Coolant tank and machine tool

Abstract

The present invention provides a coolant tank and a machine tool capable of supplying a sufficient amount of clean coolant to a machine tool main body. The coolant tank includes a first tank unit (710) which extends in a first direction (560), and a second tank unit (720) which includes a first region (721) and a second region (722) through which coolant from the first tank unit (710) flows in a second direction (570) intersecting with the first direction (560). The first region (721) is provided with a pumping portion (730). The second region (722) includes an inflow portion (740) through which the coolant pumped by the pumping portion (730) and subjected to the treatment of foreign matters contained in the coolant flows into the second tank unit (720), and a flow generation portion (750) that generates a flow of coolant in a third direction (580) intersecting with the second direction (570) with respect to the coolant flowing through the first region (721).

Description

COOLANT TANK AND MACHINE TOOL

[0001] The present invention relates to a coolant tank and a machine tool.

[0002] For example, Japanese Patent Laying-Open No. 2011-177810 (PTL 1) discloses a coolant purification apparatus that includes a vortex tank, a purification tank provided above the vortex tank, and a pump disposed outside a vortex flow in the vortex tank and configured to pump the coolant in the vortex tank into the purification tank. The purification tank is provided with a drain unit configured to return overflowed coolant to the vortex tank.

[0003] [PTL 1] Japanese Patent Laying-Open No. 2011-177810

[0004] In the coolant purification apparatus disclosed in PTL 1, the coolant is pumped from the vortex tank to the purification tank, and the coolant overflowed from the purification tank is returned to the vortex tank. However, depending on the relative positional relationship among the position where the coolant from the machine tool main body flows into the vortex tank, the position where the coolant is pumped from the vortex tank, and the position where the coolant is returned to the vortex tank, dirty coolant from the machine tool main body may be mixed with clean coolant. Thus, the coolant purification device may not be able to supply a sufficient amount of clean coolant to the machine tool main body.

[0005] An object of the present invention is to provide a coolant tank and a machine tool capable of supplying a sufficient amount of clean coolant to a machine tool main body.

[0006] A coolant tank according to one aspect of the present invention includes: a first tank unit which extends in a first direction and through which coolant from a machining area flows in the first direction; and a second tank unit which includes a first region through which coolant from the first tank unit flows in a second direction intersecting with the first direction, and a second region. The first region is provided with a pumping portion that pumps coolant. The second region is provided with an inflow portion into which the coolant pumped by the pumping portion and subjected to the treatment of foreign matters contained in the coolant flows into the second tank unit, and a flow generation portion that generates a flow of coolant in a third direction intersecting with the second direction with respect to the coolant flowing through the first region in the second direction so as to form a boundary between the first region and the second region.

[0007] A coolant tank according to another aspect of the present invention includes: a first region provided with a pumping portion that pumps sludge and coolant; and a second region provided with an inflow portion into which the coolant flows after the sludge is collected from the sludge and the coolant pumped by the pumping portion, and a flow generation portion that generates a flow of coolant in a direction intersecting with a direction in which the first region and the second region are arranged so as to form a boundary with respect to the first region.

[0008] A machine tool according to the present invention includes a machine tool main body that machines a workpiece, and a coolant tank that stores coolant to be supplied to the machine tool main body.

[0009] A coolant tank according to yet another aspect of the present invention includes: a first tank unit which extends in a first direction and into which coolant from a machining area flows; a second tank unit which extends in a second direction intersecting with the first direction and into which coolant from the first tank unit flows, and which includes a first region provided with a pumping portion that pumps coolant and a second region provided with an inflow portion into which coolant subjected to the treatment of foreign matters contained in the coolant flows; and a flow generation portion that generates a flow of coolant in a third direction intersecting with the second direction with respect to the coolant flowing through the first region in the second direction so as to form a boundary between the first region and the second region.

[0010] A machine tool according to another aspect of the present invention includes: a machine tool main body that machines a workpiece; and a coolant treatment apparatus that includes the coolant tank and is configured to treat coolant to be used in machining the workpiece in the machine tool main body.

[0011] A coolant treatment apparatus according to the present invention includes: a first tank; a second tank stacked above the first tank; a first pump provided in the first tank and configured to pump coolant stored in the first tank to the second tank; a foreign matter capturing device configured to capture foreign matters contained in the coolant from the first pump; and a coolant return mechanism provided in the second tank and configured to return the coolant overflowed from the second tank to the first tank. The first tank includes a first tank region defined with a position at which the coolant from the machine tool main body flows, a second tank region defined with a position at which the coolant from the second tank is returned by the coolant return mechanism, and a third tank region disposed between the first tank region and the second tank region in a top view and defined with a position at which the first pump is provided.

[0012] According to the present invention, it is possible to provide a coolant tank and a machine tool capable of supplying a sufficient amount of clean coolant to a machine tool main body.

[0013] Fig. 1 is a perspective view illustrating a machine tool equipped with a coolant treatment apparatus according to a first embodiment of the present invention.Fig. 2 is a perspective view illustrating the coolant treatment apparatus in Fig. 1.Fig. 3 is a system diagram illustrating a coolant treatment process performed in the coolant treatment apparatus illustrated in Fig. 1.Fig. 4 is a plan view illustrating an inner configuration of a first tank in Fig. 2.Fig. 5 is a cross-sectional view illustrating a first tank and a chip conveyor in Fig. 1.Fig. 6 is a cross-sectional view illustrating the coolant treatment apparatus taken along line VI-VI in Fig. 2.Fig. 7 is a perspective view illustrating the coolant treatment apparatus as viewed in the direction indicated by arrow VII in Fig. 2.Fig. 8 is a plan view illustrating an inner configuration of a first tank in a machine tool according to a second embodiment of the present invention.Fig. 9 is a plan view illustrating a modification of the first tank in Fig. 8.Fig. 10 is a plan view and a cross-sectional view illustrating an inclined configuration of a bottom surface and a peripheral side surface of a first tank according to a third embodiment of the present invention.Fig. 11 is a plan view illustrating a coolant tank according to a fourth embodiment of the present invention.Fig. 12 is a plan view illustrating a modification of the coolant tank illustrated in Fig. 11.Fig. 13 is a cross-sectional view illustrating the coolant tank taken along arrow line XIII-XIII in Fig. 12.

[0014] Embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding members will be denoted by the same reference numerals.

[0015] (First Embodiment) Fig. 1 is a perspective view illustrating a machine tool equipped with a coolant treatment apparatus according to a first embodiment of the present invention.

[0016] With reference to Fig. 1, a coolant treatment apparatus 100 according to the present embodiment is used in a machine tool 200. Machine tool 200 is a lathe that machines a workpiece by rotating the workpiece and bringing a tool into contact with the rotating workpiece. Machine tool 200 is an NC (Numerically Controlled) machine tool which is controlled by a computer according to numerical control to automatically perform various machining operations on a workpiece.

[0017] The machine tool equipped with the coolant treatment apparatus according to the present invention is not limited to the lathe described above, and may be, for example, a machining center that machines a workpiece by bringing a rotating tool into contact with the workpiece, a composite processing machine capable of performing a turning operation and a milling operation, or an AM / SM hybrid machine capable of performing both additive manufacturing (AM) and subtractive manufacturing (SM) on a workpiece.

[0018] Machine tool 200 includes a machine tool main body 210, a chip conveyor 230, and a coolant treatment apparatus 100. Machine tool main body 210 is a main body of machine tool 200, and is configured to machine a workpiece.

[0019] Machine tool main body 210 includes a cover body 211, a door 213, a tool post (not shown) that holds a tool in a machining area 220, a work spindle (not shown) that rotates a workpiece in machining area 220, and a bed (not shown) that supports the tool post and the work spindle.

[0020] Cover body 211 defines machining area 220, and forms an outer appearance of machine tool 200. Machining area 220 is a space where a workpiece is machined, and is enclosed by cover body 211 and door 213 so as to prevent foreign matters such as chips or coolant generated during the machining of the workpiece from leaking out of machining area 220.

[0021] Cover body 211 is provided with an opening 212. Opening 212 opens machining area 220 to an outer space. Door 213 is provided for opening 212. Door 213 is attached to cover body 211 and is slidable in the horizontal direction. Door 213 is slid to open or close opening 212.

[0022] Chip conveyor 230 discharges chips and coolant generated during the machining of the workpiece in machining area 220 to the outside of machine tool main body 210.

[0023] As illustrated in Fig. 1 and Fig. 5 (which will be described later), chip conveyor 230 includes a cover member 231 and a conveying unit 236. Cover member 231 forms an outer appearance of chip conveyor 230. Cover member 231 forms an internal space in which conveying unit 236 is disposed. Cover member 231 is provided with a chip reception port 233 and a chip discharge port 234.

[0024] Chip conveyor 230 is positioned with respect to machine tool main body 210 in such a manner that chip reception port 233 is located directly below machining area 220 and opens upward while chip discharge port 234 is offset from machine tool main body 210 in the horizontal direction and opens downward. A chip bucket (not shown) is disposed below chip discharge port 234 to collect chips.

[0025] Chips and coolant generated in machining area 220 are received into cover member 231 through chip reception port 233. The chips are conveyed by conveying unit 236 from chip reception port 233 to chip discharge port 234. The chips are discharged to the outside of cover member 231 through chip discharge port 234 and collected in the chip bucket. On the other hand, the coolant received into cover member 231 is discharged to a first tank 110 through a coolant discharge port 232. Coolant discharge port 232 and first tank 110 will be described later in detail.

[0026] Chip conveyor 230 is provided with a plurality of wheels 241. The plurality of wheels 241 are configured to contact a floor FL of a factory or the like where machine tool main body 210 is installed. The plurality of wheels 241 are spaced apart from each other in the horizontal direction. Chip conveyor 230 may be pulled out from machine tool main body 210 by sliding it in the second direction 520 together with first tank 110 (which will be described later).

[0027] Fig. 2 is a perspective view illustrating the coolant treatment apparatus in Fig. 1. Fig. 3 is a system diagram illustrating a coolant treatment process performed in the coolant treatment apparatus illustrated in Fig. 1.

[0028] With reference to Figs. 1 to 3, coolant treatment apparatus 100 is provided in parallel with machine tool main body 210. Coolant treatment apparatus 100 is configured to treat coolant used in machining a workpiece in machine tool main body 210. The coolant discharged from machine tool main body 210 during the machining of a workpiece is guided to coolant treatment apparatus 100 and stored therein. Coolant treatment apparatus 100 cleans the coolant from machine tool main body 210, and supplies the clean coolant back to machine tool main body 210.

[0029] In Figs. 1 and 2, Figs. 4 to 7 and 10 (which will be described later), a first direction 510, a second direction 520, and a third direction 530 are indicated by arrows. First direction 510 is parallel to the horizontal direction. Second direction 520 is parallel to the horizontal direction and orthogonal to first direction 510. Third direction 530 is parallel to the vertical direction. When coolant treatment apparatus 100 is provided in parallel with machine tool main body 210, first direction 510 corresponds to the rotation axis direction (Z-axis direction) of the work spindle. First direction 510 corresponds to the left-right direction (width direction) of machine tool main body 210, and second direction 520 corresponds to the front-rear direction (depth direction) of machine tool main body 210.

[0030] Coolant treatment apparatus 100 includes a first tank 110 and a second tank 160. Each of first tank 110 and second tank 160 is formed as a box for storing coolant.

[0031] First tank 110 is placed on floor FL. In a top view, a part of first tank 110 overlaps with a part of machine tool main body 210. Second tank 160 is stacked above first tank 110. In the top view, second tank 160 overlaps with a part of first tank 110. In the top view, second tank 160 is provided at a position offset from machine tool main body 210.

[0032] The area of second tank 160 in the top view is smaller than the area of first tank 110 in the top view. The volume of the coolant stored in second tank 160 is smaller than the volume of the coolant stored in first tank 110. The volume of the coolant stored in second tank 160 may be equal to or larger than the volume of the coolant stored in first tank 110.

[0033] First tank 110 includes a tank body 120 and a lid 130. Tank body 120 has a box shape, and includes a bottom surface 121 and a peripheral side surface 122. Bottom surface 121 forms a bottom of tank body 120. Peripheral side surface 122 rises from the peripheral edge of bottom surface 121. A space surrounded by bottom surface 121 and peripheral side surface 122 is defined as a first storage space 126. First tank 110 stores coolant in first storage space 126. Lid 130 is attached to an upper end of peripheral side surface 122. Lid 130 faces bottom surface 121 in third direction 530.

[0034] First tank 110 includes a plurality of wheels 111. The plurality of wheels 111 are configured to contact floor FL. The plurality of wheels 111 are spaced apart from each other in the horizontal direction. First tank 110 may be pulled out from machine tool main body 210 by sliding it in second direction 520. First tank 110 may be pulled out in first direction 510.

[0035] Second tank 160 includes a tank body 170 and a lid 180. Tank body 170 has a box shape, and includes a bottom surface 171 and a peripheral side surface 172. Bottom surface 171 forms a bottom of tank body 170. Bottom surface 171 faces lid 130 of first tank 110 in third direction 530. Peripheral side surface 172 rises from the peripheral edge of bottom surface 171. A space surrounded by bottom surface 171 and peripheral side surface 172 is defined as a second storage space 176. Second tank 160 stores the coolant in second storage space 176. Lid 180 is attached to an upper end of peripheral side surface 172. Lid 180 faces bottom surface 171 in third direction 530.

[0036] The distance between lid 130 and bottom surface 121 in third direction 530 is smaller than the distance between lid 180 and bottom surface 171 in third direction 530. The distance between bottom surface 171 and lid 180 in third direction 530 is greater than the distance between bottom surface 121 and lid 130 in third direction 530. The distance between bottom surface 171 and lid 180 in third direction 530 may be smaller than or equal to the distance between bottom surface 121 and lid 130 in third direction 530.

[0037] According to the two-floor configuration of the coolant tank formed by first tank 110 and second tank 160, it is possible to increase the tank volume of the coolant tank while reducing the installation area of coolant treatment apparatus 100 when viewed from above.

[0038] Coolant treatment apparatus 100 further includes a coolant temperature adjustment device 190. Coolant temperature adjustment device 190 adjusts the temperature of the coolant, and is configured to cool the coolant whose temperature has risen during the machining of a workpiece. Coolant temperature adjustment device 190 is provided in second tank 160. Coolant temperature adjustment device 190 cools the coolant stored in second tank 160. Coolant temperature adjustment device 190 is attached to an upper portion of second tank 160. Coolant temperature adjustment device 190 is attached to lid 180. Coolant temperature adjustment device 190 has a box shape rising from lid 180.

[0039] Coolant temperature adjustment device 190 is an immersion-type device which includes a heat exchange coil (cooling coil) to be immersed in the coolant. Since the heat exchange coil is immersed in the clean coolant stored in second tank 160, the heat exchange coil is less likely to be clogged with chips. Accordingly, the heat exchange efficiency of the heat exchange coil can be maintained for a long period of time, which reduces the labor of maintenance. In addition, since the immersion-type coolant temperature adjustment device 190 is attached to an upper portion (lid 180) of second tank 160, the installation area of coolant treatment apparatus 100 when viewed from above can be further reduced.

[0040] Fig. 4 is a plan view illustrating an inner configuration of the first tank in Fig. 2. With reference to Figs. 2 to 4, first tank 110 includes a first tank region 310, a second tank region 320, and a third tank region 330.

[0041] Third tank region 330 is disposed between first tank region 310 and second tank region 320 in second direction 520. First tank region 310, third tank region 330, and second tank region 320 are arranged in second direction 520 in this order. First tank region 310 is connected to one end of third tank region 330 in second direction 520, and second tank region 320 is connected to the other end of third tank region 330 in second direction 520.

[0042] First tank region 310 and second tank region 320 are separated from each other by third tank region 330 which is located between first tank region 310 and second tank region 320. First tank region 310 forms a boundary with only third tank region 330 of second tank region 320 and third tank region 330. Second tank region 320 forms a boundary with only third tank region 330 of first tank region 310 and third tank region 330. Third tank region 330 forms a boundary with both first tank region 310 and second tank region 320.

[0043] First tank region 310 extends in a first direction 510. First tank region 310 protrudes in first direction 510 more than third tank region 330. First tank region 310 has an elongated shape in which first direction 510 is a longitudinal direction and second direction 520 is a transverse direction (width direction) in a top view. The maximum length of first tank region 310 in first direction 510 is greater than the maximum length of first tank region 310 in second direction 520.

[0044] Second tank region 320 extends in first direction 510. Second tank region 320 protrudes in first direction 510 more than third tank region 330. The protruding direction of second tank region 320 in first direction 510 is opposite to the protruding direction of first tank region 310 in first direction 510.

[0045] The length of third tank region 330 in first direction 510 is smaller than the length of second tank region 320 in first direction 510 and smaller than the length of first tank region 310 in first direction 510. The length of second tank region 320 in first direction 510 is smaller than the length of first tank region 310 in first direction 510. The length of second tank region 320 in second direction 520 is greater than the length of first tank region 310 in second direction 520 and greater than the length of third tank region 330 in second direction 520.

[0046] Fig. 5 is a cross-sectional view illustrating the first tank and the chip conveyor in Fig. 1. In Figs. 4 and 5, the flow of coolant in first tank 110 is indicated by a solid arrow, and the discharge direction of coolant from a first nozzle 61 and the discharge direction of coolant from a second nozzle 62 (which will be described later) are each indicated by a white arrow.

[0047] With reference to Figs. 2 to 5, first tank region 310 is defined with a position 370 at which the coolant flows from machine tool main body 210 into first tank region 310. First tank region 310 is positioned directly below machining area 220.

[0048] Chip conveyor 230 is housed in first tank region 310. Cover member 231 is provided with a coolant discharge port 232. Coolant discharge port 232 opens in second direction 520. Coolant discharge port 232 opens to face peripheral side surface 122 of tank body 120. Coolant discharge port 232 has, for example, a rectangular shape in which first direction 510 is the longitudinal direction and third direction 530 is the transverse direction. A plurality of coolant discharge ports 232 may be provided in such a manner that they are spaced apart from each other in first direction 510.

[0049] The coolant flowed into cover member 231 of chip conveyor 230 from machine tool main body 210 (machining area 220) flows into first tank region 310 through coolant discharge port 232. An opening surface of coolant discharge port 232 in cover member 231 corresponds to position 370 where the coolant from machine tool main body 210 flows into first tank region 310.

[0050] Coolant treatment apparatus 100 further includes a first pump 51. First pump 51 is provided in first tank 110. First pump 51 is attached to lid 130. First pump 51 is an immersion pump, and includes a pump unit (not shown) immersed in coolant. First pump 51 pumps the coolant stored in first tank 110 to second tank 160.

[0051] Third tank region 330 is defined with a position 380 at which first pump 51 is provided. First pump 51 is provided at a position closer to second tank region 320 than first tank region 310 in second direction 520.

[0052] Peripheral side surface 122 includes a second side surface 122j and a third side surface 122k. Second side surface 122j and third side surface 122k are provided in third tank region 330. Second side surface 122j and third side surface 122k face each other with an interval therebetween in first direction 510. First storage space 126 is formed in third tank region 330 between second side surface 122j and third side surface 122k. First pump 51 is provided at a position closer to second side surface 122j than third side surface 122k in first direction 510. Position 380 where first pump 51 is provided is displaced in first direction 510 and second direction 520 from position 370 where the coolant flows from machine tool main body 210 into first tank region 310.

[0053] Coolant treatment apparatus 100 further includes a gutter 31. Gutter 31 is provided in first tank 110. Gutter 31 is configured to guide coolant from machine tool main body 210 to first pump 51.

[0054] Gutter 31 is provided in first tank region 310. Gutter 31 is provided on peripheral side surface 122. Gutter 31 extends in first direction 510. Gutter 31 is provided below coolant discharge port 232. Gutter 31 has a tray-shaped cross section when cut along a plane orthogonal to first direction 510. Gutter 31 forms a flow path for the coolant to flow therethrough. Gutter 31 is configured to receive the coolant from coolant discharge port 232 and guide the coolant toward third tank region 330 in first direction 510.

[0055] Coolant treatment apparatus 100 further includes a plurality of first nozzles 61 (61A, 61B, 61C). First nozzle 61 is provided in first tank 110. First nozzle 61 discharges coolant so as to form a coolant flow from first tank region 310 toward first pump 51.

[0056] First nozzle 61 is provided on bottom surface 121. The plurality of first nozzles 61 are provided at intervals in the planar direction of bottom surface 121. First nozzle 61 is provided in first tank region 310. First nozzle 61 discharges coolant so as to form a coolant flow in first tank region 310 toward second tank region 320.

[0057] First nozzle 61A, first nozzle 61B and first nozzle 61C are provided at intervals in first direction 510. First nozzle 61A is disposed on the most upstream side of the coolant flow from first tank region 310 toward first pump 51 among first nozzle 61A, first nozzle 61B and first nozzle 61C. First nozzle 61C is disposed on the most downstream side of the coolant flow from first tank region 310 toward first pump 51 among first nozzle 61A, first nozzle 61B and first nozzle 61C. First nozzle 61B is disposed between first nozzle 61A and first nozzle 61C in first direction 510.

[0058] First nozzle 61A discharges coolant so as to form a coolant flow toward third tank region 330 in first direction 510. First nozzle 61B discharges the coolant so as to form a coolant flow toward third tank region 330 in first direction 510. First nozzle 61C discharges coolant so as to form a coolant flow toward third tank region 330 in second direction 520. A coolant discharge port 61a of first nozzle 61C opens toward first pump 51.

[0059] First tank 110 further includes a partition wall 46. Partition wall 46 rises from bottom surface 121. Partition wall 46 is provided along the boundary between first tank region 310 and third tank region 330. Partition wall 46 is provided at a position deviated from a straight line that connects first nozzle 61C in first tank region 310 and first pump 51 in third tank region 330. Partition wall 46 extends from third side surface 122k in first direction 510. Partition wall 46 is provided at a position away from second side surface 122j in first direction 510. Partition wall 46 is configured to guide the coolant from first tank region 310 toward first pump 51 more reliably.

[0060] First tank region 310 includes a corner region 310p. Corner region 310p is an end portion of first tank region 310 in first direction 510 and is defined at a position farthest from third tank region 330. The length (width) of first tank region 310 in second direction 520 is locally reduced in corner region 310p. By providing corner region 310p in first tank region 310, the tank volume can be further increased.

[0061] Coolant treatment apparatus 100 further includes a third nozzle 63. Third nozzle 63 is provided in first tank region 310. Third nozzle 63 discharges the coolant so as to form a coolant flow toward corner region 310p. According to such a configuration, by discharging the coolant toward corner region 310p where stagnation is likely to occur in the coolant flow, the coolant stored in corner region 310p can be forced to circulate.

[0062] Fig. 6 is a cross-sectional view illustrating the coolant treatment apparatus taken along line VI-VI in Fig. 2. With reference to Figs. 2 to 6, second tank 160 is provided in second tank region 320. In a top view, second tank 160 overlaps with a part of second tank region 320.

[0063] Coolant treatment apparatus 100 further includes a coolant return mechanism 21. Coolant return mechanism 21 is provided in second tank 160. Coolant return mechanism 21 is configured to return the coolant overflowed from second tank 160 to first tank 110.

[0064] Second tank 160 is provided with an opening 173. Opening 173 is provided as a through hole that penetrates peripheral side surface 172 and communicates to second storage space 176. Opening 173 is provided at a position closer to lid 180 than bottom surface 171 in third direction 530. First tank 110 is provided with an opening 131. Opening 131 is provided as a through hole that penetrates lid 130 and communicates to first storage space 126.

[0065] Coolant return mechanism 21 includes opening 173 and opening 131 described above, and a drainage pipe 22. Drainage pipe 22 extends in third direction 530. Drainage pipe 22 extends between opening 173 and opening 131. When the liquid level of the coolant in second tank 160 exceeds a predetermined level, the coolant flows from second storage space 176 into first storage space 126 through opening 173, drainage pipe 22 and opening 131 in this order.

[0066] As illustrated in Figs. 4 and 6, second tank region 320 is defined with a position 360 at which the coolant is returned from second tank 160 by coolant return mechanism 21. An opening surface of opening 131 provided on lid 130 corresponds to position 360 where the coolant is returned from second tank 160 by coolant return mechanism 21.

[0067] Fig. 7 is a perspective view illustrating the coolant treatment apparatus as viewed in the direction indicated by arrow VII in Fig. 2. With reference to Fig. 7, coolant treatment apparatus 100 further includes a foreign matter capturing device 41. Foreign matter capturing device 41 is configured to capture foreign matters such as chips or sludge contained in the coolant. Foreign matter capturing device 41 captures foreign matters contained in the coolant from first pump 51.

[0068] Foreign matter capturing device 41 is a filterless capturing device that does not include a filter. Foreign matter capturing device 41 is a cyclone separator that captures foreign matters using centrifugal force. Foreign matter capturing device 41 has a cylindrical shape extending in third direction 530 as a whole. Foreign matter capturing device 41 is longer in third direction 530.

[0069] Foreign matter capturing device 41 includes a foreign matter separation unit 42, a foreign matter collection unit 43, a coolant inflow portion 45, and a coolant outflow unit 44. Coolant treatment apparatus 100 further includes a first pipe 410 and a second pipe 420.

[0070] Foreign matter separation unit 42 and foreign matter collection unit 43 are connected to each other in third direction 530. A lower end of foreign matter separation unit 42 is connected to an upper end of foreign matter collection unit 43. Coolant inflow portion 45 is connected to the outer peripheral surface of foreign matter separation unit 42. Coolant outflow unit 44 is connected to an upper end of foreign matter separation unit 42.

[0071] First pipe 410 extends between first pump 51 and coolant inflow portion 45. Second pipe 420 extends between coolant outflow unit 44 and second tank 160 (lid 180). Each of first pipe 410 and second pipe 420 is made of a steel pipe, a hose, or the like through which the coolant can flow.

[0072] The coolant from first pump 51 flows through first pipe 410 and enters foreign matter separation unit 42 through coolant inflow portion 45. The coolant flows in a spiral pattern inside foreign matter separation unit 42, and thereby, foreign matters contained in the coolant are separated from the coolant by centrifugal force. The cleaned coolant flows out of foreign matter separation unit 42 through coolant outflow unit 44, flows through second pipe 420 into second tank 160. The foreign matters separated from the coolant fall by gravity and are collected by foreign matter collection unit 43.

[0073] Second tank 160 is provided with a notch 161. Notch 161 is obtained by cutting one of four corners of second tank 160 into a rectangular shape when viewed from above. Foreign matter capturing device 41 is disposed in notch 161 in a top view. Foreign matter collection unit 43 is disposed above lid 130 at a position facing second tank 160 in first direction 510 and second direction 520. Foreign matter separation unit 42 is disposed above lid 180. Foreign matter separation unit 42 is disposed to face coolant temperature adjustment device 190 in first direction 510 and face a second pump 52 (which will be described later) in second direction 520.

[0074] With reference to Figs. 2 to 4, coolant treatment apparatus 100 further includes a second pump 52 and a plurality of third pumps 53.

[0075] Second pump 52 is provided in second tank 160. Second pump 52 is attached to lid 180. Second pump 52 is an immersion pump. Second pump 52 pumps the coolant stored in second tank 160 to machine tool main body 210.

[0076] The coolant from second pump 52 is supplied to at least one of a tool and a workpiece in machine tool main body 210. For example, coolant from second pump 52 is supplied to a tip coolant nozzle 253 and a through-spindle coolant unit 254. Tip coolant nozzle 253 is provided on a tool post of machine tool main body 210. Tip coolant nozzle 253 is configured to discharge coolant toward a cutting edge of the tool held by the tool rest. Through-spindle coolant unit 254 is provided on a work spindle of machine tool main body 210. Through-spindle coolant unit 254 is configured to discharge coolant from a chuck of the work spindle toward the workpiece.

[0077] The plurality of third pumps 53 are provided in first tank 110. Third pump 53 is attached to lid 130. Third pump 53 is an immersion pump. Third pump 53 pumps the coolant stored in second tank region 320 to machine tool main body 210.

[0078] The coolant from third pump 53 is supplied toward a position away from the tool and the workpiece in machine tool main body 210. For example, the coolant from third pump 53 is supplied to a base coolant nozzle 251 and a tool coolant circulation unit 252. Base coolant nozzle 251 is configured to discharge coolant toward a bed or the like disposed in machining area 220 and / or toward cover body 211 that defines machining area 220. Tool coolant circulation unit 252 is configured to circulate coolant through a coolant circulation path provided in the bed so as to uniform the temperature of a cast metal that constitutes the bed and prevent the posture of machine tool main body 210 from being changed.

[0079] The minimum opening area of the flow path for supplying the coolant from second pump 52 to machine tool main body 210 may be smaller than the minimum opening area of the flow path for supplying the coolant from third pump 53 to machine tool main body 210.

[0080] With reference to Fig. 4, coolant treatment apparatus 100 further includes a plurality of second nozzles 62 (62A, 62B, 62C, 62D). Second nozzle 62 is provided in first tank 110. Second nozzle 62 discharges coolant so as to form a swirl flow that flows along the periphery of second tank region 320 when viewed from above.

[0081] Second nozzle 62 is provided on bottom surface 121. The plurality of second nozzles 62 are provided at intervals in the planar direction of bottom surface 121. Second nozzle 62 is provided in second tank region 320. The plurality of second nozzles 62 are provided at intervals in second tank region 320 along the periphery of bottom surface 121.

[0082] Bottom surface 121 of second tank region 320 has a rectangular shape. Second nozzle 62A, second nozzle 62B, second nozzle 62C and second nozzle 62D are arranged in the circumferential direction of the periphery of bottom surface 121 in this order. Second nozzle 62A, second nozzle 62B, second nozzle 62C and second nozzle 62D are provided in second tank region 320 at four corners of bottom surface 121, respectively. A coolant discharge port 62a of second nozzle 62A opens toward second nozzle 62B, a coolant discharge port 62a of second nozzle 62B opens toward second nozzle 62C, a coolant discharge port 62a of second nozzle 62C opens toward second nozzle 62D, and a coolant discharge port 62a of second nozzle 62D opens toward second nozzle 62A.

[0083] As illustrated in Figs. 3 to 5, the coolant from machine tool main body 210 (machining area 220) flows into chip conveyor 230 and then flows into first tank 110 (first tank region 310) through coolant discharge port 232 provided in cover member 231. The coolant flowed into first tank 110 flows from first tank region 310 toward third tank region 330 where first pump 51 is provided.

[0084] First pump 51 pumps the coolant flowed into the third tank region 330 to second tank 160. During this time, foreign matter capturing device 41 captures foreign matters contained in the coolant from first pump 51 and supplies clean coolant to second tank 160. Second pump 52 supplies the coolant stored in second tank 160 toward at least one of a tool and a workpiece in machine tool main body 210, such as tip coolant nozzle 253 and through-spindle coolant unit 254.

[0085] When the liquid level of the coolant in second tank 160 exceeds a predetermined level, coolant return mechanism 21 returns the coolant overflowed from second tank 160 to first tank 110 (second tank region 320). Third pump 53 supplies the coolant stored in second tank region 320 of first tank 110 toward a position away from the tool and the workpiece in machine tool main body 210, such as base coolant nozzle 251 and tool coolant circulation unit 252.

[0086] Summarizing the configuration of coolant treatment apparatus 100 according to the first embodiment of the present invention described above, coolant treatment apparatus 100 according to the present embodiment includes a first tank 110, a second tank 160 stacked above first tank 110, a first pump 51 provided in first tank 110 and configured to pump the coolant stored in first tank 110 to second tank 160, and a foreign matter capturing device 41 configured to capture foreign matters contained in the coolant from first pump 51, a coolant return mechanism 21 provided in second tank 160 and configured to return the coolant overflowed from second tank 160 to first tank 110. First tank 110 includes a first tank region 310 defined with a position 370 at which the coolant from machine tool main body 210 flows, a second tank region 320 defined with a position 360 at which the coolant is returned from second tank 160 by coolant return mechanism 21, and a third tank region 330 which is disposed between first tank region 310 and second tank region 320 in a top view and defined with a position 380 at which first pump 51 is provided.

[0087] As described above, third tank region 330 defined with position 380 at which first pump 51 is provided is disposed between first tank region 310 defined with position 370 at which the coolant from machine tool main body 210 flows and second tank region 320 defined with position 360 at which the coolant is returned from second tank 160 by coolant return mechanism 21 in the top view. With such a configuration, the dirty coolant flowing from machine tool main body 210 into first tank region 310 of first tank 110 can be efficiently guided to first pump 51 provided in third tank region 330, and can be pumped to second tank 160 by first pump 51. Accordingly, the clean coolant from which the foreign matters have been captured by foreign matter capturing device 41 can be supplied to second tank 160. Third tank region 330 is disposed between first tank region 310 and second tank region 320 in a top view, and thus second tank region 320 is disposed on the opposite side of first tank region 310 across third tank region 330. In such a configuration, since the dirty coolant from first tank region 310 is pumped to second tank 160 by first pump 51 in third tank region 330, thereby preventing dirty coolant from entering second tank region 320.

[0088] As a result, second tank 160 can function as a clean tank that stores coolant having a high cleanliness level, and second tank region 320 of first tank 110 can function as a semi-clean tank that stores coolant having a medium cleanliness level. Accordingly, it is possible to supply a sufficient amount of clean coolant from coolant treatment apparatus 100 to machine tool main body 210.

[0089] Second tank 160 is stacked above second tank region 320. According to such a configuration, coolant return mechanism 21 can be more easily configured by bringing second tank 160 close to position 360 where the coolant is returned from second tank 160 by coolant return mechanism 21.

[0090] Coolant treatment apparatus 100 further includes a gutter 31 that is provided in first tank 110 and is configured to guide the coolant from machine tool main body 210 to first pump 51. According to such a configuration, the coolant from machine tool main body 210 can be forced to flow toward first pump 51 by gutter 31. Accordingly, the dirty coolant flowing from machine tool main body 210 into first tank region 310 can be more efficiently guided to first pump 51 provided in third tank region 330.

[0091] Coolant treatment apparatus 100 further includes a first nozzle 61 that is provided in first tank 110 and is configured to discharge coolant so as to form a coolant flow from first tank region 310 toward first pump 51.

[0092] According to such a configuration, the dirty coolant flowing from machine tool main body 210 into first tank region 310 can be more efficiently guided to first pump 51 provided in third tank region 330.

[0093] Coolant treatment apparatus 100 further includes a second nozzle 62 that is provided in first tank 110 and is configured to discharge coolant so as to form a swirl flow that flows along the periphery of second tank region 320 when viewed from above.

[0094] According to such a configuration, by actively forming a swirl flow in second tank region 320, it is possible to prevent the coolant stored in second tank region 320 from flowing toward first pump 51. As a result, it is possible to prevent the dirty coolant pumping efficiency of first pump 51 from decreasing.

[0095] Coolant treatment apparatus 100 further includes a second pump 52 that is provided in second tank 160 and is configured to supply the coolant stored in second tank 160 to machine tool main body 210, and a third pump 53 that is provided in first tank 110 and is configured to supply the coolant stored in second tank region 320 to machine tool main body 210.

[0096] According to such a configuration, the coolant stored in second tank 160 and the coolant stored in second tank region 320 of first tank 110 can be independently supplied to machine tool main body 210.

[0097] The coolant from second pump 52 is supplied toward at least one of the tool and the workpiece in machine tool main body 210. The coolant from third pump 53 is supplied toward a position away from the tool and the workpiece in machine tool main body 210.

[0098] According to such a configuration, the influence of the foreign matters contained in the coolant on the machining accuracy of the workpiece is relatively large in the coolant supplied toward at least one of the tool and the workpiece, and is relatively small in the coolant supplied toward a position away from the tool and the workpiece. Therefore, by supplying the coolant having a high cleanliness level toward at least one of the tool and the workpiece and supplying the coolant having a medium cleanliness level toward a position away from the tool and the workpiece, it is possible to efficiently improve the machining accuracy of the workpiece.

[0099] In addition, coolant treatment apparatus 100 may further include an immersion type coolant temperature adjustment device 190 attached to an upper portion of second tank 160. According to such a configuration, it is possible to improve maintainability of coolant temperature adjustment device 190 and reduce the installation area of coolant treatment apparatus 100 when viewed from above.

[0100] Hereinafter, features of first tank region 310, second tank region 320, and third tank region 330 will be described. With reference to Fig. 4, third tank region 330 has a rectangular shape having a pair of sides extending in first direction 510 and a pair of sides extending in second direction 520 in a top view. One end of third tank region 330 in second direction 520 is connected to first tank region 310, and the other end of third tank region 330 in second direction 520 is connected to second tank region 320. First tank region 310 protrudes from third tank region 330 toward one side of first direction 510 that is orthogonal to second direction 520. Second tank region 320 protrudes from third tank region 330 toward the other side of first direction 510.

[0101] The area of third tank region 330 in the top view is smaller than the area of first tank region 310 in the top view. The area of third tank region 330 in the top view is smaller than the area of second tank region 320 in the top view. The area of second tank region 320 in the top view may be equal to or larger than the area of first tank region 310 in the top view, or may be smaller than the area of first tank region 310 in the top view.

[0102] A coolant flow is formed in first tank region 310 toward third tank region 330 in first direction 510. A coolant flow is formed in second tank region 320, swirling along the periphery of second tank region 320 when viewed from above. A coolant flow is formed in third tank region 330 from first tank region 310 to first pump 51 in second direction 520.

[0103] (Second Embodiment) The machine tool according to the present embodiment has the same configuration as machine tool 200 according to the first embodiment. Hereinafter, the same components as machine tool 200 in the first embodiment will not be described. In particular, in the present embodiment, the configuration of first tank 110 will be described from a different viewpoint from the description of the first embodiment.

[0104] Fig. 8 is a plan view illustrating an inner configuration of a first tank in a machine tool according to a second embodiment of the present invention. Fig. 8 corresponds to Fig. 4 in the first embodiment.

[0105] In Fig. 8 and the following Fig. 9, a first direction 560, a second direction 570, and a third direction 580 are indicated by arrows. Second direction 570 intersects with first direction 560. Third direction 580 intersects with second direction 570. First direction 560, second direction 570, and third direction 580 are parallel to the horizontal direction.

[0106] In the present embodiment, as a representative example, first direction 560 is parallel to the rotation axis direction (Z-axis direction) of the work spindle, second direction 570 is orthogonal to first direction 560, and third direction 580 is orthogonal to second direction 570. When coolant treatment apparatus 100 is provided in parallel with machine tool main body 210, first direction 560 corresponds to the left-right direction (width direction) of machine tool main body 210, and second direction 570 corresponds to the front-rear direction (depth direction) of machine tool main body 210.

[0107] The angle formed between first direction 560 and second direction 570 may be in the range of 90°±45°, in the range of 90°±30°, or in the range of 90°±10°. The angle formed by second direction 570 and third direction 580 may be in the range of 90°±30°, in the range of 90°±10°, or in the range of 90°±5°.

[0108] First tank 110 includes a first tank unit 710. First tank unit 710 extends in first direction 560. The coolant flows from machining area 220 into first tank unit 710.

[0109] First tank unit 710 corresponds to first tank region 310 described above in the first embodiment. First tank unit 710 has an elongated shape in which first direction 560 is a longitudinal direction and second direction 570 is a transverse direction (width direction) in a top view. First tank unit 710 is defined with a position 370 at which coolant flows from machine tool main body 210 (machining area 220) into first tank unit 710. First tank unit 710 is positioned directly below machining area 220. Chip conveyor 230 is housed in first tank unit 710.

[0110] First tank 110 further includes a second tank unit 720. Second tank unit 720 extends in second direction 570 intersecting with first direction 560. The coolant flowed through first tank unit 710 flows into second tank unit 720.

[0111] Second tank unit 720 corresponds to second tank region 320 and third tank region 330 described above in the first embodiment. Second tank unit 720 is connected to an end portion of first tank unit 710 in first direction 560. Second tank unit 720 extends from first tank unit 710 in second direction 570.

[0112] Second tank unit 720 includes a first region 721 and a second region 722. First region 721 is provided with a pumping portion 730 for pumping the coolant. Second region 722 includes an inflow portion 740 into which the coolant subjected to the treatment of foreign matters contained in the coolant flows.

[0113] First region 721 corresponds to third tank region 330 described above in the first embodiment. Second region 722 corresponds to second tank region 320 described above in the first embodiment. The length (width) of second region 722 in first direction 560 is larger than the length (width) of first region 721 in first direction 560. Second region 722 protrudes from first region 721 in first direction 560.

[0114] First region 721 and second region 722 are arranged in second direction 570. First region 721 is disposed between first tank unit 710 and second region 722. First tank unit 710 and second region 722 are separated from each other with first region 721 interposed between first tank unit 710 and second region 722. First tank unit 710 forms a boundary with only first region 721 of first region 721 and second region 722. Second region 722 forms a boundary with only first region 721 of first tank unit 710 and first region 721. First region 721 forms a boundary with both first tank unit 710 and second region 722.

[0115] As described above in the first embodiment, first region 721 is defined with a position 380 at which first pump 51 is provided. Pumping portion 730 for pumping the coolant corresponds to position 380 where first pump 51 is provided. As described above in the first embodiment, second region 722 is defined with a position 360 at which the coolant is returned from second tank 160. Inflow portion 740 into which the coolant subjected to the treatment of foreign matters contained in the coolant flows corresponds to position 360 at which the coolant is returned from second tank 160.

[0116] First tank 110 further includes a flow generation portion 750. In order to form a boundary between first region 721 and second region 722, flow generation portion 750 forms a coolant flow in third direction 580 intersecting with second direction 570 with respect to the coolant flowing through first region 721 in second direction 570.

[0117] Flow generation portion 750 is disposed at the boundary between first region 721 and second region 722. Flow generation portion 750 extends in first direction 560. In Fig. 8, flow generation portion 750 is illustrated as a band-shaped region which extends in first direction 560 and has a fixed width in second direction 570, but flow generation portion 750 may be a region which has a minute width and forms the boundary between first region 721 and second region 722.

[0118] The plurality of second nozzles 62 (62A, 62B, 62C, 62D) are disposed in second region 722. The plurality of second nozzles 62 (62A, 62B, 62C, 62D) form a swirl flow that flows along the periphery of second region 722 when viewed from above. In particular, second nozzle 62A is provided adjacent to flow generation portion 750 in second direction 570. Coolant discharge port 62a of second nozzle 62A opens in third direction 580.

[0119] According to such a configuration, in flow generation portion 750 which forms a boundary between first region 721 and second region 722, a coolant flow is formed in third direction 580 intersecting with the flow direction (second direction 570) of the coolant in first region 721. Flow generation portion 750 corresponds to a region which is located between pumping portion 730 and inflow portion 740 in second direction 570 and in which a coolant flow is generated by the plurality of second nozzles 62 in third direction 580.

[0120] Fig. 9 is a plan view illustrating a modification of the first tank in Fig. 8. With reference to Fig. 9, in the present modification, the length (width) of second tank unit 720 in first direction 560 is constant regardless of its position in second direction 570. The length (width) of second region 722 in first direction 560 is the same as the length (width) of first region 721 in first direction 560.

[0121] Summarizing the configuration of first tank 110 according to the second embodiment of the present invention described above, the coolant tank (110) according to the present embodiment includes a first region (721) provided with a pumping portion (730) that pumps sludge and coolant, and an inflow portion (740) into which coolant flows after the sludge is collected from the sludge and coolant pumped by the pumping portion (730), a second region (722) provided with a flow generation portion (750) that generates a flow of coolant in a direction intersecting with a direction in which the first region (721) and the second region (722) are arranged so as to form a boundary with respect to the first region (721).

[0122] The coolant tank (110) includes a first tank unit (710) which extends in the first direction (560) and into which coolant from the machining area (220) flows in the first direction (560), and a second tank unit (720) which includes a first region (721) through which coolant from the first tank unit (710) flows in the second direction (570) intersecting with the first direction (560) and the second region (722). First region 721 includes a pumping portion 730 that pumps coolant. The second region (722) includes an inflow portion (740) that guides the coolant pumped by the pumping portion (730) and subjected to the treatment of foreign matters contained in the coolant to flow into the second tank unit (720), and a flow generation portion (750) that generates a flow of coolant in a third direction (580) intersecting with the second direction (570) with respect to the coolant flowing through the first region (721) in the second direction (570) so as to form a boundary between the second region (722) and the first region (721).

[0123] The angle formed between the second direction (570) and the third direction (580) may be 90°. The angle formed between the second direction (570) and the third direction (580) may be in the range of 90°±5°, may be in the range of 90°±10°, may be in the range of 90°±20°, or may be in the range of 90°±30°.

[0124] The coolant treatment apparatus (100) according to the present embodiment includes the coolant tank (110) described above, a first pump (51) attached to the coolant tank (110) and disposed in the pumping portion (730), a second nozzle (62) attached to the coolant tank (110) and configured to form a coolant flow in the flow generation portion (750), and a foreign matter capturing device (41) configured to treat foreign matters contained in the coolant that is pumped by the pumping portion (730).

[0125] In addition, first tank 110 which serves as the coolant tank in the present embodiment includes: a first tank unit 710 which extends in a first direction 560 and into which the coolant from machining area 220 flows; a second tank unit 720 which extends in a second direction 570 intersecting with first direction 560 and into which coolant from first tank unit 710 flows, and includes a first region 721 provided with a pumping portion 730 that pumps coolant and a second region 722 provided with an inflow portion 740 into which coolant subjected to the treatment of foreign matters contained in the coolant flows; and a flow generation portion 750 that generates a flow of coolant in a third direction 580 intersecting with second direction 570 with respect to the coolant flowing through first region 721 in second direction 570 so as to form a boundary between first region 721 and second region 722.

[0126] According to such a configuration, the dirty coolant flowed into first tank unit 710 from machining area 220 is guided to pumping portion 730 in second region 722 and pumped by pumping portion 730. In this case, it is possible to prevent the dirty coolant from entering second region 722 from first region 721 by flow generation portion 750 which forms a coolant flow in third direction 580 intersecting with second direction 570 with respect to the coolant flowing through first region 721 in second direction 570 so as to form a boundary between first region 721 and second region 722,. As a result, it is possible to prevent dirty coolant from being mixed with clean coolant in second region 722 provided with inflow portion 740 into which the coolant subjected to the treatment of foreign matters contained in the coolant flows. As a result, it is possible to supply a sufficient amount of clean coolant from first tank 110.

[0127] Machine tool 200 according to the present embodiment includes a machine tool main body 210 that machines a workpiece, and a coolant treatment apparatus 100 that includes a first tank 110 serving as a coolant tank and is configured to treat coolant to be used in machining the workpiece in machine tool main body 210.

[0128] According to such a configuration, it is possible to supply a sufficient amount of clean coolant from first tank 110 to machine tool main body 210.

[0129] In the present embodiment, second tank 160 may not be stacked above first tank 110, and may be provided separately from first tank 110.

[0130] (Third Embodiment) Fig. 10 is a plan view and a cross-sectional view illustrating an inclined configuration of a bottom surface and a peripheral side surface of a first tank according to a third embodiment of the present invention. In the present embodiment, an inclined configuration of bottom surface 121 and peripheral side surface 122 of first tank 110 in the first embodiment will be described.

[0131] With reference to Fig. 10, a first tank unit 660, a second tank unit 670, and a corner 680 are defined in tank main body 120.

[0132] First tank unit 660 extends in first direction 510 in a top view. First tank unit 660 has an elongated shape in which first direction 510 is a longitudinal direction and second direction 520 is a transverse direction (width direction). The maximum length of first tank unit 660 in first direction 510 is greater than the maximum length of first tank unit 660 in second direction 520.

[0133] Second tank unit 670 extends in second direction 520 in a top view. Second tank unit 670 has an elongated shape in which second direction 520 is a longitudinal direction and first direction 510 is a transverse direction (width direction). The maximum length of second tank unit 670 in second direction 520 is greater than the maximum length of second tank unit 670 in first direction 510.

[0134] Corner 680 connects an end of first tank unit 660 in first direction 510 and an end of second tank unit 670 in second direction 520. Corner 680 is arranged at a corner portion formed by first tank unit 660 and second tank unit 670. First tank unit 660 extends from corner 680 in first direction 510. Second tank unit 670 extends from corner 680 in second direction 520. Corner 680 has a rectangular shape in a top view.

[0135] Bottom surface 121 includes a first inclined portion 611, a second inclined portion 612, and a horizontal portion 613. First inclined portion 611 is disposed in first tank unit 660. First inclined portion 611 is inclined so as to shift downward toward corner 680 in first direction 510. First inclined portion 611 is configured to form a downward slope toward corner 680 in first direction 510.

[0136] First inclined portion 611 has a distal end 611p and a proximal end 611q. First inclined portion 611 extends between distal end 611p and proximal end 611q in first direction 510. Distal end 611p is located further away from corner 680 in first direction 510. Proximal end 611q is connected to horizontal portion 613. First inclined portion 611 has a slope (gradient) that is highest at distal end 611p and lowest at proximal end 611q. The slope of first inclined portion 611 is constant between distal end 611p and proximal end 611q. The distance between first inclined portion 611 and the liquid level of the coolant stored in first storage space 126 on first inclined portion 611 in third direction 530 (vertical direction) is minimum at distal end 611p and maximum at proximal end 611q.

[0137] Second inclined portion 612 is disposed in second tank unit 670. Second inclined portion 612 is inclined so as to shift downward toward corner 680 in second direction 520. Second inclined portion 612 is configured to form a downward slope toward corner 680 in second direction 520.

[0138] Second inclined portion 612 has a distal end 612p and a proximal end 612q. Second inclined portion 612 extends between distal end 612p and proximal end 612q in second direction 520. Distal end 612p is located further away from corner 680 in second direction 520. Proximal end 612q is connected to horizontal portion 613. Second inclined portion 612 has a slope (gradient) that is highest at distal end 612p and lowest at proximal end 612q. The slope of second inclined portion 612 is constant between distal end 612p and proximal end 612q. The distance between second inclined portion 612 and the liquid level of the coolant stored in first storage space 126 on second inclined portion 612 in third direction 530 (vertical direction) is minimum at distal end 612p and maximum at proximal end 612q.

[0139] Horizontal portion 613 is disposed in corner 680. Horizontal portion 613 extends in the horizontal direction. The distance between horizontal portion 613 and the liquid level of the coolant stored in first storage space 126 on horizontal portion 613 in third direction 530 (vertical direction) is constant in horizontal portion 613.

[0140] When the vertical difference between distal end 611p and proximal end 611q in third direction 530 per unit length of first inclined portion 611 in first direction 510 is referred to as an inclination degree of first inclined portion 611, an inclination degree (H1 / L1) of first inclined portion 611 may be in a range of 5 mm / m or more and 50 mm / m or less. Similarly, an inclination degree (H2 / L2) of second inclined portion 612 may be in a range of 5 mm / m or more and 50 mm / m or less.

[0141] A length L1 of first inclined portion 611 in first direction 510 is larger than a length L2 of second inclined portion 612 in second direction 520 (L1>L2). In this case, an angle θ1 formed by first inclined portion 611 with respect to the horizontal direction is smaller than an angle θ2 formed by second inclined portion 612 with respect to the horizontal direction (θ1<θ2). The vertical difference H1 between distal end 611p and proximal end 611q of first inclined portion 611 may be the same as the vertical difference H2 between distal end 612p and proximal end 612q of second inclined portion 612 (H1=H2).

[0142] The angle θ1 formed by first inclined portion 611 with respect to the horizontal direction may be the same as the angle θ2 formed by second inclined portion 612 with respect to the horizontal direction (θ1=θ2), or may be larger than the angle θ2 formed by second inclined portion 612 with respect to the horizontal direction (θ1>θ2).

[0143] An overhang 690 is further defined in tank body 120. Overhang 690 is provided at a position away from corner 680 in second direction 520. Overhang 690 overhangs from second tank unit 670 in first direction 510. First tank unit 660 extends from corner 680 toward one side of first direction 510. Overhang 690 protrudes from second tank unit 670 toward the other side of first direction 510.

[0144] Bottom surface 121 further has a third inclined portion 614. Third inclined portion 614 is disposed on overhang 690. Third inclined portion 614 is inclined so as to shift downward toward corner 680 in second direction 520. Third inclined portion 614 is configured to form a downward slope toward corner 680 in second direction 520.

[0145] Third inclined portion 614 has a distal end 614p and a proximal end 614q. Third inclined portion 614 extends between distal end 614p and proximal end 614q in second direction 520. Distal end 614p is located further away from corner 680 in second direction 520. Distal end 614p is aligned with distal end 612p of second inclined portion 612 in second direction 520. Proximal end 614q is located closer to corner 680 in second direction 520. Proximal end 614q is disposed between distal end 612p and proximal end 612q of second inclined portion 612 in second direction 520. Proximal end 614q is located closer to proximal end 612q of second inclined portion 612 than distal end 612p of second inclined portion 612 in second direction 520.

[0146] Third inclined portion 614 has a slope (gradient) that is highest at distal end 614p and lowest at proximal end 614q. The slope of third inclined portion 614 is constant between distal end 612p and proximal end 612q. The distance between third inclined portion 614 and the liquid level of the coolant stored in first storage space 126 on third inclined portion 614 in third direction 530 (vertical direction) is minimum at distal end 614p and maximum at proximal end 614q.

[0147] Third inclined portion 614 has the same inclination degree as second inclined portion 612. The height of distal end 614p is the same as the height of distal end 612p of second inclined portion 612. An angle θ3 formed by third inclined portion 614 with respect to the horizontal direction is the same as the angle θ2 formed by second inclined portion 612 with respect to the horizontal direction (θ3=θ2).

[0148] Peripheral side surface 122 includes a first side surface 122i and a second side surface 122j. First side surface 122i rises from third inclined portion 614. First side surface 122i rises from proximal end 614q. Second side surface 122j rises from second inclined portion 612. Second side surface 122j extends in second direction 520. Second side surface 122j is connected to first side surface 122i.

[0149] First side surface 122i is inclined so as to approach corner 680 in second direction 520 as it approaches second side surface 122j in first direction 510 in the top view. First side surface 122i extends in an oblique direction with respect to first direction 510 in the top view. First side surface 122i and second side surface 122j are connected to each other at an angle θ4 larger than 90° (θ4>90°).

[0150] In such a configuration, the height of proximal end 614q along first side surface 122i decreases as it approaches second side surface 122j in first direction 510.

[0151] Summarizing the configuration of first tank 110 according to the third embodiment of the present invention described above, first tank 110 which serves as a coolant tank according to the present embodiment includes a tank body 120 which includes a bottom surface 121 and forms a first storage space 126 as a space for storing coolant on bottom surface 121. Tank body 120 is defined with a first tank unit 660 that extends in first direction 510, a second tank unit 670 that extends in second direction 520 orthogonal to first direction 510, and a corner 680 that connects an end of first tank unit 660 in first direction 510 to an end of second tank unit 670 in second direction 520. Bottom surface 121 includes a first inclined portion 611 disposed in first tank unit 660 and inclined downward toward corner 680 in first direction 510, and a second inclined portion 612 disposed in second tank unit 670 and inclined downward toward corner 680 in second direction 520.

[0152] According to such a configuration, in the case of removing the coolant from tank body 120, the coolant remaining in first tank unit 660 and second tank unit 670 can be collected in corner 680 by the slope of first inclined portion 611 and second inclined portion 612, respectively (in Fig. 10, the flow of the coolant in the case of removing the coolant from tank body 120 is indicated by solid arrows). Thus, the coolant can be easily removed from tank body 120.

[0153] For example, when assembling machine tool 200 in a factory, after cover body 211 is attached to machine tool main body 210, an operation may be performed to remove the coolant from tank body 120. Even in such a case, the coolant collected in corner 680 can be drawn out using the pump by removing lid 130J (see Figs. 1 and 2) disposed directly above corner 680. Accordingly, it is not necessary to pull out first tank 110 from machine tool main body 210 or tilt first tank 110 so as to collect the coolant at one place, which makes it possible to significantly improve workability when removing the coolant from first tank 110.

[0154] In addition, bottom surface 121 further includes a horizontal portion 613 disposed in corner 680 and extending in the horizontal direction. According to such a configuration, by retaining the coolant from first tank unit 660 and second tank unit 670 on horizontal portion 613 of corner 680, the operation of removing the coolant from tank body 120 can be performed more easily.

[0155] The length L1 of first inclined portion 611 in first direction 510 is larger than the length L2 of second inclined portion 612 in second direction 520. The angle θ1 formed by first inclined portion 611 with respect to the horizontal direction is smaller than the angle θ2 formed by second inclined portion 612 with respect to the horizontal direction.

[0156] According to such a configuration, it is possible to sufficiently ensure the volume of first tank 110 by reducing the height of the uppermost portion (distal end 611p) of first inclined portion 611.

[0157] When the angle θ1 formed by first inclined portion 611 with respect to the horizontal direction is greater than the angle θ2 formed by second inclined portion 612 with respect to the horizontal direction, the coolant can be efficiently collected in corner 680 even when first inclined portion 611 has a relatively longer coolant path to corner 680.

[0158] In addition, tank body 120 further includes an overhang 690 that is provided at a position away from corner 680 in second direction 520 and overhangs from second tank unit 670 in first direction 510. Bottom surface 121 further defines a third inclined portion 614 that is disposed on overhang 690 and is inclined downward toward corner 680 in second direction 520. Tank body 120 further includes a peripheral side surface 122 that rises from bottom surface 121 and forms a first storage space 126 together with bottom surface 121. Peripheral side surface 122 includes a first side surface 122i rising from third inclined portion 614, and a second side surface 122j rising from second inclined portion 612, extending in second direction 520, and connected to first side surface 122i. First side surface 122i is inclined so as to approach corner 680 in second direction 520 as it approaches second side surface 122j in first direction 510 in the top view.

[0159] According to such a configuration, the coolant retaining in overhang 690 flows through third inclined portion 614 toward first side surface 122i. In this case, since first side surface 122i is inclined so as to approach corner 680 in second direction 520 as it approaches second side surface 122j in first direction 510 in the top view, the coolant can flow through first side surface 122i toward second side surface 122j. Accordingly, the coolant from overhang 690 can be merged with the coolant that flows toward corner 680 in second tank unit 670.

[0160] In addition, in tank body 120, the coolant flowed from machine tool main body 210 into first tank unit 660 flows into second tank unit 670 through corner 680, which forms a coolant flow that flows from a low position to a high position of second inclined portion 612 in second tank unit 670.

[0161] According to such a configuration, during the normal operation of machine tool 200, second inclined portion 612 hinders the coolant flow in tank body 120, while during the operation of removing the coolant from tank body 120, the coolant retaining in second tank unit 670 can be smoothly collected in corner 680 by second inclined portion 612.

[0162] Machine tool 200 according to the present embodiment includes a machine tool main body 210 that machines a workpiece, and a coolant treatment apparatus 100 that includes a first tank 110 which serves as a coolant tank and is configured to treat coolant to be used in machining the workpiece in machine tool main body 210.

[0163] According to such a configuration, machine tool 200 can easily perform the operation of removing the coolant from tank body 120.

[0164] Second tank 160 has an L-shape when viewed from above (see Figs. 2 and 7). In this configuration, bottom surface 171 of second tank 160 may also be configured to have an inclined configuration similar to bottom surface 121 of first tank 110. In this case, the coolant collected in the corner of second tank 160 can be easily removed by removing lid 180J (see Fig. 2) disposed directly above the corner of second tank 160 and inserting a suction unit of a manual pump or a small electric pump into second tank 160.

[0165] (Fourth Embodiment) Fig. 11 is a plan view illustrating a coolant tank according to a fourth embodiment of the present invention. Fig. 11 schematically illustrates a machine tool (coolant treatment apparatus) equipped with a coolant tank 900 (900S) according to the present embodiment and a coolant treatment flow. In Fig. 11, a first direction 960 and a second direction 970 are indicated by arrows. First direction 960 is parallel to the horizontal direction. Second direction 970 is parallel to the horizontal direction and orthogonal to first direction 960.

[0166] Hereinafter, the description of the components which are the same as the components of the machine tool (coolant treatment apparatus) in the first and second embodiments will not be repeated.

[0167] With reference to Fig. 11, coolant tank 900 (900S) in the present embodiment is formed as a box for storing coolant.

[0168] Coolant tank 900S includes a first region 810 and a second region 820. First region 810 and second region 820 integrally define a space for storing coolant. First region 810 and second region 820 are arranged in first direction 960. A boundary line 815 between first region 810 and second region 820 extends in second direction 970. First region 810 has a rectangular shape in the top view. Second region 820 has a rectangular shape in the top view. The length of first region 810 in second direction 970 is the same as the length of second region 820 in second direction 970. The length of first region 810 in first direction 960 may be longer than the length of second region 820 in first direction 960, may be the same as the length of second region 820 in first direction 960, or may be shorter than the length of second region 820 in first direction 960.

[0169] An inflow portion 860 is provided in first region 810. The sludge and the coolant from machine tool main body 210 flow into inflow portion 860. The sludge refers to fine chips generated during the machining of a workpiece in machine tool main body 210, and is mixed with the coolant. A part of the sludge from machine tool main body 210 passes through a filter provided in chip conveyor 230 and flows into inflow portion 860. Dirty coolant from machine tool main body 210 flows through inflow portion 860 into first region 810.

[0170] A pumping portion 830 is further provided in first region 810. Pumping portion 830 pumps the sludge and the coolant. Pumping portion 830 includes a first pump 51. Pumping portion 830 pumps the sludge and the coolant from first region 810 toward foreign matter capturing device 41 by using first pump 51. Foreign matter capturing device 41 is provided on a flow path of the coolant from pumping portion 830 toward an inflow portion 840 to be described later.

[0171] Foreign matter capturing device 41 captures the sludge contained in the coolant pumped by pumping portion 830. Foreign matter capturing device 41 collects the sludge from the coolant pumped by pumping portion 830. Foreign matter capturing device 41 cleans the coolant by collecting the sludge therefrom.

[0172] A plurality of first nozzles 66 (66A, 66B) are provided in first region 810. The plurality of first nozzles 66 are provided at corners of first region 810 having a rectangular shape in the top view. First nozzle 66A and first nozzle 66B are provided at diagonal corners of first region 810 having a rectangular shape in the top view.

[0173] In Fig. 11, the discharge direction of the coolant from first nozzle 66A and the discharge direction of the coolant from first nozzle 66B are each indicated by a white arrow. The discharge direction of the coolant from first nozzle 66A and the discharge direction of the coolant from first nozzle 66B are the same as second direction 970. The discharge direction of the coolant from first nozzle 66A and the discharge direction of the coolant from first nozzle 66B are opposite to each other in second direction 970.

[0174] Inflow portion 860 is located at a position on a straight line that connects first nozzle 66A and first nozzle 66B in the top view. Pumping portion 830 is located at a corner of first region 810 having a rectangular shape in the top view. Pumping portion 830 faces first nozzle 66B in first direction 960 and faces first nozzle 66A in second direction 970. The shortest distance from inflow portion 860 to second region 820 is longer than the shortest distance from pumping portion 830 to second region 820. The coolant flow discharged from first nozzle 66A is located between inflow portion 860 and second region 820 in first direction 960 which is the arrangement direction of first region 810 and second region 820.

[0175] The position of inflow portion 860 and the position of the scooping portion 830 in first region 810 are not limited to those described above.

[0176] An inflow portion 840 is provided in second region 820. The clean coolant which is obtained by collecting the sludge from the sludge and the coolant that are pumped by pumping portion 830 and contains the sludge flows into inflow portion 840.

[0177] A plurality of second nozzles 67 (67A, 67B, 67C, 67D) are provided in second region 820. The plurality of second nozzles 67 discharge coolant so as to form a swirl flow that flows along the periphery of second region 820 when viewed from above.

[0178] The plurality of second nozzles 67 are provided at four corners of second region 820 having a rectangular shape in the top view. Second nozzle 67A and second nozzle 67C are provided at diagonal corners of second region 820 having a rectangular shape in the top view. Second nozzle 67B and second nozzle 67D are provided at diagonal corners of second region 820 having a rectangular shape in the top view.

[0179] Second nozzle 67A and second nozzle 67B face each other in second direction 970. Second nozzle 67C and second nozzle 67D face each other in second direction 970. Second nozzle 67A and second nozzle 67D face each other in first direction 960. Second nozzle 67C and second nozzle 67B face each other in first direction 960. Second nozzle 67A and second nozzle 67B are disposed adjacent to boundary line 815 between first region 810 and second region 820.

[0180] In Fig. 11, the discharge direction of the coolant from second nozzle 67A, the discharge direction of the coolant from second nozzle 67B, the discharge direction of the coolant from second nozzle 67C, and the discharge direction of the coolant from second nozzle 67D are each indicated by a white arrow, and the coolant flow in second region 820 is indicated by a solid arrow.

[0181] Second nozzle 67A discharges coolant toward second nozzle 67B in second direction 970. Second nozzle 67B discharges coolant toward second nozzle 67C in first direction 960. Second nozzle 67C discharges coolant toward second nozzle 67D in second direction 970. Second nozzle 67D discharges coolant toward second nozzle 67A in first direction 960. Second nozzle 67A, second nozzle 67B, second nozzle 67C, and second nozzle 67D discharge coolant in one direction (i.e., the counterclockwise direction) along the periphery of second region 820 when viewed from above.

[0182] A flow generation portion 850 is further provided in second region 820. In order to form a boundary (boundary line 815) between first region 810 and second region 820, flow generation portion 850 generates a flow of coolant in a direction intersecting with a direction in which first region 810 and second region 820 are arranged. In order to form boundary line 815 between first region 810 and second region 820, flow generation portion 850 generates a flow of coolant in a third direction 980 that intersects with first direction 960 that is the arrangement direction of first region 810 and second region 820.

[0183] An angle formed by third direction 980 with respect to first direction 960 in which first region 810 and second region 820 are arranged is 90°. Third direction 980 is parallel to second direction 970. The angle formed by third direction 980 with respect to first direction 960 in which first region 810 and second region 820 are arranged may be in the range of 90°±5°, may be in the range of 90°±10°, may be in the range of 90°±20°, or may be in the range of 90°±30°. The flow direction of coolant at both ends of flow generation portion 850 in second direction 970 may be shifted between first direction 960 and third direction 980.

[0184] Flow generation portion 850 is disposed at the boundary between first region 810 and second region 820. Flow generation portion 850 extends along boundary line 815 between first region 810 and second region 820. Flow generation portion 850 extends in a strip shape in second direction 970 while having a constant width from boundary line 815 in first direction 960.

[0185] As described above, the plurality of second nozzles 67 (67A, 67B, 67C, 67D) form a swirl flow that flows along the periphery of second region 820 when viewed from above. The flow of coolant generated by flow generation portion 850 is a part of the swirl flow formed by the plurality of second nozzles 67. The flow of coolant generated by flow generation portion 850 is a flow of coolant which is discharged from second nozzle 62A toward second nozzle 62B and parallel to second direction 970.

[0186] The position of inflow portion 840 in second region 820 is not particularly limited. Inflow portion 840 is located away from flow generation portion 850. Inflow portion 840 may be located on the path of the swirl flow formed by the plurality of second nozzles 67, may be located inside the swirl flow or outside the swirl flow.

[0187] The clean coolant stored in second region 820 of coolant tank 900S is supplied to machine tool main body 210 (base coolant nozzle 251, tool coolant circulation unit 252, tip coolant nozzle 253, and through-spindle coolant unit 254) by third pump 53 described above in the first embodiment.

[0188] The coolant from which the sludge is collected by foreign matter capturing device 41 may be stored in second tank 160 described above in the first embodiment, and the coolant stored in second tank 160 may be returned to second region 820 in coolant tank 900S through inflow portion 840. In this case, coolant tank 900S corresponds to first tank 110 described above in the first embodiment.

[0189] Fig. 12 is a plan view illustrating a modification of the coolant tank illustrated in Fig. 11. Fig. 13 is a cross-sectional view illustrating the coolant tank taken along arrow line XIII-XIII in Fig. 12. With reference to Figs. 12 and 13, a coolant tank 900 (900T) according to the present modification includes a primary tank 910 and a secondary tank 920. Primary tank 910 and secondary tank 920 are arranged in first direction 960.

[0190] The volume of primary tank 910 is larger than the volume of secondary tank 920. The area of primary tank 910 in the top view is larger than the area of the auxiliary tank 920 in the top view. The length of primary tank 910 in second direction 970 is longer than the length of secondary tank 920 in second direction 970. The length of primary tank 910 in first direction 960 is longer than the length of secondary tank 920 in first direction 960.

[0191] Primary tank 910 corresponds to a coolant tank 900T having a first region 810 and a second region 820 illustrated in Fig. 11. In the present modification, secondary tank 920 further constitutes second region 820.

[0192] Inflow portion 840 is provided in second region 820. Inflow portion 840 is provided in secondary tank 920. The coolant after the sludge is collected from the sludge and the coolant that are pumped by pumping portion 830 flows into inflow portion 840.

[0193] As illustrated in Fig. 13, coolant tank 900T includes a partition wall 930. Partition wall 930 is provided along the boundary between primary tank 910 and secondary tank 920. The height of partition wall 930 from the bottom surface 950 of coolant tank 900T is lower than the height of side surface 940 rising from bottom surface 950 of coolant tank 900T. With such a configuration, when the liquid level of the coolant stored in secondary tank 920 becomes equal to or higher than a predetermined level, the coolant overflows toward second region 820 of primary tank 910 beyond partition wall 930.

[0194] The clean coolant stored in second region 820 of primary tank 910 in coolant tank 900T is supplied to machine tool main body 210 by third pump 53 described above in the first embodiment. Furthermore, the clean coolant stored in second region 820 of secondary tank 920 in coolant tank 900T may be supplied to machine tool main body 210.

[0195] Summarizing the configuration of coolant tank 900 according to the fourth embodiment of the present invention described above, coolant tank 900 according to the present embodiment includes a first region 810 provided with a pumping portion 830 that pumps sludge and coolant, and a second region 820 provided with an inflow portion 840 into which clean coolant flows after the sludge is collected from the sludge and the coolant pumped by pumping portion 830, and a flow generation portion 850 that generates a flow of coolant in a direction intersecting with a direction in which first region 810 and second region 820 are arranged so as to form a boundary with respect to first region 810.

[0196] According to such a configuration, it is possible for flow generation portion 850 which forms a flow of coolant in the direction intersecting with the direction in which first region 810 and second region 820 are arranged so as to form a boundary between first region 810 and second region 820 to prevent the coolant from first region 810 before the sludge is collected from entering second region 820. Accordingly, it is possible to prevent dirty coolant from being mixed with clean coolant in second region 820 provided with inflow portion 840 into which the clean coolant flows after the sludge is collected. As a result, it is possible to supply a sufficient amount of clean coolant from coolant tank 900 to machine tool main body 210 by using the coolant stored in second region 820.

[0197] Machine tool 200 in the present embodiment includes a machine tool main body 210 that machines a workpiece, and a coolant tank 900 that stores coolant to be supplied to machine tool main body 210.

[0198] The coolant treatment apparatus according to the present embodiment includes a coolant tank 900, a first pump 51 attached to coolant tank 900 and disposed in pumping portion 830, a second nozzle 67 attached to coolant tank 900 and configured to form a coolant flow in flow generation portion 850, and a foreign matter capturing device 41 captures foreign matters contained in the coolant pumped by pumping portion 830.

[0199] According to such a configuration, it is possible to supply a sufficient amount of clean coolant from coolant tank 900 to machine tool main body 210.

[0200] It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in all respects. The scope of the present invention is defined by the terms of the claims rather than the description of the embodiments above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[0201] This nonprovisional application is based on Japanese Patent Application No. 2024-154100 filed on September 6, 2024 and Japanese Patent Application No. 2025-121284 filed on July 18, 2025, with the Japan Patent Office, the entire contents of which are hereby incorporated by reference.

[0202] 21: coolant return mechanism; 22: drainage pipe; 31: gutter; 41: foreign matter capturing device; 42: foreign matter separation unit; 43: foreign matter collection unit; 44: coolant outflow unit; 45: coolant inflow portion; 46: partition wall; 51: first pump; 52: second pump; 53: third pump; 61, 61A, 61B, 61C, 66, 66A, 66B: first nozzle; 61a, 62a: coolant discharge port; 62, 62A, 62B, 62C, 62D, 67, 67A, 67B, 67C, 67D: second nozzle; 63: third nozzle; 100: coolant treatment apparatus; 110: first tank; 111, 241: wheel; 120, 170: tank body; 121, 171: bottom surface; 122, 172: peripheral side surface; 122i: first side surface; 122j: second side surface; 122k: third side surface; 126: first storage space; 130, 130J, 180, 180J: lid; 131, 173, 212: opening; 160: second tank; 161: notch; 176: second storage space; 190: coolant temperature adjustment device; 200: machine tool; 210: machine tool main body; 211: cover body; 213: door; 220: machining area; 230: chip conveyor; 231: cover member; 232: coolant discharge port; 233: chip reception port; 234: chip discharge port; 236: conveying unit; 251: base coolant nozzle; 252: tool coolant circulation unit; 253: tip coolant nozzle; 254: through-spindle coolant unit; 310: first tank region; 310p: corner region; 320: second tank region; 330: third tank region; 360, 370, 380: position; 410: first pipe; 420: second pipe; 510, 560: first direction; 520, 570: second direction; 530, 580: third direction; 611: first inclined portion; 611p, 612p, 614p: distal end; 611q, 612q, 614q: proximal end; 612: second inclined portion; 613: horizontal portion; 614: third inclined portion; 660, 710: first tank unit; 670, 720: second tank unit; 680: corner; 690: overhang; 721: first region; 722: second region; 730: pumping portion; 740: inflow portion; 750: flow generation portion; 810: first region; 820: second region; 815: boundary line; 830: pumping portion; 840: inflow portion; 850: flow generation portion; 860: inflow portion; 900, 900S, 900T: coolant tank; 910: primary tank; 920: secondary tank; 930: partition wall; 940: side surface; 950: bottom surface; 960: first direction; 970: second direction; 980: third direction; FL: floor.

Claims

1. A coolant tank comprising: a first tank unit which extends in a first direction and through which coolant from a machining area flows in the first direction; and a second tank unit which includes a first region through which coolant from the first tank unit flows in a second direction intersecting with the first direction, and a second region; the first region being provided with a pumping portion that pumps coolant, the second region being provided with an inflow portion into which the coolant pumped by the pumping portion and subjected to the treatment of foreign matters contained in the coolant flows into the second tank unit, and a flow generation portion that generates a flow of coolant in a third direction intersecting with the second direction with respect to the coolant flowing through the first region in the second direction so as to form a boundary between the first region and the second region.

2. A coolant tank comprising; a first region provided with a pumping portion that pumps sludge and coolant; and a second region provided with an inflow portion into which the coolant flows after the sludge is collected from the sludge and the coolant pumped by the pumping portion, and a flow generation portion that generates a flow of coolant in a direction intersecting with a direction parallel to the first region so as to form a boundary with respect to the first region.

3. A machine tool comprising: a machine tool main body that machines a workpiece; and a coolant tank according to claim 1 or 2 that stores coolant to be supplied to the machine tool main body.

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