JP2024048955A - Machine tool, control method, and program - Google Patents

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

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

Conventionally, a control system for an ATC shutter (shutter) equipped 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 to a machining chamber to exchange a tool held by a rotating arm between the inside and outside of the machining chamber. The control system described in Patent Document 1 prevents collision between the rotating arm and the ATC shutter by driving the rotating arm with a signal based on limit switches provided at positions corresponding to the start and end of opening the ATC shutter.

JP 2007-30062 A

The control system described in Patent Document 1 requires a mechanism (limit switch) for detecting the positions of the two ATC shutters, which increases the cost of implementing the system.

This disclosure has been made in consideration of these circumstances, and aims to provide a machine tool, control method, program, etc. that can prevent collisions between the shutter and the spindle head while reducing costs.

A machine tool according to an embodiment of the present disclosure includes a spindle head that detachably holds a tool for machining a workpiece, a tool exchange device that exchanges the tool held by the spindle head, a cover that covers the tool exchange device and has an opening, a shutter that can move between an open position that opens the opening and a closed position that closes the opening, a sensor that can detect 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, and 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 before transmitting the other movement command of the open command or the close command to the movement mechanism after transmitting the movement command of either the open command or the close command to the movement mechanism, and reports an abnormality when it is determined that they do not correspond.

In this disclosure, the machine tool detects whether the shutter is open or closed using only one detection mechanism (sensor), and if a sensor failure occurs, it can report the abnormality and stop the movement of the spindle head, thereby reducing costs and preventing collisions between the shutter and the spindle head.

In a machine tool according to an embodiment of the present disclosure, the movement mechanism includes an air cylinder that moves the shutter to the open position when air is supplied to one end side and moves the shutter to the closed position when air is supplied to the other end side, an open valve that supplies air to the one end side when the movement mechanism receives the open command, and a close valve that supplies air to the other end side when the movement mechanism receives the close command.

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

In a machine tool according to an embodiment of the present disclosure, the sensor is capable of detecting that 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 reports an abnormality if the sensor detects that the shutter is in the open position before transmitting the opening command to the movement mechanism.

In the present disclosure, the machine tool is capable of stopping the movement of the spindle head when the sensor detects that the shutter is in the open position when the shutter should not be in the open position, thereby preventing a collision between the shutter and the spindle head.

In a machine tool according to an embodiment of the present disclosure, the sensor is capable of detecting that the shutter is in the closed position, one of the movement commands is the closing command and the other movement command is the opening command, and the control unit reports an abnormality if the sensor does not detect that the shutter is in the closed position before transmitting the opening command to the movement mechanism.

In the present disclosure, the machine tool is capable of stopping the movement of the spindle head when the sensor does not detect that the shutter is in the closed position when the shutter should be in the closed position, thereby preventing a collision between the shutter and the spindle head.

In a machine tool according to an embodiment of the present disclosure, the sensor is capable of detecting that the shutter is in the open position, one of the movement commands is the open command and the other movement command is the close command, and the control unit reports an abnormality if the sensor does not detect that the shutter is in the open position before transmitting the close command to the movement mechanism.

In the present disclosure, the machine tool is capable of stopping the movement of the spindle head when the sensor does not detect that the shutter is in the open position when the shutter should be in the open position, thereby preventing a collision between the shutter and the spindle head.

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

In the present disclosure, the machine tool is capable of stopping the movement of the spindle head when the sensor detects that the shutter is in the closed position when the shutter should not be in the closed position, thereby preventing a collision between the shutter and the spindle head.

In a machine tool according to an embodiment of the present disclosure, the control unit is configured to read from a program a tool change command for changing the tool held by the spindle head, and then transmit a drive signal based on the tool change command, and 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.

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

In a machine tool according to one embodiment of the present disclosure, the control unit determines whether the detection result of the sensor has changed after a certain time has elapsed since the movement command was sent to the movement mechanism, and if it determines that the detection result has not changed, reports an abnormality.

In this disclosure, the machine tool is capable of reporting an abnormality when it cannot detect that the movement mechanism has correctly executed a movement command.

A control method according to an embodiment of the present disclosure is a control method for a machine tool including a spindle head that detachably holds a tool for machining a workpiece, a tool exchange device that exchanges the tool held by the spindle head, a cover that covers the tool exchange device and has an opening, a shutter that can move between an open position that opens the opening and a closed position that closes the opening, a sensor that can detect 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, and after transmitting the movement command of either the open command or the close command to the movement mechanism, a determination is made as to whether the target position of the shutter when one of the movement commands is executed corresponds to the detection result by the sensor before transmitting the other movement command of the open command or the close command to the movement mechanism, and an abnormality is notified when it is determined that they do not correspond.

In this disclosure, the machine tool is equipped with only one detection mechanism (sensor), and if a sensor failure or other problem occurs, it can report an abnormality and stop the movement of the spindle head, thereby reducing costs and preventing collisions between the shutter and the spindle head.

A program according to an embodiment of the present disclosure is a program for controlling a machine tool including a spindle head that detachably holds a tool for machining a workpiece, a tool exchange device that exchanges the tool held by the spindle head, a cover that covers the tool exchange device and has an opening, a shutter that can move between an open position that opens the opening and a closed position that closes the opening, a sensor that can detect 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, and after transmitting the movement command of either the open command or the close command to the movement mechanism, the program causes a computer to execute a process of determining whether the target position of the shutter when one of the movement commands is executed corresponds to the detection result by the sensor, and notifying an abnormality when it is determined that they do not correspond.

In this disclosure, the machine tool is equipped with only one detection mechanism (sensor), and if a sensor failure or other problem occurs, it can report an abnormality and stop the movement of the spindle head, thereby reducing costs and preventing collisions between the shutter and the spindle head.

A computer-readable storage medium on which the above program is stored is also novel and useful.

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

FIG. 2 is a perspective view of the machine tool as viewed from the upper right front. FIG. 2 is a perspective view of the machine tool as viewed from the lower front right. FIG. 2 is a perspective view of the machine tool as viewed from the upper right rear with the magazine cover omitted. FIG. 2 is a right side view of the machine tool with the magazine cover omitted. 4 is a cross-sectional view showing the inside of the magazine cover when the shutter is in an open position. FIG. 4 is a cross-sectional view showing the inside of the magazine cover when the shutter is in a closed position. FIG. FIG. 11 is an explanatory diagram showing the operation of the spindle during tool replacement. FIG. 11 is an explanatory diagram showing the operation of the spindle during tool replacement. FIG. 2 is a block diagram showing a configuration example of a control device. 4 is a flowchart illustrating processing of the control device according to the first embodiment. FIG. 11 is a cross-sectional view showing the inside of a magazine cover according to a second embodiment. 10 is a flowchart illustrating a process of a control device according to a second embodiment.

(Embodiment 1)
A machine tool and a control device according to a first embodiment will be described below with reference to the drawings. In the following description, up, down, front, back, left and right as shown in the drawings will be used. Note that 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. Also, "NC" in this embodiment is an abbreviation for "Numerical Control."

Figure 1 is a perspective view of the machine tool 1 as viewed from the upper right front. Figure 2 is a perspective view of the machine tool 1 as viewed from the lower right front. Figure 3 is a perspective view of the machine tool 1 as viewed from the upper right rear, omitting the magazine cover. Figure 4 is a right side view of the machine tool 1, omitting the magazine cover. The machine tool 1 according to this embodiment 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 direction and the Z-axis direction. The machine tool 1 includes 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.

The base 2 is an iron base having a substantially rectangular parallelepiped shape elongated in the Z-axis direction. The X-axis moving mechanism 11 is provided at the rear of the upper surface of the base 2, and supports the moving body 15 so that it can move in the X-axis direction. The Z-axis moving mechanism 12 is provided on the upper surface of the moving body 15. The Z-axis moving mechanism 12 supports the column 5 so that it can move in the Z-axis direction. The column 5 is a vertically extending upright pillar. The column 5 has a vertically elongated rectangular through hole 5A (see FIG. 3) on the front surface. The through hole 5A penetrates the column 5 in the front-rear direction. The frame cover 20 is attached to the front surface of the column 5. The frame cover 20 is a vertically elongated rectangular frame body 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 moving mechanism 13 is provided on the front surface of the column 5, and supports the spindle head 6 so that it can move in the Y-axis direction. The X-axis moving mechanism 11, the Z-axis moving mechanism 12, and the Y-axis moving mechanism 13 each have, for example, a guide and a ball screw. The X-axis moving mechanism 11 includes an X-axis motor 611 (see FIG. 9), the Z-axis moving mechanism 12 includes a Z-axis motor 612 (see FIG. 9), and the Y-axis moving mechanism 13 includes a Y-axis motor 613 (see FIG. 9). In the following description, the X-axis motor 611, the Z-axis motor 612, and the Y-axis motor 613 are collectively referred to as the spindle moving motor 61 (see FIG. 9). The X-axis moving mechanism 11, the Z-axis moving mechanism 12, and the Y-axis moving mechanism 13 move the moving body 15, the column 5, and the spindle head 6, respectively, along the guides by the power of the spindle moving motor 61, thereby moving the spindle head 6.

The spindle head 6 extends in the Z-axis direction and is movable in the Y-axis direction along the front surface of the column 5 by the Y-axis moving mechanism 13. The spindle head 6 is movable in the Y-axis direction between the machining area and the tool exchange area (see Figs. 4 and 7). The machining area is provided in the space on the base 2 side (lower side) of the Y-axis origin. The Y-axis origin is the position where the Y-axis machine coordinate is 0. The tool exchange area is provided in the space on the opposite side (upper side) of the machining area with respect to the Y-axis origin. The machining area is an area where the workpiece W (see Fig. 7) fixed to the rotary table 9 is machined. The tool exchange area is an area where tools are exchanged by the tool exchange device 30. The tool exchange area is provided above the machining area in the Y-axis direction and at a position overlapping with the machining area in the Z-axis direction.

The spindle head 6 is provided with an upper cover 28 and an armor 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 generally rectangular when viewed from the front, and extends upward from the rear end of the upper surface of the spindle head 6. The armor cover 85 is fixed in a suspended state to the rear end of the lower surface of the spindle head 6. The armor cover 85 is provided with multiple metal plates arranged in the vertical direction, and telescopically expands and contracts in the vertical direction. The upper cover 28 moves up and down together with the spindle head 6, thereby always covering the area above the spindle head 6 on the front surface of the column 5. The armor cover 85 expands and contracts in the vertical direction in response to the vertical movement of the spindle head 6, thereby always covering the area below the spindle head 6 on the front surface of the column 5.

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

The spindle 7 has a tool mounting hole 40 and a holder holding member 19 (see FIG. 7). The tool mounting hole 40 is provided at the tip (front end) of the spindle 7. The tool mounting hole 40 is a generally conical tool mounting hole 40 that expands in diameter toward the tip of the spindle 7. The holder holding member 19 is provided at the back side of the tool mounting hole 40. A tool holder 90 (see FIG. 7) is detachably attached to 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 FIG. 7) at the other end. The tapered portion is generally conical and fits closely to the tool mounting hole 40 of the spindle 7. The pull stud 93 protrudes in the axial direction from the top of the tapered portion. When the tapered portion is attached to 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.

A pair of support members 17, 18 are provided at the rear of the base 2. The support members 17, 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 FIG. 9) is housed inside the control box 8. The control device 50 has a CPU 51 and controls the operation of the machine tool 1. A fixed base 16 is provided on the front side of the upper surface of the base 2. The rotating table 9 is fixed to the fixed base 16. The rotating table 9 is located in front of the spindle head 6. The rotating table 9 has a workpiece W (see FIG. 7) fixed to its upper surface with a jig (not shown), and can rotate 360° around a rotation axis parallel to the Y-axis direction.

A pair of support columns 21, 22 are provided on the front side and on both the left and right sides of the upper surface of the base 2. As shown in FIG. 3, a connecting plate 23 is fixed between the upper parts of the support columns 21 and 22 that face each other. The tool changer 30 is fixed to the front of the connecting plate 23. The tool changer 30 is located between the column 5 and the rotary table 9 and above the spindle head 6 by the support columns 21, 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 approximately disk-shaped. The connecting plate 23 supports the magazine base 37 at the front 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 shaft (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 reducer 32. The multiple grip arms 35 are arranged in a line along the outer periphery of the magazine base 37 and extend radially outward. The tips of the grip arms 35 grip the tool holder 90 with the tool holder 90 lying horizontally. The shape of the grip arms 35 is not particularly limited, and they may be configured to grip the tool holder 90. The grip arms 35, which exchange tools with the spindle 7, move to a tool exchange position C (see FIG. 7) of the tool magazine 31. The tool exchange position C is the lowest position of the tool magazine 31.

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 periphery of the tool magazine 31. In this embodiment, the machining area and the tool exchange area are separated by the bottom wall 101 of the magazine cover 10. The magazine cover 10 prevents chips and cutting fluid from adhering to the tool magazine 31. An opening 103 is provided in the bottom wall 101 and the rear wall 102 (see FIG. 5) of the magazine cover 10. The opening 103 is located directly below the tool exchange position C of the tool magazine 31. A shutter 104 is provided in the opening 103 on the inside of the magazine cover 10. The shutter 104 is a combination of a rectangular plate parallel to the bottom wall 101 and a rectangular plate parallel to the rear wall 102, and is L-shaped in side view. The shutter 104 moves between a closed position where the opening 103 is closed and an open position where the opening 103 is opened under the control of the CPU 51. When the shutter 104 is in the open position, the spindle 7 passes through the opening 103 and can move to the tool change position C.

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 a view in which a part of the front wall 100 of the magazine cover is omitted. As described above, an opening 103 is provided in the bottom wall 101 and the rear wall 102 of the magazine cover 10, and a 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 that moves the shutter 104. The air cylinder 105 has an outer cylinder 105a and a rod 105b, and the rod 105b enters and exits the inside of the outer cylinder 105a from the right end of the outer cylinder 105a. The right end (one end) of the outer cylinder 105a is provided with an open valve 105c that draws the rod 105b into the outer cylinder 105a by supplying air, and the left end (the other end) is provided with a closed valve 105d that pushes the rod 105b out of the outer cylinder 105a by supplying air. Air supply to the open valve 105c and the closed 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 FIG. 5. When air is supplied by the closed 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 FIG. 6.

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

7 and 8 are explanatory diagrams showing the operation of the spindle 7 during tool replacement. In the machining state in which the machine tool 1 cuts the workpiece W, the spindle 7 is located in the machining area. After machining using the tool 91 attached to the spindle 7 is completed, the CPU 51 of the machine tool 1 executes a tool replacement operation. The tool replacement 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 a position where machining will start. The path along which the spindle 7 moves when storing the tool is called the forward path, and the path along which the spindle 7 moves when mounting the tool is called the return path. FIG. 7 shows the forward path, and FIG. 8 shows the return path. In this embodiment, "moving the spindle 7" is synonymous with "moving the spindle head 6."

The outward path is the path along which the spindle 7 moves from the machining end position Q1 to the tool change origin position D (see FIG. 7). The return path is the path along which the spindle 7 moves from the tool change origin position D to the machining start position Q2 (see FIG. 8). The machining end position Q1 is the position of the spindle 7 when machining of the workpiece W ends according to the NC program. The tool change origin position D is a reference point for tool change that is provided in the tool change area, and is a position to 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 starts according to the NC program, and is the position to which the spindle 7 is moved after tool change.

The forward path will be described below with reference to FIG. 7. The CPU 51 moves the spindle 7 from the machining end position Q1 in the Z-axis + direction, and moves it to the tool change preparation position B via the first return position A1. The first return position A1 is set to a position away from the machining end position Q1 in the Z-axis + direction, where the tool 91 attached to the spindle 7 does not contact the workpiece W and the jig fixed on the rotary table 9. The first return position A1 is a position with the same coordinates as the machining end position Q1 in the X-axis and Y-axis directions. The tool change preparation position B is a position with the same coordinates as the tool change position C in the X-axis and Z-axis directions. The tool change position C is a 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 a position away from the tool change position C in the Y-axis - direction, where the spindle 7 is positioned so that the grip arm 35 grips and releases the tool holder 90 in the Y-axis direction.

Then, 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 in the +Z direction from the tool change position C to the tool change origin position D. At this time, the tool holder 90 is pulled out of the spindle 7. This completes the forward movement of the spindle 7 when storing tools.

The return path will now be described with reference to Figure 8. The CPU 51 rotates the tool magazine 31 and positions the grip arm 35, which holds the next tool 91 to be loaded, directly below the tool magazine 31. At this time, 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 tool change origin position D, forward in the negative direction of the Z axis, to tool change position C. This loads the tool 91 onto the spindle 7.

When the tool 91 is attached to 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 a position away from the machining start position Q2 in the +Z axis direction, where the tool 91 attached to the spindle 7 does not contact the workpiece W and jig fixed on the rotary table 9. The second return position A2 is at the same coordinate as the machining start position Q2 in the X-axis and Y-axis directions. This completes the return movement of the spindle 7 when the tool is attached, and completes the series of tool changing operations.

Figure 9 is a block diagram showing an example of the configuration of the control device 50. The control device 50 includes a CPU (control unit) 51, a RAM 52, a storage unit 53, and the like. The storage unit 53 has a storage medium such as an EEPROM, an EPROM, or a hard disk. The storage unit 53 stores various programs such as an NC program for processing a workpiece and a shutter control program. The storage medium may be, for example, a portable storage medium 53a (such as a CD-ROM or a flash memory) shown in Figure 9. In this case, the various programs stored in 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 to read out the various programs. In addition, the 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 the various programs. In other words, the various programs are stored in a storage medium that is portable or non-portable, and constitute a program product.

The operation panel 25 is capable of displaying various information received from the control device 50 and inputting various information to be sent to the control device 50. When the control device 50 detects a malfunction of the machine tool 1, it notifies the user of the abnormality by displaying a message indicating that a malfunction has been detected on the operation panel 25.

The sensor 106 detects whether the shutter 104 is in the open position and outputs the detection result to the control device 50. The spindle movement motor 61 has an encoder 61a. The encoder 61a continuously outputs a signal indicating the rotational position of the spindle movement motor 61 to the control device 50. The CPU 51 of the control device 50 to which the signal indicating the rotational position of the spindle movement motor 61 has been input is able to continuously obtain the position of the spindle head 6.

The control device 50 transmits to the air cylinder 105 a movement command including an open command to move the shutter 104 to an open position or a close command to move the shutter 104 to a closed position. The control device 50 also transmits to the magazine motor 33 and the spindle movement motor 61 a drive signal based on a tool change command read from the NC program to cause the spindle movement motor 61 to change the tool 91 held by the tool change command.

When the CPU 51 of the control device 50 reads out a tool change command from the NC program, it transmits a drive signal based on the read out tool change command to the magazine motor 33 and the spindle movement motor 61. The magazine motor 33, which has received the drive signal, rotates the tool magazine 31 so that the tool 91 attached to the spindle head 6 is located at the tool change position C. The spindle movement motor 61, which has received the drive signal, moves the spindle head 6 as shown in Figures 7 and 8, and replaces the tool 91 it holds. 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, and moves 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, and moves the shutter 104 to the closed position. This action allows the shutter 104 to close the opening 103 when machining the workpiece, preventing chips and cutting fluid from splashing into the magazine cover 10, while allowing the spindle head 6 to be moved into the magazine cover 10 without interfering with the magazine cover 10 when changing tools.

The sensor 106 may fail to detect that the shutter 104 is in the open position even though it is in the open position, or may fail to detect that the shutter 104 is in the open position even though it is in the closed position, due to a circuit short circuit caused by cutting water attached to the tool 91 stored in the tool magazine 31. If the sensor 106 fails, the CPU 51 cannot obtain the actual position of the shutter 104, so that if the movement of the spindle head 6 continues, the spindle head 6 may collide with the shutter 104. The CPU 51 stores in the memory unit 53 either the open command or the close command transmitted to the air cylinder 105, and before transmitting the other command different from the stored command to the air cylinder, determines whether the target position of the shutter 104 when the stored command is executed corresponds to the detection result of the sensor 106, thereby determining whether the sensor 106 has failed. 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 close command, the target position of the shutter 104 is the closed position. Also, when one movement command is an open command, the other movement command is a close command, and when one movement command is a close command, the other movement command is an open command.

Figure 10 is a flowchart explaining the processing of the control device 50 according to the first embodiment. 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 memory unit 53 and starts the following processing. The CPU 51 reads a tool change command from the NC program (S1). The CPU 51 determines whether the movement command stored in the memory unit 53 is a closing command and whether the sensor 106 detects that the shutter 104 is in the open position (S2). If the movement command stored in the memory unit 53 is a closing command and the sensor 106 detects that the shutter 104 is in the open position (S2: YES), the CPU 51 reports an abnormality (S14) and ends the processing.

If the movement command stored in the memory unit 53 is a closing command and the sensor 106 does not detect that the shutter 104 is in the open position (S2: NO), the CPU 51 sends an opening command to the air cylinder 105 (S3). The CPU 51 determines whether a certain time has elapsed since sending the opening command (S4). If the certain time has not elapsed (S4: NO), the CPU 51 returns to S4 and repeats the process until the certain time has elapsed. If the certain time has elapsed (S4: 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 (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 ends the process.

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). The spindle movement motor 61 that receives the drive signal moves the spindle head 6 from the machining area to the tool change area as shown in FIG. 7, and after changing the tool 91 to be held, moves the spindle head 6 from the tool change area to the machining area as shown in FIG. 8. The CPU 51 determines whether the spindle head 6 has moved from the tool change area to the machining area based on the position of the spindle head 6 that is continuously acquired (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. When the spindle head 6 moves from the tool exchange 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 detects that the shutter 104 is in the open position (S8). When the movement command stored in the memory unit 53 is an open command and the sensor 106 does not detect that the shutter 104 is in the open position (S8: NO), the CPU 51 reports an abnormality (S14) and ends the process.

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 close command to the air cylinder 105 (S9). The CPU 51 determines whether a certain time has elapsed after sending the close command (S10). If the certain time has not elapsed (S10: NO), the CPU 51 returns to S10 and repeats the process until the certain time has elapsed. If the certain 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 detects that the shutter 104 is in the open position (S11: YES), the CPU 51 reports an abnormality (S14) and ends the process.

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 of the workpiece W (S12) and determines whether all machining of the workpiece W has been completed (S13). If all machining has been completed (S13: YES), the CPU 51 ends the process. If all machining has not been completed (S13: NO), the CPU 51 returns the process to S1 and reads a tool change command from the program.

According to the above configuration and processing, by moving the spindle head 6 while checking 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. In addition, it is possible to report an abnormality in the sensor 106 based on the movement command sent 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.

(Embodiment 2)
Hereinafter, the second embodiment will be described with respect to the differences from the first embodiment. The same reference numerals as in the first embodiment are used for the processes and configurations common to the first embodiment, and the description thereof will be omitted.

Figure 11 is a cross-sectional view showing the inside of the magazine cover 10 according to the second embodiment. In the machine tool 1 according to the second embodiment, the sensor 106 is provided near the right end of the outer cylinder 105a of the air cylinder 105. The sensor 106 according to the second embodiment is capable of detecting that the shutter 104 is in the closed position. Specifically, the sensor 106 is, for example, a magnetic sensor capable of detecting that 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. When 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.

Figure 12 is a flowchart explaining the processing of the control device 50 according to the second embodiment. The control device 50 starts the following processing, for example, after 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 closing command and whether the sensor 106 detects that the shutter 104 is in the closed position (S22). If the movement command stored in the memory unit 53 is a closing command and the sensor 106 does not detect that the shutter 104 is in the closed position (S22: NO), the CPU 51 reports an abnormality (S34) and ends the processing.

If the movement command stored in the memory unit 53 is a closing command and the sensor 106 detects that the shutter 104 is in the closed position (S22: YES), the CPU 51 sends an opening command to the air cylinder 105 (S23). The CPU 51 determines whether a certain time has elapsed since sending the opening command (S24). If the certain time has not elapsed (S24: NO), the CPU 51 returns to S24 and repeats the process until the certain time has elapsed. If the certain 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 detects that the shutter 104 is in the closed position (S25: YES), the CPU 51 reports an abnormality (S34) and ends the process.

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). The spindle movement motor 61 that receives the drive signal moves the spindle head 6 from the machining area to the tool change area as shown in FIG. 7, and after changing the tool 91 to be held, moves the spindle head 6 from the tool change area to the machining area as shown in FIG. 8. The CPU 51 determines whether the spindle head 6 has moved from the tool change area to the machining area based on the position of the spindle head 6 that is continuously acquired (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. When the spindle head 6 moves from the tool exchange 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 detects that the shutter 104 is in the closed position (S28). When 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 closed position (S28: YES), the CPU 51 reports an abnormality (S34) and ends the process.

If the movement command stored in the memory unit 53 is an open command and the sensor 106 does not detect that the shutter 104 is in the closed position (S28: NO), the CPU 51 sends a close command to the air cylinder 105 (S29). The CPU 51 determines whether a certain time has elapsed after sending the close command (S30). If the certain time has not elapsed (S30: NO), the CPU 51 returns to S30 and repeats the process until the certain time has elapsed. If the certain 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 ends the process.

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 of the workpiece W (S32) and determines whether all machining of the workpiece W has been completed (S33). If all machining has been completed (S33: YES), the CPU 51 ends the process. If all machining has not been completed (S33: NO), the CPU 51 returns the process to S21 and reads a tool change command from the program.

(Modification)
The mechanism for moving the shutter 104 to the open position or the closed position is not limited to the air cylinder 105. The shutter 104 may be moved by, for example, an electrically powered cylinder.

The shutter 104 is provided on the inside of the magazine cover 10, but may also be provided on the outside of the magazine cover 10.

The sensor 106 is not limited to a magnetic sensor. The sensor 106 may be, for example, a limit switch.

The method of reporting an abnormality is not limited to displaying the abnormality on the operation panel 25. The control unit 51 may report an abnormality by sounding an alarm, turning on a light, etc.

In each of the above-described embodiments, the CPU 51 determines the detection result of the sensor 106 after a certain time has elapsed since the movement command was sent to the air cylinder 105, but this is not limited to the above. For example, the CPU 51 may proceed to the next step if the detection result of the sensor 106 changes within a certain time since the movement command was sent to the air cylinder 105.

The embodiments disclosed herein are illustrative in all respects and should not be considered restrictive. The technical features described in each embodiment may be combined with one another, and the scope of the present invention is intended to include all modifications within the scope of the claims and equivalents to the scope of the claims. In addition, the independent claims and dependent claims described in the claims may be combined with one another in any and all combinations, regardless of the citation format. Furthermore, the claims use a format in which a claim cites two or more other claims (multi-claim format), but this is not limited to this. They may also be written in a format in which a multiple claim cites at least one other claim (multi-multi-claim).

REFERENCE SIGNS LIST 1 Machine tool 6 Spindle head 7 Spindle 10 Magazine cover 11 X-axis movement mechanism 12 Z-axis movement mechanism 13 Y-axis movement mechanism 25 Operation panel 30 Tool changer 31 Tool magazine 50 Control device 51 CPU (control unit)
52 RAM
53 Storage unit 53a Portable storage medium 61 Main shaft movement motor 61a Encoder 100 Front wall 101 Bottom wall 102 Rear wall 103 Opening 104 Shutter 105 Air cylinder 105a Outer cylinder 105b Rod 105c Open valve 105d Close valve 106 Sensor

Claims (10)

A spindle head that detachably holds a tool for machining a workpiece;
a tool changer that changes the tool held by the spindle head;
a cover covering the tool changing device and having 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 moving mechanism that moves the shutter to the open position when an opening command is received, and moves the shutter to the closed position when a closing command is received;
a control unit that transmits a movement command including the opening command or the closing command to the movement mechanism,
The control unit is
after transmitting one of the movement commands, either the open command or the close command, to the movement mechanism, and before transmitting the other of the movement commands, either the open command or the close command, to the movement mechanism, determining whether or not a target position of the shutter in the case where one of the movement commands is executed corresponds to a detection result by the sensor;
A machine tool characterized in that it notifies an abnormality when it is determined that the machine tool does not comply with the requirements. The moving mechanism includes:
an air cylinder that moves the shutter to the open position when air is supplied to one end side of the air cylinder and moves the shutter to the closed position when air is supplied to the other end side of the air cylinder;
an open valve that supplies air to the one end side when the moving mechanism receives the open command;
The machine tool according to claim 1 , further comprising: a closing valve that supplies air to the other end side when the moving mechanism receives the closing command. the sensor is capable of detecting when the shutter is in the open position;
One of the movement commands is the blocking command,
The other movement command is the opening command,
The machine tool according to claim 1 or 2, wherein the control unit notifies an abnormality when the sensor detects that the shutter is in the open position before transmitting the open command to the moving mechanism. the sensor is capable of detecting when the shutter is in the closed position;
One of the movement commands is the blocking command,
The other movement command is the opening command,
The machine tool according to claim 1 or 2, wherein the control unit notifies an abnormality when the sensor does not detect that the shutter is at the closed position before transmitting the open command to the moving mechanism. the sensor is capable of detecting when the shutter is in the open position;
One of the movement commands is the opening command,
the other movement command is the closing command,
The machine tool according to claim 1 or 2, wherein the control unit notifies an abnormality when the sensor does not detect that the shutter is in the open position before transmitting the closing command to the moving mechanism. the sensor is capable of detecting when the shutter is in the closed position;
One of the movement commands is the opening command,
the other movement command is the closing command,
The machine tool according to claim 1 or 2, wherein the control unit notifies an abnormality when the sensor detects that the shutter is in the closed position before transmitting the closing command to the moving mechanism. The control unit is
a tool change command for changing the tool held by the spindle head is read from a program, and then a drive signal based on the tool change command is transmitted;
The machine tool according to claim 1 or 2, further comprising: a determining unit that determines whether a target position of the shutter when one of the movement commands is executed corresponds to a detection result by the sensor after reading out the tool change command and before transmitting the drive signal. The control unit is
determining whether or not a detection result of the sensor has changed after a certain time has elapsed since the movement command was sent to the movement mechanism;
The machine tool according to claim 1 or 2, wherein when it is determined that there has been no change, an abnormality is notified. A spindle head that detachably holds a tool for machining a workpiece;
a tool changer that changes the tool held by the spindle head;
a cover covering the tool changing device and having 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 moving mechanism that moves the shutter to the open position when an opening command is received, and moves the shutter to the closed position when a closing command is received;
a control unit that transmits a movement command including the open command or the close command to the movement mechanism,
after transmitting one of the movement commands, either the open command or the close command, to the movement mechanism, and before transmitting the other of the movement commands, either the open command or the close command, to the movement mechanism, determining whether or not a target position of the shutter in the case where one of the movement commands is executed corresponds to a detection result by the sensor;
A control method that reports an abnormality if it is determined that the device is not compatible. A spindle head that detachably holds a tool for machining a workpiece;
a tool changer that changes the tool held by the spindle head;
a cover covering the tool changing device and having 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 moving mechanism that moves the shutter to the open position when an opening command is received, and moves the shutter to the closed position when a closing command is received;
a control unit that transmits a movement command including the open command or the close command to the movement mechanism,
after transmitting one of the movement commands, either the open command or the close command, to the movement mechanism, and before transmitting the other of the movement commands, either the open command or the close command, to the movement mechanism, determining whether or not a target position of the shutter in the case where one of the movement commands is executed corresponds to a detection result by the sensor;
A program that causes a computer to execute a process to notify an abnormality if it is determined that the device is not compatible.

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