Liquid circulation device

Abstract

A liquid circulation device (7) comprises: fixed members (2, F) that are fixedly arranged, a moving member (6) that is movably arranged with respect to the fixed member, a first heat exchanger (71) that is provided on the moving member and can move together with the moving member, a second heat exchanger (72) provided on the fixed member, a first circulation path (73) in which a first circulation liquid circulates between a first heat generating portion (64) of the moving member that is open to the atmosphere and the first heat exchanger, and a second circulation path (74) in which a second circulation liquid circulates between a second heat generating portion (62) of the moving member that is closed and the second heat exchanger. The first circulation liquid is pumped from a discharge portion of the first heat generating portion to a supply portion of the first heat generating portion through the first heat exchanger of the first circulation path, and the second circulation liquid is pumped in the second circulation path.

Description

[Technical field]

[0001] The present invention relates to a liquid circulation device. [Background technology]

[0002] For example, a liquid circulation device installed in a machining center circulates a circulating fluid (cooling oil, lubricating oil) to lubricate and cool the gears of the reducer that constitutes the rotary drive unit that rotates the spindle of the spindle device (see Patent Documents 1, 2, and 3), and to cool the jacket of the bearing that supports the spindle (see Patent Documents 2 and 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 3-10737 [Patent Document 2] International Publication No. 2015 / 037139 [Patent Document 3] Japanese Utility Model Application Publication No. 5-2859 Summary of the Invention [Problem to be solved by the invention]

[0004] The bearings supporting the spindle of the spindle device are not sealed, and the circulation path is not sealed either, so the circulating fluid cannot be pumped. The circulation path provided on the outer periphery of the bearing is sealed, so the circulating fluid can be pumped. This allows the circulation path to be freely arranged in the machining center, and the circulation path can be made compact. On the other hand, in the reducer that constitutes the rotation drive unit that rotates the spindle of the spindle device, if the circulating fluid is pressurized, the reducer will be filled with the circulating fluid, which may increase the heat of stirring or cause the fluid to leak outside the reducer.

[0005] Therefore, the inside of the reducer is open to the atmosphere, and the circulating fluid is allowed to fall by its own weight (natural fall).However, since a circulation path that allows for natural fall is required, the circulation path ends up occupying a large space in the machining center, which increases the size of the machining center cover and leads to increased costs.

[0006] An object of the present invention is to provide a liquid circulating device capable of making the circulation path of the circulating liquid compact. [Means for solving the problem]

[0007] The liquid circulation device of the present invention comprises a fixed member that is fixedly arranged, a movable member that is arranged movably relative to the fixed member, a first heat exchanger that is provided on the movable member and movable together with the movable member, a second heat exchanger that is provided on the fixed member, a first circulation path through which a first circulating liquid circulates between a first heat generating portion of the movable member that is open to the atmosphere and the first heat exchanger, and a second circulation path through which a second circulating liquid circulates between a second heat generating portion of the movable member that is sealed and the second heat exchanger, and the first circulating liquid is pumped from a discharge portion of the first heat generating portion through the first heat exchanger to a supply portion of the first heat generating portion in the first circulation path, and the second circulating liquid is pumped through the second circulation path.

[0008] This liquid circulation device includes a first heat exchanger and a second heat exchanger, each of which is provided in a first circulation path and a second circulation path that are separated from each other. The first heat exchanger is provided in a moving member, and the liquid circulation device pumps the first circulation liquid through a portion of the first circulation path, i.e., from the discharge portion of the first heat generating portion of the moving member through the first heat exchanger to the supply portion of the first heat generating portion, and does not pump the first circulation liquid through the other portion of the first circulation path, i.e., the first heat generating portion. This allows the portion of the first circulation path to be freely moved around the moving member, and allows the portion of the first circulation path to be made compact. In addition, since the first circulation liquid is not pumped through the first heat generating portion that is open to the atmosphere, which is the other portion of the first circulation path, it is possible to prevent an increase in heat generation and liquid leakage due to the first circulation liquid filling the first heat generating portion. Furthermore, since the liquid circulation device pumps the second circulation liquid through a second circulation path that circulates between the second heat generating portion of the sealed movable member and the second heat exchanger, the second circulation path can be freely routed and the second circulation path can be made compact. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of a machine tool equipped with a liquid circulation device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram showing a detailed configuration of the liquid circulating device. [Diagram 3] 13 is a diagram showing a detailed configuration of another embodiment of the first heat exchanger of the liquid circulation device. FIG. [Figure 4] 4 is a flowchart for explaining a control operation of a numerical control device of a machine tool. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] (1. Schematic configuration of machine tool 1 equipped with liquid circulation device 7) A machine tool equipped with a liquid circulation device according to an embodiment of the present invention will be described below with reference to the drawings. A three-axis machining center will be taken as an example of the machine tool. That is, the machine tool has three mutually orthogonal linear axes (X, Y, Z axes) as drive axes. As shown in Fig. 1, the machine tool 1 includes a bed 2, a column 3, a saddle 4, a table 5, a spindle device 6, a liquid circulation device 7, a numerical control device 8, and the like.

[0011] The bed 2 is fixedly disposed on a floor surface F, and is provided on the upper surface with a pair of rails 11 extending in the X-axis direction (horizontal direction) and a pair of rails 12 extending in the Z-axis direction (horizontal direction) perpendicular to the X-axis direction. The column 3 is engaged with the pair of rails 11 by an X-axis motor 9 so as to be movable in the X-axis direction relative to the bed 2. A pair of rails 13 extending in the Y-axis direction (vertical direction) perpendicular to the X-axis and Z-axis directions are provided on the front side surface of the column 3.

[0012] The saddle 4 is engaged with a pair of rails 13 so as to be movable in the Y-axis direction relative to the column 3 by a Y-axis motor 10. The table 5 is engaged with a pair of rails 12 so as to be movable in the Z-axis direction relative to the bed 2 by a Z-axis motor 14. A workpiece W is held on the upper surface of the table 5 by a clamping device (not shown).

[0013] The spindle device 6, which will be described in detail later, is provided so as to protrude forward and backward in the Z-axis direction relative to the saddle 4. The spindle device 6 includes a bearing 62 that supports the spindle 61 rotatably about its axis, and a spindle motor 63 and a reducer 64 that are rotational drive units that rotate the spindle 61 about its axis. The bearing 62 is built into a spindle housing 65, and the spindle motor 63 and the reducer 64 are built into the spindle housing 65, the saddle 4, and the column 3. The spindle 61 holds a rotating tool T at its tip side (left side in FIG. 1), and is supported by the bearing 62 and rotated by the spindle motor 63 and the reducer 64. Examples of the rotating tool T include a ball end mill, an end mill, a drill, and a tap.

[0014] The spindle device 6 moves in the X-axis direction relative to the bed 2 as the column 3 is moved by the X-axis motor 9. Furthermore, the spindle device 6 moves in the Y-axis direction relative to the bed 2 as the saddle 4 is moved by the Y-axis motor 10. In other words, the spindle device 6, which is a movable member, is disposed movably relative to the bed 2, which is a fixed member. Furthermore, the table 5 moves in the Z-axis direction relative to the spindle device 6 by the Z-axis motor 14.

[0015] The liquid circulation device 7, details of which will be described later, includes a first heat exchanger 71 and a second heat exchanger 72. The first heat exchanger 71 is attached to a spindle bracket 66 that protrudes from the spindle housing 65 toward the column 3, and is provided so as to be movable together with the spindle device 6. The first heat exchanger 71 exchanges heat (cools) the first circulating fluid used for lubricating and cooling the gears of the reducer 64, which is the first heat generating part of the spindle device 6.

[0016] The second heat exchanger 72 is installed on a floor surface F, which is a fixed member on which the bed 2 is placed. A spiral pipe 74C passing through a tank (not shown) is provided in a heat exchange section 72c of the second heat exchanger 72. A second circulation path outward hose 74A is connected to one end of the spiral pipe 74C, and a second circulation path return hose 74B is connected to the other end.

[0017] The second circulation path outward hose 74A and the second circulation path return hose 74B extending from the second heat exchanger 72 are piped to the side of the bed 2 and fed to an X-axis cable bear (registered trademark) 74D that connects the bed 2 and the column 3. Then, they are piped inside the column 3 and fed to a Y-axis cable bear (registered trademark) 74E that connects the column 3 and the spindle bracket 66.

[0018] The second circulation path outward hose 74A is piped so as to pass through the first heat exchanger 71 and reach the bearing 62, which is the second heat generating part of the spindle device 6. The second circulation path return hose 74B is piped so as to reach directly to the bearing 62. The second heat exchanger 72 exchanges heat (cools) between the refrigerant liquid sent to the tank of the heat exchange part 72c and the second circulating liquid used for cooling the bearing 62, which passes through a spiral tube 74C in the tank.

[0019] The numerical control device 8 drives and controls the spindle motor 63 based on the numerical control data to rotate the rotating tool T, and drives and controls the respective axis motors 9, 10, and 14 of the column 3, saddle 4, and table 5 to move the rotating tool T relative to the workpiece W, thereby machining the workpiece W. In addition, the liquid circulating device 7 is operated to circulate the first circulating liquid and the second circulating liquid, thereby lubricating and cooling the gears of the reducer 64 of the spindle device 6, and cooling the bearings 62 of the spindle device 6.

[0020] (2. Detailed configuration of the spindle device 6 and the liquid circulation device 7) The detailed configurations of the above-mentioned spindle device 6 and liquid circulating device 7 will be described with reference to the drawings. As shown in Fig. 2, the spindle device 6 includes a spindle 61, a bearing 62, a spindle motor 63, a reducer 64, a spindle housing 65, a spindle bracket 66, and a cylindrical member 67. The bearing 62 supports the spindle 61 so that it can rotate about its axis. The spindle motor 63 and the reducer 64 rotate the spindle 61 about its axis.

[0021] The reducer 64 includes a planetary gear reducer 64A having a sun gear, an internal gear, a planetary gear, and a planetary carrier (not shown), and a spur gear reducer 64B having a first spur gear and a second spur gear. The planetary gear reducer 64A has a sun gear connected to the main shaft motor 63 and an internal gear fixed to a reducer housing 64b. The planetary carrier is connected to the first spur gear of the spur gear reducer 64B, and the second spur gear meshing with the first spur gear is fitted onto the main shaft 61.

[0022] The cylindrical member 67 is fitted into an internal space having a circular cross section that is provided in the spindle housing 65. The bearing 62 is fitted into the inner periphery of the cylindrical member 67. A spiral groove 67a that functions as a bearing cooling jacket 68 for the bearing 62 is formed on the outer periphery of the cylindrical member 67. An inlet hole 65a and an outlet hole 65b through which the second circulating fluid flows into and out of the spiral groove 67a are formed in the inner wall of the spindle housing 65 near the start and end of the spiral groove 67a.

[0023] A spirally communicating bearing cooling jacket 68 is formed between the inner periphery of the spindle housing 65 and the spiral groove 67a, one end of the bearing cooling jacket 68 communicating with the inlet hole 65a and the other end of the bearing cooling jacket 68 communicating with the outlet hole 65b, and the second circulating liquid flows through the bearing cooling jacket 68, whereby the bearing cooling jacket 68 cools the bearing 62 via the cylindrical member 67. The bearing cooling jacket 68 is a sealed space that does not communicate with any holes other than the inlet hole 65a and the outlet hole 65b, and is capable of pumping the second circulating liquid.

[0024] 2, the liquid circulation device 7 includes a first heat exchanger 71, a second heat exchanger 72, a first circulation path 73 (shown in dashed dotted line), and a second circulation path 74 (shown in dashed two dotted line). The first heat exchanger 71 and the second heat exchanger 72 are provided in the separated first circulation path 73 and second circulation path 74, respectively.

[0025] The first heat exchanger 71, which will be described in detail later, includes a rectangular parallelepiped tank 75 that stores the first circulating liquid, and a first heat exchange piping 79 that is housed in the tank 75 and through which the second circulating liquid passes. Since the first circulating liquid collected in the tank 75 from the reduction gear 64, which is the first heat generating part of the spindle device 6, is heated, if the first circulating liquid continues to be used as is, the first circulating liquid may become hot, causing poor lubrication of the gears of the reduction gear 64. To prevent this, the first heat exchanger 71 exchanges heat (cools) between the first circulating liquid in the tank 75 and the second circulating liquid in the first heat exchange piping 79. A partition plate 75A is provided in the tank 75 to prolong the contact between the first circulating liquid and the second circulating liquid.

[0026] The second heat exchanger 72 is a general cooling device (chiller) and has a heat exchange section 72c that exchanges heat between the first circulating liquid and the cooling liquid. The refrigerant liquid is compressed by a pump (not shown) and cooled by expanding it in the heat exchange section. The second circulating liquid recovered from the bearing 62 (bearing cooling jacket 68), which is the second heat generating section of the spindle device 6, is heated, so that if it is continued to be used as it is, the second circulating liquid will become hot, and the bearing 62 will expand, which may cause a rolling failure. To prevent this, the second heat exchanger 72 cools the second circulating liquid. In this example, the second heat exchanger 72 is configured to be installed on the floor surface F, which is a fixed member, but it may be configured to be installed on the bed 2, which is a fixed member.

[0027] The first circulation path 73 is piped so that the first circulating fluid circulates in the direction of the dashed arrow between a tank 75 of the first heat exchanger 71 and the planetary gear reducer 64A which is the first heat generating part of the spindle device 6. In detail, the first circulating fluid cooled in the first heat exchanger 71 is sucked up by a pump 76 from a first liquid outlet 73b provided in the tank 75, and is sent into the inside of the planetary gear reducer 64A from a liquid inlet 64a (supply part) of the reducer housing 64b via a filter 77.

[0028] The first circulating fluid heated inside the planetary gear reducer 64A is sucked out from the drain port 64c (discharge section) of the reducer housing 64b and sent into the first heat exchanger 71 from the first liquid inlet 73a provided in the tank 75. This allows the first circulating path 73, excluding the reducer 64, to be freely routed in the spindle bracket 66. Since the inside of the planetary gear reducer 64A is not a sealed space, the first lubricating fluid cannot be pumped. The first circulating path 73 must be made thick. A conventional machine tool that sends the first circulating path 73 to the X-axis cable bear (registered trademark) 74D and the Y-axis cable bear (registered trademark) 74E becomes large. In comparison, the machine tool 1 of the present application has the effect of being compact.

[0029] The pump 76 is a general electric or air-type metering pump capable of pumping the first circulating liquid. The pump 76 is constantly driven, and sucks up the first circulating liquid in the tank 75 and sends it into the inside of the reducer housing 64b. The first circulating liquid heated by the gears of the planetary gear reducer 64A is discharged by its own weight from a drain port 64c (discharge portion) of the reducer housing 64b.

[0030] The first lubricating liquid inside the planetary gear type reducer 64A is discharged by its own weight, so the first circulating liquid that is sent in does not accumulate inside the planetary gear type reducer 64A. That is, the pump 76 supplies the first circulating liquid from the first heat exchanger 71 to the liquid inlet 64a (supply section) of the reducer housing 64b, that is, supplies it from a lower place to a higher place, and does not pump the first circulating liquid into the planetary gear type reducer 64A.

[0031] Therefore, the inside of the planetary gear type reducer 64A is not filled with the first circulating liquid, and it is possible to prevent an increase in heat of stirring and the occurrence of liquid leakage to the outside of the planetary gear type reducer 64A. Also, there is no need to provide a circulation path that requires a wide space to allow the first circulating liquid to fall under its own weight (natural fall) as in the past, so it is possible to avoid enlarging the size of the X-axis cable bear (registered trademark) 74D and the Y-axis cable bear (registered trademark) 74E, and it is possible to avoid an increase in cost due to an increase in the size of the cover of the machine tool 1.

[0032] The filter 77 is a general filter capable of removing wear powder of gears generated in the reducer 64 and contained in the first circulating fluid. As a result, the first circulating fluid sent into the inside of the reducer housing 64b does not contain wear powder of gears, so that the wear of the gears of the reducer 64 can be suppressed from being accelerated.

[0033] Furthermore, if the first circulating fluid is not normally supplied to the inside of the reducer housing 64b due to clogging of the filter 77, a malfunction of the pump 76, a fluid leak, or the like, the reducer 64 may malfunction due to an abnormal lubrication. For this reason, a general mechanical or electrical pressure switch 78 is provided downstream of the filter 77. When the supply pressure of the first circulating fluid falls below a set value, the pressure switch 78 sends an abnormality signal to the numerical control device 8 to stop the spindle 61. That is, the drive of the spindle motor 63, the first heat exchanger 71, and the pump 76 is stopped.

[0034] Furthermore, a part 73A of the first circulation path 73 extending from the filter 77 to the reducer 64 (a part surrounded by an oval of dotted lines in the drawing) may be piped in the vicinity of the cooling fan 63A provided in the spindle motor 63. This allows the first circulating fluid flowing through the part 73A of the first circulation path 73 to be air-cooled by the fan 63A, thereby reducing the load on the first heat exchanger 71 and enabling the first heat exchanger 71 to be further miniaturized and reduced in cost.

[0035] The second circulation path 74 (the second circulation path outward hose 74A and the second circulation path return hose 74B) are piped so that the second circulating fluid circulates in the direction of the two-dot chain arrow between the second heat exchanger 72, the first heat exchanger 71, and the bearing 62 which is the second heat generating part of the spindle device 6. In detail, the second circulating fluid cooled in the heat exchange part 72c of the second heat exchanger 72 is fed from the outlet 72a of the second circulation path outward hose 74A to the first heat exchanger 71 through the second inlet 74b of the first heat exchange pipe 79.

[0036] The second circulating fluid that is heat exchanged (heated) with the first circulating fluid in the first heat exchanger 71 is fed from the second outlet 74a of the first heat exchange piping 79 into the bearing cooling jacket 68 of the bearing 62, that is, into the groove from the inlet hole 65a of the spiral groove 67a. The second circulating fluid that is heated in the bearing 62 is discharged from the outlet hole 65b of the spiral groove 67a and fed into the heat exchange section 72c of the second heat exchanger 72 from the inlet 72b of the second circulation path return hose 74B. That is, the second heat exchanger 72 pressure-feeds the second circulating fluid through the second circulation path 74 because the bearing cooling jacket 68 is sealed. This allows the second circulation path 74 to be narrowed, and the X-axis cable bear (registered trademark) 74D and the Y-axis cable bear (registered trademark) 74E to be prevented from becoming large, thereby preventing an increase in cost due to an increase in the size of the cover of the machine tool 1.

[0037] (3. Detailed configuration of alternative forms of the first heat exchanger 71) A detailed configuration of another embodiment of the first heat exchanger 71 will be described. As shown in FIG. 3, the first heat exchanger 71 is configured such that the inside of a tank 75 is partitioned to provide a circulation path instead of the above-mentioned first heat exchange piping 79. A first outlet 73b and a first inlet 73a for the first circulating fluid are provided on an upper surface 75a of the tank 75, spaced apart in the horizontal direction (Z-axis direction). A second outlet 74a and a second inlet 74b for the second circulating fluid are provided on a left side surface 75b of the tank 75, spaced apart in the vertical direction (Y-axis direction). The inside of the tank 75 is divided into a plurality of (six in this example) communicating chambers 75f1-75f6 by a plurality of (seven in this example) partition plates 75e1-75e7 spaced apart from each other and extending in the vertical direction (Y-axis direction).

[0038] That is, the chamber 75f1 has a first liquid inlet 73b and is divided by partition plates 75e1 and 75e2. The chamber 75f2 is divided by partition plates 75e2 and 75e3, but the lower end of the partition plate 75e2 is spaced apart from the bottom surface 75c of the tank 75 so as to communicate with the chamber 75f1 at the bottom. The chamber 75f3 is divided by partition plates 75e3 and 75e4, but the upper end of the partition plate 75e3 is spaced apart from the upper surface 75a of the tank 75 so as to communicate with the chamber 75f2 at the top.

[0039] The chamber 75f4 is divided by partition plates 75e4 and 75e5, but the lower end of the partition plate 75e4 is spaced apart from the bottom surface 75c of the tank 75 so as to communicate with the chamber 75f3 at the lower part. The chamber 75f5 is divided by partition plates 75e5 and 75e6, but the upper end of the partition plate 75e5 is spaced apart from the upper surface 75a of the tank 75 so as to communicate with the chamber 75f4 at the upper part. The chamber 75f6 has a first liquid outlet 73a and is divided by partition plates 75e6 and 75e7, but the lower end of the partition plate 75e6 is spaced apart from the bottom surface 75c of the tank 75 so as to communicate with the chamber 75f5 at the lower part.

[0040] Furthermore, the space on the left side surface 75b side of the tank 75 adjacent to the chamber 75f1 across the partition plate 75e1 is divided into a chamber 75g1 having the second liquid outlet 74a and a chamber 75g2 having the second liquid inlet 74b. Also, the space on the right side surface 75d side of the tank 75 adjacent to the chamber 75f6 across the partition plate 75e7 is provided as one chamber 75g3. Then, piping 75h1 (two in this example) connecting the chamber 75g1 and the chamber 75g3 is provided so as to penetrate the partition plates 75e1-75e7. Similarly, piping 75h2 (two in this example) connecting the chamber 75g2 and the chamber 75g3 is provided so as to penetrate the partition plates 75e1-75e7.

[0041] The first circulating liquid fed from the first liquid inlet 73b flows downward in the chamber 75f1, flows from below the partition plate 75e2 into the chamber 75f2, flows from below to above the chamber 75f2, then flows from above the partition plate 75e3 into the chamber 75f3, flows from above to below the chamber 75f3, and flows from below to above the chamber 75f4.

[0042] Then, the first circulating liquid flows into chamber 75f5 from above partition plate 75e5, flows from top to bottom within chamber 75f5, flows into chamber 75f6 from below partition plate 75e6, flows from bottom to top within chamber 75f6, and is discharged from first liquid outlet 73a. In other words, in tank 75, a first circulation path 73 is formed that causes the first circulating liquid to flow vertically in a zigzag manner from first liquid inlet 73b to first liquid outlet 73a.

[0043] The second circulating liquid fed from the second liquid inlet 74b flows from the chamber 75g2 through the pipe 75h2 into the chamber 75g3. Then, the second circulating liquid flows from the bottom to the top in the chamber 75g3, flows through the pipe 75h1 into the chamber 75g1, and is discharged from the second liquid outlet 74a. In other words, the second circulating liquid forms a second circulation path 74 in the tank 75 between the second liquid inlet 74b and the second liquid outlet 74a, which allows the second circulating liquid to flow back and forth between the left and right.

[0044] That is, in the first heat exchanger 71, the heated first circulating fluid passing through the reducer housing 64b is cooled by the cooled second circulating fluid pumped from the second heat exchanger 72. This first circulating fluid flows in a zigzag pattern around the partition plates 75e1-75e7 in the tank 75, so that it is in contact with the pipes 75h2 and 75h1 for a long time, and heat exchange can be performed efficiently. At this time, the second circulating fluid is heated to some extent by heat exchange with the first circulating fluid, but this makes it possible to prevent the bearings 62 from being overcooled.

[0045] (4. Control operation of the numerical control device 8) Next, the control operation of the numerical control device 8 when machining the workpiece W with the rotating tool T will be described with reference to the drawings. It is assumed that the workpiece W is held on the table 5, and the rotating tool T is held on the spindle 61.

[0046] 4, the numerical control device 8 drives the pump 76 of the first heat exchanger 71 and also drives the second heat exchanger 72 (step S1). As a result, the first circulating fluid is pumped and circulated through a first circulation path 73 (excluding the inside of the reduction gear housing 64b) for lubricating and cooling the gears of the reduction gear 64 of the spindle device 6, and the second circulating fluid is pumped and circulated through a second circulation path 74 for cooling the bearings 62 of the spindle device 6.

[0047] Then, the numerical control device 8 drives the spindle motor 63 (step S2), and drives the X-, Y-, and Z-axis motors to start machining the workpiece W (step S3). The numerical control device 8 constantly monitors the operating state of the pressure switch 78, and determines whether or not the pump 76 of the first heat exchanger 71 has stopped due to the operation of the pressure switch 78 (step S4).

[0048] When the numerical control device 8 determines that the pressure switch 78 is not activated, it determines whether or not the machining of the workpiece W is completed (step S5), and when the machining of the workpiece W is not completed, it returns to step S4 and repeats the above-mentioned process. On the other hand, when the machining of the workpiece W is completed in step S5, it drives the X-, Y-, and Z-axis motors to move the rotating tool T to the initial position (step S6), and stops driving the spindle motor 63 and the X-, Y-, and Z-axis motors (step S7). Then, it stops driving the pump 76 of the first heat exchanger 71 and the second heat exchanger 72 (step S8), and all the processes are terminated.

[0049] On the other hand, in step S4, when the pressure switch 78 is activated and the pump 76 of the first heat exchanger 71 is stopped, the numerical controller 8 determines that poor lubrication of the reducer 64 has occurred, and performs an abnormal stop of the machine tool 1. That is, the numerical controller 8 drives the X-, Y-, and Z-axis motors to move the rotating tool T to a retreat position (step S9), and stops driving the spindle motor 63 and the X-, Y-, and Z-axis motors to stop machining (step S10). At this time, a warning of poor lubrication of the reducer 64 is displayed on the display screen of the numerical controller 8, and a warning sound is generated from the speaker of the numerical controller 8. Then, the pump 76 of the first heat exchanger 71 and the second heat exchanger 72 are stopped (step S8), and all processing is terminated.

[0050] (5. Other) In the above embodiment, the liquid circulating device 7 is applied to the machine tool 1, but the liquid circulating device 7 can be applied to any device that requires heat exchange by circulating liquid. [Explanation of symbols]

[0051] 1...machine tool, 2...bed, 6...spindle device, 7...liquid circulation device, 8...numerical control device, 61...spindle, 62...bearing, 63...spindle motor, 64...reduction gear, 71...first heat exchanger, 72...second heat exchanger, 73...first circulation path, 74...second circulation path, 75...tank, 75e1-75e7...partition plate, 76...pump, 77...filter, 78...pressure switch

Claims

1. A fixed member that is fixedly disposed; A movable member that is movably arranged relative to the fixed member; a first heat exchanger provided on the movable member and movable together with the movable member; A second heat exchanger provided on the fixing member; a first circulation path through which a first circulating fluid circulates between a first heat generating portion of the moving member that is open to the atmosphere and the first heat exchanger; a second circulation path through which a second circulation fluid circulates between a second heat generating portion of the movable member, which is sealed, and the second heat exchanger; Equipped with A liquid circulation device that pressure-feeds the first circulating liquid from the discharge portion of the first heat generating portion in the first circulation path through the first heat exchanger to the supply portion of the first heat generating portion, and pressure-feeds the second circulating liquid in the second circulation path.

2. 2. The liquid circulation device according to claim 1, wherein the second circulation path is configured so that a second circulating liquid circulates between a second heat generating portion of the movable member, the first heat exchanger, and the second heat exchanger, and heat exchange is performed between the first circulating liquid and the second circulating liquid in the first heat exchanger.

3. 3. The liquid circulation system according to claim 1, wherein the movable member is a spindle device having a spindle that holds a rotary tool and is driven to rotate.

4. The spindle device is a reducer constituting a rotation drive unit that rotates the main shaft as the first heat generating unit; a bearing that rotatably supports the main shaft as the second heat generating portion; Equipped with The liquid circulating device according to claim 3 , wherein the first circulating fluid lubricates and cools the reducer, and the second circulating fluid cools the bearing.

5. 5. The liquid circulation device according to claim 3, wherein the first circulation path is arranged to pass near a fan for cooling a spindle motor constituting a rotation drive unit that rotates the spindle, and the fan cools the first circulating liquid passing through the first circulation path by blowing air.

6. The liquid circulation apparatus according to claim 1 , wherein the first heat exchanger includes a tank for storing the first circulating liquid.

7. The liquid circulation device according to claim 1 , wherein the moving member includes a pump that pumps the first circulating liquid through the first circulation path to the first heat generating portion.

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