JP3362663B2 - Traverse grinding control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traverse grinding control device, and more particularly to a traverse grinding control device for controlling automatic sizing in traverse grinding.

[0002]

2. Description of the Related Art In traverse grinding, a grindstone is reciprocated in the axial direction (traverse direction) of a work mounted on a grinding machine to uniformly grind the outer peripheral surface of a cylindrical work, for example. Known as a grinding method. Further, conventionally, in order to improve the machining accuracy, the dimension of a workpiece being machined is measured in-process, and based on the measured value, control of each grinding operation such as rough grinding, fine grinding, spark out, and grinding stop is automatically performed. Automatic sizing devices are known. Such an automatic sizing device is also used in the above traverse grinding processing device, and when the work size measured in the in-process reaches a preset predetermined size, the amount of the grindstone fed into the work is reduced. The grinding operation such as rough grinding, fine grinding, spark-out, etc. is switched by switching.

[0003]

By the way, in the traverse grinding, every one cycle of the traverse grinding of the grindstone,
The dimensions of the work change discretely. Along with this, the work dimensions measured in-process also show a stepwise decrease with time. Therefore, in the case of performing automatic sizing control, it is possible to immediately switch to the grinding operation, for example, the roughing operation to the fine grinding operation, when the work size reaches a predetermined size in the case of general grinding. On the other hand, in the case of traverse grinding, there is no choice but to switch the grinding operation from the work size at each end of the traverse grinding cycle, and the timing of switching the grinding operation from the rough grinding to the fine grinding is not fixed. For this reason, the stock removal of the precision polishing machine may be almost eliminated. In this case, the number of traverses in the precision polishing machine is reduced, and the precision of the finished dimension is not stable.

On the other hand, during the conventional rough polishing,
In some cases, the traverse feed speed of the rough polishing is gradually decreased to switch to the grinding operation of the fine polishing so as not to reduce the stock removal of the fine polishing by the rough polishing. However,
In this case, there is a problem that the processing time becomes long. Further, conventionally, a method of detecting the grinding start point with a gap sensor and switching from the approach speed to the roughing feed was used, but a special sensor was required for this purpose.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a traverse grinding processing control device which shortens the processing time and improves the accuracy when performing automatic sizing control of the traverse grinding. To do.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is designed such that a grindstone is fed to a work piece from the next feeding step.
In traverse grinding cycle to write, the conjunction moved relative the grinding wheel in the axial direction of the workpiece to traverse grinding the workpiece by the grindstone, measuring the dimensions of the predetermined position of the workpiece In the traverse grinding processing control device for measuring the traverse grinding based on the measured dimension, a synchronization signal generating means for generating a synchronization signal in synchronization with the traverse grinding cycle, and the traverse grinding cycle Each said grind
Suppose dummy grinding amount varying the grinding amount of grinding in stepwise continuous manner by infeed stone period in synchronization with the dummy grinding amount in the synchronization signal before <br/> Symbol synchronizing signal generating means to the dummy grinding amount generating means for generating, issued by the dummy grinding amount generating means from the measured dimension measured by the measuring means
Predictive dimension measuring means for determining the predicted dimension of the workpiece by subtracting the generated dummy grinding amount, and grindstone feeding for adjusting the feed rate of the grindstone based on the predicted dimension determined by the predicted dimension measuring means And a quantity adjusting means.

According to the present invention, the dummy grinding amount, which continuously changes, is subtracted from the actually measured size with respect to the actually measured size which is ground stepwise for each traverse grinding, so that the apparent grinding is gradually and continuously performed. It is possible to secure a constant machining allowance under any condition, because the grinding condition is changed to, for example, from roughing to refinement based on this predicted size. It will be possible to maintain the precise polishing time and obtain stable finishing dimensions.

Further, in order to secure an allowance for grinding by the fine grinding, the traverse feeding speed during the rough grinding has been gradually decreased in the past, but in the present invention, the traverse feeding speed is kept constant during the rough grinding. Since it can be performed as a whole, the processing time can be shortened and the cycle time can be improved.
According to the invention of claim 4, when the traverse grinding is started, the movement of the grindstone from a predetermined retracted position to a position where it abuts the workpiece is detected based on a dimensional change of the workpiece, Since the feeding speed of the grindstone is switched from high speed to low speed from the time of detection, that is, the approach (semi-rapid feed) is switched to the rough-grinding feed, wasteful rough-grinding feed that has conventionally occurred due to variations in the material size of the workpiece. Can be appropriately prevented, and the processing time can be shortened and the cycle time can be improved.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a traverse grinding control apparatus according to the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is an overall configuration diagram of a traverse grinding machine to which the present invention is applied. As shown in the figure, the traverse grinding machine includes a grinder 14 and a grinder controller 1.
6 (hereinafter, simply referred to as control device 16) and an automatic sizing device (measurement head 18 and control unit 20).

The grinder 14 includes a grindstone 12 and a grindstone base 1.
1, the grindstone 12 is formed in a disc shape, and the central axis of the grindstone 12 is supported by the grindstone base 11 and is rotated by driving a motor. The grindstone 11 is configured to move in a direction toward the work 10 (A direction in the same figure) and an axial direction (traverse direction: B direction in the same figure) of the work 10 by driving the motor. Therefore, grindstone 1
2, the grinding wheel base 11 abuts the work 10 at a desired cutting depth and reciprocates in the traverse direction to grind the work 10. The work 10 is fixed on the grinder 14 by a chuck (not shown), and the work 10 also rotates about its axis as the chuck rotates. Thereby, for example, the work 10
Can be processed into a cylindrical shape having a desired diameter.

The automatic sizing device comprises a measuring head 18 fixed to the grinding machine 14 and a control unit 20. The measurement head 18 is provided with two fingers 18A and 18A, and contacts 18B and 18B attached to the tip ends of these fingers 18A and 18A are brought into contact with the outer peripheral surface of the work 10 from above and below. Then, the fingers 18A, 18A are displaced according to the size of the work 10, and this displacement is detected by the differential transformer in the main body of the measuring head 18. Thereby, the work size is detected, and the detected work size is transmitted to the control unit 20 by an electric signal.

The control unit 20 displays required information on the monitor based on the work size input from the measuring head 18, and approaches the control unit 16 and semi-rapid feed,
Outputs a command signal that commands switching of grinding operations such as roughing, precision, spark-out, and grinding stop. The control unit 2
Details of the 0 control will be described later. The control device 16 is
A control signal is output to the grinder 14 to control the rotating operation of the work 10 and the grindstone 12 and the moving operation of the grindstone base 11.
Further, based on a command signal input from the control unit 20, the control contents such as the traverse feed speed of the grindstone 12 and the feed amount of the grindstone 12 into the work 10 are switched to approach, semi-rapid feed, rough research, and refinement research. The grinding machine 14 is caused to perform various grinding operations such as, spark out, and grinding stop.

FIG. 2 is a diagram showing the configuration of the control unit 20. As shown in the figure, the control unit 20 mainly includes a signal processing unit 22, a predicted value calculation unit 24, a determination output unit 30, and the like. The signal processing unit 22 includes the measurement head 18
The electric signal indicating the work size input from is converted into a digital signal and input to the predicted value calculation unit 24.

The predicted value calculation unit 24 obtains a measured value of the work size by the digital signal input from the signal processing unit 22, and continuously attenuates the stepwise change of the work size measured in the traverse grinding. Correct the dimensional change. FIG. 3 is a diagram illustrating the processing content of the predicted value calculation unit 24. As shown by the solid line in the figure, the actual measurement value of the work size changes stepwise at every traverse grinding cycle T. On the other hand, the predicted value calculation unit 24 calculates a predicted value that decays at a constant rate with time as shown by the dotted line in the figure.
That is, in synchronism with the start point s of the traverse grinding cycle T shown in FIG.
The synchronization signal is input from the synchronization signal generation unit 26 to the prediction value calculation unit 24, and the prediction value calculation unit 24 holds the measured value of the work dimension at the start point s of the traverse feed cycle by this synchronization signal. Then, from the start point s to the start point s of the next traverse grinding cycle, dummy data increasing at a predetermined rate is input from the dummy data output unit 28 shown in FIG. 2, and the measured value of the held work dimension is input. Subtract that dummy data from.

The dummy data is preset by the user. Also, since the amount of grinding that is ground in one period of the traverse grinding cycle differs between rough grinding and fine grinding,
In the dummy data output unit 28, dummy data having different amounts of change per unit time are set for the rough and fine research, respectively. Then, the dummy data output unit 28 is adapted to select the dummy data to be output to the predicted value calculation unit 24 by inputting a signal indicating rough or fine research from the determination output unit 30 described later.

The predicted value calculated in this manner indicates a change in the work size predicted assuming that continuous grinding is performed, and ideally the starting point of each traverse grinding cycle. It becomes a straight line passing through s. As can be seen from FIG. 3, even if the actual measurement value and the predicted value differ at the end of each traverse grinding cycle, at the start point of each traverse grinding cycle, the dummy data is subtracted based on the actual measurement value at that time. Since the processing is performed, there is no problem that the deviation between the actually measured value and the predicted value increases.

Further, in the above description, the dummy data is subtracted from the actual measurement value of the starting point s of each traverse grinding cycle, but the present invention is not limited to this, and the dummy data at the time when the synchronization signal is input from the synchronization signal generator 26 is not limited to this. The dummy data may be subtracted from the measured value. Further, the synchronization signal may be input from the outside. Determination output unit 30 shown in FIG.
Inputs the predicted value of the work size calculated by the predicted value calculation unit 24, and based on the predicted value of the work size, issues a command signal for instructing the rough grinding, the fine grinding, the spark out and the grinding stop based on the predicted value. Output to 16. In particular,
The judgment output unit 30 is set by the user with a judgment value for switching from the rough grinding to the fine grinding and a sizing value for finishing the grinding. Then, when the predicted value of the work size input from the predicted value calculation unit 24 is larger than the judgment value for switching from the rough grinding to the fine grinding, the judgment output unit 30 outputs a signal (P1 signal) for instructing the rough grinding. 16 and outputs a signal (P2 signal) for instructing the rough grinding to the control device 16 when the judgment value is less than this value and is larger than the above-mentioned fixed dimension value. When the predicted value of the work size matches the fixed size value, a signal (P3 signal) for instructing spark out is output to the control device 16. When the P3 signal instructing spark out for a predetermined time is output, a grinding stop signal instructing grinding stop is output to the control device 16.

The operation of the traverse grinding machine configured as described above will be described with reference to the graph showing the operation example of FIG. The horizontal axis of FIG. 4 represents time, the vertical axis represents measured value, the waveform shown by the solid line on the graph is the measured value of the workpiece dimension detected by the measuring head 18, and the waveform shown by the dotted line is that of the control unit 20. The predicted value calculated by the predicted value calculation unit 24 is shown.

First, before the work 10 is ground, the two fingers 18A, 18A of the measuring head 18 are moved from the retracted state (the state where the fingers 18A, 18A are separated from the work 10) to the outer peripheral surface of the work 10. After moving to the position, the fingers 18A, 18A of the measuring head 18 are brought into contact with the outer peripheral surface of the work 10 from above and below. As a result, the dimension value output from the measuring head 18 changes from the point in the figure to the point, and the actual measurement of the workpiece dimension is started from the point. At this stage, since the surface of the work 10 has not been ground yet, the waveform of the measured value of the work dimension indicated by the point vibrates greatly up to the point.

On the other hand, the grindstone 12 starts moving at a high speed in the direction of contacting the work 10 from the retracted position when the start of the traverse grinding is instructed (approach), and when approaching the work 10 to some extent, the high speed is switched to the middle speed. It becomes a semi-rapid delivery. The switching position from the approach to the semi-rapid feed is preset based on the material size of the work 10.

Next, when the grindstone 12 comes into contact with the work 10 by the semi-rapid feed, the actually measured value of the work size sharply decreases as shown by the change of the points from the same figure. When the control unit 20 detects this change, the determination output unit 30 outputs the P1 signal instructing the rough research to the control device 16. That is,
The determination output unit 30 detects a change in the work size during the semi-rapid feed, and when the change exceeds a certain value, outputs a P1 signal instructing the rough grinding to the control device 16. By this processing, a function as a kind of gap sensor works, and the grinding cycle is automatically set according to the variation of the work material size. Since the grinding cycle is set according to the workpiece material size in this way, the processing time is shortened. In the above case, when the amount of change in the measured value of the work size exceeds a certain value, switching to the rough grinding is performed, but the present invention is not limited to this, and another evaluation value based on the measured value is used to determine whether the work is ground. The evaluation may be performed, and when the evaluation value becomes a value indicating that grinding has been performed, the rough grinding may be switched to.

In this way, when the P1 signal is output from the determination output unit 30 and the rough grinding by traverse grinding is started from the point in the figure, the work size decreases stepwise as shown by the solid line in the figure. . On the other hand, when the rough research is started, the work size prediction is started and the predicted value calculation unit 24 of the control unit 20 is started.
A predicted value that is attenuated at a constant rate with time as shown by the dotted line in FIG. The sync signal generator 2
From 6, a synchronization signal as shown in the lower part of the figure is output in synchronization with the traverse grinding cycle.

Then, as the rough polishing progresses, the predicted value of the work size comes to coincide with the preset P2 signal point as shown by the point in FIG. When the predicted value matches the P2 signal point, the P1 signal that has been output from the determination output unit 30 until then is switched to the P2 signal, and the control device 16
Is instructed to switch to the grinding operation of Seiken. As a result, after the traverse grinding cycle when the P2 signal is output is finished, the grinding operation by precision polishing is started from the start point (point in the figure) of the next traverse grinding cycle.

As described above, since the rough grinding is switched to the fine grinding based on the predicted value, the work 10 may be ground by the rough grinding beyond the P2 signal point as shown by the actual measurement value of the solid line in the figure. This eliminates the problem that the rough grinding removes the stock of the fine grinding. When the grinding operation is switched from the rough grinding to the fine grinding, the amount of the grindstone fed into the work 10 becomes smaller than that in the rough grinding, and the work size decreases in one period of the traverse grinding cycle as shown by the solid line in the figure. Is less than at the time of rough research. Further, when switched to the precision research, the dummy data output from the dummy data output unit 28 of the control unit 20 to the predicted value calculation unit 24 is also switched from the rough research to the dummy data set for the precision research. As shown by the dotted line in the figure, the rate of attenuation of the predicted value calculated by the predicted value calculation unit 24 also decreases.

As shown by the dotted line in the figure, when the switching from the rough research to the fine research is performed, the predicted value becomes larger than the P2 signal point again, so that the P1 signal is output from the determination output unit 30, but the P1 signal is output. Is output again, the grinding operation of the rough polishing is returned to. Therefore, in order to prevent this, the original P1 signal is not output after the P2 signal is output once.

Next, as the precision research progresses, the predicted value of the work size comes to coincide with the preset P3 signal point (fixed point) as shown by the point in FIG. When the predicted value matches the P3 signal point, the P2 signal output from the determination output unit 30 until then is switched to the P3 signal, and the control device 16 is instructed to switch to the spark-out grinding operation. . As a result, after the traverse grinding cycle when the P3 signal is output ends, the spark-out grinding operation starts from the start point (point in the figure) of the next traverse grinding cycle. In the spark-out, the feed amount of the grindstone 12 is 0, and only the traverse feed operation is performed. In addition, the predicted value calculation unit 24 also does not calculate the predicted value. As a result, when the measured value of the workpiece dimension reaches a fixed value after a predetermined time (point in the figure), the P3 signal output from the determination output unit 30 until then is switched to the grinding stop signal, and the grindstone 12 moves to the workpiece. The grinding is completed by retracting from 10.

In the above embodiment, the case where the grinding operation switching control is performed using the predicted value has been described, but the present invention is not limited to this, and the predicted value may be displayed on the monitor. When manually controlling the switching of the grinding operation, it is possible to properly secure the allowance for the precision polishing with reference to the display of the predicted value.

[0028]

As described above, according to the traverse grinding control apparatus according to the present invention, the dummy grinding amount that continuously changes is measured with respect to the actually measured dimension that is ground stepwise for each traverse grinding. By subtracting from the corrected size, the predicted size showing a change that seems to be gradually and continuously ground is corrected, and based on this predicted size, for example, the grinding condition is switched from the rough grinding to the fine grinding. It is possible to secure a constant stock removal even under the conditions, maintain a constant precision polishing time, and obtain stable finishing dimensions.

Further, in order to secure an allowance for grinding by the fine grinding, the traverse feed speed during the rough grinding has been gradually decreased in the past, but in the present invention, the traverse feed speed is kept constant during the rough grinding. Since it can be performed as a whole, the processing time can be shortened and the cycle time can be improved.
Further, at the start of traverse grinding, it is detected that the grindstone has moved from a predetermined retracted position to a position where it abuts the work piece based on the dimensional change of the work piece, and the feed speed of the grindstone from the detection time. Since the high speed is switched to the low speed, that is, the approach (semi-rapid feed) is switched to the roughing feed, it is possible to appropriately prevent the wasteful roughing feed time that was conventionally caused by the variation in the material size of the workpiece.
The processing time can be shortened and the cycle time can be improved. That is, when the grindstone is approached at a high speed from the retracted position to the position where it abuts the work piece at the start of grinding to switch to the rough grinding, conventionally, the grindstone is processed in consideration of the variation in the material size of the work piece. Since a rough position before contacting the object is switched to the rough grinding, time is wasted by the amount of the rough grinding operation performed until the grindstone contacts the workpiece. However, in the present invention, when the grindstone contacts the work piece regardless of the material size of the work piece, there is no such a problem because the grinding wheel is switched to the fine polishing at substantially the same time, and when the grindstone is moved at the approach speed. In addition, there is no problem that a large amount of the work piece is ground and the work piece is damaged.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a traverse grinding machine to which the present invention is applied.

FIG. 2 is a block diagram showing an internal configuration of a control unit of the automatic sizing device.

FIG. 3 is a diagram showing a relationship between an actually measured value and a predicted value of a work dimension.

FIG. 4 is an explanatory view showing the operation of the traverse grinding machine to which the present invention is applied.

[Explanation of symbols]

10 ... work 11 ... Whetstone stand 12 ... Whetstone 14 ... Grinding machine 16 ... Control device 18 ... Measuring head 20 ... Control Department 22 ... Signal processing unit 24 ... Prediction value calculation unit 26 ... Sync signal generator 28 ... Dummy data output section 30 ... Judgment output section

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuo Yoshimura 2-34 Minamiuematsucho, Yao City, Osaka Prefecture Koyo Kikai Kogyo Co., Ltd. (72) Hajime Ichikawa 2-34 Minamiuematsucho, Yao City, Osaka Prefecture Koyo Kikai Kogyo Co., Ltd. (56) Reference JP-A-7-328892 (JP, A) JP-A-6-270044 (JP, A) JP-A-50-153390 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) B24B 49/04 B23Q 15/02

Claims (3)

(57) [Claims] 1. From the sending of the grindstone to the work piece,
In traverse grinding cycle until infeed, the conjunction moved relative the grinding wheel in the axial direction of the workpiece to traverse grinding the workpiece by the grindstone, the dimensions of the predetermined position of the workpiece Measured by measuring means,
In the traverse grinding processing control device that performs processing control of the traverse grinding based on the measured dimensions, a synchronization signal generating unit that generates a synchronization signal in synchronization with the traverse grinding cycle, and the grinding wheel for each traverse grinding cycle. By sending
The grinding amount of grinding varies continuous manner stepwise Te assuming dummy grinding amount, the dummy grinding amount generating means for the dummy grinding amount occurs periodically in synchronism with the synchronizing signal of the synchronizing signal generating means And subtract the dummy grinding amount generated by the dummy grinding amount generation means from the actual measurement measured by the measurement means.
With a predicted size measuring means for obtaining a predicted size of the workpiece, and a quantity adjusting means infeed grinding to adjust the amount infeed of the grinding wheel based on the estimated size determined by said prediction dimension measuring means by Traverse grinding processing control device characterized by the above. 2. The traverse according to claim 1, wherein the dummy grinding amount generation means changes a change amount of the dummy grinding amount when the feed amount of the grindstone is switched based on the predicted dimension. Grinding control device. 3. The traverse grinding processing control device according to claim 2, wherein the amount of change in the dummy grinding amount can be set to a desired value corresponding to the amount of the grindstone fed.