JPS60259304A - Machining anomaly detecting apparatus - Google Patents

Abstract

PURPOSE:To obtain an automatic apparatus through which defects are hardly formed, by calculating the relative shift distance ranging from the start of approach between a tool and a workpiece up to contact and transmitting an anomaly signal when the difference from a standard relative shift distance is over an allowable value. CONSTITUTION:Pulse signals are sent-out into a counter 10 by using a pulse generator 9' for an NC machine tool and by using a pulse generator 9 which outputs pulses through the shift of a tool in case of a common tool, and the pulse signals corresponding to the shift of the tool from a standard position are calculated, and the calculation value 12 is outputted into a CPU8 through an interface 7. When the top edge of the tool 1 contacts with a workpiece 2, a contact signal is input into the CPU8, and the shift distance is calculated form the count value up to the contact, and the difference from a predetermined standard shift distance is calculated, and the obtained value is compared with an allowable difference, and when the value is over the allowable difference, an anomaly signal is transmitted. With such constitution, quality can be improved, and the formation of defects can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an abnormality detection device for a machining device and a machining device equipped with an abnormality detection function.
.

Abnormalities in machining equipment such as technology and conventional numerically controlled machine tools include tool abnormalities and workpiece abnormalities. In these machining devices, tool abnormalities (e.g. tool breakage, tool wear) can be detected by visual inspection or by measuring cutting torque, spindle motor current, cutting vibration, tool Something that detects changes in shape is used. However, in the case of a small tool, for example, a small-diameter tool used for punching with a diameter of about 3 mm or less, the above-mentioned change between normal and abnormal conditions of the tool is slight and is not easy to detect. For this reason, even though the tool is in an abnormal state,
There is a problem in that some defects are not detected, and processing continues as is, resulting in a large number of defective products.

In addition, if there is an abnormality in the workpiece such as deformation or displacement (for example, warping of a plate-shaped workpiece) due to distortion of the workpiece, the tool may be moved from the reference position as in normal processing equipment. In a machining device that processes by moving a fixed amount, the amount of processing increases or decreases by the amount of deformation, resulting in defective products. In order to prevent this, in order to know the amount of deformation, it is necessary to check the dimensions of the workpiece before machining each time to detect deformation of the workpiece, which is extremely troublesome.

Furthermore, since deformation of the workpiece may occur during machining, it has been difficult to detect it during high-speed machining. Therefore, it has been desired to develop a device that can easily detect deformation of a workpiece.

Furthermore, when the amount of machining is specified by the distance from the surface of the workpiece, such as the depth from the surface of the workpiece, the degree of tool abnormality or the amount of deformation of the workpiece is If the abnormality is small, it may not cause a problem in practice if the abnormality is compensated for and a predetermined amount is processed. However, in order to do this, it is necessary to measure the degree of abnormality in the tool or the amount of deformation of the workpiece before each machining process, and to check the deviation of the tool tip position or the surface position of the workpiece from the normal position. must be input into the tool control device, which is extremely inconvenient.

SUMMARY OF THE INVENTION An object of the present invention is to provide an abnormality detection device for a machining device that can eliminate the above-mentioned drawbacks, and a machining device having an abnormality detection function.

The object of the present invention is to provide an abnormality detection device for a machining device that processes a workpiece by changing the relative distance between the tool and the workpiece, means for detecting contact and emitting a signal; means for storing and setting a reference relative movement distance between the tool and the workpiece; detecting the contact after the relative distance between the tool and the workpiece begins to change; means for calculating the relative movement distance between the tool and the workpiece until the signal is issued; means for setting a tolerance between the reference relative movement distance and the calculated relative movement distance; and the reference. An abnormality detection device (first invention) characterized by comprising means for emitting an abnormality signal if the difference between the relative movement distance and the calculated relative movement distance is larger than the tolerance;
” In the first invention, the means for setting the tolerance is means for setting a first tolerance between the reference relative movement distance and the calculated relative movement distance, and further, means for setting a second tolerance between the relative movement distance and the calculated relative movement distance that is less than the first tolerance;
and means for emitting a correction signal for correcting the amount of machining of the workpiece by the tool in accordance with the eye difference, if the eye difference is less than or equal to the first tolerance and greater than the second tolerance. An abnormality detection device (second invention) characterized in that in the second invention, the means for emitting the abnormality signal detects a difference between the reference relative movement distance and the calculated relative movement distance. 1 tolerance, and if the calculated relative movement distance is smaller than the reference relative movement distance, means for issuing a workpiece abnormality signal, and the eye difference is larger than the first tolerance. , and an abnormality detection device f (third invention), characterized in that it is a means for emitting an abnormality signal if the calculated relative movement distance is larger than the reference relative movement distance, and a tool and a workpiece. An abnormality detection device for a machining device of the type that processes a workpiece by changing the relative distance between the tool and the workpiece, and a means for detecting contact between the tool and the workpiece and emitting a signal; means for storing and setting a reference relative movement distance between the tool and the workpiece; a means for calculating a relative movement distance between the two, a means for setting a first tolerance, a means for setting a second tolerance smaller than the first tolerance, and a means for calculating the relative movement distance ( z
means for storing the calculated relative movement distance (Zn) in the n-th machining (n is an integer of 2 or more); memorizing in the n-1-th machining; relative movement distance (
The difference (lZn-1-Znl) between the relative movement distance (Zn) calculated in the n-th processing is larger than the first tolerance, and Zn is smaller than 7n-1. means for emitting a workpiece abnormality signal if the difference is smaller than the first tolerance; the means for emitting, and the inter-eye difference (l Zn-1-Zn I) is less than or equal to the first tolerance, and the distance Zn and the relative movement distance (zl) stored in the first processing are Difference (121-Zn
l) is larger than the second tolerance, then the difference (Z 1-Z
Anomaly detection device ml (fourth invention) characterized in that it is equipped with means for emitting a correction signal for correcting the amount of machining of a workpiece by a tool according to (n) 1, between a tool and a workpiece A means for detecting contact between a tool and a workpiece and emitting a signal by using a machining device that processes a workpiece by changing the relative distance between the tool and the workpiece; A means for storing and setting a reference relative movement distance; a means for storing and setting a reference relative movement distance; means for calculating, means for setting a tolerance between the reference relative movement distance and the calculated relative movement distance, and means for setting a tolerance between the reference relative movement distance and the calculated relative movement distance; A machining device (fifth invention) characterized in that it is equipped with means for emitting an abnormal signal when the abnormality signal is detected, and the amount of machining of the workpiece by the tool can be corrected using the correction signal; the means for setting the tolerance is means for setting a first tolerance between the reference relative movement distance and the calculated relative movement distance; means for setting a second tolerance smaller than the first tolerance between the relative movement distance;
and if the eye difference is less than or equal to the first tolerance and larger than the second tolerance, means for generating a correction signal for correcting the machining amount of the workpiece by the tool k in accordance with the eye difference. A machining device [(sixth invention), characterized in that in the sixth invention, the means for emitting the abnormal signal is configured such that the difference between the reference relative movement distance and the calculated relative movement distance is means for issuing a workpiece abnormality signal if the calculated relative movement distance is greater than the first tolerance and smaller than the reference relative movement distance; and an eye difference greater than the first tolerance; A machining device (seventh invention) characterized in that the method is a means for emitting an abnormal signal if the calculated relative movement distance is larger than the reference relative movement distance, and a tool and a workpiece. A means for detecting contact between the tool and the workpiece and emitting a signal using a machining device that processes the workpiece by changing the relative distance between the tools and the workpiece. means for calculating a relative movement distance between the tool and the workpiece from when the relative distance starts to change until the contact detection signal is issued; means for setting a first tolerance; the first tolerance; Means for setting a smaller second tolerance, the calculated relative movement distance (z
means for storing the calculated relative movement distance (Z
n), a means for storing the relative movement distance (
Zn-1> and the relative movement distance (Zn) calculated in the n-th processing (lZn-1-Znl) is larger than the first tolerance, and Zn is smaller than 7n-1. means for emitting a workpiece abnormality signal if the difference (l Zn-1-Zn l ) is larger than the first tolerance and ln is larger than Zn-1; means for emitting, and the eye difference (I Zn-1-Zn l ) is less than or equal to the first tolerance, and the relative movement distance (zl) and distance (Zn) stored in the first processing are The difference between (121-Zn
l) is larger than the second tolerance, then the difference (Z 1-Z
(8th invention) This is achieved by

1 to 8 are claim correspondence diagrams corresponding to the first to eighth inventions of the present invention recited in claims 1 to 8, respectively. In the figures, reference symbols (
1) shows a tool, (2) shows a workpiece, and (5) shows a machining device. 9 to 12 are flowcharts of the present invention when the machining device is of a type in which the tool moves toward the workpiece, and FIG. 9 is a flowchart of the first and fifth inventions. , FIG. 10 is a flowchart of the second invention and the sixth invention, and FIG. 11 is a flowchart of the third invention and the seventh invention.
The flowchart of the invention, FIG. 12, is as follows.

It is a flowchart of the 4th invention and the 8th invention.

9 to 12, the reference distance between the tool and the workpiece is 71, the calculated relative movement distance in the n-th machining is zn, and the first and fifth inventions are The first tolerance of the tolerance and the second to fourth inventions and the sixth to eighth invention is indicated by α, and the second tolerance is indicated by β.

The distance relationship will be explained with reference to FIGS. 13 to 148.

FIG. 13 is an explanatory diagram when the tool is worn out or damaged. When the tool (1) is at the reference position,
When the tool (1) is normal, the tool tip and workpiece (2)
The distance between the tool (1) and the surface of the workpiece (2) is Z, but if the tool (1) is worn or broken, the distance between the tool (1) and the surface of the workpiece (2) becomes 2'. The difference ΔZ between Z' and 7 is the amount of wear or chipping of the tool.

FIG. 14A and FIG. 148 are explanatory views when deformation (distortion) occurs in the workpiece. When the tool (1) is at the reference position and there is no deformation (distortion) of the workpiece (2), the distance between the tip of the tool (1) and the surface of the workpiece (2) is Z. However, when the workpiece (2) is deformed and becomes convex, the distance between the tool (1) and the surface of the workpiece (2) becomes Z' (FIG. 14A). The difference Δ2 between 2' and Z is the amount of deformation (strain) of the workpiece. In addition, the workpiece (2
) q When it is deformed and becomes concave, the tool (1) 8 Workpiece (2). The distance i from the surface is Z. (FIG. 14B). The difference ΔZ between 2' and Z is the amount of deformation (strain) of the workpiece.

U21 The present invention will be explained below by taking as an example a machining apparatus that moves a tool toward a workpiece and performs punching to a predetermined depth.

FIG. 15 is a block diagram for hair removal according to this embodiment. - If the processing device (5) is a numerically controlled processing device, a pulse generator (
A pulse signal is sent from the pulse generator (9') to the counter (10) as the tool moves.

If the machining device (5) is not of a numerical control type, a pulse generator (9) that emits pulse signals in synchronization with the movement of the tool is attached to the machining device (5) to generate the pulse signals. What is necessary is to send it to the counter (10).

A counter (10) counts pulse signals generated in response to movement of the tool from its reference position.

The counter (10) sends the counter count value (12) to the central processing unit (8) via the interface (7). When the tip of the tool comes into contact with the surface of the workpiece due to movement of the tool, a contact signal (11) is sent to the central processing@1t (8) via the interface (7), and the central processing unit The counter count value (12) is read and the moving distance of the tool is calculated. As a means for detecting contact and emitting a contact signal, any suitable known means can be used, but in an electric circuit that is closed by contact between the tool (1) and the workpiece (2), Suitably, the contact is detected on the basis of the current flowing through the circuit due to the contact.

A reference moving distance of the tool is set in advance by a reference moving distance setting means (16). This reference movement distance may be set automatically based on the movement distance calculated during the first machining, or may be set automatically based on the movement distance calculated during the previous machining. It may be something that can be used.

The reference moving distance and the calculated moving distance are compared and calculated by the central processing unit t(8), and the difference is a (first) tolerance set in advance by the (first) tolerance setting device (13). If it is larger, some kind of abnormality has occurred in the tool or workpiece, and an abnormality signal is output. Based on this abnormality signal, automatic tool exchange or operation of the processing device may be stopped. If no abnormal signal is emitted,
A predetermined amount of processing is performed.

In the second invention and the sixth application of the present invention, in addition to the above configuration, the difference is set in advance by a second tolerance setting device (14) and a second tolerance smaller than the (first) tolerance is set. If it is larger than the tolerance, a correction signal for reducing the amount of machining of the workpiece by the tool by an amount corresponding to the eye difference is sent to the control device (15) that controls the tool, and the amount of machining is reduced. to automatically perform the correction.

In the third invention and the seventh invention, in addition to the above configuration, in place of the output of the abnormal signal, if the calculated movement distance is smaller than the reference movement distance (the 14th A.
If there is an abnormality in the workpiece/workpiece (corresponding to the case shown in the figure), a workpiece abnormality signal is issued, and if the calculated moving distance is greater than the reference moving distance (corresponding to the case shown in FIG. (corresponding to the case), an abnormal signal is emitted.

In the fourth invention and the eighth invention of the present invention, the distance setting device (16) in each of the above inventions is provided with a reference relative movement distance and (
The moving distance (Zl) in the first machining and the moving distance (Zn-1) in the immediately preceding machining are automatically set as Z), and the moving distance (Zn-1) in the n-1st machining is automatically set. and the distance (Zn) (lZn-1-Zn I) (13th to 1st
This corresponds to Δ2 in Figure 4B. ) is larger than the first tolerance,
And if 7-n-1>zn (in the case of Figure 14A)
, a workpiece abnormality signal is generated, and if Zlow1<7n (in the case of FIG. 13 or FIG. 14B), an abnormality signal is generated. The difference (I Zn-1-Zn l ) is the first
If it is less than the tolerance and the difference (12t-Zn l) between the distance (Zl) and (Zn) is greater than the second tolerance, the workpiece will be machined by the tool by the amount corresponding to the difference (Z1-Zn). A correction signal for increasing or decreasing the amount of work to be processed changes the tool to tsm.
The processing amount is automatically corrected.

In other words, in the fourth invention and the eighth invention, the distance "(Zl) in the first processing and the immediately preceding, ie, the n-1th
The distance (Zn-1) in the second machining is automatically set as the reference distance. In the first machining, there is no breakage or wear of the tool, and the deformation of the workpiece can be measured in advance, so the distance (Zl) can be used as the reference relative movement distance. Distance - (Zn-1) and distance (Z
If the difference from n) is large, this means that the tool is broken or the workpiece is suddenly deformed, so an abnormality signal is sent. When the difference between the distance (Zl) and the distance (Zn) is larger than a predetermined value, that is, when the tool is gradually worn with each machining process, or when the workpiece is gradually deformed little by little, The machining amount is corrected by an amount corresponding to the degree of wear or deformation.

In the configurations of each of the inventions described above, the operation of the processing device can be stopped when a workpiece abnormality signal or an abnormality signal is issued. Also, abnormal signals are generated and wear occurs when the difference between the set distance and the moving distance is large, and the set distance is larger than the moving distance, but the workpiece is deformed as shown in Fig. 14B. In this case, the abnormality signal may be used as a tool abnormality signal because it is relatively rare for the degree of deformation to become large.

In order to prevent malfunctions due to the influence of noise or the influence of variations in contact when detecting contact signals, each setting value is set to 2.
It is preferable to determine that a tool abnormality or a workpiece abnormality occurs when the value exceeds the limit twice or more consecutively.

In the above embodiment, instead of using distance setting 1 (16), it is also possible to memorize the counter value from the previous machining as the distance reference value and use it as the reference moving distance. can.

Detection of contact between tool (1) and workpiece (2) is
When the current flowing at a time when the two are in contact is to be used, it is preferable to electrically insulate the tool (1) and the machine body (5) with an insulator (6) in advance. Further, when the workpiece is a non-conductor, it is preferable to cover all or part of the surface of the workpiece with a conductive substance.

Next, an example of punching using the machining apparatus of the above embodiment will be shown below.

[Processing Example 1] The abnormality detection device of the second invention was attached to a machining device that performs punching, and punching was performed on a thin plate under the following conditions.

Tool driving cycle: 3.8 times per second Distance from tool reference position to workpiece = 2Illll 2nd
Setting value to the tolerance setter: 10 μm Setting value to the first tolerance setter: 20 μm Tool diameter: φ1.2 Tool tip angle: 90° Workpiece size: φ100Xt 0.6 During punching, The machine stopped when the tip of the tool was chipped by 20μ. At this time, the machine was stopped when the defect was detected twice in a row, so there were two holes punched with the defective tool.

[Processing example 2] The abnormality detection device of the third invention is attached to an NG machine tool,
Performed punching process.

Tool driving cycle: 6 times per second Distance from tool reference position to workpiece 111:2 gam Setting value to the first tolerance setting device: 1100t1 Setting value to the second tolerance setting device: 20μ Tool diameter: φ1 .2 Tool tip angle: 90' Workpiece dimensions: φ100Xt 0.6 Driving depth: 0
, 3a+a When punching 1000 holes, although deformation (distortion) of the workpiece occurred, the processing amount correction function was activated and a driving correction pulse was sent to the numerical control device of the NO machine tool, Since the amount of implantation was corrected, the variation in implantation depth was less than 20 μm.

ffl teaching 1゜Thus, according to the present invention, the machining amount by the tool can be controlled in-process in response to minute deformation (strain) of the workpiece and minute wear of the tool that occur during high-speed machining using a small-diameter tool. By doing so, processing can be performed with a uniform amount of processing, making it possible to process high-quality products.

Furthermore, by stopping the machine when an abnormality occurs in the tool or workpiece, it is possible to prevent product defects due to machining in an abnormal state, and to perform automatic tool exchange in the event of a tool abnormality. This enables unmanned operation for long periods of time.

The principle of distance calculation according to the present invention can be applied to automatically measuring three-dimensional distances, so this principle can be used to automate a three-dimensional measuring machine. In addition, if this distance calculation principle is applied to a NO machine tool, in addition to the abnormality detection function of the present invention, machining can be performed automatically by collecting machining data (for example, it can be used to automatically determine how many parts to machine from a certain surface). commands can be issued automatically).

[Brief explanation of drawings]

1 to 8 are claims correspondence diagrams corresponding to the first to eighth inventions of the present invention, FIG. 9 is a flowchart of the first invention and the fifth invention, and FIG. 10 is a flow chart of the second invention and the fifth invention. 1!11 is a flowchart of the third invention and the seventh invention, FIG. 12 is a flowchart of the fourth invention and the eighth invention, and FIG. 13 shows the distance relationship when an abnormality occurs in the tool. FIGS. 14A and 14B are explanatory diagrams illustrating the distance relationship when an abnormality occurs in the workpiece, and FIG. 15 is a block diagram illustrating one embodiment of the present invention. 1: Tool 2: Workpiece 5: I machining equipment body 6: Insulator 7: Interface 8: Central processing unit W1 9: Pulse generator 9': Pulse generator 10: Counter 11: Contact signal 12: Counter meter Numeric value 13: (1st) tolerance setter 14: 2nd tolerance setter 15: Numerical controller t 16: Distance setter procedure correction form (
Iffl ship January 21, 1985 Manabu Shiga, Commissioner of the Patent Office '9 1. Indication of the case 1988 Patent Application No. 116884 2. Invention 0 Title Mechanical power. Koko regular detection device. 3. Relationship with the case of the person making the amendment Patent applicant 4, agent 10sawa no Tsuru Building, 2 Hirano-cho, Higashi-ku, Osaka, Tel: 06-203
-0941 (6521) Patent Attorney Eiji Saegusa 6. Contents of the amendment to the number of inventions to be increased by the amendment l Figures 9 and 10 will be amended as attached. (above)

Claims (1)

[Claims] ■ An abnormality detection device for a machining device that processes a workpiece by changing the relative distance between the tool and the workpiece, means for detecting contact between the tool and the workpiece and generating a signal; means for storing and setting a reference relative movement distance between the tool and the workpiece; and means for detecting the contact after the relative distance between the tool and the workpiece begins to change means for calculating a relative movement distance between the tool and the workpiece until a detection signal is issued; means for setting a tolerance between the reference relative movement distance and the calculated relative movement distance; An abnormality detection device characterized by comprising means for emitting an abnormality signal 2 if the difference between the reference relative movement distance and the calculated relative movement distance is larger than the tolerance. ■ An abnormality detection device for machining equipment that processes the workpiece by changing the relative distance between the tool and the workpiece, and detects contact between the tool and the workpiece. means for emitting a signal, means for storing and setting a reference relative movement distance between the tool and the workpiece, and a means for storing and setting a reference relative movement distance between the tool and the workpiece; means for calculating a relative movement distance between the tool and the workpiece; means for setting a first tolerance between the reference relative vibration distance and the calculated relative movement distance; means for setting a second tolerance smaller than the first tolerance between the calculated relative movement distance, and the difference between the reference relative movement distance and the calculated relative movement distance being larger than the first tolerance; For example, means for generating an abnormal signal, and means for correcting the amount of machining of the workpiece by the tool in accordance with the eye difference if the eye difference is less than or equal to the first tolerance and larger than the second tolerance. An abnormality detection device characterized by comprising means for emitting a correction signal. ■ An abnormality detection device for machining equipment that processes the workpiece by changing the relative distance between the tool and the workpiece, and detects contact between the tool and the workpiece. means for emitting a contact detection signal; means for storing and setting a reference relative movement distance between the tool and the workpiece; and a means for storing and setting a reference relative movement distance between the tool and the workpiece; means for calculating a relative movement distance between a tool and a workpiece; means for setting a first tolerance between the reference relative movement distance and the calculated relative movement distance; means for setting a second tolerance smaller than the first tolerance between the calculated relative movement distance, and the difference between the reference relative movement distance and the calculated relative movement distance being larger than the first tolerance; , and means for issuing a workpiece abnormality signal if the calculated relative movement distance is smaller than the reference relative movement distance; and the eye difference is larger than the first tolerance, and the reference relative movement distance is smaller than the reference relative movement distance. means for emitting an abnormal signal if the calculated relative movement distance is greater than the first tolerance; An abnormality detection device characterized by comprising means for generating a correction signal for correcting the amount of machining of a workpiece by a tool. ■ An abnormality detection device for machining equipment that processes the workpiece by changing the relative distance between the tool and the workpiece, and detects when the tool and the workpiece have come into contact. means for emitting a signal; means for calculating a relative movement distance between the tool and the workpiece from when the relative distance between the tool and the workpiece begins to change until the contact detection signal is emitted; means for setting a second tolerance smaller than the first tolerance; means for setting a second tolerance smaller than the first tolerance; and means for setting the calculated relative movement distance (Z) in the first machining.
l); means for storing the calculated relative movement distance (Zn) in the n-th machining (n is an integer of 2 or more); The difference between the calculated relative movement distance (Zn-1) and the relative movement distance (Zn) calculated in the nth machining (l Zn-1-7n l
) is larger than the first tolerance, and 7 n-1
means to issue a workpiece abnormality signal if 7n is smaller than Zn-1; If it is large, a means for issuing an abnormal signal, and if the eye difference (l Zn-1-Zn l ) is less than or equal to the first tolerance, and the relative movement distance (Zl) stored in the first machining is The difference (121-Z) from the distance (Zn)
nl) is larger than the second tolerance, the difference (Z 1-
An abnormality detection device characterized by comprising means for generating a correction signal for correcting the amount of machining of a workpiece by a tool in accordance with Zn). ■ A means for detecting contact between the tool and the workpiece and emitting a signal using a machining device that processes the workpiece by changing the relative distance between the tool and the workpiece; A means for storing and setting a reference relative movement distance between the tool and the workpiece; a means for storing and setting a reference relative movement distance between the tool and the workpiece; means for calculating a distance of relative movement between the reference relative movement distance and the calculated relative movement distance; and means for setting a tolerance between the reference relative movement distance and the calculated relative movement distance; A machining device comprising: means for generating an abnormality signal if the difference between the two and the tolerance is larger than the tolerance. ■ A means for detecting contact between the tool and the workpiece and emitting a signal using a machining device that processes the workpiece by changing the relative distance between the tool and the workpiece; means for storing and setting a reference relative movement distance between the tool and the workpiece; means for calculating a relative movement distance between the reference relative movement distance and the calculated relative movement distance; means for setting a first tolerance between the reference relative movement distance and the calculated relative movement distance; means for setting a second tolerance smaller than the first tolerance between the reference relative movement distance and the calculated relative movement distance; if the difference between the reference relative movement distance and the calculated relative movement distance is larger than the first tolerance, an abnormality is detected; means for emitting a signal; and means for emitting a correction signal in accordance with the eye difference if the eye difference is smaller than the first tolerance and larger than the second tolerance, A machining device characterized in that it is capable of making corrections using the correction signal.■ A machining device that processes a workpiece by changing the relative distance between the tool and the workpiece, the tool A means for detecting contact between the tool and the workpiece and emitting a signal, a means for storing and setting a reference relative movement distance between the tool and the workpiece, and a means for detecting a change in the relative distance between the tool and the workpiece. a first tolerance between the reference relative movement distance and the calculated relative movement distance; means for setting a second tolerance smaller than the first tolerance between the reference relative movement distance and the calculated relative movement distance; means for setting a second tolerance between the reference relative movement distance and the calculated relative movement distance; means for issuing a workpiece abnormality signal if the calculated relative movement distance is smaller than the reference relative movement distance, and the distance is larger than the first tolerance; means for emitting an abnormal signal if the calculated relative movement distance is greater than the reference relative movement distance, and the eye difference is less than or equal to the tolerance, and the calculated relative movement distance is greater than the second tolerance; If the difference is large, a machining device is provided with means for emitting a correction signal according to the eye difference, and the machining amount of the workpiece by the tool can be corrected by the correction signal. ■ Tool and workpiece A means for detecting contact between a tool and a workpiece and emitting a signal by using a machining device that processes a workpiece by changing the relative distance between the tool and the workpiece; means for calculating the relative movement distance between the tool and the workpiece from when the relative distance between them starts to change until the contact detection signal is issued; means for setting a first tolerance; from the first tolerance; Means for setting a small second tolerance, the calculated relative movement distance (Z
l); means for storing the calculated relative movement distance (Zn) in the n-th machining (n is an integer of 2 or more); The difference between the calculated relative movement distance (Zn-1) and the relative movement distance (Zn) calculated in the nth machining (l Zn-1 - Zn l
) is larger than the first tolerance and Zn is smaller than Zn-1, a means for issuing a workpiece abnormality signal; and means to issue an abnormal signal if Zn is larger than Zn-1, and the inter-eye difference (I Zn-1-Zn l ) is below the JI11 tolerance, and the first processing The difference between the relative movement distance (Zl) and the distance Zn (121-Zn
l) is larger than the second tolerance, the difference (Zl-Zn
) A machining apparatus characterized in that it is equipped with means for generating a correction signal according to the correction signal, and is capable of correcting the amount of machining of a workpiece by a tool using the correction signal. (2) The calculation means calculates the relative movement distance based on the number of pulses emitted in response to changes in the relative distance between the tool and the workpiece! '1
4. The device according to any one of Items 4 to 4. (1) The calculation means calculates the relative movement distance based on the number of control pulses that control the relative distance between the tool and the workpiece. The device described in Crab. ■ The reference relative movement distance corresponds to the relationship between the tool and the workpiece during the first machining, from when the calculated relative distance between the tool and the workpiece starts to change until the contact signal is issued. The device according to any one of claims 1 to 3 and 5 to 7, wherein the relative movement distance is between. [Phase] The reference relative movement distance is the distance between the tool and the workpiece from when the calculated relative distance between the tool and the workpiece starts to change in the immediately preceding machining until the contact signal is issued. The device according to any one of claims M1 to 3 and 51R to 7, wherein the relative movement distance is between. [Phase] The detection means detects a contact in an electric circuit that is closed by contact between the tool and the workpiece based on a current flowing through the circuit due to the contact. Apparatus according to any one of ranges 1 to 12. (2) The apparatus according to claim 13, wherein all or part of the surface of the workpiece is a conductive layer. ■ Claim 3, wherein when the workpiece abnormality signal is issued, an operation stop signal for the machining device is issued;
The device according to any one of paragraphs 4, 7 and 8. [Phase] The device according to any one of claims 1 to 15, wherein the abnormality signal is a tool abnormality signal. ■ When the abnormality signal is issued, an operation stop signal for the machining device is issued. Claims 1 to 16
Apparatus according to any of paragraphs. [Phase] The device according to any one of claims 1 to 16, wherein a tool change command signal is issued when the abnormality signal is issued.