Numerical control device, machine tool, control method, program, and storage medium

Abstract

To provide a numerical control device, a machine tool, a control method, a program and a storage medium which maintain the ability to clean a tapered part of a tool holder and which can reduce the consumption of fluid for cleaning the tool holder.SOLUTION: In changing tools by means of a changing mechanism, a CPU moves a spindle head toward a next tool such that a tapered part of a tool holder fits into a fitting hole (S21). While the spindle head is moving, the CPU supplies fluid to a nozzle by means of supply means so as to eject the fluid from the nozzle toward the tool holder to which the next tool has been attached (S12). The CPU determines whether the spindle head has reached from a reference position at which the fluid no longer hits the tool holder to a contact position prior to completion of the tool change by the changing mechanism (S22). When it is determined that the spindle head has reached the contact position, the CPU stops the supply of fluid to the nozzle by the supply means (S23).SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a numerical control device, a machine tool, a control method, a program, and a storage medium. [Background technology]

[0002] In order to prevent deterioration of machining accuracy, the machine tool described in Patent Document 1 cleans the tapered portion of the tool holder, which has a tool attached to the spindle, when changing the tool. When changing the tool, the machine tool moves the spindle head from the ATC origin toward the Z-axis origin. At that time, the machine tool sprays cleaning liquid from a nozzle toward the tool holder, which passes a predetermined cleaning position. After the entire tapered portion of the tool holder passes the cleaning position, the spindle head reaches the Z-axis origin, and the tapered portion of the tool holder is attached to the attachment hole of the spindle. At that time, the machine tool stops spraying cleaning liquid from the nozzle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-234471 A Summary of the Invention [Problem to be solved by the invention]

[0004] The above machine tool continues to spray cleaning fluid onto parts of the tool holder other than the tapered part until the spindle head reaches the Z-axis origin, even after the tapered part of the tool holder has passed the cleaning position. Therefore, the machine tool has a problem of consuming more cleaning fluid than necessary. Not only cleaning fluid, but also fluids such as air may be consumed more than necessary.

[0005] An object of the present invention is to provide a numerical control device, a machine tool, a control method, a program, and a storage medium that can maintain the ability to clean the tapered portion of a tool holder and reduce the consumption of fluid for cleaning the tool holder. [Means for solving the problem]

[0006] The numerical control device of claim 1 is a numerical control device for controlling a machine tool including a tool magazine that stores a tool holder that holds a tool, a spindle that is an axis having an attachment hole into which a tapered portion of the tool holder fits and extends in a specific direction, a spindle head that rotatably supports the spindle, a tool exchange mechanism that performs a tool exchange for exchanging a current tool held by the tool holder attached to the spindle with a next tool held by the tool holder stored in the tool magazine, a nozzle provided in the spindle head that sprays a fluid toward the tool holder of the next tool, and a supply means that supplies the fluid to the nozzle, wherein the numerical control device controls a machine tool such that the tapered portion of the tool holder fits into the attachment hole during the tool exchange by the exchange mechanism. the fluid ejection control unit which ejects the fluid from the nozzle toward the tool holder to which the next tool is attached by supplying the fluid to the nozzle by the supply means during relative movement by the movement control unit; and a determination unit which determines whether the spindle head has reached a specific range from a reference position where the fluid does not hit the tapered portion of the tool holder to a position before the tool exchange by the exchange mechanism is completed, and when the determination unit determines that the spindle head has reached the specific range, the ejection control unit executes a supply stop process which stops the supply of the fluid to the nozzle by the supply means.

[0007] The numerical control device stops the supply of fluid to the nozzle by the supply means within a specific range, thereby preventing the fluid from being sprayed onto portions of the tool holder other than the tapered portion, thereby maintaining the ability to clean the tapered portion of the tool holder and reducing the consumption of fluid for cleaning the tool holder.

[0008] In the numerical control device of claim 2, the machine tool may include a detection unit that detects a relative position between the spindle head and the tool holder of the next tool, and the judgment unit may judge whether the spindle head has reached the specific range based on a detection result by the detection unit. Since the numerical control device detects the relative position using the detection unit, the relative position can be detected more accurately than in the case of judging based on elapsed time. Since the numerical control device only needs to stop the supply of fluid to the nozzle based on the detection result by the detection unit, it is easy to control the timing of stopping the supply of fluid.

[0009] In the numerical control device of claim 3, the machine tool may include a movement mechanism that moves the spindle head in the specific direction, and the movement control unit may control the movement mechanism to move the spindle head in the specific direction toward the next tool. The numerical control device can maintain the ability to clean the tapered portion of the tool holder and reduce consumption of fluid for cleaning the tool holder even in a machine tool that moves the spindle head in a specific direction to change tools.

[0010] In the numerical control device of claim 4, the movement mechanism may include a motor that moves the spindle head in the specific direction, and the detection unit may be an encoder that detects the rotational position of the motor. The numerical control device can detect the stop position based on the detection result of the encoder.

[0011] In the numerical control device of claim 5, the judgment unit may judge whether the spindle head has reached the specific range based on the elapsed time since the tool change. Since the numerical control device only needs to judge the elapsed time, there is no need to provide a sensor for detecting the position of the spindle head. Since the numerical control device only needs to check the elapsed time since the tool change, it is easy to control the timing of stopping the supply of cleaning liquid.

[0012] A machine tool according to claim 6 comprises a tool magazine which stores a tool holder for holding a tool, a spindle which is an axis having an attachment hole into which a tapered portion of the tool holder fits and extends in a specific direction, a spindle head which rotatably supports the spindle, a tool changing mechanism which performs tool changing to change a current tool held by the tool holder mounted on the spindle for a next tool held by the tool holder stored in the tool magazine, a nozzle provided in the spindle head which sprays fluid toward the tool holder of the next tool, and supply means which supplies the fluid to the nozzle, wherein, during the tool changing by the tool changing mechanism, the spindle is rotated so that the tapered portion of the tool holder fits into the attachment hole. the nozzle is adapted to supply the fluid to the nozzle by the supply means during relative movement by the movement control unit, thereby causing the fluid to be sprayed from the nozzle toward the tool holder to which the next tool is attached; and a judgment unit is adapted to judge whether the spindle head has reached a specific range from a reference position where the fluid does not hit the tapered portion of the tool holder to a position before the tool exchange is completed by the exchange mechanism, and when the judgment unit judges that the spindle head has reached the specific range, the jetting control unit executes a supply stop process to stop the supply of the fluid to the nozzle by the supply means.

[0013] The above machine tool achieves the same effects as the numerical control device of claim 1.

[0014] A control method according to claim 7 is a control method for a numerical control device for controlling a machine tool comprising: a tool magazine storing a tool holder for holding a tool; a spindle which is an axis having an attachment hole into which a tapered portion of the tool holder fits and extends in a specific direction; a spindle head rotatably supporting the spindle; a tool exchange mechanism for exchanging a current tool held by the tool holder mounted on the spindle with a next tool held by the tool holder stored in the tool magazine; a nozzle provided in the spindle head for spraying a fluid toward the tool holder of the next tool; and a supply means for supplying the fluid to the nozzle, the control method comprising the steps of: when exchanging the tool by the exchange mechanism, a nozzle is provided in the spindle head for spraying a fluid toward the tool holder of the next tool; the nozzle to eject the fluid toward the tool holder having the next tool attached thereto; and a judgment step of judging whether or not the spindle head has reached a specific range from a reference position where the fluid does not hit the tapered portion of the tool holder to a position before the tool exchange is completed by the exchange mechanism, wherein the judgment step judges that the spindle head has reached the specific range, and the ejection control step executes a supply stop process of stopping the supply of the fluid to the nozzle by the supply means when it is judged that the spindle head has reached the specific range.

[0015] The above control method achieves the same effects as the numerical control device of claim 1.

[0016] The program of claim 8 further comprises a computer of a numerical control device that controls a machine tool including: a tool magazine that stores a tool holder that holds a tool; a spindle that is an axis having an attachment hole into which a tapered portion of the tool holder fits and extends in a specific direction; a spindle head that rotatably supports the spindle; a tool exchange mechanism that performs tool exchange to exchange a current tool held by the tool holder attached to the spindle with a next tool held by the tool holder stored in the tool magazine; a nozzle that is provided in the spindle head and sprays a fluid toward the tool holder of the next tool; and a supply means that supplies the fluid to the nozzle, the computer causing the computer to program the computer to control the machine tool by the tool exchange mechanism to spray a fluid toward the spindle so that the tapered portion of the tool holder fits into the attachment hole. the nozzle is caused to eject the fluid toward the tool holder having the next tool attached thereto by a nozzle ejection control step of ejecting the fluid from the nozzle toward the tool holder having the next tool attached thereto by supplying the fluid to the nozzle by the supply means during the relative movement by the movement control step; and a judgment step of judging whether the spindle head has reached a specific range from a reference position where the fluid does not hit the tapered portion of the tool holder to a position before the tool exchange by the exchange mechanism is completed, and the jetting control step is characterized in that, when it is judged in the judgment step that the spindle head has reached the specific range, a supply stop process is executed to stop the supply of the fluid to the nozzle by the supply means.

[0017] The above program achieves the same effects as the numerical control device of claim 1.

[0018] The storage medium of claim 9 is a storage medium for storing ... a storage medium having stored therein a program for executing a movement control step of performing relative movement in the specific direction; an ejection control step of supplying the fluid to the nozzle by the supply means during the relative movement by the movement control step, thereby ejecting the fluid from the nozzle toward the tool holder to which the next tool is attached; and a judgment step of judging whether the spindle head has reached a specific range from a reference position where the fluid does not hit the tapered portion of the tool holder to a position before the tool exchange by the exchange mechanism is completed, wherein the ejection control step is characterized in that, when it is judged in the judgment step that the spindle head has reached the specific range, a supply stop process is executed to stop the supply of the fluid to the nozzle by the supply means.

[0019] The storage medium described above provides the same effects as the numerical control device of claim 1. [Brief description of the drawings]

[0020] [Figure 1] FIG. [Diagram 2] FIG. 2 is an enlarged view of the spindle head 7 and the replacement mechanism 20. [Diagram 3] FIG. 4 is an enlarged view of the lower end portion of the spindle head 7. [Figure 4] FIG. 2 is a block diagram showing the electrical configuration of the machine tool 1. [Diagram 5] 13 is a flowchart of a main process. [Figure 6] FIG. 2 is a diagram showing a state in which the spindle head 7 is positioned at the ATC origin P4. [Figure 7] FIG. 4 is a diagram showing a state in which the spindle head 7 is located at a reference position P3. [Figure 8] FIG. 4 is a diagram showing a state in which the spindle head 7 is located at a contact position P2. [Figure 9] 4 is a diagram showing a state in which the spindle head 7 is positioned at the Z-axis origin P1. FIG. [Figure 10] FIG. 4 is a diagram showing the Z position of the spindle head 7 versus time during tool replacement. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] An embodiment of the present invention will be described with reference to the drawings. In the following description, the up / down, left / right, and front / rear directions shown by arrows in the drawings will be used. The left / right direction, front / rear direction, and up / down direction of the machine tool 1 are the X-axis direction, Y-axis direction, and Z-axis direction of the machine tool 1, respectively. The orientation of the exchange mechanism 20 also follows this pattern.

[0022] The structure of the machine tool 1 will be described with reference to FIG. 1. The machine tool 1 includes a base 2, a machine body 3, a table 10, and an exchange mechanism 20. The base 2 is an iron base in the shape of a substantially rectangular parallelepiped. The machine body 3 is provided at the rear of the upper part of the base 2, and cuts a workpiece (not shown) held on the upper surface of the table 10. The table 10 is provided at the center of the upper part of the base 2, and can be moved in the X-axis direction and the Y-axis direction by an X-axis motor 46, a Y-axis motor 43, and a guide mechanism (not shown) shown in FIG. 4. The exchange mechanism 20 is fixed to a frame 8 provided on the upper part of the machine body 3. The exchange mechanism 20 performs a tool exchange to exchange a current tool 4A with a next tool 4B. The current tool 4A is a tool held by a tool holder 17 attached to a spindle 9. The next tool 4B is a tool held by a tool holder 17 stored in a tool magazine 21 described later.

[0023] The configuration of the machine body 3 will be described with reference to Figures 1 and 2. As shown in Figure 1, the machine body 3 includes a column 5, a spindle head 7, and a spindle 9. The column 5 stands on the rear of the upper part of the base 2, and supports the spindle head 7 so that it can rise and fall in the Z-axis direction.

[0024] As shown in FIG. 2, a Z-axis moving mechanism 11 is provided on the front side of the column 5. The Z-axis moving mechanism 11 moves the spindle head 7 in the Z-axis direction. The Z-axis moving mechanism 11 includes a pair of Z-axis linear guides (not shown), a Z-axis ball screw 26, and a Z-axis motor 49 (see FIG. 4). The Z-axis linear guide extends in the Z-axis direction and guides the spindle head 7 in the Z-axis direction. The Z-axis ball screw 26 is disposed between the pair of Z-axis linear guides and is rotatably provided by an upper bearing portion 27 and a lower bearing portion (not shown). The spindle head 7 includes a nut 29 on the back side. The nut 29 is screwed into the Z-axis ball screw 26. The Z-axis motor 49 rotates the Z-axis ball screw 26 in the forward and reverse directions. Therefore, the spindle head 7 moves in the Z-axis direction together with the nut 29.

[0025] The spindle head 7 rotatably supports the spindle 9 therein. The spindle 9 extends in the Z-axis direction. The spindle 9 has a rotation axis extending in the Z-axis direction. The spindle 9 is connected to the drive shaft of the spindle motor 52 via a coupling 23. The spindle motor 52 is provided on the top of the spindle head 7. The spindle 9 is rotated by the drive of the spindle motor 52. The spindle 9 has a mounting hole 18, a holder clamping member 19, and a draw bar 69. The mounting hole 18 is provided at the lower end of the spindle 9. The mounting hole 18 is approximately conical. A tool holder 17 is attached to the mounting hole 18 of the spindle 9. The holder clamping member 19 is provided above the mounting hole 18. The draw bar 69 is inserted coaxially into an axial hole that passes through the center of the spindle 9.

[0026] Tool holder 17 holds tool 4 at one end, and is equipped with tapered portion 17A and pull stud 17B at the other end. Tapered portion 17A is generally conical. Pull stud 17B protrudes in the axial direction from the top of tapered portion 17A. Tapered portion 17A fits into mounting hole 18 of spindle 9.

[0027] The spindle head 7 is provided with a crank lever 60 on the inside of its upper rear part. The crank lever 60 extends in the front-rear direction and rotates around a support shaft 61 in a side view. The support shaft 61 extends in the left-right direction and is fixed inside the spindle head 7. The front end of the crank lever 60 can engage with a pin 58 from above. The pin 58 protrudes in the left-right direction from a draw bar 69. When viewed from the right side, a tension coil spring (not shown) constantly urges the crank lever 60 clockwise. Therefore, the crank lever 60 constantly releases the downward pressure on the pin 58.

[0028] As shown in FIG. 3, the spindle head 7 is provided with a plurality of nozzles 15 on its lower end surface and around the opening of the mounting hole 18. For example, the left nozzle 15 opens from the left front direction toward the rear lower direction. The spraying direction D1 of the cleaning liquid is approximately the same as the opening direction of the left nozzle 15. For example, the right nozzle 15 opens from the top rear direction toward the front lower direction. The spraying direction D2 of the cleaning liquid is approximately the same as the opening direction of the right nozzle 15. The multiple nozzles 15 spray the cleaning liquid toward the cleaning position Pw by the supply means 37 (see FIG. 4). The cleaning position Pw is the intersection of the spraying directions D1 and D2 of the cleaning liquid. The cleaning position Pw is located below the opening of the mounting hole 18 and on the rotation center of the spindle 9.

[0029] The configuration of the replacement mechanism 20 will be described with reference to Figures 1 and 2. The replacement mechanism 20 includes a tool magazine 21 and a magazine support stand 45. The tool magazine 21 houses tool holders 17 that hold tools 4. The tool magazine 21 includes a magazine body 71 and a plurality of grip arms 90. The magazine body 71 is disk-shaped. The plurality of grip arms 90 are arranged at predetermined intervals on the outer periphery of the magazine body 71. The grip arms 90 are provided so as to be swingable in the front-rear direction of the tool magazine 21 around an axis 931. The gripping portions 92 of the grip arms 90 grip the tool holders 17 from both the left and right sides.

[0030] The magazine support base 45 is fixed to the frame 8. The magazine support base 45 rotatably supports a support shaft 75. The support shaft 75 extends diagonally downward relative to the front of the machine tool 1. The magazine body 71 is arranged facing forward relative to the front of the machine tool 1. The magazine body 71 rotates about the support shaft 75 by being driven by the magazine motor 55. Therefore, the magazine body 71 moves the grip arm 90 holding the next tool 4B for tool change to the tool change position Px (see Figures 6 and 7). When the grip arm 90 is located at the tool change position Px, the gripping portion 92 is located below the mounting hole 18.

[0031] The electrical configuration of machine tool 1 will be described with reference to Fig. 4. Machine tool 1 includes numerical control device 30, spindle motor 52, X-axis motor 46, Y-axis motor 43, Z-axis motor 49, magazine motor 55, drive circuits 152, 146, 143, 149, 155, encoders 52A, 46A, 43A, 49A, 55A, operation panel 25, supply means 37, etc.

[0032] The numerical control device 30 includes a CPU 31, a ROM 32, a RAM 33, a storage device 34, an interface 36, etc. The CPU 31 controls the machine tool 1. The CPU 31 is connected to the interface 36, drive circuits 152, 146, 143, 149, 155, supply means 37, etc. The ROM 32 stores various programs and the like. The RAM 33 temporarily stores various data. The storage device 34 is, for example, a non-volatile memory, and stores NC programs and the like. The interface 36 is connected to the operation panel 25.

[0033] Each of the motors 52, 46, 43, 49, and 55 is a servo motor. The spindle motor 52 rotates the spindle 9. The X-axis motor 46, the Y-axis motor 43, and the Z-axis motor 49 relatively move the workpiece and the spindle 9 in the X-axis, Y-axis, and Z-axis directions. The drive circuits 152, 146, 143, 149, and 155 control the motors 52, 46, 43, 49, and 55, respectively, based on control signals from the CPU 31.

[0034] The encoders 52A, 46A, 43A, 49A, and 55A detect the rotational positions of the motors 52, 46, 43, 49, and 55, respectively. The encoders 52A, 46A, 43A, 49A, and 55A transmit the detected rotational positions to the drive circuits 152, 146, 143, 149, and 155, respectively. The drive circuits 152, 146, 143, 149, and 155 feedback-control the motors 52, 46, 43, 49, and 55 based on the received rotational positions. For example, the CPU 31 can detect the Z positions of the spindle head 7, such as the Z-axis origin P1 (see FIG. 9) and the ATC origin P4 (see FIG. 6), by detecting the rotational position of the encoder 49A. The Z position of the spindle head 7 is defined at the bottom end of the spindle head 7. The same applies to a contact position P2 (see FIG. 8) and a reference position P3 (see FIG. 7) described below.

[0035] The operation panel 25 is capable of displaying and inputting various information. The supply means 37 supplies the cleaning liquid to the nozzle 15. The supply means 37 includes a compressor 371, a valve 372, and the like. The compressor 371 pressurizes a container that stores the cleaning liquid. When the valve 372 is released in this state, the cleaning liquid is supplied from the container to the nozzle 15 via a flow path (not shown). Therefore, the nozzle 15 sprays the cleaning liquid toward the cleaning position Pw. The CPU 31 controls the valve 372 to control the supply of the cleaning liquid to the nozzle 15.

[0036] The main processing will be described with reference to FIG. 5. In the following description, FIGS. 6 to 9 will be referred to as drawings corresponding to the processing of S21 to S25. Drawings corresponding to the processing of S11 to S13 will be omitted. For example, when a tool change command is received in the analysis of one block of an NC program, the CPU 31 executes the main processing. For example, as shown in FIG. 2, the main processing starts with the spindle 9 holding the current tool 4A. In FIG. 10, time t0 indicates the start time of the main processing. That is, time t0 is the time when the tool change command is received, and the spindle head 7 is located below the Z-axis origin P1. Note that when the tool change command is received, the spindle head 7 may be located at the Z-axis origin P1.

[0037] The CPU 31 controls the Z-axis movement mechanism 11 to move the spindle head 7 together with the current tool 4A from the position at the start of the main process to the Z-axis origin P1 (S11). In Fig. 10, the spindle head 7 moves from the position at the start of the main process to the Z-axis origin P1 during the period from time t0 to t1. The spindle head 7 is located at the Z-axis origin P1 from time t1 to t2, for example.

[0038] The CPU 31 controls the Z-axis moving mechanism 11 to move the spindle head 7 from the Z-axis origin P1 to the ATC origin P4 (S12). At that time, when FIG. 2 is viewed from the right side, as the spindle head 7 moves upward, the crank lever 60 rotates counterclockwise around the support shaft 61 by a cam mechanism or the like. The front end of the crank lever 60 engages with the pin 58 from above and presses the draw bar 69 downward. The draw bar 69 urges the holder clamping member 19 downward. The holder clamping member 19 releases the clamping of the pull stud 17B of the tool holder 17. Therefore, the tool holder 17 holding the current tool 4A is unclamped from the spindle 9. Therefore, the tool holder 17 holding the current tool 4A is removed from the spindle 9. In FIG. 10, the spindle head 7 moves from the Z-axis origin P1 to the ATC origin P4 during the period from time t2 to t3. The CPU 31 controls the supplying means 37 to start supplying the cleaning liquid to the nozzle 15 (S12). In FIG. 10, the start time of supplying the cleaning liquid is any one of times t2 to t4. That is, the CPU 31 supplies the cleaning liquid to the nozzle 15 by the supplying means 37, so that the cleaning liquid is sprayed from the nozzle 15 toward the cleaning position Pw. The CPU 31 cleans the tool holder 17 held by the grip arm 90 at the tool changing position Px (see FIG. 6 and FIG. 7). Note that the spindle head 7 is located at the ATC origin P4 from time t3 to t4, for example.

[0039] The CPU 31 rotates the magazine body 71 so that the grip arm 90 gripping the next tool 4B is located at the tool changing position Px (see FIG. 6) (S13). As shown in FIG. 6, the tool holder 17 to which the next tool 4B is attached is located below the spindle 9. In FIG. 10, the rotation of the magazine body 71 is performed during the period from time t3 to t4.

[0040] The CPU 31 controls the Z-axis movement mechanism 11 to start moving the spindle head 7 from the ATC origin P4 (see FIG. 6) toward the Z-axis origin P1 (see FIG. 9) (S21). That is, the CPU 31 moves the spindle head 7 in the Z-axis direction toward the next tool 4B so that the tapered portion 17A of the tool holder 17 fits into the mounting hole 18. The supply means 37 continues to supply the cleaning liquid to the nozzle 15. As the spindle head 7 moves, the tool holder 17 to which the next tool 4B is attached passes through the cleaning position Pw. Therefore, the CPU 31 cleans the tapered portion 17A of the tool holder 17 that passes through the cleaning position Pw.

[0041] The spindle head 7 shown in FIG. 7 is in a reference position P3, which is a reference for the completion of cleaning of the tapered portion 17A of the tool holder 17. In other words, the reference position P3 is a position where the cleaning liquid does not hit the tapered portion 17A. The reference position P3 of the spindle head 7 is a position where the opening direction of the multiple nozzles 15, i.e., the ejection directions D1 and D2, intersect with the lower end of the tapered portion 17A. When the spindle head 7 is in the reference position P3, the tapered portion 17A of the tool holder 17 and the mounting hole 18 are not in contact. In FIG. 10, the reference position P3 of the spindle head 7 is a position corresponding to time t5.

[0042] The CPU 31 judges whether the spindle head 7 moving toward the Z-axis origin P1 has reached contact position P2 (see FIG. 8) (S22). The CPU 31 detects contact position P2 of the spindle head 7 based on the detection result of the encoder 49A. Contact position P2 is the position where the tapered portion 17A of the tool holder 17 to which the next tool 4B is attached contacts the mounting hole 18. Contact position P2 is the position from the completion of cleaning of the tapered portion 17A of the tool holder 17 to the completion of tool replacement. In detail, contact position P2 is the position immediately after the spindle head 7 passes through reference position P3 (see FIG. 7). Note that in FIG. 10, contact position P2 of the spindle head 7 is the position corresponding to time t6.

[0043] When it is determined that the contact position P2 has not been reached (S22: NO), the CPU 31 returns to the process and continues moving the spindle head 7 to the Z-axis origin P1.

[0044] When it is determined that the contact position P2 has been reached (S22: YES), that is, when the encoder 49A detects the contact position P2, the CPU 31 stops the supply of cleaning liquid to the nozzle 15 by the supply means 37 (S23). At that time, the nozzle 15 stops spraying cleaning liquid. The CPU 31 continues to move the spindle head 7 together with the next tool 4B toward the Z-axis origin P1. At that time, when viewed from the right side in FIG. 2, the crank lever 60 rotates clockwise around the support shaft 61 by a cam mechanism or the like as the spindle head 7 moves downward. Therefore, the front end of the crank lever 60 leaves the pin 58, and the downward pressure on the draw bar 69 is released. The draw bar 69 releases the downward bias of the holder clamping member 19, and the holder clamping member 19 clamps the pull stud 17B. The tool holder 17 to which the next tool 4B is attached is clamped to the spindle 9 before it reaches the Z-axis origin P1 (see times t6 to t7 in FIG. 10).

[0045] The CPU 31 judges whether the spindle head 7 has reached the Z-axis origin P1 (see FIG. 9) (S24). If it is judged that the Z-axis origin P1 has not been reached (S24: NO), the CPU 31 continues moving the spindle head 7 toward the Z-axis origin P1. If it is judged that the spindle head 7 has reached the Z-axis origin P1 (S24: YES), the CPU 31 stops the movement of the spindle head 7 (S25). This completes the tool change. Note that in FIG. 10, the spindle head 7 reaches the Z-axis origin P1 at time t7. The CPU 31 ends the process.

[0046] The CPU 31 executes the analysis of the next block and executes the machining of the workpiece, etc. When a tool change command is received again, the CPU 31 executes the above-mentioned main process.

[0047] As described above, the CPU 31 judges whether the spindle head 7 has reached the contact position P2, which is the position before the completion of tool change, from the reference position P3 where the cleaning liquid does not hit the tapered portion 17A of the tool holder 17. When the CPU 31 judges that the spindle head 7 has reached the contact position P2, it stops the supply of cleaning liquid to the nozzle 15 by the supply means 37.

[0048] The numerical control device 30 stops the supply of cleaning liquid to the nozzle 15 by the supply means 37 at the contact position P2, thereby preventing the cleaning liquid from being sprayed onto portions other than the tapered portion 17A of the tool holder 17. Therefore, the numerical control device 30 can maintain the ability to clean the tapered portion 17A of the tool holder 17 and prevent the consumption of cleaning liquid for cleaning the tool holder 17.

[0049] The machine tool 1 is equipped with an encoder 49A that detects the position of the spindle head 7. The CPU 31 judges whether the spindle head 7 has reached contact position P2 based on the detection result by the encoder 49A. Since the numerical control device 30 detects the spindle head 7 by the encoder 49A, it can detect the position of the spindle head 7 more accurately than in the case of judging from the elapsed time. Since the numerical control device 30 only needs to stop the supply of cleaning liquid to the nozzle 15 when the tapered portion 17A abuts against the mounting hole 18, it is easy to control the timing to stop the supply of cleaning liquid.

[0050] The machine tool 1 includes a Z-axis moving mechanism 11 that moves the spindle head 7 in the Z-axis direction. The CPU 31 controls the Z-axis moving mechanism 11 to move the spindle head 7 in the Z-axis direction toward the next tool 4B. The numerical control device 30 maintains the ability to clean the tapered portion 17A of the tool holder 17 and can reduce consumption of cleaning fluid for cleaning the tool holder 17 even in the machine tool 1 that moves the spindle head 7 in the Z-axis direction to change tools.

[0051] The machine tool 1 is equipped with a Z-axis motor 49 that moves the spindle head 7 in the Z-axis direction. An encoder 49A detects the rotational position of the Z-axis motor 49. The numerical control device 30 can detect the contact position P2 based on the detection result of the encoder 49A.

[0052] The present invention can be modified in various ways in addition to the above embodiment. The modified examples described below may be combined to the extent that no contradiction occurs. The above embodiment is a vertical machine tool in which the Z-axis direction is vertical, but this is not limited to this. The machine tool 1 may be a horizontal machine tool in which the spindle 9 extends horizontally. The above machine tool 1 has the spindle head 7 move to change tools, but this is not limited to this. For example, the spindle head 7 may not move, but a swivel-type double arm may move to change tools. In this case, the double arm corresponds to the change mechanism of the present invention. The CPU 31 may move the spindle head 7 and the tool holder 17 relative to each other. The CPU 31 may detect the relative position of the spindle head 7 and the tool holder 17 based on the detection result of the encoder 49A.

[0053] In the above embodiment, cleaning liquid is sprayed from nozzle 15 to clean tool holder 17, but the present invention is not limited to this. Tool holder 17 may be cleaned by spraying a fluid such as air instead of cleaning liquid. Machine tool 1 may further include a mechanism for spraying air toward tool holder 17. At this time, machine tool 1 may clean tool holder 17 with cleaning liquid and air. In this case, the present invention can reduce air consumption.

[0054] In the above embodiment, the position of the spindle head 7 is detected by the encoder 49A, but this is not limited to the above. Instead of the encoder 49A, a limit switch may be used to detect the contact position P2. Also, instead of the encoder 49A, a pressure sensor may be used to detect fluctuations in pressure inside the mounting hole 18 to detect the contact position P2.

[0055] In the above embodiment, the CPU 31 stops the supply of the cleaning liquid at the contact position P2 of the spindle head 7, but this is not limited thereto. For example, the CPU 31 may stop the supply of the cleaning liquid at the reference position P3 shown in FIG. 7. The CPU 31 may detect the reference position P3 based on the detection result of the encoder 49A. The CPU 31 may also stop the supply of the cleaning liquid before the spindle head 7 reaches the Z-axis origin P1, that is, before the tool change is completed. The CPU 31 may stop the supply of the cleaning liquid to the nozzle 15 when the spindle head 7 reaches within a specific range from the reference position P3 to the Z-axis origin P1 (excluding the Z-axis origin P1). In FIG. 10, the Z position of the spindle head 7 corresponds to the position from t5 to t7 (excluding time t7).

[0056] In the above embodiment, the CPU 31 detects the contact position P2 of the spindle head 7 based on the detection result from the encoder 49A, but this is not limited to the above. For example, the CPU 31 may detect the contact position P2 of the spindle head 7 based on the elapsed time since the tool change. For example, the CPU 31 may detect the time t6 corresponding to the contact position P2 of the spindle head 7 with reference to FIG. 10. The CPU 31 may detect the time t5 corresponding to the reference position P3 of the spindle head 7 instead of the contact position P2, and stop the supply of the cleaning liquid to the nozzle 15. The CPU 31 may determine whether the spindle head 7 has reached a specific range based on whether the elapsed time since the tool change has reached the range from time t5 to t7 (excluding time t7). At that time, the CPU 31 may stop the supply of the cleaning liquid to the nozzle 15 in the range from time t5 to t7 (excluding time t7). Since the numerical control device 30 only needs to determine the elapsed time, there is no need to provide a separate sensor for detecting the Z position of the spindle head 7. The numerical control device 30 only needs to check the elapsed time since the tool change, and therefore it is easy to control the timing for stopping the supply of the cleaning liquid.

[0057] In the above embodiment, the supply of the cleaning liquid to the nozzle 15 is started at any time during the period from time t2 to time t4 when the tool is replaced, but this is not limited thereto. For example, the CPU 31 may start the supply of the cleaning liquid to the nozzle 15 at or after time t4.

[0058] In the above embodiment, the CPU 31 executes the main process when executing a tool change command of the NC program, but this is not limited to the above. For example, the user may operate the operation panel 25 to command a tool change. At that time, the CPU 31 executes the above main process.

[0059] Instead of CPU 31, a CPU, ASIC, FPGA (Field Programmable Gate Array), etc. may be used as a processor. The main processing may be distributed among multiple processors. Machine tool 1 may include other non-transitory storage media, such as a HDD. The non-transitory storage medium may be any storage medium capable of retaining information regardless of the period for which the information is stored. The non-transitory storage medium does not have to include a temporary storage medium (e.g., a transmitted signal).

[0060] The various programs may be downloaded (i.e., transmitted as a transmission signal) from a server connected to a network (not shown) and stored in a memory such as a HDD. In this case, the various programs may be stored in a non-transitory storage medium such as a HDD provided in the server.

[0061] In the above explanation, the cleaning liquid and air are examples of the fluid of the present invention. The Z-axis direction is an example of a specific direction of the present invention. Encoder 49A is an example of a detection unit of the present invention. Z-axis moving mechanism 11 is an example of a moving mechanism of the present invention. Z-axis motor 49 is an example of a motor of the present invention. The range from reference position P3 to Z-axis origin P1 (excluding Z-axis origin P1) is an example of a specific range of the present invention. The processing of S21 executed by CPU 31 is an example of a movement control unit of the present invention. The processing of S12 executed by CPU 31 is an example of a jetting control unit of the present invention. The processing of S23 executed by CPU 31 is an example of a supply stop processing of the present invention. [Explanation of symbols]

[0062] 1 Machine tools 4, 4A, 4B tools 7 Spindle Head 9 Main shaft 11 Z-axis movement mechanism 15 Nozzles 17 Tool holder 17A Tapered section 18 Mounting holes 20 Exchange mechanism 21 Tool Magazine 30 Numerical Control Device 31 CPU 37 Means of supply 49 Z-axis motor 49A Encoder P3 reference position

Claims

1. a tool magazine that stores tool holders that hold tools; a spindle having an attachment hole into which the tapered portion of the tool holder fits and extending in a specific direction; a spindle head that rotatably supports the spindle; a tool changing mechanism for changing a current tool held by the tool holder attached to the spindle with a next tool held by the tool holder stored in the tool magazine; a nozzle provided on the spindle head for ejecting a fluid toward the tool holder of the next tool; A supply means for supplying the fluid to the nozzle; A numerical control device for controlling a machine tool comprising: a movement control unit that relatively moves the spindle head and the next tool in the specific direction so that the tapered portion of the tool holder fits into the mounting hole when the tool is replaced by the replacement mechanism; a jetting control unit that supplies the fluid to the nozzle by the supplying means during the relative movement by the movement control unit, thereby jetting the fluid from the nozzle toward the tool holder to which the next tool is attached; a determination unit that determines whether or not the spindle head has reached a specific range from a reference position where the fluid does not hit the tapered portion of the tool holder to a position before the tool exchange is completed by the exchange mechanism; Equipped with The jetting control unit executes a supply stop process to stop the supply of the fluid to the nozzle by the supply means when the determination unit determines that the spindle head has reached the specific range. A numerical control device comprising:

2. the machine tool includes a detection unit that detects a relative position between the spindle head and the tool holder of the next tool, The determination unit determines whether the spindle head has reached the specific range based on a detection result by the detection unit.

2. The numerical control device according to claim 1 .

3. The machine tool includes a movement mechanism that moves the spindle head in the specific direction, The movement control unit controls the movement mechanism to move the spindle head toward the next tool in the specific direction.

3. The numerical control device according to claim 2 .

4. the moving mechanism includes a motor that moves the spindle head in the specific direction, The detection unit is an encoder that detects the rotational position of the motor.

4. The numerical control device according to claim 3 .

5. The determination unit determines whether the spindle head has reached the specific range based on an elapsed time since the tool change.

2. The numerical control device according to claim 1 .

6. a tool magazine that stores tool holders that hold tools; a spindle having an attachment hole into which the tapered portion of the tool holder fits and extending in a specific direction; a spindle head that rotatably supports the spindle; a tool changing mechanism for changing a current tool held by the tool holder attached to the spindle with a next tool held by the tool holder stored in the tool magazine; a nozzle provided on the spindle head for ejecting a fluid toward the tool holder of the next tool; A supply means for supplying the fluid to the nozzle; In a machine tool equipped with a movement control unit that relatively moves the spindle head and the next tool in the specific direction so that the tapered portion of the tool holder fits into the mounting hole when the tool is replaced by the replacement mechanism; a jetting control unit that supplies the fluid to the nozzle by the supplying means during the relative movement by the movement control unit, thereby jetting the fluid from the nozzle toward the tool holder to which the next tool is attached; a determination unit that determines whether or not the spindle head has reached a specific range from a reference position where the fluid does not hit the tapered portion of the tool holder to a position before the tool exchange is completed by the exchange mechanism; Equipped with The jetting control unit executes a supply stop process to stop the supply of the fluid to the nozzle by the supply means when the determination unit determines that the spindle head has reached the specific range. A machine tool characterized by:

7. a tool magazine that stores tool holders that hold tools; a spindle having an attachment hole into which the tapered portion of the tool holder fits and extending in a specific direction; a spindle head that rotatably supports the spindle; a tool changing mechanism for changing a current tool held by the tool holder attached to the spindle with a next tool held by the tool holder stored in the tool magazine; a nozzle provided on the spindle head for ejecting a fluid toward the tool holder of the next tool; A supply means for supplying the fluid to the nozzle; A method for controlling a numerical control device for controlling a machine tool comprising: a movement control step of relatively moving the spindle head and the next tool in the specific direction so that the tapered portion of the tool holder fits into the mounting hole when the tool is replaced by the replacement mechanism; a jetting control step of supplying the fluid to the nozzle by the supplying means during the relative movement in the movement control step, thereby jetting the fluid from the nozzle toward the tool holder to which the next tool is attached; a determining step of determining whether or not the spindle head has reached a specific range from a reference position where the fluid does not hit the tapered portion of the tool holder to a position before the tool exchange is completed by the exchange mechanism; Equipped with The jetting control step executes a supply stop process for stopping the supply of the fluid to the nozzle by the supply means when it is determined in the determination step that the spindle head has reached the specific range. A control method comprising:

8. a tool magazine that stores tool holders that hold tools; a spindle having an attachment hole into which the tapered portion of the tool holder fits and extending in a specific direction; a spindle head that rotatably supports the spindle; a tool changing mechanism for changing a current tool held by the tool holder attached to the spindle with a next tool held by the tool holder stored in the tool magazine; a nozzle provided on the spindle head for ejecting a fluid toward the tool holder of the next tool; a supply means for supplying the fluid to the nozzle; A computer of a numerical control device that controls a machine tool having the a movement control step of relatively moving the spindle head and the next tool in the specific direction so that the tapered portion of the tool holder fits into the mounting hole when the tool is replaced by the replacement mechanism; a jetting control step of supplying the fluid to the nozzle by the supplying means during the relative movement in the movement control step, thereby jetting the fluid from the nozzle toward the tool holder to which the next tool is attached; a determining step of determining whether or not the spindle head has reached a specific range from a reference position where the fluid does not hit the tapered portion of the tool holder to a position before the tool exchange is completed by the exchange mechanism; Run the command, The jetting control step executes a supply stop process for stopping the supply of the fluid to the nozzle by the supply means when it is determined in the determination step that the spindle head has reached the specific range. A program characterized by:

9. a tool magazine that stores tool holders that hold tools; a spindle having an attachment hole into which the tapered portion of the tool holder fits and extending in a specific direction; a spindle head that rotatably supports the spindle; a tool changing mechanism for changing a current tool held by the tool holder attached to the spindle with a next tool held by the tool holder stored in the tool magazine; a nozzle provided on the spindle head for ejecting a fluid toward the tool holder of the next tool; a supply means for supplying the fluid to the nozzle; A computer of a numerical control device that controls a machine tool having the a movement control step of relatively moving the spindle head and the next tool in the specific direction so that the tapered portion of the tool holder fits into the mounting hole when the tool is replaced by the replacement mechanism; a jetting control step of supplying the fluid to the nozzle by the supplying means during the relative movement in the movement control step, thereby jetting the fluid from the nozzle toward the tool holder to which the next tool is attached; a determining step of determining whether or not the spindle head has reached a specific range from a reference position where the fluid does not hit the tapered portion of the tool holder to a position before the tool exchange is completed by the exchange mechanism; A storage medium storing a program for executing the following: The jetting control step executes a supply stop process for stopping the supply of the fluid to the nozzle by the supply means when it is determined in the determination step that the spindle head has reached the specific range. A storage medium comprising:

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