JP2680368B2 - Buckling detection device for wire electrode during connection work of wire electric discharge machine - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a buckling detection device for a wire electrode during a wiring work of a wire electric discharge machine.

(Prior Art) Wire electric discharge machines have rapidly spread with the progress of NC technology, and most of them are equipped with an automatic wire connection device to improve the operating rate by unmanned operation. However, the wiring rate of the automatic wiring device is not 100%, and unexpected trouble may occur due to the failure of the wiring.

The reason for this connection failure is that the clearance through which the wire electrode passes the electron or the wire guide is narrow and the friction resistance is large, or the start hole of the workpiece is not completely processed, for example, at the bottom of the hole. This may be the case when burrs or the like remain, or when the wire electrode is not sufficiently processed before cutting and there is still a bend. These causes can be reduced as much as possible, but it is difficult to eliminate them completely. Therefore, in general, the automatic wire connection device is provided with a detection device for confirming the wire connection, and when the wire connection fails, the wire connection work is automatically redone.

(Problems to be solved by the invention) As described above, the automatic wire connection device is generally provided with a detection device for confirming the wire connection, but these detection devices send wire electrodes downward, for example, Normally, it is detected whether or not the wire electrode has passed through the lower guide block and reached the transfer device. Therefore, when the detection time is late and it is confirmed that the wire connection has failed, the tip of the wire electrode hits the start hole of the work piece, the wire guide, the electron, etc. and buckles, sometimes entangled, and comes off from the delivery roller etc. There were things.

The present invention was devised by focusing on such a problem, and detects buckling of a wire electrode promptly, alleviates various problems caused by buckling, and detects buckling for efficient connection work. The purpose is to provide a device.

[Structure of the Invention] (Means for Solving the Problems) The present invention has been made in view of the conventional problems as described above, and a wire electrode is provided at a lower end portion of a wire guide pipe vertically provided in a wire electric discharge machine. An upper guide block that guides the wire guide pipe, and a wire electrode that penetrates in a non-contact state inside the buckling detection member provided on the wire guide pipe via an insulating member is provided so as to be fed to the upper guide block side. At the time of wire connection work of a wire electric discharge machine, which is provided with a buckling detection circuit for detecting that a wire electrode is in contact with the buckling detection member, between the conduction provided in the upper guide block and the buckling detection member. Is a buckling detection device for wire electrodes.

(Operation) As is apparent from the above configuration, the wire guide pipe having the upper guide block for guiding the wire electrode at the lower end is provided with the buckling detection member via the insulating member,
A buckling detection circuit for detecting that the wire electrode fed to the upper guide block side in a non-contact state inside the buckling detection member comes into contact with the upper buckling detection member is provided with a current passing through the upper guide block and the buckling detection circuit. It is provided between the buckling detection member.

Therefore, the tip (lower end) of the wire electrode that has passed through the upper guide block comes into contact with the workpiece, or comes into contact with the lower guide block or the like to cause the wire electrode to buckle, and the wire electrode comes into contact with the buckling detection member. Then, the buckling can be immediately detected, and the failure of the wire electrode connection can be found. Therefore, appropriate measures can be taken immediately.

(Example) Next, the Example of this invention is described based on drawing.
FIG. 4 is an explanatory diagram of a wire traveling system of a wire electric discharge machine embodying the present invention. That is, the wire electrode 1 is fed from a wire supply reel (not shown), and includes a tension device 3, a wire guide pipe 5 having a wire electrode buckling detection member of the present invention described later, an upper guide block 7 provided at the lower end thereof, and the like. After electrical discharge machining with the workpiece 9, the lower guide block 11, the transport device 13, the winding roller
After 15 the wire is recovered by the wire recovery box 17.

The tension device 3 includes a drive roller 3a, a tension roller 3b, and an idle roller 3c, and a belt 3d is wound around the tension device 3. A brake device 21 is attached to the shaft 19 of the drive roller 3a in order to apply tension to the wire electrode. The shaft 19 has an electromagnetic clutch 23 for connection work.
A pulse motor 27 is mounted via a pair of gears 25a and 25b, and a rotary encoder 31 is mounted via a pair of gears 29a and 29b. This rotary encoder 31 is a transport device.
Since the drawing speed of the wire electrode by 13 is higher than the sending speed by the pulse motor 27, the first wire connection confirmation as to whether or not the wire electrode 1 has reached the transfer device 13 is made by detecting the speed change during wire connection. Is to do.

The upper guide block 7 and the lower guide block 11 have the conductions 33 and 35 and the wire guides 37 and 39, respectively, and the machining fluid flows into each of them as shown by the arrows and is jetted from the nozzle portion. . The transport device 13 has two upper and lower
It is composed of individual belt devices, and the wire electrode 1 is sandwiched between them and conveyed in the direction of the arrow. A wire detection plate 41 is attached to the bottom of the wire collection box 17, and when the wire electrode 1 comes into contact with the wire detection box 41, an electric circuit (not shown) is closed to confirm the second wire connection.

The clamp device 43 of the wire electrode 1 is for fixing the wire electrode by the clamper 45 and energizing it when cutting the wire electrode. Clamper 45 is bracket 47
The bracket 47 is attached to the motor 51 and screw / nut mechanism 53 along the spline shaft 49.
Can be freely moved to the left and right. The clamper 45 is opened and closed by the air cylinder 55, and the clamp device 43 is moved up and down by the motor 57. Also, the clamper
A heat storage block 59 is attached to the wire 45 to keep the cut position of the wire electrode 1 constant.

A power supply device 61 for electric discharge machining is connected between the current-carrying electrons 33, 35 and the workpiece 9, and a power supply device 63 for disconnecting the wire electrode is connected between the current-carrying electron 33 and the clamper 45. ing. The buckling detecting device 65 of the present invention is provided between the upper portion of the wire guide pipe 5 and the conducting member 33.

Next, an embodiment of the buckling detection device for the wire electrode of the first invention will be described with reference to FIG. This buckling detection device 65 is provided at the upper part of the wire guide pipe 5 with a large-diameter passage made of a conductive material, and a buckling detection member 67 and a communication between the buckling detection member 67 and the upper guide block 7. The buckling detection circuit 69 detects a change in voltage applied between the electrons 33.

A guide hole 71 made of an insulating member for guiding the wire electrode 1 is provided at the upper end of the buckling detection member 67, and a small diameter pipe for guiding the wire electrode 1 through the insulating member 73 is provided inside the lower end thereof. 75 is hung down. The outer circumference of the lower end of the buckling detection member 67 is provided by being fitted to an outer cylinder 77a made of an insulating member, and the lower end of the outer cylinder 77a is fixed to the machine frame by a fitting 79. Further, the outer periphery of the taper of the buckling detection member 67 is fixed to the machine frame via an insulating member 81, and the electrode terminal
83 and the screw 85 are connected.

Inside the outer cylinder 77a, an outer cylinder 77b
77c are provided slidably in the vertical direction, and the lower guide block 7 is attached to the lower end of the outer cylinder 77c via an insulating member 87. Therefore, the lower guide block 7 can freely move in the vertical direction.

The buckling detection circuit 69 is composed of a series circuit of a resistor R, a power source E, a switch S and the like, both ends of which are connected to the electrode terminal 83 and the conduction electron 33. Buckling can be detected.

With this configuration, the tip of the wire electrode 1 may be attached to the workpiece 9 or the lower guide block 11 during the connection work.
When the wire electrode 1 is prevented from advancing due to, for example, the buckling as shown by the dotted line in the large diameter portion of the passage of the buckling detecting member 67. When the buckling occurs, the electrode terminal 83 and the conduction electrode 33 are closed by the wire electrode 1, and the voltage V of the buckling detection circuit 69 is increased.
Becomes almost 0, and buckling can be detected by this voltage change.

Next, referring to FIG. 4, description will be given according to the flowcharts of FIGS. 2 and 3. In this case, the upper guide block 7 descends and is located directly above the start hole SP of the workpiece 9, and the tip of the wire electrode 1 hangs from the lower end thereof.

In order to guide the wire electrode 1 at S1, a high-pressure working liquid is ejected from the nozzle of the upper guide block 7.

 At S2, the transport device 13 and the winding roller 15 are operated.

The clutch 23 is excited by S3 to couple the gear 25a to the shaft 19.

At S4, the pulse motor 27 is normally rotated (in the direction of the solid line arrow), and the wire electrode 1 is sent from the upper guide block 7 to the start hole SP of the workpiece 9.

In S5, it is checked by the buckling detector 65 whether or not the wire electrode has buckled. If buckled, proceed to S6.

The pulse motor 27 is stopped at S6 and S7, and the clutch 23 is demagnetized.

S8 operation time T ₁ of the pulse motor 27 is checked whether or not a predetermined time T ₀ following. If T ₁ is less than T ₀ , proceed to S9.

The clutch 23 is excited by S9, S10 and S11, and the pulse motor 2
Reverse 7 for T ₁ hour (in the direction of the dotted arrow).

In S12 and S13, the pulse motor 27 is stopped and the clutch 23 is demagnetized.

In S14, it is checked whether the number of bucklings is within the allowable value. If it is within the allowable value, the process returns to S1 and the wiring work is repeated. If the allowable value is exceeded, a warning is displayed in S15 and the work is stopped.

If the operating time T ₁ of the pulse motor 27 exceeds S ₀ in S8, the process proceeds to S16.

The clutch 23 is excited by S16, S17 and S18, and the pulse motor
Reverse 27 for T ₁ −T ₀ hours.

The pulse motor 27 is stopped in S19 and S20, and the clutch 23 is demagnetized.

In S21, a predetermined cutting work is performed by the cutting process shown in FIG. 3, and the process returns to S1 and the connection work is repeated.

If the wire electrode 1 is not buckled in S5, the process proceeds to S22.

In S22, the first time connection is confirmed by the rotary encoder 31, and if normal, the process proceeds to S23.

In S23, the connection detection plate 41 confirms the second connection, and if normal, the process proceeds to S24.

In S24 and S25, the pulse motor 27 is stopped, the clutch 23 is demagnetized, and the wiring work is completed.

 If the connection cannot be confirmed in S22, proceed to S26.

Stop ejection of the water jet in S26 and S27, the pulse motor 27 reverses T ₂ -T ₀ hours, rewinding the wire electrode 1.
Here, T ₂ is the time during which the pulse motor 27 is operated from S4 to S22 (when it does not buckle).

In S28, a predetermined cutting work is performed by the cutting process shown in FIG. 3, and the process returns to S1 to repeat the wiring work.

If the wiring cannot be confirmed in S23, the process proceeds to S29, in which it is determined that the transport device or the like has failed, and the machine is stopped.

The contents of the cutting steps of S21 and S28 are as shown in FIG.

At S30, the upper guide block 7 is raised to its upper limit and retracted.

The clamp device 43 is set at a fixed position in S31 and S32, the clamper 45 is closed, and the wire electrode 1 is fixed.

The clutch 23 is excited by S33, S34 and 35, and the pulse motor 2
The wire electrode 1 is extended and straightened by rotating the wire 7 by a constant rotation, and after straightening, the clutch 23 is demagnetized to remove the tension of the wire electrode 1.

In S36, the wire electrode 1 between the clamper 45 and the conduction electron 33 is energized and heated. The wire electrode 1 reaches the maximum temperature in the heat storage block 59.

The clutch 23 is excited again in S37, S38 and S39, the pulse motor 27 is reversed, and the wire electrode 1 is pulled until it is disconnected. The wire electrode 1 is cut at the heat storage block 59.

In S40 and S41, the pulse motor 27 is stopped and the clutch 23 is demagnetized.

 At S42, the power switch to the wire electrode 1 is opened.

The clamper 45 is opened in S43, and the clamp device 43 is returned to the original position.

At S44, lower the upper guide block to the fixed position.
This completes the cutting process.

The connection work procedure of this embodiment is different from the conventional one in that the procedure from S5 to S21 is added. For this reason, troubles due to connection failure can be reduced, and the connection work can be made more efficient.

[Effects of the Invention] As will be understood from the above description of the embodiments, in the present invention, buckling occurs in the wire guide pipe having the upper guide block for guiding the wire electrode at the lower end through an insulating member. A detection member is provided, and a buckling detection circuit that detects that the wire electrode fed to the upper guide block side in the non-contact state inside the buckling detection member contacts the upper buckling detection member is provided in the upper guide. It is provided between the conduction of the block and the buckling detection member.

Therefore, the tip (lower end) of the wire electrode that has passed through the upper guide block comes into contact with the workpiece, or comes into contact with the lower guide block or the like to cause the wire electrode to buckle, and the wire electrode comes into contact with the buckling detection member. Then, the buckling can be immediately detected, and the failure of the wire electrode connection can be found. Therefore, appropriate measures can be taken immediately.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an embodiment of a wire electrode buckling detection device of the first invention, FIGS. 2 and 3 are flow charts of an embodiment of the second invention, and FIG. 4 is an embodiment of the invention. It is explanatory drawing of the wire traveling system of a wire electric discharge machine. Description of symbols representing main parts of the drawing 1 ... Wire electrode, 5 ... Wire guide pipe 7 ... Upper guide block, 9 ... Workpiece 11 ... Lower guide block, 13 ... Conveyor 15 ... Hoisting roller, 23 ...... Electromagnetic clutch 27 ...... Pulse motor, 31 ...... Rotary encoder 33 ...... Upper conduction, 41 ...... Connection detection plate 43 ...... Clamp device, 45 ...... Clamper 63 ...... Disconnecting power supply device , 65 …… Buckling detection device 67 …… Buckling detection member, 69 …… Buckling detection circuit

Claims (1)

(57) [Claims] 1. A buckling detection member provided with an upper guide block for guiding a wire electrode at a lower end portion of a wire guide pipe vertically provided in a wire electric discharge machine, and provided on the wire guide pipe via an insulating member. A wire electrode that penetrates the inside in a non-contact state is provided so that it can be fed to the upper guide block side, and the wire electrode detects the buckling between the conduction and the buckling detection member provided in the upper guide block. A buckling detection device for a wire electrode during connection work of a wire electric discharge machine, comprising a buckling detection circuit for detecting contact with a member.