JP7633108B2 - Robot Hand - Google Patents

Description

The present invention relates to a robot hand that can transport workpieces of different sizes.

Patent Document 1 discloses a conventional robot hand. 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.

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 the 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.

JP 2005-111573 A

As mentioned above, conventional robot hands select either a positioning clamp device for car A or a positioning clamp device for car B depending on the door inner panel being worked on. The positioning clamp device that is not being used is then retracted to the desired position during work, ensuring that it does not interfere with the door inner panel being worked on.

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. As a result, the robot hand becomes larger and is more expensive to use.

In addition, conventional robot hands are attached to the tip of the robot arm of a single handling robot when used. This poses the problem that a process is required to form unique positioning locating holes for the door inner panel for car A and the door inner panel for car B, resulting in increased manufacturing costs.

The present invention was made in consideration of the above circumstances, and provides a robot hand that can transport workpieces of different sizes.

One embodiment of the present invention relates to a robot hand, which is a robot hand that clamps and transports a workpiece with a plurality of arms supported by a hand main body, and each of the arms is equipped with a plurality of clamping sections that are selected according to the size of the workpiece, a first driving section that moves a first claw portion of the clamping section, a second driving section that moves a second claw portion of the clamping section, and a drive transmission section that transmits a driving force from the second driving section to the second claw portion of a selected one of the clamping sections, wherein the second driving section is shared by the second claw portions of each of the plurality of clamping sections, the first driving section is disposed for each of the first claw portions of the plurality of clamping sections, the second claw portions are rotatably connected to the first claw portions, and the first claw portions and the second claw portions move via the first driving section, thereby causing the second claw portions to engage with or disengage from the drive transmission section .

In a robot hand according to one embodiment of the present invention, each arm section is provided with a plurality of clamp sections that are selected according to the work size. The second claw sections of the plurality of clamp sections are operated by the driving force of a shared second drive section. With this structure, each arm section can accommodate a plurality of second claw sections via a single shared second drive section, realizing a miniaturized robot hand and reducing manufacturing costs.

1 is a perspective view illustrating a robot hand according to an embodiment of the present invention. FIG. 2 is a side view illustrating an arm portion of a robot hand according to an embodiment of the present invention. FIG. 2 is a side view illustrating an arm portion of a robot hand according to an embodiment of the present invention. FIG. 2 is a side view illustrating an arm portion of a robot hand according to an embodiment of the present invention. FIG. 2 is a side view illustrating an arm portion of a robot hand according to an embodiment of the present invention. FIG. 2 is a side view illustrating an arm portion of a robot hand according to an embodiment of the present invention. FIG. 2 is a side view illustrating an arm portion of a robot hand according to an embodiment of the present invention. FIG. 2 is a side view illustrating an arm portion of a robot hand according to an embodiment of the present invention. FIG. 2 is a side view illustrating an arm portion of a robot hand according to an embodiment of the present invention. FIG. 2 is a side view illustrating an arm portion of a robot hand according to an embodiment of the present invention. FIG. 2 is a side view illustrating an arm portion of a robot hand according to an embodiment of the present invention. 1 is a schematic diagram illustrating an arm portion of a robot hand according to an embodiment of the present invention. FIG.

First, a robot hand 10 according to one embodiment of the present invention will be described in detail with reference to the drawings. When describing this embodiment, the same components will generally be designated by the same reference numbers, and repeated description will be omitted. In addition, 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.

Figure 1 is a side view illustrating the robot hand 10 of this embodiment.

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 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.

The first and second clamping sections 14, 15 are switched appropriately depending on the workpiece 13 being transported, and the hand body section 11 is provided with a control section 17 that controls the above switching operation. The control section 17 is configured with a CPU (CENTRAL PROCESSING UNIT), ROM (READ ONLY MEMORY), RAM (RANDOM ACCESS MEMORY), etc. The control section 17 is an electronic control unit (ECU) that has one or more processors to execute various calculations for controlling the robot hand 10.

As shown in the figure, the hand main body 11 has four arms 12 arranged diagonally, and each arm 12 has two types of first and second clamps 14, 15. The first clamp 14 is used when transporting a workpiece 13 that is, for example, an inner panel of vehicle type A, and the second clamp 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.

Although details will be described later, the first and second clamping units 14, 15 each have a first claw 23, 25 (see FIG. 2A) and a second claw 24, 26 (see FIG. 2A). The first claw 23, 25 abuts against the front side of the workpiece 13, and the second claw 24, 26 abuts against the back side of the workpiece 13. When transporting a workpiece 13 of model A, the hand body 11 moves in each arm 12 with the workpiece 13 clamped between the first and second claws 23, 24 of the first clamping unit 14. When transporting a workpiece of model B (not shown), the first and second claws 25, 26 of the second clamping unit 15 are used.

Next, the operation of the robot hand 10 when clamping and transporting a workpiece 13 of model A will be described with reference to Figures 2A to 7. Note that the following description will be of the 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 Figure 1, but the same applies to the other arm units 12. When clamping and transporting a workpiece of model B (not shown) with the robot hand 10, the operation of the first and second clamp units 14, 15 is reversed. Therefore, for an explanation of clamping and transporting a workpiece of model B, refer to the explanation using the workpiece 13 of model A below, and the explanation will be omitted here.

Figure 2A is a side view illustrating the arm portion 12 of the robot hand 10 of this embodiment, showing the state of the robot hand 10 during initial operation. Figure 2B is a side view of the robot hand 10 shown in Figure 2A, seen from the first clamp portion 14 side corresponding to vehicle type A.

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 shared 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).

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 14 is in a non-contact position with the workpiece 13.

The first claw portion 23 mainly has a main body plate portion 23A fixed to the tip of the first drive 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 the 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.

Here, the first drive units 21, 22 are, for example, slider mechanisms driven by compressed air. In the first and second clamp units 14, 15, the first drive units 21, 22 and the first claw units 23, 25 are connected via round steel bars 18, 19, respectively. With this structure, the first and second clamp units 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 drive units 21, 22, respectively.

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

Figure 3A is a side view illustrating the arm portion 12 of the robot hand 10 of this embodiment, showing the state in which the second clamp portion 15 of the robot hand 10 corresponding to vehicle type B is retracted relative to the workpiece 13. Figure 3B is a side view seen from the first clamp portion 14 side of the robot hand 10 corresponding to vehicle type A shown in Figure 3A. Figure 4A is a side view illustrating the drive transmission portion 28 of the robot hand 10 of this embodiment. Figure 4B is a side view illustrating the holding portion 29 of the robot hand 10 of this embodiment. For convenience of explanation, the first and second clamp portions 14, 15 are explained together in Figures 4A and 4B.

As shown in Figures 3A and 3B, when the second clamp unit 15 retracts from the workpiece 13, the hand body unit 11 continues to wait above the workpiece 13. Only the first drive unit 22 slides to the upper end, and only the second clamp unit 15 moves diagonally upward in a direction away from the workpiece 13. During the retraction, the second clamp unit 15 is positioned at the highest point relative to the first drive unit 22.

Meanwhile, the first drive unit 21 remains at the lower end position without being driven, and the first clamp unit 14 waits in its current position. As a result, the first claw portion 23 of the first clamp unit 14 is positioned closer to the workpiece 13 than the first claw portion 25 of the second clamp unit 15.

Here, the second drive 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 drive 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 supporting the engagement blocks 33 and 34 rotatably.

As shown in Figures 3A and 4A, the engagement blocks 33, 34 are, for example, substantially U-shaped and are fixed to the inside of the second claw portions 24, 26. The dashed line 37 indicates the movement trajectory of the first and second clamp portions 14, 15, with the openings 33A, 34A of the engagement blocks 33, 34 positioned on the workpiece 13 side, which is the right side of the movement trajectory. The opening areas 33B, 34B of the engagement blocks 33, 34 are positioned along the movement trajectory from the openings 33A, 33A toward the left side.

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

As described above, the first and second clamping parts 14, 15 move linearly forward and backward in the left-right direction of the robot hand 10 in conjunction with the linear motion of the first driving parts 21, 22, respectively. The movement trajectory shown 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.

As shown in FIG. 4B, when the first drive units 21, 22 slide to the upper end, the engagement blocks 33, 34 are fitted between the holding unit 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 claws 23, 25, and the second end side of the receiving blocks 35, 36 is fixed to the second claws 24, 26. The engagement blocks 33, 34 are then arranged in a freely rotatable state within the recessed areas 35A, 36A of the receiving blocks 35, 36.

With this structure, in the state shown in FIG. 3B, the second clamp portion 15 is not used when transporting the workpiece 13 of vehicle type A, but the engagement block 34 is engaged between the holding portion 29 and the receiving block 36 at a position retreated from the workpiece 13 on the left side of the robot hand 10. The second clamp portion 15 then maintains a firmly fixed state relative to the hand main body portion 11. As a result, when the workpiece 13 is clamped and transported by the first clamp portion 14, the second clamp portion 15 is prevented from interfering with the workpiece 13.

Figure 5A is a side view illustrating the arm portion 12 of the robot hand 10 of this embodiment, showing the state in which the first clamp portion 14 of the robot hand 10 is in contact with the surface of the workpiece 13. Figure 5B is a side view of the robot hand 10 shown in Figure 5A as seen from the first clamp portion 14 side corresponding to vehicle type A.

As shown in Figures 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 portion 23B of the first claw portion 23 abuts against the surface of the workpiece 13 in the desired area. Similarly, although not shown, the clamping plate portion 23B of the first claw portion 23 of each arm portion 12 abuts against the surface of the workpiece 13 in the desired area.

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 portion 25 of the second clamp unit 15 is positioned higher than the first claw portion 23 of the first clamp unit 14. Therefore, when the hand main body unit 11 descends, the clamping plate portion 25B of the first claw portion 25 is prevented from interfering with the workpiece 13.

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

As shown in FIG. 5B, the first claws 23, 25 and the second claws 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 claws 23, 25, and are fixed in a non-rotating state relative to the second claws 24, 26. As described above, the first claws 23, 25 and the second claws 24, 26 are connected in a non-rotating state via receiving blocks 35, 36.

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

As a result, in the desired area 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.

After that, although not shown, the robot hand 10 places the workpiece 13 in 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.

When workpieces 13 of model A are continuously supplied to the work line, the robot hand 10 may immediately move to clamping the next workpiece 13 as shown in Figs. 5A and 5B without returning to the initial operating state from the standby position of the second clamping unit 15 shown in Figs. 3A and 3B.

Next, the operating state of the second claw portion 24 when the first clamp portion 14 is in use will be described with reference to Figures 4A and 7. Note that in Figure 7, for the sake of convenience, all lines showing the trajectory of the engagement block 33 are shown as solid lines.

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 to the right of the movement trajectory of the first clamp portion 14 shown by the dashed line 37. Then, when the first drive portion 21 slides to the lower end position, 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 drive portion 27 extends downward, and 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 center of rotation.

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

As shown in the figure, the engagement block 33 rotates clockwise in conjunction with the extension 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 relative to the stroke length of the piston shaft 27A.

This structure allows the locking pin 32 to continue to press the engagement block 33 in conjunction with the extending movement of the piston shaft 27A, without coming loose and detaching from the engagement block 33. As a result, the driving force of the second drive 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 back surface of the workpiece 13 in the desired area. The second claw portion 24 then continues to press the workpiece 13 in conjunction with the movement of the piston shaft 27A.

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. 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 sufficient to arrange one second drive unit 27 on each arm unit 12, which allows the robot hand 10 to be made smaller and the manufacturing costs to be reduced.

In this embodiment, a first clamp unit 14 corresponding to vehicle type A and a 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. However, this is not limited to this case. For example, three or more types of multiple clamp units may be provided on each arm unit 12, and the multiple clamp units may be appropriately selected according to the type of workpiece 13 and operated by the shared second drive unit 27. In addition, various modifications are possible without departing from the scope of the present invention.

REFERENCE SIGNS LIST 10 Robot hand 11 Hand body 12 Arm 13 Workpiece 14 First clamp 15 Second clamp 21, 22 First drive 23, 25 First claw 23A Body plate 23B Clamp plate 24, 26 Second claw 24A Body plate 24B Clamp plate 27 Second drive 27A Piston shaft 28 Drive transmission 29 Holding section 31 Body 32 Locking pin 33, 34 Engagement block 33A, 34A Opening 33B, 34B Opening area 35, 36 Receiving block 35A, 36A Recess area 43, 44 Rotation axis

Claims (4)

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 . 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. 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. 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 .

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