GB2512650A

GB2512650A - Gripping device

Info

Publication number: GB2512650A
Application number: GB201306172A
Authority: GB
Inventors: Ruben Salazar; Takayuki Motojima
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2013-04-05
Filing date: 2013-04-05
Publication date: 2014-10-08
Anticipated expiration: 2033-04-05
Also published as: GB201306172D0; GB2512650B

Abstract

A gripping device 1 individually grips a first workpiece 10 and a second workpiece 20. The shape of the second workpiece is different from the shape of the first workpiece. The gripping device is provided with a main gripper 2 capableof gripping the first workpiece and a sub-gripper 30 capable of gripping the second workpiece. The sub-gripper has an outer shape that corresponds to the first workpiece and is grasped by the main gripper. A preferred use for the device is the conveying of oil trays, with differing shapes, on a production line. The main gripper may be adjustable along a rail 5 so that the grippers 2A and 2B can adjust to the length of the first workpiece or the sub-gripper. The sub-gripper may have an elastic member 32 allowing the frame to be adjustable along its length to account for the differing length of the second workpiece.

Description

GRIPPING DEVICE

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a gripping device.

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JP-A-3-221390 discloses a workpiece conveying apparatus which includes a gripping device, such as a finger corresponding to a shape of a workpiece. and which conveys the workpiece by a carriage in a state where the workpiece is grasped by the finger.

[0003] The workpiece conveying apparatus includes a workpiece conveying carriage where a plurality of fingers for positioning the workpiece are detachably mounted on an upper surface thereof and a storage device in which a plurality of kinds of fingers according to the type of workpiece are arrayed. In the workpiece conveying apparatus, a handling robot performs replacement of fingers between the carriage and the storage device according to the type of the workpiece to be conveyed.

[0004] In the workpiece conveying apparatus disclosed in JP-A-3-221390, it is necessary to replace the finger according to the type of the workpiece and therefore there is a possibility that an increase in the takt time of the production line occurs.

SUMMARY OF THE INVENTION

[0005] According to embodiments of the invention, in a gnpping device, it is not necessary to change a main gripper even when gripping a plurality of workpieces with shapes different from one another.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Fig. 1 is a plan view of a gripping device which is gripping a first oil pan.

Fig. 2 is a perspective view of the first oil pan.

Fig. 3 is a plan view of the gripping device which is gripping a second oil pan.

Fig. 4 is a perspective view of the second oil pan.

Fig. 5 is a perspective view of a sub-gripper.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0007] A gripping device according to an exemplaiy embodiment will be described.

[0008] As shown in Fig. 1, a gripping device I of the embodiment is a device for gripping a first oil pan 10 as a first workpiece. The first oil pan 10 can be conveyed by a conveying mechanism (not shown) including the gripping device 1.

[0009] As shown in Fig. 2, the first oil pan 10 includes an oil reservoir 11 in which oil such as engine oil is stored and a protruding part 12 or lip which slightly protrudes in the X direction and the Y direction from a lower surface of the oil reservoir 11.

[0010] A convex portion 13 is formed on one-end side protruding portion 12A of the protruding part 12 located at one-end side (the positive X direction side, a right side in Fig. I and an upper right side in Fig. 2) in the X direction and extends upward (in the Z direction) from an intermediate portion of the protruding part in the Y direction. The one-end side protruding portion 12A and the convex portion 13 constitute a first gripped portion which is grasped by a first main grip section 2A (which will be described later).

[0011] Further, the other-end side protruding portion 12B of the protruding part 12 is located at the other-end side (the negative X direction side, a eft side in Fig. I and a lower left side in Fig. 2) in the X direction. Flange portions 14, 15 are formed on both side portions of the other-end side protruding portion I 2B in the Y direction and extend upward and toward the other-end side in the X direction (toward the negative X direction). The flange portions 14, 15 are composed of first quadrant extensions 14a, 15a extending upward from the other-end side protruding portion 12B and second extensions 14b, 15b extending toward the other-end side in the X direction from an upper end of the first extensions I 4a, ISa. Protrusions 14c, I Sc extending upward are formed on an upper portion of the second extensions 14b, 15b and through holes 14d.

15d extending in the X direction are formed inside the protrusions 14c. 15c. The through holes 14d, 15d constitute a second gripped portion which is grasped by a second main grip section 2B (which will be described later).

[0012] The gripping device 1 includes a main gripper 2 which is composed of first and second main grip sections 2A, 2B to grip the first oil pan 10 from both sides in a width direction (X direction), support members 4A, 4B which respectively support the first and second main grip sections 2A, 2B via coupling members 3A, 3B from above and a rail member 5 which supports the support members 4A, 4B from above and extends in the X direction.

[0013] The first main grip section 2A includes a grip part 6 which is able to grip the one-end side protruding portion 12A and the convex portion 13 of the first oil pan 10.

A concave portion 6a facing the one-end side in the X direction is provided on the other-end side surface of the grip part 6 in the X direction. As the one-end side protruding portion 12A and the convex portion 13 are inserted into the concave portion 6a of the grip part 6, the first oil pan 10 is grasped by the first main grip section 2A.

[0014] The second main grip section 2B includes a pair of grip bars 7 extending to the one-end side in the X direction. As the pair of grip bars 7 are inserted into the through holes I 4d, I Sd, the first oil pan 10 is grasped by the second main grip section 2B.

[0015] The support members 4A, 4B are movaNe in the X direction on the rail member 5. The support members 4A, 4B, the coupling members 3A, 3B and the first and second main grip sections 2A, 2B can be displaced integrally by a driving device (not shown).

[0016] According'y, when gripping the first oil pan 10 by the first and second main grip sections 2a, 2W first, the first oil pan 10 is placed on the inside of the first and second main grip sections 2A, 2B in the X direction by ajig (not shown). etc. At this time, the one-end side protruding portion 12A and the convex portion 13 of the first oil pan 10 and the concave portion 6a of the grip part 6 of the first main grip secdon 2A have the same position in the Y and Z directions (i.e. they are aligned with one another in the X direction). Further, the though ho'es 14d, lSd of the first oil pan 10 and the pair of grip bars 7 of the second main grip section 2B have the same position in the Y and Z directions (i.e. they are aligned with one another in the X direction).

[0017] Then, by displacing the first and second main grip sections 2A, 2B inward in the X direction, the one-end side protruding portion 12A and the convex portion 13 of the first oil pan 10 are inserted into the concave portion 6a of the grip part 6 of the first main grip section 2A and the pair of grip bars 7 of the second main grip section 2B are inserted into the through holes 14d. 15d of the first oil pan 10. In this way, the first oil pan 10 is grasped by the main gnpper 2. Then, the first oil pan 10 is conveyed to the next process by a conveying apparatus (not shown).

[0018] Next, a method for gripping a second oil pan 20 (second workpiece) using the gripping device i described above will be described with reference to Fig. 3 to Fig. 5.

[0019] As shown in Fig. 4, the second oil pan 20 has a shape different from the first oil pan 10 and smaller than the first oil pan 10. Further, the second oil pan 20 includes an oil reservoir 21, in which oil such as engine oil is stored in use of the second oil pan 20.

and a protruding part 22 or Up which slightly protrudes in the X direction and the Y direction from a lower surface of the oil reservoir 21.

[0020] One-end side protruding portion 23, located at one-end side (a back side in Fig. 3 and an upper left side in Fig. 4) of the protruding part 22 in the Y direction, and the other-end side protruding portion 24, located at the other-end side (a front side in Fig. 3 and a lower right side in Fig. 4) of the protruding part 22 in the Y direction, are formed with first coupling holes 23a, 24a extending in the Z direction at one-end side portion thereof in the X direction. Paired first coupling holes 23a, 24a are provided to oppose each other in the Y direction. That is, the paired first coupling holes 23a. 24a are provided at the same position in the X direction.

[0021] Further, the other-end side protruding portion 25 of the protruding part 22 located at the other-end side in the X direction is provided at an intermediate portion thereof with a second coupling hole 25a extending in the Z direction.

1 [flAil £ -) As shown in Fig. 3, the gripping device 1 includes a sub gripper 30 capable of gripping the second oil pan 20. Also, referring to Fig. 5, the sub gripper 30 includes a first sub grip section 3lA disposed at one-end side thereof (a lower right side in Fig. 5) in the X direction, a second sub grip section 31B disposed at the other-end side thereof (an upper left side in Fig. 5) in the X direction and a pair of elastic members 32 to connect the first and second sub gnp sections 31A, 31B in the X direction. [Afli

The first sub grip section 31A includes a substantially rectangular parallelepiped-shaped protrusion 34 at a lower portion of one-end surface 33 thereof in the X direction. The protrusion 34 slightly protrudes to the one-end side in the X direction from an intermediate portion of the one-end surface in the Y direction. A Y direction width A' of the protrusion 34 is set to be substantially equal to a Y direction width A (see Fig. 2) of the one-end side protruding portion 12A of the first oil pan 10 (A= A'), and a Z direction width B' of the protrusion 34 is set to be substantially equai to a Z direction total width B (see Fig. 1) of the one-end side protruding portion 12A and the convex portion 13 of the first oil pan 10 (B= B'). In this way, the protrusion 34 of the first sub grip section 31 A has a shape corresponding to the one-end side protruding portion 12A and the convex portion 13 of the first oil pan 10 and constitutes a first gripped portion which is grasped by the concave portion 6a of the grip part 6 of the first main grip section 2A.

[0024] Further, the first sub grip section 31A includes a pair of first coupling pins 38 extending downward at both end portions of a lower surface thereof in the Y direction.

A Y direction distance between the pair of first coupling pins 38 is set to be equal to a Y direction distance between the pair of first coupling holes 23a, 24a of the second oil pan 20. Therefore, the pair of first coupling pins 38 can be inserted and coupled to the pair of first coupling holes 23a, 24a.

[0025] The second sub grip section 31B includes a pair of cylindrical holes 36 at an upper portion of the other-end surface 35 thereof in the X direction. The cylthdrical holes 36 extend in the X direction from both end portions thereof in the Y direction.

Cylindrical portions 37a of bushes 37 are fitted into the cylindrical holes 36 from the other-end side in the X direction. Flange portions 37b are formed on the other-end portion of the cylindrical portions 37a in the X direction and have ai outer diameter larger than that of the cylindrical portion 37a. As the flange portions 37b abut against the other-end surface 35 in the X direction, the bushes 37 are thereby positioned in the X direction. An inner diameter of the cylindncal portions 37a is substantially the same as an inner diameter of the through h&es I 4d, I 5d of the first oil pan 10. Accordingly, the cylindrical portions 37a of the pair of bushes 37 of the second sub grip section 31 B have a shape corresponding to the through holes 14d, 15d of the first oil pan 10 and constitute the second gripped portion which is grasped by the pair of grip bars 7 of the second main grip section 2B. [flAl

Further, the second sub grip section 31B indudes a second coupfing pin 39 extending downward at an intermediate portion of a lower surface thereof in the Y direction. The second coupling pin 39 can be coup'ed to the second oil pan 20 in such a way that a leading end thereof is inserted into the second coupflng hole 25a of the second oil pan 20.

[0027] Here, a relative distance between the protrusion 34 (first gripped portion) of the sub gripper 30 and the cylindrical portions 37a (second gripped portion) of the pair of bushes 37 in a direction other than X direction is set to be equal to a relative distance between the one-end side protruding portion 12A and the convex portion 13 (first gripped portion) of the first oil pan 10 and the through-holes 14d. 15d (second gripped portion) in a direction other than X direction. That is, the relative distance between the protrusion 34 of the sub gripper 30 and the cylindrical portions 37a of the pair of bushes 37 in the Y and Z directions is set to be equal to the relative distance between the one-end side protruding portion 12A and the convex portion 13 of the first oil pan 10 and the through holes 14d, 15d in theY and Z directions.

[0028] With this configuration, it is possible to individually grip the first oil pan 10 and the sub gripper 30 by displacing the first and second main grip sections 2A and 2B in the X direction even when the first oil pan 10 and the second oil pan 20 have different widths in the X direction and thus the first oil pan 10 and the sub gripper 30 have different widths in the X direction as in the embodiment. [flAl

The elastic member 32 is configured by inserting a damper 32b inside a spring 32a. The elastic members connect the first and second sub grip sections 31A. 31B so as to be movable relative to each other in the X direction and to provide an elastic force to urge the first and second sub grip sections outward in the X direction.

[0030] Hereinafter, in the gripping device 1 configured in this way, a method for gripping the second oil pan 20 by the main gnpper 2 via the sub gripper 30 will be described. First, the sub gripper 30 is placed on the inside of the first and second main grip sections 2A, 2B in the X direction by a jig (not shown). etc. At this time, the protrusion 34 of the sub gripper 30 and the concave portion 6a of the grip part 6 of the first main grip section 2A have the same position in the Y and Z directions and also the cylindrical portions 37a of a pair of bushes 37 of the sub gripper 30 and a pair of grip bars 7 of the second main grip section 2B have the same position in the X and Y directions. Further, the sub gripper 30 is in a state of being extended in the X direction by the elastic force of the elastic members 32.

[00311 Then, as the first and second main grip sections 2A, 2B are displaced inward in the X direction, the protrusion 34 of the sub gripper 30 is inserted into the concave portion 6a of the grip part 6 of the first main grip section 2A and also the grip bars 7 of the second main grip section 2B are insered into the cylindrical portions 37a of the pair of bushes 37 of the sub gripper 30. In this way, the sub gripper 30 is grasped by the main gripper 2.

[0032] Furthermore, the first and second main grip sections 2A, 2B are displaced inward in the X direction and thus the sub gripper 30 is contracted in the X direction, so that an X-direction distance between the first and second coupling pins 38, 39 becomes equal to an X-direction distance between the first and second coupling holes 23a, 24a.

25a of the second oil pan 20. At this time, this state is maintained by setting the gripping force of the first and second main grip sections 2A. 2B inward in the X direction to the first and second sub gnp sections 31A, 31B to be equal to the elastic force of the elastic member 32 outward in the X direction to the first and second sub grip sections 31A, 31B.

[0033] Next, the first and second coupling holes 23a, 24a, 25a of the second oil pan 20 are inserted to the first and second coupling pins 38, 39 of the sub gripper 30 from below. In the inserted state, a gripping force of the first and second main grip sections 2A, 2B inward in the X direction to the first and second sub grip sections 31A, 31B is set so as not to be equal to the dastic force of the elastic members 32 outward in the X direction to the first and second sub grip sections 31 A. 31 B. For example, the gripping force may be set to be greater than the dastic force or the elastic force may be set to be greater than the gripping force. By setting in this way, the first and second coupling holes 23a, 24a, 25a and the first and second coupling pins 38, 39 are coupled to each other, and the second oil pan 20 is grasped by the main gripper 2 via the sub gripper 30.

Then, the second oil pan 20 is conveyed to the next process by a conveying apparatus (not shown).

[0034] The gripping device of the invention is not particularly limited to the configuration of the above exemplary embodiment, and variations and/or modifications may be suitably added.

[0035] In accordance with embodiments, a gripping device I, for individually gripping a first workpiece 10 and a second workpiece 20 in which a shape of the second workpiece 20 is different from a shape of the first workpiece 10, may include: a main gripper 2 capable of gripping the first workpiece 10; and a sub gnpper 30 capable of gripping the second workpiece 20. The sub gripper 30 may have an outer shape that corresponds to the first workpiece 10 and to be grasped by the main gripper 2.

According to this structure, it is not necessary to change the main gripper 2 even when gripping the first and second oil pans 10, 20 with shapes different from each other.

Accordingly, it is possible to reduce the takt time.

[0036] The main gripper 2 may include a first and second main grip sections 2A, 2B to grip the first workpiece 10 or the sub gripper 30 from both sides in a predetermined direction. The first and second main grip sections 2A, 2B may be displaceaHe in the predetermined direction. The first workpiece 10 may include first and second gripped portions 12A, 13, 14d, 15d which are to be grasped by the first and second main grip sections 2A, 2B, at both sides thereof in the predetermined direction. The sub gripper may include first and second gripped portions 34, 37a which are to be grasped by the first and second main grip sections 2A, 2B, at both sides thereof in the predetermined direction. A positional rdation between the first gripped portion 12A, 13 and the second gripped portion 14d, 15d in the first workpiece 10 in a direction other than the predetermined direction may be set to be substantially equa' to a positional relation between the first gripped portion 34 and the second gripped portion 37a in the sub gripper 30 in said direction other than the predetermined direction.

According to this structure, the first and second main grip sections 2A, 2B can be displaced in the X direction and therefore it is possiHe to individually grip the first oil pan 10 and the sub gripper 30.

[0037] The sub gripper 30 may include: a first sub grip section 31A having the first gripped portion 34 at one side in the predetermined direction; a second sub grip section 31B having the second gripped portion 37a at the other side in the predetermined direction; and an elastic member 32 which connects the first sub grip section 31A and the second sub grip section 3 lB so as to be movable relative to each other in the predetermined direction and applies an elastic force outward in the predetermined direction. The first and second sub grip sections 31A, 31B may respectively include first and second coupling pins 38, 39 each extending in a direction perpendicular to the predetermined direction. The second workpiece 20 may include first and second coupling holes 23a, 24a, 25a at both side portions of the second workpiece 20 in the predetermined direction. The first and second coupling holes 23a, 24a, 25a may extend in said direction perpendicular to the predetermined direction, The first and second coupling pins 38, 39 may be respectively inserted and coupled to the first and second coupling holes 23a, 24a, 25a.

According to this structure, the sub gripper 30 can grip the second oil pan 20 by inserting and coupling the first and second coupling pins 38. 39 of the first and second sub grip sections 3 lA, 3 lB to the first and second coupling holes 23a, 24a, 25a of the second oil pan 20.

[0038] The first and second coupling holes 23a, 24a, 25a and the first and second coupling pins 38, 39 may be coupled to each other by setting a gripping force of the first and second main grip sections 2A, 2B inward in the predetermined direction to the first and second sub grip sections 31 A, 31 B not to be equal to the elastic force of the elastic member 32 outward in the predetermined direction to the first and second sub grip sections 31A, 31B, in a state where the first and second coupling pins 38, 39 of the first and second sub grip sections 31A, 31B are inserted into the first and second coupling holes 23a, 24a. 25a of the second workpiece 20.

According to this structure, the first and second coupling h&es 23a, 24a. 25a and the first and second coupling pins 38,39 can be reliably coupled to each other and the second oil pan 20 can be more reliably grasped by the sub gripper 30.

[0039] Although the oil paris are illustrated as an example of the first and second workpieces in the foregoing embodiments, the first and second workpieces are not particularly limited, as long as the shapes thereof are different from each other.

Claims

CLAIMSI. A gripping device (I) for individually gripping a first workpiece (10) and a second workpiece (20), a shape of the second workpiece (20) being different from a shape of the first workpiece (10), the gripping device (1) comprising: a main gripper (2) capable of gripping the first workpiece (10); and a sub gripper (30) capable of gripping the second workpiece (20), wherein the sub gripper (30) has an outer shape that corresponds to the first workpiece (10) and is arranged to be grasped by the main gripper (2).
2. The gripping device (1) according to claim 1, wherein the main gripper (2) includes a first and second main grip sections (2A, 2B) to grip the first workpiece (10) or the sub gripper (30) from both sides in a predetermined direction, wherein the first and second main grip sections (2A, 2B) are displaceable in the predetermined direction, wherein the first workpiece (10) includes first and second gripped portions (12A, 13, 14d, 15d) which are to be grasped by the first and second main grp sections (2A, 2B), at both sides thereof in the predetermined direction, wherein the sub gripper (30) includes first and second gripped portions (34, 37a) which are to be grasped by the first and second main grip sections (2A, 2B), at both sides thereof in the predetermined direction, and wherein a positional relation between the first gripped portion (12A, 13) and the second gripped portion (14d, 15d) in the first workpiece (10) in a direction other than the predetermined direction is set to be equal to a positional relation between the first gripped portion (34) and the second gripped portion (37a) in the sub gripper (30) in said direction other than the predetermined direction.
3. The gripping device (1) according to claim 2, wherein the sub gripper (30) includes: a first sub grip section (31 A) having the first gripped portion (34) at one side in the predetermined direction; a second sub grip section (31 B) having the second gripped portion (37a) at the other side in the predetermined direction; and an elastic member (32) which connects the first sub grip section (3iA) and the second sub grip section (3 1B) so as to be movable relative to each other in the predetermined direction and applies an dastic force outward in the predetermined direction.wherein the first and second sub grip sections (3 IA, 31B) respectively include first and second coupling pins (38. 39) each extending in a direction perpendicular to the predetermined direction and wherein the second workpiece (20) includes first and second coupling holes (23a, 24a. 25a) at both side portions of the second workpiece (20) in the predetermined direction, wherein the first and second coupfing holes (23a, 24a, 25a) extend in said direction perpendicular to the predetermined direction, and wherein the first and second coupling pins (38, 39) are to be respectively inserted and coupled to the first and second coupling holes (23a, 24a, 25a).
4. The gripping device (1) according to claim 3, wherein the first and second coupling holes (23a, 24a. 25a) and the first and second coupling pins (38, 39) are coupled to each other by setting a gripping force of the first and second main grip sections (2A, 2B) inward in the predetermined direction to the first and second sub grip sections (31A, 31B) so as not to be equal to the elastic force of the elastic member (32) outward in the predetermined direction to the first and second sub grip sections (3 1A, 31 B), in a state where the first and second coupling pins (38. 39) of the first and second sub grip sections (31 A, 31 B) are inserted into the first and second coupling h&es (23a, 24a, 25a) of the second workpiece (20).
5. The gripping device (1) according to any one of claims 1 to 4, wherein the first and second workpieces (10, 20) are oil pans.
6. A method of individually gripping a first workpiece (10) and a second workpiece (20), a shape of the second workpiece (20) being different from a shape of the first workpiece (10), the method comprising: gripping the first workpiece (10) with a main gripper (2); releasing the first workpiece (10) from the main gripper (2); gripping a sub gripper (30) with the main gripper (2), wherein the sub gripper (30) has an outer shape that corresponds to the first workpiece (10); and gripping the second workpiece (20) with the sub gripper (30.
7. The method according to claim 6, wherein the main gripper (2) includes a first and second main grip sections (2A. 2B) to grip the first workpiece (10) or the sub gripper (30) from both sides in a predetermined direction; wherein gripping the first workpiece (10) comprises: displacing the first and second main grip sections (2A, 2B) in the predetermined direction, and grasping, by the first and second main grip sections (2A, 2B), first and second gripped portions (12A, 13, 14d. 15d) of the first workpiece (10), which are at both sides thereof in the predetermined direction; wherein gripping the sub gripper (30) comprises: displacing the first and second main grip sections (2A, 2B) in the predetermined direction, and grasping, by the first and second main grip sections (2A, 2B), first and second gripped portions (34, 37a) of the sub gripper (30), which are at both sides thereof in the predetermined direction; and wherein a positional relation between the first gripped portion (12A, 13) and the second gripped portion (14d, 15d) in the first workpiece (10) in a direction other than the predetermined direction is set to be equal to a positional relation between the first gripped portion (34) and the second gripped portion (37a) in the sub gnpper (30) in said direction other than the predetermined direction.
8. The method according to claim 7, wherein the sub gripper (30) includes: a first sub grip section (31 A) having the first gripped portion (34) at one side in the predetermined direction; a second sub grip section (31B) having the second gripped portion 37a) at the other side in the predetermined direction; and an elastic member (32) which connects the first sub grip section (3 IA) and the second sub grip section (31 B) so as to be movable relative to each other in the predetermined direction and which applies an elastic force outward in the predetermined direction, wherein the first and second sub grip sections (3 IA, 3 IB) respectively include first and second coupling pins (38. 39) each extending in a direction perpendicular to the predetermined direction, wherein the second workpiece (20) includes first and second coupling holes (23a.24a, 25a) at both side portions of the second workpiece (20) in the predetermined direction, wherein the first and second coupling holes (23a, 24a, 25a) extend in said direction perpendicular to the predetermined direction, and wherein gripping the second workpiece (20) with the sub gripper (30) comprises inserting the first and second coupling pins (38, 39) respectively into the first and second coupling holes (23a, 24a, 25a) and coupling the first and second coupling pins (38, 39) to the first and second coupling holes (23a, 24a, 25a).
9. The method according to claim 8, wherein the first and second coupling h6les (23a. 24a, 25a) and the first and second coupling pins (38, 39) are coupled to each other by setting a gripping force of the first and second main grip sections (2A, 2B) inward in the predetermined direction to the first and second sub grip sections (3 IA, 31B) so as not to be equal to the elastic force of the elastic member (32) outward in the predetermined direction to the first and second sub gnp sections (31A, 31B), in a state where the first and second coupling pins (38, 39) of the first and second sub grip sections (31A, 31B) are inserted into the first and second coupling holes (23a, 24a, 25a) of the second workpiece (20).
10. The method according to any one of claims 6 to 9, wherein the first and secondAMENDMENTS TO THE CLAIMS HAVE BEEN FILED AS FOLLOWS1. A gripping device (1) for individually gripping a first workpiece (10) and a second workpiece (20), a shape of the second workpicce (20) being different from a shape of the first workpiccc (10), the gripping device (1) comprising: s a main gripper (2) capable of directly gripping the first workpiece (10) at H portions (l2A, 13, 14d, 15d) of the first workpiece (10); and a sub gripper (30) capable of gripping the sccond workpiece (20), wherein the sub gripper (30) is arranged to he gripped directly by the main gripper (2) at portions (34, 37) of the sub gripper (30), and the gripped portions (34, 37) io of the sub gripper (30) correspond to the gripped portions (12A, 13, 14d, 15d) of first 2. The gripping device (1) according to claim I, wherein thc main gripper (2) includes a first and second main grip sections (2A, 2B) to grip the first workpiece (10) or the sub gripper (30) from both sides in a predetermined direction, wherein the first and second main grip sections (2A, 2B) are displaceable in the o predetermined direction, (0 wherein the gripped portions (12A, 13, 14d, lSd) of the first workpiece (10) O include first and second gripped portions (12A, 13, 14d, 1 Sd) which are to be grasped by the first and second main grip sections (2A, 2B), at both sides thereof in the predetermined direction, wherein the gripped portions (34, 37) of the sub gripper (30) include first and second gripped portions (34, 37) which are to be grasped by the first and second main grip sections (2A, 2B), at both sides thereof in the predetermined direction, and wherein a positional relation between the first gripped portion (1 2A, 13) and the second gripped portion (14d, 15d) in the first workpieee (10) in a direction other than the predetermined direction is set to be equal to a positional relation between the first gripped portion (34) and the second gripped portion (37a) in the sub gripper (30) in said direction other than the predetermined direction.3. The gripping device (1) according to claim 2, wherein the sub gripper (30) includes: a first sub grip section (3 1A) having the first gripped portion (34) at one side iii the predetermined direction; s a second sub grip section (3 IB) having the second gripped portion (37) at the other side in the predetermined direction; and an elastic member (32) which connects the first sub grip section (31 A) and the second sub grip section (3 1B) so as to be movable relative to each other in the predetermined direction and applies an elastic force outward in the predetermined ic direction, wherein the first and second sub grip sections (3 1A, 3 1B) respectively include first and second coupling pins (38, 39) each extending in a direction perpendicular to the predetermined direction and wherein the second workpiece (20) includes first and second coupling holes (23a, 24a, 25a) at both side portions of the second workpiece (20) in the predetermined direction, wherein the first and second coupling holes (23a, 24a, 25a) extend in said o direction perpendicular to the predetermined direction, and wherein the first and second coupling pins (38, 39) are to be respectively inserted and coupled to the first and second O coupling holes (23a, 24a, 25a).4. The gripping device (1) according to claim 3, wherein the first and second coupling holes (23a, 24a, 25a) and the first and second coupling pins (38, 39) are coupled to each other by setting a gripping force of the first and second main grip sections (2A, 2B) inward in the predetermined direction to the first and second sub grip sections (3lA, 3lB) so as not to be equal to the elastic force of the elastic member (32) outward in the predetermined direction to the first and second sub grip sections (31 A, 3111), in a state where the first and second coupling pins (38, 39) of the first and second sub grip sections (3 1A, 3 IB) are inserted into the first and second coupling holes (23a, 24a, 23a) of the second workpiece (20).5. The gripping device (1) according to any one of claims ito 4, wherein the first and second workpieces (10, 20) arc oil pans.s 6. A method of individually gripping a first workpiece (1 0) and a second workpiece (20), a shape of the second workpiece (20) being different from a shape of the first workpiece (10), the method comprising: directly gripping the first workpiece (10) with a main gripper (2) at portions (12A, 13, 14d, lSd) of the first workpiece (10); releasing the first workpiece (10) from the main gripper (2); directly gripping a sub gripper (30) with the main gripper (2) at portions (34, 37) of the sub gripper (30), wherein the gripped portions (34, 37) of the sub gripper (30) correspond to the gripped portions (1 2A, 13, 1 4d, I Sd) of the first workpiece (10); and gripping the second workpiece (20) with the sub gripper (30).7. The method according to claim 6, wherein the main gripper (2) includes a first o and second main grip sections (2A, 2B) to grip the first workpiece (10) or the sub (0 gripper (30) from both sides in a predetermined direction; O wherein gripping the first workpiece (10) comprises: displacing the first and second main grip sections (2A, 2B) in the predetermined direction, and grasping, by the first and second main grip sections (2A, 2B), first and second gripped portions (12A, 13, 14d, 15d) of the gripped portions (12A, 13, 14d, 15d) of the first workpiece (10), which are at both sides thereof in the predetermined direction; wherein gripping the sub gripper (30) comprises: displacing the first and second main grip sections (2A, 2B) in the predetermined direction, and grasping, by the first and second main grip sections (2A, 2B), first and second gripped portions (34, 37) of the gripped portions (34, 37) of the sub gripper (30), which are at both sides thereof in the predetermined direction; and wherein a positional relation between the first gripped portion (12A, 13) and the second grpped portion (1 4d, 1 Sd) in the first workpieee (10) in a direction other than the predetermined direction is set to be equal to a positional relation between the first s gripped portion (34) and the second gripped portion (37a) in the sub gripper (30) in said direction other than the predetermined direction.8. The method according to claim 7, wherein the sub gripper (30) includes: a first sub grip section (31A) having the first gripped portion (34) at one io side in the predetermined direction; a second sub grip section (3 1B) having the second gripped portion (37) at the other side in the predetennined direction; and an elastic member (32) which connects the first sub grip section (31 A) and the second sub grip section (3 1 B) so as to be movable relative to each other is in the predetermined direction and which applies an elastic force outward in the predetermined direction, wherein the first and second sub grip sections (3 IA, 31 B) respectively include (0 first and second coupling pins (38, 39) each extending in a direction perpendicular to o the predetermined direction, wherein the second workpieee (20) includes first and second coupling holes (23a, 24a, 25a) at both side portions of the second workpiece (20) in the predetermined direction, wherein the first and second coupling holes (23a, 24a, 25a) extend in said direction perpendicular to the predetermined direction, and wherein gripping the second workpiece (20) with the sub gripper (30) comprises inserting the first and second coupling pins (38, 39) respectively into the first and second coupling holes (23a, 24a, 25a) and coupling the first and second coupling pins (38, 39) to the first and second coupling holes (23a, 24a, 25a).9. The method according to claim 8, wherein the first and second coupling holes (23a, 24a, 25a) and the first and second coupling pins (38, 39) are coupled to each other by setting a gripping force of the first and second main grip sections (2A, 2B) inward in the predetermined direction to the first and second sub grip sections (3 1A, 3 1B) so as not to be equal to the elastic force of the elastic member (32) outward in the £ predetermined direction to the first and second sub grip sections (31 A, 31 B), in a state where the first and second coupling pins (38, 39) of thc first and second sub grip sections (31A, 31B) are inserted into the first and second coupling holes (23a, 24a, 25a) of the second workpiece (20).ic 1 0. The method according to any one of claims 6 to 9, wherein the first and secondCDCD