JPS61288923A - Quill speed setter for electric discharge machine - Google Patents

Abstract

PURPOSE:To enable usage of setting quill speed over the entire speed table region by detecting the inter-electrode voltage between a work and an electrode then comparing with a setting voltage to produce an error voltage which is inputted directly into the speed table as the output from amplifier. CONSTITUTION:Upon detection of the machining gap 3 between an electrode 1 and a work 2 as an inter-electrode voltage through detecting section 4, error voltage generating amplifier 5 will compare said gap 3 with predetermined one to provide minus voltage to speed table 6 when it is narrower than predetermined gap while plus voltage when it is wider. Upon provision of voltages corresponding with the errors produced through comparison to the speed table at several dozen positions, only one speed table which is close to preset quill speed is selected to determine actual quill speed. When corresponding the output variable voltage from the amplifier 5 with the entire region of table, the table 6 can function completely for any setting quill speed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a servo-based quill speed setting device for an electrical discharge machine.

[Background of the invention]

Some methods for setting the quill speed in conventional electrical discharge machines utilize speed tables.

An outline of this is shown in Figure 2. In the figure, 1 is an electrode, 2 is a workpiece, 3 is a machining gap, 4 is a voltage detection section between electrodes, 5 is an error voltage generation amplifier, 6 is a speed table, 7 is a pulse generation section, and 8 is a motor.

The voltage between the electrodes 1 and the workpiece 2 is detected by the electrode-to-electrode voltage detection section 4, the error is compared with a predetermined gap set in advance by the error voltage generation amplifier 5, and the voltage corresponding to the difference is recorded in the speed table. is applied to determine the quill speed.

However, in the conventional device shown in FIG.

There is only one speed table, and therefore the maximum speed for each quill speed setting value is limited to the voltage variable range of the operation amplifier provided before the speed table. Therefore, as the voltage variable range of the amplifier becomes smaller, the speed table becomes less effective.

[Purpose of the invention]

The present invention solves the above-mentioned problems with conventional devices, makes maximum use of the speed table for setting quill speed, and allows the variable range of error (input) voltage to correspond to the entire speed table. The purpose is to submit a quill speed setting device.

[Summary of the invention]

The quill speed setting device in the electrical discharge machine according to the present invention is configured to control the voltage between the workpiece and the electrode (i.e., the distance between the two).
This device detects the error voltage and compares it with a preset voltage value to obtain an error voltage, which is input directly to the speed table as the output of the amplifier to set the quill speed.

[Embodiments of the invention]

An outline of a quill speed setting device constructed based on the present invention is shown in FIG. 1, and an embodiment will be specifically described below with reference to this diagram.

The device includes electrodes 1. Work 2. It consists of an electrode-to-electrode voltage detection section 4, an error voltage generation amplifier 5, a dozen speed tables 6, a pulse generation section 7, and a motor 8.

When the machining gap 3 between the electrode 1 and the workpiece 2 is detected and output by the machining gap voltage detecting section 4, the error voltage generating amplifier 5 compares it with a predetermined machining gap and outputs the machining gap 3 as the machining gap voltage.
For example, if the gap is narrower than a predetermined gap, a negative voltage is output to the speed table 6, and if the gap is wider, a positive voltage is output to the speed table 6.

In this way, the voltage corresponding to the error obtained by comparison is expressed as
When zero speed tables are entered, only one speed table that is close to the preset quill speed is selected and the actual quill speed is determined based on this.

At this time, it is necessary to make the output variable voltage of the error voltage generation amplifier 5 correspond to the entire range of the speed table 6, and by taking this consideration, it is possible to determine what quill speed is set. Even then, the speed table 6 can be fully operated.

The quill speed determined by the speed table 6 causes the pulse generator 7 to generate and output pulses at a rate corresponding to the quill speed, thereby driving the motor 8.

〔Effect of the invention〕

The quill speed setting device for the electric discharge machine of the present invention can be used flexibly because the speed table can be used in the entire range no matter how the quill speed is set, and machining can be performed by changing the quill speed. This is extremely effective during finishing machining, where changes in condition are noticeable.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram illustrating a quill speed setting device of the present invention, and FIG. 2 is a schematic diagram of a conventional device. ■... Electrode, 2... Workpiece, 3... Machining gap, 4...
... Voltage detection section between electrodes, 5... Error voltage generation amplifier, 6
...Speed table, 7...Pulse generator, 8...
motor. Special γr applicant Hitachi Seiko Co., Ltd. agent Patent attorney Tadashi Akimoto Minoru No. 1! ll

Claims (1)

[Claims] In the servo system that determines the relative position between the workpiece and electrode of an electrical discharge machine, there is a voltage detection unit that detects the voltage between the workpiece and the electrode, and the output voltage is compared with a predetermined voltage setting value to determine the amount of error. A quill generator in an electric discharge machine consists of an error voltage generation amplifier, multiple speed tables that provide quill speeds corresponding to the error voltages, and a pulse generator that outputs pulse signals corresponding to the quill speeds to the drive motor. Speed setting device.