JP2905844B2 - Device for detecting the balance and wear of a grinding wheel - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting a balance state of a grinding wheel and a device for detecting a worn state of a grinding wheel.

[Prior Art] Conventionally, in a balance state display device for measuring and displaying the balance state of a grindstone, the balance state is determined based on vibration caused by imbalance of the grindstone itself. Vibration due to other factors such as grinding must be avoided. Therefore, the operator operates the display device to measure the balance state during non-grinding, in which the grinding wheel is running idle without grinding.

Further, in a wear state display device for measuring and displaying the wear state of a grindstone described in Japanese Patent Application No. 63-237860 filed by the present applicant, vibration generated when the grindstone is grinding a work is disclosed. The amount of wear is determined based on the difference between the amount of vibration and the amount of vibration when the grindstone spins without grinding the work. Therefore, the operator presses the buttons at the time of grinding when grinding is performed and at the time of non-grinding not performed, and causes the display device to distinguish between grinding and non-grinding.

[Problems to be Solved by the Invention] However, in the above two types of measuring devices, it is necessary for an operator to distinguish between grinding and non-grinding.
It was very complicated to make measurements in parallel with the grinding operation.

In addition, when the NC grinding machine is regularly measured with the above-mentioned balance state display device or wear state display device, even though the grinding operation is automatically performed by NC control, the operator is required to perform the measurement every time. However, there is a problem that the advantage of the NC control is halved because it is necessary to stop at the grinding machine.

An object of the first invention is to provide a grinding wheel balance state detecting device capable of automatically discriminating between a grinding state and a non-grinding state and completely automating a detecting operation of a grinding state of a grinding wheel. .

A second object of the present invention is to provide a grindstone wear state detecting device capable of automatically discriminating between a grinding state and a non-grinding state and completely automating a grinding operation of the grinding state of the grindstone. .

Means for Solving the Problems A first invention is a sound collecting means for detecting a grinding sound when a grindstone of a grinding machine is grinding a work, and a grinding sound detected by the sound collecting means. Discriminating means for discriminating between grinding and non-grinding, vibration detecting means for detecting a vibration generated in the grinding wheel, and a detection signal from the vibration detecting means, and the discrimination result of the discriminating means is The gist of the present invention is a grinding wheel balance state detecting device including a grinding wheel balance state determining device based on the vibration detected by the vibration detecting unit at the time of non-grinding.

The second invention is a sound collecting means for detecting a grinding sound when a grindstone of a grinding machine is grinding a workpiece, and during grinding and non-grinding based on the grinding sound detected by the sound collecting means. Discriminating means for discriminating, a vibration detecting means for detecting a vibration generated in the grinding stone, and a detection signal from the vibration detecting means is input, and the vibration detecting means when the discrimination result of the discriminating means is grinding. A grinding wheel wear state detecting device comprising: a determination unit configured to determine a wear state of a grinding wheel based on a difference between the vibration amount detected by the vibration detection unit and the vibration amount detected by the vibration detection unit when the determination result is non-grinding. This is the gist.

[Operation] In the first invention, based on the vibration amount detected by the vibration detecting means when the determining means determines that the grinding is not performed,
The determining means determines the balance state of the grindstone. For this reason,
There is no need for the operator to distinguish between grinding and non-grinding.

In the second invention, the difference between the vibration amount detected by the vibration detecting means when the determining means determines that the grinding is being performed and the vibration amount detected by the vibration detecting means when determining that the grinding is not being performed. The determination means determines the wear state of the grindstone based on the above.
Therefore, there is no need for the operator to discriminate between grinding and non-grinding.

[Embodiment] Hereinafter, a first embodiment in which the present invention is embodied in a balance state display device that measures and displays the balance state of a grindstone will be described as first and second embodiments.
Explanation will be given according to FIG.

As shown in FIG. 1, an acceleration pickup 3 is attached to a spindle head 2 of the grinding machine 1 as a vibration detecting means for detecting vibration generated in the entire grinding machine 1. A motor 5 for rotating and driving the grindstone 4 of the grinding machine 1 is provided with an origin detection sensor 6, and the origin detection sensor 6 outputs an origin detection signal once while the grindstone 4 makes one rotation. An AE (acoustic emission) sensor 7 as sound collecting means is installed in the spindle head 2 so as to detect a grinding sound generated when the grindstone 4 grinds the workpiece W.

The acceleration pickup 3, the origin detection sensor 6, and the AE
The sensor 7 is connected to a control box 8 of the balance display device. A large number of LEDs 9 are provided on the front of the control box 8 to display a balance state.
a is arranged in a ring to form a position display section 9, and a numerical value display section 10 is provided at the center of the position display section 9.

Next, the electrical configuration of the balance state display device of this embodiment will be described with reference to FIG.

The acceleration pickup 3 is connected to a central processing unit 11 (hereinafter, referred to as a CPU) provided in the control box 8 via a band-pass filter 12, and the origin detection sensor 6 is connected thereto. or,
The AE sensor 7 is connected to the CPU 11 via a comparison circuit 16, a rectifier circuit 15, a band-pass filter 14, and an amplifier circuit 13, and the position display unit 9 and the numerical value display unit 10 described above.
Is connected.

Then, the grinding sound detected by the AE sensor 7 is converted into an electric sound wave signal, and the amplifier circuit 13 amplifies the sound wave signal. The center frequency of the band-pass filter 14 is set near 1 MHz, and a sound wave signal of that frequency is extracted from the sound wave signal and input to the rectifier circuit 15. The sound wave signal rectified by the rectification circuit 15 is input to the comparison circuit 16. The comparison circuit 16 compares a predetermined reference voltage value with the voltage value of the sound wave signal. The detection code is “0” if the reference voltage value is higher, and “1” if the voltage value of the sound wave signal is higher. Signal
Output to CPU11.

The CPU 11 has a random access memory 17 (RA
M), and read-only memory 18 (ROM) are connected,
The ROM 18 stores a program for determining the balance state of the grinding wheel 4 and a program for determining grinding and non-grinding times. The CPU 11 measures and displays the balance state of the grinding wheel 4 according to these programs. It is supposed to. Note that the RAM 17 temporarily stores the data of the processing performed by the CPU 11.

When the CPU 11 receives the detection code signal of “0” from the comparison circuit 16, it determines that the grinding is not performed, and when the CPU 11 receives the detection code signal of “1” from the comparison circuit 16, it determines that it is grinding.

Only when it is determined that the grinding is not performed, the CPU 11 performs the following measurement / display operation of the balance state of the grinding wheel 4. That is, the CPU 11 determines the rotation speed of the grindstone 4 by measuring the pulse period of the home position signal from the home position detection sensor 6, and controls the bandpass filter 12 so that the center frequency corresponds to the rotation speed. Outputs control signal. The CPU 11 inputs a detection signal from the acceleration pickup 3 through the band-pass filter 12, determines the maximum vibration amount of the grinding wheel 4 indicated by the detection signal, and determines the phase position at which the maximum vibration amount occurs at the origin. The determination is made based on the origin position signal from the detection sensor 6. further,
The CPU 11 displays the maximum vibration amount on the numerical value display unit 10 and turns on the LED 9a of the position display unit 9 corresponding to the phase position where the maximum vibration amount occurs.

Then, in the actual grinding work, when the power of the balance state display device is turned on to perform the measurement, the CPU 11
Based on the sound wave signal from the sensor 7, it is determined whether or not grinding is being performed, and the balance state of the grindstone 4 is measured and displayed only during non-grinding. Therefore, both the display units 9 and 10 of the control box 8 perform the display operation only when no grinding is performed.

It is ideal that the balance state of the grinding wheel 4 is determined based only on the vibration caused by the imbalance of the grinding wheel 4. For this purpose, avoid the grinding time affected by the vibration due to other factors such as grinding. It is said that it is desirable to determine the balance state based on vibration during non-grinding when the grinding wheel 4 is spinning. In the balance state display device of the present embodiment, the balance state of the grinding wheel 4 is measured and measured only during non-grinding.
Since the display operation is performed, a highly reliable determination result can be displayed without being affected by grinding vibration or the like.

Further, since it is configured to automatically discriminate between the time of grinding and the time of non-grinding, there is no need for the operator to make this discrimination, and the measurement work of the balance state can be completely automated.

Note that the present embodiment is embodied in a balance state display device that displays the balance state of the grindstone 4, for example,
The present invention may be embodied in a grindstone balance correcting device described in Japanese Patent Application No. 63-131065 previously filed by the present applicant. Even in the case of such a configuration, a highly reliable determination result can be obtained based on the vibration during non-grinding, and the imbalance of the grindstone 4 can be automatically corrected with high accuracy according to the determination result. . Also, in this case, it is not necessary for the operator to discriminate between the time of grinding and the time of non-grinding, so that it is possible to achieve fully automatic balance correction work.

Next, a second embodiment in which the present invention is embodied in a wear state display device for measuring and displaying the wear state (including clogging and omission) of a grindstone will be described with reference to FIGS.

As shown in FIG. 3, the wear state display device according to the present embodiment has almost the same configuration as the balance state display device according to the first embodiment, except that the position display section 9 is provided in the control box 21. The difference is that a grindstone designation switch 22 for designating the type of the grindstone 4 used for grinding is provided in the control box 21. 4th
As shown in the figure, differences in the electrical configuration are also
The position display section 9 is abolished, and the grinding wheel designation switch 22 is
Is connected to the Also, ROM connected to CPU23
The program 24 stores a program for determining the wear state of the grindstone 4 and a program for determining whether the grinding is performed or not. Further, the ROM 24 stores the vibration amount at the time of the wear limit corresponding to the type of each grindstone 4 designated by the grindstone designation switch 22. The CPU 23 measures and displays the wear state according to these programs, and the RAM 25 temporarily stores data of the processing performed by the CPU 23.

Then, similarly to the first embodiment, the CPU 23 discriminates between the time of grinding and the time of non-grinding based on the sound wave signal from the AE sensor 7.

Also, the CPU 23 measures and displays the wear state of the grinding wheel 4 described below based on the difference between the vibration amount detected by the acceleration pickup 3 during grinding and the vibration amount detected by the acceleration pickup 3 during non-grinding. Perform the operation. Hereinafter, a procedure for measuring the wear state of the grindstone 4 by the wear state display device of the present embodiment will be described in detail.

First, the operator designates the type of the grindstone 4 to be measured by the grindstone designation switch 22 and also uses the grindstone 4 to specify the grinding conditions specified in advance, namely, the predetermined grindstone rotation speed, feed speed, cutting depth, Grind with the work material. With the traverse, the grinding wheel 4 alternately repeats a grinding operation in which the grinding operation is performed in contact with the work W and a non-grinding operation in which the grinding operation is performed away from the work W and grinding is not performed. The CPU 23 specifies the amount of vibration generated on the grindstone 4 during grinding and non-grinding, respectively, and obtains the difference between the two amounts of vibration.

Generally, since the wear of the grindstone 4 occurs unevenly on its outer periphery, a portion having a large grinding resistance and a portion having a small grinding resistance occur on the outer periphery of the grindstone. Therefore, only at the time of work grinding, vibrations caused by the fluctuation of the grinding resistance occur on the grindstone 4.
On the other hand, vibration occurs even when the grinding wheel 4 is unbalanced, but the vibration caused by the vibration occurs both during grinding and during non-grinding. Therefore, the difference between the respective amounts of vibration at the time of grinding and at the time of non-grinding can be regarded as the amount of vibration generated by wear of the grindstone 4.

The CPU 23 compares the difference in the vibration amount with the vibration amount of the unusable grinding stone 4 stored in the ROM 24, that is, the vibration amount at the time of the wear limit (this value is a numerical value much larger than 0). The ratio of the difference between the amount of vibration during grinding and the amount of vibration during non-grinding with respect to the amount of vibration is calculated, and is displayed in% on the numerical value display section 10. Therefore, in the initial stage of grinding using an unused grindstone 4, the difference in the amount of vibration is almost 0, and the ratio is almost 0%.
The display 10 shows a numerical value near 0%. According to the unusable grindstone 4 due to the progress of wear, the difference in the amount of vibration is substantially equal to the amount of vibration at the time of wear limit.
It is near and the display unit 10 shows a value near 100%. Further, according to the whetstone 4 in use, the ratio of the difference in the vibration amount to the vibration amount at the time of the wear limit is an intermediate value between 0 and 100%, and the display unit 10 displays a numerical value corresponding to the degree of progress of the wear. Is shown.

Thus, in the wear state display device of the present embodiment, the wear state of the grindstone 4 can be accurately grasped by the operator.

Further, as described above, the determination of the wear state is performed based on the amount of vibration of the grindstone 4 at the time of grinding and at the time of non-grinding. Is automatically determined, so that the wear determination operation can be completely automated. Therefore, when measuring the state of wear, the operator only needs to execute the grinding according to the designated grinding conditions.

In the balance state display device of the first embodiment and the wear state display device of the second embodiment, the sound wave signal detected by the AE sensor 7 is further converted to a 1M signal by the band-pass filter 14.
Only the signal of the frequency around Hz is extracted, and the time of grinding and the time of non-grinding are determined based on this sound wave signal.The frequency of the sound wave signal is not limited to this, and is, for example, audible much lower than 1 MHz. The determination operation may be performed based on a sound wave signal having a frequency in the range.

In the balance state display device of the first embodiment and the wear state display device of the second embodiment, the sound wave signal detected by the AE sensor 7 is converted into a detection code signal of 1, 0 by the comparison circuit 16 and then the CPU 11 , 23, but the sound wave signal may be directly input to the CPUs 11, 23 via the AD converter instead.

[Effects of the Invention] As described in detail above, according to the grinding wheel balance state detecting device of the first invention, the grinding state and the non-grinding state are automatically determined, and the detection operation of the grinding state of the grinding wheel is performed. It has an excellent effect that it can be completely automated.

Also, according to the grinding wheel wear state detecting device of the second invention,
There is an excellent effect that it is possible to automatically discriminate between the time of grinding and the time of non-grinding and to completely automate the operation of detecting the wear state of the grindstone.

[Brief description of the drawings]

1 and 2 show a device for detecting a balance state of a grinding wheel according to a first embodiment of the present invention. FIG. 1 is a front view of a grinding machine and a balance state detection device, and FIG. FIG. 3 is a block diagram showing an electrical configuration of the detecting device, and FIGS. 3 and 4 show a grinding wheel wear state detecting device according to a second embodiment of the present invention. FIG. 3 shows a grinding machine and a wear state detecting device. FIG. 4 is a block diagram showing an electrical configuration of the wear state detecting device. 1 is a grinding machine, 3 is an acceleration pickup as a vibration detecting device, 4 is a grindstone, 7 is an AE sensor as a sound collecting means, 11, 2
3 is a CPU as a determining means and a determining means, and W is a work.

Continuation of the front page (56) References JP-A-50-155249 (JP, A) JP-A-59-72045 (JP, A) JP-A-3-28733 (JP, A) JP-A-62-28032 (JP) JP-A-2-88170 (JP, A) JP-A-1-301060 (JP, A) JP-A-57-162329 (JP, U) JP-A-61-202043 (JP, U) (58) Surveyed field (Int.Cl. ⁶ , DB name) G01M 1/14 B24B 45/00

Claims (2)

(57) [Claims] The grinding wheel (4) of a grinding machine (1) is a work (W).
Collecting means (7) for detecting the grinding sound when grinding
Determining means (11) for determining between grinding and non-grinding based on the grinding sound detected by the sound collecting means (7); and vibration detection for detecting vibration generated in the grinding wheel (4). Means (3), and a detection signal from the vibration detecting means (3), and a vibration detected by the vibration detecting means (3) when the discrimination result of the discriminating means (11) is not grinding. And a determining means (11) for determining a balance state of the grinding wheel (4) based on the grinding wheel balance state detecting device. 2. The grinding wheel (4) of the grinding machine (1) is a work (W).
Collecting means (7) for detecting the grinding sound when grinding
Determining means (23) for determining between grinding and non-grinding based on the grinding sound detected by the sound collecting means (7); and vibration detection for detecting vibration generated in the grinding wheel (4). Means (3), a detection signal from the vibration detecting means (3), and a vibration amount detected by the vibration detecting means (3) when the result of the determination by the determining means (23) is grinding. A determination means (23) for determining a wear state of the grinding wheel (4) based on a difference from the vibration amount detected by the vibration detection means (3) when the determination result is non-grinding; Detection device.