Machining apparatus and method of control

Abstract

To prevent a dent from occurring in an object under machining upon making an interrupt operation in machining.SOLUTION: A machining apparatus for machining an object of machining using a main spindle 11 gripping a tool 12 temporarily stops, if an alarm for temporary stop occurs during machining, machining operation after executing a code for performing a spindle-retracting operation to retract the main spindle 11 such that a tool 12 included in machining data moves away from a work-piece. In the spindle retracting operation, an operation may be executed to retract upward. The alarm may be related to the flow rate of coolant.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a processing apparatus for processing a workpiece and a control method for a processing system including the processing apparatus.

Background Art

[0002] When the processing operation is stopped, it is necessary to safely return to the interruption point during processing and calculate a path for resuming the processing. Further, when the processing is interrupted, indentations are generated on the workpiece. This is because deflection occurs in the direction opposite to the feed direction during processing, and when the processing is stopped, this deflection disappears, and the portion that was left uncut due to the conventional deflection is cut off, resulting in a non-continuous processed surface and indentations.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Patent Document 1 describes a processing apparatus that automatically creates a path for safely resuming processing, eliminating the need for an operator to create a restoration command during resumption.

Means for Solving the Problems

[0005] In order to solve the above problems, a processing apparatus of the present invention is a processing apparatus that performs processing on a workpiece fixed to a jig using a tool, and is capable of executing a cleaning operation on chips generated during processing, and the cleaning operation is characterized by being executed according to the jig to be used.

Effects of the Invention

[0006] According to the present invention, processing can be safely resumed, and it is also possible to prevent indentations on the workpiece due to the interruption operation.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

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Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0008] The embodiments will be described with reference to the drawings. First, the overall configuration of the processing system 1 of the present embodiment will be described with reference to FIGS. 1 and 2.

[0009] [Processing System] The processing system 1 includes a processing device 200 and a coolant supply device 210. The processing device 200 performs processing of a workpiece with a tool in a processing area 120. The processing device 200 houses a processing machine 100 in an exterior cover 101 as a housing. That is, the exterior cover 101 has a spindle, a tool magazine, etc. to be described later disposed therein. An openable and closable opening / closing door (not shown) is provided at the front side opening of the exterior cover 101. When the opening / closing door is open, access to the inside of the housing, that is, the processing area 120 to be described later is possible, and workpiece replacement and manual tool replacement are possible.

[0010] The coolant liquid supply device 210 is a device that supplies coolant liquid, which is a liquid for cooling workpieces, tools, etc., into the processing area 120 of the processing device 200. The coolant liquid supply device 210 of the present embodiment is arranged below the processing device 200 and has a tank 211, a pump 212, a flow meter 213, a solenoid valve 214, etc., which are connected by pipes 220 to 224. Also, the arrows shown in FIGS. 1 and 2 indicate the path and direction in which the coolant liquid flows. The tank 211 stores the coolant liquid, and the pump 212 sucks out the coolant liquid from the tank 211 through the pipe 220 and sends it into the pipe 221. The coolant liquid sent into the pipe 221 passes through the flow meter 213 through the pipe 222. The flow meter 213 measures the flow rate of the coolant liquid supplied from the pump 212 and sends a signal to the CPU 85 (FIG. 4), which is the main control unit of the processing system 1 described later. A strainer 215 is provided in the middle of the pipe 222 to remove foreign matter in the pipe path.

[0011] The coolant liquid that has passed through the flow meter 213 is sent to the pipe 223 and reaches the solenoid valve 214 provided in the pipe 223. The solenoid valve 214 opens and closes the flow path and is controlled by the above-mentioned CPU 85 to supply and stop the coolant liquid to the processing device 200. The pipe 223 is connected to the processing device 200, and the coolant liquid that has passed through the open solenoid valve 214 is supplied into the processing area 120 through the coolant discharge part 202 as the coolant liquid supply part provided in the spindle head 201 of the processing device 200. When the solenoid valve 214 is in the closed state, the coolant liquid supplied from the pump 212 is returned to the tank 211 through the pipe 224 branched from the pipe 221.

[0012] The coolant discharge unit 202 is, for example, a nozzle provided around the spindle 11 (Fig. 3) of the spindle head 201. By discharging the coolant liquid downward, the coolant liquid is supplied toward the tool held by the spindle 11 and the workpiece which is the object to be machined. The coolant liquid supplied from the coolant discharge unit 202 accumulates in the lower part within the machining area 120 and is discharged from the lower part of the machining apparatus 200. A tray 216 is provided below the machining apparatus 200 to receive the coolant liquid discharged from the machining apparatus 200 and return it to the tank 211. Thus, in the machining system 1 of the present embodiment, the coolant liquid is used to cool the tool and the workpiece during machining. Note that in the present embodiment, an air blow unit 87 (Fig. 4) for blowing air onto the tool or the like is provided.

[0013] [Machine tool] Next, the machine tool 100 disposed inside the exterior cover 101 of the machining apparatus 200 will be described with reference to Fig. 3. The machine tool 100 includes a frame 1xz as a moving mechanism support member, a first moving mechanism (Z-axis moving mechanism) 10, a second moving mechanism (X-axis moving mechanism) 20, and a third moving mechanism (Y-axis moving mechanism) 30 each supported by the frame 1xz, a support mechanism 40 for supporting a workpiece W as an object to be machined, a first rotation mechanism (rotating device) 50 and a second rotation mechanism 60 as rotation means for rotatably supporting the support mechanism 40, a tool magazine 70, and an electrical equipment unit 80. The first moving mechanism 10, the second moving mechanism 20, and the third moving mechanism 30 constitute a moving device 100A as a moving means for relatively moving the spindle 11 and the holding device 41, which will be described later, in the three axial directions of X, Y, and Z.

[0014] The first moving mechanism 10 is supported by the first frame portion 3 of the frame 1xz via the second moving mechanism 20, and is capable of moving the spindle 11 in the Z-axis direction (vertical direction, first direction). A tool 12 is detachably attached to the spindle 11 via a tool holder. That is, the spindle 11 can grip the tool 12. The spindle 11 is rotationally driven by a motor 13. The first moving mechanism 10 has a motor 14 and a guide shaft (not shown) arranged 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 on the guide shaft via a Z-axis support member (not shown). The guide shaft and the Z-axis support member are covered by a cover 17.

[0015] The second moving mechanism 20 as a moving part is supported by the first frame portion 3 of the frame 1xz, and is capable of moving the spindle 11 together with the first moving mechanism 10 in the X-axis direction (predetermined direction, horizontal direction, second direction) orthogonal to the Z-axis direction. The second moving mechanism 20 has a motor 21, a guide shaft 22 arranged in the X-axis direction, and rails 23, 24 arranged in the X-axis direction, and reciprocates the first moving mechanism 10 in the X-axis direction along the guide shaft 22 by driving the motor 21. Specifically, the guide shaft 22, which is a screw shaft, is inserted through a nut member 19 fixed to a holding portion 18 that holds the spindle 11 and the first moving mechanism 10. Further, engaging portions 25, 26 that engage with the rails 23, 24 are provided on the holding portion 18. When the guide shaft 22 rotates by the motor 21, the nut member 19 screwed with the guide shaft 22 moves along the guide shaft 22. Then, the holding portion 18 to which the nut member 19 is fixed and the spindle 11 and the first moving mechanism 10 held by the holding portion 18 move in the X-axis direction based on the engagement between the engaging portions 25, 26 and the rails 23, 24. The second frame portion 4 is connected so as to extend in the Y-axis direction from the lower end portion of the first frame portion 3, and the first frame portion 3 and the second frame portion 4 are further connected by a reinforcing plate 29.

[0016] The third moving mechanism 30 is supported on the lower surface of the second frame portion 4 of the frame 1xz, and is capable of moving the support mechanism 40 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 32 and a guide shaft (not shown) arranged in the Y-axis direction, and reciprocates the support mechanism 40 along the guide shaft in the Y-axis direction by driving the motor 32. As shown in FIG. 3, the side of the gantry 2 on the support mechanism 40 side in the Y-axis direction is open. And the third moving mechanism 30 is 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 detail later.

[0017] The support mechanism 40 supports, for example, a workpiece W as an object to be machined that is machined by a tool 12 such as a dental prosthesis. Such a support mechanism 40 has a holding device 41 as a holding portion for holding the workpiece W, and a support portion 42 whose both ends are respectively connected to the rotating portions 51 of the first rotating mechanism 50 and supports the workpiece W via the holding device 41.

[0018] The first rotating mechanism 50 as a rotating device is capable of rotating the support mechanism 40 about an a-axis as a rotation axis orthogonal to the Z-axis direction. In the present embodiment, the a-axis is parallel to the X-axis direction. Such a first rotating mechanism 50 has a support frame 53 that rotatably supports the rotating portion 51, and a motor that rotationally drives the rotating portion 51. The support frame 53 is formed in a substantially U-shape so as to surround the support mechanism 40, and includes a first support portion 53a that supports the motor and the rotating portion 51 on one side (driving side), a second support portion 53b that supports the rotating portion on the other side (driven side), and a connecting portion 53c that connects the first support portion 53a and the second support portion 53b.

[0019] The rotating portion 51 supported by the first support portion 53a and the rotating portion supported by the second support portion 53b are arranged so as to face each other in the a-axis direction and be rotatable about the a-axis as a rotation axis. And both ends of the support mechanism 40 in the a-axis direction are respectively supported by the rotating portions on both sides. Thereby, the first rotating mechanism 50 supports the support mechanism 40 so as to be rotatable about the a-axis (X-axis).

[0020] The first rotation mechanism 50 is rotatable by at least 180° and can reverse the front and back of the workpiece W supported by the support mechanism 40. In this embodiment, the first rotation mechanism 50 can rotate the support mechanism 40 by 360° about the a-axis.

[0021] The second rotation mechanism 60 can rotate the support mechanism 40 about another rotation axis, the b-axis, which is orthogonal to the Z-axis direction and the a-axis. In this embodiment, the b-axis is parallel to the Y-axis direction. Such a second rotation mechanism 50 has a rotating part to which the support frame 53 of the first rotation mechanism 50 is attached, and a motor that rotationally drives the rotating part. The rotating part is attached with the connecting part 53c of the support frame 53 and can rotate the support frame 53 about the b-axis by being rotationally driven by the motor.

[0022] The tool magazine 70 as a tool holding part can store a plurality of tools and is arranged adjacent to the first rotation mechanism 50. The tool magazine 70 can be moved in the Y-axis direction together with the support mechanism 40 and the like by the third moving mechanism 30. However, even when the support mechanism 40 rotates about the a-axis, the tool magazine 70 does not rotate, and even when the support mechanism 40 rotates about the b-axis, the tool magazine 70 does not rotate.

[0023] In the tool magazine 70, a plurality of types of tools integrally formed with the tool holders 12a are arranged side by side in a plurality of rows along the Y-axis direction in a state of being held. And the tool attached to the spindle 11 can be exchanged.

[0024] Also, in this embodiment, before and after tool storage and removal, an operation of checking whether the tool 12 is gripped by the spindle 11 is performed by bringing the tip of the tool 12 into contact with a touch sensor 96 as a tip detection means capable of detecting the tip of the tool 12 gripped by the spindle 11.

[0025] The electrical equipment unit 80 is mounted inside the frame 1xz. That is, the electrical equipment unit 80 is disposed on the upper side of the second frame portion 4 on the side opposite to the side where the first moving mechanism 10 of the first frame portion 3 is supported. Such an electrical equipment unit 80 controls the processing system 1 or the processing device 200, and has a control board for controlling the driving of the spindle and the motors of each axis, and calculates pulses output to the motors from the signals of the rotary encoders of the corresponding motors, and has a plurality of control units for appropriately controlling the rotation of the corresponding motors.

[0026] Moreover, the processing machine 100 of the present embodiment is an NC processing device that performs automatic processing under computer control. Specifically, processing data is created by a CAD / CAM system using an external terminal such as a personal computer, and the workpiece W is processed numerically based on this data. For this purpose, an external terminal such as a personal computer for giving commands to the processing machine 100 is connected to the processing machine 100. Note that a computer equipped with a CPU and a memory capable of numerical control may be provided in the processing machine 100 itself. The control means described later may be provided either in the processing device or in the computer connected to the processing device.

[0027] For example, when creating a dental prosthesis (dental material) with the processing machine 100, the data of the dental prosthesis measured by a three-dimensional 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 machine 100 is controlled to cut the workpiece W with the tool 12 to create a dental prosthesis.

[0028] Next, the control configuration within the electrical equipment unit 80 will be described with reference to FIG. 4. The electrical equipment unit 80 includes a CPU 85 which is a control means (main control unit), input / output ports (I / O) 86i, control units 84x, 84y, 84z for each motor, a control unit 84c for the main spindle, a control unit 84a for the a-axis, a control unit 84b for the b-axis, and the like. The CPU 85 performs various operations using the memory 86m based on the input data and signals, and transmits instructions regarding the rotational speed and position to the control units 84x, 84y, 84z, 84a, 84b, 84c which serve as connected servo amplifiers.

[0029] The I / O 86i is connected to the compressor 350, the pump 212, the touch sensor 96, the air pressure detection sensor 91, the flow meter 213, and the solenoid valve 214. The compressor 350 supplies air to the air blow portion 87 of the processing apparatus 200. The air blow portion 87 blows the air supplied from the compressor 350 onto the tool 12 attached to the main spindle 11 to cool the tool 12 and remove the chips adhering to the tool 12. The pressure of the air supplied to the air blow portion 87 is detected by the air pressure detection sensor 91, and the detection signal of the air pressure detection sensor 91 is sent to the CPU 85 via the I / O 86i.

[0030] As described above, the pump 212 supplies the coolant liquid to the coolant discharge portion 202. The coolant discharge portion 202 supplies the coolant liquid toward the tool 12 and the workpiece. In addition to being used to confirm whether the tool 12 is gripped by the main spindle 11 during the tool change operation as described above, the touch sensor (tool length sensor) 96 as the tip detection means detects the length of the tool 12 and sends a signal to the CPU 85.

[0031] The control units 84x, 84y, and 84z of the respective motors provided in the CPU 85 drive the X, Y, and Z motors based on commands from the CPU 85. Encoders are provided for the respective motors 21, 32, and 14 as position detection means. The encoder detects, for example, the number of rotations, the rotation angle, and the rotation direction of the rotation shafts of the respective motors 21, 32, and 14. Then, the amount by which each stage x, y, z has actually moved due to the driving of the respective motors 21, 32, and 14 (the actual position, the relative position with respect to the holding device 41 of the spindle 11) is detected.

[0032] The spindle control unit 84c controls a motor (not shown) that rotates the spindle 11 to control the rotation speed of the spindle (spindle). Further, the control units 84a and 84b of the a and b axes drive the motors 54 and 62 of the a and b axes based on commands from the CPU 85. Encoders 54a and 62a are also provided for these respective motors 54 and 62, and it is possible to detect the rotation angles around the a axis and the b axis of the support mechanism 40.

[0033] By thus controlling each part of the processing machine 100 by the CPU 85, predetermined processing is performed on the workpiece W held as described above. Each operation and process described later is executed by the CPU 85 developing a program in a storage means such as the memory 86m.

[0034] FIG. 5 shows an example in which an external terminal 800 is connected as a terminal for controlling the processing device 200 and the coolant circulation device 210 that constitute the above-described processing system.

[0035] FIG. 6 shows a flowchart of the processing operation and interruption / resumption.

[0036] In S301, processing is started. In S302, the processing operation is being performed.

[0037] In S303, it is confirmed whether an alarm event has occurred. For example, the coolant flow rate is NG or the filter is clogged. If no alarm event has occurred, the process returns to S302 to continue the processing. If an alarm event has occurred, the alarm flag for the alarm is turned ON and the process proceeds to S304. In S304, the processing is continued.

[0038] In S305, it is confirmed whether the current instruction is an instruction for axis retraction. If it is an instruction for axis retraction, a pause command is issued and the process proceeds to S306, otherwise the process returns to S304 and continues machining.

[0039] To determine whether or not an axis retraction operation is being performed, the code for the G00 rapid traverse operation is searched for. An axis retraction operation is used when the tool 12 is moved upward when it is not in contact with the workpiece W during machining. G00 is a G code used when moving the tool at a rapid traverse speed, and performs an axis retraction operation. Here, the axis retraction operation may be performed in a direction other than upward, as long as the spindle is retracted so that the tool is away from the workpiece.

[0040] A pause command is issued on the line where G00 is found. If G00 is not found, machining may be stopped after a certain time or a certain number of lines have been machined. When issuing a pause command, it may be determined which alarm flag was turned ON in S303, and a display may be displayed on the display unit in the control device 800 via the application unit to prompt the user to take a different action for each alarm. It is also possible to switch the interruption operation depending on the machining method by determining whether the current machining is rough machining or finish machining and determining whether to search for G00. Also, a code other than G00 may be used to determine whether an axis retraction operation is required.

[0041] In S306, the state transitions to a paused state. In S307, the alarm is cleared by the user taking action against the alarm. Actions against the alarm will be described with reference to Figs. 7 and 8.

[0042] In S308, machining is resumed. If machining is resumed without the alarm being released, the machine transitions again to the pause state in S306 before starting machining. In the case of a flow rate confirmation error, if the flow rate meets the specified value here, the alarm may be released.

[0043] Fig. 7 shows the procedure for resetting the coolant flow rate alarm. Both insufficient and excessive coolant flow rates can be reset using the same procedure.

[0044] A coolant flow rate alarm has occurred on the S310.

[0045] In step S311, the user adjusts the coolant flow rate. A valve for adjusting the flow rate may be included in the coolant circulation device 210.

[0046] The S312 circulates the coolant.

[0047] In S313, the count of seconds i is set to 0.

[0048] In S314, it is confirmed that the flow rate is within a specified range. The flow rate is measured using a flow meter 213. For example, the specified ranges are an undershoot threshold of 1.5 L / s and an overshoot threshold of 2.3 L / s. If the undershoot threshold is not met, the life of the blade of the tool 12 will be shortened, for example causing chipping of the cutting edge. If the flow rate exceeds the overshoot threshold, there is a possibility of unexpected splashing, so a limit is set to prevent breakdowns. If it is determined that the flow rate is normal, the process proceeds to S315, and if it is not within the range, the process returns to S313.

[0049] In S315, the second count is increased by 1.

[0050] In S316, it is determined whether 5 seconds have passed. If 5 seconds have passed, the process proceeds to S317, and if not, the process returns to S314.

[0051] The coolant flow rate alarm has been reset in the S317.

[0052] Fig. 8 shows the procedure for clearing a clogged filter alarm. In S320, a coolant flow rate alarm occurs. In S321, the user replaces the filter. In S322, it is determined whether the user has issued a replacement command from the application section in the external terminal 800. If a replacement command has been issued, the process proceeds to S323. In S323, the clogged filter alarm is cleared. [Explanation of symbols]

[0053] 11...Spindle 20... Second moving mechanism (moving part) 800...external device

Claims

Claim 1 A processing apparatus that performs processing on a workpiece using a spindle that holds a tool, wherein when an alarm for a temporary stop occurs during processing, after executing a code for performing an axis retraction operation that retracts the spindle so that the tool included in the processing data moves away from the workpiece, the processing operation is temporarily stopped. The processing apparatus is characterized by this. Claim 2 The processing apparatus according to claim 1, wherein the axis retraction operation is an operation of retracting upward. Claim 3 The processing apparatus according to claim 1 or 2, wherein the alarm relates to the coolant flow rate. Claim 4 A control method for a processing system including a processing apparatus that performs processing on a workpiece using a tool that holds a tool, wherein when an alarm for a temporary stop occurs during processing, after executing a code for performing an axis retraction operation that retracts the spindle so that the tool included in the processing data moves away from the workpiece, the processing operation is temporarily stopped. The control method is characterized by this.

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