JPS62124828A - Narrow hole electric discharge machine - Google Patents

Abstract

PURPOSE:To enable automatic continuous machining through the exchange of electrodes on a machining process after the detection of the erroneous insertion of the electrode in an electrode guide by letting a contact position detecting mechanism detect said erroneous insertion as restricted with a limit distance. CONSTITUTION:While a worker preliminarily sets a limit distance 'd' as a distance between the tip of a narrow hole electrode 16 and a workpiece 10 plus 'alpha', the electrode 16 is inserted in an electrode guide 40, and the contact position of the electrode 16 and a workpiece 10 is detected. In this case, a travel distance 'd'' when the narrow hole electrode 16 is properly inserted in the guide 40, becomes less than the limit distance 'd'. On the contrary, the electrode 16 when erroneously inserted in the guide 40, does not come in contact with the workpiece 10. In this case, contact position detection is finished when a travel distance 'd''' has exceeded the limit distance 'd'. In this way, when the narrow hole electrode 16 has been properly inserted in the electrode guide 40, a program sequence is changed. In the case of erroneous insertion, a program is resumed, starting from the exchange of the electrode.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a small-hole electrical discharge machining apparatus that detects insertion errors of small-hole electrodes into electrode guides.

[Conventional technology]

FIG. 2 is an explanatory diagram showing an example of a conventional small-hole electrical discharge machining apparatus. In the figure, α1 is the workpiece immersed in the insulating machining liquid aU sphere stored in the machining tank (Iz), and the workpiece αQ is opposed to the small hole electrode αe through the machining liquid U. The machining fluid Q4) is circulating between the tank α second outside the machining tank CI3 and the machining tank α2, and the machining fluid α leaked from the machining tank (17J to the tank (1gJ) The workpiece α in the processing tank (Iz) is moved from the nozzle (A) to
It is injected into the gap between Q and the small hole electrode αe. In addition, the relative movement between the workpiece and the thin and large electrode part is performed by moving the workpiece α1 (on the table on which it is placed) to the plane containing the table using the X-axis drive motor (c) and the X-axis drive motor (c). The small hole electrode (16) can be moved in the vertical direction using the Z-axis drive motor (c), or the small hole electrode (16) can be rotated to any angle using the C-axis drive motor (1). This is done by In addition, the small hole electrode αe is fixed to the head 01),
By interposing the small hole electrode H and the insulated electrode guide), vibration of the electrode during processing is prevented. 0) is a processing power source that supplies electrical energy between the small hole electrode (16) and the workpiece 01, and includes, for example, a DC power source E1, a switching element Tr, a capacitor C1, a charging resistor R1, and a switching element control circuit (b). It consists of (6)
is an automatic electric fence replacement device that replaces the small hole electrode Oe.

(g) is each x and y.

N that performs automatic control such as driving the Z and C axis drive motors (C), H, (C), and (1) or starting the electrode exchange device.
C (numerical control), a copying device, or a numerical control device such as a computer.

FIG. 3 is a waveform diagram showing the waveform of a pulse train output from the machining power source in the small hole electric discharge machining apparatus shown in FIG. The figure shows a pulse train output by the switching element Tr of the processing power source t2, where υ, Ip is the current peak value, and τ
, is the pulse width, and τ is the pulse pause width.

[Problem that the invention seeks to solve]

According to the conventional small-hole electrical discharge machining apparatus configured as described above, when replacing the small-hole electrode (161), the small-hole electrode α (to) is pulled out from the electrode guide ■, and after the electrode is replaced, the small-hole electrode (+6
) into the electrode guide ρQ. Therefore, if a mistake occurs in the insertion of the small hole electrode 116+ into the electrode guide 61, there is a problem in that the machining cannot be continued unless the operator manually intervenes from point 7 onwards.

The present invention has been made to solve the above-mentioned problems, and is further improved by checking for errors in the insertion of the small-hole electrode into the electrode guide, and determining an incorrect state when all insertion errors are detected. The purpose of the present invention is to obtain a small-hole electric discharge machining device that can continuously perform automatic machining by replacing the electrode with a new one.

[Means for solving problems]

The present invention has been made to achieve the above objects,
The operator can arbitrarily set the limit distance that the axis can move for the contact position detection mechanism between the workpiece and the electrode, and if contact cannot be detected even after moving to this limit distance at the time of contact position detection, contact position detection is performed. The present invention provides a complete small hole electrical discharge machining apparatus with an additional finishing mechanism.

[Effect]

At the end of the contact position detection process, the distance traveled by the contact position detection VC is calculated, and this distance is compared with a limit distance set by the operator, and the sequence of the Niprogram is changed depending on the magnitude relationship. Here, the movement distance calculation, size comparison, and sequence change are all performed using N in the Canadian program.
[Embodiment of the invention] Figures 1 (a'), (b3, and (c) show the small hole electrode (1f9) according to the present invention when inserted into the electrode guide (6). α61 Hole electrode (from the tip of IO to the workpiece αCi
This is the limit distance set by the operator as the distance at t + α. From this state, the contact position detection mechanism detects the small hole electrode (
Insert the IED into the electrode guide) and insert the small hole electrode α
The contact position between e and the workpiece 01 is detected. Figure 1 (b
) shows a state in which the contact position detection has been completed when the small hole electrode aω has been properly inserted into the electrode guide (2).

At this time, the distance traveled by the contact position detection is d', which is smaller than the limit distance d set by the operator.

Further, FIG. 1(c) shows a state in which contact position detection has been completed in a case where a mistake has occurred in inserting the small hole electrode αe into the electrode guide (g). At this time, since the small hole electrode body e does not come into contact with the workpiece α0, the contact position detection ends when the distance d'' moved during contact position detection exceeds the limit distance dt- set by the operator.Here, the actual contact position detection is completed. The change in the sequence of the cannibal program is realized by the current coordinate value reading mechanism and calculation mechanism of the numerical control device (to), and the changing mechanism of the cannibal program sequence to be executed, and all are performed by NC commands in the cannibal program. An example of a Canadian program is the following.

■ N10: ...Sequence number 10
■ T1; ...Replace with the next electrode.

■ N20; ... Sequence number 2
0■ MB2: ...Turn on the processing power
do.

@GIZ-5-: ” Process 25ml.

According to the above-mentioned Canadian program, the electrodes are replaced in steps ① to ①, and the insertion error of the electrode (I6) into the electrode guide ② is detected. 010 in ■ is the limit distance set by the operator. If the small hole electrode (1e) is inserted correctly into the electrode guide (6), the program sequence will change from ■→■. Then, the process is executed again in the order of ■→■→■ starting with electrode replacement.

Note that in the above embodiment, the small hole electrode (161 electrode guide (
As explained above, the Kani program replaces the electrode again when an insertion error is detected in the 41, but since the process when an insertion error is detected is all managed by the Kani program, the operator can freely change it. .

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the detection of insertion errors of the electrode into the electrode guide is performed by a contact position detection mechanism limited by a limit distance, and the structure is further managed by a control program. It has remarkable effects such as being able to freely decide what to do after detection and enabling automatic operation as intended by the operator.

[Brief explanation of drawings]

Fig. 1 (a), (b), and (c) are explanatory diagrams of the operation of the embodiment of the present invention, Fig. 2 is an explanatory diagram showing an example of a conventional small-hole electrical discharge machining device, and Fig. 6 is an explanatory diagram of a small-hole electrical discharge machining device. This is a waveform diagram showing the waveform of the pulse train output from the processing power source in the device. αO...Workpiece, α■...Processing tank, I...Processing liquid, (1e...Small hole electrode, αQ...Tank, (to)
...Nozzle, (2)...Table, (c)...X
Axis drive motor, (c)... Y-axis drive motor, 2...
2-axis drive motor, (1)... C-axis drive motor, 62-mount machining power supply, (b)... Switching element control circuit, (
g)... Numerical control device, ■... Electrode guide, 0])
... head, (6) ... electrode exchange device. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] The relative movement between the workpiece and the small-hole electrode is commanded using a numerical control device equipped with a current coordinate value reading mechanism, a calculation mechanism, a condition judgment mechanism, and a contact position detection mechanism. In the small-hole electrical discharge machining device for machining the workpiece into a desired shape by generating an electrical discharge phenomenon using electrical energy supplied to the A small-hole electric discharge machining apparatus characterized by comprising a mechanism for terminating contact position detection processing upon movement of the movement limit distance.