Robot Hand

Abstract

To solve a problem that a conventional robot hand is provided with drive mechanisms corresponding to respective clamp parts, which makes reduction of a size of a whole device and reduction of manufacturing cost difficult.SOLUTION: A robot hand 10 includes a hand main body part 11, and a plurality of arm parts 12 which are supported by the hand main body part 11. Each of the arm parts 12 includes two kinds of clamp parts, a first clamp part 14 and a second clamp part 15, which correspond to a size of a conveyed workpiece 13. Second claw parts 24, 26 of the first and second clamp parts 14, 15 are operated by a shared second drive part 27. With this structure, reduction of a size of the robot hand 10 and reduction of manufacturing cost can be achieved.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a robot hand capable of transporting workpieces of different sizes. [Background technology]

[0002] A conventional robot hand is disclosed in Patent Document 1. The robot hand is attached to the tip of the robot arm of a handling robot, and can handle door inner panels with slightly different shapes and specifications.

[0003] Specifically, the robot hand is equipped with a pair of positioning clamp devices for car A, a positioning clamp device for car B, and a positioning clamp device shared by cars A and B, on its hand frame. When handling the door inner panel for car A, the robot hand retracts the positioning clamp device for car B to a desired position and performs work using the positioning clamp device for car A and the shared positioning clamp device. Similarly, when handling the door inner panel for car B, work is performed using the positioning clamp device for car B and the shared positioning clamp device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2005-111573 A Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, in the conventional robot hand, a positioning clamp device for car A or a positioning clamp device for car B is selected depending on the door inner panel to be worked on. The positioning clamp device that is not used is retracted to a desired position during work, so that it does not interfere with the door inner panel being worked on.

[0006] However, the positioning clamp device for car A and the positioning clamp device for car B each have their own drive mechanism using an air cylinder, which results in an increase in the size of the robot hand and an increase in the cost of the robot hand.

[0007] In addition, the conventional robot hand is attached to the tip of the robot arm of a single handling robot when used, which necessitates a process of forming unique locating holes for positioning in the door inner panel for car A and the door inner panel for car B, resulting in an issue of increased manufacturing costs.

[0008] The present invention has been made in consideration of the above circumstances, and provides a robot hand capable of transporting workpieces of different sizes. [Means for solving the problem]

[0009] In a robot hand according to an embodiment of the present invention, a workpiece is clamped and transported by a plurality of arms supported by a hand main body, and each of the arms includes a plurality of clamps selected according to a size of the workpiece, a first drive unit that moves a first claw of the clamps, a second drive unit that moves a second claw of the clamps, and a drive transmission unit that transmits a drive force from the second drive unit to the second claw of one selected one of the clamps, and the second drive unit is shared by the second claws of each of the plurality of clamps. The first drive unit is disposed with respect to the first claw portion of each of the plurality of clamp units, the second claw portion is rotatably connected to the first claw portion, and the first claw portion and the second claw portion move via the first drive unit, whereby the second claw portion engages with the drive transmission unit or disengages from the drive transmission unit. It is characterized by: Effect of the Invention

[0010] In a robot hand according to an embodiment of the present invention, each arm has a plurality of clamps that are selected according to the size of the workpiece. The second jaws of the clamps are driven by a driving force from a shared second drive unit. This structure allows each arm to operate with the plurality of second jaws via a single shared second drive unit, realizing a compact robot hand and reducing manufacturing costs. [Brief description of the drawings]

[0011] [Figure 1] 1 is a perspective view illustrating a robot hand according to an embodiment of the present invention. [Figure 2A] FIG. 2 is a side view illustrating an arm portion of a robot hand according to an embodiment of the present invention. [Figure 2B] FIG. 2 is a side view illustrating an arm portion of a robot hand according to an embodiment of the present invention. [Figure 3A] FIG. 2 is a side view illustrating an arm portion of a robot hand according to an embodiment of the present invention. [Figure 3B] FIG. 2 is a side view illustrating an arm portion of a robot hand according to an embodiment of the present invention. [Figure 4A] FIG. 2 is a side view illustrating an arm portion of a robot hand according to an embodiment of the present invention. [Figure 4B] FIG. 2 is a side view illustrating an arm portion of a robot hand according to an embodiment of the present invention. [Figure 5A] FIG. 2 is a side view illustrating an arm portion of a robot hand according to an embodiment of the present invention. [Figure 5B] FIG. 2 is a side view illustrating an arm portion of a robot hand according to an embodiment of the present invention. [Figure 6A] FIG. 2 is a side view illustrating an arm portion of a robot hand according to an embodiment of the present invention. [Figure 6B] FIG. 2 is a side view illustrating an arm portion of a robot hand according to an embodiment of the present invention. [Figure 7] 1 is a schematic diagram illustrating an arm portion of a robot hand according to an embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] First, a robot hand 10 according to an embodiment of the present invention will be described in detail with reference to the drawings. In the description of this embodiment, the same components will be designated by the same reference numerals as a rule, and repeated description will be omitted. In the following description, the up-down direction refers to the height direction of the robot hand 10, the left-right direction refers to the vertical width direction of the robot hand 10, and the front-rear direction refers to the horizontal width direction of the robot hand 10.

[0013] FIG. 1 is a side view illustrating a robot hand 10 according to the present embodiment.

[0014] As shown in FIG. 1, the robot hand 10 includes a hand body 11 and a plurality of arms 12 supported by the hand body 11. Each arm 12 has two types of first and second clamps 14 and 15 corresponding to the size of the workpiece 13 to be transported. The first and second clamps 14 and 15 are operated, for example, via first and second drive units 21 and 22 and a second drive unit 27 driven by compressed air. The hand body 11 is provided with a compressed air supply mechanism 16 and a control unit 17, and the compressed air supply mechanism 16 is controlled by the control unit 17 to supply compressed air to each arm 12 of the robot hand 10 as appropriate and to collect compressed air from each arm 12. The compressed air supply mechanism 16 is connected, for example, to a compressed air supply line (not shown) installed in a factory.

[0015] The first and second clamp parts 14, 15 are switched appropriately depending on the workpiece 13 to be transported, and a control part 17 that controls the above switching operation is disposed in the hand main body part 11. The control part 17 is configured with a CPU (CENTRAL PROCESSING UNIT), a ROM (READ ONLY MEMORY), a RAM (RANDOM ACCESS MEMORY), etc. The control part 17 is an electronic control unit (ECU) having one or more processors for executing various calculations for controlling the robot hand 10.

[0016] As shown in the figure, four arm sections 12 are arranged diagonally on the hand main body 11, and two types of first and second clamp sections 14, 15 are arranged on each arm section 12. The first clamp section 14 is used when transporting a workpiece 13 that is, for example, an inner panel of vehicle type A, and the second clamp section 15 is used when transporting a workpiece (not shown) that is, for example, an inner panel of vehicle type B. The workpiece 13 of vehicle type A and the workpiece of vehicle type B have different sizes and shapes.

[0017] Although details will be described later, the first and second clamping units 14, 15 have first claws 23, 25 (see FIG. 2A) and second claws 24, 26 (see FIG. 2A), respectively. The first claws 23, 25 abut against the front side of the workpiece 13, and the second claws 24, 26 abut against the back side of the workpiece 13. When transporting the workpiece 13 of vehicle type A, the hand main body 11 moves in a state in which the workpiece 13 is clamped by the first and second claws 23, 24 of the first clamping unit 14 in each arm unit 12. When transporting a workpiece (not shown) of vehicle type B, the first and second claws 25, 26 of the second clamping unit 15 are used.

[0018] Next, the operation of the robot hand 10 when clamping and transporting a workpiece 13 of vehicle type A will be described with reference to Fig. 2A to Fig. 7. In the following description, a case where the workpiece 13 is clamped and transported using the first clamp unit 14 of one arm unit 12 of the robot hand 10 shown in Fig. 1 will be described, but the same applies to the other arm units 12. When the robot hand 10 clamps and transports a workpiece of vehicle type B (not shown), the operations of the first and second clamp units 14, 15 are reversed. Therefore, for the description of clamping and transporting a workpiece of vehicle type B, refer to the description below using the workpiece 13 of vehicle type A, and the description will be omitted here.

[0019] Fig. 2A is a side view illustrating the arm unit 12 of the robot hand 10 of this embodiment, and shows the initial operation state of the robot hand 10. Fig. 2B is a side view of the robot hand 10 shown in Fig. 2A, seen from the first clamp unit 14 side corresponding to vehicle type A.

[0020] 2A and 2B, the arm 12 mainly includes a first clamp 14, a second clamp 15, a first drive unit 21 for driving the first clamp 14, a first drive unit 22 for driving the second clamp 15, a first claw 23 and a second claw 24 constituting the first clamp 14, a first claw 25 and a second claw 26 constituting the second clamp 15, a second drive unit 27 for driving the second claws 24 and 26, a drive transmission unit 28 for transmitting the drive force of the second drive unit 27 to the second claws 24 and 26, and a holding unit 29 for holding the first or second clamp 14 and 15 when not in use. The second drive unit 27 of the arm 12 is fixed to and supported by the hand body 11 (see FIG. 1).

[0021] As shown in FIG. 2B, during the initial operation of the robot hand 10, the hand body 11 waits above the workpiece 13 so that the first clamp portion 14 is in a position where it is not in contact with the workpiece 13.

[0022] The first claw portion 23 mainly has a main body plate portion 23A fixed to the tip of the first driving portion 21 and a clamping plate portion 23B fixed to the tip of the main body plate portion 23A. The second claw portion 24 mainly has a main body plate portion 24A fixed to a receiving block 35 and a clamping plate portion 24B fixed to the tip of the main body plate portion 24A. The receiving block 35 is fixed to the main body plate portion 23A of the first claw portion 23 and moves together with the first claw portion 23.

[0023] Here, the first driving parts 21, 22 are, for example, slider mechanisms driven by compressed air. In the first and second clamp parts 14, 15, the first driving parts 21, 22 and the first claw parts 23, 25 are connected via round steel bars 18, 19, respectively. With this structure, the first and second clamp parts 14, 15 move linearly back and forth in the left-right direction of the robot hand 10 in conjunction with the linear motion of the first driving parts 21, 22, respectively.

[0024] During the initial operation, the first drive units 21, 22 slide to the bottom end, and the first and second clamp units 14, 15 are disposed at the lowest point relative to the first drive units 21, 22. At this point, the first and second clamp units 14, 15 are not selected by the control unit 17 and are in a standby state in approximately the same position.

[0025] FIG. 3A is a side view illustrating the arm unit 12 of the robot hand 10 of this embodiment, showing a state in which the second clamp unit 15 of the robot hand 10 for vehicle type B has retreated relative to the workpiece 13. FIG. 3B is a side view of the robot hand 10 shown in FIG. 3A, seen from the first clamp unit 14 for vehicle type A. FIG. 4A is a side view illustrating the drive transmission unit 28 of the robot hand 10 of this embodiment. FIG. 4B is a side view illustrating the holding unit 29 of the robot hand 10 of this embodiment. For convenience of explanation, the first and second clamp units 14, 15 are explained together in FIG. 4A and FIG. 4B.

[0026] 3A and 3B, when the second clamp unit 15 retreats from the workpiece 13, the hand main body 11 continues to wait above the workpiece 13. Only the first driving unit 22 slides to the upper end, and only the second clamp unit 15 moves obliquely upward in a direction away from the workpiece 13. During the retreat, the second clamp unit 15 is located at the highest point relative to the first driving unit 22.

[0027] On the other hand, the first drive unit 21 remains at the lower end position without being driven, and the first clamp unit 14 waits in the current position. As a result, the first claw portion 23 of the first clamp unit 14 is located closer to the workpiece 13 than the first claw portion 25 of the second clamp unit 15.

[0028] Here, the second driving unit 27 is, for example, a cylinder mechanism driven by compressed air. The drive transmission unit 28 mainly includes a main body 31 connected to the tip of the piston shaft 27A of the second driving unit 27, a locking pin 32 supported by the main body 31, engagement blocks 33 and 34 fixed to the second claws 24 and 26, respectively, and appropriately engaged with the locking pin 32, and support blocks 35 and 36 fixed to the first claws 23 and 25, respectively, and rotatably supporting the engagement blocks 33 and 34.

[0029] 3A and 4A, the engagement blocks 33, 34 are, for example, substantially U-shaped and fixed to the inside of the second claws 24, 26. A dashed line 37 indicates the movement trajectory of the first and second clamping parts 14, 15, and openings 33A, 34A of the engagement blocks 33, 34 are located on the workpiece 13 side, which is the right side of the movement trajectory. Opening regions 33B, 34B of the engagement blocks 33, 34 are disposed toward the left side of the openings 33A, 33A along the movement trajectory.

[0030] With this structure, when the first drive parts 21, 22 slide to the lower end, the engagement blocks 33, 34 engage with the locking pin 32. On the other hand, when the first drive parts 21, 22 slide toward the upper end, the engagement blocks 33, 34 disengage from the locking pin 32.

[0031] As described above, the first and second clamp parts 14, 15 move linearly forward and backward in the left and right directions of the robot hand 10 in conjunction with the linear motion of the first drive parts 21, 22, respectively. The movement trajectory indicated by the dashed dotted line 37 is designed, for example, within a range of 45 degrees ±10 degrees with respect to the horizontal plane (the installation surface of the robot hand 10). The angle of the movement trajectory can be arbitrarily changed in design.

[0032] 4B, when the first driving parts 21, 22 slide to the upper end, the engaging blocks 33, 34 are fitted between the holding part 29 and the receiving blocks 35, 36. As shown in the figure, the first end side of the receiving blocks 35, 36 is fixed to the first claw parts 23, 25, and the second end side of the receiving blocks 35, 36 is fixed to the second claw parts 24, 26. The engaging blocks 33, 34 are disposed in the recessed areas 35A, 36A of the receiving blocks 35, 36 in a freely rotatable state.

[0033] 3B, the second clamp unit 15 is not used when transporting the workpiece 13 of vehicle type A, but the engagement block 34 is fitted between the holding unit 29 and the receiving block 36 at a position retracted from the workpiece 13 on the left side of the robot hand 10. The second clamp unit 15 then maintains a state in which it is firmly fixed to the hand main body 11. As a result, when the workpiece 13 is clamped and transported by the first clamp unit 14, the second clamp unit 15 is prevented from interfering with the workpiece 13.

[0034] Fig. 5A is a side view illustrating the arm unit 12 of the robot hand 10 of this embodiment, showing a state in which the first clamp unit 14 of the robot hand 10 abuts against the surface of the workpiece 13. Fig. 5B is a side view of the robot hand 10 shown in Fig. 5A as seen from the first clamp unit 14 side corresponding to vehicle type A.

[0035] 5A and 5B, the hand main body 11 is controlled by the control unit 17 to descend from a standby position above the workpiece 13 to a position where the clamping plate 23B of the first claw 23 abuts against the surface of the workpiece 13 in a desired area. Similarly, although not shown, the clamping plate 23B of the first claw 23 of each arm 12 abuts against the surface of the workpiece 13 in a desired area.

[0036] As described above, the second clamp unit 15 moves diagonally upward on the left side of the robot hand 10 so as to move away from the workpiece 13, and the first claw unit 25 of the second clamp unit 15 is positioned higher than the first claw unit 23 of the first clamp unit 14. Therefore, when the hand body unit 11 descends, the clamping plate unit 25B of the first claw unit 25 is prevented from interfering with the workpiece 13.

[0037] Fig. 6A is a side view illustrating the arm unit 12 of the robot hand 10 of this embodiment, showing a state in which the robot hand 10 is clamping a workpiece 13. Fig. 6B is a side view of the robot hand 10 shown in Fig. 6A, seen from the side of the first clamp unit 14 corresponding to vehicle type A. Fig. 7 is a schematic diagram illustrating an operating state of the engagement block 33 of the robot hand 10 of this embodiment.

[0038] 5B, the first claw portions 23, 25 and the second claw portions 24, 26 are connected via connecting plates 41, 42. The connecting plates 41, 42 are rotatably supported by rotating shafts 43, 44 relative to the first claw portions 23, 25, and are fixed in a non-rotating state relative to the second claw portions 24, 26. As described above, the first claw portions 23, 25 and the second claw portions 24, 26 are connected in a non-rotating state via the receiving blocks 35, 36.

[0039] 6A and 6B, in response to the downward extension of the piston shaft 27A of the second drive unit 27, the second claw unit 24 rotates around the first claw unit 23 with the rotation axis 43 as the center of rotation. The piston shaft 27A extends until the clamping plate unit 24B of the second claw unit 24 abuts against the back surface of the workpiece 13 in the desired area. Similarly, although not shown, the clamping plate unit 24B of the second claw unit 24 of each arm unit 12 abuts against the back surface of the workpiece 13 in the desired area.

[0040] As a result, in the desired region of the workpiece 13, the workpiece 13 is clamped between the clamping plate portion 23B of the first claw portion 23 and the clamping plate portion 24B of the second claw portion 24. Then, the hand main body portion 11 is controlled by the control portion 17 to rise while clamping the workpiece 13 at four points, and the workpiece 13 is removed from the work line and transported to the desired location.

[0041] After that, although not shown, the robot hand 10 places the workpiece 13 at the desired location and then returns to the initial operation position described with reference to Figures 2A and 2B. Then, the second clamp unit 15 returns from the standby position shown in Figures 3A and 3B via the first drive unit 22, and the robot hand 10 returns to the initial operation state shown in Figures 2A and 2B.

[0042] Furthermore, when workpieces 13 of vehicle type A are continuously supplied to the work line, the robot hand 10 may immediately transition to the operation of clamping the next workpiece 13, as shown in Figures 5A and 5B, without returning to the initial operating state from the waiting position of the second clamp portion 15 shown in Figures 3A and 3B.

[0043] Next, the operating state of the second claw portion 24 when the first clamp portion 14 is used will be described with reference to Figures 4A and 7. For ease of explanation, in Figure 7, all lines showing the trajectory of the engagement block 33 are shown as solid lines.

[0044] As described above with reference to FIG. 4A, the engagement block 33 is fixed to the second claw portion 24 so that the opening 33A is located on the workpiece 13 side, which is the right side of the movement trajectory of the first clamp portion 14 shown by the dashed line 37. Then, the first driving portion 21 slides to the lower end position, so that the engagement block 33 is engaged with the locking pin 32 of the drive transmission portion 28. In this engaged state, the piston shaft 27A of the second driving portion 27 extends downward, so that the engagement block 33 is pushed downward by the locking pin 32. Then, the second claw portion 24 to which the engagement block 33 is fixed rotates around the first claw portion 23 with the rotation axis 43 as the rotation center.

[0045] 7 shows a state in which the engagement block 33 rotates in conjunction with the extending motion of the piston shaft 27A of the second driving part 27. As described above, the engagement block 33 is fixedly disposed inside the second claw part 24, and the second claw part 24 rotates around the first claw part 23 with the rotation axis 43 as the center.

[0046] As shown in the figure, the engagement block 33 rotates clockwise in conjunction with the extending motion of the piston shaft 27A. The opening 33A of the engagement block 33 is designed not to be located directly below the locking pin 32 with respect to the stroke length of the piston shaft 27A.

[0047] With this structure, the locking pin 32 can continue to press the engagement block 33 in conjunction with the extending movement of the piston shaft 27A, without coming off and disengaging from the engagement block 33. As a result, the driving force of the second driving unit 27 continues to be transmitted to the second claw portion 24, and the second claw portion 24 can continue to rotate until the clamping plate portion 24B abuts against the rear surface of the workpiece 13 in the desired area. Then, the second claw portion 24 continues to press the workpiece 13 in conjunction with the movement of the piston shaft 27A.

[0048] As described above, in this embodiment, the first clamp unit 14 or the second clamp unit 15 is selected depending on the type of workpiece 13 supplied to the work line. Then, the second claws 24, 26 of the selected first or second clamp unit 14, 15 are operated by the driving force of the shared second drive unit 27. With this structure, it is only necessary to arrange one second drive unit 27 on each arm unit 12, thereby realizing miniaturization of the robot hand 10 and reduction in manufacturing costs.

[0049] In this embodiment, a case has been described in which the first clamp unit 14 corresponding to vehicle type A and the second clamp unit 15 corresponding to vehicle type B are provided on each arm unit 12, and the second claw units 24, 26 selected by the control unit 17 are operated by the shared second drive unit 27, but the present invention is not limited to this case. For example, it is also possible that three or more types of multiple clamp units are provided on each arm unit 12, and the multiple clamp units are appropriately selected according to the type of workpiece 13 and operated by the shared second drive unit 27. In addition, various modifications are possible within the scope of the present invention. [Explanation of symbols]

[0050] 10 Robot Hand 11 Hand body 12 Arm section 13 Work 14 First clamp part 15 Second clamp part 21,22 First drive unit 23,25 First claw 23A Main body plate 23B Clamping plate part 24,26 Second claw 24A Main body plate 24B Clamping plate part 27 Second Drive Unit 27A Piston shaft 28 Drive transmission section 29 Holding part 31 Main body 32 Locking pin 33,34 Engagement block 33A,34A opening 33B,34B opening area 35,36 Block 35A, 36A Recess area 43,44 Rotation axis

Claims

1. A robot hand that conveys a workpiece by clamping it with a plurality of arms supported by a hand body, Each of the arm portions is A plurality of clamping parts selected according to the size of the workpiece; a first drive unit that moves a first claw portion of the clamp unit; a second drive unit that moves a second claw portion of the clamp unit; a drive transmission unit that transmits a drive force from the second drive unit to the second claw portion of a selected one of the clamp portions, the second drive portion is shared by the second claw portions of the plurality of clamp portions, the first drive portion is disposed for each of the first claw portions of the plurality of clamp portions, The second claw portion is rotatably connected to the first claw portion, A robot hand characterized in that the first claw portion and the second claw portion move via the first drive unit, causing the second claw portion to engage with or disengage from the drive transmission unit.

2. A substantially U-shaped engagement block is fixed to each of the second claw portions to engage with a locking pin of the drive transmission portion, The first drive unit moves forward or backward in a straight line diagonally downward relative to the surface of the workpiece, 2. The robot hand according to claim 1, wherein the engagement block disengages from the locking pin as the first driving unit moves backward, and the engagement block engages with the locking pin as the first driving unit moves forward.

3. The arm portion is A receiving block formed on each of the first claw portions; a holding portion for holding the engagement block separated from the locking pin, 3. The robot hand according to claim 2, wherein the holding portion holds the engagement block between the holding portion and the receiving block when the first driving portion is in a retracted position.

4. The robot hand according to claim 2 or claim 3, characterized in that the second claw portion rotates relative to the first claw portion and abuts against the back side of the workpiece when the locking pin presses the engagement block via the second drive unit.

Images