JPH0960690A - Damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tortional damper with a structure in which the spring constant of an elastic body is variable and the natural oscillation frequency of a damper is variable and the elastic body always works as a rule. SOLUTION: A mass body 3 is connected to a hub 1 via an elastic body 2 made of elastic rubber. A moving body 5 which is made of elastic rubber and can expand in the radial direction by centrifugal force is provided on the outer periphery of the elastic body 2 via a connecting part 4 expanding in the radial direction and is disposed between the hub 1 and the mass body 3. Guides 6, 7 which allow the moving part 5 to move in the radial direction and are engaged with the moving part 5 in the tortional direction are provided on the hub 1 and the mass body 3, respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torsional damper for suppressing vibrations generated in various rotary drive systems such as a crankshaft of an automobile engine.

[0002]

2. Description of the Related Art Conventionally, there has been known a torsional damper in which a mass body is connected to a hub via an elastic body made of a rubber-like elastic material. However, in the conventional torsional damper, the spring constant of the elastic body and the Since the inertial mass of the mass body is constant for each product, the natural frequency of the torsional damper is invariable for each product. Therefore, the conventional torsional damper has a problem that the operable range is narrower than the case where the natural frequency of the torsional damper is variable. For example, a low order torsional vibration level in a high rotation range is not good. Problems can arise.

In the damper (dynamic damper) disclosed in Japanese Utility Model Publication No. 7-24678, the elastic constant of the elastic body is variable and the natural frequency of the damper is variable. When the part (second elastic body) operates only in the high rotation range, the spring constant may change extremely before and after the operation, and the subtlety of the adjustment must be overcome. There is.

[0004]

In view of the above points, the present invention has a structure in which the spring constant of the elastic body is variable and the natural frequency of the damper is variable, and in addition, the elastic body always operates in principle. The purpose is to provide a damper.

[0005]

In order to achieve the above object, the damper of the present invention is such that a mass body is connected to a hub via an elastic body made of a rubber-like elastic material, and a radial direction is provided on the outer peripheral side of the elastic body. A moving part made of a rubber-like elastic material, which is movable in the radial direction by a centrifugal force via a stretchable connecting part, is provided, the moving part is arranged between the hub and the mass body, and the hub and the mass are provided. Each of the bodies is provided with a guide portion that allows the moving portion to move in the radial direction and engages with the moving portion in a torsional direction.

[0006]

In the damper of the present invention having the above structure,
The above-mentioned "spring constant of the elastic body", which is one of the determinants of the natural frequency of the damper, is the spring constant of the elastic body in the narrow sense connecting the hub and the mass body and the connecting portion on the outer peripheral side of this elastic body. It is determined by the combination with the spring constant of the moving part made of rubber-like elastic material connected via the moving part.When the rotational speed of the rotary drive system increases and the centrifugal force increases, the moving part stretches the connecting part. While moving outward in the radial direction, the spring constant in the torsional direction of the moving part increases, and the natural frequency of the damper increases. When the rotational speed of the rotary drive system decreases from this state and the centrifugal force decreases, the moving part is pulled back to the connecting part and moves inward in the radial direction, and the spring constant in the twisting direction of the moving part decreases. The natural frequency of the damper decreases. The reason why the spring constant in the torsional direction changes due to the radial movement of the moving portion is that the torque changes (proportional to the diameter) due to the radial movement even if the lateral elastic modulus is the same.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION As described above, an element which is "expandable and contractible in the radial direction" like a rubber cord is required for the connecting portion, and the elastic member made of rubber-like elastic material is connected through this connecting portion. The moving part made of rubber-like elastic material is connected. Therefore,
When molding these, it is the most labor-saving to mold them integrally, and it is also advantageous in terms of cost.

[0008]

Embodiments of the present invention will now be described with reference to the drawings.

As shown in FIGS. 1 to 4, a pair of hub constituent parts 1a and 1b are fixed to each other by bolts and the like, and a pair of elastic body constituent parts 2a are provided between the pair of hub constituent parts 1a and 1b. , 2b and a mass body (also referred to as a vibrating ring) 3 are sandwiched between them to form a basic shape of a torsional damper in which "the mass body 3 is connected to the hub 1 via the elastic body 2". Hub component 1a,
1b is formed into an annular shape by a rigid material such as sheet metal,
The mass body 3 is formed in a ring shape by a rigid material such as cast iron, and the elastic body components 2a and 2b are formed in a ring shape by a predetermined rubber. The hub constituent parts 1a and 1b and the elastic body constituent parts 2a and 2b, and the elastic body constituent parts 2a and 2b and the mass body 3 are integrated by sandwiching, that is, they are not adhered, but the respective parts are integrated by adhesion. May be.

As well shown in FIGS. 1 and 4, a large number of connecting portions 4 each having a substantially columnar shape are formed on the outer peripheral side of each elastic component 2a, 2b so as to be integrally formed in a radial shape. Each of the connecting portions 4 and the moving portion 5 is disposed between the mutually facing surfaces of the hub components 1a and 1b and the mass body 3, and the moving portions 5 each having a substantially block shape are integrally formed at the tip of the one. ing. As shown well in FIG. 2, the guide portions 6 having a long hole shape are provided radially in the same number as the connecting portions 4 and the moving portions 5 on the facing surfaces of the respective hub components 1a and 1b. As shown, the guide portion 7 having a groove shape on the facing surface (both axial end surfaces) of the mass body 3 has the connecting portion 4
And the same number as the moving parts 5 are provided radially, and each moving part 5
Is inserted into the guide portion 6 on the hub 1 side at one end portion 5a in the axial direction and is inserted into the guide portion 7 on the side of the mass body 3 at the other end portion 5b in the axial direction.
The guide portions 7 on the side of the mass body 3 and the guide portions 7 on the side of the mass body 3 respectively form a pair, permit the radial movement of the moving portion 5, and engage with the moving portion 5 in the twisting direction. The connecting part 4 is expandable / contractible in the radial direction, the moving part 4 is movable in the radial direction by centrifugal force, and both parts 4, 5 are integrally formed with the elastic component parts 2a, 2b by a predetermined rubber. ing.

The torsional damper having the above structure is
A hub 1 composed of a pair of hub components 1a and 1b is mounted on a rotary shaft such as a crankshaft to form a kind of resonance system to suppress torsional vibration generated in the rotary drive system. Of the "spring constant of elastic body" and "inertial mass of mass body" that are the determinants of natural frequency of torsional damper, the former "spring constant of elastic body"
Is a spring constant of a pair of elastic body components 2a and 2b connecting the pair of hub components 1a and 1b and the mass body 3, and
A large number of moving parts 5 made of rubber-like elastic material, which are connected to the outer peripheral side of the pair of elastic body constituent parts 2a, 2b through a connecting part 4.
It is determined by the combination with the spring constant of. Then, when the rotation speed of the rotary drive system increases and the centrifugal force increases, the moving parts 5 move outward in the radial direction (direction of arrow A) while simultaneously extending the connecting part 4, and the moving parts 5 move. The torsional spring constant increases, and the natural frequency of the torsional damper increases. Further, when the rotational speed of the rotary drive system decreases from this state and the centrifugal force decreases, the moving parts 5 are simultaneously pulled back by the connecting part 4 and move inward in the radial direction (direction of arrow B) to move the moving parts. 5, the spring constant in the torsion direction is reduced, and the natural frequency of the torsional damper is reduced. Therefore, the natural frequency of the torsional damper can be steplessly changed by increasing / decreasing the number of rotations, and a high-performance torsional damper capable of absorbing vibration over a wide rotation range can be provided. .

Further, the moving parts 5 are always engaged with the guide part 6 on the hub 1 side and the guide part 7 on the mass body 3 side in the torsional direction regardless of the radial position thereof, and the hub 1 And when the mass body 3 is displaced in the same direction, it immediately elastically deforms,
In this sense, it always operates regardless of the number of revolutions. Therefore, unlike the prior art disclosed in the above publication, since the structure does not operate only when the rotation speed rises to a certain value, the spring constant may change extremely before and after the operation. Absent. Therefore, it is possible to provide a torsional damper whose natural frequency can be easily adjusted.

The structure of the torsional damper according to the above embodiment can be modified as follows. In the above embodiment, the elastic body 2, the connecting portion 4 and the moving portion 5 arranged in a pair in the axial direction are, as shown in FIG.
These may be arranged on only one side of the mass body 3. In this case, a bearing 8 is interposed between the hub component 1b and the mass body 3 to support the mass body 3 in a freely rotatable manner. In the above embodiment, the guide portion 6 on the side of the hub 1 which has a long hole penetrating in the axial direction may have a groove shape which does not penetrate the same as shown in FIG.

[0014]

The present invention has the following effects.

That is, in the damper of the present invention having the above-mentioned structure, the moving portion moves in the radial direction according to the increase or decrease of the rotation speed, and the spring constant changes accordingly, and the natural frequency of the damper becomes zero. Since it can be changed in stages, it is possible to provide a high-performance damper that exhibits a vibration absorbing operation over a wide rotation range, and for example, the torsional vibration level in the high rotation range can be suppressed lower than the conventional specification. . Further, since the moving part made of rubber-like elastic material is always operated regardless of the number of rotations, it is possible to provide a damper whose natural frequency can be easily adjusted.

[Brief description of drawings]

FIG. 1 is a half sectional view of a damper according to an embodiment of the present invention.

FIG. 2 is a partial side view of the damper according to the same embodiment, which is a view in the direction of arrow C in FIG.

FIG. 3 is a partial side view of a mass body according to the same embodiment.

FIG. 4 is a partial side view of an elastic body, a connecting portion, and a moving portion according to the same embodiment.

FIG. 5 is a half cutaway view of a damper according to another embodiment of the present invention.

FIG. 6 is a half sectional view of a damper according to still another embodiment of the present invention.

[Explanation of symbols]

 1 Hub 1a, 1b Hub component 2 Elastic body 2a, 2b Elastic body component 3 Mass body 4 Connecting part 5 Moving part 5a Axial one end 5b Axial other end 6,7 Guide part 8 Bearing

Claims (1)

[Claims] 1. A mass body (3) is connected to a hub (1) through an elastic body (2) made of a rubber-like elastic material, and the elastic body (2) is radially expandable and contractable on the outer peripheral side. A moving part (5) made of a rubber-like elastic material is provided which is movable in the radial direction by centrifugal force via the part (4), and the moving part (5) is provided between the hub (1) and the mass body (3). ) Are arranged to allow radial movement of the moving portion (5) to the hub (1) and the mass body (3), respectively, and a guide portion (engaged with the moving portion (5) in a torsional direction). 6) A damper provided with (7).