A cutting fluid circulation system for CNC machine tools

Abstract

The present invention relates to a cutting fluid circulation system for a numerically controlled machine tool, which effectively solves the problem that oil and iron chips in the cutting fluid cannot be removed at one time; the technical solution thereof comprises a box body with an upward opening, the box body is divided into three chambers by two left and right partitions, which are a filter box, a liquid storage tank, and an oil storage tank from left to right; a rotatable filter is provided in the filter box; an oil removal tank is provided in the liquid storage tank, the upper end of the oil removal tank is provided with a vertical pipe, the middle part of the vertical pipe is bent, and the end part is placed above the oil storage tank; a piston chamber is provided at the bottom of the box body, a piston # is provided in the piston chamber, a piston rod is fixed to the left side of the piston #, and the piston # divides the piston chamber into a return chamber on the left and a feeding chamber on the right; after the piston # moves back and forth, the feeding chamber can send the liquid in the filter box to the oil removal tank, and the return chamber can send the liquid in the oil removal tank to the liquid storage tank. The present invention can realize the simultaneous removal of debris and oil.

Description

Technical Field

[0001] The invention relates to the technical field of machining, in particular to a cutting fluid circulation system for a numerically controlled machine tool. Background Art

[0002] Cutting fluid is a commonly used coolant and lubricant in metalworking and machining. During use, cutting fluid can contaminate metal debris, dust, oil, and other contaminants. Due to the high volume of cutting fluid used, most machine tools currently utilize filtration and other methods to recycle the fluid.

[0003] Patent documents such as CN115090023B and CN113953885B generally use vibration, stirring and other methods to filter metal debris and self-clean the filter screen, thereby achieving the purpose of removing metal debris. However, these patent documents mainly solve the problem of removing particulate debris, but the oil residue in the cutting fluid cannot be removed in time. When the oil residue accumulates, it will breed bacteria and cause the cutting fluid to deteriorate and stink. In other words, a separate degreasing device is still required for removal. Traditional cutting fluid degreasing equipment generally uses an oil suction pipe set on the water surface to absorb surface oil. However, in practice, it is found that after the local floating oil is absorbed, water will continue to be absorbed.

[0004] To achieve simultaneous removal of oil and chips, patent document CN113857933B describes a cutting fluid filtration device for CNC machine tools. This device utilizes a traditional scraper oil-water separator, combined with a filter press for final purification. This system presents the following major issues: 1. The oil-water separator is bulky and requires equipment such as an air compressor, which is noisy and has high liquid level requirements, resulting in poor separation effectiveness. 2. De-oiling prior to chip removal can easily damage pipes and pumps due to the high volume of cutting fluid. 3. The filter assembly is not cleaned thoroughly enough, resulting in waste of cutting fluid during cleaning. Summary of the Invention

[0005] In view of the above situation, in order to solve the problems existing in the prior art, the purpose of the present invention is to provide a CNC machine tool cutting fluid circulation system, which can effectively solve the problem that oil stains and iron filings in the cutting fluid cannot be removed in one go.

[0006] The technical solution is to include a box body with an upward opening, which is divided into three chambers by two left and right partitions, namely a filter box, a liquid storage tank, and an oil storage tank from left to right; the filter box is provided with a rotatable filter; the liquid storage tank is provided with an oil removal tank, and a vertical pipe is provided at the upper end of the oil removal tank, the middle part of the vertical pipe is bent, and the end part is placed above the oil storage tank;

[0007] The filter comprises a filter frame with an upward opening, a vertical pull rod fixed in the middle of the filter frame, a plurality of liquid separation plates evenly distributed on the pull rod from top to bottom, and the upper and lower liquid separation plates are staggered with each other;

[0008] The bottom of the box body is provided with a piston chamber, in which a piston # is provided, and a piston rod is fixed to the left side of the piston #. The piston # divides the piston chamber into a return chamber on the left and a feed chamber on the right; after the piston # moves back and forth, the feed chamber can send the liquid in the filter box to the de-oiling tank, and the return chamber can send the liquid in the de-oiling tank to the liquid storage tank;

[0009] A sensor is fixed at the bottom of the bend of the vertical pipe, and a water pump is arranged above the box body. The water pump can send the liquid in the oil tank to the liquid storage tank. The sensor controls the start and stop of the water pump through the controller.

[0010] A vertical rotating shaft is fixed to the bottom of the filter box, and a sleeve is fixed to the bottom of the filter frame. The sleeve can be sleeved on the rotating shaft, and the cross-section of the part where the rotating shaft and the sleeve cooperate is square; the upper end of the liquid separation plate and the end facing the side wall of the filter frame are both open, and multiple liquid separation plates are distributed along the pull rod spiral.

[0011] A gear is installed on the rotating shaft, and a tooth segment meshing with the gear is provided on the left side of the piston rod; the rotating shaft is driven by a motor to rotate forward and backward.

[0012] The right end of the feeding chamber is connected to the bottom of the filter box and the de-oiling tank through two pipes respectively; the left end of the return chamber is connected to the bottom of the de-oiling tank and the liquid storage tank through two pipes respectively, and a one-way valve is provided in the middle of each pipe.

[0013] Advantages of the present invention: 1. The device is compact and can be directly arranged or replaced in an existing machine tool cutting fluid box, achieving the purpose of integrated storage and filtration, thereby improving integration. 2. The device first performs centrifugal chip removal and then uses floating and sinking to remove oil, which can prevent debris from affecting equipment operation. 3. The debris removal part of the device utilizes the reciprocating rotation of the filter frame. At the same time, through the ingenious internal design, it can utilize all sides of the filter frame for filtering, thereby improving the filtration effect. At the same time, under the action of gravity, debris can be deposited at the bottom of the filter frame, thereby avoiding full clogging of the filter frame. 4. The oil removal part of the device utilizes the difference in oil and water density to remove oil contamination. At the same time, the oil removal tank is filled with raw material while the filtered cutting emulsion is extracted. The difference in the amount of the two is utilized to slowly increase the liquid level inside the oil removal tank, thereby extending the oil-water separation time and allowing the oil contamination to fully float. At the same time, it can avoid the large-scale discharge of raw material liquid when the oil removal tank is about to be full. 5. The drive part of the device is cleverly arranged, and one motor is used to drive the two parts, thereby reducing equipment investment. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is the front view of the present invention.

[0015] Figure 2 It is a front cross-sectional view of the present invention.

[0016] Figure 3 It is a three-dimensional schematic diagram of the cooperation between the pull rod and the liquid separation plate of the present invention.

[0017] Figure 4 It is a front cross-sectional view of the piston chamber of the present invention.

[0018] In the figure: filter box 1; liquid storage tank 2; oil storage tank 3; filter 4; oil removal tank 5; standpipe 6; piston chamber 7; sensor 8; water pump 9; filter frame 401; pull rod 402; liquid separator 403; rotating shaft 404; sleeve 405; gear 406; piston 701; piston rod 702; return chamber 703; feed chamber 704. Implementation Method

[0019] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

[0020] Depend on Figures 1 to 4 The present invention comprises a box body with an upward opening, which is divided into three chambers by two left and right partitions, namely, a filter box 1, a liquid storage tank 2, and an oil storage tank 3 from left to right; a rotatable filter 4 is provided in the filter box 1; an oil removal tank 5 is provided in the liquid storage tank 2, and a vertical pipe 6 is provided at the upper end of the oil removal tank 5, and the middle part of the vertical pipe 6 is bent, and the end thereof is placed above the oil storage tank 3;

[0021] The filter 4 includes a filter frame 401 with an upward opening. A vertical pull rod 402 is fixed in the middle of the filter frame 401. A plurality of liquid separation plates 403 are evenly distributed on the pull rod 402 from top to bottom. The upper and lower liquid separation plates 403 are staggered with each other.

[0022] The bottom of the box body is provided with a piston chamber 7, in which a piston 701 is provided. A piston rod 702 is fixed to the left side of the piston 701. The piston 701 divides the piston chamber 7 into a return chamber 703 on the left and a feed chamber 704 on the right. After the piston 701 moves back and forth, the feed chamber 704 can deliver the liquid in the filter box 1 to the de-oiling tank 5, and the return chamber 703 can deliver the liquid in the de-oiling tank 5 to the liquid storage tank 2.

[0023] A sensor 8 is fixed at the bottom of the bend of the vertical pipe 6, and a water pump 9 is provided above the box body. The water pump 9 can deliver the liquid in the oil removal tank 5 to the liquid storage tank 2. The sensor 8 controls the start and stop of the water pump 9 through the controller.

[0024] In order to realize the rotation of the filter 4 and the material distribution of the liquid separation plate 403, a vertical rotating shaft 404 is fixed to the bottom of the filter box 1, and a sleeve 405 is fixed to the bottom of the filter frame 401. The sleeve 405 can be sleeved on the rotating shaft 404, and the cross-section of the part where the rotating shaft 404 and the sleeve 405 cooperate is square; the upper end of the liquid separation plate 403 and the end facing the side wall of the filter frame 401 are both open, and multiple liquid separation plates 403 are spirally distributed along the pull rod 402.

[0025] In order to realize the left and right reciprocating movement of the piston rod 702 in the piston chamber 7, a gear 406 is installed on the rotating shaft 404, and the left part of the piston rod 702 is provided with a tooth segment meshing with the gear 406; the rotating shaft 404 is driven by the motor to rotate back and forth.

[0026] In order to realize the liquid transportation by the feeding chamber 704 and the return chamber 703, the right end of the feeding chamber 704 is connected to the bottom of the filter box 1 and the oil removal tank 5 respectively through two pipes; the left end of the return chamber 703 is connected to the oil removal tank 5 and the bottom of the liquid storage tank 2 respectively through two pipes, and a one-way valve is provided in the middle of each pipe.

[0027] In order to prevent oil stains from adhering to the inner wall of the oil removal tank 5 , the inner wall of the oil removal tank 5 and the inner wall of the vertical pipe 6 are coated with an oleophobic layer.

[0028] In order to realize the sensor 8 controlling the start and stop of the water pump 9, the sensor 8 adopts a humidity sensor 8. After the sensor 8 detects that the cutting fluid passes through, the water pump 9 starts and then automatically shuts down.

[0029] In order to realize the sensor 8 controlling the start and stop of the water pump 9, the sensor 8 adopts a conductivity sensor 8. After the sensor 8 detects that the cutting fluid passes through, the water pump 9 starts and then automatically shuts down.

[0030] The present invention is box-type as a whole, which is consistent with the existing cutting fluid box of the machine tool. It can be directly modified on the basis of the existing machine tool, or it can be directly replaced, thereby realizing a cutting fluid box with self-circulation function, without the need for additional equipment, and realizing the machine tool's self-circulation system.

[0031] From left to right in this device are filter box 1, liquid storage tank 2, and oil storage tank 3; the liquid storage tank 2 is the area for storing filtered clean cutting fluid, and the cutting fluid suction pump on the machine tool can directly suck from the liquid storage tank 2; the used cutting fluid is collected and uniformly flowed into the filter frame 401 of the filter box 1 through a pipeline, thereby realizing automatic filtration and circulation.

[0032] Once the waste cutting fluid enters the filter frame 401, the motor reciprocates, causing the filter frame 401 to rotate reciprocally. Under the dual effects of gravity and centrifugal force, the cutting fluid is filtered through the side walls of the filter frame 401 and flows into the filter box 1. Because the filter frame 401 has a certain height, the central portion of the filter frame 401 in this device is provided with multiple spiral-shaped liquid separation plates 403 via pull rods 402. After the cutting fluid flows into the liquid separation plates 403, it is intercepted in sections and, as the filter frame 401 rotates, is flung toward the side walls of the filter frame 401 under the action of centrifugal force for filtration. The design of the liquid separation plates 403 allows the cutting fluid to be filtered along the side walls of the filter frame 401 at different heights, thereby increasing the filtration area and improving filtration speed and efficiency.

[0033] At the same time, due to the reciprocating rotation of the filter frame 401, debris adhering to the side walls of the filter frame 401 will be collected in a linear shape or fall to the bottom of the filter frame 401 due to the reciprocating rotation, thus preventing debris from clogging the side walls of the filter frame 401 and achieving self-cleaning of the filter frame 401. Specifically, the rotation can: firstly, utilize centrifugal force to increase the filtration speed; secondly, enable the cutting fluid to be filtered in layers within the filter frame 401; and thirdly, it can aggregate debris to prevent large-scale clogging of the filter frame 401.

[0034] After a certain period of time, the filter frame 401 is pulled out by the pull rod 402 to discharge the slag and clean the filter frame 401 thoroughly.

[0035] The cutting fluid after the filter residue is present at the bottom of the filter box 1. Subsequently, as the piston rod 702 in the piston chamber 7 reciprocates, the feed chamber 704 can pump the cutting fluid at the bottom of the filter box 1 into the de-oiling tank 5. During the pumping process, the return chamber 703 can suck the oil-free cutting fluid at the bottom of the de-oiling tank 5 into the liquid storage tank 2. In other words, the cutting fluid at the bottom of the filter box 1 enters the de-oiling tank 5, and after de-oiling, enters the liquid storage tank 2.

[0036] The principle of degreasing is as follows: First, since the piston rod 702 is provided on the left side of the piston 701, the volume of liquid sucked and discharged by the feed chamber 704 on the right side is larger than that of the return chamber 703 on the left side during one reciprocating movement of the piston 701. From the perspective of the degreasing tank 5, the amount of liquid entering each time is larger than the amount of liquid discharged, but the amount of difference each time is not very large. Therefore, the liquid in the degreasing tank 5 will slowly increase, and the liquid level in the degreasing tank 5 will slowly rise. Due to the difference in density between oil and water, the oil stains in the mixture and cutting fluid will gradually move upward and be in the upper layer. As the liquid level in the degreasing tank 5 rises, the oil stains will be in the upper layer and will first enter the vertical pipe 6, and then flow into the oil storage tank 3 from the end of the vertical pipe 6.

[0037] After a certain period of time, most of the oil in the vertical pipe 6 has been drained, and the cutting fluid needs to be drained next. At this time, the cutting fluid will flow through the bend of the vertical pipe 6. The sensor 8 located there will be activated, and the controller will control the water pump 9 to start, sucking some of the cutting fluid from the de-oiling tank 5 and placing it into the liquid storage tank 2. This will cause the liquid level in the de-oiling tank 5 to drop significantly, generally by one-fifth of the total height of the de-oiling tank 5. The above process will then be repeated.

[0038] Due to the design of the piston chamber 7, the liquid in the de-oiling tank 5 flows in and out simultaneously, and the liquid level rises very slowly. This has the following advantages: 1. The de-oiling tank 5 takes a longer time to overflow each time, and a large amount of oil-free cutting fluid is stored at the bottom of the de-oiling tank 5, allowing the oil in the mixed liquid in the de-oiling tank 5 to float up fully. 2. When the de-oiling tank 5 is about to overflow, the amount of liquid overflowing each time is also relatively small, preventing a large amount of unde-oiled cutting fluid from flowing out. 3. A large amount of de-oiled cutting fluid is retained at the bottom of the de-oiling tank 5, preventing oil from adhering to the inner wall of the de-oiling tank 5 and facilitating cleaning. 4. By utilizing the characteristics of the chambers at both ends of the piston chamber 7, the above-mentioned effects are achieved without adding additional equipment, realizing the de-oiling buffer function of the de-oiling tank 5 and ensuring a continuous supply of cutting fluid.

[0039] The upper end of the pipe connecting the feed chamber 704 to the de-oiling tank 5 is placed in the upper right corner of the de-oiling tank 5; the upper end of the pipe connecting the return chamber 703 to the de-oiling tank 5 is placed in the lower left corner of the de-oiling tank 5. This prevents the oil in the de-oiling tank 5 from being sucked into the liquid storage tank 2.

[0040] This device cleverly features a filter box 1 on the left and a liquid reservoir 2 on the right, with a piston chamber 7 positioned between them. This achieves the following benefits: 1. It filters cuttings before degreasing, preventing them from affecting the subsequent operation of pipes, pistons, and pumps, thereby increasing the device's service life. 2. Its reciprocating motion collects debris within the filter 4 and precisely drives the reciprocating movement of the piston rod 702, enabling the operation of the piston chamber 7.

[0041] This device cleverly utilizes the design of the piston chamber 7. Through the different capacities on both sides of the piston chamber 7, the difference in the liquid entering and discharging from the de-oiling tank 5 is achieved, thereby achieving the effect of slowly rising the liquid level in the de-oiling tank 5, and ultimately achieving continuous cutting fluid supply and sufficient separation of oil and water in the de-oiling tank 5.

[0042] In this device, the bending of the vertical pipe 6 realizes the automatic removal of oil pollution in normal time. When the oil pollution is drained, the sensor 8 is used to achieve a quick response, lowering the liquid level in the oil tank 5 to achieve continued circulation and avoid excessive waste of cutting fluid.

Claims

1. A CNC machine tool cutting fluid circulation system, comprising a box body with an upward opening, wherein the box body is divided into three chambers by two left and right partitions, which are a filter box (1), a liquid storage tank (2), and an oil storage tank (3) from left to right; characterized in that: A rotatable filter (4) is provided in the filter box (1); an oil removal tank (5) is provided in the liquid storage tank (2); a vertical pipe (6) is provided at the upper end of the oil removal tank (5); the middle portion of the vertical pipe (6) is bent, and the end portion is placed above the oil storage tank (3); The filter (4) comprises a filter frame (401) with an upward opening, a vertical pull rod (402) being fixed in the middle of the filter frame (401), a plurality of liquid separation plates (403) being evenly distributed on the pull rod (402) from top to bottom, and the upper and lower plurality of liquid separation plates (403) being staggered with each other; The bottom of the box body is provided with a piston chamber (7), a piston (701) is provided in the piston chamber (7), a piston rod (702) is fixed on the left side of the piston (701), and the piston (701) divides the piston chamber (7) into a return chamber (703) on the left side and a feed chamber (704) on the right side; after the piston (701) moves back and forth, the feed chamber (704) can send the liquid in the filter box (1) to the de-oiling tank (5), and the return chamber (703) can send the liquid in the de-oiling tank (5) to the liquid storage tank (2); A sensor (8) is fixed at the bottom of the bend of the vertical pipe (6), and a water pump (9) is provided above the box body. The water pump (9) can deliver the liquid in the oil removal tank (5) to the liquid storage tank (2). The sensor (8) controls the start and stop of the water pump (9) through the controller.

2. A CNC machine tool cutting fluid circulation system according to claim 1, characterized in that: A vertical rotating shaft (404) is fixed to the bottom of the filter box (1), and a sleeve (405) is fixed to the bottom of the filter frame (401). The sleeve (405) can be sleeved on the rotating shaft (404), and the cross-section of the matching part of the rotating shaft (404) and the sleeve (405) is square; the upper end of the liquid separation plate (403) and the end facing the side wall of the filter frame (401) are both open, and multiple liquid separation plates (403) are spirally distributed along the pull rod (402).

3. A CNC machine tool cutting fluid circulation system according to claim 2, characterized in that: A gear (406) is mounted on the rotating shaft (404), and a tooth segment meshing with the gear (406) is provided on the left side of the piston rod (702); the rotating shaft (404) is driven by a motor to rotate back and forth.

4. A CNC machine tool cutting fluid circulation system according to claim 1, characterized in that: The right end of the feed chamber (704) is connected to the bottom of the filter box (1) and the de-oiling tank (5) respectively through two pipes; the left end of the return chamber (703) is connected to the bottom of the de-oiling tank (5) and the liquid storage tank (2) respectively through two pipes, and a one-way valve is provided in the middle of each pipe.

5. The cutting fluid circulation system for CNC machine tools according to claim 1, characterized in that: The inner wall of the oil removal tank (5) and the inner wall of the vertical pipe (6) are both coated with an oleophobic layer.

6. A CNC machine tool cutting fluid circulation system according to claim 1, characterized in that: The sensor (8) is a humidity sensor (8). After the sensor (8) detects that the cutting fluid has passed through, the water pump (9) starts and then automatically shuts down.

7. A CNC machine tool cutting fluid circulation system according to claim 1, characterized in that: The sensor (8) is a conductivity sensor (8). After the sensor (8) detects that the cutting fluid has passed through, the water pump (9) starts and then automatically shuts down.

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