Processing apparatus, control method, and program

Abstract

To provide a machining apparatus, control method, and program capable of making the machining suspension due to a decrease of an air pressure, hardly occur.SOLUTION: In order to solve the problem, a machining apparatus 100 of the present invention includes: a main shaft 11 that retains and rotates a tool 12; a control unit 85 that controls the rotation of the main shaft 11; and an air pressure detection sensor 301 that detects an air pressure of air for use in cooling the main shaft 11. The control unit 85 determines, based on the number of rotations of the main shaft 11 and a result of the detection by the air pressure detection sensor 301, whether or not to continue machining.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a processing apparatus, a control method, and a program for performing machining of a workpiece using a tool.

Background Art

[0002] In a processing apparatus, it is well known to supply compressed air for cooling the spindle and preventing chips from flowing into the spindle.

[0003] If the air pressure of the spindle cooling air by compressed air is insufficient, sufficient cooling of the spindle and prevention of chip inflow may not be achieved. Therefore, generally, the spindle control unit is equipped with an air pressure detection sensor for monitoring the air pressure of spindle cooling. For example, in order to prevent air pressure shortage, a method of supplying sufficient air pressure by switching the flow path as in Patent Document 1 is known.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when sharing an air compressor with other devices or blowing air at multiple locations simultaneously, the air pressure may temporarily decrease. Conventionally, when the air pressure decreases, the machining stops halfway when the substrate firmware receives an air pressure shortage error.

[0006] The present invention can provide a processing apparatus, a control method, and a program that are less likely to stop halfway due to a decrease in air pressure.

Means for Solving the Problems

[0007] To solve the above problems, the processing apparatus of the present invention comprises a spindle that holds and rotates a tool, a control unit that controls the rotation of the spindle, and an air pressure detection sensor that detects the air pressure of the air used to cool the spindle, wherein the control unit determines whether or not to continue processing according to the rotation speed of the spindle and the detection result of the air pressure detection sensor.

[0008] Furthermore, in order to solve the above problems, the present invention provides a control method for a machining apparatus, which includes a control unit for controlling the rotation of a spindle that rotates a tool, and is characterized by comprising an air pressure detection step for detecting the air pressure of air for cooling the spindle, and a step for determining whether or not to continue machining according to the rotation speed of the spindle and the detected air pressure. [Effects of the Invention]

[0009] According to the present invention, by monitoring the spindle speed, if the spindle speed is below a predetermined speed, machining can continue even if the air pressure drops, making it less likely for machining to stop midway. [Brief explanation of the drawing]

[0010] [Figure 1] External perspective view of a processing apparatus according to one embodiment of the present invention. [Figure 2] A perspective view of the internal configuration of a processing apparatus according to an embodiment. [Figure 3] A schematic cross-sectional view of the electrical unit according to this embodiment. [Figure 4] Figure 4(a) is a perspective view, and Figure 4(b) is a cross-sectional view, showing the air blow section of the main shaft according to the embodiment. [Figure 5] A control block diagram of a processing apparatus according to an embodiment. [Figure 6] Block diagram of compressed air supply according to an embodiment [Figure 7] Flowchart for monitoring rotational speed according to the embodiment and determining whether machining can continue. [Figure 8]A flowchart for determining whether or not to perform an air blow after a specific sequence according to the embodiment. [Figure 9] Flowchart of adhesion detection according to the embodiment [Figure 10] Flowchart showing the process until the return to the origin is initiated according to the embodiment. [Modes for carrying out the invention]

[0011] The present invention will be described in detail below based on embodiments.

[0012] <Embodiment> A processing apparatus according to an embodiment of the present invention will be described with reference to Figures 1 to 5. Figure 1 is an external perspective view of a processing apparatus according to one embodiment of the present invention.

[0013] As shown in Figure 1, the processing device 100 houses the main body of the processing device within an outer cover 101. The outer cover 101 has an opening / closing door 102, and by opening the opening / closing door 102, the workpiece can be replaced.

[0014] The processing apparatus 100 comprises a frame 1 as a support member for the moving mechanism, a first moving mechanism 10, a second moving mechanism 20, and a third moving mechanism 30 supported on the frame 1, a support mechanism 40 for supporting the workpiece W as the object to be processed, a first rotating mechanism (rotating mechanism) 50 and a second rotating mechanism (another rotating mechanism) 60 that can rotate the support mechanism 40, a tool magazine 70, and an electrical unit 80.

[0015] Frame 1 is placed on a base 2 having an internal cavity, and as shown in Figure 2, it consists of a first frame section 3 and a second frame section 4 bent at a right angle from the end of the first frame section 3. In this embodiment, the first frame section 3 is arranged along the vertical direction, and the second frame section 4 is arranged along the horizontal direction. The second frame 4 may be constructed by connecting a portion along the Y-axis and a portion along the Z-axis using screws or the like, and providing beams.

[0016] The first moving mechanism 10 is supported on the first surface 3a of the first frame portion 3 of the frame 1 via the second moving mechanism 20, and the spindle 11 is movable in the Z-axis direction (vertical direction, first direction). A cutting tool 12 is detachably attached to the spindle 11 via a tool holder (clamp). The spindle 11 is rotationally driven by a motor 13. As shown in FIG. 2, the first moving mechanism 10 has a motor 14 and a guide shaft (not shown) disposed in the Z-axis direction, and reciprocates (moves up and down) the spindle 11 in the Z-axis direction along the guide shaft by driving the motor 14. The spindle 11 is movably supported along the guide shaft via a Z-axis support member 16. For example, the guide shaft is a ball screw, and the Z-axis support member 16 is a member that moves along the guide shaft (ball screw) that rotates by driving the motor 14. The guide shaft and the Z-axis support member 16 are covered by a cover 17.

[0017] The second moving mechanism 20 is supported on the first surface 3a of the first frame portion 3 of the frame 1, and the spindle 11 can be moved together with the first moving mechanism 10 in the X-axis direction (horizontal direction, second direction) orthogonal to the Z-axis direction. The second moving mechanism 20 has a motor 21 and a guide shaft (not shown) disposed in the X-axis direction, and reciprocates the first moving mechanism 10 in the X-axis direction along the guide shaft by driving the motor 21. Similarly to the first moving mechanism 10, for the second moving mechanism 20, for example, a ball screw may be used as the guide shaft.

[0018] The third moving mechanism 30 is supported on the second surface 4a of the second frame portion 4 of the frame 1, and the support mechanism 40 is movable in the Y-axis direction (horizontal direction, third direction) orthogonal to the Z-axis direction and the X-axis direction. The third moving mechanism 30 has a motor (not shown) and a guide shaft (not shown) disposed in the Y-axis direction, and reciprocates the support mechanism 40 in the Y-axis direction along the guide shaft by driving the motor. Similarly to the first moving mechanism 10, for the third moving mechanism 30, for example, a ball screw may be used as the guide shaft.

[0019] Furthermore, the third moving mechanism 30 is equipped with a support plate portion 31 that supports the second rotating mechanism 60, and the support plate portion 31 reciprocates along the guide axis in the Y-axis direction. As shown in Figure 2, the support mechanism 40 side of the frame 2 in the Y-axis direction is open, preventing interference with the frame 2 even when the support plate portion 31 and the second rotating mechanism supported by the support plate portion 31 move in the Y-axis direction. The third moving mechanism 30 is also capable of moving the support mechanism 40 in the Y-axis direction together with the second rotating mechanism 60 and the first rotating mechanism 50, as will be described in more detail later.

[0020] The support mechanism 40 supports a workpiece W, which is a workpiece to be cut by a processing tool 12, such as a dental prosthesis. Such a support mechanism 40 has a holding part 41 that holds the workpiece W, and a support part 42 whose both ends are connected to the rotating part 51 of the first rotating mechanism 50, and which supports the workpiece W via the holding part 41. The holding part 41 and the support part 42 are separate parts, and as will be described in detail later, the holding part 41 is fixed to the support part 42. However, the holding part 41 and the support part 42 may be made as a single unit.

[0021] The first rotation mechanism 50 is rotatable about the a-axis, which is a rotation axis perpendicular to the Z-axis direction of the support mechanism 40. In this embodiment, the a-axis is parallel to the X-axis direction. Such a first rotation mechanism 50 includes a support frame 53 that rotatably supports a rotating part 51 and a motor that rotationally drives the rotating part 51. The support frame 53 is formed in a substantially U-shape so as to surround the support mechanism 40 and consists of a first support part 53a that supports the motor and the rotating part 51, a second support part 53b that supports a rotating part (not shown) provided opposite the rotating part 51, and a connecting part 53c that connects the first support part 53a and the second support part 53b.

[0022] The rotating part 51 supported by the first support part 53a and the rotating part supported by the second support part 53b are arranged to face each other in the a-axis direction and to be rotatable about the a-axis as the axis of rotation. The a-axis ends of the support mechanism 40 are each supported by the rotating parts. In this way, the first rotating mechanism 50 supports the support mechanism 40 so that it can rotate about the a-axis.

[0023] The first rotation mechanism 50 is rotatable at least 180° and can reverse the front and back sides of the workpiece W supported by the support mechanism 40. In this embodiment, the first rotation mechanism 50 can rotate the support mechanism 40 360° around the a-axis.

[0024] The second rotation mechanism 60 is capable of rotatable support mechanism 40 about a b-axis, which is another axis of rotation perpendicular to the Z-axis and a-axis. In this embodiment, the b-axis is parallel to the Y-axis. Such a second rotation mechanism 60 has a rotating part to which the support frame 53 of the first rotation mechanism 50 is attached, and a motor that rotates the rotating part 61. The connecting part 53c of the support frame 53 is attached to the rotating part 61, and the motor 62 rotates the support frame 53, allowing it to rotate about the b-axis. Therefore, the second rotation mechanism 60, together with the first rotation mechanism 50, supports the support mechanism 40 so that it can rotate about the b-axis.

[0025] The tool magazine 70, which serves as a tool holder, is capable of holding multiple workpieces and is positioned adjacent to the first rotating mechanism 50. It is also supported so as not to rotate together with the second rotating mechanism 60. Furthermore, the tool magazine 70 is movable in the Y-axis direction together with the support mechanism 40 and the like by the third moving mechanism 30.

[0026] The tool magazine 70 holds multiple types of work tools, each integrally formed with a tool holder 12a, arranged in multiple rows along the Y-axis. The work tools attached to the spindle 11 are interchangeable. The tool holder 12a is the part held by the spindle 11 and may be integrally formed with the work tool or formed separately. In this embodiment, the work tool 12 is attached to a tool holder 12a with a chuck, and the tool-holding chuck portion of the spindle 11 holds it via the tool holder 12a, resulting in a double chuck configuration. However, the work tool may also be attached directly to the spindle 11. The work tool may be changed by an operator or automatically by the processing device 100.

[0027] When changing workpieces automatically, the second and third moving mechanisms 20 and 30 move the empty space in the tool magazine 70 below the spindle 11. Then, the first moving mechanism 10 lowers the spindle 11 and operates a chuck or other attachment / detachment device on the spindle 11 to remove the workpiece 12 attached to the spindle 11 and place it in the empty space in the tool magazine 70. Next, the first moving mechanism 10 raises the spindle 11, and the second and third moving mechanisms 20 and 30 move the position in the tool magazine 70 where the workpiece 12 to be replaced is located below the spindle 11. Then, the first moving mechanism 10 lowers the spindle 11 again and operates the attachment / detachment device to mount the workpiece 12 to be replaced onto the spindle 11. The workpiece 12 may be, for example, a drill or an end mill.

[0028] The electrical unit 80 is mounted inside a space enclosed by a rectangular parallelepiped that includes the longest sides of the frame 1 in the XYZ directions. That is, the electrical unit 80 is located on the opposite side of the first surface 3a of the first frame section 3 and on the opposite side of the second surface 4a of the second frame section 4. By arranging the electrical unit 80 inside the L-shaped frame 1, where the various moving and rotating mechanisms are not located, space can be used effectively, and the device can be made smaller.

[0029] The electrical unit 80 shown in Figure 2 controls the processing device 100. As detailed in Figure 3, the control board 83 and the control units 84a, 84b, 84c, 84x, 84y, and 84z are supported on the frame 81. The control board 83 controls the drive of the spindle and the motors of each axis. Each control unit 84a, 84b, 84c, 84x, 84y, and 84z calculates, for example, the pulse to be output to the motor from the signal of the rotary encoder of the corresponding motor, and appropriately controls the rotation of the corresponding motor. In response to the NC code executed in the circuit of the control board 83, each control unit 84a, 84b, 84c, 84x, 84y, and 84z, which are servo amplifiers, rotates the corresponding motor to the instructed position and rotation speed.

[0030] Specifically, the control unit 84a controls the motor 54 of the first rotation mechanism 50 to rotate the support mechanism 40 around the a-axis. The control unit 84b controls the motor of the second rotation mechanism 60 to tilt the support mechanism 40 around the b-axis and determine the orientation of the support mechanism 40. The control unit 84x also controls the motor 21 of the second movement mechanism 20 to move the main shaft 11 in the X-axis direction and determines the position of the main shaft 11 in the X-axis direction. The control unit 84y controls the motor of the third movement mechanism 30 to move the support mechanism 40 in the Y-axis direction and determines the position of the support mechanism 40 in the Y-axis direction. The control unit 84z controls the motor 13 of the first movement mechanism 10 to move the main shaft 11 in the Z-axis direction and determines the position of the main shaft 11 in the Z-axis direction. This determines the relative positions of the main shaft 11 and the support mechanism 40 in the X-axis, Y-axis, and Z-axis directions.

[0031] Furthermore, the processing apparatus 100 in this embodiment is an NC processing apparatus that performs automatic processing under computer control. Specifically, it creates processing data using a CAD / CAM system with an external terminal such as a personal computer, and processes the workpiece W based on this data using numerical control. For this purpose, an external terminal such as a personal computer that issues commands to the processing apparatus 100 is connected to the control board 83 of the processing apparatus 100 in a communication manner. The external terminal may create NC code according to conditions and transmit it to the control board 83. In addition, the processing apparatus 100 itself may be equipped with a computer that has a CPU and memory capable of numerical control.

[0032] For example, when creating a dental prosthesis using the processing device 100, data of the dental prosthesis measured by a 3D measuring instrument is transferred to a CAD / CAM system, and processing data is created by the CAD / CAM system. Then, based on this processing data, the processing device 100 is controlled to cut the workpiece W with the processing tool 12, thereby creating the dental prosthesis.

[0033] Let's explain Figure 4. The air blow section 87 in Figure 4(a) is part of the spindle 11's structure. When compressed air is supplied from the air inlet 122, it is blown from the four air outlets 121 towards the tool located at the tip of the spindle 11, cooling the tool and removing any chips adhering to it. Having four air outlets 121 allows air to be applied to the entire tool. Of course, there may be more than four air outlets 121.

[0034] Figure 4(b) is a cross-sectional view of the air outlet 121 of the air blow section 87. The air outlet 121 has a narrower blowing-side hole 124 that is angled toward the main shaft 11 side relative to the air inlet-side hole 123, which allows for an increase in the flow velocity of the blown air. The blowing-side hole 124 widens from the narrowed part to the tip. This simplifies the manufacturing process of the air outlet 121.

[0035] As shown in Figure 5, the electrical unit 80 includes a CPU 85 (control unit) which is a calculation means, input / output ports (I / O) 86i, control units 84x, 84y, and 84z for each motor, a control unit 84c for the main spindle, a control unit 84a for the a-axis, and a control unit 84b for the b-axis. The CPU 85, located on the control board 83, performs various calculations using the memory 86m based on the input data and signals, and transmits instructions for rotation speed and position to the connected servo amplifier control units 84x, 84y, 84z, 84a, 84b, and 84c.

[0036] The I / O 86i is connected to the air blow unit 87, dust collector 88, and tool length sensor 96 of the processing machine body. As described above, the air blow unit 87 blows air onto the tool, and the removed chips are collected by the dust collector 88. The tool length sensor 96 detects the length of the tool and sends a signal to the CPU 85.

[0037] The control units 84x, 84y, and 84z for each motor drive the X, Y, and Z motors based on commands from the CPU 85. Each of the control units 84x, 84y, and 84z for each motor is equipped with an encoder. The encoder detects, for example, the number of rotations, rotation angle, and rotation direction of the rotation axis of each motor control unit 84x, 84y, and 84z. It also detects the amount (position) that each stage x, y, and z has moved as a result of the drive of each motor control unit 84x, 84y, and 84z.

[0038] The control unit 84c controls a motor (not shown) that rotates the spindle 11, thereby controlling the rotational speed of the spindle. In addition, the control units 84a and 84b for the a and b axes drive the motors for the a and b axes, respectively, based on commands from the CPU 85.

[0039] By controlling each part of the processing device 100 with the CPU 85 in this manner, the workpiece W held as described above is subjected to predetermined processing.

[0040] The CPU 85 loads the program into a memory device such as memory 86m and executes each of the methods and processes described later.

[0041] Figure 5 is a control block diagram of the processing apparatus 100.

[0042] If the air pressure of the spindle cooling air does not meet the threshold, the spindle control unit 84c issues an air pressure shortage error. When the first air pressure detection sensor 301, described later, detects an air pressure shortage and the spindle control unit 84c issues an air pressure shortage error, the spindle may continue to rotate by inertia. Therefore, a second air pressure detection sensor 302, described later, is installed in the machine to monitor the air pressure supplied to the spindle control unit 84c, in addition to the first air pressure detection sensor 301. The second air pressure detection sensor 302 has a shorter threshold time for when it detects an air pressure shortage and issues an error than the first air pressure detection sensor 301. By monitoring the air pressure with the second air pressure detection sensor 302, the second air pressure detection sensor 302 can detect the air pressure shortage before the first air pressure detection sensor 301 issues an air pressure shortage error, preventing the spindle from rotating by inertia. As described later, a check valve 304 is installed in the air supply path to the first air pressure detection sensor 301 of the spindle control unit 84c. Therefore, at the location where the first air pressure detection sensor 301 is installed, which is downstream of the check valve 304 in the air path, the change in air pressure is slow. The second air pressure detection sensor 302, which is installed at a location where the check valve 304 is not installed (a location where the change in air pressure is immediately reflected), measures a value closer to the air pressure of the air compressor described later than the first air pressure detection sensor 301. In this configuration, even if the first air pressure detection sensor 301 outputs a value higher than the output value corresponding to insufficient air pressure, depending on the detection result of the second air pressure detection sensor 302, it may be better not to continue processing.

[0043] In the following embodiment, the threshold for detecting a drop in air pressure is set to 0.25 MPa relative to the normal air pressure of 0.3 MPa. The first air pressure detection sensor 301 issues an error after 4 seconds have elapsed since the air pressure reached 0.25 MPa, while the second air pressure detection sensor 302 issues an error after 0.1 seconds have elapsed since the air pressure reached 0.25 MPa. Therefore, the second air pressure detection sensor 302 is configured to detect a drop in air pressure earlier than the first air pressure detection sensor 301. Alternatively, the threshold for detecting a drop in air pressure for the second air pressure detection sensor 302 may be set higher than that for the first air pressure detection sensor 301, so that the second air pressure detection sensor 302 detects a drop in air pressure earlier than the first air pressure detection sensor 301.

[0044] The second air pressure detection sensor 302 monitors the air supplied to the spindle 11. If the air pressure monitored by the second air pressure detection sensor 302 falls below a threshold, the CPU 85 checks the rotational speed of the spindle 11. If the rotational speed of the spindle 11 is below a predetermined value, machining continues even if the spindle cooling air supply has decreased.

[0045] Figure 6 is a block diagram of the compressed air supply. Compressed air is supplied from the air compressor 200 to various parts of the processing machine 100.

[0046] To prevent the spindle control unit 84c from immediately issuing an air pressure shortage error, a check valve 304 is placed in the air supply path to the first air pressure detection sensor 301 of the spindle control unit 84c. This slows down fluctuations in air pressure, preventing an air pressure shortage error from occurring immediately, and thus the circuit board firmware no longer stops machining immediately. In addition, by monitoring the spindle rotation speed, it is possible to determine whether machining can continue when the air pressure drops, and if the spindle rotation speed is 30,000 rpm or less, machining will continue even when the air pressure drops. The second air pressure detection sensor 302 measures the air pressure before it enters the check valve 304. Air for spindle cooling and nozzle air 303 blown towards the tool located at the tip of the spindle are supplied by the air compressor 200.

[0047] Figure 7 is a flowchart that monitors the rotational speed and determines whether or not to continue machining.

[0048] In S401, the CPU 85 uses the second air pressure detection sensor 302 to determine whether the air pressure has fallen below a predetermined threshold. If the air pressure has fallen below the predetermined threshold, the process proceeds to S402. If the air pressure is above the predetermined threshold, the process proceeds to S404 and continues machining.

[0049] In S402, CPU85 checks the spindle speed. If the spindle speed is below the default value of 30,000 rpm, the process proceeds to S404 and continues machining. If the spindle speed exceeds 30,000 rpm, the process proceeds to S403.

[0050] In S403, check for recovery of air pressure. If air pressure is recovered, proceed to S404 and continue machining. If air pressure is not recovered, proceed to S405.

[0051] In S405, CPU85 determines whether a certain amount of time has passed since the air pressure became insufficient. In this case, one minute is set as the certain amount of time. Until one minute has elapsed, it returns to S403 to check whether the air pressure has recovered. If the air pressure does not recover after one minute, the process stops. The timer function, used to measure time, utilizes the capabilities of the CPU85.

[0052] As described above, if the settings are configured as described, machining will continue unconditionally if the rotational speed is 30,000 rpm or less.

[0053] If the rotational speed exceeds 30,000 rpm, machining will continue for a maximum of 1 minute. If the air pressure recovers during the 1 minute period, machining will continue after recovery; otherwise, machining will stop due to an insufficient air pressure error.

[0054] In this embodiment, the waiting time for air pressure to recover was set to 1 minute, but the length of this waiting period can be changed, and the specified value for the spindle speed can also be changed.

[0055] When a chip-scattering sequence occurs, air supplied from an air compressor is ejected as nozzle air 303 through the ejection holes 121 shown in Figure 4. The purpose of ejecting nozzle air 303 is to cool the tool tip during machining, to remove chips adhering to the tool holder during tool changes, and to remove chips adhering to the touch sensor during tool length measurement. Because the ejection of nozzle air 303 fills the chamber with chips, ejecting spindle cooling air for a certain period of time after the chip-scattering sequence using nozzle air 303 has ended can prevent chips from entering the spindle. At this time, if dust collection is performed by a dust collector 88 and the chips in the chamber are sucked out, it becomes more difficult for chips to enter the spindle. The timer values ​​for the cooling air and dust collection after the chip-scattering sequence has ended can also be changed by the user.

[0056] Furthermore, after the chip-scattering sequence is complete, the spindle chuck may be closed to reduce the path for chips to enter the spindle. The spindle chuck will close simultaneously with the timer activation and will remain closed even after the timer has finished.

[0057] After the machining operation is completed, this timer is activated, and cooling air is ejected from the spindle and dust is collected by the dust collector 88.

[0058] Tool changes and tool length measurements are performed during machining, when returning to the origin, and during manual operation. When a tool change or tool length measurement occurs, it is determined whether it is being performed during machining, returning to the origin, or by manual operation. If it occurs during machining, spindle cooling air is being blown out and machining has not ended, so the timer is not activated and machining continues. If a tool change or tool length measurement occurs while returning to the origin or operating by manual operation, the timer is activated, spindle cooling air is blown out, and dust is collected by the dust collector 88. If an external dust collector is used as the dust collector, the dust collector may be kept running during machining without linking the air blown out and dust collection.

[0059] Figure 8 is a flowchart for determining whether or not to perform an air blow after the sequence in which metal chips are scattered.

[0060] In S501, CPU85 determines whether or not the machining process is complete. If it is complete, the process proceeds to S506, then S507 and S508, and finally ends.

[0061] In S506, turn on the spindle cooling air and dust collection, and close the spindle chuck. In S507, it waits for the set timer to elapse.

[0062] In the S508, once the timer for the S507 finishes, the spindle cooling air and dust collection are turned off.

[0063] S502 determines whether the tool change or tool length measurement is complete. If it is complete, proceed to S503. If it is not complete, the timer will not start and the process will end.

[0064] S503 determines whether a tool change or tool length measurement was performed during machining. If machining is in progress, the timer is not started and the process ends. Otherwise, it proceeds to S504.

[0065] In S504, it is determined whether a tool change or tool length measurement occurred during the return to the origin position. If it was during the return to the origin position, proceed to S506. Otherwise, proceed to S505.

[0066] S505 determines whether the tool change or tool length measurement was performed manually. If it was a manual operation, the process proceeds to S506. Otherwise, the timer is not started and the process ends.

[0067] If chips remain attached to the tapered surface of the spindle 11 and a tool is gripped, the tool may become stuck to the tapered surface. If tool sticking occurs, and the chuck on the spindle 11 opens after the tool is stored in the tool magazine, vibrations may be applied to the spindle 11 due to movement or other reasons, potentially causing the tool to fall in an unintended location. Therefore, closing the chuck during movement can prevent the tool from falling.

[0068] Figure 9 shows the flowchart for detecting sticking.

[0069] At the start, the value indicating the number of times sticking has been detected is set to 1. In steps S601 to 605, the machining device 100 performs a tool storage operation. In S601, the CPU 85 drives the motors that drive the X-axis and Y-axis drive mechanisms, moving the spindle 11 so that it is positioned on the tool magazine 70. In S602, the motor that drives the Z-axis drive mechanism is driven, lowering the spindle 11 so that it is in the tool release position. In S603, the chuck is opened and the tool release operation is performed. At this time, air may be discharged to make it easier to release the stuck tool.

[0070] In the S604, after releasing the tool, the chuck remains open for a certain period of time to make it easier to release any stuck tools. In the S605, the Z-axis moves to a retracted position.

[0071] In S606, after releasing the tool, the chuck is closed, and in S607, the XY axes move onto the tool length sensor 96. At this point, it is unclear whether the tool is attached to the spindle 11 or not, but because the chuck is closed, even if the tool is attached, it can be prevented from falling due to movement.

[0072] In S608, the tool detection operation is performed using the tool length sensor 96, which is a touch sensor. At this time, the CPU 85 determines whether a tool is present or absent based on the previous tool length detection position stored in memory 86m. If no tool is present, S609 determines that the tool is not stuck and the system stops normally. If a tool is present, S609 determines that the tool is stuck and proceeds to S610 to determine if it is the first time the tool has stuck. If it is the first time, the system attempts to release the tool again, so the value indicating whether or not sticking has been detected is incremented to 2, and the system returns to S601 with sticking detected.

[0073] If the number indicating the number of times sticking has been detected in S610 is 2, it is determined that sticking has been detected for the second time, and the process proceeds to S611, where the chuck is closed and the XY axis is moved so that its position is above the tool magazine 70. In S612, the Z axis is lowered by a predetermined amount and stopped at a position where the user can remove the tool, and in S613 the chuck is opened. Then, in S614, the CPU 85 notifies the user that there is an error state due to tool sticking and prompts them to remove the tool. The predetermined amount refers to, for example, a position where the tool has been lowered 25 mm from the retracted position.

[0074] Furthermore, there is a possibility that the power to the machining device 100 may be turned off while the tool is stuck to the spindle 11. Therefore, it is necessary to close the chuck when returning to the home position to prevent the tool from falling. However, if the power is turned off while the tool on the tool magazine 70 is in a position where it can be gripped, and the return to the home position is started from that position and the chuck is closed, it is possible that the machine may mistakenly grip a tool that is not stuck to it. In such cases, it is possible to prevent the machine from mistakenly gripping a tool by moving the Z-axis from the tool gripping position on the tool magazine 70 to a position that is not a tool gripping position.

[0075] Figure 10 shows a flowchart of the process leading up to the start of the return to the home position.

[0076] In S701, the CPU 85 issues a command to start returning to the home position. In S702, the CPU 85 determines whether the home positioning is complete. If the home positioning is complete, S703 determines whether the current position of the spindle 11 is on the tool magazine 70. If it is on the tool magazine 70, S704 moves the Z-axis to the retracted position and then S705 closes the chuck. If the home positioning is not complete, the precise position of each axis cannot be obtained, so in S706 the Z-axis is raised by a predetermined amount and S707 the chuck is closed to prevent accidentally gripping a tool if the machine had stopped in a position where it could grip a tool. The predetermined amount is, for example, 5 mm.

[0077] After the origin setting operation is performed in S708, in S709 the CPU 85 controls the processing device 100 to start the return to origin operation. [Explanation of Symbols]

[0078] 11 Spindle 12 Processing tools 84c Spindle Control Unit 85 CPU 86MB memory 87 Air blow section 100 Processing equipment (processing equipment) 301 First air pressure detection sensor 302 Second air pressure detection sensor

Claims

1. A spindle that holds and rotates the tool, A control unit that controls the rotation of the main spindle, The system includes an air pressure detection sensor that detects the air pressure of the air used to cool the spindle, The processing apparatus is characterized in that the control unit determines whether or not to continue processing according to the rotational speed of the spindle and the detection result of the air pressure detection sensor.

2. The control unit stops machining when the rotational speed of the spindle is above a predetermined threshold and the detection result of the air pressure detection sensor is below a predetermined threshold. When the rotational speed of the main spindle is less than a predetermined threshold, The processing apparatus according to claim 1, characterized in that it continues processing regardless of the detection result of the air pressure detection sensor.

3. Furthermore, it is equipped with a timekeeping device for measuring time, The machining apparatus according to claim 1, characterized in that the control unit continues machining until the timing means has measured that a predetermined time has elapsed, when the rotation speed of the spindle is equal to or greater than a predetermined threshold and the detection result of the air pressure detection sensor is less than a predetermined threshold, and then stops machining.

4. The system includes a check valve provided in the air path of the air supplied to the main shaft, The aforementioned air pressure detection sensor is A first air pressure detection sensor is provided downstream of the aforementioned check valve, It includes a second air pressure detection sensor that detects the air pressure before it enters the check valve, The control unit, when the output of the first air pressure detection sensor is equal to or greater than the output value corresponding to insufficient air pressure, and the output of the second air pressure detection sensor is less than a predetermined threshold, The processing apparatus according to claim 1, characterized in that it determines whether or not to continue processing.

5. The processing apparatus according to claim 1, characterized in that the air for cooling the spindle is blown from an air blow section provided on the spindle.

6. A program that causes a computer to function as the control unit of the processing apparatus according to any one of claims 1 to 5.

7. A control method for a machining apparatus, comprising a control unit that controls the rotation of a spindle that holds and rotates a tool, An air pressure detection step for detecting the air pressure of the air used to cool the spindle, A control method for a machining apparatus, characterized by comprising the step of determining whether or not to continue machining according to the rotational speed of the spindle and the detected air pressure.

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