JPH0217823Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to a gripper that is attached to an industrial robot or the like and grips and releases objects such as workpieces and tools.

(Prior Art) One of this type of gripper is described in Japanese Utility Model Application Publication No. 48-86565. This gripper includes (a) a gripper body, (b) a pair of gripping claws held by the gripper body so as to be able to approach and separate from each other along a straight line, and (c) a pair of gripping claws provided on the gripper body. (d) a pair of rotating members rotatably provided on mutually opposing surfaces of a pair of gripping claws around an axis parallel to the straight line and concentrically with each other; and (f)
The gripper includes a rotational drive device that is provided on the gripper body and rotates one of a pair of rotational members.
When the pair of gripping claws are closed by the opening/closing drive device, the object is gripped via the pair of rotational members, and in this state, one of the rotational members is rotated by the rotational drive device, thereby gripping the object. The object is rotated, and the object can be rotated around an axis parallel to the opening/closing direction of the gripping claws while the gripper body remains stationary. Therefore, the rotation drive device only needs to rotate the object and the rotating member that grips it, and compared to the case where the entire gripper is rotated, the rotation drive device can be smaller and lighter, and its weight can be reduced. Accordingly, the payload capacity of industrial robots, etc. can be increased accordingly.

In addition, it is not necessary to rotate the gripper itself in order to rotate the object around the part gripped by the gripping claws, and there is no need to rotate the gripper support member in conjunction with the rotation, so it is free for industrial robots, etc. This has the advantage of requiring less power and a smaller operating space.

(Problem to be Solved by the Invention) However, in this gripper, only one of the rotating members that sandwich the object from both sides is driven by the rotational drive device, and the other only rotates as the object member rotates. That is, the pair of rotating members can freely rotate relative to each other when they are not gripping an object.

However, it may not be desirable for these rotating members to be free to rotate relative to each other. For example, if a V-groove is formed on the surfaces of a pair of rotating members that contact the object, the object can be accurately positioned and gripped. It is necessary that the V-grooves of the rotating member be substantially parallel to each other. If the extending directions of both V-grooves are slightly different, the rotating member can rotate relative to the object when gripping the object, and the V-grooves can be in an accurately parallel state, but the extending directions of the V-grooves are too different. This can no longer be expected if, for example, they are at right angles to each other.

In view of this point, the present invention has been developed with the object of making it possible to maintain the relative phase of a pair of rotating members constant at all times.

(Means for Solving the Problems) The gist of the present invention is as follows: (a) a gripper body, (b) a pair of gripping claws, (c) an opening/closing drive device, (d) a pair of rotating members, and (e) A gripper including a rotational drive device is provided with a rotation transmission device that transmits the rotation of one rotational member to the other rotational member while allowing a pair of gripping claws to approach and separate from each other.

(Function) In the gripper having the above rotation transmission device, when one rotation member rotates, the rotation is always transmitted to the other rotation member by the rotation transmission device, and the pair of rotation members always maintain a constant relative phase. That will happen.

Moreover, since this rotation transmission device allows the pair of gripping claws to approach and separate, the pair of gripping claws and the rotating member can grip and release the object without any problem.

(Effects of the invention) As described above, in the gripper according to the invention, even when the object is not sandwiched between the rotating members, free relative rotation of the rotating members is prevented. Therefore, for example, even if V-grooves are formed on the surfaces of the pair of rotating members that contact the object, the V-grooves are always maintained in a parallel state and do not interfere with gripping the object. Furthermore, even when a light emitting element and a light receiving element are installed in a portion of the opposing surfaces of a pair of rotating members away from the center of rotation to detect whether or not an object is gripped by a gripper, the light emitting element It is guaranteed that the light receiving element and the light receiving element always maintain opposing positions.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

In FIG. 1, reference numeral 10 denotes a gripper body, which has a pair of arm portions 12 and 14 facing each other, forming an approximately U-shape, and a portion corresponding to the bottom of the U-shape is connected to an arm of an industrial robot. It is becoming fixed. This gripper body 10
A pair of air cylinders 16 and 18 are provided in parallel to each other on one arm portion 12 of the arm portion 12, and their piston rods 20 and 22 are connected to the other arm portion 1.
4 in a slidable manner. Air cylinder 1
As shown in FIG. 2, ports 28, 28 are formed in each of the lid members 24, 24 of 6, 18, respectively, and the air cylinders 16, 18 are supplied through these ports 28, 28. It consists of a pair of single-acting cylinders operated by compressed air.

Further, as shown in FIG. 1, the piston rods 20 and 22 have racks 3 facing each other at the portions thereof passing through the arm portion 14 of the gripper body 10.
0 and 30 are formed, and a pinion 32 rotatably supported by the gripper body 10 is meshed with them. When the air cylinder 16 is actuated, the piston rod 20 is moved to the right in FIG. 1, while the piston rod 22 is moved to the left by the same amount. When actuated, the piston rod 22 is projected to the right in the figure, while the piston rod 20 is moved to the left by the same amount. In addition, in the figure, 34 is an O-ring. Further, 38 is a dust seal.

40 and 42 are gripping claws, and gripper body 1
They are provided parallel to each other with the arm portions 14 of 0 interposed therebetween. One gripping claw 40 has a through hole 44 at the base end.
The gripping claw 42 is fixed to the distal end of the piston rod 20 at the through hole 46 and is slidably fitted to the distal end of the piston rod 22 at the through hole 46 . It is fixedly fitted and also slidably fitted to the piston rod 20 in the through hole 50. In other words, the gripping claws 40,
As the piston rods 20 and 22 move relative to each other due to the operation of the air cylinders 16 and 18, the piston rods 42 move closer to each other along their axial direction while maintaining the posture of facing each other across the arm portion 14 of the gripper body 10. They are becoming more distant. As is clear from this, in this embodiment, the air cylinders 16, 18 and the pinion 32
An opening/closing drive device for the gripping claws 40, 42 is constructed by the above. In addition, in the figure, what is indicated by the reference numeral 52 is a sliding sleeve.

A pair of rotating members 54, 56 are provided at the tips of the gripping claws 40, 42, which are moved toward and away from each other by the alternative operation of the air cylinders 16, 18, and extend concentrically through them, respectively. It is being The rotating members 54 and 56 each have a gripping claw 4
Shaft portions 58 and 60 passing through 0 and 42, and those shaft portions 5
It consists of rectangular flat plate portions 62 and 64 provided in parallel to each other at the ends of opposite sides of the shaft portions 58 and 60, and is supported by bearings 66 and 68 and 70 and 72 in the respective shaft portions 58 and 60. The connecting member 7 is supported rotatably around the axis and immovably in the axial direction, and is attached to the side surfaces of the flat plate parts 62 and 64 on opposite sides.
4 and 76, they are connected to each other so that they can approach and separate from each other, and cannot rotate relative to each other. connecting member 74,
76, as shown in FIG.
A pair of arms 82, 82 and 84, 84 are shaped to extend parallel to each other from mounting portions 78, 80 fixed to 2, 64, and as shown in FIG. The guide parts 88, 88 formed on the arms 84, 84 are connected to guide parts 86, 86 formed on the arms 84, 84 in a slidable manner. In other words, the gripping claws 40, 42
As the rotating members 54 and 56 move closer to each other and move away from each other, the rotating members 54 and 56 also move closer to each other and move away from each other, and as will be described later, when one rotating member 54 is rotated, the other rotating member 56 also rotates. The connecting member 7 can be rotated with a constant relative phase, and in this embodiment, the connecting member 7
4 and 76 constitute a rotation transmission device.

On the other hand, the gripping claw 40 is provided with an air cylinder 90, as shown in FIG. This air cylinder 90 includes a main body portion that surrounds the inside of a through hole 92 formed perpendicularly to the direction in which the rotating member 54 is disposed,
A cylinder chamber is formed by closing the intermediate portion of the through hole 92 and the opening on the proximal end of the gripping claw with a closing member 94 and a lid member 96, respectively. A piston 98 is slidably fitted in the cylinder chamber, and ports 1 and 1 are respectively placed in pressure chambers 100 and 102 separated by the piston 98.
Compressed air can be supplied through 04,106. The piston 98 is moved in its axial direction by alternatively supplying compressed air to the pressure chambers 100, 102.

Further, a piston rod 108 extends from the piston 98 through the closing member 94 in an airtight and slidable manner. This piston rod 10
A rack 110 is formed at the tip of 8.
It is engaged with a pinion 112 fixed to an intermediate portion of the shaft portion 58 of the rotating member 54 . In other words, the rotating member 54 is configured to rotate around the axis based on the operation of the air cylinder 90, and as is clear from this, the air cylinder 90, the rack 110, the pinion 112
etc. constitute a rotational drive device that rotates the rotating member 54. In FIG. 4, reference numeral 114 is an adjustment screw screwed into the lid member 96, and the maximum movable range of the piston 98 can be adjusted by this adjustment screw 114.

In addition, in this embodiment, as shown in FIGS. 1 and 3, the shaft portion 58 of the rotating member 56,
A stopper member 116 is fixed to the end opposite to the side where the flat plate portion 62 is provided, and a pair of stopper bolts 118 and 11 are fixed to the side of the gripping claw 40.
8 are provided, and when the stopper member 116 comes into contact with the stopper bolts 118, 118, the rotating member 54, Rotation of 56 is restricted.

Further, as shown in FIGS. 1 and 2, a rotational phase detection plate 120 is provided at the end of the shaft portion 60 of the rotating member 56 on the opposite side to the side where the flat plate portion 64 is provided. At the same time, the gripper body 1
A pair of proximity sensors 124 are disposed on a bracket 122 provided at the tip of the arm portion 12 of 0, and the rotation ends of the rotation members 54, 56 are detected by these sensors 124.

According to such a gripper, air cylinder 1
By selectively operating the grippers 6 and 18, the gripping claws 40 and 42, as well as the flat plate portions 62 and 64 of the rotating members 54 and 56, can be brought closer to and separated from each other to grip and release objects such as workpieces and tools. It is,
Furthermore, by selectively supplying compressed air to the pressure chambers 100, 102 of the air cylinder 90, the rotating members 54, 5 can be rotated without rotating the entire gripper.
6, and by extension, the object held between the flat plate portions 62 and 64, can be rotated around one axis within the angular range in which the stopper member 116 contacts the stopper bolts 118, 118.

Note that in the gripper of this embodiment, the rotating member 5
Although it is possible to directly grip the object between the flat plate parts 62 and 64 of 4 and 56, the grip of the target object is normally achieved by gripping members attached to the flat plate parts 62 and 64 according to the object. will be held. For example, when the object is cylindrical or disc-shaped, if a V block is used as the gripping member, the object can be held not only in the opening and closing directions of the gripping claws 40 and 42, but also at right angles to the opening and closing directions. It is possible to grip the device while accurately positioning it in any direction. In this case, if the V block is considered as a part of the rotating members 54 and 56, the rotating member 5
This means that a V-groove is formed on the surface that contacts the objects No. 4 and 56.

Although one embodiment of the present invention has been described above, this is literally an illustration, and the present invention should not be interpreted as being limited to this embodiment.

For example, in the embodiment, the rotating members 54, 56
Although the rotation range of the piston 98 is limited to 90 degrees, it is not limited to this and can be set arbitrarily within the maximum movable range of the piston 98 that is limited by the adjustment screw 114. Further, the rotation range of the rotating members 54 and 56 may be restricted by the adjustment screw 114 and the contact between the closing member 94 and the piston 98.

Further, in the embodiment described above, the rotating members 54 and 56 are connected by the connecting members 74 and 76, and when the rotating member 54 is rotated by one air cylinder 90 provided on the gripping claw 40, the rotating members 54 and 56 are rotated. The member 56 was also designed to be rotated at the same time with a certain relative phase, but while a gear mechanism for rotating the rotating members 54 and 56, respectively, is provided inside the gripping claws 40 and 42, it is necessary to rotate these gear mechanisms at the same time. A long gear to be driven is slidably disposed between the gripping claws 40 and 42, and by driving the long gear, the rotating members 54 and 56 are rotated with a constant relative phase. is also possible. In this case, one of the gear mechanisms provided inside the gripping claws 40 and 42, a long gear, and a drive source that rotationally drives the long gear constitute a rotational drive device,
The other gear mechanism and a portion of the long gear constitute a rotation transmission device. Furthermore, the rotating member 5
Other drive sources such as a hydraulic cylinder or an electric motor may be used as the drive source for rotationally driving the parts 4 and 56.

Further, in the above embodiment, the grippers 40 and 42 are moved closer to each other and separated by the parallel movement of the two piston rods 20 and 22 by the alternative actuation of the air cylinders 16 and 18. The invention was applied to grippers whose gripping claws are moved closer and farther apart by other drive sources such as hydraulic cylinders or electric motors, links, wires, etc.
Alternatively, the present invention can also be applied to a type of gripper that can be moved toward and away from the gripper using another gear mechanism or the like.

Further, in the embodiment described above, both the gripping claws 40 and 42 can be moved relative to the gripper body 10, but it is also possible to use a type in which one of the gripping claws is fixed to the gripper body. Can apply ideas.

Although not listed in detail, it goes without saying that the present invention can be implemented with various modifications and improvements without departing from the spirit thereof.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view showing an embodiment of the present invention. FIG. 2 is a left side view of FIG. 1, and FIG. 3 is a right side view of FIG. Figure 4 is the − of Figure 1.
FIG. FIG. 5 is a partially cutaway plan view of FIG. 1 excluding the gripper body. FIG. 6 is an explanatory diagram showing an enlarged view of the connecting member shown in FIG. 5. FIG. 10: Gripper body, 16, 18, 90: Air cylinder, 20, 22: Piston rod, 30,
110: Rack, 32, 112: Pinion, 4
0, 42: Gripping claw, 54, 56: Rotating member, 6
2, 64: flat plate portion, 74, 76: connecting member.

Claims (1)

[Claims for Utility Model Registration] A gripper body; a pair of gripping claws held by the gripper body so as to be able to approach and move away from each other along a straight line; an opening/closing drive device configured to open and close the gripper body; a pair of rotating members rotatably provided on opposing surfaces of the pair of gripping claws around an axis parallel to the straight line and concentric with each other; and a rotating member provided on the gripper body. a rotation drive device that rotates one of a pair of rotating members, the gripper grips an object via the rotating member by approaching a pair of gripping claws, and rotates the object by rotating the rotating member, A gripper characterized in that a rotation transmission device is provided that transmits the rotation of the one rotating member to the other rotating member while allowing the pair of gripping claws to approach and separate.