JPH042368B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wire electrode guide for wire cut electrical discharge machining.

A wire cut electrical discharge machining device moves a wire electrode between a pair of positioning guides while maintaining a predetermined tension while reeling the wire electrode from one reel and winding it onto the other reel. A machining gap is formed by facing the workpiece from a direction approximately perpendicular to the axis of the wire electrode moving between the two.
In addition to supplying a machining fluid such as water or oil to this gap, a machining voltage pulse is also supplied to generate a pulse discharge, and while this discharge is repeated, the workpiece and the wire electrode are relatively machining-feeded. The cutting process is carried out by

For example, a wire cut electric discharge machining apparatus 100 shown in FIG. 1 will be explained. This wire-cut electric discharge machining apparatus 100 is unwound from a reel provided in a column or the like of the apparatus main body (not shown) via a brake roller, etc., extends downward via a guide roller 11 of an arm 1, and is provided facing a radius 1 downward. In addition, there is an intermittent gap between the guide rollers of the arm (not shown), the take-up roller, the column, etc. between the guide rollers of the wire electrode 2 that reaches the take-up reel of the main body or the collection container, and the workpiece 3. Electrical discharge machining is performed by applying voltage pulses. The upper part of a support member 13 having an L-shaped cross section is attached to the arm 1 disposed above so as to be substantially orthogonal to the arm 1 and can be vertically moved and positioned by a manual handle or a motor 12. . A wear-resistant, normally cylindrical current-carrying pin 4 made of cemented carbide or the like is attached to the lower front surface of the support member 13 for contacting the wire electrode 2 and applying a voltage pulse. It is in contact with the wire electrode 2 in the straight portion. Further, an appropriate portion such as the upper end of a hollow cylindrical nozzle main body 5 is fixed to the lower end of the support member 13 so that the position can be minutely adjusted as necessary.
Openings 51 and 5 are provided on the upper and lower end surfaces of this nozzle body 5.
These openings 51 and 52 are formed approximately at the center axis of the nozzle body 5, and are arranged in a positional relationship such that the wire electrode 2 between the guide rollers 11 is coaxially inserted therethrough. . Furthermore, an upper positioning guide 6 is provided inside the nozzle body 5.
1 guide holder 6 is inserted coaxially,
Further, a nozzle 7 for injecting machining fluid toward the machining gap of the workpiece 3 is coaxially fitted into the lower end face opening 52 so as to be movable in the axial direction. The guide holder 6 is a hollow cylinder having a hole 6a, and a dice-shaped positioning guide 61 is attached to the lower end of the guide holder 6. The guide 61 is used to position the wire electrode 2 above the workpiece 3. There is. The guide holder 6 is fixed to the nozzle body 5 so that its position can be minutely adjusted as necessary. Further, the nozzle 7 is arranged at the lower part of the nozzle body 5, and is fitted into the opening 52 at the lower end of the nozzle body 5 so as to be able to move up and down according to the supply pressure and flow rate of the machining fluid, the distance from the workpiece 3, etc. There is. The nozzle 7 is a hollow cylindrical body having a desired axial length, inner diameter, and axial inner diameter restriction, and the outer diameter of the end 71 of the flange portion located inside the nozzle body 5 is equal to the opening at the lower end of the nozzle body 5. The inner diameter of the opening 52 is approximately equal to the inner diameter of the opening 52, and the end 71 fits and contacts the inner wall of the opening 52.
This prevents the nozzle 7 from falling off from the nozzle body 5. A pressurized machining fluid supply hose 53 is attached to an appropriate position on the upper side of the nozzle body 5, from which the machining fluid is supplied into the nozzle body 5, cools the positioning guide 61 inside, and cools the positioning guide 61 in the lower part. It is ejected from the nozzle 7 to the processing part of the workpiece 3, and
The current-carrying pin 4 is ejected upward from the upper opening 51.
A machining fluid is also supplied between the wire electrode 2 and the wire electrode 2 to cool the wire electrode 2 and the current-carrying pin 4. Further, the workpiece 3 is fixed to a processing table 31, and the processing table 31 is moved along a predetermined contour shape etc. on a plane perpendicular to the two axes of the wire electrode by motors 32 and 33 under the control of a numerical controller. It is now possible to move around freely. Note that many of the configurations and members described above are provided not only above the workpiece 3 but also below the workpiece 3. The explanation will be omitted since it is the same as the above explanation except that each member is arranged so as to be substantially symmetrical in the upper and lower directions.

The wire-cut electric discharge machining apparatus 100 is configured as described above, and the wire electrode 2 is moved while a voltage pulse is applied between the upper and lower current-carrying pins 4 and the workpiece 3, and a discharge pulse current is flowing. Therefore, the vicinity of the machining gap formed between the workpiece 3 and the workpiece 3 is of course exposed to high temperatures, and the wire electrode 2 between the pair of upper and lower current-carrying pins 4 is easily heated by electricity and becomes high temperature. Therefore, a pair of upper and lower guides 61
In addition, there is a risk that the energizing pin 4 may be exposed to high temperatures and cause abnormal wear or damage. Therefore, as described above, the guide 61 is provided in the machining fluid injection nozzle body 5 so that it can be cooled by supplying machining fluid. It's summery. In particular, the guide 61 is for holding the wire electrode 2 in a predetermined position, and since the wire electrode 2 is moving, there is a problem in that frictional heat is generated between the two. Therefore, the machining fluid must be effectively supplied to the guide 61,
With the conventional guide configuration, it was not possible to obtain a sufficient supply of machining fluid and the cooling effect associated with the supply.
The guide 61 will be described in detail as an example of a conventional guide.
1, it consists of a die 62 through which the wire electrode 2 is inserted, and a die holder 63 that holds the die 62, and is provided so as to be removably and positionably attachable to the guide holder 6 by appropriate structures and means (not shown). The die 62 is made of diamond, sapphire, agate, cemented carbide, etc.
A guide hole 62a through which the wire electrode 2 is inserted is formed approximately at the center thereof. The guide hole 62a has a large diameter at the openings at the upper and lower ends, and the diameter narrows toward the center, and in the middle part, the diameter is approximately the same as the diameter of the wire electrode 2, about several μm or less. It is configured to have a predetermined clearance. In other words, the intermediate portion of the guide hole 62a comes into contact with the outer peripheral portion of the wire electrode 2 with slight deviation or vibration. The guide 61 is configured in this way, and if machining fluid is supplied from above the guide 61 or from further below toward the die 62, the supplied machining fluid will flow as indicated by the arrow in FIG. As shown, the wire electrode 2 and the die 62
It enters between the wire electrode 2 and the die 62 and flows along its surface to cool the wire electrode 2 and the die 62, but as mentioned above, there is only an extremely small gap between the wire electrode 2 and the guide hole 62a. Once the machining fluid is supplied to the gap between the wire electrode 2 and the die 62 or in the vicinity thereof, it cannot be easily moved.In other words, once the machining fluid is supplied, it cannot flow smoothly and be renewed. This makes it difficult to smoothly supply new machining fluid between the die 62 and the wire electrode 2, and as a result, the guide holder 6 holding the guide 61 is inserted into the nozzle body 5 as shown in FIG. Even in a configuration in which the nozzle body 5 is inserted into
The configuration was such that the wire electrode 2, particularly the die 62, could not be sufficiently cooled by the machining fluid flowing therein. In other words, the wire electrode 2 and the die 62
The machining fluid supplied between the two was in a so-called stagnation state, and sufficient cooling ability could not be obtained despite the machining fluid being supplied.

The present invention has been made in view of the above-mentioned conventional circumstances, and has a novel configuration in which the machining fluid supplied to the wire electrode guide in wire cut electric discharge machining passes through the die in the wire electrode axial direction. The present invention aims to provide a wire electrode guide for wire cut electrical discharge machining.

The present invention will be explained below with reference to the illustrated embodiments.

FIGS. 3A and 3B are a vertical cross-sectional view and a cross-sectional view of a wire electrode guide 20 for wire cut electric discharge machining, which is an embodiment of the present invention, and FIG. 3A is a y-y line in FIG.
3B is a sectional view taken along line xx in FIG. 3A, and FIG. 3A is a sectional view of the same portion as in FIG. 2. The guide 20 functions if it is attached to the guide holder 6 in place of the guide 61 in FIG. 1, and the configuration of other parts is almost the same as that in FIG. The explanation will be omitted. Guide 2 held in cylindrical guide holder 6
0 is a guide hole 21 through which the wire electrode 2 is inserted.
It consists of a die 22 on which is formed, and a die holder 23 that holds this die 22. Therefore, the dice 22 are fixedly held in a state where they are surrounded and embedded in the holder 23, but a part of this fixed holding part is hollowed out, and in the case of the illustrated embodiment, an interval of about 60° is formed. Assuming that there are three communicating holes 24 each having an arcuate cross section and a width corresponding to approximately 60° when placed in the guide holder 6, and that there is a machining fluid flow as shown by the arrow 30 in the guide holder 6, the die 22 portion hand,
Some of it passes through the extremely fine gap between the wire electrode 2 and the guide hole 21, but most of it passes through the communication hole 2.
4 as shown by the arrow 31, and can more effectively cool the die 22, the holder 23, and the wire electrode 2 in front and behind the guide 20 portion.

FIGS. 4A and 4B are cross-sectional views showing another embodiment of the present invention similar to those shown in FIGS. The die 22 is connected to the arm 2 extending radially from the inner peripheral wall of the cylindrical die holder 23.
5, and the gap in the circumferential direction between the arms 25 is used as the communication hole 24, and the arrows 30, 31 point from the place where the die 22 is provided in an exposed state.
Cooling by the machining fluid cooling flow is performed more effectively.

The guide 20 configured as shown in FIGS. 3 and 4, A and B, guides the wire electrode 2 to a predetermined position by inserting the wire electrode 2 into the guide hole 21 of the die 22. A voltage pulse is applied between the wire electrode 2 and the workpiece 3 to cut the workpiece into a predetermined shape and perform electrical discharge machining. During this machining, machining fluid is supplied to the guide 20, and since the supplied machining fluid flows between the die 22 and the die holder 23 through the communication hole 24 formed between the die holder 23 and the die 22,
The heat of the wire electrode 2, the die 22 and die holder 23 to which heat is applied from the wire electrode 2, and the frictional heat generated between the wire electrode 2 and the die 22 can be absorbed by the flow of the machining fluid. It is possible.

In the above embodiment, there were three communication holes formed between the die 22 and the die holder 23 around the die 22, but the number of communication holes is not limited to three, and any number of communication holes may be formed as long as there are two or more. It's okay to be,
Preferably, it is provided as a radiation isomorphism. Further, other configurations are not limited to the above embodiments, and may be modified without departing from the gist of the present invention.

As explained above, according to the present invention, a hole is provided between the die that guides the wire electrode and the die holder that holds the die, which communicate with each other in the axial direction of the wire electrode 2, for example, in the upper and lower positions. The machining fluid as a cooling fluid flows through the die, and new machining fluid is constantly supplied around the die, which can efficiently absorb the heat of the wire electrode, die, and die holder, and cool the wire electrode and die. Therefore, disconnection of the wire electrode and deterioration of the die can be prevented. In addition, there is a sufficient gap between the outer wall of the guide holder and the inner wall of the nozzle body for the flow of machining fluid, so the amount of machining fluid supplied can be set arbitrarily to achieve a sufficient cooling effect. is possible.

[Brief explanation of drawings]

Fig. 1 is a partially omitted side cross-sectional view showing the main parts of a wire-cut electric discharge machining device, Fig. 2 is a vertical cross-sectional view showing a conventional guide, and Fig. 3 A and B are a guide showing an embodiment of the present invention. Longitudinal cross-sectional view and cross-sectional view, Figure 4 A, B
FIG. 2 is a vertical cross-sectional view and a cross-sectional view of another embodiment. 2... Wire electrode, 6... Guide holder, 20
... Guide, 21 ... Guide hole, 22 ... Dice,
23...Dice holder, 24...Communication hole.

Claims (1)

[Claims] 1. In the wire electrode guide, which determines the position of the processing part to be formed by facing the workpiece from a direction substantially perpendicular to the electrode axis to the wire electrode that is updated and fed in the axial direction, the wire electrode is coaxially inserted into the cylinder. A guide holder in the form of a wire electrode positioning guide consisting of a die and a die holder is held at one end of the guide holder, and the guide holder is disposed within a nozzle body and between an inner wall of the nozzle body and an outer wall of the guide holder. The positioning guide holding end of the guide holder is disposed coaxially at a predetermined interval so as to form a main processing fluid flow path between them, and the positioning guide holding end of the guide holder is directed toward the injection opening side of the nozzle body; A wire for wire cut electrical discharge machining, characterized in that through holes in the insertion direction of the wire electrode are distributed in the circumferential direction in the die holder portion around the die of the positioning guide, and the through holes are configured to allow machining fluid to flow. Electrode guide.