JPH0547331B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a wire electrode feeding mechanism in a wire electrical discharge machining device, and particularly relates to tension control of a wire electrode when a heavy wire supply reel is used. It is something.

[Conventional technology]

FIG. 2 is a diagram showing the wire electrode path of a conventional wire electrical discharge machining device. In the figure, 1 is a wire supply reel, which is connected to a torque motor 2 to obtain a braking force to the extent that the wire electrode 3 does not slacken. Therefore, reverse torque is applied.
A brake roller 4 is connected to an electromagnetic brake 5. Reference numeral 6 denotes a presser roller which is pressed against the brake roller 4 by a spring force. The wire electrode 3 is connected to the brake roller 4 and the presser roller 6.
It is sandwiched between the two, and a constant tension is applied to prevent it from slipping.

7 is a direction conversion roller, 8 is a wire feed pinch roller, and 9 is a wire feed presser roller, and the wire feed pinch roller 8 is rotated by the pinch roller motor 10 only during the automatic wire feeding operation. . Further, the wire feeding press roller 9 is pressed against the wire feeding pinch roller 8 by a spring force. When the wire is inserted in the automatic wire feeding operation, the wire electrode 3 is sandwiched between the rollers 8 and 9, and is fed downward in the figure through the pipe guide 11 without slipping. In addition, the pipe guide 11
An upper die guide 12 for supporting the wire electrode 3 is attached to the tip.

13 is a wire electrode cutting arm, and cutting of the wire electrode 3 is performed by rotating the wire electrode cutting arm 13 by 180 degrees by an arm rotation motor 14 and using a built-in cutter.

An upper box 15 is provided with an upper nozzle 17 for jetting the machining liquid 47 and supplying it to the machining section 16. 18 is a workpiece placed on a table 19, 20 is a lower box fixed to a lower arm 23, and has a lower nozzle 21 and a lower die guide 22 for supplying machining fluid 47 to the machining section 16. It is provided.

The wire electrode 3 passing through the lower die guide 22 is fed by a lower roller 24 and a lower pinch roller 25. The wire electrode 3 that has passed through the collection pipe 26 is further fed by a collection roller 27 and a collection pinch roller 28, and is collected into a collection box 29. Note that the feeding speed of the wire electrode 3 is variable by a motor 30 provided on the collection roller 27. Further, the collection roller 27 and the lower roller 24 are transmitted by a belt, and since both rollers 24 and 27 have the same diameter, they rotate synchronously. As a result, the wire 3 is stretched and collected into the collection box 29 without slipping due to the frictional force of the lower roller 24 and the collection roller 27.

Next, the cutting operation of the wire electrode 3 in the automatic wire feeding operation will be explained with reference to FIG.

First, in FIG. 3a, the wire electrode 3 is connected to the workpiece 1.
8 is a diagram illustrating a case in which a cutting operation is started by initially setting a state in which the hole 31 passes through the machining start hole 31 of No. 8. FIG. At this time, the collecting roller 27 shown in FIG. 2 is stopped, and the wire traveling is also stopped. First, the pipe guide 11 moves up in the direction of the arrow in the figure and stops at a certain predetermined position. At this time, the wire feeding pinch roller 8 and the wire feeding press roller 9 rise and stop integrally with the pipe guide 11, and also rotate idly in the direction of the arrow in the figure. Although the upper nozzle 17 is always fixed, the upper die guide 12 has enough clearance to rub against the wire electrode 3 when the pipe guide 11 rises. Here, the lower end position of the upper die guide 12 shown in FIG. 3a will be referred to as the cutting position.

Next, in FIG. 3b, the wire electrode cutting arm 13 is moved to the cutting position to cut the wire electrode 3.
The figure shows the state in which it is rotated 180 degrees and held. Thereby, the wire electrode 3 is cut by the cutter built in the wire electrode cutting arm 13. At this time, the wire feeding pinch roller 8 and the wire feeding press roller 9 are stopped. Moreover, a one-way clutch (not shown) is attached to the wire feeding pinch roller 8 so that it does not rotate in the direction opposite to the direction of the arrow in FIG. 3a.

Next, FIG. 3c shows the state after the wire electrode 3 is cut. That is, the wire electrode cutting arm 13 reversely rotates 180 degrees and returns to its original position. Detecting that the wire electrode cutting arm 13 has returned to its original position, the collection roller 27 shown in FIG. 29
It will be recovered to.

Next, FIG. 3d shows a state in which the wire electrode 3 has been completely cut. That is, the pipe guide 11 is shown lowered to the same position as shown in FIG. 2 after the wire electrode 3 is cut.
The lower end of the upper die guide 12 at this time will be referred to as the home position.

Note that while the pipe guide 11 is descending, the wire electrode 3 is sandwiched between the wire feeding pinch roller 8 and the wire feeding presser roller 9, and the wire feeding pinch roller 8 is equipped with a one-way clutch. Since it is attached and does not reverse, it will not come off the tip of the upper die guide 12 and come out upward. As described above, the wire electrode 3
The cutting operation is completed in the state shown in FIG. 3d. Note that during the cutting operations shown in FIGS. 3a to 3d, the second
The braking force of the electromagnetic brake 5 connected to the brake roller 4 shown in the figure is extremely weakened.

In addition, although the cutting operation process from the state where the wire electrode 3 passes through the machining start hole 31 of the workpiece 18 has been described above, in the cutting operation from a state where the wire electrode 3 is disconnected in the middle of machining, the wire slightly The movement of electrode 3 is different. That is, the pipe guide 11
When the wire electrode 3 is not broken when the wire electrode 3 is raised, the wire feeding pinch roller 8 idles as shown by the arrow in FIG. 3A, and the wire electrode 3 is in a stopped state. However, when the wire electrode 3 is broken, the wire electrode 3 is not pulled downward, so as the pipe guide 11 and the wire feeding pinch roller 8 rise, the wire electrode 3
runs in the opposite direction. Then, the wire electrode 3 that has slackened due to running in the reverse direction is rewound onto the wire supply reel 1 by the brake torque of the brake roller 4, which is extremely weakened during the cutting operation, and the reverse rotation torque of the wire supply reel 1, as described above. It will be.

Next, referring to FIG. 4, the insertion operation of passing the wire electrode 3 through the processing start hole 31 and the lower die guide 22 will be explained. Here, the process of guiding the wire electrode 3 through the processing start hole 31 to the lower die guide 22 and collecting it in the collection box 29 will be referred to as the insertion operation of the wire electrode 3. First, Figure 4a
The state shown in is the initial state of the insertion operation of the wire electrode 3. This is the same state as the final state of the cutting operation shown in FIG. 3d. That is, the upper die guide 12, the machining start hole 31, and the lower die guide 22 are aligned in the vertical direction.

Next, as shown in FIG. 4b, the pipe guide 11
is lowered and passed through the machining start hole 31, and the upper die guide 12 and lower die guide 22 are made to face each other. The lower end of the upper die guide 12 in this state will be referred to as the lower limit. This position is detected by a limit switch or the like (not shown).

Next, as shown in FIG. 4c, due to the rotational force of the wire feeding pinch roller 8 and the wire feeding press roller 9, the wire electrode 3 sandwiched between them starts to move in the direction of the arrow. At the same time, the lower roller 24 and collection roller 27 start rotating. At this time, the brake torque of the brake roller 4 and the reverse torque of the wire supply reel 1 are controlled by the rotation of the wire feeding pinch roller 8 and the wire feeding presser roller 9 so that the wire electrode 3 is smoothly inserted into the lower die guide 22. It is set based on the relationship with power. When the wire electrode 3 passes through the lower die guide 22 and is sandwiched between the lower roller 24 and the lower pinch roller 25, the wire electrode 3 moves to the collection pipe 26 at a speed faster than the rotation of the wire feeding pinch roller 8.
It passes through and is collected into a collection box 29. At this time, the wire feed pinch roller 8 rotates.

As described above, the running speed of the wire electrode 3 increases immediately after it is sandwiched between the lower rollers 24, but at this time, the wire electrode 3 is suddenly pulled and the wire supply reel 1 is rotated. In order to prevent the wire electrode 3 from becoming slack in the middle and deviating from the wire running path, the reverse torque of the wire supply reel 1 is adjusted to
Change the settings so that it is stronger than when the wire is inserted.

Next, the fifth step is to increase the size of the wire supply reel in order to carry out long-time processing.
2 is a diagram showing a case where the device is installed separately from the main body of the device. The difference from the normal case in which a wire supply reel is attached to the device body is that the wire supply reel 33 of the heavy wire supply device 32 has a large diameter.
When the reverse torque is constant, the tension applied to the wire electrode 3 increases as the wire electrode 3 is consumed, so it is well known that a constant tension mechanism is adopted inside the heavy wire supply device 32 in order to prevent this. be. Therefore, the tension of the wire electrode 3 during processing can be changed by changing the brake torque of the brake roller 4. Furthermore, during the wire automatic feeding operation, if the normal wire feeding reel 1 is used, the reverse torque must be weakened as described above, but in the case of the heavy wire feeding device 32, the tension is constant, so A rubber roller 34 is attached to the wire supply reel mounting portion of the rubber roller 34, and the wire electrode 3 is wound once around the rubber roller 34, and a reverse torque is applied in the direction of weakening the wire tension. Since the heavy wire supply device 32 has a constant tension, the reverse torque is equivalent to the wire tension during lifting of the pipe guide 11 or wire insertion during automatic wire supply operation, which is equivalent to that when using a normal wire supply reel 1. Set it so that FIG. 6 shows the reverse rotation torque of the wire supply reel section consisting of the heavy wire supply device 32 and the rubber roller 34 for each automatic wire supply operation mode. In this figure, when the reverse torque is A to F, D<B<C
The relationship <F<A<E is established, and as can be seen from this, the reverse torque of the wire supply reel section when the heavy wire supply device 32 is attached is completely different from when using a normal wire supply reel. .

[Problem that the invention seeks to solve]

Conventional wire electrical discharge machining equipment is configured as described above, so when a heavy wire feeding device 32 for long-time machining is added to the existing equipment, the reversal torque of the wire supply reel section can be controlled in various ways. It had to be changed depending on the operating mode, and it was necessary to modify the conventional circuit by adding a switching circuit for this purpose.

This invention was made to solve the above-mentioned problems, and even when long-term processing is performed, the heavy wire feeding device required for this can be easily added to existing equipment. It is an object of the present invention to provide a wire feeding device for a wire electrical discharge machining apparatus, which is capable of automatically controlling wire tension according to the operating mode.

[Means for Solving the Problems] A wire feeding device for a wire electrical discharge machining device according to the present invention is a wire feeding device installed separately from the wire electrical discharge machining device. and means for controlling the torque of the wire supply reel according to each operation mode of the automatic wire supply device.

[Effect]

In this invention, a signal indicating the wire supply operation mode from the setting circuit and a signal representing the type of wire electrode from the switching circuit are input to the selection circuit,
Here, the reverse torque of the wire supply reel is selected, and this is input to the correction circuit as a reference value.
On the other hand, the wire electrode remaining amount signal from the detection circuit is also input to the correction circuit. At this point, the correction circuit performs a correction calculation on the reference value based on the remaining amount signal and outputs the result. As a result, the reverse torque of the wire supply reel is controlled in accordance with the remaining amount of the wire electrode.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

In Fig. 1, 33 is a heavy wire supply reel used for long-time processing, and 35 is a wire electrode 3.
36 is a lever for detecting the remaining diameter of the wire electrode 3 of the heavy wire supply reel 33. When the wire electrode 3 is consumed, it moves downward in the figure, and its position is detected by the potentiometer 37, and its detection circuit 38 is input. On the other hand, a signal of the wire automatic supply operation mode, such as when the pipe guide 11 is being raised or when the wire electrode 3 is being inserted, which is given from the outside by an NC device (not shown) or the like, is transmitted to the setting circuit 3.
9 is input.

Further, a signal indicating the type of wire electrode 3, for example, a wire electrode having a different diameter or material, is inputted from a changeover switch 40 to a changeover circuit 41.

The output signals of the setting circuit 39 and the switching circuit 41 are input to the selection circuit 42, which selects the reverse torque of the heavy wire supply reel 33 that is suitable for the automatic wire supply operation and the type of wire electrode 3, and outputs the output signal. The signal is corrected by a correction circuit 43 based on a signal from a detection circuit 38 for the remaining diameter of the wire electrode 3 of the heavy wire supply reel 33. That is, the reference value of the reverse rotation torque selected by the selection circuit 42 is multiplied by a coefficient corresponding to the remaining diameter of the wire electrode 3. The output signal of the correction circuit 43 is amplified by the amplifier circuit 44 and then output to the motor 45 that applies reverse torque to the heavy wire supply reel 33.

Further, a signal for setting the reverse rotation torque during machining is input to the input circuit 46, corrected by the correction circuit 43, amplified by the amplifier circuit 44, and then output to the motor 45.

In the above embodiment, a changeover switch 40 is provided to obtain a signal representing the type of wire electrode 3, but the switch 40 may be configured to be switched by external input means such as an NC device, or a wire may be installed inside the main body of the device. A means for automatically determining the type of electrode 3 may be provided, and the switching may be performed based on a signal from the means.

Further, the number of heavy wire supply reels 33 is not limited to one type, and may be configured to be inputtable or automatically determined depending on the type.

〔Effect of the invention〕

As described above, according to the present invention, in the wire supply device installed separately from the wire electric discharge machining device, the wire supply reel and the wire automatic feed device of the wire electric discharge machining device Since the configuration includes a means for controlling the torque of the supply reel, when a separate type wire feeding device is adopted as a wire feeding device of a general wire electric discharge machining device, the present invention can be used as a separate type wire feeding device. If you adopt the wire feeding device of
This eliminates the need to modify existing wire electrical discharge machining equipment, such as adding control circuits, etc. In other words, it allows unmanned operation for long periods of time without modifying existing wire electrical discharge machining equipment. It is possible to adopt a separate type wire feeding device required for this purpose.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing a wire supply reel reversal torque control mechanism of a wire electric discharge machining apparatus according to an embodiment of the present invention, FIG. 2 is a wire electrode feeding route diagram of a conventional wire electric discharge machining apparatus, and FIG. Explanatory diagram of wire cutting operation in automatic wire feeding operation, 4th
FIG. 5 is an explanatory diagram of the wire insertion operation, FIG. 5 is a configuration diagram when a heavy wire supply reel is added to the conventional device, and FIG. 6 is a comparison diagram of reverse rotation torque in the operating mode. In the figure, 3 is a wire electrode;
3 is a wire supply reel, 38 is a detection circuit, 39 is a setting circuit, 41 is a switching circuit, 42 is a selection circuit, 4
3 is a correction circuit. In addition, in the figures, the same reference numerals indicate the same parts.

Claims (1)

[Claims] 1. In a wire feeding device installed separately from the wire electrical discharge machining device, a wire feeding reel and means for controlling the torque of the wire feeding reel according to each operation mode of the automatic wire feeding device of the wire electrical discharge machining device; A wire feeding device for a wire electrical discharge machining device.