JPH0547352B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a grinding robot.

"Prior Art" In recent years, grinding robots that automatically grind materials to be ground have been employed in various industrial fields.

A conventional grinding robot of this type is disclosed in, for example, Japanese Patent Application Laid-Open No. 58-90461.

In the grinding robot (grinding unit) described in this publication, a coil spring is used as a means for adjusting the contact pressure of the grinding wheel against the material being ground.

``Problems to be Solved by the Invention'' By the way, as mentioned above, when a coil spring is used as a means for optimizing the contact pressure of the grinding wheel against the material to be ground, it is difficult to directly apply the grinding wheel to the surface of the material to be ground. Unless you make contact with it, you won't know how much load it is under, and there is a risk of damaging the grinding wheel.

Moreover, in the case of the grinding robot described in the above-mentioned publication, no consideration has been given to a means for detecting the wear of the grinding wheel, and the necessary minimum outer diameter of the grinding wheel cannot be determined, which is extremely dangerous. .

"Means for Solving the Problems" The present invention has been made to solve the problems of the conventional art as described above, and its gist is to constantly reduce the contact force of the grinding wheel against the material to be ground. The purpose is to maintain it at an appropriate value and grind it.

"action" The operation of the present invention will be explained based on FIG.

First, teach the finished shape of the material to be ground to the robot, then measure the shape of the material to be ground, then measure the outer diameter of the grinding wheel, and then compare the taught finished shape and the actual shape of the material to be ground. Grind based on the difference in shape.

On the other hand, measure the time required for grinding, and when the predetermined time is reached, measure the amount of wear on the grinding wheel again, compare the finished shape and the actual shape, continue grinding until they match, and if they match, start grinding. to stop.

``Embodiment'' As shown in FIGS. 2 and 3, a motor 3 and a grinding wheel 4 attached to the rotating shaft of the motor 3 are installed at the tip of an arm 2 that is controlled to move forward and backward, elevate, turn, and rotate. In the grinding robot 1 which automatically grinds the surface of the workpiece W, the surface of the workpiece W is supported on the lower surface of the motor 3 at a predetermined position from the axis of the grinding wheel 4 at a predetermined position. As shown in FIG. 4, a current detector 6 for detecting the load current of the motor 3 is provided in the power supply circuit of the motor 3. Compare the distance measurement value from the current detector 6 with the target distance setting value, and grind until the comparison value becomes zero, and compare the load current detection value from the current detector 6 with the reference load current setting value, A comparison calculation controller 7 is provided to control the arm 2 to adjust the contact force of the grinding wheel 4 to the workpiece W to be ground until the comparison value becomes zero, and the grinding wheel when the load current is detected by the current detector 6 is provided. 4 and the initial distance measurement value by the distance meter 5.
A controller 8 is provided which calculates the outer diameter of the grinding wheel 4, compares it with the required minimum outer diameter setting value of the grinding wheel 4, and stops grinding and displays an alarm when the outer diameter is less than this set value.

Note that as the non-contact distance meter 5, a laser distance meter, an eddy current distance meter, or the like may be used.

Thus, the material to be ground W is transferred to the grinding robot 1.
Therefore, when grinding to obtain the target shape, first, the finished shape of the material to be ground W after grinding is
Teach the robot automatic control device (not shown).

Next, the distance between the surface of the workpiece W supported at a predetermined position by an arbitrary support means (not shown) and the axis of the grinding wheel 4 at the predetermined position is determined by a non-contact distance as shown in FIG. 5, the measured value is used as an input signal to the comparison calculation controller 7, and the target distance setting value preset in the comparison calculation controller 7 is compared with the distance measurement value. Grind until the value is zero.

Note that when grinding, the tip of the arm 2 is placed in the third position so that the distance meter 5 does not interfere with the material W to be ground.
Rotate 180° as shown in the figure.

On the other hand, the load current of the motor 3 during grinding is detected by the current detector 6, and the detected value is used as an input signal to the comparison calculation controller 7. The arm 2 is controlled via the comparison calculation controller 7 to compare the current set value and the detected load current value, and adjust the contact force of the grinding wheel 4 to the workpiece W until the comparison value becomes zero. control.

Furthermore, the information on the axis center position of the grinding wheel 4 when the load current is detected by the current detector 6 and the initial distance measurement value by the distance meter 5 are input signals to the controller 8, and the outer diameter of the grinding wheel 4 is determined. At the same time, the controller 8 compares the required minimum outer diameter of the grinding wheel 4 with a set value preset in the controller 8, and when the outer diameter is less than this set value, the material to be ground is stopped and an alarm is displayed.

"Effects of the Invention" As described above, according to the grinding robot of the present invention, grinding can be carried out while maintaining the contact force of the grinding wheel against the workpiece at an appropriate value at all times, thereby extending the life of the grinding wheel. It can be extended longer than before.

In addition, since the wear status of the grinding wheel can be checked at all times, it is possible to prevent the grinding wheel from being used in a dangerous state where the outer diameter is less than the necessary minimum diameter.

[Brief explanation of the drawing]

FIG. 1 is a flow chart showing the operation of the present invention;
Fig. 2 shows an embodiment of the grinding robot of the present invention, and is an explanatory diagram showing a distance meter measuring the distance between the material to be ground and the axis of the grinding wheel, and Fig. 3 shows an example of the robot grinding the material to be ground. FIG. 4 is a control block diagram for adjusting the contact force of the grinding wheel against the material to be ground and calculating the outer diameter of the grinding wheel. 1... Grinding robot, 2... Arm, 3... Motor, 4... Grinding wheel, 5... Non-contact distance meter, 6... Current detector, 7... Comparison calculation controller, 8... Controller.

Claims (1)

[Claims] 1. In a grinding robot that automatically grinds the surface of a material to be ground, which is equipped with a motor and a grinding wheel attached to the rotating shaft of the motor at the tip of an arm that is controlled to move back and forth, elevate, turn, and rotate. , a non-contact distance meter is provided on the lower surface of the motor to measure the distance from the axis of the grinding wheel at a predetermined position to the surface of the workpiece supported at a predetermined position; A current detector is provided to detect the load current of the current detector, and the distance measurement value from the distance meter is compared with the target distance setting value, and the grinding is performed until the comparison value becomes zero. A comparison calculation controller is provided that controls the arm to compare the detected load current value and the reference load current setting value and adjust the contact force of the grinding wheel to the workpiece until the comparison value becomes zero, and The outer diameter of the grinding wheel is calculated from the axial center position information of the grinding wheel when the load current is detected by the detector and the initial distance measurement value by the distance meter, and is compared with the required minimum outer diameter setting value of the grinding wheel. A grinding robot characterized in that it is provided with a controller that stops grinding and displays an alarm when the value is less than the set value.