KR20040094130A - Filtering apparatus for cutting oil - Google Patents

Abstract

PURPOSE: An apparatus for filtering cutting oil is provided to capable of filtering a large quantity of cutting oil and minimize a mounting area thereof by storing the filtered cutting oil in a clean tank. CONSTITUTION: An apparatus for filtering cutting oil is composed of a magnetic separator(10) for separating metallic chips from the cutting oil, a dirt tank(20) for storing the cutting oil separated from metallic chips or sludge, a first pump(30) disposed above the dirt tank and feeding the cutting oil stored in the dirt tank, a filter unit(50), and a second pump(70). The filter unit has a multi-layered filter(40) therein, and filters the cutting oil fed by the first pump. A connecting pipe(51) connects the center of the filter to a clean tank(60). The clean tank stores the cutting oil filtered by the filter unit. The second pump discharges the cutting oil stored in the clean tank to the outside.

Description

Coolant Filtering Equipment {FILTERING APPARATUS FOR CUTTING OIL}

The present invention relates to a coolant filtering device, and more particularly, to a coolant filtering device capable of minimizing an installation area while processing a large amount of coolant.

In general, the cutting oil used in the machine tool includes a large amount of metallic or nonmetallic chips and sludge. In order to reuse the cutting oil, a method of filtering metallic chips by magnetic force or a filtering method by follicles has been used.

In the past, however, metallic workpieces were the mainstream, but with the development of modern industry, the workpieces contain non-metallics, which limits the use of magnetic materials. Filtration is more effective.

An example of such a cutting fluid filtering device is described in Korean Patent Publication No. 10-0314211.

The conventional cutting oil filtering apparatus will be described in detail with reference to the accompanying drawings.

As shown in FIGS. 1 to 6, a conventional cutting oil filtering device is a cutting oil chip filtering method for filtering cutting oil discharged from various machine tools to remove chips or sludge included in the cutting oil. Primary filtration of the cutting oil discharged from the machine tool to the dirty tank 110 (S1), chips or sludge of the cutting oil collected by the supply process (S1) by magnetic force The chip discharging step (S3) for discharging the chips and sludge filtered by the magnetic filtration step (S2) and the scraper 111 attached to the conveyor 109 by the magnetic filtration step (S2). ), And through the magnetic filtration process (S2) receives the cutting oil collected in the pump room 108 to the filter pump 113, the second and second filtration to the first and second follicles 106, 107 after the pump room Re-feeding to (108) and crosslinking to the follicle eye (114) by the supplied diatomaceous earth When the cross-linking phenomenon occurs in the eye 114 of the follicle by the filtration preparation process (S4) and the filtration preparation process (S4) to be carried out for a predetermined time to achieve the first, second follicles 106, 107 And the first and second receiving bodies 104 and 105 to detect clogging of the follicles during the performing of the follicle filtration step (S5) and the follicle filtration step (S5). Pressure measurement step (S6) to measure the pressure of the) and, if the value measured in the pressure measurement step (S6) is smaller than the set value, the cutting oil collected in the clean tank (115) various machine tools or cutting oil tank ( (Not shown) and the value measured in the resupply process (S7) and the pressure measurement process (S6) is larger than the set value of any one of the first and second receiving bodies (104, 105). If it is equal to or less than 1, control the flow direction of the cutting oil to remove clogging of the follicles attached to the receiving body and pump the cutting oil. After the backwashing step S8 for resupplying to the prum 108 and the filtration preparation step S4 for a predetermined time after the backwashing step S8 is performed, the follicle filtration step S5 is performed.

In the chip filtration apparatus of the cutting oil for filtering the cutting oil discharged from various machine tools to remove chips or sludge contained in the cutting oil, the metallic chip of the cutting oil collected in the dirty tank 110 The magnetic part 103 attached to the bottom surface of the dirty tank 110 and the predetermined amount of chips gathered in the magnetic part 103 may be a chip box outside the dirty tank 110 so that the magnetic force may be collected by the magnetic force. The discharge means of the chip for continuous discharge to the 112, and the pump room is spaced apart from the magnetic portion 103 by a predetermined distance upward to transfer the coolant first filtered by the magnetic portion 103 to the pump room 108 ( A transfer chute 102 connected to 108, a first accommodating body 104 to receive the cutting oil from the pump room 108 to accommodate the cutting oil, and an upper flange 116 of the first accommodating body 104. A first upper cover 118 coupled to the bolt 117 by The second accommodating body 105, which is coupled to the upper portion of the upper cover 118 by a bolt 117, receives the cutting oil of the pump room 108 to accommodate a predetermined amount, and the upper part of the second accommodating body 105. The second upper cover 119 coupled to the flange 116 by a bolt 117 and the bottom surface of the first and second upper covers 118 and 119 are coupled to the chip and the nonmetal body included in the cutting oil. First and second follicles 106 and 107 which are to be filtered, and coupling pipes 123 protruding downward from the bottom of the first and second upper covers 118 and 119 to a predetermined length, A plurality of frames 124 having one end attached to an outer circumferential surface of the coupling pipe 123, a coupling part 125 attached to the other end of the frame 124, and somewhat loosely coated outside the frame 124. The upper and lower clamps 126 and 127 to fix the follicles at the upper and lower ends, and the first and second receiving bodies 104 and 105 with the filter pump at the upper portion of the pump room 108. Supply to The first and second supply pipes 129 and 130, the cutting means for discharging the cutting oil filtered by the follicles to the clean tank 115, and the follicle for relieving the capillary force of the outer surface of the follicle. Clogging means, the water level detecting means of the pump room 108 for detecting the level of cutting oil collected in the pump room 108, and the fine passing through the follicles of the cutting oil collected in the clean tank 115 Separation means of the chip for separating the chip into the pump room 108 and the system coupled to the upper portion of the clean tank 115 to supply the coolant collected in the clean tank 115 to the coolant storage tank disposed remotely It is equipped with the pump 122.

In addition, the discharge means of the chip is coupled to the conveyor 109 in the dirty tank 110, scraping the chips gathered in the magnetic portion 103 to detach from the magnetic portion 103 to the outer chip box 112 It is preferable to provide a scraper 111 of the 'b' shape for transferring the furnace chips.

In addition, the discharge means of the cutting oil is communicated from the second upper cover 119 to the first upper cover 118 and spaced apart from the first upper cover 118 by a predetermined distance downward one end is closed, the other end of the second The discharge pipe 131 extending from the upper cover 119 connected to the clean tank 115, the cutting oil filtered by the follicle of the first receiving body 104 and the cutting oil filtered by the follicle of the second receiving body 105 Preferably, the discharge pipe 131 includes at least one discharge hole 132 formed on the outer circumferential surface of the discharge pipe 131 on the first receiving body 104 side and the second receiving body 105 side, respectively.

In addition, the clogging means for removing the follicle is coupled to the first and second supply pipes (129, 130) below the lower cover 125, respectively, the first and second triangular to selectively change the flow direction of the cutting oil A third three-way valve coupled to the discharge pipe 131 to selectively supply the valves 133 and 134 and the cutting oil discharged to the discharge pipe 131 to the filter pump 113 ( 135 and piezoelectric sensors 136 attached to predetermined positions outside the first and second accommodating bodies 104 and 105, respectively, and measuring pressure inside the first and second accommodating bodies 104 and 105. When the measured value of the piezoelectric sensor is equal to or greater than a set value, the direction of the flow path is changed by controlling the first and third three-way valves 133 and 135 or the second and third three-way valves 134 and 135. As the direction of the flow path is changed by the controller (not shown) and the controller, the cutting oil in the first accommodating body 105 or the second accommodating body 106 is dirty. The first and second backwash pipes 137 and 138 coupled to the first and second three-way valves 133 and 134 and the third three-way valve 135 so as to be discharged to the tank 110. A resupply pipe 139 connected to the pump room 108 and a ball valve 140 coupled to the resupply pipe 139 to adjust the discharge amount so that only a predetermined amount of cutting oil can be discharged to the pump room 108 is provided. .

In addition, the water level detecting means of the pump room 108 is a floating body 141 floating on the surface of the cutting oil in the pump room 108, coupled to the upper portion of the pump room 108 and has a predetermined diameter toward the upper side A guide tube 142 formed in a longitudinal direction and inserted into the guide tube 142 and coupled to the floating body 141 to move up and down in the guide tube 142 according to the amount of cutting oil; Preferably, the first and second detection sensors 144 and 145 attached to the outermost peak and the lowest point of the guide tube 142 according to the top dead center of the bottom of the pump room 108 and the cutting oil. .

In addition, the first and second receiving bodies 104 and 105 have a predetermined slope to form a vortex when cutting oil is supplied or discharged to the inside of the lower cover 128 and the inside of the first upper cover 118. It further includes a vortex guide 146 formed in.

The chip filtration method of the conventional cutting oil and the filtration apparatus having the above-described configuration will be described with reference to FIGS. 1 to 7.

First, the cutting oil supply process (S1) to transfer the cutting oil discharged from various machine tools to a transfer device (not shown) to supply to the dirty tank 110.

At this time, the dirty tank 110 is preferably to be able to inject a predetermined amount of diatomaceous earth according to the intention of the operator to control the degree of filtration during the follicle filtration step (S4) to be described later.

The coolant collected in the dirty tank 110 passes through a transfer chute 102 installed in the dirty tank 110 with a predetermined flow rate by driving the filter pump 113, as shown in FIG. 2. 108 is transferred to, and the metallic chip and the like contained in the cutting oil is carried out to perform a magnetic filtration process (S2) to be attached to the magnetic portion (103).

As described above, the metallic chips attached to the magnetic part 103 may include a conveyor 109 embedded in the dirty tank 110 and a plurality of scrapers 111 attached to the conveyor 109 as shown in FIGS. 1 and 2. The chip discharge step (S3) to discharge the chip to the chip box 112 disposed on the outside by scratching).

On the other hand, the cutting oil collected in the pump room 108 through the transfer chute 102 is supplied into the first and second receiving bodies 104 and 105 by the filter pump 113.

At this time, the cutting oil supplied to the first and second accommodating bodies 104 and 105 is vortexed as shown in FIG. 2 by the flow rate and the vortex guide 146 by the filter pump 113, The sludge, etc. is caught in the vortex and floats together with the cutting oil without remaining in a certain position so that the whole amount can be filtered through the follicle.

In addition, the cutting oil supplied to the first and second accommodating bodies 104 and 105 is filtered out of the first and second follicles 106 and 107 in which the cutting oil is impregnated. In the eye 114 of the first and second follicles 106 and 107, crosslinking occurs as shown in FIG. 5, and the cutting oil filtered by the first and second follicles 106 and 107 to increase the filtration efficiency is predetermined. The flow path of the third three-way valve 135 is opened by the controller to the resupply pipe 139 as shown in FIG. 2 so that the pump chamber 108 is supplied to the pump room 108 for re-filtration, and at this time, the resupply pipe 139 The ball valve 140 coupled to the filter valve is opened to allow the entire amount of cutting oil to be discharged to perform a filtration preparation process (S4) to allow the cutting oil to be discharged to the pump room 108.

After the filtration preparation process (S4) performed for a predetermined time as described above is entered into the full-fledged follicle filtration process (S5), at this time, the cutting oil filtered by the first and second follicles 106, 107 In order to collect the clean tank 115, the third three-way valve 135 is blocked by the controller to the resupply pipe 139 and the clean tank 115 is opened as shown in FIG. 3.

In addition, the cutting oil collected in the clean tank 115 may be supplied to a cutting oil tank (not shown) separately provided or may be directly supplied to various machine tools (S6).

At this time, the bottom surface of the clean tank 115 is formed with a guide plate 147 having a predetermined inclination, as shown in Figs. 2 to 4, the cutting oil supplied is inclined to a predetermined region by the induction plate 147. The fine chips or sludges flowing through the first and second follicles 106 and 107 overflow to the separation hole 149 formed in the partition wall of the pump room 108 and the clean tank 115 as shown in FIG. 3. To allow it to be refiltered.

That is, the fine chips gathered in a predetermined region by the guide plate 147 flow through the separation membrane 148 and the partition wall and flow into the pump room 108 by the flow rate of the cutting oil supplied (OVERFLOW).

On the other hand, if the chip or sludge is laminated to a large amount of the outside of the follicle during the follicle filtration step (S5) and the crosslinking phenomenon is intensified, clogging occurs, as shown in FIG. The pressure inside the first and second receiving bodies 104 and 105 is measured by a piezoelectric sensor 136 attached to the outside of the receiving bodies 104 and 105, and the controller presets this value. If any one of the first and second accommodating bodies 104 and 105 is greater than or equal to a preset value compared to the set value, clogging occurs in the first and second follicles 106 and 107. The pressure measurement step (S6) to be judged to be performed.

Therefore, if the measured value in the pressure measurement step (S6) is smaller than the set value, the re-supply step (S7) and the follicle filtration step (S5) continue to be performed, and if the measured value is greater than or equal to the set value, the back washing step In this case, the controller controls the opening / closing state of the first, second, and third three-way valves 133, 134, and 135 to change the flow direction so that the back washing process S8 is performed. It is done.

An example of the above backwashing process S8 will be described with reference to FIGS. 4A and 4B.

The first accommodating body 104 is disposed at a position where cutting oil may be supplied earlier than the second accommodating body 105 so that the clogging of the first follicle 106 is preceded by the second follicle 107. (When the clogging occurs in any of the first and second follicles 106 and 107 first during operation, the piezoelectric sensor 136 and the controller are identified. It is assumed that the blockage occurs at 106.

Therefore, the filtration efficiency of the first follicle 106 is lowered before the second follicle 107, thereby increasing the pressure inside the first accommodating body 104, which is the piezoelectric sensor 136 shown in FIG. Will be detected.

In addition, when the measured value of the piezoelectric sensor 136 is equal to or larger than the set value of the controller compared to the set value, the first three-way valve 133 coupled to the supply pipe 101 is illustrated in FIG. 4A. And the flow path direction of the third three-way valve 135 coupled to the discharge pipe 131 for a predetermined time to perform a backwash process (S8).

That is, the first three-way valve 133 blocks the cutting oil supplied from the supply pipe 101 and prevents the cutting oil of the first accommodating body 104 from closing the first backwashing pipe 137 as shown in FIG. 4A. Open to be discharged to the dirty tank 110 through.

The third three-way valve 135 blocks the clean tank 115 and allows the cutting oil to be discharged to the resupply pipe 139. At this time, the ball valve 140 coupled to the resupply pipe 139 is provided. It can be opened about half so that only about 50% of the coolant discharged to pass through it can be supplied to the pump room (108).

At this time, depending on the amount of cutting oil ball valve 140 may be more than 50% or less than 50% as intended by the operator.

Therefore, when 100% of the cutting oil is introduced into the discharge hole 132 of the second accommodating body 105, only about 50% of the cutting oil is discharged into the ball valve 140, and the remaining cutting oil is the second accommodating body ( The first follicle 106 loosely coupled to the frame 124 by the cutting oil discharged back into the discharge hole 132 of the first accommodating body 104 and introduced into the discharge hole 132 on the 105 side. 5 is expanded to the state of FIG. 6 and at the same time the cutting oil flows from the inside of the first follicle 106 to the outside, the chip or sludge attached to the outer surface of the first follicle 106 and diatomaceous earth as shown in FIG. Detachment will eliminate clogging.

The chip, sludge and diatomaceous earth detached from the first follicle 106 are dirty tank 110 by the first backwashing pipe 137 via the first supply pipe 129 and the first three-way valve 133. It is supplied to the re-filtered by the magnetic portion 103 is transferred to the pump room (108).

In addition, when clogging occurs in the second follicle 107 of the second accommodating body 105, the piezoelectric sensor 136 attached to the outer side of the second accommodating body 105 is formed inside the second accommodating body 105. As described above, the second three-way valve 134 measures the pressure of the second receiving valve 105 through the second supply pipe 130 and the second three-way valve 134. Control the flow direction as shown in Figure 4b to be discharged to the dirty tank 110 through the two backwash pipe 138, the flow direction of the third three-way valve 135 is opened to the resupply pipe 139 side and the dirty tank ( The flow path direction is changed as shown in FIG. 4B for a predetermined time so that about 50% of the cutting oil may be discharged to the pump room 108 by the ball valve 140.

Therefore, the cutting oil filtered by the first follicle 106 of the first accommodating body 104 flows into the discharge hole 132 on the side of the first accommodating body 104 and discharges about 50% to the resupply pipe 140. The remaining cutting oil is discharged into the second follicle 107 through the discharge hole 132 of the second accommodating body 105, and the cutting oil is filtered from the inside of the second follicle 107 to the outside of the second follicle ( As the 107 is expanded from the state of FIG. 5 to the state of FIG. 6, chips, sludge, diatomaceous earth, and the like are detached from the second follicle 107 to eliminate clogging.

As described above, the back washing process S8 is performed by measuring the degree of clogging of the first and second follicles 106 and 107 according to the pressure change in the first and second receiving bodies 104 and 105. Control the direction of the first, second, and third three-way valves 133, 134 and 135 according to the control of the controller to automatically reverse the clogging of the first and second follicles 106, 107. It will be able to wash.

In addition, when the backwashing process (S8) is performed and the cutting oil is discharged to the first supply pipe 129 or the second supply pipe 130, it is swirled by the vortex guide 146 as shown in Figure 4a, 4b By discharging, it is possible to obtain an effect of quickly discharging cutting oil.

As described above, when the backwashing process (S8) of any one of the first foam 106 or the second foam 107 is completed for a predetermined time, the above-described filtration preparation process (S4) may be performed for a predetermined time. First, the cross-linking phenomenon is made on the outer surface of the second follicles 106 and 107 as shown in FIG. 5, and after the filtration preparation step S4 is performed, the filtration step S5 is performed again. To supply the filtered cutting oil to the clean tank 115.

Meanwhile, the water level of the pump room 108 is increased during the filtration preparation process (S4) and the follicle filtration process (S5), so that the floating body 141 and the guide 143 are higher than the predetermined water level along the guide pipe 142. When rising or falling, the first and second detection sensors 144 and 145 detect this and send a signal to the controller. Accordingly, an alarm light attached to a control panel (not shown) lights and a beep sound. In this regard, the operator can promptly cope with the cutting oil in the pump room 108 or increase the supply amount.

However, such a conventional cutting oil filtering device has to use a device having a large installation area in order to process a large amount of cutting oil, and thus there is a problem in that the installation position is not easily secured and the installation cost increases.

The present invention in view of the above problems is to provide a coolant filtering device that can minimize the installation area while filtering a large amount of coolant at the same time.

The present invention for achieving the above object is a cylindrical body is sealed bottom; A lid covering an upper portion of the main body; An inlet provided on the bottom of the main body to introduce cutting oil stored in the dirty tank into the main body introduced by the operation of the pump; An outlet provided at the center of the bottom surface of the main body to allow the filtered cutting oil to flow out to the clean tank located at the lower part of the main body; It is characterized by consisting of a plurality of filters sequentially stacked on top of the outlet.

1 to 6 is a configuration diagram for explaining a conventional coolant filtering device.

7 is a flow chart of a conventional cutting fluid filtering method.

8 is a plan view of a coolant filtering device according to the present invention;

9 is a side view of the coolant filtering device according to the present invention;

10 is a detailed block diagram of a filter part in the cutting oil filtering device according to the present invention;

11 is an exploded perspective view of a filter applied to the present invention.

12 is a cross-sectional view of the metal plate in FIG. 11.

Figure 13a is a plan view of a coupling substrate for fixing the filter applied to the present invention.

Figure 13b is a cross-sectional view of the bonding substrate applied to the present invention.

* Description of the symbols for the main parts of the drawings *

10: magnetic separator 20: dirty tank

30: first pump 40: filter

41: metal plate 42: diatomaceous earth coated cloth

43: bonding base 50: filter unit

51: clean tank connector 52: dirty tank connector

When described in detail with reference to the accompanying drawings an embodiment of the present invention configured as described above are as follows.

FIG. 8 is a plan view of the cutting fluid filtering apparatus of the present invention, and FIG. 9 is a side view of the magnetic separator 10 for removing the metallic chip from the cutting oil conveyed as shown therein; A dirty tank 20 for storing cutting oil from which metallic chips or sludge has been removed through the magnetic separator 10; A first pump 30 positioned at an upper side of the dirty tank 20 to transfer cutting oil stored in the dirty tank; A filter unit 50 having a built-in multi-layer filter 40 to filter the cutting oil transferred by the first pump 30 using each filter 40, and store the filter oil in the clean tank 60. It consists of a second pump 70 for flowing out the cutting oil stored in the clean tank 60 to the outside.

10 is a detailed configuration diagram of the filter unit 50. As shown in FIG. 10, a plurality of filters 40 are stacked so as to be spaced apart from each other by a predetermined distance, and a central portion of the filter 40 is formed of the clean tank 60. As shown in FIG. Clean tank connecting pipe 51 is connected to the inside.

In addition, the upper portion of the clean tank connecting pipe 51 is provided with a coupling base 43 which is respectively coupled to the central portion of the plurality of filters 40 and can be stacked on top of the clean tank connecting pipe 51. .

The coupling base 43 is different in size of the sphere seen from the plane and the bottom surface to be laminated and fixed to each other, which allows the lower portion of the other coupling base to be coupled to the upper portion of the coupling base 43.

In addition, the coupling base 43 is provided with an inlet through which the filtered cutting oil is introduced, which will be described in more detail below.

The side surface portion of the clean tank connecting pipe 51 is provided with a dirty tank connector 52 to allow the cutting oil transferred from the dirty tank 20 to enter the filter unit 50.

That is, the filter unit 50 is separated into the main body 53 and the cover 54, and during operation, the main body 53 and the cover 54 are fixed by using the fixing unit 55.

Hereinafter, the operation of the present invention configured as described above will be described.

First, the cutting oil is introduced into the dirty tank 20 through the magnetic separator 10 through a conveying means such as a conveyor belt.

At this time, the magnetic separator 10 separates the metal chip contained in the cutting oil using a magnet.

In this way, the cutting oil in which the metal chips are separated flows into the dirty tank 20, and the first pump 30 operates to cut the cutting oil stored in the dirty tank 20 through the dirty tank connector 52 to the inside of the filter unit 50. Transfer to.

The cutting oil thus transferred rises along the inner wall of the filter part 50 by the pressure of the first pump 30 and flows into the upper portion of each filter 40.

FIG. 11 is an exploded perspective view of the filter, and FIG. 12 is a cross-sectional view of the metal plate. As shown in FIG. 12, the filter includes a circular metal plate 41 having a plurality of perforations, and diatomaceous earth located on the metal plate 41. Is coated cloth 42, the coolant is filtered by the diatomaceous earth coated cloth 42 to remove foreign matter.

The diatomaceous earth coated cloth 42 uses a PE-based nonwoven fabric.

Thus, the cutting oil from which the foreign matter is removed is moved to the bottom surface of the metal plate 41 through the perforation of the metal plate 41.

The structure of the metal plate 41 is inclined from the outer circumference to the center so that the bottom of the central portion is lower than the outer circumference.

13A is a plan view of the coupling base 43, and FIG. 13B is a side cross-sectional view thereof, as shown in FIG. 13A, a metal plate coupling part 46 to which the metal plate 41 is coupled, and the metal plate coupling part 46. Cutting oil inlet 44 located below the () is located.

Filtered cutting oil, which is moved to the center along the bottom surface of the metal plate 41, is introduced into the coupling base 43 through the cutting oil inlet 44, which flows downward to open the clean tank connector 51. It is stored in the clean tank 60 through.

A feature of the coupling base 43 serves to fix one filter 40, respectively, and stacks the coupling base 43 to which the filter 40 is coupled to connect with the clean tank connector 51. To form a tube.

The lower coupling hole 45 of the coupling base 43 has a structure that is engaged with the upper side 46 of the other coupling base 43, which can maintain a sufficient coupling force when laminated.

The cutting oil stored in the clean tank 60 may flow out to the outside by the operation of the second pump 70.

As described above, the present invention can be installed in a small area compared to the filtering throughput by providing a coupling base for stacking a filter for filtering cutting oil in a multi-layer, collecting the cutting coolant at the center of the filter and storing it in a clean tank. It works

Claims (4)

A cylindrical body whose bottom is sealed; A lid covering an upper portion of the main body; An inlet provided on the bottom of the main body to introduce cutting oil stored in the dirty tank into the main body introduced by the operation of the pump; An outlet provided at the center of the bottom surface of the main body to allow the filtered cutting oil to flow out to the clean tank located at the lower part of the main body; Cutting oil filtering device, characterized in that consisting of a plurality of filters sequentially stacked on top of the outlet. 2. The filter of claim 1, wherein the filter comprises: a disk-shaped metal plate having a plurality of perforations and having a coupler formed at the center thereof; Diatomaceous earth coated cloth provided on the metal plate; It is coupled to the coupling hole of the metal plate to fix the metal plate, and through the diatomaceous earth-coated cloth and the metal plate to collect the filtered cutting oil and consists of a coupling base for outflow to the clean tank through the outlet coupled to the lower Coolant filtering device. The method of claim 2, wherein the plurality of coupling substrates have a cylindrical structure, each having a coupling hole on the lower side and a plurality of cutting oil inlet on the side so that the upper side is inserted and coupled to the lower side of each other coupling substrate. Coolant filtering device characterized in that. The magnetic tank of claim 1, wherein the dirty tank and the clean tank are located in contact with each other in the transverse direction to the bottom surface side of the main body, and are located on the top of the dirty tank to further remove a magnetic foreign material from the cutting oil using magnetic force. Cutting fluid filtering device, characterized in that it comprises.