JP3324940B2 - Wire saw - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire saw for cutting a brittle material such as a semiconductor material, a magnetic material, and a ceramic with a wire, and more particularly to controlling a cutting feed amount at the time of cutting.

[0002]

2. Description of the Related Art In a wire saw, a cutting wire is wound at a predetermined pitch between a plurality of processing rollers, and the wire runs in an extending direction with the rotation of the processing roller, and a slurry containing abrasive grains is formed on the wire. Supplied. In this state, the work is pressed against the wire, and the work is simultaneously cut into a plurality of wafers by the lapping action of the abrasive grains.

[0003]

However, even when the running direction of the wire is reversed, the cutting and feeding of the work is continued. For this reason, the rising load of the motor that drives the wire running increases. Therefore, a large-capacity motor is required as the motor, and accordingly, the entire apparatus has been increased in size. In addition, the frictional force acting on the wire at the start of the reverse running increases, and the load on the wire is large, and the wire may be deformed or disconnected.

[0004] The present invention has been made by focusing on such problems existing in the prior art. An object of the present invention is to provide a wire saw capable of reducing loads on a wire traveling drive motor and a processing wire.

[0005]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a wire saw for reducing a pressing force of a work against a wire when the wire traveling direction is reversed. From the wire
It is provided with control means for moving in the direction in which it is separated .

[0006] In the invention of the wire saw according to claim 2, the wire saw
When pressing the work against the wire when the running direction is reversed
As the cutting length of the workpiece increases to reduce
Thus, control means for reducing the wire traveling speed is provided .

[0007]

[0008]

Therefore, according to the first aspect of the invention, the load on the motor for driving the wire running can be reduced when the wire running direction is reversed. According to the second aspect of the present invention, it is possible to reduce the resistance applied to the wire at the time of wire running reversal, and to suppress the risk of wire breakage.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS.

As shown in FIGS. 1 and 2, a cutting mechanism 1 is mounted on a frame 2 and has one driving working roller 3 and two driven working rollers 4 arranged in parallel with each other.
5 is provided. A large number of annular grooves 3a, 4a, 5a are formed at a predetermined pitch on the outer periphery of each processing roller 3, 4, 5.

One cutting wire 6 made of a steel wire is continuously wound around each of the annular grooves 3a, 4a and 5a of each of the processing rollers 3, 4 and 5. The drive processing roller 3 is directly rotated by the main roller motor 7 and the rollers 4 and 5 rotate with the running force of the wire 6, whereby the wire 6 rotates the respective processing rollers 3, 4 and 5. The vehicle is driven stepwise in the extension direction with reversal.

The work support mechanism 9 is supported by a column 30 on the frame 2 above and below the cutting mechanism 1 so as to be vertically movable, and a work 10 is detachably set below the work support mechanism 9. The work elevating motor 11 is arranged on a column 30, and the work supporting mechanism 9 is vertically moved by the work elevating motor 11 via a ball screw or the like (not shown). The pair of slurry supply pipes 12 are supported on the frame 2 so as to be located slightly above the wires 6 in the cutting mechanism 1, and extend in a direction perpendicular to the running direction of the wires 6.

Then, while the wire 6 is running, the work supporting mechanism 9 is lowered toward the cutting mechanism 1. At this time, the slurry containing abrasive grains falls from the slurry supply pipe 12 onto the wire 6 between the processing rollers 3 and 5 and is supplied on the wire 6 in a screen shape. The work 10 is pressed, and the work 10 is sliced by the lapping action so that the work 10 is simultaneously made into a large number of thin pieces.

The reel mechanism 13 is mounted on the frame 2 and includes a pay-out reel 14 for feeding out the wire 6 and a take-up reel 15 for winding up the wire 6. The reel motors 16 and 17 are disposed on the frame 2, and the reel motors 16 and 17 are used to control both reels 1 and 2.
4 and 15 are directly rotated, whereby the wire 6 is unwound from the pay-out reel 14 and simultaneously wound up on the take-up reel 15. The traverse mechanism 18 is mounted on the frame 2 adjacent to the reel mechanism 13 and guides the feeding of the wire 6 from the feeding reel 14 and the winding of the wire 6 to the take-up reel 15 while traversing. The tension applying mechanism 19 for the wire 6 is connected to the reel mechanism 13.
Weight mounted on the frame 2 and positioned on the dancer arm 20 so as to be located between the
Thus, a predetermined tension is applied to the wire 6 between the processing rollers 3, 4, and 5.

As shown in FIG. 2, a control device 24 is disposed close to the rear of the frame 2, and a control panel 25 having various operation keys and a display unit is disposed on the front surface thereof. The keyboard 26 is arranged on the control panel 25, on which a number of input keys 27 are arranged.

As shown in the circuit diagram of FIG. 3, a central processing unit (CPU) 28 and a memory 29 are mounted inside the control device 24. This CPU 28 controls the operation of the entire apparatus. The memory 29 stores an operation program for controlling the operation of the apparatus, and also temporarily stores various input data and detection data. In this example,
The memory 29 stores, for example, data relating to the rotation speed of the motor 7 for driving the processing rollers 3 to 5 and the rotation speed of the work elevating motor 11, and also stores various operation programs. Then, from an input key 27 on the keyboard 26 to the CPU 28,
The size, shape, and material of the work 10, the rotation speed of the roller motor 7, and the rotation speed of the work lifting motor 11 are input and stored in the memory 29.

When the workpiece 10 is cut, the work supporting mechanism 9 is lowered toward the cutting mechanism 1 while the wire 6 is running between the processing rollers 3, 4, and 5 of the cutting mechanism 1. Is pressed against the workpiece 10. At this time, a slurry including abrasive grains is supplied from the slurry supply pipe 12 onto the wire 6, and the work 10 is sliced. As shown in FIG. 4, during this cutting,
The work 10 is pressed against the wire 6, and the wire 6 bends downward.

Next, as shown in FIG. 5, the relationship between the work feed amount and the travel of the wire 6 between the processing rollers 3 to 5 will be described with a graph. The wire 6 is rotated in one direction while accelerating to a certain speed range based on the operation program (t1), and when reaching the speed range, runs at a constant speed for a certain time (t2). Next, the traveling speed is reduced and stopped (t3). When the running speed becomes 0, the running direction is reversed, accelerated (t4), reaches the constant speed running range (t5), and then shifts to deceleration (t6). The above operation constitutes one cycle, and is thereafter repeated until the operation is stopped in this cycle.

On the other hand, when the wire 6 is accelerating, the workpiece 10 maintains the fixed position (t1). When the wire 6 moves to the constant speed traveling, the work 10 is lowered (t2). During the deceleration until the traveling direction of the wire 6 is reversed, the work 10 is stopped (decelerated as necessary) or / and slightly raised (t3). When the wire 6 is accelerated in the reversed direction, the work 10 is stopped. Is stopped (t4), and when the wire 6 shifts to the constant speed traveling, the work 10 is lowered (t5), and while the wire 6 is decelerating, the work 10 is stopped or / and raised (t6). . The above operation constitutes one cycle, and this cycle is thereafter repeated until the operation is stopped. The control shown in FIG. 5 described above is performed based on a signal from a time counter (not shown) in the control device 24.

As described above, the workpiece 10 is cut and fed when the wire 6 is traveling at a constant speed, and is stopped (decelerated as necessary) or / and slightly raised from deceleration to stop of the wire 6, and the wire 6 is moved up. Stopped when accelerating. For example, when the cross section of the work 10 is circular, as the cutting of the work 10 proceeds to the center of the work 10, that is, as the cutting length of the work 10 increases, the two-dot chain line (L1) in FIG. As shown by, the constant traveling speed of the wire 6 is reduced. For this reason, even if the cutting length increases, efficient cutting can be maintained by controlling the wire load so as not to be excessive. Incidentally, the control of the constant traveling speed is performed by detecting an inrush current of the motor 7. That is, since the cutting length increases toward the center of the work 10, the cutting resistance increases, and the load on the motor 7 that drives the traveling of the wire 6 increases. For this reason, the value of the inrush current at the time of the reversal of the wire 6 increases, and the constant speed traveling speed is selected according to the value of the inrush current.

According to the present embodiment configured as described above, the following effects can be obtained. (A) When the traveling direction of the wire 6 is reversed, the work 10
Is raised, the frictional resistance between the wire 6 and the work 10 is reduced. Therefore, the load at the start of rotation of the motor 7 is reduced, so that the life of the motor 7 can be extended and a motor having a small output can be used.

(B) When the running direction of the wire 6 is reversed, the load on the wire 6 is reduced, and the disconnection rate can be reduced. (C) Since the resistance between the wire 6 and the work 10 is reduced, the time required for accelerating the wire 6 to run at a constant speed is reduced, so that a substantial cutting time can be effectively secured and the cutting efficiency is improved. it can.

(D) The running speed of the wire 6 is changed in accordance with the cutting length, and control is performed so that the load on the wire does not become excessive. The present invention can be embodied with the following modifications.

(1) As shown by a two-dot chain line (L2) in FIG. 5, the workpiece feed is stopped when the traveling direction of the wire 6 is reversed. (2) As shown by a two-dot chain line (L3) in FIG.
The work feed is stopped only when the running direction is reversed.

(3) As shown by a two-dot chain line (L4) in FIG. 5, when the wire 6 reaches a constant speed, the descent speed of the work is reduced until just before the cut end of the work comes into contact with the wire again. Set higher than the cutting feed speed. (Cutting starts at the re-contact point earlier than S1, S2... S1 ', S2'.) (4) The work feed speed is reduced when the running direction of the wire 6 is reversed.

(5) According to the present invention, the rollers 3 to 5
The embodiment is embodied in a wire saw that is moved so that cutting and feeding can be performed.

[0028]

As described above, according to the present invention, the following excellent effects can be obtained. According to the first aspect of the present invention, the load on both the wire and the roller drive motor is reduced when the wire running direction is reversed, so that the wire breakage rate is reduced and a motor having a small output is used. Can be achieved, the size can be reduced, and the cost can be reduced.

According to the second aspect of the present invention, even if the cut length of the workpiece changes, the processing accuracy can be improved by controlling the load on the wire so as not to be excessive.

[Brief description of the drawings]

FIG. 1 is a front view showing a wire saw according to an embodiment.

FIG. 2 is a plan view of the wire saw according to the embodiment;

FIG. 3 is a circuit configuration diagram of an embodiment.

FIG. 4 is a partially enlarged cross-sectional view showing a processed part in the middle of cutting.

FIG. 5 is a graph showing a relationship between a work feed amount and a wire traveling speed.

[Description of Signs] 1 ... cutting mechanism, 2 ... frame, 3 ... roller for drive processing,
4, 5: driven working roller, 6: cutting wire, 7: main roller motor, 9: work supporting mechanism, 10: work, 11: work elevating motor, 12: slurry supply pipe, 13: reel mechanism, 14 … Payout reel, 15…
Take-up reel, 16, 17 ... reel motor, 18 traverse mechanism, 19 ... tension applying mechanism, 20 ... dancer arm, 21 ... weight, 22, 23 ... guide roller, 24
... Control device, 25 ... Control panel, 26 ... Keyboard, 2
7 ... key, 28 ... CPU, 29 ... memory, 30 ... column.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-9-66522 (JP, A) JP-A-9-70823 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B28D 5/04 B24B 27/06

Claims (2)

(57) [Claims] 1. A method in which a wire wound between a plurality of processing rollers travels, the traveling direction is periodically reversed, and a workpiece is pressed while supplying a slurry containing abrasive grains to the wire. In a wire saw configured to cut the work, the wire saw is used to reduce the pressing force of the work against the wire when the wire traveling direction is reversed.
A wire saw provided with control means for moving a workpiece in a direction away from a wire. 2. A method according to claim 1, wherein said plurality of processing rollers are wound.
Run the wire and periodically change its running direction.
Turn over and supply slurry containing abrasive grains to the wire
Press the work while cutting it
Pressing the work against the wire when reversing the wire running direction
To increase the cutting length of the workpiece to reduce the force
Control means to reduce the wire running speed
Girder wire saw.