JP2922272B2 - Automatic connection device for wire cut electric discharge machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to an automatic wire connection device (hereinafter referred to as AWT-Automatic Wire Threading-
Abbreviated as device. In particular, in the type in which a wire is inserted through a machining start hole (initial hole) using a guide pipe at the start of electric discharge machining work or when the work is resumed after disconnection, the state of the wire tip such as bending or habit, AW that can securely set the wire in the starting hole even if buckling occurs due to the wire abutting on the upper end of the pipe
T device.

(Prior Art) In recent years, AWT apparatuses have been widely used for speeding up and unmanned wire-cut electric discharge machining operations. This AWT device is described in PP186-189 in the July 1986 issue of the magazine "Applied Mechanical Engineering" by Nobuo Fujimoto of the Patent Office.
A detailed discussion has been made entitled "Patent Highlight-Automatic Wire Supply of EDM". In this article, the technique described in this specification is introduced as a technique for realizing insertion of a wire using a guide pipe (hereinafter, referred to as a pipe guide method).
No. 4438 (Japanese Patent Publication No. 62-11970) is exemplified. Other prior examples of this pipe guide type AWT apparatus are disclosed in JP-A-56-89436 (JP-B-63-31333) and JP-A-Hei.
160422 and others.

FIG. 12 is a perspective view showing an example of a conventional wire cut electric discharge machine, showing a state where wires are connected to the machine. In FIG. 1, an AWT apparatus 1 includes a wire feed mechanism 4 including a pair of rollers 4a and 4b and an upper guide piece 4c for supplying a wire 2 in a direction of a workpiece 3 (hereinafter, referred to as a work). 2 is inserted through it and work 3
Guide pipe 5 for guiding the start hole 3a of the
Lifting mechanism 6 with the upper end fixed to raise and lower the pipe 5
A driving mechanism 7 for driving the lifting mechanism 6 up and down,
It is roughly composed of a cutting mechanism 8 for cutting the wire 2 as necessary, and a wire guiding and feeding mechanism 9. Inside the guide / power supply mechanism 9, a wire guide for guiding the wire 2 and a power supply piece for supplying a discharge pulse current to the wire 2 as an electrode during electric discharge machining (both not shown).
Is provided.

The elevating mechanism 6 is composed of a fixed rail 6a fixed between the feed mechanism 4 and the cutting mechanism 8, and a movable member 6b that reciprocates in the groove direction by a guide portion engaging with a guide groove of the fixed rail 6a. It is configured.

Although various types of drive mechanisms 7 can be considered, a belt and a pulley are used here. That is, a power transmission belt 7a having both ends fixed to the upper and lower ends of the movable member 6b, an upper pulley 7b and a lower pulley 7c for guiding the belt 7a, respectively, and the movable member 6b fixed to the fixed rail 7a.
And upper and lower guide rolls 7d and 7e rotatably fixed to upper and lower ends of a fixed rail for sliding along the groove as much as possible.

Further, the guide / power supply mechanism 9 includes a main body 9a in which a frame-shaped power supply body and a wire guide for guiding the wire 2 are housed, and a lower end portion of the main body 9a serves as a machining liquid jet nozzle. And a support frame 9b.

In the conventional AWT device 1 having the above configuration, after the start or cut end of the wire 2 is inserted into the guide hole of the upper guide piece 4c, the motor (not shown) is rotationally driven to feed the feed roller 4a.
And 4b are supplied in the direction of the work 3 by rotating in the feed direction. At this time, the elevating mechanism 6 is raised so that the movable member 6b is located at the uppermost position. When the tip of the wire 2 on which the feed rollers 4a and 4b rotate is sent to the work 3, the upper end of the pipe 5 whose upper end slightly projects from the upper end of the movable member 6b captures the tip of the wire 2. The wire 2 is inserted through the pipe 5.

Thereafter, the wire 2 is fed until it protrudes from the lower end opening of the pipe 5 with the rotation of the rollers 4a and 4b. At the same time, the elevating mechanism 6 starts to descend based on the driving of the driving mechanism 7, so that the pipe 5 moves from the guide hole of the cutting mechanism 8 to the starting hole of the workpiece 3 through the guide hole of the guiding / power feeding mechanism 9.
The work 3 is inserted into the work 3a, and is drawn out so as to be sandwiched between lower draw-out rollers (not shown) provided below the work 3.

Thereafter, the wire 2 is also pulled by a take-up reel (not shown) through a pulley (not shown) for changing the wire supply direction.
After the end of the roller is wound, the drive mechanism 7 moves the lifting mechanism 6
Is stopped again when the lower end of the pipe 5 is pulled up above the guide hole of the cutting mechanism 8 as shown in the figure, and the stretching of the wire 2 is completed. Thereafter, a discharge pulse current is supplied through a power supply frame (not shown) of the guide / power supply mechanism 9 and the work 3 is moved along a machining shape programmed by an XY table (not shown), thereby performing wire cut electric discharge machining. Done.

(Problem to be Solved by the Invention) The AWT device in the conventional wire cut electric discharge machine that operates as described above with the above configuration has the following problems.

First, even when the distance between the lower end of the pair of rollers 4a and 4b of the wire feed mechanism 4 on the exit side of the wire and the upper end of the pipe 5 when the elevating mechanism 6 is operated to the uppermost position is minimized. As the pipe 5 descends, a gap indicated by reference symbol D in FIG. 12 is formed. Since the feed mechanism 4 and the guide pipe 5 are separated by the gap D, the wire tip is bent when the tip of the wire 2 is inserted into the pipe 5 before the start of processing and before the restart of processing after disconnection. In such a case, the tip is deviated from the upper end of the pipe 5, and there has been a problem that the wire cannot be reliably set.

Also, due to the presence of the gap D, the wire 2 is fed by the rollers 4a and 4b, and after passing through the guide pipe, is further fed through the upper and lower wire guides to the winding roller until the tip of the wire reaches the winding roller. There is also a problem that the tip of the buckle deviates laterally from the supply direction, and buckling B occurs as shown in FIG.

Further, when the conventional guide pipe 5 is lowered to the lowermost limit by the elevating mechanism 4, the gap D is further increased, so that the wire 2 buckles in the enlarged gap D, and the connection ratio is reduced. There was also the problem of lowering it.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem. It is an object of the present invention to provide an automatic wire connection device of a wire cut electric discharge machine capable of preventing a wire supplied in a direction from buckling or preventing a wire tip from deviating from an opening on an insertion side of a pipe in this gap.

[Configuration of the invention]

(Means for Solving the Problems) In order to achieve the above object, an automatic connection device of a wire cut electric discharge machine according to the present invention includes a wire feed mechanism for sending a wire electrode to a machining start hole, and an outlet of the wire feed mechanism. A first wire guide member, which is provided on the side and guides the distal end of the wire electrode to a machining start hole, and which can be moved up and down;
A second wire guide member which is provided in the gap so as to change as the first wire guide member moves up and down and surround a gap corresponding to a space between the wire feed mechanism and the first wire guide member. And the following.

Further, the second wire guide member may be configured such that a tip of the wire supplied by the wire feed mechanism is deviated from an insertion opening of the first wire guide member, or the wire is connected to an outlet of the wire feed mechanism and the second wire guide member. In order to prevent buckling during supply between the wire guide member and the insertion port of the wire guide member, a buckling prevention mechanism constituted by an eccentric rotating body including an eccentric hollow portion and a rotating mechanism is also used. good.

Further, the second wire guide member is provided between the buckling prevention mechanism and the first wire guide member, and can be inserted into the wire insertion opening as the first wire guide member rises. A guide pipe having a diameter may be further provided.

(Operation) Since the present invention is configured as described above, the leading end of the wire supplied from the supply reel by the feed mechanism before the start of electric discharge machining is moved along with the gap between the wire feed supply mechanism and the guide pipe as the guide pipe moves up and down. Even when the wire is deviated from the normal supply locus to some extent due to the bending or habit of the tip of the wire when the wire is inserted into the wire insertion port of the guide pipe, the wire is used as the second wire guide member. Is provided, the leading end of the supplied wire is reliably caught and guided in the guide pipe. In this situation, the buckling prevention mechanism functions as the second wire guide member.

Also, once the wire is inserted into the guide pipe, conditions such as the wire supply speed, the frictional stress between the wire and the pipe inner wall, and a slight displacement between the center of the guide hole of the lower wire guide and the axis of the wire, etc. This makes it easier for the wire to buckle between the feed mechanism exit side and the guide pipe insertion port,
According to the present invention, since the second wire guide member is provided, even if slack occurs due to a change in various conditions during the supply of the wire, the wire is reliably guided by the second wire guide member. Buckling, catching and cutting of the wire are prevented.

(Embodiments) Some preferred embodiments of the automatic connection device of the wire cut electric discharge machine according to the present invention will be described in detail below with reference to the addition drawings.

1 to 5 show an automatic wiring (AWT) device according to a first embodiment of the present invention.

In FIGS. 1 and 2, the components denoted by the same reference numerals as those in FIG. 12 are the same as or equivalent to the components of the conventional AWT apparatus, and the duplicate description will be omitted. The AWT device 10 according to the first embodiment includes a wire feed mechanism 4
A buckling prevention mechanism 11 as a second wire guide member fixed in a gap D between the movable member 6b of the pipe lifting mechanism 6 and the movable member 6b of the pipe lifting mechanism 6.

The structure of the buckling prevention mechanism 11 as the second wire guide member is shown in FIGS. 1, 3 and 4. That is, the prevention mechanism 11 includes a box-shaped casing 12 and an eccentric hole 13a that is rotatably supported inside the casing 12 with a regular passage locus of the wire as a rotation center axis and is eccentrically formed from the locus. Eccentric rotator 13 and rotator 1
3, a pulley 15 and 16 for rotating the rotating body 13, a belt 17 stretched between the pulleys 15 and 16, and a rotation in which the pulley 16 is mounted on a rotating shaft 18a. It comprises a motor 18 for rotationally driving the body 13. The bearing 14 is provided with an outer race 14a fixed to the inner wall of the casing 12, an inner race 14b fixed to the outer periphery of the rotating body 13, and a plurality of rollingly rotatable members between the races 14a and 14b. It is composed of a rolling ball 14c. The pulley 15 is fixed to the lower end of the eccentric rotator 13.

The buckling prevention mechanism 11 as the second wire guide member having the above-described configuration is driven by the rotation of the motor 18 so that its output shaft
The pulley 16 fixed to 18a rotates, and its rotation output is transmitted to the pulley 15 via the belt 17. The rotation of the pulley 15 rotates the eccentric rotator 13 to guide the wire 2 to the guide pipe 5. This guiding operation will be described with reference to FIG. 4. The eccentric hole 13a is bored in the eccentric rotating body 13 so as to sufficiently include the extension of the diameter of the guide pipe 5 regardless of the position at which the eccentric rotating member 13 is rotated. The eccentric hole 13a can catch the tip 2a at any position even when the wire is bent like the wire tip 2a shown in FIG. Therefore, the wire 2 is inserted into the insertion port of the guide pipe 5.
It will be securely inserted into 5a.

Further, during a period from the time when the wire 2 is fed into the guide pipe 5 to the time when the tip 2a of the wire 2 reaches a winding roller (not shown), the wire receives a contact resistance for some reason and buckles or bends. When this occurs, the bent portion is pushed toward the center of the eccentric rotator, which is a regular passing locus, by the inner wall of the eccentric hole 13a. , The wire 2 is reliably fed into the guide pipe 5.

When the gap D shown in FIG. 1 is wider than the height of the casing 12, as shown in FIG. 4, the stop position when the pipe insertion port 5a is raised is determined and the funnel-shaped guide portion 19a is determined. May be provided.

Further, in the first embodiment, the buckling prevention mechanism as the second wire guide member has been described as being constituted by the eccentric rotating body. However, the present invention is not limited to this, and FIGS. The buckling prevention mechanisms 20, 30, and 40 having the configuration as in the second to fourth embodiments shown in FIG.

A buckling prevention mechanism 20 as a second wire guide member in the second embodiment shown in FIG. 6 is a cylindrical body 21 fixed so that its upper end is located as close to the exit side of the feed mechanism 4 as possible. And a spring 22 having an upper end fixed to the inner end face 21a of the cylindrical body 21 and a lower end fixed to a countersunk hole 6c formed on the upper surface of the movable member 6b of the elevating mechanism 6. A transmission hole 21b is formed at the center of the end face 21a.

In such a configuration, the feed mechanism 4 uses the wire 2
Is supplied, the wire tip 2a is guided inside the cylindrical body 21 and the spring 22 through the transmission hole 21b. Then, it is guided into the guide pipe 5 through the countersink 6c. In addition, this countersink
6c may be connected to the upper end of the guide pipe 5 in a funnel shape, leaving a spring receiving portion on the outermost peripheral side.

According to the buckling prevention device as the second wire guide member in the second embodiment, when the movable member 6b of the elevating mechanism 6 descends most to insert the pipe 5 into the starting hole of the work, the spring 22 This is the most expanded state, and the diameter of the spring is the thinnest, so that an effect peculiar to this embodiment that the buckling of the wire when the wire is set on the work can be more reliably prevented.

Next, a third embodiment of the present invention will be described with reference to FIG.
A buckling prevention mechanism as a second wire guide member in the AWT device will be described.

The buckling prevention mechanism 30 as a second wire guide member in the third embodiment is provided for fixing a bellows tube 31 which can be extended and contracted in the axial direction and an upper end 31a of the bellows tube 31 to the main body side of the electric discharge machine. It is composed of a fixing member 32. The lower end 31b of the bellows tube 31 is fixed to a movable member 6b having a countersink 6c having the same configuration as that of the second embodiment. The configuration of the countersink 6c in this embodiment may also be configured to have a funnel-shaped or tapered inner peripheral surface as in the second embodiment.

Further, a buckling prevention mechanism 40 as a second wire guide member in the fourth embodiment shown in FIG. 8 is a telescopic tub having a small diameter on the upper side and a large diameter on the lower side.
e) 41, and a fixing member 42 for fixing the upper end 41a of the insertion tube 41 to the processing machine main body side. The lower end 41b of the insertion tube 41 is fixed to the countersunk hole 6c of the movable member 6b of the elevating mechanism 6 having the same configuration as the second and third embodiments.

With the above configuration, as the movable member 6b of the lifting mechanism 6 reciprocates, the insertion tube 41 expands and contracts to surround the wire electrode in the gap between the exit side of the feed mechanism (not shown) and the movable member 6b. Therefore, it is possible to prevent the tip 2a of the wire 2 from jumping out of the gap or to prevent the wire 2 from buckling in the gap.

In each of the AWT devices according to the first to fourth embodiments described above, a special configuration is applied as the buckling prevention mechanism. However, the present invention is not limited to the above configuration, and is configured by a simpler mechanism. Is also good.

FIG. 9 shows a fifth embodiment of the automatic connection device according to the present invention. As shown in FIG. 9, a buckling prevention mechanism 50 as a second wire guide member in the fifth embodiment includes a small-diameter and fixed buckling prevention pipe 51,
It is composed of a fixing member 52 for fixing 51,
In this embodiment, the guide pipe 5 is also connected to the buckling prevention pipe 51 when the movable member 6b of the elevating mechanism 6 is at the uppermost position. From the large diameter portion 55. The large-diameter portion 55 is a small-diameter portion having a small diameter on the work side via the step portion 56.
It is connected to 57.

Each of the second to fifth embodiments has a buckling prevention mechanism 20, 30, 40 and a single structure as a second wire guide member.
Although 50 has been described as being applied, the present invention is not limited to this, and some types of buckling prevention mechanisms may be used in combination.

For example, the second wire guide member according to the sixth embodiment shown in FIGS. 10 and 11 is a buckling prevention mechanism of the first embodiment.
This is a combination of the eleventh embodiment and the buckling prevention mechanism 50 of the fifth embodiment.

10 and 11, FIG. 1, FIG. 3 and FIG.
Portions denoted by the same reference numerals as those in the drawings show corresponding components of the first and fifth embodiments. Reference numeral 61 denotes an upper wire guide member located above the work 3, and a lower wire guide member 63 having a wire guide 62 is provided below the work 3.

The operation of the sixth embodiment will be described. In the state where the guide pipe 5 is raised to the uppermost position shown in FIG. 10, the tip 2a of the wire 2 is fixed to the rotation of the eccentric rotator 13 and the lower side thereof. The guide 2 is guided by the buckling prevention pipe 50 to the guide pipe 5, and as the movable member 6b descends, the wire 2 is inserted into the machining start hole 3a formed in the workpiece 3 as shown in FIG. The tip 2a is inserted. Thereafter, the distal end 2a is inserted through the tapered hole of the wire guide 62 of the lower wire guide member 63, and is taken up on a take-up reel (not shown) via a pulley (not shown). When the wire 2 is set in the processing start hole 3a, the movable member 6b of the elevating mechanism 6 is raised again, and the large-diameter portion 55 of the guide pipe 5 and the fixed buckling prevention pipe 50 are linked again, The small diameter portion 57 on the lower side of the guide pipe 5 is pulled out from the start hole 3a.

〔The invention's effect〕

As described in detail above, according to the automatic wire connection device of the wire cut electric discharge machine according to the present invention, the wire feed mechanism, the first wire guide member that can move up and down, and the wire feed mechanism to the first wire guide member And a second wire guide member provided in the gap so as to surround the gap that changes as the first wire guide member moves up and down. It is possible to prevent buckling of the wire in the gap formed between the reciprocating pipe and the receiving end, and it is possible to reliably set the wire to be an electrode in the work start hole of the workpiece during electric discharge machining. Become.

In addition, since the buckling prevention mechanism is provided even before the wire is mounted on the machine by starting the processing or by cutting the wire,
It is possible to prevent the tip of the wire from deviating from the pipe insertion port in the gap.

Further, even when the guide pipe moves to the lowest position to mount the wire in the starting hole of the workpiece and the gap between the lower side of the feed mechanism and the insertion port of the pipe increases, Since a buckling prevention mechanism is provided between
The generation of buckling of the wire can be prevented as much as possible, and the connection ratio of the AWT device can be greatly improved.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing an automatic connection device of a wire cut electric discharge machine according to a first embodiment of the present invention, FIG. 2 is a front view thereof, and FIG. 3 is eccentricity of the automatic connection device according to the second embodiment. FIG. 4 is a partially cutaway perspective view showing a rotating body.
FIG. 5 is a schematic sectional view showing the entirety of the automatic connection device according to the embodiment, FIG. 5 is a cross-sectional plan view of the same eccentric rotary member, and FIG. 7 is a partially cut perspective view showing the buckling prevention mechanism of FIG.
FIG. 8 is a schematic perspective view showing a buckling prevention mechanism as a second wire guide member of the automatic connection device according to the third embodiment of the present invention. FIG. 8 is a second perspective view of the automatic connection device according to the fourth embodiment of the present invention. FIG. 9 is a perspective view schematically showing a buckling prevention mechanism as a wire guide member, FIG. 9 is a perspective view showing a buckling prevention mechanism as a second wire guide member of an automatic connection device according to a fifth embodiment of the present invention, FIGS. 10 and 11 are schematic sectional views showing a buckling prevention mechanism as a second wire guide member of an automatic wiring device according to a sixth embodiment of the present invention. FIG. 12 is a sectional view of a conventional wire cut electric discharge machine. It is a perspective view showing the outline of an automatic connection device. 2 ... wire, 2a ... wire tip, 3 ... workpiece (work), 3a ... working start hole, 4 ... wire feed mechanism, 5
…… Guide pipe, 5a… Wire insertion port, 5b …… Pipe tip, 6 …… Elevating mechanism, 6b …… Movable member, 11 …… Buckling prevention mechanism, 13 …… Eccentric rotating body, 20, 30, 40 , 50… buckling prevention mechanism, 22… spring (expandable member), 31… bellows tube (expandable member), 41… insertion tube (expandable member), 50… buckling prevention mechanism, 51… Buckling prevention pipe.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B23H 7/10 B65H 57/12 B65H 51/00

Claims (3)

(57) [Claims] 1. A vertically movable first wire comprising a wire feed mechanism for sending a wire electrode to a machining start hole, and a pipe provided on an outlet side of the wire feed mechanism for guiding a tip of the wire electrode to the machining start hole. A guide member, and a second member provided in the gap so as to change as the first wire guide member moves up and down and surround a gap corresponding to a space between the wire feed mechanism and the first wire guide member. An automatic wire connection device for a wire-cut electric discharge machine, comprising: 2. The second wire guide member according to claim 1, wherein the tip of the wire supplied by the wire feed mechanism is the first wire guide member.
Eccentricity to prevent deviation from the insertion opening of the wire guide member and buckling of the wire during supply between the outlet of the wire feed mechanism and the insertion opening of the first wire guide member. 2. The automatic wire connection device for a wire-cut electric discharge machine according to claim 1, wherein the buckling prevention mechanism is constituted by an eccentric rotating body including a hollow portion and a rotating mechanism. 3. The second wire guide member is provided between the buckling prevention mechanism and the first wire guide member.
3. The automatic wire connection device according to claim 2, further comprising a guide pipe having a diameter that can be inserted into the wire insertion port as the first wire guide member rises.