JPH06331006A - Damper pulley - Google Patents

Abstract

PURPOSE:To prevent a damper mass from abutting on the web part of a second damper mass, and hold a relative position to a constant level at all times in relation to the cylindrical part of the second damper mass. CONSTITUTION:In a pulley main body 1 having a boss part 2 installed on a rotary output shaft and having the cylindrical part 4 connected to the boss part 2 through a web part 3, a first damper mass 6 is installed through a first elastic body 5 on the outer circumferential side of a cylinder part 4, and also a cylindrical member 10 in which a second damper mass 8 is installed through a second elastic body 9 is pressure-fitted and fixed on the inner circumferential side of the cylindrical part 4. In the cylindrical member 10, the end surface of the second damper mass 8 formed in a cylindrical shape as a whole is fixed through the second elastic body 9 on an inner direction flange 11 positioned on an end part apart from the web part 3 or an end wall, and also the end rim of the web part side of the cylindrical member 10 is positioned by projecting from the end rim same as the second damper mass 8, and a small diameter step part 12 for specifying the press-in margin of the cylindrical member 10 is provided on the pulley main body 1 side.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is of a dual type which is mounted on a rotary output shaft, for example, a crankshaft of an engine, and effectively absorbs both the vibration in the twisting direction and the vibration in the bending direction of the crankshaft. It relates to a damper pulley.

[0001]

2. Description of the Related Art A conventional damper pulley of this type is disclosed in, for example, Japanese Utility Model Publication No. 62-93455. This is because, with respect to the pulley body in which the cylindrical portion is integrated with the boss portion via the web portion, the first damper mass is directly or indirectly provided on the outer peripheral side of the cylindrical portion via the first elastic body. When the tubular member having the second damper mass attached thereto is press-fitted and fixed to the inner peripheral side of the cylindrical portion, the end of the tubular member separated from the web portion is attached. The end face of the second damper mass having a cylindrical shape is fixed to the inward flange located in the portion through the second elastic body, and the end of the second damper mass on the web side is fixed to the tubular member. It is located so as to be pushed out from the same edge of.

According to this, the vibration of the crankshaft of the engine in the twisting direction is mainly caused by the rotational displacement of the first damper mass due to the deformation of the first elastic body, and the bending of the crankshaft. The vibration in the direction can be absorbed mainly by the displacement of the second damper mass in the direction orthogonal to its axis, which is mainly due to the deformation of the second elastic body.

[0003]

However, in the prior art, there is provided any means for specifying the press-fitting margin of the cylindrical member to which the second damper mass is attached to the cylindrical portion. Therefore, the second damper mass protruding from the open end of the tubular member to the web portion side is not attached when the tubular member is assembled, or
In addition to the problem that the second damper mass comes into contact with the web portion when it acts, the mounting position of the tubular member with respect to the cylindrical portion varies, and the bending vibration absorption characteristic of the second damper mass is reduced. There was a problem that it was not constant.

The present invention has been made as a result of studies to solve such problems of the prior art, and an object of the present invention is to attach the second damper mass to the pulley body web portion. It is an object of the present invention to provide a damper pulley capable of sufficiently preventing contact and, at the same time, making the vibration absorption characteristics of the second damper mass always constant.

[0005]

SUMMARY OF THE INVENTION A damper pulley according to the present invention comprises a boss portion attached to a rotary output shaft, and a pulley body having a cylindrical portion connected to the boss portion via a web portion. A cylindrical member in which a first damper mass is mounted on the outer peripheral side of the first elastic body via a first elastic body, and a second damper mass is mounted on the inner peripheral side of the cylindrical portion via a second elastic body. Where the end face of the second damper mass, which is generally cylindrical, is attached to the inward flange or end wall of the tubular member, which is located at the end portion away from the web portion, when the second elastic body is attached to the second elastic body. And the end of the tubular member on the web side is pushed out from the same end of the second damper mass and the press-fitting margin of the tubular member is specified on the pulley body side. Provide positioning means Those were.

[0006]

In this damper pulley, the vibration of the rotation output shaft in the twisting direction is mainly due to the shear deformation of the first elastic body in the circumferential direction of the cylindrical portion, and the first damper mass is the cylindrical body of the pulley body. By pivotally displacing with respect to the part,
The vibration of the rotary output shaft in the bending direction is displaced mainly in the direction in which the second damper mass intersects with the axis of the second elastic body based on the shear deformation of the inward flange or the end wall of the tubular portion. Each of them will be effectively absorbed.

Here, the second damper mass fixed to the inward flange or end wall of the tubular member by the second elastic member is lowered by a predetermined distance from the edge of the tubular member on the web side. Since the second damper mass is positioned, the second damper mass is reliably prevented from coming into contact with the web section regardless of how the cylindrical member is assembled to the cylindrical section, so that the second damper mass can always vibrate properly. Can be secured.

Further, here, the press-fitting margin of the cylindrical member into the cylindrical portion is specified by the positioning means provided in the cylindrical portion or the like, so that the cylindrical member, and by extension, the second damper fixed thereto. The relative position of the mass in the lengthwise direction with respect to the inner cylindrical portion can be made constant at all times, and as a result, the vibration absorption characteristics of the second damper mass can be made steady for any damper pulley. be able to.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of the present invention.
In the figure, reference numeral 1 denotes a pulley main body, and this pulley main body 1 has a boss portion 2 fitted and fixed to a rotation output shaft (not shown), and a cylinder integrally connected to the boss portion 2 via a web portion 3. It has a part 4, the cylindrical part 4 of which is
The boss portion 2 is located slightly offset to one side in the axial direction.

On the outer peripheral side of the cylindrical portion 4 of such a pulley body 1, a first damper mass having a belt groove is provided via a first elastic body 5 which can be rubber or a rubber-like elastic body. Install 6. Here, the first elastic body 5
Can be directly fixed to both the first damper mass 6 and the cylindrical portion 4 by vulcanization adhesion or the like, but in the drawing, the first elastic body 5 is 1 inner peripheral surface of the damper mass 6 and the thin-walled tubular member 7
Then, the first elastic body 5 is indirectly attached to the cylindrical portion 4 by caulking and fixing the thin-walled tubular member 7 to the cylindrical portion 4. The structure of the vulcanizing mold used for vulcanizing and bonding the elastic body 5 can be made extremely simple.

Further, on the inner peripheral side of the cylindrical portion 4, a second damper mass 8 having a cylindrical shape as a whole is fixed by press-fitting a cylindrical member 10 attached via a second elastic body 9. To do. Here, this attachment of the second damper mass 8 is performed by mounting the end face of the damper mass 8 with the second elastic body 9 on the inner surface of the inward flange 11 provided in one end portion of the tubular member 10. Under this mounting state, the end of the tubular member 10 on the side opposite to the inward flange 11 is pushed out by a required length from the end of the damper mass 8 on the same side. Let

[0012] According to this, the second damper mass 8 is fixed in a state where the tubular member 10 is press-fitted and fixed, as shown by an imaginary line in the drawing.
Can be reliably prevented from coming into contact with the web portion 3.

Further, here, a small-diameter step portion 12 as a positioning means is provided on the inner peripheral surface of the tubular portion 4 for specifying the press-fitting end position of the tubular member 10. This small-diameter stepped portion 12 limits the approach of the tubular member 10 to the web portion 3 thereby, so that the press-fitting position of the tubular member 10 into the cylindrical portion 4 is always made constant, and the second damper is provided. The relative position of the mass 8 in the lengthwise direction of the cylindrical portion 4 may be as it is initialized.

According to the damper pulley constructed as described above, in particular, the edge of the tubular member 10 on the opening side is
By locating the second damper mass 8 so as to protrude from the edge of the second damper mass 8, the second damper mass 8 can be sufficiently prevented from contacting the web portion 3, and the small-diameter step portion 12 is provided. Under the action of, the press-fitting margin of the cylindrical member 10 into the cylindrical portion 4 is always made constant, and the relative position of the second damper mass 8 to the cylindrical portion 4 can be set to a fixed position as expected. it can.

FIG. 2 is a cross-sectional view showing another embodiment of the present invention. In this example, the positioning means for specifying the press-fitting end position of the tubular member 10 is the web portion itself. According to the example, in addition to the above, there is an advantage that special processing for the positioning means is unnecessary.

[0016]

As described above, according to the present invention, the contact of the second damper mass with the web portion can be prevented, and the second damper mass can always function properly. By making the relative position of the damper mass with respect to the cylindrical portion constant, it is possible to effectively prevent the variation of the vibration damping characteristic.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 Pulley body 2 Boss part 3 Web part 4 Cylindrical part 5 1st elastic body 6 1st damper mass 8 2nd damper mass 9 2nd elastic body

Claims (1)

[Claims] 1. A first elastic body is provided on the outer peripheral side of the cylindrical portion of a pulley body having a boss portion attached to a rotation output shaft and having a cylindrical portion connected to the boss portion via a web portion. A damper pulley in which a first damper mass is mounted through the cylindrical member, and a tubular member having the second damper mass mounted through a second elastic body is press-fitted and fixed to the inner peripheral side of the cylindrical part. While fixing the end surface of the second damper mass, which has a generally cylindrical shape, to the inward flange or the end wall of the tubular member located at the end portion away from the web portion via the second elastic body, , The edge of the tubular member on the web side,
A damper pulley which is positioned so as to be pushed out from a similar end edge of the second damper mass and which is provided with positioning means for specifying the press-fitting margin of the tubular member on the pulley body side. [0001]