Control device, machine tool, and control method

Abstract

A control device (14) for a machine tool (10) having a table (26) for supporting an object to be processed, a spindle (18) to which a tool is attached, and a mist collector (34) for collecting mist, the control device (14) being provided with: an acquisition unit (73) for acquiring at least one piece of information among a processing load (LO), a relative movement speed (VR) of the spindle with respect to the table (26), and a rotation speed (VS) of the spindle; an activation determination unit (75) that determines whether or not to activate the mist collector on the basis of the acquired at least one piece of information; and a collector control unit (76) that automatically controls the mist collector on the basis of the determination.

Description

Technical Field

[0001] The invention relates to a control device, a machine tool and a control method. Background Art

[0002] The mist collector collects the mist generated in the processing area of ​​the machine tool (refer to Japanese Patent Publication No. 2012-76006). The mist collector collects the mist in the processing area to prevent the mist from leaking out of the processing area. The mist is a particulate coolant suspended in the air. Summary of the invention

[0003] The mist collector vibrates during operation, and depending on the content of the processing performed by the machine tool, the vibration of the mist collector has a significant adverse effect on the processing accuracy of the machine tool.

[0004] The object of the present invention is to solve the above-mentioned problems.

[0005] The first embodiment of the present invention is a control device for a machine tool, wherein the machine tool comprises: a worktable that supports an object to be processed by a tool in a processing area; a spindle that is equipped with the tool and moves relative to the worktable while rotating; and a mist collector that recovers the mist in the processing area, wherein the control device comprises: an acquisition unit that acquires at least one of a processing load applied to the tool by processing the object to be processed, a relative moving speed of the spindle relative to the worktable, and a rotation speed of the spindle; a start determination unit that determines whether to start the mist collector based on at least one of the information acquired by the acquisition unit; and a collector control unit that automatically controls the mist collector based on the decision content of the start determination unit.

[0006] A second aspect of the present invention is a machine tool including the control device of the first aspect.

[0007] The third embodiment of the present invention is a control method for a machine tool, wherein the machine tool comprises: a worktable, which supports a processing object processed by a tool in a processing area; a spindle, which is equipped with the tool and moves relative to the worktable while rotating; and a mist collector, which recovers the mist in the processing area, and the control method includes: an acquisition step, in which a computer acquires at least one of the processing load applied to the tool by processing the processing object, the relative movement speed of the spindle relative to the worktable, and the rotation speed of the spindle; a start judgment step, in which the computer determines whether to start the mist collector based on at least one of the information acquired in the acquisition step; and a collector control step, in which the computer controls the mist collector based on the decision content in the start judgment step.

[0008] According to the present invention, since the mist collector is automatically controlled according to the content of processing, it is possible to prevent the vibration of the mist collector from having a significant adverse effect on the processing accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic diagram of a machine tool according to an embodiment. Figure 2 is a block diagram of the control device. Figure 3 is a flowchart illustrating a control method according to an embodiment. Figure 4 It is a schematic diagram of a machine tool according to Modification 1. Figure 5 This is a block diagram of a control device according to Modification 2. Figure 6 This is a block diagram of a control device according to Modification 3. DETAILED DESCRIPTION

[0010] [Implementation Method] Figure 1 It is a schematic diagram of the machine tool 10 according to the embodiment.

[0011] in addition, Figure 1 The X direction and the Y direction shown are directions parallel to the horizontal plane. The X direction and the Y direction are orthogonal to each other. Figure 1 The Z direction shown is a direction parallel to the gravity direction. Therefore, the Z direction is orthogonal to the X direction and the Y direction. However, Figure 1 The Z direction shown indicates the direction opposite to the direction of gravity.

[0012] The machine tool 10 includes a processing machine 12 and a control device 14 .

[0013] The processing machine 12 is a machine for processing an object using a tool 16. The processing machine 12 includes a spindle 18, a spindle head 20, a column 22, a base 24, a table 26, a table drive unit 28, a cover 30, a coolant supply device 32, and a mist collector 34.

[0014] A tool holder 36 (see Figure 1 ). The tool holder 36 can be attached and detached relative to the spindle 18. The tool holder 36 holds the tool 16. The tool 16 is, for example, a spring turning tool, a drill, an end mill, a milling cutter, etc.

[0015] The processing machine 12 further includes a tool magazine 38. The tool magazine 38 detachably holds a plurality of tools 16. One tool 16 of the plurality of tools 16 held in the tool magazine 38 is replaceably mounted on the tool holder 36.

[0016] The spindle head 20 supports the spindle 18. The spindle head 20 has a spindle motor 21 for rotating the spindle 18. The spindle motor 21 is, for example, a spindle motor. The spindle motor 21 has a shaft (not shown). The tool 16 mounted on the spindle 18 via the tool holder 36 rotates as the shaft of the spindle motor 21 rotates.

[0017] In addition, the spindle motor 21 has a torque sensor 23 and an encoder 25. The torque sensor 23 outputs a detection signal corresponding to the output torque of the spindle motor 21. The encoder 25 is a rotary encoder. The encoder 25 outputs a detection signal corresponding to the rotational position of the shaft of the spindle motor 21. The detection signal of the torque sensor 23 and the detection signal of the encoder 25 are input to the control device 14. In addition, a more detailed description of the control device 14 will be described later.

[0018] The column 22 supports the spindle head 20 . The column 22 includes a motor for moving the spindle head 20 in the Z direction. The column 22 is supported by a base 24 .

[0019] The pedestal 24 is installed on a setting surface. The setting surface is, for example, a floor of a factory. The setting surface may also be a supporting surface of a table installed on the floor. The setting surface extends, for example, parallel to a horizontal plane. The pedestal 24 may also have a plurality of legs 24a. Each leg 24a is, for example, a caster, a jack, or the like.

[0020] The table driving unit 28 is supported by the base 24. The table driving unit 28 includes a first slide 42, a saddle 44, a second slide 46, and a plurality of feed axis motors 47 (47X, 47Y). The plurality of feed axis motors 47 are composed of a Y-axis motor 47Y and an X-axis motor 47X.

[0021] The first slide portion 42 is provided on the pedestal 24 . The first slide portion 42 includes, for example, a guide rail extending in the Y direction. The first slide portion 42 supports the saddle 44 .

[0022] The saddle 44 moves in the Y direction by driving the Y-axis motor 47Y. The Y-axis motor 47Y is controlled by the control device 14. The saddle 44 moves while being guided by the first slide portion 42.

[0023] The Y-axis motor 47Y is, for example, a servo motor. The Y-axis motor 47Y includes a shaft 49Y and an encoder 29 (29Y). The shaft 49Y rotates according to the driving current supplied to the Y-axis motor 47Y. The encoder 29Y is a rotary encoder. The encoder 29Y outputs a detection signal corresponding to the rotation position of the shaft 49Y. The detection signal of the encoder 29Y is input to the control device 14.

[0024] The second slide portion 46 is provided on the saddle 44. The second slide portion 46 includes, for example, a guide rail extending in the X direction.

[0025] The table 26 supports a processing object (not shown) below the spindle 18. The table 26 is supported by the second slide portion 46. The table 26 moves in the X direction by driving the X-axis motor 47X. The X-axis motor 47X is controlled by the control device 14. The table 26 moves while being guided by the second slide portion 46.

[0026] The X-axis motor 47X is, for example, a servo motor. The X-axis motor 47X has a shaft 49X and an encoder 29 (29X). The shaft 49X rotates according to the drive current supplied to the X-axis motor 47X. The encoder 29X is a rotary encoder. The encoder 29X outputs a detection signal corresponding to the rotation position of the shaft 49X. The detection signal of the encoder 29X is input to the control device 14.

[0027] The cover 30 covers the spindle 18, the spindle head 20, the column 22, the pedestal 24, the table 26, and the table driving unit 28. Thus, the cover 30 forms a processing area 48. The processing object is processed in the processing area 48.

[0028] The cover 30 further includes a door and a window, which are not shown. The operator can carry out operations such as carrying the processing object into the processing area 48 through the door in an open state. In addition, the operator can easily check the state in the processing area 48 through the window.

[0029] The coolant supplier 32 is a device that supplies coolant to the processing area 48. The coolant supplier 32 includes a coolant tank 50, a nozzle 52, a supply pipe 54, and a pump 56.

[0030] The coolant tank 50 stores coolant and is disposed outside the processing area 48 .

[0031] The nozzle 52 is a spraying portion that sprays the coolant. The nozzle 52 is disposed in the processing area 48. In addition, the coolant supplier 32 may include a plurality of nozzles 52.

[0032] The supply pipe 54 is a pipe connecting the coolant tank 50 and the nozzle 52. The coolant supplier 32 may include a plurality of supply pipes 54. The number of supply pipes 54 is determined, for example, by the number of nozzles 52. The supply pipe 54 penetrates the cover 30 and connects the coolant tank 50 and the nozzle 52.

[0033] The pump 56 is connected to the supply pipe 54. The pump 56 draws the coolant in the coolant tank 50 and delivers it to the nozzle 52. Thus, the coolant is sprayed from the nozzle 52 into the processing area 48. In addition, the pump 56 is controlled by the control device 14.

[0034] The coolant sprayed into the processing area 48 cools the tool 16 and the object to be processed. When processing is performed in the processing area 48, mist of the coolant is generated. The mist may leak out of the processing area 48 through a small gap generated in the processing machine 12.

[0035] The mist collector 34 is a device for collecting mist in the processing area 48. The mist collector 34 is provided outside the processing area 48. In addition, the mist collector 34 is connected to the cover 30 via a duct 58. The mist collector 34 collects the mist by sucking the air in the processing area 48. Thus, the mist can be prevented from leaking out of the processing area 48.

[0036] When the tool 16 cuts the object to be processed, fine chips are generated as dust in the processing area 48. Like mist, this dust may leak out of the processing area 48 through a small gap generated in the processing machine 12. The mist collector 34 can collect not only the mist but also the dust by sucking the air in the processing area 48. This can also prevent the dust from leaking out of the processing area 48.

[0037] The mist collector 34 may be connected to the coolant tank 50. Thus, the mist collected by the mist collector 34 can be returned to the coolant tank 50 as a cooling medium.

[0038] When the mist collector 34 and the coolant tank 50 are connected, the mist collector 34 and the coolant tank 50 are preferably connected via a filter device (filter) not shown. The filter device removes impurities in the coolant sent from the mist collector 34 to the coolant tank 50. If the mist collector 34 and the coolant tank 50 are connected via the filter device, clean coolant can be returned from the mist collector 34 to the coolant tank 50. Impurities in the coolant are, for example, chips recovered together with the mist.

[0039] Figure 2 is a block diagram of the control device 14 .

[0040] The control device 14 is a computer that controls the processing machine 12. The control device 14 is, for example, a numerical control device. The control device 14 includes a display unit 60, an operation unit 62, a storage unit 64, a calculation unit 66, and a backup power supply unit 68.

[0041] The display unit 60 is a display device including a display screen 60d. The display unit 60 is, for example, a liquid crystal display device or an OEL (Organic Electro-Luminescence) display device.

[0042] The operation unit 62 is an input device for receiving instructions from the operator to the control device 14. The operation unit 62 includes, for example, an operation panel 62a, a touch panel 62b, etc. The touch panel 62b is provided on the display screen 60d. The operation unit 62 (operation panel 62a) may also include a keyboard, a mouse, etc.

[0043] The storage unit 64 may be composed of a volatile memory (not shown) and a non-volatile memory (not shown). Examples of volatile memory include RAM (Random Access Memory). Examples of non-volatile memory include ROM (Read Only Memory), flash memory, etc. Data, etc. may be stored in a volatile memory, for example. Programs, data tables, mappings, etc. may be stored in a non-volatile memory, for example. At least a portion of the storage unit 64 may also be provided in a processor, an integrated circuit, etc. as described above. The storage unit 64 stores a control program 70, a processing program 72, and a plurality of threshold values ​​TH (TH1, TH2, TH3).

[0044] The control program 70 is a program for causing the control device 14 to execute the control method of the present embodiment. A more detailed description of the control method will be given later.

[0045] The processing program 72 is a program including control commands for the processing machine 12. The processing program 72 includes, for example, a plurality of control commands for controlling the plurality of motors (21, 47) described above. In addition, the processing program 72 includes, for example, a plurality of control commands for controlling the coolant supply device 32. The processing program 72 is created or edited in advance by the operator.

[0046] The plurality of threshold values ​​TH are composed of a threshold value TH1 for a machining load LO, a threshold value TH2 for a relative moving speed VR, and a threshold value TH3 for a rotation speed VS of the spindle 18. The machining load LO is a load applied to the tool 16 that processes the machining object. The relative moving speed VR is a relative moving speed of the spindle 18 relative to the table 26. The relative moving speed VR includes a relative moving speed VRX and a relative moving speed VRY. The relative moving speed VRX is a relative moving speed of the spindle 18 relative to the table 26 in the X direction. The relative moving speed VRY is a relative moving speed of the spindle 18 relative to the table 26 in the Y direction.

[0047] The threshold TH1 is, for example, the maximum allowable value of the machining load LO in the prescribed machining. The prescribed machining is a machining in which the vibration of the mist collector 34 has a great influence on the machining accuracy. The prescribed machining is, for example, finishing machining, precision machining, etc. The threshold TH2 is, for example, the maximum allowable value of the relative moving speed VR in the prescribed machining. The storage unit 64 may also store the threshold TH2 for the relative moving speed VRX and the threshold TH2 for the relative moving speed VRY. In this case, the threshold TH2 for the relative moving speed VRX may be equal to or different from the threshold TH2 for the relative moving speed VRY. The threshold TH3 is, for example, the maximum allowable value of the rotation speed VS of the spindle 18 in the prescribed machining. The specific value of each threshold TH (TH1 to TH3) is determined based on experiments. In addition, the specific value of each threshold TH (TH1 to TH3) may also be provided to the operator by the manufacturer of the machine tool 10.

[0048] The calculation unit 66 may be composed of a processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit). In other words, the calculation unit 66 may be composed of a processing circuit.

[0049] The operation unit 66 includes an acquisition unit 73, a processing control unit 74, a start determination unit 75, and a collector control unit 76. The acquisition unit 73, the processing control unit 74, the start determination unit 75, and the collector control unit 76 are implemented by the operation unit 66 executing the control program 70. In addition, at least a part of the acquisition unit 73, the processing control unit 74, the start determination unit 75, and the collector control unit 76 can also be implemented by an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array). In addition, at least a part of the acquisition unit 73, the processing control unit 74, the start determination unit 75, and the collector control unit 76 can also be constituted by an electronic circuit including discrete devices.

[0050] The acquisition unit 73 acquires at least one of the machining load LO, the relative moving speed VR, and the rotation speed VS. When acquiring the relative moving speed VR, the acquisition unit 73 may acquire both the relative moving speed VRX and the relative moving speed VRY, or may acquire only one of them. When acquiring only one of the relative moving speed VRX and the relative moving speed VRY, the acquisition unit 73 may acquire the one with the larger absolute value.

[0051] The machining load LO is calculated based on the torque of the spindle motor 21. The torque of the spindle motor 21 is calculated based on the detection signal output from the torque sensor 23. Therefore, the acquisition unit 73 can acquire information on the machining load LO based on the detection signal output from the torque sensor 23.

[0052] The relative movement speed VRX is calculated based on the rotation speed of the shaft 49X. The rotation speed of the shaft 49X is calculated based on the detection signal output from the encoder 29X. Therefore, the acquisition unit 73 can acquire information on the relative movement speed VRX based on the detection signal output from the encoder 29X.

[0053] The relative movement speed VRY is calculated based on the rotation speed of the shaft 49Y. The rotation speed of the shaft 49Y is calculated based on the detection signal output from the encoder 29Y. Therefore, the acquisition unit 73 can acquire information on the relative movement speed VRY based on the detection signal output from the encoder 29Y to the control device 14.

[0054] The rotation speed VS is calculated based on the rotation speed of the shaft of the spindle motor 21. The rotation speed of the shaft of the spindle motor 21 is calculated based on the detection signal output from the encoder 25. Therefore, the acquisition unit 73 can acquire information on the rotation speed VS based on the detection signal output from the encoder 25.

[0055] The processing control unit 74 controls the processing machine 12 according to the processing program 72, thereby processing the processing object. For example, the processing control unit 74 controls the spindle motor 21, the plurality of feed axis motors 47, etc. according to the processing program 72. However, the control of the mist collector 34 in the processing machine 12 is performed by the collector control unit 76.

[0056] The start determination unit 75 determines whether a predetermined start condition is satisfied based on the information (machining load LO, relative moving speed VR, rotation speed VS) acquired by the acquisition unit 73. When at least one of the machining load LO, relative moving speed VR, and rotation speed VS acquired by the acquisition unit 73 is greater than the threshold value TH, the predetermined start condition is satisfied.

[0057] In order to determine whether the predetermined start condition is satisfied, the start determination unit 75 determines whether at least one of the following (1) to (3) is satisfied. (1) Whether the machining load LO is greater than or equal to a threshold value TH1. (2) Whether the relative moving speed VR is greater than or equal to a threshold value TH2. (3) Whether the rotation speed VS is greater than or equal to a threshold value TH3.

[0058] When at least one of the above (1) to (3) is satisfied, the start determination unit 75 determines that the predetermined start condition is satisfied. When it cannot be determined that the predetermined start condition is satisfied, the start determination unit 75 determines that the predetermined start condition is not satisfied.

[0059] When the predetermined activation condition is satisfied, the activation determination unit 75 determines to activate the mist collector 34. When the predetermined activation condition is not satisfied, the activation determination unit 75 determines not to activate the mist collector 34.

[0060] The collector control unit 76 controls the mist collector 34 according to the decision content of the activation determination unit 75 .

[0061] For example, when the activation determination unit 75 determines to activate the mist collector 34 , the collector control unit 76 automatically activates the mist collector 34 to collect the mist in the processing area 48 into the mist collector 34 .

[0062] On the other hand, when the start determination unit 75 determines not to start the mist collector 34, the collector control unit 76 does not automatically start the mist collector 34. Assuming that the start determination unit 75 determines not to start the mist collector 34, the collector control unit 76 stops the operation of the mist collector 34 when the mist collector 34 is in operation.

[0063] The mist collector 34 is automatically activated when a predetermined activation condition is satisfied by the collector control unit 76 . Thus, mist, dust, and the like in the processing area 48 are collected in the mist collector 34 .

[0064] The mist collector 34 vibrates by the action. Due to the vibration of the mist collector 34, there is a possibility that the object to be processed will vibrate. However, when the predetermined start-up conditions are met, it is highly likely that the vibration of the mist collector 34 will not have a significant effect on the processing accuracy. Therefore, when the predetermined start-up conditions are met, it is low that the vibration of the mist collector 34 will have an adverse effect on the processing accuracy.

[0065] Processing in which the vibration of the mist collector 34 has no great influence on the processing accuracy is, for example, processing in which a stronger vibration than the vibration generated by the mist collector 34 is generated from a part other than the mist collector 34 in the processing machine 12. As such processing, for example, rough processing can be cited. In addition, rough processing has a tendency to produce more cutting than fine processing. Therefore, rough processing has a tendency to produce more mist, dust, etc. in the processing area 48. That is, when a lot of mist, dust, etc. are generated in the processing area 48, the control device 14 can automatically start the mist collector 34.

[0066] When the prescribed start-up conditions are not met, there is a high possibility that the vibration of the mist collector 34 will have a great influence on the processing accuracy. In this regard, according to the collector control unit 76, when the prescribed start-up conditions are not met, the mist collector 34 does not operate. Thus, when the prescribed start-up conditions are not met, the mist collector 34 is prevented from vibrating the processing object. Therefore, the possibility of a significant deterioration in processing accuracy can be reduced. In addition, the processing in which the vibration of the mist collector 34 has a great influence on the processing accuracy is, as mentioned above, for example, finishing, precision processing, etc. Finishing, precision processing, etc. tend to generate less fog, dust, etc. in the processing area 48. That is, when the fog, dust, etc. generated in the processing area 48 is less, the control device 14 can automatically stop the mist collector 34. Thus, the power consumption of the mist collector 34 is suppressed.

[0067] In addition, it is preferred that the acquisition unit 73 sequentially acquires at least one of the processing load LO, the relative moving speed VR, and the rotation speed VS during the processing by the processing control unit 74. In addition, it is preferred that the start determination unit 75 sequentially determines whether to start the mist collector 34 using the latest information acquired by the acquisition unit 73 during the processing by the processing control unit 74. Thus, according to the change of at least one of the processing load LO, the relative moving speed VR, and the rotation speed VS during the processing, the collector control unit 76 can appropriately turn on and off the mist collector 34.

[0068] In addition, it is preferred that the acquisition unit 73 acquires all information of the machining load LO, the relative moving speed VR, and the rotation speed VS during machining by the machining control unit 74. By using all information of the machining load LO, the relative moving speed VR, and the rotation speed VS, the start determination unit 75 can correctly determine whether a predetermined start condition is satisfied.

[0069] The backup power supply unit 68 is a power supply different from the main power supply of the control device 14. The backup power supply unit 68 includes, for example, a battery. The backup power supply unit 68 is built into the control device 14. However, the backup power supply unit 68 may be provided on the machine tool 10 as an external power supply of the control device 14. In addition, the main power supply of the control device 14 is omitted from the illustration.

[0070] When the main power supply of the control device 14 is turned off during the operation of the mist collector 34, the backup power supply unit 68 supplies power to each unit of the control device 14. Thus, the collector control unit 76 can continue to control the mist collector 34 even after the main power supply is turned off.

[0071] For example, the main power supply of the control device 14 may be turned off before the collector control unit 76 stops the mist collector 34. In this case, the collector control unit 76 can automatically stop the mist collector 34 even after the main power supply of the control device 14 is turned off by supplying power from the backup power supply unit 68. Thus, it is possible to suppress the mist collector 34 from wasting power.

[0072] Figure 3 is a flowchart illustrating a control method according to an embodiment.

[0073] The control device 14 may, for example, execute Figure 3 During the machining process performed by the machining control unit 74 based on the machining program 72, the control device 14 executes Figure 3 In addition, at the start time of the control method, the mist collector 34 is stopped. Figure 3 The control method comprises an acquisition step S1, a start determination step S2, a collector control step S3 and an end determination step S4. The collector control step S3 comprises a collector start step S31 and a collector stop step S32.

[0074] In the acquisition step S1, the acquisition unit 73 acquires at least one of the machining load LO, the relative movement speed VR, and the rotation speed VS. The acquisition unit 73 preferably acquires all of the machining load LO, the relative movement speed VR, and the rotation speed VS.

[0075] In the start determination step S2, the start determination unit 75 determines whether to start the mist collector 34. To determine whether to start the mist collector 34, the start determination unit 75 determines whether a predetermined start condition is satisfied based on the information (LO, VR, VS) acquired by the acquisition unit 73 in the acquisition step S1.

[0076] When the predetermined start-up condition is satisfied (S2: Yes), the start-up determination unit 75 determines to start the mist collector 34. When the predetermined start-up condition is not satisfied (S2: No), the start-up determination unit 75 determines not to start the mist collector 34. According to the decision content in the start-up determination step S2, the collector start-up step S31 or the collector stop step S32 is started.

[0077] If it is determined in the start determination step S2 to start the mist collector 34, the collector start step S31 is started. In the collector start step S31, the collector control unit 76 controls the mist collector 34 to automatically start the mist collector 34. If the mist collector 34 has already been operated, the collector control unit 76 maintains the operation state of the mist collector 34.

[0078] If it is determined in the start determination step S2 that the mist collector 34 is not started, the collector stop step S32 is started. In the collector stop step S32, the collector control unit 76 controls the mist collector 34 to automatically stop the mist collector 34. If the mist collector 34 has already stopped, the collector control unit 76 maintains the stopped state of the mist collector 34.

[0079] In the end determination step S4, the processing control unit 74 determines whether the processing based on the processing program 72 is completed. If the processing is not completed (S4: "No"), the process from the acquisition step S1 to the end determination step S4 is repeated. If the processing is completed (S4: "Yes"), Figure 3 The control method ends. In addition, when the mist collector 34 is still in operation at the end of the processing, the collector control unit 76 automatically stops the mist collector 34.

[0080] [Modifications] The following describes a modified example of the above embodiment. However, in the following description, the description that overlaps with the above embodiment is appropriately omitted. Unless otherwise specified, the elements described in the above embodiment are given the same reference numerals as in the above embodiment.

[0081] (Variant 1) Figure 4 This is a schematic diagram of a machine tool 101 ( 10 ) according to Modification 1.

[0082] The machine tool 101 further includes a sub-controller 78. In the machine tool 101, the backup power supply unit 68 of the control device 14 may be omitted.

[0083] The sub-controller 78 is a computer different from the control device 14. The sub-controller 78 includes, for example, a processor and a memory. The sub-controller 78 may include an integrated circuit, a discrete device, or the like.

[0084] When the control device 14 stops, the sub-control device 78 controls the mist collector 34 instead of the collector control unit 76. Therefore, even when the control device 14 stops, the mist collector 34 is controlled by the sub-control device 78 in the same manner as in the embodiment.

[0085] For example, when the main power supply of the control device 14 is turned off before the collector control unit 76 stops the mist collector 34 , the sub-control device 78 may stop the mist collector 34 instead of the control device 14 .

[0086] In addition, it is preferred that the sub-control device 78 and the control device 14 communicate appropriately and share data required for controlling the mist collector 34. For example, the sub-control device 78 and the control device 14 share information acquired by the acquisition unit 73, the content of the decision of the start determination unit 75, or the progress of the processing. As a result, the sub-control device 78 can smoothly take over the control performed by the collector control unit 76. According to this modified example, even after the control device 14 stops, the control of the mist collector 34 can be continued by the sub-control device 78.

[0087] (Variant 2) Figure 5 This is a block diagram of the control device 142 (14) according to the second modification.

[0088] The control device 142 further includes an alarm output unit 80 .

[0089] The alarm output unit 80 outputs an alarm when an abnormality occurs in the machine tool 10. For example, the machine tool 10 is appropriately equipped with sensors (not shown) for detecting failures in various parts such as the spindle 18, the spindle head 20, and the table drive unit 28. The alarm output unit 80 determines whether a failure has occurred in the machine tool 10 based on the signals output by the sensors. When a failure in various parts of the machine tool 10 is detected, the alarm output unit 80 notifies the operator of the failure, for example, via the display unit 60.

[0090] When the alarm output unit 80 outputs an alarm before the start of processing, the processing control unit 74 does not start processing until the cause of the alarm is eliminated. In addition, when the alarm output unit 80 outputs an alarm after the start of processing, the processing control unit 74 interrupts the processing based on the processing program 72 until the cause of the alarm is eliminated.

[0091] When the alarm output unit 80 outputs an alarm, the collector control unit 76 prohibits the operation of the mist collector 34 regardless of the decision of the start determination unit 75 until the cause of the alarm is resolved. When the mist collector 34 is in operation at the time when the alarm is output, the collector control unit 76 stops the mist collector 34 regardless of the decision of the start determination unit 75.

[0092] According to this modification, it is possible to prevent mist collector 34 from operating when an abnormality occurs in machine tool 10 .

[0093] (Variant 3) Figure 6 This is a block diagram of the control device 143 (14) according to the third modification.

[0094] The control device 143 further includes an estimating unit 82 .

[0095] The estimating unit 82 estimates (calculates) at least one estimated value of the machining load LO, the relative movement speed VR, and the rotation speed VS based on the machining program 72 .

[0096] For example, the machining program 72 includes a control command for driving the spindle motor 21 at a predetermined torque. The estimation unit 82 estimates the machining load LO based on the control command. In addition, for example, the machining program 72 includes a control command for rotating the shaft 49X at a predetermined speed. The estimation unit 82 estimates the relative movement speed VRX based on the control command. In addition, for example, the machining program 72 includes a control command for rotating the shaft of the spindle motor 21 at a predetermined speed. The estimation unit 82 estimates the rotation speed VS based on the control command.

[0097] The estimating unit 82 estimates at least one of the machining load LO, the relative moving speed VR, and the rotation speed VS using a formula. The formula is predetermined based on an experiment. The estimating unit 82 may use different formulas when estimating the machining load LO, when estimating the relative moving speed VR, and when estimating the rotation speed VS.

[0098] In order to estimate at least one of the estimated value of the machining load LO, the relative moving speed VR, and the rotation speed VS, the estimating unit 82 may appropriately refer to information other than the machining program 72. For example, the machining load LO varies depending on the material of the machining object or the tool 16. Therefore, in order to calculate the estimated value of the machining load LO, the estimating unit 82 may also refer to the material of the machining object or the tool 16. In this case, the storage unit 64 may also store the material of the machining object or the tool 16.

[0099] The acquisition unit 73 may acquire the estimated value estimated by the estimation unit 82 as information.

[0100] According to this modification, before the start of processing, the start determination unit 75 can determine whether to start the mist collector 34. That is, before the start of processing, the estimation unit 82 can estimate (calculate) at least one estimated value of the processing load LO, the relative movement speed VR, and the rotation speed VS based on the processing program 72. In addition, before the start of processing, the acquisition unit 73 can acquire the estimated value. Thus, before the start of processing, the start determination unit 75 can determine whether to start the mist collector 34 based on the comparison between the estimated value and the threshold value TH.

[0101] (Combination of multiple variations) The above-mentioned multiple modified examples may be appropriately combined within a range not inconsistent with each other.

[0102] [Modified embodiment] The present invention is not limited to the above-described embodiment, and various configurations may be employed without departing from the gist of the present invention.

[0103] For example, according to the above-mentioned embodiment, the processing control unit 74 ends the processing and the mist collector 34 stops. However, during the period from the end of the processing to the elapse of the prescribed time, the collector control unit 76 may control the mist collector 34 to collect the mist in the processing area 48 into the mist collector 34. By operating the mist collector 34 after the processing is completed, it is possible to prevent leakage of the mist. The prescribed time is indicated in advance to the collector control unit 76 by the operator via the operating unit 62, for example. However, the prescribed time may also be specified by the manufacturer of the machine tool 10.

[0104] In addition, for example, according to the above-mentioned embodiment, the acquisition unit 73 acquires the machining load LO based on the torque of the spindle motor 21. However, the machining load LO may also be calculated based on the drive current of the spindle motor 21. Therefore, the machine tool 10 may further include, for example, a current sensor for detecting the drive current of the spindle motor 21. Thus, the acquisition unit 73 can acquire information on the machining load LO based on the detection signal output from the current sensor.

[0105] For example, according to the above embodiment, the relative movement speed VR is the relative movement speed VRX in the X direction or the relative movement speed VRY in the Y direction. However, the relative movement speed VR may be a composite speed of the relative movement speed VRX and the relative movement speed VRY.

[0106] In addition, for example, the spraying method of the coolant is not limited to the embodiment. The coolant may be sprayed using a center supply method, for example. In this case, the coolant supplier 32 supplies the coolant to the spindle 18. The coolant may also flow along the inner wall of the cover 30 (processing area 48).

[0107] In addition, for example, the processing machine 12 may also be provided with a recovery member (not shown) for recovering the coolant that falls under the workbench 26. The recovery member is, for example, an oil pan disposed on the base 24. A portion of the cooling medium supplied to the processing area 48 does not become mist, but falls under the workbench 26. According to this variation, the coolant that falls under the workbench 26 can be recovered. The recovered coolant can be returned to the coolant tank 50. Thus, the coolant supplier 32 can reuse the recovered coolant. Here, it is preferred to configure a filtering device (filter) between the recovery member and the coolant tank 50. Thus, clean coolant can be returned to the coolant tank 50.

[0108] In addition, at least one of the X-axis motor 47X and the Y-axis motor 47Y may be a linear motor. When the X-axis motor 47X is a linear motor, the encoder 29X is a linear encoder. When the Y-axis motor 47Y is a linear motor, the encoder 29Y is a linear encoder.

[0109] [Inventions that can be understood from the embodiments] The invention that can be grasped from the above-mentioned embodiment and modified examples is as follows.

[0110] <First Invention> The first invention is a control device (14) for a machine tool (10), the machine tool comprising: a worktable (26) which supports a processing object to be processed by a tool (16) in a processing area (48); a spindle (18) on which the tool is mounted and which moves relative to the worktable while rotating; and a mist collector (34) which recovers the mist in the processing area, the control device comprising: an acquisition unit (73) which acquires at least one of a processing load (LO) applied to the tool by processing the processing object, a relative movement speed (VR) of the spindle relative to the worktable, and a rotation speed (VS) of the spindle; a start determination unit (75) which determines whether to start the mist collector based on at least one of the information acquired by the acquisition unit; and a collector control unit (76) which automatically controls the mist collector based on the decision content of the start determination unit.

[0111] Thus, the mist collector is automatically controlled according to the content of the processing, so it is possible to prevent the vibration of the mist collector from having a significant adverse effect on the processing accuracy.

[0112] In the above control device, the acquisition unit may acquire the information of the machining load based on the driving current or torque of the spindle motor (21) of the spindle, thereby automatically turning the mist collector on and off based on the machining load acquired during machining.

[0113] In the control device, the acquisition unit may acquire the information of the rotation speed based on a detection signal of an encoder (25) provided in a spindle motor (21) of the spindle, thereby automatically turning the mist collector on and off based on the rotation speed acquired during machining.

[0114] In the control device, the acquisition unit may acquire the information of the relative moving speed based on a detection signal of an encoder (29) provided in a feed shaft motor (47) for relative movement of the spindle and the worktable, thereby automatically turning the mist collector on and off based on the relative moving speed acquired during processing.

[0115] The control device may further include an estimating unit (82) for estimating at least one of the machining load, the relative moving speed, and the rotational speed based on a machining program (72) for performing the machining, and the acquiring unit acquires the estimated value as the information. Thus, it is possible to determine whether to automatically start the mist collector before starting the machining.

[0116] In the above control device, the start determination unit may determine whether a specified start condition is met, and decide not to start the mist collector when the specified start condition is not met, and the specified start condition is met when at least one of the machining load, the relative moving speed, and the rotation speed obtained by the acquisition unit is above a threshold value (TH). Thus, it is possible to prevent the machining accuracy from being deteriorated due to the vibration of the mist collector.

[0117] In the above control device, the activation determination unit may use different threshold values ​​according to the machining load, the relative moving speed, and the rotation speed. This can prevent the machining accuracy from being deteriorated due to the vibration of the mist collector.

[0118] In the above control device, the start-up determination unit may decide to start the mist collector when the specified start-up condition is met. Thus, the mist collector is automatically started, thereby preventing the mist from leaking out of the processing area. Thus, in the case where the possibility of deterioration of the processing accuracy due to the vibration of the mist collector is small, the mist collector can be made to collect the mist.

[0119] The control device further comprises an alarm output unit (80) for outputting an alarm when an abnormality occurs in the machine tool, and when the alarm output unit outputs the alarm, the collector control unit prohibits the operation of the mist collector regardless of the content of the decision of the start determination unit. Thus, the mist collector can be prevented from operating when an abnormality occurs in the machine tool.

[0120] <Second Invention> A second invention is a machine tool including the control device of the first invention.

[0121] Thus, the mist collector is automatically controlled according to the content of the processing, so it is possible to prevent the vibration of the mist collector from having a significant adverse effect on the processing accuracy.

[0122] The machine tool may further include a sub-control device (78), and when the control device stops, the sub-control device (78) controls the mist collector instead of the collector control unit. Thus, even when the control device stops, the mist collector is automatically controlled.

[0123] <Third Invention> The third invention is a control method for a machine tool (10), wherein the machine tool comprises a worktable (26) supporting an object to be processed by a tool (16) in a processing area (48); a spindle (18) on which the tool is mounted and which moves relative to the worktable while rotating; and a mist collector (34) for recovering mist in the processing area, the control method comprising: an acquisition step (S1), in which a computer (14) acquires at least one of a processing load (LO) applied to the tool by processing the object to be processed, a relative movement speed (VR) of the spindle relative to the worktable, and a rotation speed (VS) of the spindle; a start determination step (S2), in which the computer determines whether to start the mist collector based on at least one of the information acquired in the acquisition step; and a collector control step (S3), in which the computer controls the mist collector based on the decision content in the start determination step.

[0124] Thus, the mist collector is automatically controlled according to the content of the processing, so it is possible to prevent the vibration of the mist collector from having a significant adverse effect on the processing accuracy. Explanation of symbols 10, 101... Machine tools 12... Processing machines 14, 142, 143...control device 16...tool 18…Spindle 21…Spindle motor 25, 29...Encoder 26...Workbench 34...Mist collector 47...Feed axis motor 48…Processing area 72…Processing program 73 ... Acquisition unit 75 ... Startup determination unit 76 ... Collector control unit 78 ... Sub-control device 80 ... Alarm output unit 82 ... Estimation unit LO…Processing load TH…Threshold value VR…Relative moving speed VS…Rotation speed.

Claims

1. A control device (14) for a machine tool (10), the machine tool comprising: a table (26) supporting an object to be processed by a tool (16) in a processing area (48); a spindle (18) on which the tool is mounted and which moves relative to the table while rotating; and a mist collector (34) for collecting mist in the processing area, the control device comprising: an acquisition unit (73) for acquiring at least one of a machining load (LO) applied to the tool by machining the object, a relative moving speed (VR) of the spindle relative to the table, and a rotation speed (VS) of the spindle; an activation determination unit (75) for determining whether to activate the mist collector based on at least one of the information acquired by the acquisition unit; and A collector control unit (76) automatically controls the mist collector according to the decision content of the start determination unit.

2. The control device according to claim 1, characterized in that: The acquisition unit acquires the information on the machining load based on a drive current or torque of a spindle motor (21) of the spindle.

3. The control device according to claim 1 or 2, characterized in that: The acquisition unit acquires the information on the rotation speed based on a detection signal of an encoder (25) provided in a spindle motor (21) of the spindle.

4. The control device according to any one of claims 1 to 3, characterized in that: The acquisition unit acquires the information on the relative movement speed based on a detection signal of an encoder (29) provided in a feed axis motor (47) for relatively moving the spindle and the worktable.

5. The control device according to claim 1, characterized in that: The invention further comprises an estimating unit (82) for estimating at least one estimated value of the machining load, the relative moving speed, and the rotation speed based on a machining program (72) for performing the machining. The acquisition unit acquires the estimated value as the information.

6. The control device according to any one of claims 1 to 5, characterized in that: The activation determination unit determines whether a predetermined activation condition is satisfied, and decides not to activate the mist collector if the predetermined activation condition is not satisfied. When at least one of the machining load, the relative movement speed, and the rotation speed acquired by the acquisition unit is equal to or greater than a threshold value (TH), the predetermined activation condition is satisfied.

7. The control device according to claim 6, characterized in that: The activation determination unit uses different threshold values ​​depending on the machining load, the relative movement speed, and the rotation speed.

8. The control device according to claim 6 or 7, characterized in that: The activation determination unit determines to activate the mist collector when the predetermined activation condition is satisfied.

9. The control device according to any one of claims 1 to 8, characterized in that: It also includes an alarm output unit (80) which outputs an alarm when an abnormality occurs in the machine tool. When the alarm output unit outputs the alarm, the collector control unit prohibits the operation of the mist collector regardless of the content of the determination of the activation determination unit.

10. A machine tool, characterized in that: A control device according to any one of claims 1 to 9.

11. The machine tool according to claim 10, characterized in that A sub-control device (78) is further provided, and when the control device is stopped, the sub-control device (78) controls the mist collector instead of the collector control unit.

12. A control method for a machine tool (10), the machine tool comprising: a table (26) supporting an object to be processed by a tool (16) in a processing area (48); a spindle (18) on which the tool is mounted and which moves relative to the table while rotating; and a mist collector (34) for collecting mist in the processing area, the control method comprising: an acquisition step (S1), wherein a computer (14) acquires at least one of a machining load (LO) applied to the tool by machining the object, a relative moving speed (VR) of the spindle relative to the table, and a rotation speed (VS) of the spindle; A start determination step (S2), wherein the computer determines whether to start the fog collector according to at least one of the information acquired in the acquisition step; as well as The collector control step (S3) controls the mist collector by the computer according to the decision content in the start determination step.

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