JP6732567B2 - Machine tool control device and machine tool - Google Patents

Description

The present invention relates to a machine tool control device and a machine tool, and more particularly to a machine tool control device and a machine tool that machine a work into a cutting tool at a predetermined vibration frequency.

Conventionally, a work holding means for holding a work, a cutting tool for cutting a work, a rotating means for relatively rotating the work and the cutting tool, and a work holding means and a cutting tool are sequentially moved toward a predetermined position. By virtue of this, the work and the cutting tool are vibrated by a predetermined number of vibrations with respect to the relative rotation, and the work holding means and the cutting tool are relatively moved to cause vibration by the vibrating means. There is known a machine tool that processes a workpiece (for example, Patent Document 1).

International Publication No. 2015/146946

By the way, it is desirable that the number of rotations of the rotating means and the number of vibrations by the vibrating means can be arbitrarily set depending on processing conditions.
However, since the work holding means and the cutting tool are sequentially moved toward the predetermined position, the moving direction is changed at the moved position, and the moving destination is the changed position of the vibration direction. There is a problem in that it may not be possible to vibrate at an arbitrary frequency with respect to the number.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a machine tool control device and a machine tool that can be driven so as to vibrate at an arbitrary number of vibrations with respect to an arbitrary number of rotations. To do.

The present invention, firstly, a work holding means for holding a work, a cutting tool for cutting the work, a rotating means for relatively rotating the work and the cutting tool, the work holding means or the the cutting tool, by moving sequentially toward each predetermined position commanded by the operation command of the predetermined cycle, the workpiece or the cutting engineering tools, the predetermined relative relative rotation between the workpiece and the cutting tool A control device for a machine tool, comprising: a vibrating unit that vibrates at a number of times of vibration, by relatively moving the work holding unit and the cutting tool to machine the work with the vibration of the vibrating unit. there are, the workpiece holding means or the cutting tool is from the positive direction of the cutting tool position between a predetermined position location of a given position location and other side of the one contiguous to the negative direction, or the cutting tool position negative And a vibration means control unit for setting follow-up responsiveness of movement of the work holding means or the cutting tool with respect to the predetermined position so as to move with a change in the moving direction from the direction to the forward direction. To do.

Secondly, the vibrating means controller sets the tracking response of the movement by setting the gain of servo control.

Thirdly, there is provided an amplitude setting means for setting the amplitude of the vibration on the basis of the set gain so that the processed portion at the time of forward movement and the processed portion at the time of returning movement by the vibrating means overlap. Is characterized by.

Fourthly, it has a phase setting means for setting the phase of the vibration based on the set tracking response.

Fifth, a work holding means for holding a work, a cutting tool for cutting the work, a rotating means for relatively rotating the work and the cutting tool, and the work holding means or the cutting tool . vibrations by sequentially moving toward each predetermined position commanded by the operation command of the predetermined cycle, the workpiece or the cutting engineering tool, a predetermined number of vibrations to the relative rotation between the workpiece and the cutting tool A machine tool that includes a vibrating unit that causes the work holding unit and the cutting tool to move relative to each other, thereby machining the work with the vibration of the vibrating unit. or the cutting tool, moving from the positive direction of the cutting tool position between a predetermined position location of a given position location and other side of the one contiguous to the negative direction or from the negative direction of the cutting tool position to the forward direction The responsiveness of the movement of the work holding means or the cutting tool to the predetermined position of the vibrating means is set so that the vibrating means moves along with the change of the direction.

The present invention can obtain the following effects.
(1) Arbitrary rotation of relative rotation is set by setting the follow-up responsiveness of the vibrating means so as to move from one predetermined position side toward the other predetermined position side with a change in the moving direction. Any number of vibrations can be easily realized by the number.

(2) The tracking response can be easily set by setting the gain of servo control.

(3) Even if the follow-up response is changed, it is possible to perform machining with desired vibration by setting the amplitude.

(4) Even if the lead or lag of the phase occurs due to the change of the tracking response, the desired processing can be performed by setting the arbitrary phase.

(5) It is possible to provide a machine tool that can easily obtain an arbitrary number of vibrations at an arbitrary number of relative rotations.

It is a figure which shows the outline of the machine tool by one Example of this invention. It is a schematic diagram showing a relation between a cutting tool and a work. It is a figure explaining reciprocating vibration and a position of a cutting tool. It is a figure which shows the relationship of the blade edge path at the time of each rotation of the nth rotation of a main spindle, n+1 rotation, and n+2 rotation. It is a block diagram of a control apparatus. 5 is a flowchart of a processing process performed by the control unit according to the first embodiment. 6 is a flowchart of a correction process performed by the control unit according to the first embodiment. FIG. 4 is a diagram illustrating a blade edge path according to the first embodiment. FIG. 4 is a diagram illustrating a blade edge path according to the first embodiment. 9 is a flowchart of a correction process performed by the control unit according to the second embodiment. FIG. 7 is a diagram illustrating a blade edge path according to a second embodiment. 9 is a flowchart of a correction process performed by a control unit according to the third embodiment. It is a figure explaining the cutting-edge path of Example 3.

Hereinafter, a machine tool control device and a machine tool of the present invention will be described with reference to the drawings.
As shown in FIG. 1, a machine tool 100 according to the present invention includes a spindle 110, a cutting tool base 130A, and a controller 180.

A chuck 120 is provided at the tip of the main shaft 110. The main shaft 110 is used as a work holding means, and the work W is held on the main shaft 110 via a chuck 120. The spindle 110 is rotatably supported by the spindle stock 110A and is rotationally driven by the power of the spindle motor. The spindle motor may be, for example, a known built-in motor provided between the headstock 110A and the spindle 110.

The Z-axis direction feed mechanism 160 is provided on the bed of the machine tool 100.
The Z-axis direction feed mechanism 160 includes a base 161 integral with the bed, and a Z-axis direction guide rail 162 fixed to the base 161. A Z-axis direction feed table 163 is slidably supported on the Z-axis direction guide rail 162 via a Z-axis direction guide 164. The headstock 110A is mounted on the Z-axis feed table 163. The headstock 110A is arranged so that the axial direction of the main shaft 110 coincides with the extending direction of the Z-axis direction guide rail 162.

The linear servomotor 165 has a mover 165a and a stator 165b, the mover 165a is provided on the Z-axis direction feed table 163, and the stator 165b is provided on the base 161. When the Z-axis feed table 163 moves along the Z-axis guide rail 162 by the driving of the linear servo motor 165, the headstock 110A moves in the axial direction of the spindle 110 (Z-axis direction in the drawing), and the spindle 110 moves. It moves along the Z-axis direction via the headstock 110A.

The cutting tool base 130A is equipped with a cutting tool 130 such as a cutting tool for processing the work W, and constitutes a tool rest that holds the cutting tool.
The X-axis direction feed mechanism 150 is provided on the bed side of the machine tool 100.

The X-axis feed mechanism 150 includes a base 151 that is integral with the bed side, and an X-axis guide rail 152 that extends in the X-axis direction that is orthogonal to the Z-axis direction in the vertical direction. The X-axis direction guide rail 152 is fixed to the base 151, and an X-axis direction feed table 153 is slidably supported on the X-axis direction guide rail 152 via an X-axis direction guide 154. A cutting tool base 130A is mounted on the X-axis direction feed table 153.

The linear servomotor 155 has a mover 155a and a stator 155b, the mover 155a is provided on the feed table 153, and the stator 155b is provided on the base 151. When the X-axis direction feed table 153 moves in the X-axis direction along the X-axis direction guide rail 152 by the driving of the linear servo motor 155, the cutting tool base 130A moves in the X-axis direction and the cutting tool 130 moves in the X-axis direction. Moving.

A Y-axis direction feed mechanism may be provided. The Y-axis direction is a direction orthogonal to the illustrated Z-axis direction and X-axis direction. The Y-axis direction feed mechanism may have the same structure as the X-axis direction feed mechanism 150. By mounting the X-axis direction feed mechanism 150 on the bed via the Y-axis direction feed mechanism, the Y-axis direction feed table is moved in the Y-axis direction by the drive of the linear servo motor, and the cutting tool base 130A is moved in the X-axis direction. In addition, the cutting tool 130 can be moved in the Y-axis direction to move the cutting tool 130 in the X-axis direction and the Y-axis direction.
The Y-axis feed mechanism may be mounted on the bed via the X-axis feed mechanism 150, and the cutting tool base 130A may be mounted on the Y-axis feed table.

The controller 180 controls the rotation of the main shaft 110 and the movement of the X-axis direction feed mechanism 150, the Z-axis direction feed mechanism 160, and the like.
The X-axis direction feed mechanism 150 and the Z-axis direction feed mechanism 160, or a feed means including a Y-axis direction feed mechanism, constitutes the X-axis direction feed mechanism 150 or the Y-axis direction feed mechanism and the Z-axis direction feed mechanism 160. As shown in FIG. 2, the headstock 110A and the cutting tool base 130A can be moved to predetermined positions by the cooperation of the above. By moving the headstock 110A and the cutting tool base 130A to predetermined positions, the cutting tool 130 is relatively moved with respect to the main spindle 110, and the main spindle 110 is relatively moved between the work W and the cutting tool 130. The work W can be processed into a desired shape by driving the work W with respect to the cutting tool 130 by driving the work W as a rotating means for rotating the work W.

In the present embodiment, both the headstock 110A and the cutting tool base 130A are configured to be movable, but the headstock 110A is fixed to the bed, and the cutting tool base 130A is moved in the X-axis direction, the Y-axis direction, and the Z-axis direction. It may be movable. In this case, the feeding means is constituted by a feeding mechanism that moves the cutting tool base 130A. Alternatively, the cutting tool base 130A may be fixed, and the headstock 110A may be movable in the X axis direction, the Y axis direction, and the Z axis direction. In this case, the feeding means is composed of a feeding mechanism provided on the bed.

In this embodiment, an example in which a linear servomotor is used for the X-axis direction feed mechanism 150 and the Z-axis direction feed mechanism 160 has been described, but a known ball screw and servomotor may be used.
In the present embodiment, the work W is rotated with respect to the cutting tool 130, but a rotating tool such as a drill may be used as the cutting tool 130 and the cutting tool 130 may be rotated with respect to the work W. In this case, the motor that rotates the cutting tool 130 corresponds to the rotating means of the present invention.

The control device 180 moves the cutting tool base 130A with respect to the headstock 110A forward (forward) by a predetermined forward amount as shown in FIG. 3 along the feed direction, and then moves backward by a predetermined backward amount. By moving (returning), the cutting tool 130 can be fed to the work W in the feeding direction by a difference (advancement amount) between the forward movement amount and the backward movement amount with vibration along the feeding direction.
A vibrating means is constituted by the feed means including the X-axis direction feed mechanism 150 and the Z-axis direction feed mechanism 160, or the Y-axis direction feed mechanism, and moves the headstock 110A and the cutting tool base 130A forward and backward. As a result, the cutting tool 130 can be vibrated with respect to the work W. The cutting tool 130 is fed with vibration along the feeding direction with respect to the work W by the feeding means that also serves as the vibrating means to process the work W.

The cutting tool base 130A is fed along the feed direction for one rotation of the spindle 110, that is, while the spindle phase changes from 0° to 360°, and the total amount of the above progress is the feed amount in the Z-axis direction.
As the cutting tool 130 repeatedly performs the forward movement and the backward movement along the feed direction, the peripheral surface of the work W is processed into a sinusoidal shape by the cutting tool 130 as illustrated in FIG. 4. FIG. 4 shows an example in which the number of vibrations N of the headstock 110A per rotation of the main shaft 110 is 3.5 (also referred to as the frequency N=3.5).

Circumferential surface shape of the work W at the n-th (n is an integer of 1 or more) rotation of the spindle 110 processed by the cutting tool 130 (shown by a solid line in FIG. 4) and the circumferential surface of the work W at the n+1-th rotation of the spindle 110. The shape (indicated by a broken line in FIG. 4) deviates in the main axis phase direction (horizontal axis direction in the graph of FIG. 4).
The position of the lowest point of the valley of the peripheral surface shape of the workpiece W (the highest point of the peak in the cutting tool 130) shown by the broken line in FIG. 4 is the lowest point of the valley of the peripheral surface shape of the workpiece W shown by the solid line in FIG. The position of (the highest point of the peak in the cutting tool 130) does not match in the spindle phase direction.

As a result, the cutting edge of the cutting tool 130 overlaps the cutting portion during the present forward movement and the cutting portion during the next backward movement, and has, for example, the peripheral surface shape of the work W at the (n+1)th rotation of the spindle 110. Since the peripheral surface shape of the work W at the n-th rotation of the main shaft 110 is included, the cutting tool 130 causes an idling motion in which the work W is not processed. During this idling operation, the chips generated from the work W are divided. The machine tool 100 smoothly processes the outer shape and the like of the work W while dividing the chips.

The number of vibrations N of the cutting tool base 130A (cutting tool 130) per one revolution of the spindle 110 (workpiece W) can be 1.1, 1.25, 2.6, 3.75 times, or the like, It can be set to a value smaller than once. When the number of vibrations N is set to a value smaller than one time, the spindle 110 rotates more than one rotation before the cutting tool base 130A makes one reciprocation. The number of vibrations N can also be set as the number of rotations of the main shaft 110 per one vibration.

As shown in FIG. 5, the control device 180 has, for example, a control unit 181, a numerical value setting unit 182, a display unit 183, and a storage unit 184, which are connected via a bus.
The control unit 181 includes a CPU and the like, loads various programs and data stored in, for example, the ROM of the storage unit 184 into the RAM, and executes the programs. Thereby, the operation of the machine tool 100 can be controlled based on the program. The storage unit 184 includes a table 194 for the gain G1 and the gain G2.
The gain G1 and the gain G2 represent control gains in PID control of the servomotor that controls the Z-axis direction feed mechanism and the X-axis direction feed mechanism.

The reciprocating vibration of the cutting tool 130 by the vibrating means is executed by the control unit 181 at the command frequency fc based on the predetermined command cycle T.
When the control unit 181 can send an operation command 250 times per second, for example, the operation command can be output in a cycle of 1/250=4 (ms) (also referred to as a reference cycle IT). Generally, the command period T is an integral multiple of this reference period.

When the command cycle T is 16 (ms), which is four times the reference cycle 4 (ms), the motor control unit 190 causes the cutting tool 130 to perform reciprocating vibration every 16 (ms) along the feed direction. Further, a drive signal is output to the Z-axis direction feed mechanism 160, the X-axis direction feed mechanism 150, or the Y-axis direction feed mechanism. In this case, the cutting tool 130 oscillates reciprocally at the command frequency fc=1/T=1÷(0.004×4)=62.5 (Hz) due to the command cycle T=16 (ms). That is, by causing the movement of the cutting tool base 130A to follow the position instructed by the control unit 181, the cutting tool 130 is moved to, for example, 5 times 20 (ms), 6 times 24 (ms), or 7 times the reference cycle. The reciprocating vibration can be executed every 28 (ms) and 32 times (8). In this case, the cutting tool 130 has a command frequency fc=1÷(0.004×5)=50 (Hz), 1÷(0.004×6)=41.666 (Hz), 1÷(0.004). It is possible to perform reciprocating vibration at a plurality of limited frequencies of ×7)=35.714 (Hz), 1÷(0.004×8)=31.25 (Hz).

When the rotation speed of the spindle 110 is S (r/min), the vibration frequency of the cutting tool 130 with respect to the rotation of the work W is N (times), and the vibration frequency f of the cutting tool 130 with respect to the work W is f (times/sec). N is N=f×60/S. The rotation frequency S and the vibration frequency N are inversely proportional to each other with the vibration frequency f as a constant, and the spindle 110 can rotate at a higher speed as the vibration frequency f becomes higher, and can rotate at a higher speed as the vibration frequency N becomes smaller. it can.

The control unit 181 rotates the main shaft 110 at the rotation speed S, and vibrates the cutting tool 130 at the vibration frequency N to machine the cutting tool 130 in the feed direction. At this time, when the vibration frequency f that becomes the frequency N with respect to the rotation speed S matches any of the plurality of limited command frequencies, the necessary command frequency is set as the target command frequency fc. The motor control unit 190 sets a gain G1 for the headstock 110A or the cutting tool base 130A to follow the operation command for each reference cycle so that the cutting tool 130 passes the position commanded by the operation command for each reference cycle. .. This gain G1 is set from the storage unit 184. The motor control unit 190 outputs an operation command to the linear servo motor 155 or the like at each reference cycle, and the headstock 110A or the cutting tool base 130A follows the coordinate position at which the operation is commanded to move, thereby issuing a command. The cutting tool 130 can be vibrated at the frequency fc.

On the other hand, when the vibration frequency f that becomes the frequency N with respect to the rotation speed S does not match any of the plurality of limited command frequencies, the motor control unit 190 causes the vibration waveform of the vibration frequency f. The operation command for each reference cycle is output so that the cutting tool 130 moves to the target moving position, with the position corresponding to the predetermined command cycle as the target moving position. The motor control unit 190 sets the followability of movement of the headstock 110A or the cutting tool base 130A by the gain G2. The gain G2 is set, for example, by the vibrating means control unit 191 calling from the gain G2 table 194 of the storage unit 184. By setting the gain G2 instead of the gain G1, it is possible to change the sensitivity of the servo control and adjust and set the tracking response. By setting the gain G2, the Z-axis direction feed mechanism 160, the X-axis direction feed mechanism 150, and the Y-axis direction feed mechanism have lower tracking responsiveness and a tracking delay.

The movement of the cutting tool 130 is performed toward the position instructed by the operation command with a follow-up delay. For example, the next operation command is issued before reaching the instructed position, so that the cutting tool 130 is moved. Moves from one predetermined continuous position instructed by the operation command for each reference period to the other position with a change in the moving direction. Accordingly, the cutting tool 130 can be moved along the vibration waveform of the vibration frequency f at which the inflection point is located during the reference period.

The rotation speed S, the vibration frequency N, and the vibration frequency f can be set by a machining program or by inputting to the numerical value setting unit 182. Thereby, the cutting path (start point, end point, linear interpolation or circle interpolation) of the cutting tool 130 and the vibration condition (the rotation speed S of the spindle 110, the vibration frequency N of the cutting tool 130 with respect to the rotation of the spindle 110) are set. It
The control unit 181 obtains the vibration frequency f, superimposes the vibration condition on the cutting path, and obtains the vibration waveform (step S1 in FIG. 6).

The control unit 181 determines whether the vibration frequency f is an integral multiple of the reference period IT (step S2). When the vibration frequency f matches any of the plurality of limited command frequencies (YES in step S2), the gain of servo control is set to the gain G1. The motor control unit 190 outputs an operation command to the linear servo motor 155 etc. for each reference cycle (step S3). At each command cycle T corresponding to the command frequency, the operation command coincides with the most advanced position or the last retracted position of the vibration frequency f, and this operation command is the same as being output every command cycle T. The cutting tool 130 can process the work W in accordance with the reciprocating vibration (step S4).

When the vibration frequency f coincides with any of the above-mentioned limited command frequencies, the path of the cutting edge of the cutting tool 130 is 72°, and the most advanced position of the target waveform is 72°, as indicated by the ♦ mark. To reach the most retracted position at 144°, reach the most advanced position at 216°, reach the most retracted position at 288°, and reach the most advanced position at 360°. In this way, the path of the cutting edge of the cutting tool 130 connects the most advanced position and the most retracted position of the target waveform.

On the other hand, if the vibration frequency f does not match any of the plurality of limited command frequencies (NO in step S2 in FIG. 6), the vibration waveform correction process is executed (step S5).
Specifically, the control unit 181 selects a target command frequency fc (for example, a value that is closest to the vibration frequency f among the limited command frequencies described above), and sets the command cycle T corresponding to the target command frequency fc. Set. The vibrating means controller 191 calls from the table 194 for the gain G2, and sets the gain G2 to the gain of servo control (step S11 in FIG. 7). When the gain G1 for the command frequency fc selected by the control unit 181 has already been set, it is changed to the gain G2. The gain G2 is set to a value lower than the gain G1, for example, and the follow-up response is set to be low so as to make the servo control sensitivity dull. Then, the motor control unit 190 outputs an operation command to the linear servo motor 155 or the like for each reference cycle with the position corresponding to the command cycle T of the vibration waveform of the vibration frequency f as the target moving position (step S3 in FIG. 6). ). In accordance with the operation command for each reference cycle, the command moves from the predetermined one continuous position instructed by the operation command for each reference cycle to the other position with the change in the moving direction toward the target moving position, The cutting tool 130 processes the work W with reciprocating vibration along the vibration waveform of the vibration frequency f where the inflection point is located during the cycle (step S4).

An example of the case where the vibration frequency f does not match any of the above-mentioned limited command frequencies will be described with reference to FIG. 9. The solid line in FIG. 9 is the waveform of the vibration frequency f, and there is an inflection point at a different timing (different spindle phase) from 72°, 144°, 216°, 288°, and 360°.
● When moving with the above-mentioned gain G1 in response to the operation command of the mark, since it moves linearly between the adjacent marks ●, it does not become the path of the cutting edge shown by the solid line, but the path of the desired cutting edge shown by the broken line. Not even. In the embodiment, by adjusting the gain of the servo control and setting the tracking response, the path of the cutting edge can be set to a desired vibration frequency.

The path of the cutting edge of the cutting tool 130 when the servo control gain is set to the gain G2 and an operation command is issued with a ● mark is shown by a broken line in FIG. The path of the cutting edge of the cutting tool 130 tries to reach the position corresponding to the target waveform at 72°, but a gain G2 lower than the gain G1 is set and a follow-up delay occurs, so a command is made at 72°. The target position is not reached. Since there is a drive delay in the feed mechanism, the path of the cutting edge of the cutting tool 130 moves toward the commanded target position even after passing 72°.
When the position for moving to the ● mark of 72° is passed, the cutting edge of the cutting tool 130 moves in the positive direction of the cutting tool position, but it moves toward the ● mark of 144° and the cutting tool position is moved by the next operation command. Since it moves in the negative direction of, it moves with the change of the moving direction so that the inflection point is located during the reference period. Similarly, when an operation command to move to the ● marks of 216°, 288°, and 360° is output, the path of the cutting edge of the cutting tool 130 moves on the broken line. The frequency of the waveform of this broken line corresponds to the set vibration frequency f. By setting different gains G1 and G2 in the same command period T, the cutting tool 130 can be moved at different desired vibration frequencies.

Note that, for example, as the gain G2, a value corresponding to the target vibration frequency f can be experimentally determined in advance and stored in the storage unit 184 as a table for the gain G2.

<Example 2 (correction of vibration amplitude): FIGS. 5, 10, and 11>
When the gain G2 is set, the amplitude may be attenuated, for example, as shown by the vibration waveform of the broken line in FIG. 9, and as shown in FIG. 5, the control unit 181 is provided with the waveform correction unit 192. It is also possible to correct the attenuation of the amplitude and move the cutting tool 130 with the vibration waveform of the desired vibration frequency.
Specifically, the vibrating means control unit 191 calls and sets the gain G2 from the table 194 for the gain G2 based on the vibration frequency f such that the vibration frequency N becomes the number of revolutions S (step of FIG. 10). S21). Next, the waveform correction unit 192 acquires a value that supplements the amplitude of the vibration waveform by the gain G2 from the table of the storage unit 184 (step S22). In this table, for example, the reciprocal of the amplitude attenuation rate is stored in advance, so that the gain G2 is multiplied by the reciprocal of the amplitude attenuation rate, and the amplitude of the target waveform is increased in advance to obtain the amplitude attenuation amount. The waveform correction unit 192 can be configured to correct (step S23). The waveform correction unit 192 corresponds to the amplitude setting means of the present invention.

For example, in the case of the above-described first embodiment, since the gain G2 is set to a value lower than the gain G1, the cutting edge of the cutting edge having a small amplitude as shown by the broken line is set to the path of the cutting tool 130 shown by the solid line in FIG. Become a route. Here, in order to facilitate the explanation, it is assumed that there is no amplitude delay.
In the case of the second embodiment, the one-dot chain line vibration is obtained by multiplying the amplitude component of the vibration waveform of the vibration frequency f having the frequency N with respect to the rotation speed S by the reciprocal of the attenuation rate of the amplitude generated by the gain G2. The operation command is determined based on the waveform. That is, as shown in FIG. 11, the position indicated by the symbol ⋄ in the vibration waveform obtained by amplifying the amplitude of the vibration waveform of the vibration frequency f such that the vibration frequency N becomes the vibration frequency N with respect to the rotation speed S, for each command cycle T. By setting the target movement position, the cutting tool 130 can move on the cutting edge path indicated by the solid line, which is the vibration waveform of the vibration frequency f such that the vibration frequency N corresponds to the rotation speed S. In this way, by correcting the amount of attenuation of the amplitude due to the setting of the gain G2, the overlap between the machining portion during forward movement and the machining portion during backward movement is maintained. It is desirable that the amplitude is corrected so that the cutting edge locus of the cutting tool during the backward movement reaches the cutting edge locus of the cutting tool during the forward movement. However, the amount of amplitude may be such that the cutting edge locus of the cutting tool during the backward movement and the cutting edge locus of the cutting tool during the forward movement are close to each other so that the chips generated from the work W are actually divided.

<Example 3 (phase correction): FIGS. 12 and 13>
When the gain G2 is set, a phase delay may occur as shown in FIG. 9, for example, and the waveform correction unit 192 is used as a phase setting unit to correct the amount of attenuation of the amplitude or to adjust the amplitude. In addition to the correction of the attenuation amount, it is possible to correct the phase delay and move the cutting tool 130 with the vibration waveform of the desired vibration frequency.
Specifically, the tracking adjuster 191 calls and sets the gain G2 corresponding to the vibration frequency f such that the vibration frequency N becomes the vibration frequency N with respect to the rotation speed S from the table 194 for the gain G2 (step of FIG. 12). S31). Next, the waveform correction unit 192 acquires a value that supplements the amplitude attenuation amount and the phase delay amount of the vibration waveform by the gain G2 from the table of the storage unit 184 (step S32). In this table, for example, the reciprocal of the amplitude attenuation rate and the amount of phase delay are stored in advance, so that the gain G2 is multiplied by the reciprocal of the attenuation rate to increase the amplitude of the target waveform in advance to attenuate the amplitude. The waveform correction unit 192 may be configured to correct the amount (step S33), advance the waveform by the amount of phase delay, advance the phase of the target waveform in advance to correct the phase delay (step S34). it can.

For example, in the case of the first embodiment, since the gain G2 is set to a value lower than the gain G1, the amplitude is small and the phase is small as shown by the broken line with respect to the path of the cutting tool 130 shown by the solid line in FIG. It becomes the route where the delay occurred.
In the case of the third embodiment, the vibration waveform obtained by multiplying the amplitude component of the vibration waveform of the vibration frequency f that becomes the frequency N with respect to the rotation speed S by the reciprocal of the attenuation rate of the amplitude generated by the gain G2 is shown in FIG. The phase delay of the phase generated by the gain G2 is corrected with respect to the phase component of the vibration waveform of the vibration frequency f, which is indicated by the one-dot chain line in FIG. ) The vibration waveform is shown by the two-dot chain line in FIG. By setting the position indicated by □ in the vibration waveform indicated by the two-dot chain line as the target moving position for each command period T, the cutting tool 130 has the frequency N with respect to the rotation speed S. It is possible to move on the path of the vibration frequency f. Thus, by supplementing the amount of attenuation of the amplitude and the amount of delay of the phase caused by setting the gain G2, even if the sensitivity of the servo control is reduced, the cutting tool 130 can obtain a desired cutting edge with a desired vibration frequency. You can move on the route.

In the present embodiment, the phase delay is advanced after the reciprocal of the attenuation rate is multiplied, but the phase delay may be advanced and then the reciprocal of the attenuation rate may be multiplied.
Further, values such as the amplitude attenuation rate and the phase delay amount may be stored in advance in the table for the gain G2, and the gain, the amplitude attenuation rate, and the phase delay amount may be simultaneously called from the obtained vibration frequency f.
Further, a plurality of gains different from the gain G1 for the command frequency fc may be set. For example, the vibration frequency may be divided into a plurality of sections, the predetermined section may have the gain G2, and the adjacent section may have the gain G3.

100... Machine tool 110... Spindle 110A... Spindle base 120... Chuck 130... Cutting tool 130A... Cutting tool stand 150... X-axis direction feed mechanism 151... Base 152 ... X-axis direction guide rail 153 ... X-axis direction feed table 154 ... X-axis direction guide 155 ... Linear servo motor 155a ... Mover 155b ... Stator 160 ... Z-axis Direction feed mechanism 161 ・・・ Base 162 ・・・ Z axis direction guide rail 163 ・・・ Z axis direction feed table 164 ・・・ Z axis direction guide 165 ・・・ Linear servo motor 165a ・・・ Mover 165b ・・・Stator 180 Control device 181 Control unit 182 Numerical value setting unit 183 Display unit 184 Storage unit 190 Motor control unit 191 Vibrating unit control unit 192 ... Waveform correction unit 194 ... Gain G2 table

Claims (5)

A work holding means for holding a work, a cutting tool for cutting the work, a rotating means for relatively rotating the work and the cutting tool, and the work holding means or the cutting tool for every fixed cycle. by sequentially moving toward each predetermined position commanded by the operation command, the workpiece or the cutting engineering tool, a vibration means for vibrating in a predetermined number of vibrations to the relative rotation between the workpiece and the cutting tool A machine tool control device for processing the work with the vibration by the vibrating means by relatively moving the work holding means and the cutting tool,
The workpiece holding means or the cutting tool, the positive from the negative direction of the positive direction from the negative direction, or the cutting tool position of the cutting tool position between a predetermined position location of a given position location and other side of one continuous A control device for a machine tool, comprising a vibrating means control section for setting a follow-up response of the movement of the work holding means or the cutting tool with respect to the predetermined position so as to move with a change in the moving direction. The machine tool control device according to claim 1, wherein the vibrating means control unit sets the tracking response of the movement by setting a gain of servo control. It has an amplitude setting means for setting the amplitude of the vibration based on the set gain so that the processed portion during the forward movement and the processed portion during the backward movement by the vibrating means overlap. The machine tool control device according to claim 2. The machine tool control device according to any one of claims 1 to 3, further comprising a phase setting unit that sets a phase of the vibration based on the set tracking response. A work holding means for holding a work, a cutting tool for cutting the work, a rotating means for relatively rotating the work and the cutting tool, and the work holding means or the cutting tool for every fixed cycle. by sequentially moving toward each predetermined position commanded by the operation command, the workpiece or the cutting engineering tool, a vibration means for vibrating in a predetermined number of vibrations to the relative rotation between the workpiece and the cutting tool A machine tool for processing the workpiece with the vibration by the vibrating means by relatively moving the workpiece holding means and the cutting tool,
The workpiece holding means or the cutting tool, the positive from the negative direction of the positive direction from the negative direction, or the cutting tool position of the cutting tool position between a predetermined position location of a given position location and other side of one continuous A machine tool in which the vibrating means is set to follow the movement of the work holding means or the cutting tool with respect to the predetermined position so that the vibrating means moves along with the change of the moving direction.