JPH02100831A - Wire cut electric discharge device - Google Patents

Abstract

PURPOSE:To improve an interlock function by stopping and controlling the motion of a movable article depending upon whether or not there is a workpiece to be machined or a clamping jig. CONSTITUTION:The bottom section of the front stocker 48a of the stocker 48 of a machining device is provided with a recess section 48c to contain a workpiece detector 80 for detecting whether or not there is a workpiece to be machined in the front stocker 48a. The first clamping jig detectors 81 and 81 composed of a flood-lights 81a and light receivers 81b for detecting the clamping jig 49 at a workpiece exchanging position are provided so that the clamping jig 49 may not be detected simultaneously at positions other than a workpiece exchanging position because of the mutual crossing of light axes. Therefore, whether or not the clamping jig 49 has been moved to the workpiece exchanging position is detected. The second jig detector 82 is also arranged on the surface plate 5 on which the clamping jig 49 is mounted. Therefore, the motion of a movable article is stopped and controlled depending upon whether there is a workpiece to be machined or the clamping jig resulting in the improvement of an interlock function.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a wire electrical discharge machining device, and more specifically, to a wire electrical discharge machining device that has an interlock function that can stop or restrict mutual movement of movable parts in the device when an abnormality occurs. The present invention relates to a wire electrical discharge machining apparatus equipped with the present invention.

[Prior Art] Fig. 2 is a configuration diagram showing an example of a conventional wire electric discharge machining apparatus disclosed in, for example, Japanese Patent Application Laid-Open No. 80-180728. ) is the wire electrode, (3) is the wire automatic feed mechanism, (4) is the bed of the processing machine, (5) is the surface plate, and (6) is the surface plate (5) fixed in the Y direction (relative to the page). (7) is the X table that feeds in the X direction (horizontal direction), (7a) is the surface plate (5), Y table (6), and X table. (7) is a processing table, (8) is a column that fixes the wire automatic feed mechanism (3), (9) is fixed to this column (8), and the wire electrode (
2) is the head that guides it to the processing part, (10) is the wire electrode (
2) at the bottom of the workpiece (1), and a lower arm for applying processing voltage to the wire electrode (2);
Reference numeral (11) denotes a nozzle for spouting machining fluid to the machining section, which is provided above and below the workpiece (1) to face each other, and together with the automatic wire feed mechanism (3), constitutes an automatic wire connection device.

Figure 3 is an enlarged view showing the processed part of the workpiece (1) after being processed by the wire electrode (2), where (12) is the cut-off part to be discarded after processing, and (13) is the part for starting processing. This is a small hole drilled into the hole.

Next, the operation of the wire electrical discharge machining apparatus having the above configuration will be explained. Before performing electrical discharge machining, a small hole (13) through which the wire electrode (2) passes through the workpiece (1) is drilled at a point on the machining trajectory as shown in Figure 3, and the workpiece ( 1) is fixed on the surface plate (5), the wire electrode (2) is passed through the narrow diameter (13), and a machining voltage is applied between the wire electrode (2) and the workpiece (1). , the wire electrode (2) is fed by an automatic wire feeding mechanism (3). On the other hand, the workpiece (
In 1), electric discharge machining is performed while drawing a locus of a predetermined shape with respect to the wire electrode (2) by automatic feeding using the Y table (6) and the X table (7). During this electrical discharge machining, machining fluid is supplied from the nozzle (11) to the machining portion of the workpiece (1).

By the way, the nozzle (11) is provided above and below the workpiece (1) to face the workpiece (1), and injects the machining liquid onto the machining part, supports the wire electrode (2), and machining the wire electrode (2). It supplies power. Figure 4 shows the lower nozzle (11) installed at the bottom of the workpiece (1).
In the figure, (lla) is the nozzle body, (30
) is a die that supports the wire electrode (2), (31) is a power supply die that supplies processing power to the wire electrode (2), (3
2) is a holder for the power feeding die (31), (33) is a guide die that positions the wire electrode (2) so that it contacts the power feeding die (31), (34) is a guide block, (
35) is a guide block (
(34) is a fixing plate to be fixed to, (36) is a pin for positioning the holder (32) in the rotational direction, (37) is an O-ring,
(38) is an inflow path for machining fluid, and (39) is a stopper attached to the guide block (34) with a screw or the like. In addition,
The nozzle body (lla) is slidably moved in the vertical direction relative to the guide block (34) and the stopper (39). In the above configuration, before machining, the nozzle body (lLa) is in a lowered state as shown by the solid line in FIG.
38), this machining fluid flows into the nozzle body (l
It hits the inner wall of the nozzle body (lla), and its pressure lifts the nozzle body (lla) upward as shown by the imaginary line in the figure. When the supply of machining fluid is stopped with the completion of machining, the nozzle body (lla) descends due to its own weight or is hit by the cut-off part (12) of the falling workpiece (1), and will be kept in the same state. In other words, since the machining fluid is continuously supplied during machining, the gap between the nozzle body (ila) and the workpiece (1) is dl, and the machining fluid supply is stopped after machining and other than during machining. In other words, the gap between the nozzle body (lla) and the workpiece (1) is d2.

The reason why the nozzle body (lla) is set at the upper limit position during machining is to efficiently supply machining fluid to the machining section, and also to set the nozzle body (lla) to the upper limit position after machining and other than during machining.
The reason why la) is set to the lower limit position is to prevent the nozzle (11) from colliding with other objects when moving the table during setup work such as positioning the workpiece (1). .

Next, an automatic processing device for the cut-off portion (I2) of the workpiece (1) generated after the above processing will be explained.

In FIG. 2, (14) is an automatic processing device for the cut-off portion, (15) is a container for the cut-off portion (12), and (1B) is an automatic removal device section (1B) which is a movable part of the automatic processing device (14).
A guide for holding 14a) during movement in the X direction, (
17) is a drive motor for moving the automatic removal device section (14a) in the X direction, and (18) is a drive motor for similarly moving it in the vertical direction.

Note that FIG. 5 shows the automatic removal device section (14a) in FIG.
) is an enlarged sectional view schematically showing the structure of (1).
9) is a holder, and (20) is a gear connected to the drive motor (17), which meshes with a rack (16a) provided on the guide (16). (21) is a vertical drive shaft, (22) is a gear connected to the drive motor (18), and the gear (22) meshes with a rack (21a) provided on the vertical drive shaft (21). (23) is an electromagnet, (25) is a casing, (26) is a compression spring, and (27) has one end fixed to the lower end of the vertical drive shaft (21) and the casing (25) fixed to the other end. in the arm, the electromagnet (23) is attached to the casing (2
5) is constantly pressed downward by a compression spring (26). (29) is a contact detection switch attached to the attracting surface side of the electromagnet (23), which detects the cut-off portion (12) that is attracted and transferred by the electromagnet (23) and sends a signal to the SNC device (1, not shown). Output.

Therefore, when the machining fluid stops at the end of electrical discharge machining,
As described above, the nozzle body (lla) is lowered to the position shown by the solid line in FIG. At this time, the cut-off portion (12) is supported by the upper end surface of the nozzle body (lla). Next, after recovering the wire electrode (2), a cut-off portion (12
) so that the is lowered, and the attraction surface of the electromagnet (23) comes into contact with the surface of the cut-off portion (12).

Furthermore, the vertical drive shaft (21) is connected to a compression spring (26).
When the electromagnet (23) descends against the reaction force of the electromagnet (23) and reaches a position where it is pressed against the surface of the cut-out part (12) with a predetermined pressing force,
The contact detection switch (29) operates and transmits a signal to the NC device. When this signal is transmitted, the electromagnet (23) is excited by the command from the NC device, and the cut-off part (12) is attracted and at the same time the gear (22) starts rotating and the vertical drive shaft (
21). When this vertical drive shaft (21) rises to a predetermined position, it stops, commands the drive motor (17) to rotate the gear (20), and automatically removes the device (14a).
is moved in the X direction and stops when it reaches directly above the container (15). Simultaneously with this stop, the excitation state of the electromagnet (23) is released, and the cut-off portion (12) falls into the container (15). When the cut-off portion (12) has been accommodated, the drive motor (17) rotates again to move the automatic removal device (14) in the X-axis direction and return it to its original position.

By repeating the above operations, it is possible to automatically operate the wire electrical discharge machining apparatus that performs electrical discharge machining at a plurality of locations on one workpiece or a plurality of workpieces placed on a surface plate at the same time.

FIG. 6 is a configuration diagram showing another example of a conventional wire electric discharge machining apparatus, and the same parts as in FIG. 2 are given the same reference numerals, and the explanation thereof will be omitted. This wire electrical discharge machining device shown in Fig. 6 is
This is the one shown in the figure with an automatic workpiece changer added.
In the figure, (41) is the horizontal X-axis, (42) is the vertical Z-axis arranged perpendicular to this, (48),
(44) is a drive motor for driving the X axis (41),
It is for driving the Z axis (42).

(45) is a hand, which is secured to the lower end of the Z-axis (42) with a bolt (not shown), and whose tip has the function of gripping the workpiece (1), that is, it is arranged at a distance as shown in Fig. 7. A pair of magnets (45a), (45a)
and these magnets (45a)
.

(45a), there is provided a workpiece detector (45b) for detecting the workpiece (1) held by the hand by suction. On the other hand, X1lh (41) is a bet (4
) is fixed to a frame (46) with bolts (not shown) with bolts (47), and the Z-axis (42) and the Z-axis (42) are attached in a predetermined relationship to the main body of the wire electrical discharge machining apparatus.

The above X-axis (41), Z-axis (42), drive motor (43)
.

(44), hand (45), magnet (45a),
The frame (46) and bolt (47) constitute an automatic workpiece changer (60).

Therefore, (48) is a stocker for storing the workpiece (1), and a front stocker (48) for loading the workpiece (1a) before processing.
8a) and a rear stocker (48b) on which the processed workpiece (1b) is loaded. (49) is a clamp jig for positioning and fixing the workpiece (1), (50) is a clamp cylinder built into this clamp jig (49), and (51) is the workpiece after machining (
1b) is a saucer placed below the stocker (48) to collect the dripping portion of the machining fluid that has adhered to the stocker (48).

FIG. 8 is a plan view of the clamp jig (49), and in the figure,
In (52), the support for supporting the workpiece (1) is made of gold;
(53) is provided at one end of the clamp jig (49),
This is a reference piece for positioning the workpiece (1).

Next, the operation of the wire electrical discharge machining apparatus having the above configuration will be explained. First, before performing electrical discharge machining on the workpiece (1), a small hole (13) is made through which the wire electrode (2) is passed.
) is drilled at one point on the machining trajectory as shown in Figure 3,
Thereafter, the workpiece (1) is positioned and fixed on the clamp jig (49) on the surface plate (5) by the workpiece (1) loading operation described later, and then the wire electrode (
2), the machining voltage is applied to the wire electrode (2) and the workpiece (
1), and the wire electrode (2) is fed by the automatic wire feeding mechanism (3). On the other hand, the workpiece (1
) is automatically fed by the Y table (6) and the X table (7), and electrical discharge machining is performed while drawing a locus of a predetermined shape with respect to the wire electrode (2). During this electrical discharge machining,
Machining fluid is supplied from the nozzle (11) to the machining section of the workpiece (1). While performing electric discharge machining, the wire electrode (2) goes around the locus of the predetermined shape of the workpiece (1) and the machining process ends when it reaches the position of the small hole (13) at the machining start point. , the wire electrode (
2) is cut, and the cut-off portion (12) of the workpiece (1) produced after processing is removed to the outside by the above-mentioned automatic processing device (14).

Next, the workpiece (1), which has been processed automatically by the X table (7) and Y table (6), is transferred to the XY table in the same way.
Z-axis (
42) to a position where it can be held by the hand (45) provided at the tip. Then, in response to a workpiece (1) positioning release command from an NC device (not shown), the clamp cylinder (50) is moved back, and the positioning of the workpiece (1) is released. On the other hand, automatic workpiece changer (60)
The drive motor (43) moves the Z-axis (42) along the arrow (5).
4), and the hand (45) moves in the direction 7, and the hand (45) moves to the workpiece (1).
Stop at a place directly above (point A).

Next, at this point A position, the Z axis (42) (shown by an imaginary line in Fig. 6) is moved by the drive motor (44) as shown by the arrow (55).
When the workpiece detector (45b) incorporated in the hand (45) detects the processed workpiece (1), the lowering operation is stopped. Then, after attracting and holding the workpiece (1) by energizing the magnet (45a) of the hand (45), the drive motor (
44), raise the Z-axis (42) one step in the direction of the arrow (56) and lift the workpiece (1) to the upper point of the Z-axis (42), that is, to the point located above the upper edge of the stocker (48). . Furthermore, the drive motor (43) drives the Z-axis (4
2) in the direction of the arrow (57), the workpiece (1) held by the hand (45) is moved to the rear stocker (
48b) Transfer to the upper position and lower the Z axis (42) in the direction of the arrow (55). The Z-axis (42) stops when the lower stopping point is confirmed by a lower detector (not shown), and the magnet (45a) is deenergized (demagnetized) to remove the workpiece (1). Then, move the Z-axis (
42) is again driven by the arrow (56) by the drive motor (44).
After ascending in the direction and reaching the upper point, as shown in Figure 6,
The hand (45) is moved in the direction of the arrow (57) by the drive motor (43) so that it is positioned above the front stocker (48a). The Z axis (42) is connected to the drive motor (
44) in the direction of arrow (55), and the workpiece (la) to be processed is loaded in the front stocker (48a).
Among them, the highest one is detected by a detector (not shown) and held by magnets (4, 5a).

Next, the Z-axis (42) is raised in the direction of arrow (56) by the drive motor (44), moved to the above-mentioned point A by the drive motor (43), and then stopped. After that, move the Z axis (4
2) is a workpiece to be processed (1a) that is lowered by a drive motor (44) and held by suction with its hand (45).
Transfer it onto the clamp jig (49) and hold it with gold (
52). At this time, the hand (45) receives the output of the lower detector (not shown) from the magnet (45a).
) to release the attraction of the workpiece (1).

After the Z-axis (42) has finished transferring the unprocessed workpiece (1a) to the clamp jig (49) in this way, it returns to its origin position on the stocker (48) by following the opposite path to the above. It returns and waits for the next command from the NC device.

On the other hand, the clamp jig (49) on which the workpiece (1) is placed
) operates a clamp cylinder (50) incorporated therein by a command from a control device (not shown) to position and hold the workpiece (1) and press it against the reference piece (53).

When the above operation is completed, the X table (7) and Y table (6) are automatically fed according to the command from the NC device.
Move the workpiece (1) directly below the nozzle (11) and drill the small hole (
Pass the wire electrode (2) through 13) and start electric discharge machining again. Note that the saucer (
51) is for preventing the machining liquid adhering to the workpiece (1b) from dripping down after machining and wetting the floor surface.

By the way, in each of the above-mentioned conventional devices, when the following conditions occur, a well-known detector and a control device (not shown) detect this and stop the operation of the movable part, limit the operating range, or limit the operating speed. It is equipped with an interlock function to prevent related moving parts from interfering with each other.

■ Automatically when the automatic removal device section (14a) and holder (19) of the automatic cut-off section processing device (14) are located at a position other than the position where they do not interfere with other devices (hereinafter referred to as the fixed position of the automatic cut-off section processing device). Stop the operation or limit the operating range of the wire connection device and cut-off portion automatic processing device (14).

■ The position of the upper nozzle (11) of the automatic wire connection device is such that it does not interfere with the automatic cut-off portion processing device (14) and the automatic workpiece change device (60) when these devices operate (usually the upper nozzle preparation position). (set to nozzle upper limit)
If not, the operation of the cut-off portion automatic processing device (14) and the automatic workpiece changing device (60) is stopped or the operating range is limited.

■ Even if the upper nozzle (11) of the automatic wire connection device is in the nozzle preparation position, if the wire electrode is being connected or the wire electrode has already been connected, the cut-off portion automatic processing device (14) and the automatic workpiece The operation of the exchange device (60) is stopped or the operation range is limited.

■ If the movable parts of the automatic workpiece changer, such as the Z-axis, are located at a position other than the position where they do not interfere with other devices (hereinafter referred to as the fixed position of the automatic workpiece changer), the automatic wire connection device and automatic cut-off part processing The operation of the device (14) is stopped or the operating range is limited.

(2) If the number of workpieces to be replaced exceeds the number of workpieces inputted in advance to the control device, all devices are stopped.

■ During suction operation of the workpiece, if the workpiece is not suctioned or if the workpiece comes off the suction part during transportation, this is detected by the workpiece detector (82). Stop operation of all equipment.

[Problems to be Solved by the Invention] Since the conventional wire electrical discharge machining device is configured as described above, it is possible to combine an automatic wire connection device and an automatic cut-off section processing device, or to add an automatic covering device to each of these devices. When a workpiece changer is combined, the movement of each related movable part becomes complicated, and input errors when creating a cannibal program may result in a defective cannibal program or incorrect operation procedure. In such a case, the above-mentioned interference prevention function alone cannot cope with unexpected movement of the movable parts, and there is a risk that each device will come into contact with each other and be damaged, which requires careful operation.

In view of the above points, it is an object of the present invention to obtain a wire electrical discharge machining device that can further enhance the interlock function.

[Means for Solving the Problems] The wire electrical discharge machining apparatus according to the present invention has a clamp jig at a workpiece exchange position at a predetermined position on the fixed side that is an absolute position system with respect to the movable system on the processing table side. A first clamp jig detector for detecting the presence of a clamp jig is installed on the processing table, and a second clamp jig detector for detecting the presence or absence of a clamp jig is installed on the processing table, and the stocker is equipped with a second clamp jig detector for detecting the presence or absence of a clamp jig. Pre-processing workpiece detectors are installed to detect the presence or absence of workpieces, and the movement of the movable parts of each device is stopped or restricted based on the detection results of these detectors.

[Function] In the present invention, when the clamp jig detector detects that the clamp jig attached to the surface plate has not moved to the position where the workpiece should be replaced, or when the clamp jig is detected to be in a predetermined position. If it is detected that the automatic workpiece changer is not installed in this position, the operation of the automatic workpiece changer is stopped or the operating range is limited. In addition, after the pre-processing workpiece detector detects that there is no pre-processing workpiece in the stocker, if there is a command to feed the pre-processing workpiece to the clamp jig, all devices will be activated. Stop. In this way, based on the detection results of each detector, mutual movement of the movable parts of each device is stopped or restricted to prevent interference between them.

[Embodiments of the Invention] The present invention will be described below with reference to illustrated embodiments. Figure 1 (a
) and (b) are both enlarged views of main parts of a wire electrical discharge machining apparatus according to an embodiment of the present invention;
FIG. 2A is a front view of the stocker section, and FIG. 1B is a plan view of the clamping jig of the processing table. In each figure, the same parts as in the prior art are denoted by the same reference numerals, and the explanation thereof will be omitted. Note that, except for the part shown in FIG. 1 above, other structures and their normal operations are the same as those shown in FIG. 6, so the present invention will be explained with reference to FIG. 6. At the bottom of the front stocker (48a) of the stocker (48) of the device,
As shown in FIG. 1(a), a recess (48c) is provided, and within this recess (48c) is the front stocker (48a).
) An unprocessed workpiece detector (80) for detecting unillustrated workpieces loaded in the stocker is installed with its operation button facing into the stocker. As a result, it is possible to detect the presence or absence of the workpiece to be processed in the front stocker (48a), and the workpiece to be processed detector can detect that there is no stock of the workpiece to be processed in the front stocker (48a). (80
) is detected, and if there is a command to feed the unprocessed workpiece to the clamp jig, the automatic wire connection device, automatic workpiece change device (60), and cut-off section automatic processing device are activated by a control device (not shown). (14) All movements of the parts having movable parts are stopped.

In addition, there are two locations on the fixed side of the bed (4), etc., which serve as an absolute position system for movable systems such as the processing table (7a), as shown in Figure 1 (
As shown in b), a light emitter (81a) and a light receiver (81b) detect the clamp jig (49) at the workpiece exchange position.
) an optical first clamp jig detector (81) consisting of
, (81), and these first clamp jig detectors (81), (lit) are located outside the movable range of the processing table (7a) so that their respective optical axes intersect with each other. The clamp jig (49) cannot be captured at the same time except at the workpiece exchange position. This allows the machining table (
The clamp jig (49) attached to the workpiece (1)
) has moved to the position where it should be replaced, and if it is detected that it has not moved, the control device stops or stops the operation of the automatic workpiece changer (60). It is designed to limit the range of motion.

Furthermore, the surface plate (5) to which the clamp jig (49) is attached
) is also installed at a predetermined location of the clamp jig (49).
) is attached to the processing table (7a), and if it is detected that it is not attached, the control device controls the operation of the automatic workpiece changer (60). It is designed to stop the operation or limit the operating range. Further, in this embodiment, in each of the above states, an abnormality is displayed based on the output of each detector.

In this way, the wire electrical discharge machining apparatus of this embodiment not only has the conventional function of preventing interference with moving parts, but also has the ability to detect the presence or absence of a workpiece before machining.
Since the movement of the movable parts is stopped or restricted depending on the presence or absence of the clamp jig, the interlock function is further enhanced and the reliability of the device is improved, as well as being able to indicate abnormal conditions. This allows the manager to easily detect this and take immediate action, thereby increasing the operating rate of the fruiting device.

In the above embodiment, the automatic wire connection device, the automatic cut-off portion processing device (14), and the automatic workpiece change device (60) are controlled by the same control device, but the present invention is not limited to this. First, a dedicated control device may be used for each device, and the interlock function may be activated by transmitting and receiving signals between these control devices.

In addition, in the above embodiment, the present invention includes an automatic wire connection device, an automatic workpiece change device (60), and an automatic cut-off portion processing device (14).
), but this is, for example, a combination of an automatic wire connection device using automatic enlarging processing and an automatic workpiece change device (60) that does not generate cut-off parts. It is also possible to apply the present invention to a device, and in such a case, the same effects as in the above embodiment can be achieved.

[Effects of the Invention] As described above, according to the present invention, the movement of the movable part is stopped or restricted depending on the presence or absence of the workpiece before machining or the presence or absence of the clamp jig, so the interlock function is effective. This has the effect of increasing the reliability of the device.

[Brief explanation of the drawing]

1(a) and 1(b) are both enlarged views of essential parts of an embodiment of the present invention, in which FIG. 1(a) is a front view of the stocker section, and FIG. 1(b) is a front view of the processing table. 2 is an overall configuration diagram showing an example of a conventional wire electric discharge machining device, FIG. 3 is a perspective view showing a workpiece after machining, and FIG. FIG. 5 is an enlarged vertical sectional view showing the cut-off part automatic processing device shown in FIG. 2, and FIG. Figure 2 shows an example of
6 is an enlarged side view of the hand portion of the device shown in FIG. 6, and FIG. 8 is a plan view of the clamp jig mounting portion of the device shown in FIG. 6. In the figure, (1) is the workpiece, (1a) is the workpiece before machining, (lb) is the workpiece after machining, (2) is the wire electrode, and (3) is the automatic wire feed mechanism (automatic connection device)
, (4) is the bed, (6) is the Y table, (7) is the X table, (7a) is the processing table, (11) is the nozzle (
(48) is a stocker, (49) is a clamp jig, (60) is an automatic workpiece changer, (80)
) is a pre-processing workpiece detector, (81) is a first clamp jig detector, and (82) is a second clamp jig detector. In each figure, the same reference numerals indicate the same or corresponding parts. Agent Patent Attorney Muneharu Sasaki Figure 2 (b) Karoe monomatatacho missing place

Claims (1)

[Claims] A clamp jig attached to a machining table that is driven in a two-dimensional plane on a bed to position a workpiece and fix the workpiece, and a clamp jig that is attached to a machining table that is driven in a two-dimensional plane on a bed, and a clamp jig that positions the workpiece and fixes the workpiece before and after machining. A stocker for accommodating each workpiece, and a workpiece to be processed from this stocker is carried onto the clamp jig and placed thereon,
It also includes an automatic workpiece changer for transporting the processed workpiece from the clamp jig and storing it in the stocker, and an automatic workpiece changer for transporting the processed workpiece from the clamp jig and storing it in the stocker, and an automatic workpiece changer for supporting the wire electrode, supplying processing power to it, and supplying processing liquid to the processing part. In a wire electrical discharge machining device equipped with an automatic wire connection device consisting of a jetting nozzle and an automatic wire feed mechanism, a clamp jig is attached to the workpiece at a predetermined position on the fixed side, which is an absolute position system with respect to the movable system on the processing table side. A first clamp jig detector is installed to detect the presence of a clamp jig at the replacement position, and a second clamp jig detector is installed on the processing table to detect the presence or absence of a clamp jig. A pre-processing workpiece detector for detecting the presence or absence of a workpiece is installed, and the mutual movement of the movable parts of the respective devices is stopped or restricted based on the detection results of these detectors. Wire electrical discharge machining equipment.