Coolant treatment device

Abstract

To provide a coolant processing device which can achieve reduction of an installation area while securing a sufficient capacity of a tank, and to provide a machine tool including the coolant processing device.SOLUTION: A coolant processing device includes: a tank (21) which may store a coolant and sludge; a pump (31) which is located below the tank (21) to pump the coolant and the sludge; a pipe (46) which is arranged so that the coolant and the sludge flow from the tank (21) to an area below the tank (21) to form a flow toward the pump (31) below the tank (21) and then flow upward by the pump (31); and a filter (51) which filters the sludge from the coolant and the sludge flowing upward.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This invention relates to a coolant processing device and a machine tool.

Background Art

[0002] For example, Japanese Patent Application Laid-Open No. 2018-161689 (Patent Document 1) discloses a coolant processing device including a tank for storing coolant and a chip conveyor housed in the tank.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As disclosed in the above Patent Document 1, a coolant processing device used in a machine tool is known. In such a coolant processing device, since it is necessary to supply a large amount of coolant to the machining area of the machine tool, it is necessary to ensure a sufficient capacity of the tank. On the other hand, since the coolant processing device greatly affects the floor area (installation area) of the entire machine tool, it is required to reduce the installation area of the coolant processing device.

[0005] Therefore, an object of this invention is to solve the above problems, and to provide a coolant processing device in which the capacity of the tank is sufficiently ensured while the installation area is kept small, and a machine tool including such a coolant processing device.

Means for Solving the Problems

[0006] A coolant treatment apparatus according to one aspect of this invention comprises a tank capable of storing coolant and sludge, a pump located below the tank for pumping up the coolant and sludge, a pipe arranged so that the coolant and sludge flow from the tank to below the tank, then become a flow towards the pump below the tank, and are pumped upward, and a filter for filtering the sludge from the coolant and sludge flowing upward.

[0007] A coolant processing apparatus according to another aspect of this invention comprises a tank having a bottom and capable of storing coolant, and a pump positioned below the bottom. The bottom is provided with an opening from which the coolant in the tank flows out. In a top view, the pump is positioned offset from the opening.

[0008] A coolant processing device according to yet another aspect of this invention comprises a chip conveyor tank capable of storing coolant, a chip conveyor for transporting chips in the chip conveyor tank, a pump for drawing up the coolant from the chip conveyor tank, a filter for filtering the coolant, and a supply pump for supplying the filtered coolant to the processing area.

[0009] A coolant processing apparatus according to yet another aspect of this invention has a bottom and sides rising from the periphery of the bottom, and includes a tank capable of storing coolant above the bottom and surrounded by the sides. The maximum length of the sides in the vertical direction is greater than the length of the straight line connecting the two furthest points on the periphery of the bottom when viewed from above.

[0010] With a coolant treatment system configured in this way, a tall tank can be used to ensure sufficient tank capacity while keeping the installation area of ​​the coolant treatment system small.

[0011] Preferably, the coolant treatment device further includes a pump. The tank is configured to form a space below the bottom for the pump to be located.

[0012] With this configuration of the coolant treatment device, the pump is located in the space below the bottom, so the installation area of ​​the coolant treatment device can be kept small regardless of the pump's placement.

[0013] Preferably, the coolant treatment system further includes piping that connects the pump and the tank and is connected to the bottom.

[0014] With a coolant treatment device configured in this way, the tall tank collects the sludge contained in the coolant at the bottom of the tank, and the pump drives the sludge to recover it through the piping.

[0015] Preferably, the coolant processing device further includes a filter provided on the path of the coolant flow from the tank, which is formed when the pump is driven.

[0016] With a coolant treatment apparatus configured in this way, sludge recovered from the tank can be removed by a filter.

[0017] Preferably, the pump includes a shaft for rotating the impeller, and is positioned in space with the shaft extending horizontally.

[0018] With a coolant treatment system configured in this way, the pump is positioned in a way that reduces its overall height, making it easier to place the pump in the space below the bottom of the tank.

[0019] Preferably, the coolant processing device further includes a first pump and a second pump, a first pipe connecting the first pump and the tank and connected to the bottom, a filter provided on the path of the coolant flow from the tank formed by the operation of the first pump, a second pipe connecting the second pump and the tank and connected to the bottom, and a guide section disposed inside the tank, extending along the periphery of the bottom when viewed from above, and guiding the coolant so that a swirling flow of coolant is generated on the bottom. The shortest distance between the connection of the first pipe to the bottom and the guide section is greater than the shortest distance between the connection of the second pipe to the bottom and the guide section.

[0020] With the coolant treatment apparatus configured in this way, sludge that has accumulated in the center of the bottom due to the swirling flow of coolant generated on the bottom can be recovered through a first pipe connected near the center of the bottom. As a result, the sludge can be efficiently removed by a filter installed in the path of the coolant flow from the tank, which is formed when the first pump is driven.

[0021] Preferably, the coolant processing device further includes a plate member positioned within the tank and projected onto the connection point of the second piping to the bottom when viewed from above.

[0022] With the coolant treatment apparatus configured in this way, sludge that would otherwise fall towards the connection point of the second pipe to the tank can be blocked by the plate member.

[0023] Preferably, the coolant processing device further includes a pump, piping connecting the pump and the tank and connected to the bottom, a sensor capable of detecting an indicator corresponding to the amount of coolant stored in the tank, and a control device that drives the pump with a first output when the amount of coolant stored corresponding to the indicator detected by the sensor is relatively large, and drives the pump with a second output greater than the first output when the amount of coolant stored corresponding to the indicator detected by the sensor is relatively small.

[0024] According to the coolant processing device configured as described above, by controlling the output of the pump, it is possible to suppress variations in the coolant discharge amount from the pump caused by the coolant storage amount in the tank.

[0025] The machine tool according to this invention includes the coolant processing device described in any of the above, and a machine tool main body that is supplied with coolant from the coolant processing device and performs machining of a workpiece.

[0026] According to the machine tool configured as described above, it is possible to keep the floor area (installation area) of the entire machine tool including the coolant processing device small.

Advantages of the Invention

[0027] As described above, according to this invention, it is possible to provide a coolant processing device in which the installation area is kept small while ensuring a sufficient capacity of the tank, and a machine tool including such a coolant processing device.

Brief Description of the Drawings

[0028] [Figure 1] It is a system diagram showing a machine tool in which the coolant processing device in Embodiment 1 of this invention is used. [Figure 2] It is a side view showing the tank and the first pump as viewed in the direction indicated by arrow II in FIG. 1. [Figure 3] It is a perspective view showing the tank and the first pump in FIG. 1. [Figure 4] It is another perspective view showing the tank and the first pump in FIG. 1. [Figure 5] It is a cross-sectional view showing the tank as viewed in the arrow viewing direction on line V-V in FIG. 1. [Figure 6] It is a side view and a bottom view for explaining the dimensional relationship of the side portion and the bottom portion of the tank in FIG. 1. [Figure 7] It is a partial cross-sectional view showing a modified example of the tank in FIG. 1. [Figure 8]This is a partial cross-sectional view of the tank as seen in the direction indicated by arrow VIII in Figure 7. [Figure 9] This is a rear view showing a machine tool. [Figure 10] This is a block diagram showing the configuration for controlling the first pump in the coolant processing apparatus of Embodiment 2 of the present invention. [Figure 11] This is a schematic cross-sectional view illustrating the relationship between the coolant storage volume (large) and the coolant discharge volume in the tank. [Figure 12] This is a schematic cross-sectional view illustrating the relationship between the amount of coolant stored in the tank (small) and the amount of coolant discharged. [Figure 13] This is a system diagram showing a machine tool in which the coolant processing device according to Embodiment 3 of this invention is used. [Modes for carrying out the invention]

[0029] Embodiments of this invention will be described with reference to the drawings. In the drawings referred to below, the same or equivalent components are given the same numbers.

[0030] (Embodiment 1) Figure 1 is a system diagram showing a machine tool in which the coolant processing device according to Embodiment 1 of this invention is used.

[0031] Referring to Figure 1, machine tool 100 is a machining center that processes a workpiece by bringing a rotating tool into contact with the workpiece. Machine tool 100 is an NC (Numerically Controlled) machine tool in which various operations for workpiece processing are automated by computer numerical control.

[0032] The machine tool in this invention is not limited to a machining center, but may also be a lathe that processes a workpiece by bringing a tool into contact with a rotating workpiece, a multi-tasking machine having both turning and milling functions, or an AM / SM hybrid machine capable of both additive manufacturing (AM) and subtractive manufacturing (SM) processes.

[0033] The machine tool 100 comprises a machine tool body 110 and a coolant processing device 10. The machine tool body 110 performs workpiece machining.

[0034] The machine tool body 110 comprises a cover body that demarcates the workpiece processing area and forms the external appearance of the machine tool 100, a tool holding section (such as a tool spindle or cutting post) for holding tools in the processing area, and a workpiece holding section (such as a workpiece spindle or table) for holding workpieces in the processing area.

[0035] The coolant processing device 10 is installed alongside the machine tool body 110. The coolant processing device 10 is a device for processing the coolant used for workpiece machining in the machine tool body 110. Coolant discharged from the machine tool body 110 during workpiece machining is guided into the coolant processing device 10, where it is stored. The coolant processing device 10 cleans the coolant from the machine tool body 110 and supplies the clean coolant back to the machine tool body 110.

[0036] First, the overall coolant treatment system of the machine tool 100 will be described. The coolant treatment device 10 includes a tank 21, a first pipe 41 (corresponding to "pipe" in this invention), a first pump 31 (corresponding to "pump" in this invention), and a filter 51.

[0037] Tank 21 consists of a box-shaped structure capable of storing coolant. Tank 21 is made of metal. Tank 21 may also be made of resin. First piping 41 is connected to tank 21. First piping 41 connects first pump 31 and tank 21. First piping 41 forms a coolant flow path through which coolant can flow. First piping 41 may be made of steel pipe or coolant hose.

[0038] The coolant processing device 10 is provided with a first coolant passage 46. The first coolant passage 46 extends from and is connected to the tank 21. The first coolant passage 46 forms a circulation path for coolant that leaves the tank 21 and returns to the tank 21. The first piping 41, at the point where it extends from the tank 21, constitutes a part of the first coolant passage 46.

[0039] The first pump 31 is located along the path of the first coolant flow path 46. The filter 51 is located along the path of the coolant flow from the tank 21, which is formed when the first pump 31 is driven. The filter 51 is located along the path of the first coolant flow path 46. The filter 51 is located downstream of the first pump 31 in the coolant flow in the first coolant flow path 46.

[0040] The filter 51 is capable of removing foreign matter contained in the coolant flowing through the first coolant passage 46. For example, the filter 51 consists of a cyclone-type filtration device that separates the coolant from the sludge contained in the coolant by centrifugal force. The filter 51 may be provided in a form supported by the tank 21.

[0041] As the first pump 31 is driven, a flow of coolant is formed in the first coolant passage 46. As the coolant flows through the first coolant passage 46 and passes through the filter 51, foreign matter such as sludge contained in the coolant is removed. The cleaned coolant is returned to the tank 21.

[0042] The coolant processing device 10 further comprises a second pipe 42, a second pump 52, a valve 53, and a third pump 91.

[0043] The second pipe 42 is connected to the tank 21. The second pipe 42 connects the second pump 52 and the tank 21. The second pipe 42 forms a coolant flow path through which coolant can flow. The second pipe 42 may be made of a steel pipe or a coolant hose.

[0044] The coolant processing device 10 is further provided with a second coolant passage 48 and a third coolant passage 47. The third coolant passage 47 extends from the tank 21 and is connected to the machine tool body 110. The second piping 42 forms part of the third coolant passage 47 at the point where it extends from the tank 21. The second coolant passage 48 extends from the machine tool body 110 and is connected to the tank 21. As shown in Figure 1, the second coolant passage 48 may merge with the first coolant passage 46 and be connected to the tank 21, or it may be connected to the tank 21 separately from the first coolant passage 46.

[0045] The third coolant passage 47 and the second coolant passage 48 form a coolant circulation path that starts from the tank 21, passes through the machine tool body 110, and returns to the tank 21. The third coolant passage 47 corresponds to a coolant supply passage that supplies coolant from the tank 21 to the machine tool body 110. The second coolant passage 48 corresponds to a coolant recovery passage that recovers the coolant discharged from the machine tool body 110 into the tank 21.

[0046] The second pump 52 and valve 53 are located along the path of the third coolant passage 47. When the second pump 52 is driven, a flow of coolant is formed in the third coolant passage 47.

[0047] Valve 53 is located downstream of the second pump 52 in the coolant flow in the third coolant passage 47. Valve 53 controls the coolant flow supplied to the machine tool body 110. Valve 53 controls the coolant flow supplied to multiple coolant discharge points (ceiling coolant, base coolant, or spindle coolant, etc.) in the machine tool body 110.

[0048] The third pump 91 is located along the path of the second coolant passage 48. The third pump 91 is attached to the chip conveyor 14 (see Figure 9) of the machine tool body 110, which will be described later. When the third pump 91 is driven, a flow of coolant is formed in the second coolant passage 48.

[0049] Next, the structure of the tank 21 and the first pump 31, and the piping connection structure to the tank 21 will be described in detail.

[0050] Figure 2 is a side view showing the tank and the first pump as seen in the direction indicated by arrow II in Figure 1. Figures 3 and 4 are perspective views showing the tank and the first pump in Figure 1. Figure 5 is a cross-sectional view showing the tank as seen in the direction of the arrow on line VV in Figure 1. Figure 6 is a side view and a bottom view illustrating the dimensional relationship of the side and bottom of the tank in Figure 1.

[0051] Referring to Figures 1 to 6, the tank 21 has a bottom 25 and side portions 23. The bottom 25 is located at the bottom of the tank 21. The side portions 23 rise from the periphery of the bottom 25. Above the bottom 25, surrounded by the side portions 23, a storage space 20 capable of storing coolant is formed.

[0052] The tank 21 has a rectangular parallelepiped shape. The bottom 25 is made of plate material arranged parallel to the horizontal plane. In its top view, the bottom 25 has a rectangular shape. The periphery of the bottom 25 corresponds to the four sides of its rectangular shape. As shown in Figure 5, the periphery of the bottom 25 corresponds to a pair of sides having length B1 and a pair of sides having length B2 which is shorter than length B1.

[0053] The side portion 23 consists of plate material arranged parallel to the vertical plane. The side portion 23 extends upward from the periphery of the bottom portion 25. The lower end of the side portion 23 is connected to the periphery of the bottom portion 25.

[0054] The side portion 23 has a first side portion 23A, a second side portion 23B, a third side portion 23C, and a fourth side portion 23D. Each of the first side portion 23A, the second side portion 23B, the third side portion 23C, and the fourth side portion 23D has a rectangular shape in its side view. The first side portion 23A and the fourth side portion 23D face each other in the horizontal direction. The shapes of the first side portion 23A and the fourth side portion 23D are identical. The second side portion 23B and the third side portion 23C face each other in the horizontal direction. The shapes of the second side portion 23B and the third side portion 23C are identical.

[0055] The vertical length of each side of the first side 23A and the fourth side 23D is the same as the vertical length of each side of the second side 23B and the third side 23C. As shown in Figure 5, each side of the first side 23A and the fourth side 23D has a horizontal length B1. Each side of the second side 23B and the third side 23C has a horizontal length B2 that is smaller than the horizontal length B1.

[0056] The tank 21 further has a top portion 22. The top portion 22 is located on the ceiling of the tank 21. The top portion 22 faces the bottom portion 25 in the vertical direction. The top portion 22 is made of a plate material arranged parallel to the horizontal plane. The top portion 22 is detachably attached to the upper end of the side portion 23. The top portion 22 constitutes a lid that closes the upper end opening of the side portion 23.

[0057] As shown in Figure 6, the maximum length Hmax of the side portion 23 in the vertical direction is greater than the length Bmax of the straight line connecting the two furthest points on the periphery of the bottom portion 25 when viewed from above (Hmax > Bmax).

[0058] Hmax corresponds to the vertical length of each side portion, the first side portion 23A, the second side portion 23B, the third side portion 23C, and the fourth side portion 23D. Bmax corresponds to the length between two diagonally positioned corners in the rectangular base portion 25.

[0059] The maximum length Hmax of the side portion 23 in the vertical direction may be greater than 1.2 times the length Bmax of the straight line connecting the two furthest points on the periphery of the bottom portion 25 when viewed from above (Hmax > 1.2 × Bmax). The maximum length Hmax of the side portion 23 in the vertical direction may be less than or equal to 2 times the length Bmax of the straight line connecting the two furthest points on the periphery of the bottom portion 25 when viewed from above (Hmax ≤ 2 × Bmax), or less than or equal to 1.5 times (Hmax ≤ 1.5 × Bmax).

[0060] The base portion 25 may be positioned at an angle to the horizontal plane. In such a configuration, if the heights of the upper ends of the side portions 23 are the same, the maximum length Hmax of the side portion 23 in the vertical direction is the vertical length of the side portion 23 rising from the periphery of the base portion 25 at the lowest position of the base portion 25.

[0061] The shape of the base 25 in a top view is not limited to a rectangular shape; for example, it may be a polygon other than a rectangle, a circle, or an L-shape. The straight line connecting the two furthest points on the periphery of the base 25 for determining the length Bmax may pass through a position between the two furthest points on the periphery of the base 25 that is not projected onto the base 25 in the vertical direction.

[0062] This configuration of a tall tank 21 allows for sufficient capacity of the tank 21 while keeping the installation area of ​​the coolant treatment device 10 small.

[0063] As shown in Figures 1 to 6, the tank 21 is configured to form a space 40 below the bottom 25 in which the first pump 31 is located.

[0064] The coolant processing device 10 further comprises a base plate 62 and a plurality of column portions 61. The base plate 62 faces the bottom portion 25 in the vertical direction. The base plate 62 is placed on the floor surface of a factory or the like where the coolant processing device 10 is installed. The column portions 61 extend in the vertical direction. The upper end of each column portion 61 is connected to the bottom portion 25. The lower end of each column portion 61 is connected to the base plate 62. The plurality of column portions 61 are spaced apart from each other. In a top view, the plurality of column portions 61 are arranged to overlap with the periphery of the bottom portion 25. In a top view, the plurality of column portions 61 are arranged to overlap with the four corners of the rectangular bottom portion 25.

[0065] This configuration creates a space 40 between the base plate 62 and the bottom 25. The length of the space 40 in the vertical direction is less than the maximum length Hmax of the side portion 23 in the vertical direction. The length of the space 40 in the vertical direction is less than the length Bmax of the straight line connecting the two furthest points on the periphery of the bottom 25 when viewed from above. The length of the space 40 in the vertical direction is less than the lengths B1 and B2 of each side of the bottom 25.

[0066] The first pump 31 is positioned in the space 40 such that, in a top view, its entirety overlaps with the bottom 25. The first pump 31 is fixed to the base plate 62.

[0067] The first pump 31 includes a motor section 32, a shaft 36, an impeller 33, a coolant inlet 34, and a coolant discharge section 35.

[0068] The motor unit 32 is provided as a power source for the first pump 31. When power is supplied to the motor unit 32, it outputs rotational motion around a virtual central axis 101. The impeller 33 is provided at a distance from the motor unit 32 in the axial direction of the central axis 101. The shaft 36 extends along the axis of the central axis 101 and is connected at both ends to the motor unit 32 and the impeller 33. The shaft 36 transmits the rotational motion output from the motor unit 32 to the impeller 33. The impeller 33 rotates around the central axis 101 in response to the rotational motion transmitted from the shaft 36.

[0069] The coolant inlet 34 opens on the axis of the central axis 101. The coolant inlet 34 opens at the end of the first pump 31 in the axial direction of the central axis 101. The first piping 41 is connected to the coolant inlet 34. The coolant discharge 35 opens at a position radially outward from the central axis 101. The coolant discharge 35 opens at a position upward from the central axis 101. Piping that constitutes the first coolant flow path 46 and extends toward the filter 51 is connected to the coolant discharge 35.

[0070] The first pump 31 is positioned in space 40 with its shaft 36 (central axis 101) extending horizontally. The first pump 31 is positioned in space 40 such that its shaft 36 (central axis 101) extends parallel to the first side portion 23A and the fourth side portion 23D. The total length (total height) of the first pump 31 in the vertical direction is less than the total length of the first pump 31 in the axial direction of the central axis 101.

[0071] With this configuration, the overall height of the first pump 31 can be reduced by positioning the shaft 36 (central axis 101) of the first pump 31 so that it extends horizontally. As a result, even if the length (height) of the space 40 in the vertical direction is small, the first pump 31 can be easily placed in the space 40.

[0072] As shown in Figures 1 to 5, the first pipe 41 has a first connection part 41p. The first connection part 41p is open at one end of the first pipe 41. The first connection part 41p is connected to the tank 21. The first connection part 41p is connected to the bottom 25.

[0073] As described above, the maximum length Hmax of the side portion 23 in the vertical direction is greater than the length Bmax of the straight line connecting the two furthest points on the periphery of the bottom portion 25 when viewed from above. In other words, the length Bmax of the straight line connecting the two furthest points on the periphery of the bottom portion 25 when viewed from above is less than the maximum length Hmax of the side portion 23 in the vertical direction. Therefore, within the tank 21, the sludge contained in the coolant accumulates on the bottom portion 25, which has a smaller area. In this case, since the first pipe 41 is connected to the bottom portion 25, the sludge accumulated on the bottom portion 25 can be efficiently collected through the first pipe 41 and removed from the coolant by the filter 51.

[0074] The second pipe 42 has a second connection part 42p. The second connection part 42p is open at one end of the second pipe 42. The second connection part 42p is connected to the tank 21. The second connection part 42p is connected to the bottom 25.

[0075] The coolant processing device 10 further includes a guide section 66. The guide section 66 is located in the storage space 20 within the tank 21. The guide section 66 extends along the periphery of the bottom 25 when viewed from above. The guide section 66 guides the coolant so that a swirling flow of coolant is generated on the bottom 25. The swirling flow of coolant is the flow of coolant along the circumferential direction of the periphery of the bottom 25.

[0076] The guide portion 66 consists of a plate material erected on the base portion 25. When viewed from above, the guide portion 66 extends in a curved manner. When viewed from above, the guide portion 66 has a curved shape that is convex from the center of the base portion 25 towards the periphery. When viewed from above, the guide portions 66 are provided at the four corners of the base portion 25, which has a rectangular shape. The guide portions 66 are separated between the corners of adjacent base portions 25.

[0077] As shown in Figure 5, the shortest distance dmin between the first connection point 41p of the first pipe 41 relative to the bottom 25 and the guide portion 66 is greater than the shortest distance Dmin between the second connection point 42p of the second pipe 42 relative to the bottom 25 and the guide portion 66 (dmin > Dmin).

[0078] The shortest distance fmin between the first connection portion 41p of the first pipe 41 to the bottom 25 and the periphery of the bottom 25 is greater than the shortest distance Fmin between the second connection portion 42p of the second pipe 42 to the bottom 25 and the periphery of the bottom 25 (fmin > Fmin). The first connection portion 41p of the first pipe 41 to the bottom 25 is located in the central region of the bottom 25 when viewed from above. The second connection portion 42p of the second pipe 42 to the bottom 25 is located in the peripheral region of the bottom 25 when viewed from above.

[0079] The first connection portion 41p of the first pipe 41 to the bottom portion 25 is positioned at a position equal to the distance from the first side portion 23A and the fourth side portion 23D. The first connection portion 41p of the first pipe 41 to the bottom portion 25 is positioned at a position equal to the distance from the second side portion 23B and the third side portion 23C.

[0080] As the coolant is discharged from the tank 21 through the first pipe 41 and the second pipe 42 connected to the bottom 25, it is guided by the guide section 66, which generates a swirling flow of coolant on the bottom 25. Along with this swirling flow of coolant, the sludge accumulating on the bottom 25 collects in the center of the bottom 25, away from the guide section 66 that extends along the periphery of the bottom 25.

[0081] In this case, the shortest distance dmin between the first connection point 41p of the first pipe 41 and the guide portion 66 relative to the bottom 25 is greater than the shortest distance Dmin between the second connection point 42p of the second pipe 42 and the guide portion 66 relative to the bottom 25. Therefore, the amount of sludge recovered through the first pipe 41 is greater than the amount of sludge recovered through the second pipe 42. This allows the filter 51, through which coolant is supplied from the first pipe 41 and the first pump 31, to efficiently remove the sludge, while suppressing the supply of a large amount of sludge-containing coolant to the machine tool body 110 through the second pipe 42.

[0082] Figure 7 is a partial cross-sectional view showing a modified version of the tank in Figure 1. Figure 8 is a partial cross-sectional view showing the tank as seen in the direction indicated by arrow VIII in Figure 7.

[0083] Referring to Figures 7 and 8, in this modified example, the coolant processing device 10 further includes a plate member 81. The plate member 81 is positioned in the storage space 20 within the tank 21. When viewed from above, the plate member 81 is positioned to project onto the second connection portion 42p of the second pipe 42 relative to the bottom 25.

[0084] The plate member 81 is located directly above the second connecting portion 42p. The plate member 81 is fixed to the side portion 23. The plate member 81 extends horizontally from the side portion 23. In the vertical direction, the plate member 81 faces the second connecting portion 42p. The distance between the bottom portion 25 and the plate member 81 in the vertical direction is smaller than the distance between the top portion 22 and the plate member 81 in the vertical direction. That is, in the vertical direction, the plate member 81 is located closer to the bottom portion 25 than to the top portion 22.

[0085] With this configuration, the second connection portion 42p is shielded by the plate member 81 positioned above it, further reducing the amount of sludge recovered through the second pipe 42. This makes it even more effective to suppress the supply of coolant containing a large amount of sludge to the machine tool body 110.

[0086] Figure 9 is a rear view showing a machine tool. Referring to Figure 9, the machine tool body 110 further includes a chip conveyor 14 and a duct 18.

[0087] The chip conveyor 14 discharges chips and coolant generated during workpiece machining within the machining area to the outside of the machining area. The tank 21 is installed horizontally alongside the chip conveyor 14. The chip conveyor 14 is not placed inside the tank 21. The tank 21 is installed separately from the chip conveyor 14. The piping forming the second coolant flow path 48 in Figure 1 extends between the chip conveyor 14 and the tank 21.

[0088] Duct 18 carries various pipes, including air pipes, lubricating oil pipes, and hydraulic pipes, as well as electrical wiring. Duct 18 extends horizontally above the chip conveyor 14 and the tank 21. The tank 21 is positioned so as to overlap with the duct 18 when viewed from above.

[0089] To summarize the structure of the coolant processing apparatus 10 and machine tool 100 in Embodiment 1 of the present invention described above, the coolant processing apparatus 10 in this embodiment has a bottom portion 25 and side portions 23 rising from the periphery of the bottom portion 25, and is equipped with a tank 21 capable of storing coolant above the bottom portion 25 and surrounded by the side portions 23. The maximum length Hmax of the side portions 23 in the vertical direction is greater than the length Bmax of the straight line connecting the two furthest points on the periphery of the bottom portion 25 when viewed from above.

[0090] The machine tool 100 comprises a coolant processing device 10 and a machine tool body 110 that receives coolant from the coolant processing device 10 and performs workpiece machining.

[0091] With the coolant treatment device 10 and machine tool 100 configured in this manner according to Embodiment 1 of the present invention, it is possible to keep the installation area of ​​the coolant treatment device 10 small while ensuring sufficient capacity of the tank 21, and consequently, to reduce the floor area (installation area) of the machine tool 100.

[0092] Furthermore, the coolant treatment device (10) in this embodiment includes a tank (21) capable of storing coolant and sludge, a pump (31) located below the tank (21) for pumping up the coolant and sludge, a pipe (46) through which the coolant and sludge flow from the tank (21) to below the tank (21), then become a flow towards the pump (31) below the tank (21), and are arranged to flow upward by the pump (31), and a filter (51) for filtering sludge from the coolant and sludge that have flowed upward.

[0093] Furthermore, the coolant processing device (10) in this embodiment includes a tank (21) having a bottom (25) and capable of storing coolant, and a pump (31) positioned below the bottom (25). The bottom (25) is provided with an opening (an opening communicating with the first connection part 41p) through which the coolant in the tank (21) flows out. In a top view, the pump (31) is positioned offset from the opening (an opening communicating with the first connection part 41p) (a position that does not overlap with the opening).

[0094] Furthermore, the coolant processing device (10) in this embodiment includes a chip conveyor tank (tank portion housing the chip conveyor 14) capable of storing coolant, a chip conveyor (14) for transporting chips in the chip conveyor tank (tank portion housing the chip conveyor 14), a pumping pump (91) for drawing up the coolant from the chip conveyor tank (tank portion housing the chip conveyor 14), a filter (51) provided in a position that does not overlap with the chip conveyor tank (tank portion housing the chip conveyor 14) in a top view for filtering the coolant, and a supply pump (52) for supplying the coolant filtered by the filter (51) to the processing area.

[0095] (Embodiment 2) Figure 10 is a block diagram showing the configuration for controlling the first pump in the coolant processing apparatus of Embodiment 2 of the present invention. Figure 11 is a schematic cross-sectional view showing the relationship between the amount of coolant stored in the tank (large) and the amount of coolant discharged. Figure 12 is a schematic cross-sectional view showing the relationship between the amount of coolant stored in the tank (small) and the amount of coolant discharged.

[0096] The coolant processing apparatus in this embodiment has basically the same structure as the coolant processing apparatus 10 in Embodiment 1. The same structural details will not be repeated below.

[0097] Referring to Figures 10 to 12, the coolant processing device in this embodiment further includes a water level sensor 72 and a control device 71.

[0098] The water level sensor 72 is located in the storage space 20 within the tank 21. The water level sensor 72 can detect the water level of the coolant in the tank 21. The water level sensor 72 generates a signal of the detected coolant level and outputs this signal to the control device 71. The type of water level sensor 72 is not particularly limited and may be a float type or a laser type, for example.

[0099] The coolant level detected by the water level sensor 72 is an indicator corresponding to the amount of coolant stored in the tank 21. The higher the coolant level detected by the water level sensor 72, the larger the amount of coolant stored in the tank 21, and the lower the coolant level detected by the water level sensor 72, the smaller the amount of coolant stored in the tank 21.

[0100] The control device 71 controls the drive of the first pump 31 based on the signal from the water level sensor 72. When the coolant level detected by the water level sensor 72 is relatively high, the control device 71 drives the first pump 31 with a first output Pa, and when the coolant level detected by the water level sensor 72 is relatively low, the control device 71 drives the first pump 31 with a second output Pb which is higher than the first output Pa.

[0101] In a tall tank 21, a large difference in the coolant pressure inside the tank 21 occurs depending on whether the coolant level (coolant storage volume) inside the tank 21 is relatively large or relatively small. Due to this pressure difference, when the coolant level (coolant storage volume) inside the tank 21 is relatively large, the coolant discharge rate from the first pump 31 increases, and when the coolant level (coolant storage volume) inside the tank 21 is relatively small, the coolant discharge rate from the first pump 31 decreases.

[0102] In contrast, when the coolant level detected by the water level sensor 72 is relatively high, the first pump 31 is driven at a first output Pa, and when the coolant level detected by the water level sensor 72 is relatively low, the first pump 31 is driven at a second output Pb which is higher than the first output Pa. This suppresses the occurrence of differences in the amount of coolant discharged from the first pump 31 due to the coolant level (coolant storage amount) in the tank 21.

[0103] Furthermore, the pump control method in the present invention is not limited to the first pump 31, but may also be applied to the second pump 52, or to both the first pump 31 and the second pump 52. In addition, as a sensor capable of detecting an indicator corresponding to the amount of coolant stored in the tank, for example, a weight sensor capable of detecting the weight of the coolant may be used.

[0104] The coolant treatment apparatus in Embodiment 2 of the present invention, as described above, can similarly achieve the effects described in Embodiment 1.

[0105] (Embodiment 3) Figure 13 is a system diagram showing a machine tool in which the coolant processing device according to Embodiment 3 of this invention is used.

[0106] The coolant processing apparatus in this embodiment has basically the same structure as the coolant processing apparatus 10 in Embodiment 1. The same structural details will not be repeated below.

[0107] Referring to Figure 13, in this embodiment, the second connection portion 42p of the second pipe 42 is connected to the tank 21 at a position higher than the first connection portion 41p of the first pipe 41. The second connection portion 42p of the second pipe 42 is connected to the side portion 23 (second side portion 23B). The distance between the bottom portion 25 and the second connection portion 42p in the vertical direction is smaller than the distance between the top portion 22 and the second connection portion 42p in the vertical direction. That is, the second connection portion 42p is connected to the side portion 23 at a position closer to the bottom portion 25 than to the top portion 22 in the vertical direction.

[0108] The first connection part 41p of the first pipe 41 is connected to the bottom part 25. The first connection part 41p of the first pipe 41 is open facing upward. The second connection part 42p of the second pipe 42 is open facing horizontally.

[0109] With this configuration, since the second connection point 42p is connected to the tank 21 at a position higher than the first connection point 41p, the amount of sludge recovered through the second pipe 42 can be reduced. This prevents a large amount of sludge-containing coolant from being supplied to the machine tool body 110.

[0110] The coolant processing apparatus in Embodiment 3 of this invention, configured in this manner, can similarly achieve the effects described in Embodiment 1.

[0111] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the claims rather than the foregoing description, and all modifications within the meaning and scope of equivalents of the claims are intended. [Industrial applicability]

[0112] This invention is primarily used in coolant treatment systems for machine tools such as machining centers and lathes. [Explanation of symbols]

[0113] 10 Coolant processing unit, 14 Chip conveyor, 18 Duct, 20 Storage space, 21 Tank, 22 Top, 23 Side, 23A First side, 23B Second side, 23C Third side, 23D Fourth side, 25 Bottom, 31 First pump, 32 Motor section, 33 Impeller, 34 Coolant inlet, 35 Coolant outlet, 36 Shaft, 40 Space, 41 First piping, 41p First connection, 42 Second piping, 42p Second connection, 46 First coolant flow path, 47 Third coolant flow path, 48 Second coolant flow path, 51 Filter, 52 Second pump, 53 Valve, 61 Column section, 62 Base plate, 66 Guide section, 71 Control device, 72 Water level sensor, 81 Plate member, 91 Third pump, 100 Machine tool, 101 Center axis, 110 machine tool body.

Claims

[Claim 1] A coolant supply channel supplies coolant to the machine tool body via a pump, and a tank stores coolant and sludge from a coolant recovery channel that recovers coolant and sludge discharged from the machine tool body. A pump located below the aforementioned tank for pumping up coolant and sludge, A pipe is located below the tank, and is arranged so that the coolant and sludge flow in the following order: (i) from the tank to below the tank, (ii) below the tank towards the pump, and (iii) upward by the pump. The system includes a filter for filtering sludge from the coolant and sludge that flow upward, A coolant processing apparatus wherein the length from the bottom of the tank to the top of the tank is longer than the length from the bottom of the tank to the surface on which the tank is installed.

Images