JPH0650386A - Dynamic damper and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a dynamic damper which requires a small number of manufacturing processes and has excellent durability for the large displacement quantity in resonance. CONSTITUTION:A dynamic damper is equipped with a mass body 10 having a cut part 11 at one place in the circumferential direction, elastomer member 20 which is attached on the inner peripheral surface of the mass body 10 and has a vacant part 21 corresponding to the cut part 11 and the axial press- attached surface of the inside diameter, and a screw member 30 which connects and tightens the edge parts 12 and 13 on both the sides of the cut part 11, and the elastomer member 20 is integrally subjected to vulcanization-molding on the inner peripheral surface of the mass body 10 having the edge parts 12 and 13 tightened by the screw member 30.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dynamic damper which absorbs vibration generated on a rotary shaft such as a drive shaft of an automobile by a resonance action and a method for manufacturing the same.

[0002]

2. Description of the Related Art As a typical conventional example of this type of dynamic damper, as shown in FIG. 4, for example, a fixed ring 1 fixed on the outer peripheral surface of a rotary shaft 4 and a concentric ring on the outer peripheral surface of the fixed ring 1 are provided. Annular mass member 2 having a larger diameter than that of the outer peripheral surface of the fixed ring 1, and an annular elastomer member sandwiched between the opposed peripheral surfaces of the fixed ring 1 and the annular mass body 2. Three
It consists of and. This dynamic damper basically matches the mass of the annular mass body 2 and the natural frequency determined by the spring constant of the elastomer member 3 with the vibration generated on the rotating shaft 4 during driving, so that the annular mass body 2 The vibration energy of the rotating shaft 4 can be effectively absorbed by the resonance action of the resonance system including the elastomer member 3.

[0003]

In the dynamic damper of the above-mentioned conventional structure, the elastomer member 3 is integrally vulcanized and molded between the opposed peripheral surfaces of the fixed ring 1 and the annular mass body 2 in the mold, or separately. It is manufactured by press-fitting an annular vulcanization-molded elastomer member 3 as a body between the opposed peripheral surfaces. However, in the former manufacturing method, tensile stress due to molding contraction is likely to occur in the elastomer member 3 molded between the fixed ring 1 and the annular mass body 2, so that there is a problem in the strength when the displacement becomes large due to resonance. In the latter manufacturing method, the number of steps is large, and most of the adhesive applied to the inner peripheral surface and the outer peripheral surface of the elastomer member 3 in advance is press-fitted between the fixed ring 1 and the inertial mass body 2. At this time, it is scraped off, and thus also in this case, there is a problem that peeling is likely to occur at the adhesive portion when the displacement becomes large due to resonance.

The present invention has been made under the above circumstances, and its main purpose is to obtain a dynamic damper which has a small number of manufacturing steps and is excellent in durability against a large displacement amount at the time of resonance. is there.

[0005]

The above-mentioned technical problems are as follows.
The present invention can effectively solve the problem. That is, the dynamic damper according to the present invention includes a mass body having an original C-shape having a cut portion at one position in the circumferential direction, and a cavity portion and an inner diameter shaft which are adhered to the inner peripheral surface of the mass body and correspond to the cut portion. An elastomer member having a crimping surface and a screw member for connecting and tightening both end portions of the cut portion are provided. Further, in order to obtain the dynamic damper having the above-described structure, the manufacturing method of the present invention forms a substantially C-shaped mass body having a cut portion at one location in the circumferential direction and having a gap between the end portions on both sides thereof, An elastomer member is integrally vulcanized and molded, in which the ends on both sides are fastened together by screwing them together, and the inner peripheral surface of the mass body in the tightened state has a cavity portion corresponding to the cutting portion and an axial crimping surface with an inner diameter. Including the step of

[0006]

In the dynamic damper of the present invention, the elastomer member has both a function as a spring member of the resonance system and a function as a fixing means to the rotating shaft, and the rotating shaft is inserted into the inner diameter of the elastomer member. Then, by screwing a screw member over both ends of the cut portion of the mass body and tightening the both ends, the inner peripheral surface of the mass body and the outer circumference of the rotating shaft are appropriately reduced in diameter. A required compressive stress is applied to the elastomer member between the surface and the surface, and the shaft crimping surface of the inner diameter is crimped and fixed to the outer peripheral surface of the rotating shaft. The cavity of the elastomer member prevents concentration of compressive stress near the inner diameter side due to tightening the cut portion of the mass body.

In this dynamic damper, the end portions on both sides of the cut portion of the mass body are fastened to each other by a screw member, and the hollow portion corresponding to the cut portion is axially pressure-bonded to the inner peripheral surface of the mass body. Since the elastomer member having the surface is integrally vulcanized and molded, when the screw member is removed and the mass body is returned to the original shape of the substantially C-shape after molding, the cavity is opened accordingly. Non-uniform internal stress is generated in the deformed elastomer member in the circumferential direction, but this stress is generated by tightening the mass body in an annular shape again with the screw member when the dynamic damper is attached to the rotating shaft. Since this is eliminated, the stress applied to the elastomer member between the rotating shaft and the mass body becomes uniform in the circumferential direction.

[0008]

1 to 3 show a typical embodiment of a dynamic damper according to the present invention. In each drawing, reference numeral 10 is a mass body made of a metal material. As shown in FIG. 3, the mass body 10 has an original shape of a substantially C shape, that is, a cut portion 11 is formed at one location in the circumferential direction, and the end portions 12 and 13 on both sides of the cut portion 11 are formed. There is a narrow gap δ between them. A screw member insertion hole 14 extending in a direction perpendicular to the cutting surface 12a is formed in one end 12 of the cutting portion 11, and the other end 13 is formed in the other end 13.
A female screw portion 15 is provided which extends in a direction perpendicular to the cut surface 13a and extends concentrically with the screw member insertion hole 14. A seating surface 14a is formed stepwise in the screw member insertion hole 14.

Reference numeral 20 is an elastomer member integrally bonded to the inner peripheral surface 10a of the mass body 10. The elastomer member 20 has a hollow portion 21 formed at a position corresponding to the cut portion 11 of the mass body 10, and has an inner diameter at which the rotary shaft 4 is provided.
Shaft crimping surface 2 for crimping with an outer peripheral surface of 0 and an appropriate tightening margin
2 is formed.

Reference numeral 30 is a screw member composed of a screw shaft 31 and a head portion 32 having a diameter larger than that of the screw shaft 31. In the screw member 30, the screw shaft 31 is passed through the screw member insertion hole 14 in the one end 12 of the mass body 10 to the other end 1.
3 is screwed into the female screw portion 15 and the head portion 32 is pressed against the seat surface 14a of the screw member insertion hole 14 to connect the both end portions 12 and 13 to each other in a tightened state.

In the dynamic damper described above, first, for example, a metal annular body is cut at one position in the circumferential direction, and the cut portion 1 is cut.
The mass member 10 is manufactured by forming the screw member insertion hole 14 and the female screw portion 15 at both end portions 12 and 13 of the first member 1. The mass member 10 of which the original shape is substantially C-shaped is formed into an annular shape by coupling and tightening with a screw member 30 screwed in, and an elastomer member is formed on the inner peripheral surface of the mass member 10 in a mold (not shown). It is manufactured through a process of integrally vulcanizing 20.

When mounting the dynamic damper, the screw member 30 is loosened to return the mass body 10 to the original C-shape, the rotary shaft 40 is inserted into the inner diameter of the elastomer member 20, and then the screw member 30 is again inserted. The mass body 10 is clamped in an annular shape so that the both end portions 12 and 13 abut each other. As a result, this mass body 1 is appropriately reduced in diameter.
The elastomer member 20 is appropriately compressed between the inner peripheral surface of 0 and the outer peripheral surface of the rotary shaft 40, and the shaft crimping surface 22 having the inner diameter thereof is crimped to the outer peripheral surface of the rotary shaft 40. Here, assuming a case where the elastomer member 20 is formed in a simple annular shape, in this case, as the clearance δ of the cut portion 11 is reduced by tightening the screw member 30, the elastomer member on the inner diameter side thereof is reduced. Excessive compressive stress is concentrated on a part of the elastic member 20. However, in the illustrated dynamic damper, since the elastomer member 20 has the cavity 21 corresponding to the cut portion 11, the dynamic damper is Partial stress concentration does not occur.

As described above, in this dynamic damper, the elastomer member 20 is formed by clamping the mass body 10 in an annular shape.
Is returned to its original C-shape, the elastomer member 20
Is deformed to cause distortion, but when the mass body 10 is tightened and deformed into an annular shape, the elastomer member 20 is returned to the original shape at the time of molding, and the distortion is eliminated. Therefore,
When the mass body 10 is attached to the rotating shaft 40 by tightening it in an annular shape, the strain cannot occur, and the mass body 10 and the rotating shaft 4 are attached to the elastomer member 20.
Internal stress due to compression between 0 and 0 is uniformly applied in the circumferential direction.

Further, according to the above-mentioned structure, the elastomer member 20 has both the function as the spring member of the resonance system and the function as the fixing means to the rotating shaft. The fixing member to the shaft becomes unnecessary, and the manufacturing is performed by manufacturing the mass body 10 and molding the elastomer member 20 on the inner peripheral surface thereof, so that the number of steps can be reduced. Moreover, this dynamic damper is provided with the screw member 3 at one place.
It can be mounted on the rotary shaft 40 only by tightening 0, and the imbalance (non-concentricity) of the mounted state can be suppressed to a small level. At the same time, appropriate compression stress is applied to the elastomer member 20. Therefore, the strength of the elastomer member 20 at the time of large displacement due to resonance with the vibration of the rotating shaft 40 can be increased.

[0015]

According to the present invention, the following effects can be obtained. (1) Since the elastomer member has both a function as a spring member of the resonance system and a function as a fixing means to the rotating shaft, the number of parts and the number of manufacturing steps can be reduced. (2) By inserting the rotating shaft into the inner diameter of the elastomer member and tightening the screw member, the mounting on the rotating shaft is facilitated. (3) Since the required compressive stress is applied to the elastomer member at the same time as it is mounted on the rotating shaft, the strength of the elastomer member at the time of large displacement due to resonance movement is improved. (4) The elastomer member is compressed when mounted. Since the stress is uniformly applied in the circumferential direction, the imbalance of the mounted state and the progress or deterioration of partial permanent strain do not occur.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a dynamic damper according to an embodiment of the present invention in a mounted state, taken along a plane orthogonal to an axis shown together with a rotary shaft.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a cross-sectional view taken along a plane orthogonal to the axial center, showing a state in which a screw member is removed in the above embodiment.

FIG. 4 is a cross-sectional view of a mounted state of a dynamic damper according to a conventional example, which is taken along a plane passing through an axial center shown together with a rotating shaft.

[Explanation of symbols]

 10 mass body 11 cutting part 12, 13 end part 12a, 13a cutting surface 14 screw member insertion hole 14a seat surface 15 female screw part 20 elastomer member 21 cavity part 22 shaft crimping surface 30 screw member 31 screw shaft 32 head 40 rotating shaft δ gap

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B29K 105: 24

Claims (2)

[Claims] 1. A mass body 10 having a substantially C-shaped original shape having a cutting portion 11 at one location in the circumferential direction, a cavity portion 21 adhered to the inner peripheral surface of the mass body 10 and corresponding to the cutting portion 11, and a shaft having an inner diameter. A dynamic damper comprising: an elastomer member 20 having a crimping surface 22; and a screw member 30 for connecting and tightening both ends 12 and 13 of the cutting portion 11 to each other. 2. A step of obtaining a substantially C-shaped mass body 10 having a cut portion 11 at one position in the circumferential direction and having a gap δ between the end portions 12 and 13 on both sides thereof; A step of connecting 13 with a screw member 30 and tightening each other; and an elastomer member 20 having a cavity portion 21 corresponding to the cutting portion 11 and an axial crimping surface 22 having an inner diameter on the inner peripheral surface of the mass body 10 in the tightened state. And a step of integrally vulcanizing and molding, and a method for manufacturing a dynamic damper.