JPH0553567B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a wire electrical discharge machining apparatus, and particularly to a water column (hereinafter referred to as jet water column) that guides a wire electrode from an upper wire electrode guide to a lower wire electrode guide when connecting a wire electrode. This relates to the improvement of the nozzle for generation.

[Prior Art] FIG. 5 is a sectional view of the vicinity of a machining fluid nozzle for explaining a wire electrode connection method using a jet water column in a conventional wire electric discharge machining apparatus, and FIG. 6 is an explanatory view of its operation. In both figures, 1 is a wire electrode, 2 is a workpiece, 3 is a machining liquid, 4 is an upper wire electrode guide, 5 is an upper diamond die, 6 is a lower wire electrode guide, 7 is a lower diamond die, and 8 is an upper machining The liquid nozzle 9 is a lower machining liquid nozzle, and 10 is an upper machining liquid nozzle support member fixed to the head. Further, 11 is a jet water column generation liquid, 12 is a jet water column generation nozzle (hereinafter referred to as a jet nozzle), and 13 is a jet nozzle 12.
14 is a jet water column, 15 is a machining start hole, and 16 is a machining fluid passage provided in the upper machining fluid nozzle 8 around the jet nozzle 12.

Next, the operation of the apparatus configured as described above will be explained. As shown in Fig. 5, the wire electrical discharge machining device has a wire electrode 1 and a workpiece 2 facing each other with a microscopic distance between them via a machining fluid 3, and generates an electric discharge by applying a high-frequency pulsed voltage between the two. This energy is then applied to the workpiece 2. The wire electrode 1 is disposable and is fed under a certain tension from the supply reel to the collection section. During this time, the workpiece 2 is penetrated and machining is performed at the penetrating portion, but the upper wire electrode guide 4 is located near the upper and lower surfaces of the workpiece 2.
The diamond die 5 of the lower wire electrode guide 6 and the diamond die 7 of the lower wire electrode guide 6 support the wire electrode 1, and the machining fluid 3 is supplied to the machining part from the upper machining fluid nozzle 8 and the lower machining fluid nozzle 9 for cooling and machining sludge discharge. It is ejected almost coaxially with the wire electrode 1. When performing taper processing, the upper wire electrode guide 4 is moved relative to the lower wire electrode guide 6, and the wire electrode 1 is tilted using the upper diamond die 5 and the lower diamond die 7 as fulcrums.

At the start of processing or when the wire electrode 1 is broken, the wire electrode 1 must be stretched from the upper wire electrode guide 4 to the lower wire electrode guide 6 to the recovery section, and this connection is made as shown in FIG. The wire electrode 1 sent out through the upper wire electrode guide 4 and the upper diamond die 5 by a wire electrode sending mechanism (not shown) is directed from the nozzle outlet 13 of the jet nozzle 12 toward the lower wire electrode guide 6 with the jet water column generating liquid 11. The jet is guided by the formed jet water column 14, passes through the machining start hole 15, the lower diamond die 7, and the lower wire electrode guide 6, and is then conveyed to the recovery section by a fluid, a belt, etc. (not shown).

[Problems to be Solved by the Invention] Since the conventional jet water column connection type wire electrical discharge machining apparatus is configured as described above, the jet water column 14 is close to the hydrostatic pressure inside the jet nozzle 12, and the jet nozzle outlet 13 The larger the distance between the flow obstacle (in this case, the upper wire electrode guide 4), the further the flow will travel straight without spreading.
That is, the larger the distance L between the lower end surface of the upper wire electrode guide 4 and the inner lower end surface of the jet nozzle 12 in FIG. 7a, the thicker the workpiece 2 can be wired. However, if L is made large, the diameter of the jet nozzle outlet 13 will be 1
Since it is approximately 2 mm, the taper machining possible angle θ becomes small as shown in Fig. 7a, and in the case of an electrical discharge machining device that does not have a taper machining function,
There is a concern that the space between the machining fluid nozzle 8 and the jet nozzle 12 will become smaller, making it impossible to supply a sufficient amount of machining fluid during machining. In order to solve these problems, conversely, if L is made smaller as shown in FIG. There was a problem that the reliability of the wire connection decreased.

The present invention has been made in order to solve the above-mentioned problems.In the case of an electric discharge machining device equipped with a taper machining function, the angle at which taper machining can be performed can be increased, and in the case of an electric discharge machining device equipped with a taper machining function, it is possible to obtain a large taper machining angle. In the case of equipment, machining fluid can be sufficiently supplied to the machining section,
Moreover, it is an object of the present invention to obtain a wire electrical discharge machining device that can connect wires with high reliability even in the case of a thick workpiece.

[Means for Solving the Problems] The wire electrical discharge machining apparatus according to the present invention includes a machining fluid nozzle having a through hole and a machining fluid passage, and a water column generation fluid passage therein,
A wire electrode guide is disposed in this passage, and a water column generation nozzle disposed movably in the axial direction in the through hole of the processing fluid nozzle is connected to the water column generation nozzle. The water column generating nozzle is moved in the axial direction so that the gap between the tip of the nozzle and the tip of the wire electrode guide is widened, and the gap between the tip and the tip of the wire electrode guide is sandwiched during processing.

[Function] The water column generation nozzle moving means in the present invention is as follows:
The water column generating nozzle is moved so that the distance between its tip and the wire electrode guide tip is large when the wire electrode is connected, and the distance is small during electrical discharge machining.

[Embodiment of the invention] FIG. 1 is a sectional view showing the main part of an embodiment of the invention.
Components that are the same as or corresponding to those of the conventional example shown in FIG. 5 are given the same reference numerals, and explanations thereof will be omitted. In the figure, 8a is an upper machining liquid nozzle, which has a through hole formed in the center and is provided with a chamber A from the upper part, a chamber B with a smaller diameter than this, a support part 21 protruding from the chamber B, and a chamber C. A positioning stopper 22 is formed between chamber A and chamber B. Further, a machining fluid passage 23 communicating from the support member 10 to the chamber C is provided around the chambers A, B and the support portion 21. Reference numeral 12a designates a jet nozzle having a flange 24 on the upper part, and the flange 24 and its lower circumferential surface serve as sliding surfaces and slide up and down in the chambers A, B, support part 21, and chamber C of the upper processing liquid nozzle 8a. possible. 25
is a compression spring interposed between the support portion 21 of the upper processing liquid nozzle 8a and the flange 24 of the jet nozzle 12a. A control device for controlling the amount or pressure of these fluids is provided on the inlet side of the machining fluid 3 and the jet water column generation fluid 11, and in this embodiment, this control device and the jet water column generation fluid 11 are The liquid 11, the compression spring 25, the flange 24, and the support portion 21 of the machining liquid nozzle 8a constitute a water column generation nozzle moving means.

Next, the operation of this embodiment configured as described above will be explained. When connecting the wire electrodes, as shown in FIG. 1, if the jet water column generating liquid 11 is flowed to overcome the spring force of the compression spring 25, the jet nozzle 12a will receive liquid pressure on the upper surface of the flange 24 and the inner bottom surface of the jet nozzle 12a. , the flange 24 is pushed down until it hits the positioning stopper 22. As a result, L increases, and the jet water column 14 ejected from the jet nozzle outlet 13 travels straight ahead without spreading, making it possible to connect the wire electrode 1 even when the thickness of the workpiece is large, increasing reliability. .

During electrical discharge machining, if the jet water column generating liquid 11 is stopped or weakened as shown in FIG.
4 is pushed up until it hits the upper machining liquid nozzle support member 10. As a result, L becomes smaller, and the angle θ that allows taper processing can be made larger. In this case, the machining fluid 3 is supplied to the workpiece from the machining fluid passage 23 through the chamber C.

In the above embodiment, the jet water column generating liquid 11 and the compression spring 25 are used as the water column generating nozzle moving means.
Although a case has been shown in which the jet nozzle 12a is moved up and down using a cylinder, an actuator such as an air cylinder may be used as the water column generating nozzle moving means. FIG. 3 is a sectional view showing a main part of another embodiment of the present invention, that is, a modification of the water column generating nozzle moving means. Note that the same or equivalent parts as in the embodiment shown in FIG. 1 are given the same reference numerals, and the explanation thereof will be omitted. In this embodiment, a plurality of machining fluid passages 2 communicating chambers B and C are provided in the support portion 21 of the upper machining fluid nozzle 8a.
In addition, a hole 26 is provided in the side wall of the chamber B to communicate with the machining fluid supply pipe 27, and the compression spring is omitted.

Next, the operation of this embodiment will be explained. When connecting the wire electrode, as shown in FIG. 3, if the jet water column generating liquid 11 is flowed from the jet nozzle 12a, the jet nozzle 12a receives the liquid pressure on the upper surface of the flange 24 and the inner bottom surface of the jet nozzle 12a, and the flange 24 Positioning stopper 22
It is pushed down until it hits. As a result, L increases, and the jet water column ejected from the jet nozzle outlet 13 travels straight ahead without spreading out.
Even when the plate thickness is large, the wire electrode 1 can be connected, and reliability is also improved.

During electrical discharge machining, by stopping or weakening the jet water column generating fluid 11 and flowing the machining fluid 3 for electrical discharge machining from the machining fluid supply pipe 27, an upward force is applied to the lower surface of the flange 24 as shown in FIG. As a result, the jet nozzle 12a is pushed up until the flange 24 touches the upper working fluid nozzle support member 10.
As a result, L becomes smaller and the angle at which taper processing is possible can be made larger. Note that the machining fluid 3 is supplied to the machining portion from the chamber B through machining fluid passages 23 arranged on the circumference.

In each of the above embodiments, L is a relative value, so the upper wire electrode guide 4 to which the jet nozzle 12a is fixed may be made movable, but since moving the upper wire electrode guide 4 causes a decrease in accuracy, it is not practical. In this case, it is better to use the jet nozzle 12a as the movable part, and the structure is simple.

[Effects of the Invention] As is clear from the above description, according to the present invention, by moving the jet nozzle, the distance between the nozzle outlet and the tip of the wire electrode guide can be increased during wire electrode connection, and decreased during electrical discharge machining. As a result, even if the workpiece is thick, the wire electrode can be connected with high reliability, and in the case of electric discharge machining equipment equipped with a taper machining function, the angle at which taper machining can be performed can be increased. In addition, in the case of an electric discharge machining apparatus that does not have a taper machining function, the implementation has great effects, such as being able to supply a sufficient amount of machining fluid to the machining section.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of an embodiment of an upper processing liquid nozzle including a jet nozzle according to the present invention, FIG. 2 is an explanatory diagram of its operation, FIG. 3 is a cross-sectional view of another embodiment of the present invention, and FIG. Figure 5 is a cross-sectional view of the vicinity of the machining liquid nozzle, including a conventional jet nozzle.
FIG. 6 is an explanatory diagram of its operation, and FIGS. 7a and 7b are sectional views showing the relationship between the distance between the jet nozzle outlet and the upper wire electrode guide and the angle at which taper processing is possible. In the figure, 1 is a wire electrode, 2 is a workpiece, 3 is a machining liquid, 4 is an upper wire electrode guide, 5 is an upper diamond die, 6 is a lower wire electrode guide, 7
1 is a lower diamond die, 8 and 8a are upper machining liquid nozzles, 9 is a lower machining liquid nozzle, 10 is an upper machining liquid nozzle support member, 11 is a jet water column generating liquid, 12 and 12a are jet nozzles, 13 is a jet nozzle outlet, 14 15 is a jet water column, 15 is a machining start hole, 21 is a support portion, 22 is a positioning stopper, 24 is a flange, 25 is a compression spring, and 27 is a machining fluid supply pipe. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. A wire electrical discharge machining device that generates a water column between opposing wire electrode guides and guides and connects the wire electrode using this water column, comprising: a machining fluid having a through hole and a machining fluid passage; It has a nozzle and a passage for water column generation liquid inside,
A wire electrode guide is disposed in this passage, and a water column generation nozzle is disposed in the through hole of the machining liquid nozzle so as to be movable in the axial direction, and when the water column generation nozzle is connected, the water column generation A wire electric discharge machining device comprising: a water column generating nozzle moving means for moving in the axial direction so that the gap between the tip of the nozzle and the tip of the wire electrode guide widens and the gap narrows during machining.