JP2004036828A - Torsional damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve durability by enhancing the heat radiation property of an elastic body 42 in an auxiliary vibration system 4 arranged in a space surrounded by a hub 1 and an inward flange 24 in a torsional damper having a plurality of auxiliary vibration systems 3, 4. <P>SOLUTION: This torsional damper is provided with the first auxiliary vibration system 3 comprising a first annular mass body 31 arranged on the outer peripheral side of a sleeve body part 21 of a sleeve 2, and a first elastic body 32 for connecting the first annular mass body 31 to the sleeve body part 21; and a second auxiliary vibration system 4 comprising a second annular mass body 41 arranged between the hub 1 and the inward flange 24 of the sleeve 2, and a second elastic body 42 for connecting the second annular mass body 41 to the inward flange 24. A pumping hole 25 radially piercing on the outer peripheral side of the second auxiliary vibration system 4 is opened in the sleeve 2, and an air hole 13 is opened in a disc part 11 of the hub 1. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a torsional damper that absorbs torsional vibration generated on a rotating shaft such as a crankshaft of an internal combustion engine.
[0002]
[Prior art]
The torsion damper basically has a structure in which an annular mass body is concentrically and elastically connected to a hub attached to a crankshaft via an elastic body, and a spring constant of the elastic body, A sub-vibration system having a constant resonance frequency in the torsional direction determined by the inertial mass of the annular mass body is formed, and torsional vibration in a specific rotation speed range is reduced by a dynamic vibration absorbing effect due to the resonance. Further, among this type of torsional damper, there is a torsion damper of a double mass type having two sets of sub-vibration systems in which different torsional resonance frequencies are set for the purpose of obtaining vibration damping performance in a wide rotation speed range ( See, for example, Japanese Utility Model Publication No. 6-40991.
[0003]
FIG. 3 is a half sectional view showing a conventional torsion damper of the double mass type disclosed in the above publication. That is, the torsion damper includes a hub 101 attached to the shaft end of the crankshaft at an inner peripheral boss portion 101a, a sleeve main body portion 102a fitted to the outer peripheral surface of a rim portion 101b of the hub 101, and a shaft of the hub 101. A sleeve 102 having an inward flange 102b extending in one direction toward the inner peripheral side, and a first annular mass body 103b on the outer peripheral side of the sleeve main body 102a via a first elastic body 103a made of a rubber-like elastic material. The first sub-vibration system 103 having a connected structure is provided between the hub 101 and the inward flange 102b of the sleeve 102, and the inward flange 102b is provided with a second elastic body 104a made of a rubber-like elastic material. And a second auxiliary vibration system 104 having a structure in which the annular mass bodies 104b are connected to each other. Different torsional resonance frequencies are set in the first sub-vibration system 103 and the second sub-vibration system 104.
[0004]
[Problems to be solved by the invention]
However, in this kind of torsional damper, the first elastic body 103a and the second elastic body 104a absorb and attenuate torsional vibration by converting kinetic energy due to vibration into heat energy. For example, when the first elastic body 103a and the second elastic body 104a are repeatedly torsionally deformed by vibration input, heat is generated by internal friction. When such heat is accumulated and the temperature becomes high, the material of the rubber-like elastic material constituting the first elastic body 103a and the second elastic body 104a is deteriorated, and the initial vibration absorbing performance may not be obtained. There is.
[0005]
In particular, in the case of the conventional double-mass type torsional damper as shown in FIG. 3, even if the second elastic body 104a breaks during rotation due to fatigue or the like due to repetitive deformation, the second elastic body 104a does not have the second elastic body 104a. The second auxiliary vibration system 104 is provided in a space surrounded by the inward flange 102b of the hub 101 and the sleeve 102 so that the annular mass body 104b does not fly out and collide with the internal combustion engine. Therefore, the air easily stays around the second sub-vibration system 104, and it is difficult for the second elastic body 104a to efficiently radiate heat, and the heat deteriorates the material or breaks down early. There is fear.
[0006]
The present invention has been made in view of the above-described problems, and a technical problem thereof is that in a torsional damper having a plurality of sub-vibration systems, a space surrounded by a hub and an inward flange. Another object of the present invention is to enhance the heat radiation of the elastic body in the sub-vibration system disposed in the sub-vibration, thereby improving its durability.
[0007]
[Means for Solving the Problems]
As means for effectively solving the above technical problem, a torsional damper according to the invention of claim 1 includes an inward flange formed on a rim portion of a hub or a sleeve integrated with the rim portion, A first annular mass body disposed on the outer peripheral side of the rim portion and a first auxiliary vibration system including a first elastic body connecting the first annular mass body to the rim portion side; A second annular mass body disposed between the inward flanges and a second auxiliary vibration system including a second elastic body that connects the second annular mass to the inward flange, A pumping hole is formed in the rim portion or the sleeve in a radial direction on the outer peripheral side of the second auxiliary vibration system. The pumping hole produces a centrifugal pumping action by rotation, and provides a flow of air around the second auxiliary vibration system.
[0008]
A torsion damper according to a second aspect of the present invention is the torsion damper according to the first aspect, wherein a vent hole is opened in a disk portion of the hub. Thereby, the flow of air around the second auxiliary vibration system by the centrifugal pump action of the pumping hole formed in the metal ring can be further smoothed.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a half sectional view showing a preferred embodiment of a torsional damper 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. The torsion damper according to the illustrated embodiment is of a double mass type, and includes a hub 1, a sleeve 2 fixed to a rim portion 12 of the hub 1, and a first auxiliary vibration system provided on the outer peripheral side of the hub 1. 3 and a second auxiliary vibration system 4 provided on one axial side of the hub 1.
[0010]
Specifically, the hub 1 is made of a casting such as an iron-based metal or aluminum, and has a disk portion 11 and a cylindrical rim portion 12 formed on the outer periphery thereof. The shaft hole 11a is inserted through a shaft end of a crankshaft (not shown) of the internal combustion engine, and is fixed by a bolt (not shown) inserted into a bolt insertion hole 11b. A plurality of (four at intervals of 90 degrees in the example of FIG. 2) ventilation holes 13 are formed in the disk portion 11 at regular intervals in the circumferential direction.
[0011]
The sleeve 2 is made by stamping and pressing a metal plate such as a steel plate. The sleeve body 21 is fitted on the outer peripheral surface of the rim 12 of the hub 1. The positioning step 22 bent inward at the one end, the cylindrical step 23 extending in the axial direction from the inner diameter of the positioning step 22, and the end of the cylindrical step 23 An inward flange 24 extending toward the inner peripheral side at a position appropriately distant from the disk portion 11 is provided.
[0012]
A plurality of (four at 90-degree intervals in the example of FIG. 2) pumping holes 25 at predetermined intervals in the circumferential direction are formed in the cylindrical step 23 between the sleeve body 21 and the inward flange 24 of the sleeve 2. Opened in the direction. The pumping hole 25 has a centrifugal pump function of sending air from the inner peripheral side to the outer peripheral side by centrifugal force during rotation.
[0013]
The first auxiliary vibration system 3 includes a first annular mass body 31 disposed on the outer peripheral side of the sleeve main body portion 21 in the sleeve 2, and a first annular mass body 31 connecting the first annular mass body 31 to the sleeve main body portion 21. Elastic body 32. The first annular mass body 31 is made of an iron-based metal casting or the like, and has an outer peripheral surface formed with a poly-V groove 31a around which an endless belt for power transmission is wound. Further, the first elastic body 32 is vulcanized and molded into an annular shape with a rubber-like elastic material, and is integrally vulcanized and bonded to the first annular mass body 31 and the sleeve body 21.
[0014]
The second sub-vibration system 4 is disposed between the disk portion 11 of the hub 1 and the inward flange 24 of the sleeve 2 that are axially opposed to each other, and includes a second annular mass body 41 and the second annular mass body 41. It comprises a second elastic body 42 connecting the mass body 41 to the inward flange 24. The second annular mass body 41 is made of an iron-based metal casting or the like, and has a smaller cross-sectional area and a smaller diameter than the cross-sectional area of the first annular mass body 31. The second elastic body 42 is formed in an annular shape by a rubber-like elastic material, and is integrally vulcanized and bonded to the second annular mass 41 and the inward flange 24. The pumping hole 25 formed in the cylindrical step 23 of the sleeve 2 is located on the outer peripheral side of the second elastic body 42.
[0015]
The first sub-vibration system 3 has a main surface with respect to the hub 1 because the bonding surface between the first elastic body 32 and the sleeve main body 21 of the sleeve 2 and the first annular mass body 31 face in the radial direction. Has a degree of freedom in the torsional direction. Further, the second sub-vibration system 4 has an adhesion surface between the second elastic body 42 and the inward flange 24 of the sleeve 2 and the second annular mass body 41 facing in the axial direction. It has a degree of freedom mainly in the torsional and radial directions.
[0016]
The first annular mass body 31 and the second annular mass body 41 have different inertial masses due to differences in their cross-sectional areas and radii, and the first elastic body 32 and the second elastic body 42 The circumferential shear shear constants differ from each other due to differences in thickness, radius, and width. Accordingly, the resonance frequency in the torsional direction of the first auxiliary vibration system 3 including the first annular mass body 31 and the first elastic body 32 and the second resonance frequency including the second annular mass body 41 and the second elastic body 42 Have different resonance frequencies in the torsional direction. These resonance frequencies are set, for example, in a frequency range where the amplitude of torsional vibration generated in the crankshaft is maximized.
[0017]
In manufacturing the torsion damper of the present embodiment having the above-described configuration, first, the hub 1, the first annular mass body 31 and the second annular mass body 41 are manufactured by casting or the like, and the sleeve 2 is made of a metal plate. It is manufactured by a punching press or the like. The sleeve main body 21 of the sleeve 2 is formed such that its inner diameter is slightly smaller than the outer diameter of the rim 12 of the hub 1.
[0018]
Next, the first annular mass body 31, the sleeve 2, and the second annular mass body 41 are concentrically positioned and fixed in a predetermined rubber vulcanization mold. By filling the unvulcanized rubber material between the facing peripheral surfaces of one annular mass body 31 and between the facing end faces of the inward flange 24 of the sleeve 2 and the second annular mass body 41, and heating and pressing, The molding (vulcanization bonding) of the first elastic body 32 and the second elastic body 42 is performed simultaneously. As a result, a molded article having the first annular mass body 31, the first elastic body 32, the second annular mass body 41, and the second elastic body 42 integrally formed on the sleeve 2 is obtained.
[0019]
Next, the sleeve body 21 of the sleeve 2 of the molded product obtained by the vulcanization bonding step is pressed into the outer peripheral surface of the rim 12 of the hub 1. At this time, as shown in FIG. 2, the ventilation holes 13 formed in the disk portion 11 of the hub 1 and the pumping holes 25 formed in the cylindrical step portion 23 of the sleeve 2 are in phase with each other, as shown in FIG. Thus, the angles of the hub 1 and the sleeve 2 are adjusted.
[0020]
In the press-fitting process described above, the sleeve body 21 of the sleeve 2 is expanded in diameter by the rim portion 12, so that the first elastic body 32 is pre-compressed in the radial direction, and residual tensile stress generated by shrinkage after vulcanization molding is reduced. Will be resolved. The first sub-vibration system 3 and the second sub-vibration system are pressed into each other until the positioning step 22 formed on the sleeve 2 comes into contact with the end of the rim 12 in the hub 1. 4 are attached to the hub 1 at a time, resulting in the torsional damper shown in FIG.
[0021]
The torsional damper of the present embodiment rotates in conjunction with the crankshaft of the internal combustion engine of the automobile, and operates in the frequency range where the amplitude of the torsional vibration of the crankshaft input via the hub 1 is maximized. Alternatively, the peak of torsional vibration of the crankshaft is effectively reduced by the second sub-vibration system 4 resonating with a phase angle different from the input vibration, and the torque due to the resonance motion is generated in a direction to offset the torque of the input vibration. Is done. Since different resonance frequencies are set for the first sub-vibration system 3 and the second sub-vibration system 4, excellent vibration damping functions are achieved in a wide rotational speed range.
[0022]
Here, when the torsional damper rotates, the air existing in the space between the rim portion 12 of the hub 1 and the second auxiliary vibration system 4 rotates together with the rim portion 12 and the second auxiliary vibration system 4. As a result, it receives centrifugal force and is thrown out of each pumping hole 25 formed in the cylindrical stepped portion 23 of the sleeve 2 to the outer peripheral side thereof. Then, by this centrifugal pump action, the space between the disk portion 11 of the hub 1 and the second annular mass body 41 is removed from the air hole 13 of the hub 1 and the space on the inner peripheral side of the second auxiliary vibration system 4. , Via the space between the rim portion 12 of the hub 1 and the second annular mass body 41 and the space between the cylindrical stepped portion 23 of the sleeve 2 and the second elastic body 42. An air current is released from the air to the outside.
[0023]
Since the first elastic body 32 in the first sub-vibration system 3 and the second elastic body 42 in the second sub-vibration system 4 are repeatedly subjected to torsional deformation along with the resonance operation, heat is generated by internal friction. Due to the above-described pump action, relatively low-temperature air on the front side of the internal combustion engine is constantly flowing around the first sub-vibration system 3, so that heat is actively exchanged with this air. Accumulation of heat in the second elastic body 42 is prevented. Therefore, it is possible to effectively prevent the material of the second elastic body 42 from deteriorating due to heat and changing properties due to the heat, and generating cracks due to heat, effectively.
[0024]
In addition, since the air flows through the ventilation holes 13 of the hub 1, a rise in the temperature of the hub 1 due to radiant heat from the internal combustion engine is suppressed. For this reason, the temperature rise of the first elastic body 32 provided on the outer periphery of the rim 12 of the hub 1 via the sleeve main body 21 can be suppressed.
[0025]
When the hub 1 is a press-formed product of a metal plate and the inward flange portion 24 is formed integrally with the rim portion 12 of the hub 1, the pumping hole 25 is formed in the rim portion 12.
[0026]
【The invention's effect】
According to the torsion damper according to the first aspect of the present invention, a pumping action is generated during rotation by the pumping hole formed in the sleeve, and an air flow is generated around the second sub-vibration system. The heat radiation from the second elastic body in the second sub-vibration system arranged in the space surrounded by the flange can be enhanced, and the deterioration of the characteristics and the damage due to the thermal deterioration can be prevented.
[0027]
According to the torsion damper according to the second aspect of the present invention, in addition to the configuration of the first aspect, the vent hole is opened in the hub, so that the pumping hole causes a centrifugal pump action around the second auxiliary vibration system. The air flow can be made smoother, and the heat radiation of the first elastic body can be promoted through the hub.
[Brief description of the drawings]
FIG. 1 is a half sectional view showing a preferred embodiment of a torsional damper according to the present invention by cutting along a plane passing through an axis thereof.
FIG. 2 is a view in the direction of arrow II in FIG.
FIG. 3 is a half sectional view showing a conventional torsional damper.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Hub 11 Disk part 12 Rim part 13 Vent hole 2 Sleeve 21 Sleeve main body part 22 Positioning step part 23 Cylindrical step part 24 Inward flange 25 Pumping hole 3 First auxiliary vibration system 31 First annular mass body 32 First Elastic body 4 second auxiliary vibration system 41 second annular mass body 42 second elastic body

Claims (2)

An inward flange (24) formed on a rim (12) of the hub (1) or a sleeve (2) integrated with the rim (12);
A first annular mass body (32) arranged on the outer peripheral side of the rim portion (12) and a first elastic body (31) connecting the first annular mass body (31) to the rim portion (12) side. 32) a first auxiliary vibration system (3) consisting of:
A second annular mass (41) disposed between the hub (1) and the inward flange (24) and connecting the second annular mass (41) to the inward flange (24). A second auxiliary vibration system (4) comprising a second elastic body (42);
A torsion damper characterized in that a pumping hole (25) is formed in the rim portion (12) or the sleeve (2) so as to penetrate in the radial direction on the outer peripheral side of the second auxiliary vibration system (4). The torsion damper according to claim 1, characterized in that a ventilation hole (13) is opened in the disc portion (11) of the hub (1).

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