JP5032345B2 - Vibration suppression device and vibration suppression method - Google Patents

Description

  The present invention relates to a vibration suppression device and a vibration suppression method for suppressing vibration generated in a structure during machine operation such as machining in a machine tool or the like that is supported by a structure having a rotating shaft. is there.

  Conventionally, as a configuration for suppressing vibration generated in a predetermined structure in a machine tool, a configuration in which a dynamic vibration absorber is separately installed in the machine tool is generally employed. Here, it is known that the natural frequency of vibration generated in a structure that is subject to vibration suppression is defined by the shape, material, size, and the like of the structure. Therefore, the dynamic vibration absorber is required to be able to adjust the natural frequency (the natural vibration frequency of the dynamic vibration absorber) in order to improve the versatility. As such a dynamic vibration absorber, for example, the natural frequency can be adjusted by adjusting the distance between the support location and the weight member (Patent Document 1), the number of load weights attached, etc. are changed. By doing so, there is one that can adjust the natural frequency (Patent Document 2).

JP 2004-263767 A JP 2002-188680 A

  However, since the dynamic vibration absorbers disclosed in Patent Document 1 and Patent Document 2 have a special configuration for adjusting the natural frequency, many of them are expensive, and the dynamic vibration absorber is installed. In doing so, there is a problem of increasing the cost. In addition, when a dynamic vibration absorber is newly installed, it is necessary to secure an installation space at a position where the vibration suppressing effect can be sufficiently exhibited, and there is a problem that it is difficult to ensure the movement. The vibration absorber also has a problem that the installation work is complicated.

  Therefore, the present invention has been made in view of the above problems, and vibration suppression that can effectively suppress vibration while using the dynamic vibration absorber having a complicated structure and corresponding to the natural frequency of the structure. An apparatus and a vibration suppression method are to be provided.

In order to achieve the above object, the invention according to claim 1 of the present invention is a machine comprising a structure having a rotating shaft and a fixed support portion that pivotally supports the rotating shaft. A vibration suppressing device that suppresses vibration generated in the structure with rotation of the moving support portion that supports the rotating shaft at one place between the structure and the fixed support portion. The rotation is provided by changing the distance between the support position by the moving support part and the support position by the fixed support part according to the natural frequency of the vibration generated in the structure. It is possible to change and set the natural frequency of anti-resonance vibration generated in the shaft.
In order to achieve the above object, the invention according to claim 2 of the present invention includes a structure having a rotating shaft, a fixed support portion that supports the rotating shaft, the structure, and the fixed support. In a machine provided with a moving support portion that supports the rotating shaft at one location between the rotating portion and is movable in the axial direction of the rotating shaft, vibration generated in the structure is applied to the rotating shaft. A vibration suppression method that suppresses vibration caused by generated anti-resonance vibration, and determines a support position of the rotating shaft by the movable support portion that can obtain the optimum anti-resonance vibration with respect to vibration generated in the structure. A first step and a second step of positioning the movable support portion at the determined support position are performed.

  According to the present invention, the moving support portion that supports the rotation shaft is provided between the structure and the fixed support portion, and the movement support portion can be moved in the axial direction of the rotation shaft. Since the natural frequency of the anti-resonant vibration generated on the rotating shaft can be changed by changing the distance between the rotation support and the support position by the fixed support portion, the rotating shaft itself can function as a dynamic vibration absorber. Accordingly, it is not necessary to install an expensive dynamic vibration absorber having a complicated structure as in the conventional case, and the same vibration damping effect can be achieved, the cost can be reduced, and labor for installation work is also reduced. Can be reduced. Moreover, since it can comprise by providing a movement support part in the position with comparatively space, such as between a structure and a fixed support part, there is no worry which causes trouble in ensuring installation space.

  Hereinafter, a vibration suppression device and a vibration suppression method in a machine tool according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram showing a machine tool 1 and a vibration suppressing device 2. FIG. 2 is an explanatory cross-sectional view in the axial direction of the moving support portion 21, and FIG. 3 is an explanatory cross-sectional view in a direction orthogonal to the axial direction of the moving support portion 21.
The machine tool 1 includes a structure 4 having a rotation shaft 3, a fixed support portion 5 and an auxiliary support portion 6 that support the rotation shaft 3, and a vibration suppression device 2 for suppressing vibration generated in the structure 4. It is equipped with. The vibration suppression device 2 includes a moving support portion 21 that supports the rotary shaft 3 at a position between the structure 4 and the fixed support portion 5, and a moving support portion 21 for moving the moving support portion 21 in the axial direction of the rotary shaft 3. The moving mechanism includes a ball screw 22, a nut 23, and a motor 24. Reference numeral 25 denotes a support portion for supporting the ball screw 22.

The moving support portion 21 includes a cylindrical support ball holder 27 and three support balls 28, 28... Arranged in the support ball holder 27. The rotating shaft 3 is sandwiched and supported from three directions by the spherical portion. Then, the distance between the support position by the movement support part 21 and the support position by the fixed support part 5 can be changed by moving the movement support part 21 in the axial direction of the rotary shaft 3 by the moving mechanism.
Each support ball 28 is fitted and installed in a recessed portion 29 that is recessed on the inner peripheral surface of the support ball retainer 27 with the spherical portion facing inward. Further, the three support balls 28, 28... Are installed at equal intervals in the circumferential direction on the inner peripheral surface of the support ball retainer 27.

Here, vibration suppression by the vibration suppression device 2 having the moving support portion 21 will be described.
When the rotating shaft 3 is rotated and the structure 4 is rotated during processing or the like, vibration is generated in the structure 4 along with the rotation. Alternatively, vibrations are generated in the structure 4 in accordance with vibrations generated by cutting force fluctuations during processing and vibrations input from an external vibration source such as a compressor. Therefore, in this embodiment, the rotation shaft 3 itself is used as a dynamic vibration absorber, and the vibration generated in the structure 4 is canceled by generating anti-resonance vibration on the rotation shaft 3. Since the natural frequency of the anti-resonance vibration changes depending on the support position by the moving support portion 21, that is, the distance between the support position by the moving support portion 21 and the support position by the fixed support portion 5, the moving mechanism is driven. If the moving support portion 21 is positioned at a position where an optimum anti-resonance vibration is obtained, the vibration generated in the structure 4 can be canceled out, and a suitable processing can be performed. The moving support portion 21 is positioned at an optimum position by a known method as described in, for example, Japanese Patent Application Laid-Open No. 9-280310, that is, an acceleration sensor is attached to the rotary shaft 3 and the measuring instrument is set to a frequency. In addition to analyzing, the method of rotating and positioning the motor 24 while detecting the rotation position by the encoder based on the analysis value (that is, the support position by the movable support portion 21 that can obtain the optimum anti-resonance vibration) The first step to be determined and the second step of positioning the moving support portion 21 at the determined support position may be performed in parallel.

  According to the vibration suppression device 2 having the above-described configuration, the moving support portion 21 that supports the rotating shaft 3 is provided between the structure 4 and the fixed support portion 5, and the moving support portion 21 is connected to the rotating shaft. 3 so that the distance between the support position by the movable support portion 21 and the support position by the fixed support portion 5 can be changed. Therefore, the rotary shaft 3 itself can function as a dynamic vibration absorber. Accordingly, it is not necessary to install an expensive dynamic vibration absorber having a complicated structure as in the conventional case, and the same vibration damping effect can be achieved, the cost can be reduced, and labor for installation work is also reduced. Can be reduced.

Moreover, since it can comprise by providing the movement support part 21 in the position with comparatively space, such as between the structure 4 and the fixed support part 5, there is no fear that it will interfere with securing installation space.
Furthermore, since the moving support portion 21 is configured to support the rotating shaft 3 by the spherical surface portions of the support balls 28, 28,..., The moving support portion 21 is in contact with the rotating shaft 3 when moving in the axial direction. The frictional resistance between them can be reduced, and the rotating shaft 3 is not damaged.

  The configuration related to the vibration suppressing device in the machine tool of the present invention is not limited to the aspect described in the above embodiment, and the configuration related to the machine tool, the fixed support portion, the moving support portion, and the like is The present invention can be appropriately changed as necessary without departing from the spirit of the invention.

  For example, each time the natural frequency of the vibration generated in the structure changes, the moving support unit may be positioned so as to obtain the optimum natural frequency by the method described in the above embodiment. The natural frequency can be calculated from the relational expression such as the natural frequency that the rotating shaft originally has, the support position by the moving support part, the rotation speed and phase of the motor, etc., so the optimum by the moving support part based on the relational expression In such a configuration, the driving amount of the motor for positioning to the supporting position is calculated and the motor is driven and controlled by a control device (not shown) (second step). Good.

In the above-described embodiment, the auxiliary support portion is provided between the structure and the moving support portion. However, the number and position of the auxiliary support portions can be changed as appropriate, and the moving support portion and the fixed support portion can be changed. It is also possible to install between a plurality of auxiliary support sections.
Further, the moving mechanism for moving the moving support portion in the axial direction of the rotating shaft is not limited to the one described in the above embodiment, and there is no problem even if the support position is changed manually. .
In addition, the configuration related to the support of the rotary shaft in the moving support portion is not limited to the configuration described in the above embodiment, and the configuration may be such that the rotary shaft is supported using rollers instead of the support balls. Of course, it is possible, and you may make it support using more support balls.

It is the schematic which showed the machine tool and the vibration suppression apparatus. It is sectional explanatory drawing in the axial direction of a movement support part. It is sectional explanatory drawing in the direction orthogonal to the axial direction of a movement support part.

Explanation of symbols

  1 .... Machine tool 2 .... Vibration suppression device 3 .... Rotary shaft 4 .... Structure 5 .... Fixed support part 6 .... Auxiliary support part 21 ... Move support part 27 ... Support Ball cage, 28 ... support balls.

Claims (2)

In a machine comprising a structure having a rotating shaft and a fixed support portion that supports the rotating shaft, a vibration suppressing device that suppresses vibration generated in the structure with rotation of the rotating shaft,
A moving support portion that supports the rotating shaft at one location between the structure and the fixed supporting portion is provided so as to be movable in the axial direction of the rotating shaft;
By changing the distance between the support position by the movable support part and the support position by the fixed support part in accordance with the natural frequency of the vibration generated in the structure, the characteristic of the anti-resonant vibration generated in the rotating shaft is changed. A vibration suppressing device characterized in that the frequency can be changed and set. A structure having a rotation shaft, a fixed support portion that supports the rotation shaft, and the rotation shaft is supported at one position between the structure and the fixed support portion and moved in the axial direction of the rotation shaft A vibration suppression method for suppressing vibration generated in the structure by anti-resonance vibration generated in the rotating shaft in a machine including a movable support portion made possible,
A first step of determining a support position of the rotating shaft by the moving support unit capable of obtaining the anti-resonance vibration optimum for vibration generated in the structure;
And a second step of positioning the movable support portion at the determined support position.

Images