JPH04315520A - Electrode guiding energizing device for wire cut electric discharge - Google Patents

Abstract

PURPOSE:To provide an electrode guiding energizing device for wire cut electric discharge which performs continuous machining at a high speed by means of a high current and has high machining precision. CONSTITUTION:A plurality of guide members 11, 12, and 13 to position a wire electrode at a machining part are manufactured by using a rigid material, and at least one thereof is additionally functioned as an energizer 13 to a wire electrode. In desired embodiment, the guide members 11, 12, and 13 comprises a pair of guide members 11 and 12 located facing each other to a holder 10 with a wire electrode 2 therebetween and the energizer 13 having a tip edge inserted in a gap between a pair of the guide members 11 and 12 and additionally functioning as a guide member brought into contact with the wire electrode 2. A machining liquid injection nozzle 9 may be attached to the holder 10.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for positioning and energizing a wire electrode in a wire-cut electrical discharge machining apparatus.

0002

[Prior Art] With the development of NC equipment, wire-cut electrical discharge machining equipment that cuts or punches workpieces by electrical discharge machining using wire electrodes has become capable of long-term unmanned operation. Both are widely used today.

In wire-cut electrical discharge machining equipment, diamond, sapphire, etc. have been conventionally used as electrode guides to accurately straighten the wire electrode at a predetermined position in the machining area where the workpiece is installed. A guide member made of a single member such as the following has been used, but this has the following problems.

(2) Machining accuracy is poor because there is play between the wire electrode insertion hole of the guide member and the wire electrode. ■As the guide member wears out, the machining accuracy gradually decreases, making long-term continuous machining difficult. ■Inserting the wire electrode at the start of processing is troublesome. ■Due to poor cooling efficiency, high current cannot be passed through the wire electrode, making high-speed processing difficult.

[0005] In addition to the guide member, a conductor made of WCCo, WCNi, etc. was used to conduct electricity to the wire electrode, but the hardness of WC-based materials is Hv.
1,200 to 1,300, and the coefficient of friction is large, so it easily causes wear, and it takes about 30 to 50 hours (for rough machining, it takes 2 to 5 hours).
The lifespan was about 1 hour). Furthermore, since this conductor must be provided at a position farther from the workpiece than the guide member, the distance from the workpiece to the workpiece becomes large, the conduction loss is large, it is difficult to increase the machining speed, and the power source is There was a problem in that a large-sized device was also required.

[0006]

[Problems to be Solved by the Invention] The present invention has been made to solve the above-mentioned problems, and its purpose is to enable high-speed continuous machining using a large current,
An object of the present invention is to provide an electrode guide energization device for wire cut electrical discharge machining with high machining accuracy.

[0007]

[Means for Solving the Problems] The above object is to fabricate a plurality of guide members made of hard material for positioning the wire electrode in the processed portion, and to also use at least one of them as a current conductor for the wire electrode. This can be achieved by the electrode guide energization device for wire-cut electrical discharge machining.

[0008] The structure of the guide member is that a pair of guide members are attached to the holder so as to face each other with the wire electrode in between, and the distal end edges of the guide members are inserted into the opposing gap between the pair of guide members, and the wire electrode and It is preferable to use a conductor which also serves as a guide member and which is brought into contact with the guide member.

[0009] Furthermore, the structure of the guide member is such that a pair of guide members are attached to the holder so as to face each other with the wire electrode in between, and the tip edge of the guide member is approximately the same as the wire electrode within the opposing gap between the pair of guide members. It is also preferable to include a conductor which also serves as a plate-shaped guide member that is brought into contact with the wire electrode in an orthogonal state, and is provided with a mechanism for moving the conductor in a direction substantially orthogonal to the wire electrode.

It is recommended that at least one of the pair of guide members be biased toward the other guide member so that the surfaces of both guide members are kept in contact with the wire electrode. Furthermore, it is recommended that the conductor, which also serves as the guide member, be biased toward the wire electrode and maintained in contact with the wire electrode even when the tip edge of the conductor is worn out.

[0011] Furthermore, the structure of the guide member includes a pair of guide members attached to the holder so as to face each other with the wire electrode in between, and a pair of guide members that are close to and intersect with the pair of guide members in the axial direction of the wire electrode. It is also preferable to include a pair of conductor members that also serve as guide members and are attached to the holder so as to face each other with the wire electrode in between.

In that case, it is recommended that at least one of the pair of guide members be biased toward the other guide member so that the surfaces of both guide members remain in contact with the wire electrode. Further, at least one of the pair of conductive currents that also serves as the guide member is biased toward the other conductive current, so that the contact state with the wire electrode is maintained even when the surface of the current conductive current is worn out. It is recommended that you configure

[0013] As the above-mentioned guide member and the material for the current conducting material that also serves as the guide member, materials containing ultra-hard fine particles such as diamond and c-BN, materials containing Ti or TiSi, and furthermore, borium of Ti are used. Materials mainly composed of carbide are recommended. It is also recommended that a machining fluid spray nozzle be attached to the electrode guide energization device configured as described above.

[0014]

[Operation] With the above configuration, the wire electrode is held between a plurality of guide members made of hard material with a constant pressure, so the wire electrode can be securely held and positioned without wobbling. By moving the guide member, which also serves as a current conductor, as the process progresses and gradually moving the contact position with the wire electrode, local wear of the guide member can be avoided, resulting in high performance over a long period of time. In addition to enabling precision machining, at least one of the multiple guide members also serves as a current conductor, making it possible to conduct current in close proximity to the workpiece, resulting in low current loss and high-speed machining using large currents. is possible.

[0015] Furthermore, WC alloys that have been conventionally used as materials for guide members and conductors that also serve as guide members have a problem of high friction coefficients and severe wear.
If a material mainly composed of boron carbide of Ti is used as in the present invention, the friction coefficient will be 1/3 to 1/4, and the hardness will be as high as Hv 4000 to 6000, so the wear rate will be 1/5 to 1/10. Reduce to a certain extent. In addition, since the guide member has high hardness, the wire electrode is applied with a constant pressure of 300 g/cm2 to 1 kg/c against the guide member.
It can be used under pressure of 2 m2 (the tensile torque of the wire electrode in that case is about 300 to 500 g), and it becomes possible to eliminate looseness between the guide member and the wire electrode.

Furthermore, when manufacturing the guide member and the material for the guide member and conductive conductor by sintering or the like, it is possible to contain and bond ultrahard fine particles such as diamond or c-BN in the material, thereby reducing the amount of Ti ions. The wear resistance of carbide can be improved by about 100 to 1000 times, and the positioning of the wire electrode can be performed accurately, and machining can be performed while moving the contact position of the conductor that also serves as a guide member with the wire electrode as necessary. By doing so, the continuous machining time can be reduced to 300
Continuous processing for ~1000 hours is now possible, compared to the conventional 2
It is possible to achieve a lifespan of 0 to 200 times longer.

Furthermore, in the past, since a guide member had to be placed between the conductor and the processing section, the voltage drop across the wire electrode from the conductor to the processing section was 10V.
This ratio was extremely large compared to the discharge sustaining voltage of 13 to 16V. However, if the electrode guide current-carrying device according to the present invention has a conductor that also serves as a guide member, the voltage drop in the wire electrode from the conductor to the processing part is reduced to about 2 to 3 V, and the output of the power supply device is lower than that of the conventional one. It is possible to perform the same processing as in the past with approximately 1/2 of the size of the original, which means that the cost of the power supply device can be significantly reduced.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically explained below with reference to the drawings. FIG. 1 is an enlarged plan view sectional view showing an embodiment of the electrode guide energization device for wire-cut electric discharge machining according to the present invention, FIG. 2 is a longitudinal sectional view taken along the line A-A in FIG. 1, and FIG. A perspective view showing another embodiment of the guide member-cum-current energizing device in the electrode guide energizing device shown in FIGS. 1 and 2, and FIG. FIG. 5 is an explanatory diagram showing the main parts of a cut electric discharge machining device. FIG. 5 is an explanatory diagram showing an embodiment in which a machining fluid jet nozzle is attached to the electrode guide energization device for wire cut electric discharge machining according to the present invention. FIG. FIG. 7 is an explanatory diagram showing still another embodiment of the electrode guide energizing device for wire-cut electrical discharge machining.

In FIG. 1, numeral 1 denotes an electrode guide energizing device for wire cut electric discharge machining according to the present invention, 2 a wire electrode, 10 a holder for the electrode guide energizing device, 11 and 12
The holders 10 are arranged so as to face each other with the wire electrode 2 in between.
A pair of guide members 13 made of a hard material and attached to the wire electrode 2 are made of a hard material with excellent conductivity, and their tip edges are inserted into the opposing gap between the pair of guide members 11 and 12, and the wire electrode 2 14 is a leaf spring that pushes the guide member 12 toward the other guide member 11; 15 is a plate spring that pushes the guide member 13 toward the other guide member 11; Coil spring pushing in the direction of entering the inside, 16
An adjustment screw is screwed into the holder 10 and adjusts the extrusion force of the coil spring 15 by adjusting the screwing amount, and an energizing cable 17 conducts machining current from the electrical discharge machining power supply device to the electric current 13.

The guide member 11 is fixed to a holder 10 which is made of an insulating material, and the guide member 12 and the communication wire 13 which also serves as a guide member are movably attached to the holder 10, and the wire electrode 2 is The guide member 11 is moved by the action of the guide member 12 pushed out by the leaf spring 14.
and 12 with a predetermined pressure, and is held in a fixed position by the tip edge of a conductor 13 which also serves as a guide member. During machining, the wire electrode 2 is made to run slowly and continuously, for example from top to bottom in FIG. It has become.

Therefore, even if the leading edge of the conductor 13 which also serves as a guide member wears out as the machining progresses, the conductor 13 will continue to move the guide members 11 and 12 due to the action of the coil spring 15.
Since the wire electrode 2 is fed into the opposing gap, accurate positioning of the wire electrode 2 is always performed, and a good contact state between the wire electrode 2 and the conductor 13 is maintained, allowing continuous processing for a long time.

As the guide member/current wire 13, for example, one having a shape as shown in FIG. A thin plate portion 13b having a thickness approximately equal to the diameter of the guide members 11 and 12
It is adapted to be pushed into the opposing gap between the two.

The materials of the guide members 11 and 12 are as follows:
Particle size of base material powder of 50% TiB2 and 50% B4 C
A sintered product containing diamond fine particles of about 150 to 200 μm in a concentration of about 250 was used, and the material of the conductor 13 that also serves as a guide member was the same as the base material powder of 30% TiB2 and 70% B4C. It is preferable to use a material obtained by mixing diamond fine particles with a particle size of about 150 to 200 μm in a concentration of about 250 μm and sintering the powder.

In this case, a Br electrode is used as the wire electrode, and is fed at a speed of 8 m/min, so that the height 15 of the thin plate portion 13b of the wire electrode 13 shown in FIG.
mm, thickness 0.19 mm, electric discharge machining current I
As a result of continuous processing at p = 162 A, it could be used continuously for 480 hours. In addition, a thin plate portion 13b having a height of 15 mm and a thickness of 0.25 mm was used, and the discharge current I
As a result of continuous processing at p = 140 A, it could be used continuously for 920 hours. The distance between the electrode guide energizing device and the workpiece was 3.4 mm, which was much shorter than before.

FIG. 4 shows the main parts of a wire-cut electric discharge machining apparatus equipped with an electrode guide current supply device according to the present invention constructed as described above. Electrode guide energizing devices 1, 1 according to the present invention are provided in close proximity to the upper and lower surfaces of the workpiece 3, respectively, and the wire electrode 2 inserted through these devices is slowly run along the direction in which it is stretched. Machining is performed by applying a machining pulse voltage from a machining power source 8 between a wire electrode 2 and a workpiece 3 through a guide member-cum-conductor 13 provided in an electrode guide energizing device 1 to generate electric discharge between the two. It is.

In this case, since the electrode guide energizing device 1 including the energizing element 13 which also serves as a guide member is provided at a close distance from the workpiece 3, the section in which the discharge current flows through the wire electrode is short, and therefore the energizing loss is small. Therefore, high-speed machining can be performed using a large current. Furthermore, the number of times the wire electrode is heated and cut due to the discharge current is significantly reduced compared to a conventional device in which a conductor is provided at a position away from the workpiece.

When performing taper processing, one or both of the upper and lower electrode guide and energizers are moved in the U-V axis direction so that the wire electrode stretched between the upper and lower electrode guide and energizers is inclined. A device is provided to move the

FIG. 5 shows an embodiment in which the machining fluid injection nozzles 9, 9 are directly attached to the holder of the electrode guide energizing device 1, 1 for wire-cut electric discharge machining according to the present invention, and the structure is as follows. By doing so, the machining fluid can be jetted and supplied from a close distance to the machining part, and even if the machining fluid supply power is a fraction of the conventional power, it is possible to improve the machining speed by several tens of percent. That is, in cutting out S55C material with a thickness of 50 mm, a pressure of 1.5 kgf/cm2 was used and a nozzle with an orifice diameter of 0.4 mm was used to cut out 10 cm of material into the processed part.
As a result of machining with a wire electrode with a wire diameter of 0.3 mmφ at an electrical discharge machining current of Ip = 140 A while supplying machining fluid from a 120° direction at a flow rate of c/sec, the result was 210
A processing speed of mm2/min was obtained. this is,
This corresponds to an increase of about 30% compared to the machining speed of 160 mm2/min when the same process was performed using a conventional method with a pressurizing force of 22 kgf/cm2.

FIG. 6 shows a further different embodiment of the electrode guide energizing device for wire cut electric discharge machining according to the present invention. In this embodiment, a pair of guide members 11 and 12 are arranged in a holder (not shown) so as to face each other, and the wire electrode 2 is applied with a predetermined pressure as in the embodiment shown in FIGS. 1 and 2. The guide member 11 is configured to sandwich the wire electrode 2 in a direction perpendicular to the wire electrode 2.
, 12 (guide member 11
The slit formed in is hidden in the figure and cannot be seen. ) A plate-shaped conductor 130 which also serves as a guide member is slidably inserted into the inside. The edge of the guide member 130 on the side inserted into the slits of the guide members 11 and 12 comes into contact with the wire electrode 2, so that electrical discharge machining current is supplied. The plate-shaped guide member/current wire 130 is brought into contact with the wire electrode 2 with a predetermined pressure by the action of a spring or the like not shown in the figure, and is slowly reciprocated in the longitudinal direction by feed rollers 18 and 19. This allows the point of contact with the wire electrode 2 to constantly move, thereby compensating for wear of the plate-like guide member/current element 130. With this type of current-carrying current, it is possible to cope with continuous machining for a longer period of time compared to the current-carrying current 13 shown in FIGS. 1 and 2, which moves only in one direction.

FIG. 7 shows yet another embodiment, in which a pair of guide members 101 and 102 are arranged in the holder 10 so as to face each other, and sandwich the wire electrode 2 with a predetermined pressure. The pair of guide members (101) are arranged in the axial direction of the wire electrode.
, 102) and in a direction that intersects with the wire electrode (2), a pair of guide members (103, 104) which also serve as guide members are placed so as to face each other with the wire electrode (2) in between. It is set up like this. Another pair of guide members 105 and 106 are auxiliary guide members. In order to compensate for wear, each guide member is configured to be moved by a minute amount in the longitudinal direction as machining progresses by a drive mechanism not shown in the drawings.

[0031] Communication terminals 103 and 104 that also serve as guide members
The material used for the guide members 101, 102, 105, and the guide members 101, 102, 105, As the material for 106, we used a Ti boron carbide containing Ti mixed with the same artificial diamond fine particles as above to a concentration of about 360 and sintered, and as a result, we were able to process it for approximately 400 hours. . In addition, hardness Hv6000
When using energization using TiTi boron carbide, processing could be performed for about 760 hours.

In addition to the above materials, the materials of these guide members include TiSi, Fe, Ni, B-Cr, Ta,
Boron carbides of Ti and metals such as Zr can be suitably used. Further, resins and ceramics can also be used to fix diamond fine particles, c-BN, etc. in the base material. Furthermore, in order to improve the conductivity of the conductor that also serves as a guide member, it is recommended to mix about 1 to 10% by weight of graphite.

Note that in order to enable automatic insertion of the wire electrode 2, at least some of the plurality of guide members may be configured to be movable relative to the holder 10 using an electromagnet, water pressure, or pneumatic drive mechanism. It is possible.

[0034]

Effects of the Invention Since the present invention is constructed as described above, the present invention provides an electrode guide energizing device for wire-cut electric discharge machining that can perform continuous machining for a long time at high speed through large current and has high machining accuracy. can be provided.

It should be noted that the present invention is not limited to the embodiments described above, but includes all modified embodiments that can be easily conceived by a person skilled in the art from the above description within the scope of the purpose of the present invention. It is.

[Brief explanation of drawings]

FIG. 1 is an enlarged plan sectional view showing an embodiment of an electrode guide energization device for wire-cut electrical discharge machining according to the present invention.

FIG. 2 is a longitudinal cross-sectional view taken along line A-A in FIG. 1;

FIG. 3 is a perspective view showing another embodiment of the guide member-cum-conductor in the electrode guide current-carrying device shown in FIGS. 1 and 2;

FIG. 4 is an explanatory view showing a main part of a wire-cut electrical discharge machining apparatus equipped with an electrode guide energization device for wire-cut electrical discharge machining according to the present invention.

FIG. 5 is an explanatory diagram showing an embodiment in which a machining fluid ejection nozzle is attached to the electrode guide energization device for wire-cut electrical discharge machining according to the present invention.

FIG. 6 is an explanatory view showing still another embodiment of the electrode guide energization device for wire-cut electric discharge machining according to the present invention.

FIG. 7 is an explanatory diagram showing yet another embodiment.

[Explanation of symbols]

1 Electrode guide energization device 2 Wire electrode 3 Workpiece 4 Machining tables 5, 6 Machining feed motor 7 Numerical control device 8 Machining power source 9 Machining fluid jet nozzles 11, 12 Guide member 13 Guide member double-use current wire 14
Leaf spring 15 Coil spring 16 Adjustment screw 17 Current-carrying cables 18, 19 Feed rollers 101, 102 Guide members 103, 104 Current-carrying elements 105, 106 that also serve as guide members
Auxiliary guide member

Claims (12)

[Claims] Claim 1: A plurality of guide members (11, 12, 13) for positioning the wire electrode in the processed part are made of a hard material, and at least one of them is also used as a current conductor (13) for the wire electrode. An electrode guide energization device for wire cut electrical discharge machining, characterized by: [Claim 2] The guide member (11, 12, 13) comprises:
The holders (
A pair of guide members (11, 12) attached to
), and its tip edge is connected to the pair of guide members (11, 1
2) The electrode guiding and energizing device for wire-cut electrical discharge machining according to claim 1, comprising a energizing element (13) which also serves as a guide member and is inserted into the opposing gap of the wire electrodes (2) and brought into contact with the wire electrode (2). 3. The guide members include a pair of guide members (11, 12) that are attached to the holder (10) so as to face each other with the wire electrode (2) in between; 11, 12) and a plate-shaped conductor (130) that also serves as a guide member and is brought into contact with the wire electrode in a state substantially orthogonal to the wire electrode in the opposing gap. The electrode guide energization device for wire-cut electric discharge machining according to claim 1, further comprising a mechanism (18, 19) for moving in orthogonal directions. 4. At least one guide member (12) of the pair of guide members (11, 12) is urged toward the other guide member (11), and the surfaces of both guide members are aligned with the wire electrode (2). ) The electrode guide energizing device for wire cut electric discharge machining according to claim 2 or 3, configured to maintain a contact state with the electrode guide energizing device for wire cut electrical discharge machining. 5. A conductor (13, 13) which also serves as the guide member.
0) toward the wire electrode (2), and conducts electricity (1
5. The electrode guide energization device for wire-cut electric discharge machining according to claim 2, wherein the electrode guide energization device for wire-cut electrical discharge machining is configured to maintain contact with the wire electrode even when the tip edge of the electrode 3, 130) is worn. 6. The guide member includes a pair of guide members (101, 102) attached to the holder (10) so as to face each other with the wire electrode (2) in between, and a pair of guide members (101, 102) arranged in the axial direction of the wire electrode. Members (101, 102
), and the holders (10) are disposed in a direction that is close to and intersects with the wire electrode (2), and are opposite to each other with the wire electrode (2) in between.
A pair of conducting wires (10
3,104) The electrode guide energization device for wire cut electrical discharge machining according to claim 1, comprising: 7. The pair of guide members (101, 102)
at least one guide member is urged toward the other guide member, and the surfaces of both guide members are connected to the wire electrode (
2) The electrode guide energization device for wire-cut electric discharge machining according to claim 6, configured to maintain a contact state with. 8. A conductor (10
3,104), wherein at least one conductive current is biased toward the other conductive current, and the contact state with the wire electrode is maintained even when the surface of the conductive current (103, 104) is worn. Item 8. The electrode guide energization device for wire-cut electric discharge machining according to item 6 or 7. 9. The guide member (11, 12) and the conductor (13, 103, 104, 130) that also serves as the guide member.
The electrode guide current supply device for wire-cut electric discharge machining according to any one of claims 1 to 8, wherein the electrode guide current supply device for wire-cut electric discharge machining is made of a material containing ultrahard fine particles such as diamond and c-BN. 10. The guide member (11, 12) and the conductor (13, 103, 104, 130) that also serves as the guide member.
) is made of a material containing Ti or TiSi. 11. The guide member (11, 12) and the conductor (13, 103, 104, 130) that also serves as the guide member.
) is made of a material mainly consisting of boron carbide of Ti. 12. The electrode guide energization device for wire-cut electric discharge machining according to claim 1, wherein a machining fluid injection nozzle (9) is attached to the holder (10).