and the driven shaft
for eccentricity 44 are passed through shaft insertion holes (not
illustrated) respectively formed in the gear holding plate 32 and
the coupling plate 30. A first rotating shaft for eccentricity 48
and a second rotating shaft for eccentricity 50 are respectively
coupled, via eccentric joints 46, to tips of the driving shaft for
eccentricity 36 and the driven shaft for eccentricity 44, the tips
being on a side facing the polishing mechanism 16 and projecting
from the coupling plate 30. An eccentric rotation mechanism 52 for
eccentrically rotating the polishing mechanism 16 is configured as
above. Note that an unillustrated bearing is inserted between the
shaft insertion hole and the driving shaft for eccentricity 36 or
driven shaft for eccentricity 44.
[0040] The first rotating shaft for eccentricity 48 and the second
rotating shaft for eccentricity 50 are coupled to a supporting body
60 configuring the polishing mechanism 16. Specifically, as shown
in FIGS. 2 and 4, the supporting body 60 is configured by
combining: a motor holding wall section 62 whose height is
greatest; a first side wall section 64 that supports a rear surface
of the motor holding wall section 62 and has a region that inclines
downwardly as the first side wall section 64 is separated from the
motor holding wall section 62; a second side wall section 66 whose
height is substantially half that of the motor holding wall section
62; and a mechanism holding wall section 68 bridged between the
first side wall section 64 and the second side wall section 66. The
first rotating shaft for eccentricity 48 and the second rotating
shaft for eccentricity 50 are coupled to the upper side of the
motor holding wall section 62 among these wall sections. In this
case, the first rotating shaft for eccentricity 48 and the second
rotating shaft for eccentricity 50 are arranged along a
longitudinal direction of the motor holding wall section 62.
[0041] In this way, the tip arm 14 of the articulated robot 12
holds the supporting body 60 configuring the polishing mechanism
16, via the coupling plate 30 and the eccentric rotation mechanism
52. Note that as may be understood from the above, the first side
wall section 64 and the second side wall section 66 have their one
ends coupled to the motor holding wall section 62 and have their
other ends coupled to the mechanism holding wall section 68. The
mechanism holding wall section 68 is separated by a predetermined
distance from the motor holding wall section 62, by the first side
wall section 64 and the second side wall section 66 interposed
between the mechanism holding wall section 68 and the motor holding
wall section 62.
[0042] As shown in FIG. 2, a motor for turning 72 (a driving force
applying unit), which applies a driving force for turning an
endless belt 70 serving as a polishing body configuring the
polishing mechanism 16, is attached to the motor holding wall
section 62 at a position not interfering with the first rotating
shaft for eccentricity 48 and the second rotating shaft for
eccentricity 50. A long columnar driving pulley 76 is fitted over a
driving shaft for turning 74 of the motor for turning 72. The
driving pulley 76 drives the endless belt 70.
[0043] The supporting body 60 is provided with three bearing
sections not illustrated. As shown in FIG. 3, the bearing sections
each axially support in a rotatable manner a supporting shaft 80
provided to a long columnar driven pulley 78. Each of side
peripheral walls of the driven pulleys 78 also drive the endless
belt 70. Due to the driving pulley 76 and the three driven pulleys
78, the endless belt 70 is stretched so as to have a rectangular
shape in planar view.
[0044] The endless belt 70 is formed of a stacked body of an inner
peripheral belt 82 and an outer peripheral belt 84. The inner
peripheral belt 82 is made of a material excelling in wear
resistance, and the outer peripheral belt 84 is made of a material
excelling in polishing performance. Due to the inner peripheral
belt 82 being driven by the driving pulley 76 and the driven
pulleys 78, the outer peripheral belt 84 turns integrally with the
inner peripheral belt 82. The outer peripheral belt 84 makes
sliding contact with the region-to-be-polished of the workpiece
22.
[0045] An exterior tensioner 86 (a tension applying unit) makes
sliding contact with the outer peripheral belt 84. The exterior
tensioner 86 presses the outer peripheral belt 84 toward the inner
peripheral belt 82 side, and thereby applies a tension to the
endless belt 70. The larger the pressing force is, the more the
endless belt 70 is tensioned, and, as a result, the larger the
tension applied to the endless belt 70 becomes. Conversely, when
the pressing force is small, the tension applied to the endless
belt 70 is reduced.
[0046] The mechanism holding wall section 68 supports a plurality
of pressing force applying mechanisms 90 that press the endless
belt 70 from the inner peripheral belt 82 side. Next, this pressing
force applying mechanism 90 will be described.
[0047] FIG. 5 is a schematic cross-sectional front view showing one
pressing force applying mechanism 90 along the longitudinal
direction thereof. The pressing force applying mechanism 90
includes: an air cylinder 92 configuring an advancing or retracting
section; and a swinging section 94.
[0048] The air cylinder 92 includes a cylinder tube 98 to which a
supply/discharge tube 96 is coupled. The cylinder tube 98 is held
by the mechanism holding wall section 68, whereby the pressing
force applying mechanism 90 is supported by the mechanism holding
wall section 68.
[0049] An unillustrated piston is housed in the cylinder tube 98,
and a pressing rod 100 that is displaced integrally with the piston
is exposed on an outside of the cylinder tube 98. Furthermore, the
mechanism holding wall section 68 is integrally attached to tips of
all of the cylinder tubes 98. The mechanism holding wall section 68
has a plurality of rod insertion holes 102 (refer to FIG. 3), and
the pressing rods 100 are passed through the rod insertion holes
102.
[0050] A tip of the pressing rod 100 is provided with a ball joint
104. That is, as shown in FIG. 5, a screw-shaped shaft section 106
of the ball joint 104 is screwed into a screw hole provided in the
tip of the pressing rod 100. Moreover, an engaging shaft section
109 that projects from a ball section 108 joined to the
screw-shaped shaft section 106, is fitted into an unillustrated
bearing hole being one region on an interior of a swinging cover
110. The swinging cover 110 swings around the ball section 108 as
the ball section 108 rolls relatively to the bearing hole. An end
surface (a pressing surface 114), on a side facing the inner
peripheral belt 82, of the swinging cover 110 is configured as a
flat surface having a substantially square shape.
[0051] In addition, the swinging cover 110 includes two inclined
sections 116 that are joined to end sections of the pressing
surface 114 and are inclined so as to approach the pressing rod
100. Therefore, an external appearance of the swinging cover 110 is
configured in a substantially isosceles triangle shape.
[0052] A predetermined number of the pressing force applying
mechanisms 90 configured in this way are aligned so as to form a
plurality of rows and a plurality of columns. That is, the
plurality of pressing force applying mechanisms 90 are aligned not
only in a surface direction of FIG. 2, but also in a direction
orthogonal to a paper surface.
[0053] Note that the control section 20 controls the motor for
eccentric rotation 34, the motor for turning 72, the exterior
tensioner 86, and a supply/discharge mechanism (not illustrated)
for performing supply/discharge of compressed air to/from the air
cylinder 92 via the supply/discharge tube 96.
[0054] The polishing device 10 according to the first embodiment is
basically configured as above, and the operational advantages
thereof will be next described in relation to a control method
(operation) of the polishing device 10.
[0055] In order to move the endless belt 70 along the
region-to-be-polished in a state where the endless belt 70 has been
abutted on the polishing start point of the workpiece 22, teaching
is performed beforehand in the articulated robot 12 so that each of
the shaft sections 26 rotates or revolves by a predetermined angle.
In addition, among the plurality of pressing force applying
mechanisms 90, regarding a pressing force applying mechanism 90
that, as a result of the teaching, has been determined not to enter
the region-to-be-polished, the control section 20 maintains the
pressing rod 100 in a state where the pressing rod 100 is
positioned at a backward end. This is achieved by not supplying
compressed air to the cylinder tube 98 from the supply/discharge
mechanism.
[0056] For example, when implementing polishing on the workpiece 22
shown in FIG. 6, the polishing mechanism 16 is displaced in order
of a section-A 120.fwdarw.a section-B 122.fwdarw.a section-C
124.fwdarw.a section-D 126 of the workpiece 22, due to the
articulated robot 12 operating according to the teaching. That is,
the section-A 120 is the polishing start point, and the section-D
126 is the polishing end point. In this case, in the section-A 120,
one column, namely, a lowest column, in the section-B 122 and the
section-C 124, two columns, namely, the lowest column and a column
one above the lowest column, and in the section-D 126, three
columns, namely, the lowest column and columns one and two above
the lowest column, fall outside the region-to-be-polished. That is,
the lowest column does not overlap the region-to-be-polished from
the polishing start point to the polishing end point. Hence, in
this case, compressed air is not supplied to the air cylinders 92
of the pressing force applying mechanisms 90 forming the lowest
column.
[0057] When starting polishing, the control section 20 first
controls the exterior tensioner 86. Specifically, the exterior
tensioner 86 is displaced so as to approach the endless belt 70,
and presses the endless belt 70. Due to this pressing, the endless
belt 70 is tensioned so that the tension thereof increases. In
addition, the control section 20 supplies compressed air from the
supply/discharge mechanism to the air cylinders 92 configuring the
pressing force applying mechanisms 90 other than the pressing force
applying mechanisms 90 of the lowest column. The compressed air is
introduced into the cylinder tube 98 via the supply/discharge tube
96, and presses the piston. As a result, the pressing rod 100
advances to a forward end, and the flat pressing surface 114 of the
swinging cover 110 presses the endless belt 70 from the inner
peripheral belt 82 side.
[0058] The shaft sections 26 of the articulated robot 12 each
suitably operate, and the endless belt 70 abuts on the section-A
120. In the case where a projection 130 due to undulations or
curvature is present in the section-A 120, the pressing force of
the air cylinder 92 (the pressing rod 100) facing the projection
130 may be reduced, if required. This is achieved by discharging a
small amount of compressed air from the cylinder tube 98 via the
supply/discharge tube 96. By thus regulating (correcting) the
pressing force from the pressing rod 100 according to the
projection 130 (refer to FIG. 8) of the section-A 120, the
section-A 120 can be evenly polished.
[0059] Next, the control section 20 drives the motor for eccentric
rotation 34 and the motor for turning 72. In association with the
rotation of the driving shaft for eccentricity 36 of the motor for
eccentric rotation 34, the driving gear 38 rotates, and the first
driven gear 40 (refer to FIGS. 2 and 4) engaged with the driving
gear 38 and the second driven gear 42 engaged with the first driven
gear 40, rotate. Following this, the driven shaft for eccentricity
44 also rotates.
[0060] As described above, the first rotating shaft for
eccentricity 48 and the second rotating shaft for eccentricity 50
are respectively coupled, via the eccentric joints 46, to the
driving shaft for eccentricity 36 and the driven shaft for
eccentricity 44. Hence, the first rotating shaft for eccentricity
48 and the second rotating shaft for eccentricity 50 move with loci
of circles centered on respective rotation centers of the driving
shaft for eccentricity 36 and the driven shaft for eccentricity 44.
As a result, the polishing mechanism 16, in which the first
rotating shaft for eccentricity 48 and the second rotating shaft
for eccentricity 50 are coupled to the supporting body 60,
eccentrically rotates.
[0061] Moreover, when the motor for turning 72 is driven, the
driving shaft for turning 74 and the driving pulley 76 (refer to
FIG. 4) rotate. Therefore, the endless belt 70 pulled by the
driving pulley 76 begins to turn. Turning of the endless belt 70 is
assisted by the three driven pulleys 78. That is, in this case, the
endless belt 70 turns due to the driving pulley 76 and the three
driven pulleys 78, while being applied with tension by the exterior
tensioner 86 and being pressed by the pressing rod 100 from the
inner peripheral belt 82 side.
[0062] Due to the above eccentric rotation of the polishing
mechanism 16 and turning of the endless belt 70, polishing of the
section-A 120 is started. That is, the endless belt 70 makes
sliding contact with the section-A 120, thereby polishing the
section-A 120. The endless belt 70 is applied with tension by being
pressed from the exterior tensioner 86, hence the pressing force on
the region-to-be-polished decreases. However, in the first
embodiment, the pressing rod 100 configuring the pressing force
applying mechanism 90 advances, whereby the endless belt 70 is
pressed to the region-to-be-polished side. In other words, the
endless belt 70 is pressed against the section-A 120. As a result,
the endless belt 70 makes sliding contact with the section-A 120
with sufficient surface pressure, while eccentrically rotating, so
the section-A 120 is favorably polished.
[0063] In this state, the control section 20 operates each of the
shaft sections 26 of the articulated robot 12 in such a manner that
the polishing mechanism 16 moves to the section-D 126 through the
section-B 122 and the section-C 124. In the course of this, when
the pressing force applying mechanism 90 has moved to the section-B
122 side by one row, the control section 20 performs
supply/discharge of compressed air in such a manner that the
pressing rod 100 advances or retracts according to the shape of the
region-to-be-polished of the workpiece 22. However, the air
cylinders 92 forming the lowest column, which is outside the
region-to-be-polished, do not undergo supply/discharge of
compressed air.
[0064] By supply/discharge of compressed air to/from the air
cylinder 92, the pressing rod 100 advances or retracts.
Furthermore, it is possible for the swinging cover 110 to swing.
This is because, as described above, the engaging shaft section 109
of the ball joint 104 is fitted into the bearing hole of the
swinging cover 110. In this way, by a combination of advancement or
retraction of the pressing rod 100 and swinging of the swinging
cover 110, a position of the pressing surface 114 of the swinging
cover 110 changes according to the shape of the
region-to-be-polished.
[0065] FIG. 7 shows one example of the position of the pressing
surface 114 or attitude of the swinging cover 110 when a recess 132
is present in the region-to-be-polished. In this case, the pressing
rod 100 of the air cylinder 92 positioned in an intermediate column
advances more than the pressing rod 100 of the air cylinder 92
positioned below or above the intermediate column. It is therefore
possible for the endless belt 70 to make sliding contact with a
bottom section of the recess 132.
[0066] Contrarily, when the projection 130 is present in the
region-to-be-polished, the endless belt 70 undergoes pressing from
the projection 130, so the endless belt 70 is applied with further
tension. Accordingly, the control section 20 performs
supply/discharge of compressed air in such a manner that, as shown
in FIG. 8, the pressing rod 100 of the air cylinder 92 positioned
in the intermediate column retracts more than the pressing rod 100
of the air cylinder 92 positioned below or above the intermediate
column. Therefore, tension acting on the endless belt 70 is
relieved. Hence, an appropriate surface pressure is applied to the
region-to-be-polished. As a result, the region-to-be-polished is
prevented from being excessively polished. Note that in order to
facilitate understanding regarding differences in
advancement/retraction amount of the pressing rods 100 or
differences in attitude of the swinging covers 110, FIG. 8 shows an
example of the case where all of the pressing force applying
mechanisms 90 enter the region-to-be-polished.
[0067] As described above, the surface pressure of the endless belt
70 when the endless belt 70 makes sliding contact with the
region-to-be-polished is appropriately regulated by the control
section 20 suitably advancing or retracting the pressing rods 100.
Moreover, when the endless belt 70 deforms according to the shape
of the region-to-be-polished, the swinging cover 110 swings.
Therefore, deformation (expansion/contraction) of the endless belt
70 is never hindered. Hence, the region-to-be-polished can be
favorably polished, regardless of the shape of the
region-to-be-polished. Note that, even within the
region-to-be-polished, when a place not requiring polishing is
passed, it is also possible to cause the pressing rods 100 facing
the place not requiring polishing to be retracted to the backward
end.
[0068] When the polishing mechanism 16 reaches the section-D 126,
rotation or revolution of each of the shaft sections 26 of the
articulated robot 12 stops, and movement of the polishing mechanism
16 ends. At this time, the control section 20 stops both the motor
for eccentric rotation 34 and the motor for turning 72, whereby
eccentric rotation of the polishing mechanism 16 and turning of the
endless belt 70 are stopped. The control section 20 further
supplies compressed air to the cylinder tubes 98 other than the
cylinder tubes 98 of a total of three columns, namely, the lowest
column and the columns one and two above the lowest column, and
maintains the pressing rods 100 in a forward end position.
[0069] As described above, in the first embodiment, a configuration
is adopted such that by increasing a propelling force of the air
cylinder 92 at the polishing start point (section-A 120) and the
polishing end point (section-D 126) regardless of the shape of the
region-to-be-polished, the region-to-be-polished is applied with a
larger surface pressure compared to another region-to-be-polished.
As a result, insufficient polishing at the polishing start point
and the polishing end point is avoided. Moreover, since polishing
can be performed automatically by the polishing device 10, a burden
of an operator is reduced.
[0070] In this case, the endless belt 70 is turning, so an
unspecific place of the outer peripheral belt 84 makes sliding
contact with the region-to-be-polished. In other words, it is
avoided that a specific place alone of the outer peripheral belt 84
is involved in polishing. Therefore, the outer peripheral belt 84
is not easily worn down. Hence, the same outer peripheral belt 84
can be employed over a long time. Note that when the outer
peripheral belt 84 has worn down due to repeated polishing over a
long time, and polishing accuracy has thereby lowered, the outer
peripheral belt 84 may be replaced with a new one.
[0071] Next, a polishing device according to a second embodiment
will be described. Note that constituent elements the same as
constituent elements configuring the polishing device 10 according
to the first embodiment will be assigned with the same reference
symbols as those assigned in the first embodiment, and
illustrations or detailed descriptions thereof will be omitted.
[0072] The polishing device includes a polishing mechanism 150
shown in FIG. 9. A supporting body 152 configuring the polishing
mechanism 150 includes a coupling wall section 154 and a guide
plate section 156. A coupling cylinder 157 is bridged between the
guide plate section 156 and the coupling wall section 154.
Moreover, as shown in detail in FIG. 10, the guide plate section
156 is provided with an insertion hole 158 through which the
pressing rod 100 of the air cylinder 92 configuring a pressing
force applying mechanism 159 is passed, and a fixture 160 provided
to a tip of the cylinder tube 98 is housed in the insertion hole
158. The fixture 160 prevents the guide plate section 156 from
falling off.
[0073] A plurality of (for example, two) guide holes 162 are formed
in the guide plate section 156 at positions surrounding the
pressing rod 100. Bushes 164 are respectively housed in the guide
holes 162, and guiding rods 166 are passed through the bushes 164.
A tip, of the guiding rod 166, provided with a screw section is
passed through a through-hole 170 formed in a displacement plate
168, and then a nut 172 is screwed onto the tip. In addition, a tip
of the pressing rod 100 is attached to the displacement plate 168.
Hence, due to extension/contraction of the pressing rod 100, the
displacement plate 168 is displaced, and the guiding rod 166
extends/contracts.
[0074] A stepped holder 174 having a step section is attached to
the displacement plate 168. A screw hole is formed in a tip of the
stepped holder 174, and the screw-shaped shaft section 106 of the
ball joint 104 is screwed into the screw hole. Moreover, a
separable swinging cover 180 is screwed onto and thereby attached
to two engaging shaft sections 109 projecting from the ball section
108 of the ball joint 104.
[0075] A first holding rod 184 that holds a first roller 182 in a
rotatable manner, and a second holding rod 188 that holds a second
roller 186 in a rotatable manner are coupled to the supporting body
152.
[0076] A first coil spring 192 and a second coil spring 194 as a
tension applying unit are hooked on hook sections 190 provided to
the coupling wall section 154. Furthermore, a sheet body 196, which
is a polishing body, is hooked on the first coil spring 192 and the
second coil spring 194 to be held thereby. A predetermined tension
acts on the sheet body 196 due to the first coil spring 192 and the
second coil spring 194 contracting and due to the flat pressing
surface 114 of the swinging cover 180 abutting on the sheet body
196.
[0077] The polishing device according to the second embodiment is
basically configured so as to comprise: the polishing mechanism 150
configured as above; and the eccentric rotation mechanism 52
configured similarly to that of the polishing device 10 according
to the first embodiment. Next, operation of the polishing device
will be described.
[0078] In order to move the sheet body 196 along the
region-to-be-polished in a state where the sheet body 196 has been
abutted on the polishing start point of the workpiece 22, teaching
is performed beforehand in the articulated robot 12 so that each of
the shaft sections 26 rotates or revolves by a predetermined
angle.
[0079] When starting polishing, the control section 20 supplies the
air cylinder 92 with compressed air from the supply/discharge
mechanism. The compressed air is introduced into the cylinder tube
98 via the supply/discharge tube 96, and presses the piston. As a
result, the pressing rod 100 advances to the forward end, and the
flat pressing surface 114 of the swinging cover 180 presses the
sheet body 196, as shown in FIG. 11. Consequently, the sheet body
196 extends while being aided by making sliding movement relatively
to the first roller 182 and the second roller 186. In addition, the
first coil spring 192 and the second coil spring 194 extend,
whereby a predetermined tension is applied to the sheet body
196.
[0080] The shaft sections 26 of the articulated robot 12 each
suitably operate, and the sheet body 196 abuts on the polishing
start point (section-A 120 in FIG. 6). Similarly to above, in the
case where a projection 130 due to undulations or curvature is
present in the section-A 120, the pressing force of the air
cylinder 92 (the pressing rod 100) facing the projection 130 may be
reduced, if required. This is achieved by discharging a small
amount of compressed air from the cylinder tube 98 via the
supply/discharge tube 96. By thus regulating (correcting) the
pressing force from the pressing rod 100 according to the
projection 130 of the section-A 120, the section-A 120 can be
evenly polished.
[0081] Next, the control section 20 drives the motor for eccentric
rotation 34 (refer to FIGS. 2 and 3). In association with the
rotation of the driving shaft for eccentricity 36 of the motor for
eccentric rotation 34, the driving gear 38 rotates, and the first
driven gear 40 (refer to FIGS. 2 and 4) engaged with the driving
gear 38 and the second driven gear 42 engaged with the first driven
gear 40, rotate. Following this, the driven shaft for eccentricity
44 also rotates. Furthermore, the first rotating shaft for
eccentricity 48 and the second rotating shaft for eccentricity 50
are driven to rotate, whereby the polishing mechanism 150
eccentrically rotates.
[0082] Due to the polishing mechanism 150 eccentrically rotating in
this way, the sheet body 196 makes sliding contact with the
section-A 120. Since the sheet body 196 makes sliding contact with
the section-A 120 with sufficient surface pressure, while
eccentrically rotating, the section-A 120 is favorably
polished.
[0083] In this state, the control section 20 operates each of the
shaft sections 26 of the articulated robot 12, and moves the
polishing mechanism 150. In the course of this, the air cylinder 92
undergoes supply/discharge of compressed air, and the pressing rod
100 advances or retracts. Furthermore, the swinging cover 180
swings, and a position of the pressing surface 114 thereof changes
according to the shape of the region-to-be-polished. Hence, even
when the recess 132 or the projection 130 is present in the
region-to-be-polished, an appropriate surface pressure is applied
to the region-to-be-polished from the sheet body 196. Therefore,
the region-to-be-polished can be accurately polished, regardless of
the shape of the region-to-be-polished.
[0084] Note that, similarly to the polishing device 10 according to
the first embodiment, the air cylinder 92 outside the
region-to-be-polished between the polishing start point and the
polishing end point may not undergo supply/discharge of compressed
air.
[0085] When the polishing mechanism 150 reaches the polishing end
point, rotation or revolution of each of the shaft sections 26 of
the articulated robot 12 stops, and movement of the polishing
mechanism 150 ends. At this time, the control section 20 stops the
motor for eccentric rotation 34, and stops eccentric rotation of
the polishing mechanism 150 and turning of the endless belt 70. The
control section 20 further supplies compressed air to the cylinder
tubes 98 other than the cylinder tubes 98 of a total of three
columns, namely, the lowest column and the columns one and two
above the lowest column, and maintains the pressing rods 100 in a
forward end position.
[0086] Thus, operational advantages similar to those of the first
embodiment are obtained also in the second embodiment.
[0087] Moreover, in the polishing mechanism 150, there is no need
to turn the sheet body 196, so the motor for turning, pulleys, and
so on, are rendered unnecessary. As a result, a simpler
configuration may be adopted for the polishing mechanism 150.
[0088] The present invention is not particularly limited to the
above-described first embodiment and second embodiment, and may be
variously modified in a range not departing from the spirit of the
present invention.
[0089] For example, in the second embodiment, the first coil spring
192 and the second coil spring 194 are adopted as the tension
applying unit. However, a cylinder may be adopted instead.
[0090] Moreover, instead of the polishing mechanism 16, the
polishing mechanism 150 may be arranged in the endless belt 70 to
configure the polishing device 10.
[0091] Furthermore, polishing may be performed similarly to above
except that the motor for eccentric rotation 34 is not operated (in
other words, except that the polishing mechanism 16 is not
eccentrically rotated). Also in this case, sufficient polishing is
performed. As may be understood from this, the eccentric rotation
unit, such as the motor for eccentric rotation 34, is not
indispensable.
[0092] Further still, adjacent pressing force applying mechanisms
90 (or pressing force applying mechanisms 159) may be supported by
the supporting body 60 (or the supporting body 152) in such a
manner that the phases of the swinging covers 110 (or swinging
covers 180) differ by 90.degree..
[0093] Moreover, the pressing force applying mechanisms 90 may be
arranged in a so-called zigzag manner.
* * * * *