JPH0459115B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a robot hand, and particularly to a robot hand that opens and closes a pair of grippers using a motor.

[Conventional technology]

Figures 3 and 4 are, for example,
This shows the conventional robot hand shown in Publication No. 20482. In the figure, 1 is the robot body, 2 is the arm, 3 is the hand provided at the tip of the arm 2, 4 is the motor, and 5 is the motor shaft. , 6 is a motor direct-coupled arm whose longitudinal center portion is fixed to the motor shaft 5 and swings as the motor 4 rotates in forward and reverse directions; 7 is a first arm connected to one end of the motor-directly coupled arm 6; 8 is this arm; A second arm 10 connected to one end of the first arm 7 and having one gripper shaft 9a attached to its longitudinal center portion transmits the swinging motion of the second arm 8 to the fourth arm 11 with the operating direction reversed. The third arm 9b is the other gripper shaft attached to the fourth arm 11, and the third arm 9b is the other gripper shaft attached to the fourth arm 11.
1 constitutes a link mechanism. 12a,
12b is a pair of grippers that are opened and closed by the forward and reverse rotation of the motor 4 attached to each gripper shaft 9a, 9b, and 13 is a pair of grippers that restricts the swing range of the motor-directly connected arm 6 to fully open the pair of grippers 12a, 12b. This is a stopper for maintaining the position and the fully closed position at specified dimensions.

The conventional robot hand is configured as described above, and the pair of grippers 12 are operated by the forward and reverse rotation of the motor 4.
a, 12b are opened and closed, and the contact between the motor-directly connected arm 6 and the stopper 13 maintains the fully open and fully closed positions of the pair of grippers 12a, 12b at specified dimensions. At this time, a constant current is applied to the motor 4 to apply torque even after the contact is made so that the motor direct coupling arm 6 remains in contact with the stopper 13 as shown in FIG.

[Problem that the invention seeks to solve]

In the conventional robot hand as mentioned above, the fifth
As shown in the figure, the same value (α) of current is flowing through the motor 4 during the opening/closing operation of the pair of grippers 12a and 12b even after the grippers are fully opened and fully closed, so if the current value is high, the motor 4 fixed part There is a risk that high torque will be applied to the link mechanism and damage them.
On the other hand, when the current value is low, there is a problem that sufficient torque cannot be obtained due to loss in the link mechanism and the operation becomes sluggish.

This invention was made in order to solve this problem, and it is possible to obtain sufficient torque when the gripper opens and closes, but does not have a negative effect on the link mechanism etc. due to low torque in the fully open and fully closed positions. The purpose is to obtain a robot hand that does not have a robot hand.

[Means for solving problems]

The robot hand according to the present invention is provided with a switch that operates to reduce the current value of the motor just before the pair of grippers are in the fully open position and just before the fully closed position.

[Effect]

In this invention, the current value of the motor is reduced by the switch just before the fully open position and just before the fully closed position, so even if the torque during the opening/closing operation of the gripper is increased, the current value of the motor at the fully open and fully closed positions is reduced. Torque becomes low and does not adversely affect the link mechanism etc.

〔Example〕

1 and 2 show an embodiment of the present invention, and in the figures, the same reference numerals as in FIGS. 3 to 5 indicate the same or corresponding parts. Reference numerals 14a and 14b indicate opening/closing detection switches that are installed within the swing locus of the motor directly coupled arm 6 and are activated by contacting the motor directly coupled arm 6 just before the motor directly coupled arm 6 contacts the stopper 13. As a result, as shown in FIG. 2, the current supplied to the motor 4 is reduced from the current value (α) to the current value (β).

In the robot hand configured as described above, the open/close detection switches 14a and 14b are activated just before the motor direct-coupled arm 6 comes into contact with the stopper 13, and the current value of the motor 4 decreases from (α) to (β). . Therefore, when the motor directly connected arm 6 is in contact with the stopper 13, that is, when the pair of grippers 12a and 12b are fully open and fully closed, the torque is low and there is no risk of damage to the link mechanism or the like. On the other hand, a pair of grippers 12a, 12
During the opening/closing operation of b, the current value of the motor 4 is (α), so high torque is obtained and a sharp operation is ensured.

In the above embodiment, the open/close detection switch 14
Although a and 14b are shown as being installed within the swing locus of the motor-directly connected arm 6, they may be installed within the swing locus of the second arm 8, the fourth arm 11, or the like.

〔Effect of the invention〕

As explained above, this invention is provided with a switch that operates just before the fully open position and just before the fully closed position of the pair of grippers to reduce the current value of the motor, so that the grippers operate with high torque when opening and closing. When opening and closing, the grip is held with low torque, which has the effect of maintaining the function of the hand without adversely affecting the link mechanism or the like.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a motor current waveform diagram, Fig. 3 is an overall block diagram showing a conventional robot hand, and Fig. 4 is an enlarged arrow of the - line in Fig. 3. The perspective view corresponds to FIG. 1, and FIG. 5 is a conventional motor current waveform diagram. 3...Hand, 4...Motor, 6...Motor directly connected arm, 7...First arm, 8...Second arm, 9a, 9b...Gritzpa shaft, 10...
Third arm, 11...Fourth arm, 12a, 12
b... Gritspa, 13... Stopspa, 14a, 1
4b...Open/close detection switch. In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] 1 The rotational force of the motor is transmitted to a pair of grippers via a link mechanism, and the forward and reverse rotation of the motor opens and closes the pair of grippers, and the operating range of the link mechanism is restricted within the operating locus of the link mechanism. In a robot hand equipped with a stopper that maintains the fully open and fully closed positions of the pair of grippers at specified dimensions, the robot hand operates just before the fully open position and just before the fully closed position of the pair of grippers to control the current value of the motor. A robot hand characterized by being equipped with a switch that reduces the amount of electricity.