Air bubble liquid manufacturing device

Abstract

To provide an air bubble-containing liquid manufacturing apparatus capable of stabilizing treatment.SOLUTION: An air bubble-containing liquid manufacturing apparatus 1 is provided on a flow channel P where a coolant used in a grinder G (machine tool) is circulated, and contains air bubbles in the coolant circulated in the flow channel P. The air bubble-containing liquid manufacturing apparatus 1 includes an air bubble-containing treatment part 10, a pump part 20, and a filtration part 30. The air bubble-containing treatment part 10 executes air bubble-containing treatment on the coolant flowed in, and discharges the coolant to the flow channel P on the downstream side. The pump part 20 is provided integrally with the air bubble-containing treatment part 10, and feeds the coolant to an annular gap C as the flow channel on the side of the air bubble-containing treatment part 10. The filtration part 30 performs filtration treatment on the coolant flowed in.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an apparatus for producing a gas bubble-containing liquid. [Background technology]

[0002] Patent Document 1 discloses a conventional device for manufacturing a liquid containing gas bubbles. This device for manufacturing a liquid containing gas bubbles circulates a gas-liquid mixture between two plate-like members with uneven surfaces facing each other, and performs a process of making the gas bubbles finer by shear flow and turbulence to contain UFBs (ultra fine bubbles). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-149120 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the above-mentioned air bubble-containing liquid manufacturing device is used as a device for incorporating air bubbles into coolant, which is a liquid used in machining by machine tools such as grinding machines, there is a risk that the sludge and chips contained in the coolant will clog the uneven surface of the plate-shaped member, making it impossible to incorporate sufficient air bubbles.

[0005] The present invention has been made in consideration of the above-mentioned conventional circumstances, and an object of the present invention is to provide an apparatus for manufacturing a gas bubble-containing liquid that can stabilize the processing. [Means for solving the problem]

[0006] The air bubble-containing liquid manufacturing device according to the present invention is provided in a flow path through which a coolant used in a machine tool flows, and is a device for incorporating air bubbles into the coolant flowing through this flow path. The air bubble-containing liquid manufacturing device includes an air bubble-containing treatment section, a pump section, and a filtration section. The air bubble-containing treatment section performs air bubble-containing treatment on the coolant that has flowed in and discharges it into the downstream flow path. The pump section is provided integrally with the air bubble-containing treatment section, and sends the coolant to the flow path on the air bubble-containing treatment section side. The filtration section performs filtration treatment on the coolant that has flowed in.

[0007] In the gas bubble-containing liquid manufacturing device, the coolant filtered by the filtering section is sent to the gas bubble-containing treatment section via the pump section, which makes it possible to prevent clogging of the gas bubble-containing treatment section due to sludge or the like.

[0008] Therefore, the gas bubble-containing liquid manufacturing apparatus of the present invention can stabilize the processing.

[0009] The above-mentioned machine tool refers to any machine that performs processing by supplying coolant to a processing point, such as a grinding machine, a lathe, a milling machine, or a machining center.

[0010] In the apparatus for producing a gas-containing liquid, the filtration section Multiple It has a filter. Multiple The filter is parallel to the flow path. Distributed to In this case, by switching between multiple filters, even if a filter becomes clogged, processing can be continued without stopping the device. Furthermore, when multiple filters are used simultaneously, the filtration area can be easily adjusted according to the number of filters used. This allows the pump section to optimally utilize its capabilities, and the desired discharge pressure can be easily obtained.

[0011] The gas bubble-containing liquid manufacturing device is equipped with a switching unit. ElThe switching unit can freely switch the communication state between each of the multiple filters and the flow path individually. In this case, even if the filtering ability of one of the multiple filters decreases, the switching unit can switch to another filter, allowing processing to continue without stopping the device.

[0012] The gas bubble-containing liquid manufacturing device is equipped with a backwash flow path. El The backwash flow path is connected to the filtration section, and washing water for washing the filter flows through it. In this case, maintenance of the filter can be easily performed. The backwash passage causes cleaning water to flow through the filter in a direction opposite to the flow direction of the coolant.

[0013] In the gas bubble-containing liquid manufacturing apparatus, a cleaning water tank for storing cleaning water may be provided downstream of the filtration section in the backwash flow path. This cleaning water tank may have a storage section for storing impurities contained in the cleaning water used to clean the filter. In this case, the impurities contained in the cleaning water used to clean the filter can be separated. Therefore, the filter can be backwashed using cleaning water with relatively few impurities, and the filter can be cleaned more efficiently.

[0014] In the gas bubble-containing liquid manufacturing apparatus, when switching one of the filters from a connected state to a non-connected state with the coolant flow path, the switching unit switches the filter from a non-connected state to a connected state with the backwash flow path. El In this case, the coolant flow path and the backwash flow path can be switched simultaneously, which is convenient.

[0015] In the gas bubble-containing liquid manufacturing apparatus, the switching unit switches one of the multiple filters from a non-communicating state to a communicating state with the coolant flow path before switching one of the multiple filters from a communicating state to a non-communicating state with the coolant flow path. In this case, the flow of coolant in the original filter can be continued until the flow of coolant in the filter to be switched is established, so that the filter can be switched smoothly without causing a malfunction such as the so-called water hammer phenomenon. [Brief description of the drawings]

[0016] [Figure 1] 1 is a diagram showing a schematic configuration of a flow path in which a gas bubble-containing liquid manufacturing device according to an embodiment is provided; [Diagram 2] FIG. 2 is a diagram illustrating a configuration of a filtering section according to an embodiment. [Diagram 3] FIG. 2 is a diagram showing a schematic configuration of a bubble-containing treatment section according to the embodiment; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0018] As shown in FIG. 1, the gas bubble-containing liquid manufacturing apparatus 1 is provided in a flow path P through which a coolant used in a grinding machine G as a machine tool flows. The grinding machine G performs processing while supplying coolant to a processing point. The grinding machine G is provided with a coolant tank Tc for storing the coolant. The flow path P is a circulation flow path that circulates the coolant in the coolant tank Tc and returns it to the coolant tank Tc. The gas bubble-containing liquid manufacturing apparatus 1 performs a process of incorporating gas bubbles into the coolant flowing through the flow path P.

[0019] As shown in Fig. 1, the gas bubble-containing liquid manufacturing apparatus 1 includes a gas bubble-containing processing section 10, a pump section 20, and a filtration section 30. These are connected by a flow path P. As shown in Fig. 2, the gas bubble-containing liquid manufacturing apparatus 1 includes a cleaning water tank 40. The cleaning water tank 40 is connected to the filtration section 30 by a backwash flow path R, which will be described later. Each of these sections of the gas bubble-containing liquid manufacturing apparatus 1 is controlled by a control section 50.

[0020] As shown in FIG. 3, the bubble-containing treatment unit 10 is configured to have a casing 11 and a rotor 12. The casing 11 is formed in a cylindrical shape. A first inlet section 13, a second inlet section 14, and an outlet section 15 are formed in the casing 11. The first inlet section 13 and the outlet section 15 are formed to open in the wall sections at both axial ends of the casing 11. The coolant flowing through the flow path P flows into the casing 11 from the first inlet section 13 and flows out from the outlet section 15 to the downstream flow path P. The second inlet section 14 is formed in the peripheral wall of the casing 11. The second inlet section 14 introduces compressed air into the casing 11.

[0021] The rotor 12 is formed in a cylindrical shape and is housed in the casing 11 so as to be rotatable around the axis of the casing 11. An annular gap C is formed between the outer peripheral surface of the rotor 12 and the inner peripheral surface of the casing 11, and the coolant flows through this gap C. That is, the gap C between the outer peripheral surface of the rotor 12 and the inner peripheral surface of the casing 11 constitutes a flow path P. A large number of dimples are formed on the outer peripheral surface of the rotor 12 and the inner peripheral surface of the casing 11. The coolant in the casing 11 flows through the gap C while the rotor 12 is rotated by the motor 16, and a shear force is applied to the coolant. As a result, air bubbles in the coolant are broken down into fine particles to generate UFB.

[0022] The pump section 20 delivers coolant to the flow path P on the air bubble-containing treatment section 10 side. The pump section 20 is provided integrally with the air bubble-containing treatment section 10. Specifically, as shown in FIG. 3, the pump section 20 has a base section 21 and a plurality of blade sections 22. The base section 21 is attached to an end of the rotor 12 corresponding to the upstream side of the flow path P, and rotates integrally with the rotor 12. The base section 21 has a disk shape with an outer diameter equal to that of the rotor 12. The plurality of blade sections 22 are provided integrally with the base section 21 so as to protrude from an end face of the base section 21 corresponding to the upstream side of the flow path P.

[0023] The pump section 20 constitutes a centrifugal pump (volute pump), and the plurality of blades 22 correspond to a centrifugal impeller. That is, the pump section 20 forms a flow of coolant from the center (rotation axis) of the base section 21 in the centrifugal direction. The plurality of blades 22 apply a swirling force to the coolant to increase its energy, and the coolant is sucked into the casing 11 from the first inlet section 13, and the coolant is delivered to the annular gap C between the inner circumferential surface of the casing 11 and the outer circumferential surface of the rotor 12 that constitutes the flow path P. The pump section 20 forms a discharge pressure that transports the coolant toward the annular gap C downstream of the pump section 20 and the outlet section 15.

[0024] The filtering unit 30 is disposed in the flow path P upstream of the pump unit 20. The filtering unit 30 filters the coolant supplied from the grinding machine G, which is the upstream side. As shown in FIG. 2, in this embodiment, the filtering unit 30 is configured to have two filters, a first filter 31 and a second filter 32. The first filter 31 and the second filter 32 are disposed in parallel in the flow path P upstream of the pump unit 20. The filters 31 and 32 are configured to have a filter medium made of stainless steel mesh.

[0025] As shown in FIG. 2, switching valves 31A and 31B are provided on the upstream side and downstream side of the first filter 31, respectively. The switching valves 31A and 31B switch the communication state between the first filter 31 and the flow path P. In other words, the switching valves 31A and 31B switch the state in which the coolant flowing through the flow path P flows through the first filter 31 and the state in which the coolant does not flow through the first filter 31. Similarly, switching valves 32A and 32B are provided on the upstream side and downstream side of the second filter 32, respectively. The switching valves 32A and 32B switch the communication state between the second filter 32 and the flow path P. In other words, the switching valves 32A and 32B switch the communication state between the second filter 32 and the flow path P and the state in which the coolant flowing through the flow path P flows through the second filter 32 and the state in which the coolant does not flow through the second filter 32.

[0026] Each of the switching valves 31A, 31B, 32A, and 32B is an automatic valve driven by an actuator. Each of the switching valves 31A, 31B, 32A, and 32B is driven and controlled by a control unit 50. Each of the switching valves 31A, 31B, 32A, and 32B and the control unit 50 can freely switch the communication state of the first filter 31 and the second filter 32 with the flow path P individually. In other words, each of the switching valves 31A, 31B, 32A, and 32B and the control unit 50 functions as a switching unit according to the present invention.

[0027] As shown in Fig. 2, the first filter 31 and the second filter 32 are provided with differential pressure gauges 31C and 32C, respectively. The differential pressure gauges 31C and 32C measure the differential pressure in the flow paths P on the upstream and downstream sides of each filter 31 and 32. For example, when a filtration process is performed in the filters 31 and 32 and clogging of the filter media progresses, a relatively large differential pressure is measured. On the other hand, immediately after the filters 31 and 32 are washed, clogging of the filter media is eliminated and a relatively small differential pressure is measured. Each differential pressure gauge 31C and 32C feeds back the measured differential pressure to the control unit 50.

[0028] 2, the filtration unit 30 is connected to the cleaning water tank 40 by a backwash flow path R. The first filter 31 and the second filter 32 of the filtration unit 30 are cleaned by cleaning water flowing through the backwash flow path R. The backwash flow path R is a circulation flow path through which cleaning water flows through the cleaning water tank 40, the backwash water pump 41, and the filtration unit 30 in this order. The backwash flow path R is connected in parallel to the flow path P with respect to the filtration unit 30.

[0029] In this embodiment, each of the switching valves 31A, 31B, 32A, and 32B is a three-way valve. As shown in Fig. 2, the backwash flow path R is connected to each of the switching valves 31A, 31B, 32A, and 32B. When the first filter 31 and the flow path P are not connected to each other, the switching valves 31A and 31B connect the first filter 31 to the backwash flow path R. Similarly, when the second filter 32 and the flow path P are not connected to each other, the switching valves 32A and 32B connect the second filter 32 to the backwash flow path R.

[0030] The cleaning water tank 40 stores cleaning water for backwashing to clean the first filter 31 and the second filter 32. As shown in FIG. 2, the cleaning water tank 40 has an inlet 40A and an outlet 40B. The inlet 40A is connected to the downstream side of the filtration section 30 in the backwash flow path R, and the cleaning water that has cleaned the filters 31 and 32 flows in. The inlet 40A opens at the top of one end of the cleaning water tank 40. The outlet 40B opens at the bottom of the other end of the cleaning water tank 40. The outlet 40B is connected to the upstream side of the filtration section 30 in the backwash flow path R. A water pump 41 for backwashing is provided between the outlet 40B and the filtration section 30. The water pump 41 draws in the cleaning water in the cleaning water tank 40 that flows out from the outlet 40B and sends it to the filtration section 30. The water pump 41 is driven and controlled by the control section 50.

[0031] As shown in FIG. 2, two partition plates 40C, 40D are provided between the inlet 40A and the outlet 40B in the flush water tank 40. The partition plate 40C is provided extending in the vertical direction at a position close to the inlet 40A. The upper end of the partition plate 40C extends to a height substantially equal to the upper edge of the flush water tank 40. The lower end of the partition plate 40C is configured to form a gap between the bottom surface of the flush water tank 40. Meanwhile, the upper end of the partition plate 40D is located at a height lower than the upper edge of the flush water tank 40 at a position close to the outlet 40B, and the lower end is connected to the bottom surface of the flush water tank 40. In the flush water tank 40, the flush water flowing in from the inlet 40A flows under the partition plate 40C and above the partition plate 40D, and flows out from the outlet 40B. The upstream bottom of the partition plate 40D is made into a deposition section 40E. The accumulation section 40E is an example of a storage section according to the present invention. A discharge port 40F is formed in the bottom surface of the flush water tank 40 in the accumulation section 40E. Also, a water supply port 40G is formed in the upper downstream portion of the partition plate 40D.

[0032] A sediment sensor 42 that detects sediments and a water level sensor 43 that detects the level of the wash water in the wash water tank 40 are disposed in the wash water tank 40. The sediment sensor 42 detects sediments in the wash water tank 40. The water level sensor 43 detects the water level in the wash water tank 40.

[0033] The deposit sensor 42 is disposed above the deposition section 40E. Specifically, the deposit sensor 42 is disposed near the bottom surface of the space between the two partition plates 40C, 40D and above the discharge port 40F. In the process in which the cleaning water flows through the cleaning water tank 40, contaminants such as sludge contained in the cleaning water are separated. Among the separated contaminants, those having a specific gravity greater than that of the cleaning water are deposited on the bottom surface of the cleaning water tank 40. The deposits are deposited in the deposition section 40E at the bottom of the space on the inlet 40A side of the partition plate 40D. As shown in FIG. 2, the bottom surface of the cleaning water tank 40 is provided in a sloping manner such that it becomes lower from the end on the inlet 40A side toward the end on the outlet 40B side. As a result, the deposits in the cleaning water tank 40 are gathered and deposited near the partition plate 40D. The deposit sensor 42 is capable of detecting that the deposits in the deposition section 40E have accumulated to a predetermined height.

[0034] The detection result by the deposit sensor 42 is fed back to the control unit 50. The control unit 50 executes control to automatically discharge the deposits in the cleaning water tank 40 based on the detection result of the deposit sensor 42. Specifically, as shown in FIG. 2, a discharge valve 44 is provided in the flow path connected to the discharge port 40F. The discharge valve 44 is an automatic valve, and is driven and controlled by the control unit 50. When the deposit sensor 42 detects that the deposits in the cleaning water tank 40 have accumulated to a predetermined height, the control unit 50 opens the discharge valve 44 to discharge the deposits. The discharged deposits are separated from the water in the recovery tank 45 and recovered.

[0035] The water level sensor 43 is a float-type sensor arranged in the space downstream of the partition plate 40D. The detection result by the water level sensor 43 is fed back to the control unit 50. The control unit 50 executes control to automatically supply cleaning water into the cleaning water tank 40 based on the detection result of the water level sensor 43. Specifically, as shown in FIG. 2, a water supply valve 46 is provided in the flow path connected to the water supply port 40G. The water supply valve 46 is an automatic valve, and is driven and controlled by the control unit 50. When the water level sensor 43 detects that the water level in the cleaning water tank 40 has dropped to a predetermined height, the control unit 50 opens the water supply valve 46 to replenish the cleaning water. Also, when the water level sensor 43 detects that the water level in the cleaning water tank 40 is equal to or higher than a predetermined level, the control unit 50 executes control to open the discharge valve 44 to discharge the cleaning water together with the sediment.

[0036] Next, the operation of the gas bubble-containing liquid manufacturing apparatus 1 having the above configuration will be described.

[0037] First, the air bubble-containing treatment device 10 is started. Specifically, the motor 16 is driven to rotate the rotor 12. Then, the coolant is sucked from the coolant tank Tc of the grinding machine G by the action of the pump unit 20, and the coolant flows through the flow path P. The coolant flows through the flow path P from the coolant tank Tc of the grinding machine G through the filtration unit 30, the pump unit 20, and the air bubble-containing treatment device 10 in this order. The flow path P forms a circulation flow path that circulates the coolant through the coolant tank Tc, the filtration unit 30, the pump unit 20, and the air bubble-containing treatment device 10 in this order.

[0038] In the air bubble-containing treatment section 10, the coolant flowing in from the first inlet section 13 flows through the pump section 20 in the annular gap C between the inner peripheral surface of the casing 11 and the outer peripheral surface of the rotor 12. In the annular gap C, the coolant is subjected to a shear force by the relative movement of the outer peripheral surface of the rotor 12, on which a large number of dimples are formed, and the inner peripheral surface of the casing 11 together with the compressed air flowing in from the second inlet section 14 (air bubble-containing treatment). As a result, the air bubbles in the coolant are broken down into fine particles, and a coolant containing fine air bubbles such as UFB (air bubble-containing coolant) is generated. The generated air bubble-containing coolant is sent to the coolant tank Tc by the action of the pump section 20.

[0039] In addition, the coolant flowing through the flow path P is filtered in the filtration section 30 upstream of the air bubble-containing treatment section 10 before being subjected to the air bubble-containing treatment in the air bubble-containing treatment section 10. In the filtration process, the first filter 31 and the second filter 32 remove impurities such as sludge in the coolant. This suppresses problems caused by impurities such as sludge in the pump section 20 downstream of the filtration section 30 and the air bubble-containing treatment section 10. In particular, in the case of this embodiment, the air bubble-containing treatment section 10 employs a method of applying shear force by relative movement of the outer circumferential surface of the rotor 12 on which a large number of dimples are formed and the inner circumferential surface of the casing 11. For this reason, in the case of a coolant containing a large amount of impurities such as sludge, there is a concern that the impurities in the coolant will clog the dimples, resulting in a decrease in the treatment efficiency. In the air bubble-containing liquid manufacturing device 1, the coolant before the air bubble-containing treatment is filtered to remove impurities such as sludge, thereby suppressing a decrease in the efficiency of the air bubble-containing treatment.

[0040] In the filtration process in the filtration unit 30, two filters, a first filter 31 and a second filter 32, are alternately used. In this way, even if the filter material of one filter becomes clogged, the other filter can be used to continuously perform the bubble-containing process. The two filters 31 and 32 are switched by the control unit 50 by controlling the opening and closing of four switching valves 31A, 31B, 32A, and 32B. For example, when performing the filtration process using the first filter 31, the control unit 50 opens the switching valves 31A and 31B on the upstream and downstream sides of the first filter 31, and closes the switching valves 32A and 32B on the upstream and downstream sides of the second filter 32 (see FIG. 2). Then, the first filter 31 is in communication with the flow path P, and the second filter 32 is in non-communication with the flow path P. In this way, during the filtration process, the four switching valves 31A, 31B, 32A, and 32B are controlled to open and close by the control unit 50, ensuring the flow of coolant to the pump unit 20 and the bubble-containing processing unit 10 via one of the first filter 31 and the second filter 32.

[0041] In this embodiment, the control unit 50 switches between the two filters 31 and 32 based on the measurement values ​​of the differential pressure gauges 31C and 32C. For example, when the first filter 31 is used for filtration, the control unit 50 refers to the measurement value fed back from the differential pressure gauge 31C corresponding to the first filter 31. When the measurement value of the differential pressure gauge 31C is equal to or greater than a predetermined threshold, the control unit 50 determines that a certain degree of clogging has occurred in the filter material of the first filter 31. In this case, the control unit 50 closes the switching valves 31A and 31B corresponding to the first filter 31 and opens the switching valves 32A and 32B corresponding to the second filter 32. Then, the first filter 31 is not connected to the flow path P, and the second filter 32 is connected to the flow path P. As a result, the flow of the coolant in the flow path P is switched from the flow via the first filter 31 to the flow via the second filter 32.

[0042] In addition, in this embodiment, when switching the communication state of the first filter 31 and the second filter 32 with the flow path P, the filter not in communication with the flow path P is switched to a communication state before switching the filter in communication with the flow path P to a non-communicating state among the first filter 31 and the second filter 32. That is, in this embodiment, when switching the communication state between each filter 31, 32 and the flow path P, two switching valves in a closed state among the four switching valves 31A, 31B, 32A, 32B are opened first, and then the other two switching valves are changed from an open state to a closed state. This makes it possible to smoothly switch from a flow passing through one of the first filter 31 and the second filter 32 in the flow path P to a flow passing through the other. In addition, it is possible to avoid closing all of the four switching valves 31A, 31B, 32A, 32B, and to continuously perform the bubble-containing process.

[0043] As described above, the backwash flow passage R is connected to each of the switching valves 31A, 31B, 32A, and 32B. The first filter 31 and the second filter 32, which are not connected to the flow passage P by switching the switching valves 31A, 31B, 32A, and 32B, are connected to the backwash flow passage R. Then, the first filter 31 and the second filter 32, which are switched from not connected to the backwash flow passage R to connected to it, are subjected to a backwash process using cleaning water. In the backwash process, cleaning water is circulated through the filters 31 and 32 in a direction opposite to the flow direction of the coolant. This cleans sludge and the like accumulated on the filter media surfaces of the filters 31 and 32.

[0044] The backwash process is carried out as follows. First, the backwash water pump 41 shown in FIG. 2 is driven. In this embodiment, the water pump 41 is driven and controlled by the control unit 50. The control unit 50 executes control to start the water pump 41 after the flow path is switched by the switching valves 31A, 31B, 32A, and 32B. When the water pump 41 is driven, the cleaning water in the cleaning water tank 40 is sent to the filtration unit 30 via the water pump 41. In the filtration unit 30, the cleaning water flows through the filter that is in communication with the backwash flow path R, among the first filter 31 and the second filter 32. At this time, the cleaning water flows through the filters 31 and 32 in the opposite direction to the flow direction of the coolant. For example, when performing a backwash process on the first filter 31, the cleaning water sent from the water pump 41 flows through the switching valve 31B, the first filter 31, and the switching valve 31A in this order. As a result, sludge and the like on the surface of the filter medium is washed away by the cleaning water, and clogging of the filter medium is eliminated. Whether or not the clogging of the filter media has been eliminated is determined based on the measured values ​​of the differential pressure gauges 31C and 32C. When the measured values ​​of the differential pressure gauges 31C and 32C during the backwashing process become equal to or lower than a predetermined threshold value, the control unit 50 executes control to stop the operation of the water pump 41 and terminate the backwashing process.

[0045] The wash water that has washed the filter media of the filters 31, 32 in the filtration section 30 flows through the backwash flow path R and into the wash water tank 40. In the wash water tank 40, mixtures such as sludge contained in the wash water are separated. Specifically, as the wash water flows through the wash water tank 40 from the inlet 40A to the outlet 40B, impurities having a smaller specific gravity than the wash water are separated by the partition plate 40C, and impurities having a larger specific gravity than the wash water are separated by the partition plate 40D.

[0046] In the cleaning water tank 40, impurities with a large specific gravity are deposited on the bottom surface of the cleaning water tank 40. Since the bottom surface of the cleaning water tank 40 is formed in an inclined shape so as to become lower toward the outlet 40B side, the deposited impurities are accumulated and deposited in the deposition section 40E at the bottom of the upstream side of the partition plate 40D. The control unit 50 executes control to discharge the deposits in the deposition section 40E based on the detection result of the deposit sensor 42. Specifically, when the deposit sensor 42 detects that the deposits have been deposited in the deposition section 40E to a predetermined height, the control unit 50 opens the discharge valve 44. As a result, the deposits deposited in the deposition section 40E are discharged together with the cleaning water. The discharged deposits are further separated from the cleaning water and collected in the recovery tank 45. Based on the detection result of the deposit sensor 42, the control unit 50 closes the discharge valve 44 after the deposits in the deposition section 40E have decreased to a predetermined height or less.

[0047] The flush water in the flush water tank 40 gradually decreases as it is discharged as sediments are discharged from the discharge valve 44, evaporates, and so on. The water level in the flush water tank 40 is monitored by a water level sensor 43. The control unit 50 replenishes flush water into the flush water tank 40 based on the detection results of the water level sensor 43. When the water level sensor 43 detects that the water level in the flush water tank 40 has fallen below a predetermined water level, the control unit 50 executes control to open the water supply valve 46 to replenish the flush water. Furthermore, when the water level sensor 43 detects that flush water has been replenished into the flush water tank 40 and the water level has risen to or above the predetermined water level, the control unit 50 executes control to close the water supply valve 46 to stop the water supply.

[0048] As described above, the air bubble-containing liquid manufacturing device 1 according to the first embodiment is provided in the flow path P through which the coolant used in the grinding machine G as a machine tool flows, and causes air bubbles to be contained in the coolant flowing through the flow path P. The air bubble-containing liquid manufacturing device 1 includes an air bubble-containing processing unit 10, a pump unit 20, and a filtration unit 30. The air bubble-containing processing unit 10 performs air bubble-containing processing on the coolant that has flowed in and discharges it into the flow path P on the downstream side of the grinding machine G. The pump unit 20 is provided integrally with the air bubble-containing processing unit 10 and sends the coolant into the annular gap C as a flow path on the air bubble-containing processing unit 10 side. The filtration unit 30 is disposed in the flow path P upstream of the pump unit 20 and performs filtration processing of the coolant supplied from the upstream side of the grinding machine G.

[0049] In the air bubble-containing liquid manufacturing device 1, the coolant filtered by the filtration section 30 is sent to the air bubble-containing treatment section 10 via the pump section 20. This makes it possible to suppress clogging of the air bubble-containing treatment section 10 due to sludge, etc. In addition, since the filtered coolant is introduced into the pump section 20, the discharge flow rate and delivery pressure of the coolant by the pump section 20 can be stabilized compared to when unfiltered coolant containing a relatively large amount of impurities is introduced.

[0050] Therefore, the gas bubble-containing liquid manufacturing apparatus 1 can stabilize the processing.

[0051] Further, the filtering section 30 has a first filter 31 and a second filter 32 arranged in parallel in the flow path P. The gas bubble-containing liquid manufacturing apparatus 1 switches between the first filter 31 and the second filter 32. Therefore, processing can be continued without stopping the apparatus.

[0052] The gas bubble-containing liquid manufacturing apparatus 1 also includes switching valves 31A, 31B, 32A, and 32B as switching units, and a control unit 50. The control unit 50 controls the opening and closing of the switching valves 31A, 31B, 32A, and 32B, so that the gas bubble-containing liquid manufacturing apparatus 1 can freely switch the communication state between the first filter 31 and the second filter 32 and the flow path P individually. Therefore, even if the filtering ability of one of the first filter 31 and the second filter 32 decreases, it is possible to easily switch to the other filter.

[0053] The gas bubble-containing liquid manufacturing apparatus 1 also includes a backwash flow path R. The backwash flow path R is connected to the filtration section 30, and wash water for washing the first filter 31 and the second filter 32 flows through the backwash flow path R. This allows for easy maintenance of the filters.

[0054] Further, downstream of the filtration section 30 in the backwash flow path R, a cleaning water tank 40 for storing cleaning water is provided. This cleaning water tank 40 has a deposition section 40E for depositing impurities contained in the cleaning water used to clean the first filter 31 and the second filter 32. Therefore, it is possible to separate impurities contained in the cleaning water used to clean the first filter 31 and the second filter 32, and it is possible to backwash the first filter 31 and the second filter 32 using cleaning water with relatively little impurities. This allows the first filter 31 and the second filter 32 to be cleaned more efficiently.

[0055] Furthermore, when switching one of the first filter 31 and the second filter 32 from a connected state to a disconnected state with the flow path P, the control unit 50 as a switching unit switches the one filter from a disconnected state to a connected state with the backwash flow path R. In this way, the gas bubble-containing liquid manufacturing apparatus 1 is easy to use because it can simultaneously switch the flow path P and the backwash flow path R.

[0056] Furthermore, the control unit 50 as a switching unit switches the other of the first filter 31 and the second filter 32 from a non-communicating state to a communicating state with the flow path P before switching one of the first filter 31 and the second filter 32 from a communicating state to a non-communicating state with the flow path P. This allows the flow of coolant in the original filter to continue until the flow of coolant in the filter to be switched is established. As a result, it is possible to realize smooth filter switching without causing problems such as the so-called water hammer phenomenon.

[0057] The present invention is not limited to the embodiments described above and illustrated in the drawings, and the following embodiments, for example, are also included within the technical scope of the present invention.

[0058] (1) In the above embodiment, the device for manufacturing an air bubble-containing liquid is exemplified as a device for incorporating air bubbles into a coolant used in a grinding machine, but this is not essential. The device for manufacturing an air bubble-containing liquid according to the present invention may also be one for incorporating air bubbles into a coolant used in other machine tools such as a lathe, a milling machine, a machining center, etc.

[0059] (2) In the above embodiment, the produced gas bubble-containing coolant is returned to the coolant tank of the grinding machine, which is a machine tool, but the gas bubble-containing coolant may be directly supplied to the processing point of the machine tool. The gas bubble-containing liquid treatment device may be provided independently of the machine tool. In this case, the produced gas bubble-containing coolant may be introduced into the coolant tank of the machine tool in a batch manner or via a pipe constituting a separate flow path.

[0060] (3) In the above embodiment, the bubble-containing treatment section has a rotor, but this is not essential. The bubble-containing treatment section may have a flow path with many convex and concave portions without a rotor, as long as it performs some kind of bubble-containing treatment on the coolant.

[0061] (4) In the above embodiment, the pump unit is a centrifugal pump, but this is not essential. The pump unit may have another pump structure, such as a vane pump or a cascade pump (vortex pump).

[0062] (5) In the above embodiment, the filtering section is provided with two filters, but this is not essential. The filtering section may be configured to have, for example, one filter or three or more filters.

[0063] (6) In the above embodiment, the filtration unit has a plurality of filters arranged in parallel, and includes a switching valve and a control unit as a switching unit for switching between the plurality of filters, but this is not essential. For example, the filtration unit may be configured such that the plurality of filters arranged in parallel are not switched and perform filtration processing simultaneously. In this case, the filtration area can be freely set according to the number of filters used.

[0064] (7) In the above embodiment, the filter unit has a configuration in which a plurality of filters are arranged in parallel in the flow path, but this is not essential. When the filter unit has a plurality of filters, the filters may be arranged in series in the flow path, or a combination of parallel and series arrangements may be used. When the filters are arranged in series, the mesh size of the filter material may be made different for each filter, for example, by gradually decreasing the mesh size of the filter material toward the downstream side.

[0065] (8) In the above embodiment, a configuration including a backwash flow path is illustrated, but this is not essential. The device for producing a gas-containing liquid according to the present invention may be configured to be manually cleaned by, for example, attaching and detaching the filter material of the filter without including a backwash flow path.

[0066] (9) In the above embodiment, the accumulation section in which sludge and the like are accumulated is exemplified as the storage section, but this is not essential. In other words, it is sufficient that the sludge and the like in the storage section are accumulated in the storage section by floating on the liquid surface of the coolant, floating in the coolant, or the like.

[0067] (10) In the above embodiment, the filtration unit is disposed upstream of the bubble-containing treatment unit, but this is not essential. The filtration unit may be disposed at any position in the flow path, for example, downstream of the bubble-containing treatment unit. [Explanation of symbols]

[0068] Reference Signs List 1...Air bubble-containing liquid manufacturing apparatus, 10...Air bubble-containing treatment section, 20...Pump section, 30...Filtration section, 31, 32...Filters (31...First filter, 32...Second filter), 31A, 31B, 32A, 32B...Switching valve (switching section), 40...Cleaning water tank, 40E...Sedimentation section (storage section), 50...Control section (switching section), C...Annular gap (coolant flow path), G...Grinding machine (machine tool), P...Flow path (coolant flow path), R...Backwash flow path

Claims

1. 1. An apparatus for manufacturing an air bubble-containing liquid, the apparatus being provided in a flow path through which a coolant used in a machine tool flows, for causing air bubbles to be contained in the coolant flowing through the flow path, an air bubble-containing treatment section that performs an air bubble-containing treatment on the coolant that has flowed in and discharges the coolant to the downstream side of the flow path; a pump unit provided integrally with the air bubble-containing treatment unit and configured to deliver the coolant to the flow path on the air bubble-containing treatment unit side; A filtering unit having a plurality of filters and performing a filtering process on the coolant that has flowed in; a backwash flow path connected to the filtration unit, for circulating cleaning water through the filter in a direction opposite to a flow direction of the coolant to clean the filter; A switching unit capable of individually switching a communication state between each of the plurality of filters and the flow path, The switching unit, when switching one of the filters and the flow path from a connected state to a disconnected state, switches the one of the filters and the backwash flow path from a disconnected state to a connected state, and switches the other of the filters and the flow path from a disconnected state to a connected state before the one of the filters is connected to the backwash flow path.

2. The bubble-containing liquid manufacturing apparatus as described in Claim 1, characterized in that the multiple filters are arranged in parallel in the flow path.

3. A cleaning water tank for storing the cleaning water is provided downstream of the filtration section in the backwash flow path, 2. The apparatus for producing a gas-containing liquid according to claim 1, wherein the cleaning water tank has a storage section for storing impurities contained in the cleaning water used to clean the filter.

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