JPS63120032A - Automatic wire inserting device for wire-cut electric discharge machine - Google Patents

Abstract

PURPOSE:To make more than two types of wire electrodes different in each diameter automatically insertable, by making a wire electrode of more than the specified limit in diameter so as to be guided by a tubular electrode guide and another electrode of less than the specified limit to be inserted by another introducing and inserting device, respectively. CONSTITUTION:In the automatic wire insertion of a wire electrode 7 of more than about 0.1mm in diameter, a motor 18 is driven, a feed screw 17 is rotated and an electrode feed head 15 is made to go down, while a capstan 12 is rotated, feeding the electrode 7 downward, and when a tubular electrode guide 20 and a tip of the electrode 7 are approached to a work body 42, discharge takes place between both, thus machining is carried out. Next, in finishing operation using a wire electrode 33 of less than about 0.1mm in diameter, a lower end of the electrode 7 subjected to roughing is cut by a cutter 30 and then the capstan 12 and an electrode feed drum 5 are rotated in reverse, pulling the work body 42 out of a machining hole, then it is reset. Then, a tip of the electrode 33 held between rollers 34 and 35 is received by a drawer arm 41, stretching it in the orthogonal direction with the electrode 7. And, the head 15 is made to go down, and the electrode 33 is inserted into the machining hole of the work body 42 with a guide rod 40.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic wire threading device for a wire cap electrical discharge machining machine.

[Conventional technology]

Wire-cut electric discharge machining equipment is currently widely used for various types of machining, including mold machining, because it can be machined in any shape and can be operated automatically for long periods of time using an NG device. The accuracy is also extremely high.

However, the wire electrode has a diameter of 1 mm or less,
The wire is usually extremely thin, about 0.05 to 0.3 mm, and during machining, the wire electrode and the workpiece may become short-circuited or have a concentrated discharge state, or an excessive current (average current) may flow. When a discharge occurs (discharge with large discharge duration and discharge current amplitude), and furthermore, when the discharge pressure decreases and the deflection of the wire electrode decreases, the machining gap decreases and various concentrated discharge conditions and short circuits occur. It becomes easier. If these abnormal discharges, short circuits, etc. continue to occur, the wire electrode will break and the machining will be interrupted.

In that case, it is necessary to reinsert the wire electrode into the workpiece in order to resume machining, but if this complicated work had to be done manually, wire cutting is now possible for long periods of unattended operation. Several automatic wire electrode threading methods have been proposed to date, since this would compromise the important advantages of electrical discharge machining.

However, conventionally known wire passing means are based on the assumption that the same wire electrode is always used during the machining period. This method is not necessarily suitable when different processing devices are used for different processing operations.

In other words, thin wire electrodes for finishing, for example, with a wire diameter of 0.1 mm or less, do not have sufficient rigidity, so devices for automatically threading thick wire electrodes for rough processing are It was impossible to thread the wire because it got caught in the starting hole of the mold.

[Problems to be Solved by the Present Invention] The present invention has been made to solve the above-mentioned problems, and its purpose is to provide wire electrodes with two or more different wire diameters. An object of the present invention is to provide a wire threading device for a wire-cut electrical discharge machining apparatus that can automatically wire wires.

[Means for solving problems]

Therefore, the above object is to provide a tubular electrode guide for guiding a wire electrode having a diameter greater than a certain limit along the main axis, and a device for delivering a wire electrode having a diameter greater than the certain limit into the interior of the tubular electrode guide. , a device for stretching a wire electrode having a diameter not more than the above certain limit along a path perpendicular to the main axis, and a device for placing the wire electrode stretched along the path perpendicular to the main axis, below the device. This is achieved by an automatic wire threading device for a wire-cut electrical discharge machining machine, which is comprised of a device for introducing and inserting the wire into the prepared hole of the workpiece, and a device for gripping the wire electrode that has passed through the prepared hole of the workpiece.

[For production]

With the above configuration, a wire electrode having a diameter exceeding a certain limit is passed through the workpiece while being guided by the tubular electrode guide, and a wire electrode having a diameter below a certain limit is passed through the workpiece while being guided by the tubular electrode guide. Since wires are threaded by two introducing and threading devices, an automatic wire threading device is provided which can perform wire cutting electrical discharge machining unattended for an hour while using different wire electrodes of different wire diameters.

〔Example〕

Hereinafter, details of the present invention will be specifically explained with reference to the drawings.

FIG. 1 is an explanatory diagram showing the essential parts of an embodiment of an automatic wire threading device for a wire-cut electrical discharge machining apparatus according to the present invention, and FIG. 2 is a side view of the electrode transfer head seen from the direction of the arrow in FIG. 1. , FIG. 3 is a sectional view taken along the line B-B in FIG. Explanatory diagram showing 6th
Figures 8 through 8 are explanatory diagrams showing step-by-step the operation of threading a thin wire electrode using the wire threading device shown in Figure 1, and Figure 9 shows a reciprocating two-wire cut using a thin wire electrode. FIG. 3 is an explanatory diagram showing a wire connection state in the case of performing the above.

In each figure, 1 is a column of the wire-cut electric discharge machining device, 2 is a machining head, and 3 is a machining head 2 connected to column 1.
4 is a driving motor thereof; 5 is a wire electrode supply drum around which a relatively thick wire electrode 7 having a wire diameter of 0.1 mm or more is wound; 6;
1 is a motor for rotating the wire electrode supply drum 5 as necessary; 8 to 10 are guide rollers; 11 is a tension mechanism for maintaining constant tension on the wire electrode;
2 is a capstan, 13 is a motor that rotates the capstan 12, 14 is a pinch roller, 15 is an electrode transport head, 16 is a driving motor thereof, and 17 is a motor that moves the electrode transport head 15 up and down along the processing head 2. a feed screw 18 for rotating the feed screw 17;
Reference numeral 19 indicates an energizing pin for energizing the wire electrode 7 for electrical discharge machining; 20 indicates a tubular electrode guide attached to the electrode transfer head 15; 21 to 24 indicate electrode guides for positioning the electrode in the machining area; 2 is an actuator for advancing and retracting each of the electrode guides;
9 is an electrode pulling device; 30 is a cutter for cutting the wire electrode if necessary; 31 is a wire electrode supply drum around which a relatively thin wire electrode 33 having a wire diameter of 0.1 mm or less is wound; and 32 is the wire electrode described above. A motor rotates the supply drum 31 as necessary; 34 and 35 are wire electrode feed rollers; 37 is an energizing pin that energizes the wire electrode 33 for electrical discharge machining; 38 and 39 are wire electrode feed rollers; 2, 3, and 5 to 9) is a wire electrode guide rod, 41 is a wire electrode pull-out arm,
42 is a workpiece, 43 is a stage, 44 is a cross slide table, and 45 and 46 are motors for driving the cross slide table 44.

In addition, a machining power source for applying a voltage pulse for electric discharge machining between the workpiece 42 and the wire electrode 7 or 33, a device for supplying machining fluid to the machining part during machining, and driving of each part of the device , a numerical control device for controlling the figures, etc. are omitted to avoid complicating the drawings.

As shown in FIGS. 2 and 3, the electrode transport stage 15 is
A base 15a is moved up and down relative to the processing head 2 by a feed screw 17, a carriage 15b is slidably supported on the base in a dovetail groove, and the carriage 15b is mounted on the base 15a. The carriage 15b is composed of a feed screw 15C that moves the feed screw 15C in the left-right direction in FIG. 2, and a motor 16 that rotates the feed screw 15c.
A tubular electrode guide 20 used for passing the thick wire electrode 7 and an electrode guide rod 40 used for passing the thin wire electrode 33 are attached to the .

First, the wire diameter is 0. A case will be described in which automatic wiring of the wire electrode 7 of In+m or more is performed.

Wire electrode 7 pulled out from wire electrode supply drum 5
As shown in FIG. 1, the electrode is sent downward in the figure by a capstan 12 and a pinch roller 14 via guide rollers 8 to 10, and its tip is attached to a thin tubular electrode attached to the electrode transport head 15. It is inserted into the guide 20. A voltage pulse for electric discharge machining is applied between the workpiece 42, the wire electrode 7, and the tubular electrode guide 20 via a current supply bottle 19 or the like. Further, the tubular electrode guide 20 includes a machining fluid supply means that can spray machining fluid from the tip when machining a hole for inserting a wire electrode into a workpiece 42, which will be described later. It is preferable to provide a liquid supply and ejection means which also serves as the machining liquid to assist in this process.

In this state, the motor 18 is driven and the feed screw 17 is rotated to lower the electrode transport head 15, and the capstan 12 is rotated in synchronization with this to similarly send the wire electrode 7 downward, and the tubular electrode guide 20 and When the tip of the wire electrode 7 approaches the workpiece 42, an electric discharge is generated between the two and the workpiece 42 is machined. From then on, the tubular electrode guide 20 and the workpiece are slowly moved at a constant speed. By lowering the wire electrode 7, drilling progresses using the guide 20 and the wire electrode 7 as drilling electrodes, and finally the fourth
As shown in the figure, the tubular electrode guide 20 and the wire electrode 7 are inserted through the processing hole formed in the workpiece 42. Then, preferably, the tip of the tubular electrode guide 20 is further fed out to the vicinity of the electrode take-up device 29, and the wire electrode 7 is continuously fed downward to be inserted into the processing hole of the workpiece 42, as shown in FIG. wire electrode 7
The tips of the rotating rollers 29a and 29 in the hole of the electrode pulling device
When the electrode transfer head 15 is taken up by the electrode transfer head 15, the motor 18 is reversed and the electrode transfer head 15 is pulled up.

At the same time, the actuators 1 to 4 are actuated to advance the electrode guides 21 to 24 toward the wire electrode 7, respectively, to hold the wire electrode at a constant position at the processing position, and further drive the motors 45 and 46 to cross the wire. By slowly moving the slide table 44 in a desired direction within a horizontal plane, the wire electrode 7 performs electric discharge machining on the workpiece 42 along a desired machining contour.

The used wire electrode 7 may be appropriately cut and discarded using the cutter 30, or may be wound up and collected on a separately provided electrode collection drum or the like.

Therefore, when performing finishing processing using the thin wire electrode 33 with a wire diameter of 0.11 or less, first cut the lower end of the relatively thick wire electrode 7 used for rough processing with the cutter 30, and then By reversing the capstan 12 and the wire electrode supply drum 5, the wire electrode 7 is pulled out from the processing hole of the workpiece 42 and returned to the state shown in FIG.

Thereafter, the tip of the wire electrode 33, which has been pulled out from the wire electrode supply drum 31 and held between the electrode feed rollers 34 and 35, is pulled out by the wire electrode pull-out arm 41 (see FIG. 6), and the wire electrode 33 is stretched in a direction perpendicular to the direction in which the wire electrode 7 is stretched (horizontal direction in FIG. 6). The wire electrode pull-out arm 41 includes a telescoping arm 41b having an electrode gripper 41a at its tip;
It consists of a hydraulic ram 41c etc. for expanding and contracting this,
It can move forward and backward through an opening 2a provided in the processing head 2 and between electrode feed rollers 38 and 39 that can be freely approached and separated.

Next, the electrode transport head 15 is lowered, and the wire electrode 33 stretched in the horizontal direction as described above is transported downward by the wire electrode guide rod 40, and inserted into the processing hole already made in the workpiece 42. .

That is, as shown in FIG. 2, the tubular electrode guide 20 and the electrode guide iron 40 are attached to the carriage 15b of the electrode transport head 15, and the motor 16 is driven to move the carriage 15b to the left and right sides in FIG. direction (perpendicular to the plane of the paper in FIG. 7), adjust the electrode guide rod 40 so that it is directly above the wire electrode 33 stretched in the horizontal direction, and then lower the electrode transport head 15. A roller 40a attached to the tip of the guide iron 40
The wire electrode 33 is captured and conveyed downward.

After that, the motor 36 is driven to move the wire electrode feed roller 3
5 is rotated to make the wire electrode 33 hang down further, its lower end touches the rotating roller 29a of the electrode pulling device 29.
At this point, if the tip of the electrode held by the wire electrode pull-out arm 41 is released, the wire electrode 33 will be automatically inserted into the machining hole of the workpiece 42 as shown in FIG. It is something that is passed through the wire.

Thereafter, in the same way as when using the wire electrode 7, the actuators 25 to 28 are operated, and the electrode guides 21 to 2 are activated.
4 toward the wire electrode 33 to hold the wire electrode at a fixed position at the processing position, and further drive the motors 45 and 46 to slowly move the cross slide table 44 in a desired direction within a horizontal plane. As a result, the wire electrode 33 performs electric discharge machining on the workpiece 42 along the desired machining contour.

Alternatively, the roller 40a attached to the tip of the electrode guide rod 40 may be configured to be detachable, and this roller 40a may be attached to a roller take-up device 47 (No. 9) provided below the workpiece 42.
(see figure), and the wire electrode 33 is configured so that it passes back and forth twice over the machining part.
It is also possible to use a reciprocating two-wire force cut type wire-cut electric discharge machining apparatus disclosed in Japanese Patent No. 9-260029 and the like.

〔Effect of the invention〕

Since the present invention is constructed as described above, according to the present invention, wire electrodes of different wire diameters are automatically exchanged sequentially as necessary for processing using an electrode automatic threading means suitable for the wire diameter used. In addition, if the wire electrode breaks during processing, or if a different wire electrode with a different wire diameter is to be replaced as appropriate, the wire electrode can be automatically inserted by returning to the position of the pilot hole for electrode insertion. Since wiring can be carried out, work efficiency can be greatly improved.

Note that the present invention is not limited to the embodiments described above. That is, for example, the configurations of the electrode transfer head 15, the electrode extraction arm 41, the electrode extraction device 29, etc. can be changed in design as appropriate, or other equivalent mechanisms can be widely adopted, and the method of controlling each part, etc. , the design can be freely changed within the scope of the purpose of the present invention, and the present invention encompasses all of them.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing essential parts of an embodiment of an automatic wire threading device for a wire-cut electric discharge machining apparatus according to the present invention, and FIG. 2 is a side view of the electrode transfer head seen from the left and right directions in FIG. Third
The figures are a sectional view along the left and right direction in Figure 2, Figures 4 and 5.
The figure is a step-by-step explanatory diagram showing the operation of passing a thick wire electrode using the wire passing device shown in FIG. 1, and FIGS. FIG. 9 is an explanatory diagram showing step-by-step the operation when wiring a wire electrode. FIG. 9 is an explanatory diagram showing a wiring state when performing a reciprocating two-wire cut using a thin wire electrode.

Claims (1)

[Scope of Claims] A tubular electrode guide for guiding a wire electrode having a diameter equal to or greater than a certain limit along a main axis; a device for delivering a wire electrode having a diameter equal to or greater than the predetermined limit into the interior of the tubular electrode guide; A device for stretching a wire electrode having a diameter below a certain limit along a path perpendicular to a main axis, and a workpiece in which the wire electrode stretched along a path perpendicular to the main axis is positioned below the device. An automatic wire threading device for a wire-cut electrical discharge machining machine, which comprises a device for introducing and inserting the wire into the pilot hole of the workpiece, and a device for gripping the wire electrode that has passed through the pilot hole of the workpiece.