JPS6056887A - Robot hand - 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 Application of the Invention] The present invention relates to a robot hand using a motor as a driving source,
In particular, the present invention relates to a robot hand that makes it possible to select the opening/closing stroke of the hand, to select the gripping force, and to monitor the falling of a workpiece during the workpiece hand linking process.

[Background of the invention]

A hand that uses a pulse motor or a servo motor as a drive source of a robot hand and whose gripping stroke can be selected from the outside is known. However, in most conventional robot hands, the gripping force is fixed even though the opening/closing stroke can be externally selected. Therefore, the size of the workpiece shape can be determined using a pair of robot hands.

Regardless of the quality or flexibility, it is impossible to grasp parts arbitrarily, place parts in a narrow space, and assemble the workpiece without interfering with the surroundings. [Object of the Invention] The present invention has been made to eliminate the above-mentioned drawbacks. When parts are being positioned and aligned, or when parts are placed in a narrow space, it is possible to open the hand without interfering with the surrounding conditions by adjusting the opening stroke of the hand. Also, depending on the part, there may be restrictions on the grasping force of the hand and you want it to be gripped lightly, or there is a risk of the part falling during the hand link if it is not gripped firmly due to its weight. It is an object of the present invention to provide a robot hand suitable for carrying out automatic assembly work by a robot while selecting a corresponding gripping force.

[Summary of the invention]

In order to achieve the above object, the present invention is characterized by a motor that can be controlled externally, a feed screw driven by the motor, a moving piece that moves on the feed screw, and a moving piece that moves on the feed screw. A chuck with a stone supported via a spring which is disposed on the chuck, a moving sensor attached to a part of the chuck, and a moving dog attached to a part of the moving piece. The present invention is characterized in that when the chuck grips a workpiece, a preload force of the strip 11 ring is actuated, and the preload force is applied to the motor as an electric signal from the outside.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

Figure 2 (a), (b) is an example of a hand in which the rotation axis of the pulse motor and the guide rod of the chuck are arranged parallel to each other, and Figures 2 (a), (b), and (C) are examples of the hand in which the rotation axis of the pulse motor and the guide rod of the chuck are arranged parallel. This is an example of a hand in which the rotating shaft of the motor and the guide rod are arranged perpendicularly to each other.

In FIG. 1, l is the housing of the hand, 2 is a motor fixedly installed in the housing 1, for example, a pulse motor, 3 is a shaft 41 of the pulse motor 2, n is attached to the shaft 41, and gears 11. 9. Tensioned with the active pulley.
The driven side boot I+ 6 is rotated via the timing belt 5. Reference numeral 7 denotes a feed screw which rotates together with the driven side boob 116, and has a reverse screw thread that sandwiches the driven side pulley 6. 8A.

8B is screwed into the reverse screw with a nut shape, and is moved along the guide rod 9 with two sets of moving pieces, and the feed screw 7
9. Therefore, when the movable pieces 8A, 8B move, the movable pieces 8A, 8B are rotated so that they do not move. ], O
A and 10B are the stripes 11 rings, 11 is the chuck for grasping objects, and the springs IOA and IOB of the moving pieces 8A and 8B
Z is installed between snap links 12A and 12B against
ll, the other end is slidably fitted into the guide rod 9,
ing. Further, 13 is a moving piece 8A, 8. A stone is fixed to B, and a moving sensor (photoelectric switch) 1, which will be described later, is installed on the moving dock.
4 moves down against the springs IOA and 10B. 14 is attached to a part of chuck IIB and 21. A moving sensor 15a is attached to the housing 1, and a fixed sensor generates an output signal such as an open end of the hand, and a fixed sensor 15b is attached to the housing 1 and generates an output signal such as a closed end of the hand. . In addition, Figure 3 shows an example of a control configuration for driving the chuck 11 of the robot hand, where 20 is a 3-gram controller (hereinafter abbreviated as PC), and 21 is a pulse controller that receives commands from the PC 16. 22 is a driver for power driving the pulse smoke 2.

Next, the operation of the present invention will be explained below. FIG. 4 is a diagram to show the characteristics of the hand, and the third quadrant shows that when the chuck 11 grips the workpiece, the moving pieces 8A and 8B move against the springs OA and IQB at the center of the feed screw 7. Grasping force of the hand when the spring is pressed down (211177
The second quadrant shows the relationship between the gripping force of the hand and the required motor torque.If the closed end of the chuck 11 is CL and the open end is OL, then the chuck 11
When the point where the contact point with the workpiece is set as the workpiece touch point OT, and the most closed end CL is set on the side of the driven pulley 6, the open end OL is the first
The characteristic diagram shown in the figure (illustrating the movement status of one chuck 11).

Now, when the hand is open, the normal position of the chuck 11 is always between the open end OL and the work touch point OT. It moves inward, that is, toward the workpiece touch point OT side. The movement mechanism of the chuck 11 consists of a feed screw 71 with left and right reverse threads screwed into moving pieces 8A and 8B, and a driven side boo 116 fixed at the center of the feed screw 7 being connected to the pulse motor 2 via the timing belt 5. This is done by rotationally driving the main drive pulley 3. Thus, the chuck 11 comes into contact with the side surface of the workpiece at the workpiece touch point (OT). When the chuck 1 is further closed, the spring IOA is released against the chuck 1.

] If the pressing force of OB is applied as a reaction and the spring pushing amount PL is, for example, as shown in the fourth figure) < 1 hm), then the workpiece W! , the gripping force (L) for this is about 6[t] or more, and the motor torque is (approx. 3.50)-cm)
becomes. That is, when a gripping force is applied with the chuck 11 in contact with the workpiece W, the position of the chuck 11 is fixed depending on the dimensions of the workpiece W, but the movable pieces 8A and 8B
When the feed screw 7 is in a rotating state, it moves, so the springs IOA and IOB are compressed, and the gripping force can be selected by selecting the spring pushing amount PLi. He's talented.
The chuck 11 is supported in the moving direction by 2 as shown in FIG.
It has a point support mechanism. 1 point is moving piece 8A...8
Spring B], which slides against OA and IOH, and the back of chuck 11 is attached to snap rings 12A and 12.
At the time when removal is stopped by 13, a spring reaction force GL of, for example, slightly less than 5 [93] is applied to the chuck 11 as illustrated in FIG. Also,
The second point is that the other end of the chuck 11
This slidable insertion facilitates parallel movement of the chuck 11 and improves mechanical strength. Mobile sensor]
4 are fixed to the chuck sliding portion on the guide roller 9 in several cases, and a movable dog 13 for activating the movement sensor 14 is fixedly attached to one end of the movable pieces sA, sB. Therefore, the chuck 11 is the workpiece W.
while holding the moving piece 8A.

As the moving dog 813 continues to move, the moving sensor 14 and the moving dock 13 gradually approach each other, and at a certain point, the moving dog 13 activates the moving sensor 14, and the workpiece W
A gripping confirmation signal indicating that the workpiece is gripped with a predetermined gripping force, that is, a tightening signal for the workpiece is output. This retightening signal is generated when the amount of push-in PL reaches a constant (direct).The gripping force naturally needs to be selected depending on the weight and material of the workpiece, so the number of pulses generated by the pulse motor is adjusted to the workpiece. This is done by selecting the most ideal gripping force suitable for the weight and material.

In the case of the robot hand of this embodiment, one of the workpiece gripping completion signals is a gripping confirmation signal from the movement sensor 14, and the other one is a gripping completion signal from the movement sensor 14.
One is to have an AND condition for the two signals of the pulse end signal of the pulse motor.

Therefore, if either the gripping confirmation signal or the pulse end signal is missing during workpiece handling and the AND condition is not satisfied, it is determined that the workpiece has fallen from the hand, and a stop signal is automatically transmitted to the robot. be done.

The characteristics of the first quadrant in Figure 4 are spring 1°A, I.
This varies depending on the design conditions of the OB, and similarly, the motor torque in the characteristics of the second quadrant also naturally changes depending on the motor characteristics.

FIG. 2 shows another embodiment of the present invention, in which the same parts as in FIG. 1 are designated by the same reference numerals. In particular, although FIGS. 1 and 2 are similar to FIG. 4 in terms of characteristics, they differ in the motor torque transmission mechanism. In other words, in Fig. 1, the motor shaft and the feed screw 7 of the chuck 11 are arranged in parallel, and rotational torque is transmitted between them by a timing belt, whereas in Fig. 2, the feed screw 7 is directly connected to the motor shaft. The two rods 71 guiding the chuck 11 are disposed perpendicular to the idle rods 91 and 92, so that the movable piece 81 screwed into the feed screw 71 moves up and down due to the rotation of the motor. Moving. Figure 2 (b), (C) shows the tightening groove of the workpiece.
It was shown to. 16 is a movable rod attached to the movable piece 81 by the screw 17, 18 is a fixed rod attached by the screw pin 19 on the side surface of the sliding part of the kite rod 91, 92 of the chuck 11, and the spring 10A (or IQB) It is mounted by pressing between the movable rod 16 and the fixed rod 18. If the chuck 11 can grip the workpiece, the feed screw 7
1 and move the moving piece 81 upward in the case shown. When the chuck 11 comes into contact with the workpiece, the stone 5
The above movement of the chuck 11 is impossible. However, the motor 2 continues to be driven, so the moving piece 8] (now moves. The movement of the moving piece 81 - 2) ζ compression is carried out by Ruko♂.Thus, when the 1st drive of 2 stops and descends, '7-ri ζ vs. Rumasu)
The gripping force of the claw 11 is given by the compressive force of the sub-1 ring. Of course, although not shown, the movement of the moving rod 6 is detected by the sensor ζ as a feed increase signal.

Further, FIG. 3 shows an example of a control system for a main bot node. Naturally, when a workpiece W is given, the dimensions and material of the gripping portion, and the gripping force associated with the weight of the workpiece are determined, so an HCD output signal is transmitted from the program controller 20 to the pulse generator. That BCD
The pulse transmitter that receives the signal converts the signal into a serial pulse number and transmits it to the driver 221, and the pulse motor 2 is driven by the drive signal from the driver 22.
Ru. When the motor is driven and the chuck 11 grips the workpiece W and a predetermined gripping force is applied, a sense-up signal from the movement sensor 14 is fed back to the block controller 20 (n5), and at the same time, the pulse generator 21 outputs a pulse end signal. A signal is given to the controller 20 at the same time. In this way, the block controller 20 considers that gripping is completed upon the AND condition of the sense up signal and the pulse end signal, and moves on to the next sub-stub operation. The hand opening photon signal is generated with only the pulse end signal, and the program controller moves to the next step operation.

〔Effect of the invention〕

As described above, according to the present invention, the IE opens and closes the chuck using a motor whose rotation amount can be controlled from the outside as a drive source,
Even if the chuck touches the workpiece, the motor is still driven.

11 is compressed, and the gripping force of the hand is increased by 4 by the compressive force of the streak 11 ring. At the same time, when the compressive force is generated in the spring, the sensor is activated to generate an increase signal, so the amount of opening and closing of the chuck is controlled by the amount of workpiece. Since it can be selectively opened and closed arbitrarily and at high speed depending on the dimensions and the ambient conditions of the work tower, high-density mounting of assembled parts is possible.

Also, while the work hand is being linked, the sensor signal that detects the compression of the spring is continuously output, so if the work is dropped midway, the sensor signal will be cut off. Since it is possible to stop the robot operation by using this function, it is a fail-safe operation. Furthermore, the amount of spring push-in can be varied by the pulse number selection function of the pulse motor, which reduces the weight of the workpiece.

It has a very quick and effective effect, as it allows you to reliably grip the workpiece with any gripping force depending on the material.

[Brief explanation of drawings]

FIG. 1 is a mechanical diagram showing one implementation of the present invention;
Figure 1(a) is a cutaway front view, Figure 1(b) is a front view of Figure 1(a).
)f lb-, shown by cutting along the lb line, and Fig. 2 shows another embodiment of the present invention. Figure 2(b) and 2nd
Figure (C) shows the tightening mechanism part of Figure 2 (a) extracted (
Figure 3 is a system diagram showing one embodiment of the side leg system of the load hand, Figure 4 is the tightening machine groove and
It is a characteristic diagram showing an example of a bar. 1: Housing, 2: Pulse motor, 3: Driving side pulley, 5: Soimink belt, 6: Follower (ill). -ri, 7: Feed screw, 8A, 813: Moving piece, 9 Ni guide JOB varnish blink, 11; chuck, 13: mobile dock, 14: mobile sensor, 15:
Fixed sensor, 16: Moving rod, 18: Fixed rod No. 2 Fig. IQ small f (Tl Fig. 3 Fig. 4 Fig. J)

Claims (1)

[Claims] 1. A motor that can be controlled externally, a feed screw driven by the motor, a moving piece that moves down on the feed screw, and a moving piece that is placed on the moving piece and has a preload. A chuck supported via a spring, a movement sensor attached to a part of the chuck, and a moving dog (!-) attached to a part of the moving piece are provided, and the chuck is connected to the workpiece. A robot hand characterized in that when gripping the moving piece, a preload force of the spring is actuated, and the preload force is applied as an electric signal from outside the motor.2. The chuck is supported by applying a preload, a movement sensor is attached to a part of the chuck, and a moving dog is attached to a part of the moving piece, and when the chuck grips a workpiece, the moving piece is moved by a spring. When the moving sensor and the moving dock are in the operating state, when an abnormal condition occurs in which the workpiece is removed, the workpiece is removed. 2. The robot hand according to claim 1, wherein said movement sensor monitors said movement sensor and generates an output signal.