JPH04203544A - Balance correcting device for rotary body - Google Patents

Abstract

PURPOSE:To correct balance with high precision in a short time in the state where a rotary body is stabilized, by arranging an electric discharge electrode, keeping a prescribed gap from a dummy weight and installing an electric discharge generating device for generating electric discharge in the gap between the dummy weight and the electric discharge electrode. CONSTITUTION:When a grinding wheel 9 is revolved by revolving a main shaft 3 of a grinder, the accelerating speed pick-up 20 of a grinder head detects the vibration generated on the whole of the grinder, and a control circuit 19 for an electric discharge generating device 16 specifies the max. vibration quantity of the grinding wheel 9 and the imbalance position generated by the max. vibration quantity, on the basis of the vibration signal. The control circuit 19 outputs the control signal into a pulse generating circuit 18 slightly before the imbalance position of the grinding wheel 9 reaches above the electric discharge electrodes 18a and 18b, and the pulse generating circuit 18 outputs the prescribed pulse wave form to the electric discharge electrodes 18a and 18b, on the basis of the control signal. Then, electric discharge is generated in the gap between the electric discharge electrodes 18a and 18b and a dummy weight 11 on the basis of the pulse wave form, and the outer peripheral surface of the dummy weight 11 is cut by this electric discharge.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a balance correction device for correcting unbalance of a rotating body.

[Prior Art] Conventionally, when grinding a workpiece by rotating a grinding wheel of a grinding machine, the surface roughness accuracy of the machined surface can be improved by balancing the grinding wheel. In other words, the grinding accuracy of the workpiece can be improved.

Therefore, the grindstone is often statically balanced without being rotated. In addition, when balancing the whetstone while it is rotating, a dummy weight with an unbalanced amount is provided with respect to the whetstone, and this dummy weight is cut with a cutting tool to balance the whetstone. ing.

[Problem to be solved by the invention] However, even if the balance is statically maintained without rotating the whetstone, the balance may be lost when the whetstone is rotated, and it takes time to balance the whetstone while it is rotating. There is a problem that it takes.

Furthermore, cutting the dummy weight with a cutting tool applies an external load to the rotation of the grindstone, which causes the grindstone to rotate unstablely during balance adjustment, resulting in the problem that balance adjustment takes time. Furthermore, since there is a limit to increasing the driving speed of the cutting tool, there is a problem that the faster the grindstone rotates, the more inappropriate the balance correction by the cutting tool becomes.

An object of the present invention is to be able to perform highly accurate balance correction in a short time, to perform balance correction while keeping a rotating body stable, and to easily perform balance correction for a rotating body that rotates at high speed. An object of the present invention is to provide a balance correction device for a rotating body.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a dummy weight made of a conductor having an unbalanced amount with respect to a rotating body, and also provides a dummy weight having a predetermined gap with respect to the dummy weight. The gist of the invention is that a discharge electrode is provided, and the discharge electrode is provided with a discharge generating device that generates a discharge in a gap between the dummy weight and the discharge electrode.

[Operation] Therefore, a discharge is generated in a predetermined gap provided between the dummy weight and the discharge electrode by the discharge generator,
This electric discharge allows the dummy weight to be cut in a non-contact manner to correct the balance of the rotating body.

[Example] Hereinafter, an example embodying the present invention will be described based on the drawings.

As shown in FIGS. 1 and 2, a main shaft 3 is rotatably provided on a grindstone head 2 of a grinding machine (not shown). A tapered portion 3a is provided at the tip of the main shaft 3, and a grindstone flange 4 is fastened and fixed along this tapered portion 3a.

That is, the grindstone flange 4 is formed with a through hole 5 that abuts the tapered portion 3a of the main shaft 3, and the main shaft 3 is inserted therethrough. The grindstone flange 4 is fastened to the main shaft 3 by a nut 6 screwed onto the tip of the main shaft 3. The grindstone flange 4 is composed of a projecting portion 4a and a cylindrical portion 4b, and the cylindrical portion 4b includes the
A recess 7 is formed in which the cylinder 6 is housed, and a male thread 8 is carved on the outer circumferential surface of the cylindrical portion 4b.

Further, a grindstone 9 as a rotating body is inserted through the cylindrical portion 4b of the grindstone flange 4, and one side of the grindstone 9 is in contact with the protruding portion 4a of the grindstone flange 4. A grindstone flange 10 is screwed onto a male thread 8 carved in the cylindrical portion 4b of the grindstone flange 4, and the grindstone 9 is attached to the grindstone flange 4. It is attached and fixed to the main shaft 3 by IO.

Further, a dummy weight ll screwed onto the external thread 8 of the cylindrical portion 4b of the grindstone flange 4 is fastened and fixed so as to abut against the side surface of the grindstone flange 10. A through hole 12 is provided in the outer peripheral portion of the dummy weight 11 (see FIG. 3) to provide an unbalance amount.

On the other hand, a slide mechanism 13 is provided above the grindstone head 2, and this slide mechanism 13 is driven by a motor 14 adjacent thereto. A lift mechanism 15 is placed on the top of the slide mechanism 13, and the lift mechanism 15 is configured to slide horizontally by the slide mechanism 13.

Further, a discharge generating device 16 which is in a horizontal state is supported by the lifting mechanism 15 in a state where it projects toward the grindstone 9 side.

A motor 1 provided at the top of the lifting mechanism 15
7, the discharge generating device 16 is moved up and down via a lifting mechanism 15.

As shown in FIG. 1.3, a pair of discharge electrodes 18a and 18b are provided on the lower surface of the tip of the discharge generator 16 (see FIG. 1).
The discharge electrodes 18 a +18b are disposed with a predetermined gap on the outer peripheral surface of the dummy weight 11 screwed onto the cylindrical portion 4b of the grindstone flange 4.

The discharge generating device 16 is composed of a pulse generating circuit 18 and a control circuit 19, and each of the motors 14, 17 and an acceleration pickup 20 provided in the grinding wheel head 2 are connected to the control circuit 19. .

The acceleration pickup 20 detects vibrations of the entire grinding machine while the grindstone 9 is rotated by the main shaft 3, and outputs a vibration signal to the control circuit 19. and,
The control circuit 19 determines the balanced state based on the vibration signal from the acceleration pickup 20, that is, the maximum amount of vibration of the grinding wheel 9 and the unbalanced position where it occurs.
It is designed to specify which

Then, calculate which part of the dummy weight 11 and how much to cut, and based on this calculation result, the discharge electrode 18
The discharge current value, discharge pulse width, etc. of the pulse waveform for a and 18b are calculated, and the motors 14 and 17 are driven and controlled to generate the discharge electrode 18a.

The gap between 18b and dummy weight 11 can be adjusted.

That is, based on the results calculated by the control circuit 19, a predetermined square wave pulse waveform as shown in FIG. 4 is outputted from the pulse generation circuit 18 to the discharge electrodes 18a and 18b. Then, by this pulse waveform, the discharge electrode 18a
, '18b are generated to cut the outer circumferential surface of the dummy way) 11.

In this embodiment, the control circuit 19 is configured to output the pulse waveform so that the discharge electrodes 18a and 18b discharge the dummy weight 11 when the pulse waveform is output at the same position as the unbalanced position or at a position slightly earlier than the unbalanced position. The pulse generating circuit 18 is controlled.

Further, the discharge electrodes 18a, 18b are made of copper or graphite, and the dummy weight 11 is the discharge electrode 18a.
, 18b, so aluminum and steel are used.

Next, the operation of the balance correction device configured as described above will be explained.

When the main shaft 3 of the grinding machine is rotated to rotate the grindstone 9, the acceleration pickup 20 of the grindstone head 2 detects vibrations generated in the entire grinding machine. Then, the control circuit 19 of the discharge generator 16 specifies the maximum amount of vibration of the grindstone 9 and the unbalance position where it occurs based on the vibration signal of the acceleration pickup 20.

Next, the control device 19 calculates how much to remove the unbalanced position of the dummy weight 11, and calculates the discharge current value, discharge pulse width, etc. to be output to the discharge electrodes 18a and 18b based on the calculation result. to be determined.

The control circuit 19 controls the motors 14 and 17 to drive the discharge generating device 16 by the sliding mechanism 13 and the lifting mechanism 15. and a discharge electrode 18a provided in the discharge generator 16.

The gap between 18b and dummy weight 11 is adjusted.

In this state, the control circuit 19 outputs a control signal to the pulse generation circuit 18 shortly before the unbalanced position of the grinding wheel 9 reaches the discharge electrodes 18a, 18b, and the pulse generation circuit 18 generates a predetermined pulse based on the control signal. The waveform is output to discharge electrodes 18a and 18b. Then, based on the pulse waveform, a discharge is generated at the tips of the discharge electrodes 18a, 18b, that is, in the gap between the discharge electrodes 18a, 18b and the dummy weight 11, and the outer peripheral surface of the dummy weight 11 is cut by this discharge. .

Therefore, by controlling the control circuit 19 in the discharge generating device 16 to generate discharge in the discharge electrodes 18a and 18b and repeatedly cutting the outer circumferential surface of the dummy weight 11, the mass at the unbalanced position becomes lighter. The balance can be corrected.

As a result, the dummy weight 11 is cut by the discharge electrode 18a.
, 18b, that is, the dummy weight 11 can be cut in a non-contact state. Therefore, since no external load is applied to the dummy weight 11, the balance can be corrected in a state of stable rotation. Since the balance is corrected while the grindstone 9 is being rotated, the balance correction time can be shortened.

Furthermore, since the discharge speed of the pulse waveform is sufficiently faster than the speed at which the grindstone 9 rotates once, the balance of the grindstone 9 which rotates at high speed can be easily adjusted.

Furthermore, the amount of cutting of the dummy weight 11 can be adjusted by the pulse waveform output from the pulse generation circuit 18. In other words, by increasing the discharge current value and the discharge current pulse width, the amount of cutting of the dummy weight 11 can be increased, and by decreasing the discharge current value and the discharge current pulse width, the amount of cutting of the dummy weight 11 can be increased. Can be made smaller.

Therefore, highly accurate balance correction can be achieved by increasing the discharge current value and discharge current pulse width when the unbalance amount is large, and decreasing the discharge current value and discharge current pulse width as the unbalance amount decreases.

Further, the grinding wheel 9 is
Since the balance can be corrected by discharging twice before rotation, the balance correction time can be shortened. Therefore, it is also possible to provide a large number of discharge electrodes.

Furthermore, since the dummy weight 11 is simply screwed onto the cylindrical portion 4b, the dummy weight 11 can be easily replaced.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and may be modified as follows without departing from the spirit of the present invention.

As shown in FIG. 5, it is also possible to carve a male thread 21 on the main shaft 3 near the grinding wheel head 2, and to screw the dummy way 11 onto this main shaft 3.

Further, in this embodiment, a pair of discharge electrodes 18a, 18
b, but it is also possible to provide only one discharge electrode 18a and generate a discharge in the gap between the discharge electrode 18a and the dummy weight 11 to cut the dummy weight 11 and correct the balance of the grindstone 9. It is possible.

[Effects of the Invention] As detailed above, according to the present invention, it is possible to perform highly accurate balance correction in a short time, and the balance can be corrected while the rotating body is stabilized. This has the effect of making it easier to correct the balance of the body.

[Brief explanation of the drawing]

FIG. 1 is a partially enlarged side view showing the main parts of the present invention, FIG. 2 is a partially enlarged sectional view showing the mounting structure of the grindstone and dummy weight, and FIG. 3 is a block diagram showing the configuration of the discharge generator.
FIG. 4 is a pulse waveform diagram applied to the discharge electrode, and FIG. 5 is a partially enlarged cross-sectional view showing the side tilting of the present invention. 9... Grindstone as a rotating body, 11... Dummy weight, 16... Discharge generator, 18a, 18b... Discharge electrode.

Claims (1)

[Claims] 1. A dummy weight made of a conductor having an unbalanced amount is provided with respect to the rotating body, and a discharge electrode is arranged with a predetermined gap between the dummy weight and the discharge electrode. A balance correction device for a rotating body, characterized in that a discharge generating device for generating a discharge is provided in a gap between the rotating bodies.