U.S. patent application number 17/041008 was filed with the patent office on 2021-05-13 for sewing device, workpiece holding jig, and sewing method.
The applicant listed for this patent is HONDA MOTOR CO., LTD.. Invention is credited to Yosuke Ikadai, Shuji Kanamoto, Toru Takamura.
Application Number | 20210140084 17/041008 |
Document ID | / |
Family ID | 1000005354638 |
Filed Date | 2021-05-13 |
![](/patent/app/20210140084/US20210140084A1-20210513\US20210140084A1-2021051)
United States Patent
Application |
20210140084 |
Kind Code |
A1 |
Takamura; Toru ; et
al. |
May 13, 2021 |
SEWING DEVICE, WORKPIECE HOLDING JIG, AND SEWING METHOD
Abstract
A sewing device that, when interposing a workpiece-to-be-sewn
between a post head and a pressing mechanism and sewing same by
penetrating a machine needle therethrough, shapes the
workpiece-to-be-sewn in a prescribed shape and sews same, by
seating the workpiece-to-be-sewn in a workpiece holding jig having
a plurality of seats arranged along a sewing line for the
workpiece-to-be-sewn.
Inventors: |
Takamura; Toru; (Hagagun,
Tochigi-ken, JP) ; Ikadai; Yosuke; (Hagagun,
Tochigi-ken, JP) ; Kanamoto; Shuji; (Hagagun,
Tochigi-ken, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HONDA MOTOR CO., LTD. |
Minato-ku, Tokyo |
|
JP |
|
|
Family ID: |
1000005354638 |
Appl. No.: |
17/041008 |
Filed: |
January 29, 2019 |
PCT Filed: |
January 29, 2019 |
PCT NO: |
PCT/JP2019/002915 |
371 Date: |
September 24, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
D05B 31/00 20130101;
D05B 39/00 20130101 |
International
Class: |
D05B 31/00 20060101
D05B031/00; D05B 39/00 20060101 D05B039/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 30, 2018 |
JP |
2018-068189 |
Claims
1. A sewing device for performing sewing along a certain sewing
line on a workpiece-to-be-sewn in a state of the
workpiece-to-be-sewn having been shaped in a certain shape, the
sewing device comprising: a sewing mechanism including: a sewing
machine needle configured to, by moving in a reciprocating manner,
penetrate through or withdraw from the workpiece-to-be-sewn; a post
bed that faces the sewing machine needle across the
workpiece-to-be-sewn; and a pressing mechanism configured to press
the workpiece-to-be-sewn against the post bed from a side of the
sewing machine needle; a drive mechanism configured to move the
sewing mechanism; and a workpiece holding jig configured to hold
the workpiece-to-be-sewn, wherein the workpiece holding jig
includes: a plurality of seating portions disposed in a moving
direction of the sewing mechanism, each of the seating portions
being configured to hold the workpiece-to-be-sewn shaped in a
certain shape by the workpiece-to-be-sewn being seated on a seating
surface of a certain shape; and a retraction mechanism configured
to, according to a position of the sewing mechanism, retract at
least one of the seating portions from the workpiece-to-be-sewn in
such a manner that interference between the sewing mechanism and
the seating portion is avoided.
2. The sewing device according to claim 1, wherein in a retraction
region where both surfaces of the workpiece-to-be-sewn have been
set adrift due to retraction of the seating portion, sewing is
performed with the sewing mechanism pinching the
workpiece-to-be-sewn to adjust the surface of the
workpiece-to-be-sewn to a flat surface.
3. The sewing device according to claim 1, comprising a plurality
of suction holes provided in the seating surface of the seating
portion, wherein the workpiece-to-be-sewn is held by being sucked
through the suction holes.
4. The sewing device according to claim 1, further comprising a
second workpiece holding jig disposed in a position not interfering
with the moving direction of the sewing mechanism, and configured
to support the workpiece-to-be-sewn.
5. The sewing device according to claim 1, wherein the retraction
mechanism is configured by a cylinder or cam mechanism.
6. A workpiece holding jig used in a sewing device that includes a
sewing mechanism and a drive mechanism configured to move the
sewing mechanism, the sewing mechanism including: a sewing machine
needle configured to, by moving in a reciprocating manner,
penetrate through or withdraw from a workpiece-to-be-sewn; a post
bed that faces the sewing machine needle across the
workpiece-to-be-sewn; and a pressing mechanism configured to press
the workpiece-to-be-sewn against the post bed from a side of the
sewing machine needle, the workpiece holding jig comprising: a
plurality of seating portions disposed in a moving direction of the
sewing mechanism, each of the seating portions being configured to
hold the workpiece-to-be-sewn maintained in a certain shape by the
workpiece-to-be-sewn being seated on a seating surface of a certain
shape; and a retraction mechanism configured to, according to a
position of the sewing mechanism, retract at least one of the
seating portions from the workpiece-to-be-sewn in such a manner
that interference between the sewing mechanism and the seating
portion is avoided.
7. A sewing method for performing sewing along a certain sewing
line on a workpiece-to-be-sewn in a state of the
workpiece-to-be-sewn having been shaped in a certain shape, the
sewing being performed using a sewing mechanism including: a sewing
machine needle configured to, by moving in a reciprocating manner,
penetrate through or withdraw from the workpiece-to-be-sewn; a post
bed that faces the sewing machine needle across the
workpiece-to-be-sewn; and a pressing mechanism configured to press
the workpiece-to-be-sewn against the post bed from a side of the
sewing machine needle, the sewing method comprising: a step of
shaping the workpiece-to-be-sewn in a certain shape by the
workpiece-to-be-sewn being seated on a plurality of seating
portions disposed along a sewing line of the workpiece-to-be-sewn;
a step of forming a retraction region where both surfaces of the
workpiece-to-be-sewn have been set adrift by retracting some of the
seating portions; and a step of performing sewing with the both
surfaces of the workpiece-to-be-sewn being pinched by the sewing
mechanism, in the retraction region of the workpiece-to-be-sewn.
Description
TECHNICAL FIELD
[0001] The present invention relates to a sewing device, a
workpiece holding jig, and a sewing method for implementing sewing
on a skin material.
BACKGROUND ART
[0002] Sometimes, in order to create a high-quality feeling in a
vehicle interior of an automobile, a skin material that has been
cut or molded to match a shape of an interior base material such as
an instrument panel undergoes implementation of stitch pattern
sewing (is provided with a seam). The sewing has conventionally
been performed by a worker using a fixed type sewing machine. In
the sewing machine, a workpiece-to-be-sewn is disposed on a sewing
machine table, and sewing is performed by a sewing machine needle
through which a thread has been passed being caused to penetrate
through and withdraw from that workpiece-to-be-sewn.
[0003] When performing such sewing, sometimes too, in order to
prevent deformation, the sewing is performed with the
workpiece-to-be-sewn fixed by a jig of a certain shape. For
example, Japanese Laid-Open Patent Publication No. 2017-071382
relates to a method of forming a stitch pattern by a needle thread
alone, and describes the workpiece-to-be-sewn being supported by a
receiving jig. Moreover, Japanese Laid-Open Patent Publication No.
2017-197163 and Japanese Patent No. 6151117 describe sewing being
performed while the workpiece-to-be-sewn is being pressed pinched
between a pressing mechanism and a receiving jig.
SUMMARY OF INVENTION
[0004] However, in a conventional sewing device, which is for
sewing a comparatively flat portion of the workpiece-to-be-sewn, it
is difficult for the receiving jig to be disposed on a narrow
portion curved with a small radius of curvature like a portion
curved at an acute angle, for example. Therefore, there is a
problem that a workpiece-to-be-sewn which has been shaped having a
curved portion cannot be accurately sewn.
[0005] Hence, there is desired a sewing device, a workpiece holding
jig, and a sewing method that enable sewing to be accurately
performed even on a workpiece-to-be-sewn in a shaped state.
[0006] A sewing device according to an aspect of the present
invention is a sewing device for performing sewing along a certain
sewing line on a workpiece-to-be-sewn in a state of the
workpiece-to-be-sewn having been shaped in a certain shape, the
sewing device comprising: a sewing mechanism including: a sewing
machine needle configured to, by moving in a reciprocating manner,
penetrate through or withdraw from the workpiece-to-be-sewn; a post
bed that faces the sewing machine needle across the
workpiece-to-be-sewn; and a pressing mechanism configured to press
the workpiece-to-be-sewn against the post bed from a side of the
sewing machine needle; a drive mechanism configured to move the
sewing mechanism; and a workpiece holding jig configured to hold
the workpiece-to-be-sewn, wherein the workpiece holding jig
includes: a plurality of seating portions disposed in a moving
direction of the sewing mechanism, each of the seating portions
being configured to hold the workpiece-to-be-sewn shaped in a
certain shape by the workpiece-to-be-sewn being seated on a seating
surface of a certain shape; and a retraction mechanism configured
to, according to a position of the sewing mechanism, retract at
least one of the seating portions from the workpiece-to-be-sewn in
such a manner that interference between the sewing mechanism and
the seating portion is avoided.
[0007] According to the above-described sewing device, the
workpiece-to-be-sewn is held by the workpiece holding jig including
the seating portions each holding the workpiece-to-be-sewn shaped
by being seated on the seating surface of the certain shape. As a
result, the shaped workpiece-to-be-sewn can be certainly held, and
sewing can be performed by the sewing mechanism even on a portion
curved at an acute angle, for example, without there being any
positional misalignment. Moreover, by providing a retraction
mechanism that retracts the seating portion in a region where there
is interference with the sewing mechanism, the sewing mechanism can
be moved along the sewing line without there being interference
with the seating portion.
[0008] In the above-described sewing device, in a retraction region
where both surfaces of the workpiece-to-be-sewn have been set
adrift due to retraction of the seating portion, sewing may be
performed with the sewing mechanism pinching the
workpiece-to-be-sewn to adjust the surface of the
workpiece-to-be-sewn to a flat surface.
[0009] According to the above-described configuration, the
workpiece-to-be-sewn is held by the workpiece holding jig including
the seating portions each holding the workpiece-to-be-sewn shaped
by being seated on the seating surface of the certain shape, and a
portion where some of those seating portions have been retracted is
sewn pinched by the sewing mechanism. Thus, a local portion between
the pressing portion and the post bed of the sewing device can be
flattened, and an optimal posture of the workpiece-to-be-sewn can
be obtained, while the shape that has been shaped is maintained for
adjacent portions. As a result, even a portion curved at an acute
angle, for example, can be accurately sewn without being affected
by its shape.
[0010] In the above-described sewing device, the sewing device may
comprise a plurality of suction holes provided in the seating
surface of the seating portion, and the workpiece-to-be-sewn may be
held by being sucked through the suction holes.
[0011] According to the above-described configuration, the
workpiece-to-be-sewn can be seated on the seating surface of the
seating portion by being sucked. Moreover, by suction being
stopped, the workpiece-to-be-sewn can be released, and a retraction
operation can be quickly performed.
[0012] In the above-described sewing device, the sewing device may
further comprise a second workpiece holding jig disposed in a
position not interfering with the moving direction of the sewing
mechanism, and configured to support the workpiece-to-be-sewn.
[0013] According to the above-described configuration, the
workpiece-to-be-sewn can be more certainly held, and can be
accurately sewn.
[0014] In the above-described sewing device, the retraction
mechanism is configured by a cylinder or cam mechanism.
[0015] According to the above-described configuration, the
retraction mechanism can be configured by a simple device
configuration, and a device configuration of the sewing device can
be simplified.
[0016] Moreover, a workpiece holding jig of another aspect of the
present invention is a workpiece holding jig used in a sewing
device that includes a sewing mechanism and a drive mechanism
configured to move the sewing mechanism, the sewing mechanism
including: a sewing machine needle configured to, by moving in a
reciprocating manner, penetrate through or withdraw from a
workpiece-to-be-sewn; a post bed that faces the sewing machine
needle across the workpiece-to-be-sewn; and a pressing mechanism
configured to press the workpiece-to-be-sewn against the post bed
from a side of the sewing machine needle, the workpiece holding jig
comprising: a plurality of seating portions disposed in a moving
direction of the sewing mechanism, each of the seating portions
being configured to hold the workpiece-to-be-sewn maintained in a
certain shape by the workpiece-to-be-sewn being seated on a seating
surface of a certain shape; and a retraction mechanism configured
to, according to a position of the sewing mechanism, retract at
least one of the seating portions from the workpiece-to-be-sewn in
such a manner that interference between the sewing mechanism and
the seating portion is avoided.
[0017] Moreover, a sewing method of yet another aspect of the
present invention is a sewing method for performing sewing along a
certain sewing line on a workpiece-to-be-sewn in a state of the
workpiece-to-be-sewn having been shaped in a certain shape, the
sewing being performed using a sewing mechanism including: a sewing
machine needle configured to, by moving in a reciprocating manner,
penetrate through or withdraw from the workpiece-to-be-sewn; a post
bed that faces the sewing machine needle across the
workpiece-to-be-sewn; and a pressing mechanism configured to press
the workpiece-to-be-sewn against the post bed from a side of the
sewing machine needle, the sewing method comprising: a step of
shaping the workpiece-to-be-sewn in a certain shape by the
workpiece-to-be-sewn being seated on a plurality of seating
portions disposed along a sewing line of the workpiece-to-be-sewn;
a step of forming a retraction region where both surfaces of the
workpiece-to-be-sewn have been set adrift by retracting some of the
seating portions; and a step of performing sewing with the both
surfaces of the workpiece-to-be-sewn being pinched by the sewing
mechanism, in the retraction region of the
workpiece-to-be-sewn.
[0018] According to the above-described sewing device, workpiece
holding jig, and sewing method, sewing can be accurately performed
on the workpiece-to-be-sewn.
BRIEF DESCRIPTION OF DRAWINGS
[0019] FIG. 1 is a schematic configuration diagram of a sewing
device according to a first embodiment of the present
invention;
[0020] FIG. 2 is a side view of a workpiece holding jig of FIG.
1;
[0021] FIG. 3A is a front view of immediately before retraction of
a first seating portion of the workpiece holding jig of FIG. 1, and
FIG. 3B is a front view showing a state where the first seating
portion has retracted;
[0022] FIG. 4 is a front view of a state where a second seating
portion of the workpiece holding jig has retracted;
[0023] FIG. 5 is an enlarged perspective view of a sewing portion
of the sewing device of FIG. 1;
[0024] FIG. 6 is an enlarged perspective view showing dispositions
of a workpiece-to-be-sewn and a seating portion thereof according
to a second embodiment of the present invention;
[0025] FIG. 7A is a cross-sectional view showing a cross section
taken along the line VIIA-VIIA of FIG. 6, along with an enlarged
view of part thereof, and FIG. 7B is a cross-sectional view taken
along the line VIIB-VIIB of FIG. 6; and
[0026] FIGS. 8A to 8C are schematic views showing a retraction
mechanism according to a third embodiment, along with operation
thereof.
DESCRIPTION OF EMBODIMENTS
[0027] Preferred embodiments of the present invention will be
presented and described in detail below with reference to the
accompanying drawings. Note that "up", "down", "left", and "right"
in the description below respectively correspond to upward,
downward, leftward, and rightward in the drawings. However, this is
an indication of directions which has been adopted for convenience
in order to facilitate understanding, and does not define
directions when a sewing device, a workpiece holding jig, and a
sewing method are actually used.
First Embodiment
[0028] As shown in FIG. 1, a sewing device 10 according to the
present embodiment includes: a workpiece holding jig 12; a sewing
mechanism 14; and a conveyor robot 16 as a drive mechanism for
conveying the sewing mechanism 14. The sewing mechanism 14 is
fitted to a tip arm 18 of the conveyor robot 16.
[0029] As shown in FIG. 2, the workpiece holding jig 12 comprises a
seating portion 20, a guide pin 22, an air cylinder 24, a vacuum
generator 40, and a frame body 26. The seating portion 20 has a
seating surface 20a formed in its upper portion. The seating
surface 20a is formed in the same shape as a workpiece-to-be-sewn
58 (refer to FIG. 3A), in order for shape of the
workpiece-to-be-sewn 58 to be maintained. Note that in the example
illustrated, the seating surface 20a includes in its uppermost
portion a portion which is curved at an acute angle. That seating
surface 20a has a plurality of suction holes 30 formed therein.
These suctions holes 30 communicate with a negative pressure
passage 32 on an inside of the seating portion 20, and that
negative pressure passage 32 communicates with an air hose 36a
connected to a lower end portion of the seating portion 20. This
seating portion 20 is supported by the guide pin 22 via a
supporting member 22a.
[0030] The guide pin 22 is fitted to the frame body 26 via a guide
bush 42. Moreover, a lower end portion of the guide pin 22 is
connected to a piston rod 24a of the air cylinder 24. The guide pin
22 is configured capable of moving in an up-down direction
integrally with the piston rod 24a while being guided by the guide
bush 42.
[0031] The air cylinder 24 has its lower end portion fixed to a
base portion 28 of the frame body 26, has its upper end portion
(its end portion on the piston rod 24a side) upwardly disposed, and
has its piston rod 24a configured capable of moving in an up-down
direction of the drawing. This air cylinder 24 is connected with an
air hose 44a and an air hose 44b, and operates by supply of
compressed air from an external air supplying means (not
illustrated).
[0032] The above-described air cylinder 24 and guide pin 22
configure a retraction mechanism of the seating portion 20, and the
seating portion 20 is configured retractable in the up-down
direction. Note that a retracting direction of the seating portion
20 is not limited to the up-down direction, and there may be
movement in a horizontal direction or movement with
three-dimensional displacement.
[0033] The vacuum generator 40 is fitted to the frame body 26. This
vacuum generator 40 is supplied with compressed air via air hoses
36c, 36d and an electromagnetic valve 39. The vacuum generator 40
is configured by the likes of a vacuum ejector, for example, and
can generate a negative pressure under action of compressed air
supplied via the electromagnetic valve 39. The negative pressure
generated by the vacuum generator 40 is supplied to an air manifold
38 via an air hose 36b.
[0034] The air manifold 38, as well as including passages that
branch on its inside, comprises valves that control opening/closing
of each of the passages. That air manifold 38 is connected with the
air hose 36a. As shown in FIG. 1, in the workpiece holding jig 12,
a plurality of the seating portions 20 are provided, and a
plurality of the air hoses 36a connected to these plurality of
seating portions 20 are connected to the air manifold 38 of FIG. 2.
ON/OFF of suction of the individual seating portions 20 can be
switched with opening/closing of the valves on the inside of the
air manifold 38. In the case of there being several seating
portions 20, a plurality of the air manifolds 38 and vacuum
generators 40 may be provided. Note that a configuration may be
adopted whereby ON/OFF of suction of the individual seating
portions 20 is switched by the electromagnetic valves 39, instead
of by the air manifold 38. In this case, the air manifold 38 need
not be provided with the valves, and the air manifold 38 functions
solely as a branching path of a passage joining the vacuum
generator 40 and the seating portion 20.
[0035] Note that instead of the air manifold 38 being connected
with the air hoses 36a from the plurality of seating portions 20,
it is also possible for each of the seating portions 20 to be
individually provided with the vacuum generator 40.
[0036] As shown in FIG. 1, a plurality of the seating portions 20
are disposed along a sewing direction of the sewing mechanism 14.
The seating surfaces 20a of these seating portions 20 are provided
along a sewing line where the sewing mechanism 14 performs sewing,
and have substantially the same shape as a shape of the
workpiece-to-be-sewn 58 lying along the sewing line (refer to FIG.
5).
[0037] The seating portions 20 are each respectively provided with
the air cylinder 24 and the guide pin 22, and the individual
seating portions 20 are configured to be retractable. That is, the
seating portions 20 are configured to be retractable, in order,
with approach of the sewing mechanism 14.
[0038] As shown in FIG. 1, the sewing mechanism 14 comprises a main
body 50 formed in a U shape when viewed from the side, and
projections 50a, 50b facing each other of that main body 50 are
provided with a post bed 46, a pressing mechanism 48, and a sewing
machine needle 49. As shown enlarged in FIG. 5, the pressing
mechanism 48 and the sewing machine needle 49 are provided on a
side of one of the projections, that is, the projection 50a, and
extend out toward the other of the projections, that is, the
projection 50b. The post bed 46 is provided on a side of the other
projection 50b, and extends out toward the pressing mechanism 48
and the sewing machine needle 49.
[0039] The pressing mechanism 48 is configured projectable toward
the post bed 46 via a shaft 48a, and is configured in such a manner
that, when sewing is performed on the workpiece-to-be-sewn 58, the
pressing mechanism 48 presses the workpiece-to-be-sewn 58 against a
tip of the post bed 46. A tip of the pressing mechanism 48 is
provided with a pair of through-holes 48b allowing insertion
therethrough of a tip of the sewing machine needle 49.
[0040] The sewing machine needle 49 is fitted so as to be enabled
to move in a reciprocating manner in the up-down direction by a
drive mechanism (not unillustrated) of the projection 50a.
Reciprocating movement of the sewing machine needle 49 describes an
elliptical locus when viewed from a front of the main body 50. This
results in it being configured such that even when the main body 50
is moved at a constant speed, the sewing machine needle 49 is
penetrated through the workpiece-to-be-sewn 58 while maintaining a
constant position with respect to the workpiece-to-be-sewn 58. The
tip of this sewing machine needle 49 has a thread 52 inserted
therethrough, and is inserted into a receiving portion of the post
bed 46 via the through-hole 48b. Although the sewing machine needle
49 is not specifically limited, two items of the sewing machine
needle 49 are illustrated, and these can form two parallel stitch
patterns S.
[0041] The post bed 46 is provided with an unillustrated looper
that holds a loop portion of the thread 52 formed by penetration of
the sewing machine needle 49. That post bed 46 catches the loop
portion of the sewing machine needle 49 on the next loop portion
formed by a penetrating portion of the sewing machine needle 49 to
connect up the loop portions, whereby sewing is performed.
[0042] The conveyor robot 16 proceeds to convey the sewing
mechanism 14 and move a sewing portion of the sewing mechanism 14
along the sewing line at a constant speed. The conveyor robot 16
inclines the main body 50 in accordance with a shape of a sewing
position of the workpiece-to-be-sewn 58, and thereby disposes the
sewing machine needle 49 at an inclination perpendicular to the
sewing position of the workpiece-to-be-sewn 58.
[0043] In the above configuration, the workpiece holding jig 12,
the sewing mechanism 14, and the conveyor robot 16 operate under
control action of an unillustrated control circuit. The sewing
device 10 according to the present embodiment is basically
configured as above. Operational advantages thereof, along with
operation of the sewing device 10, will be described below.
[0044] As shown in FIG. 3A, the workpiece-to-be-sewn 58 is placed
on top of the workpiece holding jig 12. The workpiece-to-be-sewn 58
is held by the workpiece holding jig 12 in a state of being seated
on the seating surface 20a by being sucked through the suction
holes 30 of the seating portion 20. In the case of the
workpiece-to-be-sewn 58 used in an interior material of a vehicle,
the strength thereof is comparatively high, hence even if a back
surface of the workpiece-to-be-sewn 58 is partially seated on the
seating portion 20, without the entire back surface being seated
thereon, posture can be maintained to a certain extent. In this
case, a portion where the seating portion 20 has been retracted can
be elastically deformed to a certain degree with respect to
pinching by the sewing mechanism 14.
[0045] Immediately after the workpiece-to-be-sewn 58 has been
placed on the workpiece holding jig 12, sewing is started in a
state of the workpiece-to-be-sewn 58 being sucked by all of the
seating portions 20. Subsequently, an end portion of the
workpiece-to-be-sewn 58 is pinched by the pressing mechanism 48 and
the post bed 46 of the sewing mechanism 14, and sewing is performed
while penetrating and withdrawing the sewing machine needle 49
through/from the workpiece-to-be-sewn 58.
[0046] As shown in FIG. 5, the post bed 46 is arranged separated in
a vertical direction from the back surface of the
workpiece-to-be-sewn 58 in order to prevent interference with the
workpiece-to-be-sewn 58. In the case of the present embodiment, it
may be separated by about 5 mm to 10 mm, for example. As a result,
the shape of the workpiece-to-be-sewn 58 shaped by the seating
portion 20 can be prevented from being deformed by the post bed 46,
and positional misalignment of the sewing line can be prevented.
The pressing mechanism 48 pushes the workpiece-to-be-sewn 58 to a
position of a tip surface of the post bed 46, whereby the pressing
mechanism 48 forms a flat surface on a surface of the
workpiece-to-be-sewn 58 at a portion between the post bed 46 and
the pressing mechanism 48, and adjusts an inclination of the flat
surface to be substantially perpendicular to the sewing machine
needle 49.
[0047] The sewing mechanism 14 moves at a constant speed in a
rightward direction in the drawings, by means of the conveyor robot
16. Accordingly, as shown in FIG. 3B, the first seating portion 20
at a position interfering with the sewing mechanism 14 is
retracted. When the seating portion 20 is retracted, supply of
negative pressure to the seating portion 20 is stopped, thereby
releasing suction of the workpiece-to-be-sewn 58. Then, by the air
cylinder 24 being lowered, the seating portion 20 is retracted to a
position not interfering with the sewing mechanism 14.
[0048] As a result, the workpiece-to-be-sewn 58 attains a state
where both surfaces thereof have been set adrift from the seating
portion 20, and in that portion, the sewing mechanism 14 can be
moved along the sewing line. Note that even when the first seating
portion 20 has been retracted, the shape of the
workpiece-to-be-sewn 58 is maintained by the second seating portion
20, hence sewing can be performed in a state where the
workpiece-to-be-sewn 58 has been shaped.
[0049] Depending on the inclination of the surface at the sewing
position of the workpiece-to-be-sewn 58, the sewing mechanism 14
may be obliquely inclined. In that case, a plurality of the seating
portions 20 in a range interfering with the sewing mechanism 14
should be retracted.
[0050] Next, as shown in FIG. 4, the second seating portion 20 is
retracted in accordance with movement of the sewing mechanism 14.
Moreover, the seating portion 20 that has been passed by the sewing
mechanism 14 is returned to its original position.
[0051] As described above, the seating portion 20 that interferes
with the sewing mechanism 14 is retracted in accordance with
movement of that sewing mechanism 14, whereby it can be prevented
that the seating portion 20 interferes with the sewing mechanism
14. As a result, sewing can be performed by the sewing mechanism 14
while maintaining a state of the workpiece-to-be-sewn 58 having
been shaped by the seating portion 20.
Second Embodiment
[0052] In the present embodiment, an example where sewing of the
stitch pattern S is implemented assuming an interior material
configuring an instrument panel of a vehicle to be a
workpiece-to-be-sewn 68, will be described. Note that a
configuration of the sewing device 10 used in the present
embodiment is basically similar to that shown in FIG. 1, and a
description thereof will be omitted.
[0053] As shown in FIG. 6, the workpiece-to-be-sewn 68 is supplied
in a state of having been shaped in a shape of the instrument
panel. As shown in the enlarged portion of FIG. 7A, this
workpiece-to-be-sewn 68 is configured from: a base material 68b
constituted by a hard synthetic resin, that is formed in a required
shape; and a skin material 68a that is soft, and is adhered to a
surface of the base material 68b. The base material 68b is
constituted by extrusion-molded polypropylene, for example, and the
skin material 68a is constituted by a soft elastomer material that
has been applied with a leather-like pattern, for example.
[0054] As shown in FIG. 6, a curve L of the workpiece-to-be-sewn 68
is a sewing line where sewing is performed, and the stitch pattern
S is formed along this sewing line L. In the present embodiment, a
plurality of the seating portions 20 are provided along the sewing
line L. The seating surface 20a of the seating portion 20 is
configured with substantially the same shape as the
workpiece-to-be-sewn 68, and is provided with the suction holes 30
(refer to FIG. 1). Each of the seating portions 20 is provided with
a retraction mechanism (not illustrated) that retracts the seating
portion 20 in the Z direction of FIG. 6. A configuration of this
retraction mechanism is similar to that described with reference to
FIG. 2.
[0055] The sewing mechanism 14 (refer to FIG. 1) proceeds to move
along the sewing line L of the workpiece-to-be-sewn 68. By the
seating portions 20 of portions interfering with the sewing
mechanism 14 proceeding to be retracted with movement of the sewing
mechanism 14, sewing can be performed while shape distortion and
positional misalignment of the workpiece-to-be-sewn 68 are
prevented. Moreover, a configuration may be adopted whereby the
workpiece-to-be-sewn 68 is supported making combined use of a fixed
type workpiece holding jig 60 (a second workpiece holding jig) that
does not include the retraction mechanism, for a portion separated
from the sewing line L where there is no risk of there being
interference with the sewing mechanism 14.
[0056] Moreover, the conveyor robot 16 (refer to FIG. 1) detects an
inclination of a surface of a sewing portion of the
workpiece-to-be-sewn 68, and controls an inclination of the sewing
mechanism 14 so that the sewing machine needle 49 of the sewing
mechanism 14 is perpendicular to the surface of the sewing portion.
That is, as shown in the enlarged perspective view of FIG. 6, the
sewing device 10 (refer to FIG. 1) detects two tangents B, C that
are orthogonal at a portion between the two sewing machine needles
49, and finds a direction of a perpendicular line D to those
tangents B, C. Then, the sewing device 10 controls the inclination
of the sewing mechanism 14 so that an axial direction of the sewing
machine needle 49 coincides with the perpendicular line D. Note
that when the shape of the workpiece-to-be-sewn 68 is fixed, there
is no need for the inclination of its surface to be detected by the
conveyor robot 16 on each occasion of sewing. In this case, a
configuration may be adopted whereby the conveyor robot 16 moves
according to a teaching operation that is input in advance.
[0057] For example, in the cross section taken along the line
VIIA-VIIA of FIG. 6, the inclination of the perpendicular line D at
the sewing position is greatly inclined in a horizontal direction,
as shown in FIG. 7A. In sewing of this portion, a plurality of the
seating portions 20 that may interfere with the sewing mechanism 14
are retracted.
[0058] Note that for a portion curved at an acute angle as shown in
FIG. 7B, the shape of the workpiece-to-be-sewn 68 cannot be
maintained by the fixed type workpiece holding jig 60 alone.
Therefore, in a conventional sewing device, tilting where the
workpiece-to-be-sewn 68 inclines to left and right of the drawing
ends up occurring when the pressing mechanism 48 is pressed against
the post bed 46 of the sewing mechanism 14, and sewing cannot be
accurately performed. In contrast, according to the present
embodiment, the shape of the workpiece-to-be-sewn 68 can be
maintained by the seating portions 20 on both sides, that is, a
frontward side and a rearward side in the moving direction of the
sewing mechanism 14, hence sewing can be accurately performed even
on a portion curved at an acute angle.
Third Embodiment
[0059] In the present embodiment, an example where a cam mechanism
70 has been adopted for the retraction mechanism of the workpiece
holding jig 12 (refer to FIGS. 1 and 2), will be described. As
shown in FIG. 8A, in the present embodiment, the cam mechanism 70
is provided under the guide pin 22.
[0060] The cam mechanism 70 of the present embodiment comprises: a
roller 72; and a sliding portion 76 that abuts on that roller 72.
The roller 72 is supported by a shaft portion 72a to rotate in an
arrow direction of the drawing by that shaft portion 72a. A recess
74 receding in an axial direction is formed in the roller 72. The
sliding portion 76 is connected to a base end portion of the guide
pin 22. This sliding portion 76 is configured to slide along an
outer peripheral portion of the roller 72.
[0061] As shown in FIG. 8B, the sliding portion 76 moves downwardly
with passage of the recess 74 of the sliding portion 76, and,
accordingly, the guide pin 22 and the seating portion 20 connected
to an upper end thereof descend. As a result, a retraction
operation of the seating portion 20 can be performed.
[0062] Moreover, as shown in FIG. 8C, by the sliding portion 76
coming out of the recess 74 with rotation of the roller 72, the
guide pin 22 rises, and the seating portion 20 returns to its
original position. The workpiece holding jig 12 (refer to FIG. 1)
can be realized by a plurality of such cam mechanisms 70 being
disposed in the moving direction of the sewing mechanism 14. In
this case, by staggering phases of the rollers 72 of the cam
mechanisms 70, there can be realized a retraction mechanism that
retracts the seating portions 20 in synchronization with movement
of the sewing mechanism 14. Thus, according to the present
embodiment, a device configuration of the workpiece holding jig
including the retraction mechanism can be simplified.
[0063] In the above description, the present invention has been
described by presenting preferred embodiments thereof. However, the
present invention is not limited to the above-described
embodiments, and it goes without saying that various modifications
thereof are possible in a range not departing from the spirit of
the present invention.
* * * * *