JP3411849B2 - Wire saw processing liquid supply device - Google Patents

Description

BACKGROUND OF THE INVENTION [0001] [Technical Field of the Invention The present invention relates to working-fluid supply device of a wire saw that as working fluid such as slurry is supplied to the pressing coated portion by the pump drive It is. 2. Description of the Related Art Generally, in a wire saw in which a workpiece made of ingot is cut into a wafer,
While the wire is running, an aqueous or oily slurry containing loose abrasive grains is supplied onto the wire, and in this state, the work is pressed against the wire and is brought into contact with the wire to cut the work. At this time, the slurry is supplied by a pump, and loose abrasive grains contained in the slurry wear the impeller of the pump. When the impeller wear progresses to a certain degree or more, even if the impeller rotation speed is increased,
Predetermined slurry flow cannot be maintained. [0003] On the other hand, the pump is controlled by an inverter so that the slurry flow rate is constant.
It is also conceivable to have the speed adjusted automatically. However, in this case, since the slurry flow rate is kept constant, the impeller wear degree is not apparent. As the impeller wear progresses, there is a possibility that the slurry flow rate suddenly decreases. In such a case, for example, in a wire saw,
The processing accuracy before and after the change in the slurry flow rate will be different, and even a defective product may be produced.
In order to avoid this, regular inspection of the impeller part is indispensable, but since the impeller part is arranged in the slurry flow path, inspection work involving disassembly of the pump is troublesome. Met. The present invention has been made by paying attention to such problems existing in the prior art. An object of the present invention is to provide a wire saw machining fluid supply device capable of confirming the impeller replacement time in advance without disassembling the pump. [0005] In order to achieve the above object, according to the first aspect of the present invention, a processing fluid is supplied to a processing section by driving a supply pump. in the device, a detection means for detecting a variation in the load acting on the front Symbol feed pump, the detection means, the supply Pont
To detect the flow rate of machining fluid supplied from the pump to the machining section
A detecting unit for detecting the load fluctuation,
The flow rate of the machining fluid is determined quantitatively according to the detection result from the detector.
To control the impeller speed of the feed pump
A speed controller is provided, and the frequency of this speed controller is
Exceeding the warning value previously determined will result in impeller wear
However, the gist is that display means for displaying a warning is provided. Therefore, in order to maintain uniform processing accuracy,
In addition, the supply flow rate of the working fluid can be kept constant. Further
Then, the load acting on the pump fluctuates according to the degree of wear of the impeller, and the fluctuation is detected by the detecting means. Then, according to the detection result, the degree of wear of the impeller can be easily and always confirmed by the display means. [0007] [0008] [0009] [0010] DETAILED DESCRIPTION OF THE INVENTION Hereinafter, embodiments ingredients embody the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, in a wire saw in which a workpiece 12 is cut into a wafer, a slurry as a working fluid is supplied from a slurry supply pipe 13 onto the wire 11 while the wire 11 is running. You. In this state, the work 12 is pressed into contact with the wire 11, and the work 12 is cut into a slice. The slurry is a mixture of an oily or aqueous dispersion and abrasive grains. The slurry storage tank 14 stores slurry therein, and the slurry storage tank 14 and the slurry supply pipe 13 are connected by a supply pipe 15. The slurry collection tank 16 is disposed below the wire 11, and is connected between the slurry collection tank 16 and the slurry storage tank 14 by a collection pipe 17. The recovery pump 18 is disposed in the recovery pipe line 17, and the slurry dropped from the wire 11 into the slurry recovery tank 16 is moved to the slurry storage tank 14 via the recovery pipe line 17 by the operation of the recovery pump 18. Will be returned. In this way, the slurry is supplied in the slurry supply device in the direction of the arrow in the figure. The supply pump 19 is connected to the slurry storage tank 14.
The slurry in the slurry storage tank 14, which is disposed in the nearby supply pipe 15 and is operated by the supply pump 19,
The slurry is supplied from the slurry supply pipe 13 onto the wire 11 of the wire saw via the supply pipe 15. The heat exchanger 20 is arranged downstream of the supply pump 19. And the slurry is heat exchanger 2
Cooled to zero and maintained at a constant temperature. The slurry return mechanism 22 is disposed at the highest position in the slurry supply device as shown in FIG. 2 and is connected to the supply pipe line 15 via a branch pipe 21 via a cylinder valve 23. The cylinder case 25 of the cylinder valve 23 is provided with a cylindrical cylinder chamber 25 opened downward. A port 26 is connected to the cylinder chamber 25 so as to communicate with the lower end of the cylinder chamber 25. A piston-shaped valve 27 is provided in the cylinder chamber 25, and the valve 27 faces a valve seat 28 to open and close a port 26. On the side surface of the valve case 24, two ports 29, 30 are vertically arranged with a valve body 27 interposed therebetween so as to communicate with the cylinder chamber 25. The two ports 29 and 30 are connected to the air supply source 31 by the switching valve 3.
2 respectively. In the slurry return mechanism 22, when the wire saw is operated, the switching valve 32 is at one of the switching positions, compressed air is being sent from the air supply source 31 to the port 29, and the valve seat 28 is shown in FIG. Port 26 is closed at the position where Thereby, the slurry is supplied to the supply piping 15
The slurry is sent out inside the slurry supply pipe 13 without flowing out to the slurry return mechanism 22. On the other hand, when the slurry staying in the supply pipe line 15 is returned to the slurry storage tank 14 or the slurry recovery tank 16 when the wire saw is not operated, the switching valve 32 is switched to the other position, and By sending compressed air from the air supply source 31, the valve seat 2
8 is moved upward from the position shown in FIG. 2 and port 26 is opened. As a result, the compressed air is sent into the supply pipes 15 on both sides through the branch pipe 21, and the compressed air is supplied into the supply pipes 15 and the heat exchanger 20.
The slurry staying in the inside is returned to the slurry storage tank 14 or the slurry recovery tank 16, and the slurry is prevented from staying in the supply pipe 15 and the heat exchanger 20. A flow meter 33 serving as a detection unit is disposed downstream of the heat exchanger 20 in the supply pipe 15, and the flow rate of the slurry flowing through the supply pipe 15 is detected by the flow meter 33. The detected slurry flow rate is converted into a voltage value and sent to an inverter 34 as a speed control device. After this voltage value is processed by the inverter 34, the frequency is converted and output to a motor (not shown) of the supply pump 19, so that the impeller rotation speed of the supply pump 19 is controlled. Thus, the slurry flow rate detected by the flow meter 33 is fed back to the supply pump 19 via the inverter 34, and the slurry supply pipe 1
The slurry amount supplied from 3 is kept at a predetermined amount. A display 35 as a display means is connected to the inverter 34. And the inverter 34
When the frequency exceeds a warning value determined in advance, the degree of impeller wear is displayed as a warning. Next, the operation of the slurry supply device configured as described above will be described. As shown in FIG. 1, when cutting the work 12 with a wire saw, a slurry is supplied to the wire 11 from a slurry supply pipe 13. At this time, the slurry is sucked up from the slurry storage tank 14 by the supply pump 19 and sent out to the heat exchanger 20. Heat exchanger 2
After being cooled to a predetermined temperature in the heat exchanger 20, the slurry sent to 0 is supplied through the supply pipe line 15, through the flow meter 33, from the slurry supply pipe 13 onto the wire 11. The slurry supplied from the slurry supply pipe 13 is once collected in a slurry collection tank 16 and collected by a collection pump 18.
Is returned to the slurry storage tank 14. After the cutting of the workpiece 12 is completed, the recovery pump 18 and the supply pump 19 are stopped, and the air supply source 31 switches the switching valve 32 from the air supply source 31 to the cylinder chamber 25 of the slurry return mechanism 22 shown in FIG. Compressed air is delivered to port 30 by operation. This compressed air is sent from the port 26 through the branch pipe 21 into the supply pipe 15, and the slurry that has accumulated in the supply pipe 15 is returned to the slurry storage tank 14 or the slurry recovery tank 16. . During the circulation of the slurry such as the cutting of the work 12, the flow rate of the slurry flowing through the supply pipe 15 is detected by the flow meter 33. Then, using the detected value as an input, the impeller rotation speed of the supply pump 19 is controlled by the inverter 34, and the slurry flow rate is maintained at a predetermined amount. By monitoring the frequency change of the inverter 34, the degree of wear of the impeller in the supply pump 19 can be confirmed. That is, for example, 1 per minute
When the slurry of 00 liter is supplied from the supply pipe 13, the frequency of the inverter 34 with respect to the load acting on the supply pump 19 at the start of use of the impeller indicates 40 Hz. The time when the frequency exceeds 60 Hz is defined as the impeller replacement time. When the degree of wear of the impeller of the supply pump 19 progresses, and the frequency of the inverter 34 necessary for the quantitative supply of the slurry gradually increases to increase the rotation speed of the supply pump 19, and exceeds 60 Hz. At the same time, a signal is output to the display 35, and the warning display is performed. Here, the effects exerted by the first embodiment will be described. (1) In this embodiment, since the display 35 is provided as a display unit for indicating the degree of impeller wear,
The degree of impeller wear can be constantly checked without requiring any inspection work such as disassembling the supply pump 19. Therefore, it is not necessary to check the degree of wear of the impeller, and it is possible to avoid an unexpected situation where the slurry flow rate changes and the machining accuracy differs. (2) In the present embodiment, by detecting the slurry supply flow rate by the flow meter 33, the control of the supply pump 19 and the confirmation of the impeller wear degree can be performed at the same time via the inverter 34. (3) In the present embodiment, a slurry return mechanism 22 is provided. Therefore, when the cutting process is completed, the slurry staying in the supply pipe 15 and the heat exchanger 20 can be easily returned to the slurry tanks 14 and 16 in a short time. Therefore, it is possible to prevent the slurry from accumulating in the supply pipe 15 and the heat exchanger 20. (4) In this embodiment, since the inverter 34 as a speed control device also serves as a control means for the slurry flow rate, the structure of the working fluid supply device can be simplified. The above embodiment can be modified as follows. In the above embodiment, as shown in FIG. 3, a slurry supply system passing through the work processing section and a slurry supply system passing through the heat exchanger 20 are separately provided. In this case, the slurry return mechanism 22 is also provided separately for each system. The present invention is configured as described above, and has the following effects. According to the first aspect of the present invention, in order to maintain uniform processing accuracy, a processing liquid
Can be maintained at a constant flow rate. Furthermore, since the display means for indicating the impeller wear degree is provided, the impeller wear degree can always be easily checked. [0034]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a slurry supply device of the present embodiment. FIG. 2 is a sectional view showing a slurry return mechanism. FIG. 3 is a diagram showing a slurry supply device according to another embodiment. [Description of References] 19, 42: slurry supply pump, 22: slurry return mechanism, 33: flow meter, 34: inverter, 35: display.

Claims (1)

(57) [Claims] 1. A working fluid is driven by a supply pump to cause a working fluid to flow.
In the machining fluid supply device that is supplied to the, Previous Detection means for detecting fluctuations in the load acting on the supply pump
StepWith That Detection meansIs supplied to the processing unit from the supply pump.
ToDetecting the flow rate of machining fluidThe fluctuation of the load
To detectA detection unit forthisTo the detection result from the detector
Depending onSo that the flow rate of machining fluid is constantSupply pump b
A speed control device for controlling the impeller speed., The frequency of this speed controllerExceeds a predetermined warning value
WhenImpeller wearwarningIs displayeddisplay
Of the wire saw with the meansProcessing fluid supply device.