JPH0318132Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a grinding overload prevention device and is intended to prevent damage to a grinder.

<Conventional technology> Currently, industrial robots are widely used in factories, etc., and deburring work from castings, which used to rely on the skill and hard labor of workers, has come to be performed by industrial robots. ing. In order to remove burrs efficiently, it is necessary to keep the grinder attached to the arm of the industrial robot at high rotational speed.
Therefore, adaptive control is performed in which the arm feed speed is increased when the burr is small, and conversely, when the burr is large, the arm feed speed is slowed down to prevent the rotation speed from decreasing due to grinding resistance. In other words, as shown in FIG. 5, when grinding the burr 3a of the grinding work 3 with the grinder 2 attached to the arm 1a of the industrial robot 1,
A current sensor 5 detects the grinder current supplied from the grinder power source 4 to the grinder 2, and inputs the detected value to the microcomputer 7 via the A/D converter 6. After comparison, the robot controller 8 controls the robot 1 so that the two match. Since the feed speed of the arm 1a is controlled so that the grinder current remains constant, the grinder 2 can always exhibit its maximum grinding ability.

<Problems to be solved by the invention> By the way, in the above conventional technology, due to the response delay of the robot controller 8 and the delay in the change of the grinder current, the above-mentioned adaptive control is delayed (several tens of milliseconds to several tens of milliseconds).
100ms) was hot. Therefore, if a large burr suddenly appears, the adaptive control will not be able to keep up with it, and the rotational speed of the grinder 2 will decrease due to grinding resistance, reducing grinding efficiency. Furthermore, the grinding wheel of the grinder will become stuck in the burr and be damaged. Something happened.

SUMMARY OF THE INVENTION In view of the above-mentioned prior art, it is an object of the present invention to provide a grinding overload prevention device that can prevent damage to a grinder and further increase the grinding efficiency.

<Means for Solving the Problems> The present invention which achieves the above object is equipped with a slide mechanism consisting of a slide base and a slider between the arm of the industrial robot and the grinder, and normally the slider is moved by the spring force of the spring. is restrained to the slide base, and when an excessive force is applied, the spring is elastically deformed and the slider slides relative to the slide base.

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

Fig. 1 is a front view showing the present invention, Fig. 2 is a front view showing the main parts thereof, Fig. 3 is a plan view showing the main parts without the balancer, and Fig. 4 is a plan view showing the main parts without the balancer. FIG. As shown in these figures, in this embodiment, a slide base 10 is attached to the tip of the arm 1a, and a slider 1 is attached to this slide base 10 via a slide guide 11.
2 is slidably attached. Spring 1
3 has one end engaged with a spring hook 14 fixed to the slide base 10, and the other end engaged with a spring hook 15 fixed to the slider 12. Therefore, the slider 12 normally has the spring 1
3 is pressed against the vibration isolating rubber 16 fixed to the slide base 10. The slider 12 supports a grinder 2 having a grindstone 2a via connecting members 17a and 17b. On the other hand, the slider 12 is equipped with dogs 18a and 18b, and the slide base 10 is equipped with limit switches 19a and 19b. Further, a shock absorber 20 is interposed between the slide base 10 and the slider 12. The balancer 21 has its fulcrum 21a rotatably supported by the slide base 10, and its fulcrum 21b rotatably supported by the slider 12. In this embodiment, the arm 1a is moved along the sliding direction of the slider 12. In this embodiment, when the burr 3a is small, the grinding force acting on the slider 12 through the grinder 2 is small, so the slider 12 is biased by the spring force of the spring 13 and restrained by the slide base 10. In this normal state, the burr 3a is efficiently ground by the adaptive control of the industrial robot 1.
On the other hand, when grinding a large burr 3a, the grinding force acting on the slider 12 through the grinder 2 increases, and when this exceeds a certain set value, the slider 12 slides against the slide base 10 against the spring force of the spring 13. do. When there is a large burr 3a in this way, the arm 1a is fed, but the slider 12 slides in the direction opposite to the feeding direction of the arm 1a with respect to the slide base 10, so the feeding speed of the grinder 2 decreases or the feeding speed becomes zero. Therefore, the grinding resistance of the grinding wheel 2a of the grinder 2 becomes large, and the grinding wheel 2a of the grinder 2 increases.
It is also possible to prevent a from getting stuck. After a while, the adaptive control of the robot 1 causes the large burr 3a to be removed.
The feed speed of the arm 1a is controlled so as to correspond to this, and the extended spring 13 is compressed and the slider 12 is restrained by the slide base 10. When the slider 12 starts sliding, the dog 18a turns on the micro switch 19a, and a turning signal indicating the start of the slider is sent to the controller. Furthermore, slider 12
If the spring 13 is stretched too much, the dot 18
b turns on the micro switch 19b, and when a turn-on signal instructing this emergency stop is sent to the controller, the robot 1 comes to an emergency stop.
Furthermore, when the slider 12 slides to the right, the balancer 21 rotates to the left about the fulcrum 21a, and even if the slider 12 slides to the left, when it returns to this position, it rotates to the right about the fulcrum 21a. and return to an upright position. In this way, the balancer 21 rotates in accordance with the slide of the slider 12, so that the entire balance can be maintained.

<Effects of the invention> As explained in detail with the embodiments above, according to the invention, the control delay when grinding large burrs is absorbed by the elastic deformation of the spring, thereby maximizing the ability of the grinder. This increases grinding efficiency, prevents overload from being applied to the grinder's grinding wheel, prevents the grinding wheel from becoming wedged, prevents damage to the grinding wheel, and extends the life of the grinding wheel.

[Brief explanation of the drawing]

Fig. 1 is a front view showing an embodiment of the present invention, Fig. 2 is a front view showing the main parts thereof, Fig. 3 is a plan view showing the main parts without the balancer, and Fig. 4 is a front view showing the main parts without the balancer. FIG. 5 is a side view showing the main parts, and FIG. 5 is a configuration diagram showing the prior art. In the drawing, 1 is an industrial robot, 1a is an arm,
2 is a grinder, 2a is a grindstone, 3a is a burr, 10
12 is a slide base, 12 is a slider, and 13 is a spring.

Claims (1)

[Claim for Utility Model Registration] A grinder is attached to an arm of an industrial robot, and the arm is sent so that the grinding direction of the grinder is parallel to the grinding surface of the workpiece to be ground, and the grinder current flowing through the grinder is constant. A grinding overload prevention device provided in a mechanism for controlling the feed rate of the arm so that A spring force is applied to the slider in the direction along the arm's feeding direction to restrain the slider against the slide base under normal conditions, and when an excessive force in the direction opposite to the arm's feeding direction is applied to the slider, the spring force is applied to the slider. A spring that deforms and allows the slider to slide relative to the slide base in the opposite direction to the arm feed direction, and a spring that detects the relative movement of the slider relative to the slide base, and outputs a signal indicating the start of the slide when the relative movement starts. A grinding overload prevention device comprising: a switch mechanism that outputs a signal instructing an emergency stop when the amount of relative movement exceeds an upper limit value.