JP2620899B2 - Wire electric discharge machining method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire discharge apparatus which takes necessary measures in accordance with the rate of decrease in the machining speed when the machining speed changes due to abrasion or deterioration of a power supply portion or the like. Related to processing method.

[0002]

2. Description of the Related Art FIG. 3 is a schematic view of a conventional wire electric discharge machine. In the figure, reference numeral 1 denotes a wire electrode for supplying a high-frequency current and processing a workpiece 10 with a small gap;
Is an XY cross table for fixing the workpiece 10,
Reference numeral 4 denotes an X-axis driving motor and a Y-axis driving motor for driving the XY cross table 2, respectively. Reference numeral 5 denotes a control device for instructing the X-axis and Y-axis driving motors 3 and 4 to rotate. 1 is a processing power supply for supplying electric energy to the power supply 1.

Next, the operation will be described with reference to the flowchart of FIG. First, the material and plate thickness of the workpiece 10,
An operator sets processing conditions such as a processing speed in the controller 5 based on the material and diameter of the wire electrode 1 used for processing (step S1). Next, processing by the optimal feed method is started (step S2). Here, the optimum feeding method means that a voltage (inter-electrode voltage) generated in a gap between the workpiece 10 and the wire electrode 1 is detected, and an appropriate feeding (processing speed) is performed by the control device 5 while keeping the inter-electrode voltage constant. ) To the X-axis and Y-axis driving motors 3 and 4. As the machining progresses, the machining speed may change due to wear of the power supply unit, the wire guide, and other components.
The change status of the machining speed output from the LM is periodically checked (step S3). If there is no abnormality, the machining is continued (step S4). If there is an abnormality, the abnormal part is maintained (step S5). The processing was restarted, and the processing was performed while taking appropriate measures corresponding to such a change in the processing speed (step S6).

[0004]

In conventional wire electric discharge machining, an operator must be constantly attached to the machine to monitor the machining status, and if the operator does not check the machining speed, the wire electrode may be disconnected. There has been a problem that the processing frequently occurs and processing becomes impossible, and thus the operation rate of the machine does not increase.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and the operator can quickly know the necessity of maintenance by detecting the reduction rate of the machining speed even if the operator is not always stuck to the machine. It is an object of the present invention to obtain a wire electric discharge machining method in which an appropriate measure is taken as described above and the operating rate of the machine is increased.

[0006]

In order to achieve the above-mentioned object, a wire electric discharge machining method according to the present invention samples a machining speed based on a detected value of a voltage between contacts, and sets a preset machining speed in a normal state. Calculate the decrease rate of the actual machining speed by comparing with (reference machining speed), and calculate the actual machining speed.
Normal operation when the rate of decrease is less than the specified lower limit
And a warning when the value is between the lower limit and the upper limit.
And processing is stopped if the upper limit is exceeded.
Stopping the process .

[0007]

The processing speed that changes with time is detected at regular intervals from the detected value of the voltage between the electrodes, and if the reduction rate of the actual processing speed is obtained by comparison with the reference processing speed, the rate of reduction is determined according to the degree of the reduction rate. Appropriate action can be taken, prompting workers to take necessary maintenance early.

[0008]

FIG. 1 is a flowchart showing an embodiment of the present invention. The operation of the embodiment will be described below with reference to this flowchart. First, processing conditions are set based on the material and thickness of the workpiece 10 and the material and diameter of the wire electrode 1 (step S1). This is exactly the same as the conventional example. Next, the processing speed estimated in the main processing is input to the control device 5 (step S2). This is the basic normal processing speed (reference processing speed). Thereafter, machining by the optimal feed method is started (step S3), and a machining speed within a certain time is calculated by the control device 5 (step S3).
4). This processing speed is calculated based on the detected value of the voltage between the electrodes, and an average value or a minimum value of the actual processing speed is obtained by sampling every predetermined time. Then, the actual machining speed is compared with the above-mentioned reference machining speed to calculate a reduction rate of the actual machining speed (step S5). This reduction rate is, for example, 10
If it is within 10%, processing is continued as normal operation (step S6). For example, if it is 10% to 30 %, a warning is displayed on the CRT (step S7), and 30% to 50 %.
In this case, a buzzer sound is generated (step S8), and if it is 50% or more, the processing is automatically stopped immediately (step S9). CRT
When a warning is displayed or a buzzer sound is generated, the operator temporarily monitors the processing state and continues the processing for the time being (step S10). The above procedure is repeated until the machining is completed while repeatedly checking the change in the machining speed (step S11).

[0009]

As described above, according to the present invention, it is possible to automatically monitor a processing speed that changes with time even if an operator is not always attached to a machine, and to detect a decrease rate of the processing speed. As a result, appropriate measures are taken in accordance with the degree of the reduction rate of the processing speed, so that the time required for maintenance can be known at an early stage, stable processing can be realized, and the operating rate of the machine can be increased. effective.

[Brief description of the drawings]

FIG. 1 is a flowchart showing one embodiment of the present invention.

FIG. 2 is a flowchart showing an operation of a conventional example.

FIG. 3 is a schematic view of a conventional wire electric discharge machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wire electrode 2 XY cross table 3 X-axis drive motor 4 Y-axis drive motor 5 Control device 6 Processing power supply 10 Workpiece

Claims (1)

(57) [Claims] A voltage generated in a gap between a wire electrode and a workpiece is detected, a processing speed is detected at regular intervals based on a detected value of a voltage between the electrodes, and the actual processing speed is set to a predetermined normal time. the by comparing the processing rate from the reduction rate of the actual machining speed, rate of decrease in the actual machining speed is predetermined
A step of normal operation when smaller than the lower limit of;
A warning process when the value is between the lower limit and the upper limit, and
Stopping the machining when it is larger than the upper limit value .