JPH0249852B2 - WAIYAHODENKAKOSOCHINIOKERUWAIYADENKYOKUJIDOKYOKYUSOCHI - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an automatic wire electrode feeding device in a wire electrical discharge machining device, and more particularly to a device having a function of controlling the wire feeding force during automatic feeding of the wire electrode. It is.

[Prior art]

A conventional device of this type is shown in FIG. In Fig. 1, 1 is a wire supply reel;
It is connected to a torque motor (not shown), and is configured to apply a reverse torque to obtain a braking force sufficient to prevent the wire electrode 2 from slackening. 3
is a brake roller 3, which is connected to an electromagnetic brake (not shown). Reference numeral 4 denotes a presser roller, which is pressed against the brake roller 3 by a spring force. The wire electrode 2 is sandwiched between the brake roller 3 and the presser roller 4, and a constant tension is applied to the wire electrode 2 without slipping. 5 is a direction conversion roller, 6 is a positioning die, and the inner diameter is:
It is slightly larger than the diameter of the wire electrode 2. 7 is a pinch roller for feeding the wire, and 8 is a presser roller for feeding the wire. The roller 7 is rotated by a pinch roller motor 10 attached to the elevating plate 9 only during automatic wire feeding.
Further, the roller 8 is pressed against the roller 7 by a spring force, and during automatic wire feeding, the wire electrode 2 is sandwiched between the rollers 7 and 8 so that it is fed downward in the figure without slipping. It's summery. The positioning die 6 prevents the wire electrode 2 from coming off between the rollers 7 and 8.

The lifting plate 9 is raised and lowered by rotation of a ball screw 13 connected to a lifting motor 11 by a coupling 12. A ball nut for converting the rotation of the ball screw 13 into vertical linear motion is attached to the back side of the elevating plate 9 in the drawing. This ball screw 13 is supported at one end by a motor mounting portion 15 attached to the lifting guide 14, and the other end is supported by a bearing 16, so that it is supported at both ends.

Incidentally, since the elevating plate 9 is supported in elevating and lowering by the elevating guide 14, accurate vertical linear movement is possible.

Further, a pipe guide 17 is fixed to the elevating plate 9 via a guide fixing plate 18. Since the pipe guide 17 moves up and down as the elevating plate 9 moves up and down, it is supported by a bearing 19 to prevent it from wobbling. Furthermore, a die guide 20 for supporting the wire electrode 2 is provided at the tip of the pipe guide 17.
is installed. Note that the bearings 16 and 19 and the lifting guide 14 are attached to a fixed plate 21.

Next, 22 is a cutting motor, and 23 is an arm rotation motor, both of which are fixed to a box 24. 25 is a wire cutting section, 26 is a cutting arm, 2
7 is a tray for discarding wire chips after cutting the wire. The cutting device 24 and the saucer 27
is attached to the fixed plate 21.

The pipe guide 17 is connected to the reference V-groove plate 28 during processing.
It is pressed against and fixed by a pressing plate 29. This reference V-groove plate 28 is received by the V-groove surface so that the pipe guide 17 fits therein, and its position is determined. In addition, the reference V groove plate 28
is always fixed to the box 30, and the box 30 is attached to the fixing plate 21. Further, a nozzle 33 is attached to the box 30 for supplying the machining liquid 31 to the machining section 32 in a jet manner.

In addition, the pipe guide 17 has three notches as shown in the figure, and during processing, power supply pins 34 and 35 are located in these notches and are in contact with the wire electrode 2 at three points, from which power is supplied. supply. Power supply pin 3
4 is fixed to a movable plate 36, and when the pipe guide 17 moves up and down, it moves to the right in the figure to avoid contact. Similarly, the power supply pin 35 is fixed to a movable plate 37, and is pushed to the left in the figure by the plate 2.
It is now moving along with 9. 38 is a workpiece, and 39 is a table. Further, 40 is a lower die guide, and 41 is a lower power feeding die, both of which are fixed to the box 42 and attached to the lower arm 43.
installed on. A nozzle 78 for jetting and supplying the machining liquid 31 to the machining section 32 is attached to the box 42, and a guide nozzle 44 for guiding the wire electrode 2 is also attached.

The wire electrode 2 passing through the guide nozzle 44 is
Lower belt 4 stretched over belt rollers 45 and 46
7 and the lower roller 48 , and is led to the wrapper tube 49 . Thereafter, the wire electrode 2 passes through the collection pipe 50, is sandwiched between the collection belt 53 stretched between the collection rollers 51 and 52, and the collection roller 54, and advances to the collection box 55.
As shown in the figure, the wire electrode 2 is discarded in a circular manner. Note that the feeding speed of the wire electrode 2 is variable by the rotation of a motor with a reduction gear attached to the back side of the collection roller 54 in the figure, and furthermore, the collection roller 54 and the lower roller 48 are transmitted by a belt on the back side.

Moreover, since the two rollers 48 and 54 have the same diameter, they rotate synchronously. Therefore, the wire electrode 2 is pulled without slipping by the frictional force of the lower roller 48 and the collection roller 54, and is collected into the collection box 55.

Next, referring to FIG. 2, the insertion operation for passing the wire electrode 2 through the processing start hole and the lower die guide will be described.

Here, the process of passing the wire electrode through the machining start hole, then the lower die guide, and sending it to the collection box 55 in FIG. 1 will be referred to as the insertion operation of the wire electrode 2. First, the state shown in FIG. 2a is the initial state of the wire insertion operation. That is, the upper die guide 2
0 and machining start hole 77 and lower die guide 40
are aligned vertically.

Next, as shown in FIG. 2b, the pipe guide 17 is lowered and passed through the machining start hole 77, and the upper die guide 20 and lower die guide 4
0 is placed opposite. The lower end of the upper die guide 20 in this state will be referred to as the lower limit.
This position is detected by a limit switch or the like.

Next, as shown in FIG. 2c, a wire feeding pinch roller 7 and a wire feeding press roller 8 are shown.
The wire electrode 2 sandwiched between the two starts to move due to the rotational force of the two. FIG. 4c shows the state in which the wire electrode 2 has passed through the lower die guide 40.

Figure 2 d shows that after the wire electrode 2 arrives at the collection box,
The pipe guide 17 rises to a fixed position and stops,
The state in which the moving plates 36 and 37 to which the power supply pins 34 and 35 are attached and the pressing plate 29 to which the moving plate 37 is attached are pressed against the pipe guide 17 side and the insertion operation is completed is shown.

Further, FIG. 3 shows a control circuit for the electromagnetic brake 101 attached to the brake roller 3.
In FIG. 3, switching of the force applied to the wire electrode 2 during processing is performed by an electromagnetic brake 10.
This is done by controlling 1. That is, the resistor group 103 is switched by the multi-contact rotary switch 102 provided on the operation surface, and the transistor 104 is switched.
By changing the base voltage of the electromagnetic brake 101 and finally changing the current of the electromagnetic brake 101, the wire tension is set to be suitable for the processing content. Note that 98 is a DC power source for the electromagnetic brake 101, and 99 is a current limiting resistor.

On the other hand, during automatic wire electrode supply, the NC device 10
Upon receiving the wire electrode automatic supply signal from 5, 1
06 relay RAsk turns on, relay RAsk B
The contact disconnects the circuit of the multi-contact rotary switch 102, and conversely, the A contact of the relay RAsk connects the circuit of the resistor 107.
The brake torque corresponds to the voltage determined by 7 and resistor 108. The wire electrode feeding force during automatic wire electrode supply is determined by the tension applied to the wire electrode 2 (normally It is a constant value after subtracting the extremely low tension that does not cause the wire electrode 2 to sag.

Since the conventional wire electrode automatic feeding device is configured as described above, the wire electrode feeding force during automatic wire electrode feeding is constant regardless of the type of wire electrode, for example, regardless of the wire diameter. However, when the wire diameter is large, the burrs caused by cutting are large, so the wire cannot pass through the lower die smoothly unless the wire electrode feeding force is increased.
On the other hand, when the diameter of the wire is small and the wire electrode feeding force is large, there is a drawback that the wire buckles even against slight resistance in the wire path, and the wire electrode protrudes from the wire path.

[Summary of the invention]

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and it is possible to switch the wire tension in multiple stages according to the type of wire electrode during automatic wire electrode feeding. Accordingly, it is an object of the present invention to provide an automatic wire electrode feeding device for a wire electrical discharge machining device that has a high success rate regardless of the type of wire electrode.

[Embodiment of the Invention] An embodiment of the invention will be described below with reference to the drawings. FIG. 4 shows a control circuit for the electromagnetic brake 101 attached to the brake roller 3 similarly to FIG. 3, and the same reference numerals as in FIG. 3 indicate the same or corresponding parts. In FIG. 4, a paper tape 109 containing information indicating the type of wire electrode is shown.
When input to the NC device 105, one of the plurality of relays 110 is turned on depending on the type of wire electrode, and one of the resistor groups 111 is selected by the A contact of the relay 110. The resistor and 10
A current corresponding to the voltage determined by resistor 8 flows through the electromagnetic brake and generates brake torque. Therefore, depending on the type of wire electrode, the NC device 10
By changing the information input to 5, it is possible to obtain the brake torque according to that information. Therefore, as described above, the wire electrode feeding force by the pinch roller 7 during automatic wire electrode supply is the value obtained by subtracting the brake torque and the reverse rotation torque (approximately constant) of the wire supply reel 1 from the rotational torque of the pinch roller 7. Therefore, by changing the brake torque, the wire electrode feeding force can be changed.

In the above embodiment, information indicating the type of wire electrode was given to the NC device using paper tape.
Manual data input may be used, or the same effect can be obtained by using a multi-contact changeover switch or variable resistor to change the resistance value in accordance with the type of wire electrode, regardless of the NC device.

〔Effect of the invention〕

As described above, according to the present invention, the wire tension during wire electrode automatic feeding is changed over to multiple levels depending on the type of wire electrode, so that the wire tension is changed to a wire tension that is suitable for the wire electrode. can be set, regardless of the type of wire electrode, protrusion due to wire buckling and lack of wire electrode feeding force are eliminated, and the success rate of automatic wire electrode supply is significantly improved, and the system can be stopped during unattended operation. This has the effect of significantly reducing the rate of deterioration and improving productivity.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a conventional wire electrode automatic supply device, FIG. 2 is an explanatory diagram showing a conventional wire electrode insertion operation, FIG. 3 is a diagram showing a conventional electromagnetic brake control circuit, and FIG. The figure shows an embodiment of the present invention. In the figure, 1 is a wire supply reel, 2 is a wire electrode, 55 is a wire electrode collection box, and 77 is a processing start hole. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] 1. In a wire electrode automatic supply device in a wire electric discharge machining apparatus that passes a wire electrode supplied from a wire supply reel to a machining start hole of a workpiece and automatically feeds the wire electrode, during the wire electrode automatic supply, An automatic wire electrode feeding device for a wire electrical discharge machining device, comprising a device that switches the feeding force for feeding the wire electrode into a plurality of stages corresponding to the type of the wire electrode.