JP4036777B2 - Wire electrode cutting device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wire electrode cutting apparatus that cuts and processes a wire electrode used in wire electric discharge machining of a wire electric discharge machine to a predetermined length.
[0002]
[Prior art]
A wire electric discharge machine supplies a machining voltage between a wire electrode and a workpiece, and processes the workpiece by electric discharge. Since the wire electrode is consumed by electric discharge during the electric discharge machining, the wire electric discharge machine runs the wire electrode at a predetermined speed and performs machining while always supplying a new wire electrode to the machining portion.
The wire electrode used in the wire electric discharge machining is wound up by a winding roller and discharged out of the machine. It was very difficult to treat and handle the wound wire electrode. As a method for the discharge processing, a method (apparatus) is used in which a used wire electrode is cut into a predetermined length and collected in a collection box.
[0003]
Techniques for cutting wire electrodes used in wire electric discharge machining are disclosed in Japanese Patent Application Laid-Open Nos. 9-108951 and 5-253752. The technology (first prior art) disclosed in Japanese Patent Application Laid-Open No. 9-108951 cuts a wire electrode with a fixed blade that passes the wire electrode through an inner hole and a rotary blade similar to a milling cutter provided in front of the fixed blade. The cutter is configured. Further, FIG. 9 of the same publication describes that the fixed blade is evenly generated on the entire blade surface of the fixed blade by rotating the fixed blade with a motor.
Japanese Patent Laid-Open No. 5-253752 (second prior art) discloses a wire electrode composed of a fixed blade that allows a wire electrode to pass through an inner hole and a movable blade that performs a swinging motion of a substantially elliptical locus provided on an end surface of the fixed blade. Is a cutter that cuts the frame.
[0004]
[Patent Document 1]
JP-A-9-108951 [Patent Document 2]
Japanese Patent Application Laid-Open No. 5-253752
[Problems to be solved by the invention]
In the first conventional technique described above, a used wire electrode is cut by a fixed blade and a rotary blade (cutter) that rotates at the tip of the fixed blade. In this structure, when the cutting edge portions of the fixed blade and the rotating blade are worn even a little, a gap is generated between the two blades, so that there is a problem that the cutter is not sharp and the wire electrode cannot be cut.
In the second prior art, a used wire electrode is cut by a fixed blade and a movable blade that swings at the tip of the fixed blade. In this structure, since the wire electrode is cut at the same position of the fixed blade and the movable blade, there is a problem that the cutting blade portion is worn quickly and the cutter life is short.
[0006]
The present invention has been made to solve these problems of the prior art, and an object of the present invention is to reduce the wear of the cutting edge portion of a cutter that cuts a used wire electrode to a predetermined length. An object of the present invention is to provide a wire electrode cutting apparatus having a good sharpness and a long cutter life.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, in a wire electrode cutting apparatus for cutting a wire electrode used in wire electric discharge machining, a base that is a frame and a bore that is rotatably provided on the base and that passes through the wire electrode are cut. a ring-shaped rotary blade having a cutting edge, and a pair of the crankshaft that rotates in conjunction with the rotatably coupled to the ring-shaped rotary blade by the rotation transmission mechanism provided rotation of the ring-shaped rotary blade to said base, said ring A cutting blade that contacts the end face of the ring-shaped rotary blade on both sides and interlocks with the rotation of the crankshaft so that the cutting blade crosses in a reciprocating manner from one outer side to the other outer side of the inner hole of the ring-shaped rotary blade. A rod-shaped movable blade that swings and slides, an elastic member that presses the rod-shaped movable blade against an end surface of the ring-shaped rotary blade, and a motor that rotates the ring-shaped rotary blade and the pair of crankshafts Comprising a, the wire electrode cutting apparatus for cutting across the wire electrode is provided between the ring-shaped rotary blade and the rod-shaped movable blade.
As described above, the cutter for cutting the wire electrode includes a ring-shaped rotary blade that rotates and a rod-shaped movable blade that slides. When cutting the wire electrode, the wire electrode is sandwiched between both blades while pressing the rod-shaped movable blade against the ring-shaped rotary blade. The cutting of the wire electrode with this structure is not a so-called chopping but a cutting state, and the cutting resistance is reduced. And since the rod-shaped movable blade is pressed against the ring-shaped rotary blade by the elastic member, there is no gap between the two blades and the sharpness is good.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of the wire electrode cutting device of the present invention, and FIG. 2 is a cross-sectional view taken along the line II-II of FIG. FIG. 3 is a schematic view of a conventional wire electrode cutting apparatus.
Since the main part of the wire electric discharge machine to which the wire electrode cutting device of the present invention is attached is the same as the conventional wire electric discharge machine, the schematic diagram of the conventional wire electrode cutting device shown in FIG. 3 will be described first. The wire electrode 53 obtained by processing the workpiece 51 is guided to the roller 55 and the conduit 57. The winding roller 59 winds the wire electrode 53 by the winding motor 61. The wire electrode 53 is guided into the inner hole 67 of the fixed blade 65 attached to the housing 63. A rotary blade 69 is provided at the tip of the fixed blade 65 and is rotated by a motor 71. The fixed blade 65 and the rotary blade 69 constitute a cutter that cuts the wire electrode 53. The wire electrode 53 cut to a predetermined length is collected in the collection box 72.
[0012]
An embodiment of the present invention will be described with reference to FIGS. The wire electrode cutting device of the present invention describes in detail a portion corresponding to the housing 63 of the conventional wire electrode cutting device shown in FIG. 3, and the other portions are the same as those of the conventional wire electrode cutting device of FIG. Are the same. 1 and 2, the ring-shaped rotary blade 5 is rotatably supported at the center portion of the base 1 by a bearing 11. The ring-shaped rotary blade 5 has an inner hole 7, and a used wire electrode 53 is guided into the inner hole 7. The tip portion of the ring-shaped rotary blade 5 is joined as a cutting blade portion 9 such that a ceramic member or cemented carbide member having high hardness and excellent wear resistance can be bonded or removed. Since the ring-shaped rotary blade 5 is relatively small, the whole may be made of a ceramic member or a cemented carbide member.
[0013]
A driving gear 13 is attached to the ring-shaped rotary blade 5. A crankshaft 15 is rotatably supported on the base 1 by a bearing 17. A driven gear 19 is attached to one end of the crankshaft 15, and a crankpin 21 is attached to the other end that is eccentric with respect to the rotational axis of the crankshaft 15. The rotation transmission mechanism attached to the base 1 is covered with a cover 3 for safety. It is desirable that at least one of the number of teeth of the driving side gear 13 and the driven side gear 19 of the rotation transmission mechanism is a prime number. The reason is that when the wire electrode 53 is cut, there are a number of positions (points) where the wire electrode 53 is pressed against the ring-shaped rotary blade 5 so that the cutting blade portion 9 is consumed evenly over the entire blade surface. It is to do.
The number of teeth of the gear of the rotational transmission mechanism of the present embodiment is that the prime number of the driving gear is 71 and the number of teeth of the driven gear is 45. When the cutting positions (points) of the ring-shaped rotary blade 5 are calculated, there are 142 locations on the circumference, which are evenly formed on the entire blade surface of the cutting blade portion.
[0014]
A rod-shaped movable blade 23 is provided on the front surface of the ring-shaped rotary blade 5, and a cutting blade portion 25 is detachably mounted on the rod-shaped movable blade 23. The cutting blade portion 25 can move the mounting position of the cutting blade portion 25 by loosening the clamp screw 27 and adjusting the clamping position. When the cutting blade portion 25 is worn due to the cutting of the wire electrode 53, the mounting position can be shifted and the wire electrode 53 can be cut at the new cutting blade portion. The cutting edge portion 25 is made of a ceramic member or a cemented carbide member having high hardness and excellent wear resistance. The rod-shaped movable blade 23 and the cutting blade portion 25 may be integrally made of a ceramic member or a cemented carbide member without being separated.
[0015]
One end of the rod-shaped movable blade 23 is supported by one crank pin 21 by a bearing 29, and the other end is engaged with the other crank pin 21 by a long hole 31. The long hole 31 is for absorbing interference due to an attachment error of the crank pin 21. The long hole 31 is not necessarily required as long as the crank pin 21 can be attached at an accurate position, and may be supported in the same manner as the bearing 29. An elastic member 33 is provided between the rod-shaped movable blade 23 and the crank pin 21 and presses the rod-shaped movable blade 23 against the ring-shaped rotary blade 5. The elastic member 33 is made of a disc spring or a coil spring. A motor 35 for rotating the ring-shaped rotary blade 5 is provided on the base 1, and a motor gear 37 attached to the motor 35 meshes with the driving-side gear 13 attached to the ring-shaped rotary blade 5.
[0016]
When the motor 35 is rotated, the driving gear 13 meshed with the motor gear 37 is rotated, and the pair of driven gears 19 and the crankshaft 15 are rotated. When the crankshaft 15 rotates, the crankpin 21 rotates eccentrically, so that the rod-shaped movable blade 23 supported by the crankpin 21 swings and slides. Now, when the driving gear 13 shown in FIG. 2 rotates in the direction of arrow A and the driven gear 19 rotates 90 degrees in the direction of arrow B, the rod-shaped movable blade 23 slides to the position C indicated by the imaginary line. . The rocking and sliding movement of the rod-shaped movable blade 23 is performed so as to cross the inner hole 7 of the ring-shaped rotary blade 5 while being pressed against the end surface of the cutting blade portion 9 of the ring-shaped rotary blade 5.
[0017]
The used wire electrode 53 is cut when the wire electrode 53 passes through the inner hole 7 of the ring-shaped rotary blade 5 at a predetermined speed at a predetermined length, and then the wire electrode 53 is connected to the ring-shaped rotary blade 5 and the rod-shaped movable blade. 23 and cut between them. If edges are formed on both side surfaces of the cutting blade portion 25 of the rod-shaped movable blade 23, the wire electrode 53 can be cut by reciprocation of the operation in which the rod-shaped movable blade 23 crosses the inner hole 7 of the ring-shaped rotary blade 5. The length for cutting the wire electrode is determined by setting the feed speed of the wire electrode 53 and the rotation speed of the motor 35 with a known device (not shown).
[0018]
【The invention's effect】
As described above, according to the present invention, the wire electrode is cut by sandwiching the wire electrode between the rotating ring-shaped rotary blade and the sliding-movable rod-shaped movable blade. Since the cutting resistance is small, a compact device can be obtained. Since the rod-shaped movable blade slides while being pressed against the ring-shaped rotary blade by the elastic member, there is no gap between the two blades, and a cutter with good sharpness can be obtained. Furthermore, since the cutting edge is provided on both side surfaces of the rod-shaped movable blade and the wire electrode is cut by reciprocation, the cutter life is doubled.
[0019]
Further, since the number of teeth of at least one of the gears on the driving side and the driven side of the rotation transmission mechanism is made a prime number, there are many positions (points) for cutting the wire electrode in the cutting edge portion of the ring-shaped rotating blade. Therefore, wear of the cutting edge portion occurs evenly on the entire blade surface, and the cutter life is extended. In addition, the cutting blades of the ring-shaped rotary blade and the rod-shaped movable blade are made of ceramics or cemented carbide and can be removed from the body, so even if the cutting blade wears, only the cutting blade can be easily removed. As a result, an inexpensive device was obtained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a wire electrode cutting device showing an embodiment of the present invention as seen from the front.
FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1, and shows the wire electrode cutting device as viewed from the side.
FIG. 3 is a schematic view of a conventional wire electrode cutting device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Base 5 ... Ring-shaped rotary blade 7 ... Inner hole 9 ... Cutting blade part 11 ... Bearing 13 ... Driving side gear 15 ... Crank shaft 19 ... Driven side gear 21 ... Crank pin 23 ... Rod-shaped movable blade 25 ... Cutting blade part 29 ... Bearing 33 ... Elastic member 35 ... Motor 37 ... Motor gear

Claims (1)

In the wire electrode cutting device for cutting the wire electrode used for wire electric discharge machining,
A base that is a frame,
A ring-shaped rotary blade that is rotatably provided on the base and has a cutting blade in an inner hole through which the wire electrode passes;
A pair of crankshafts provided rotatably on the base, coupled to the ring-shaped rotary blade by a rotation transmission mechanism, and rotating in conjunction with the rotation of the ring-shaped rotary blade;
It has cutting edges that contact the end face of the ring-shaped rotary blade on both sides, and rotates the crankshaft so that the cutting blade crosses in a reciprocating manner from one outer side to the other outer side of the inner hole of the ring-shaped rotary blade. A rod-shaped movable blade that swings and slides in conjunction with it,
An elastic member that presses the rod-shaped movable blade against an end surface of the ring-shaped rotary blade;
A motor for rotating the ring-shaped rotary blade and the pair of crankshafts;
A wire electrode cutting device comprising: cutting the wire electrode between the ring-shaped rotary blade and the rod-shaped movable blade.

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