Coolant device and machine tool

Abstract

To provide a coolant device which facilitates control for bringing the output of a coolant pump into a suitable state even when a plurality of coolant discharge parts are provided.SOLUTION: A coolant device 10 includes: a coolant tank 20 which is used when a material is processed and stores a coolant; a coolant pump 30 for sucking up the coolant stored in the coolant tank 20; a coolant circulation passage which is a flow channel where the coolant sucked up by the coolant pump 30 is returned up to the coolant tank 20; a coolant valve 27 that is provided on a flow channel 31 for a discharge part branched in a branch place from the coolant circulation passage, and opens / closes the flow channel for the discharge part to which a first coolant discharge part 21 is connected; and a measurement device 70 which is provided on the downstream of the branched place of the flow channel 31 for the discharge part, on the coolant circulation passage, and measures the state of the coolant. The coolant pump 30 controls the output so that the measured value by the measurement device 70 becomes constant.SELECTED DRAWING: Figure 3

Description

Technical Field

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

Background Art

[0002] In a machine tool, processing is performed while discharging coolant supplied from a coolant device for the purpose of removing chips, lubricating, and cooling. In such a machine tool, a plurality of coolant discharge parts for discharging coolant are arranged according to the application (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] If a machine tool has a plurality of coolant discharge parts, there will be a large number of combinations of the ON / OFF of each coolant discharge part and the discharge amount in each coolant discharge part, and the process of determining the appropriate output of the coolant pump for each combination pattern tends to become complicated.

[0005] The present invention has been made paying attention to such problems, and an object thereof is to provide a coolant device and a machine tool that can easily control the output of the coolant pump to an appropriate state even if a plurality of coolant discharge parts are provided.

Means for Solving the Problems

[0006] To achieve the above object, a coolant device according to a first aspect of the present invention includes a coolant tank in which coolant used when processing a material is stored, a coolant pump that sucks up the coolant stored in the coolant tank, a coolant circulation path that is a flow path through which the coolant sucked up by the coolant pump returns to the coolant tank, a coolant valve provided in a discharge portion flow path branched from the coolant circulation path at a branch point and that opens and closes the discharge portion flow path to which a coolant discharge portion is connected, and a measuring instrument provided downstream of the branch point of the discharge portion flow path in the coolant circulation path and that measures the state of the coolant. The output of the coolant pump is controlled such that the measurement value by the measuring instrument becomes constant.

[0007] To achieve the above object, a coolant device according to a second aspect of the present invention includes a coolant tank in which coolant used when processing a material is stored, a coolant pump that sucks up the coolant stored in the coolant tank, a coolant circulation path that is a flow path through which the coolant sucked up by the coolant pump returns to the coolant tank, a coolant valve provided in a discharge portion flow path branched from the coolant circulation path at a branch point and that opens and closes the discharge portion flow path to which a coolant discharge portion is connected, and a measuring instrument provided downstream of the branch point of the discharge portion flow path in the coolant circulation path and that measures the state of the coolant. The coolant pump controls its own output such that the measurement value by the measuring instrument becomes constant.

[0008] To achieve the above object, a machine tool according to the present invention includes a machine body having a processing chamber for processing a material, and the above-described coolant device that opens the coolant valve and supplies the coolant stored in the coolant tank to the coolant discharge portion provided in the processing chamber.

Advantages of the Invention

[0009] According to the present invention, even if a plurality of coolant discharge portions are provided, it is possible to provide a coolant device and a machine tool that can easily control the output of the coolant pump to a suitable state.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0011] Hereinafter, a coolant device and a machine tool according to an embodiment of the present invention will be described with reference to the drawings.

[0012] The machine tool 1 according to the present embodiment is, for example, a turning center. The machine tool 1 has a machine body 2 and a coolant device 10 provided in the machine body 2.

[0013] The machine body 2 includes a bed S which is the base of the machine body 2, and a control unit 100 that controls the overall operation of the machine tool 1. Inside the machine body 2, as shown in FIG. 2, a machining chamber 3 for performing cutting of the workpiece W and the like is provided. In the machining chamber 3, there are provided a first spindle unit 5 provided with a spindle 4 for gripping one end of the workpiece W, a tool spindle unit 7 for holding a tool 6 at one end, a rear tool rest 9 to which a plurality of tools 8 are attached, and a second spindle unit (not shown). The second spindle unit is provided at a position facing the first spindle unit 5.

[0014] The first spindle unit 5 rotates while holding the workpiece W. The second spindle unit (not shown) rotates while holding the workpiece W received from the first spindle unit 5.

[0015] The tool spindle unit 7 processes the workpiece W gripped by the first spindle unit 5 and the second spindle unit with the held tool 6.

[0016] The rear tool rest 9 processes the workpiece W gripped by the second spindle unit (not shown) with the held tool 8.

[0017] The control unit 100 includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory) that stores a program defining the procedure of processing by the CPU, and the like. The control unit 100 operates the first spindle unit 5, the tool spindle unit 7, the rear tool rest 9, the second spindle unit, etc. provided in the machine body 2 according to a previously created NC (Numerical Control) program, and executes a machining process.

[0018] During the machining of the workpiece W in the machining chamber 3, a coolant is used for chip removal, cooling, and lubrication. As shown in FIG. 1, the coolant stored in the coolant tank 20 is sucked up by the coolant pump 30 and discharged from the first to fourth coolant discharge portions 21, 22, 23, 24 provided in the machining chamber 3.

[0019] As shown in FIG. 2, the first coolant discharge portion 21 is provided near the first spindle unit 5. The first coolant discharge portion 21 supplies coolant toward the workpiece W held by the first spindle unit 5 to remove chips, cool, and lubricate.

[0020] The second coolant discharge portion 22 is provided at the lower part of the machining chamber 3. The second coolant discharge portion 22 discharges coolant onto the bottom surface of the machining chamber 3 to flow and remove the chips accumulated on the bottom surface.

[0021] The third coolant discharge portion 23 is provided on the side wall or ceiling of the machining chamber 3. The third coolant discharge portion 23 discharges coolant in the direction in which the workpiece W is provided. As shown in FIG. 2, the third coolant discharge portion 23 discharges coolant downward from the upper part of the machining chamber 3 to cool, lubricate, and remove chips of the workpiece W.

[0022] The fourth coolant discharge portion 24 is provided at the tip of the tool spindle unit 7. The fourth coolant discharge portion 24 discharges the coolant that has passed through the inside of the tool spindle unit 7 from the tip of the tool 6 to remove chips, cool, and lubricate.

[0023] The coolant device 10 separates the chips contained in the coolant discharged from the machining chamber 3 to perform regeneration processing of the coolant, and supplies the coolant to the machining chamber 3. As shown in FIG. 1, the coolant device 10 includes a coolant tank 20 for storing coolant, a coolant pump 30 for sucking up the coolant stored in the coolant tank 20, and a filter 40 provided downstream of the coolant pump 30.

[0024] The coolant tank 20 stores the coolant discharged in the machining chamber 3 together with the chips generated during the machining of the workpiece W and stores the coolant to be supplied to the machining chamber 3. Before flowing into the coolant tank 20, larger chips are removed as the coolant passes through a chip receiver (not shown) formed of a perforated steel plate.

[0025] The coolant pump 30 is provided in the coolant tank 20 and sucks up the coolant stored in the coolant tank 20. The coolant pump 30 is inverter-controlled by the control unit 100 and can freely change the output of the pump. The pipe for sending the coolant sucked up by the coolant pump 30 branches into three discharge-section pipes 31, 32, and 33 in which discharge-section flow paths for sending the coolant to the first to third coolant discharge sections 21 to 23 are formed, and a filter pipe 34 for sending the coolant to the filter 40.

[0026] The filter 40 is, for example, a cyclone filter and is arranged outside the coolant tank 20. The coolant sucked up by the coolant pump 30 flows into the filter 40 through the filter pipe 34. The filter 40 is supplied with the coolant pressurized by the coolant pump 30. The sludge pushed against the wall surface by the vortex generated by the flow of the coolant is stored in the sludge accumulation section 45 provided at the lower part. On the other hand, the coolant from which the sludge has been removed is sent from the filter 40 to the outside. The pipe for sending the coolant from the filter 40 branches into a discharge-section pipe 41 in which a discharge-section flow path for sending the coolant to the fourth coolant discharge section 24 is formed, and a tank pipe 42 for sending the coolant to the coolant tank 20. Thus, in the coolant device 10, a coolant circulation path formed by the coolant pump 30, the filter pipe 34, the filter 40, and the tank pipe 42 is formed. This coolant circulation path is a flow path for sucking up the coolant from the coolant tank 20, filtering it, and returning it to the coolant tank 20.

[0027] The discharge section pipe 31 is connected to the first coolant discharge section 21 and sends coolant to the first coolant discharge section 21. A coolant valve 27 is provided in the discharge section pipe 31. Similarly, the discharge section pipe 32 is connected to the second coolant discharge section 22 and sends coolant to the second coolant discharge section 22. A coolant valve 28 is provided in the discharge section pipe 32. Similarly, the discharge section pipe 33 is connected to the third coolant discharge section 23 and sends coolant to the third coolant discharge section 23. A coolant valve 29 is provided in the discharge section pipe 33.

[0028] The coolant valves 27, 28, and 29 open and close the flow path. As shown in FIG. 4, the coolant valves 27, 28, and 29 are electrically connected to the control unit 100 and open and close the valves based on an instruction from the control unit 100.

[0029] As shown in FIG. 1, the filter pipe 34 connects the coolant pump 30 and the filter 40. A measuring instrument 70 is provided in the filter pipe 34.

[0030] The measuring instrument 70 is, for example, a flow meter that measures the flow rate of the coolant passing through the filter pipe 34. As shown in FIG. 4, the measuring instrument 70 is electrically connected to the control unit 100, and the flow rate data measured by the measuring instrument 70 is input to the control unit 100.

[0031] Further, the coolant device 10 has a high-pressure discharge section coolant pump 43 attached to the discharge section pipe 41. As shown in FIG. 4, the discharge section coolant pump 43 is electrically connected to the control unit 100, and its on / off is controlled based on an instruction from the control unit 100. The discharge section coolant pump 43 is turned on when the fourth coolant discharge section 24 is in use and supplies high-pressure coolant to the fourth coolant discharge section 24.

[0032] Note that the coolant pipe 41 for the discharge section, to which the coolant pump 43 for the discharge section is attached, is located downstream of the measuring instrument 70. Therefore, the on / off switching of the coolant pump 43 for the discharge section does not affect the measurement data of the measuring instrument 70. On the other hand, the coolant pipes 31, 32, 33 for the discharge section, to which the coolant valves 27, 28, 29 are attached, branch upstream of the measuring instrument 70. Therefore, the opening and closing of the valves of the coolant valves 27, 28, 29 increase or decrease the flow rate of the coolant at the location where the measuring instrument 70 is attached, changing the measurement data. The measuring instrument 70 measures the flow rate affected by the opening and closing of the valves of the coolant valves 27, 28, 29, and the measurement data is input to the control unit 100. The control unit 100 controls the output of the coolant pump 30 based on the measurement data input from the measuring instrument 70 so that the flow rate of the coolant passing through the filter pipe 34 (the measured value by the measuring instrument 70) becomes constant.

[0033] Next, the path through which the coolant flows and the method of controlling the output of the coolant pump 30 based on the measurement data measured by the measuring instrument 70 will be described. Fig. 5 shows the ratios of the coolant amounts used in the first to fourth coolant discharge sections 21 to 24 with respect to the maximum discharge amount of the coolant pump 30. For example, with respect to the maximum discharge amount of the coolant pump 30, 25% of the coolant is used (discharged) in the first coolant discharge section 21, 20% in the second coolant discharge section 22, 15% in the third coolant discharge section 23, and 20% in the fourth coolant discharge section. Also, the output of the coolant pump 30 is controlled by the control unit 100 so that the measurement data by the measuring instrument 70 becomes constant at 40% with respect to the maximum discharge amount of the coolant pump 30.

[0034] Figure 6 also describes the relationship between the on / off combination of each coolant discharge section and the output (%) of the coolant pump 30. If the variable is X, when the coolant pump 30 is used at an output of X%, it discharges a coolant volume of X% of the maximum discharge volume. Thus, there is a linear relationship between the output and the discharge volume of the coolant pump 30, and this relationship holds in the range of 0 ≦ X ≦ 100. Here, the usage amount (flow rate) of the coolant in the first coolant discharge section 21 is described as F1(25). Here, the subscript "1" at the lower right of F1(25) corresponds to the "1" of the first coolant discharge section 21. Also, the number "25" inside the parentheses of F1(25) corresponds to the ratio "25" (%) to the maximum discharge volume of the coolant pump 30. Similarly, the usage amount (flow rate) of the coolant in the second coolant discharge section 22 is F2(20), the usage amount (flow rate) of the coolant in the third coolant discharge section 23 is F3(15), the usage amount (flow rate) of the coolant in the fourth coolant discharge section 24 is F4(20), and the flow rate of the coolant flowing through the tank piping 42 is described as F5(20) or F5(40). Also, since the amount of coolant flowing through the measurement location of the measuring instrument 70 is controlled to be constant (40%) with respect to the maximum discharge volume of the coolant pump 30, F const (40) is described.

[0035] First, the case where all the coolant discharge sections 21, 22, 23, 24 are not in use (CASE1) will be described. Since the first to third coolant discharge sections 21, 22, 23 are not in use, as shown in FIG. 3, all the coolant sucked up by the coolant pump 30 passes through the filter piping 34 and the flow rate is measured by the measuring instrument 70. Therefore, as shown in FIG. 6, the output of the coolant pump 30 is controlled to an output of 40% that discharges a flow rate F const (40). Also, since the fourth coolant discharge section 24 is not in use, all of the coolant that has passed through the measuring instrument 70 and been filtered by the filter 40 passes through the tank piping 42. Therefore, a coolant with a flow rate F5(40) corresponding to 40% of the output of the coolant pump 30 flows through the tank piping 42. The coolant that has passed through the tank piping 42 is discharged into the coolant tank 20.

[0036] Next, the case (CASE2) of using only the fourth coolant discharge section 24 will be described. In response to an instruction from the control unit 100, the coolant pump 43 for the discharge section shown in FIG. 3 is turned on, and thereby, half of the flow rate F const (40) of the coolant passes through the discharge-section piping 41 and is discharged from the fourth coolant discharge section 24. The remaining half of the flow rate F5 (20) of the coolant passes through the tank piping 42 and is returned to the coolant tank 20. Thus, regardless of whether the coolant pump 43 for the discharge section is on or off, the coolant that has always passed through the filter 40 flows through the tank piping 42 and is returned to the coolant tank 20. Thereby, the coolant stored in the coolant tank 20 can be kept in a clean state. Note that the coolant pump 43 for sending coolant to the fourth coolant discharge section 24 is installed downstream of the measuring instrument 70. Therefore, switching the on / off of the coolant pump 43 for the discharge section does not affect the measured value of the measuring instrument 70. As shown in FIG. 6, the output of the coolant pump 30 is controlled to 40% of the output for discharging the flow rate F const (40).

[0037] Next, the case (CASE3) of using the first coolant discharge section 21 and the fourth coolant discharge section 24 will be described. When the coolant valve 27 shown in FIG. 3 opens in response to an instruction from the control unit 100, among the coolant sucked up by the coolant pump 30, the coolant with a flow rate F1 (25) passes through the branched discharge-section piping 31 and is discharged from the first coolant discharge section 21. Since the discharge-section piping 31 branches upstream of the measuring instrument 70, the flow rate measured by the measuring instrument 70 decreases as coolant flows through the discharge-section piping 31. The control unit 100 increases the output of the coolant pump 30 by an amount corresponding to the decrease in the flow rate measured by the measuring instrument 70. That is, as shown in FIG. 6, the output of the coolant pump 30 is increased by 25% corresponding to the flow rate F1 (25) discharged from the first coolant discharge section 21. Thereby, the output of the coolant pump 30 is controlled to 65%.

[0038] Next, the case (CASE4) where all the coolant discharge parts 21, 22, 23, 24 are used will be described. Compared with CASE3, among the coolant sucked up by the coolant pump 30, a further coolant with a flow rate F2 (20) is discharged from the second coolant discharge part 22 through the branched discharge part pipe 32, and a coolant with a flow rate F3 (15) is discharged from the third coolant discharge part 23 through the branched discharge part pipe 33. Thereby, the control unit 100 increases the output of the coolant pump 30 by 35% corresponding to the sum of the flow rate F2 (20) and the flow rate F3 (15). Thereby, the output of the coolant pump 30 is controlled to 100%.

[0039] Next, the case (CASE5) where only the fourth coolant discharge part 24 is not used will be described. According to an instruction from the control unit 100, the coolant discharge part coolant pump 43 shown in FIG. 3 is turned off, and all of the coolant with a flow rate F const (40) is discharged into the coolant tank 20 through the tank pipe 42. As described above, since the on / off switching of the coolant discharge part coolant pump 43 does not affect the measured value of the measuring instrument 70, as shown in FIG. 6, the output of the coolant pump 30 is controlled to 100% as in CASE4.

[0040] In addition, as another example of the above embodiment, a so-called smart pump having a control function of its own output may be adopted for the coolant pump that sucks up the coolant in the coolant tank 20. That is, as shown in FIG. 7, the measured value of the measuring instrument 70 is input to the coolant pump 130, and the output of the coolant pump 130 is controlled with only the measuring instrument 70 and the coolant pump 130. Thereby, it is not necessary to feedback the measured value to the control unit 100, and simpler control can be realized.

[0041] (Effect) According to the embodiment described above, the following effects can be obtained. (1) In the above-described embodiment, the coolant device 10 includes a coolant tank 20 in which coolant used when processing a material is stored, a coolant pump 30 that sucks up the coolant stored in the coolant tank 20, a coolant circulation path that is a flow path through which the coolant sucked up by the coolant pump 30 returns to the coolant tank 20, coolant valves 27, 28, 29 that are provided in the discharge portion flow paths (discharge portion pipes 31, 32, 33) branched at a branch point from the coolant circulation path and that open and close the discharge portion flow paths to which coolant discharge portions 21, 22, 23 are connected, and a measuring instrument 70 that is provided downstream of the branch point of the discharge portion flow paths in the coolant circulation path and that measures the state of the coolant. The output of the coolant pump 30 is controlled so that the measurement value by the measuring instrument 70 becomes constant. Accordingly, the output of the coolant pump 30 only needs to be automatically changed by the control unit 100 in accordance with fluctuations in the measurement value by the measuring instrument 70. The output of the coolant pump can be controlled to an appropriate state, and the power consumption of the coolant pump is reduced. Further, even when changing the number of coolant discharge portions due to a specification change of the machine body 2 or the like, it is only necessary to add or delete pipes and coolant valves upstream of the measuring instrument 70, and it is not necessary to create an output matrix for each combination of coolant discharge portions or to perform an operation check on the actual machine.

[0042] (2) In the above-described embodiment, the coolant device 10 includes a coolant tank 20 in which coolant used when processing materials is stored, a coolant pump 130 that sucks up the coolant stored in the coolant tank 20, a coolant circulation path that is a flow path through which the coolant sucked up by the coolant pump 130 returns to the coolant tank 20, coolant valves 27, 28, 29 provided in a discharge portion flow path (discharge portion pipes 31, 32, 33) branched at a branch point from the coolant circulation path and for opening and closing the discharge portion flow path to which coolant discharge portions 21, 22, 23 are connected, and a measuring instrument 70 provided downstream of the branch point of the discharge portion flow path in the coolant circulation path for measuring the state of the coolant. The coolant pump 130 controls its output so that the measured value by the measuring instrument 70 becomes constant. As a result, the output of the coolant pump 130 is automatically adjusted by the coolant pump 130 based on the measured value of the measuring instrument 70, and the commands from the control unit 100 are only for starting and stopping the coolant pump 30 and the discharge portion coolant pump 43 and for opening and closing the coolant valves 27, 28, 29, enabling a simpler control design.

[0043] (3) In the coolant device 10 according to the above-described embodiment, the coolant pumps 30, 130 are inverter-controlled and can change the output of the pumps. As a result, the output of the pump can be changed as the measured value by the measuring instrument 70 fluctuates.

[0044] (4) In the coolant device 10 according to the above-described embodiment, the measuring instrument is a flow meter. As a result, the amount of coolant flowing through the coolant circulation path can be measured, and the measured value can be fed back to the control unit 100 to control the output of the pump.

[0045] (5) In the coolant device 10 according to the above-described embodiment, a filter 40 for filtering the coolant sucked up by the coolant pumps 30, 130 is provided in the coolant circulation path. A coolant circulation path is provided to constantly flow the coolant to measure the state of the coolant and discharge it to the coolant tank 20. Since a filter 40 is provided in this coolant circulation path, sludge in the coolant can always be removed while the coolant pumps 30 and 130 are operating. Therefore, the state of the coolant stored in the coolant tank 20 can be kept clean.

[0046] (6) In the above embodiment, the machine tool 1 includes a machine body 2 having a machining chamber 3 for machining a material, and the coolant valves 27, 28, and 29 are opened to supply the coolant stored in the coolant tank 20 to the coolant discharge portions 21, 22, and 23 provided in the machining chamber 3, and the coolant device 10 according to any one of (1) to (5) above. Thereby, the machine tool 1 having the effects of (1) to (5) above can be provided.

[0047] Also, in the coolant circulation path, a coolant discharge portion for the discharge portion branched downstream from the attachment location of the measuring instrument 70 is provided with another coolant discharge portion 24. Since the presence or absence of coolant discharge from the coolant discharge portion 24 does not affect the measurement result of the measuring instrument 70, a simple control design can be maintained even if the coolant discharge portion 24 is added.

[0048] The present invention is not limited to the above embodiment, and various modifications and applications are possible. In the above embodiment, as an example of the filter 40, a cyclone filter is shown, but other filters may be used, for example, a drum filter or a bag filter may be used.

[0049] Also, instead of installing a coolant pump 43 for the discharge portion that sends coolant to the fourth coolant discharge portion 24, a coolant valve that opens and closes the flow path may be installed.

[0050] Also, as an example of the measuring instrument 70, a flow meter was shown, but other measuring instruments may be used, for example, a pressure gauge may be used. In this case, the outputs of the coolant pumps 30 and 130 may be controlled so that the pressure in the flow path through which the coolant flows becomes constant.

[0051] Also, the number of installations and the installation locations of the coolant discharge parts are arbitrary, and they can be appropriately changed according to the workpiece processed in the processing chamber 3. For example, upstream of the measuring instrument 70, the number of branches from the coolant circulation path can be increased or decreased, and the number of installations of the coolant discharge parts can be increased or decreased compared to the above-described embodiment. Also, if the total flow rate of the piping 41 for the discharge parts does not exceed F const (40), the piping 41 for the discharge parts branched downstream of the measuring instrument 70 can be further branched, and a coolant valve and a coolant discharge part can be additionally installed. Specifically, the fifth coolant discharge part 25 and the sixth coolant discharge part 26 shown in FIG. 1 may be provided in the branched piping.

[0052] Here, the fifth coolant discharge part 25 is provided on the side of the rear tool rest 9 and discharges the coolant toward the tool 8 held by the rear tool rest 9. The fifth coolant discharge part 25 performs chip removal, cooling, and lubrication with the discharged coolant. Also, the sixth coolant discharge part 26 discharges the coolant that has passed through the inside of the rear tool rest 9 from the tip of the tool 8 to perform chip removal, cooling, and lubrication.

[0053] Also, the piping can be further branched downstream of the coolant valves 27, 28, and 29 to install an additional coolant discharge part, or an additional coolant valve and a coolant discharge part can be installed at the branch destination. Also, as a mode, the first to third coolant discharge parts 21, 22, and 23 connected to the piping branched upstream of the measuring instrument 70 may be connected to the piping branched downstream of the measuring instrument 70, or the fourth to sixth coolant discharge parts 24, 25, and 26 may be connected to the piping branched upstream of the measuring instrument 70.

[0054] In addition, the coolant discharge amount in each discharge section shown in FIG. 5 is an example, and the discharge amount can be appropriately set according to the location where the coolant is discharged. Further, the coolant pumps 30, 130 and the discharge-section coolant pump 43 can be arbitrarily selected from those for low pressure to those for high pressure.

[0055] Also, the filter 40 is installed downstream of the measuring instrument 70, but the installation position is arbitrary. The filter 40 may be arranged upstream of the measuring instrument 70, or may be arranged upstream of the branch points of the discharge-section pipes 31, 32, 33. Further, by storing clean coolant from which the coolant has been removed in advance in the clean tank, the filter 40 installed in the coolant circulation path may be omitted.

[0056] Moreover, other coolant valves may be used for the coolant valves 27, 28, 29. For example, a handle cock or the like may be attached to manually switch the opening and closing of the pipe. Even if the pipe is switched manually in this way, if the state of the coolant flowing through the coolant circulation path is measured by the measuring instrument 70, the output of the coolant pump 30 can be appropriately controlled based on the measurement result.

[0057] Also, it has been described that the coolant always flows through the tank pipe 42 regardless of whether the discharge-section coolant pump 43 is on or off. However, the discharge-section coolant pump 43 may be configured to output the coolant of flow rate F const (40) so that no coolant flows through the tank pipe 42 when the discharge-section coolant pump 43 is in use.

[0058] In addition, it has been described that the coolant pump 30 and the coolant amount have a linear relationship such that when the coolant pump 30 is used at an output of X%, the coolant pump 30 discharges an X% of the maximum discharge amount. However, the relationship is not limited to such a relationship. For example, they may have a non-linear relationship, or may have a linear relationship in some ranges and a non-linear relationship in other ranges.

Explanation of Reference Numerals

[0059] 1... Machine tool, 2... Machine body, 3... Machining chamber, 4... Spindle, 5... First spindle unit, 6... Tool, 7... Tool spindle unit, 8... Tool, 9... Rear tool rest, 10... Coolant device, 20... Coolant tank, 21... First coolant discharge part, 22... Second coolant discharge part, 23... Third coolant discharge part, 24... Fourth coolant discharge part, 25... Fifth coolant discharge part, 26... Sixth coolant discharge part, 27, 28, 29... Coolant valves, 30... Coolant pump, 31, 32, 33... Discharge part piping (flow path), 34... Filter piping, 40... Filter, 41... Discharge part piping, 42... Tank piping, 43... Discharge part coolant pump, 45... Sludge deposition part, 70... Measuring instrument, 100... Control unit, 130... Coolant pump, S... Bed, W... Workpiece

Claims

1. A coolant tank storing coolant used when processing a material, a coolant pump that sucks up the coolant stored in the coolant tank, a coolant circulation path that is a path through which the coolant sucked up by the coolant pump returns to the coolant tank, a coolant valve provided in a discharge section flow path branched at a branch point from the coolant circulation path, for opening and closing the discharge section flow path to which a coolant discharge section is connected, a measuring instrument provided downstream of the branch point of the discharge section flow path in the coolant circulation path, for measuring the state of the coolant, and the coolant pump is controlled such that the output becomes constant according to the measurement value by the measuring instrument, a coolant device.

2. A coolant tank storing coolant used when processing a material, a coolant pump that sucks up the coolant stored in the coolant tank, a coolant circulation path that is a path through which the coolant sucked up by the coolant pump returns to the coolant tank, a coolant valve provided in a discharge section flow path branched at a branch point from the coolant circulation path, for opening and closing the discharge section flow path to which a coolant discharge section is connected, a measuring instrument provided downstream of the branch point of the discharge section flow path in the coolant circulation path, for measuring the state of the coolant, and the coolant pump controls its own output such that the measurement value by the measuring instrument becomes constant, a coolant device.

3. The coolant pump is inverter-controlled and can change the output of the pump, The coolant device according to claim 1 or 2.

4. The measuring instrument is a flow meter, The coolant device according to claim 1 or 2.

5. A filter for filtering the coolant sucked up by the coolant pump is provided in the coolant circulation path, The coolant device according to claim 1 or 2.

6. A machine body having a processing chamber for processing a material, The coolant device according to claim 1 or 2, which opens the coolant valve and supplies the coolant stored in the coolant tank to the coolant discharge section provided in the processing chamber, A machine tool.

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