JPH0724724A - Non-contact detection method for wire position - Google Patents

Abstract

(57) [Abstract] [Purpose] It is possible to detect the displacement of the wire winding position on the reel in a non-contact state. [Configuration] In traverse control of the wire saw device,
While running the wire in a non-contact state between the two magnetic sensors at a position near the reel, a current is passed through the wire, and the magnetic field due to the current of the wire is detected by a coil as each magnetic sensor. The position of the wire is detected from the output difference of the sensor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting the position of a wire in a wire saw device by a magnetic sensor in a non-contact state.

[0002]

2. Description of the Related Art In a wire saw device, a traverse device is attached at a wire feeding position or winding position with respect to a reel. The traverse device moves the guide roller in the displacement direction according to the change in the winding position of the wire on the reel when feeding the wire from the reel of the aligned winding or winding the wire as the aligned winding on the reel. Move in sync. In this traverse control, wire position detection is indispensable. Since the conventional wire position detecting means is configured as a contact type roller or the like, this contact portion is worn and needs to be replaced periodically. Thus, according to the contact-type wire position detecting means, its life is limited due to wear,
Further, in the case of a rotary roller or the like, there is a defect that the inertia of the roller itself causes an error in the detection operation or an operation delay.

[0003]

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to allow a wire saw device to detect a displacement of a winding position of a wire with respect to a reel in a non-contact state, and solve a drawback of the prior art.

[0004]

According to the present invention, in traverse control of a wire saw device, the present invention causes a wire to run in a non-contact state between two magnetic sensors at a position near a reel, and to cause a current to flow to the wire. The magnetic field due to the current of the wire is detected by each magnetic sensor, and the position of the wire is detected from the output difference of both magnetic sensors. Here, the magnetic sensor is composed of a coil or a magnetic sensor element such as a Hall element or a magnetoresistive effect element.

[0005]

FIG. 1 shows a traverse device 2 of a wire saw device 1. The traverse device 2 is provided on both the feeding side and the winding side of the wire 3, but the above embodiment shows only the feeding side traverse device 2 as an example, and the winding side traverse device is omitted. . The wire 3 made of a conductive material is wound around the reel 4 in an aligned winding state, and after being pulled out from the reel 4, the wire 3 passes between the two magnetic sensors 5a and 5b in a non-contact state, and a plurality of, for example, It is supplied to the wire saw device 1 while being in contact with the three guide rollers 6.

Here, the above-mentioned two magnetic sensors 5a and 5b.
The guide roller 6 and the guide roller 6 are both the traverse table 7
Mounted on top of the reel 4 and parallel to the axial direction of the reel 4, a feed screw shaft 8, a feed screw nut 9, a bearing 12 of the feed screw shaft 8, a traverse motor 10, a belt.
The pulley 11 or the like can drive the reel 4 in the axial direction, that is, the traverse direction.

The traverse motor 10 is driven by a traverse controller 13 and a driver 14. The traverse controller 13
Is connected to the magnetic sensors 5a and 5b, takes the difference between the outputs of the two magnetic sensors 5a and 5b, and specifies the rotation direction of the traverse motor 10 according to the magnitude relationship between them.
The rotation amount corresponding to the absolute value of the difference is output to the driver 14 as a command value.

Next, FIG. 2 shows an example in which the magnetic sensors 5a and 5b are constituted by a coil 51. These coils 51
The center lines of both are oriented in the tangential direction of the magnetic field due to the current flowing through the wire 3, and are arranged at equal distances with the wire 3 interposed therebetween. And on this wire 3,
An AC power supply 15 for generating a magnetic field is connected. Normally, this AC power source 15 is provided with a support base 16 for the reel 4 on the delivery side,
It is connected between the wire 3 near the wire saw device 1 or the support 16 of the reel 4 on the winding side. Therefore, the alternating current from the alternating-current power supply 15 passes through the support 16 and the bearing 17 of the support 16 and the like, and the wire 3 made of a conductive material
Flowing through. At this time, the bearing 17 acts as a capacitor with respect to the AC circuit and is in an AC conductive state.

During the cutting operation of the wire saw device 1, the wires 3 of the reel 4 on the delivery side are aligned and wound.
The wire 3 sent out from the wire saw device 1 to the wire saw device 1 and wound after the cutting operation is wound around the reel 4 on the winding side in an aligned winding state. During this cutting operation, an alternating current is being applied to the wire 3 by the alternating current power supply 15. Therefore, the alternating current flowing through the wire 3 generates an alternating magnetic field, which acts on the coil 51 as the magnetic sensors 5a and 5b. Therefore, an alternating current is generated in the coil 51 by electromagnetic induction. Moreover, the magnitude of this alternating current depends on the strength of the alternating magnetic field, that is, the wire 3
Occurs in inverse proportion to the distance from to each coil 51. Therefore, the distance from the wire 3 to each coil 51 can be indirectly measured by the magnitude of this alternating current.

Therefore, the outputs of these coils 51 become the inputs of the traverse controller 13, respectively. The traverse controller 13 obtains the difference in the strength of the magnetic field at each detection position, that is, the difference in the distance from each coil 51 to the wire 3, by obtaining the difference in output between the outputs of the two coils 51. Thus, the position of the wire 3 is detected, the rotation direction of the traverse motor 10 is designated according to the magnitude result, and at the same time, a command signal of the rotation amount of the traverse motor 10 is generated with an output proportional to the difference, and the driver 14 Is driven to rotate the traverse motor 10.

Therefore, the traverse motor 10 drives the feed screw shaft 8 in accordance with the specified instruction content, moves the traverse table 7 in a predetermined direction by the feed screw nut 9, and moves the guide roller 6 to the wire position. Three
The same amount is moved in the same direction according to the change of the contact position of. Thus, near the reel 4, the wire 3
Is always orthogonal to the axial direction of the reel 4. If the wire 3 is cut during the cutting operation, the AC current stops flowing through the wire 3 and the outputs of the magnetic sensors 5a and 5b are lost. Thereby, the disconnection of the wire 3 can be detected.

[0012]

Other Embodiments In the above embodiment, the coil 51 is used as the magnetic sensor. However, the magnetic field detection is not limited to the above coil, and a Hall element or a magnetoresistive effect element may be used. The magnetoresistive effect element is usually incorporated as a bridge circuit, and the distance between the wire 3 and the magnetoresistive effect element is indirectly measured from the unbalanced state of the resistance values of both.

[0013]

According to the present invention, since the position of the wire near the reel can be detected by a non-contact type magnetic sensor, the conventional drawbacks such as abrasion of the contact portion in the case of a contact type roller and inertial rotation at the time of contact are caused. The effects are eliminated, the consumables are reduced, the running cost of the device is reduced, and if the current flowing in the wire is AC, the AC current-carrying state is maintained even in the electrically non-contact part such as the bearing. It is possible to obtain a unique effect that the current is stabilized, and when the wire is broken, a magnetic field is not generated and the output of the magnetic sensor is lost, so that the wire break can be detected.

[Brief description of drawings]

FIG. 1 is a plan view of a traverse device according to the present invention.

FIG. 2 is a side view of an arrangement state of magnetic detection coils.

[Explanation of symbols]

 1 Wire Saw Device 2 Traverse Device 3 Wire 4 Reel 5a Magnetic Sensor 5b Magnetic Sensor 6 Guide Roller 10 Traverse Motor 13 Traverse Controller 15 AC Power Supply 51 Coil

Claims (3)

[Claims] 1. In a wire saw device, in a traverse control in which a guide roller is moved in a displacement direction in synchronization with a displacement amount in accordance with a displacement of a winding position of the wire with respect to a reel, the wire is moved to a position close to the reel by two magnetic wires. While running as a non-contact state between the sensors, current is passed through the wire, the magnetic field due to the current of the wire is detected by each magnetic sensor, and the position of the wire is detected from the output difference of both magnetic sensors. Non-contact method for detecting wire position. 2. Each magnetic sensor is constituted by a coil,
The method for detecting non-contact of a wire position according to claim 1, wherein an alternating current is passed through the wire. 3. The method for non-contact detection of a wire position according to claim 1, wherein both magnetic sensors are composed of magnetic sensor elements.