JPS62162425A - Automatically loading method for wire electrode for wire-cut electric discharge machine and device therefor - Google Patents

Abstract

PURPOSE:To surely attain the automatic loading of a wire electrode, by providing such an arrangement that a method for detecting a slack in the wire electrode is used to correct the position and attitude of the wire electrode to be loaded unless the wire electrode is inserted into an insertion hole in s workpiece. CONSTITUTION:When the leading end of a wire electrode 10 is not inserted into an electrode insertion hole H in a workpiece W but abuts against the outer surface of the workpiece W so that it slacks and comes off from a predetermined conveying path, this slack is detected at once by a photosensor W in a contactless manner. This detection signal is delivered to a control device 88 which therefore stops at one the pay-out operation by a wire electrode feed roller 22. Simultaneously, an actuator 78 is abruptly operated. As a result, a part of the wire electrode which has been suspended from a guide roller 26 onto the outer surface of the workpiece is pulled up to take up its slack, and is returned to the predetermined conveying path by means of the feed-in force of a fluid jet feed means 34. When the sensor 74 detects the return of the electrode 10, the control device 88 releases the stop of the pay-out operation of the roller 22, thereby it is possible to perform the automatically loading operation of the electrode 10.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a wire electrode automatic loading method and device for a wire-cut electric discharge machine, and in particular, to a reliable automatic loading of a wire electrode into an electrode insertion hole of a workpiece. The present invention relates to an improved wire electrode automatic loading method and device that can be carried out.

[Prior art]

A wire-cut electric discharge machine has a workpiece and a wire electrode facing each other through a small gap, and electricity is applied to both to generate an electrical discharge in the small gap, and the discharge energy produces a desired machining action on the workpiece. In order to give the workpiece the desired dimensions and shape, a configuration is provided that provides relative movement between the workpiece and the wire electrode within a plane defined by orthogonal X and Y axes. ing. Here, the wire electrode is always fed in the direction of the wire to prevent wire breakage due to electrode consumption during discharge, but it is impossible to completely prevent wire breakage accidents. For this reason, in conventional wire-cut electric discharge machines, the disconnection of the wire electrode is detected, and thereafter, the wire electrode is automatically loaded, and the wire-cut electric discharge machining is restarted. A typical example of such a conventional wire-cut electric discharge machine is the Japanese Patent Publication No. 60-17653 by the applicant of the present application.
As shown in FIG. 2, a wire electrode 10 is fed out toward a workpiece from a wire electrode reel 14 driven by a wire electrode feeding motor 16. , energization is carried out via the feeder 12.12, and the workpiece W is also energized, so that discharge energy is generated through a minute gap between the workpiece and the wire electrode 10. Processing action progresses. At this time, the wire electrode 10 is fed forward by a wire electrode feeding mechanism consisting of a pressure roller 18 and a wire electrode feeding roller 22 which is rotationally driven by a wire electrode feeding motor 20, and is discharged via a dancing roller 24. The process advances to guide rollers 26 provided in the processing area. The wire electrode IO that has passed through the guide roller 26 further passes between the indoor roller 28 and a new wire feeding roller 30 for feeding out a new wire electrode that is in contact with the indoor roller 28. This new wire feeding roller 30 is rotationally driven by a drive motor 32. The latter drive motor 32 itself is inactive during normal electrical discharge machining, but is activated when a break occurs in the wire electrode 10. Perform a new vA rollout. Note that the wire electrode feeding motor 16 and the wire electrode feeding motor 20
The drive motors 32 and the like are torque motors, which apply appropriate tension to the wire electrode 10, and these torque motors 16
．． 20 and 32 are driven and stopped under the control of the control device 68.

The wire electrode 10 that has passed between the guide roller 28 and the new wire feed-out roller 30 is composed of a pressure water flow port 34a and a pressure water spout 34b, and when the wire electrode 10 is broken, the new wire is delivered to the electrical discharge machining section by fluid pressure. Through the fluid jet feeding means 34, the next wire electrode clamping device 3 is fed.
Proceed to step 6. This wire electrode clamping device 36 has a roller 38 with a reverse rotation prevention mechanism and a clamp roller 40 that is constantly pressed against this roller 38 by the spring force of a spring 42, and is normally held between these two rollers 38 and 40. Meanwhile, the wire electrode 10 further advances to the electrical discharge machining section. The clamp roller 40 is pivotally attached to the tip of one arm 48 of a bifurcated link 46 which is pivoted to a fulcrum 44, and a guide roller 52 is pivotally attached to the tip of the other arm 50. The wire electrode 10 is normally fed between the above-mentioned rollers 38 and 40 via this guide roller 52, but a pressure-responsive actuator 54 consisting of an air cylinder disposed in the center of the arm 50 is used. The bifurcated link 46 is connected to the spring 4 by the piston rod.
When the clamp roller 40 is rotated around the fulcrum 44 against the spring force of 2, the clamp roller 40 is disengaged from the anti-reverse mechanism roller 38, so that a large passing gap is formed between the two rollers 38 and 40, and the wire electrode 10, and is operated to form the above-mentioned passage gap during automatic loading after wire breakage, for example. The wire electrode IO that has passed through the wire electrode clamp device 236 is connected to appropriate wire guides 5 directly above and below the electrical discharge machining area with the workpiece W.
6.56, the wire passes through the electrical discharge machining section facing the workpiece W, and then passes between the pressing roller 58 and the wire electrode winding roller 60, and then is wound up on a winding reel (not shown). . The wire electrode winding roller 60 is driven by a wire electrode winding motor 62. When a break occurs in the wire electrode 10, the dancing roller 24 detects the break by connecting the link 64 caused by the slack of the wire electrode 10 with the limit switch 66, and sends a detection signal to the control device 68. and,
As detailed in Japanese Patent Publication No. 60-17653, feeding of the wire electrode 10 is temporarily stopped in response to this detection signal, and then the new wire after the breakage is activated by the fluid jet feeding means 34 to feed the fluid jet. Thus, so-called automatic loading is performed in which the wire electrode is fed through the electrode insertion hole of the workpiece W to the wire electrode winding roller 60. In addition, this automatic loading of wire electrodes is useful not only when a wire breaks, but also when using a new wire electrode or performing multi-piece machining, the wire electrode is intentionally cut and the wire electrode is loaded into the start hole for the next machining. It is sometimes carried out similarly.

[Problems to be solved]

In the automatic loading of the wire electrode described above, the detection of whether the wire electrode has correctly penetrated and loaded into the electrode insertion hole of the workpiece is done by checking whether the wire electrode and the workpiece have come into contact with each other during loading. It was detected based on the presence or absence of occurrence. If electrical continuity is detected during automatic loading, the electrode was not properly penetrated and loaded into the electrode insertion hole and came into contact with it, in other words, the automatic loading was deemed to have failed and the automatic loading was restarted. For this reason, if the hole diameter is large, loading can be completed without causing contact, so there is no problem, but if the hole diameter of the electrode insertion hole is small, the wire electrode and workpiece may be connected even if the wire electrode is inserted correctly. This may cause contact with the hole wall, and therefore it may be detected as if an automatic loading failure has occurred. As a result, a problem has occurred in which the success rate of automatic loading decreases. Therefore, it is an object of the present invention to provide a wire electrode automatic loading method and apparatus that are free from such problems and are configured to reliably accomplish automatic wire electrode loading.

[Means of solution and action]

In order to achieve the above object of the invention, the present invention provides a detection means for detecting the presence or absence of a wire electrode, and focuses on the fact that the wire electrode deviates from a fixed electrode feeding path when the wire electrode is automatically loaded. is detected, the wire electrode is pulled up from the workpiece in response to the detection signal, the wire electrode is returned to the fixed feeding path, and the wire electrode loading operation is repeated again, thereby achieving automatic loading of the wire electrode. This is what we are trying to do. That is, the present invention provides a method for automatically loading a wire electrode in a wire-cut electrical discharge machine that automatically loads a wire electrode into an electrode insertion hole of a workpiece using fluid jet feeding during wire-cut electrical discharge machining. activating a feeding motor to start automatic loading of the wire electrode along a constant feeding path toward the electrode insertion hole of the workpiece;
When the wire electrode detecting means detects that the wire electrode has loosened or deviated from the constant feeding path due to improper loading into the electrode insertion hole, the wire electrode feeding motor is stopped, and the wire electrode is removed by a predetermined amount. activating the wire electrode pull-back means to pull up the wire electrode from the workpiece to remove slack in the wire electrode, and when the wire electrode detection means detects that the wire electrode has returned to the constant feeding path; Wire electrode automatic loading of a wire-cut electrical discharge machine, characterized in that the wire electrode retracting means is moved back, and the automatic loading is restarted by restarting the operation of the wire electrode feeding motor and the fluid jet feeding. The present invention provides a method.

Further, in order to directly implement this method, the present invention provides a wire electrode automatic machine for a wire cut electric discharge machine that automatically loads a wire electrode into an electrode insertion hole of a workpiece using fluid jet feeding during wire cut electric discharge machining. In the loading device,
a wire electrode feed roller coupled to a wire electrode feed motor; and a plurality of roller means arranged to form a constant feed path for the wire electrode from the wire electrode feed roller toward the workpiece; a fluid jet feeding means disposed at an upstream position of the workpiece in a constant feeding path of the wire electrode and loading and running the wire electrode toward the electrode insertion hole of the workpiece; and upstream of the fluid jet feeding means. a wire electrode detection means provided at a position to detect the presence or absence of the wire electrode in the fixed feeding path of the wire electrode; and a wire electrode detection means provided between the wire electrode feeding roller and the wire electrode detection means, the wire electrode detection means being provided between the wire electrode feeding roller and the wire electrode detection means, a wire electrode pull-back means for raising and operating the wire electrode by a predetermined amount; and a detection signal from the wire electrode detection means to control the operation timing of the wire electrode feeding motor and the wire electrode pull-back means to move the wire electrode to the constant feeding path. Let me return to
The present invention provides an automatic wire electrode loading device for a wire-cut electric discharge machine, characterized in that it is configured to include a control means for causing automatic loading by the fluid jet feeding means.

Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.

〔Example〕

FIG. 1 is a perspective view showing essential parts of an embodiment of the wire electrode automatic loading device for a wire-cut electric discharge machine according to the present invention, which is essential for automatic loading of the wire electrode provided above the workpiece. It shows the constituent elements of. In addition, the second
The same reference numbers as in the figures indicate the same functional elements.

In FIG. 1, a wire electrode supply reel 14 is installed at the rear of a machine body 70 of a wire-cut electric discharge machine.
It is driven by a wire electrode payout motor (not shown) housed in the wire electrode IO, and winds and holds the new wire of the wire electrode IO so as to pay it out. The wire electrode 10 is fed from the wire electrode supply reel 14 through the press roller 18 and the wire electrode feed roller 22, and further,
It reaches the guide roller 26 via the dancing roller 24 having a swinging arm 64.

Note that the wire electrode feeding roller 22 is driven by a wire electrode feeding motor (not shown) housed within the body 70. The wire electrode 10 that has passed through the guide roller 26 is then held between a guide roller 28 and a feeding roller 30, and is further subjected to a feeding action by the feeding action of the latter feeding roller 30.

The feeding roller 30 is also driven by a drive motor (not shown in the figure) housed in the machine body 70, and as will be described later, when the wire electrode 10 is automatically loaded due to a disconnection, etc. Even when the tip of the new wire is once pulled up from the workpiece (placed in the same position as shown in Fig. 2), it is prevented from being lifted out of the gripping position between the feed roller 30 and the guide roller 28. There is.

The wire electrode 10 let out from the sandwiched position between the guide roller 28 and the feed-out roller 30 further passes through the guide ring 72 and descends toward the workpiece. That is, the fluid jet flow passes in front of the optical sensor 74 above the workpiece (upstream position as seen in the feeding direction of the wire electrode) and is placed in the fluid jet feeding means 34 formed by the fluid jet nozzle. It is sent toward the electrode insertion hole of the workpiece while receiving the action. The fluid jet feeding means 3
A bracket member 76 that holds the optical sensor 74 and forms a guide ring is attached above the optical sensor 4 . The optical sensor 74 is a means for non-contactly detecting the wire electrode IO passing through a fixed feeding path, and can be a photoelectronic switch using a commercially available optical fiber. That is, when the wire electrode 10 deviates from the constant feed path formed by the rollers 22, 24, 26, 28, 30 including the above-mentioned pressure roller I8, the signal state changes, thereby causing the wire electrode 10 to move away from the constant feed path. It is detected whether or not it is on the road.

Further, as an important element according to the present invention, an actuator 78 for pulling back the wire electrode is provided in the middle of the wire electrode feeding path from the dancing roller 24 to the guide roller 26.
is provided. This actuator 78 is
a gripping engager 84 provided at the tip of a fluid-operated shaft attached to the guide roller 26.
If there is a disconnected or hanging wire electrode 10 between the wire electrode 10 and the workpiece, the wire electrode 10 acts to pull it upward. Note that the dancing roller 24 located below the actuator 78 detects the disconnection of the wire electrode IO in the same way as shown in FIG. Needless to say, it has the function of detecting recovery. Furthermore, a control device 88 similar to the conventional control device 68 in FIG. It is connected to a control signal line. The main structure of the automatic loading device for wire electrodes 10 according to the present invention has been described above, but in addition to these, it is also equipped with a feeder, a wire electrode winding mechanism for collecting the wire electrode after passing through the workpiece, etc. The wire cut electric discharge machining is performed using the wire cut electric discharge machining. Next, the automatic loading operation by the wire electrode automatic bag FjL' device having the above-mentioned configuration will be explained as follows.
The explanation will be given with reference to FIGS. 3 and 4 together with the drawings.

If the wire electrode 10 breaks in the electric discharge machining section, or the wire electrode on the wire electrode supply reel 14 is completely consumed, or the electric discharge machining starting point changes, etc., automatic loading of a new wire electrode becomes necessary. First, the electrode insertion hole of the workpiece is positioned with respect to the fixed feeding path of the wire electrode 10. This positioning action is performed by moving the table of the wire-cut electric discharge machine on which the workpiece is placed within a plane defined by the X, Y orthogonal coordinate system.

Step (1) in FIG. 3 shows a state in which this positioning has already been completed, the first feeding action has been performed by the fluid jet feeding means 34 using a fluid jet, and insertion failure has occurred. That is, the tip of the wire electrode IO is not inserted into the electrode insertion hole H of the workpiece W, but contacts the surface of the workpiece W, and therefore the wire electrode 10, which is fed out from above, is near the workpiece W. As a result, it deviates from the constant feed path. This loosening of the wire electrode 10 from the constant feeding path is immediately detected by the optical sensor 74 in a non-contact manner as indicating that the wire electrode 10 is not in the constant feeding path. Since this detection signal is input to the control device 88, the control device 88 immediately stops the feeding action of the wire electrode feeding roller 22. At the same time, the actuator 78 is operated to protrude. As a result, the workpiece W is removed from the guide roller 26.
The wire electrode portion hanging down on the surface of the wire is subjected to a pulling action to eliminate slack due to the bending of the upstream portion. Step (2) shows the state in which the wire electrode 10 is pulled up in this manner. That is, the wire electrode 10 that has been subjected to the pulling action hangs down in the space, and is also pulled downward by the fluid jet feeding force of the fluid jet feeding means 34, so that it returns to the constant feeding path by itself. When the optical sensor 74 detects that the wire electrode 10 has returned to the constant feeding path, this detection signal is sent to the control device 8 again.
8, the control device 88 immediately releases the stoppage of the feeding operation of the wire electrode feeding roller 22. Further, the arm 82 of the actuator 78 is moved backward. As a result, the restriction of the wire electrode 10 in the constant feeding path is released, and the action of the fluid jet feeding means 34 causes the wire electrode 10 to be released in step (3).
), the autoloading operation is performed again. In this way, the wire electrode IO is inserted into the electrode insertion hole H of the workpiece W. The wire electrode 10 inserted into the electrode insertion hole H is held and rolled up by a wire electrode winding device (not shown). When the dancing roller 24 detects that the winding of the wire electrode 10 progresses and a constant tension is applied to the wire electrode IO, the wire cut electric discharge machining operation is started.

Here, referring to step (4) in FIG. 3, this step (4) is performed even when the arm 82 of the actuator 78 and the gripping engager 84 are actuated to protrude toward the constant feeding path of the wire electrode IO. Regardless, the wire electrode 10 hanging down from the guide roller 26 to the surface of the workpiece W is not fully pulled up, and the tip of the electrode remains stagnant on the surface of the workpiece W.

When such a condition occurs, the optical sensor 74 continues to apply a detection signal to the controller 88 indicating that the wire electrode 10 is still not in the constant feed path. Therefore, the control device 88 operates the wire electrode feeding roller 22 in the reverse direction in response to the logical sum of the signal indicating that the actuator 78 has completed the ejection operation and the detection signal of the optical sensor 74. As a result, the wire electrode IO is subjected to a pulling action between the guide roller 26 and the workpiece W, so that it returns to the constant feeding path in the same manner as in step (2) described above. When the wire electrode IO returns to the constant feeding path, the optical sensor 74 detects the wire electrode IO as shown in step (5). Therefore, in response to the detection signal, the reverse rotation of the wire electrode feeding roller 22 is stopped, and the feeding action is restarted instead, and step (
Automatic loading of the wire electrode 10 is performed again in the same manner as in 2) and (3). If the automatic loading is successful in this manner, the wire cut electrical discharge machining operation is resumed as described above.

FIG. 4 is a flowchart illustrating the automatic wire electrode loading operation described above. According to the flowchart, it can be seen that the automatic loading of the wire electrode 10 is repeatedly performed until it is successfully completed. Furthermore, when the arm 82 of the actuator 78 moves backward after the actuator 78 protrudes, that is, when the actuator 78 is turned off, the optical sensor 74 is activated to detect the presence or absence of the wire electrode 10 in the fixed feeding path. If the wire electrode 10, which has returned to the constant feeding path by the pulling action of the actuunitaf, still deviates from the constant feeding path even after the actuator 78 is moved back, the actuator 78 is operated to protrude again to keep the wire electrode 10 constant. It is explained that the automatic loading operation is performed after returning to the feeding path. From this fact, it can be understood that according to the present invention, the wire electrode 10 is inserted into the electrode insertion hole H of the workpiece W with an extremely high probability.

〔Effect of the invention〕

From the above explanation, the present invention automatically corrects the position and posture of the wire electrode, repeats the loading operation, and ultimately completes the loading unless the wire electrode is inserted into the electrode insertion hole of the workpiece. A method for detecting slack in a wire electrode that does not rely on an electrical i1 check to detect defects in the conventional wire electrode loading method and device, which can sometimes be detected as a failure even though the wire electrode has been inserted into the electrode insertion hole as the wire is tightened. By using , we were able to completely eliminate this problem. Moreover, as mentioned above, the position and feeding posture of the wire electrode are corrected to repeatedly perform the automatic loading operation,
Since the process is completed successfully, automatic wire electrode loading can be achieved with high probability even when the diameter of the electrode insertion hole in the workpiece is small.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the main structure of an embodiment of the wire electrode automatic loading device for a wire-cut electrical discharge machine according to the present invention, FIG. 2 is a mechanical diagram showing the structure of a conventional wire-cut electrical discharge machine, and FIG. FIG. 3 is an operation diagram illustrating the automatic loading of wire electrodes according to the present invention, and FIG. 4 is a flowchart of the same. DESCRIPTION OF SYMBOLS 10... Wire electrode, 14... Wire electrode supply reel, 18... Press roller, 22... Wire electrode feed path roller, 24... Dancing roller, 26... Guide roller, 28... - Guide roller, 3-0... Feeding roller, 34... Fluid jet feeding means, 74... Optical sensor, 78... Actuator, 84... Gripping engager, 8th... Control device , W...workpiece, H...electrode insertion hole.

Claims (1)

[Scope of Claims] 1. In a wire electrode automatic loading method for a wire cut electric discharge machine, which automatically loads a wire electrode into an electrode insertion hole of a workpiece using fluid jet feeding during wire cut electric discharge machining, the wire activating the electrode feeding motor to start automatic loading of the wire electrode along a constant feeding path toward the electrode insertion hole of the workpiece; When the wire electrode detection means detects that the wire electrode has loosened or deviated from the workpiece, the wire electrode feeding motor is stopped, and the wire electrode pulling back means for pulling up the wire electrode by a predetermined amount is activated to remove the wire electrode from the workpiece. pulling up the wire electrode to remove slack in the wire electrode; when the wire electrode detecting means detects that the wire electrode has returned to the constant feeding path, the wire electrode pulling back means is operated to retreat, and the wire electrode feeding motor A wire electrode automatic loading method for a wire-cut electrical discharge machine, characterized in that the automatic loading is restarted by restarting the operation and sending the fluid jet. 2. If the wire electrode detecting means does not detect that the wire electrode has returned to the constant feeding path after the wire electrode is pulled up by the wire electrode pulling back means, the wire electrode is moved back by operating the wire electrode feeding motor in reverse. The wire electrode automatic wire cut electric discharge machine according to claim 1, wherein the wire electrode is unwound until the wire electrode detecting means detects that the wire electrode has returned to the constant feeding path. Loading method. 3. After the wire electrode has passed through the electrode insertion hole of the workpiece, it is engaged with a wire electrode winding roller and a predetermined tension force is generated in the wire electrode, and the electric discharge machining of the wire cut electric discharge machine is performed. Starting Claim 1
A wire electrode automatic loading method for a wire-cut electric discharge machine according to item 1 or 2. 4. Connected to the wire electrode feed motor in the wire electrode automatic loading device of the wire cut electric discharge machine, which automatically loads the wire electrode into the electrode insertion hole of the workpiece using fluid jet feed during wire cut electric discharge machining. a plurality of roller means disposed to form a fixed feeding path for the wire electrode from the wire electrode feeding roller toward the workpiece; and a fixed feeding path for the wire electrode. a fluid jet feeding means disposed at an upstream position of the workpiece to load and run the wire electrode toward the electrode insertion hole of the workpiece; a wire electrode detection means for detecting the presence or absence of the wire electrode in the constant feeding path of the electrode; and a wire electrode detection means provided between the wire electrode feeding roller and the wire electrode detection means, and lifting the wire electrode by a predetermined amount from the workpiece. controlling the operating timing of the wire electrode feeding motor and the wire electrode pulling back means according to the detection signal of the wire electrode pulling means to be activated and the wire electrode detecting means to return the wire electrode to the constant feeding path; 1. A wire electrode automatic loading device for a wire-cut electrical discharge machine, comprising: a control means for causing automatic loading to be carried out by a fluid jet feeding means. 5. The wire-cut electric discharge machine according to claim 4, wherein the wire electrode detection means is constituted by an optical sensor that optically detects the presence or absence of the wire electrode in the constant feeding path of the wire electrode. Wire electrode automatic loading device. 6. The wire-cut electric discharge machine according to claim 4, wherein the wire electrode pull-back means is constituted by an actuator having a wire electrode engaging arm protruding toward a fixed feeding path of the wire electrode. Wire electrode automatic loading device. 7. The wire-cut electric discharge machine according to claim 4, wherein the plurality of roller means includes a dancing roller that generates an automatic loading completion signal when the tension of the wire electrode reaches a predetermined value. Wire electrode automatic loading device.