CN101417398B - Method for suppressing vibration and device therefor - Google Patents

Abstract

The present invention provides a vibration suppressing device capable of obtaining the optimum rotation speed capable of effectively suppressing "flutter", comprising: vibration sensors (2a to 2c) for detecting vibration in the time zone of a rotating shaft (3) during rotation Acceleration; FFT computing device (6), according to the vibration acceleration of the detected time zone, calculates the vibration acceleration of the frequency zone under the flutter number and the flutter number; the storage device (9), the vibration acceleration and the vibration acceleration of the frequency zone The number of vibrations is stored as processing information; the computing device (7), when the calculated maximum acceleration in the frequency region exceeds a predetermined threshold, stores the maximum acceleration and the vibration number etc. as new processing information in the storage device (9) , and, based on the new processing information and the past processing information stored in the storage device (9), calculate the optimal rotation speed capable of suppressing chatter; and the NC device (8) makes the rotating shaft (3) The optimal rotation speed rotates.

Description

Vibration suppression method and device

technical field

The present invention relates to a method of suppressing vibration generated during machining in a machine tool that performs machining while rotating a tool or a workpiece, and a vibration suppressing device capable of performing the method.

Background technique

As a conventional vibration suppression method for machine tools, a method described in Patent Document 1 below is known. In this vibration suppression method, in order to suppress regenerative chatter as a self-excited vibration that causes deterioration of the machining accuracy of the machined surface, the natural vibration number of the system that generates chatter, such as the tool and the workpiece, is obtained and set to 60 The value obtained by dividing by the number of teeth of the tool and a predetermined integer is taken as the rotation speed (steady rotation speed). The natural vibration number is obtained by pulse-exciting the tool and the workpiece.

Furthermore, a method described in Patent Document 2 below is also known as a vibration suppression method. In this vibration suppression method, the number of chatter vibrations during machining of the system where chatter vibrations occur is obtained, and the value obtained by multiplying this by 60 and dividing by the number of teeth of the tool and a predetermined integer is used as the rotational speed. The number of chatter during machining is obtained by arranging sound sensors near the tool and the workpiece according to the vibration frequency detected by the sound sensor during rotation.

Patent Document 1: Japanese Patent Laid-Open No. 2003-340627

Patent Document 2: Japanese PCT Publication No. 2001-517557

In the vibration suppressing method of Patent Document 1, a high-cost pulse device is required, and vibration excitation using this device requires high technology and labor. Moreover, the natural vibration number obtained before processing is not necessarily consistent with the natural vibration number during processing, so it is difficult to obtain the correct optimum rotation speed.

On the other hand, in the vibration suppression method of Patent Document 2, the vibration frequency and the natural vibration frequency during machining are slightly different values from each other, so it is still difficult to obtain an accurate optimum rotation speed. In addition, it is considered that the accuracy can be improved by estimating the natural vibration frequency from the chattering frequency during machining. However, when chattering occurs again after chattering suppression, the rotation speed has changed compared to before chattering suppression. The parameter used in the speculation and calculation of the stable rotational speed (the value of k associated with the stability critical line diagram) also tends to vary, thus causing a decrease or increase in the rotational speed as the value of k is varied, and by repeating the process, resulting in each The rotational speed decreases or increases when judder occurs.

Contents of the invention

The invention described in claim 1 provides a vibration suppressing device capable of obtaining an optimum rotational speed capable of effectively suppressing "chattering".

In addition, the object of the invention described in claims 3 and 5 is to provide a vibration suppression method and device that can obtain a correct and stable rotation speed for suppressing vibration even when vibration occurs intermittently, and the rotation speed Will not decrease or increase.

In order to achieve the above object, the invention of claim 1 provides a vibration suppressing device for suppressing chatter vibration generated when the rotating shaft is rotated in a machine tool having a rotating shaft rotating a tool or a workpiece, characterized in that , the vibration suppressing device has: a detection unit that detects the vibration of the time region of the rotating shaft during rotation; a first arithmetic unit that calculates the chattering number and the vibration number in the time region detected by the detection unit Vibration in the frequency region under the flutter number; a storage unit, which stores the vibration in the frequency region, the flutter number and the rotation speed of the rotating shaft as processing information; the second computing unit, which is calculated by the first computing unit When the vibration in the frequency region exceeds the predetermined threshold, the vibration in the frequency region, the number of flutters and the rotational speed of the rotating shaft at this time are stored in the storage unit as new processing information, and, according to the new processing information and the past machining information stored in the storage unit, calculating an optimum rotation speed of the rotation shaft capable of suppressing chatter; and a rotation speed control unit that causes the rotation shaft to be calculated by the second calculation unit Rotate at the best rotation speed. In addition, the "vibration" described in claim 1 of course includes vibration acceleration, displacement due to vibration, and vibration itself such as sound pressure due to vibration, and also includes physical components that can indirectly detect vibration caused by vibration and occur on the rotating shaft. Variety.

In addition, the invention according to claim 2 is characterized in that, in the above invention, the second arithmetic unit calculates the phase information according to the following arithmetic formulas 1 to 3, and uses the phase information and the past data stored in the storage unit Based on processing information, calculate the optimum rotation speed,

k' value = 60 x chatter number / (tool teeth x rotation speed of the rotary shaft)...Formula 1

The integer part of k value=k' value...Formula 2

Phase information=k' value-k value...Formula 3, the chattering number and the rotation speed of the rotating shaft in the above calculation formula are the chattering number and the rotating shaft rotating speed in the new processing information.

In order to achieve the above object, the invention described in claim 3 provides a vibration suppressing method for suppressing chatter vibration generated when the rotary shaft is rotated in a machine tool having a rotary shaft for rotating a tool or a workpiece, which It is characterized in that the vibration suppression method includes: a detection step of detecting the vibration of the time region of the rotating shaft during the rotation; a calculation step of calculating the vibration frequency and the vibration frequency according to the vibration of the time region detected by the detection step The vibration acceleration in the frequency region under the frequency, and, when the calculated vibration acceleration in the frequency region exceeds a predetermined threshold, calculate and store processing information determined using at least the vibration frequency, and, when the previously stored processing information does not If it exists, use the currently calculated processing information to calculate a stable rotation speed capable of suppressing chatter of the rotating shaft, and if the previously stored processing information exists, at least use the previously stored processing information to calculate the a stable rotation speed; and a rotation speed control step of rotating the rotation shaft at the stable rotation speed calculated by the calculating step.

The invention described in claim 4, in addition to the above object, simply and efficiently prevents the increase or decrease of the stable rotation speed by keeping the processing information constant. In order to achieve this object, it is characterized in that, in the above invention, In the calculation step, when the previously stored machining information exists, the stable rotational speed is calculated using only the machining information.

In order to achieve the above objects, the invention described in claim 5 provides a vibration suppressing device for suppressing chatter vibration generated when the rotary shaft is rotated in a machine tool having a rotary shaft for rotating a tool or a workpiece, which It is characterized in that the vibration suppressing device has: a detection unit that detects the vibration of the time region of the rotating shaft during the rotation; an arithmetic unit that calculates the vibration frequency and The vibration acceleration of the frequency region under the vibration frequency, and, when the calculated vibration acceleration of the frequency region exceeds a predetermined threshold value, calculate and store the processing information determined using at least the vibration frequency, and, when the previously stored processing information When the information does not exist, use the currently calculated processing information to calculate a stable rotation speed capable of suppressing chatter of the rotating shaft, and when the previously stored processing information exists, at least use the previously stored processing information to calculate the stable rotation speed; and a rotation speed control unit that rotates the rotation shaft at the stable rotation speed calculated by the arithmetic unit.

The invention described in claim 6, in addition to the above object, is characterized in that, in the above invention, when When the previously stored machining information exists, the arithmetic unit calculates the stable rotational speed using only the machining information.

According to the present invention, since the optimum rotation speed is calculated by detecting the "chatter" generated by the rotating shaft that is actually rotating, a more accurate optimum rotation speed can be calculated immediately. Therefore, amplification of "chatter" can be reliably suppressed, and chatter marks will not remain on the processed surface.

And, whenever the vibration in the frequency region exceeds a predetermined threshold, the vibration, the number of vibrations and the rotation speed of the rotating shaft are stored in the storage unit as processing information, and when the vibration exceeds the threshold next time, the data stored in the storage unit is used. The optimum rotation speed is calculated from past processing information. Therefore, it is possible to easily calculate the optimum rotational speed described in the stability critical line diagram at which regenerative chattering is least likely to occur, and it is possible to maintain high-quality machining accuracy of the machined surface.

In addition, according to the present invention, machining information is stored, and a stable rotational speed capable of suppressing vibration of the rotating shaft is calculated based on the past machining information. Therefore, there is no large difference between the calculation of the stable rotational speed and the past stable rotational speed. Even when chattering occurs intermittently, the effect of preventing the decrease or increase of the rotation speed can be exhibited.

Description of drawings

FIG. 1 is a schematic diagram showing a frame configuration of a vibration suppression device according to a first aspect of the present invention.

FIG. 2 is a schematic view showing a rotating shaft housing to be subjected to vibration suppression from the side.

Fig. 3 is a schematic view showing the rotating shaft housing from the axial direction.

FIG. 4 is a schematic diagram showing an example of Fourier analysis results of vibration acceleration in the time domain.

FIG. 5 is a flowchart related to chatter suppression control.

6 is a block diagram of a vibration suppression device according to a second aspect of the present invention.

FIG. 7 is a flowchart of a vibration suppression method performed in the vibration suppression device of FIG. 6 .

Symbol Description

1 rotating shaft housing; 2a, 2b, 2c vibration sensors; 3 rotating shaft; 5, 105 control device; 6 FFT computing device (1st computing unit); Speed control unit); 9 storage device (storage unit); 10, 110 vibration suppression device; 106 FFT computing device (computing unit); 107 stable rotation speed computing device (computing unit).

Detailed ways

Hereinafter, examples of embodiments according to the present invention will be described with reference to the drawings as appropriate. In addition, the form of this invention is not limited to this example.

[the first mode]

Hereinafter, a vibration suppressing device according to one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram showing a frame configuration of a vibration suppressing device 10 . FIG. 2 is a schematic diagram showing the rotating shaft housing 1 to be subjected to vibration suppression from the side, and FIG. 3 is a schematic diagram showing the rotating shaft housing 1 from the axial direction.

The vibration suppressing device 10 is used to suppress the "flutter" generated on the rotating shaft 3 that is provided in the rotating shaft housing 1 and can rotate along the C-axis system, by detecting the vibration acceleration of the time region generated by the rotating shaft 3 during the rotation process Vibration sensors (detection means) 2a to 2c (vibration acceleration on the time axis) and a controller 5 for controlling the rotational speed of the rotary shaft 3 based on the detection values of the vibration sensors 2a to 2c are constituted.

Vibration sensors 2a～2c as shown in Figure 2 and Figure 3, are installed in the position near the rotating shaft 3 of rotating shaft housing 1, and a vibration sensor detects the vibration acceleration towards the time zone of right angle direction to other vibration sensors (for example, detects towards Vibration acceleration in the time domain of the orthogonal X-axis, Y-axis and Z-axis directions, respectively).

On the other hand, the control device 5 has: an FFT calculation device (the first calculation unit) 6, which performs analysis based on the vibration acceleration in the time zone detected by the vibration sensors 2a-2c; a calculation device (the second calculation unit) 7 , according to the value calculated by the FFT computing device 6, calculate the optimal rotation speed, etc.; storage device (storage unit) 9, store the calculation value calculated by the computing device 7, etc.; and NC device (rotational speed control unit) 8 , to control the machining of the housing 1 on the rotating shaft. The control device 5 controls the rotational speed of the rotating shaft 3 as described later, and suppresses "chattering" generated on the rotating shaft 3 .

Here, the suppression control of "chattering" by the control device 5 will be described based on the flowchart of FIG. 5 .

First, in the FFT calculation device 6, Fourier analysis (S1) of the vibration acceleration in the time region that is always detected by the vibration sensors 2a to 2c during the rotation of the rotating shaft 3 is performed, and the maximum acceleration (frequency) shown in 4 of FIG. 4 is calculated. area vibration acceleration) and its frequency (flutter number) (S2).

Then, in the computing device 7, the maximum acceleration calculated in the above-mentioned S2 is compared with a preset predetermined threshold (S3). The number of vibrations, the number of teeth of the tool, and the rotational speed of the rotary shaft 3 are calculated using the following calculation formulas (1) to (3) to calculate the k' value, the k value, and the phase information, and the k' value, the k value, and the phase information, and The maximum acceleration and vibration count calculated in S2 above, and the rotation speed of the rotary shaft at the current point in time are stored in the storage device 9 as new machining information (S4).

k' value = 60 x chatter number / (tool teeth x rotation speed of the rotary shaft)...(1)

k value = integer part of k' value...(2)

Phase information = k'value-kvalue...(3)

Wherein, the “number of teeth of the tool” in the calculation formula (1) is input and set into the computing device 7 in advance. In addition, the rotational speed of the rotating shaft in the calculation formula (1) refers to the current (before becoming the optimum rotational speed) rotational speed.

In addition, among the processing information stored in the storage device 9, the phase information and the rotational speed of the rotating shaft (past processing information) when the threshold value was exceeded last time, and the phase information and the rotational speed of the rotating shaft when the threshold value was exceeded last time ( past processing information), the optimum rotational speed is calculated (S5) using the following calculation formulas (4) and (5).

Velocity variation = (1-last phase information)×(last rotation speed of the rotating shaft-last rotation speed of the rotating shaft)/(last phase information-last previous phase information)...(4)

Optimum rotation speed = previous rotation speed of the rotation shaft - speed variation...(5)

Then, in order to achieve the calculated optimum rotation speed, the rotation speed of the rotary shaft 3 is changed by the NC device 8 to prevent, that is, suppress, amplification of "chatter" (S6).

As described above, the control device 5 performs suppression control of "chattering".

In addition, the calculation formula (4) above cannot be used when the maximum acceleration exceeding the threshold is detected for the first time after the rotation shaft 3 starts to rotate, and when the maximum acceleration exceeding the threshold is detected for the second time. Therefore, in this case, after S3, compare the phase information obtained by using the calculation formula (3) with the set constant, if the phase information is above the set constant, then use the calculation formula (6) to calculate the k1 value, if the phase information If it is less than the set constant, use formula (7) to calculate the value of k1.

k1 value = k value + 1...(6)

k1 value = k value... (7)

Here, as a setting constant, generally, if 0.5 is set, the amount of change in the rotational speed can be minimized. However, when the change rate of the rotation speed is small, depending on the direction of changing the rotation speed, it will be lower than the cutting lower limit mentioned in the stability critical line diagram, and regenerative chatter may occur, so this lower limit can be used as a setting constant. Compare with phase information. In this case, it is preferable to adopt 0.75 as a setting constant.

And, using the k1 value obtained by the above calculation formula (6) or (7), the optimum rotation speed can be calculated by the following calculation formula (8), and the rotation speed of the rotating shaft 3 can be changed to the optimum rotation speed.

Optimum rotation speed = 60× chattering number/(tool teeth number×k1 value)…(8)

According to the vibration control device 10 described above, the "chatter" generated during the rotation of the rotating shaft 3 can be monitored in real time through the vibration sensors 2a-2c, the FFT computing device 6 and the computing device 7, and when "chattering" is detected, , immediately use the above formulas (1) to (5) to calculate the optimal rotation speed, and change the rotation speed of the rotating shaft 3 to the optimal rotation speed. In this way, "chatter" generated by the rotating shaft 3 that is actually rotating is detected and the optimum rotational speed is calculated, so that a more accurate optimum rotational speed can be calculated immediately. Therefore, amplification of "chatter" can be reliably suppressed, and chatter marks will not remain on the processed surface.

And, when the maximum acceleration of the vibration acceleration in the frequency region exceeds the threshold value, the maximum acceleration and its frequency (chattering frequency), the rotation speed of the rotating shaft, the k' value calculated by the calculation formulas (1) to (3), The k value and phase information are stored in the storage device 9 as new processing information, and the optimum rotation speed is calculated using past processing information stored in the storage device 9 when the maximum acceleration exceeds the threshold next time. Therefore, it is possible to easily calculate the optimum rotational speed described in the stability critical line diagram at which regenerative chattering is least likely to occur, and it is possible to maintain high-quality machining accuracy of the machined surface.

In addition, when there is not enough processing information stored in the storage device 9, during the first and second "chatter" detections, the phase information is compared with the setting information, and the k1 value changed based on the comparison result is used respectively. Calculate the optimal rotation speed. Therefore, "chattering" can be suppressed in a short period of time, and it is expected to improve the machining accuracy of the machined surface, suppress tool wear, and prevent tool damage.

In addition, the vibration suppressing device according to the present invention is not limited to the one described in the above-mentioned first mode, and the detection unit, the control device, and the control of the vibration suppression by the control device can be appropriately changed as needed within the range not departing from the gist of the present invention. Structure.

For example, the k' value, k value, phase information, speed change amount, etc. shown in calculation formulas (1) to (8) and their relationship can be further improved by properly investigating and determining according to the type of machine tool.

In addition, when calculating the amount of speed change, in the calculation formula (4), the previous phase information is subtracted from the constant "1". Although the constant is theoretically "1", it can also be slightly different from "1.05", etc. The value deviated from "1" finds the speed change amount.

In addition, in the above-mentioned first form, the k' value, k value and phase information, the maximum acceleration and chattering frequency calculated in the above-mentioned S2, and the rotational speed of the rotary shaft at the current point in time are used as the processing data in the storage device. information, but the k' value, k value, and phase information may not be stored, but may be configured to be calculated based on the processing information every time the calculation of the calculation formula (4) is performed.

In addition, in the above-mentioned first form, when performing Fourier analysis of the vibration acceleration in the time domain detected by the detection means, the "chattering" suppression control is performed using a waveform indicating that the vibration acceleration in the frequency domain is at a maximum value. The optimal rotation speed may be calculated using a plurality of (for example, three) waveforms having higher vibration acceleration values in the frequency domain, thereby further enhancing the "chatter" suppression effect.

In addition, in the above-mentioned first form, the vibration acceleration of the rotating shaft is detected by the vibration sensor, but it may be configured to detect the displacement and sound pressure of the rotating shaft due to vibration, and calculate the optimum rotation speed based on the displacement and sound pressure.

In addition, in the above-mentioned first form, the vibration of the rotating shaft of the machine tool is detected, but it may be configured to detect the vibration of the non-rotating side (fixed side) and calculate the optimum rotation speed, and is not limited to rotating the tool. Machining centers can also be applied to working machines such as lathes that rotate workpieces. In addition, it is of course possible to appropriately change the installation position and number of detection units according to the type and size of the machine tool.

[the second method]

FIG. 6 is a block diagram of a vibration suppression device 110 according to a second aspect of the present invention. The vibration suppressing device 110 has the same rotating shaft housing 1 (refer to FIGS. 2 and 3 ) as the object of vibration suppressing as in the first embodiment. The rotating shaft housing 1 has a rotating shaft 3 rotatable along the C-axis system. The vibration suppressing device 110 suppresses chatter vibration of the rotary shaft 3 generated during rotation. The vibration suppression device 110 has: vibration sensors 2a-2c as detection units for detecting the vibration acceleration generated in the time zone of the rotating shaft 3 during the rotation; and the control device 105, based on the detection values of the vibration sensors 2a-2c Control the rotation speed of the rotary axis 3.

As shown in Figure 2 and Figure 3, the vibration sensors 2a-2c are installed on the rotating shaft housing 1 in a state that can detect the vibration acceleration in the time region of the mutually orthogonal X axis, Y axis and Z axis direction, so as to detect each other. Vibration acceleration in the time zone in the vertical direction (vibration acceleration on the time axis).

In addition, the control device 105 has: an FFT computing device 106 for performing Fourier analysis based on the vibration acceleration in the time range detected by the vibration sensors 2a to 2c; Calculation of the stable rotation speed, etc. are performed; the NC device 108 as a rotation speed control unit controls the machining on the rotation shaft housing 1 . The NC device 108 of the control device 105 monitors the rotation speed of the rotary shaft 3 . In addition, the FFT computing device 106 and the steady rotation speed computing device 107 correspond to computing means.

An example of a method of suppressing chatter by the vibration suppressing device 110 configured in this way will be described centering on FIG. 7 . FIG. 7 shows a flowchart of this suppression control.

First, the FFT computing device 106 performs Fourier analysis on the vibration accelerations in the time region that are always detected by the vibration sensors 2a to 2c during the rotation, and the same as the first method, always calculates the maximum acceleration shown in FIG. 4 and its frequency 4 (vibration). Vibration number) (step S101 of FIG. 7, detection step). In addition, when Fourier analysis is performed on the vibration acceleration in the time domain, a plurality of patterns of the waveform shown in FIG. 4 representing the relationship between the frequency and the vibration acceleration in the frequency domain are acquired, but in this embodiment, the value of the vibration acceleration in the frequency domain is used for the largest waveform.

Then, in the stable rotation speed calculation means 107, the vibration acceleration in the frequency region calculated by the FFT calculation means 106 is compared with a preset threshold value, and when the vibration acceleration in the frequency region exceeds the predetermined threshold value (for example, it is detected that When the vibration acceleration in the frequency range of frequency 4 in 4) is considered to be "chattering" that should be suppressed in the rotating shaft 3, the k value is calculated using the following calculation formulas (101) and (102) and stored as processing information, And use the following calculation formula (103) to calculate the stable rotation speed and output it to the NC device 108 (step S102, operation step, when the previously stored machining information does not exist). In addition, the processing information refers to k value and k' value here. In addition, the number of teeth of the cutter is set in the steady rotation speed calculation device 107 in advance. In addition, the rotation speed of the rotation shaft refers to the current rotation speed of the rotation shaft 3 before reaching a stable rotation speed. In addition, the chattering frequency refers to the frequency 4 at which chattering occurs.

k' value = 60 × vibration frequency / (number of tool teeth × rotation speed of the rotary shaft)...(101)

The integer part of k value=k' value...(102)

Stabilized rotation speed = 60×vibration frequency/{number of tool teeth×(k value+1)}…(103)

Then, the NC device 108, having received the stable rotational speed output from the stable rotational speed computing device 107 in step S102, changes the rotational speed of the rotary shaft 3 to the stable rotational speed (step S103, rotational speed control step). By setting the rotational speed of the rotary shaft 3 to this stable rotational speed, chatter vibration can be suppressed and a stable machining state can be achieved.

When the vibration sensors 2a to 2c are in a stable machining state by suppressing chatter in this way, the vibration acceleration and the like in the time domain are also detected (detection step). And, when fluttering occurs again, and the vibration acceleration in the frequency region exceeds the predetermined threshold value, the same as step S102, recalculate the processing information and output the stable rotation speed, but the calculated k value is different from the previous (step S102) stored k value. If the values are different, replace the calculated k value with the stored k value, and calculate the stable rotation speed (step S104, operation step, when the previously stored processing information exists). In addition, in step S104, instead of calculating the machining information, the stable rotational speed may be calculated from the stored k value.

The NC device 108, having received the stable rotational speed output from the stable rotational speed computing device 107 in step S104, changes the rotational speed of the rotary shaft 3 to the stable rotational speed (step S5, rotational speed control step). By setting the rotational speed of the rotary shaft 3 to this stable rotational speed, chatter vibration can be suppressed and a stable machining state can be established again. Also, since this stable rotational speed is calculated based on the same k value as before (step S102), it is approximately the same value as the previous stable rotational speed and does not deviate from the previous stable rotational speed.

In addition, when the vibration acceleration in the frequency region exceeds the predetermined threshold again after such a stable processing state (when chattering occurs intermittently), the detection of the vibration sensors 2a-2c and the steps S104 and S105 are repeated, and the rotation of the rotating shaft 3 The speed is set to a new stable rotation speed to form a stable processing state. This new stable rotational speed is also calculated according to the same stored k value as in the previous step S104, so it is the same value as the previous stable rotational speed, and will not deviate from the previous stable rotational speed. When chattering occurs intermittently, The steady rotation speed also does not continuously decrease or continuously increase.

In the vibration suppressing device 110 described above, based on the k value calculated and stored based on the past machining results, the stable rotational speed is calculated by keeping the k value constant. Therefore, even when chattering occurs intermittently, the stable rotational speed and There is no large difference in the previous rotation speed, the rotation speed of the rotary shaft 3 can be prevented from decreasing or increasing, and the processing surface can be kept at high quality while considering efficiency. In addition, since the change in the rotational speed of the rotary shaft 3 is small, it is possible to prevent excessive loads from being applied to the tool and the spindle.

In addition, another aspect of the present invention formed by mainly changing the above-mentioned second aspect is exemplified. About the k value, the amount of the past several times (for example, the amount of 5 times) can be stored together, and the value after rounding the average value of the predetermined number of times (for example, 5 times) can be used as the new k value, and can also be replaced by the predetermined number of times (such as 5 times), in these cases, the blind increase or decrease of the rotation speed can be prevented. Furthermore, when the control device performs Fourier analysis, it is also possible to extract vibration frequencies of the vibration acceleration in a plurality of (for example, three upper) frequency regions, and calculate the steady rotation speed using these plurality of vibration frequencies. In addition, instead of the vibration acceleration of the rotating shaft, the vibration acceleration, displacement due to vibration, and sound pressure due to rotation may be detected and used to calculate the steady rotation speed.

In addition, detection means may be arranged instead of the rotating shaft side, or on the rotating shaft side and the fixed side (the workpiece and/or its vicinity). In addition, the present invention can also be applied to other working machines typified by lathes that rotate workpieces. In a machine tool that rotates a workpiece, it is possible to detect vibration on the spindle side that holds the workpiece, or detect vibration on the tool side that is a fixed side. In addition, the number, arrangement, and the like of the detection units may be appropriately changed according to the type, scale, and the like of the machine tool. In addition, various computing devices may be integrated or separated, or other storage devices other than the computing device may be provided.

Claims (6)

1. an equipment for inhibiting of vibration is used at the work mechanism with the rotating shaft that makes cutter or workpiece rotation, and the flutter that produces when suppressing said rotating shaft is rotated is characterized in that said equipment for inhibiting of vibration has:

Detecting unit, it detects the vibration of the time zone of the said rotating shaft in the rotary course;

The 1st arithmetic element, its according to by detection to the vibration of time zone, the vibration of calculating the frequency field under flutter number and this flutter number;

Memory cell, the vibration of its frequency field, flutter number and rotating shaft rotary speed are stored as machining information;

The 2nd arithmetic element; When its vibration at the frequency field that is calculated by said the 1st arithmetic element surpasses predetermined threshold value; Be stored in the vibration of this frequency field, flutter number and the rotating shaft rotary speed of this moment in the memory cell as new machining information; And according to this new machining information and the machining information that is stored in the past in the said memory cell, calculating can suppress the best rotary speed of the said rotating shaft of flutter; And

The rotary speed control module, it makes the best rotary speed rotation of said rotating shaft to be calculated by said the 2nd arithmetic element.

2. equipment for inhibiting of vibration according to claim 1 is characterized in that, the 2nd arithmetic element is calculated phase information according to following operational formula 1～formula 3; And; With this phase information be stored in the machining information in the past in the memory cell and be the basis, the calculating optimum rotary speed

K ' value=60 * flutter number/(cutter number of teeth * rotating shaft rotary speed) ... Formula 1

The integer portion of k value=k ' value ... Formula 2

Phase information=k ' value-k value ... Formula 3,

Flutter number in the above-mentioned operational formula and rotating shaft rotary speed are flutter number and the rotating shaft rotary speed in the new machining information.

3. a vibration suppressing method is used at the work mechanism with the rotating shaft that makes cutter or workpiece rotation, and the flutter that produces when suppressing said rotating shaft is rotated is characterized in that said vibration suppressing method comprises:

Detect step, detect the vibration of the time zone of the said rotating shaft in the rotary course;

Calculation step according to detecting the vibration of the detected time zone of step through this, is calculated the vibration acceleration of the frequency field under beat frequency and this beat frequency; And; When the vibration acceleration of this frequency field that calculates surpasses predetermined threshold value, calculate and store the machining information that uses beat frequency to confirm at least, and; When before the said machining information of storage when not existing; Use the current said machining information that calculates to calculate the steady rotation speed of the flutter that can suppress said rotating shaft, when before the said machining information of storage when existing, the said machining information of storage calculates said steady rotation speed before using at least; And

Rotary speed control step makes the steady rotation speed rotation of said rotating shaft to calculate through this calculation step.

4. vibration suppressing method according to claim 3 is characterized in that, in said calculation step, when before the said machining information of storage when existing, only use this machining information to calculate said steady rotation speed.

5. an equipment for inhibiting of vibration is used at the work mechanism with the rotating shaft that makes cutter or workpiece rotation, and the flutter that produces when suppressing said rotating shaft is rotated is characterized in that said equipment for inhibiting of vibration has:

Detecting unit, it detects the vibration of the time zone of the said rotating shaft in the rotary course;

Arithmetic element, its according to by this detection to the vibration of time zone, calculate the vibration acceleration of the frequency field under beat frequency and this beat frequency; And; When the vibration acceleration of this frequency field that calculates surpasses predetermined threshold value, calculate and store the machining information that uses beat frequency to confirm at least, and; When before the said machining information of storage when not existing; Use the current said machining information that calculates to calculate the steady rotation speed of the flutter that can suppress said rotating shaft, when before the said machining information of storage when existing, the said machining information of storage calculates said steady rotation speed before using at least; And

The rotary speed control module, it makes the steady rotation speed rotation of said rotating shaft to be calculated by this arithmetic element.

6. equipment for inhibiting of vibration according to claim 5 is characterized in that, when before the said machining information of storage when existing, said arithmetic element only uses this machining information to calculate said steady rotation speed.

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