JP3174848B2 - Gripping device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an industrial robot,
The present invention relates to a gripping device that grips various workpieces, daily necessities such as cups, and various other objects in a robot such as an assistance robot or a home robot, or a transport device or an automation device in various manufacturing processes.

[0002]

2. Description of the Related Art As a conventional gripping device for an industrial robot, there is a gripping device 1 as shown in FIGS. 1 and 2 of JP-A-4-159092. This is Base 1
A detector 8 having an auxiliary claw 6 for gripping an object 9 to be gripped, which is operated via a piston 7 by air cylinders 5a to 5c provided above and in synchronization with the links 3a to 3c and the rotating plate 4, and It is provided with gripping claws 2a to 2c. Such a conventional gripping device is provided with a driving device such as an air cylinder corresponding to a plurality of gripping claws, and has a complicated mechanism.

[0003] In addition, a gripping device of a type driven by a rope via a pulley is introduced in Japanese Patent Application Laid-Open No. 52-91266, Japanese Utility Model Application Laid-Open No. 61-64985, and the like. To use,
A large number of pulleys and gears were provided, and the mechanism was complicated.

[0004]

According to the present invention, a single drive source such as a motor for driving a gripper of a gripper is used, and a mechanism for transmitting a driving force to the gripper uses a single rope. The aim is to realize a gripping device that is as simple as possible, simple and lightweight, and has a compact structure.Furthermore, since all of the plurality of gripping tools have an equal gripping force regardless of the shape of the object to be gripped, An object of the present invention is to precisely and stably hold an object to be gripped and to prevent damage to the object to be gripped due to uneven gripping force.

[0005]

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a support frame which is movable on the same straight line or a straight line parallel to each other so as to be capable of moving toward and away from each other. Each of a plurality of pairs of grippers attached and each independently movable, and a gripper pulley attached to one of the two grippers of each pair of the plurality of pairs of grippers, A frame pulley attached to the support frame, the gripper pulley and the frame pulley, one end of which can be pulled in one direction, and the other end of which is a single drive rope fixed to the support frame. And a single drive source that pulls the one drive rope and moves the plurality of pairs of grippers in a direction to grip the object to be gripped ,
When the drive rope is pulled by the drive source,
In each pair of the pair of grippers, the grippers are connected symmetrically to each other.
Moving and moving, and each pair up independently
Provided is a gripping device that moves in a direction in which an object to be gripped is gripped .

[0007] Further, the pair of grippers of the present invention are always urged by a spring in a direction away from each other.

Further, each of the two grippers of each pair has a rack, and the rack engages with the pinion and moves in conjunction with each other while being guided by a guide rod attached to the support frame.

Further, the two grippers of each pair move by being guided by a guide rod attached to the support frame in conjunction with each other by a connecting rope.

[0010]

FIG. 3 and FIG. 4 are conceptual diagrams for explaining the principle of the present invention. In FIG. 3A, when the object to be grasped 14 is gripped by the two pairs of grippers 10, 11, 12 and 13, the two pairs of grippers 10, 11 and 12, 1 are used.
The mechanism 3 is provided in advance with a mechanism in which each pair independently moves symmetrically from the grip center O.

In FIG. 3B, two pairs of grippers 10,
Each pair of 11, 12, and 13 is movably provided on a base (support frame) (not shown) so as to be able to approach and move away in conjunction with each other. A gripper pulley 15 and a gripper pulley 16 are provided on one gripper 10 and gripper 12 in each pair.

Further, the frame pulleys 17, 1 and
8 are provided. One rope 19 is stretched over these pulleys 15 to 18, and one end thereof is indicated by an arrow F.
The other end is fixed to the base. Now, when one end of the rope 19 is pulled in the direction of arrow F, the grippers pulleys 15 and 16 are moved toward the center by the rope 19, and the grippers 11 and 13 are moved toward the center in conjunction with the pulleys. Tools 10, 11 and 12, 13
Thus, the object to be grasped can be grasped.

According to such a principle, as shown in FIGS. 4A to 4D, objects of various shapes can be uniformly, precisely and stably gripped by two pairs of grippers.

An embodiment of the present invention based on the above principle will be described based on an embodiment with reference to the drawings. 5 and 6
1 shows an embodiment of the present invention, in which a gripping device 20 has a base (frame) 21 fixed to a portion to which the gripping device is attached, such as a tip of a movable portion of a robot or an automation device. A flange 22 is formed on the periphery of the base 21. Two pairs of support pieces 23, 24 and 25, 26 protrude from a substantially central bottom surface of the base 21. Two pairs of guide rods 27, 2 extending in the radial direction along the base 21 between the flange portion 22 and the two pairs of support pieces 23, 24, 25, 26.
8 and 29, 30 are installed.

Two pairs of guide rods 27, 28 and 29,
Two pairs of grippers 3 guided radially by 30
1, 32 and 33, 34 are slidably provided on the guide rod. In FIG. 5, a guide rod is provided on the base 21 as a guide for guiding the gripper. Instead, the gripper is slidably mounted on the upper surface of the base via a linear sliding bearing (linear bearing). Is also good.

The upper part of the two pairs of grippers 31, 32 and 33, 34 has grips 35, 3 having a cylindrical gripping surface inside.
6 and 37, 38 are formed. The gripping device 20
Each of the pair of grippers 31, 32, 33, and 34 has a gripper release mechanism that constantly urges in a direction away from each other, and a gripper drive mechanism that drives in a direction approaching each other when gripping an object to be gripped. The gripper release mechanism and the gripper drive mechanism are operated to release or grip the object to be gripped.

First, the gripper releasing mechanism will be described. One gripping tool 3 of two pairs of gripping tools 31, 32 and 33, 34
Release rope take-up domes 39, 40 are arranged on the base 21 on the sides of 1, 33. The release rope winding drums 39, 40 are urged to rotate in the winding direction (counterclockwise in FIG. 5) by springs 41, 42 disposed coaxially.

The release rope winding drums 39, 40
, One ends of release ropes 43 and 44 are wound in the direction of being wound by the mainsprings 41 and 42.
The other ends of the release ropes 43 and 44 are connected to two pairs of grippers 3 via guide pulleys 45 and 46 provided on the base 21.
1, 32, and 33, 34 are attached to the outer surface of one of the grippers 31, 33.

Pinions 47, 48 are independently rotatably provided at the center of the base 21, and two pairs of grippers 31,
32 and 33, 34 have these pinions 47, 48
Two pairs of racks 49, 50 and 51, 52
The base 21 is fixed so as to extend in the center direction. The pair of racks 49 and 50 and the pair of racks 51 and 52 are attached with their positions shifted downward and upward, respectively.
Correspondingly, the pinions 47 and 48 are arranged so as to mesh with each other.

By the gripper releasing mechanism, the release ropes 43, 4 are always attached to the release rope winding drums 39, 40.
4 is urged in the direction in which it is wound up, so that the release ropes 43 and 44 allow one of the grippers 3 in each pair to be wound.
1 and 33 are urged outward of the base 21, and further, via pinions 47 and 48 and two pairs of racks 49, 50 and 51, 52, the other gripping tool 3 in each pair.
2 and 34 are similarly urged outward from the center of the base 21. That is, the pair of gripping tools 31, 32 or 33, 34 constituting the two pairs of gripping tools are normally urged in a direction away from each other.

A pair of grippers 31, 32 or 33,
34, the rack and the pinions 47 and 48 are configured to move on the base in cooperation with each other as described above.
By the connecting rope, when one gripping tool moves outward (inward), in conjunction with this, the other gripping tool moves outward (inward) and moves away from each other (approaching).
It is good also as composition which connected a pair of two graspers.

Next, the gripper driving mechanism will be described. The gripper pulleys 53, 54 are provided on the one gripper 31, 33 of the two pairs of grippers 31, 32, 33, 34.
Further, frame pulleys 55 and 56 are provided on the outer side of the guide rods 28 and 30. These gripper pulleys 5
One drive rope 57 is wrapped around 3, 54 and the frame pulleys 55, 56, and one end thereof is wound around a drive rope take-up drum 58, and the other end is attached to a fixture 59 provided on the flange 22 of the base.

The driving rope take-up drum 58 has a normal rotation
The rotatable motor 60 is driven to rotate so that the drive rope 57 can be wound and unwound.

The operation of the gripping device according to the embodiment of the present invention having the above configuration will be described. Mainspring spring 4
Due to the elastic winding force of the release ropes 1, 4,
4 is urged in the direction in which it is wound by the release rope winding drums 39 and 40, so that the pair of gripping tools 31, 32 or 33, 34 constituting the two pairs of gripping tools are moved outward in the direction away from each other. It is biased and the gripper is in the released state.

Now, when the motor 60 rotates the driving rope winding drum 58 in the winding direction by an electric signal instructing the gripping of the object to be gripped, the driving rope 57 is wound on the driving rope winding drum 58, Drive rope 57
Is pulled in the direction of arrow F. Then, the pinion 4
7, 48 and the pair of racks 49, 50 or 51, 52 move the two pairs of grippers 31, 32 and 33, 34 in directions approaching each other against the elastic winding force of the mainspring springs 41, 42. Then, the object to be grasped is grasped.

Conversely, when releasing the gripped object to be gripped, the motor 60 is rotated in the opposite direction by the electric signal for instructing the grip release, whereby the rope wound around the winding drum 58 is released. Unwind and loosen 57. Then, the ropes 43, 44 are wound around the release rope winding drums 39, 40 by the elastic winding force of the mainspring springs 41, 42, and the pinions 47, 4 are wound.
The pair of racks 49, 50 or 51, 52 causes the pair of grippers 31, 32, or 33, 34 to move outward from the center of each other to release the gripping of the object to be gripped.

In the above embodiment, the pair of grippers 31, 3
2 or 33, 34 can be moved by the rods 27, 28 or 29, 30 on the same straight line, but as shown in FIG. 7, a pair of grippers 31 ', 32'
1, moving on L2, and further holding part 3
5 ', 36' may be extended outward and attached. With such a configuration, the gripper 31 ′,
32 'can be moved crossing each other, the movable range (stroke S) thereof is greatly expanded, and it can be used for objects to be gripped in a wide range of dimensions.

The gripping force of the gripping device of the present invention is determined by the torque of the motor 60 and the elasticity of the mainspring. The spring characteristics of the mainspring are designed so that the restoring force is substantially constant regardless of the displacement. This makes it possible to equalize the forces generated by the respective gripping tools on the object to be gripped, regardless of the difference in the opening width of the two pairs of gripping tools.

Although not directly related to the essence of the present invention, a detailed description thereof will not be given, but a known potentiometer or encoder for detecting the amount of rotation of the motor 60, a gripping pressure detector provided on the gripper, etc. The movement position of the gripper or the gripping state is detected by a detection signal from a detector or the like, and the rotation amount control, torque control, and the like of the motor are performed.

The above embodiment is an example of a specific configuration of the present invention. The essence of the present invention is that a plurality of grippers are simultaneously moved by a single driving source and a single rope driven by the driving source. The purpose of the present invention is to provide a simple, lightweight and compact gripping device while achieving a uniform and stable gripping by performing a gripping operation, and within the scope of this essence, various specific configurations are included. Needless to say.

[0031]

According to the gripping device of the present invention, a plurality of gripping tools can be simultaneously moved by a single drive source and a single rope driven by the same to perform a gripping operation. The gripping force of the gripping tool is made uniform, and a precise and stable gripping of the object to be gripped can be realized, and the configuration of the gripping device is simple, lightweight and compact.

In particular, the present invention is characterized in that the gripping force by the gripper is uniform regardless of the shape of the gripping object.
It is extremely useful in gripping devices in manufacturing processes that have to grip workpieces of various shapes, hands of assisting robots that need to grip various daily necessities, automated food manufacturing equipment that grips soft foods, etc. .

[Brief description of the drawings]

FIG. 1 is a plan view of a conventional gripping device.

FIG. 2 is a front view of FIG.

FIG. 3 is a principle view of the present invention.

FIG. 4 is an example of use of the device according to the principle of FIG.

FIG. 5 is a plan view of an embodiment of the present invention.

6 is a sectional view taken along line AA of FIG.

FIG. 7 is a diagram illustrating a modified example of the gripper of the present invention.

[Explanation of symbols]

 Reference Signs List 1 base 2 gripping claw 5 air cylinder 10, 11, 12, 13 gripping tool 14 gripped object 15, 16, 53, 54 gripping tool pulley 19, 57 drive rope 20 gripping device 21 base 22 flange portion 27, 28, 29, Reference Signs List 30 Guide rod 31, 32, 33, 34 Holder 35, 36, 37, 38 Holder 39, 40 Release rope winding drum 41, 42 Spring spring 17, 18, 55, 56 Frame pulley 58 Drive rope winding drum 60 motor

Claims (4)

(57) [Claims] 1. A supporting frame and a plurality of a pair of gripping tools, each of which is movably mounted on a same straight line or a straight line parallel to each other so as to be able to move toward and away from each other so as to be independently movable. A plurality of pairs of grippers, a gripper pulley attached to one of the two grippers of each pair of the plurality of pairs of grippers, a frame pulley attached to the support frame, the gripper pulley, and It is passed over the frame pulley, one end of which can be pulled in one direction,
The other end is one drive rope fixed to the support frame, and a single drive source that pulls the one drive rope and moves the plurality of pairs of gripping tools in a direction to grip the object to be gripped. comprising, pulling the drive rope by the drive source, the
In each pair of multiple pairs of grippers, the grippers are symmetrical to each other
Each pair is independent of each other
Moving in the direction of gripping the object to be gripped
And a gripping device. 2. The gripping device according to claim 1, wherein the two gripping members of each pair are always urged by a spring in a direction away from each other. 3. The two grippers of each pair each have a rack, and the racks are engaged with a pinion to move together with each other while being guided by a guide rod attached to the support frame. The gripping device according to claim 1 or 2, wherein: 4. The device according to claim 1, wherein the two grippers of each pair move by being guided by a guide rod attached to the support frame in conjunction with each other by a connecting rope. Gripping device.