JPS61178190A - Gripper - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a gripping device used in an articulated manipulator or robot.

[Prior Art] A gripping device includes an arm and a gripping portion connected to the tip of the arm and capable of gripping a workpiece. The gripping portion is formed by, for example, a pair of gripping claws arranged opposite each other, and the gripping claws can be driven to open and close, that is, in the gripping and non-gripping directions, by a driving portion including a motor or the like.

By the way, it is necessary for the gripping device to adjust the gripping force applied to the gripping portion depending on the type of workpiece as the object to be gripped. In other words, depending on the material, size, etc. of the workpiece,
This is because it is necessary to adjust the gripping force applied to the gripping portion by a considerable amount to grip the workpiece safely and reliably.

For this reason, in conventional gripping devices, a strain gauge is disposed within the gripping part to detect the gripping force applied to the gripping part when gripping a workpiece, and the gripping force detected by the strain gauge is The foot bank mechanism was used to add feet/henk to the drive section.

The drive part.

The grip force applied by the feeder is compared with a preset grip force, and as a result of the comparison, the drive f of the drive unit consisting of a motor, etc.
I was trying to adjust t. As a result, the gripping device
It was possible to apply a grip force to the grip part that was set according to the type of each workpiece.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional gripping device, there is a need to directly arrange a strain gauge as a gripping force detection means on the gripping part, and moreover, there is a need to dispose a strain gauge as a gripping force detection means directly on the gripping part, and moreover, In the meantime, wiring, etc. had to be routed.

As a result, there have been problems such as parts such as the gripping portion becoming excessively large and unreasonable loads being applied to the wiring routed around the gripping portion.

The present invention makes it possible to easily detect the gripping force applied to the gripping part, simplifies the structure of the gripping device, and
The purpose is to simplify the control mechanism for adjusting grip strength.

[Means for solving the problems] In order to achieve the above object, the gripping device according to the present invention has the following features:
an arm, a gripping part connected to the tip of the arm and capable of gripping a workpiece, a driving part capable of generating at least a driving force in the gripping direction to the workpiece, and a driving force of the driving part directly connected to the driving part. a first transmission part that is movable by a second transmission part, a second transmission part directly connected to the grip part, and a first transmission part and a second transmission part that are movable by
A pressure member is interposed between the transmission parts, and when the grip part is in the non-grasping state, the first transmission part and the second transmission part are movable together in the grip direction, and the grip part is in the grip state. In the step, the grip force applying means is configured to make only the first transmission part movable by deformation of the pressure member, and to apply grip force based on the deformation of the pressure member to the grip part via the second transmission part. The gripping force detecting means is capable of detecting the gripping force applied to the gripping part by the pressure applying means by measuring the amount of deformation of the pressing member.

[Sakukawa] According to the present invention, the grip force applied by the grip force applying means to the grip part can be easily detected by measuring the deformation of the pressure member interposed between the first transmission part and the second transmission part. It becomes possible to do so. As a result, there is no need to provide a strain gauge as a grip force detection means directly on the grip as in the past, and it is no longer necessary to make the grip too large or route wiring etc. to the grip. It becomes possible to simplify the structure of the gripping device.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a side view of a manipulator to which a gripping device according to an embodiment of the present invention is applied, and FIG. 2 shows II of FIG.
- An enlarged sectional view taken along the line II, Figure 3 is an enlarged sectional view similar to Figure 2 showing a state in which a workpiece is gripped by the gripping part, and Figure 4 is an enlarged sectional view taken along the line I'V-IV in Figure 2. It is a diagram.

The manipulator 10 is of a multi-joint type and includes a rotating arm 12 that can rotate in the direction of arrow A with respect to a base 11.
Furthermore, a swinging arm 13 is provided at the tip of the swinging arm 12 and is capable of swinging in the direction of arrow B with respect to the swinging arm 12. The swinging arm 13 is provided with a gripping device 14 . This gripping device 14 has a gripping part 15 connected to the tip of a swinging arm 13, which swings in the direction of arrow C, and the gripping part 15 is capable of gripping a workpiece as an object to be gripped. There is. As a result, the manipulator 10 can grasp and move a workpiece or rotate it by operating the operation section.

The swinging arm 13 supported by the swinging arm 12 has a cylindrical shape as a whole, and the tip of the swinging arm 13 has a grip support 16.
The zero grip part support 16 is attached by screwing together the female threaded part 17 of the swinging arm 13 and the male threaded part 18 of the grip part support 16, as shown in FIG. The grip part 15 supported by the support body 16 has a rotation shaft part 19.
is provided, and the rotating shaft portion 19 is supported by the grip support 16 via a bearing 20. Thereby, the grip part 15 is made swingable in the direction of arrow C with respect to the grip part support body 16 supported by the reciprocating arm 13 by a driving operation of a drive source (not shown).

The grip portion 15 is provided with a grip claw support portion 21 that swings around a rotation shaft portion 19 . The gripping claw supporter 21 supports the gripping claws 22 via link members 23 and 24, and the gripping claws 22 supported by the gripping claw supporter 21 are provided in pairs, facing each other. There is.

That is, among the two link members 23 and 24, one end of the link member 23 is supported by the gripping claw supporter 21 via the connecting shaft 25, and the other end is supported by the gripping claw via the connecting shaft 26. 22 will be supported. This makes it possible to move the pair of gripping claws 22 that are arranged opposite to each other in the opening/closing direction [direction D] with respect to the gripping claw supporter 21 as shown in FIG.

Further, the other link member 24 has one end portion 1'L.
! It is supported by the gripping claw support part 21 via the j+'+ shaft 25A, and the intermediate part thereof is connected to a transmission part 27 which is movable in the direction of arrow E, and roughly the other end is connected to the connection shaft 28. It is connected to the gripping claw 22 via. Link member 23
and the link member 24, there are gripping claws 2 disposed opposite to each other.
Tension springs 2 that bias 2 in the opening direction, respectively.
9 is interposed. As a result, it becomes possible to drive the opposing gripping claws 22 in the gripping direction by moving the transmission portion 27 in the direction of arrow E.

A motor 30 serving as a drive unit that enables movement of the transmission unit 27, that is, drive of the gripping claws 22 in the gripping direction, is disposed inside the swing arm 13. That is, a frame 31 is provided inside the swing arm 13 so as to be supported by the grip support 16 , and a motor 30 is attached to the frame 31 via a motor bracket 32 .

A screw shaft 35 is connected to the output shaft 33 of the motor 30 via a connection part 34 supported by the frame 31, and the screw shaft 35 is further connected to the transmission part 2.
7 are connected.

The transmission section 27 includes a first transmission section 8B36 that is directly connected to the screw shaft 35 and a second transmission section 37 that is directly connected to the link member 24 of the grip section 15. The force can be transmitted to the gripping portion 15 side.

That is, the first transmission part 36 includes the screw shaft 3
A screw hole portion 39 is provided to be screwed into the screw portion 38 of No. 5,
Thereby, the first transmission section 36 can be slid in the direction of arrow F through the rotation of the screw shaft 35 driven by the motor 30. At this time, in order to prevent the first transmission part 36 from rotating in the direction around the axis of the screw shaft 35, a keyway 40 is provided in the sliding direction [F direction] of the first transmission part 36, and the key yI40 is attached to the frame. 3
A key 41 supported by 1 is fitted into the key 41. Two holes 42 are formed in the first transmission part 36 in the sliding direction of the first transmission part 36, and a slide shaft provided in the second transmission part 37 is inserted into the holes 42. 43 is inserted. That is, the second transmission part 37 includes a movable body 44 that is slidable in the direction of arrow F, and the two slide shafts 4 are connected to the motor 30 side of the movable body 44.
3 is installed. The slide shaft 43 is longer than the length of the movable body 44 in the sliding direction [F direction], so that the tip of the slide shaft 43 inserted into the hole 42 can be moved from the hole 42 to the motor 30 side. It is exposed and protrudes.

A stopper portion 45 is provided at the tip of the slide shaft 43, and a stopper portion 45 is provided between the stopper portion 45 and the first transmission portion 36 in a state in which it is sheathed around the axis of the tip portion of the slide shaft 43 in an exposed state. A coil spring 46 is interposed as a pressure member. On the other hand, a chain support section 47 is provided on the grip section 15 side of the movable body 44, and one end side of a chain 48 interposed between the chain support section 47 and the grip section 15 side is supported. Become. The chain 48 is disposed inside the gripping claw support 21, and a chain connecting body 49 is provided at the other end of the chain 48.

The chain connection body 49 includes chains 50A and 50.
One end of B is connected. The other end side of each chain 5OA and 50B is connected to each link member 24 arranged oppositely. The gripping claw support part 21 includes
Sprockets 51A and 51B are attached to each chain 50A and 50B. Further, a pair of support rollers 52 are provided at the center of rotation of the gripping claw supporter 21 in the chain 48, as shown in FIG. 4, for supporting the chain 48 when the gripping claw supporter 21 rotates. . Chains 50A and 50B connected to link member 24 are always urged in the opening direction [G direction] by the spring force of tension spring 29. As a result,
The entire second transmission part 37 is always pulled toward the grip part 15 side. The motor 30 is driven, and the first transmission part 36
When the is slid in the direction of arrow F, the second transmission part 37 becomes slidable, and the opposing gripping claws 22 can be moved to grip and release by adjusting the drive of the motor 30. Become. By driving the motor 30,
When the gripping claws 22 are driven in the gripping direction, the second
As shown in the figure, when the gripping claws 22 are in the non-gripping state, the first transmission part 36 and the second transmission part 37 are moved together in the gripping direction. On the other hand, when the gripping claws 22 are gripping the workpiece 53 as shown in FIG. Accordingly, a gripping force based on the deformation of the coil spring 46 can be applied to the gripping claw 22 via the second transmission part 37.

As a result, the gripping force acts on the workpiece 53, and the workpiece 53 can be gripped by the gripping claws 22.

Between the first transmission part 36 and the second transmission part 37, there is a grip force detection means 5 that can detect the grip force applied to the gripping claws 22.
4 is attached. This gripping force detection means 54 measures the amount of deformation of the coil spring 46 when the gripping claws 22 are in the gripping state, that is, the displacement of the coil spring 46, based on the length of the coil spring 46 when the gripping claws 22 are in the non-gripping state. Let's measure the length, so that
The gripping force applied to the gripping claws 22 is detected.

That is, since the amount of deformation of the coil spring 46 is proportional to the stress, the grip force can be easily detected by measuring the displacement length of the coil spring 46 with respect to the reference length. Here, the amount of deformation of the coil spring 46 can be detected by measuring the relative displacement knee between the detection section 55 forming the grip force detection means 54 and the test rod 56. The detection section 55 is fixed to the first transmission section 36 , and the test rod 56 is fixed to the movable body 44 of the second transmission section 37 .

Next, the operation of the gripping device 14 of the manipulator 1o will be explained.

First, a case will be explained in which the gripping claws 22 in the non-gripping state shown in FIG. 2 are activated and the workpiece 53 is gripped as shown in FIG. The workpiece 5 is held between the gripping claws 22 arranged.
The manipulator 10 is operated so that 3 is positioned.

Once the workpiece 53 is positioned between the gripping claws 22, the motor 30 is then driven to rotate the screw shaft 35. Then, the first transmission part 36 is moved in the direction of arrow E, and the second transmission part 36 connected to the first transmission part 36 is moved.
The transmission part 37 will also be moved integrally. Second transmission part 3
7 is moved in the direction of arrow E, the link members 24 connected to the chains 50A and 50B of the second transmission section 37 are driven in the gripping direction, and thereby the gripping claws 22 disposed opposite to each other are also moved in the gripping direction. It will be driven by As a result, the workpiece 53 positioned between the gripping claws 22 can be gripped by the gripping claws 22. When the motor 3o is roughly driven while the workpiece 53 is being gripped by the gripping claws 22, the first Only the transmission section 36 is roughly moved in the direction of arrow E, and the coil spring 46 is moved accordingly.
is deformed in the compression direction. When the coil spring 46 is deformed, a grip force based on the deformation is applied to the gripping claws 22, and the amount of deformation of the coil spring 46 is detected by the grip force detection means 54.
By detecting this, the grip force acting on the workpiece 53 is detected.

The detected grip force is transmitted to the motor 3 by a feedback mechanism.
The grip force is fed back to the drive control unit (not shown) of No. 0, and is compared with a preset gripping force depending on the type of workpiece 53 to be gripped in the drive control unit. As a result of the comparison, the drive amount of the motor 30 is adjusted in the control section, and the gripping claw 22
It becomes possible to control the grip force to the set grip force.

Next, when the workpiece 53 is to be brought into a non-grip state, the motor 30 is first rotated in the opposite direction. Then, the first transmission part 36 and the second transmission part 37 are moved in the opposite direction, and the spring 29 is biased in the direction of arrow G.
Due to the urging force, the gripping claws 22 are moved open. As a result, the gripping claws 22 can release the workpiece 53.

Next, the operation of the above embodiment will be explained.

According to the gripping part M14 according to the above embodiment, the first transmission part 3
By measuring the amount of deformation of the coil spring 46 interposed between the coil spring 6 and the second transmission part 37, the gripping force applied to the gripping claw 22 can be easily detected. As a result, it is no longer necessary to provide a strain gauge as a grip force detection means directly on the grip as in the past, and it is no longer necessary to make the grip too large or to connect wiring etc. to the grip. It becomes possible to simplify the structure of the gripping device.

[Effect 1 of the Invention As described above, the gripping device according to the present invention includes an arm, a gripping portion connected to the tip of the arm and capable of gripping a workpiece, and a driving force applied to the workpiece at least in the gripping direction. a first transmission section that is directly connected to the drive section and movable by the driving force of the drive section; a second transmission section that is directly connected to the grip section; A pressure member is interposed between the two transmission parts, and when the grip part is in a non-grasping state, the first transmission part and the second transmission part can be moved together in the grip direction, and the grip part In the grasping state, only the first transmission part is movable by deformation of the pressure member, and a grip force is imparted to the grip part through the second transmission part, based on the deformation of the pressure member. means and
Since the gripping force detection means is provided which can detect the gripping force applied to the gripping part by the pressure applying means by measuring the amount of deformation of the pressure member, it becomes possible to easily detect the gripping force applied to the gripping part. , it becomes possible to simplify the structure of the gripping device and to simplify the control mechanism for adjusting the gripping force.

[Brief explanation of drawings]

FIG. 1 shows a side view of a manipulator to which a gripping device according to an embodiment of the present invention is applied, and FIG. 2 shows II of FIG.
Fig. 3 is an enlarged sectional view similar to Fig. 2 showing a state in which a workpiece is gripped by the gripper, and Fig. 4 is an enlarged sectional view taken along line IV-IV in Fig. 2. be. 13... Swinging arm, 14... Gripping device, 15...
- Gripping part, 27... Transmission part, 30... Motor, 36
...First transmission part, 37...Second transmission part, 46...
Coil spring, 53... Workpiece, 54... Grip force detection means. Agent Patent Attorney Osamu Shiokawa Figure 1

Claims (1)

[Claims] (1) An arm, a gripping part connected to the tip of the arm and capable of gripping a workpiece, a driving part capable of generating at least a driving force in the gripping direction to the workpiece, and a driving part directly connected to the driving part. A first transmission part that is movable by a driving force of When in the non-grasping state, the first transmission part and the second transmission part are movable together in the gripping direction, and when the gripping part is in the gripping state, the deformation of the pressure member causes the first transmission part and the second transmission part to move together in the gripping direction.
a gripping force applying means that allows only the transmission part to move and applies gripping force based on the deformation of the pressure member to the gripping part via the second transmission part; and pressure application by measuring the amount of deformation of the pressure member. A gripping device comprising a gripping force detecting means capable of detecting a gripping force applied by the means to a gripping portion.