JPH0357421Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a grinding tool control device that is used in machine tools, robots, etc. and controls the pressing force of a grinding tool such as a grindstone against a workpiece. be.

[Prior art] Conventionally, in order to obtain the target amount of grinding, this type of device has used a method that uses the difference between the weight of the grinding wheel, etc., and the force of the actuator that lifts the grinding wheel to be applied to the workpiece, regardless of the posture of the grinding wheel. What is set as a force is known. That is, if the target grinding amount is the same, the lifting force of the actuator is set constant regardless of the attitude of the grindstone.

[Problems to be solved by the invention] However, when the grinding wheel is driven three-dimensionally along the curved surface of the workpiece, the pressing force changes depending on the attitude of the grinding wheel, and the target amount of grinding cannot be achieved with high precision. There was a problem that it could not be achieved.

[Means for solving the problem] The present invention was made to solve the above problem.
As shown in FIG. 1, an air cylinder applies a lifting force to generate a desired pressing force on a disc-shaped grinding tool m2 attached to a rotating shaft m1 perpendicular to the surface to be ground of the workpiece. The lifting force is variably controlled with respect to m3, and the grinding tool m2
This is a control device for a grinding tool that three-dimensionally controls the movement of the grinding tool m2, and the pulling force WcosA based on the own weight of the grinding tool m2 acts in the biasing direction of the air cylinder m3 from the own weight W and attitude angle A of the grinding tool m2. A lifting force calculation in which the pressing force F of the grinding tool m2, which is uniquely determined from the target grinding amount of the workpiece, is subtracted from the pulling force WcosA is calculated as the lifting force FS of the air cylinder m3. and a control means m5 for driving the air cylinder m3 based on the calculation result of the lifting force calculation means m4.

[Function] The target grinding amount of the workpiece is as shown in Figure 2.
It is uniquely determined by the pressing force of the grinding tool. Therefore, in order to obtain the target amount of grinding, it is necessary to control the pressing force of the grinding tool with high precision so that the pressing force is a predetermined pressing force.

In the present invention, the lifting force calculation means m4 calculates the lifting force FS=WcosA−F of the air cylinder m3 from the dead weight W and attitude angle A of the grinding tool m2, and the control means m5 calculates this lifting force. FS=
Air cylinder m3 is driven based on WcosA-F. Therefore, when grinding a curved surface or the like with the grinding tool m2, it is possible to always grind with a constant amount of grinding, and it is possible to perform grinding according to the target amount of grinding with high accuracy.

In addition, the disc-shaped grinding tool m2 is attached to the rotating shaft m1 perpendicular to the surface to be ground of the workpiece, and the lifting force is applied by the air cylinder m3 that also functions as a damper. During grinding, good adhesion between the grinding tool m2 and the surface to be ground of the workpiece is maintained, and no vibration is generated.

For example, if the grinding tool is configured to be biased by a coil spring, as in the device described in Japanese Patent Application Laid-open No. 55-164464, there may be a problem of vibration due to resonance of the coil spring. Further, when the apparatus described in this publication is configured to grind a workpiece with the circumferential surface of a disc-shaped grindstone, the adhesion to the workpiece becomes poor and vibrations are likely to occur.

In addition, in the device described in this publication, the posture is controlled as a posture, the pressing force is controlled as a pressing force, and a configuration is adopted in which the pressing force and posture are kept constant through feedback control. Feedback control of the pressing force means controlling the pressing force by increasing and decreasing it around an optimum value, which results in excessive control and further aggravates vibrations.

The present invention calculates and controls the lifting force of the air cylinder through calculations, and is not limited to copying grinding devices in particular, so there is no need to perform such feedback control. It is. The fact that such feedback control is not performed is also an important configuration in achieving the remarkable effect of preventing vibrations from occurring.

[Example] An example of the present invention will be described below with reference to the drawings. In FIG. 3, reference numeral 1 denotes a so-called gate-shaped processing machine main body, and a beam 5 that can be moved in the vertical direction spans a gate-shaped support 3, and a head 7 wraps around the beam 5. It is provided. Below this head 7 is a pallet 10 on which a workpiece 9 is placed.
is provided, and the pallet 10 is movable in the front and back directions of the page by a moving table 12.

As shown in FIG. 4, a grindstone 24 as a polishing tool is attached to the head 7 and is moved up and down by an actuator 22 via an attachment 20. The actuator 22 is composed of a piston, a cylinder, and a spring driven by air pressure.

Three-dimensional movement control of the grindstone 24 and control of the pressing force of the actuator 22 are performed based on commands from the control device 30. That is,
The control device 30 includes an input section 31, a main CPU 32,
1st to 6th axis CPU41 which calculates and controls 1st to 6th axes
46, a 6-axis regulator controller 50 that operates according to commands from the CPU 46, an electropneumatic regulator 52 that converts electrical signals to pneumatic pressure, and a pneumatic regulator 54 that converts pneumatic pressure to electrical signals.

Next, the operation will be explained.

In the following explanation, numbers shown in brackets indicate processing steps in the flowchart of FIG. In the input section 31 shown in FIG.
Data is sent to the CPU 32. CPU32 is 6
Distribute each axis data (110), each CPU41 ~
Send to 46. The 1st to 5th axes CPUs 41 to 45 process the given data (210) to (250), operate each axis, and perform the 5th axis operation of the machine body (310).
~(350). At the same time, the 6-axis CPU 46 has
The data on the pressing force F and the vertical attitude angle A of the grindstone 24 are sent, and the lifting force of the actuator 22 is calculated based on these data (400). That is, as shown in FIG.
The dead weight of the 4th grade is W, and the lifting force of the actuator 22 is
FS, the lifting force FS can be found as FS=WcosA−F.

This control signal for the lifting force FS is sent to the regulator controller 50 (410), and the controller 50 operates the electropneumatic regulator 52 in response to the control signal (420). As a result, the actuator 22 driven by the regulator 52
The cylinder generates a lifting force FS (430).

Therefore, according to the above configuration, even if the grindstone 24 moves along the curved surface of the workpiece 9 and the attitude of the grindstone 24 is tilted, the lifting force of the actuator 22 is maintained to keep the pressing force F on the workpiece 9 constant. controlled. Therefore, the target grinding amount can be achieved with high accuracy.

Note that the pressure applied to the actuator 22 is converted into an electrical signal by the pneumatic regulator 54, and the
By executing feedback control in step 46, the accuracy of the target grinding amount can be further improved.

In addition, as a means of feedback control, a strain gauge is installed on the rotating drive shaft of the grinding wheel, and this detection signal is input to the CPU via a dynamic strain meter and an A/D converter to directly control feedback and improve accuracy. You can also do that.

[Effect of the invention] As explained above, according to the invention, the lifting force of the air cylinder can be calculated from the weight and attitude angle of the grinding tool, and the air cylinder can be driven to obtain a constant pressing force. Therefore, even when grinding and finishing a curved surface, etc., it is possible to always grind at a constant amount of grinding, and grinding can be performed in accordance with the target amount of grinding with high accuracy.

In addition, in addition to attaching a rotating shaft perpendicular to the grinding surface of the workpiece to the disc-shaped grinding tool and applying lifting force using an air cylinder that also functions as a damper, Since it is not a feedback control, it is possible to maintain good adhesion between the grinding tool and the surface to be ground of the workpiece during grinding, and vibrations are not generated. As a result, grinding can be performed with extremely high precision.

[Brief explanation of the drawing]

Figure 1 is a schematic configuration diagram showing the configuration of the present invention;
The figure is a graph explaining the operation of the present invention, Figure 3 is a schematic diagram of an embodiment of the invention, Figure 4 is an explanatory diagram showing the main parts of the embodiment, and Figure 5 is a flowchart of the embodiment. It's a chat. m2, 24...Grinding tool (grindstone), m3, 22
...Air cylinder, m4, 32... Lifting force calculation means (main CPU), m5, 30... Control means.

Claims (1)

[Scope of Claim for Utility Model Registration] For an air cylinder that applies a lifting force to generate a desired pressing force on a disc-shaped grinding tool attached to a rotating shaft perpendicular to the surface to be ground of a workpiece. A grinding tool control device that variably controls the lifting force and three-dimensionally controls the movement of the grinding tool, which acts in the biasing direction of the air cylinder from the weight and attitude angle of the grinding tool. The pulling force based on the own weight of the grinding tool is determined, and the pressing force of the grinding tool, which is uniquely determined from the target grinding amount of the workpiece, is subtracted from the pulling force, and the result is calculated as the lifting force of the air cylinder. A control device for a grinding tool, comprising: a lifting force calculation means; and a control means for driving the air cylinder based on the calculation result of the lifting force calculation means.