JP6744815B2 - Machine tool control device and machine tool - Google Patents

Description

The present invention relates to a machine tool control device and a machine tool.

When turning a workpiece with a tool, so-called flow-shaped continuous chips are generated and discharged to the surroundings. When the continuous chips are wound around the work and the tool, the work and the tool are damaged. Therefore, for example, Patent Documents 1 and 2 disclose a technique of a vibration cutting process in which a work is reciprocally moved with respect to a tool and chips can be discharged in a state of chips.

Here, the length of the swarf changes according to changes in the diameter of the work and the number of revolutions of the work. If the swarf is too short, the swarf is scattered around, and if the swarf is too long, the work or the tool is damaged. Patent Document 1 discloses that the vibration frequency is changed according to the change in the work diameter to adjust the length of the cutting chips to a predetermined length. Further, Patent Document 2 discloses changing the amplitude of vibration in order to adjust the length of the chips.

JP 2001-150201 A JP, 2009-190119, A

However, in the technique of Patent Document 1 described above, the vibration frequencies corresponding to changes in the work diameter are calculated before the cutting process is started, and the calculated vibration frequencies must be input in advance for each work diameter. , Was inconvenient for the machine tool worker.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a machine tool control device and a machine tool that reduce the burden on the operator.

The present invention is, firstly, a cutting tool for cutting a workpiece, a rotation means for relatively rotating said workpiece and said cutting tool, the workpiece or the cutting tool, and the workpiece and the cutting tool and a vibration means for reciprocating in a predetermined number of vibrations for relative rotation, a control device of a machine tool for cutting the workpiece with the chips due to contact with the cutting tool, before Symbol workpiece The number of vibrations is calculated from the diameter and the set length of the chips, and the number of vibrations is corrected by adding or subtracting 0.5 to the integer part of the calculated number of vibrations. A vibration frequency determining means having a first vibration frequency determining mode for determining the frequency , and the vibration frequency determining means determines the vibration frequency that is the set length of the chips as the target vibration frequency of the vibrating means. Is characterized by.

Second, the relative rotation of the cutting tool for cutting a workpiece, a rotation means for relatively rotating said workpiece and said cutting tool, the workpiece or the cutting tool, and the workpiece and the cutting tool and a vibration means for reciprocating in a predetermined number of oscillations with respect to the a control apparatus for a machine tool for cutting the workpiece with the chips due to contact with the cutting tool, switching said diameter before Symbol workpiece The number of vibrations is calculated from the set length of powder, and the n-th (n is an integer of 1 or more) cutting locus and the n+1-th cutting locus according to the calculated number of vibrations, while the rotating means makes one revolution. It is determined whether or not it intersects, and when each of the cutting trajectories intersects, a vibration frequency determination unit having a second vibration frequency determination mode that determines the calculated vibration frequency as the vibration frequency is provided, and the vibration frequency determination is performed. It is characterized in that the means determines the number of times of vibration of the chip to be the set length as the target number of times of vibration of the vibrating means .

Third, the relative rotation of the cutting tool for cutting a workpiece, a rotation means for relatively rotating said workpiece and said cutting tool, the workpiece or the cutting tool, and the workpiece and the cutting tool and a vibration means for reciprocating in a predetermined number of oscillations with respect to the a control apparatus for a machine tool for cutting the workpiece with the chips due to contact with the cutting tool, switching said diameter before Symbol workpiece The number of vibrations is calculated from the set length of powder, and the n-th (n is an integer of 1 or more) cutting locus and the n+1-th cutting locus according to the calculated number of vibrations, while the rotating means makes one revolution. It is determined whether or not they intersect, when each of the cutting trajectories intersects, the calculated number of vibrations is determined as the number of vibrations, and when each of the cutting trajectories does not intersect, the amplitude of the reciprocating movement is corrected. After the correction of the amplitude of the reciprocating movement, it is determined whether or not the n-th cutting locus and the (n+1)-th cutting locus based on the calculated number of vibrations intersect during one rotation of the rotating means. When the cutting trajectories intersect, a vibration frequency determining means having a third vibration frequency determining mode for determining the calculated vibration frequency as the vibration frequency is provided, and the vibration frequency determining means is the set length of the chips. Is determined as the target number of vibrations of the vibrating means .

Fourth, characterized first oscillation number determination mode described above, the second vibration number determination mode, that is selectably forms one of the third number of vibrations determined mode.

Fifth, wherein the setting the length of the chips is set at a predetermined range.

Sixth , it is a machine tool provided with the above machine tool control device.

The present invention can obtain the following effects.
(1) Since the vibration frequency determining means determines the vibration frequency for each rotation according to the work diameter so that the set length of the chips can be obtained, for example, a desired chip length, a work diameter before machining Once the cutting speed is input, it is not necessary to newly input the number of vibrations due to the change of the work diameter. Therefore, the burden on the operator of the machine tool can be reduced.

(2) A value obtained by adding or subtracting 0.5 to the integer part is determined as a new number of vibrations, and the nth (n is an integer of 1 or more) cutting trajectory and the (n+1)th cutting trajectory are determined by the rotation means. Since the phase is inverted, the chips are reliably crossed, which makes it easier to divide the chips. Therefore, it is possible to improve the processing accuracy of the work.

(3) In order to determine the number of vibrations, a discriminant is used that determines whether the n-th cutting locus and the (n+1)-th cutting locus intersect during one rotation of the rotating means, and this discriminant is satisfied. In this case, since the calculated value is determined as the number of vibrations, the length of the chips can be brought closer to the set length. Also, if this calculated value is determined as the number of vibrations, the cutting speed can be made closer to the initially set speed.

(4) In order to determine the number of vibrations, a discriminant is used that determines whether the n-th cutting locus and the (n+1)-th cutting locus intersect during one rotation of the rotating means, and this discriminant is satisfied. In this case, since the calculated value is determined as the number of vibrations, the length of the chips can be brought closer to the set length. Also, if this calculated value is determined as the number of vibrations, the cutting speed can be made closer to the initially set speed. On the other hand, when this discriminant is not satisfied, the above-mentioned discriminant is used after changing the amplitude of the reciprocating movement. When the discriminant is satisfied by changing the amplitude of the reciprocating movement, the calculated value is determined as the number of vibrations. Therefore, the length of the cutting chips can be made closer to the set length, and the cutting speed can be made closer to the initially set speed.

(5) The convenience of the operator can be further improved.

(6) If the set length of the cutting chips can be designated within a range, the operator can easily specify the set length of the cutting chips, which also contributes to the improvement of the convenience of the worker.

(7) It is possible to provide a machine tool that can reduce the burden on the operator of the machine tool.

It is a figure which shows the outline of the machine tool by one Example of this invention. It is a schematic diagram showing the relation between a cutting tool and a work. It is a figure explaining reciprocating movement 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. It is a flow chart of a processing process by a control part. 5 is a flowchart of a target vibration frequency determination process according to the first embodiment. It is a figure explaining an example of the frequency of vibration, the number of rotations of a main shaft, and a vibration frequency. FIG. 6 is a diagram illustrating a setting example of a work diameter, a vibration frequency, a vibration frequency, and a cutting speed according to the first embodiment. 9 is a flowchart of a target vibration frequency determination process according to the second embodiment. FIG. 9 is a diagram illustrating a setting example of a work diameter, a vibration frequency, a vibration frequency, and a cutting speed according to the second embodiment. 9 is a flowchart of a target vibration frequency determination process according to a third embodiment. FIG. 9 is a diagram illustrating a setting example of a work diameter, a vibration frequency, a vibration frequency, and a cutting speed according to a third embodiment. 9 is a flowchart of a process of determining a target number of vibrations according to another embodiment. 9 is a flowchart of a process of determining a target number of vibrations according to another embodiment. 9 is a flowchart of a process of determining a target number of vibrations according to another embodiment. It is a figure explaining the setting example of the workpiece diameter, the frequency of vibration, the number of rotations of the spindle, and the cutting speed according to still another embodiment.

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, the machine tool 100 includes a spindle 110, a cutting tool 130 such as a cutting tool for machining a work W, and a controller 180.
A chuck 120 is provided at the tip of the spindle 110, and the work W is held by the spindle 110 via the chuck 120. The spindle 110 is rotatably supported by the spindle stock 110A and is rotated by the power of a spindle motor (for example, a built-in motor) provided between the spindle stock 110A and the spindle 110, for example.

A Z-axis feed mechanism 160 is provided on the bed of the machine tool 100. The Z-axis direction feed mechanism 160 includes a base 161 integrated with the bed, and a Z-axis direction guide rail 162 installed on the base 161. A Z-axis feed table 163 is slidably supported on the Z-axis guide rail 162 via a Z-axis guide 164.
The headstock 110A is mounted on the Z-axis direction feed table 163, and the axis 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 direction feed table 163 moves along the Z-axis direction guide rail 162 by the drive 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. Move along the Z axis.

The cutting tool 130 is mounted on the cutting tool base 130A.
The bed of the machine tool 100 is also provided with an X-axis direction feed mechanism 150. The X-axis direction feed mechanism 150 includes a base 151 integrated with the bed, and an X-axis direction guide rail 152 installed on the base 151. 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.
The cutting tool base 130A is mounted on the X-axis direction feed table 153, and the axial direction of the cutting tool base 130A coincides with the extending direction of the X-axis direction guide rail 152.

The linear servo motor 155 has a mover 155a and a stator 155b, the mover 155a is provided on the X-axis direction feed table 153, and the stator 155b is provided on the base 151. When the X-axis direction feed table 153 moves 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 orthogonal to the Z-axis direction shown in the drawing, The cutting tool 130 moves in the X-axis direction.

The Y-axis feed mechanism may be provided in the machine tool 100. The Y-axis direction is a direction orthogonal to the illustrated Z-axis direction and X-axis direction. The Y-axis direction feed mechanism also has a Y-axis direction feed table that can be driven by a linear servomotor. When the X-axis feed mechanism 150 is mounted on the bed of the machine tool 100 via the Y-axis feed mechanism, the cutting tool 130 can be moved in the Y-axis direction in addition to the X-axis direction. The Y-axis direction feed mechanism may be mounted on the bed of the machine tool 100 via the X-axis direction feed mechanism 150, and the cutting tool table 130A may be mounted on the Y-axis direction feed table.

The rotation of the main shaft 110 and the movement of the Z-axis direction feed mechanism 160, the X-axis direction feed mechanism 150, and the Y-axis direction feed mechanism (hereinafter referred to as the Z-axis direction feed mechanism 160 and the like) are controlled by the control device 180. The controller 180 drives the spindle motor to relatively rotate the work W and the cutting tool 130, and drives the Z-axis direction feed mechanism 160 and the like to relatively move the work W and the cutting tool 130.

Although it has been described that both the headstock 110A and the cutting tool base 130A are movable, the present invention is not limited to this example. The headstock 110A may be fixed to the bed, and the cutting tool base 130A may be movable in the X, Y, and Z axis directions. Alternatively, the cutting tool base 130A may be fixed to the bed, and the headstock 110A may be movable in the X, Y, and Z axis directions.
Although an example in which a linear servo motor is used for the Z-axis direction feed mechanism 160 and the like has been described, a known ball screw and servo motor may be used.

In FIG. 2, for example, the work W rotates with respect to the cutting tool 130, and the work W reciprocates in the Z-axis direction with respect to the cutting tool 130. In this case, the spindle motor corresponds to the rotating means of the present invention, and the Z-axis direction feed mechanism 160 corresponds to the vibrating means of the present invention.
The control device 180 moves (forwards) the work W in the positive direction of the Z axis by a predetermined forward amount, and then moves (returns) the work W in the negative direction of the Z axis by a predetermined backward amount. ) Let me. As a result, as shown in FIG. 3, the cutting tool 130 can be fed to the work W by the difference (progress amount) between the forward movement amount and the backward movement amount.
Although the example in which the work W reciprocates in the Z-axis direction with respect to the cutting tool 130 has been described above, the X-axis direction feed mechanism 150, the Y-axis direction feed mechanism, or the Z-axis direction feed mechanism for the cutting tool 130 may be used. A vibrating means is constituted by the feeding means included therein, and the cutting tool 130 can be vibrated with respect to the work W by moving the headstock 110A and the cutting tool 130 in forward and backward movements. In that case, the cutting tool 130 can also be processed by the feeding means that also serves as the vibrating means and is fed to the work W with vibration along the feeding direction to process the work W.

The cutting tool 130 is fed in the X-axis direction shown in FIG. 2 with a predetermined depth of cut. On the other hand, the work W is rotated in a predetermined direction by the spindle motor and is sent in the positive Z-axis direction by repeating forward and backward movements by the Z-axis feed mechanism 160. The feed amount is one revolution of W, that is, the total amount of the progress while the main shaft phase changes from 0° to 360°.
As a result, the peripheral surface of the work W is processed by the cutting tool 130 into a sinusoidal shape. FIG. 4 shows an example in which the number of times the work W reciprocates during one rotation of the work W (also referred to as the number of vibrations D for each rotation) is 3.5 (times/r).

The peripheral surface shape of the work W (indicated by a solid line in FIG. 4) at the n-th (n is an integer of 1 or more) rotation of the spindle 110 processed by the cutting tool 130 and the circumference of the work W at the n+1-th rotation of the spindle 110. The phase of the vibration is inverted from the surface shape (shown by the broken line in FIG. 4), and is shifted in the main axis phase direction (horizontal axis direction in the graph of FIG. 4). Specifically, since the sinusoidal waveforms are reversed, the lowest point of the valley of the peripheral surface shape of the work W shown by the broken line in FIG. 4 (the highest point of the peak in the cutting tool 130) at the same spindle phase. 4 is opposed to the position of the highest point (the lowest point of the valley in the cutting tool 130) of the peripheral surface shape of the work W shown by the solid line in FIG.

As a result, the cutting edge path of the cutting tool 130 surely overlaps the cutting processing portion at the time of the forward movement and the cutting processing portion at the time of the next returning movement, and, for example, the peripheral surface of the work W at the (n+1)th rotation of the spindle 110. Since the shape includes the peripheral surface shape of the work W at the n-th rotation of the main shaft 110, 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 into chips. In this way, the machine tool 100 processes the outer shape of the work W while generating chips.

The number of vibrations D for each rotation can be set to 1.1 or 1.25 (times/r), for example, or can be set to a value smaller than 1 (times/r). When the vibration frequency D is set to a value smaller than 1 (times/r), for example, 0.5, the main shaft 110 makes two revolutions while the main shaft 110 reciprocates once in the Z-axis direction.
In the present embodiment, the work W is rotated with respect to the cutting tool 130, but when a drill or the like is used as the cutting tool 130, the work W may be rotated, or the cutting tool 130 may be rotated with respect to the work W. You may rotate.

As shown in FIG. 5, the control device 180 has a control unit 181, an input unit 182, and a storage unit 183, which are connected via a bus.
The control unit 181 includes a CPU and the like, and a motor control unit 190 that controls the operation of each motor, and a parameter calculation that calculates a correction value for the vibration frequency f, the vibration frequency D for each rotation, the spindle rotational speed R, and the cutting speed V. The unit 191 is provided. The parameter calculation unit 191 includes a vibration frequency determination unit 192 that determines the vibration frequency D to be used. The vibration frequency determination unit 192 corresponds to the vibration frequency determination means of the present invention.

The control unit 181 loads various programs and data stored in, for example, the ROM of the storage unit 183 into the RAM, and executes the various programs to cause the machine tool 100 and the parameter calculation unit 191 to execute the machine tool 100. Can control the operation of.
The reciprocating movement of the work W is executed at the vibration frequency f based on the predetermined command period 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 IT.

When the command period T is 16 (ms), which is four times the reference period 4 (ms), for example, the motor control unit 190 feeds the workpiece W in the Z-axis direction so that the work W reciprocates every 16 (ms). The drive signal is output to the mechanism 160. In this case, the work W can reciprocate at the vibration frequency f=1/T=1/(0.004×4)=62.5 (Hz).
The command cycle T can be set to, for example, 3.5 times 14 (ms), 3 times 12 (ms), and 2.5 times 10 (ms) of the reference cycle IT. In this case, the vibration frequency f=1÷(0.004×3.5)=71.4 (Hz), 1÷(0.004×3)=83.3(Hz), 1÷(0.004×) 2.5)=100 (Hz) can be used to reciprocate the work W.

In addition, the command cycle T is, for example, 4.5 times 18 (ms), 5 times 20 (ms), 5.5 times 22 (ms), 6 times 24 (ms), and 6. When set to 5 times 26 (ms), 7 times 28 (ms), 7.5 times 30 (ms), and 8 times 32 (ms), the vibration frequency f=1÷(0.004×4) .5)=55.6 (Hz), 1÷(0.004×5)=50 (Hz), 1÷(0.004×5.5)=45.5 (Hz), 1÷(0. 004×6)=41.7 (Hz), 1÷(0.004×6.5)=38.5 (Hz), 1÷(0.004×7)=35.7 (Hz), 1÷ (0.004×7.5)=33.3 (Hz), 1÷(0.004×8)=31.3 (Hz) can be used.

In this way, the vibration frequency for reciprocating the work W is selected from these usable limited values (also referred to as the command frequency fc).
In the control device 180, the operator uses the input unit 182 to set the cutting speed of the work W to V (m/min), the work diameter before processing to L (mm), and, for example, the set length of cutting chips desired by the user to X. (Mm) and cutting conditions such as the depth of cut (step S1 in FIG. 6), the parameter calculation unit 191 determines the vibration frequency f (Hz) and the vibration frequency determination unit 192 determines the vibration frequency D (times/ r) is calculated (step S2). Each calculation result is stored in the storage unit 183.

The vibration frequency is obtained by f=V/X, and the parameter calculation unit 191 selects a value that is closest to the obtained vibration frequency from the limited plurality of values (command frequency fc), and the usable vibration is obtained. It is corrected to the frequency f (step S3). For example, when the cutting speed V of the workpiece W=50 (m/min) and the set length X of the chips X=20 (mm) are input, the vibration frequency f=50×1000/(20×60)=41.66 .. (Hz), it is corrected to a value 41.7 (Hz) that is the closest to the calculated value.

On the other hand, the number of vibrations for each rotation is obtained by D=π×L/X. For example, when the workpiece diameter L=8 (mm) before processing is input, the number of vibrations D=π×8/20=1.26 (times/r) is obtained. The vibration frequency determination unit 192 corrects the calculated vibration frequency as described later to determine the vibration frequency D to be used (step S4).

Next, the parameter calculator 191 calculates the spindle rotation speed R (r/min) from the usable vibration frequency f and the determined vibration frequency D (step S5). The spindle rotation speed is calculated by R=f/D. After that, the parameter calculation unit 191 obtains the cutting speed V (m/min) of the work W from the obtained spindle rotation speed R and the work diameter L. The cutting speed is calculated by V=R×π×L, and the input cutting speed is corrected to the calculated cutting speed V (step S6).

Then, the machining of the work W is started (step S7), and the motor control unit 190 rotates the work W at the spindle rotational speed R and outputs an operation command to the linear servo motor 165 for each reference cycle IT. , The work W is caused to follow the coordinate position according to the operation command and vibrates at the vibration frequency f.

FIG. 7 is a flowchart of the target vibration frequency determination process according to the first embodiment (first vibration frequency determination mode).
The vibration frequency determination unit 192 calls the vibration frequency D calculated from the workpiece diameter L before machining input by the operator from the storage unit 183 (step S10), and the vibration reaches the set chip length X input by the operator. The number of vibrations is determined as the number of vibrations D to be used (corresponding to the target number of vibrations of the present invention).
For example, when the calculated vibration frequency D is 1.26 (times/r), the latest integer part is 1, so the vibration frequency determination unit 192 sets 0.5 to the nearest integer part 1. The added value is corrected to 1.5 (step S11), and the vibration frequency D to be used is determined to be 1.5 (times/r) (step S12).

As described above, when the usable vibration frequency f is 41.7 (Hz) and the vibration frequency D to be used is determined to be 1.5 (times/r), as shown in FIG. Is determined to be 1668 (r/min), and the motor control unit 190 drives the spindle motor at this spindle rotation speed R.
When the work diameter L is input to 8 (mm), the cutting speed V of the work W is calculated to be 41.92 (m/min) as shown in FIG. Therefore, the input value of the cutting speed of 50 (m/min) is corrected to 41.92 (m/min).

Since the vibration frequency determination unit 192 determines the vibration frequency D for each rotation according to the workpiece diameter L so that the input set length X of the cutting chips is obtained, for example, a desired cutting chip length, before machining Once the workpiece diameter and the cutting speed are input, it becomes unnecessary to newly input the number of vibrations accompanying the reduction of the workpiece diameter.
Specifically, when the machining progresses and the work diameter L becomes 7 (mm), the vibration frequency D is found to be 1.1, and the nearest integer part is 1, so the vibration frequency D to be used is It can be determined to be 1.5 (times/r). As shown in FIG. 9, the cutting speed V of the work W in this case is calculated to be 36.68 (m/min). Therefore, the cutting speed V may be corrected from 41.92 (m/min) to 36.68 (m/min).

After that, when the machining progresses and the workpiece diameter L changes to 6 (mm), the vibration frequency D is 0.94, and the nearest integer part is 0. Therefore, the vibration frequency D to be used is 0.5 (times). /R). As shown in FIG. 8, the spindle rotational speed R in this case is determined to be 5004 (r/min), and as shown in FIG. 9, the cutting speed V of the work W in this case is 94.32 (m/min). Is required. Therefore, the cutting speed V may be corrected from 36.68 (m/min) to 94.32 (m/min).

After that, the number of vibrations D and the cutting speed V can be set by predicting that the work diameter becomes thin. As a result, the burden on the operator of the machine tool can be reduced.
Further, a value obtained by adding 0.5 to the integer part is determined as a new number of vibrations, and the cutting locus of the n-th time and the cutting locus of the (n+1)-th time surely intersect due to the phase inversion of the spindle 110. It becomes easy to divide. Therefore, it is possible to improve the processing accuracy of the work.

FIG. 10 is a flowchart of the target vibration frequency determination process according to the second embodiment (second vibration frequency determination mode). Similarly to the first vibration frequency determination mode, the second vibration frequency determination mode determines the vibration frequency at which the set length X of the chips becomes the vibration frequency D to be used. This is different from the first vibration frequency determination mode in that it is determined whether the n-th cutting locus and the (n+1)-th cutting locus depending on the number of times intersect during one rotation of the work W.

Specifically, when the vibration frequency D calculated from the workpiece diameter L before machining is 1.26 (times/r), the value of this vibration frequency D is called (step S20), and the vibration frequency D is 1. The following discriminant is satisfied as to whether or not the n-th cutting locus at the time of 26 (times/r) and the n+1-th cutting locus intersect during one rotation (0≦θ<2π) of the work W. Is determined (step S21).
The n-th cutting locus can be approximated by a sine curve as shown in Formula 1, and the n+1-th cutting locus can be approximated by a sine curve as shown in Formula 2.

Q is the amplitude feed ratio, F is the feed amount, and the amplitude can be obtained by multiplying the feed amount F by the amplitude feed ratio Q. The amplitude feed ratio Q and the feed amount F can be set in the machining program.
Then, in order to determine whether or not θ (0≦θ<2π) that satisfies A _n =A _n+1 is set, D _n =D _n+1 =D (constant), and n=1 is substituted, the following equation 3 is obtained. Can be obtained.

When θ (0≦θ<2π) exists in the mathematical expression 3, it is determined that the discriminant is satisfied (YES in step S21), and the called vibration frequency D=1.26 (times/r) is used as the vibration frequency D. Is determined (step S22).
On the other hand, when θ (0≦θ<2π) does not exist, it is determined that the discriminant is not satisfied (NO in step S21), and the process proceeds to step S23. When the calculated vibration frequency D is 1.26 (times/r), the latest integer part is 1, so the vibration frequency determination unit 192 adds 0.5 to this latest integer part 1. The value is corrected so as to approach the value 1.5 (for example, 1.4) (step S23), and the process returns to step S21.

Then, regarding whether or not the n-th cutting locus and the (n+1)-th cutting locus when the vibration frequency D is corrected to 1.4 (times/r) intersects during one rotation of the workpiece W, It is determined whether or not it is satisfied (step S21). When θ (0≦θ<2π) exists, it is determined that the discriminant is satisfied (YES in step S21), and the corrected vibration frequency D=1.4 (times/r) is determined as the vibration frequency D to be used. (Step S22).
When the vibration frequency D to be used can be determined to be 1.4 (times/r), the work diameter L is input to 8 (mm), so that the cutting speed V of the work W is 44.92, as shown in FIG. (M/min). Therefore, in this case, the input value 50 (m/min) of the cutting speed is corrected to 44.92 (m/min).

In order to determine the number of vibrations, a discriminant is used that determines whether the n-th cutting locus and the (n+1)th cutting locus intersect during one rotation of the work W. If this discriminant is satisfied, calculation is performed. Since the value is determined as the number of vibrations, the length of the cutting chips can be made closer to the set length X, as compared with the case of determining a unique value such as a value obtained by adding 0.5 to the integer part. If this calculated value is determined as the number of vibrations, the cutting speed V can be made closer to the initially set speed.

On the other hand, when this discriminant is not satisfied, the number of vibrations is determined by correcting so as to approach the value obtained by adding 0.5 to the integer part, and the n-th cutting locus and the (n+1)-th cutting locus are likely to intersect. Become. Then, if the number of vibrations is corrected to 1.4 (times/r), the cutting speed V becomes 44.92 (m/min) when the work diameter L is 8 (mm). Compared with the determination mode (when the work diameter L is 8 (mm) shown in FIG. 9, the cutting speed V is 41.92 (m/min)), the cutting speed V is set to the input value 50 (m/min). ) Can be closer.

FIG. 12 is a flowchart of a target vibration frequency determination process according to the third embodiment (third vibration frequency determination mode). In the third vibration frequency determination mode, similar to the first and second vibration frequency determination modes, the vibration frequency at which the set length X of the chips becomes X is determined as the vibration frequency D to be used. The amplitude of the reciprocating movement is corrected when it is determined whether the n-th cutting locus and the (n+1)-th cutting locus due to the number of vibrations intersect during one rotation of the work W. This is different from the second vibration frequency determination mode.

Specifically, when the vibration frequency D calculated from the workpiece diameter L before machining is 1.26 (times/r), the value of the vibration frequency D is called (step S30), and the second vibration frequency is calculated. Similar to the determination mode, whether the n-th cutting locus and the n+1-th cutting locus when the vibration frequency D is 1.26 (times/r) intersects during one rotation (0≦θ<2π) of the work W. It is determined whether or not the above determination formula is satisfied (step S31).
When θ (0≦θ<2π) exists in the mathematical expression 3, it is determined that the discriminant is satisfied (YES in step S31), and the called vibration frequency D=1.26 (times/r) is used as the vibration frequency D. Is determined (step S32).

On the other hand, when θ (0≦θ<2π) does not exist, it is determined that the discriminant is not satisfied (NO in step S31), the process proceeds to step S33, and after the amplitude feed ratio Q of Equation 3 is corrected, n Whether or not the cutting locus of the first time and the cutting locus of the (n+1)th time intersect during one rotation (0≦θ<2π) of the work W is determined by satisfying the above determination formula (step S34).
If θ (0≦θ<2π) exists when the amplitude feed ratio Q is changed, the discriminant is determined to be satisfied (YES in step S34), and the called vibration frequency D=1.26 (times/r) is set. , The number of vibrations D to be used is determined (step S32).

On the other hand, if θ (0≦θ<2π) does not exist even if the amplitude feed ratio Q is changed, it is determined that the discriminant is not satisfied (NO in step S34), and the process proceeds to step S35. When the calculated vibration frequency D is 1.26 (times/r), the latest integer part is 1, so the vibration frequency determination unit 192 adds 0.5 to this latest integer part 1. The value is corrected to a value close to 1.5 (for example, 1.3) (step S35), and the process returns to step S34.

Next, when the amplitude feed ratio Q is changed and the number of vibrations D is corrected to 1.3 (times/r), the n-th cutting locus and the (n+1)-th cutting locus intersect during one rotation of the work W. It is determined whether or not the above-mentioned discriminant is satisfied (step S34). When θ (0≦θ<2π) exists, it is determined that the discriminant is satisfied (YES in step S34), and the corrected vibration frequency D=1.3 (times/r) is determined as the vibration frequency D to be used. (Step S22).

On the other hand, when θ (0≦θ<2π) does not exist, it is determined that the discriminant is not satisfied (NO in step S34), and the vibration frequency determination unit 192 determines the value 1. The value is corrected so as to approach 5 (for example, 1.4) (step S35), and the process returns to step S34. Then, when the amplitude feed ratio Q is changed and the vibration frequency D is corrected to 1.4 (times/r), the n-th cutting locus and the (n+1)-th cutting locus intersect during one rotation of the work W. Whether or not to perform is determined by whether or not the above determination formula is satisfied (step S34). After that, until θ (0≦θ<2π) exists, that is, until the discriminant is satisfied (YES in step S34), the determination in step S34 and the correction in step S35 are repeated.

If the vibration frequency D to be used could be determined to be 1.3 (times/r), the work diameter L was input to 8 (mm). Therefore, as shown in FIG. 13, the cutting speed V of the work W was 48. It is calculated as 37 (m/min). Therefore, in this case, the input value 50 (m/min) of the cutting speed is corrected to 48.37 (m/min).

In order to determine the number of vibrations, a discriminant is used that determines whether the n-th cutting locus and the (n+1)th cutting locus intersect during one rotation of the work W. If this discriminant is satisfied, calculation is performed. Since the value is determined as the number of vibrations, the length of the cutting chips can be made closer to the set length X, as compared with the case of determining a unique value such as a value obtained by adding 0.5 to the integer part. If this calculated value is determined as the number of vibrations, the cutting speed V can be made closer to the initially set speed.

On the other hand, when this discriminant is not satisfied, the above-mentioned discriminant is used after changing the amplitude of the reciprocating movement. When the discriminant is satisfied by changing the amplitude of the reciprocating movement, the calculated value is determined as the number of vibrations Therefore, the length of the cutting chips can be made closer to the set length, and the cutting speed can be made closer to the initially set speed.
If the discriminant is not satisfied even if the amplitude of the reciprocating movement is changed, the vibration frequency is determined by correcting so as to approach the value obtained by adding 0.5 to the integer part. The cutting trajectories are easy to intersect. If the number of vibrations is corrected to 1.3 (times/r), the cutting speed V becomes 48.37 (m/min) when the work diameter L is 8 (mm), and the second number of vibrations is obtained. Compared with the determination mode (when the work diameter L is 8 (mm) shown in FIG. 11, the cutting speed V is 44.92 (m/min)), the cutting speed V is input at 50 (m/min). ) Can be closer.

By the way, the input unit 182 may be formed so that any one of the first vibration frequency determination mode, the second vibration frequency determination mode, and the third vibration frequency determination mode can be selected.
In the first vibration frequency determination mode, the vibration frequency D is always determined as a value obtained by adding 0.5 to the integer part, and when the work diameter L is 7 (mm), as shown in FIG. The cutting speed V has a minimum value of 36.68 (m/min), and the cutting speed V has a maximum value of 94.32 (m/min) when the work diameter L is 6 (mm).

On the other hand, in the second vibration frequency determination mode, the vibration frequency D is brought close to 1.5 only when the work W does not intersect during one rotation, and as shown in FIG. 11, the work diameter L is 7 (mm). ), the cutting speed V has a minimum value of 39.30 (m/min), and when the work diameter L is 6 (mm), the cutting speed V has a maximum value of 78.60 (m/min). ..
On the other hand, in the third vibration frequency determination mode, the vibration frequency D is brought close to 1.5 only when the amplitude is changed and the work W does not intersect during one rotation, as shown in FIG. In addition, when the work diameter L is 7 (mm), the cutting speed V has a minimum value of 45.85 (m/min), and when the work diameter L is 6 (mm), the cutting speed V has a maximum value of 58.95. (M/min).

When the work diameter L is reduced from 10 (mm) to 3 (mm), the difference between the maximum value and the minimum value of the cutting speed V is determined by the first vibration frequency determination mode, the second vibration frequency determination mode, and the third vibration frequency determination mode. In the order of the vibration frequency determination mode, and the difference between the cutting speed V and the input value 50 (m/min) is also the first vibration frequency determination mode, the second vibration frequency determination mode, and the third vibration frequency determination mode. It becomes smaller in the order of vibration frequency determination mode. Therefore, it is understood that the third vibration frequency determination mode requires less load on the work W and the cutting tool 130 than the first vibration frequency determination mode.

The operator selects one of the first vibration frequency determination mode, the second vibration frequency determination mode, and the third vibration frequency determination mode according to the surface accuracy of the work W and the degree of demand for the life of the cutting tool 130. If it is possible, the convenience of the operator can be further improved.

In each of the above-described embodiments, an example in which the set length X of the chips is set pinpoint is described. However, the present invention is not limited to this example, and the set length X of chips may be set within a predetermined range from the upper limit value to the lower limit value. Since the operator can easily set the set length of the cutting chips, this also contributes to the improvement of the convenience of the operator.
Specifically, when the set length of cutting chips is input within a predetermined range of X=20 (mm) to 18 (mm) and the work diameter L before processing is L=8 (mm), the number of vibrations is determined. The unit 192 obtains the minimum value Dmin=π×8/20=1.26 (times/r) and the maximum value Dmax=π×8/18=1.40 (times/r) of the number of vibrations. Each calculation result is stored in the storage unit 183.

The vibration frequency determination unit 192 calls the minimum value Dmin and the maximum value Dmax of the vibration frequency calculated from the workpiece diameter L before machining from the storage unit 183 (step S40 in FIG. 14), and the nearest integer part in this case is 1. Therefore, it is determined whether or not the value 1.5 obtained by adding 0.5 to the integer part 1 is included between the minimum value Dmin and the maximum value Dmax (step S41).
If it is determined that the value 1.5 obtained by adding 0.5 to the integer part 1 is not included between the minimum value Dmin and the maximum value Dmax (NO in step S41), the minimum value Dmin (or The maximum value Dmax) is corrected to a value of 1.5 by adding 0.5 to the integer part 1 (step S43), and the vibration frequency D to be used is determined to be 1.5 (times/r) (step S42).

Alternatively, the vibration frequency determination unit 192 may employ the determination process of FIG. The calculated minimum value Dmin and maximum value Dmax of the number of vibrations are retrieved from the storage unit 183 (step S50 in FIG. 15). When the value 1.5 obtained by adding 0.5 to the integer part 1 is not included between the minimum value Dmin and the maximum value Dmax (NO in step S51), the process proceeds to step S53, and the minimum value Dmin and the maximum value Dmax. Of these, a value closer to 1.5, which is a value obtained by adding 0.5 to the integer part 1, is selected. When the minimum value Dmin of the vibration frequency is 1.26 (times/r) and the maximum value Dmax is 1.40 (times/r), the maximum value Dmax is selected.

Next, whether the n-th cutting locus and the n+1-th cutting locus when the vibration frequency D is 1.40 (times/r) intersects during one rotation (0≦θ<2π) of the work W. , It is determined whether the above discriminant is satisfied (step S54).
When θ (0≦θ<2π) is present in Expression 3, it is determined that the discriminant is satisfied (YES in step S54), and the selected vibration frequency D=1.40 (times/r) is used as the vibration frequency D. Is determined (step S52).
On the other hand, when θ (0≦θ<2π) does not exist, it is determined that the discriminant is not satisfied (NO in step S54), and the process proceeds to step S55. When the calculated vibration frequency D is 1.40 (times/r), the latest integer part is 1, so the vibration frequency determination unit 192 adds 0.5 to the latest integer part 1. The value is corrected to a value close to 1.5 (for example, 1.5) (step S55), and the process returns to step S54.

Then, regarding whether or not the n-th cutting locus and the (n+1)-th cutting locus when the vibration frequency D is corrected to 1.5 (times/r) intersects during one rotation of the work W, It is determined whether it is satisfied (step S54). When θ (0≦θ<2π) is satisfied, it is determined that the discriminant is satisfied (YES in step S54), and the corrected vibration frequency D=1.5 (cycles/r) is determined as the vibration frequency D to be used ( Step S52).

Alternatively, the vibration frequency determination unit 192 can also employ the determination step of FIG. A minimum value Dmin and a maximum value Dmax of the calculated number of vibrations are called from the storage unit 183 (step S60 in FIG. 16), and a value 1 obtained by adding 0.5 to the integer part 1 between the minimum value Dmin and the maximum value Dmax. .5 is not included (NO in step S61), the process proceeds to step S63, and one of the minimum value Dmin and the maximum value Dmax that is closer to the value 1.5 obtained by adding 0.5 to the integer part 1 is selected. To do. When the minimum value Dmin of the vibration frequency is 1.26 (times/r) and the maximum value Dmax is 1.40 (times/r), the maximum value Dmax is selected.

Next, whether the n-th cutting locus and the n+1-th cutting locus when the vibration frequency D is 1.40 (times/r) intersects during one rotation (0≦θ<2π) of the work W. , Is determined by satisfying the above determination formula (step S64 in FIG. 16).
When θ (0≦θ<2π) exists in the mathematical expression 3, it is determined that the discriminant is satisfied (YES in step S64), and the selected vibration frequency D=1.40 (times/r) is used. Is determined (step S62).
On the other hand, when θ (0≦θ<2π) does not exist, it is determined that the discriminant is not satisfied (NO in step S64), the amplitude feed ratio Q of Expression 3 is changed (step S65), and the n-th time is changed. Whether the cutting locus and the (n+1)th cutting locus intersect during one rotation (0≦θ<2π) of the work W is determined by satisfying the above determination formula (step S66).

If θ (0≦θ<2π) exists when the amplitude feed ratio Q is changed, it is determined that the discriminant is satisfied (YES in step S66), and the selected vibration frequency D=1.40 (times/r) is set. , The number of vibrations D to be used is determined (step S62).
On the other hand, if θ (0≦θ<2π) does not exist even if the amplitude feed ratio Q is changed, it is determined that the discriminant is not satisfied (NO in step S66), as in the example described with reference to FIG. The vibration frequency determination unit 192 corrects the value so as to approach the value 1.5 (for example, 1.5) obtained by adding 0.5 to the nearest integer part 1 (step S67), and returns to step S66.

Next, when the amplitude feed ratio Q is changed and the number of vibrations D is corrected to 1.5 (times/r), the n-th cutting trajectory and the (n+1)-th cutting trajectory intersect during one rotation of the work W. It is determined whether or not the above-described discriminant is satisfied (step S66). When θ (0≦θ<2π) is satisfied, it is determined that the discriminant is satisfied (YES in step S66), and the corrected vibration frequency D=1.5 (times/r) is determined as the vibration frequency D to be used ( Step S62).

By the way, in each of the above-described embodiments, an example in which 0.5 is added to the integer part has been described, but the present invention is not necessarily limited to this example. For example, a value obtained by subtracting 0.5 from the integer part may be determined as the new vibration frequency. Even in this case, the n-th cutting locus and the (n+1)-th cutting locus surely intersect due to the phase inversion of the main shaft 110.
For example, when the cutting speed V of the work W=50 (m/min), the set length of chips X=15.71 (mm), and the work diameter L before processing=20 (mm) are input, the number of vibrations D =π×20/15.71=4.0 (times/r).

When the vibration frequency D is determined to be 4.0 (times/r) and the value obtained by adding 0.5 to the integer part, that is, 4.5 (times/r) is determined as the vibration frequency D to be used, FIG. As shown in, the spindle rotational speed R is determined to be 556.00 (r/min), and the cutting speed V of the work W is determined to be 34.93 (m/min).
On the other hand, when the vibration frequency D is calculated to be 4.0 (times/r) and 0.5 is subtracted from the integer part, that is, 3.5 (times/r) is determined as the vibration frequency D to be used. As shown in FIG. 17, the spindle rotational speed R is calculated to be 714.86 (r/min), and the cutting speed V of the work W is calculated to be 44.92 (m/min).

When the vibration frequency D to be used is determined to be 4.5 (cycles/r) and the vibration frequency D to be used is determined to be 3.5 (cycles/r), the input value of the cutting speed V is 50 The difference of (m/min) is smaller in the latter cutting speed V.
Further, even when the workpiece diameter L before machining is input as L=10 (mm) and the number of vibrations D=π×10/15.71=2.0 (times/r) is obtained, the integer part is 0. When the value obtained by adding 5 or 2.5 (times/r) is determined as the vibration frequency D to be used, the spindle rotational speed R is calculated to be 1000.80 (r/min), as shown in FIG. The cutting speed V of the work W is calculated to be 31.44 (m/min).

On the other hand, when the value obtained by subtracting 0.5 from the integer part, that is, 1.5 (times/r) is determined as the vibration frequency D to be used, as shown in FIG. 17, the spindle rotational speed R is 1668.00 (r /Min), and the cutting speed V of the workpiece W is calculated as 52.40 (m/min).
Therefore, also in this case, the difference between the cutting speed V and the input value 50 (m/min) was smaller in the latter cutting speed V obtained by subtracting 0.5 in the integer part, and was calculated. When the vibration frequency D is an integer, a value obtained by subtracting 0.5 from this integer part may be determined as the vibration frequency D to be used.

100... Machine tool 110... Spindle 110A... Spindle stock 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-Input unit 183-Storage unit 190-Motor control unit 191-Parameter calculation unit 192-Vibration frequency determination unit

Claims (6)

A cutting tool for cutting a work, a rotating means for relatively rotating the work and the cutting tool, and a predetermined vibration for the work or the cutting tool relative to the relative rotation of the work and the cutting tool. A control device for a machine tool, comprising: a vibrating unit that reciprocates at a number of times, and that cuts the work with chips generated by contact with the cutting tool,
The number of vibrations from the setting length of the pre SL diameter as the chips of the workpiece is calculated, the number of vibrations is corrected by adding or subtracting 0.5 to the integer portion of the number of vibrations that the calculated vibration after the correction A vibration frequency determination means having a first vibration frequency determination mode for determining the frequency as the vibration frequency ;
The vibration number determination unit determines the number of oscillations made in setting the length of the chips to the target number of vibrations of said vibrating means, machine tool controller. A cutting tool for cutting a work, a rotating means for relatively rotating the work and the cutting tool, and a predetermined vibration for the work or the cutting tool relative to the relative rotation of the work and the cutting tool. A control device for a machine tool, comprising: a vibrating unit that reciprocates at a number of times, and that cuts the work with chips generated by contact with the cutting tool,
Before Symbol calculates the diameter and the number of vibrations from the setting length of the chips of the workpiece, n-th by vibration number of times the calculation (n is an integer of 1 or more) of the cutting trajectory and the (n + 1) th cutting path of the It is determined whether or not the rotating means intersects during one rotation, and when each of the cutting trajectories intersects, a vibration frequency determination having a second vibration frequency determination mode that determines the calculated vibration frequency as the vibration frequency. Equipped with means,
The vibration number determination unit determines the number of oscillations made in setting the length of the chips to the target number of vibrations of said vibrating means, machine tool controller. A cutting tool for cutting a work, a rotating means for relatively rotating the work and the cutting tool, and a predetermined vibration for the work or the cutting tool relative to the relative rotation of the work and the cutting tool. A control device for a machine tool, comprising: a vibrating unit that reciprocates at a number of times, and that cuts the work with chips generated by contact with the cutting tool,
Before Symbol calculates the diameter and the number of vibrations from the setting length of the chips of the workpiece, n-th by vibration number of times the calculation (n is an integer of 1 or more) of the cutting trajectory and the (n + 1) th cutting path of the It is determined whether or not the rotating means intersects during one rotation, and when the cutting trajectories intersect, the calculated number of vibrations is determined as the number of vibrations. When the cutting trajectories do not intersect, the reciprocating motion is performed. After correcting the amplitude of the movement, it is judged whether or not the n-th cutting locus and the (n+1)-th cutting locus based on the calculated number of vibrations intersect during one rotation of the rotating means, and the reciprocating movement is performed. When each of the cutting trajectories after the amplitude of is corrected intersects, a vibration frequency determination means having a third vibration frequency determination mode for determining the calculated vibration frequency as the vibration frequency is provided,
The vibration number determination unit determines the number of oscillations made in setting the length of the chips to the target number of vibrations of said vibrating means, machine tool controller. First oscillation number determination mode according to claim 1, the second number of vibrations determined mode according to claim 2, selectably formed one of the third number of vibrations determined mode according to claim 3 The machine tool controller. Wherein the setting the length of the chips is set at a predetermined range, the machine tool control apparatus according to any one of claims 1-4. Machine tool having a control device of a machine tool according to any one of claims 1-5.