Cutting processing control device and cutting processing device

Abstract

To provide a cutting control device and a cutting device capable of suppressing entanglement of chips in a workpiece.SOLUTION: A cutting control device 10 includes a generation unit 33 and a feed control unit 34. The generation unit 33 generates a machining locus T2 represented by the relative position in the machining direction between a workpiece 22 and a tool 23 and the rotation phase of a spindle 21 to which the workpiece 22 is attached. The feed control unit 34 moves the tool 23 in the machining direction based on the machining locus T2. The machining locus T2 repeats a first phase period R1 in which the feed amount is set and a second phase period R2 in which the reverse feed amount is set. The cycle of the machining locus T2 gradually increases and then gradually decreases as the rotation phase progresses.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a cutting processing control device and a cutting processing device. [Background technology]

[0002] Patent Document 1 discloses a method for breaking up chips generated by cutting a workpiece by vibrating the tool at a low frequency in the machining direction relative to the workpiece in a machine tool that uses a tool to cut the workpiece. The method described in Patent Document 1 makes it possible to prevent the chips from becoming entangled in the workpiece. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-190119 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the method described in Patent Document 1, the tool is vibrated at a low frequency, so there is a limit to how finely the chips can be broken down.

[0005] Although chips can be broken down into smaller pieces by vibrating the tool at a high frequency, if the drive motor that vibrates the tool is driven at a frequency exceeding the limit frequency at which the drive motor can be controlled, the tool will essentially stop vibrating.

[0006] Furthermore, if the limit frequency could be known, the chips could be broken into small pieces by driving the drive motor at the limit frequency. However, since the limit frequency differs depending on the specifications (performance) of the drive motor, it is difficult to find out the limit frequency of every drive motor in advance.

[0007] Therefore, it is not easy to break up the chips by vibrating the tool at high frequencies.

[0008] The present disclosure aims to provide a cutting control device and a cutting device capable of suppressing entanglement of chips in a workpiece. [Means for solving the problem]

[0009] A cutting processing control device according to an embodiment of the present disclosure includes a generating unit and a feed control unit. The generating unit generates a processing trajectory represented by the relative positions of the workpiece and the tool in the processing direction and the rotation phase of a spindle to which one of the workpiece and the tool is attached. The feed control unit moves the other of the workpiece and the tool in the processing direction based on the processing trajectory. The processing trajectory repeats a first phase period in which a feed amount toward the feed side in the processing direction is set and a second phase period in which a reverse feed amount toward the reverse feed side in the processing direction is set. The frequency of the processing trajectory gradually increases or decreases with the progression of the rotation phase. Effect of the Invention

[0010] According to the present disclosure, it is possible to provide a cutting processing control device and a cutting processing device capable of suppressing entanglement of chips in a workpiece. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram showing a configuration of a cutting device according to an embodiment; [Diagram 2] Graph showing an example of a program path and a machining path [Diagram 3] Flowchart showing the flow of a cutting processing control method [Figure 4] Graph showing the processing trajectory of a triangular wave DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] (Cutting equipment) The configuration of a cutting apparatus 10 according to this embodiment will be described with reference to the drawings.

[0013] The cutting device 10 includes a cutting section 20 and a cutting control device 30.

[0014] [Cutting section] The cutting section 20 has a spindle 21, a workpiece (hereinafter referred to as "work") 22, a tool 23, a spindle drive section 24, and a feed drive section 25. In this embodiment, a metal round bar is used as the workpiece 22, and the outer diameter of the round bar is cut to a desired outer diameter by the tool 23.

[0015] The main shaft 21 rotates about a rotation axis L. The workpiece 22 is attached to the main shaft 21. The workpiece 22 rotates together with the main shaft 21 about the rotation axis L.

[0016] The tool 23 is used to cut the workpiece 22. The tool 23 moves in a cutting direction (Z-axis direction). As a result, the tool 23 cuts the workpiece 22 while moving relative to the workpiece 22. The cutting direction is a so-called feed direction. In this embodiment, the cutting direction is a direction parallel to the rotation axis L.

[0017] As described below, the tool 23 moves along the machining direction while vibrating in the feed side and the reverse feed side. The feed side is the side in the machining direction where machining of the workpiece 22 proceeds, and the reverse feed side is the side opposite to the feed side in the machining direction.

[0018] The spindle drive unit 24 rotates the spindle 21. As the spindle drive unit 24, for example, a drive motor can be used.

[0019] The feed drive unit 25 moves the tool 23 along the machining direction while vibrating the tool 23 in the feed side and reverse feed side. The feed drive unit 25 can vibrate the tool 23 at or below a limit frequency. The limit frequency differs depending on the specifications (performance) of the feed drive unit 25. In this embodiment, the limit frequency of the feed drive unit 25 is unknown. As the feed drive unit 25, for example, a drive motor can be used.

[0020] The feed drive unit 25 can also move the tool 23 in a radial direction perpendicular to the rotation axis L (X-axis direction) as appropriate.

[0021] [Cutting processing control device] The cutting processing control device 30 has an acquisition unit 31, a spindle control unit 32, a generation unit 33, and a feed control unit .

[0022] The acquisition unit 31 acquires the spindle speed S and the program path T1 from an NC (Numerical Control) program used for cutting the workpiece 22 with the tool 23. The NC program is an example of a machining program according to the present disclosure. The spindle speed S is the number of rotations of the spindle 21 per unit time. The program path T1 is a planned movement path of the tool 23 in the machining direction. The program path T1 is represented by a feed command value described in the NC program.

[0023] The spindle speed S is input to the spindle control unit 32 from the acquisition unit 31. The spindle control unit 32 outputs a rotation command to the spindle drive unit 24 based on the received spindle speed S. The spindle drive unit 24 drives the spindle 21 to rotate in response to the rotation command.

[0024] The generating unit 33 receives the program path T1 from the acquiring unit 31. The generating unit 33 generates a machining path T2 based on the program path T1. The machining path T2 is an actual movement path of the tool 23 in the machining direction.

[0025] Here, Fig. 2 is a graph showing an example of a program path T1 (dashed line) and a machining path T2 (solid line). In Fig. 2, the horizontal axis is the rotation phase of the spindle 21, and the vertical axis is the feed position of the tool 23 in the machining direction. The feed position is the relative position of the workpiece 22 and the tool 23 in the machining direction.

[0026] 2, the program trajectory T1 is represented by a straight line. In the program trajectory T1, the feed position increases linearly with the progression of the rotation phase.

[0027] As shown in FIG. 2, the machining trajectory T2 is represented by a sine wave. Reverse feed side to Reverse feed amount A first phase period R1 in which Sending side to Feed rate The first phase period R2 in which the feed position is set is repeated. Therefore, in the machining trajectory T2, the feed position is alternately increased and decreased with the progression of the rotation phase. In this manner, the tool 23 is vibrated in the machining direction, so that the cutting process is intermittently performed on the workpiece 22, and the chips can be broken up.

[0028] Furthermore, as shown in FIG. 2, the frequency of the machining locus T2 gradually increases as the rotation phase progresses in the first section Q1 from the initial phase P0 to the first phase P1, and gradually decreases as the rotation phase progresses in the second section Q2 from the first phase P1 to the second phase P2.

[0029] Therefore, the frequency of the machining locus T2 repeats between the lowest frequency (the frequency at the initial phase P0 and the second phase P2) and the highest frequency (the frequency at the first phase P1) as the rotation phase progresses.

[0030] 2, in the first section Q1, the frequency of a first phase period R1 is higher than the frequency of a second phase period R2 located before the first phase period R1, and the frequency of the second phase period R2 is higher than the frequency of the first phase period R1 located before the second phase period R2. On the other hand, in the second section Q2, the frequency of a first phase period R1 is lower than the frequency of a second phase period R2 located before the first phase period R1, and the frequency of the second phase period R2 is lower than the frequency of the first phase period R1 located before the second phase period R2.

[0031] The maximum frequency of the machining trajectory T2 can be determined based on the desired length for breaking the chips by the vibration of the tool 23. The desired length for breaking the chips can be obtained from the size and shape of the workpiece 22. Note that the maximum frequency is a predetermined value that is set in advance by an input device (not shown) or the like, and is stored in a memory unit (not shown) of the cutting processing control device 30.

[0032] In this embodiment, since the limit frequency of the feed drive unit 25 is unknown, the maximum frequency of the machining path T2 cannot be determined based on the limit frequency of the feed drive unit 25. The maximum frequency of the machining path T2 may be higher or lower than the limit frequency of the feed drive unit 25. In this embodiment, it is assumed that the maximum frequency of the machining path T2 is higher than the limit frequency of the feed drive unit 25.

[0033] The minimum frequency of the machining trajectory T2 can be determined based on a desired frequency multiplication factor. For example, when the frequency multiplication factor is an odd multiple of 0.5, the circumferential position of the workpiece 22 where the feed position of the tool 23 is maximum during the nth rotation and the circumferential position of the workpiece 22 where the feed position of the tool 23 is minimum during the n+1th rotation overlap, so that the chips can be reliably cut. Therefore, it is preferable that the frequency multiplication factor is an odd multiple of 0.5 (for example, 0.5).

[0034] In this way, sweep vibration is performed in the first section Q1, so that the chips can be broken up until the frequency of the machining locus T2 exceeds the limit frequency of the feed drive unit 25. In addition, sweep vibration reduction is performed in the second section Q2 following the first section Q1, so that the chips can be broken up after the frequency of the machining locus T2 becomes equal to or lower than the limit frequency of the feed drive unit 25. In both the first section Q1 and the second section Q2, when the frequency of the machining locus T2 is near the limit frequency of the feed drive unit 25, the chips can be broken up particularly finely.

[0035] Therefore, even if the limit frequency of the feed drive unit 25 is not known, it is possible to prevent the chips from becoming entangled in the workpiece 22 and to break the chips into smaller pieces to a certain extent.

[0036] The generator 33 generates the machining path T2 by increasing the feed amount in the first phase period R1 in the program path T1 and gradually increasing or decreasing the frequency of the program path T1 with the progression of the rotation phase. The generator 33 outputs the generated machining path T2 to the feed control unit 34.

[0037] The feed control unit 34 receives the machining trajectory T2 from the generation unit 33. The feed control unit 34 acquires the rotation phase W of the spindle 21 from the spindle drive unit 24. The feed control unit 34 outputs a feed command to the feed drive unit 25 to move the tool 23 to a feed position associated with the rotation phase of the spindle 21 based on the machining trajectory T2. The feed drive unit 25 moves the tool 23 in the machining direction in response to the feed command. As a result, the tool 23 moves in the machining direction while vibrating in accordance with the machining trajectory T2.

[0038] (Cutting process control method) Next, the cutting control method according to this embodiment will be described with reference to the drawings. Fig. 3 is a flowchart showing the flow of the cutting control method.

[0039] In step S1, the generating unit 33 generates a machining trajectory T2 from the program trajectory T1. Specifically, as shown in Fig. 2, the generating unit 33 generates the machining trajectory T2 by increasing the feed amount in the first phase period R1 in the program trajectory T1 and gradually increasing or decreasing the frequency of the program trajectory T1 with the progression of the rotation phase.

[0040] In steps S2 to S5, the feed control unit 34 moves the tool 23 to a feed position associated with the rotation phase of the spindle 21 based on the machining trajectory T2.

[0041] First, in step S2, the feed control unit 34 gradually increases the vibration frequency of the tool 23 from the minimum frequency to the maximum frequency as the rotation phase progresses.

[0042] In step S3, the feed control unit 34 determines whether or not the vibration frequency of the tool 23 has reached the maximum frequency. If the vibration frequency of the tool 23 has not reached the maximum frequency, the process returns to step S2, and if the vibration frequency of the tool 23 has reached the maximum frequency, the process proceeds to step S4.

[0043] In step S4, the feed control unit 34 gradually decreases the vibration frequency of the tool 23 from the maximum frequency to the minimum frequency as the rotation phase progresses.

[0044] In step S5, the feed control unit 34 determines whether or not the vibration frequency of the tool 23 has reached the minimum frequency. If the vibration frequency of the tool 23 has not reached the minimum frequency, the process returns to step S4, and if the vibration frequency of the tool 23 has reached the minimum frequency, the process returns to step S2.

[0045] (Modification of the embodiment) The present disclosure is not limited to the above-described embodiments, and various modifications and alterations are possible without departing from the scope of the present disclosure.

[0046] (Variation 1) In the above embodiment, the machining trajectory T2 is represented by a sine wave, but it may be represented by a triangular wave as shown in Fig. 4. When the machining trajectory T2 is represented by a sine wave, the acceleration and deceleration of the tool 23 is gradual, so that wear on the tool 23 and the feed drive unit 25 can be suppressed. When the machining trajectory T2 is represented by a triangular wave, the number of lines of the NC program can be reduced, so that the NC program can be simplified and the processing load on the generation unit 33 and the feed control unit 34 can be reduced.

[0047] (Variation 2) In the machining trajectory T2 according to the above embodiment, the sweep vibration is performed after the sweep vibration is performed, but the sweep vibration may be performed after the sweep vibration is reduced. In addition, in the machining trajectory T2, only one of the sweep vibration and the sweep vibration reduction may be performed. In addition, when both the sweep vibration and the sweep vibration reduction are repeatedly performed, the number of times the sweep vibration and the sweep vibration reduction are repeated is not particularly limited.

[0048] (Variation 3) In the above embodiment, the tool 23 moves relative to the workpiece 22 by moving in the machining direction, but the tool 23 may move relative to the workpiece 22 by moving in the machining direction. For example, in boring, which is one type of cutting process, there may be a form in which the workpiece 22 is attached to the spindle 21, and a form in which the tool 23 is attached to the spindle 21. [Explanation of symbols]

[0049] 10 Cutting equipment 20 Cutting section 21 Spindle 22 Workpiece 23 Tools 24 Spindle drive unit 25 Feed drive unit 30 Cutting processing control device 31 Acquisition Department 32 Spindle control unit 33 Generation part 34 Feed control section P0 Initial phase P1 1st phase P2 Second phase Q1 1st Section Q2 2nd Section R1 First phase period R2 Second phase period S Spindle speed T1 Program Trajectory T2 Machining trajectory

Claims

1. A generating unit that generates a machining trajectory represented by a relative position of a workpiece and a tool in a machining direction and a rotation phase of a spindle to which one of the workpiece and the tool is attached; a feed control unit that moves the other of the workpiece and the tool in the processing direction based on the processing trajectory; a spindle control unit that rotates the spindle at a constant spindle rotation speed; Equipped with When the spindle is rotationally driven at the constant spindle rotation speed, the machining trajectory repeats a first phase period in which a reverse feed amount in the reverse feed side of the machining direction is set and a second phase period in which a feed amount in the feed side of the machining direction is set, The frequency of the machining trajectory gradually increases or decreases as the rotation phase progresses. Cutting processing control device.

2. The machining trajectory is represented by a sine wave. The cutting processing control device according to claim 1 .

3. The processing trajectory is represented by a triangular wave. The cutting processing control device according to claim 1 .

4. An acquisition unit for acquiring a program trajectory from a machining program, the generating unit generates the machining trajectory by increasing a reverse feed amount in the first phase period in the program trajectory and gradually increasing or decreasing a frequency of the program trajectory with the progression of the rotation phase. The cutting control device according to any one of claims 1 to 3.

5. The frequency of the machining trajectory repeats between a minimum frequency and a maximum frequency as the rotation phase progresses. The cutting control device according to any one of claims 1 to 4.

6. A cutting processing control device according to any one of claims 1 to 5, a feed drive unit that moves the other of the workpiece and the tool in accordance with a feed command value output from the feed control unit; A cutting device comprising:

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