JPH0760609A - Response delay time measuring method and device for grinding work control system - Google Patents

Abstract

PURPOSE:To measure accurately response delay time proper to a control system by measuring time until radial feed speed becomes a prescribed speed preset value or less from a radial feed speed switching signal generating time of an in-process gauge. CONSTITUTION:An outside diameter dimension of a work 6 whose outside diameter is ground by a grinding wheel 1 is detected by an in-process gauge 7, and a detected dimension signal 2 is sent into a control system. When this dimension signal reaches a cutting feed speed switching signal generating time point, a cutting speed switching command to a finish grinding cutting speed from rough grinding cutting speed is outputted to a radial feed driving part 5 from the control system, and this command is taken out of the in-process gauge 7, and is used as a measurement starting signal of a response delay time measuring part 11. Next, operation is carried out on cutting speed by an operation - comparison part 10 by using a cutting slide position signal by a slide position detecting part 8, and this is compared with a speed preset value, and response delay time in the control system is measured by the response delay time measuring part 11 according to the compared result.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for measuring a response delay time of a grinding control system for correcting a response delay of a control system to improve processing accuracy in size control of a work in grinding. Is.

[0002]

2. Description of the Related Art Generally, a grinding process is carried out in the order of rough grinding, finish grinding, and spark out, and a planned machining size is set for each process. The planned machining size is set for each process because it is necessary to secure a machining allowance in the next process. For example, in finish grinding, a certain amount or more of finishing allowance is required to remove the deteriorated layer on the work surface caused by rough grinding. I am trying. By the way, with a grinder equipped with an automatic sizing device,
The in-process gauge continuously detects the size of the workpiece being machined, and the detected value is fed back to the control system of the grinding machine to automatically control the cutting feed of the grinding wheel. At that time, considering the influence of grinding heat, the thermal expansion amount of the work is detected and calculated by an appropriate means, and the control means for correcting the set value of the in-process gauge based on this calculated value has been conventionally adopted. Came. That is, the value obtained by subtracting the thermal expansion amount of the workpiece from the value detected by the in-process gauge is managed as the actual dimension of the workpiece, and the cutting feed of the grindstone is controlled based on this actual dimension.

[0003]

However, the control system has a response delay time peculiar to the control system, and the cutting of the grindstone is performed after the dimension detection of the work by the in-process gauge and the correction amount calculation by the control device. A time lag is unavoidable until the feed is actually switched.
Therefore, before the control device outputs the rough grinding end signal and the cutting feed of the grindstone is actually switched to the finish grinding feed, the machining progresses by the dimension corresponding to the response delay time. In this case, the finishing stock removal in the finish grinding is reduced accordingly, and the stock removal for removing the deteriorated layer on the surface of the work caused by the rough grinding cannot be secured. Moreover, the work size generation speed slightly changes depending on the sharpness of the grindstone, etc., and therefore, the machining progress size corresponding to the response delay time varies, so if an attempt is made to secure a certain amount of finish grinding allowance, It is necessary to set the finishing grinding allowance to some extent in consideration of the variation in the machining progress dimension. This is
This leads to increased processing time and reduced processing efficiency. The same thing occurs at the transition from finish grinding to spark-out and at the end of spark-out, and affects the machining accuracy.

In order to eliminate the above-mentioned adverse effects caused by the response delay time of the control system, it is necessary to measure the response delay time of the control system. Conventionally, however, the response delay time of such a control system has been measured. No means for accurately measuring is provided, and the harmful effects resulting from this have not been resolved.

An object of the present invention is to provide a method and a device for measuring the response delay time of a grinding control system for eliminating the above-mentioned problems caused by the response delay time of the control system.

[0006]

In order to achieve the above object, the first method of the present invention is to detect the size of a work piece being machined by an in-process gauge and control the cutting feed of the grindstone based on the detected value. However, in the grinding control system that processes the workpiece to the specified dimension for each process, the cutting feed speed switching signal is detected and the cutting slide position signal is measured. The time until the cutting speed calculated from the changing speed of the cutting slide position signal becomes equal to or less than a predetermined speed set value set in advance is measured.

A second method is to detect the cutting feed speed switching signal generation time point, measure the cutting feed speed, and set the cutting feed speed to a predetermined speed set value or less from the generation time of the cutting feed speed switching signal. It measures the time until it becomes.

A third method is to detect a cutting feed speed switching signal generation time point and measure a grinding power or a grinding power change speed, and preset the grinding power or the changing speed from the generation time of the cutting feed speed switching signal. The time until the predetermined grinding power or a predetermined grinding power change speed becomes equal to or less than a set value is measured.

According to the first apparatus of the present invention, the size of the work being processed is detected by the in-process gauge, and the work is designated for each process while controlling the cutting feed of the grindstone based on the detected value. In a grinding control system that processes up to dimensions, an in-process gauge that generates a cutting feed speed switching signal, a cutting slide position detection unit that detects a cutting slide position signal, and a cutting feed speed based on the signal detected by the cutting slide position detection unit Is calculated and outputs a signal when the calculated cutting feed speed becomes equal to or less than a preset predetermined speed set value, and the calculation / comparison unit from the time when the cutting feed speed switching signal of the in-process gauge is generated. And a response delay time measuring unit for measuring the time until the output signal is generated.

The second device compares an in-process gauge for generating a cutting feed speed switching signal, a cutting speed detection unit, and a cutting speed detected by the cutting speed detection unit with a preset predetermined speed set value. , A calculating / comparing unit that outputs a signal when the cutting feed speed becomes equal to or less than a preset predetermined speed setting value, and from the time when the cutting feed speed switching signal of the in-process gauge is generated to the time when the output signal of the calculation / comparison unit is generated. And a response delay time measuring unit for measuring the time.

The third device is an in-process gauge for generating a cutting feed rate switching signal, a grinding power measuring unit for measuring the grinding power of a grinding wheel drive motor, and a grinding power measured by the grinding power measuring unit or a grinding power measured by the grinding power. The calculated grinding power change speed is compared with the preset grinding power value or its change speed value, and when the former is less than the latter, a calculation / comparison section that outputs a signal, and a cutting feed speed switching signal of the in-process gauge And a response delay time measuring unit for measuring the time from the generation time of the above to the generation time of the output signal of the calculation / comparison unit.

[0012]

According to the present invention, the time from the generation of the cutting feed speed switching signal of the in-process gauge until the cutting feed speed becomes equal to or less than a predetermined speed set value set in advance,
The time until the grinding power or the grinding power change speed obtained from the grinding power becomes equal to or lower than a preset predetermined grinding power value or the change speed value thereof is measured. As a result, the response delay time peculiar to the control system can be accurately measured.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the method and apparatus of the present invention is shown in FIG.
~ It demonstrates based on FIG. In FIG. 1, cutting speeds V1r (during rough grinding), V1f (during finish grinding), cutting slide position signal X1, workpiece dimension signal X2, grinding power P, and grinding power change speed dP / dt during grinding are the same in order from the top. It is a chart shown on the time axis (horizontal axis).

FIG. 2 shows a first embodiment of the device of the present invention. (1) is a grindstone, (2) is a bed of a grinding machine, and (3).
Is a wheel head, (4) is a wheel axis drive motor, (5) is a cutting feed drive unit, (6) is a workpiece, (7) is an in-process gauge, (8) is a cutting slide position detection unit, and (9).
Is a cutting speed detection unit, (10) is a calculation / comparison unit, and (1
1) shows a response delay time measuring unit.

FIG. 3 shows a second embodiment of the device of the present invention, and FIG. 4 shows a third embodiment of the device of the present invention. In each embodiment, the same reference numerals indicate the same members. In FIG. 4, (12) indicates a grinding power measuring unit.

2 to 4, the grindstone (1) is mounted on the grindstone base (3) and is rotationally driven by the grindstone shaft drive motor (4). Then, the cutting feed drive unit (5) moves the grindstone (1) forward and backward toward the work (6) via the grindstone base (3) with respect to the bed (2) of the grinding machine. 2 to 4 exemplify a case where the work (6) is ground by the grindstone (1).

The in-process gauge (7) is a grindstone (1).
The case where the outer diameter dimension of the workpiece (6) whose outer diameter has been ground is detected is illustrated. The workpiece size detected by the in-process gauge (7) is sent to the control system as a size signal X2, and when the size signal X2 reaches the cutting feed speed switching signal generation point, the grinding machine including the in-process gauge (7) The control system of (1) issues a cutting speed switching command from the rough grinding cutting speed V1r to the finish grinding cutting speed V1f to the cutting feed drive unit (5).
In this embodiment, this command is taken out from the in-process gauge (7) and used as the measurement start signal of the response delay time measuring section (11). This point is common to each of the embodiments.

First, in the first embodiment, as shown in FIG.
The cut slide position detector (8) is used. The cutting slide position detection unit (8) detects the cutting movement amount by the cutting feed drive unit (5) of the grindstone base (3) during the grinding process as the cutting slide position signal X1. In the first embodiment, the cutting / sliding position signal X1 is used to calculate the cutting speed dX1 / dt in the calculation / comparison unit (10), and the preset speed setting value V1r-ΔV1r is obtained. Are compared, and this is dX
When 1 / dt <V1r-ΔV1r, a signal is output to the response delay time measuring unit (11). Response delay time measurement unit (11)
Is the dX1 from the time when the cutting speed switching signal from the rough grinding cutting speed V1r to the finish grinding cutting speed V1f is output from the in-process gauge (7).
The time until the signal satisfying / dt <V1r−ΔV1r is output from the arithmetic / comparison unit (10), that is, the response delay time Δtr of the control system is measured.

The same applies to the finish grinding process. That is, when the dimension signal X2 reaches the cutting feed speed switching signal generation timing, the cutting retreat command is sent from the control system of the grinding machine including the in-process gauge (7) to the cutting feed drive unit (5) of the wheel head (3) and the present invention. Is sent to the response delay time measuring unit (11). As a result, the response delay time measuring section (11) starts its measurement. On the other hand, the calculation / comparison unit (10) calculates the cutting speed dX1 / dt from the cutting slide position signal X1 from the cutting slide position detection unit (8), and this and the preset speed setting value V1f-Δ. Compared with V1f, dX1 / dt <
When V1f−ΔV1f, the response delay time measuring unit (1
Send a signal to 1). The response delay time measuring unit (11) calculates the above-mentioned calculation / comparing unit (1) from the time when the cutting back command from the control system of the grinding machine including the in-process gauge (7) is generated.
The time until the signal of dX1 / dt <V1f-ΔV1f from 0), that is, the response delay time Δtf of the control system is measured.

Next, in the embodiment shown in FIG. 3, the cutting speed is set to the cutting slide position signal X1 as in the previous embodiment.
The cutting speed signal VB from a pulse generator or the like connected to the cutting feed motor or the like of the cutting feed drive unit (5) is used instead of being obtained more. In this case, the calculation / comparison unit (10) compares the preset speed setting values V1r-ΔV1r and VB during rough grinding, and if VB <V1r-ΔV1r, the response delay time A signal is sent to the measuring section (11). The response delay time measuring unit (11) performs the above calculation from the time when the cutting speed switching signal from the rough grinding cutting speed V1r to the finish grinding cutting speed V1f is generated from the control system of the grinding machine including the in-process gauge (7). VB <from the comparison unit (10)
The time until the V1r-ΔV1r signal is output, that is, the response delay time Δtr of the control system is measured.

Further, in the embodiment of FIG. 3, during the finish grinding,
The preset speed setting values V1f-ΔV1f and VB
And VB <V1f−ΔV1f, a signal is output to the response delay time measuring section (11). The response delay time measuring unit (11) outputs a signal of VB <V1f-ΔV1f from the calculation / comparison unit (10) from the time when the cutting back command is issued from the control system of the grinding machine including the in-process gauge (7). Time until output, that is, response delay time of control system Δtf
To measure.

Further, in the embodiment of FIG. 4, the cutting speed V
Instead of B, the grinding power P of the grindstone (1) that is grinding the outer diameter of the work (6) is calculated from the current value, the voltage value, the power consumption value or the like of the grindstone shaft drive motor (4). ). Then, one is a case where the grinding power P is used as it is, and the other is a case where the grinding power change speed dP / dt is obtained and used.

When the grinding power P is used as it is, as shown in the characteristic diagram of FIG. 1, the rough grinding cutting speed V1r from the control system of the grinding machine including the in-process gauge (7) is used for the finish grinding. A predetermined grinding power value Pr is set in advance for the time point at which the cutting speed switching signal to the cutting speed V1f is generated, and at the time of finish grinding,
A predetermined grinding power value Pf is set in advance with respect to the time point at which the cutting back command is issued from the control system of the grinding machine including the in-process gauge (7). Then, the calculation / comparison unit (1
In 0), the time when P <Pr and P <Pf are respectively monitored, and a signal is output. The response delay time measuring unit (11)
The above calculation is performed from the time when the cutting feed rate switching command is issued from the control system of the grinding machine including the in-process gauge (7).
The time until the output signal of the comparison unit (10) is generated is measured. These are the response delay times Δtr and Δtf of the control system.

When the grinding power change speed dP / dt is determined and used, the grinding power change speed dP / dt is calculated by the calculation / comparison unit (10) by the grinding power P measured by the grinding power measurement unit (12). Calculate. Then, a predetermined grinding power change speed value Vpr is set in advance with respect to the time when the cutting speed switching signal from the rough grinding cutting speed V1r to the finish grinding cutting speed V1f is generated by the control system of the grinding machine including the in-process gauge (7). Is set in advance, and at the time of finish grinding, a predetermined grinding power change speed value Vpf is set in advance with respect to the time point when the cutting back command is generated from the control system of the grinding machine including the in-process gauge (7). And
In the calculation / comparison unit (10), dP / dt <Vpr and d, respectively.
A signal is output by monitoring the time when P / dt <Vpf. The response delay time measuring unit (11) calculates and compares the cutting feed speed switching command from the control system of the grinding machine including the in-process gauge (7) from the time when the calculation and comparison unit (10) is generated.
Measure the time until the output signal is generated. These are the response delay times Δtr and Δtf of the control system.

The present invention may be applied to any of the above-mentioned embodiments, and the response delay times Δtr and Δtf of the control system of the grinding machine thus measured and the work size generation speed dX2 / dt. Using and to predict the machining dimension amounts Δdr and Δdf during this response delay time, and from the preset workpiece machining dimensions (actual dimensions at the end of each grinding process such as rough grinding and finish grinding) Also, the cutting speed switching signal is output in front of the above amounts Δdr and Δdf to suppress the variation of the work size and the variation of the machining allowance during the rough grinding and the finish grinding, thereby improving the machining accuracy. You can The same applies to the case of spark-out.

In the above embodiment, ΔV1r and ΔV1
f is to measure the cutting feed rate data and determine it appropriately. Further, at the time point when the cutting feed speed switching command is issued, the workpiece dimension signal X2 by the in-process gauge (7) has a preset value (Schmidt point) S.
This is the time when r and Sf are reached.

[0027]

According to the present invention, the response delay time peculiar to the control system of the grinding machine can be quantitatively and accurately measured. As a result, it is possible to eliminate adverse effects such as variations in work size and variations in machining allowance due to the response delay time of the control system, and it is possible to improve machining accuracy.

[Brief description of drawings]

FIG. 1 shows the cutting speed, cutting slide position signal, workpiece size signal, grinding power, and grinding power change speed during grinding in order from the top for explaining the method of the present invention on the same time axis (horizontal axis). The chart.

FIG. 2 is a block diagram showing an outline of the entire first embodiment of the device of the present invention.

FIG. 3 is a block diagram showing an outline of the entire second embodiment of the device of the present invention.

FIG. 4 is a block diagram showing the outline of the entire third embodiment of the device of the present invention.

[Explanation of symbols]

 1 Grindstone 2 Grinding machine bed 3 Grindstone base 4 Grindstone axis drive motor 5 Cutting feed drive unit 6 Workpiece 7 In-process gauge 8 Cutting position detection unit 9 Cutting speed detection unit 10 Calculation / comparison unit 11 Response delay time measurement unit 12 Grinding power Measuring unit P Grinding power X1 Cutting slide position signal X2 In-process gauge size signal V1r, V1f Cutting speed Δtr, Δtf Control system response delay time

Claims (6)

[Claims] 1. A grinding control system for detecting a size of a work piece being processed by an in-process gauge, and controlling a cutting feed of a grindstone based on the detected value, and processing the work up to a specified size for each process. In, the cutting feed speed switching signal generation time is detected, the cutting slide position signal is measured, and the cutting speed calculated from the cutting slide position signal change speed from the cutting feed speed switching signal generation time is the preset speed setting. A method for measuring a response delay time of a grinding control system, which comprises measuring a time until the value becomes a value or less. 2. A grinding control system for detecting a work size during processing by an in-process gauge, and controlling a cutting feed of a grindstone based on the detected value, and processing a work up to a specified size for each process. In, the detection of the cutting feed speed switching signal generation time, the cutting feed speed is measured, and the time from the generation of the cutting feed speed switching signal until the cutting feed speed becomes equal to or less than the preset speed set value is measured. A method for measuring a response delay time of a grinding control system, which is characterized in that 3. A grinding control system for detecting a work size during processing by an in-process gauge, and controlling a cutting feed of a grindstone based on the detected value, and processing a work up to a specified size for each process. At the time of occurrence of the cutting feed speed switching signal, the grinding power or the grinding power change speed is measured, and the grinding power or its changing speed is set to the predetermined grinding power or the predetermined grinding power from the time the cutting feed speed switching signal is generated. A method for measuring a response delay time of a grinding control system, which comprises measuring the time until the grinding power change speed falls below a set value. 4. A grinding control system for detecting a work size during processing by an in-process gauge, and controlling a cutting feed of a grindstone based on the detected value, and processing a work up to a specified size for each process. In, the in-process gauge that generates the cutting feed speed switching signal, the cutting slide position detection unit that detects the cutting slide position signal, and the cutting feed speed are calculated from the signals detected by the cutting slide position detection unit. The calculation / comparison section that outputs a signal when the feed speed falls below the preset speed setting value, and the time from the time when the infeed gauge cut feed speed switching signal is generated to the time when the output signal of the calculation / comparison section is generated. Response delay time measurement of grinding control system characterized by having a response delay time measurement unit for measuring Location. 5. A grinding control system for detecting a work size during processing by an in-process gauge, and controlling a cutting feed of a grindstone based on the detected value, and processing a work up to a specified size for each process. In, the in-process gauge that generates the cutting feed speed switching signal, the cutting speed detection unit, the cutting speed detected by the cutting speed detection unit and the preset speed setting value are compared, and the cutting feed speed is set in advance. Computation / comparison section that outputs a signal when the speed is less than the specified speed setting value, and response delay that measures the time from the time when the infeed gauge cut feed speed switching signal is generated to the time when the calculation / comparison section output signal is generated. A response delay time measuring device for a grinding control system, comprising: a time measuring unit. 6. A grinding control system for detecting a work size during processing by an in-process gauge, and controlling a cutting feed of a grindstone based on the detected value, and processing a work up to a specified size for each process. In, the in-process gauge that generates the cutting feed speed switching signal, the grinding power measurement unit that measures the grinding power of the grinding wheel drive motor, and the grinding power measured by the grinding power measurement unit or the grinding power change speed obtained from it. A calculation / comparison unit that compares a preset grinding power value or its changing speed value and outputs a signal when the former falls below the latter, and a calculation / comparison from the time when the infeed feed rate switching signal of the in-process gauge is generated. Delay time of the grinding control system characterized by having a response delay time measuring section for measuring the time until the output signal of the machine section is generated. Constant apparatus.