JPH056074Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a robot hand suitable for application to various machine tools.

[Conventional technology]

Conventionally, the fifth robot hand is used in processing machines that grind and polish plate-shaped objects such as glass substrates for photomask blanks and ceramics.
A device constructed as shown in FIG. 6 and FIG. 6 is known. That is, this robot hand 1 grasps a plate-shaped object 4 as a workpiece on a surface plate 5 with two fingers 2 and 3 that can be opened and closed. The supporting shafts 7 and 8 provided at the base of the frame 6 are moved in the axial direction by a drive device (not shown) (generally a motor, an air cylinder, etc.) built into the frame 6, so that they can be moved toward each other. The gripping claws 9 and 10, which are disposed opposite to each other on the inner surfaces of the tips of the fingers 2 and 3, can grasp the plate-like object 4. V-shaped grooves 11 and 12 are horizontally formed on the inner surfaces of the gripping claws 9 and 10, and the gripping operation of the plate-shaped object 4 is controlled by the lower slopes 11a and 12a of the grooves 11 and 12. This is done by scooping up the object 4 from above the surface plate 5. In addition, 14 is an arm of a robot hand that moves the frame 6 to an arbitrary position within the working range;
5 and 16 are guide bars for each finger 2 and 3.

[Problem that the invention attempts to solve]

In the conventional robot hand having such a configuration, when gripping the plate-shaped object 4, the gripping position is stored in advance in the arm control section, and a corresponding drive signal is sent to the robot hand 1 to control the finger 2. , 3 are moved to the gripping position, and the gripping operation of the plate-shaped object 4 is performed. Therefore, if the height of the surface of the surface plate 5 of the processing machine on which the plate-like object 4 is installed changes, the gripping position will be different from the one stored in the arm control unit, so that the plate-like object 4 cannot be accurately gripped. There was a problem in that the gripping position could not be adjusted and the gripping position had to be corrected frequently. That is, the height of the surface plate 5 changes due to expansion and contraction due to wear and temperature changes, and in particular, the fingers 2 and 3 are stopped at a predetermined gripping position by a drive signal from the arm control section. If the lower surfaces of the gripping claws 9, 10 do not touch the surface of the surface plate 5 and stop slightly floating, the lower slopes 11a, Since the tip of the plate 12a comes into contact with the side surface of the plate-like object 4, the plate-like object 4 cannot be scooped up, making it difficult to grip it with the V-shaped grooves 11 and 12. Therefore, in such a case, it is necessary to correct the gripping position using the arm control unit and send the drive signal again based on the correction.
As a result, the circuit configuration of the arm control section becomes complicated, and the gripping operation takes a long time, resulting in poor work efficiency.

Therefore, the present invention improves the above-mentioned drawbacks, and even when the surface plate surface fluctuates due to wear, expansion or contraction due to temperature changes, etc., it is possible to reliably hold a plate-like object without adjusting the gripping position of the fingers. The present invention provides a robot hand that can be grasped.

[Means for solving problems]

In order to achieve the above object, the robot hand according to the present invention includes a frame, an arm that holds the frame vertically or rotatably, and a pair of arms that are disposed on the frame and that open and close along the upper surface of the surface plate. and a grasping claw provided at the tip of each finger for grasping a plate-like object on the surface plate, and the frame is urged toward the surface plate at a connecting portion between the arm and the frame and grasped. A reaction force absorbing means is provided to absorb the impact when the claw comes into contact with the top surface of the surface plate.

[Effect]

In the present invention, the reaction force absorbing means absorbs the impact force when the gripping claw collides with the surface plate, and also elastically presses the gripping claw so as not to separate from the upper surface of the surface plate.

〔Example〕

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 is a partially cutaway side view showing an embodiment of the robot hand according to the present invention, and FIG. 2 is a side view showing the state when gripping a plate-shaped object. In the drawings, the same components as in FIGS. 5 and 6 are designated by the same reference numerals, and their explanations will be omitted. In these figures, in this embodiment, a frame 6 is connected to the tip of an arm 14 via a spline shaft 20 so as to be movable up and down, and a compression coil spring 21 as a reaction force absorbing means is elastically mounted on this shaft 20. The feature is that the frame 6 is urged downward. The spline shaft 20 has its base connected to the arm 1.
A collar 20a is integrally provided at the lower end to prevent the frame 6 from coming off. A spline bearing 23 is embedded in the base of the frame 6, and the spline shaft 20 is fitted into and passes through the bearing 23.

In the robot hand 1 having such a configuration, the arm 14 when grasping the plate-like object 4
The amount of descent is slightly (2 to
(approximately 3mm) is set large. Therefore,
When the arm 14 descends by a predetermined stroke, the grip claws 9 and 10 are pressed onto the surface plate 5, and the reaction force at this time is absorbed by the frame 6 rising along the spline 20 and compressing the spring 21, and the robot hand 1. Prevent damage etc. When the left and right fingers 2 and 3 (2 not shown) are brought close to each other in this pressed state, the grip claws 9 and 10 slide while being pressed against the surface plate surface. At this time, there is no gap between the surface plate surface and the gripping claws 9, 10, so that the lower slopes 11a, 12a (see FIG. 4 can be grasped by scooping it off the surface of the surface plate.
In this case, if the downward stroke of the arm 14 is set in consideration of the maximum amount of variation in the height of the surface plate 5 due to wear, temperature changes, etc., the grip claws 9 and 10 are always kept in position on the surface plate 5 during the gripping operation. Therefore, unlike the conventional robot hand described above, there is no need to adjust the gripping position each time according to the height of the surface plate, and the gripping position can be set at once, and the plate-shaped object 4 can be securely held. It is possible to prevent poor gripping due to fluctuations in the height of the surface plate.

That is, in this embodiment, the frame 6 is connected to the arm 14.
By connecting the frame 6 with a spline connection so that it can freely move up and down, and urging the frame 6 downward with a spring 21, fluctuations in the height of the surface plate can be effectively absorbed.
The plate-like object 4 can be held securely at all times. The reason for using the spline shaft 20 is to prevent the frame 6 from rotating in the horizontal direction, and is not limited to this.
Various alternatives (eg keys and keyways) can be used.

FIGS. 3 and 4 are side views showing another embodiment of the present invention, showing an initial position state and a gripping state. In this embodiment, the base of the frame 6 is connected to the lower end of the arm 14 by a shaft 25 so as to be rotatable in the directions of arrows A and B (up and down), and is biased in the direction of arrow B by a tension coil spring 26. It is brought into pressure contact with a stopper 27 provided on the lower surface of the arm 14. In this case, the fingers 3 are set and held in an inclined state with respect to the surface plate surface such that the gripping claw 10 side is lower than the frame 6 side in the initial position shown in FIG. 3, and when pressed against the surface plate 5 during gripping, Since the frame 6 rotates about the shaft 25 in the direction of arrow A against the spring 26, it becomes substantially horizontal, and in this state, the gripping operation of the plate-shaped object 4 is performed.

In this case as well, since the gripping claws 10 are pressed against the surface plate 5, the plate-like object 4 can be reliably gripped without having to adjust the gripping position according to variations in the height of the surface plate, as in the above embodiment. should be obvious. Further, the spring 26 absorbs the reaction force when the grasping claw 10 comes into contact with the surface plate 5, thereby preventing breakage or damage to the robot hand 1.

However, in the structure of this embodiment, since the finger 3 cannot be moved horizontally in the vertical direction, the permissible amount of variation in the horizontal position is smaller than in the above embodiment, but it has been confirmed through experiments that it is sufficient for practical use. There is.

[Effect of idea]

As described above, according to the robot hand according to the present invention, there is provided a reaction force at the connection part between the arm and the frame that urges the frame toward the surface plate and absorbs the impact when the gripping claw comes into contact with the upper surface of the surface plate. Since the force absorption means is installed, it is possible to absorb fluctuations in the height of the surface plate due to wear, temperature changes, etc., so there is no need to frequently adjust the gripping position, and plate-shaped objects can be gripped reliably and fixed. It is possible to prevent gripping errors due to variations in the height of the board surface. In addition, since the reaction force when the gripping claw comes into contact with the surface plate surface is absorbed by the reaction force absorbing means, it is possible to prevent breakage and damage to the robot hand.
It has a very simple structure and has great practical effects.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view of an embodiment of the robot hand according to the present invention in an initial position;
FIG. 2 is a side view showing the state when gripping, FIG. 3 is a side view showing another embodiment of the present invention in the initial position state,
Figure 4 is a side view showing the state when gripping, Figure 5a,
b and c are plan views showing conventional examples of robot hands;
A side view and a front view, and FIG. 6 is a front view showing a state in which a plate-shaped object is gripped. 1... Robot hand, 2, 3... Finger, 4...
Plate-shaped object, 5... Surface plate, 6... Frame, 9, 10
...Gripping claw, 14...Arm, 20...Spline shaft, 21...Compression coil spring, 25...
...Shaft, 26...Tension coil spring, 27...
Stotspa.

Claims (1)

[Scope of utility model registration request] a frame; an arm that holds the frame vertically or rotatably; a pair of fingers disposed on the frame that open and close along the top surface of the surface plate; A gripping claw that grips the upper plate-like object is provided at the connecting portion between the arm and the frame, and the frame is biased toward the surface plate and absorbs the impact when the gripping claw comes into contact with the upper surface of the surface plate. A robot hand characterized by being equipped with a reaction force absorption means.