Machine tool, control method, and program

Abstract

To provide a machine tool, a control method, a program, etc., capable of preventing collision of a shutter with a main spindle head while reducing cost.SOLUTION: The machine tool is configured such that a control unit determines, before transmission of the other moving command of an opening command and a closing command to a moving mechanism after transmission of one moving command of the opening command and the closing command to the moving mechanism, whether the target position of a shutter when one of the moving commands is executed corresponds to the detection result of a sensor, and notifies an abnormality when it determines no correspondence.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This technology relates to machine tools, control methods, and programs.

Background Art

[0002] Conventionally, a control system for an ATC shutter (shutter) provided in a machine tool has been disclosed. The control system described in Patent Document 1 controls an ATC shutter that opens and closes at the entrance of a machining chamber in order to exchange a tool gripped by a rotating arm between the inside and the outside of the machining chamber. The control system described in Patent Document 1 drives the rotating arm by signals based on limit switches provided at positions corresponding to the start and end of ATC shutter opening, respectively, to avoid a collision between the rotating arm and the ATC shutter.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The control system described in Patent Document 1 requires a detection mechanism (limit switch) for the positions of two ATC shutters, which increases the cost for realizing the system.

[0005] In view of such circumstances, the present disclosure has been made, and an object thereof is to provide a machine tool, a control method, a program, etc. that can prevent a collision between a shutter and a spindle head while reducing costs.

Means for Solving the Problems

[0006] A machine tool according to one embodiment of the present disclosure comprises a spindle head that detachably holds a tool for machining a workpiece, a tool changer for changing the tool held by the spindle head, a cover that covers the tool changer and has an opening, a shutter that is movable between an open position that opens the opening and a closed position that closes the opening, a sensor capable of detecting whether the shutter is in the open position or the closed position, a movement mechanism that moves the shutter to the open position when an open command is received and moves the shutter to the closed position when a close command is received, and a control unit that transmits a movement command including the open command or the close command to the movement mechanism, wherein the control unit, after transmitting the movement command of either the open command or the close command to the movement mechanism, and before transmitting the other movement command of the open command or the close command to the movement mechanism, determines whether the target position of the shutter when one of the movement commands is executed corresponds to the detection result by the sensor, and notifies an abnormality if it determines that they do not correspond.

[0007] In this disclosure, the machine tool can detect the opening and closing of the shutter using only one detection mechanism (sensor), and if a sensor malfunction occurs, it can notify the abnormality and stop the movement of the spindle head, thereby reducing costs and preventing collisions between the shutter and the spindle head.

[0008] A machine tool according to one embodiment of the present disclosure includes a moving mechanism comprising: an air cylinder that moves the shutter to the open position when air is supplied to one end and moves the shutter to the closed position when air is supplied to the other end; an open valve that supplies air to the one end when the moving mechanism receives the open command; and a closed valve that supplies air to the other end when the moving mechanism receives the closed command.

[0009] In this disclosure, the shutter can be moved using air supplied based on a movement command transmitted from the control unit as the power source.

[0010] In one embodiment of the present disclosure, the machine tool is capable of detecting when the shutter is in the open position, one of the movement commands is the closing command and the other movement command is the opening command, and the control unit notifies of an abnormality if the sensor has detected that the shutter is in the open position before transmitting the opening command to the movement mechanism.

[0011] In this disclosure, the machine tool can stop the movement of the spindle head when the sensor detects that the shutter is in the open position, in cases where the shutter should not be in the open position, thereby preventing a collision between the shutter and the spindle head.

[0012] In one embodiment of the present disclosure, the machine tool is capable of detecting when the shutter is in the closed position, one of the movement commands is the closing command, and the other of the movement commands is the opening command, and the control unit notifies of an abnormality if the sensor has not detected that the shutter is in the closed position before transmitting the opening command to the movement mechanism.

[0013] In this disclosure, the machine tool can stop the movement of the spindle head when the shutter should be in the closed position, but the sensor does not detect that the shutter is in the closed position, thereby preventing a collision between the shutter and the spindle head.

[0014] In one embodiment of the present disclosure, the machine tool is capable of detecting when the shutter is in the open position, one of the movement commands is the open command, and the other of the movement commands is the close command, and the control unit notifies of an abnormality if the sensor has not detected that the shutter is in the open position before transmitting the close command to the movement mechanism.

[0015] In this disclosure, the machine tool can stop the movement of the spindle head when the shutter should be in the open position, but the sensor does not detect that the shutter is in the open position, thereby preventing a collision between the shutter and the spindle head.

[0016] In one embodiment of the present disclosure, the machine tool is capable of detecting when the shutter is in the closed position, one of the movement commands is the open command, and the other of the movement commands is the closed command, and the control unit notifies of an abnormality when the sensor detects that the shutter is in the closed position before transmitting the closed command to the movement mechanism.

[0017] In this disclosure, the machine tool can stop the movement of the spindle head when the sensor detects that the shutter is in the closed position, in cases where the shutter should not be in the closed position, thereby preventing a collision between the shutter and the spindle head.

[0018] In one embodiment of the present disclosure, the machine tool is configured such that the control unit reads a tool change command from a program to change the tool held in the spindle head, and then transmits a drive signal based on the tool change command. After reading the tool change command and before transmitting the drive signal, the control unit determines whether the target position of the shutter when one of the movement commands is executed corresponds to the detection result by the sensor.

[0019] In this disclosure, the machine tool can determine whether or not there is an abnormality before the spindle head begins to move through the opening.

[0020] In one embodiment of the present disclosure, the machine tool includes a control unit which, after a certain period of time has elapsed since transmitting the movement command to the movement mechanism, determines whether or not the detection result of the sensor has changed, and if it determines that there has been no change, it notifies of an abnormality.

[0021] In this disclosure, the machine tool is capable of notifying of an abnormality if it cannot detect that the moving mechanism has correctly executed the movement command.

[0022] A control method according to one embodiment of the present disclosure is a control method for a machine tool comprising: a spindle head that detachably holds a tool for machining a workpiece; a tool changer for changing the tool held by the spindle head; a cover that covers the tool changer and has an opening; a shutter that is movable between an open position that opens the opening and a closed position that closes the opening; a sensor capable of detecting whether the shutter is in the open position or the closed position; a movement mechanism that moves the shutter to the open position when an open command is received and moves the shutter to the closed position when a close command is received; and a control unit that transmits a movement command including the open command or the close command to the movement mechanism, wherein after transmitting the movement command of either the open command or the close command to the movement mechanism, and before transmitting the other movement command of the open command or the close command to the movement mechanism, it is determined whether the target position of the shutter when one of the movement commands is executed corresponds to the detection result by the sensor, and if it is determined that they do not correspond, an abnormality is reported.

[0023] In this disclosure, the machine tool is equipped with only one detection mechanism (sensor), which allows it to notify of an abnormality in the event of a sensor failure or other issue and stop the movement of the spindle head. This reduces costs while preventing collisions between the shutter and the spindle head.

[0024] A program according to an embodiment of the present disclosure controls a machine tool including a spindle head that detachably holds a tool for machining a workpiece, a tool changer that exchanges the tool to be held by the spindle head, a cover that covers the tool changer and has an opening, a shutter that is movable between an open position where the opening is open and a closed position where the opening is closed, a sensor that can detect either the shutter being in the open position or the closed position, a moving mechanism that moves the shutter to the open position when receiving an open command and moves the shutter to the closed position when receiving a close command, and a control unit that transmits a movement command including the open command or the close command to the moving mechanism. After transmitting either the open command or the close command of the movement command to the moving mechanism, before transmitting the other movement command of the open command or the close command to the moving mechanism, it is determined whether the target position of the shutter when one of the movement commands is executed corresponds to the detection result by the sensor, and when it is determined that they do not correspond, the computer is caused to execute a process of notifying an abnormality.

[0025] In the present disclosure, since the machine tool includes only one detection mechanism (sensor), when a failure of the sensor or the like occurs, an abnormality can be notified and the movement of the spindle head can be stopped, so that it is possible to prevent a collision between the shutter and the spindle head while reducing costs.

[0026] A computer-readable storage medium storing the above program is also novel and useful.

Effects of the Invention

[0027] In a machine tool according to an embodiment of the present disclosure, it is possible to prevent a collision between the shutter and the spindle head even when there is only one detection mechanism.

Brief Description of the Drawings

[0028] [Figure 1] It is a perspective view of the machine tool seen from the upper right front. [Figure 2] This is a perspective view of a machine tool seen from the front right and lower. [Figure 3] This is a perspective view of a machine tool, taken from the upper right rear, with the magazine cover omitted. [Figure 4] This is a right-side view of a machine tool, with the magazine cover omitted. [Figure 5] This is a cross-sectional view showing the inside of the magazine cover when the shutter is in the open position. [Figure 6] This is a cross-sectional view showing the inside of the magazine cover when the shutter is in the closed position. [Figure 7] This is an explanatory diagram showing the movement of the spindle during tool changes. [Figure 8] This is an explanatory diagram showing the movement of the spindle during tool changes. [Figure 9] This is a block diagram showing an example of a control device configuration. [Figure 10] This is a flowchart illustrating the processing of the control device according to Embodiment 1. [Figure 11] This is a cross-sectional view showing the inside of the magazine cover according to Embodiment 2. [Figure 12] This is a flowchart illustrating the processing of the control device according to Embodiment 2. [Modes for carrying out the invention]

[0029] (Embodiment 1) The machine tool and control device according to Embodiment 1 will be described below with reference to the drawings. In the following description, the directions shown in the figures (up, down, front, back, left, and right) will be used. The left and right direction of the machine tool 1 corresponds to the X-axis direction, the up and down direction corresponds to the Y-axis direction, and the front and back direction corresponds to the Z-axis direction. In this embodiment, "NC" is an abbreviation for "Numerical Control".

[0030] Figure 1 is a perspective view of machine tool 1 seen from the front upper right. Figure 2 is a perspective view of machine tool 1 seen from the front lower right. Figure 3 is a perspective view of machine tool 1 seen from the rear upper right, with the magazine cover omitted. Figure 4 is a right side view of machine tool 1, with the magazine cover omitted. In this embodiment, machine tool 1 is a column traverse type machine tool in which the spindle 7 extends in the front-rear direction and the column 5 moves in the X-axis and Z-axis directions. Machine tool 1 comprises a base 2, a column 5, an X-axis movement mechanism 11, a Z-axis movement mechanism 12, a Y-axis movement mechanism 13, a spindle head 6, a spindle 7 (see Figure 2), a control box 8, a rotary table 9, a tool changer 30 (see Figure 3), a magazine cover 10, etc.

[0031] The base 2 is a roughly rectangular iron base that is elongated in the Z-axis direction. The X-axis movement mechanism 11 is provided on the rear upper surface of the base 2 and supports the movable body 15 so that it can move in the X-axis direction. The Z-axis movement mechanism 12 is provided on the upper surface of the movable body 15. The Z-axis movement mechanism 12 supports the column 5 so that it can move in the Z-axis direction. The column 5 is an upright column that extends in the vertical direction. The column 5 has a vertically elongated rectangular through-hole 5A (see Figure 3) on its front surface. The through-hole 5A penetrates the column 5 in the front-to-back direction. The frame cover 20 is attached to the front of the column 5. The frame cover 20 is a vertically elongated rectangular frame when viewed from the front and covers the space between the column 5 and the spindle head 6 located in front of the column 5. The Y-axis movement mechanism 13 is provided on the front of the column 5 and supports the spindle head 6 so that it can move in the Y-axis direction. The X-axis movement mechanism 11, the Z-axis movement mechanism 12, and the Y-axis movement mechanism 13 each include, for example, a guide and a ball screw. Furthermore, the X-axis movement mechanism 11 is equipped with an X-axis motor 611 (see Figure 9), the Z-axis movement mechanism 12 is equipped with a Z-axis motor 612 (see Figure 9), and the Y-axis movement mechanism 13 is equipped with a Y-axis motor 613 (see Figure 9). In the following description, the X-axis motor 611, Z-axis motor 612, and Y-axis motor 613 will be collectively referred to as the spindle movement motor 61 (see Figure 9). The X-axis movement mechanism 11, Z-axis movement mechanism 12, and Y-axis movement mechanism 13 move the moving body 15, column 5, and spindle head 6 respectively along the guides using the power of the spindle movement motor 61, thereby moving the spindle head 6.

[0032] The spindle head 6 extends in the Z-axis direction and is provided to be movable in the Y-axis direction along the front surface of the column 5 by a Y-axis movement mechanism 13. The spindle head 6 is movable in the Y-axis direction between the machining area and the tool changing area (see Figures 4 and 7). The machining area is located in the space below the base 2 side of the Y-axis origin. The Y-axis origin is the position where the Y-axis machine coordinate is 0. The tool changing area is located in the space opposite to the machining area from the Y-axis origin (above). The machining area is the area where the workpiece W (see Figure 7) fixed to the rotary table 9 is machined. The tool changing area is the area where the tool is changed by the tool changing device 30. The tool changing area is located above the machining area in the Y-axis direction and overlaps with the machining area in the Z-axis direction.

[0033] The spindle head 6 is equipped with an upper cover 28 and a protective cover 85. The upper cover 28 is fixed to the rear end of the upper surface of the spindle head 6. The upper cover 28 is a metal plate that is roughly rectangular in shape when viewed from the front, and extends upward from the rear end of the upper surface of the spindle head 6. The protective cover 85 is fixed in a suspended state to the rear end of the lower surface of the spindle head 6. The protective cover 85 is equipped with multiple metal plates arranged in the vertical direction and telescopically extends and retracts in the vertical direction. The upper cover 28 moves up and down together with the spindle head 6, so as to constantly cover the area above the spindle head 6 on the front of the column 5. The protective cover 85 extends and retracts in the vertical direction in response to the vertical movement of the spindle head 6, so as to constantly cover the area below the spindle head 6 on the front of the column 5.

[0034] The spindle 7 is mounted within the spindle head 6 so as to extend in the Z-axis direction. The spindle head 6 rotatably supports the spindle 7. A motor holder 27 (see Figure 3) is fixed to the rear of the spindle head 6. The motor holder 27 extends rearward from the rear of the spindle head 6 and holds the spindle motor (not shown) inside. The motor holder 27 protrudes rearward from the through-hole 5A of the column 5. The output shaft of the spindle motor extends forward and is connected coaxially to the rear end of the spindle 7.

[0035] The spindle 7 is equipped with a tool mounting hole 40 and a holder holding member 19 (see Figure 7). The tool mounting hole 40 is located at the tip (front end) of the spindle 7. The tool mounting hole 40 is a substantially conical tool mounting hole that widens towards the tip of the spindle 7. The holder holding member 19 is located behind the tool mounting hole 40. A tool holder 90 (see Figure 7) is detachably mounted in the tool mounting hole 40. The tool holder 90 holds a tool 91 at one end and has a tapered portion and a pull stud 93 (see Figure 7) at the other end. The tapered portion is substantially conical and fits tightly into the tool mounting hole 40 of the spindle 7. The pull stud 93 protrudes axially from the top of the tapered portion. When the tapered portion is mounted in the tool mounting hole 40, the holder holding member 19 holds the pull stud 93, and the tool holder 90 is fixed to the spindle 7.

[0036] A pair of support members 17 and 18 are provided at the rear of the base 2. The support members 17 and 18 are spaced apart from each other in the left-right direction and extend upward, supporting the control box 8 from below. A control device 50 (see Figure 9) is housed inside the control box 8. The control device 50 is equipped with a CPU 51 and controls the operation of the machine tool 1. A fixed base 16 is provided on the front upper surface of the base 2. The rotary table 9 is fixed to the fixed base 16. The rotary table 9 is located in front of the spindle head 6. The rotary table 9 can rotate 360° around a rotation axis parallel to the Y-axis direction, with a workpiece W (see Figure 7) fixed to its upper surface with a jig (not shown).

[0037] A pair of support columns 21 and 22 are provided on the front upper surface of the base 2, on both the left and right sides. As shown in Figure 3, a connecting plate 23 is fixed between the upper parts of the support columns 21 and 22, which are opposite each other. The tool changer 30 is fixed to the front of the connecting plate 23. The tool changer 30 is positioned between the column 5 and the rotary table 9 and above the spindle head 6 by the support columns 21 and 22. The tool changer 30 includes a tool magazine 31, a reducer 32, a magazine motor 33, etc. The tool magazine 31 includes a magazine base 37 and a plurality of grip arms 35. The magazine base 37 is roughly disc-shaped. The connecting plate 23 supports the magazine base 37 on its front surface so that it can rotate around a single axis parallel to the Z-axis direction. The reducer 32 and the magazine motor 33 are attached to the tool magazine 31. The output shaft (not shown) of the magazine motor 33 is connected to the rotation axis (not shown) of the magazine base 37 via the reducer 32. The power of the magazine motor 33 is transmitted to the rotating shaft of the magazine base 37 via the reduction gear 32. Multiple grip arms 35 are arranged along the outer circumference of the magazine base 37 and extend radially outward. The tips of the grip arms 35 grip the tool holder 90 when it is lying horizontally. The shape of the grip arms 35 is not particularly limited, and any configuration that can grip the tool holder 90 is acceptable. The grip arms 35 that perform tool changes with the spindle 7 move to the tool change position C (see Figure 7) of the tool magazine 31. The tool change position C is the lowest position of the tool magazine 31.

[0038] As shown in Figures 1 and 2, a magazine cover 10 is fixed to the front of the upper part of each of the support columns 21 and 22. The magazine cover 10 is box-shaped and covers the perimeter of the tool magazine 31. In this embodiment, the machining area and the tool changing area are separated by the bottom wall 101 of the magazine cover 10. The magazine cover 10 prevents chips and cutting fluid splashes from adhering to the tool magazine 31. Openings 103 are provided in the bottom wall 101 and the rear wall 102 (see Figure 5) of the magazine cover 10. The openings 103 are located directly below the tool changing position C of the tool magazine 31. A shutter 104 is provided inside the magazine cover 10 at the openings 103. The shutter 104 is an L-shape in side view, consisting of a rectangular plate in bottom view parallel to the bottom wall 101 and a rectangular plate in front view parallel to the rear wall 102. The shutter 104 moves between a closed position that closes the opening 103 and an open position that opens the opening 103, under the control of the CPU 51. When the shutter 104 is in the open position, the spindle 7 can pass through the opening 103 and move to the tool change position C.

[0039] Figure 5 is a cross-sectional view showing the inside of the magazine cover 10 when the shutter 104 is in the open position. Figure 6 is a cross-sectional view showing the inside of the magazine cover 10 when the shutter 104 is in the closed position. Figures 5 and 6 show diagrams in which a portion of the front wall 100 of the magazine cover is omitted. As described above, openings 103 are provided in the bottom wall 101 and the rear wall 102 of the magazine cover 10, and the shutter 104 is provided in the opening 103 inside the magazine cover 10. An air cylinder 105 is provided to the left of the shutter 104. The air cylinder 105 constitutes a moving mechanism for moving the shutter 104. The air cylinder 105 comprises an outer cylinder 105a and a rod 105b, and the rod 105b moves in and out of the inside of the outer cylinder 105a from the right end of the outer cylinder 105a. An open valve 105c is provided at the right end (one end) of the outer cylinder 105a to draw the rod 105b into the outer cylinder 105a by supplying air, and a close valve 105d is provided at the left end (other end) to push the rod 105b out of the outer cylinder 105a by supplying air. The air supply to the open valve 105c and the close valve 105d is controlled by the CPU 51. The right end of the rod 105b is connected to the shutter 104. When air is supplied by the open valve 105c, the rod 105b and the shutter 104 move to the left, and the shutter 104 moves to the open position as shown in Figure 5. When air is supplied by the close valve 105d, the rod 105b and the shutter 104 move to the right, and the shutter 104 moves to the closed position as shown in Figure 6.

[0040] A sensor 106 is provided on the left end of the outer cylinder 105a. The sensor 106 in this embodiment is capable of detecting when the shutter 104 is in the open position. Specifically, the sensor 106 is a magnetic sensor capable of detecting, for example, when a rod 105b is inside the outer cylinder 105a. Note that if the sensor 106 is a magnetic sensor, the rod 105b is a magnetic material. When the sensor 106 detects that the rod 105b is inside the outer cylinder 105a, it detects that the shutter 104 is in the open position. If the rod 105b is not inside the outer cylinder 105a, the sensor 106 does not detect that the shutter 104 is in the open position.

[0041] Figures 7 and 8 are explanatory diagrams showing the operation of the spindle 7 during tool change. In the machining state where the machine tool 1 is cutting the workpiece W, the spindle 7 is located in the machining area. After machining with the tool 91 mounted on the spindle 7 is completed, the CPU 51 of the machine tool 1 performs a tool change operation. The tool change operation includes a tool storage operation in which the used tool 91 is stored in the tool magazine 31, and a tool mounting operation in which the next tool 91 to be used is mounted on the spindle 7 and moved to the position where machining will begin. The path the spindle 7 moves when storing the tool is called the forward path, and the path it moves when mounting the tool is called the return path. Figure 7 shows the forward path, and Figure 8 shows the return path. In this embodiment, "moving the spindle 7" is synonymous with "moving the spindle head 6".

[0042] The forward path is the route by which the spindle 7 moves from the machining end position Q1 to the tool change origin position D (see Figure 7). The return path is the route by which the spindle 7 moves from the tool change origin position D to the machining start position Q2 (see Figure 8). The machining end position Q1 is the position of the spindle 7 when machining of the workpiece W is completed according to the NC program. The tool change origin position D is a reference point for tool changes provided in the tool change area, and is the position from which the tool magazine 31 can rotate. The machining start position Q2 is the position of the spindle 7 when machining of the workpiece W is started according to the NC program, and is the position to which the spindle 7 is moved after tool changes.

[0043] The forward journey will be explained below with reference to Figure 7. The CPU 51 moves the spindle 7 from the machining end position Q1 in the Z-axis direction, via the first return position A1, to the tool change preparation position B. The first return position A1 is set to be away from the machining end position Q1 in the Z-axis direction, so that the tool 91 mounted on the spindle 7 does not come into contact with the workpiece W and fixture fixed on the rotary table 9. The first return position A1 is at the same coordinates as the machining end position Q1 in the X-axis and Y-axis directions. The tool change preparation position B is at the same coordinates as the tool change position C in the X-axis and Z-axis directions. The tool change position C is the position where the grip arm 35 of the tool magazine 31 grips the tool holder 90 that holds the tool 91. The tool change preparation position B is away from the tool change position C in the Y-axis direction, so that the spindle 7 is positioned to grip and release the tool holder 90 by the grip arm 35 in the Y-axis direction.

[0044] Next, the CPU 51 raises the spindle 7 from the tool change preparation position B to the tool change position C. At this time, the tool holder 90 attached to the spindle 7 engages from below with the empty grip arm 35 located directly below the tool magazine 31. In this state, the CPU 51 moves the spindle 7 backward from the tool change position C in the Z-axis direction to the tool change origin position D. At this time, the tool holder 90 is withdrawn from the spindle 7. This completes the forward movement of the spindle 7 when storing the tool.

[0045] The return journey will now be explained with reference to Figure 8. The CPU 51 rotates the tool magazine 31 and positions the grip arm 35, which holds the next tool to be mounted 91, directly below the tool magazine 31. At this point, the tool 91 is positioned in front of the spindle 7. In this state, as shown in Figure 8, the CPU 51 moves the spindle 7, which is at the tool change origin position D, forward in the Z-axis direction to the tool change position C. As a result, the tool 91 is mounted on the spindle 7.

[0046] When the tool 91 is mounted on the spindle 7, the CPU 51 lowers the spindle 7 from the tool change position C to the tool change preparation position B. Next, the CPU 51 moves the spindle 7 from the tool change preparation position B to the second return position A2, and then moves it to the machining start position Q2. The second return position A2 is set to be away from the machining start position Q2 in the Z-axis direction, so that the tool 91 mounted on the spindle 7 does not come into contact with the workpiece W and fixture fixed on the rotary table 9. The second return position A2 is at the same coordinates as the machining start position Q2 in the X-axis and Y-axis directions. This completes the return movement of the spindle 7 during tool mounting, and the series of tool change operations is completed.

[0047] Figure 9 is a block diagram showing an example configuration of the control device 50. The control device 50 includes a CPU (control unit) 51, RAM 52, storage unit 53, etc. The storage unit 53 has a storage medium such as an EEPROM, EPROM, or hard disk. The storage unit 53 stores various programs such as NC programs for processing workpieces and shutter control programs. The storage medium may be, for example, a portable storage medium 53a (such as a CD-ROM and flash memory) as shown in Figure 9. In this case, the various programs stored on the portable storage medium 53a may be stored in the storage unit 53, or the portable storage medium 53a may be connected to the control device 50 and the various programs may be read. Alternatively, various programs may be stored in the storage unit 53 from a server via a network. The CPU 51 reads the various programs into the RAM 52 and executes them. That is, the various programs are stored on a portable or non-portable storage medium and constitute a program product.

[0048] The control panel 25 can display various information received from the control device 50 and input various information to be transmitted to the control device 50. When the control device 50 detects a malfunction in the machine tool 1, it notifies the user of the malfunction by displaying a message on the control panel 25 indicating that a malfunction has been detected.

[0049] Sensor 106 detects whether the shutter 104 is in the open position and outputs the detection result to control device 50. The spindle motor 61 has an encoder 61a. The encoder 61a continuously outputs a signal indicating the rotational position of the spindle motor 61 to control device 50. The CPU 51 of the control device 50, which receives a signal indicating the rotational position of the spindle motor 61, is able to continuously acquire the position of the spindle head 6.

[0050] The control device 50 transmits a movement command to the air cylinder 105, which includes an open command to move the shutter 104 to the open position or a close command to move the shutter 104 to the closed position. The control device 50 also transmits a drive signal to the spindle motor 61 based on a tool change command read from the NC program to change the holding tool 91, to the magazine motor 33 and the spindle motor 61.

[0051] When the CPU 51 of the control device 50 reads a tool change command from the NC program, it transmits a drive signal based on the read tool change command to the magazine motor 33 and the spindle movement motor 61. Upon receiving the drive signal, the magazine motor 33 rotates the tool magazine 31 so that the tool 91 to be mounted on the spindle head 6 is in the tool change position C. Upon receiving the drive signal, the spindle movement motor 61 moves the spindle head 6 as shown in Figures 7 and 8, and changes the tool 91 being held. Before the spindle head 6 moves from the machining area to the tool change area, the CPU 51 transmits an open command to the air cylinder 105, moving the shutter 104 to the open position. After the spindle head 6 moves from the tool change area to the machining area, the CPU 51 transmits a close command to the air cylinder 105, moving the shutter 104 to the closed position. This operation allows the shutter 104 to close the opening 103 during workpiece machining, preventing chips and cutting fluid splashes from entering the magazine cover 10, while also allowing the spindle head 6 to be moved into the magazine cover 10 without interfering with the magazine cover 10 during tool changes.

[0052] Sensor 106 may malfunction due to a short circuit caused by cutting fluid adhering to the tool 91 stored in the tool magazine 31, resulting in the sensor failing to detect that the shutter 104 is in the open position when it is actually open, or detecting that it is in the open position when it is actually closed. If sensor 106 malfunctions, the CPU 51 cannot obtain the actual position of the shutter 104, and if the spindle head 6 continues to move, there is a risk that the spindle head 6 will collide with the shutter 104. The CPU 51 stores either the open command or the closed command sent to the air cylinder 105 in the storage unit 53, and before sending the other movement command, which is different from the stored movement command, to the air cylinder, it determines whether the detection result of sensor 106 corresponds to the target position of the shutter 104 when the stored movement command is executed, thereby determining whether sensor 106 has malfunctioned. Note that if the movement command is an open command, the target position of the shutter 104 is the open position, and if the movement command is a closed command, the target position of the shutter 104 is the closed position. Furthermore, if one movement command is an open command, the other movement command is a block command, and if one movement command is a block command, the other movement command is an open command.

[0053] Figure 10 is a flowchart illustrating the processing of the control device 50 according to Embodiment 1. For example, after the machining of the workpiece W by the tool 91 held by the spindle head 6 is completed, the CPU 51 of the control device 50 reads the shutter control program from the storage unit 53 and starts the following processing. The CPU 51 reads the tool change command from the NC program (S1). The CPU 51 determines whether the movement command stored in the storage unit 53 is a closure command and whether the sensor 106 has detected that the shutter 104 is in the open position (S2). If the movement command stored in the storage unit 53 is a closure command and the sensor 106 has detected that the shutter 104 is in the open position (S2: YES), the CPU 51 reports an abnormality (S14) and terminates the processing.

[0054] If the movement command stored in the memory unit 53 is a block command and the sensor 106 has not detected that the shutter 104 is in the open position (S2:NO), the CPU 51 sends an open command to the air cylinder 105 (S3). The CPU 51 determines whether a certain amount of time has elapsed since sending the open command (S4). If a certain amount of time has not elapsed (S4:NO), the CPU 51 returns to S4 and repeats the process until a certain amount of time has elapsed. If a certain amount of time has elapsed (S4:YES), the CPU 51 determines whether the detection result of the sensor 106 has changed and the sensor 106 has detected that the shutter 104 is in the open position (S5). If the sensor 106 has not detected that the shutter 104 is in the open position (S5:NO), the CPU 51 reports an abnormality (S14) and terminates the process.

[0055] If the sensor 106 detects that the shutter 104 is in the open position (S5:YES), the CPU 51 transmits a drive signal based on the tool change command to the magazine motor 33 and the spindle movement motor 61 (S6). Upon receiving the drive signal, the spindle movement motor 61 moves the spindle head 6 from the machining area to the tool change area as shown in Figure 7, changes the tool 91 to be held, and then moves the spindle head 6 from the tool change area to the machining area as shown in Figure 8. Based on the position of the spindle head 6 that is continuously acquired, the CPU 51 determines whether or not the spindle head 6 has moved from the tool change area to the machining area (S7). If the spindle head 6 has not moved from the tool change area to the machining area (S7:NO), the CPU 51 returns the process to S7 and repeats the process until the spindle head 6 moves from the tool change area to the machining area. If the spindle head 6 moves from the tool change area to the machining area (S7:YES), the CPU 51 determines whether the movement command stored in the memory unit 53 is an open command and whether the sensor 106 has detected that the shutter 104 is in the open position (S8). If the movement command stored in the memory unit 53 is an open command and the sensor 106 has not detected that the shutter 104 is in the open position (S8:NO), the CPU 51 reports an abnormality (S14) and terminates the process.

[0056] If the movement command stored in the memory unit 53 is an open command and the sensor 106 detects that the shutter 104 is in the open position (S8:YES), the CPU 51 sends a closure command to the air cylinder 105 (S9). After sending the closure command, the CPU 51 determines whether a certain amount of time has elapsed (S10). If a certain amount of time has not elapsed (S10:NO), the CPU 51 returns to S10 and repeats the process until a certain amount of time has elapsed. If a certain amount of time has elapsed (S10:YES), the CPU 51 determines whether the detection result of the sensor 106 has changed and whether the sensor 106 has detected that the shutter 104 is in the open position (S11). If the sensor 106 has detected that the shutter 104 is in the open position (S11:YES), the CPU 51 reports an abnormality (S14) and terminates the process.

[0057] If the sensor 106 does not detect that the shutter 104 is in the open position (S11: NO), the CPU 51 causes the spindle head 6 to perform machining on the workpiece W (S12) and determines whether all machining on the workpiece W is complete (S13). If all machining is complete (S13: YES), the CPU 51 terminates the process. If all machining is not complete (S13: NO), the CPU 51 returns the process to S1 and reads a tool change command from the program.

[0058] With the above configuration and processing, by moving the spindle head 6 while confirming the position of the shutter 104 with the sensor 106, it is possible to replace the tool 91 being held while preventing the spindle head 6 from colliding with the shutter 104. Furthermore, it is possible to notify of any abnormality in the sensor 106 based on the movement command transmitted to the air cylinder 105 and the detection result of the sensor 106. As a result, even if only one sensor 106 is provided, it is possible to prevent the spindle head 6 from colliding with the shutter 104.

[0059] (Embodiment 2) The differences between Embodiment 2 and Embodiment 1 will be described below. Processes and configurations common to Embodiment 1 are denoted by the same reference numerals as in Embodiment 1, and their descriptions will be omitted.

[0060] Figure 11 is a cross-sectional view showing the inside of the magazine cover 10 according to Embodiment 2. In the machine tool 1 according to Embodiment 2, the sensor 106 is provided near the right end of the outer cylinder 105a of the air cylinder 105. The sensor 106 according to Embodiment 2 is capable of detecting when the shutter 104 is in the closed position. Specifically, the sensor 106 is a magnetic sensor capable of detecting, for example, when the rod 105b is outside the outer cylinder 105a, and when it detects that the rod 105b is outside the outer cylinder 105a, it detects that the shutter 104 is in the closed position. If the rod 105b is not outside the outer cylinder 105a, the sensor 106 does not detect that the shutter 104 is in the closed position.

[0061] Figure 12 is a flowchart illustrating the processing of the control device 50 according to Embodiment 2. The control device 50 starts the following processing after, for example, the machining of the workpiece W by the tool 91 held by the spindle head 6 is completed. The CPU 51 reads a tool change command from the program (S21). The CPU 51 determines whether the movement command stored in the memory unit 53 is a closure command and whether the sensor 106 has detected that the shutter 104 is in the closed position (S22). If the movement command stored in the memory unit 53 is a closure command and the sensor 106 has not detected that the shutter 104 is in the closed position (S22: NO), the CPU 51 reports an abnormality (S34) and terminates the processing.

[0062] If the movement command stored in the memory unit 53 is a block command and the sensor 106 detects that the shutter 104 is in the closed position (S22: YES), the CPU 51 sends an open command to the air cylinder 105 (S23). The CPU 51 determines whether a certain amount of time has elapsed since sending the open command (S24). If a certain amount of time has not elapsed (S24: NO), the CPU 51 returns to S24 and repeats the process until a certain amount of time has elapsed. If a certain amount of time has elapsed (S24: YES), the CPU 51 determines whether the detection result of the sensor 106 has changed and the sensor 106 has detected that the shutter 104 is in the closed position (S25). If the sensor 106 has detected that the shutter 104 is in the closed position (S25: YES), the CPU 51 reports an abnormality (S34) and terminates the process.

[0063] If the sensor 106 does not detect that the shutter 104 is in the closed position (S25:NO), the CPU 51 transmits a drive signal based on the tool change command to the magazine motor 33 and the spindle movement motor 61 (S26). Upon receiving the drive signal, the spindle movement motor 61 moves the spindle head 6 from the machining area to the tool change area as shown in Figure 7, changes the tool 91 to be held, and then moves the spindle head 6 from the tool change area to the machining area as shown in Figure 8. Based on the position of the spindle head 6 that is continuously acquired, the CPU 51 determines whether or not the spindle head 6 has moved from the tool change area to the machining area (S27). If the spindle head 6 has not moved from the tool change area to the machining area (S27:NO), the CPU 51 returns the process to S27 and repeats the process until the spindle head 6 moves from the tool change area to the machining area. If the spindle head 6 moves from the tool change area to the machining area (S27:YES), the CPU 51 determines whether the movement command stored in the memory unit 53 is an open command and whether the sensor 106 has detected that the shutter 104 is in the closed position (S28). If the movement command stored in the memory unit 53 is an open command and the sensor 106 has detected that the shutter 104 is in the closed position (S28:YES), the CPU 51 reports an abnormality (S34) and terminates the process.

[0064] If the movement command stored in the memory unit 53 is an open command and the sensor 106 has not detected that the shutter 104 is in the closed position (S28: NO), the CPU 51 sends a closure command to the air cylinder 105 (S29). After sending the closure command, the CPU 51 determines whether a certain amount of time has elapsed (S30). If a certain amount of time has not elapsed (S30: NO), the CPU 51 returns to S30 and repeats the process until a certain amount of time has elapsed. If a certain amount of time has elapsed (S30: YES), the CPU 51 determines whether the detection result of the sensor 106 has changed and whether the sensor 106 has detected that the shutter 104 is in the closed position (S31). If the sensor 106 has not detected that the shutter 104 is in the closed position (S31: NO), the CPU 51 reports an abnormality (S34) and terminates the process.

[0065] If the sensor 106 detects that the shutter 104 is in the closed position (S31:YES), the CPU 51 causes the spindle head 6 to perform machining on the workpiece W (S32) and determines whether all machining on the workpiece W is complete (S33). If all machining is complete (S33:YES), the CPU 51 terminates the process. If all machining is not complete (S33:NO), the CPU 51 returns the process to S21 and reads a tool change command from the program.

[0066] (modified version) The mechanism for moving the shutter 104 to the open or closed position is not limited to that of the air cylinder 105. The shutter 104 may be moved, for example, by an electrically powered electric cylinder.

[0067] The shutter 104 is located inside the magazine cover 10, but it may also be located outside the magazine cover 10.

[0068] Sensor 106 is not limited to a magnetic sensor. Sensor 106 may be, for example, a limit switch.

[0069] The method of notifying of an abnormality is not limited to a display on the operation panel 25. The control unit 51 may also notify of an abnormality by sounding an alarm or turning on a light.

[0070] In each of the embodiments described above, the CPU 51 determined the detection result of the sensor 106 after a certain period of time had elapsed since transmitting the movement command to the air cylinder 105, but this is not limited to this. For example, the CPU 51 may proceed to the next step if the detection result of the sensor 106 changes within a certain period of time after transmitting the movement command to the air cylinder 105.

[0071] The embodiments disclosed herein should be considered in all respects as illustrative and not restrictive. The technical features described in each embodiment can be combined with each other, and the scope of the present invention is intended to include all modifications within the claims and scope equivalent to the claims. Furthermore, the independent and dependent claims described in the claims can be combined with each other in any combination, regardless of the form of reference. In addition, the claims use a multi-claim format in which claims refer to two or more other claims (multi-claim format), but are not limited to this. They may also be described using a multi-claim format in which at least one multi-claim refers to another multi-claim (multi-multi-claim format). [Explanation of symbols]

[0072] 1 Machine tools 6. Spindle head 7 Spindle 10 Magazine Covers 11 X-axis movement mechanism 12 Z-axis movement mechanism 13 Y-axis movement mechanism 25 Control Panel 30 Tool changer 31 Tool Magazine 50 Control device 51 CPU (Control Unit) 52 RAM 53 Storage section 53a Portable storage medium 61. Main spindle movement motor 61a encoder 100 front wall 101 Bottom wall 102 Back wall 103 Opening 104 Shutter 105 Air Cylinder 105a Outer cylinder 105b Rod 105c Open valve 105d Shut-off valve 106 Sensors

Claims

1. A spindle head that detachably holds a tool for machining a workpiece, A tool changing device for changing the tool held in the spindle head, A cover that covers the tool changing device and has an opening, A shutter that is movable between an open position that opens the opening and a closed position that closes the opening, and stops in either the open position or the closed position, A sensor capable of detecting whether the shutter is in the open position or the closed position, A moving mechanism that moves the shutter to the open position when an open command is received, and moves the shutter to the closed position when a close command is received, The moving mechanism includes a control unit that transmits a moving command including the open command or the closed command. Equipped with, The control unit, After transmitting either the open command or the close command to the moving mechanism, and before transmitting the other move command to the moving mechanism, it is determined whether the target position of the shutter when one of the move commands is executed corresponds to the detection result by the sensor. If it determines that no action is needed, it will notify of an anomaly. A machine tool characterized by the following features.

2. The aforementioned moving mechanism is An air cylinder that moves the shutter to the open position when air is supplied to one end, and moves the shutter to the closed position when air is supplied to the other end, When the moving mechanism receives the release command, an open valve is provided to supply air to the one end side, When the moving mechanism receives the blocking command, a closing valve is used to supply air to the other end. The machine tool according to claim 1, comprising:

3. The sensor is capable of detecting when the shutter is in the open position. The other movement command is the block command, The other movement command is the release command, Before transmitting the open command to the moving mechanism, the control unit shall notify of an abnormality if the sensor detects that the shutter is in the open position. The machine tool according to claim 1 or 2.

4. The sensor is capable of detecting when the shutter is in the closed position. The other movement command is the block command, The other movement command is the release command, The control unit shall notify of an abnormality if the sensor has not detected that the shutter is in the closed position before transmitting the open command to the moving mechanism. The machine tool according to claim 1 or 2.

5. The sensor is capable of detecting when the shutter is in the open position. The other movement command is the release command, The other movement command is the block command, The control unit shall notify of an abnormality if the sensor has not detected that the shutter is in the open position before transmitting the closing command to the moving mechanism. The machine tool according to claim 1 or 2.

6. The sensor is capable of detecting when the shutter is in the closed position. The other movement command is the release command, The other movement command is the block command, The control unit shall notify of an abnormality if the sensor detects that the shutter is in the closed position before transmitting the closing command to the moving mechanism. The machine tool according to claim 1 or 2.

7. The control unit, The system is configured to read a tool change command from the program to change the tool held in the spindle head, and then transmit a drive signal based on the tool change command. After reading the tool change command and before transmitting the drive signal, it is determined whether the target position of the shutter when one of the movement commands is executed corresponds to the detection result by the sensor. The machine tool according to claim 1 or 2.

8. The control unit, After a certain period of time has elapsed since transmitting the movement command to the movement mechanism, it is determined whether or not the detection result of the sensor has changed. If it is determined that there has been no change, an anomaly will be reported. The machine tool according to claim 1 or 2.

9. A spindle head that detachably holds a tool for machining a workpiece, A tool changing device for changing the tool held in the spindle head, A cover that covers the tool changing device and has an opening, A shutter that is movable between an open position that opens the opening and a closed position that closes the opening, and stops in either the open position or the closed position, A sensor capable of detecting whether the shutter is in the open position or the closed position, A moving mechanism that moves the shutter to the open position when an open command is received, and moves the shutter to the closed position when a close command is received, The moving mechanism includes a control unit that transmits a moving command including the open command or the closed command. A control method for a machine tool, comprising: After transmitting either the open command or the close command to the moving mechanism, and before transmitting the other move command to the moving mechanism, it is determined whether the target position of the shutter when one of the move commands is executed corresponds to the detection result by the sensor. If it determines that no action is needed, it will notify of an anomaly. Control method.

10. A spindle head that detachably holds a tool for machining a workpiece, A tool changing device for changing the tool held in the spindle head, A cover that covers the tool changing device and has an opening, A shutter that is movable between an open position that opens the opening and a closed position that closes the opening, and stops in either the open position or the closed position, A sensor capable of detecting whether the shutter is in the open position or the closed position, A moving mechanism that moves the shutter to the open position when an open command is received, and moves the shutter to the closed position when a close command is received, The moving mechanism includes a control unit that transmits a moving command including the open command or the closed command. A program for controlling a machine tool equipped with the following features: After transmitting either the open command or the close command to the moving mechanism, and before transmitting the other move command to the moving mechanism, it is determined whether the target position of the shutter when one of the move commands is executed corresponds to the detection result by the sensor. If it determines that no action is needed, it will notify of an anomaly. A program that instructs a computer to perform a process.

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