JPH04193475A - Correction method and device for grinding wheel of grinder - Google Patents

Abstract

PURPOSE:To extend the life of a grinding wheel, by grinding the body to be ground while detecting the output of a grinding wheel driving motor, at the notching speed constant grinding time, stopping the grinding once, when it is detected that the output of the motor comes out of a motor output allowable range during a stationary grinding, and dressing the grinding wheel. CONSTITUTION:When the sharpness of a grinding wheel 1 is changed, during a stationary grinding, the dressing of the grinding wheel 1 by a dresser 13 is executed, because a notching speed comes out of a preset notching speed allowable range with its being increased or decreased, and the sharpness of the grinding wheel 1 becomes to be restored. Also in the case of a notching speed constant grinding, the dressing of the grinding wheel 1 by the dresser 13 is executed, because the output of a grinding wheel driving motor becomes out of a preset motor output allowable range by a setting means 7 with its being increased or decreased, when the sharpness of the grinding wheel 1 is changed, during the stationary grinding, and the sharpness of the grinding wheel 1 becomes restored.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a grinding wheel correction method and apparatus for a grinding machine.

[Conventional technology]

Conventionally, grinding machines that use a whetstone to grind a workpiece have been configured to perform cutting speed controlled grinding, in which the workpiece is ground by controlling the cutting speed, and grinding machines that use a grinding wheel to grind the workpiece. It is known that a grinder is configured to perform constant cutting speed grinding for grinding an object to be ground.

The former type of grinding machine has the advantage that it can grind quickly, has high productivity, and is suitable for mass production. However, the output of the grindstone drive motor that drives the grindstone must be set to a constant value, and in order to properly set this, there is a drawback that a large number of grinding wheels must be actually ground to find the appropriate value. For this reason, it is not suitable for low-volume, high-mix production as it increases costs.

On the other hand, the latter type of grinder does not require setting the output of the grindstone drive motor and is suitable for small-lot, high-mix production, but has the disadvantage that the grinding speed is slow and is not suitable for mass production.

Therefore, in order to compensate for the drawbacks of both of the above-mentioned grinders, a machine was developed that is capable of performing cutting speed controlled grinding and cutting speed-constant grinding, respectively, and is also configured to be able to switch between the two types of grinding. ing.

By the way, when a grinder grinds for a long time, the grinding wheel gets damaged and becomes clogged and the abrasive grains fall off.
The sharpness changes and the object to be ground cannot be processed as required, so dress the whetstone at an appropriate time.
The grindstone needs to be fixed.

For this reason, conventionally, in the above-mentioned grinding machines, both in the case of cutting speed controlled grinding and in the case of constant cutting speed grinding,
Dressing is performed at a predetermined time, for example, before each object to be ground is ground, or every time a plurality of objects to be ground are ground.

[Problems to be Solved by the Invention] The amount of grinding of the object to be ground, that is, the machining allowance, is not always constant due to machining errors in the previous process.

For this reason, in the conventional grinding wheel correction method, if the machining allowance of the workpiece is extremely larger than the fixed size, the damage to the grinding wheel will be large, so the sharpness of the grinding wheel will be adjusted earlier than planned (before the next dressing). There is a possibility that the grinding object may not be able to be machined to the required surface roughness and shape. In addition, if the machining allowance of the object to be ground is extremely larger than the standard size, the grinding wheel will be severely damaged and the grinding surface of the grinding wheel will become extremely rough, resulting in the need to increase the number of dressings per operation. Therefore, the problem arises that the life of the grinding wheel is shortened.

Therefore, in order to solve the above problem, conventionally, if the machining allowance of the workpiece is extremely larger than the fixed size, the grinding operation is stopped, the workpiece is returned to the previous process, and the workpiece is machined to the fixed size. After that, I tried to start grinding again. For this reason, work efficiency was poor, leading to a decrease in productivity.

In view of the above circumstances, the present invention makes it possible to always keep the sharpness of the grindstone good and to always process the workpiece as required, whether in the case of cutting speed controlled grinding or constant cutting speed grinding. In addition, it is an object of the present invention to provide a method and apparatus for repairing a grinding wheel for a grinding machine, which can extend the life of the grinding wheel and improve productivity.

(Means for Solving Problem I!) The grinding wheel repair method for a grinding machine according to the present invention includes cutting speed control grinding in which the cutting speed is controlled to grind the workpiece, and cutting speed control grinding in which the cutting speed is kept constant to grind the workpiece. In a grinding machine configured to be able to perform constant cutting speed grinding and constant cutting speed grinding, and to switch between the two types of grinding, in the case of cutting speed controlled grinding, the grinding machine can grind the workpiece while detecting the cutting speed. During steady grinding, when it is detected that the cutting speed is out of the preset allowable cutting speed range, the grinding is stopped and the grinding wheel is dressed, and in the case of constant cutting speed grinding, the grinding wheel is driven. The object to be ground is ground while detecting the output of the grinding wheel drive motor, and when it is detected that the output of the motor is out of the preset allowable motor output range during steady grinding, the grinding is temporarily stopped and the grinding wheel is turned off. It's like dressing.

Further, the grinding wheel correction device for a grinding machine according to the present invention is capable of performing cutting speed controlled grinding, which grinds a workpiece by controlling the cutting speed, and constant cutting speed grinding, which grinds a workpiece by keeping the cutting speed constant. In addition to being able to perform each of the following,
In the grinding machine configured to be capable of switching between the two types of grinding, the grinding machine includes a determining means for determining whether to perform cutting speed controlled grinding or constant cutting speed grinding, a cutting speed detecting means for detecting the cutting speed, and a cutting speed. a cutting speed permissible range setting means for setting a permissible range of the cutting speed, and a detection value of the cutting speed detecting means and the permissible range of the cutting speed permissible range setting means, and the determining means determines that cutting speed controlled grinding is to be performed. cutting speed control grinding dressing command means that outputs a grindstone dressing signal when the detected value deviates from the allowable range during steady grinding; and a motor output that detects the output of a grindstone drive motor that drives the grindstone. a pressure detecting means; a motor output permissible range setting means for setting a permissible range of the output of the motor; and a determining means that compares a detected value of the motor output detecting means with the permissible range of the motor output permissible range setting means. and dress command means for constant cutting speed grinding, which outputs a dressing signal for the grindstone when the detected value deviates from the allowable range during steady grinding when it is determined that constant cutting speed grinding is to be performed. It is.

[Effect]

According to the above configuration, in the case of cutting speed controlled grinding, if the sharpness of the grinding wheel changes during steady grinding, the cutting speed increases or decreases and deviates from the preset allowable cutting speed range. Dressing is performed to restore the sharpness of the whetstone. Also,
Cutting speed - In the case of constant grinding, if the sharpness of the grinding wheel changes during steady grinding, the output of the grinding wheel drive motor increases or decreases and falls outside the preset allowable motor output range, so dressing the grinding wheel is necessary. Re,
The sharpness of the whetstone will be restored.

〔Example〕

FIG. 1 shows an embodiment of the device of the invention.

In the figure, A is a grinding machine with a grinding wheel 1 and a table 1.
5, a work head 4, and a dresser 13.

The grindstone 1 is rotationally driven by a grindstone drive motor 3, which is placed on a table 15 and is moved together with the table 15 in the directions of arrows M and N in the figure by a table drive motor 16. It is configured.

Reference numeral 2 denotes a workpiece to be ground by the grindstone 1, which is mounted on the work head 4. This work head 4 is configured to be moved in the L direction in the figure by an infeed feed motor 5, as indicated by an arrow.

As a result, the workpiece 2 is ground by the grindstone 1 by rotating the grindstone 1 and applying it to the workpiece 2, and moving the work head 4 in the direction of the arrow in the figure using the cutting feed motor 5. It has become.

The speed at which the work head 4 moves in the direction of the arrow in the figure, ie, the cutting speed (2), can be changed by changing the rotational speed of the cutting feed motor 5.

Further, the cutting speed V is detected by a cutting feed motor rotational speed detection sensor (cutting speed detecting means) 20 as the rotational speed of the cutting feed motor 5 corresponding to this speed.

6 is a motor output detector (motor output detection means) that detects the output of the grindstone drive motor 3, that is, the grinding force P, and the detected value P detected by this motor output detector 6 is the first
It is output to the addition/subtraction calculator 8.

In addition to the detected value P from the motor output detector 6, the first addition/subtraction calculator 8 receives a motor output reference value (grinding force reference value) Pa that is preset and stored in the motor output reference value storage circuit 7. Ru. This motor output reference value Po is set according to the type of the object to be ground 2, the type of the grindstone 1, etc.

The first addition/subtraction calculator 8 subtracts the motor output reference value Pa of the motor output reference value storage circuit 7 from the detection value P of the motor output detector 6 to obtain an output change value ΔP.
P is configured to be output to the cutting feed motor control circuit 17 and the second dress command circuit 18.

The cutting feed motor control circuit 17 sets the output change value ΔP from the first addition/subtraction calculator 8 to zero based on the output change value ΔP obtained by the first addition/subtraction calculator 8, that is, the grinding force is kept at a constant value ( The target cutting speed required to achieve the grinding force reference value) is calculated, and the cutting feed motor rotation speed detection sensor 2
The cutting feed motor 5 is controlled so that the cutting feed speed V detected at 0 converges to the target cutting speed. Therefore, in this grinding machine A, the rotational speed (cutting speed) of the cutting feed motor 5 can be controlled so that the grinding force is constant, and the cutting speed at which the cutting speed is controlled to grind the workpiece 2. Controlled grinding is now possible.

The cut feed motor 5 is configured to be driven by a command from the sequence control circuit 10 when no control signal is input from the cut feed motor control circuit 17. In this case, the rotational speed is driven to a constant value suitable for each process during the rough grinding and finish grinding processes. Therefore, this grinding machine A is also capable of constant cutting speed grinding in which the workpiece 2 is ground at a constant cutting speed.

A first opening/closing switch 22 is interposed between the first addition/subtraction calculator 8 and the cutting feed motor control circuit 17, and when the first opening/closing switch 22 is closed, the first addition/subtraction calculator 8
A signal is transmitted from to the cutting feed motor control circuit 17,
From the cutting feed motor control circuit 17 to the cutting feed motor 5
Since the control signal is output to
Since the signal is not transmitted from the first addition/subtraction calculator 8 to the cutting feed motor control circuit 17 and the control signal is not output from the cutting feed motor control circuit 17 to the cutting feed motor 5,
Grinding is performed at a constant cutting speed.

1a is a changeover switch, and this changeover switch 1
By operating a, it is possible to specify whether to perform constant cutting speed grinding or cutting speed controlled grinding. This changeover switch 1a outputs a signal corresponding to the type of grinding to the sequence control circuit 10.

The sequence control circuit 10 is a discrimination circuit (discrimination means) 1 that discriminates whether to perform constant cutting speed grinding or controlled cutting speed grinding based on the -1 changeover switch 1a to 9 signals.
It is equipped with 0a. The sequence control circuit 10 outputs a first opening/closing switch open command signal to the first gate circuit 23 when the discrimination circuit 10a determines that constant cutting speed grinding is to be performed, and when it is determined that cutting speed controlled grinding is to be performed. A first open/close switch close command signal is output.

The first gate circuit 23 opens the first open/close switch 22 when a first open/close switch opening command signal is input from the sequence control circuit 10, and opens/closes the first open/close switch 22 when a first open/close switch close command signal is input. It is configured to close the switch 22. For this reason, the changeover switch 1a
When it is specified that constant cutting speed grinding is to be performed, the determination circuit 10a determines that constant cutting speed grinding is to be performed, and the sequence control circuit 10 outputs a first open/close switch open command signal, and the first open/close switch 22 is opened. Then, constant cutting speed grinding is performed. On the other hand, when the changeover switch 1a specifies that cutting speed controlled grinding is to be performed, the determination circuit 10a determines that cutting speed controlled grinding is to be performed, the sequence control circuit 10 outputs a first closing switch command signal, and the first The open/close switch 22 is closed and cutting speed controlled grinding is performed. That is, in this grinding 11A, it is possible to easily switch between constant cutting speed grinding and 6 cutting speed controlled grinding by operating the changeover switch 1a.

The cutting feed speed V detected by the cutting feed motor rotational speed detection sensor 20 is output to the second addition/subtraction calculator 28 in addition to the cutting feed motor control circuit 17 . In addition to the detected value V from the cutting feed motor rotation speed detection sensor 20, the second adjustment calculator 28 also contains a cutting speed reference value Vo that is preset and stored in the cutting speed reference value storage circuit 21.
is input. This cutting speed reference value Vo is set depending on the type of the object to be ground 2, the type of the grindstone 1, etc.

The second adjustment calculator 28 subtracts the cutting speed reference value Vo of the cutting speed reference value storage circuit 21 from the detection value V of the cutting feed motor rotational speed detection sensor 20 to obtain the cutting speed change value Δ■, and calculates the cutting speed. It is configured to output the change value Δ■ to the first dress command circuit 12.

The first dress command circuit 12 includes the second addition/subtraction calculator 28.
In addition to the cutting speed change value ΔV from , an allowable range (-ΔV1 to ΔV2) of the cutting speed change value that is preset and stored in the cutting speed change value allowable range storage circuit 14 is also input. This allowable range of cutting speed change value (-ΔV1 to ΔV2
) is set within the range of the cutting speed change value ΔV when the sharpness of the grindstone 1 is good and dressing is not necessary.

The first dress command circuit 12 outputs the cutting speed change value ΔV of the second addition/subtraction calculator 28 and the cutting speed change value permissible range (-Δv1 to ΔV2) of the cutting speed change value permissible range storage circuit 14.
), when the cutting speed change value Δ■ is out of the allowable range, that is, the detection value ■ of the cutting feed motor rotational speed detection sensor 20 falls within the cutting speed allowable range (
V1 to V2, that is, Vo-Δv1 to Vo+ΔV2), a dress command is output to the sequence control circuit 10.

A second opening/closing switch 11 that is opened and closed by a second gate circuit 9 is interposed between the second adjustment performance 128 and the first dress command circuit 12. A second opening/closing switch opening command signal is input to the second gate circuit 9 from the sequence control circuit 10 when the discrimination circuit 10a determines that grinding with constant cutting feed rate is to be performed, and it is determined that grinding with controlled cutting feed rate is to be performed. In this case, a second opening/closing switch closing command signal is input. The second gate circuit 9 includes a sequence control circuit 10
When the second open/close switch open command signal is input from the second P! When the close switch 11 is opened and the second open/close switch close command signal is input, the second open/close switch 11 is opened.
is configured to close. Therefore, except when performing cutting feed rate controlled grinding, no signal is output from the second addition/subtraction calculator 28 to the first dressing command circuit 12, and a dressing command is output from the first dressing command circuit 12 to the sequence control circuit 1o. It is designed so that it will not happen.

Also, the first dress command circuit 12 and the sequence control circuit 1
A third open/close switch 29 that is opened and closed by the third gate circuit 14 is interposed between the third gate circuit 14 and the third gate circuit 14 . A steady grinding start signal is input from the sequence control circuit 10 to the third gate circuit 14 when the rough grinding process starts and the steady grinding state is reached, and a steady grinding end signal is input when the steady grinding state ends. be done. The third gate circuit 14 is
When the steady grinding start signal is input from the sequence control circuit 10, the third open/close switch 29 is opened, and when the steady grinding end signal is input, the third open/close switch 29 is opened.
is configured to close. Therefore, even if cutting feed rate controlled grinding is performed, the dressing command is not output from the first dressing command circuit 12 to the sequence control circuit 10 except during the steady grinding state during the rough grinding process, for example, during the finish grinding process. It has become.

That is, the cutting speed reference value storage circuit 21 and the cutting speed change value permissible range storage circuit 14 constitute a cutting speed permissible range setting means for setting the permissible cutting speed range (1 to V2). In addition, the second addition/subtraction calculator 28
, the first dress command circuit 12, the second opening/closing switch 11, the second gate circuit 9, the third opening/closing switch 29, and the third gate circuit 14 are connected to the cutting feed motor rotational speed detection sensor 2.
The detection value ■ of 0 is compared with the cutting speed permissible range (V1 to V2) of the cutting speed permissible range setting means, and the determination circuit 10
When it is determined that cutting speed controlled grinding is to be performed in step a, the detected value V falls within the cutting speed allowable range (v1 to v1) during steady grinding.
V2) constitutes dressing command means during cutting speed control grinding which outputs a dressing signal for the grindstone 1 when the grinding wheel 1 deviates from the grinding wheel 1.

The second dress command circuit 18 stores, in addition to the output change value ΔP from the first addition/subtraction calculator 8, an output change value permissible range (-
ΔP1 to ΔP2) are input. The allowable range of the output change value (-ΔP1 to ΔP2) is set to the range of the output change value ΔP when the grindstone 1 has good sharpness and does not require dressing.

The second dress command circuit 18 compares the output change value ΔP of the first addition/subtraction calculator 8 with the output change value permissible range (-ΔP1 to ΔP2) of the output change value permissible range storage circuit 19, and determines the above output change value. When the value ΔP deviates from the permissible range, that is, the detected value P of the motor output detector 6 falls within the motor output permissible range (P1 to P2, that is, Pa−ΔP1 to Pa+ΔP2
), a dress command is output to the sequence control circuit 10.

A fourth opening/closing switch 24, which is opened and closed by a fourth gate circuit 25, is interposed between the first addition/subtraction calculator 8 and the second dress command circuit 18. The fourth gate circuit 25 includes
From the sequence control circuit 10, a command signal to open the fourth opening/closing switch is input when the discrimination circuit 10a determines that grinding with controlled cutting feed rate is to be performed, and when it is determined that grinding with constant cutting feed rate is to be performed, the fourth opening/closing switch is closed. A command signal is input. The fourth gate circuit 25 opens the fourth on-off switch 24 when a fourth on-off switch open command signal is input from the switch control circuit 10, and opens the fourth on-off switch 24 when a fourth on-off switch close command signal is input. It is configured to close the fourth opening/closing switch 24. Therefore, unless grinding is performed at a constant cutting feed rate, the first adjuster 8
No signal is output from the second dress command circuit 18 to the second dress command circuit 18.
A dress command is not output from the dress command circuit 18 to the sequence control circuit 10.

Further, the second dress command circuit 18 and the sequence control circuit 1
A fifth opening/closing switch 26 that is opened and closed by a fifth gate circuit 27 is interposed between the gate and the gate 0. A steady grinding start signal is input from the sequence control circuit 10 to the fifth gate circuit 27 when the rough grinding process starts and the steady grinding state is reached, and a steady grinding end signal is input when the steady grinding state ends. be done. The fifth gate circuit 27 is
When the steady grinding start signal is input from the sequence control circuit 10, the fifth open/close switch 26 is opened, and when the steady grinding end signal is input, the fifth open/close switch 26 is opened.
is configured to close. Therefore, even if grinding is performed at a constant cutting feed rate, the second dressing command circuit 18 does not output a dressing command to the sequence control circuit 10 except in the steady grinding state during the rough grinding process.

That is, the motor output reference value storage circuit 7 and the output change value tolerance range storage circuit 19 constitute a motor output tolerance range setting means for setting the tolerance range (P1 to P2) of the output of the grindstone drive motor 3. Also, the first addition/subtraction calculator 8, the second dress command port 18, and the fourth open/close switch 2
4, the fourth gate circuit 25, the fifth percent close switch 26, and the fifth gate circuit 27 detect the detected value P of the motor output detector 6.
and the permissible range of the motor output permissible range setting means (P1 to P2
), and when the determination circuit 10a determines that constant cutting speed grinding is to be performed, the dressing signal of the grinding wheel 1 is generated when the detected value P deviates from the motor output allowable range (P1 to P2) during steady grinding. This constitutes a dressing command means for constant cutting speed grinding which outputs the following.

When the sequence control circuit 10 receives a dressing command from the first dressing command circuit 12 or the second dressing command circuit 18, it outputs a grinding stop command to the cutting feed motor 5, table drive motor 16, etc., and also outputs a grinding stop command to the dresser 13. It is configured to output an operation command. The cutting feed motor 5 moves the work head 4 in the direction of the arrow in the figure in response to the grinding stop command, and the table drive motor 16 moves the grindstone drive motor 3 in the direction of the arrow N in the figure in response to the grinding stop command. It is configured. Further, the dresser 13 is configured to come into contact with the grindstone 1 and dress the grindstone 1 upon receiving an operation command from the sequence control circuit 10. In addition to the above-mentioned control, the sequence control circuit 10 also controls the aforementioned cutting feed motor 5.
It is also configured to perform sequence control necessary for grinding work, such as control of .

In the above configuration, when cutting speed controlled grinding is specified with the changeover switch 1a, the determination circuit 10a determines that cutting speed controlled grinding is to be performed, the first gate circuit 23 closes the first R close switch 22, and the cutting feed motor 5 is activated. Controlled by the cutting feed motor control circuit 17, cutting speed controlled grinding is performed. "At the same time, the second gate circuit 9 closes the second open/close switch 11, and a signal is transmitted from the second addition/subtraction calculator 28 to the first dress command circuit 12. Then, the rough grinding process begins and the steady grinding In this state, the third gate circuit 30 closes the third open/close switch 29, and the first dress command circuit 12 becomes ready to transmit a signal to the sequence control circuit 10.

In this state, when the sharpness of the grindstone 1 is good, the cutting speed V detected by the cutting feed motor rotational speed detection sensor 20 is within the cutting speed allowable range (between t1 and t2 shown in FIG. 2). v1 to V2). As a result, the first dressing command circuit 12 determines that the cutting speed change value ΔV is within the permissible cutting speed change value range (-ΔV1 to ΔV2). Therefore, the first dress command circuit 12
A dress command is not issued to the sequence control circuit 10 from then on.

When grinding continues and the grinding wheel 1 is damaged and the sharpness of the grinding wheel 1 changes, the cutting speed V increases or decreases in order to keep the grinding force, which is affected by the sharpness of the grinding wheel 1, constant. For example, if grinding wheel 1 becomes clogged and grinding wheel 1
When the ground surface of the grinding wheel 1 becomes flat, the cutting speed (2) decreases, and when the grinding surface of the grindstone 1 becomes rough due to drop-off of abrasive grains, the cutting speed V increases. Therefore, in the former case, the cutting speed V detected by the cutting feed motor rotational speed detection sensor 20 becomes smaller than the lower limit value ■1 of the allowable cutting speed range, as shown by the two-dot chain line in FIG. In this case, on the contrary, the cutting speed becomes larger than the upper limit value v2 of the permissible cutting speed range. As a result, the first dressing command circuit 12 determines that the cutting speed change value ΔV is within the permissible cutting speed change value range (-Δ■
1 to Δ■2), and a dress command is issued from the first dress command circuit 12 to the sequence control circuit 10. As a result, the sequence control circuit 10
A grinding stop command and an operation command are output from the
Grinding is temporarily stopped, the grindstone 1 is dressed by the dresser 13, and the sharpness of the grindstone 1 is restored.

In addition, when performing the above-mentioned cutting speed control grinding,
Since the first R close switch 24 is opened by the fourth gate circuit 25, no signal is transmitted from the first addition/subtraction calculator 8 to the second dress command circuit 18, and the dress signal is not transmitted from the second dress command circuit 18 to the sequence control circuit 10. No commands are issued.

On the other hand, when constant cutting speed grinding is specified with the changeover switch 1a, the determination circuit 10a determines that cutting speed-constant grinding is to be performed, the first gate circuit 23 opens the first open/close switch 22, and the cutting feed motor 5 is activated in sequence. The rotational speed is driven to a constant value by a command from the control circuit 10, and grinding at a constant cutting speed is performed. At the same time, the fourth
The fourth open/close switch 24 is closed by the gate circuit 25, and a signal is transmitted from the first addition/subtraction calculator 8 to the second dress command circuit 18. Then, when the rough grinding process begins and the steady grinding state is reached, the fifth gate circuit 27 closes the fifth open/close switch 26, and the second dress command circuit 1
9 becomes ready to transmit a signal to the sequence control circuit 10.

In this state, if the sharpness of the grindstone 1 is good, the output P of the grindstone drive motor 3 detected by the motor output detection 1i6
is a value within the motor output allowable range (P1 to P2), such as between t3 and t4 shown in FIG. As a result, the second
The dress command circuit 18 determines that the motor output change value ΔP is within the permissible range of motor output change values (-ΔP1 to ΔP2). Therefore, no dress command is issued from the second dress command circuit 18 to the sequence control circuit 10.

If grinding continues and the grinding wheel 1 is damaged and the sharpness of the grinding wheel 1 changes, the grinding force increases or decreases.
The output P of the grindstone drive motor 3 begins to rise or fall. That is, when the grinding wheel 1 becomes clogged and the grinding surface of the grinding wheel 1 becomes flat, the output P of the grinding wheel drive motor 3 increases, and conversely, when the grinding surface of the grinding wheel 1 becomes rough due to the occurrence of abrasive particles 1121, the output P of the grinding wheel drive motor 3 increases. The output P of No. 3 begins to decrease. Therefore, in the former case, the output P of the grindstone drive motor 3 detected by the motor output detector 6 becomes larger than the upper limit P2 of the motor output allowable range, as shown by the two-dot chain line in FIG. In the latter case, on the contrary, it becomes smaller than the lower limit P1 of the motor output allowable range. As a result, the second dress command circuit 18 determines that the motor output change value ΔP is outside the allowable range of motor output change values (-ΔP1 to ΔP2), and the second dress command circuit 18 issues a dress command to the sequence control circuit 10. begins to be emitted. As a result, a grinding stop command and an operation command are respectively output from the sequence control circuit 10, the grinding is temporarily stopped, the grindstone 1 is dressed by the dresser 13, and the sharpness of the grindstone 1 is restored.

In addition, when performing the above-mentioned constant cutting speed grinding,
Since the second opening/closing switch 11 is opened by the second gate circuit 9, no signal is transmitted from the second addition/subtraction calculator 28 to the first dress command circuit 12, and the dress signal is not transmitted from the first dress command circuit 12 to the sequence control circuit 10. No commands are issued.

In addition, in each of the cutting speed controlled grinding and the constant cutting speed grinding, the third opening/closing switch 29 or the fifth opening/closing switch 2 is used except for the steady grinding state during the rough grinding process.
6 is opened, so even if the cutting speed change value ΔV or the output change value ΔP deviates from the allowable range in a finish grinding process or the like where the grinding force is fundamentally different from that in the rough grinding process, dressing will not occur erroneously.

Further, in each of the cutting speed controlled grinding and the constant cutting speed grinding, when dressing is completed, grinding is performed again.

As described above, according to the configuration of this grinding wheel correction device, in the case of cutting speed control grinding, the workpiece 2 is ground while detecting the cutting speed V, and the cutting speed Set permissible cutting speed range (v1 to V2)
When it is detected that the grinding wheel 1 has come off, the grinding is temporarily stopped and the grinding wheel 1 is dressed. In the case of constant cutting speed grinding, the grinding wheel 1 is removed while detecting the output P of the grinding wheel drive motor 3 that drives the grinding wheel 1. During steady grinding, the output P of the motor 3 falls within the preset motor output allowable range (P1~
P2),) Grinding is started when it is detected that it has come off from S.
The method of the present invention can be carried out by temporarily stopping and dressing the grindstone 1. Therefore, as described above, in each of the cutting speed controlled grinding and the constant cutting speed grinding, if the sharpness of the grinding wheel 1 changes during steady grinding during the rough grinding process, this can be changed to the cutting speed V (cutting speed change value ΔV) or the grinding wheel 1. The sharpness of the grindstone 1 can be restored by reliably detecting the output P (output change value ΔP) of the drive motor 3 and dressing the grindstone 1.

Therefore, in each of cutting speed controlled grinding and constant cutting speed grinding, even if the machining allowance of the workpiece 2 is large or small, the sharpness of the grindstone 1 can always be maintained at a good level.
The workpiece 2 to be ground can always be processed as required.

Furthermore, even if the machining allowance of the object 2 to be ground is extremely larger than the specified size, it is possible to grind while maintaining the sharpness of the grindstone 1 at all times, so even such an object 2 to be ground can be processed as required. This eliminates the need to stop the grinding work midway, as is the case in the past.

Moreover, if the sharpness of the whetstone 1 changes, dressing is performed immediately. In other words, dressing is performed early before the grinding surface of the whetstone 1 becomes rough, so the amount of dressing of the whetstone 1 is small each time. The sharpness can be restored and the life of the grindstone 1 can be extended.

In the above embodiment, the cutting speed ■ and the output P of the grindstone drive motor 3 are converted into the cutting speed change value ΔV and the output change value ΔP, respectively, and the dressing is executed based on the cutting speed change value ΔV or the output change value ΔP. Although the timing is determined, it is also possible to directly determine the dressing execution timing based on the cutting speed V or the output P of the grindstone drive motor 3. In other words, as shown in FIGS. 2 and 3, the cutting speed V and the output P of the grindstone drive motor 3
are respectively lower limit values V1. The determination may be made based on whether or not it is within the range from P1 to the upper limit value V2°P2. Further, the method of the present invention may be applied not only to the rough grinding process but also to all grinding processes such as the finish grinding process.

[Effects of the Invention] - In the case of cutting speed controlled grinding, the present invention grinds the object to be ground while detecting the cutting speed, and eliminates the possibility that the cutting speed deviates from a preset allowable cutting speed range during steady grinding. When this is detected, grinding is temporarily stopped and the grinding wheel is dressed, and in the case of cutting speed - constant grinding, the workpiece is ground while detecting the output of the grinding wheel drive motor that drives the grinding wheel, and during steady grinding When it is detected that the output of the motor is out of the preset allowable motor output range, grinding is temporarily stopped and the grindstone is dressed. Even in such cases, it is possible to reliably detect a change in the sharpness of the whetstone and restore the sharpness of the whetstone. Therefore, in both cutting speed controlled grinding and constant cutting speed grinding, the sharpness of the grinding wheel can always be kept good and the workpiece can always be machined as required, and the amount of dressing can be reduced. The life of the grinder can be extended, and grinding work can be performed continuously, improving productivity.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram showing an embodiment of the grinding wheel correction device for a grinding machine according to the present invention, Fig. 2 is a graph showing changes in cutting speed, and Fig. 3 is a graph showing changes in the output of the grinding wheel drive motor. be. DESCRIPTION OF SYMBOLS 1... Grinding wheel, 2... Grinding object, 3... Grinding wheel drive motor, 6... Motor output detection means, 7.19... Motor output tolerance range setting means, 8.18.24. 25,2
6゜27...Dress command means during constant cutting speed grinding,
9゜11.12.28.29.30...Dress command means during cutting speed control grinding, 10a...Discrimination means, 14
゜21... Cutting speed allowable range setting means, 20...
Cutting speed detection means. Patent applicant: Toyo Eighth Tech Co., Ltd. Agent: Etsushi Kotani, patent attorney
Patent Attorney Chief 1) Masamukai Patent Attorney
Takao Ito Figure 2 Cutout 3 Figures

Claims (1)

[Claims] 1. It is possible to perform cutting speed controlled grinding, which grinds the workpiece by controlling the cutting speed, and constant cutting speed grinding, which grinds the workpiece while keeping the cutting speed constant. In the grinding machine configured to be able to switch between the two types of grinding, in the case of cutting speed control grinding, the workpiece is ground while detecting the cutting speed, and during steady grinding, the cutting speed is set to a preset depth of cut. When it is detected that the speed is out of the allowable range, grinding is temporarily stopped and the grinding wheel is dressed, and in the case of constant cutting speed grinding, the workpiece is ground while detecting the output of the grinding wheel drive motor that drives the grinding wheel. A method for repairing a grinding wheel for a grinding machine, comprising: temporarily stopping grinding and dressing the grinding wheel when it is detected that the output of the motor deviates from a preset allowable motor output range during steady grinding. 2. It is possible to perform cutting speed controlled grinding, which grinds the workpiece by controlling the cutting speed, and constant cutting speed grinding, which grinds the workpiece while keeping the cutting speed constant, and to switch between the two types of grinding. In a grinding machine configured to be able to perform cutting, a determination means for determining whether to perform cutting speed controlled grinding or constant cutting speed grinding, a cutting speed detection means for detecting the cutting speed, and an allowable range of the cutting speed are set. The cutting speed permissible range setting means compares the detected value of the cutting speed detecting means with the permissible range of the cutting speed permissible range setting means, and if the determining means determines that cutting speed controlled grinding is to be performed, steady grinding is performed. a cutting speed control grinding dressing command means for outputting a dressing signal for the grinding wheel when the detected value deviates from the allowable range; a motor output detection means for detecting the output of a grinding wheel drive motor for driving the grinding wheel; A motor output permissible range setting means for setting a permissible range of the output of the motor, a detection value of the motor output detecting means and a permissible range of the motor output permissible range setting means are compared, and the determining means performs constant cutting speed grinding. A grinding wheel for a grinding machine, characterized in that it is equipped with dressing command means for constant cutting speed grinding, which outputs a dressing signal for the grinding wheel when the detected value deviates from the allowable range during steady grinding. Correction device.