JPH03234425A - Underneath drawing device for wire - Google Patents

Abstract

PURPOSE:To stably transfer a small-diameter wire or soft wire, in a wire underneath drawing device to be used for a wire-cut electric discharge machining device, by providing through-holes in the wire-guide groove of a direction- changing roller for drawing a machining solution and for discharging a fluid. CONSTITUTION:When a wire 3 is passed at the time of start of machining or at the time of breakage of the wire, a motor on the work feed side is operated, and a machining solution is injected along a machining hole from the top of the work, and also a slower feed is given by a roller or the like for feeding the wire 3. At the same time, a direction-changing roller 13 is turned, and the machining solution flowing down a curved guide part 12a is drawn by a drawing device through through-holes 13e and a recessed part 22c on the inside of the direction-changing roller 13 and through a flow passage 16a to attract the wire 3 to a wire guide groove 13d. On the other hand, a liquid or air is discharged by a fluid discharging device to the space between drawing rollers 9 through a flow passage 16b, a recessed part 22d, and through-holes 13e, so that the wire 3 is separated from the wire guide groove 13d, and is guided toward the space between the drawing rollers 9.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is used in a wire-cut electric discharge machining device to change the direction of a wire after passing through a workpiece by passing through a curved guide part and to apply a conveying force to the wire. It relates to a lower drawer device.

(Prior art) Fig. 6 shows a conventional lower wire drawing device in a wire-cut electrical discharge machining device, where l is a workpiece set on a processing table z, 3 is a wire, and 4 is attached to a device frame 5. 6 is a lower feeder; 7 is a lower wire drawing device; the drawing device 7 includes a curved guide portion 8a attached to the frame 5;
It consists of a direction change curve guide 8 having a # curve guide 8, a pair of pull-out rollers 9 provided at the exit of the # curve guide 8, and a guide tube lO provided at the exit side of the pull-out rollers 9.

This device feeds the wire 3 from a wire supply device (not shown) installed above the workpiece 1 at the start of machining or when the wire breaks.
is fed out and passed through the workpiece 1, the direction is changed using the curved guide portion 8a of the guide 8 and the pull-out roller 9, and the guide tube 10
or wind it up with a take-up reel (not shown) through a suitable guide roller or shock absorber, or cut it into predetermined lengths, or accumulate it by swirling it in a container or rolling it up and dropping it. .

In addition, as a conventional lower wire drawing device, there is a structure in which the wire is pressed along the horse surface of the direction changing roller by spraying pressure fluid in the tangential direction of the direction changing roller (Japanese Patent Publication No. 19343/1983). There is something like that.

(Question 8 to be solved by the invention) In the conventional device shown in FIG. The jet stream flows along the wire 3 and contributes to the conveyance of the wire 3, but since the jet stream is blocked by the positioning member 4, the feeder 6, and others, the gap between the pull-out rollers 9 is blocked. The opening/closing of the positioning member 4, as well as the retraction/advancing method, causes the shet flow to be disturbed in front of the pull-out roller 9, causing the wire 3 to protrude from the side of the curved guide 8 or become tangled. Further, since the jet flow is disturbed at the portion where the wire 3 contacts the pull-out roller 9, there is a problem that the wire 3, which is particularly small in diameter or soft, is not stable.

In addition, what was disclosed in Japanese Patent Publication No. 19343/1983 is
The jet stream flowing along the wire collides with the jet stream colliding at right angles to the jet stream for changing the direction of the wire, causing the flow to become turbulent, which again poses the problem of unstable conveyance of small-diameter or soft wires.

In view of the above-mentioned problems, the present invention provides a lower wire drawing device which is configured so that even if the wire has a small diameter or is relatively soft, the wire can be drawn out stably and discharged to a winding section or the like. The purpose is to provide.

(Means for Solving Problem 'f1) In order to achieve the above object, the present invention is used in a wire-cut electric discharge machining device, in which the wire after passing through the workpiece is passed through a cart guide to change direction, and the conveying force is In the lower wire drawing device, a curved guide having a curved guide section is fixed to the frame of the electrical discharge machining device, and the wire guide groove is widened beyond a part of the inner surface of the curved guide section. A fixed shaft is provided concentrically with the curved guide portion of the curved guide, and a direction changing roller rotated by a motor is provided on the fixed shaft concentrically with the fixed shaft and the direction changing roller is surrounded by the curved guide portion. a wire guide groove facing the wire guide groove is provided around the direction change roller, and a wire guide groove is provided at the bottom of the wire guide groove that extends approximately radially through the outer periphery of the direction change roller. A suction device is provided with a large number of through holes all around the circumference, and the machining liquid flowing down the curved guide portion is sucked into the inside of the direction changing roller through the through holes to attract the wire to the wire guide groove of the direction changing roller. It is characterized by having been established.

(Operation) Since the present invention has the above-described structure, the wire passing through the inner surface of the curved guide portion or the groove formed therein is guided by the suction force at the outer circumferential portion of the direction change roller together with the intervening machining fluid. The wire is attracted to the groove, and the direction change roller rotates in this state, thereby providing driving force for transporting the wire.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 5. FIG. 1 is a front sectional view showing an embodiment of a lower wire drawing device according to the present invention, FIG. 2 is an exploded perspective view thereof,
FIG. 3 is a side sectional view thereof, FIG. 4 is a front view showing its roller rotation mechanism, and FIG. 5 is a sectional view showing the overall structure of the lower wire drawing device of this embodiment.

In FIG. 5, the same reference numerals as in FIG. 6 indicate the same components. 13 and a pair of pull-out rollers 9.

As shown in FIGS. 1 to 3, the curved guide 12 has a partially arcuate concave portion 12f on one side formed as a curved guide portion 12a. A V-shaped wire guide groove 12b is provided over a desired portion according to the requirements or necessary, and the wire guide groove 12b is wide on the wire introduction hole 12c side and wide on the exit 1 side.
The 2d side is formed to be narrow or disappear. A through hole 12e is provided at the center of the arc-shaped recess 12f of the curved guide 12.
The fixed shaft 16 is fitted into the through hole 12e, and
As shown in FIG. 3, the fixing shaft 16 is mounted on the frame 5 by being fitted into the hole 17.

The fixed shaft 16 is connected to the direction changing roller 13 via bearings 18, 19, or to the recess 1 of the curve guide 12 around the direction changing roller 13.
2f (a part of the inner peripheral surface of the recess 12f or the curved guide portion 1
2a) so as to be rotatably slidably in contact with or close to.

The direction changing roller 13 includes a ring 13a having a protruding edge 13b protruding in the axial direction from the outer periphery of one side;
It consists of a ring-shaped gear 13c fixed to the protruding edge 13b of 3a with a screw 21.

A wire guide groove 13d facing the wire guide groove 12b of the curved guide 12 is formed over the entire circumference on the outer periphery of the ring 13a, that is, on the outer periphery of the protrusion 13b, and a large number of through holes are formed in the radial direction at the bottom of the wire guide groove 13d. 13e is drilled all around the circumference.

At a portion of the fixed shaft 16 located inside the direction changing roller 13, a fluid suction/blowing channel forming body 22, which is combined with discs 22a and 22b or a screw 23, is fitted in a non-rotating manner. The recesses 22c and 22d provided in the fixed shaft 16 communicate with a fluid suction channel 16a for air or machining fluid, etc. provided in the fixed shaft 16, and a fluid blowout channel 16b for a fluid such as air or water, respectively. , constitutes a suction flow path and a blowout flow path for fluid such as air or machining liquid. As shown in FIG. 1, the recessed portion 22c forming the suction flow path faces the curved guide portion 12a (excluding the folding outlet 12d), and the recessed portion 22d forming the blowing flow path faces the pull-out roller 9.9. The part in between is facing each other. Fixed shaft 16
A pipe line connected to the air or processing liquid suction passage 16a is connected to a suction pump (not shown), and a pipe line connected to the air or processing liquid suction passage 16a is
The line leading to is connected to a liquid delivery pump or compressor.

As shown in FIG. 4, a drive gear 25 rotated by a motor (not shown) is meshed with the gear 13c coupled to the direction changing roller 13.

The operation of this device will be explained. In order to pass the wire 3 through the wire 3 at the start of machining or at the time of wire breakage, in FIG. While spraying along the positioning member 4, the hole 5q of the frame 5,
The wire 3 is passed through the wire introduction hole 12c of the curve guide 12, or at this time, the wire 3 is affected by the braking force applied to the wire 3 by the jet force of machining fluid etc. from a jet nozzle provided above the workpiece 1. The wire 3 is fed out either by being fed out with a strong force, or by simultaneously applying slow feeding to the wire 3 using a roller or the like in addition to the jetting force. At the same time, the direction changing roller 13
and operates the suction pump connected to the fluid suction channel 16a of the fixed shaft 16, such as air or machining liquid, and the fluid discharge pump (or compressor) connected to the fluid blowout channel 16b.

As a result, the machining liquid flowing down the curved guide portion 12a is sucked into the inner side of the direction change roller 13 through the recess 22c and the flow path 16a through the through hole 13e, and is attracted to the wire 3 or the wire guide groove 13d. A rotational force is applied to the wire 3, and a driving force is applied to the wire 3.

On the other hand, liquid or air from the fluid discharge pump (or compressor) flows through the channel 16b, the recess 22d, and the through hole 13.
The wire 3 is blown away from the wire guide groove 13d by being blown through the wire 3 to the area between the pull-out rollers 9 and 9,
It is guided between the pull-out rollers 9.9.

(Effects of the Invention) According to claim 1, by sucking machining fluid into the inside of the direction change roller from the portion facing the curved guide portion around the direction change roller through the through hole provided in the wire guide groove, the wire Since the driving force for conveying the wire is provided by sucking the wire into the groove and rotating the direction changing roller, disturbances in wire guidance do not occur at the direction changing roller. Therefore, even small-diameter or soft wires can be transported stably without causing phenomena such as extrusion due to turbulence in the machining fluid.

According to claim 2, since the fluid is blown out near the exit of the direction change roller, the distance from the direction change roller to the pull-out roller is shortened, and the probability of buckling of the wire in front of the pull-out roller is reduced. This allows the wire to be transported stably.

According to claim 3, since the V-shaped wire guide groove is provided around the direction changing roller, it is possible to accommodate wires of various diameters and prevent wire deflection.

[Brief explanation of drawings]

Fig. 1 is a front sectional view showing an embodiment of the lower wire drawing device according to the present invention, Fig. 2 is an exploded perspective view thereof, Fig. 3 is a side sectional view thereof, and Fig. 4 shows its roller rotation mechanism. A front view, FIG. 5 is a sectional view showing the overall structure of the lower wire drawing device of this embodiment, and FIG. 6 is a front sectional view showing the structure of the conventional lower wire drawing device.

Claims (1)

[Claims] 1. A lower wire drawing device used in a wire-cut electrical discharge machining device, which causes the wire after passing through a workpiece to pass through a curved guide to change its direction and to apply a conveying force to the frame of the electrical discharge machining device. A curved guide having a curved guide section is fixed, a wire guide groove is provided in a portion or more of the inner surface of the curved guide section, a fixed shaft is provided concentrically with the curved guide section of the curved guide, and a motor is attached to the fixed shaft. A direction-changing roller rotated by is provided concentrically with the fixed shaft and with the periphery of the direction-changing roller close to or in sliding contact with the curved guide portion, and facing the wire guide groove around the direction-changing roller. A wire guide groove is provided, and at the bottom of the wire guide groove, a large number of through holes are provided around the entire circumference, passing through the outer circumference of the direction changing roller in a substantially radial direction,
A lower drawer for the wire, characterized in that a suction device is provided for sucking the machining fluid flowing down the curved guide portion into the inside of the direction changing roller through the through hole and adsorbing the wire to the wire guide groove of the direction changing roller. Device. 2. The apparatus of claim 1 further includes a fluid ejecting device that ejects pressurized fluid from inside the direction change roller through the through hole to spray the wire at the wire outlet of the curved guide portion and guide it to the drawing roller. A lower wire drawing device characterized by: 3. The lower wire drawing device according to claim 1 or 2, wherein the wire guide groove provided around the direction changing roller is formed in a V shape.