JP5321412B2 - Tool cleaning equipment for machine tools - Google Patents

Description

  The present invention relates to a tool cleaning device for a machine tool for cleaning chips and the like adhering to a tool surface mounted on a spindle.

  2. Description of the Related Art Conventionally, machine tools have been designed to improve machining accuracy and tool life by injecting a coolant liquid onto a cutting portion of an object to be cut by a tool.

  A machine tool such as a recent machining center has a tool changer, and automatically changes a tool composed of a cutting tool and a tool holder.

  When the tool is mounted on the main shaft with chips adhering to the main shaft mounting surface of the tool holder when the tool is changed, the tool is displaced relative to the main shaft, and the cutting accuracy decreases. In order to solve the above-described problems, the conventional machine tool cleans the spindle mounting surface of the tool holder with a coolant liquid or air blow as a cleaning liquid.

  In Patent Document 1, a cleaning nozzle capable of injecting a coolant liquid is provided at the tip of a spindle, and the cleaning nozzle and an air compressor as an air source are connected, and the coolant liquid is air-assisted to the spindle mounting surface of the tool holder. It proposes a technology to inject while. In patent document 1, the coolant liquid which mixed air wash | cleans the chip etc. which adhere to the spindle mounting surface of a tool holder.

JP 2002-273640 A

  The coolant liquid sprayed to the cutting portion of the workpiece is configured to be sent from a coolant tank to the spray nozzle opening by a pump having a predetermined spray pressure, for example, about 0.03 MPa. A machine tool generally also uses a coolant liquid sprayed from the pump as a cleaning liquid for cleaning chips and the like adhering to the spindle mounting surface of the tool holder. Therefore, the machine tool is configured to branch the coolant liquid to be sent to the cutting location and send it to the cleaning nozzle.

  The coolant liquid sprayed to the cutting location has a main function of lubrication and cooling of the cutting location, and the pump is set to an injection pressure that conveys the coolant fluid. In the tool cleaning, since the cleaning liquid needs to have a function of removing chips and the like adhering to the spindle mounting surface of the tool holder with the injection pressure, a sufficient cleaning effect cannot be obtained with the pump injection pressure as described above.

  In patent document 1, since the mixture of coolant liquid and pressurized air is injected to a tool, the amount of coolant liquid per unit time injected to the tool decreases. In removing chips and the like, it is most effective to wash away with a liquid such as a coolant, and air is inferior in removal efficiency as compared with a cleaning liquid. Moreover, since it is a mixture of the coolant and pressurized air, the supply pressure of the air source, so-called output, is not sufficiently added to the injected coolant. In other words, a high-power air source is required to obtain an injection pressure coolant liquid with an enhanced cleaning effect.

  Further, in the tool cleaning, it is necessary to stably and stably inject a coolant liquid having a predetermined injection pressure within a short time during tool replacement. When the coolant is transported from the coolant tank to the cleaning nozzle, the passage is long and the passage resistance is large. Further, there are factors that hinder responsiveness such as clogging of the filter in the middle of the passage and pump drive pulsation.

  An object of the present invention is to provide a tool cleaning apparatus capable of injecting a high-pressure cleaning liquid having supply stability and responsiveness of the cleaning liquid.

  A tool cleaning device for a machine tool according to claim 1, wherein a tank for storing a cleaning liquid for cleaning a tool mounted on a spindle, nozzle means capable of injecting the cleaning liquid stored in the tank into the tool, and the cleaning liquid from the tank. In a tool cleaning apparatus for a machine tool having a cleaning liquid supply means that can be supplied to the nozzle means, the cleaning liquid is disposed between the tank and the nozzle means, stores the cleaning liquid supplied from the cleaning liquid supply means, and stores the cleaning liquid. Is stored in the cleaning liquid storage container, the cleaning liquid passage connecting the nozzle means and the cleaning liquid storage container, the first valve means capable of opening and closing the cleaning liquid passage, and the cleaning liquid storage container. A pressurizing means for pressurizing the cleaning liquid, an air supply means for generating pressurized air, and supplying the pressurized air from the air supply means to the cleaning liquid storage container A pressurizing means having an air supply passage, a second valve means capable of opening and closing the air supply passage, and the air supply passage, and supplying the cleaning liquid from the cleaning liquid storage container to the nozzle means. After the cleaning, when closing the first valve means and the second valve means, the closing timing delays the timing for closing the first valve means from the timing for closing the second valve means. And a valve delay means.

  In this machine tool cleaning apparatus, the cleaning liquid supplied from the cleaning liquid supply means is stored and the cleaning liquid storage container capable of supplying the stored cleaning liquid to the nozzle means is provided, so that the cleaning liquid passage for sending the cleaning liquid to the nozzle means is shortened. And the passage resistance can be reduced. Moreover, it is possible to store the cleaning liquid required for the tool cleaning in advance, and it is possible to prevent the cleaning liquid from being interrupted during the cleaning. Furthermore, since the cleaning liquid pressurized by the pressurizing means is supplied to the nozzle means, the cleaning power can be increased without requiring a pump with a large capacity.

  When the first valve means and the second valve means are closed after the tool cleaning is completed, the valve closing delay means delays the closing timing of the first valve means relative to the closing timing of the second valve means. . During the period from when the second valve means is closed until the first valve means is closed, the pressure of the pressurized air applied to the cleaning liquid is weakened by the amount of the cleaning liquid stored in the cleaning liquid storage container flowing into the cleaning liquid passage. Therefore, when the pressure in the cleaning liquid storage container is released, the cleaning liquid does not flow out to the outside vigorously.

  A tool cleaning device for a machine tool according to claim 2 is the invention according to claim 1, wherein when the cleaning liquid is supplied to the cleaning liquid storage container by the cleaning liquid supply means, the pressurized air inside the cleaning liquid storage container is exhausted to the tank. And a third valve means capable of opening and closing the exhaust passage.

  According to a third aspect of the present invention, there is provided a tool cleaning device for a machine tool according to the first or second aspect, wherein a first pilot air passage for supplying pilot air to the first valve means and a first pilot air passage are provided. A first electromagnetic directional valve mounted, a second pilot air passage for supplying pilot air to the second valve means, a second electromagnetic directional valve interposed in the second pilot air passage, Drive control means for driving and controlling the first electromagnetic directional valve and the second electromagnetic directional valve; and the valve closing delay means sets the timing for switching the first electromagnetic directional valve to the second electromagnetic directional valve. The drive control means controls the drive so as to delay the timing of switching the electromagnetic directional valve.

  A tool cleaning device for a machine tool according to claim 4 is the invention according to claim 1 or 2, wherein the first pilot air passage for supplying pilot air to the first valve means and the pilot air to the second valve means are supplied. A second pilot air passage, wherein the valve closing delay means is interposed in the first pilot air passage and has an operating speed when the first valve means is closed. It is characterized by comprising a flow restrictor that makes the operating speed slower than when the valve is closed.

  According to a fifth aspect of the present invention, there is provided the machine tool cleaning apparatus according to the first or second aspect, wherein the first pilot air passage for supplying pilot air to the first valve means and the pilot air to the second valve means are supplied. And a second pilot air passage, wherein the valve closing delay means has a length of the first pilot air passage longer than that of the second pilot air passage.

  According to the first aspect of the present invention, it is possible to obtain a cleaning apparatus capable of injecting a high-pressure cleaning liquid having the supply stability and responsiveness of the cleaning liquid without changing the capacity of the pump. Since the passage resistance can be reduced by the cleaning liquid storage container, supply stability and responsiveness of the cleaning liquid can be ensured. Moreover, since the cleaning liquid in the cleaning liquid storage container is pressurized by the pressurizing means, the pressurized cleaning liquid can be sprayed onto the tool during tool cleaning. Therefore, the cleaning power can be increased without increasing the capacity of the pump.

  After the tool cleaning is completed, the valve closing delay means delays the timing for closing the first valve means from the timing for closing the second valve means, so that the cleaning liquid supply passage is closed after the air supply passage is closed. During this period, the pressure of the pressurized air applied to the cleaning liquid is weakened by the amount that the cleaning liquid in the cleaning liquid storage container flows into the cleaning liquid passage. Therefore, when the pressure in the cleaning liquid storage container is released, the cleaning liquid can be prevented from flowing out to the outside.

  According to the invention of claim 2, the third valve means enables the exhaust passage for exhausting the pressurized air inside the cleaning liquid storage container to the tank and the exhaust passage can be opened and closed. When the exhaust passage is opened to depressurize the pressure in the storage container, the cleaning liquid flows out to the tank side by the pressurized air through the exhaust passage, but the pressure of the pressurized air to the cleaning liquid is weakened, and the cleaning liquid It is possible to prevent the cleaning liquid from overflowing from the tank when it flows into the tank through the exhaust passage.

  According to the invention of claim 3, the valve closing delay means controls the drive so that the timing for switching the first electromagnetic direction valve is delayed from the timing for switching the second electromagnetic direction valve. The timing for closing the first valve means can be delayed from the timing for closing the second valve means in accordance with the switching timing of the first and second electromagnetic directional valves. Therefore, the same effects as in the first and second aspects are obtained.

  According to the invention of claim 4, the valve closing delay means is interposed in the first pilot air passage and the operating speed when the first valve means closes is when the second valve means closes. Therefore, the flow rate of the air flowing through the first pilot air passage can be adjusted, and the timing of closing the first valve means is closed when the second valve means is closed. It can be delayed from the timing of the valve. Therefore, the same effects as in the first and second aspects are obtained.

  According to the fifth aspect of the invention, the valve closing delay means has the length of the first pilot air passage longer than the length of the second pilot air passage. Can be shifted, and the timing for closing the first valve means can be delayed from the timing for closing the second valve means. Therefore, the same effects as in the first and second aspects are obtained.

It is a perspective view (before tank mounting) of the tool washing apparatus concerning Example 1 of the present invention. It is a side view (after tank mounting) of FIG. It is a front view of a spindle and a spindle head. It is a side view (part) of FIG. It is a bottom view (part) of FIG. It is principal part sectional drawing of a spindle and a spindle head. It is a circuit diagram of a tool cleaning apparatus. It is a block diagram of the control system of a tool washing apparatus. It is a flowchart which shows tool washing | cleaning control. It is a circuit diagram of the tool washing | cleaning apparatus which concerns on Example 2. FIG. FIG. 6 is a circuit diagram of a tool cleaning device according to a third embodiment.

  Hereinafter, modes for carrying out the present invention will be described based on examples.

  As shown in FIGS. 1 to 3, a machining center 1 as a machine tool includes a base portion 2 fixed to a floor surface as an installation surface and an XY axis drive mechanism (not shown) in the X axis and Y axis directions. A movable table (not shown), a control box 3 that houses a control unit 51 that numerically controls each mechanism such as a table, and a column 4 that stands on the upper surface of the rear part of the base unit 2 and extends upward. Have.

  Further, the machining center 1 includes a spindle head 5 that is mounted on the column 4 so as to be movable up and down, a spindle 6 provided on the spindle head 5, a drive mechanism 7 that can move the spindle head 5 in the Z-axis direction, The column 4 has an ATC 8 (automatic tool changer) and a storage tank 50 (cleaning liquid storage container). The storage tank 50 is disposed above the column 4.

  The coolant tank 10 is arranged so that the front end face thereof faces below a coolant discharge portion 9 provided behind the machining center 1. In the drawing, a stage before the coolant tank 10 is mounted on the coolant discharge portion 9 is shown. The coolant tank 10 includes a substantially box-shaped storage tank 11 having a part of the upper surface opened, and a recovery tank 12 that can be attached to and detached from the storage tank 11. The collection tank 12 removes chips mixed with the used coolant liquid flowing out from the coolant discharge unit 9. The storage tank 11 stores the coolant liquid from which chips are removed in the recovery tank 12.

The pair of first pump 13 and second pump 14 are configured to suck up coolant liquid from which chips and the like are removed from the storage tank 11 and to circulate and supply the coolant to the machining center 1.
The first pump 13 (cleaning liquid supply means) is configured to supply a coolant liquid that is injected toward a cutting portion where the tool 20 and the workpiece are in contact with each other. The discharge pressure of the first pump 13 is in the range of 0.030 to 0.045 MPa. The second pump 14 is configured to supply a coolant liquid for discharging chips and the like from the cutting location, and the discharge pressure is set to be higher than that of the first pump 13.

  A substantially box-shaped drainage reservoir 53 that opens downward is fixed between the first pump 13 and the second pump 14 at the upper end of the storage tank 11. The exhaust passage 37 for releasing the pressure in the storage tank 50 at the end of the tool change is connected to an inlet provided in the front portion of the upper end portion of the drainage reservoir 53 via the socket 52.

  As shown in FIGS. 3 to 5, the column 4 is equipped with an ATC 8. The ATC 8 has a magazine 17 in which a plurality of pods 15 are connected to a chain-like member 16. In each pod 15, various tool holders 21 with cutting tools 20a (see FIG. 6) are selectively inserted in a detachable manner. The magazine 17 moves those pods 15 in response to the command signal, and conveys the commanded pods 15 to a predetermined replacement position. Hereinafter, the tool holder 21 to which the cutting tool 20a is attached is referred to as a tool 20.

  The ATC 8 includes a revolving arm 18 that revolves around an axis parallel to the main shaft 6. The revolving arm 18 lowers the revolving arm 18 after gripping the tool 20 attached to the main shaft 6 and the tool 20 conveyed to the replacement position. Then, after removing the tool 20 from the main shaft 6 and the pod 15, the tool 20 is rotated 180 degrees. Next, the swivel arm 18 is raised to attach another tool 20 to the main shaft 6 and the tool 20 removed from the main shaft 6 is returned to the pod 15 at the replacement position.

  As shown in FIG. 6, the tool 20 includes a cutting tool 20a such as a drill and a tool holder 21 for holding the cutting tool 20a. The tool holder 21 has a shank part 21a, a flange part 21b, and a V-groove part 21c. In a state where the tool 20 is attached to the main shaft 6, the shank portion 21 a of the tool holder 21 is taper-engaged with the taper engagement hole 19. The axial center position restricting surface 21d of the flange portion 21b comes into contact with the end surface 24 at the tip of the main shaft 6. Therefore, the main shaft 6 has a two-surface constraining configuration in which the position of the tool holder 21 is regulated by the taper engagement hole 19 and the end surface 24. The main shaft 6 has a holding mechanism that engages with a clamping engagement portion (not shown) of the tool holder 21 and pulls it upward.

Next, a cleaning mechanism for cleaning the tool 20 mounted in the taper engagement hole 19 of the main shaft 6 will be described.
As shown in FIG. 6, the annular spindle cap 22 is fixed to the lower end of the spindle head 5 that rotatably supports the spindle 6 with a plurality of bolts 23.

  The distal end surface of the annular nozzle forming member 26 that closes the annular passage 25 formed at the distal end portion of the main shaft cap 22 is set at substantially the same height as the end surface 24 of the main shaft 6. The annular passage 25 is connected to a coolant supply port 27, and the coolant supply port 27 is connected to a storage tank 50 via a coolant hose 28 (cleaning liquid passage).

  The nozzle forming member 26 is formed with an annular injection nozzle 29 (nozzle means) that injects the coolant liquid in an inclined direction toward the axis of the main shaft 6. The injection nozzle 29 is connected to the annular passage 25 by a plurality of passage holes 30. The annular passage 25 and the plurality of passage holes 30 supply coolant liquid to the injection nozzle 29. The injection nozzle 29 injects a tapered cylindrical injection flow A of the coolant liquid, and cleans the surface of the shank portion 21 a of the tool holder 21 that moves upward toward the taper engagement hole 19 of the main shaft 6.

Next, the cleaning liquid circuit of the tool cleaning device 67 will be described with reference to FIG.
The tool cleaning device 67 includes the above-described coolant tank 10, injection nozzle 29, first pump 13, coolant hose 28, storage tank 50, exhaust passage 37, and drainage reservoir 53. Further, the tool cleaning device 67 includes an air source 39, a first air passage 40, a second air passage 41, a third air passage 42, a branch passage 32, and a plurality of switching valves 35, 38, 45, which will be described later. And a plurality of solenoid valves 43, 44 and 56.

  The first pump 13 discharges the coolant sucked from the storage tank 11 to the coolant supply passage 31 and sends it to the cutting location. A branch passage 32 branched from the coolant supply passage 31 is connected to the lower end portion of the storage tank 50.

  The branch passage 32 is provided between the filter unit 33 for removing foreign matters mixed in the coolant and the check valve 34 that is provided between the filter unit 33 and the storage tank 50 and allows only the flow in the direction of the storage tank 50. And are arranged.

  The coolant hose 28 or the pipe connecting the lower end of the storage tank 50 and the injection nozzle 29 has a first switching valve 35 (first valve means). The first switching valve 35 can be switched between a valve closing position that closes the passage of the coolant hose 28 and a valve opening position that enables flow in the direction of the injection nozzle 29. The first switching valve 35 is switched to a valve closing position by an urging means (spring member), and is switched to a valve opening position by pressurized air described later.

  The storage tank 50 includes a liquid level sensor 36 at a predetermined height from the lower end. The mounting height of the liquid level sensor 36 is such that when the remaining amount of the coolant liquid is equal to or higher than the above height, the coolant liquid injection is interrupted even if the standard cleaning process is performed once, for example, for 5 seconds. It is installed in a position that does not. The amount of liquid that does not cause interruption of the coolant liquid even when spraying for 5 seconds corresponds to the predetermined amount. The predetermined amount is an amount to be ejected from the ejection nozzle 29 from the start to the end of the tool change based on one tool change command.

  A so-called depressurizing exhaust passage 37 is provided in an intermediate region in the vertical direction of the storage tank 50 to connect the drainage reservoir 53 fixed to the coolant tank 10 and release the pressure in the storage tank 50. The exhaust passage 37 is provided with a second switching valve 38 (third valve means) that can be switched between a valve closing position that blocks the passage and a valve opening position that allows flow in the direction of the drainage reservoir 53. is there. The second switching valve 38 is switched to a valve opening position by an urging means (spring member), and is switched to a valve closing position by pressurized air described later.

  In this embodiment, a factory air source 39 is used for pressurizing the coolant liquid. Since the factory air source 39 can obtain a discharge pressure (pressurized air) of about 0.5 MPa, it does not require a separate air compressor or the like for pressurizing the coolant liquid. One end of each of the first to third air passages 40, 41, and 42 is connected to the air source 39.

  The vicinity of the other end of the first air passage 40 is connected to a first electromagnetic valve 43 (first electromagnetic directional valve). The first solenoid valve 43 prohibits air supply in the downstream direction of the first solenoid valve 43 and releases the pressure downstream of the first solenoid valve 43 to the atmosphere via the silencer 43a, and downstream of the first solenoid valve 43. The second position where the air supply in the direction can be electrically switched is possible.

  The first electromagnetic valve 43 is switched to the first position in the OFF state by the biasing means (spring member), and is switched to the second position by the ON operation by the control unit 51. A fourth air passage 46 (first pilot air passage) capable of supplying pressurized air from the air source 39 to the first switching valve 35 is connected downstream of the first electromagnetic valve 43.

  The other end of the second air passage 41 is connected to the second electromagnetic valve 44. The second solenoid valve 44 prohibits air supply in the downstream direction of the second solenoid valve 44 and releases the pressure downstream of the second solenoid valve 44 to the atmosphere via the silencer 44a, and the downstream direction of the second solenoid valve 44. The second position where the air can be supplied can be electrically switched.

  The second electromagnetic valve 44 is switched to the first position in the OFF state by the biasing means (spring member), and is switched to the second position by the ON operation by the control unit 51. A fifth air passage 47 capable of supplying pressurized air from the air source 39 to the second switching valve 38 is connected downstream of the second electromagnetic valve 44.

  The other end of the third air passage 42 is connected to the upper end portion of the storage tank 50. The third air passage 42 includes a variable throttle valve 48, a third switching valve 45 (second valve means), and a check valve 49 that allows only air supply in the direction of the storage tank 50.

  The other end of the first air passage 40 is connected to a third electromagnetic valve 56 (second electromagnetic directional valve). The third solenoid valve 56 prohibits the air supply in the downstream direction of the third solenoid valve 56 and also releases the pressure downstream of the third solenoid valve 56 to the atmosphere via the silencer 56a, and the third solenoid valve 56 downstream. The second position where the air supply in the direction can be electrically switched is possible.

  The third electromagnetic valve 56 is switched to the first position in the OFF state by the biasing means (spring member), and is switched to the second position by the ON operation by the control unit 51. A sixth air passage 55 (second pilot air passage) that can supply pressurized air from the air source 39 to the third switching valve 45 is connected downstream of the third electromagnetic valve 56.

  The third switching valve 45 can be switched between a valve closing position that blocks the passage and a valve opening position that enables air supply in the direction of the storage tank 50 via the check valve 49. The third switching valve 45 is switched to a valve closing position by an urging means (spring member), and is switched to a valve opening position by pressurized air described later.

  The control unit 51 switches and controls the first electromagnetic valve 43, the second electromagnetic valve 44, and the third electromagnetic valve 56 described above between the first position and the second position. When the control unit 51 operates the first electromagnetic valve 43 to be turned on, that is, the so-called second position, the pressurized air of the air source 39 passes through the first electromagnetic valve 43 and flows into the fourth air passage 46. The pressurized air that has flowed into the fourth air passage 46 compresses the urging means of the first switching valve 35 and switches the first switching valve 35 to the valve open position. As a result, the coolant liquid stored in the storage tank 50 is injected from the injection nozzle 29.

  When the controller 51 turns on the second electromagnetic valve 44 (actuates to the so-called second position), the pressurized air from the air source 39 passes through the second electromagnetic valve 44 and flows into the fifth air passage 47. The pressurized air that has flowed into the fifth air passage 47 compresses the urging means of the second switching valve 38, switches the second switching valve 38 to the valve closing position, and closes the exhaust passage 37.

  When the control unit 51 turns on the third electromagnetic valve 56 (actuates to a so-called second position), the pressurized air of the air source 39 passes through the third electromagnetic valve 56 and flows into the sixth air passage 55. The pressurized air that has flowed into the sixth air passage 55 compresses the urging means of the third switching valve 45 and switches the third switching valve 45 to the valve opening position. Thus, the pressurized air flowing through the third air passage 42 pressurizes the coolant liquid that passes through the variable throttle valve 48, the third switching valve 45, and the check valve 49 and is stored in the storage tank 50. The pressurizing means includes an air source 39 and a third air passage 42.

  Next, the electrical configuration of the tool cleaning device 67 will be described. As shown in FIG. 8, the control unit 51 includes a control circuit 71 and various drive circuits 77 to 86. The control circuit 71 controls a machining operation of the machining center 1 and a tool cleaning control of the tool cleaning device 67 by executing a control program (see FIG. 9 described later) stored in a ROM 73 described later.

  The control circuit 71 basically includes a microcomputer including a CPU 72, a ROM 73, and a RAM 74, an input interface 75, and an output interface 76. The RAM 74 stores and holds a machining program for causing the machining center 1 to perform desired machining. The machining program includes a plurality of operation blocks, and is created by an operator via an operation panel described later.

  In the input interface 75, a keyboard 70 of an operation panel (not shown) provided on the front surface of the machining center 1, the liquid level sensor 36, and the pressure sensor 68 are electrically connected. The keyboard 70 is used for the operator to input information necessary for the machining operation. The pressure sensor 68 detects the pressure (air pressure) of the pressurized air from the air source 39.

  The output interface 76 includes a drive circuit 77 that drives the X-axis motor 87, a drive circuit 78 that drives the Y-axis motor 88, a drive circuit 79 that drives the Z-axis motor 89, and a drive circuit 80 that drives the spindle motor 90. A drive circuit 81 for driving the magazine motor 91, a drive circuit 82 for driving the first pump 13, a drive circuit 83 for driving the CRT 92 of the operation panel, and a first electromagnetic valve 43. The drive circuit 84, the drive circuit 85 for driving the second electromagnetic valve 44, and the drive circuit 86 for driving the third electromagnetic valve 56 are electrically connected to each other.

  The X-axis motor 87 includes an encoder 87a that detects the position of the table in the X-axis direction. The encoder 87a is connected to the input interface 75. The Y-axis motor 88 includes an encoder 88a that detects the position of the table in the Y-axis direction. The encoder 88a is connected to the input interface 75. The Z-axis motor 89 includes an encoder 89a that detects the position of the spindle head 5 in the Z-axis direction. The encoder 89a is connected to the input interface 75.

Next, delay control means as valve closing delay means provided in the control unit 51 will be described.
The delay control means controls the first electromagnetic valve 43 and the third electromagnetic valve 56 to be turned off (operated from the first position to the second position) after the tool 20 is washed. That is, the delay control means delays the timing for closing the first switching valve 35 after the cleaning of the tool 20 from the timing for closing the third switching valve 45, so that the first electromagnetic valve 43 is moved from the first position to the second position. Delay control is executed to delay the timing for switching to the position by a predetermined short time (for example, 1 second) from the timing for switching the third electromagnetic valve 56 from the first position to the second position.

Next, the tool cleaning control of the cleaning mechanism executed by the delay control means will be described based on the flowchart of FIG. Si (i = 1, 2,...) Indicates each step.
Tool cleaning control is an interrupt process executed by the CPU 72 at a predetermined cycle. First, the CPU 72 reads various signals from the respective mechanisms such as a tool change command for the machining center 1, an operating state of the first pump 13, an operating state of the air source 39, a detected value of the liquid level sensor 36 (S1), and the processing is performed in S2. Migrate to

  The CPU 72 determines whether or not the air pressure of the air source 39 is normal by comparing the detected value of the pressure sensor 68 with a value stored in advance in the ROM 73 (S2). When the air pressure is normal (Yes in S2), the CPU 72 determines whether or not the first pump 13 is driven (S3). When the CPU 72 drives the first pump 13 via the drive circuit 82, the CPU 72 stores that the first pump 13 is in a driving state in the RAM 74. Therefore, the CPU 72 determines whether or not the first pump 13 is driven with reference to the RAM 74.

When the first pump 13 is driven (Yes in S3), the CPU 72 determines whether or not the coolant liquid in the storage tank 50 is equal to or larger than a predetermined amount by the liquid level sensor 36 (S4). When there is a predetermined amount or more of the coolant in the storage tank 50 (Yes in S4), the CPU 72 determines whether or not there is a tool change command (S5).

In the machining program process control, the CPU 72 stores the fact that the tool change command is stored in the RAM 74 before executing the tool change command when each mechanism is controlled according to the machining program. Therefore, the CPU 72 determines whether or not there is a tool change command with reference to the RAM 74. The machining program processing control described above is executed at a predetermined cycle, and is executed by interpreting a plurality of operation blocks of the machining program for each block. When there is a tool change command (Yes in S5), the CPU 72 turns on the first electromagnetic valve 43, the second electromagnetic valve 44, and the third electromagnetic valve 56 (S6).

  After turning on the first solenoid valve 43, the second solenoid valve 44, and the third solenoid valve 56, the CPU 72 permits the start of tool replacement (S7). When the CPU 72 permits the start of the tool change, the tool change is started in a tool change process (not shown). The tool change process is a program stored in the ROM 73. When the start of the tool change is permitted, the CPU 72 executes the interrupt process separately from the interrupt process described above. Thereafter, the CPU 72 waits until the tool change is completed (S8). Whether or not the tool change has been completed is determined by whether or not the position of the spindle head 6 in the Z-axis direction has reached the tool change completion position. The position of the spindle head 6 in the Z-axis direction is detected by an encoder. When the tool change is completed (Yes in S8), the CPU 72 shifts the process to S9, turns off the third electromagnetic valve 56, and shifts the process to S10. In S10, the CPU 72 starts counting of the timer T1, and determines whether or not 1 second has elapsed after the start of counting (S11). Therefore, the tool cleaning device 67 stops supplying pressurized air to the storage tank 50.

  In a state where the pressurized air supply is stopped, when a predetermined time, for example, 1 second elapses when the coolant liquid flows out from the storage tank 50 to the coolant hose 28 (Yes in S11), the CPU 72 determines the first solenoid valve 43 and the second solenoid valve. 44 is turned off (S12), and the process proceeds to S13. Note that if the result of determination in S11 is that the timer T1 has not elapsed for 1 second, the CPU 72 continues to count the timer T1. In S13, the CPU 72 starts counting of the timer T2, and proceeds to S14. In S <b> 12, the tool cleaning device 67 stops the injection of the coolant and releases the pressure in the storage tank 50 from the exhaust passage 37. By releasing the pressure, the coolant liquid in the coolant tank 10 is supplied to the storage tank 50 by the first pump 13.

  If the determination result of S14 indicates that a predetermined time, for example, 5 seconds has elapsed, when the depressurization of the storage tank 50 is completed, the CPU 72 proceeds to S15. The CPU 72 turns on the second electromagnetic valve 44 (S15) and ends the process. Note that if the result of determination in S14 is that decompression has not been completed, that is, if the timer T2 has not elapsed for 5 seconds, the CPU 72 continues to count the timer T2.

If the result of determination in S <b> 8 is No, the CPU 72 waits until the tool change is completed. In this case, the injection of the coolant liquid continues.
As a result of the determination in S4, in the case of No, since the coolant liquid is at a position lower than the position of the liquid level sensor 36, the CPU 72 determines that there is a liquid level error (S16), and the process proceeds to S9.

  If the determination result in S2 is No, the CPU 72 turns off the third electromagnetic valve 56 (S17), stops the supply of pressurized air to the storage tank 50, and shifts the processing to S18. In S18, the CPU 72 starts counting of the timer T1, and proceeds to S19. If, for example, one second has elapsed in the pressurized air supply stop state as a result of the determination in S19 (Yes in S19), the CPU 72 turns off the first electromagnetic valve 43 and the second electromagnetic valve 44 and ends the process. .

The operation and effect of the tool cleaning device 67 of the machining center 1 described above will be described.
When the coolant is supplied from the storage tank 50 to the injection nozzle 29 to clean the tool 20, the first solenoid valve 43 and the third solenoid valve 56 are turned off (operated from the first position to the second position). The timing for switching the first solenoid valve 43 is delayed from the timing for switching the third solenoid valve 56.

  The closing timing of the first switching valve 35 is delayed from the closing timing of the third switching valve 45 in accordance with the switching timing of the first solenoid valve 43 and the third solenoid valve 56. As a result, for a predetermined time (for example, 1 second) from when the third air supply passage 42 is closed by the third switching valve 45 to when the coolant hose 28 is closed by the first switching valve 35, the coolant liquid in the storage tank 50 is cooled to the coolant hose. The pressure applied to the coolant liquid by the pressurized air is weakened by the amount that flows out to 28.

  When the exhaust passage 37 is opened by the second switching valve 38 to release the pressure of the storage tank 50, the coolant liquid also flows out to the tank side through the exhaust passage 37 due to the pressurized air, but the coolant liquid passes through the exhaust passage 37. Thus, it does not flow out into the storage tank 50 vigorously. Therefore, it is possible to prevent the cleaning liquid from overflowing from the storage tank 50 when the cleaning liquid flows out to the storage tank 50 through the exhaust passage 37.

  Next, a tool cleaning device 67A according to a second embodiment of the present invention will be described with reference to FIG. However, the same components as those in the first embodiment are denoted by the same reference numerals, and only different components will be described. The difference from the first embodiment is that the delay control means is provided as the valve closing delay means in the first embodiment, whereas the flow restriction means for adjusting the air flow rate is provided as the delay means in the second embodiment. It is.

  As shown in FIG. 10, the first air passage 40 includes a first electromagnetic valve 43 interposed in the upstream portion of the passage. The other end of the first air passage 40 is connected to one end of a seventh air passage 60 (first pilot air passage) and an eighth air passage 62 (second pilot air passage) that are bifurcated from the other end. The other end of the seventh air passage 60 is connected to the first switching valve 35 (first valve means). The other end of the eighth air passage 62 is connected to the third switching valve 45 (second valve means).

  The first solenoid valve 43 has a first position where the pressure in the seventh air passage 60 and the eighth air passage 62 is released to the atmosphere via the silencer 43 a, and a first position via the seventh air passage 60 and the eighth air passage 62. The first switching valve 35 and the third switching valve 45 can be electrically switched to a second position where air can be supplied.

  The seventh air passage 60 includes a speed controller 61 (flow restrictor) interposed in the downstream portion of the passage. The speed controller 61 is provided to make the operating speed when the first switching valve 35 closes slower than the operating speed when the third switching valve 45 closes.

  When the first solenoid valve 43 is switched to the second position and the pressure in the seventh air passage 60 and the eighth air passage 62 is released, the speed controller 61 causes the air flowing through the seventh air passage 60 to flow through the flow control path. It has a function as a valve closing delay means that guides to 61a and adjusts the flow rate by the variable throttle 61c. That is, the speed controller 61 makes the flow rate of air flowing through the seventh air passage 60 by the variable throttle 61 c smaller than the flow rate of air flowing through the eighth air passage 62. Therefore, the closing timing of the first switching valve 35 is delayed from the closing timing of the third switching valve 45 due to the time difference when the pressure in the seventh air passage 60 and the eighth air passage 62 is released.

  Pressurized air from the air source 39 flows into the seventh air passage 60 via the first air passage 40 and the first electromagnetic valve 43 and flows on the check valve 61b side, so that the air flow rate is controlled. It is designed to flow freely. In the first embodiment, the first switching valve 35 is set to the closed position after the third switching valve 45 by turning off the first solenoid valve 43 later than the third solenoid valve 56. . In the second embodiment, the first switching valve 35 is set to the closed position after the third switching valve 45 based on the speed controller 61 only by turning off the first electromagnetic valve 43. Therefore, the cleaning control of the second embodiment only eliminates the portion related to the third electromagnetic valve 56 in the tool cleaning control of the first embodiment shown in FIG. Therefore, the steps S17, S18, and S19 and the steps S9, S10, and S11 in FIG. 9 are deleted, and the process of turning on the third electromagnetic valve 56 in the step S6 is excluded.

The operation and effect of the tool cleaning device 67A of the second embodiment described above will be described.
A speed controller that lowers the operating speed when the first switching valve 35 is closed after the first solenoid valve 35 is turned off from on by the control unit 51 than the operating speed when the third switching valve 45 is closed. 61, when the pressure in the seventh air passage 60 and the eighth air passage 62 is released, the flow rate of the air in the seventh air passage 60 is adjusted by the variable throttle 61c of the speed controller 61.

  As a result, the flow rate of the air flowing through the seventh air passage 60 is made smaller than the flow rate of the air flowing through the eighth air passage 62, and the timing at which the first switching valve 35 is closed closes the third switching valve 45. It can be delayed from the timing to do. Therefore, until the first switching valve 35 is closed after the third switching valve 45 is closed, the pressure of the pressurized air to the coolant liquid is weakened by the amount that the coolant liquid in the storage tank 50 flows out to the coolant hose 28. . Therefore, the same effects as those of the first embodiment are obtained.

  Next, a tool cleaning device 67B of Example 3 of the present invention will be described with reference to FIG. However, the same components as those in the second embodiment are denoted by the same reference numerals, and only different components will be described. The difference from the second embodiment is that the speed controller 61 is provided as a flow restrictor for adjusting the flow rate of air, whereas in the third embodiment, the length of the air passage is increased instead of the speed controller 61. is there.

  The difference between FIG. 10 of the second embodiment and FIG. 11 of the third embodiment is that the length of the air passage from the first electromagnetic valve 43 to the first switching valve 35 and the first electromagnetic valve 43 to the third switching valve 45 are different. And the presence / absence of the speed controller 61.

  The length of the air passage from the first electromagnetic valve 43 to the first switching valve 35 is longer in the tenth air passage 64 (Example 3) than in the seventh air passage 60 (Example 2). The length from the first electromagnetic valve 43 to the third switching valve 45 is shorter in the ninth air passage 63 (Example 3) than in the eighth air passage 62 (Example 2).

  The speed controller 61 is not required in the third embodiment. The lengths of the tenth air passage 64 and the ninth air passage 63 are such that the timing of closing the first switching valve 35 is set by providing a time difference in the pressure release of the pressure in the ninth air passage 63 and the tenth air passage 64. It has a function as a valve closing delay means for delaying the valve closing timing of the third switching valve 45. Note that the tool cleaning control of the cleaning mechanism of the present embodiment is the same as that of the second embodiment, and a description thereof will be omitted.

The operation and effect of the tool cleaning device 67B of the third embodiment described above will be described.
Since the length of the tenth air passage 64 connected to the first switching valve 35 is longer than the length of the ninth air passage 63 connected to the third switching valve 45, the first electromagnetic valve 35 is turned on by the control unit 51. After the OFF operation is performed, the valve closing timing of the first switching valve 35 is delayed from the valve closing timing of the third switching valve 45 due to the time difference of the depressurization due to the difference in length. Therefore, until the first switching valve 35 is closed after the third switching valve 45 is closed, the pressure of the pressurized air to the coolant liquid is weakened by the amount that the coolant liquid in the storage tank 50 flows out to the coolant hose 28. . Therefore, the same effects as those of the first and second embodiments are obtained.

Next, a modified example in which the above embodiment is partially modified will be described.
1] Although the length of the tenth air passage 64 is longer than the length of the ninth air passage 63 in the third embodiment, the diameter of the passage may be different. In this case, the diameter of the tenth air passage 64 may be made smaller than the diameter of the ninth air passage 63.

1 machining center 10 coolant tank 13 first pump 20 tool 28 coolant hose 29 injection nozzle 31 coolant supply passage 35 first switching valve 37 exhaust passage 38 second switching valve 39 air source 42 third air passage 43 first solenoid valve 44 second Solenoid valve 45 Third switching valve 46 Fourth air passage 50 Storage tank 51 Control unit 55 Sixth air passage 56 Third electromagnetic valve 60 Seventh air passage 61 Speed controller 62 Eight air passage 63 Ninth air passage 64 Tenth air Passage 67, 67A, 67B Tool cleaning device

Claims (5)

A tank for storing a cleaning liquid for cleaning a tool mounted on the spindle, nozzle means capable of spraying the cleaning liquid stored in the tank to the tool, and a cleaning liquid supply means capable of supplying the cleaning liquid from the tank to the nozzle means. In a tool cleaning device for a machine tool having
A cleaning liquid storage container disposed between the tank and the nozzle means, storing the cleaning liquid supplied from the cleaning liquid supply means, and capable of supplying the stored cleaning liquid to the nozzle means;
A cleaning liquid passage connecting the nozzle means and the cleaning liquid storage container, and a first valve means capable of opening and closing the cleaning liquid passage;
Pressurizing means for pressurizing the cleaning liquid stored in the cleaning liquid storage container, an air supply means for generating pressurized air, and an air supply passage for supplying pressurized air from the air supply means to the cleaning liquid storage container Pressurizing means comprising:
A second valve means capable of opening and closing the air supply passage and the air supply passage;
After the cleaning liquid is supplied from the cleaning liquid storage container to the nozzle means and the tool is cleaned, the first valve means is closed when the first valve means and the second valve means are closed. A tool cleaning device for a machine tool, comprising: a valve closing delay means for delaying the timing of closing the second valve means relative to the timing of closing the second valve means.   An exhaust passage for exhausting the pressurized air inside the cleaning liquid storage container to the tank when the cleaning liquid is supplied to the cleaning liquid storage container by the cleaning liquid supply means, and a third valve means capable of opening and closing the exhaust passage. The tool cleaning device for a machine tool according to claim 1, further comprising: A first pilot air passage for supplying pilot air to the first valve means, a first electromagnetic directional valve interposed in the first pilot air passage, and supply of pilot air to the second valve means Drive control for driving and controlling the second pilot air passage, the second electromagnetic directional valve interposed in the second pilot air passage, the first electromagnetic directional valve and the second electromagnetic directional valve And further comprising means
2. The valve closing delay means is controlled by the drive control means so as to delay the timing of switching the first electromagnetic directional valve from the timing of switching the second electromagnetic directional valve. Or the tool cleaning apparatus of the machine tool of 2. A first pilot air passage for supplying pilot air to the first valve means; and a second pilot air passage for supplying pilot air to the second valve means;
The valve closing delay means is interposed in the first pilot air passage and makes the operating speed when the first valve means closes slower than the operating speed when the second valve means closes. 3. The machine tool cleaning device according to claim 1, wherein the machine tool cleaning device is constituted by a flow restrictor. A first pilot air passage for supplying pilot air to the first valve means; and a second pilot air passage for supplying pilot air to the second valve means;
3. The tool cleaning device for a machine tool according to claim 1, wherein the valve closing delay means makes the length of the first pilot air passage longer than the length of the second pilot air passage. 4.

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