JP4280849B2 - Variable rigidity dynamic vibration absorber - Google Patents

Description

The present invention relates to a variable stiffness dynamic vibration absorber.

In the industry, regular patterns are gradually formed on the roll and the system in contact with the roll as the contact rotation system is operated, and it also induces severe vibration or is transferred to the product. There are many phenomena that result in defective products. For example, railroad vehicles and rails, drive rolls and bobbin holders via yarn balls of textile machinery winders, a pair of paper machine rubber rolls, automobile tires and roads, steelmaking machines, machine tools, etc. have specific patterns. It is formed. These phenomena are called pattern formation phenomena, and the mechanism of their occurrence has been elucidated and countermeasures have been studied.

In particular, in steelmaking machines, chatter marks for tension levelers and chattering during hot / cold rolling have become serious problems in product management as the accuracy of products increases. On the other hand, the roll polygonalization phenomenon of smoother rolls and gate roll size presses in the press part of the paper machine is also the main cause that hinders the improvement of the line speed.
Most of these phenomena are pattern formation phenomena that occur in a contact roll system in which the roll rotates in contact with the roll.

From the viewpoint of global research, this kind of contact rotation system pattern formation phenomenon is mainly researched on chattering of machine tools and corrugation of railway rails in Japan. The research on the pattern formation phenomenon of the contact roll system in which the roll rotates is in the developing stage. In particular, the chattering phenomenon that occurs in steelmaking machines such as hot rolling and cold rolling, the polygonal deformation phenomenon of rolls in paper machines, and the abnormal vibration in the winding process of thin strips of paper, etc., still have a clear mechanism. It has not been elucidated. Therefore, as a countermeasure in the field against the pattern formation phenomenon that occurs in such a contact roll system, only the line speed is slowed down or the rolls are replaced early, and the fundamental problem is not solved.
When this phenomenon occurs, the industry has to deal with fatal damage or set an upper limit of the line speed. Therefore, the industry is urgently required to develop a countermeasure.

However, such preventive measures have not yet been studied.
In previous studies, as measures to prevent the pattern formation phenomenon, we studied methods for reducing the instability by optimizing the roll diameter ratio and measures for delaying pattern formation that fluctuates the roll rotation speed, and proposed design guidelines. I have done it. The method by the diameter ratio optimization is effective when the paired rolls are uniformly and objectively deformed, but is not effective when one of the rolls is deformed. Moreover, since there are many cases where it is necessary to operate at a constant rotation speed, such as an iron-making machine or a papermaking machine, the types of machines that can take countermeasures are limited.
In addition, we theoretically analyzed how the pattern formation phenomenon is affected by attaching a passive dynamic vibration absorber. As a result, unlike the vibration damping effect of a dynamic vibration absorber for general self-excited vibration, there is a problem that a drastic vibration damping cannot be expected and a vibration mode to be damped appears newly.

Therefore, the present invention provides a variable stiffness type dynamic vibration absorber that solves the above-mentioned problems, and the characteristic features thereof are as follows, as shown in the drawings .
(1). Each axis (C1, C2) is located in parallel on the same orthogonal plane (H2 ) with respect to the linear vibration direction (V) of the vibrating body (1) , and the major axis (L1, L2) and minor axis are in the cross section. A pair of identical rigid long rigid bodies (3, 4) having a vibration absorbing body (2) attached to the vibrating body (1) and rotatably mounted at one end of the pair of rigid bodies (3, 4 ) ; The weight (5) rotatably mounted on the other end of the pair of rigid bodies and supported only by the rigid bodies (3, 4 ) and the pair of rigid bodies (3, 4) in a plane-symmetrical state. rotate backward consist of a rotary device for changing the composite stiffness coefficient while retaining the composite vibration direction of the pair of rigid bodies (3, 4) to the linear vibration direction of the vibrating body (V) Variable rigidity type dynamic vibration absorber.

In other words, the variable stiffness type dynamic vibration damping device of the present invention changes the combined stiffness coefficient of a pair of rigid bodies by changing the rotation angle of a rigid body having anisotropy in the stiffness coefficient in a plane-symmetric state, thereby The natural frequency on the side is made to coincide with the natural frequency of the vibrating body to stop, reduce, or delay the vibration of the vibrating body.
In terms of structure, the rigidity coefficient changing mechanism of the pair of rigid bodies can be either a manual type or an automatic type and is simple.
Furthermore, the rotation angle of a pair of rigid bodies can be adjusted symmetrically, and the natural frequency of the vibration absorption body can be adjusted to the natural vibration of the vibration body, enabling compact, wide frequency range vibration suppression, reduction, and delay control. It makes it possible.
As described below, the present invention has a number of applications to iron making machines, paper making machines, and the like, and has an extremely beneficial effect industrially. When a roll rotates like an iron-making machine or a paper-making machine, the following methods are conceivable in addition to using a vibration absorber attached to the roll bearing part.
a). A bearing such as a slide bearing can be provided in a cylindrical roll via a central shaft, and the invention of (1) can be arranged via the bearing.
b). A backup roll is attached to the roll surface, and the invention of (1) is attached to the backup roll bearing.
In these examples, the vibration damping effect can be obtained even in the vibration mode in which the amplitude of the roll bearing portion contacting the roll surface is small.
c). The invention of (1) is applied as a device for preventing rail corrugation and wheel polygonalization.
As the train repeats running, the surface of the rail and the wheels are deformed into a polygon (corrugation), and noise, a decrease in the service life of the rail, and driving safety problems occur. Corrugation is prevented by attaching a vibration absorber to the axle portion through a bearing and suppressing the vertical vibration of the wheel.
d). The invention of (1) above is applied to machine tools.
In order to suppress chatter vibration of the machine tool, a vibration absorber is mounted on the tool.
e). The invention (1) is applied to a brake squeal prevention device for automobiles.
The disc brake squeal of an automobile is self-excited vibration caused by the combination of a rotor and a pad or a rotor and a caliper. The latter, which is a particular problem, can be reliably suppressed by attaching a dynamic vibration absorber to the caliper. However, when a dynamic vibration absorber tuned by a bench test is attached to an actual vehicle, the effect is often not obtained due to the difference in chassis structure. Since this vibration absorber can be easily tuned, it is also effective in the brake squeal phenomenon of an actual vehicle. Possible mounting locations include calipers, rotor interiors (in which case a plurality are required), and hydraulic piston interiors. In addition, the former squeal is attached to the pad.
f). The invention (1) is applied to a suspension for automobiles.
By mounting this device on the suspension upper part of the automobile, it is possible to minimize the vibration to the vehicle body due to the forced vibration of the road surface.
g). In addition, the invention of (1) is applied to suppression of building vibration due to earthquakes, suppression of self-excited vibration (galloping) of electric wires, prevention of train squeal noise and the like.

In the variable stiffness type dynamic vibration damping device of the present invention, the shape of the rigid bodies is the same in pairs, and the combined vibration direction received by the weight from the pair of rigid bodies is always the same direction as the vibration direction of the vibrator and rotates. The cross-sectional shape has a long axis and a short axis such as a rectangle and an ellipse in which the combined stiffness coefficient continuously changes by changing the plane symmetry state of the corners.
In addition, as the rigidity coefficient changing mechanism of the rigid body, a single or shared rigid body rotating device is used. For example, in the example of the gear type rotation device as introduced in the embodiments described later, the pair of rigid bodies and the vibration absorbing body or the weight are respectively connected so that the pair of rigid bodies rotate in the plane of symmetry simultaneously with the directions of rotation reversed. A gear of the same size is provided in the rotation mounting portion and meshed with each other at a reference position where the cross-sectional major axis of each rigid body is parallel to the vibration direction, and one of the gears is meshed with the drive gear mechanism of the rotation adjustment motor. Things are simple.
Next, modifications of the present invention will be listed.
(I). The variable stiffness type dynamic vibration damping device in which a plurality of pairs of rigid bodies are provided and the stiffness coefficient between the pairs is changed.
For example, two pairs are provided for rough frequency adjustment, and the other two pairs are provided for fine frequency adjustment.
(B). The variable stiffness type dynamic vibration damping device in which a viscous fluid is sealed in the weight so that the damping effect can be controlled.
(C). The variable stiffness type dynamic vibration absorber, wherein the vibration absorbing body is mounted on a vibrating body so as to be three-dimensionally rotatable, and the vibration absorbing body is rotated in a direction corresponding to vibration of an external force.
(D). The variable rigidity type dynamic vibration absorber capable of moving a tuning range by inserting an elastic rod between the weight and the vibration absorbing body.
(E). A control method of the natural frequency of the vibration absorbing body that performs tuning based not only on the amplitude of the vibrating body but also on the phase difference between the vibration of the vibrating body and the weight.
(F). Hybrid variable stiffness dynamic vibration absorber.
By connecting multiple pairs of rigid bodies and weights in parallel or in series, and expanding the vibration absorber from a single-degree-of-freedom vibration system to a multi-degree-of-freedom vibration system, multiple vibration frequencies can be simultaneously controlled by a single vibration absorber. Hybrid type variable stiffness type dynamic vibration absorber.
(G). A variable stiffness type dynamic vibration absorber in which a rigid body rotating motor of a stiffness coefficient changing mechanism is miniaturized in place of the weight portion.
(H). A variable-rigidity dynamic vibration absorber that can control both viscosity and rigidity by using MR fluid or the like in the vibration absorber body or the operating part of the stiffness coefficient changing mechanism.

Next, an embodiment (specific example) of the present invention (1) will be described with reference to FIGS.
FIG. 1 is an explanatory view showing an embodiment of the device of the present invention, and is a plan sectional view taken along line AA in FIG. FIG. 2 is a side cross-sectional view from the arrow BB in FIG. FIG. 3 is a front view from the arrow CC of FIG.
1 to 3, a vibration absorbing body 2 is attached to the vibration body 1, and one end of a pair of leaf springs (long rigid bodies) 3 and 4 having the same rigidity coefficient is rotatably attached to the vibration absorption body 2, A spring stiffness coefficient changing mechanism 6 is attached, and the other ends of the leaf springs 3 and 4 are rotatably attached to the weight 5.
The lower surface of the vibration absorbing body 2 is attached to the vibrating body 1 as a plane H1 orthogonal to the vibration direction V of the vibrating body 1.
The leaf springs 3 and 4 have the same rectangular shape (a kind of rectangle) as shown in FIG. 3, and their axial centers C 1 and C 2 are parallel to the orthogonal plane H 1 with respect to the vibration direction V of the vibrating body 1. is located in parallel relationship to Do orthogonal plane H2, also match parallel to the vibration direction V the sectional major axis L1, L2 at the reference position.
The one end of the leaf springs 3 and 4 and the vibration absorbing body 2 are mounted by forming one end of the leaf springs 3 and 4 on the rotating shafts 3a and 4a and providing the bearing body 2a and 2b on the vibration absorbing body 2 with the bearing type. The rotary shafts 3a and 4a are mounted on the bearings 2a and 2b, and the other ends of the leaf springs 3 and 4 and the weight 5 are attached to the other ends of the leaf springs 3 and 4 with the rotation shafts 3b and 4b. The bearing 5 is provided with bearings 5a and 5b, and the bearings 5a and 5b are provided with rotating shafts 3b and 4b.
The leaf spring stiffness coefficient changing mechanism 6 fixes gears 6a and 6b of the same size to the rotating shafts 3a and 4a of the leaf springs 3 and 4 at the reference position, and meshes them with each other to rotate the gears. Then, the rotation angle of the pair of leaf springs 3 and 4 is continuously changed symmetrically in the range of 0 to 90 degrees of the reference position, and the pair of leaf springs is made into a C shape or an inverted C shape, and the combined rigidity coefficient is obtained. It is possible to change the natural frequency of the entire device by changing the descent, and the rotation drive of this gear is enabled by engaging the drive gear mechanism 6c of the servo motor 6g for rotation adjustment with one of them, and the servo for rotation adjustment The motor 6g is provided with a controller 6f that controls the rotational operation to a leaf spring rotation angle that matches the vibration frequency detectors 6d and 6e of the vibration body 1 and the vibration absorbing body 2 based on the detected vibration frequencies.

The variable stiffness type dynamic vibration damping device of the present invention can easily reduce the vibration of the vibration body by making the natural frequency on the vibration damping device side coincide with the natural frequency of the vibration body, such as up and down or rotation, by the above-described compact configuration. It can be stopped or reduced or delayed, and can be widely applied to many vibrators introduced in the above-mentioned effects, and this industrial applicability is extremely high.

It is explanatory drawing which shows one Example of this invention apparatus (1), and is a plane sectional view from arrow AA-AA of FIG. 2, and arrow AA of FIG. The sectional side view from arrow BB-BB of FIG. 1 and arrow BB of FIG. The front view from arrow CC-CC of FIG. 1 and arrow CC of FIG.

Explanation of symbols

1 Vibrating body 2 Vibration absorbing body 3, 4 Rigid body 5 Weight
3a, 4a rotation axis
2a, 2b Bearing bearing
5a, 5b Bearing bearing 6 Rigidity coefficient changing mechanism
6a, 6b gear
6c Drive gear mechanism
6f controller
6g Servo motor for rotation adjustment

Claims (1)

Each axis (C1, C2) is located in parallel on the same orthogonal plane (H2 ) with respect to the linear vibration direction (V) of the vibrating body (1) , and the major axis (L1, L2) and minor axis are in the cross section. A pair of identical rigid long rigid bodies (3, 4) having a vibration absorbing body (2) attached to the vibrating body (1) and rotatably mounted at one end of the pair of rigid bodies (3, 4 ) ; The weight (5) rotatably mounted on the other end of the pair of rigid bodies and supported only by the rigid bodies (3, 4 ) and the pair of rigid bodies (3, 4) in a plane-symmetrical state. rotate backward consist of a rotary device for changing the composite stiffness coefficient while retaining the composite vibration direction of the pair of rigid bodies (3, 4) to the linear vibration direction of the vibrating body (V) Variable rigidity type dynamic vibration absorber.

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