JPH08300346A - Motor control circuit of wire saw - Google Patents

Abstract

PURPOSE: To inexpensively realize the brake of a motor in a space conserving manner by connecting a regenerative resistor to the input terminal of a motor when the abnormality of a power supply is detected by a power supply abnormality detection means at the time of the operation of a wire saw. CONSTITUTION: When no voltage is outputted from a power supply 100 by the abnormality of the power supply such as power failure, that is, no power is supplied to a drive motor 104 or an energency stop command is issued in order to prevent danger, the current of a relay coil 114 is cut off and the relay contacts 106A, 106B, 108A, 108B are changed over. By this constitution, the current loop of the drive motor 104 and a resistor 109 is formed and the regenerative current 109 generated from the rotating drive motor 104 flows toward the resistor 109 and the inertial energy of the drive motor 104 is consumed. Therefore, the rotation of the drive motor 104 is stopped instantly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire saw, and more particularly to a regenerative brake for stopping the rotation of a wire saw motor.

[0002]

2. Description of the Related Art A motor is used to drive a wire feed reel, a wire take-up reel, etc. of a wire saw, but when a power failure occurs during operation of the wire saw or an emergency stop circuit operates, The motor is de-energized and the motor is free running. In the free-run state, the energy accumulated in the rotation of the wire reel is not easily consumed, and it takes a considerable time to stop the rotation.

In particular, in a wire saw for cutting an ingot of silicon or the like into wafers, as the diameter of the wafer becomes larger, the wire storage amount also increases and the weight of the wire reel becomes considerably heavy, so that the supply of electric power to the motor is stopped. After that, it takes several minutes to stop the rotation of the wire reel. If the wire reel continues to rotate when there is a sudden power failure while the wire saw is operating or when the emergency stop circuit operates, it is extremely dangerous because of injury or damage to the wafer or the like.

For this reason, a motor with a brake is usually used, and when the power is turned off, the brake is mechanically driven by a spring force to prevent the motor from entering a free-run state.

[0005]

However, in the case of the motor with a brake, there is a drawback that the brake is expensive and the size of the motor is large.
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a motor control circuit for a wire saw that realizes a motor brake at low cost and in a small space.

[0006]

In order to achieve the above-mentioned object, the present invention rotates a pair of wire reels by a motor to feed a wire from one wire reel of the pair of wire reels while A wire saw that winds a wire with a wire reel, runs the wire, and presses a work against a wire row to cut the work into thin pieces. A power source connected to the input terminal of the motor and an abnormality of the power source are detected. A power source abnormality detecting means for connecting to the input terminal of the motor,
When connected to the input terminal of the motor, a regenerative resistor that consumes regenerative power output from the motor, and when an abnormality of the power supply is detected by the power supply abnormality detection means during operation of the wire saw, the motor And a connecting means for connecting the regenerative resistor to the input terminal of.

[0007]

According to the present invention, when the wire saw is in operation, the voltage of the power supply applied to the motor of the wire reel is detected by the power supply abnormality detecting means, and when the detected voltage drops below a predetermined value, Switch the input terminal connection to the regenerative resistor. As a result, the regenerative electric power generated from the motor is consumed by the regenerative resistor, and the motor can be prevented from entering the free run state. That is, the rotation of the motor is immediately stopped.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a wire saw motor control circuit according to the present invention will be described below in detail with reference to the accompanying drawings. FIG.
FIG. 3 is a configuration diagram showing an example of a wire saw applied to the present invention. As shown in the figure, the wire 14 wound around one reel 12 passes through a wire guide device 16, a plurality of fixed guide rollers 18 and 18, and a dancer roller 20, and three grooved rollers 22 and 22, 22 is sequentially wound around 22 to form a wire row 24, and then a plurality of fixed guide rollers 1
A wire traveling path is formed which is wound around the other reel 26 through the rollers 18, 18, the dancer roller 20, and the wire guide device 16.

A weight 44 having a predetermined weight is suspended from the dancer roller 20, and the load of the weight 44 always applies a required tension to the wire 14 traveling along the wire traveling path. A wire cleaning device 46 is provided in the middle of the wire traveling path, and the machining liquid 40 attached to the wire 14 is removed from the wire 14 by the wire cleaning device 46. Further, the wire array 24 is supplied with a machining liquid 40 containing abrasive grains (usually about GC # 600 to # 1000) stored in a polishing liquid storage tank 38 from a polishing liquid supply nozzle 42. It

A work feed table 48 is provided below the wire row 24, and the work feed table 48 is provided.
Is provided so as to be movable in a cutting feed direction (Y-Y direction in the drawing) by a screw rod 52 rotated by a motor 50, and a semiconductor ingot 54 which is a workpiece is provided on the wire row 24 side of the work feed table 48. Are supported via a work block 56 and a slice base 58. As a result, the work feed table 48 is moved in the cutting feed direction (wire row 24
When moved to the side), the semiconductor ingot 54 is pressed against the high-speed wire array 24, and the semiconductor ingot 54 is lapped into a large number of thin wafers by the lapping action of the abrasive grains of the machining liquid 40 supplied to the wire array 24. Disconnect.

The reels 12 and 26 are connected to drive motors 28 and 30 that can rotate in the forward and reverse directions, and one of the three grooved rollers 22 is connected to a drive motor 32 that can rotate in the forward and reverse directions. Be connected. As a result, one reel 1
The wire 14 fed from 2 is wound around the other reel 26 while traveling at high speed in the direction of the solid arrow 34 in the figure,
The wire 14 wound on the other reel 26 travels backward in the direction of the broken line arrow 36 in the figure and is wound on the one reel 12. That is, the wire 14 reciprocates between the one reel 12 and the other reel 26.

The running of the wire of the wire saw is carried out in the running pattern of FIG. As shown in the figure, the wire 14 is reciprocated in the directions shown by the solid arrow 36 and the broken arrow 34 in FIG. 1 to wind the wire 14 around the reel 26. That is, during the period A, the wire 14 is accelerated in the direction of the solid arrow 36, and during the period 1 minute of the steady speed (700 m
/ Min). Then, after the wire 14 is run at a steady speed for 1 minute, the wire 14 is decelerated in the period C, and the running direction of the wire 14 is reversed to the direction of the broken arrow 34. In the direction of the broken line arrow 34, the wire 14 is accelerated in the period D, and the constant velocity (700 m / mi) is maintained for 40 seconds in the period E.
Drive in n).

In this way, the wire 14 is reciprocated, and the wire is run in the direction of the solid arrow 36 for a long time.
The wire 14 is wound from the reel 12 to the reel 26. During this time, the drive motor 32 rotates in synchronization with the traveling speed of the wire 14 and performs the same rotation operation as the drive motors 28 and 30. FIG. 3 is a circuit diagram showing a motor control circuit of the wire saw according to the present invention. The drive motor 104 shown in FIG.
Any one of 32 is shown.

As shown in the figure, an AC voltage is output from the AC power supply 100 to the servo driver 102 and the DC stabilized power supply 110. The servo driver 102 is a drive motor 104
Is a circuit for controlling the rotation speed and the rotation direction of the relay contact 10 by converting the input AC voltage into a desired voltage signal.
Output to the drive motor 104 via 6A and 106B.

The relay contacts 106A and 106B are A contacts and are in a contact contact state (conduction state) when a current is flowing through the relay coil 114, and are in a contact non-contact state (non-conduction state) when no current flows through the relay coil 114. become. Further, the drive motor 104 has a relay B contact 10
The resistor 109 is connected via 8A and 108B.
The relay contacts 108A and 108B are the relay coil 11
4 is in a contact non-contact state (non-conducting state) when a current is flowing in 4, and is in a contact contact state (conducting state) when no current flows in the relay coil 114.

As will be described later, the relay coil 114 is used when power is no longer supplied from the power source due to a power failure such as a power failure or when an emergency stop command is issued by a switch for emergency stop to prevent danger. The current to is cut off. At this time, relay contact 1
06A and 106B are in a non-contact state (non-conductive state), and relay contacts 108A and 108B are in a non-contact state (conductive state), and a current loop between the drive motor 104 and the resistor 109 is formed.

The relay coil 114 is a DC stabilized power supply 1
When the AC power supply 100 is connected to the output terminal 10 and a voltage is output, a DC current flows through the relay coil 114, and when the AC power supply 100 is not outputting a voltage,
No electric current flows through the relay coil 114. That is, when the voltage is no longer output from the power supply 100 due to an abnormality in the power supply such as a power failure during the driving of the wire saw, the current does not flow in the relay coil 114, and the contact points of the relay contacts 106A, 106B, 108A, 108B are switched as described above. To be

An emergency stop circuit 116 is connected in series with the relay coil 114. This emergency stop circuit 1
Reference numeral 16 is normally a contact contact state (conduction state), but in order to prevent danger, when an emergency stop command is issued by an unillustrated emergency stop switch or the like, the contact non-contact state (non-conduction state)
Then, the current of the relay coil 114 is cut off. As a result, the relay contacts 106A, 106B,
The contacts of 108A and 108B are switched.

As described above, when the voltage is no longer output from the power source 100 due to an abnormality in the power source such as a power failure, that is, when the power is not supplied to the drive motor 104, and an emergency stop is performed to prevent danger. When instructed, the current of the relay coil 114 is cut off and the contacts of the relay contacts 106A, 106B, 108A and 108B are switched. As a result, the drive motor 104 and the resistor 10
9, a current loop is formed, and a regenerative current generated from the rotating drive motor 104 flows to the resistor 109 side,
The inertial energy of the drive motor 104 is consumed. Therefore, the rotation of the drive motor 104 is immediately stopped.

A capacitor 112 is connected between the output terminals of the stabilized DC power supply 110. The capacitor 112 prevents the drive motor 104 from stopping due to an instantaneous power failure of the AC power supply 100 or the like. , A current is supplied from the capacitor 112 to the relay coil 114 for a moment when a power failure or the like occurs, and the relay contacts 106A, 10
It prevents the contacts of 6B, 108A, and 108B from switching.

The relay contact 106 shown in the above embodiment is used.
Electronic switches such as thyristors may be used for A, 106B, 108A, and 108B. Further, in the above embodiment, the power supply abnormality such as a power failure is detected by the current flowing through the relay coil, but the invention is not limited to this, and the power supply voltage is directly detected, and the power supply abnormality is detected based on the detected voltage. You may do it. Then, if an abnormality of the power supply is detected, that is, if the detected voltage becomes a predetermined voltage or less, the relay contacts 106A, 106B, 108A, 10
Switch the contact of 8B.

[0022]

As described above, according to the wire saw motor control circuit of the present invention, when the wire saw is in operation,
When a power failure such as a power failure occurs, the input terminal of the motor is connected to the regenerative resistor, so the regenerative power generated from the motor is consumed by the regenerative resistor. This allows
In the event of a power failure or power failure, the motor rotation will stop immediately and an accident will be prevented. Further, the brake using the regenerative resistor is very inexpensive, and the space for the motor is reduced by the fact that the motor does not need a brake.

Further, when an emergency stop of running of the wire is instructed during the operation of the wire saw, the regenerative resistance is connected to the input terminal of the motor and the power supply is disconnected from the motor, so that the electric power is supplied to the motor. When the motor is stopped, the inertial energy of the motor is consumed by the regenerative resistance, and the rotation of the motor is immediately stopped.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an example of a wire saw to which a motor control circuit for a wire saw according to the present invention is applied.

FIG. 2 is an explanatory diagram showing an example of a wire traveling pattern.

FIG. 3 is a configuration diagram showing an embodiment of a motor control circuit for a wire saw according to the present invention.

[Explanation of symbols]

 100 ... AC power supply 102 ... Servo driver 104 ... Drive motor 106A, B ... Relay contact 108A, B ... Relay contact 109 ... Resistor 110 ... DC stabilized power supply 112 ... Capacitor 114 ... Relay coil 116 ... Emergency stop circuit

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Shigeru Okubo 9-7 Shimorenjaku, Mitaka City, Tokyo Stock Company Tokyo Seimitsu Co., Ltd. (72) Inventor Yasuhiro Takahashi 9-7 Shimorenjaku, Mitaka City, Tokyo Stock Company In Tokyo Seimitsu (72) Inventor Satoru Matsubara, 318, Ishida, Isehara, Kanagawa 3 NES Engineering Co., Ltd. (72) Inventor, Atsushi Sekiyama, 318, Ishida, Isehara, Kanagawa

Claims (4)

[Claims] 1. A pair of wire reels is rotated by a motor to feed a wire from one wire reel of the pair of wire reels and a wire is wound on the other wire reel to run the wire and work. In a wire saw that presses against a wire row to cut the work into thin pieces, a power supply connected to the input terminal of the motor, a power supply abnormality detection unit for detecting an abnormality of the power supply, and a connection possible to the input terminal of the motor And a regenerative resistor that consumes regenerative power output from the motor when connected to the input terminal of the motor, and when an abnormality of the power supply is detected by the power supply abnormality detection means during operation of the wire saw. And a connecting means for connecting the regenerative resistor to the input terminal of the motor, Over of the motor control circuit. 2. When an emergency stop of running of the wire is instructed during operation of the wire saw, the connection means connects the regenerative resistor to the input terminal of the motor and disconnects the power supply from the motor. The motor control circuit for the wire saw according to claim 1. 3. The power supply abnormality detecting means comprises a direct current voltage generating means for generating a direct current voltage from the power source and a relay coil connected to the direct current voltage generating means, and the connecting means connects the relay coil to the relay coil. 2. The wire saw motor control circuit according to claim 1, further comprising a relay contact for connecting the regenerative resistor to an input terminal of the motor when current stops flowing. 4. The power supply abnormality detection means comprises a power supply voltage detection means for detecting the voltage of the power supply, and when the voltage detected by the power supply voltage detection means drops below a predetermined voltage, the power supply abnormality is detected. The wire saw motor control circuit according to claim 1, wherein: