JP2753350B2 - Workpiece groove position measuring device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a groove position measuring device such as a work having a plurality of grooves, for example, a rotor of a vane pump or a rotary valve used for hydraulic control of power steering. is there.

"Conventional technology" When finishing or chamfering each groove of a work with multiple grooves formed on the outer circumference, mount the work on the spindle of the grinder and refer to one groove position as a reference. The processing is performed in the groove arrangement order. Therefore, it is necessary to accurately determine the position of each groove from a predetermined reference position. Therefore, in a grinding machine or the like for automatic processing, a center position from a reference position indicated in a production drawing is input as setting data in advance, and the center position is automatically determined based on the data to perform grinding or the like.

However, as described above, when the center position of the groove is determined based on the setting data and grinding or the like is performed, the pitch error between the center positions of the grooves formed in the work causes The grinding allowance for both sides is different for each groove. For this reason, there is a problem that the grinding resistance acting on both sides of the grindstone is different, which adversely affects the grinding accuracy and shortens the life of the grindstone.

The present invention has been made in order to solve these problems.In addition to obtaining the center position of each groove formed in the work from the reference position, and minimizing the influence of the pitch error, the center of the groove is determined in advance. The minimum value of the integrated value of the deviation between the center of the set data and the measured value of the measured value is determined, and the minimum value is further divided by the number of grooves to obtain an average value, and the average value of each groove is determined based on the average value. It is an object of the present invention to provide a workpiece groove position measuring device for calculating a center position.

"Means for Solving the Problems" As concrete means for achieving the above object, as shown in FIG. 1, a sensor 7 for detecting the presence or absence of a groove formed in a work, and a predetermined reference position of the work A position detection sensor 4 for detecting a position from a position sensor, a counter 6 for counting pulses output from the position detection sensor 4, and a counter 6 for obtaining a detection output of the sensor 7 as a trigger signal.
Calculating means 50 for calculating the center position of the groove from a predetermined reference position based on the count value of the above, measured value storing means 51 for storing the calculated value as a measured value, and storing the center position of each groove of the work 1 in advance. A set value storage unit 52 that inputs the groove arrangement and stores it as a set value, and integrates each deviation between the center position of each groove corresponding to the measured value and the set value, and compares each deviation integrated value. A comparison means 53 for obtaining a minimum value, and a center position calculation means 54 for calculating an average value by dividing the minimum value by the number of grooves to calculate a center position of each groove based on the average value. The present invention provides a device for measuring a groove position of a work to be performed.

“Operation” The operation of the groove position measuring device for a work is as follows.

Based on the count value of the counter 6 that counts the pulses output from the position detection sensor 4 using the detection output of the sensor 7 when detecting the presence or absence of the groove in the work as a trigger signal, the calculating means 50 Calculates the center position of each groove from a predetermined reference position, and stores the calculated value in the measured value storage means 51 as a measured value. Set value storage means
Numeral 52 stores in advance the center position of each groove of the work as a set value in the groove arrangement order. The comparing means 53 integrates each deviation between the center position of each groove corresponding to the measured value and the set value, and compares each deviation integrated value to obtain the minimum value. Then, the center position calculating means 54 calculates the average value by dividing the minimum value by the number of grooves, and calculates the center position of each groove based on the average value.

"Example" An example of the present invention will be described with reference to the accompanying drawings.

 FIG. 2 shows a schematic block diagram of the apparatus of this embodiment.

The circumference of the work 1 is formed with grooves 2 and lands 3 alternately, and supports both ends of the work 1 so that the work 1 can rotate around the rotation center axis. 4 is a motor 5 for rotating the work 1
And outputs its pulse output to the counter 6. The rotor encoder 4 makes one rotation each time the work 1 makes one rotation. The non-contact sensor 7 for detecting the presence / absence of the groove 2 in the work 1 is disposed orthogonally to the rotation center axis of the work 1 using a known eddy current displacement meter. The output of the non-contact sensor 7 can be detected by changing the output voltage between the case where the output is applied to the groove and the land of the work 1, and the presence or absence of the groove 2 can be detected. In the comparator 8, the analog output of the non-contact sensor 7 is binarized into TTL levels [1] and [0] by a comparator voltage which is a fixed threshold value, and the binary signals [1] to [0] are used. The timing of the change from [0] and [0] to [1] is output to the buffer 9 as a trigger signal, and the integrated counter value output from the counter 6 to the buffer 9 is read and output to the arithmetic processing unit 10. The arithmetic processing device 10 includes an arithmetic processing circuit such as an integrating circuit and a comparing circuit, a memory, and the like, and measures a groove position by predetermined programming. The center position of the groove 2 is obtained by calculating the average of the input integrated counter values, and based on the average value, the absolute position of the center position of the width of the groove 2 as angle information θ from a predetermined reference position. The calculation is performed and stored as a measured value in the memory of the arithmetic processing unit 10. The predetermined reference position is determined by a reset signal of the integrating counter which is sent out every one rotation of the rotary encoder 4. Further, a personal computer (hereinafter simply referred to as a personal computer) 11 is connected to the arithmetic
To input various operation command signals and data.

FIG. 3 is a timing chart showing the basic principle of detecting the center position of the groove 2 in the device. First, the non-contact sensor 7 is inserted into the groove 2 and the land 3 formed on the circumference of the work.
Sequentially correspond to each other, the output voltage changes as shown in FIG. 3B. If the comparator voltage is used as a threshold to binarize, the output of the comparator 8 becomes a TTL level square wave (see FIG. c)). The timing of the change from [0] to [1] and [1] to [0] of the square wave is used as a trigger signal to read the integrated counter value of the counter 6 ((d) in the figure). The arithmetic processing device 10 calculates the average of the counter values read at the above timing, and outputs the absolute position of the center position of the groove width as angle information (FIG. 9E).

Although the above is an example of the groove width, it is needless to say that the present invention can be applied to a land width.

FIG. 4 (a) shows measured values obtained by actually calculating the center position of the groove 2 of the work 1 as described above as angle data θ from a predetermined reference position.

FIG. 4 (b) shows the center position of each groove 2 of the work 1 as angle information θ 'from a predetermined reference position in the groove arrangement order.
Is input to the memory of the arithmetic processing unit 10 as a set value. In this case, the position of the edge of each groove 2 of the work 1 is input as data, and the above-mentioned arithmetic processing unit 10 calculates the position of the center.

Then, the apparatus according to the present embodiment matches the center position of the first groove of the setting data with the center position of one groove of the measurement data on the data, and calculates the deviation (that is, the pitch) between the center positions of the other corresponding grooves. Error), the minimum value is calculated from the deviation integrated values obtained as described above for the center position of all grooves in the measurement data, and the average value is divided by the minimum number of grooves. And calculating the center position of each groove based on the average value.

Hereinafter, the process of calculating the center position of the groove measuring device for a workpiece according to the present embodiment will be described with reference to the flowchart of FIG.

First, in step 100, the position of the edge of each groove 2 formed in the work 1 is input as an angle from a predetermined reference position and stored as a set value. In the following step 105, it calculates the measurement spindle rotation angle theta _s wearing the workpiece 1.
In this case, the angle θ _s becomes θ _s = 360 ° because it is necessary to find the deviation of the center positions of all the grooves 2. Step 110 ~
At 120, the measurement spindle is rotationally driven to determine that the measurement is completed, and the measurement spindle is stopped. Measurements completed, judged by the measuring spindle rotation angle ≧ theta _s. In step 125, the center position of the groove and the groove width of each groove are calculated from the set values. In the following step 130, the groove based on the set value obtained in step 125 and the groove based on the measurement are matched on data based on their respective center positions or groove widths. Specifically, a combination that minimizes the integrated value of the deviation of the center position of each groove and minimizes the difference in the width of each groove is obtained.

In the case of equally divided grooves, as shown in FIG. 6 (a), the center position of a predetermined groove of the setting data is matched with the center position of one groove of the measurement data, and the deviation (pitch) of the center position of each groove is adjusted. Error) ε _i is obtained. Theoretically, ε _i is calculated by the following equation.

ε _i = 0 ε _i = (θ _i −θ _i ) −P (i−1) / n (i = 2,3,... n) where n: Number of grooves (the same applies hereinafter) P: One round of encoder Minute pulse count value or 360 ゜ (the same applies hereinafter).

Then, the integrated value ε of the deviation ε _i is Is calculated by

Subsequently, as shown in FIG. 6 (b), the groove of the measurement data is moved by one groove, the center position thereof is matched with the center position of the predetermined groove of the setting data, and the integrated value of the deviation is obtained as described above. . The above process is performed for all the grooves of the measurement data, and the minimum value of each deviation integrated value is obtained. At this time, the groove width may not match as shown in FIG. 6 (c) even if the integrated value of the deviation is minimum. Therefore, a combination that minimizes the difference between the groove widths is determined. Subsequently, the routine proceeds to step 135, where the minimum value of the deviation integrated value is divided by the number of grooves n to obtain the average value.

It is.

In step 140, the center position of each groove is calculated based on the average value obtained in step 135. Assuming that the center position of a predetermined groove in the setting data is θ _i , the calculated center position θ _i ′ of the groove is θ _i ′ = θ ₁ +, and the center position θ of the other groove is
_i 'is calculated as follows:? _i ' =? _i '+ P (i-1) / n =? _i ++ P (i-1) / n (i = 1, 2, 3, ... n).

FIG. 7 shows a specific example of the above-described groove center position calculation process.

FIG. 6A shows the groove center position θ _i , and θ _i
Is set as a reference position θ = 0 to 20 °, and thereafter equally divided into θ ₂ , θ ₃ ,..., Θ _{12 at} intervals of 30 °.

FIG (b), the measurement data, a data table of the deviation (pitch error) and the measured data the groove center position theta _i, a case where the deviation integrated value described above is the minimum value. At this time, the average value of the deviation integrated value is And the sum of squares of the average value (pitch error) is 223.

FIG. 9C shows that the correction process makes θ _i ′ = θ.
It is a data table of the center position of the groove | channel of the measurement data calculated by _i + and (theta) _i '= (theta) _i ++ P (i-1) / n, and the deviation between this center position and the groove center position (theta) _i . The sum of squares of the deviation at this time is 106.75.

As described above, θ _i is calculated from the average value for obtaining the minimum value of the integrated value of the deviation, and the center position of the other groove is calculated based on the value θ _i ′ = θ _i +. Are minimized.

Therefore, when considering the entire work, it is possible to minimize the variation in the allowance during grinding.

In the above-described embodiment, the equally divided grooves are described. However, in the case of unequally divided grooves, the pitch error can be obtained by inputting the pitch of the groove center in advance, so that the above-described center position correction process is used. It becomes possible.

In the above-described embodiment, the position of the groove formed on the outer periphery of the work (rotary body) is described. However, the work is not limited to the rotary body, and may be a linear work. Good. In this case, when measuring the position of the groove formed in the work, a linear encoder or the like is used as a position detection sensor.

[Effect of the Invention] The work groove position measuring apparatus of the present invention has the above-described configuration, and measures a center position of a groove formed in the work from a predetermined reference position and a center value of a previously input groove center. While integrating each deviation between the center position of each groove corresponding to the set value of the position, calculating the minimum value, further dividing the minimum value by the number of grooves, obtaining an average value, and calculating the center position of each groove. Since the calculation is performed based on the average value, the influence of the pitch error at the center position of each groove can be minimized, and therefore, the variation in the allowance during the groove grinding is minimized, and the grinding acting on the grindstone is reduced. This has the effect of eliminating the disadvantages of the prior art, such as different resistances which adversely affect the grinding accuracy and shorten the life of the grinding wheel.

[Brief description of the drawings]

The accompanying drawings show an embodiment of the present invention, FIG. 1 is a diagram corresponding to claims, FIG. 2 is a schematic block diagram, FIG. 3 is a timing chart showing the basic principle of groove center position detection, and FIG. ) And (b) are explanatory diagrams showing measurement data and setting data, respectively. FIG. 5 is a flowchart, and FIG.
7 (a) to 7 (c) are explanatory diagrams for explaining the data processing performed in the flowchart of FIG. 5, and FIGS. 7 (a) to 7 (c) show specific examples of the process of calculating the center position of the groove. FIGS. 4B and 4C are explanatory diagrams showing the center position of the groove, and FIGS. 4B and 4C are data tables. 1 ... work, 2 ... groove, 3 ... land, 4 ... rotary encoder, 6 ... counter, 7 ... non-contact sensor, 10 ... calculation processing device, 50 ... calculation means, 51 ... measurement Value storage means, 52: Set value storage means, 53: Comparison means, 54: Center position calculation means.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-50-22416 (JP, A) JP-A-48-35506 (JP, A) Patent 2694019 (JP, B2)

Claims (1)

(57) [Claims] A sensor for detecting the presence or absence of a groove formed in the work; a position detection sensor for detecting a position of the work from a predetermined reference position; and a counter for counting pulses output from the position detection sensor. Calculating means for calculating a center position of a groove from a predetermined reference position based on a count value of a counter obtained by using a detection output of the sensor as a trigger signal, and measured value storing means for storing the calculated value as a measured value; Setting value storage means for inputting the center position of each groove of the work in advance in the groove arrangement order and storing it as a setting value, and integrating each deviation between the center position of each groove corresponding to the measured value and the setting value. A comparison means for comparing each deviation integrated value to obtain a minimum value, and a center position calculation means for calculating an average value by dividing the minimum value by the number of grooves and calculating a center position of each groove based on the average value. Be prepared Groove position measuring device of a work, characterized in that the.