JP4022741B2 - Damper pulley - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a damper pulley that is attached to a rotating shaft such as a crankshaft of an automobile engine and that exhibits a dynamic vibration absorbing function against vibration of the rotating shaft by a sub-vibration system that includes a pulley body and an elastic body.
[0002]
[Prior art]
FIG. 3 is a half sectional view showing a typical prior art of a damper pulley attached to a shaft end of a crankshaft of an engine in a vehicle, cut along a plane passing through the axis. The damper pulley 100 includes a hub 101 attached to the shaft end of the crankshaft, a sleeve 102 press-fitted into the outer peripheral surface of the rim portion 101a, a pulley main body 103 disposed concentrically on the outer peripheral side, and the pulley main body 103. The first elastic body 104 vulcanized and bonded between the sleeve 102, the inner damper mass 105 arranged concentrically in the axial direction with the rim portion 101a, and the inner damper mass 105 and the rim portion 101a. It consists of a second elastic body 106 vulcanized and bonded between them (see JP-A-7-71521).
[0003]
That is, the damper pulley 100 transmits the driving force of the crankshaft to another rotating device via a belt wound around the pulley main body 103, and at the predetermined rotational speed range, the first elastic body 104 and the pulley main body 103. Torsional vibration is reduced by resonating in the torsional direction, and the secondary vibrationing system consisting of the second elastic body 106 and the inner damper mass 105 is resonated in the radial direction to cause radial vibration (bending). Vibration).
[0004]
[Problems to be solved by the invention]
According to the conventional damper pulley 100 described above, an anti-vibration function is provided for torsional vibration and radial vibration, but an active anti-vibration function cannot be expected for axial vibration. Further, in the manufacture thereof, the step of vulcanizing and bonding the first elastic body 104 between the pulley body 103 and the sleeve 102, and the second elastic body 106 between the inner damper mass 105 and the rim portion 101a of the hub 101 are provided. The vulcanization and bonding process requires two molding steps, resulting in an increase in production costs.
[0005]
The present invention has been made in view of the above problems, and a technical problem thereof is to provide a damper pulley that has an excellent vibration-proof function and can be manufactured at low cost.
[0006]
[Means for Solving the Problems]
As a means for effectively solving the above technical problem, a damper pulley according to the invention of claim 1 includes a hub, a pulley body, an axial mass body, and a radial mass body arranged concentrically with each other. An elastic body made of a rubber-like elastic material is vulcanized and bonded between the annular plate integrally attached to the pulley body, the axial mass body, and the radial mass body, and the elastic body is coupled to the pulley body. A torsional elastic part having a degree of freedom in the torsional direction between the annular plate and the axially elastic part having an axial degree of freedom between the axial mass body and the annular plate ; A radial elastic part between the radial mass body and the annular plate and having a radial degree of freedom, wherein the axial elastic part is continuous with the torsion elastic part in the axial direction, and the shaft Directional elastic part, circumferential direction In which currant extending intermittent toward the torsion elastic part is formed.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a sectional view showing a preferred embodiment of a damper pulley according to the present invention by cutting along a plane passing through its axis, and FIG. 2 is a view taken in the direction of arrow II in FIG. In the following description, “front” means the left side in FIG. 1, and “back” means the right side in FIG.
[0008]
The damper pulley of this form includes a hub 1 attached to a shaft end of a crankshaft of a vehicle engine (not shown), a pulley body 2 and a shaft arranged concentrically and relatively displaceably on the outer peripheral side of the hub 1. A directional mass body 3, a radial mass body 4 disposed concentrically and relatively displaceably on the front side of the hub 1, an annular plate 5 integrally attached to the hub 1, and the annular plate 5 And an elastic body 6 made of a rubber-like elastic material vulcanized and bonded between the pulley body 2, the axial mass body 3, and the radial mass body 4. Therefore, the pulley body 2, the axial mass body 3 and the radial mass body 4 are elastically connected to the hub 1 via the annular plate 5 and the elastic body 6.
[0009]
The hub 1 is made of a metal such as iron or aluminum, and has a boss portion 11 that is a fixed portion to the shaft end of the crankshaft and a disk portion 12 that extends from the boss portion 11 to the outer peripheral side. And a rim portion 13 extending in a cylindrical shape from the outer periphery to the front side and the back side.
[0010]
The pulley body 2 is made of a metal such as iron, and has a poly V groove 21 around which a belt (not shown) is wound on the outer peripheral surface, and is disposed on the outer peripheral side of the rim portion 13 of the hub 1. Yes.
[0011]
The axial mass 3 is made of a metal such as an iron-based material, and has an annular shape in which the area of a cross section (cross section shown in FIG. 1) cut along a plane passing through the axis is smaller than that of the pulley body 2. It is disposed on the outer peripheral side of the rim portion 13 of the hub 1 and is located on the back side of the pulley body 2.
[0012]
The radial mass body 4 is made of a metal such as iron, and has an annular shape in which the area of a cross section (cross section shown in FIG. 1) cut along a plane passing through the axis is smaller than that of the pulley body 2. The hub 1 is disposed on the front side of the disk portion 12 and on the inner peripheral side of the rim portion 13, that is, is formed to have a smaller diameter than the pulley body 2 and the axial mass body 3.
[0013]
The annular plate 5 is formed by stamping and pressing a metal plate such as a steel plate, along a sleeve 51 press-fitted to the outer peripheral surface of the rim portion 13 of the hub 1, and along the front end portion of the rim portion 13. The positioning step portion 52 is bent to the inner peripheral side, and the inner peripheral flange 53 extends from the positioning step portion 52 to the inner peripheral side.
[0014]
The elastic body 6 is made of a rubber-like elastic material such as EPDM (ethylene / propylene rubber) which has excellent heat resistance, cold resistance and mechanical strength and has little internal heat generation, and includes an annular plate 5 and a pulley body 2. These are vulcanized and bonded between the axial mass body 3 and the radial mass body 4. Specifically, the elastic body 6 includes a torsional elastic portion 61 interposed between the outer peripheral surface of the sleeve 51 and the inner peripheral surface of the pulley body 2 in the annular plate 5, and the torsional elastic portion 61 to be continuous with the annular plate. The axial elastic part 62, the torsion elastic part 61 and the axial elastic part 62 interposed between the outer peripheral surface of the sleeve 51 and the inner peripheral surface of the axial mass body 3 in FIG. And a radial elastic portion 63 interposed between the inner circumferential flange 53 and the radial mass body 4 arranged on the back side thereof.
[0015]
The pulley body 2 mainly has a degree of freedom in the twisting direction between the sleeve 51 of the annular plate 5 and the torsion elastic portion 61 of the elastic body 6. For this reason, the pulley body 2 and the torsion elastic part 61 constitute a vibration system in the torsion direction.
[0016]
The axial mass 3 has a degree of freedom mainly in the axial direction between the sleeve 51 of the annular plate 5 and the axial elastic part 62 of the elastic body 6. For this reason, the axial mass body 3 and the axial elastic part 62 constitute an axial vibration system. Further, the axial elastic portion 62 is formed with a curly edge 62a that is intermittent in the circumferential direction, whereby the axial spring constant is adjusted.
[0017]
The radial mass body 4 mainly has a degree of freedom in the radial direction between the inner circumferential flange 53 of the annular plate 5 via the radial elastic portion 63 of the elastic body 6. For this reason, the radial mass 4 and the radial elastic part 63 constitute a radial vibration system.
[0018]
By the way, the driving of an engine such as an automobile is performed while repeating the steps of intake, compression, explosion (expansion), and exhaust, and the reciprocating motion of the piston is converted into the rotational motion of the crankshaft. Generates torsional vibration (vibration in the rotational direction) and bending vibration with rotation. Further, the bending vibration includes an axial vibration component in addition to a radial vibration component. Therefore, the torsional direction resonance frequency of the vibration system in the torsional direction constituted by the pulley body 2 and the torsion elastic portion 61 is tuned to a frequency region where the amplitude of the torsional vibration of the crankshaft is maximized. The axial resonance frequency of the axial vibration system constituted by the mass body 3 and the axial elastic portion 62 is tuned to a frequency region where the amplitude of the axial component in the bending vibration of the crankshaft is maximized, and is in the radial direction. The radial resonance frequency of the radial vibration system composed of the mass body 4 and the radial elastic portion 63 is tuned to a frequency region where the amplitude of the radial component in the bending vibration of the crankshaft is maximized.
[0019]
In the manufacture of the damper pulley having the above configuration, first, the hub 1, the pulley body 2, the axial mass body 3, and the radial mass body 4 are manufactured by casting or the like, and the annular plate 5 is formed by punching and pressing a metal plate. To manufacture. The inner diameter of the sleeve 51 in the annular plate 5 is formed to be slightly smaller than the outer diameter of the rim portion 13 in order to give an appropriate tightening allowance to the rim portion 13 of the hub 1.
[0020]
Next, an annular plate 5, a pulley body 2, an axial mass body 3, and a radial mass body 4 previously coated with a vulcanizing adhesive are set in a predetermined vulcanization mold, The elastic body 6 is formed into an annular shape by filling the molding space defined by the annular plate 5, the pulley body 2, the axial mass body 3 and the radial mass body 4 with unvulcanized rubber and heating and pressurizing it. At the same time as vulcanization molding, the annular plate 5, the pulley body 2, the axial mass body 3 and the radial mass body 4 are vulcanized and bonded. In addition, although the torsional elastic part 61, the axial elastic part 62, and the radial elastic part 63 in the elastic body 6 are separated, they can be molded in one step.
[0021]
Next, the sleeve 51 of the annular plate 5 in which the pulley body 2, the axial mass body 3, and the radial mass body 4 are integrated via the elastic body 6 by the above-described molding process is attached to the rim portion 13 of the hub 1. From the front side, the outer peripheral surface is press-fitted until the positioning step portion 52 of the annular plate 5 comes into contact with the front end portion of the rim portion 13. As a result, the damper pulley is assembled in the state shown in FIG.
[0022]
The damper pulley according to the present embodiment is fixed to a shaft end of a crankshaft (not shown) at the boss portion 11 of the hub 1 and is rotated together with the crankshaft when the engine is driven, via a belt wound around the pulley body 2. Rotating devices such as auxiliary machines are driven.
[0023]
In the frequency range where the amplitude of the torsional vibration generated in the crankshaft is maximized, a vibration system in the torsional direction constituted by the pulley body 2 and the torsion elastic portion 61 of the elastic body 6 is input via the hub 1. Resonates with a waveform having a phase opposite to that of torsional vibration, and exhibits a dynamic vibration absorption effect that effectively reduces the peak of torsional vibration of the crankshaft. Similarly, in the frequency range in which the axial amplitude in the bending vibration generated in the crankshaft is maximized, the axial vibration system constituted by the pulley body 2 and the axial elastic portion 62 of the elastic body 6 passes through the hub 1. Resonates with a waveform having a phase opposite to that of the axial vibration input, and exhibits a dynamic vibration absorption effect that effectively reduces the peak of the axial amplitude of the crankshaft. Further, in the frequency range where the radial amplitude of the bending vibration generated in the crankshaft is maximized, the radial vibration system constituted by the pulley body 2 and the radial elastic portion 63 of the elastic body 6 passes through the hub 1. Resonates with a waveform having an opposite phase to the input radial vibration, and exhibits a dynamic vibration absorption effect that effectively reduces the peak of the radial amplitude of the crankshaft.
[0024]
Therefore, according to the pulley damper of this embodiment, it is possible to effectively reduce the axial component in bending vibration as well as the radial vibration component in crankshaft torsional vibration and bending vibration.
[0026]
【The invention's effect】
According to the damper pulley of the invention of claim 1, an elastic body made of a rubber-like elastic material is added between the annular plate integrally attached to the hub and the pulley body, the axial mass body, and the radial mass body. Because it is glued by vulcanization, the pulley body, axial mass body and radial mass body can be integrated on the hub side by a single vulcanization molding (vulcanization adhesion) process, reducing production costs can do. In addition to the radial vibration component in torsional vibration and bending vibration, the axial component in bending vibration can also be effectively reduced, so that the vibration isolation performance can be improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a preferred embodiment of a damper pulley according to the present invention by cutting along a plane passing through its axis.
FIG. 2 is a view taken in the direction of the arrow II in FIG.
FIG. 3 is a cross-sectional view showing a typical conventional example of a damper pulley cut along a plane passing through its axis.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Hub 11 Boss part 12 Disk part 13 Rim part 2 Pulley main body 21 Poly V groove 3 Axial mass body 4 Radial mass body 5 Annular plate 51 Sleeve 52 Positioning step part 53 Inner peripheral flange 6 Elastic body 61 Torsion elastic part 62 Axis Direction elastic part 63 radial direction elastic part

Claims (1)

An annular plate (1), a pulley body (2), an axial mass body (3) and a radial mass body (4) arranged concentrically with each other and integrally attached to the hub (1). 5) and an elastic body (6) made of a rubber-like elastic material is vulcanized and bonded between the pulley body (2), the axial mass body (3), and the radial mass body (4), and the elastic body (6) a torsion elastic portion (61) between the pulley body (2) and the annular plate (5) and having a degree of freedom in the torsional direction; the axial mass body (3); An axial elastic part (62) between the plate (5) and having an axial degree of freedom, and between the radial mass (4) and the annular plate (5) in the radial direction It consists of a radial elastic part (63) having a degree of freedom, and the axial elastic part (62) is the torsion elastic part (61 Damper pulley according to the axial direction it is continuous, in the axial direction the elastic portion (62), characterized in that currant that intermittently circumferentially extending toward the torsion elastic part to (61) (62a) are formed .

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