JPH0650115Y2 - Coolant filtering device for machine tools - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coolant filtering device used in a machine tool capable of performing wet processing on various materials such as graphite, ceramics, bakelite and other resins in addition to metals.

[0002]

2. Description of the Related Art In the case of wet processing with a machine tool, it is generally equipped with a coolant filtering device to filter the used coolant once, remove foreign particles such as chips contained in the coolant, and reuse the coolant. Is. As a coolant filtering device used, it is necessary to remove foreign particles having a diameter as small as possible to maintain the quality of the coolant. Therefore, the applicant of the present application has proposed, as Japanese Patent Application No. 61-111201, a coolant filtering device that uses a centrifugal separator. This is because the centrifugal separator can separate and remove fine chips discharged from the coolant by processing graphite or the like due to the difference in specific gravity.

[0003]

By the way, when a centrifugal separator is used for filtering the coolant as described above, foreign matter such as cutting chips can be effectively removed from the coolant, but Since the foreign substances such as the cut chips are sequentially accumulated in the centrifugal separator, the centrifugal separator must be stopped and the accumulated foreign substances must be removed when the accumulated amount reaches a certain amount. Therefore, there is a problem that the operation of the machine tool is interrupted during that time. The present invention has been made to solve the above problems, and an object of the present invention is to provide a coolant filtering device for a machine tool capable of continuously performing a machining operation without interrupting wet machining. It is in.

[0004]

In order to achieve the above object, the present invention switches the outflow destination of the coolant containing foreign particles such as chips discharged from the machining portion of the machine tool to either of two systems. A switching unit, a first tank connected to one system of the switching unit and storing a coolant containing inflowing foreign particles, and a first tank pumping up the coolant stored in the first tank and containing foreign particles. The pump and the coolant containing foreign particles that are pumped from the first pump are taken in from the inlet on the side surface of the main body to separate the coolant and the foreign particles suspended in the coolant, and to remove the foreign particles that partially contain the coolant. The cyclone, which discharges the coolant from which the foreign particles are mostly removed from the lower outlet, is discharged from the upper outlet, and the foreign particles which are discharged from the lower outlet of the cyclone, The foreign matter particle collection tank that stores and overflows the coolant that has separated upward during storage and returns it to the first tank, and the coolant that has been discharged from the upper outlet of the cyclone is branched into multiple systems, and an on-off valve for each system Is supported by inserting the manifold equipped with a pipe and the pipe connected to the on-off valve of the manifold, respectively, and injecting the coolant from the pipe and passing only the coolant without passing the smaller foreign particles remaining in the coolant. And a filter cloth bag supported by each pipe, and a filter cloth bag storage container for collecting and discharging the coolant that has passed through the filter cloth bag and is discharged from the filter cloth bag storage container. A second tank for storing the coolant and a heat exchange section in the second tank are provided to keep the stored coolant at a predetermined temperature. A cooling device to keep below the suction coolant reserved in the second tank, characterized in that a second pump for pumping the working portion of the machine tool.

[0005]

In the present invention, the destination of the coolant containing foreign particles such as chips discharged from the machining section of the machine tool is switched to either of two systems by the switching means. Here, when the system of the outflow destination is switched to the side of the first tank, the inflowing coolant containing the foreign particles enters the first tank and is temporarily stored therein, and then is pumped up by the first pump to be discharged into the cyclone. Pumped to the side entrance. The coolant containing the foreign particles that has flowed into the cyclone is separated from the coolant and the foreign particles, and the foreign particles that partially contain the coolant are discharged from the lower discharge port and sent to the foreign particle collection tank. On the other hand, the coolant from which most of the foreign particles have been removed by the cyclone is discharged from the upper outlet and sent to the manifold.

The foreign particles sent to the foreign particle collecting tank separate the coolant upward during storage, and the coolant overflows from the foreign particle collecting tank and is returned to the first tank. Most of the foreign particles are removed and the coolant sent to the manifold is branched into multiple systems,
It is sent to the filter cloth bag through the on-off valve and the piping.
In the filter cloth bag, foreign particles having a smaller diameter, which are still left in the inflowing coolant, do not pass through, but only the coolant passes outside and drops into the filter cloth bag storage container, and then flows into the second tank.

The coolant that has flowed into and stored in the second tank is cooled to a predetermined temperature by the heat exchange section of the cooling device installed in the second tank.
It is pumped to the processing section of the machine tool by the second pump. By selectively operating the on-off valve provided in the manifold to supply the coolant to the plurality of filter cloth bags, the filter cloth bag filled with foreign particles can be replaced even during operation.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a system diagram of an embodiment of the present invention. In the figure, a gutter 1 introduces a coolant C1 flowing out from a processing section (not shown) of a machine tool on the left side into a distribution box 2 which is a switching means. The coolant C1 is mixed with cutting chips of a work, abrasion powder of a tool, and the like in a processing section of a machine tool. The bottom of one end of the distribution box 2 is open, and the coolant C1 is made to flow down to the dirty tank 3, which is the lower first tank. The distribution box 2 can be reversed to the left and right. When the distribution box 2 is reversed from the state shown in the figure, the outlet of the distribution box 2 moves and the coolant C1 is sent to another coolant filtering device 4. The coolant C1 once stored in the dirty tank 3 is sucked up by the dirty pump 5 which is the first pump and sent to the inlet 6a on the side surface of the cyclone 6.

The cyclone 6 separates foreign particles such as chips contained in the coolant C1 from the coolant C1 and discharges it from the lower discharge port 6b, and the coolant C3 from which the foreign particles are separated is discharged from the upper outlet 6c. Send out.
The foreign matter particles discharged from the discharge port 6b of the cyclone 6 still sufficiently contain the coolant C2, and after falling into the sludge tank 7 which is a foreign matter particle recovery tank, the coolant contained in the foreign matter particles is dropped. C2 separates at the top due to the difference in specific gravity. Separated coolant C2
Returns to the dirty tank 3 through the overflow pipe 8.
Further, in the sludge tank 7, foreign particles are precipitated due to their own weight and accumulated as sludge S. The sludge S is scraped to the outside in consideration of the degree of its accumulation. The coolant C3 discharged from the other outlet 6c of the cyclone 6 still contains foreign particles with a small diameter that the cyclone 6 could not separate, and this coolant C3 is sent to the manifold 9. The manifold 9 has a plurality of branch passages formed on the outlet side, and each branch passage is connected with a valve 11 which is an on-off valve, and further with a pipe 12.

The pipes 12 are arranged in parallel inside a box-shaped container 13 which is a filter cloth bag storage container, and a filter cloth bag 14 is inserted into each pipe 12 so as to cover the outside thereof. In the figure, only one system is shown because the valve 11, the pipe 12, and the filter cloth bag 14 overlap in the vertical direction of the paper surface. The cloth of the filter cloth bag 14 has a fineness enough to filter foreign particles having a small diameter that could not be separated by the cyclone 6, and when the coolant C3 is discharged from the tip of the pipe 12, Since the foreign particles contained therein cannot pass through the filter cloth bag 14 and remain, the passed coolant C4 further increases in purity. The coolant C4 that has passed through the filter cloth bag 14 and dropped on the bottom of the container 13 flows down to the clean tank 16, which is a second tank below the discharge pipe 15 formed on the bottom surface of the container 13.

The inside of the filter cloth bag 14 is divided into a plurality of compartments except for the upper portion by a partition in the vertical direction.
The tip of 2 is opened above the innermost compartment, so that the coolant C3 is initially discharged to the innermost compartment. When the inner compartment is filled with the foreign particles that cannot pass and remains, the supply liquid surface flows over the partition of the compartment to the compartment in front of it, and the filtration of the coolant C3 is newly started in the compartment in front. Further, since a plurality of filter cloth bags 14 are arranged in parallel in the container 13, by switching the valve 11, the flow rate of the entire filter can be adjusted. Furthermore, when the inside of the filter cloth bag 14 is filled with foreign particles, the filter cloth bag 14 can be replaced with a new filter cloth bag 14 without stopping the entire apparatus by closing only the valve 11 of the filter cloth bag 14.

Next, the clean tank 16 is formed continuously and integrally with the dirty tank 3, and the heat exchanging portion 18 of the cooling device 17 is arranged in the clean tank 16 to keep the coolant C4 at a predetermined temperature. Cool to: While the coolant C circulates, the liquid temperature rises due to the heat generated in the machining part of the machine tool, the resistance of the pumps 5 and 19, the cyclone 6, and other parts of the piping, so it is always suitable for machining. This is for cooling to the temperature. Cooling device 1
The operation of 7 is controlled by a room temperature tunable sensor (not shown). When adjusting the flow rate of each part, the flow rate supplied from the cyclone 6 through the container 13 to the clean tank 16 is set to be larger than the pumping amount of the clean pump 19. As a result, the coolant C4 normally overflows from the clean tank 16 to the dirty tank 3 side.

In this way, the foreign material particles such as cutting chips are almost removed, and the coolant C4 which has been cooled to an appropriate temperature and regenerated is sent by the clean pump 19 to the machining section (not shown) of the machine tool. Used for wet processing. After that, the coolant C circulates between the processing section of the machine tool and the coolant filtering device shown in the figure.

FIG. 2 is a perspective view of a device for applying the present invention to a coolant filtering device for graphite in a machining center capable of cutting both metal and graphite materials. Since the structure of each part is almost the same as that in FIG. 1, the same parts are denoted by the same reference numerals, and different parts will be mainly described. In the figure, a machining center 21 is used as a machine tool, and when machining graphite, the coolant C1 for the graphite that has flowed out.
Is supplied from the gutter 1 to the coolant filtering device for graphite by the distribution box 2. When the machining center 21 processes metal, the metal coolant filtering device 4 installed on the right front side by reversing the distribution box 2 is used. The main flow of each of the coolants C1 to C4 is as shown by the arrows in the figure. As for the positional relationship between the dirty tank 3 and the clean tank 16, the rear side is the dirty tank 3 and the front side is the clean tank 16.

The sludge tank 7 is installed on the left side of the tanks 3 and 16 and below the cyclone 6. Six filter cloth bags 14 are arranged in parallel in the container 13. The recycled coolant C4 is composed of two clean pumps 19
It is sent to the machining section of the machining center 21 by a and 19b. The clean pump 19a pumps the coolant C4 to a nozzle that directly injects to the processing section,
In b, the coolant C4 is pressure fed to a ring-shaped nozzle that forms a liquid film of a cylindrical coolant around the processed portion. Casters 22 to 24 are attached to the coolant filtering device 4 for metal, the tanks 3 and 16, and the sludge tank 7, respectively, to facilitate replacement of coolant and removal of sludge.

FIG. 3 is a system diagram showing the configuration of the coolant filtering apparatus for graphite shown in FIG. 2 in more detail. In the structure of each part, the same parts as those in FIG. 1 and FIG. In the figure, an internal tank 31 is installed in the dirty tank 3, and a box-shaped strainer 32 is installed at a position on the inner upper side thereof where the coolant C1 flows down from the distribution box 2. The strainer 32 installs a wire mesh in the passage portion of the coolant C1, so that the inflow coolant C1
It is possible to remove relatively large foreign matter contained therein. Specifically, a wire mesh with a mesh interval of 1.3 mm was used for the strainer 32 of the example.

A communication hole 33 is formed in the bottom of the inner tank 31 so that the coolant C1 can be communicated with the outer dirty tank 3.
Freely enter and leave. Furthermore, the suction pipe of the dirty pump 5 is connected to the bottom of the internal tank 31, and the dirty pump 5 sends the coolant C1 in the internal tank 31 to the cyclone 6. Here, the dirty pump 5
Is set to be larger than the inflow amount of the coolant C1, the insufficient amount of the inflow coolant C1 is supplied from the external dirty tank 3 through the communication hole 33.

The cyclone 6 has an outlet 6d for bypass, and when a large amount of coolant C1 is supplied from the dirty pump 5 or the resistance after the outlet 6c is large, a part of the supplied coolant C1 is dirty tank. Return to 3. A valve 34 is connected between the outlet 6c of the cyclone 6 and the manifold 9 to enable flow rate adjustment to the manifold 9 and thereafter. That is, the amount of bypass from the outlet 6d of the cyclone 6 is adjusted by adjusting the valve 34.
An overflow receiving tank 13a is formed in the container 13 in which the filter cloth bag 14 is housed, and a level detection switch 35 is attached inside thereof. When the inside of the filter cloth bag 14 is filled with foreign particles, the coolant C3 flows out from the opening of the filter cloth bag 14 and collects in the overflow receiving tank 13a. When the liquid level in the tank 13a rises, the level detection switch 35 detects it and sends it as an abnormal signal to a control panel (not shown) to display an alarm and turn on the signal lamp 39.

In addition to the discharge pipe 15 inside the container 13, a discharge pipe 36 for maintenance work of the overflow receiving tank 13a is connected together with a valve 37, and the filter cloth bag 14 is filled with foreign particles. In this case, maintenance is performed by closing only the valve 11 of the filter cloth bag 14 and opening the valve 11 of the new filter cloth bag 14. In addition, the coolant C3 that is not filtered by the filter cloth bag 14 during maintenance work
But overflows into the overflow receiving tank 13a,
By opening the valve 37 and returning the overflowed coolant C3 to the internal tank 31, the level detection switch 35 is restored and the abnormal signal and the lighting of the signal lamp 39 are released. Furthermore, inside the overflow receiving tank 13a,
When the overflow pipe 38 is connected and the liquid level of the coolant C3 in the container 13a rises due to a clogging abnormality, it overflows and returns to the internal tank 31. Float switches 41 and 42 are attached to the dirty tank 3 and the clean tank 16, respectively, and when the liquid level of each tank 3 and 16 reaches the minimum water level, it is detected and sent to a control panel (not shown) as an abnormal signal. .

The sludge tank 7 has an overflow pipe 8
A partition plate 43 is installed to a certain depth on the wall side to which is connected. Since the partition plate 43 is provided, only the coolant C2 that precipitates the sludge S and further separates the suspended matter passes below the partition plate 43 and overflows to return to the internal tank 31. Further, an inclined surface 7a is formed on the other side wall of the sludge tank 7 so that the sludge S deposited on the bottom can be easily scraped up. The sludge S scraped up on the inclined surface 7a and the draining partition plate 7b is once placed on the draining inclined surface 7c, drains, drops below the chute 7d, and falls below the sludge recovery container 4
4 and then discarded.

FIG. 4 is an explanatory view showing switching of the distribution box 2 in the embodiment shown in FIG. If the shunt box 2 is pulled out to the left from below the gutter 1 and rotated 180 degrees and the opened bottom part is in front, the coolant C1 is sent to the coolant filter device 4 for metal, and the opened bottom part is on the other side. Then, the coolant C1 is sent to the dirty tank 3 (which is a position behind the clean tank 16 in the figure) which is a coolant filtering device for graphite. In the drawing, in order to remove relatively large chips contained in the coolant C1, the chip holders 45 and 46 are housed in the distribution box 2. Specifically, a chip holder 45 for graphite
Is prepared by a punching plate having a hole diameter of 3 mm, and the chip holder 46 for metal is prepared by stretching a wire mesh on the punching plate having a large hole diameter.

FIG. 5 is a sectional view for explaining the general structure and operation of the cyclone 6. When the coolant C1 that has flowed in from the inlet nozzle 61 is injected in the tangential direction of the cylindrical chamber 62, it descends as a descending flow D while swirling inside the conical chamber 63. At this time, as the descending flow D descends, the flow velocity increases and the centrifugal force increases. As a result, the foreign particles having a large specific gravity floating in the coolant C1 separate from the coolant C1 and descend while adhering to the wall surface of the conical chamber 63, and discharged as sludge S from the lower nozzle 64. On the other hand, the descending flow D is reversed at the lower end of the conical chamber 63 due to its throttling effect to become the ascending flow U, passes through the inside of the descending flow D and the upper nozzle 65.
To the outside of cyclone 6 as coolant C3.

FIG. 6 is an explanatory view showing a process in which the coolant C3 filters the filter cloth bag 14 set in the container 13. The filter cloth bag 14 is a bag made of a filter cloth having a rectangular shape with an opening 14a without sewing only one end of one side. The interior is divided into a plurality of sections B1 to B8 except for the upper portion by vertically partitioning and partitioning. The filter cloth bag 14 is supported by inserting the pipe 12 which also functions as a supporting arm from the opening 14a. By opening the tip of the inserted pipe 12 above the innermost section B1,
At first, the coolant C3 is injected into the inner section B1. The filter cloth that forms the section B1 does not allow foreign particles to pass through, but allows only the coolant C3 to pass through. The coolant C4 from which the foreign particles have been removed and which has passed therethrough drips downward.
As the filtering of the coolant C3 progresses, the section B1 is filled with foreign particles, and the liquid level of the coolant C3 gradually rises to flow into the section B2 beyond the partition with the adjacent section B2, and the filtration also starts in the section B2. After that, in the same way as section B
When 2 is filled with foreign particles, it moves to the adjacent section B3, and the filtration position of the coolant C3 sequentially moves.

In this way, in the filter cloth bag 14, since the coolant C3 is sequentially filtered for each section, the whole is not clogged at one time, and the capacity of the filter cloth bag 14 is excellent in durability. It has a filtering ability. Also,
When all the sections B1 to B8 are filled with foreign particles, the filter cloth bag 14 can be easily replaced by pulling out the filter cloth bag 14 from the pipe 12 and inserting a new filter cloth bag 14, thus facilitating the maintenance work. The size of the mesh of the filter cloth used in the filter cloth bag 14 is appropriately selected based on the quality of the recycled coolant according to the processing conditions.

Next, the filtering ability of each part when graphite processing is carried out in the above-mentioned embodiments of FIGS. 2 and 3 will be specifically described. Chip holder 46 stored in distribution box 2
Then, the foreign particles having an outer shape of 3 mm or more are removed. Similarly, the strainer 32 removes 1.3 mm or more. Cyclone 6 is 30 μm or more, filter cloth bag 2 is 2
Fine particles of 0 μm or larger are filtered. Thus, the finally regenerated coolant C4 does not include foreign particles such as chips having an outer diameter of 20 μm or more.

As described above, in this embodiment, the flow of the coolant C1 from the machining portion of the machining center 21 is set to 2
By using the distribution box 2 that switches to a system, two types of coolant filtering devices for graphite and metal can be used as a dual-purpose machine by simply changing the setup according to the processing conditions such as the material of the work As a result, the operating rate of the machining center 21 can be improved. Further, the cyclone 6 having a large filtration capacity is used for filtering, and then the smaller foreign particles which cannot be filtered by the cyclone 6 are filtered by the filter cloth bag 14 having a filtering ability for extremely fine particles. A highly efficient coolant regenerator having various capabilities can be obtained.

Further, by using the cyclone 6 and the filter cloth bag 14, the cyclone 6 can continuously remove the sludge S composed of the foreign particles separated from the coolant C1. By switching the valve 11 of the manifold 9, the filter cloth bag 14 filled with the sludge S can be replaced without interrupting the flow of the coolant C3. Therefore, machining
The machining of the center 21 will not be interrupted due to the coolant filtering device side, and the operating efficiency of the machining center 21 will be improved.

Furthermore, while the coolant circulates between the machining center 21 and the coolant filtering device, the machining heat generated in the machining part of the machining center 21 and the resistance of the pumps 5, 19, the cyclone 6, and other piping parts. Although the liquid temperature of the coolant rises due to such reasons, the heat exchange part 18 of the cooling device 17 installed in the clean tank 16
With this, it is possible to cool to a predetermined temperature and always send the coolant C4 having an appropriate temperature to the machining portion of the machining center 21 to perform optimum wet machining.

Further, the sludge S which is discharged from the cyclone 6 and is composed of foreign particles including a part of which still contains the coolant.
While the coolant is being sent to and stored in the sludge, the coolant is separated upward so that the coolant overflows and is collected in the dirty tank 3.
If only the sludge S that has settled out is taken out and discarded, the amount of the coolant C contained in the sludge S to be discarded can be made smaller, the consumption amount of the coolant C is reduced, and the economy is excellent.

In order to further improve the filtering capacity and the processing capacity of the coolant filtering device, the cyclones 6 may be connected in multiple stages or the number of filter cloth bags 14 and the size of the filter cloth may be changed. It will be possible. Further, in order to change the flow of the inflowing coolant C1, the distribution box 2 is inverted in the embodiment, but the switching operation can be automated by using an electric gate or the like.
Furthermore, the present invention can be applied not only to the processing of graphite, but also to the grinding and polishing of ceramics and metals, and the processing of resins such as bakelite.

[0031]

As described above, according to the present invention, the coolant containing foreign particles such as chips discharged from the machining section of the machine tool is first transferred to the strainer 45 in the distribution box, the dirty tank, and the internal tank. The upper strainer 32 removes relatively large chips, the cyclone removes foreign particles, and the filter cloth bag removes even smaller foreign particles that could not be removed by the cyclone. Can be done well. In addition, by using a cyclone and a filter cloth bag branched into multiple,
In the cyclone, foreign particles separated from the coolant are continuously removed, and in the filter cloth bag, the on / off valve of the manifold is switched to replace the filled filter cloth bag without interrupting the flow of the coolant. As a result, the machining of the machine tool is not interrupted due to the coolant filtering device side, and the operating efficiency of the machine tool can be improved.

Further, during the circulation between the machine tool and the coolant filtering device, the coolant causes heat generation in the machining section of the machine tool, resistance of the first and second pumps, cyclones, and other piping sections. Although the liquid temperature rises, the heat exchange section of the cooling device installed in the second tank cools it to a predetermined temperature and always sends an appropriate temperature coolant to the processing section of the machine tool for wet processing. You can Furthermore, the foreign particles discharged from the cyclone and still partially containing the coolant are sent to the foreign particle collection tank, and the coolant is separated upward while being stored, and the separated coolant is overflowed. Since it was collected in the first tank, if only the precipitated foreign particles are taken out and discarded, the amount of coolant contained in the discarded foreign particles will be smaller and the consumption of coolant can be reduced. it can. Further, by providing a switching means for switching the flow of the coolant from the machining section of the machine tool to two systems, a filtering device or the like having a different coolant is installed in advance, and the flow can be switched depending on the material of the work. As a result, the versatility of machining of the machine tool can be increased.

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of the present invention.

FIG. 2 is a perspective view of an embodiment in which the present invention is applied to a coolant filtering device of a machine tool for machining graphite.

FIG. 3 is a system diagram showing the configuration of the coolant filtering device shown in FIG. 2 in more detail.

FIG. 4 is an explanatory diagram showing a switching operation of a distribution box.

FIG. 5 is a cross-sectional view illustrating a general structure and operation of a cyclone.

FIG. 6 is an explanatory diagram showing a process in which the filter cloth bag filters the coolant.

[Explanation of symbols]

 2 Dividing box 3 Dirty tank 4 Coolant filtration device 5 Dirty pump 6 Cyclone 6a Inlet 6b Discharge port 6c, 6d Outlet 7 Sludge tank 8 Overflow pipe 9 Manifold 11 Valve 12 Piping 13 Container 13a Overflow receiving tank 16 Clean tank 17 Cooling device 18 Heat exchange section 19 Clean pump 21 Machining center 31 Internal tank 32 Strainer 33 Communication hole 39 Signal light 45,46 Chip holder C1 to C4 Coolant S Sludge

Claims (1)

[Scope of utility model registration request] 1. A switching means for switching the outflow destination of a coolant containing foreign particles such as chips discharged from a machining part of a machine tool to one of two systems, and an inflow connected to one system of the switching means. Including a first tank for storing a coolant containing foreign matter particles, a first pump for pumping up the coolant containing foreign matter particles stored in the first tank, and a foreign matter particle pumped from the first pump The coolant was taken in through the inlet on the side of the main body, the coolant and the foreign particles suspended in the coolant were separated, and the foreign particles that partially contained the coolant were discharged from the lower outlet, and most of the foreign particles were removed. The cyclone that discharges the coolant from the upper outlet and the foreign particles discharged from the lower outlet of the cyclone are temporarily stored, and the coolant that has separated above is accumulated during storage. The foreign particle collection tank that flows and returns it to the first tank, the coolant discharged from the upper outlet of the cyclone is branched into multiple systems, and each manifold has an on-off valve and an on-off valve for the manifold. The filter cloth bag that inserts and supports the connected pipes and that allows the coolant to be injected from the pipes and allows only the coolant to pass without passing the smaller foreign particles remaining in the coolant, and is supported by each pipe. A filter cloth bag storage container that stores the discharged filter cloth bag, collects and discharges the coolant that has passed through the filter cloth bag, and a second tank that stores the coolant discharged from the filter cloth bag storage container; A cooling device for arranging a heat exchange section in the second tank to keep the stored coolant at a predetermined temperature or lower, and a cooling device stored in the second tank. Suction coolant, and a second pump for pumping the working portion of the machine tool coolant filtration device for a machine tool, characterized in that it comprises a.