JP2024021598A - torsional damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a torsional damper capable of reducing noise while suppressing complication of a constitution.

SOLUTION: A torsional damper 1 includes: a hub 2 connected to a shaft member of an internal combustion engine; a vibration ring 3 disposed on an outer peripheral side of the hub 2; a damper portion 41 disposed between the hub 2 and the vibration ring 3; and a cover portion 42 disposed in a manner of covering the hub 2 from an opposite side with respect to the shaft member. The damper portion 41 and the cover portion 42 are integrally formed.

SELECTED DRAWING: Figure 2

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a torsional damper.

Conventionally, as a torsional damper for reducing vibrations generated in a crankshaft in an internal combustion engine, one in which a damper rubber is fitted between a hub and a vibration ring has been proposed (see, for example, Patent Document 1). In the torsional damper described in Patent Document 1, torsional vibration and bending vibration are reduced by alternately arranging two portions of the damper rubber made of elastic materials having different hardnesses in the circumferential direction.

Japanese Patent Application Publication No. 2021-188691

When a torsional damper as described in Patent Document 1 is provided, the hub and the vibration ring may receive an axial vibration force from the crankshaft, causing resonance. Such resonance can cause radiated sound toward the opposite side of the crankshaft. Therefore, in order to reduce such radiated sound, a configuration may be considered in which a lid portion is provided to cover the hub from the side opposite to the crankshaft. However, the hub is a member that rotates together with the crankshaft, and since relative rotation between the hub and the lid portion causes wear and the like, it is necessary to restrict the relative rotation, which complicates the configuration.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a torsional damper that can reduce noise while suppressing the complexity of the structure.

In order to achieve the above object, a torsional damper according to the present invention includes a hub connected to a shaft member of an internal combustion engine, a vibration ring provided on the outer peripheral side of the hub, and a vibration ring between the hub and the vibration ring. A damper section is provided, and a lid section is provided to cover the hub from the side opposite to the shaft member, and the damper section and the lid section are integrally formed.

The torsional damper according to one aspect of the present invention includes a sleeve provided on an outer peripheral side of the hub and an inner peripheral side of the damper part, and the damper part is assembled to the hub by press fitting.

In the torsional damper according to one aspect of the present invention, an opening is formed in the center of the lid.

According to the torsional damper according to the present invention, noise can be reduced while suppressing the complexity of the configuration.

1 is a side view of a torsional damper according to an embodiment of the present invention. 1 is a sectional view of a torsional damper according to an embodiment of the present invention.

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 and 2, a torsional damper 1 according to an embodiment of the present invention includes a hub 2 connected to a shaft member of an internal combustion engine, a vibration ring 3 provided on the outer peripheral side of the hub 2, and a hub 2. 2 and the vibration ring 3, and a lid part 42 provided to cover the hub 2 from the side opposite to the shaft member, and the damper part 41 and the lid part 42 are integrated. It is formed.

The torsional damper 1 is provided in an internal combustion engine, and the internal combustion engine includes a crankshaft as a shaft member. This crankshaft extends with an axis x. Hereinafter, for convenience of explanation, the direction of arrow a (see Figure 2) in the axis x direction will be referred to as one side (shaft member side), and the direction of arrow b (see Figure 2) in the axis x direction will be referred to as the other side (the side opposite to the shaft member). ; outside). In addition, in the direction perpendicular to the axis x (hereinafter also referred to as the "radial direction"), the direction away from the axis x (direction of arrow c in Fig. 1) is the outer peripheral side, and the direction approaching the axis x (arrow d in Fig. 1) is the outer peripheral side. direction) is the inner circumferential side. In the following description, when explaining the positional relationships and directions of each member, the positional relationships and directions shown in the drawings are merely shown, and do not indicate the positional relationships and directions when assembled into an actual vehicle or the like.

The torsional damper 1 includes a hub 2, a vibration ring 3, a vibration isolating member 4, and a sleeve 5.

The hub 2 is connected to a crankshaft of an internal combustion engine so that it cannot rotate relative to it (that is, can transmit rotation), and is connected to a boss part 21 and a connecting part 22 in order from the inner circumferential side to the outer circumferential side. and a rim portion 23 integrally. The entire hub 2 may be made of, for example, a metal material.

The boss portion 21 is formed in a cylindrical shape centered on the axis x. A key groove 211 extending along the axis x direction is formed in the inner circumferential surface of the boss portion 21 so as to be able to fit with a key (convex portion) of the crankshaft. The connecting portion 22 is formed in an annular plate shape along a plane perpendicular to the axis x, and its inner peripheral portion is continuous with the end of the boss portion 21 on the other side in the axis x direction. The rim part 23 is formed in a cylindrical shape centered on the axis x, and the outer peripheral part of the connecting part 22 is continuous with the inner peripheral surface of the rim part 23. The rim portion 23 protrudes from the connecting portion 22 on both sides of the axis x, and in this embodiment, the amount of protrusion toward the other side is larger. In this way, the boss portion 21 and the rim portion 23, which are two cylindrical portions, the inner and outer portions, are connected by the annular plate-shaped connecting portion 22.

The vibration ring 3 is formed in a cylindrical shape centered on the axis x, and is provided on the outer peripheral side of the rim portion 23 of the hub 2 . The vibration ring 3 is made of, for example, a metal material and is configured to have a predetermined mass. The inner diameter of the vibrating ring 3 is larger than the outer diameter of the rim portion 23 by a predetermined dimension, and a gap G is formed between the vibrating ring 3 and the rim portion 23. A plurality of pulley grooves 31, which are V-shaped grooves, are formed on the outer circumferential surface of the vibration ring 3. The pulley grooves 31 are V-shaped grooves for winding an endless belt that transmits the rotational torque of the crankshaft to an external mechanism. Note that a configuration may be adopted in which the pulley groove 31 is not formed.

In this embodiment, in the axis x direction, one end 3A of the vibrating ring 3 is arranged at the same position (on the same plane) as the one end 23A of the rim part 23, and the other end 3A of the vibrating ring 3 The side end 3B is located on the other side of the rim portion 23 from the other side end 23B.

The vibration isolating member 4 is entirely made of rubber and includes a damper portion 41 and a lid portion 42. That is, the damper part 41 and the lid part 42 are integrally molded. The vibration isolating member 4 may be made of an elastic member such as an elastic resin other than rubber.

The damper portion 41 is formed in a cylindrical shape centered on the axis x, and is disposed in the gap G between the rim portion 23 of the hub 2 and the vibration ring 3. In the axis x direction, one end 41A of the damper part 41 is arranged at the same position (on the same plane) as the one end 3A of the vibration ring 3 and the one end 23A of the rim part 23, The other end 41B of the damper portion 41 is arranged at the same position (on the same plane) as the other end 3B of the vibration ring 3.

The lid part 42 is continuous with the other end 41B of the damper part 41 and is formed in an annular plate shape along a plane perpendicular to the axis x. The lid portion 42 is disposed on the other side of the entire hub 2 in the axis x direction, thereby covering the hub 2 from the side opposite to the crankshaft. Here, "the lid part 42 covers the hub 2" does not mean only that the entire hub 2 is completely hidden by the lid part 42 when viewed from the other side in the axis x direction, but also that a part of the hub 2 (for example, It also includes a configuration that is visible from the other side in the axis x direction (through an opening 421 to be described later).

An opening 421, which is a through hole, is formed in the center of the lid 42, and a plurality of through holes 422 are also formed around the opening 421. The inner diameter (diameter) D1 of the opening 421 is larger than the inner diameter (diameter) D2 of the portion of the boss portion 21 other than the keyway 211, so that the boss portion 21 is visible from the axis x direction. The plurality of through holes 422 are arranged at equal intervals on a circumference centered on the axis x, and are provided at positions overlapping with the rim portion 23.

The other side surface of the lid part 42 is arranged at the same position (on the same plane) as the other side end 41B of the damper part 41 and the other side end 3B of the vibration ring 3, so that the vibration isolating member 4 It is designed not to protrude from the vibration ring 3 to the other side.

The sleeve 5 is made of, for example, a metal material, and is formed into a cylindrical shape as a whole centered on the axis x, and is provided on the outer circumferential side of the rim portion 23 and the inner circumferential side of the damper portion 41 of the hub 2 . In the axis x direction, one end 5A of the sleeve 5 is the same as one end 23A of the rim part 23, one end 3A of the vibration ring 3, and one end 41A of the damper part 41. (on the same plane).

A folded portion 51 extending toward the inner circumferential side is formed at the other end of the sleeve 5 . The folded portion 51 is formed in an annular shape centered on the axis x, and is arranged so as to be in contact with the other end 23B of the rim portion 23 and to cover it from the other side in the axis x direction. Further, the plurality of through holes 422 of the lid portion 42 are formed at positions overlapping the folded portion 51, and a portion of the folded portion 51 is visible from the other side in the axis x direction through the through holes 422.

Here, a specific example of a method for manufacturing the torsional damper 1 will be described. In this embodiment, the damper portion 41 is mounted using a so-called bush type mounting method. First, the vibration isolating member 4 is formed between the vibration ring 3 and the sleeve 5 by vulcanizing and molding a rubber material. At this time, not only the damper part 41 but also the lid part 42 are formed at the same time. By press-fitting the vibration ring 3, vibration isolating member 4, and sleeve 5 that are integrally provided into the hub 2 (that is, inserting the hub 2 inside the sleeve 5), the vibration between the hub 2 and the vibration is reduced. A vibration isolating member 4 is arranged between the ring 3 and the ring 3 . That is, the damper portion 41 is assembled into the hub 2 by press fitting. At this time, since the through hole 422 is formed at a position overlapping the folded part 51, a rod-shaped jig, for example, is inserted through the through hole 422 and brought into contact with the folded part 51, and the jig applies force to the sleeve 5. Additionally, it can be pushed in.

In the state in which the hub 2, vibration ring 3, vibration isolating member 4, and sleeve 5 are assembled in this way, the boss portion 21 is visible from the other side in the axis x direction through the opening 421, so that work can be carried out from the other side. This allows the boss portion 21 and the crankshaft to be fastened together.

In addition, the hub 2, the vibration ring 3, the vibration isolating member 4, and the sleeve 5 cannot rotate relative to each other when assembled by press fitting as described above. Particularly, the damper part 41 of the vibration isolating member 4 cannot rotate relative to the hub 2, and therefore the lid part 42, which is integrally formed with the damper part 41, also cannot rotate relative to the hub 2.

Specific examples of dimensions of each part in the torsional damper 1 will be described below. It is assumed that the inner diameter D1 of the opening 421 is 44 mm, the hub open inner diameter D3, which is the inner diameter (diameter) of the rim portion 23 of the hub 2, is 92 mm, and the speed of sound is 340 m/s. When sound generated on one side of the lid 42 in the axis x direction passes through the opening 421 and attempts to head to the other side, the lowest frequency of the sound (radiated sound) that can pass through the opening 421 is (sound velocity )/(inner diameter D1), which is 7.7kHz. Further, the proportion of such high-frequency sound that can pass through the opening 421 is calculated as (inner diameter D1) ² /(hub open inner diameter D3) ² and is 22.9%. Therefore, under these conditions, it is possible to reduce 77.1% of the radiated sound of 7.7 kHz or more, and to block the radiated sound of less than 7.7 kHz.

Therefore, the inner diameter D1 of the opening 421 is preferably 44 mm or less, and the inner diameter D1 of the opening 421 is preferably 47.8% (=44/92) or less of the hub open inner diameter D3.

In this manner, according to the torsional damper 1 according to the embodiment of the present invention, noise can be reduced by providing the lid portion 42 that covers the hub 2 from the other side in the axis x direction. At this time, since the damper part 41 and the lid part 42 are integrally formed, there is no need to restrict the relative rotation between the hub 2 and the lid part 42, reducing the number of parts and suppressing the complexity of the configuration. can do.

Furthermore, since the damper section 41 and the lid section 42 are integrally formed, there is no need for the step of attaching and detaching only the lid section, and the number of assembly steps can be reduced compared to a structure in which the lid section is a separate body. Can be done.

In addition, since the damper part 41 and the lid part 42 are integrally formed, there is no need to restrict the relative rotation between the hub 2 and the lid part 42 as described above, and the crankshaft moves at high speed during operation. Even when rotating and accelerating/decelerating, relative rotation can be easily suppressed, and minute relative vibrations and the like occurring between the lid part 42 and the hub 2 can be easily suppressed. Thereby, it is possible to suppress the occurrence of wear, scratches, etc. on the lid part 42, and improve durability.

Further, since the opening 421 is formed in the lid 42, the boss 21 and the crankshaft can be connected through the opening 421, thereby improving workability. At this time, even if the opening 421 is formed, the frequency and proportion of the radiated sound that can pass through the opening 421 are limited, and noise can be reduced compared to a configuration without a lid. . In particular, if the inner diameter D1 of the opening 421 is 44 mm or less and the inner diameter D1 of the opening 421 is 47.8% or less of the hub open inner diameter D3, noise can be easily reduced.

Further, the sleeve 5 is provided on the outer circumferential side of the hub 2 and the inner circumferential side of the damper part 41, and the damper part 41 is assembled to the hub 2 by press fitting, so that the damper part 41 and the lid part 42 are connected to each other. Even in the integrally formed configuration, the damper portion 41 can be easily assembled to the hub 2.

Note that the present invention is not limited to the above-described embodiments, but includes other configurations that can achieve the object of the present invention, and the present invention also includes the following modifications. For example, in the above embodiment, the inner diameter D1 of the opening 421 is 44 mm or less, and the inner diameter D1 of the opening 421 is 47.8% or less of the hub open inner diameter D3. The relationship is not limited to this, and may be set as appropriate depending on the frequency, sound pressure, etc. of the radiated sound that may be generated.

Further, in the above embodiment, the opening 421 is formed in the lid 42, but for example, when the damper is assembled after the hub and the crankshaft (shaft member) are connected, or when the damper is installed at another position. If the hub and crankshaft can be connected from each other, the lid may not have an opening. According to such a configuration, noise can be further reduced.

Further, in the above embodiment, the sleeve 5 is provided on the outer peripheral side of the hub 2 and the inner peripheral side of the damper part 41, and the damper part 41 is assembled to the hub 2 by press fitting, a so-called bush type is adopted. However, other assembly methods may be used. For example, a so-called fitting type may be adopted in which the damper portion is fitted between the hub and the vibration ring without a sleeve. That is, the unevenness formed on the outer circumferential surface of the hub and the unevenness formed on the inner circumferential surface of the damper section fit together, and the unevenness formed on the outer circumferential surface of the damper section and the unevenness formed on the inner circumferential surface of the vibration ring. The structure may be such that the projections and depressions fit into each other.

Although the embodiments of the present invention have been described above, the present invention is not limited to the torsional damper according to the above-described embodiments of the present invention, and can be applied to all aspects included in the concept of the present invention and the scope of the claims. including. Moreover, each structure may be selectively combined as appropriate so as to achieve at least some of the problems and effects described above. For example, the shape, material, arrangement, size, etc. of each component in the above embodiments may be changed as appropriate depending on the specific usage of the present invention.

DESCRIPTION OF SYMBOLS 1...Torsional damper, 2...Hub, 21...Boss part, 211...Keyway, 22...Connection part, 23...Rim part, 23A...One side end part, 23B...Other side end part, 3... Vibration ring , 31... Pulley groove, 3A... End on one side, 3B... End on the other side, 4... Vibration isolating member, 41... Damper part, 41A... End on one side, 41B... End on the other side, 42 ...Lid part, 421...Opening part, 422...Through hole, 5...Sleeve, 51...Folding part, 5A...One side end

Claims (3)

a hub connected to a shaft member of an internal combustion engine;
a vibration ring provided on the outer peripheral side of the hub;
a damper section provided between the hub and the vibration ring;
a lid portion provided to cover the hub from the opposite side to the shaft member,
A torsional damper, wherein the damper portion and the lid portion are integrally formed. a sleeve provided on the outer circumferential side of the hub and on the inner circumferential side of the damper part;
The torsional damper according to claim 1, wherein the damper portion is assembled to the hub by press fitting. The torsional damper according to claim 1 or 2, wherein an opening is formed in the center of the lid.

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