Control device, machining path generation method, and computer program

Abstract

To provide a machine tool making it possible to diminish correction work to be performed by an operator for the purpose of generating a highly precise processing route.SOLUTION: A machine tool performs an approach motion of causing a main shaft to approach the perimeter of a master workpiece along a reference route on an external or internal circumference of the master workpiece determined based on plural reference points, and determines whether a tool comes into contact with the perimeter during the approach motion. When the tool comes into contact with the perimeter, the machine tool acquires the coordinates of the main shaft, performs a receding motion of causing the main shaft to recede from the reference route in a receding angle direction or a direction of a predetermined angle, performs the approach motion and receding motion, acquires the coordinates of the main shaft every time the tool comes into contact with the perimeter during the approach motion, generates a processing route of the main shaft on the basis of plural sets of coordinates, computes a reference angle that is an angle defined with the coordinates of the main shaft and the coordinates of the reference point, determines whether the receding angle is larger or smaller than a border angle that is 180 degrees or an angle based on the reference angle, corrects the receding angle on the basis of a result of the determination and a predetermined angle, and then performs the receding motion using the corrected receding angle.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present technology relates to a control device that generates a machining path for a spindle on which a tool is attached, a machining path generation method, and a computer program. [Background technology]

[0002] When removing burrs on the surface of a workpiece, for example, the outer periphery of the workpiece or the inner periphery of a hole in the workpiece, a tool is attached to the spindle of a machine tool, and the spindle moves along the outer or inner periphery of the workpiece to remove the burrs. Before the spindle moves, the machine tool generates a machining path. The spindle moves along the machining path.

[0003] The machining path of the spindle can be generated by offline teaching, which can automatically generate the machining path of the spindle based on CAD data of the workpiece to avoid interference between the workpiece and the spindle (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-150864 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the machining path is a rough path, and after generating the machining path, the operator needs to correct the machining path while checking the operation of the spindle in order to create a highly accurate machining path.

[0006] The present disclosure has been made in consideration of the above circumstances, and aims to provide a control device, a machining path generation method, and a computer program that can reduce the operator's correction work required to generate highly accurate machining paths. [Means for solving the problem]

[0007] A control device according to an embodiment of the present disclosure includes a first moving unit that performs an approaching operation of a spindle, on which a tool is attached, to a peripheral portion of a master workpiece along a reference path on an outer circumferential side or an inner circumferential side of the master workpiece, the reference path being determined based on a plurality of reference points; a contact determination unit that determines whether or not the tool has come into contact with the peripheral portion during the approaching operation by the first moving unit; an acquisition unit that acquires coordinates of the spindle when the contact determination unit determines that the tool has come into contact; and a second moving unit that performs a separating operation of the spindle in a separating angle direction that is a predetermined angle with respect to the reference path after the acquisition unit acquires the coordinates of the spindle. The numerical control device acquires coordinates of the spindle each time the tool contacts the peripheral portion during an approach operation, and generates a machining path for the spindle based on the acquired multiple coordinates. The numerical control device includes: a reference angle calculation unit that calculates a reference angle, which is the angle formed by the coordinate of the spindle acquired by the acquisition unit and the coordinate of the reference point; a magnitude judgment unit that judges whether the separation angle is larger or smaller than a boundary angle, which is an angle based on 180 degrees or the reference angle calculated by the reference angle calculation unit; and a correction unit that corrects the separation angle based on the judgment result of the magnitude judgment unit and a predetermined angle, and the second moving unit performs a separation operation using the separation angle corrected by the correction unit.

[0008] In this disclosure, the spindle moves toward and away from the peripheral edge of the master workpiece along a reference path. If the tool contacts the peripheral edge during the approaching operation, the control device acquires the coordinates of the spindle and generates a machining path based on the coordinates. The control device also calculates a reference angle formed by the current coordinates of the spindle and the coordinates of the reference point, determines whether the separation angle, which indicates the direction of the separation operation, is larger or smaller than a boundary angle, which is an angle based on 180 degrees or the reference angle, and corrects the separation angle based on the determination result. If the separation angle needs to be corrected, i.e., if there is a possibility of contact with the master workpiece, the separation angle is corrected. This automatically prevents the spindle from interfering with the master workpiece during the separation operation, reducing the operator's correction work.

[0009] In a control device according to one embodiment of the present disclosure, the reference angle calculation unit calculates the angle formed by a first coordinate of the main axis acquired by the acquisition unit, a second coordinate of the main axis acquired by the acquisition unit before acquiring the first coordinate, and the reference point after acquiring it by the acquisition unit.

[0010] In the present disclosure, an appropriate reference angle is calculated based on the first coordinate, the second coordinate, and the reference point.

[0011] In a control device according to one embodiment of the present disclosure, the magnitude determination unit includes a first calculation unit that calculates a first comparative angle based on 180 degrees, and a first angle determination unit that determines whether the reference angle calculated by the reference angle calculation unit is smaller than the first comparative angle, and when the first angle determination unit determines that the reference angle is smaller than the first comparative angle, the correction unit performs a first correction by adding a correction amount to the separation angle.

[0012] In the present disclosure, the magnitude of the first comparative angle based on the reference angle and 180 degrees is determined, thereby preventing contact with the master workpiece.

[0013] In a control device according to one embodiment of the present disclosure, the magnitude determination unit includes a second calculation unit that calculates a second comparative angle based on the separation angle, and a second angle determination unit that determines whether the reference angle calculated by the reference angle calculation unit is smaller than the second comparative angle, and when the correction unit determines that the reference angle is smaller than the second comparative angle, it adds a correction amount to the separation angle to perform a second correction.

[0014] In the present disclosure, when the reference angle is smaller than the second comparative angle, a correction is made to prevent contact with the master workpiece.

[0015] In one embodiment of the control device of the present disclosure, the magnitude determination unit includes a third calculation unit that calculates a third comparison angle based on the separation angle, and a third angle determination unit that determines whether the reference angle calculated by the reference angle calculation unit is greater than the third comparison angle, and when the correction unit determines that the reference angle is greater than the third comparison angle, it adds a correction amount to the separation angle to perform a third correction.

[0016] In the present disclosure, when the reference angle is greater than the third comparison angle, a correction is made to prevent contact with the master workpiece.

[0017] In the control device according to an embodiment of the present disclosure, the first comparative angle is an angle obtained by adding a first additional angle to 180 degrees and subtracting the separation angle from the added angle.

[0018] In the present disclosure, the first comparative angle is based on the sum of 180 degrees and the first additional angle, thereby reliably preventing contact between the master workpiece and the tool.

[0019] In the control device according to an embodiment of the present disclosure, the correction unit adds a value obtained by subtracting the reference angle from the first additional angle to the separation angle.

[0020] In the present disclosure, the correction unit calculates an appropriate correction amount to prevent contact with the master workpiece.

[0021] In the control device according to the embodiment of the present disclosure, the second comparative angle is an angle obtained by adding a second additional angle to the separation angle.

[0022] In the present disclosure, the second additional angle is added to the separation angle to determine an appropriate second comparison angle.

[0023] In the control device according to an embodiment of the present disclosure, the correction unit adds a value obtained by subtracting the second comparative angle from the reference angle to the separation angle.

[0024] In the present disclosure, the correction unit calculates an appropriate correction amount to prevent contact with the master workpiece.

[0025] In the control device according to an embodiment of the present disclosure, the third comparative angle is an angle obtained by subtracting a third additional angle from the separation angle.

[0026] In the present disclosure, the third additional angle is subtracted from the separation angle to determine an appropriate third comparison angle.

[0027] In the control device according to an embodiment of the present disclosure, the correction unit adds a value obtained by subtracting the third comparative angle from the reference angle to the separation angle.

[0028] In the present disclosure, the correction unit calculates an appropriate correction amount to prevent contact with the master workpiece.

[0029] a machining path generation method according to an embodiment of the present disclosure, which performs an approach operation of a spindle to a peripheral portion of a master workpiece along a reference path on an outer peripheral side or an inner peripheral side of the master workpiece, the reference path being determined based on a plurality of reference points; determines whether a tool attached to the spindle has come into contact with the peripheral portion during the approach operation; acquires coordinates of the spindle; if it is determined that the tool has come into contact with the peripheral portion, performs a separation operation of the spindle in a direction of a separation angle that is a predetermined angle relative to the reference path; acquires the coordinates of the spindle each time the tool comes into contact with the peripheral portion during the approach operation; and generates a machining path for the spindle based on the plurality of acquired coordinates; calculates a reference angle that is an angle formed by the acquired coordinates of the spindle and the coordinates of the reference point; determines whether the separation angle is larger or smaller than 180 degrees or a boundary angle that is an angle based on the reference angle; corrects the separation angle based on the determination result and a predetermined angle; and performs the separation operation using the corrected separation angle.

[0030] In this disclosure, the spindle moves toward and away from the peripheral edge of the master workpiece along a reference path. If the tool comes into contact with the peripheral edge during the approaching operation, the control device acquires the coordinates of the spindle and generates a machining path based on the coordinates. The spindle also moves away from the master workpiece based on a separation angle based on a line connecting the current coordinates of the spindle and the coordinates of the reference point. If the separation angle needs to be corrected, i.e., if there is a possibility of contact with the master workpiece, the separation angle is corrected.

[0031] A computer program according to an embodiment of the present disclosure performs an approaching operation of a spindle to a peripheral portion of a master workpiece along a reference path on an outer circumferential side or an inner circumferential side of the master workpiece, the reference path being determined based on a plurality of reference points, determines whether or not a tool attached to the spindle has come into contact with the peripheral portion during the approaching operation, acquires coordinates of the spindle when it is determined that the tool has come into contact with the peripheral portion, and after acquiring the coordinates of the spindle, performs a separating operation of the spindle in a separating angle direction that is a predetermined angle with respect to the reference path, performs the approaching operation and the separating operation, and executes the approaching operation. In a computer program executable by a control device, the coordinates of the spindle are acquired each time the tool comes into contact with the peripheral portion, and a machining path of the spindle is generated based on the acquired coordinates. The computer program causes the control device to calculate a reference angle, which is the angle formed by the acquired coordinates of the spindle and the coordinates of the reference point, determine whether the separation angle is larger or smaller than a boundary angle, which is an angle based on 180 degrees or the reference angle, correct the separation angle based on the determination result and a predetermined angle, and perform a separation operation using the corrected separation angle.

[0032] In this disclosure, the spindle moves toward and away from the peripheral edge of the master workpiece along a reference path. If the tool comes into contact with the peripheral edge during the approaching operation, the control device acquires the coordinates of the spindle and generates a machining path based on the coordinates. The spindle also moves away from the master workpiece based on a separation angle based on a line connecting the current coordinates of the spindle and the coordinates of the reference point. If the separation angle needs to be corrected, i.e., if there is a possibility of contact with the master workpiece, the separation angle is corrected. [Effects of the Invention]

[0033] In a control device, machining path generation method, and computer program according to an embodiment of the present disclosure, a spindle alternately repeats an approaching operation to and a retracting operation from the peripheral edge of a master workpiece along a reference path. If the tool contacts the peripheral edge during the approaching operation, the control device acquires the coordinates of the spindle and accurately generates a machining path based on the coordinates, thereby reducing the operator's correction work. Furthermore, the spindle separates from the master workpiece based on a separation angle based on a line connecting the current coordinates of the spindle and the coordinates of the reference point located closest to the spindle. If the separation angle needs to be corrected, i.e., if there is a possibility of contact with the master workpiece, the separation angle is corrected. This automatically prevents the spindle from interfering with the master workpiece during the retracting operation, reducing the operator's correction work. [Brief explanation of the drawings]

[0034] [Figure 1] FIG. 1 is a schematic perspective view of a machine tool. [Figure 2] FIG. 2 is a block diagram showing the configuration of a machine tool. [Figure 3] FIG. 10 is an explanatory diagram for explaining generation of a reference trajectory. [Figure 4] FIG. 10 is an explanatory diagram for explaining generation of a processing path. [Figure 5] FIG. 10 is an explanatory diagram for explaining machining based on a machining path. [Figure 6] 10 is an example of a display screen of a display unit. [Figure 7] FIG. 10 is an explanatory diagram illustrating a method for generating a processing path. [Figure 8] FIG. 8 is a partially enlarged view of FIG. [Figure 9] FIG. 10 is a plan view illustrating an example of first correction. [Figure 10] FIG. 10 is a plan view illustrating another example of the first correction. [Figure 11] FIG. 10 is a plan view illustrating a second correction. [Figure 12] FIG. 10 is a plan view illustrating a third correction. [Figure 13]10 is a flowchart illustrating a machining path generation process by a CPU. [Figure 14] 10 is a flowchart illustrating a correction process by a CPU. DETAILED DESCRIPTION OF THE INVENTION

[0035] The present invention will be described below with reference to the drawings showing a machine tool according to an embodiment. Figure 1 is a schematic perspective view of machine tool 1, and Figure 2 is a block diagram showing the configuration of machine tool 1. In the following description, the up, down, front, back, left and right directions shown in the figure will be used.

[0036] The machine tool 1 is equipped with a base 2 that is rectangular in plan view. A number of reinforcing cylinders 2a are formed on the top surface of the base 2, and are parallel to the top of the base 2. A support table 3 is provided on the reinforcing cylinders 2a in the center of the base 2. The support table 3 is shaped like a flat cylinder and holds a workpiece.

[0037] Three upright pillars 4 are provided around the periphery of the support base 3. The upright pillars 4 extend upward from the reinforcing cylinder 2a. The three upright pillars 4 are arranged at phase intervals of approximately 120 degrees in plan view. A track 5 is provided on the side of each upright pillar 4 facing the support base 3. The track 5 extends in the vertical direction.

[0038] A moving unit 6 is provided on the track 5. A drive source, for example, a ball screw 14 and a moving axis motor 13 (see FIG. 2), is provided on the track 5. The moving unit 6 can move up and down along the track 5 by the ball screw 14 driven by the moving axis motor 13. In other words, the moving unit 6 can move in a direction intersecting with a first support plate 10, which will be described later. Mounting portions for mounting a first link 11 and a second link 21, which will be described later, are provided on the side surface of the moving portion 6 on the side of the support base 3. The mounting portions are, for example, holes or protrusions.

[0039] A first support plate 10 is disposed above the support base 3. The first support plate 10 has a triangular shape in a plan view and is approximately parallel to the upper surface of the support base 3. The three sides of the first support plate 10 face the three uprights 4, respectively. That is, the three sides correspond to the three moving parts 6, respectively. Each side and each moving part 6 are connected by two parallel first links 11. The first links 11 are rod-shaped. One end of each of the two first links 11 is connected to both ends of the side via a rotatable joint 7, respectively. The other end of each of the two first links 11 is connected to the moving part 6 via a rotatable joint 7, respectively. The joints 7 are, for example, universal joints.

[0040] The first support plate 10 holds a spindle 30 that protrudes upward and downward. The spindle 30 grips a tool 30a at its end. The second support plate 20 is disposed above the first support plate 10, and a connecting tube 8 is provided between the first support plate 10 and the second support plate 20, with its axial direction extending vertically. The connecting tube 8 connects the first support plate 10 and the second support plate 20. The connecting tube 8 integrates the first support plate 10 and the second support plate 20.

[0041] The upper part of the main shaft 30 is inserted inside the connecting tube 8 and passes through the second support plate 20. The second support plate 20 has a triangular shape in a plan view and is approximately parallel to the first support plate 10. The three sides of the second support plate 20 face the three uprights 4, respectively. That is, the three sides correspond to the three moving parts 6, respectively. Each side and each moving part 6 are connected by two parallel second links 21. The second links 21 are rod-shaped. One end of each of the two second links 21 is connected to both ends of the side via a rotatable joint 7, respectively. The other end of each of the two second links 21 is connected to the moving part 6 via a rotatable joint 7, respectively. The joints 7 are, for example, universal joints.

[0042] The connecting tube 8 has a hexagonal shape in a plan view, and of the six sides at the upper end of the connecting tube 8, three adjacent sides spaced apart in the circumferential direction are connected to three sides of the second support plate 20. Of the six sides at the lower end of the connecting tube 8, three adjacent sides spaced apart in the circumferential direction are connected to three sides of the first support plate 10.

[0043] When the three moving parts 6 are at the same height, the main shaft 30 is located approximately directly above the center of the support table 3. When two moving parts 6 are at the same vertical position and another moving part 6 moves lower than the other two moving parts 6, the main shaft 30 moves horizontally toward the opposite side of the moving part 6 that is moving downward, without changing its vertical position.

[0044] When two moving units 6 are at the same vertical position and another moving unit 6 moves higher than the other two moving units 6, the spindle 30 moves horizontally toward the moving unit 6 that is moving upward without changing its vertical position. When three moving units 6 move the same distance in the vertical direction, the spindle 30 moves vertically. By combining these movements, the machine tool 1 positions the spindle 30 at the desired vertical, front-back, left-right position.

[0045] The spindle 30 is equipped with a spindle motor 12. The spindle 30 positioned at a desired position is rotated by the drive of the spindle motor 12, and a tool 30a attached to the spindle 30 machines a workpiece held on the holder 3.

[0046] As shown in FIG. 2 , the control device 40 includes a CPU 41, a storage unit 42, a RAM 43, an input / output interface 44, an operation unit 45, and a display unit 46. The CPU 41 controls the operation of each unit of the machine tool 1. The storage unit 42 is a rewritable memory, such as an EPROM or EEPROM. The storage unit 42 stores a control program (not shown) for controlling the machine tool 1, a machining program DB 421 that stores multiple machining programs for machining the workpiece 95, and a machining path generation program 422. The machining path generation program 422 is a program for executing a process for generating a machining path, and is provided in a state stored on a computer-readable recording medium 423, such as a CD-ROM, DVD-ROM, or USB memory, and is installed in the control device 40 to be stored in the storage unit 42. The machining path generation program 422 may also be acquired from an external computer (not shown) connected to a communication network and stored in the storage unit 42.

[0047] The storage unit 42 stores a threshold value and an additional angle to be compared with the torque of the spindle motor 12, which will be described later.

[0048] [Table 1]

[0049] When an operator operates the operation unit 45, a signal is input from the operation unit 45 to the input / output interface 44. The operation unit 45 is, for example, a keyboard, buttons, a touch panel, etc. The input / output interface 44 outputs a signal to the display unit 46. The display unit 46 is, for example, a liquid crystal display panel, and displays characters, figures, symbols, etc.

[0050] The control device 40 further includes a torque detector 12a that detects the torque of the spindle motor 12, a spindle control circuit 47 corresponding to the spindle motor 12, a servo amplifier 48, and a moving axis control circuit 49 and servo amplifier 50 corresponding to the moving axis motor 13. Based on a command from the CPU 41, the spindle control circuit 47 outputs a command indicating target values ​​such as the rotation direction and rotation speed of the spindle motor 12 to the servo amplifier 48. The servo amplifier 48 supplies power to the spindle motor 12 based on the command. The torque detector 12a detects the torque of the spindle motor 12, and the CPU 41 acquires this torque via the input / output interface 44. The encoder 18 detects the rotation position and speed of the spindle motor 12 and sends a detection signal to the servo amplifier 48. The servo amplifier 48 compares the detection signal with target values ​​and controls the output power.

[0051] Based on instructions from the CPU 41, the moving axis control circuit 49 outputs commands indicating target values ​​such as the moving direction and speed of the three moving parts 6 to the servo amplifier 50. The servo amplifier 50 supplies power to the moving axis motor 13 based on the commands. The encoder 19 detects the rotational position and speed of the moving axis motor 13 and sends a detection signal to the servo amplifier 50. The servo amplifier 50 compares the detection signal with the target values ​​and controls the output power.

[0052] FIG. 3 is an explanatory diagram for explaining generation of a reference path, FIG. 4 is an explanatory diagram for explaining generation of a machining path, and FIG. 5 is an explanatory diagram for explaining machining based on the machining path. In the machining path generating method of this embodiment, a deburred master workpiece 9 is held on the holder 3 of the machine tool 1. A tool 30a is attached to the tip of the spindle 30. As shown in Figure 3, a reference path L0 is generated on the outer periphery of a master workpiece 9 by using conventional CAM software or by online teaching. The reference path L0 is formed by using a plurality of teaching points P n (n is a natural number). The teaching point corresponds to the reference point. Based on the machining path generation program 422, the spindle 30 alternately moves toward and away from the periphery of the master workpiece 9 along the reference path L0. The periphery includes the outer periphery and the inner periphery. The approaching movement is the movement toward the master workpiece 9, and the moving away movement is the movement away from the master workpiece 9.

[0053] The CPU 41 determines whether the tool 30a has come into contact with the peripheral portion during the approaching operation, and acquires the coordinates of the center P of the spindle 30 each time it determines that contact has occurred. The CPU 41 acquires the rotational position of the moving axis motor 13 using the encoder 19, and calculates the coordinates of the center P of the spindle 30 using the acquired rotational position. As shown in FIG. 4, the CPU 41 generates a machining path L1 based on the acquired coordinates of the multiple centers P. When deburring a workpiece 95 having a burr, the workpiece 95 is held on the holder 3. Based on the corresponding machining program, the spindle 30 to which the tool 30a is attached is moved along the machining path L1, as shown in FIG. 5, to machine the workpiece 95.

[0054] 6 is an example of a display screen of the display unit 46. In order to generate the machining path L1, the CPU 41 displays a master work and teaching points P on the right side of the display screen. n(n=1, 2, 3, . . .) and the reference path L0 are displayed as a perspective view or a plan view. The perspective view or the plan view may be switched by an operator's operation. The CPU 41 displays input fields for the search pitch, the separation amount, and the movement amount during measurement on the left side of the display screen. The search pitch, the separation amount, and the movement amount during measurement will be described in detail later.

[0055] The operator checks the reference path L0 displayed by the CPU 41 on the display unit 46, and indicates with an arrow any portion of the reference path L0 that the operator wishes to correct using the operation unit 45. The operator inputs the search pitch, the distance, and the movement amount during measurement. Candidates for the search pitch, the distance, and the movement amount during measurement may be displayed so that the operator can select one.

[0056] The CPU 41 acquires the search pitch, separation amount, and movement amount during measurement input by the operator, and inputs any correction portion if acquired, and sets the search conditions by reducing the search pitch for the correction portion, etc. Based on the set conditions, the CPU 41 generates the machining path L1.

[0057] FIG. 7 is an explanatory diagram for explaining a method for generating a machining path L1, and FIG. 8 is a partial enlarged view of FIG. 7. A reference path L0 is a path initially stored in the machining program DB 421. A plurality of teaching points P n (n=1, 2, 3, . . .) The CPU 41 generates a search path T along which the spindle 30 moves in a zigzag pattern, based on the set search pitch, separation amount, and movement amount during measurement, along the reference path L0. a is the center point of the main shaft 30 when separated, and point P 1a , P 1b , P 1c , P 2a , P 2b , ... is the center point of the spindle 30 when it comes into contact with the master workpiece 9 during the approach operation. Point P a and the center point P of the main shaft 30 1a , P 1b , P 1c , P 2a , P 2b The polygonal line connecting , , , is the search path T.

[0058] As shown in Fig. 7, the center point of the spindle 30 moves from P0 to P1, approaches the master workpiece 9, and comes into contact with the master workpiece 9. As shown in Fig. 8, the center point of the spindle 30 at the time of contact is P 1a The CPU 41 detects the center point P of the main shaft 30. 1a From point P1 to point P2, a first vector a having a first length and a second vector b perpendicular to the first vector a and having a second length are calculated. The first length is the search pitch in FIG. 7. The second length is the separation amount in FIG. 7. The coordinates of point Pa are determined by calculating the first vector a and the second vector b.

[0059] The CPU 41 calculates a third vector c, which is the sum of the first vector a and the second vector b, and moves the main shaft 30 apart based on the third vector c. The calculation of the first vector a and the third vector c determines the angle θ between the first vector a and the third vector c. a The angle θa is the separation angle. a is stored in advance in the storage unit 42 or is calculated in advance, and the angle θ a The third vector c may be determined so as to satisfy the following equation.

[0060] Next, the spindle 30 is moved closer based on a fourth vector d having a direction opposite to that of the second vector b and a third length obtained by adding the measurement movement amount (see FIG. 7) to the second length. The measurement movement amount is a distance added to the second length for the approaching operation. The end point P of the fourth vector d inside the master workpiece 9 is moved until contact with the master workpiece 9 is detected. b The approach motion is aimed at the end point P b The spindle 30 comes into contact with the master workpiece 9 before reaching the end point P b The moving axis motor 13 rotates by the amount necessary to reach the target position.

[0061] Center P of main shaft 30 at the time of contact 1c When the distance D between the teaching point P2 and the target point P2 is less than the search pitch, 1cThe spindle 30 is moved away from the master workpiece 9 toward the next taught point P3 based on a third vector c which is the sum of a first vector a having a first length and a second vector b which is perpendicular to the first vector a and has a second length. In this way, the CPU 41 alternately performs the moving-away operation and the contacting operation, and the CPU 41 stores the coordinates of the center point of the spindle 30 every time the spindle 30 comes into contact with the master workpiece 9 during the approaching operation. The CPU 41 generates a machining path for the spindle 30 based on the stored coordinates.

[0062] 9 is a plan view illustrating an example of the first correction. As shown in FIG. 9, the master workpiece 9 has one surface 9a and the other surface 9b, and the one surface 9a and the other surface 9b form a right-angled or acute-angled corner. When the spindle 30 moves near the corner, the CPU 41 performs the first correction. Point P in FIG. 9 s1 is the position of the center point of the spindle 30 when it comes into contact with the master workpiece 9, and is the current, i.e., latest, position (corresponding to the first coordinate). s0 is the position of the center point of the spindle 30 when it comes into contact with the master workpiece 9, and point P s1 The previous position (corresponding to the second coordinate) of point P s0 , point P s1 is point P in Figure 8 1a , P 1b , P 1c , P 2a , P 2b , corresponds to point P k (k=2, 3, 4, . . . ) are teaching points (corresponding to the reference points in claim 2) corresponding to teaching point P2 in FIG. 8, and are teaching points used in the calculation of the first vector a. s0 , point P s1 The teaching point P faces the surface 9a and is aligned along the surface 9a. k faces the other surface 9b. k is the point P s1 This is the teaching point with the shortest distance from the teaching point P. k is the point P in the direction of the spindle s1 It is enough if it is the teaching point of the other party, point P s1 The teaching point is not limited to the teaching point having the shortest distance from the target point.

[0063] Point P in Figure 9a is the center point of the main shaft 30 when separated, and point P in Figs. a The point P a ' is the center point of the main axis 30 when separated, and is the center point after the first correction. θ is the angle P s0 P s1 P k is the reference angle. a is the line segment P s1 P k and line segment P s1 P a The angle of separation θ a , first additional angle θ c is stored in advance in the storage unit 42. e is the correction amount. L1 is the point P s0 , point P s1 It is a straight line passing through.

[0064] As described above, the CPU 41 separates the main shaft 30 based on the third vector c. After the separation, the center of the main shaft 30 is at point P a That is, it is located at θ+θ counterclockwise from the line L1. a The main axes 30 move apart in the rotated direction (the direction of the third vector c).

[0065] When the spindle 30 moves away from the corner of the master workpiece 9, there is a possibility that the spindle 30 may come into contact with the master workpiece 9. Angle θ+θ a is greater than 180 degrees, the spindle 30 will not come into contact with the master workpiece 9. In order to reliably avoid contact, the first additional angle θ is added to 180 degrees. c The angle obtained by adding the above is the boundary angle. The boundary angle is the angle between contact and non-contact. That is, the angle θ + θ a is 180 degrees + first additional angle θ c If the angle θ is greater than or equal to the angle θ, the spindle 30 does not contact the master workpiece 9. a <180 degrees + first additional angle θ c That is, θ<180 degrees + first additional angle θ c -θ a If this is the case, there is a possibility that the master work 9 may come into contact with the master work 9 when it is separated. Therefore, the separation angle θ aThe first correction is made to the angle θ. Note that the spindle 30 does not move in the direction opposite to the direction of travel, so 0<θ. 180 degrees + θ c -θ a corresponds to the first comparative angle. The first comparative angle may be calculated by multiplying 180 degrees by a predetermined coefficient.

[0066] In the first correction, the CPU 41 calculates a correction amount θ e Calculate θ+θ a The correction amount θ e The angle added is 180 degrees + the first additional angle θ c Therefore, θ+θ a +θ e =180 degrees+θ c Therefore, θ e =180°-θ-θ a +θ c The CPU 41 is a θ e and executes the separation operation.

[0067] Fig. 10 is a plan view for explaining another example of the first correction. In Fig. 10, the same components as those in Fig. 9 are given the same reference numerals, and detailed explanations thereof will be omitted. As shown in Fig. 10, the master work 9 has a curved surface 9c that protrudes in a predetermined direction. 9t is the vertex of the curved surface 9c, and L2 is a line that passes through the vertex 9t. A point P is located in one of the regions bounded by the line L2. s0 , point P s1 is located in the other area, and the teaching point P k is located.

[0068] As in Figure 9, the angle θ + θ a <180 degrees + first additional angle θ c If this is the case, there is a possibility that the master work 9 may come into contact with the master work 9 when it is separated. Therefore, the separation angle θ a The CPU 41 performs a first correction on the correction amount θ e Calculate θ a θ e Add.

[0069] 11 is a plan view for explaining the second correction. In FIG. 11, the same components as those in FIG. 9 are given the same reference numerals, and detailed explanations thereof will be omitted. As shown in FIG. 11, a narrow groove 9d is formed in the master work 9. Point P s0 is located on one side surface 9d1 of the groove 9d, and point P s1 is located on the end surface 9d3 of the groove 9d, and the teaching point P k The one side surface 9d1 and the other side surface 9d2 are opposite to each other. s1 may be located on one side surface 9d1 or the other side surface 9d2. k P s1 P s0 is the reference angle. d is the second additional angle. L3 is at point P k , point P s1 It is a straight line passing through.

[0070] As shown in Figure 11, the angle θ is rotated counterclockwise from the line L3. a The main shaft 30 moves away in the direction of rotation. a <θ, the spindle 30 does not contact the master workpiece 9 when it is separated. d The angle obtained by subtracting the angle θ is the boundary angle. a is θ-θ d In the following cases, the spindle 30 does not come into contact with the master workpiece 9. a >θ-θ d In other words, when θ<θ a +θ d In this case, the spindle 30 may come into contact with the master workpiece 9, so the separation angle θ a The second correction is performed on the axis 30. Since the spindle 30 does not move in the direction opposite to the direction of travel, 0<θ. θ a +θ d corresponds to the second comparative angle. a may be multiplied by a predetermined coefficient to obtain the second comparative angle.

[0071] In the second correction, the CPU 41 calculates the correction amount θ e Calculate θ a The correction amount θ e The angle obtained by addingd Therefore, θ a +θ e =θ-θ d Therefore, θ e =θ-θ a -θ d =θ-(θ a +θ d )=-(θ a +θ d -θ). The CPU 41 a θ e and executes the separation operation.

[0072] Figure 12 is a plan view for explaining the third correction. In Figure 12, the same components as those in Figures 9 to 11 are given the same reference numerals, and detailed explanations thereof will be omitted. As shown in Figure 12, a narrow portion 9e cut at an acute angle is formed in the master workpiece 9. Teaching point P k is the point P s1 This is the teaching point with the shortest distance from teaching point P. k+1 is point P s1 This is the teaching point with the second shortest distance from point P. s1 is located on one side surface 9e1 of the narrow portion 9e. k is located at the corner of the narrow section 9e. k+1 is located on the other side surface 9e2 of the narrow portion 9e. θ is angle P k P s1 P k+1 is the reference angle. f is the third additional angle. Teaching point P k , P k+1 The distance does not necessarily have to be the shortest, but the teaching point P k is teaching point P k+1 than point P s1 Close to.

[0073] As shown in Figure 12, the angle θ is rotated counterclockwise from the line L3. a The main shaft 30 moves away in the direction of rotation. a If θ is greater than θ, the spindle 30 will not contact the master workpiece 9 when it is released. The boundary angle between contact and non-contact is θ. To ensure contact is avoided, a third additional angle θ is added to θ. fThe angle obtained by adding the angle θ is the boundary angle. a is θ+θ f In the above cases, the spindle 30 does not come into contact with the master workpiece 9. a <θ+θ f In other words, when θ>θ a -θ f In this case, the spindle 30 may come into contact with the master workpiece 9, so the separation angle θ a The third correction is performed on the axis 30. Since the spindle 30 does not move in the direction opposite to the direction of travel, 180 degrees > θ. θ a -θ f corresponds to the third comparative angle. a -θ f may be multiplied by a predetermined coefficient to obtain the third comparison angle.

[0074] In the third correction, the CPU 41 calculates the correction amount θ e Calculate θ a The correction amount θ e The angle added is θ+θ f Therefore, θ a +θ e =θ+θ f Therefore, θ e =θ+θ f -θ a =θ-(θ a -θ f ) The CPU 41 is a θ e and executes the separation operation. In the first to third corrections, the reference angle, the separation angle, and the correction amount may be stored in advance in association with each other in the storage unit , and the CPU 41 may acquire the separation angle and the correction amount corresponding to the reference angle from the storage unit .

[0075] 13 is a flowchart illustrating the machining path generation process by the CPU 41. The CPU 41 acquires the reference path L0, search teaching points, corrected teaching points, etc. (S1). The CPU 41 acquires the number of the machining program by an operator's operation, refers to the machining program DB 421, and acquires the reference path L0 in the machining path column of the machining program with the corresponding number. Alternatively, the spindle 30 is moved to bring the tool 30a into contact with the master workpiece 9, and the coordinates of the points indicating the corners of the master workpiece 9 and the points where the attitude of the tool 30a changes are acquired, and these teaching points P n Based on this, the reference path L0 is acquired. Also, a search teaching point, which is a teaching point to be used for calculating the search path, is acquired. In the initial state, the search teaching point is teaching point P2.

[0076] The CPU 41 displays the reference path L0 and input fields for the conditions of the search pitch, the distance, and the movement amount during measurement on the display unit 46 (S2, see FIG. 6). The CPU 41 acquires the search pitch, the distance, and the movement amount during measurement input by the operator, and inputs any correction portions acquired, and sets the search conditions by reducing the search pitch, etc. for the correction portions (S3).

[0077] The CPU 41 executes an approaching operation of the spindle 30 (S4) and determines whether or not the tool 30a has come into contact with the master workpiece 9 (S5). The CPU 41 drives the moving axis motor 13 to bring the spindle 30 closer to the master workpiece 9 while rotating the spindle motor 12 at a low speed (forward or reverse rotation). The low speed is, for example, 100 to 1000 rpm. The CPU 41 determines whether or not the torque of the spindle motor 12 is equal to or greater than a threshold value stored in the memory unit 42, and if the torque of the spindle motor 12 is equal to or greater than the threshold value, determines that the tool 30a has come into contact with the master workpiece 9.

[0078] If it is determined that the tool 30a is not in contact with the master workpiece 9 (S5: NO), the CPU 41 returns the process to step S5. If it is determined that the tool 30a is in contact with the master workpiece 9 (S5: YES), the CPU 41 acquires the coordinates of the spindle 30, i.e., the center coordinates of the spindle 30 (S6). The CPU 41 that executes step S5 corresponds to a contact determination unit, and the CPU 41 that executes step S6 corresponds to an acquisition unit.

[0079] The CPU 41 determines whether or not the distance D between the center of the spindle 30 and the search teaching point at the time of contact is less than the search pitch (S7). If the distance D is not less than the search pitch (S7: NO), the CPU 41 determines whether or not the center point P of the spindle 30 at the time of separation is less than the search pitch. a (S9). If the distance D is less than the search pitch (S7: YES), the CPU 41 updates the searched teaching point (S8) and proceeds to step S9. In step S8, for example, the CPU 41 updates the searched teaching point from teaching point P2 to P3.

[0080] After the process of step S9, the CPU 41 calculates the reference angle θ (S10) and calculates the boundary angle (S11). a (S12). The details of the correction process will be described later. After the process of step S12, the CPU 41 executes a correction process for the corrected separation angle θ a The separating operation is performed based on the above (S13).

[0081] After processing step S13, the CPU 41 determines whether or not searching for all center coordinates of the spindle 30 has been completed (S14). If it is determined that searching for all center coordinates of the spindle 30 has not been completed (S14: NO), the CPU 41 returns the process to step S4. If it is determined that searching for all center coordinates of the spindle 30 has been completed (S14: YES), the CPU 41 generates a machining path based on the stored plurality of center coordinates, stores the generated machining path in the memory unit 42 (S15), and ends the process.

[0082] 14 is a flowchart illustrating the correction process by the CPU 41. In step S12, the CPU 41 calculates the boundary angle between the reference angle θ and the separation angle θa That is, the CPU 41 determines whether the first comparative angle 180 degrees + θ is greater than the sum of the first comparative angle 180 degrees + θ c -θ a The reference angle θ is calculated as 180 degrees + θ c -θ a (See Figures 9 and 10.) c -θ a The CPU 41 that calculates the above corresponds to the first calculation unit, and the reference angle θ is 180 degrees + θ c -θ a The CPU 41 that determines whether the boundary angle is larger than the sum of the reference angle θ and the separation angle θa corresponds to the first angle determination unit. When it is determined that the boundary angle is larger than the sum of the reference angle θ and the separation angle θa (S21: YES), that is, when the reference angle θ is 180 degrees + θ c -θ a If it is determined that the separation angle θ a That is, the CPU 41 executes the first correction for the correction amount θ e Calculate the calculated correction amount θ e is added to the separation angle θa. e is 180 degrees -θ-θ a +θ c The separation angle θa may be calculated by calculation, may be stored in advance in the storage unit 42, may be input using the operation unit 45, or may be set in the machining program. The CPU 41 that executes S22 corresponds to the correction unit.

[0083] If it is determined that the boundary angle is not greater than the sum of the reference angle θ and the separation angle θa (S21: NO), that is, if the reference angle θ is 180 degrees + θ c -θ a If it is determined that the boundary angle is equal to or greater than the separation angle θa, the CPU 41 determines whether the boundary angle is smaller than the separation angle θa (S23). a +θ d The reference angle θ is calculated as θ a +θ d (See FIG. 11.) a +θ d The CPU 41 that calculates the above corresponds to the second calculation unit, and the reference angle θ is θ a +θd The CPU 41 that determines whether the boundary angle is smaller than the separation angle θa corresponds to the second angle determination unit. When it is determined that the boundary angle is smaller than the separation angle θa (S23: YES), that is, when the reference angle θ is smaller than θ a +θ d If it is determined that the separation angle θ a That is, the CPU 41 executes the second correction for the correction amount θ e Calculate the calculated correction amount θ e is added to the separation angle θa. e is θ-θ a -θ d The CPU 41 that executes S24 corresponds to the correction unit.

[0084] If it is determined that the boundary angle is not smaller than the separation angle θa (S23: NO), that is, if the reference angle θ is θ a +θ d If it is determined that the boundary angle is equal to or greater than the separation angle θa, the CPU 41 determines whether the boundary angle is greater than the separation angle θa (S25). a -θ f The reference angle θ is calculated as θ a -θ f (See FIG. 12.) a -θ f The CPU 41 that calculates the above corresponds to the third calculation unit, and the reference angle θ is θ a -θ f The CPU 41 that determines whether the boundary angle is greater than the separation angle θa corresponds to the third angle determination unit. When it is determined that the boundary angle is greater than the separation angle θa (S25: YES), that is, when the reference angle θ is greater than θ a -θ f If it is determined that the separation angle θ a That is, the CPU 41 executes the third correction for the correction amount θ e The calculated correction amount θ e is added to the separation angle θa. e is θ+θ f -θ a The CPU 41 that executes S26 corresponds to the correction unit.

[0085] If it is determined that the third correction is not necessary (S25: NO), or after the processing of step S22, S24, or S26, the CPU 41 executes the separating operation (S13).

[0086] In the machine tool according to the embodiment, the spindle 30 alternately repeats an approaching operation to the peripheral portion of the master workpiece 9 and a moving away operation from the peripheral portion along the reference path L0. If the tool 30a comes into contact with the peripheral portion during the approaching operation, the machine tool 1 acquires the coordinates of the spindle 30 and generates the machining path L1 with high accuracy based on the coordinates, thereby reducing the operator's correction work. In addition, the machine tool 1 calculates a reference angle formed by the current coordinates of the spindle 30 and the coordinates of the reference point, and calculates a moving away angle θ, which is the direction of the moving away operation. a and a boundary angle, which is an angle based on 180 degrees or a reference angle, and based on the determination result, a separation angle θ a Correct the separation angle θ a If correction is required for the distance angle θ a Since the above correction is performed, the spindle 30 is automatically prevented from interfering with the master workpiece 9 during the separating operation, and correction work by the operator can be reduced.

[0087] Furthermore, since the reference angle is calculated based on the first coordinates where the master workpiece 9 and 30 a come into contact, the second coordinates, and the reference point, the reference angle is more faithful to the shape of the master workpiece 9 . The reference angle θ is 180 degrees + θ c -θ a , that is, if it is smaller than the first comparative angle, the first correction is performed to prevent contact with the master workpiece 9. e =180°-θ-θ a +θ c This prevents contact with the master workpiece 9. The comparison angle is the first additional angle θ c This reliably prevents the tool 30a from coming into contact with the master workpiece 9.

[0088] Also, the reference angle θ is θ a +θ d, that is, if it is smaller than the second comparative angle, the second correction is performed to prevent contact with the master workpiece 9. e =-(θ a +θ d -θ) is calculated to prevent contact with the master workpiece 9. The comparison angle is the second additional angle θ d This reliably prevents the tool 30a from coming into contact with the master workpiece 9.

[0089] Also, the reference angle θ is θ a -θ f , that is, if it is larger than the third comparison angle, the third correction is performed to prevent contact with the master workpiece 9. e =θ-θ a +θ f The comparison angle is the third additional angle θ f is subtracted, so that the tool 30a is reliably prevented from coming into contact with the master workpiece 9. The CPU 41 that executes S4 corresponds to the first moving part, and the CPU 41 that executes S14 corresponds to the second moving part. s1 is the vertex, and the position P of the center of the spindle 30 that contacted the master workpiece 9 before (in the past) s0 and the subsequent teaching point P k The reference angle is calculated using the following formula: The third correction is the position P of the center of the spindle 30 currently in contact with the master workpiece 9. s1 is the vertex, and the two teaching points P k The reference angle is calculated using

[0090] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The technical features described in each embodiment can be combined with each other, and the scope of the present invention is intended to include all modifications within the scope of the claims and the scope equivalent to the claims. [Explanation of symbols]

[0091] 1 Machine tools 6 Moving part 30 main shaft 30a tools 40 Control device 41 CPU 42 Storage section 43 RAM

Claims

1. a first moving unit that moves a spindle, on which a tool is attached, toward a peripheral portion of a master workpiece along a reference path on an outer circumferential side or an inner circumferential side of the master workpiece, the reference path being determined based on a plurality of reference points; a contact determination unit that determines whether the tool has come into contact with the peripheral edge portion during the approaching operation by the first moving unit; an acquisition unit that acquires coordinates of the main axis when the contact determination unit determines that contact has occurred; a second moving unit that performs a separating operation of the main shaft in a separating angle direction that is a predetermined angle with respect to the reference path after the coordinates of the main shaft are acquired by the acquiring unit; Equipped with a control device that performs an approaching operation by the first moving unit and a separating operation by the second moving unit, acquires coordinates of the spindle each time the tool contacts the peripheral edge portion during the approaching operation, and generates a machining path for the spindle based on the acquired coordinates, a reference angle calculation unit that calculates a reference angle formed by a first coordinate of the main axis acquired by the acquisition unit, a second coordinate of the main axis acquired by the acquisition unit immediately before the acquisition of the first coordinate, and the reference point that is ahead of the first coordinate in the traveling direction of the main axis, the reference angle being formed by a line segment connecting the second coordinate and the first coordinate and a line segment connecting the first coordinate and the reference point; a magnitude determination unit that calculates a first comparative angle by adding 180 degrees and a first additional angle and subtracting the separation angle from the calculated first comparative angle, and determines whether the reference angle is smaller than the first comparative angle; a first correction unit that corrects the separation angle by subtracting the reference angle from the first comparison angle when it is determined that the reference angle is smaller than the first comparison angle; and Equipped with The second moving unit performs a separation movement using the separation angle corrected by the first correcting unit. Control device.

2. a second calculation unit that calculates a second comparative angle by adding a second additional angle to the separation angle when the magnitude determination unit determines that the reference angle is not smaller than the first comparative angle; a second angle determination unit that determines whether the reference angle calculated by the reference angle calculation unit is smaller than the second comparison angle; a second correction unit that, when determining that the reference angle is smaller than the second comparative angle, adds a value obtained by subtracting the second comparative angle from the reference angle to the separation angle; Equipped with The control device according to claim 1 .

3. a second reference angle calculation unit that calculates a second reference angle, when the second angle determination unit determines that the reference angle calculated by the reference angle calculation unit is not smaller than the second comparison angle, the second reference angle being an angle formed by the first coordinate, a first reference point that is closest to the first coordinate, and a second reference point that is second closest to the first coordinate, the second reference angle being formed by a line segment connecting the first reference point and the first coordinate, and a line segment connecting the first coordinate and the second reference point; a third calculation unit that calculates a third comparison angle by subtracting a third additional angle from the separation angle; a third angle determination unit that determines whether the second reference angle calculated by the second reference angle calculation unit is greater than the third comparison angle; a third correction unit that, when determining that the second reference angle is greater than the third comparison angle, adds a value obtained by subtracting the third comparison angle from the second reference angle to the separation angle; Equipped with The control device according to claim 2 .

4. a machining path generation method for generating a machining path for the spindle, the method comprising: performing an approaching operation of a spindle to a peripheral portion of a master workpiece along a reference path on an outer or inner peripheral side of the master workpiece, the reference path being determined based on a plurality of reference points; determining whether or not a tool attached to the spindle has come into contact with the peripheral portion during the approaching operation; acquiring coordinates of the spindle when it is determined that the tool has come into contact with the peripheral portion; acquiring the coordinates of the spindle; performing a separating operation of the spindle in a separating angle direction that is a predetermined angle with respect to the reference path after acquiring the coordinates of the spindle; performing the approaching operation and separating operation; acquiring the coordinates of the spindle each time the tool comes into contact with the peripheral portion during the approaching operation; and generating a machining path for the spindle based on the acquired plurality of coordinates; calculating a reference angle formed by the acquired first coordinate of the main axis, the second coordinate of the main axis acquired immediately before the acquisition of the first coordinate, and the reference point located ahead of the first coordinate in the direction of travel of the main axis, the reference angle being formed by a line segment connecting the second coordinate and the first coordinate and a line segment connecting the first coordinate and the reference point; calculating a first comparative angle by adding 180 degrees and a first additional angle and subtracting the separation angle from the calculated first comparative angle; and determining whether the reference angle is smaller than the first comparative angle; If it is determined that the reference angle is smaller than the first comparative angle, the value obtained by subtracting the reference angle from the first comparative angle is added to the separation angle to correct the separation angle; The separation operation is performed using the corrected separation angle. Machining path generation method.

5. a computer program executable by a control device that performs an approaching operation of a spindle to a peripheral portion of a master workpiece along a reference path on an outer peripheral side or an inner peripheral side of the master workpiece, the reference path being determined based on a plurality of reference points; determines whether or not a tool attached to the spindle has come into contact with the peripheral portion during the approaching operation; acquires coordinates of the spindle when it is determined that the tool has come into contact with the peripheral portion; after acquiring the coordinates of the spindle, performs a separating operation of the spindle in a separating angle direction that is a predetermined angle with respect to the reference path; performs the approaching operation and separating operation; acquires coordinates of the spindle each time the tool comes into contact with the peripheral portion during the approaching operation; and generates a machining path for the spindle based on the acquired plurality of coordinates; The control device calculating a reference angle formed by the acquired first coordinate of the main axis, the second coordinate of the main axis acquired immediately before the acquisition of the first coordinate, and the reference point located ahead of the first coordinate in the direction of travel of the main axis, the reference angle being formed by a line segment connecting the second coordinate and the first coordinate and a line segment connecting the first coordinate and the reference point; calculating a first comparative angle by adding 180 degrees and a first additional angle and subtracting the separation angle from the calculated first comparative angle; and determining whether the reference angle is smaller than the first comparative angle; If it is determined that the reference angle is smaller than the first comparative angle, the value obtained by subtracting the reference angle from the first comparative angle is added to the separation angle to correct the separation angle; The separation operation is performed using the corrected separation angle. A computer program that executes a process.

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