JP2023051252A - Machine tool, processing route generation method, and computer program - Google Patents

Abstract

To provide a machine tool capable of eliminating an operator's correction work needed to generate a highly precise processing route.SOLUTION: A machine tool includes: a main shaft on which a tool is mounted; a movement unit that performs an approach motion, which causes the main shaft to approach the rim of a master workpiece along a reference route on an outer circumference or inner circumference of the master workpiece determined based on plural reference points, or a receding motion causing the main shaft to recede from the rim; a receding time contact determination unit that determines whether or not the tool comes into contact with the master workpiece during the receding motion; a change unit that, when the receding time contact determination unit determines that the tool comes into contact with the master workpiece, changes receding directions in the receding motion; an approach time contact determination unit that determines whether or not the tool comes into contact with the rim during the approach motion made by the movement unit; an acquisition unit that acquires coordinates of the main shaft every time the approach time contact determination unit determines that the tool has come into contact with the rim; and a generation unit that generates a processing route of the main shaft on the basis of plural sets of coordinates acquired by the acquisition unit.SELECTED DRAWING: Figure 2

Description

The present technology relates to a machine tool, a machining path generation method, and a computer program that generate a machining path for a spindle on which a tool is mounted.

When removing burrs formed on the surface of a work, for example, the outer circumference of the work or the inner circumference of a hole in the work, the tool is mounted on the spindle of the machine tool, and the spindle moves along the outer circumference or inner circumference of the work, removing burrs. remove. The machine tool generates a machining path before moving the spindle. The spindle moves along the machining path.

The machining path of the spindle can be generated by off-line teaching. Off-line teaching can automatically generate a spindle machining path for avoiding interference between the workpiece and the spindle based on the CAD data of the workpiece (see Patent Document 1, for example).

JP 2019-150864 A

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

The present disclosure has been made in view of such circumstances, and aims to provide a machine tool, a machining path generation method, and a computer program that can reduce operator's correction work for generating a highly accurate machining path. and

A machine tool according to an embodiment of the present disclosure is a spindle on which a tool is mounted, and along a reference path on the outer peripheral side or the inner peripheral side of the master work determined based on a plurality of reference points, to the peripheral edge of the master work. a moving unit that performs an approaching operation of the main shaft and a separating operation of the main shaft from the peripheral edge portion; a separation contact determination unit that determines whether the tool contacts the master work during the separating operation; When the separation contact determination unit determines that the tool contacts the master work, a change unit that changes the separation direction in the separation operation, and whether the tool contacts the peripheral edge portion during the approach operation by the moving unit an acquisition unit that acquires the coordinates of the main axis each time the approach contact determination unit determines that there is contact; and based on the plurality of coordinates acquired by the acquisition unit, the a generation unit that generates a machining path for the spindle.

In the present disclosure, the spindle repeats an approaching motion to and away from the peripheral edge of the masterwork along the reference path. When the tool touches the periphery during the approaching operation, the machine tool acquires the coordinates of the spindle and generates a machining path based on the coordinates. Further, the direction in which the masterwork can be separated without interfering with the masterwork differs depending on whether the spindle is positioned on the outer peripheral side or the inner peripheral side of the masterwork, for example. When passing through the reference point, it is determined whether or not the tool will contact the master work during the separation operation. to prevent.

In the machine tool according to an embodiment of the present disclosure, the separated contact determination unit determines that the tool contacts the master work when the torque acting on the spindle is equal to or greater than a predetermined threshold.

In the present disclosure, during the separation operation, it is determined whether or not the torque acting on the spindle is equal to or greater than a predetermined threshold value, and the presence or absence of interference of the tool with the masterwork is confirmed.

In the machine tool according to one embodiment of the present disclosure, the moving part has a first moving part bounded by a line connecting the center of the spindle and the reference point positioned closest to the spindle in the traveling direction of the spindle. When the separation operation to one of the region and the second region is performed, and the separation contact determination unit determines that the tool has come into contact with the master work, the change unit performs the first region and the second region. The separating direction is changed so as to perform the separating operation to the other of the two regions.

In the present disclosure, in the case of performing a separation operation to one of the first region and the second region, when it is determined that the tool contacts the master work, to the other region of the first region and the second region to prevent interference with the master work during the separating operation.

A machining path generation method according to an embodiment of the present disclosure is a machining path generation method for generating a machining path for a spindle on which a tool is mounted, wherein the reference points on the outer or inner circumference side of the masterwork are determined based on a plurality of reference points. Along the path, the spindle on which the tool is mounted is moved toward the peripheral edge of the master work and the spindle is moved away from the peripheral edge, and whether or not the tool contacts the master work during the moving away. If it is determined that the tool will come into contact with the master work during the separating operation, the separation direction in the separating operation is changed, and it is judged whether the tool will come into contact with the peripheral portion during the approaching operation. and acquiring the coordinates of the main axis each time it is determined that the tool comes into contact with the peripheral portion during the approaching operation, and generating the machining path based on the acquired plurality of coordinates.

In the present disclosure, the spindle alternately repeats an approaching motion to the peripheral edge of the masterwork and a moving away from the peripheral edge along the reference path. When the tool touches the periphery during the approaching operation, the machine tool acquires the coordinates of the spindle and generates a machining path based on the coordinates. Further, the direction in which the masterwork can be separated without interfering with the masterwork differs depending on whether the spindle is positioned on the outer peripheral side or the inner peripheral side of the masterwork, for example. When passing through the reference point, it is determined whether or not the tool will contact the master work during the separation operation. to prevent.

A computer program according to an embodiment of the present disclosure is a computer program that is executable by a machine tool that generates a machining path for a spindle on which a tool is mounted. Along the reference path on the outer peripheral side or the inner peripheral side, the spindle on which the tool is mounted is moved toward the peripheral edge of the masterwork and the spindle is separated from the peripheral edge. It is determined whether or not the tool will come into contact with the master work, and if it is determined that the tool will come into contact with the master work during the separating operation, the separating direction in the separating operation is changed, and the tool moves toward the peripheral edge portion during the approaching operation. each time it is determined that the tool contacts the peripheral portion during the approaching operation, the coordinates of the main axis are acquired, and the processing path is generated based on the acquired plurality of coordinates. let it run.

In the present disclosure, the spindle alternately repeats an approaching motion to the peripheral edge of the masterwork and a moving away from the peripheral edge along the reference path. When the tool touches the periphery during the approaching operation, the machine tool acquires the coordinates of the spindle and generates a machining path based on the coordinates. Further, the direction in which the masterwork can be separated without interfering with the masterwork differs depending on whether the spindle is positioned on the outer peripheral side or the inner peripheral side of the masterwork, for example. When passing through the reference point, it is determined whether or not the tool will contact the master work during the separation operation. to prevent.

In the machine tool, machining path generation method, and computer program according to an embodiment of the present disclosure, the spindle repeats the movement of approaching and separating from the peripheral edge of the masterwork along the reference path. When the tool comes into contact with the peripheral edge during the approaching operation, the machine tool acquires the coordinates of the spindle, accurately generates the machining path based on the coordinates, and can reduce the operator's correction work. Further, the direction in which the masterwork can be separated without interfering with the masterwork differs depending on whether the spindle is positioned on the outer peripheral side or the inner peripheral side of the masterwork, for example. When passing through the reference point, it is determined whether or not the tool will contact the master work during the separation operation. This can be automatically prevented and the operator's correction work can be reduced.

1 is a schematic perspective view of a machine tool; FIG. It is a block diagram which shows the structure of a machine tool. FIG. 4 is an explanatory diagram for explaining generation of a reference route; FIG. 4 is an explanatory diagram for explaining generation of a machining path; FIG. 5 is an explanatory diagram for explaining machining based on a machining path; It is an example of a display screen of a display unit. It is an explanatory view explaining a method of generating a machining path. FIG. 8 is a partially enlarged view of FIG. 7; FIG. 5 is a schematic perspective view of the masterwork for explaining a change in the separation direction of the main shaft; 5 is a flowchart for explaining machining path generation processing by a CPU;

Hereinafter, the present invention will be described based on the drawings showing a machine tool 1 according to an embodiment. 1 is a schematic perspective view of a machine tool 1, and FIG. 2 is a block diagram showing the construction of the machine tool 1. As shown in FIG. In the following description, up, down, front, back, left, and right shown in the drawings are used.

A machine tool 1 includes a base 2 that is rectangular in plan view. A plurality of reinforcing cylinders 2a are formed on the upper surface of the base 2 in parallel with the top of the base 2. - 特許庁A holding table 3 is provided on a reinforcing tube 2a in the center of the base 2. As shown in FIG. The holding table 3 has a flat columnar shape and holds a work.

Three standing pillars 4 are provided around the holding base 3 . The vertical column 4 extends upward from the reinforcing tube 2a. The three standing pillars 4 are arranged with a phase interval of about 120 degrees in plan view. A track 5 is provided on the side surface of each standing pillar 4 on the holding base 3 side. The track 5 extends vertically.

A moving part 6 is provided on the track 5 . The track 5 is provided with a drive source, for example, a ball screw 14 and a moving shaft motor 13 (see FIG. 2). The moving part 6 is vertically movable along the track 5 by the ball screw 14 driven by the moving shaft motor 13 . That is, the moving part 6 can move in a direction crossing the first support plate 10, which will be described later.
A mounting portion for mounting a first link 11 and a second link 21, which will be described later, is provided on the side surface of the moving portion 6 on the holding table 3 side. The attachment part is, for example, a hole or a protrusion.

A first support plate 10 is arranged above the holding base 3 . The first support plate 10 has a triangular shape in plan view and is substantially parallel to the upper surface of the holding table 3 . Three sides of the first support plate 10 face the three vertical columns 4 respectively. That is, the three side portions correspond to the three moving portions 6, respectively. Each side portion and each moving portion 6 are connected by two parallel first links 11 . The first link 11 is rod-shaped. One ends of the two first links 11 are connected to both ends of the sides via rotatable joints 7 respectively. The other ends of the two first links 11 are connected to the moving part 6 via rotatable joints 7, respectively. The joint 7 is, for example, a universal joint.

The first support platen 10 holds a spindle 30 protruding upward and downward. The spindle 30 grips a tool 30a at its end. A second support plate 20 is arranged above the first support plate 10, and a connecting cylinder 8 whose axial direction is the vertical direction is provided between the first support plate 10 and the second support plate 20. - 特許庁The connecting tube 8 connects the first supporting board 10 and the second supporting board 20 . The connecting tube 8 integrates the first support plate 10 and the second support plate 20 .

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

The connecting tube 8 has a hexagonal shape in plan view, and among the six side portions at the upper end of the connecting tube 8, three side portions adjacent to each other in the circumferential direction are connected to the three side portions of the second support plate 20. do. Of the six sides at the lower end of the connecting tube 8 , three sides adjacent to each other in the circumferential direction are connected to the three sides of the first support plate 10 .

When the three moving parts 6 are at the same height position, the main shaft 30 is positioned substantially right above the center of the holding base 3 . When the two moving parts 6 are in the same vertical position and the other moving part 6 moves lower than the two moving parts 6, the main shaft 30 moves downward without changing the vertical position. It moves horizontally toward the opposite side of the moving part 6 .

When the two moving parts 6 are in the same vertical position and the other moving part 6 moves higher than the two moving parts 6, the main shaft 30 moves upward without changing the vertical position. Towards the part 6, move horizontally. When the three moving parts 6 move vertically by the same distance, the main shaft 30 moves vertically. By combining these movements, the machine tool 1 positions the spindle 30 at desired vertical, front, rear, left and right positions.

The spindle 30 has a spindle motor 12 . The main shaft 30 positioned at the desired position is rotated by the drive of the main shaft motor 12, and the tool 30a mounted on the main shaft 30 processes the work held on the holding base 3. FIG.

As shown in FIG. 2, the control device 40 includes a CPU 41, a storage section 42, a RAM 43, an input/output interface 44, an operation section 45, and a display section 46. The CPU 41 controls operations of each part of the machine tool 1 . The storage unit 42 is a rewritable memory such as EPROM, EEPROM, or the like. The storage unit 42 stores program products, and in this embodiment, stores a control program (not shown) for controlling the machine tool 1, a machining program DB 421 storing a plurality of machining programs for machining the workpiece 95, and a machining path generation program 422. do. The program 422 is a program for executing processing for generating a machining path, and is provided in a state stored in a computer-readable recording medium 423 such as a CD-ROM, DVD-ROM, or USB memory. It is stored in the storage unit 42 by installing it in the . Alternatively, the program 422 may be obtained from an external computer (not shown) connected to a communication network and stored in the storage unit 42 .

The storage unit 42 stores a threshold value for comparison with the torque of the spindle motor 12, which will be described later, and a flag indicating the separation direction, that is, a flag "1" indicating the direction toward the first area A1 or a flag "1" indicating the direction toward the second area A2. 2” etc. are stored.

When the 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, touch panel, or the like. The input/output interface 44 outputs signals to the display section 46 . A display unit 46 is a liquid crystal display panel or the like, and displays characters, graphics, symbols, and the like.

The control device 40 further includes a torque detector 12a for detecting the torque of the spindle motor 12, a spindle control circuit 47 corresponding to the spindle motor 12, a servo amplifier 48, a movement axis control circuit 49 and a servo amplifier 50 corresponding to the movement axis motor 13. Prepare. Based on a command from the CPU 41 , the spindle control circuit 47 outputs to the servo amplifier 48 a command indicating target values such as the direction of rotation and the number of revolutions of the spindle motor 12 . The servo amplifier 48 supplies power to the spindle motor 12 based on the command. The torque detector 12 a detects the torque of the spindle motor 12 , and the CPU 41 acquires the torque via the input/output interface 44 . The encoder 18 detects the rotational position and speed of the spindle motor 12 and sends a detection signal to the servo amplifier 48 . A servo amplifier 48 compares the detection signal with a target value to control the power to be output.

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

3 is an explanatory diagram for explaining the generation of the reference path, FIG. 4 is an explanatory diagram for explaining the generation of the machining path, and FIG. 5 is an explanatory diagram for explaining machining based on the machining path. .
In the machining path generation method of this embodiment, the deburred master work 9 is held on the holding table 3 of the machine tool 1 . A tool 30 a is attached to the tip of the spindle 30 .
As shown in FIG. 3, a reference path _L0 is generated on the outer peripheral side of the masterwork 9 by a method such as online teaching using conventional CAM software. The reference path _L0 is taught by a plurality of teaching points _Pn (n is a natural number) on the reference path _L0 . A teaching point corresponds to a reference point.
Based on the program 422, along the reference path _L0 , the main shaft 30 alternately performs an approaching motion to the peripheral edge of the master work 9 and a moving away from the peripheral edge. The peripheral edge includes an outer peripheral edge and an inner peripheral edge. The approaching motion is the motion of approaching the masterwork 9 , and the separating motion is the motion of moving away from the masterwork 9 .

The CPU 41 determines whether or not the tool 30a contacts the peripheral portion during the approaching operation, and acquires the coordinates of the center P of the spindle 30 each time it determines that the tool 30a has contacted. The CPU 41 acquires the rotational position of the moving shaft motor 13 using the encoder 19 and calculates the coordinates of the center P of the main shaft 30 using the acquired rotational position.
As shown in FIG. 4, the CPU 41 generates the machining path _L1 based on the obtained coordinates of the center P. As shown in FIG.
When deburring a work 95 with burrs, the work 95 is held on the holding base 3 . As shown in FIG. 5, the workpiece 95 is machined by moving the spindle 30 with the tool 30a mounted thereon along the machining path _L1 based on the corresponding machining program.

FIG. 6 is an example of a display screen of the display unit 46. As shown in FIG. In order to generate the machining path L ₁ , the CPU 41 displays the master work, the teaching points P _n (n=1, 2, 3, . . . ), and the reference path L ₀ on the right side of the display screen. Or display as a plan view. The perspective view or plan view may be switched by the 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. Details of the search pitch, the separation amount, and the movement amount during measurement will be described later.

The operator confirms the reference route L ₀ displayed by the CPU 41 on the display unit 46, and if there is a portion of the reference route L ₀ to be corrected by the operation unit 45, it is indicated by an arrow. The operator inputs the search pitch, separation amount, and movement amount during measurement. Candidates for the search pitch, the separation amount, and the movement amount during measurement may be presented and selected by the operator.

The CPU 41 acquires the search pitch, separation amount, and movement amount at the time of measurement input by the operator, inputs the corrected portion when it is acquired, and sets search conditions such as reducing the search pitch for the corrected portion. do. Based on the set conditions, the CPU 41 generates the machining path _L1 .

FIG. 7 is an explanatory diagram for explaining the method of generating the machining path _L1 , and FIG. 8 is a partial enlarged view of FIG. The reference path L ₀ is the path initially stored in the machining program DB 421 . It has a plurality of teaching points P _n (n=1, 2, 3, . . . ) on the reference path L ₀ . The CPU 41 generates a search route T along which the main shaft 30 moves in a zigzag manner along the reference route L ₀ based on the set search pitch, separation amount, and movement amount during measurement. In FIG. 7, the point P _a is the center point of the main shaft 30 when it is separated, and the points P _1a , P _1b , P _1c , P _2a , P _2b , . 9 is the center point of the main shaft 30 when it comes into contact with it. A polygonal line connecting the point P _a and the center points P _1a , P _1b , P _1c , P _2a , P _2b , .

As shown in FIG. 8, the center point of spindle 30 moves from P ₀ to P ₁ , approaches masterwork 9 and contacts masterwork 9 . The center point of the main axis 30 at contact is _P1a . The CPU 41 generates a first vector a having a first length from the center point _P1a of the main shaft 30 toward the teaching point _P2 , and a second vector b having a second length and orthogonal to the first vector a. to calculate The first length is equal to the search pitch in FIG. 7 and is the distance from the center point of the main axis 30 at the time of contact during approach motion. The second length is the separation amount in FIG. 7, which is the distance that the main shaft 30 is separated from the peripheral edge of the masterwork 9 after it contacts the peripheral edge.

The CPU 41 calculates a third vector c, which is the sum of the first vector a and the second vector b, and separates the main shaft 30 based on the third vector c. Alternatively, the angle θ _a may be stored in advance in the storage unit 42 or obtained, and the third vector c may be obtained so as to form the angle θ _a with respect to the vector a.

Next, based on a fourth vector d having a direction opposite to that of the second vector b and having a third length obtained by adding the movement amount during measurement (see FIG. 7) to the second length, the main shaft 30 is approached. Let The movement amount at the time of measurement is the distance added to the second length for the approach motion. Until the contact with the master work 9 is detected, the approach operation is performed aiming at the end point P _b of the fourth vector d inside the master work 9 . Actually, the main shaft 30 contacts the master work 9 before reaching the end point _Pb , and after the contact, the main shaft 30 does not move, and the moving shaft motor 13 rotates the necessary amount to reach the end point _Pb .

When the distance D between the center _P1c of the spindle 30 and the teaching point _P2 at the time of contact becomes less than the search pitch, from _P1c to the next teaching point _P3 , the first distance having the first length is reached. The principal axis 30 is spaced apart based on a third vector c which is the sum of vector a and a second vector b which is orthogonal to the first vector a and has a second length. In this manner, the CPU 41 alternately performs the separating operation and the contacting operation, and stores the coordinates of the center point of the main shaft 30 each time the main shaft 30 contacts the master work 9 during the approaching operation. The CPU 41 generates a machining path for the spindle 30 based on the stored coordinates.

As shown in FIG. 8, when the line connecting the center point _P1a of the spindle 30 and the teaching point (reference point) _P2 located closest to the spindle 30 in the traveling direction of the spindle 30 is used as the boundary, the area is defined as the second It can be divided into one area A1 and a second area A2. In FIG. 8, the main shaft 30 performs a separation motion to the first area A1.

FIG. 9 is a schematic perspective view of the masterwork 9 for explaining a change in the separation direction of the main shaft 30. As shown in FIG. Small circles in FIG. 9 are teaching points P _n (n=1, 2, . . . ). As shown in FIG. 9, the masterwork 9 includes a base 9d, a cylindrical portion 9a projecting from the base 9d, and a hole portion 9b passing through the base 9d. The tubular portion 9a and the hole portion 9b are adjacent to each other. The arrow in FIG. 9 indicates the traveling direction of the spindle 30 when the machining path is generated. As indicated by the arrow in FIG. 9, the main shaft 30 goes around the outer circumference of the cylindrical portion 9a, moves along the path 9c, and goes around the inner circumference of the hole portion 9b. The path 9c is the shortest path connecting the teaching point of the cylindrical portion 9a and the teaching point of the hole portion 9b.

When the main shaft 30 moves on the outer circumference of the cylindrical portion 9a, the direction in which it can be separated is the left side with respect to the traveling direction. On the other hand, when moving along the inner circumference of the hole portion 9b, the separable direction is the right side with respect to the traveling direction. The area on the left side with respect to the traveling direction corresponds to the first area A1 in FIG. 8, and the area on the right side with respect to the traveling direction corresponds to the second area A2 in FIG. That is, it is necessary to change the direction in which the spindle 30 separates from the masterwork 9 when generating the machining path. When moving along the path 9c, the main shaft 30 is separated to the left, but may be moved to the right.

Each time the main shaft 30 passes through the teaching point, the CPU 41 executes processing for confirming whether or not it is necessary to change the separation direction. The CPU 41 separates the main shaft 30 in the same direction as the previous separation direction, and rotates the main shaft motor 12 at a low speed. It is determined whether or not the torque of the spindle motor 12 is equal to or greater than the threshold value stored in the storage unit 42. If the torque is equal to or greater than the threshold value, it is determined that the tool 30a contacts the master work 9 during the separation operation, and the separation direction is changed.

FIG. 10 is a flowchart for explaining machining path generation processing by the CPU 41 . The CPU 41 acquires the reference route L ₀ , search teaching points, correction teaching points, etc. (S1). The CPU 41 changes the machining program No. according to the operator's operation. , and refer to the machining program DB 421 to obtain the corresponding No. Acquire the reference path L ₀ in the machining path column of the machining program. Alternatively, the spindle 30 is moved to bring the tool 30a into contact with the master work 9, the coordinates of the point indicating the corner of the master work 9 and the point at which the attitude of the tool 30a changes are acquired, and based on these teaching points P _n , to obtain the reference path L ₀ . Also, a search teaching point, which is a teaching point to be used for calculation of the search path, and a change teaching point, which is a teaching point to be used for changing the separation direction, are acquired. In the initial state, both the search teaching point and the change teaching point are the teaching point _P2 .

The CPU 41 displays on the display unit 46 the reference route L ₀ and the input fields for the conditions of the search pitch, the separation amount, and the movement amount during measurement (S2, see FIG. 6). The CPU 41 acquires the search pitch, separation amount, and movement amount at the time of measurement input by the operator, inputs the corrected portion when it is acquired, and sets search conditions such as reducing the search pitch for the corrected portion. (S3).

The CPU 41 executes the approaching operation of the spindle 30 (S4), and determines whether or not the tool 30a has come into contact with the master work 9 (S5). The CPU 41 causes the spindle 30 to approach the master work 9 while rotating the spindle motor 12 at a low speed (forward rotation or reverse rotation). A low speed is, for example, 100-1000 rpm. The CPU 41 determines whether or not the torque of the spindle motor 12 is greater than or equal to the threshold value stored in the storage unit 42, and determines that the tool 30a has come into contact with the master work 9 when the torque of the spindle motor 12 is greater than or equal to the threshold value.

When determining that the tool 30a is not in contact with the master work 9 (S5: NO), the CPU 41 returns the process to step S5. When determining that the tool 30a has come into contact with the master work 9 (S5: YES), the CPU 41 acquires the coordinates of the spindle 30, that is, the central coordinates of the spindle 30 (S6). The CPU 41 executing step S5 corresponds to an approach contact determination unit, and the CPU 41 executing step S6 corresponds to an acquisition unit.

The CPU 41 determines whether or not the distance D between the center of the spindle 30 at the time of contact and the search teaching point is less than the search pitch (S7). If the distance D is not less than the search pitch (S7: NO), the CPU 41 calculates the search path, that is, the target center position of the main shaft 30 when separated (S9). If the distance D is less than the search pitch (S7: YES), the CPU 41 updates the search teaching point (S8), and proceeds to step S9. In step S8, for example, the CPU 41 updates the search teaching point from teaching point _P2 to teaching point _P3 .

After the process of step S9, the CPU 41 determines whether or not the change teaching point has been passed (S10). The CPU 41 compares the coordinates of the change teaching point with the coordinates acquired in step S6, and determines whether or not the acquired coordinates are located on the forward side in the traveling direction of the main shaft 30 with respect to the coordinates of the change teaching point.

If the change teaching point has not been passed (S10: NO), the CPU 41 executes the separation operation of the main shaft 30 in the direction indicated by the flag (S11). In the initial state, for example, the flag indicating the separation direction is "1", the main shaft 30 is separated toward the first area A1, and does not contact the master work 9 during separation. The CPU 41 determines whether or not the search for all the center coordinates of the spindle 30 has ended (S12). When determining that the search for all the center coordinates of the spindle 30 has not ended (S12: NO), the CPU 41 returns the process to step S4.

If the change teaching point is passed (S10: YES), the CPU 41 updates the change teaching point (S14). For example, the CPU 41 updates the change teaching point from teaching point _P2 to teaching point _P3 . The CPU 41 updates the search teaching point if the distance D is less than the search pitch even if the search teaching point is not passed, but updates the change teaching point only when the change teaching point is passed.

The CPU 41 executes the separation operation at low speed (S15). While rotating the main shaft 30 at low speed, the CPU 41 moves the main shaft 30 in the direction opposite to the moving direction of the approaching motion, that is, toward the first area A1 side at low speed. The CPU 41 determines whether or not the torque of the spindle motor 12 is equal to or greater than the threshold (S16).

If the torque is equal to or greater than the threshold (S16: YES), that is, if the main shaft 30 cannot be separated, the main shaft 30 stops moving (S17), and the separating direction is changed (S18). That is, the CPU 41 changes the flag indicating the separation direction to "2". The CPU 41 returns the spindle 30 to its original position, that is, the position indicated by the coordinates acquired in step S6 (S19). In step S16, if the torque is not equal to or greater than the threshold (S16: NO), that is, if the main shaft 30 can be separated, the process proceeds to step S12. The CPU 41 executing step S16 corresponds to the separated contact determination unit, and the CPU 41 executing step S18 corresponds to the changing unit.

After executing step S19, the CPU 41 advances the process to step S9. In step S12, when it is determined that the search for all the center coordinates of the spindle 30 has ended (S12: YES), the CPU 41 generates a machining path based on the plurality of stored center coordinates, and stores the generated machining path in the storage unit. 42 (S13), and the process ends. The CPU 41 that executes step S13 corresponds to the generator.

A force sensor is provided on the spindle 30, and when the load detected by the force angle sensor is greater than or equal to a predetermined value, or when the torque acting on the moving axis motor 13 is greater than or equal to a predetermined value, the tool 30a and the master It may be determined that the workpiece 9 is in contact with the contact.

In the machine tool 1 according to the embodiment, the spindle 30 alternately repeats the approaching motion to the peripheral edge portion of the masterwork 9 and the separating motion from the peripheral edge portion along the reference path. When the tool 30a comes into contact with the peripheral portion during the approaching operation, the CPU 41 acquires the coordinates of the spindle 30, accurately generates the machining path based on the coordinates, and can reduce the operator's correction work. Further, the direction in which the master work 9 can be separated without interfering with it differs depending on whether the spindle is positioned on the outer peripheral side or the inner peripheral side of the master work 9 . When passing through the teaching point, it is determined whether or not the tool 30a contacts the master work 9 during the separation operation. This automatically prevents the operator from doing so, reducing the operator's correction work.

Also, during the separation operation, it is possible to determine whether or not the torque acting on the spindle 30 is equal to or greater than a predetermined threshold value, and to confirm whether or not the tool 30a interferes with the masterwork 9. FIG. Further, when the separation operation to one of the first area A1 and the second area A2 is performed and it is determined that the tool 30a contacts the masterwork 9, the other of the first area A1 and the second area A2 It is possible to change the separation direction so as to perform the separation operation to the area, and prevent interference with the master work 9 during the separation operation.

The embodiments disclosed this time should be considered as examples 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 of equivalents to the scope of the claims. be done.

1 machine tool 30 spindle 30a tool 40 control device 41 CPU
42 storage unit 43 RAM

Claims (5)

a spindle on which the tool is mounted;
The main spindle is moved toward and away from the peripheral edge of the masterwork along a reference path on the outer or inner peripheral side of the masterwork determined based on a plurality of reference points. a moving part;
a separation contact determination unit that determines whether or not the tool contacts the master work during the separation operation;
a changing unit that changes the separation direction in the separation operation when the separation contact determination unit determines that the tool contacts the master work;
an approaching contact determination unit that determines whether or not the tool has contacted the peripheral portion during the approaching operation by the moving unit;
an acquisition unit that acquires the coordinates of the main axis each time the approach contact determination unit determines that a contact has occurred;
A machine tool comprising: a generation unit that generates a machining path for the spindle based on the plurality of coordinates acquired by the acquisition unit. 2. The machine tool according to claim 1, wherein the separated contact determination unit determines that the tool contacts the master work when torque acting on the spindle is equal to or greater than a predetermined threshold value. The moving part moves the moving part to one of the first area and the second area bounded by a line connecting the center of the main axis and the reference point positioned closest to the main axis in the advancing direction of the main axis. perform a separation action,
When the separation contact determination unit determines that the tool has come into contact with the master work, the change unit performs the separation operation to the other of the first region and the second region. The machine tool according to claim 1 or 2, wherein the separating direction is changed. In a machining path generation method for generating a machining path for a spindle on which a tool is mounted,
Along the reference path on the outer or inner peripheral side of the master work determined based on a plurality of reference points, the spindle on which the tool is mounted approaches the peripheral edge of the master work and separates the spindle from the peripheral edge. perform the action,
determining whether or not the tool contacts the master work during the separating operation;
changing the separating direction in the separating operation when it is determined that the tool contacts the master work during the separating operation;
determining whether or not the tool contacts the peripheral portion during the approaching operation;
acquiring the coordinates of the spindle each time it is determined that the tool contacts the peripheral portion during the approaching operation;
A machining path generation method for generating the machining path based on a plurality of acquired coordinates. In a computer program executable on a machine tool that generates a machining path for a tool-mounted spindle,
to said machine tool,
Along the reference path on the outer or inner peripheral side of the master work determined based on a plurality of reference points, the spindle on which the tool is mounted approaches the peripheral edge of the master work and separates the spindle from the peripheral edge. perform the action,
determining whether or not the tool contacts the master work during the separating operation;
changing the separating direction in the separating operation when it is determined that the tool contacts the master work during the separating operation;
determining whether or not the tool contacts the peripheral portion during the approaching operation;
acquiring the coordinates of the spindle each time it is determined that the tool contacts the peripheral portion during the approaching operation;
A computer program for executing a process of generating the machining path based on a plurality of acquired coordinates.

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