JPH06300117A - Dual type damper pulley - Google Patents

Abstract

PURPOSE:To increase the durability of a second elastic body by reducing the axial length of an inner damper mass and increasing its size in radial direction to form a sufficiently large mass so as to suppress oscillating motion. CONSTITUTION:A cylindrical outer damper mass 7 on the periphery which a power transmission belt is wound concentrically with a cylindrical part 3 is installed through a first elastic body 6 on the radial outer side of the cylindrical part 3 of a pulley main body 5 comprising a boss 2 installed on a rotating shaft, a cylindrical part 3 positioned at radial outer side of the boss 2, and a connection part 4 for connecting the cylinder part 3 to the boss 2. The end of the outer damper mass 7 on the boss 2 side is extended to the boss 2 side to form a space 9 with the boss 2 and the connection part 4, and the inner damper mass 10 is arranged so that the outer periphery edge of the cylindrical part 3 is positioned on the radial outer side and it is at least partly within the space 9. Then a second elastic body 11 is stuck on the end surface of the cylindrical part 3 on the boss 2 side, and the inner damper mass 10 is stuck on the opposite side of the second elastic body 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dual type dynamic damper pulley, and in particular, it is attached to a rotary shaft such as a crankshaft of an internal combustion engine and is rotated integrally with the rotary shaft so that it is wound around the outer peripheral surface. A damper mechanism that transmits a rotational driving force to a predetermined succeeding member via a power transmission belt, and that absorbs the vibration of the rotating shaft and reduces the vibration and noise of the rotating shaft and the engine. And a dual type damper pulley.

[0002]

2. Description of the Related Art As a conventional dual type damper pulley, the one described in Japanese Utility Model Laid-Open No. 62-68053 is known. As shown in FIG. 4, this includes a boss 2 to which a rotary shaft 1 such as a crankshaft is attached, a cylindrical cylindrical portion 3 located outside of the boss 2 in the radial direction, and the cylindrical portion 3 and the boss 2. A pulley body 5 is constituted by the connecting portion 4 to be connected. An outer damper mass 7 is concentrically arranged on the outer side of the cylindrical portion 3 in the radial direction via a first elastic body 6, and a power transmission belt is wound around the outer peripheral surface. Further, it is located inside the cylindrical portion 3 and the connecting portion 4
The inner damper mass 10 through the second elastic body 100.
1 is attached. Set bolt 102 for rotating shaft 1
The leg portion 104 extending from the flange portion 103 is screwed in to fix the rotary shaft 1 to the boss 2. Set bolt 1
A stopper metal fitting 106 is attached to an end surface of the head portion 105 of No. 02 in the direction perpendicular to the axis with a mounting bolt 107. The inner damper mass 101 housed in the cylindrical portion 3 is connected to the connecting portion 4
Two through holes 108 extending in the axial direction are provided in the cylindrical wall portion corresponding to the two holding holes 4A located on the diameter of the connecting portion 4 among the four holding holes 4A provided in the. .

[0003]

In the conventional damper pulley, since the inner damper mass 101 is attached inside the cylindrical portion 3 and to the connecting portion 4 via the second elastic body 100, the diameter of the inner damper mass 101 is reduced. There was a limit to how large. Since the conventional inner damper mass 101 whose diameter is regulated by the inner diameter of the cylindrical portion 3 requires a constant mass, it is necessary to make the length in the axial direction a certain length or more. The direction length had to be almost full. Therefore, the inner damper mass 101 has a structure similar to that of a cantilever, and the swinging motion of the tip becomes large, which may cause the second elastic body 100 to crack and come off. Also, inner damper mass 1
01, the second elastic body 100, and the fixing jig holes 108 and 4A for inserting and removing the damper that penetrate the connecting portion 4, local stress concentration occurs on the second elastic body 100, and the durability of the second elastic body 100 is improved. It had the drawback of getting worse.

Therefore, according to the present invention, the axial length of the inner damper mass is shortened and the radial size is increased to obtain a sufficiently large mass, and the swinging motion is suppressed to improve the durability of the second elastic body. An object of the present invention is to provide a dual damper pulley that is improved and prevents the inner damper mass from peeling off from the second elastic body.

[0005]

In order to achieve the above object, the present invention provides a boss attached to a rotary shaft, a cylindrical cylindrical portion located radially outside of the boss, and the cylindrical portion and the boss. An outer damper mass, which is cylindrical and has a power transmission belt wound around an outer peripheral surface thereof via a first elastic body, is concentrically arranged with the cylindrical portion on the outer side in the radial direction of the cylindrical portion of the pulley body including a connecting portion connecting Attaching, extending the boss side end surface of the outer damper mass to the boss side to form a space with the boss and the connecting portion, and existing at least partially in the space so that the outer peripheral edge is located radially outside the cylindrical portion. Thus, the inner damper mass is arranged so that the second elastic body is adhered to the end surface of the cylindrical portion on the boss side, and the inner damper mass is adhered to the opposite side of the second elastic body.

[0006]

The outer diameter of the inner damper mass according to the present invention is larger than the outer diameter of the cylindrical portion, and the mass can be sufficiently large without increasing the length in the axial direction. Also,
Since the length in the axial direction is not long, the swinging motion is suppressed, and the durability of the second elastic body for attaching the inner damper mass to the end surface of the cylindrical portion is also improved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

In the embodiment shown in FIG. 1, a boss 2 to which a rotary shaft 1 such as a crankshaft similar to that shown in FIG. 4 is mounted.
And a cylindrical portion 3 located on the outer side in the radial direction of the boss 2, and a connecting portion 4 connecting the cylindrical portion 3 and the boss 2 to the outer side in the radial direction of the cylindrical portion 3 of the pulley body 5. The damper mass 7 is attached via the first elastic body 6. The first elastic body 6 is a gap between the outer damper mass 7 and a metal sleeve 8 that is concentrically arranged inside the outer damper mass 7 with a predetermined distance therebetween and has a thin cylindrical shape whose length is substantially the same as that of the outer damper mass 7. Inside, they are vulcanized and molded integrally with them. By press-fitting and fixing the metal sleeve 8 on the outer peripheral surface of the cylindrical portion 3,
The outer damper mass 7 is integrally connected to the pulley body 5. A power transmission belt (not shown) is wound around the outer peripheral surface of the outer damper mass 7.

An end surface of the outer damper mass 7 on the boss 2 side extends to the boss 2 side, and a space 9 is formed by the boss 2 and the connecting portion 4. The inner damper mass 10 is arranged so as to exist at least partially in the space 9 and have an outer peripheral edge located radially outside the cylindrical portion 3. The second elastic body 11 is adhered to the end surface of the cylindrical portion 3 on the boss 2 side, and the inner damper mass 10 is adhered to the opposite side of the second elastic body 11.

A portion 7A indicates a portion of the outer damper mass 7 extending toward the boss 2 side in the axial direction of the cylindrical portion 3.
A taper portion 7B is formed on the inner surface side of the extending portion 7A so as to widen toward the tip side. Due to the presence of the tapered portion 7B, the inner damper mass 10 can be made larger in the radial direction.

FIG. 2 shows the inner damper mass 10,
When the radial length is R and the axial length is W,
Since R> W and the diameter can be made large, the mass can be made relatively large. In addition, the length W can be reduced, the bending input due to cantilever can be suppressed, and the swinging motion can be further reduced. Further, since the inner damper mass 10 having such a shape is attached to the end surface of the cylindrical portion 3 via the second elastic body 11, the adhesion area with the second elastic body 11 becomes large and the inner damper mass 10 may be peeled off. Less. Further, since the rotating shaft 1 to be attached to the hub 2 can be attached with equipment such as engine equipment on the right side in FIG. 1, it is not necessary to provide a stopper metal fitting as in the prior art. That is, the rotating shaft 1
The devices attached to will function as stopper fittings.

FIG. 3 is a front view of FIG. 1, in which a fixing jig hole 12 for attaching and detaching the damper is formed on the end face side of the cylindrical portion 3, and auxiliary holes 13 are formed on both sides of the hole 12. is there.
The auxiliary hole 13 is for attaching a pulley used when it is necessary to attach the pulley. Also, these holes 12,
The wall thickness of the cylindrical portion 3 where 13 is formed is made thicker, and the other portions are made thinner to suppress the increase in the weight of the cylindrical portion 3.

[0013]

As described above, according to the present invention, the boss side end surface of the outer damper mass is extended to the boss side to form a space between the boss and the connecting portion, and the outer side is radially outward of the cylindrical portion. The inner damper mass is arranged so that the peripheral edge is located and at least partially exists in the space, the second elastic body is bonded to the end surface of the cylindrical portion on the boss side, and the opposite side of the second elastic body is arranged. Since the inner damper mass is bonded to the inner damper mass, the inner damper mass can have a large radial length, and the mass can be relatively large even if the axial length is shortened. Also, since the length in the axial direction can be shortened, the swinging motion due to cantilever can be suppressed,
Moreover, unlike the conventional case, a holding hole and a through hole that cause local stress concentration in the second elastic body are not required, and the durability of the second elastic body can be improved. Furthermore, since the inner damper mass can be lengthened in the radial direction, the adhesive area with the second elastic body also increases. Furthermore, since the inner damper mass is arranged on the boss side, the devices attached to the rotary shaft serve as stopper fittings, and it is not necessary to provide special stopper fittings, and the structure is simple.

[Brief description of drawings]

FIG. 1 is a sectional view showing a preferred embodiment of the present invention.

FIG. 2 is a partially cutaway perspective view of an inner damper mass.

FIG. 3 is a front view of FIG.

FIG. 4 is a sectional view showing a conventional example.

[Explanation of symbols]

 1 Rotating Shaft 2 Boss 3 Cylindrical Part 4 Connecting Part 5 Pulley Main Body 6 First Elastic Body 7 Outer Damper Mass 7A Extending Part 9 Space 10 Inner Damper Mass 11 Second Elastic Body

Claims (1)

[Claims] 1. A radius of the cylindrical portion of a pulley body, which comprises a boss attached to a rotating shaft, a cylindrical cylindrical portion located radially outside the boss, and a connecting portion connecting the cylindrical portion and the boss. The outer damper mass, which is cylindrical and has a power transmission belt wound around the outer peripheral surface through the first elastic body, is attached concentrically with the cylindrical portion, and the boss side end surface of the outer damper mass is extended to the boss side. A space is formed by the boss and the connecting portion, and the inner damper mass is arranged so that the outer peripheral edge is located on the outer side in the radial direction of the cylindrical portion and at least partially exists in the space. A dual type damper pulley characterized in that a second elastic body is adhered to an end face and an inner damper mass is adhered to the opposite side of the second elastic body.