JP2004074358A - Coolant filtering device of machine tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent early-stage clogging of a suction filter provided in an end part on a coolant tank side in a circulation passage. <P>SOLUTION: The suction filter 10 is attached to the tip of a pipe 9 connected to a suction port of a medium pressure pump 4 for sucking the coolant from the coolant tank 3. Chips removed from the filter when cleaning the filter provided in the circulation passage returning the coolant in the coolant tank 3 to a machine tool pass a drainage pipe 16 and are drained to the coolant tank 3. The opening in the tip of the drainage pipe 16 is oppositely disposed to the outer surface of the suction filter 10. The coolant drained from the tip of the drainage pipe 16 is discharged toward the outer surface of the suction filter 10. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a coolant filtering apparatus for a machine tool, which filters used coolant discharged from the machine tool and then returns the used coolant to the machine tool.
[0002]
[Problems to be solved by the invention]
Lathes, cutting machines, etc., have a coolant filtration device that collects the coolant used for cooling the tool, removes chips and chips contained in the coolant, and returns the coolant to the machine tool. Some are equipped with. The coolant filtration device includes a coolant tank that stores collected coolant, a pump that sucks coolant in the coolant tank, a suction filter that is provided at a suction port of the pump, and that removes relatively large chips and the like, and is suctioned by the pump. A return path for returning the coolant to the machine tool, a filtration filter provided at an intermediate portion of the return path for removing fine chips and the like in the coolant, and the like.
[0003]
Since the filtration filter is provided in the middle of the return path, cleaning work and replacement work when clogging is troublesome. Therefore, the coolant filtering device is provided with a backwashing mechanism for washing the filter by flowing a coolant through the filter in a reverse direction when the filter is clogged.
[0004]
On the other hand, the above-mentioned coolant filtration device usually does not have a special configuration for cleaning the suction filter. Therefore, when the suction filter is clogged, it is necessary to remove the suction filter from the suction port of the pump for cleaning or replacement. In particular, in the case of a coolant filtering device provided in a machine tool capable of producing a large amount of relatively large chips during processing, cleaning and replacement of the suction filter must be performed frequently, which is troublesome.
[0005]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a coolant filter for a machine tool capable of preventing early clogging of a suction filter provided at an end of a return path on a coolant tank side. It is to provide a device.
[0006]
[Means for Solving the Problems]
The coolant filtering apparatus for a machine tool according to claim 1 of the present invention includes a coolant tank that collects and stores used coolant discharged from the machine tool, a return path for returning coolant in the coolant tank to the machine tool, A filter provided in the return path for filtering coolant flowing in the return path toward the machine tool; a suction filter provided at an end of the return path on the coolant tank side; and Backwash means for washing the filtration filter by backflowing a coolant, and a discharge path for discharging the coolant that has flown back through the filtration filter to the coolant tank, wherein the discharge path is discharged from a tip end thereof. This is characterized in that the coolant is configured to flow toward the suction filter.
[0007]
According to the above configuration, the coolant that has flowed back through the filtration filter is discharged into the coolant tank through the discharge path. At this time, since the coolant is discharged from the tip of the discharge path toward the suction filter, chips attached to the suction filter are removed by the force.
[0008]
In this case, the suction filter may be formed in a hollow shape, and the tip of the discharge passage may be disposed to face the outer surface of the suction filter (the invention of claim 2).
[0009]
According to the above configuration, the coolant discharged from the discharge path at the time of back washing of the filtration filter directly hits the outer surface of the suction filter, and chips and the like adhering to the outer surface of the suction filter are scattered by the momentum.
[0010]
Further, the suction filter may be formed in a hollow shape, and the distal end of the discharge passage may be disposed inside the suction filter (claim 3).
[0011]
According to the above configuration, the coolant discharged from the discharge path when the filter is backwashed flows from the inside to the outside of the suction filter. That is, since the coolant flows in the suction filter in the reverse direction, chips or the like attached to the outer surface of the suction filter can be efficiently removed.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows an overall configuration of a coolant filtration device according to the present embodiment. In FIG. 1, a coolant filtration device 1 includes a coolant tank 3 that collects and stores used coolant discharged from a machine tool 2, and a medium-pressure pump 4 (a discharge pressure of 1.5 to 7.) That sucks up coolant in the coolant tank 3. 0 MPa), a first return pipe 5 connected to the discharge port 4 a of the intermediate pressure pump 4, and a second return pipe 7 connected to the first return pipe 5 via a filter device 6. .
[0013]
The machine tool 2 includes a main shaft (not shown), a motor 2a for driving the main shaft to rotate, and the like. Coolant is supplied to a hole passing through the inside of a tool 8 mounted on the main shaft. I have. Thereby, coolant is discharged from the tip of the tool 8 during machining. The coolant discharged from the tip of the tool 8 is recovered and stored in the coolant tank 3 through a recovery tank (not shown) provided at a lower portion of the machine tool 2.
[0014]
As shown in FIGS. 2 and 3, the coolant tank 3 includes a lid 3a for closing an upper opening of the coolant tank 3, and a medium-pressure pump 4 is mounted on the lid 3a (in FIG. 1, FIG. The description of the lid 3a is omitted). A pipe 9 connected to the suction port 4b of the medium pressure pump 4 extends through the lid 3a to the inside of the coolant tank 3. A cylindrical suction filter 10 is connected to the lower end of the pipe 9. The suction filter 10 is disposed substantially parallel to the bottom surface of the coolant tank 3.
[0015]
As shown in FIG. 1, the filter device 6 includes a housing 11 having a liquid inlet 11a, a liquid outlet 11b, and a liquid outlet 11c, and a hollow cylindrical filtration filter 12 housed in the housing 11. Have been. A space is formed between the outer peripheral surface of the filtration filter 12 and the housing 11, the liquid inlet 11a and the liquid outlet 11c communicate with the space, and the liquid outlet 11b communicates with the inside of the filtration filter 12. I have.
[0016]
The first and second reflux pipes 5 and 7 are connected to a liquid inlet 11a and a liquid outlet 11b of the housing 11, respectively. The first and second return pipes 5 and 7 are connected to a differential pressure switch 13 for detecting clogging of the filtration filter 12 based on the pressure of both. The end of the second return pipe 7 is connected to a through hole of the main shaft via a rotary joint 14 above the motor 2a. A valve A is attached to the second recirculation pipe 7 in front of the rotary joint 14, and an air source 15 is connected to the vicinity of the filter device 6 via a valve B.
[0017]
On the other hand, a drain pipe 16 (corresponding to a discharge path) is connected to the liquid discharge port 11c of the housing 11. A valve C is mounted in the middle of the drainage pipe 16. The lower end of the drainage pipe 16 is disposed inside the coolant tank 3. The distal end of the drainage pipe 16 located in the coolant tank 3 is configured to extend substantially parallel to the bottom surface of the coolant tank 3 and toward the outer peripheral surface of the suction filter 10 (FIGS. 2 and 5). 3). With the above configuration, the backwashed coolant discharged from the distal end opening of the drainage pipe 16 is directed to the outer peripheral surface of the suction filter 10.
[0018]
The operation of each part of the machine tool 2 and the operation of each part of the filter device 6 are configured to be controlled by a control device (not shown). The control device executes a work of machining a workpiece by the tool 8 mounted on the spindle, an exchange of the workpiece, an exchange of the tool 8, and the like based on a machining program stored in advance. Further, during machining by the machine tool 2, the coolant filtering device 1 is driven based on an operation signal input from the outside or a control program stored in advance, and after collecting and filtering the coolant discharged from the machine tool 2, the coolant is filtered again. Return to machine tool 2.
[0019]
That is, the control device drives the intermediate pressure pump 4 with the valve A opened and the valves B and C closed. Thereby, the coolant is sucked up from the coolant tank 3 through the pipe 9 by the pump action of the intermediate pressure pump 4. At this time, relatively large chips contained in the coolant are removed by the suction filter 10.
[0020]
The coolant drawn from the coolant tank 3 is pressure-fed through the first reflux pipe 5 toward the filter device 6 and flows into the housing 11 of the filter device 6 from the liquid inlet 11a. Thereafter, the liquid passes through the filter 12 from the outer surface toward the inner surface, and is returned from the liquid outlet 11b to the machine tool 2 through the second reflux pipe 7. At this time, relatively small chips contained in the coolant are removed by the filter 12. Therefore, in this embodiment, the pipe 9, the first and second return paths 5 and 7 function as return paths.
[0021]
Further, the control device executes a cleaning operation (backwash operation) of the filtration filter 12 according to a control program stored in advance at a predetermined timing set in advance (for example, during work replacement performed during a processing cycle). .
[0022]
That is, the driving of the intermediate pressure pump 4 is stopped, the valve A is closed, and the valve B is opened for 0.3 seconds while the valve C is opened. Thereby, pressurized air (pressure 0.4 to 0.6 MPa) from the air source 15 flows into the casing 11 through the liquid outlet 11b, and the coolant in the filter 12 is removed by the air pressure. 12 is ejected from the inside to the outside, that is, in the direction opposite to the path for returning the coolant from the coolant tank 3 to the machine tool 2. That is, in this embodiment, the air source 15 functions as a backwashing unit.
[0023]
As a result, chips and the like adhering to the filtration filter 12 are peeled off and fall into the space between the outer surface of the filtration filter 12 and the casing 11. Subsequently, the control device drives the medium pressure pump 4 and closes the valve B for 1.7 seconds. As a result, the coolant in the coolant tank 3 flows into the filter device 6 through the first return pipe 5, and passes through the drain pipe 16 from the liquid outlet 11 c together with chips and the like accumulated in the casing 11. To flow into the coolant tank 3.
[0024]
At this time, the coolant discharged from the distal end opening of the drainage pipe 16 is sprayed toward the outer surface of the suction filter 10. Therefore, relatively large chips attached to the suction filter 10 are removed by the force of the coolant discharged from the drainage pipe 16.
[0025]
In this embodiment, the valve A was provided before the rotary joint 14 and the valve A was closed during the backwashing operation. Therefore, even if the air discharged from the air source 15 remains in the second return pipe 7, it is possible to prevent the coolant in the main shaft and the tool 8 from being pushed out by the air and leaking from the tip of the tool 8.
[0026]
When the control device detects the clogging of the filtration filter 12 based on the output signal of the differential pressure switch 13, the control device notifies the fact. In this case, the user can operate the operation panel to perform the backwashing operation of the filtration filter 12.
[0027]
As described above, according to the present embodiment, every time the backwash operation of the filtration filter 12 is performed, the chips attached to the outer surface of the suction filter 10 are removed by the coolant discharged from the distal end opening of the drainage pipe 16. be able to. Therefore, the time for cleaning or replacing the suction filter 10 can be delayed.
[0028]
FIG. 4 shows a second embodiment of the present invention, and points different from the first embodiment will be described. The same parts as those in the first embodiment are denoted by the same reference numerals. That is, in the second embodiment, the drainage pipe 16 is inserted into the pipe 9 from an intermediate portion of the pipe 9, and the end is located inside the suction filter 10. Then, the coolant discharged from the distal end opening of the drainage pipe 16 is configured to be ejected from the inside to the outside of the suction filter 10.
[0029]
According to the above configuration, the coolant can pass through the suction filter 10 in the reverse direction, and chips and the like adhering to the outer surface of the suction filter 10 can be efficiently removed.
[0030]
【The invention's effect】
As is clear from the above description, in the coolant filtering apparatus for a machine tool of the present invention, every time the washing operation of the filtration filter provided in the return path for returning the coolant in the coolant tank to the machine tool is performed, the coolant is removed from the coolant tank. The discharged coolant can remove chips and the like attached to the outer surface of the suction filter provided at the end of the return path, so that the time for cleaning or replacing the suction filter can be delayed. it can.
[Brief description of the drawings]
FIG. 1 shows a first embodiment of the present invention, and is a schematic overall configuration diagram of a coolant filtering device for a machine tool. FIG. 2 shows a suction filter and a drainage pipe as viewed from the side of a pump. FIG. 3 is a diagram for explaining a positional relationship. FIG. 3 is a diagram for explaining a positional relationship between a suction filter and a drain pipe viewed from the front of the pump. FIG. 4 is a diagram showing a second embodiment of the present invention. 3 equivalent figure [Explanation of reference numerals]
In the drawing, 1 is a coolant filtration device, 2 is a machine tool, 3 is a coolant tank, 5 is a first return pipe (return path), 7 is a second return pipe (return path), and 9 is a pipe (return path). Reference numeral 10 denotes a suction filter, 12 denotes a filtration filter, 15 denotes an air source (backwash means), and 16 denotes a drain pipe (discharge path).

Claims (3)

A coolant tank for collecting and storing used coolant discharged from the machine tool,
A return path for returning the coolant in the coolant tank to the machine tool;
A filtration filter provided in the return path and filtering a coolant flowing in the return path toward the machine tool;
A suction filter provided at an end of the return path on the coolant tank side,
Backwashing means for washing the filtration filter by backflowing a coolant to the filtration filter,
A coolant filtration device for a machine tool, comprising: a discharge path for discharging the coolant flowing backward through the filtration filter to the coolant tank.
A coolant filtering device for a machine tool, wherein the discharge path is configured such that coolant discharged from a tip portion thereof is directed to the suction filter. The suction filter is hollow,
2. The coolant filtering device for a machine tool according to claim 1, wherein a distal end portion of the discharge path is disposed to face an outer surface of the suction filter. 3. The suction filter is hollow,
2. The coolant filtering device for a machine tool according to claim 1, wherein a distal end portion of the discharge path is disposed inside the suction filter. 3.

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