JP2023108500A - Cutting control device and cutting device - Google Patents

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

The present disclosure relates to a cutting control device and a cutting device.

Patent Literature 1 discloses a method of cutting chips generated by cutting in a machine tool that cuts a workpiece using a tool by vibrating the tool at a low frequency in the machining direction with respect to the workpiece. ing. According to the method described in Patent Literature 1, it is possible to suppress entanglement of chips with the workpiece.

JP 2009-190119 A

However, in the method described in Patent Document 1, since the tool is vibrated at a low frequency, there is a limit to finely dividing the chips.

If the tool is vibrated at a high frequency, chips can be made finer, but if the drive motor that vibrates the tool is driven at a frequency that exceeds the controllable limit frequency, the tool will not vibrate substantially.

Also, if the limit frequency can be known, chips can be finely divided by driving the drive motor at the limit frequency. It is difficult to keep track of.

Therefore, it is not easy to reduce chips by vibrating the tool at high frequency.

An object of the present disclosure is to provide a cutting control device and a cutting device that can suppress chips from getting entangled in a workpiece.

A cutting control device according to an aspect of the present disclosure includes a generator and a feed controller. The generator generates a machining trajectory represented by relative positions of the workpiece and the tool in the machining direction and a rotation phase of the 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 machining direction based on the machining locus. The machining locus repeats a first phase period in which a feed amount to the feed side in the machining direction is set and a second phase period in which a reverse feed amount to the reverse feed side in the machining direction is set. The frequency of the machining trajectory gradually increases or decreases as the rotation phase progresses.

Advantageous Effects of Invention According to the present disclosure, it is possible to provide a cutting control device and a cutting device capable of suppressing entanglement of chips in a workpiece.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic diagram which shows the structure of the cutting apparatus which concerns on embodiment Graph showing an example of program trajectory and machining trajectory Flowchart showing the flow of the cutting control method Graph showing the machining trajectory of the triangular wave

(Cutting equipment)
A configuration of a cutting apparatus 10 according to this embodiment will be described with reference to the drawings. FIG. 1 is a schematic diagram showing the configuration of a cutting apparatus 10. As shown in FIG.

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

[Cutting part]
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 a case where the outer diameter of the round bar is cut to a desired outer diameter by a tool 23 will be described as an example.

The main shaft 21 rotates around the rotation axis L. As shown in FIG. A work 22 is attached to the spindle 21 . The workpiece 22 rotates around the rotation axis L together with the main shaft 21 .

The tool 23 is used for cutting the workpiece 22 . The tool 23 moves in the machining direction (Z-axis direction). As a result, the tool 23 cuts the work 22 while moving relative to the work 22 . The processing direction is the so-called feeding direction. In this embodiment, the processing direction is a direction parallel to the rotation axis L. As shown in FIG.

As will be described later, the tool 23 moves along the machining direction while vibrating to the feed side and the reverse feed side. The feed side is the side on which the work 22 is machined in the machining direction, and the reverse feed side is the side opposite to the feed side in the machining direction.

The main shaft driving section 24 rotationally drives the main shaft 21 . A drive motor, for example, can be used as the spindle drive unit 24 .

The feed drive unit 25 moves the tool 23 along the machining direction while vibrating the tool 23 toward the feed side and the reverse feed side. The feed driving section 25 can vibrate the tool 23 at a limit frequency or less. The limit frequency differs depending on the specifications (performance) of the feed driving section 25 . In this embodiment, it is assumed that the limit frequency of the feed driving section 25 is unknown. A drive motor, for example, can be used as the feed drive unit 25 .

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

[Cutting control device]
The cutting control device 30 has an acquisition unit 31 , a spindle control unit 32 , a generation unit 33 and a feed control unit 34 .

The acquiring unit 31 acquires the spindle speed S and the program trajectory T1 from an NC (Numerical Control) program used for cutting the workpiece 22 with the tool 23 . An 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 trajectory T1 is a planned movement trajectory of the tool 23 in the machining direction. The program locus T1 is represented by a feed command value described in the NC program.

The main shaft rotation speed S is input from the acquisition unit 31 to the main shaft control unit 32 . The spindle control unit 32 outputs a rotation command to the spindle drive unit 24 based on the spindle rotation speed S received. The spindle driving section 24 rotationally drives the spindle 21 according to the rotation command.

The program trajectory T<b>1 is input from the acquisition unit 31 to the generation unit 33 . The generator 33 generates a machining trajectory T2 based on the program trajectory T1. The machining trajectory T2 is the actual movement trajectory of the tool 23 in the machining direction.

Here, FIG. 2 is a graph showing an example of the program trajectory T1 (broken line) and the machining trajectory T2 (solid line). In FIG. 2, the horizontal axis is the rotational phase of the spindle 21, and the vertical axis is the feed position of the tool 23 in the machining direction. A feed position is a relative position of the workpiece 22 and the tool 23 in the machining direction.

As shown in FIG. 2, program trajectory T1 is represented by a straight line. In the program locus T1, the feed position increases linearly as the rotation phase advances.

As shown in FIG. 2, the machining locus T2 is represented by a sine wave. In the machining trajectory T2, a first phase period R1 in which a feed amount to the feed side is set and a second phase period R2 in which a reverse feed amount to the reverse feed side is set are repeated. Accordingly, in the machining locus T2, the feed position is alternately increased and decreased as the rotation phase progresses. As described above, the tool 23 vibrates in the machining direction, so that the workpiece 22 is intermittently cut, so that chips can be separated.

Further, as shown in FIG. 2, the frequency of the machining trajectory T2 gradually increases as the rotation phase progresses in the first section Q1 from the initial phase P0 to the first phase P1. In the second interval Q2 up to the second phase P2, it gradually decreases as the rotational phase progresses.

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.

Specifically, as shown in FIG. 2, in a first interval Q1, the frequency of a given first phase period R1 is higher than the frequency of a second phase period R2 that precedes the first phase period R1. and the frequency of a second phase period R2 is higher than the frequency of the first phase period R1 that precedes the second phase period R2. On the other hand, in the second interval Q2, the frequency of a certain first phase period R1 is lower than the frequency of a second phase period R2 positioned before the first phase period R1, and the frequency of a certain second phase period R2 is lower than the frequency of the first phase period R1 that precedes the second phase period R2.

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

In this embodiment, since the limit frequency of the feed drive section 25 is unknown, the maximum frequency of the machining locus T2 cannot be determined based on the limit frequency of the feed drive section 25. FIG. The maximum frequency of the machining locus T2 may be higher or lower than the limit frequency of the feed drive section 25. In this embodiment, it is assumed that the maximum frequency of the machining locus T2 is higher than the limit frequency of the feed driving section 25. FIG.

The lowest frequency of the machining trajectory T2 can be determined based on a desired frequency magnification. For example, when the frequency multiplier is an odd multiple of 0.5, the circumferential position of the workpiece 22 at which the feed position of the tool 23 is maximized during the n-th rotation and the feed position of the tool 23 during the n+1-th rotation are: The frequency multiplier is preferably an odd multiple of 0.5 (for example, 0.5) because it overlaps with the position in the circumferential direction of the workpiece 22, which is the minimum, so that chips can be reliably divided.

Since the sweep excitation is performed in the first section Q1 in this manner, chips can be divided until the frequency of the machining locus T2 exceeds the limit frequency of the feed drive unit 25. FIG. In addition, since the sweep vibration reduction is performed in the second section Q2 following the first section Q1, chips can be cut 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 trajectory T2 is near the limit frequency of the feed driving section 25, chips can be divided particularly finely.

Therefore, even if the limit frequency of the feed drive unit 25 is not known, it is possible to prevent chips from entangling with the work 22 and to break the chips finely to some extent.

The generation unit 33 increases the feed amount in the first phase period R1 in the program trajectory T1 and gradually increases or decreases the frequency of the program trajectory T1 as the rotation phase progresses to generate the machining trajectory T2. The generation unit 33 outputs the generated machining locus T2 to the feed control unit 34 .

The machining locus T<b>2 is input from the generation unit 33 to the feed control unit 34 . The feed control unit 34 acquires the rotation phase W of the main shaft 21 from the main shaft driving unit 24 . The feed control unit 34 outputs a feed command to the feed drive unit 25 so as to move the tool 23 to the feed position associated with the rotation phase of the spindle 21 based on the machining locus T2. The feed drive unit 25 moves the tool 23 in the machining direction according to the feed command. As a result, the tool 23 moves along the machining locus T2 while vibrating in the machining direction.

(Cutting control method)
Next, a cutting control method according to this embodiment will be described with reference to the drawings. FIG. 3 is a flow chart showing the flow of the cutting control method.

In step S1, the generator 33 generates a machining trajectory T2 from the program trajectory T1. Specifically, as shown in FIG. 2, the generation unit 33 increases the feed amount of the first phase period R1 in the program trajectory T1, and gradually increases the frequency of the program trajectory T1 as the rotation phase advances. A machining locus T2 is generated by raising or lowering.

In steps S2 to S5, the feed control unit 34 moves the tool 23 to the feed position associated with the rotational phase of the spindle 21 based on the machining locus T2.

First, in step S2, the feed control unit 34 gradually increases the vibration frequency of the tool 23 from the lowest frequency to the highest frequency as the rotation phase progresses.

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.

In step S4, the feed control unit 34 gradually lowers the vibration frequency of the tool 23 from the highest frequency to the lowest frequency as the rotation phase progresses.

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

(Modification of embodiment)
The present disclosure is not limited to the embodiments as described above, and various modifications or modifications are possible without departing from the scope of the present disclosure.

(Modification 1)
In the above embodiment, the machining locus T2 is represented by a sine wave, but may be represented by a triangular wave as shown in FIG. When the machining locus T2 is represented by a sine wave, the acceleration and deceleration of the tool 23 are moderate, so wear of the tool 23 and the feed drive section 25 can be suppressed. When the machining locus T2 is represented by a triangular wave, the number of lines in the NC program can be reduced, so the NC program can be simplified and the processing load on the generator 33 and the feed controller 34 can be reduced.

(Modification 2)
In the machining trajectory T2 according to the above embodiment, the sweep excitation is performed after the sweep excitation is performed, but the sweep excitation may be performed after the sweep excitation. Alternatively, only one of sweep excitation and sweep damping may be performed in the machining locus T2. Moreover, when both the sweep excitation and the sweep vibration reduction are repeatedly performed, the number of repetitions of the sweep excitation and the sweep vibration reduction is not particularly limited.

(Modification 3)
In the above embodiment, the tool 23 moves relative to the work 22 as the tool 23 moves in the machining direction. You may move. For example, in boring, which is one of cutting processes, 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 .

10 cutting device 20 cutting part 21 spindle 22 workpiece (work)
23 tool 24 spindle drive unit 25 feed drive unit 30 cutting control device 31 acquisition unit 32 spindle control unit 33 generation unit 34 feed control unit P0 initial phase P1 first phase P2 second phase Q1 first section Q2 second section R1 1st phase period R2 2nd phase period S Spindle speed T1 Program trajectory T2 Machining trajectory

Claims (6)

a generator that generates a machining trajectory represented by the relative positions of the workpiece and the tool in the machining direction and the rotational 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 machining direction based on the machining locus;
with
The machining locus repeats a first phase period in which a feed amount to the feed side in the machining direction is set and a second phase period in which a reverse feed amount to the reverse feed side in the machining direction is set,
The frequency of the machining trajectory gradually increases or decreases as the rotation phase progresses,
Cutting control device. The machining trajectory is represented by a sine wave,
The cutting control device according to claim 1. The machining trajectory is represented by a triangular wave,
The cutting control device according to claim 1. further comprising an acquisition unit that acquires the program locus from the machining program,
The generation unit generates the machining trajectory by increasing a feed amount in the first phase period in the program trajectory and gradually increasing or decreasing a frequency of the program trajectory as the rotation phase progresses. ,
The cutting control device according to any one of claims 1 to 3. The frequency of the machining trajectory repeats between a minimum frequency and a maximum frequency as the rotational phase progresses.
The cutting control device according to any one of claims 1 to 4. A cutting control device according to any one of claims 1 to 5;
a feed drive unit for moving the other of the workpiece and the tool according to a feed command value output from the feed control unit;
Cutting equipment.

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