JPH10180750A - Slurry temperature control device in wire saw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slurry temperature control device having high temperature control efficiency in a wire saw which retains the temperature of slurry within a range of allowable temperatures. SOLUTION: A cooling water pipe 23 is arranged in a heat exchanger 19. A flow control valve 24 is provided outside the exchanger 19 and the flow rate or flow speed of cooling water flowing through the pipe 23 is controlled depending on the degree of opening of the valve 24. As a result, the heat exchange capacity of the exchanger 19 can be adjusted. A temperature sensor 25 is provided between the exchanger 19 and a group of slurry feed pipes 13. The sensor 25 senses the temperature of slurry S to output the data relating to the sensing temperature as a sensing signal SG. And a feedback control is conducted on the degree of opening of the valve 24 based on the signal SG in response to a command of a setting device 27.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for supplying a slurry to a running wire from a slurry tank storing a slurry composed of abrasive grains and a dispersion liquid, and cutting the workpiece based on the lapping action of the wire and the abrasive grains. In addition, the present invention relates to a wire saw for recovering the slurry supplied to the wire to the slurry tank and circulating and using the slurry, and particularly to a temperature control device for the slurry.

[0002]

2. Description of the Related Art Generally, a wire saw is provided with two to four rollers having a large number of grooves formed at a predetermined pitch. On these grooved rollers, the cutting wire fed from the pay-out reel is supported around the grooves at a predetermined pitch, and then wound and collected by the take-up reel. When the wire saw is activated, the grooved rollers
By synchronously rotating the payout reel and the take-up reel,
A cutting wire is run. Then, the slurry obtained by dispersing the abrasive grains in a water-based or oil-based dispersion liquid is supplied to the traveling wire to attach the abrasive grains to the wire surface, and the wire in this state has a columnar or prismatic shape. The work is pressed and the work is cut into a number of slices based on the lapping action of the abrasive grains. Then, a slurry circulation system is constructed in which the used slurry is collected in a slurry tank, and the collected slurry is resupplied to the wire.

At the time of cutting, the temperature of the slurry collected in the slurry tank due to heat or the like based on friction between the wire and the workpiece rises higher than before the supply to the wire. The temperature of the slurry also rises due to heat generated by a pump provided in the circulation path for circulating the slurry. When such a high-temperature slurry is directly supplied to a wire involved in cutting a work, the wire and the work thermally expand, and the cutting accuracy of the work is significantly reduced. Therefore, it is necessary to prevent the temperature of the slurry from rising when the slurry is recycled. For this purpose, there has been known an apparatus in which a cooling device is attached to a slurry tank in order to control the temperature of the slurry in the slurry tank. For example, Japanese Patent Application No. 8-99261 discloses a slurry temperature control system provided with such a cooling device.

According to the slurry temperature management system of this publication, as shown in FIG. 3, the slurry S whose temperature has increased after being supplied to the wire 50 is once collected in a slurry tank 52 via a collection pipe 51. . In the slurry tank 52, a cooling circulation pipe 5 separate from a circulation utilization system including a pump 56, a recovery pipe 51, and a supply pipe 58 is provided.
5 is attached. The slurry S is pumped by a pump 53 provided in a cooling circulation pipe 55 to a heat exchanger 54 provided above the slurry tank 52. In the heat exchanger 54, the heat of the slurry S is exchanged with cooling water flowing through the heat exchanger 54 to cool the slurry S. The cooled slurry S is supplied to the slurry tank 52 again.
Is returned to. Thus, the temperature of the slurry in the slurry tank 52 is maintained at a constant temperature that does not cause any inconvenience to the cutting accuracy of the wire 50.

[0005]

However, the above-mentioned conventional slurry temperature control system has the following problems.
First, the cooling device for the slurry S is a slurry tank 52
And the cooling of the entire slurry stored in the slurry tank 52 is employed. Therefore, it takes a long time to cool the slurry S, and the cooling efficiency is poor. Moreover, since the slurry S to be cooled is the entire slurry S in the slurry tank 52, the amount of the slurry is large and the temperature of the slurry cannot be finely adjusted in a short time. A large capacity cooling device was required.

Second, when the slurry is supplied from the slurry tank 52 to the wire 50 via the supply pipe 58,
Actually, it was difficult to keep the temperature of the slurry to which the wire 50 was supplied constant. That is, although the slurry recovered in the slurry tank 52 is once cooled by the heat exchanger 54, the temperature of the slurry rises due to heat generated by the pump 56 while passing through the supply pipe 58. I was holding it.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a slurry temperature control device for a wire saw which is excellent in temperature control efficiency while keeping the slurry temperature within an allowable temperature range. is there.

[0008]

In order to solve the above-mentioned problems, according to the first aspect of the present invention, a slurry containing abrasive grains and a dispersion liquid is transferred from a slurry tank to a wire running the slurry. Supply and cut the work based on the wrapping action of the wire and abrasive grains,
In a wire saw that collects the slurry supplied to the wire in the slurry tank and circulates and uses the slurry, a temperature adjusting means for adjusting the temperature of the slurry is provided in a slurry circulation path between the slurry tank and the wire. The gist is that it is provided.

In this wire saw, the temperature of the slurry moving through the circulation path is controlled by passing through the temperature control device. Therefore, even if the slurry is supplied to the wire and as a result, the temperature of the slurry tends to increase, the slurry is maintained at a desired temperature by the temperature control means provided on the slurry circulation path.

[0010] In the second aspect of the present invention, the temperature control means is provided in a supply pipe for transferring the slurry from the slurry tank toward the wire. For this reason, the temperature of only the required amount of slurry is adjusted as needed immediately before it is supplied to the wire. Therefore, the temperature of the slurry is efficiently adjusted.

In the invention described in claim 3, the temperature adjusting means adjusts a heat exchanger for performing heat exchange between the slurry and the refrigerant, and adjusts a supply amount of a heat exchange fluid to the heat exchanger. A flow control valve, and controls a valve opening of the flow control valve based on control information from an external control device.

According to this configuration, the heat exchange capacity of the heat exchanger can be variably adjusted based on external control information. Therefore, it is possible to optimize the temperature control of the slurry according to the situation.

In the invention described in claim 4, the temperature adjusting means further includes a temperature sensor provided on an outlet side of the heat exchanger, and the temperature sensor transmits a temperature detection signal as the control information. Output to the control device.

Therefore, since the heat exchange capacity of the heat exchanger is controlled based on the temperature information from the temperature sensor on the outlet side of the heat exchanger, the temperature of the slurry supplied to the wire is finely controlled.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. As shown in FIG. 1, a reel mechanism 3 having a cutting mechanism 2 and a traverse mechanism 4 is mounted on a wire saw machine base 1 and is positioned between the cutting mechanism 2 and the reel mechanism 3. A wire tension applying mechanism 5 is provided. A work support mechanism 6 is provided on the machine base 1 so as to be located above the cutting mechanism 2.

The cutting mechanism 2 includes three grooved rollers 7,
8 and 9 are provided. A number of annular grooves are formed on the outer circumference of each of the rollers 7, 8, 9 at a predetermined pitch. One cutting wire 10 made of steel wire is provided to the cutting mechanism 2 from the reel mechanism 3 via a traverse mechanism 4 and a wire tension applying mechanism 5. The cutting wire 10 is continuously and sequentially wound around each annular groove of each grooved roller 7, 8, 9. The grooved drive roller 7 is a servo motor (not shown)
, Whereby the wire 10 travels in one direction or two directions.

In the reel mechanism 3, the wire 10 is paid out from the pay-out reel 3a toward the cutting mechanism 2, and the wire 10 from the cutting mechanism 2 is taken up by a take-up reel (not shown). The traverse mechanism 4 guides the unwinding of the wire 10 from the unwinding reel 3a and the winding of the wire 10 onto the winding reel while traversing up and down. The wire tension applying mechanism 5 applies a predetermined tension to the wire 10 running between the rollers 7, 8, and 9. The work supporting mechanism 6 supports the work W so as to be able to move up and down, and presses the work W to a cutting position of the wire 10 running between the rollers 7 and 8. Examples of the work W include a semiconductor material, a magnetic material, and ceramic.

A slurry tank 11 is provided inside the machine base 1 and stores a slurry S in which abrasive grains are dispersed in a water-based or oil-based dispersion. Similarly, a waste slurry drum 12 is provided inside the machine base 1.

Each of the rollers 7, 8, 9 is connected to the front and rear frames 1
5 are arranged so as to form an inverted isosceles triangle. A slurry recovery mechanism 16 is disposed in the lower and inner regions of the wire 10 between the rollers 7, 8, and 9.

As shown in FIG. 2, a pair of slurry supply pipes 13 are provided above the cutting position of the wire 10 so as to sandwich the work W. These supply pipes 13 extend in a direction orthogonal to the traveling direction of the wire 10. In the lower part of each supply pipe 13, a hole or a groove for drop-supplying the slurry S on the running wire 10 in a screen shape is formed. These slurry supply pipes 13 are connected to the slurry tank 11 by slurry supply pipes 14.

The slurry tank 11 is connected to each slurry supply pipe 13 by a supply pipe 14. The pump 1 is connected to the supply pipe 14 from the slurry tank 11 side.
7, a first valve 18 and a heat exchanger 19 are provided. A discharge pipe 20 branches from the supply pipe 14 between the pump 17 and the first valve 18. The discharge pipe 20 is for guiding the slurry S in the slurry tank 11 to the waste slurry drum 12, and a second valve 21 and an integrating flow meter 22 are provided in the middle thereof. First valve 18 and second valve 21
Is opened and closed based on an external drive control signal. The integrating flow meter 22 detects the slurry S passing through the discharge pipe 20.
The total flow is measured.

By driving the pump 17 with the second valve 21 closed and the first valve 18 open, the slurry S in the slurry tank 11 is pumped up and the slurry S is supplied through the supply pipe 14. Each slurry supply pipe 13 can be supplied under pressure. vice versa,
By driving the pump 17 with the first valve 18 closed and the second valve 21 open, the required amount of slurry S in the slurry tank 11 is discharged to the waste slurry drum 12 via the discharge pipe 20. Can be.

The heat exchanger 1 is operated by the action of the pump 17.
The slurry S is transferred through the inside of the heat exchanger 9, and a cooling water pipe 23 for circulating cooling water supplied from outside is circulated in the heat exchanger 19. A flow control valve 24 is provided outside the heat exchanger 19 on the inlet side of the cooling water pipe 23. The flow rate control valve 24 changes the valve opening degree from 0% to 100% based on an external drive control signal.
Can be adjusted arbitrarily. Therefore, the speed of the cooling water flowing through the cooling water pipe 23 per unit time is controlled by the degree of opening of the flow control valve 24. As a result, the heat exchange capacity of the heat exchanger 19 (that is, the cooling capacity of the slurry S) is obtained. ) Can be variably adjusted.

A temperature sensor 25 is provided in the supply pipe 14 between the heat exchanger 19 and the group of slurry supply pipes 13. The temperature sensor 25 detects the temperature of the slurry S that is pressure-fed in the supply pipe 14 at the location, and outputs data relating to the detected temperature as an analog or digital detection signal SG.

The wire saw system according to the present embodiment has a control device 26 for controlling various controls relating to slurry management.
It has. The control device 26 includes a CPU, a ROM,
It is configured as a control unit incorporating a RAM and an input / output interface (both not shown). The control device 26 is connected to the temperature sensor 25 between the heat exchanger 19 and the supply pipe 13 to receive the detection signal SG, and is also connected to the integrating flow meter 22 and the setting device 27 to perform various operations. Is input.

The setting unit 27 is used by a wire saw operator (operator) to input various commands and control set values relating to wire saw control and slurry management.
Specifically, it is configured by various switches and buttons provided on the operation panel, a keyboard, and the like. Further, the control device 26 includes the pump 17, the first valve 18, the second valve 2
1 and a flow control valve 24, to which corresponding control signals are output.

When the wire saw is operated and the cutting mechanism 2 is operated based on the operation of the setting device 27 by the operator, the control device 26 starts the control for circulating the slurry S. That is, the control device 26 opens the first valve 18 while driving the pump 17 while closing the second valve 21. Then, the heat exchanger 1 is removed from the slurry tank 11.
9, supply pipe 14 and slurry supply pipe 1
3. The slurry is circulated such that the slurry is collected in the slurry tank 11 again through the slurry collecting mechanism 16 and the collecting pipe 28. When the slurry S is recycled, the work W
The slurry temperature tends to increase due to frictional heat of cutting and the like.

The controller 26 can detect the temperature of the circulating slurry S based on the detected temperature information from the temperature sensor 25. For this reason, the controller 26 controls the opening degree of the flow control valve 24 so that the temperature of the slurry remains within the allowable range. More specifically, as the temperature of the slurry S approaches the upper limit of the allowable range, the valve opening of the flow control valve 24 is increased to increase the cooling capacity of the heat exchanger 19, thereby preventing the slurry temperature from rising. As the temperature of the slurry S approaches the lower limit of the allowable range, the valve opening of the diversion control valve 24 is reduced, and the cooling capacity of the heat exchanger 19 is reduced.
Thus, the temperature of the slurry S supplied to the running wire is always kept within an allowable range.

With the end of the cutting operation by the cutting mechanism 2,
The control device 26 narrows the valve opening of the flow control valve 24 and stops the drive of the pump 17 to stop the supply and circulation of the slurry S.

The cutting ability of the slurry S used for a certain period of time is reduced due to the crushing of the abrasive grains and the increase of the chips of the work W. At this time, when the discharge of the slurry S in the slurry tank 11 is instructed based on the operation of the setting device 27 by the operator, the control device 26 closes the first valve 18 and opens the second valve 21 while the pump 17 Drive again. Then, the discharge transfer of the slurry S from the slurry tank 11 to the waste slurry drum 12 via the discharge pipe 20 is started. When the driving of the pump 17 is started, the integrating flow meter 22 starts the integrated measuring of the amount of the passing slurry.
Data on the integrated slurry amount is provided from the integrated flow meter 22 to the control device 26. When the integrated slurry amount reaches the set slurry amount (for example, 50 liters) set by the setting device 27, the control device 26 stops driving the pump 17 and stops discharging the slurry S from the slurry tank 11. Thus, the amount of slurry S intended by the operator is transferred from the slurry tank 11 to the waste slurry drum 12.
Automatically discharged to Thereafter, the newly prepared slurry S is replenished into the slurry tank 11 as needed. Thereby, the cutting ability of the slurry S is regenerated.

The characteristic effects of this embodiment are as follows. (A) The slurry S, whose temperature is increasing, is cooled by passing through a heat exchanger 19 provided in the piping 14 for supplying the slurry S. Therefore, the slurry S can be maintained at a desired temperature, and the slurry S can be supplied to the wire 10. Further, since only the required amount of the slurry S can be temperature-adjusted immediately before being supplied to the wire 10, the temperature of the slurry S can be efficiently adjusted and the capacity of the cooling device can be reduced.

(B) The heat exchange capacity of the heat exchanger 19 can be variably adjusted based on external control information. Therefore, the temperature control of the slurry S can be optimized according to the situation.

(C) Since the heat exchange capacity of the heat exchanger 19 is controlled based on the temperature information from the temperature sensor 25 on the outlet side of the heat exchanger 19, the temperature of the slurry S supplied to the wire 10 can be finely adjusted. Can control.

(D) The slurry S having passed through the heat exchanger 19 is immediately supplied to the wire 10 involved in cutting.
For this reason, it is possible to prevent the temperature of the slurry S from becoming high and maintain the cutting accuracy of the work W at a high level.

(E) Since the slurry S stored in the slurry tank 11 is not cooled, the temperature of the slurry S in the slurry tank 11 becomes high. For this reason,
At the time of stirring the slurry in the slurry tank 11, the viscosity of the slurry S decreases, so that the efficiency of stirring can be improved.

(F) When the slurry S is to be replaced, the slurry S stored in the slurry tank 11 may be moved to the waste slurry drum 12 via the discharge pipe 20. Therefore, it is not necessary to replace the slurry S by removing it from the slurry tank 11, and the replacement of the slurry S can be completed easily and in a short time.

This embodiment can be embodied with the following modifications. (1) A temperature sensor is also arranged in the middle of the cooling water pipe 23 in FIG. 2, and temperature data of the cooling water is also provided to the control device 26. In this case, a control program can be set to perform feedback control of the opening degree of the flow control valve 24 while considering the temperature difference between the slurry temperature and the cooling water temperature, so that more appropriate slurry temperature control can be performed. Become.

(2) The task of controlling the temperature in the heat exchanger 19 is not only to prevent the temperature of the slurry S from becoming high, but also to keep the temperature of the slurry S from deviating from an allowable range. Therefore, the heat exchange fluid is hot water (or hot water)
Then, the heat exchanger 19 may heat the slurry S that has been cooled too much. In this case, the excessively cooled slurry S may hinder smooth flow in the pipe and cause trouble (clogging of the pipe, etc.), so that such trouble can be prevented.

(3) The discharge pipe 20 connected to the supply pipe 14 may be omitted. With this configuration,
(A), (b), (c), (d),
The same effect as (e) can be obtained, and the overall size of the wire saw can be reduced.

Incidentally, the control information in this embodiment is a general term for data required for adjusting the slurry temperature, for example, temperature data provided as a signal SG.

[0041]

As described above in detail, according to the inventions described in the claims, the temperature of the slurry that can be circulated is adjusted by the heat exchanger provided in the supply pipe. For this reason, the slurry can be maintained at a desired temperature, and the temperature of the slurry can be efficiently adjusted even with a small-capacity temperature adjusting device. Further, since the slurry that has passed through the heat exchanger is immediately supplied to the wire involved in cutting, it is possible to prevent the temperature of the slurry from becoming high and maintain the cutting accuracy of the work at a high level.

[Brief description of the drawings]

FIG. 1 is a front view showing the entire configuration of a wire saw.

FIG. 2 is a diagram showing an outline of a slurry circulation and temperature management system.

FIG. 3 is a diagram showing an outline of a conventional slurry temperature management system.

[Explanation of symbols]

Reference numeral 10: wire, 11: slurry tank, 13: slurry supply pipe, 14: supply pipe, 19: heat exchanger, 24
... Flow control valve, 25 ... Temperature sensor, 26 ... Control device, S
... Slurry, W ... Work, SG ... Control information.

Claims (4)

[Claims] The slurry is supplied to a traveling wire from a slurry tank storing a slurry composed of abrasive grains and a dispersion liquid, and the workpiece is cut based on a lapping action between the wire and the abrasive grains, and the wire is cut. In a wire saw for recycling the slurry by collecting the supplied slurry in the slurry tank, a temperature adjusting means for adjusting the temperature of the slurry is provided in a slurry circulation path between the slurry tank and the wire. A slurry temperature controller for a wire saw. 2. The wire saw according to claim 1, wherein the temperature adjusting means is provided near a slurry supply pipe in a supply pipe for transferring the slurry from the slurry tank toward the wire. Slurry temperature controller. 3. The temperature control means includes a heat exchanger for performing heat exchange between the slurry and a heat exchange fluid, and a flow control valve for controlling a supply amount of the heat exchange fluid to the heat exchanger. 3. The slurry temperature adjusting device for a wire saw according to claim 1, wherein the valve opening of the flow control valve is controlled based on control information from an external device. 4. The temperature control means further includes a temperature sensor provided on an outlet side of the heat exchanger, and the temperature sensor outputs a temperature detection signal as the control information to the control device. 4. A slurry temperature controller for a wire saw according to 3.