JP3256882B2 - Grinding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for grinding a workpiece using a grindstone, and more particularly to an improvement capable of improving the dimensional accuracy of a ground product.

[0002]

2. Description of the Related Art When a workpiece is ground using a grindstone, the grindstone is worn during the grinding and the dimensions of the grindstone change. Therefore, for example, there has been developed an apparatus which measures the dimensions of a grindstone when grinding is performed a predetermined number of times, corrects the distance between the grindstone and the work according to the measurement result, and resumes subsequent grinding.

[0003]

However, in many cases, swarf and abrasive particles that have fallen off are often reattached to the grindstone, and according to a normal dimensional measurement method, the effective grindstone size that substantially contributes to grinding is obtained. Often, other dimensions are measured.
Therefore, even if the distance between the grindstone and the work is corrected based on the measured value, the dimensional accuracy of the ground product may not be obtained. Therefore, the present invention is intended to prevent an erroneous dimension from being measured while chips and abrasive grains are attached.

[0004]

According to the present invention, there is provided:
Grindstone size measuring means, grindstone cleaning means, and
To perform a specific grinding process while controlling the grindstone position.
Grinding process control means and measurement for controlling the grinding wheel diameter measurement procedure
And (1) a predetermined grinding process is executed by the grinding process control device.
A step of measuring and storing the grindstone dimensions before it is, (2) a predetermined Grinding performed by grinding control means
And (3) comparing the difference between the measured values of the above (1) and (2) with a predetermined value.
And (4) washing the grindstone when the value is larger than the predetermined value in (3).
Cleaning and re-measurement of the grindstone dimensions after cleaning; (5) comparing the difference between the measured values of (1) and (4) with a predetermined value
And (6) an abnormal signal when the value is larger than a predetermined value in (5).
And a procedure for outputting a grinding signal.

[0005]

When grinding with a grindstone, the amount of wear of the grindstone during grinding should be within a substantially predetermined range. Therefore, if the difference between the measured values of the grindstone dimensions before and after the grinding is within a predetermined value, it can be confirmed that the effective grindstone dimensions which are not affected by chips, abrasive grains, etc. are measured. Conversely, if the difference between the measured values before and after the processing is not within the predetermined value, it is highly likely that dimensions other than the effective grindstone dimensions are measured. Therefore, the present invention detects the latter case,
When the latter case is detected, means for re-measuring the grindstone after cleaning the grindstone is added. According to the present invention, it is not overlooked that a dimension other than the effective grinding wheel dimension is measured, and unnecessary cleaning is not performed. Measures grinding wheel dimensions other than the effective grinding wheel dimensions even after cleaning
If so, an abnormal signal is output. Because of this,
To prevent subsequent grinding using the
Can be stopped.

[0006]

Next, an embodiment of the present invention will be described. In the embodiment described below, as shown in FIG. 1, a predetermined grinding process is performed after measuring a grindstone size, and after a predetermined process is completed, the grindstone size is measured again and processing is continued. The present invention is applied to a grinding device programmed in the present invention. In the case of FIG. 1, the grinding process 1-1 to 1-M1 is performed using the grindstone diameter data measured in the measurement process indicated by the measurement 1, and when the machining is completed, the grindstone diameter is reduced as shown in the measurement 2. The figure shows a case where re-measurement is performed and grinding processing 2-1 to 2-M2 is performed using the re-measured value data.

Further, in this embodiment, when a measurement / machining cycle is executed a predetermined number of times (in this case, N times), a program is performed such that a shape correcting process of a grinding stone called truing is executed. The present invention is applied to a certain grinding device.

Next, the system configuration of the present invention will be described with reference to FIGS. In the figure, reference numeral 62 denotes a head for rotatably supporting a grindstone 64, which comprises an X-axis motor 40 and a Z-axis motor 2.
By 0, it is moved in the left, right, up and down directions in the figure. The grindstone 64 is rotated at high speed around a vertical axis by a motor 54. A nozzle 5 for spraying a coolant liquid on a grindstone 64 is provided on the head 62.
8 is fixed. Below the head 62, a table 90 that is moved by the Y-axis motor 30 in the direction perpendicular to the paper of FIG. 2 is installed, and a touch sensor 70 that is turned on when the grindstone 64 abuts from the side is disposed on the table 90. Have been. A truing grinder 80 for correcting the shape of the grindstone 64 is also provided.

The X-axis motor 40, the Y-axis motor 30, and the Z-axis motor 20 are connected to the CPU 50 via drive circuits 42, 32, 22 and pulse distribution circuits 46, 36, 26, respectively. The rotation angle position is controlled. That is, the position of the head 62 and the table 9
The position of 0 can be controlled by the CPU 50. The number of pulses from each of the pulse distribution circuits 26, 36, and 46 is counted by counters 24, 34, and 44.
The position of the head 62 can be detected by being read into the PU 50.

[0010] The touch sensor 70 is connected to the C
The timing at which the grinding wheel 64 abuts on the touch sensor 70 is connected to the PU 50 and can be input to the CPU 50. The grindstone rotating motor 54, the nozzle 58, and the truing grind 80 are connected to cables 52, 56, 8 respectively.
2 is connected to the CPU 50, and its on / off state is C
It can be controlled by the PU 50. The CPU 50 is connected to the memory 2 having data storage areas 16 and 18 in addition to storing various programs 4 to 14.

The machining program 4 controls the overall operation of the grinding apparatus, and FIG. 4 shows the concept of the processing procedure. The grindstone diameter measurement subroutines 6, 8, and 10 with various re-measurement processes are called and executed during the execution of the machining program 4, and execute the abnormal measurement value->cleaning-> re-measurement process which is a feature of the present invention. I do. These are outlined in FIGS.

Next, the processing executed by the machining program 4 will be described with reference to FIG. In FIG. 4, steps S461, S462... S46N are procedures for measuring the grindstone diameter before grinding. When executing this processing, the grinding wheel diameter measurement subroutine 6 with re-measurement processing before grinding stored in the memory 2 is called and executed. When this subroutine 6 is executed, the processing of FIG. 5 is executed. Here, when an abnormal value is measured for the grinding wheel diameter, a process of cleaning and then measuring again is executed.

As shown in FIG. 5, when a subroutine 6 for measuring a grindstone diameter is called prior to the grinding process, the grindstone 64 is returned to a predetermined origin position in step S502. After the return, the counters 24, 34 and 44 are cleared to zero.

Next, in step S503, the grindstone is BH + P.
(The Z-axis motor 20 is rotated as necessary for the lowering). Here, as shown in FIG. 3, H is the length from the head 62 to the tip of the grindstone 64, and B is the head 62 located at the origin position and the probe 7 of the touch sensor 70.
0a. When the grindstone 64 is lowered by BH + P, the side surface located at a distance of P from the tip of the grindstone is placed in a positional relationship in which it touches the touch probe 70a. As the value of P, a value predetermined for each grindstone used is used. Note that a virtual line in FIG. 3 shows a state corresponding to the origin position.

After the grindstone 64 is set to the height at which the grindstone 64 contacts the touch probe 70a in step S503 of FIG. 5, the grindstone 64 starts to move rightward by the X-axis motor 40. The X-axis motor 40 continues to rotate until the touch probe 70a abuts on the grindstone 64, and stops when it abuts. The value of the counter 44 at this time is read into the CPU 50. Then, the value a (see FIG. 3) is substituted into the formula of AaK to calculate the grindstone diameter, and the calculated grindstone diameter is stored as Fnew (step S506). Here, A is the horizontal distance from the origin to the center of the touch sensor 70 as shown in FIG. 3, and K is the radius of the touch probe 70a. It is understood from FIG. 3 that the grindstone diameter is calculated by AaK.

The diameter of the grindstone measured in this way is compared in S507 in FIG. 5 to see if it is abnormal.
In S507, F is the grindstone diameter measured before that, and is constantly updated to the latest measured value by being replaced with the current measured value Fnew, for example, as shown in step S516 in FIG. However, in step S507, since the updating process in step S516 has not been performed yet, the immediately preceding measured value is stored in F.

In step S507, ΔF1 is an average value at which the grindstone diameter is reduced by the processing from measurement to measurement, and is given after being experimentally measured in advance. C1 and C2 are constants giving an allowable width. Here, if the grindstone is normally worn, step S507 should be YES. If the measured value Fnew satisfies the condition of step S507, the abnormal flag is turned off as shown in S515, and the grindstone diameter is updated in S516.

On the other hand, if the grindstone is abnormal or the grindstone itself is normal, but no chips or abrasive grains are attached and the correct grindstone diameter is not measured, the result is NO in S507. In this case, the grindstone 64 is moved leftward by a predetermined distance d and then raised by e, and the coolant is discharged to wash the grindstone 64 (S5).
08,509,510). After the cleaning, the grindstone 64 is returned to the measured height (S511), and the grindstone is moved rightward until the touch sensor 70 is turned on again (until it is turned on in S513). When the touch sensor is turned on, step S50
Calculate the grindstone diameter in the same process as in Step 6
It is stored as w (S506a). If the wheel diameter calculated in this way is normal, then step S5
It returns to the processing after 15. On the other hand, if there is still an abnormality after cleaning and re-measurement, the grindstone is returned to the origin position (S51
7) Then, the abnormal flag is turned on (S518).

In FIG. 4, when a normal grinding wheel diameter is calculated in the grinding wheel diameter measurement subroutine 6 with re-measurement processing before grinding, the movement data of the grinding wheel 64 is corrected using the updated new measured values, and the machining is performed. 1-1 to 1-M1,2-1 to 2-M
2, N-1 to N-MN are executed. As a result, the work is ground based on the correct grindstone diameter data, and the work dimensions become accurate. On the other hand, if an abnormal value is measured and the measurement is still abnormal even after cleaning and re-measurement, step S40
The operator performs an abnormal process shown in FIG.

After the measurement / machining cycle has been executed N times in this way, the grindstone diameter measurement subroutine 8 with re-measurement processing before truing is executed in step S48. This is shown in FIG. This processing is almost the same as that of FIG. 5, but differs in that the comparison processing of S61 is added. That is, also in this case, when an abnormal value is measured (NO in S507), the grindstone is washed and re-measured. When the abnormal value is measured again (NO in S514), a process of determining an abnormality is executed. Is done.

Step S61 is executed when a normal value is measured in the first measurement or the second measurement, but only when the new measurement value is smaller than the immediately preceding measurement value. Is updated, otherwise, the update process (S516) is skipped. The new measured value becomes larger than the immediately preceding measured value when the outer periphery of the grindstone slightly wears in a wavy manner, and the measured portion is different between the previous time and the present time. In this case, since it is more appropriate to correct the shape of the grindstone using the data of the smaller diameter for truing, the grindstone diameter is updated only when the data of the smaller diameter is measured from the previous time.

If the value still becomes abnormal even after cleaning and re-measurement in step S48 of FIG. 4, abnormal processing is performed (S50).
0) Notify the operator. On the other hand, when the normal value is measured, the comparison in S40 is performed. In step S40, the grindstone diameter is compared with the minimum grindstone diameter, and if it is smaller than the minimum grindstone diameter, the grindstone is replaced (S41). While the grindstone is equal to or larger than the minimum grindstone diameter, truing is performed in S412.

In this truing, the grindstone 64 is placed at a horizontal position indicated by X in FIG. 3 with respect to the truing grinder 80, and the grindstone 64 is moved downward as indicated by arrow 5 while rotating the grindstone 64 and the grinder 80. Here, the distance between the grindstone 64 and the grinder 80 is set based on the grindstone diameter measured in S48 of FIG. 4 and a predetermined truing amount. By this truing, the outer periphery of the grindstone 64 is again finished to an accurate cylindrical surface.

After the truing is completed, a grinding stone diameter measuring subroutine 10 with a post-truing re-measurement processing is executed in step S410 of FIG. In this processing, as shown in FIG. 7, the same processing as the processing in FIG. 5 is executed except for steps S707 and 714. In step S707 in FIG. 7, ΔF2 indicates a change in the grindstone diameter that should be reduced by the truing process, and C3 and C4 indicate the allowable widths at this time.

Then, if yes in step S707,
This corresponds to a case where truing is performed accurately and that is confirmed by the measured value of the grinding wheel diameter. On the other hand, if NO in S707, cleaning is performed again in this case, and measurement is performed again to determine whether the measurement is normal or abnormal (S714). Here, if an abnormality is found again, the grindstone is moved to the origin, and the abnormality flag is turned on. In this case, the truing amount is changed as shown in steps S42 and S4122 in FIG. 4, and truing is performed again. After truing, measure the grindstone diameter to determine whether it is normal or abnormal. If abnormal again, abnormal processing is performed (S600). Step S4
If any of 10 to 4102 is normal, the process returns to the normal process. When it is confirmed from the measurement of the grindstone diameter that the truing has been normally performed in this way, the processing is continued as shown in FIG. In this case, since the grindstone diameter has already been measured, the slap S461 is omitted.

In the case of this embodiment, the difference between the previous measured value and the present measured value is determined by the CPU 50 and the program (particularly, the grinding wheel diameter measuring subroutine 6 with re-measurement before grinding), which are related to step S507 and its execution. Means for determining whether or not the position is within the range is constituted. Also, slaps S510 to S516 of FIG.
The nozzle 58, the touch sensor 70, the subroutine 6, and the like constitute a cleaning remeasurement unit.

In this embodiment, before processing, before truing, and after truing, the measured value is compared with a normal value under each condition, and if an abnormal value is measured, the measured value is washed and then measured again. Is performed. Therefore, the subsequent processing is not performed using the abnormal value.Also, when the effective grinding wheel diameter is correct but only the measured value is abnormal, it is automatically returned to normal by the re-measurement processing. Therefore, the abnormality processing is executed only when the effective grinding wheel diameter is abnormal. At this time, unnecessary cleaning is not performed. Although the present embodiment shows the case where the present invention is applied to the measurement of the grindstone diameter, the present invention can be used for measuring the length of the grindstone when the work is ground on the grindstone end face.

[0028]

According to the present invention, it is determined whether the measured value of the grindstone size is normal or abnormal, and when the measured value is abnormal, the measured value is washed and re-measured. Subsequent processing is not executed on the basis of erroneous whetstone dimension data. Therefore, the dimensional accuracy of the ground product is maintained, and a highly reliable grinding device can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing an outline of an entire processing procedure.

FIG. 2 is a system configuration diagram of an embodiment.

FIG. 3 is a diagram illustrating a distance.

FIG. 4 is a view showing the entire processing procedure of the embodiment.

FIG. 5 is a flowchart of a grindstone diameter subroutine with re-measurement processing before grinding.

FIG. 6 is a flowchart of a grindstone diameter subroutine with re-measurement processing before truing.

FIG. 7 is a procedure diagram of a grindstone diameter subroutine with re-measurement processing after truing.

[Explanation of symbols]

 S507 Abnormal wheel diameter discrimination processing S510 Cleaning processing S512, S513, S506a Re-measurement processing

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-62-9867 (JP, A) JP-A-49-39191 (JP, A) JP-A-64-16354 (JP, A) JP-A 55-39 58950 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B24B 49/00-49/18 B23Q 17/00 B23Q 17/22

Claims (1)

(57) [Claims] 1. A grinding apparatus der to ground by grindstone
A grinding wheel size measuring means, a grinding wheel cleaning means, and a predetermined grinding while controlling the grinding wheel position based on the grinding wheel size.
Grinding processing control means for performing the processing, and measurement procedure control means for controlling the grinding wheel dimension measurement procedure are provided.
For example, the measurement procedure control means, a predetermined grinding by (1) grinding control means executes
A step of measuring and storing the grindstone dimensions before it is, (2) a predetermined Grinding performed by grinding control means
And (3) comparing the difference between the measured values of the above (1) and (2) with a predetermined value.
And (4) washing the grindstone when the value is larger than the predetermined value in (3).
Cleaning and re-measurement of the dimensions of the grindstone after cleaning; and (5) comparing the difference between the measured values of (1) and (4) with a predetermined value.
And (6) an abnormal signal when the value is larger than a predetermined value in (5)
Grinding apparatus characterized by and a procedure for outputting.