阅读说明：本技术 动态阻尼器 (Dynamic damper ) 是由 佐佐木康志 花田祐树 于 2020-10-19 设计创作，主要内容包括：本发明提供一种动态阻尼器,由轮毂、振动环和弹性体包围的闭合空间的压力不会上升,因而能够容易地进行组装,另外即便由于弹性体与振动环共振而使弹性体发热,所述闭合空间的压力也不会上升,因而突起部发挥稳定的限位器功能。动态阻尼器包括轮毂、振动环、一对弹性体、轴承和套筒,振动环配置于轮毂的外周侧,并具有振动环主体和凸部,弹性体具有配置为从振动环的轴向的两侧夹持凸部并向轴向外侧弯曲的弯曲部和朝向凸部突出的突起部,套筒配置于弯曲部的端部与轮毂之间并与它们固定,还包括将闭合空间和外部相连的路径,以使由轮毂、凸部和弹性体的内表面包围的闭合空间内的压力不上升。(The invention provides a dynamic damper, wherein the pressure of a closed space surrounded by a hub, a vibration ring and an elastic body is not increased, so that the dynamic damper can be easily assembled, and the pressure of the closed space is not increased even if the elastic body and the vibration ring resonate to generate heat, so that a protrusion part plays a stable stopper function. The dynamic damper includes a hub, a vibration ring, a pair of elastic bodies, a bearing, and a sleeve, wherein the vibration ring is disposed on an outer peripheral side of the hub, and has a vibration ring main body and a convex portion, the elastic bodies have a curved portion configured to sandwich the convex portion from both sides in an axial direction of the vibration ring and to be bent outward in the axial direction, and a protruding portion protruding toward the convex portion, the sleeve is disposed between an end portion of the curved portion and the hub and fixed thereto, and the dynamic damper further includes a path connecting a closed space and an outside so that a pressure in the closed space surrounded by the hub, the convex portion, and an inner surface of the elastic.)

1. A dynamic damper comprises a hub, a vibration ring, a pair of elastic bodies, a bearing and a sleeve,

the vibration ring is disposed on an outer peripheral side of the hub, and has an annular vibration ring body and a convex portion that protrudes toward an outer peripheral surface of the hub on an inner peripheral side of the vibration ring body,

the pair of elastic bodies has: a bending portion configured to sandwich the projection from both sides in an axial direction of the vibration ring, to connect the hub and the vibration ring main body via the sleeve, and to bend outward in the axial direction; and a protrusion protruding from an inner surface in the curved portion toward the convex portion,

the bearing is disposed between the boss and the hub,

the sleeve is fixed to each end portion on the inner diameter side or the outer diameter side of the bent portion,

the dynamic damper further includes a path connecting the closed space and the outside so that the pressure in the closed space surrounded by the boss in the vibration ring, the boss, and the inner surface of the elastic body does not rise.

2. The dynamic damper of claim 1,

the sleeve includes a slit as the path.

3. The dynamic damper according to claim 1 or 2,

the path connecting the closed space and the outside is provided in the vibration ring.

4. The dynamic damper according to any one of claims 1 to 3,

the path connecting the closed space and the outside is provided in the hub.

Technical Field

The present invention relates to a dynamic damper that absorbs torsional vibration generated in a rotary drive system such as a propeller shaft of an internal combustion engine. Dynamic dampers are sometimes also referred to as shock absorbers.

Background

A rear-wheel drive or four-wheel drive motor vehicle includes a propeller shaft for transmitting the output of an internal combustion engine mounted on the front portion of the vehicle to rear wheels.

Since vibration generated in the propeller shaft has a large influence on vibration of the vehicle, the propeller shaft is equipped with a dynamic damper that damps the vibration.

The dynamic damper includes a hub, a vibration ring located on an outer peripheral side of the hub, and an elastic body connecting the hub and the vibration ring. The vibration ring resonates with the elastic body to cancel vibration when the drive shaft rotates, whereby vibration in a torsional direction (rotational direction) of the drive shaft can be attenuated.

In recent years, the frequency band of vibration generated in a propeller shaft has been reduced due to weight reduction of a vehicle for the purpose of improving fuel efficiency. When the frequency of the vibration is small, the excitation input value to the dynamic damper tends to be large, and a large torsional load may be applied to the elastic body.

Here, if the elastic body is elongated in the radial direction, the durability of the elastic body is improved. However, in such a case, the radial space of the dynamic damper is enlarged. Further, when the stopper for restricting the relative displacement amount of the vibration ring is provided, although the torsional load applied to the elastic body can be prevented, the number of components increases by the number of the stopper.

In order to solve the above-described problems, a dynamic damper described in patent document 1 is proposed.

As shown in fig. 6, patent document 1 describes a dynamic damper 10 including: a hub 20; a vibration ring 30 located on the outer peripheral side of the hub 20; and a pair of elastic bodies 40 made of a rubber-like elastic material, which are located on both sides of the vibration ring 30 in the axial direction and connect the hub 20 and the vibration ring 30, wherein the vibration ring 30 includes a convex portion 32 extending to the vicinity of the outer peripheral surface of the hub 20, each elastic body 40 is formed in a shape that is bent outward in the axial direction from the hub 20 to the vibration ring 30 from the convex portion 32, a protrusion 44 made of a rubber-like elastic material extending toward the convex portion 32 is integrally formed on the surface of the elastic body 40 on the side of the convex portion 32, and a gap is provided between the convex portion 32 and the protrusion 44. The following are also described: the vibration ring 30 in the dynamic damper 10 has an annular vibration ring body 31 coupled to the outer peripheral side of the hub 20 via a sleeve 41 and an elastic body 40, and a protrusion 32 is formed from the axial center of the vibration ring body 31 in the radial direction. Further, it is described that: the dry bearing 33 is fitted to the inner peripheral surface of the projection 32.

The following is described: according to the dynamic damper 10, the elastic body 40 is formed in a curved shape, so that the torsional load on the elastic body 40 can be reduced without increasing the space in the radial direction in which the elastic body 40 is provided, and the relative displacement amount of the vibration ring 30 can be attenuated by the resistance when the protrusion 44 comes into contact with the convex portion 32, thereby also functioning as a stopper.

Documents of the prior art

Patent document

Patent document 1: international publication No. 2018/088103 booklet

Disclosure of Invention

Technical problem to be solved by the invention

In assembling the dynamic damper 10 described in patent document 1 as described above, one elastic body 40 is fitted between the hub 20 and the vibration ring main body 31, and then the other elastic body 40 is fitted between the hub 20 and the vibration ring main body 31. At this time, since the elastic body 40 is fitted so as to sandwich the convex portion 32 of the vibration ring 30 from both axial sides, a closed space surrounded by the hub 20, the vibration ring 30, and the elastic body 40 is formed. Here, when fitting the other elastic body 40, an excessive force for resisting the pressure generated by the closed space is required, so that the assembling work is not easy.

In the dynamic damper 10 described in patent document 1, the protrusion 44 comes into contact with the projection 32 to function as a stopper, thereby preventing the dynamic damper 10 from twisting to a certain degree or more. However, when the dynamic damper 10 absorbs the vibration, the elastic body 40 generates heat, and therefore the gas in the closed space expands to cause the pressure in the closed space to rise. As a result, the elastic body 40 bulges outward, and the protrusion 44 is less likely to contact the convex portion 32, and thus a stable stopper function may not be exhibited.

The present invention is intended to solve the above-described problems. That is, an object of the present invention is to provide a dynamic damper that can be easily assembled without increasing the pressure in a closed space surrounded by a hub, a vibration ring, and an elastic body, and that can exhibit a stable stopper function in a protrusion portion without increasing the pressure in the closed space even if the elastic body resonates with the vibration ring and the elastic body generates heat.

Means for solving the technical problem

The present inventors have conducted intensive studies to solve the above-mentioned problems, and have completed the present invention.

The present invention is the following (1) to (4).

(1) A dynamic damper comprises a hub, a vibration ring, a pair of elastic bodies, a bearing and a sleeve,

the vibration ring is disposed on an outer peripheral side of the hub, and has an annular vibration ring body and a convex portion that protrudes toward an outer peripheral surface of the hub on an inner peripheral side thereof,

the pair of elastic bodies has: a bending portion configured to sandwich the convex portion from both sides in an axial direction of the vibration ring, to connect the hub and the vibration ring main body via the sleeve, and to bend outward in the axial direction; and a protrusion protruding from an inner surface in the curved portion toward the convex portion,

the bearing is disposed between the boss and the hub,

the sleeves are fixed to respective ends of the bent portion on the inner diameter side or the outer diameter side,

the dynamic damper further includes a path connecting the closed space and the outside so that the pressure in the closed space surrounded by the boss in the vibration ring, the boss, and the inner surface of the elastic body does not rise.

(2) The dynamic damper according to item (1) above, wherein the sleeve includes a slit as the path.

(3) The dynamic damper according to the above (1) or (2), wherein the path connecting the closed space and the outside is provided in the vibration ring.

(4) The dynamic damper according to any one of the above (1) to (3), wherein the path connecting the closed space and the outside is provided in the hub.

Effects of the invention

According to the present invention, it is possible to provide a dynamic damper in which the pressure in the closed space surrounded by the hub, the vibration ring, and the elastic body does not increase, and therefore, the dynamic damper can be easily assembled, and in addition, even if the elastic body resonates with the vibration ring and the elastic body generates heat, the pressure in the closed space does not increase, and therefore, the protrusion portion functions as a stable stopper.

Drawings

Fig. 1 is a schematic axial sectional view of a dynamic damper according to a first embodiment.

Fig. 2 is a schematic plan view of the first dynamic damper in a direction perpendicular to the shaft.

Fig. 3 is a schematic axial sectional view of a dynamic damper according to the second embodiment.

Fig. 4 is a schematic plan view of the dynamic damper according to the second embodiment in a direction perpendicular to the shaft.

Fig. 5 is a schematic axial sectional view of a dynamic damper according to the third embodiment.

Fig. 6 is a schematic axial sectional view of a conventional dynamic damper.

Detailed Description

The dynamic damper of the present invention will be explained.

A dynamic damper according to the present invention includes a hub, an oscillation ring, a pair of elastic bodies, a bearing, and a sleeve, wherein the oscillation ring is disposed on an outer peripheral side of the hub, and has an annular oscillation ring main body and a convex portion that protrudes toward an outer peripheral surface of the hub on an inner peripheral side thereof, and the pair of elastic bodies includes: a bending portion configured to sandwich the convex portion from both sides in an axial direction of the vibration ring, to connect the hub and the vibration ring main body via the sleeve, and to bend outward in the axial direction; and a protrusion portion protruding from an inner surface of the curved portion toward the convex portion, wherein the bearing is disposed between the convex portion and the hub, and the sleeve is fixed to each end portion of the curved portion on an inner diameter side or an outer diameter side, and the dynamic damper further includes a path connecting the closed space and an outside so that a pressure in the closed space surrounded by the hub, the convex portion of the vibration ring, and an inner surface of the elastic body does not increase.

< first mode >

A first mode (mode one) of the dynamic damper according to the present invention will be described with reference to fig. 1 and 2. Fig. 1 is a schematic cross-sectional view in the axial direction of a dynamic damper according to the first embodiment, and fig. 2 is a schematic plan view in a direction perpendicular to the axial direction of the dynamic damper according to the first embodiment.

Fig. 1 and 2, and fig. 3 to 5 described later are examples of preferred embodiments of the dynamic damper according to the present invention. The dynamic damper of the present invention is not limited to the embodiment shown in fig. 1 to 5. Various modifications and changes are allowable in the present invention.

As shown in fig. 1 and 2, the dynamic damper 10 includes a cylindrical hub 20 and a cylindrical vibration ring 30 located on the outer circumferential side of the hub 20, and an elastic body 40 connects the hub 20 and the vibration ring 30. The elastic body 40 is provided in a pair on both sides in the axial direction of the vibration ring 30. The dynamic damper 10 is used by being mounted on a propeller shaft or the like located on the lower side of a vehicle such as an automobile.

The hub 20 is fixed to the propeller shaft. The outer peripheral surface 21 of the hub 20 is coupled to the vibration ring 30 via an elastic body 40.

The vibration ring 30 has a ring-shaped vibration ring main body 31. The vibration ring main body 31 is coupled to the outer peripheral side of the hub 20 via a sleeve 41 and an elastic body 40. The vibration ring 30 has a projection 32 from the axial center toward the inner diameter direction. A dry bearing 33 is fitted and fixed to the inner peripheral surface of the convex portion 32. The inner peripheral surface of the dry bearing 33 faces the outer peripheral surface 21 of the hub 20 with a slight gap. That is, a slight gap is provided between the inner peripheral surface of the dry bearing 33 and the outer peripheral surface 21 of the hub 20.

The elastic body 40 is a ring-shaped rubber-like elastic body. The elastic body 40 includes a bent portion 42, and the bent portion 42 has a shape bent toward the axially outer side (the left-right direction in fig. 1). The curved portion 42 has an annular rubber block 43 at the center of the outer surface (the apex of the curved portion 42), and an annular protrusion 44 at the center of the inner surface of the curved portion 42.

The end portion on the outer diameter side of the bent portion 42 is fixed to the sleeve 41. The sleeve 41 is fitted and fixed to the inner circumferential surface of the vibration ring main body 31. That is, the end portion on the outer diameter side of the bent portion 42 is connected to the vibration ring main body 31 via the sleeve 41.

The end portion on the inner diameter side of the bent portion 42 is fixed to the sleeve 41. The sleeve 41 is fitted and fixed to the outer peripheral surface of the hub 20. That is, the end portion on the inner diameter side of the bent portion 42 is coupled to the hub 20 via the sleeve 41.

The bent portion 42 can be fixed to the sleeve 41 by welding, vulcanization bonding, or bonding using an adhesive, for example.

Therefore, the bent portion 42 connects the hub 20 and the vibration ring 30 in a fixed state, and can be elastically deformed when the vibration ring 30 is displaced in the torsional direction X with respect to the hub 20.

The rubber block 43 is formed in the central portion of the outer surface of the curved portion 42 on the opposite side of the protruding portion 44. A part of the bent portion 42 where the rubber block 43 is located is thick, and the elastic body 40 increases the rigidity of the rubber block 43 locally.

In the dynamic damper of the present invention, the position of the rubber block 43 in the elastic body 40 is not particularly limited. However, in order to elastically deform the elastic body 40 in a balanced manner on the outer diameter side and the inner diameter side, it is preferable to dispose the rubber block 43 in the center of the elastic body 40, that is, in the vicinity of the apex of the bent portion 42.

The protrusion 44 is formed in the center portion of the inner surface of the bent portion 42 located on the opposite side of the rubber block 43. The protrusion 44 extends in the axial direction from the inner surface of the bent portion 42 toward the convex portion 32 of the vibration ring 30. A very small gap C1 is provided between the tip of the protrusion 44 and the convex portion 32. The clearance C1 is approximately 1-2 mm.

According to the dynamic damper 10 having the above-described configuration, the elastic body 40 and the vibration ring 30 resonate in a phase opposite to the phase of the displacement in the torsional direction X caused by the vibration of the propeller shaft, and therefore the vibration of the propeller shaft can be reduced.

When the vibration ring 30 of the dynamic damper 10 is displaced in the torsional direction X with respect to the hub 20 due to vibration accompanying rotation of the propeller shaft, the bent portions 42 of the elastic body 40 are stretched in the torsional direction X. At this time, the rubber block 43 formed at the bent portion 42 increases the rigidity of the elastic body 40, and the outer diameter side and the inner diameter side of the elastic body 40 are elastically deformed in a balanced manner centering on the rubber block 43, thereby preventing stress from being concentrated on a part of the elastic body 40. As a result, the durability of the elastic body 40 can be improved.

According to the dynamic damper 10 of the first aspect, when the vibration ring 30 is displaced in the torsional direction X with respect to the hub 20, the bent portion 42 having a bent shape is stretched in the torsional direction X. At this time, the radial length of the elastic body 40 is increased by the curved shape of the curved portion 42, and the allowable displacement amount of the elastic body 40 is increased. As a result, the torsional durability against the relative displacement of the vibration ring 30 is improved, and the range of the vibration reduction effect against the rotation of the propeller shaft can be increased without increasing the space occupied in the radial direction of the elastic body 40.

When the vibration ring 30 is twisted to a certain degree or more as the rotational speed of the propeller shaft increases, the bent portion 42 is stretched, and therefore the clearance C1 between the protrusion 44 and the protrusion 32 is reduced, and the protrusion 44 and the protrusion 32 come into contact with each other. When the protrusion 44 contacts the convex portion 32, the amount of attenuation of the vibration in the torsional direction X increases. At this time, the protrusion 44 functions as a stopper, and thus the vibration ring 30 can be prevented from twisting to a certain degree or more.

The dynamic damper 10 as shown in fig. 1 and 2 has a closed space S surrounded by the boss 20, the convex portion 32 of the vibration ring 30, and the inner surface of the elastic body 40, but has a path connecting the closed space S and the outside in order to avoid a pressure rise in the closed space S.Specifically, the sleeve 41 is provided with slits R₁As a path.

Due to the slit R₁The pressure in the closed space S does not rise. Therefore, the dynamic damper can be easily assembled, and even if the elastic body 40 generates heat due to resonance between the elastic body 40 and the vibration ring 30, the pressure in the closed space S does not rise, so that the protrusion 44 functions as a stable stopper. Further, since the elastic body 40 is less likely to be deformed, the durability is improved.

Since a slight gap exists between the inner peripheral surface of the dry bearing 33 and the outer peripheral surface 21 of the hub 20 as described above, the left and right closed spaces S shown in fig. 1 are connected.

Slit R₁Is a member made of a metal in a ring shape. Slit R₁The metal sheet can be manufactured by, for example, press working or cutting.

The slit R1 may be provided in the hub 20-side sleeve 41, but is preferably provided in the vibration ring 30-side sleeve 41 as shown in fig. 1. This is because, when the propeller shaft mounted on a vehicle is used, muddy water or the like is repelled by the centrifugal force due to the rotation of the vibration ring 30, and the muddy water or the like can be prevented from entering the dynamic damper 10.

In addition, although the slit R₁The moving direction of the gas in the slit R1 may be parallel to the axial direction, but at least a part of the moving direction of the gas in the slit R1 is preferably formed so as not to be parallel to the axial direction. For example, in the embodiment shown in fig. 1, the moving direction of the gas inside the slit R1 is constituted by a portion parallel to the axial direction and a portion perpendicular to the axial direction. This is because, in the case of such a structure, the muddy water or the like hardly intrudes.

< second mode >

A second mode (mode two) of the dynamic damper according to the present invention will be described with reference to fig. 3 and 4. Fig. 3 is a schematic axial sectional view of a dynamic damper according to the second embodiment. Fig. 4 is a schematic plan view of the dynamic damper according to the second embodiment in a direction perpendicular to the shaft. That is, FIG. 4 shows only one of the dynamic dampers shown in FIG. 3A diagram of a vibration ring. Note that, fig. 4 shows a path R₂Of the end portion of (a).

The second approach differs from the first approach only in the location of the path. Thus, the route of the second embodiment will be described below.

The dynamic damper 10 as shown in fig. 3 has a closed space S surrounded by the boss 20, the convex portion 32 of the vibration ring 30, and the inner surface of the elastic body 40, but has a path connecting the closed space S and the outside in order to avoid a pressure rise in the closed space S. Specifically, a path R connecting the closed space S and the outside is provided in the vibration ring 30₂。

Route R₂For example, the path may have a circular cross section and a cross-sectional diameter of about 1 mm.

Due to the path R₂The pressure in the closed space S does not rise. Therefore, the dynamic damper can be easily assembled, and even if the elastic body 40 generates heat due to resonance between the elastic body 40 and the vibration ring 30, the pressure in the closed space S does not rise, so that the protrusion 44 functions as a stable stopper. Further, since the elastic body 40 is less likely to be deformed, the durability is improved.

Route R₂It may be manufactured by, for example, machining.

In a second mode (mode two) of the dynamic damper according to the present invention, the path R₂Having at least 1, but preferably path R in order to maintain the balance of the vibrating ring 30₂There are a plurality of. Particularly preferably, the path R is provided at a position symmetrical with respect to the axis in the circumferential direction₂。

< third mode >

A third aspect (aspect three) of the dynamic damper according to the present invention will be described with reference to fig. 5. Fig. 5 is a schematic axial sectional view of a dynamic damper according to the third embodiment.

Mode three only the position of the path is different from the mode one. Thus, the route of the third embodiment will be described below.

As shown in FIG. 5, the dynamic damper 10 includes a hub 20 and a vibration ring 30The convex portion 32 and the inner surface of the elastic body 40 surround the closed space S, but in order to avoid a pressure rise in the closed space S, a path is provided to connect the closed space S to the outside. Specifically, a path R connecting the closed space S and the outside is provided in the hub 20₃。

In fig. 5, a route R is shown₃Formed between the dry bearing 33 and the sleeve 41, but is aligned with the path R₃The position of (b) is not particularly limited.

Route R₃For example, the path may have a circular cross section and a cross-sectional diameter of about 1 mm.

Due to the path R₃The pressure in the closed space S does not rise. Therefore, the dynamic damper can be easily assembled, and even if the elastic body 40 generates heat due to resonance between the elastic body 40 and the vibration ring 30, the pressure in the closed space S does not rise, so that the protrusion 44 functions as a stable stopper. In addition, since the elastic body 40 is less likely to be deformed, the durability is improved.

Conventionally, when a dynamic damper is mounted on a propeller shaft of a vehicle for use, the dynamic damper is sometimes soaked with muddy water, dust, and the like. At this time, there are the following cases: when muddy water, dust, or the like intrudes into the dynamic damper, the natural vibration expected as the dynamic damper changes, and the expected vibration-proof performance cannot be sufficiently exhibited. In addition, the mass balance of the dynamic damper in the circumferential direction may be deviated by the intrusion of muddy water or the like, and the vibration may be increased. However, in the case of the third aspect of the dynamic damper of the present invention, the path R₃The end (inlet/outlet) of (a) is closed by the outer peripheral surface of the drive shaft, and therefore is excellent in that muddy water or the like hardly enters the dynamic damper during use.

Route R₃Can be produced by, for example, machining.

In a third aspect (aspect three) of the dynamic damper according to the present invention, the path R₃Having at least 1, but preferably path R in order to maintain the balance of the vibrating ring 30₃There are a plurality of. Particularly preferably, the axial direction is relative to the shaftIn a symmetrical position having a path R₃。

Description of the reference numerals

10 dynamic damper

20 wheel hub

21 outer peripheral surface

30 vibrating ring

31 vibration ring body

32 convex part

33 Dry bearing

40 elastomer

41 sleeve

42 bending part

43 rubber block

44 projection

C1 gap

Direction of X torsion

R₁Narrow slit (Path)

R₂、R₃Route of travel

S closed space

The present application claims priority based on the Japanese application laid-open at 11/13/2019, and the entire disclosure of which is incorporated herein by reference.