阅读说明：本技术 动态阻尼器及其制造方法 (Dynamic damper and manufacturing method thereof ) 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：本发明提供动态阻尼器,无需增大设置弹性体的径向空间就能够减小对于弹性体的扭转负荷,而且还能够限制振动环的相对位移量,以免弹性体发生破损。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,并具有环状的振动环主体和在其内周侧朝向所述轮毂的外周面突出的凸部,一对弹性体具有配置为从振动环中的轴向的两侧夹持凸部的弯曲部、和突起部,其中,套筒为圆筒状,并具有构成与轴向平行的内筒面的筒部和从筒部的一端部朝向外周侧突出的凸缘部,弹性体中的弯曲部的内径侧和外径侧的端部各自仅被固定于内筒面。(The invention provides a dynamic damper, which can reduce the torsion load to an elastic body without increasing the radial space for arranging the elastic body, and can limit the relative displacement of a vibration ring so as to prevent the elastic body from being damaged. The dynamic damper includes a hub, a vibration ring, a pair of elastic bodies, a bearing, and a sleeve, wherein the vibration ring is arranged on the outer peripheral side of the hub, and has an annular vibration ring main body and a convex portion protruding toward the outer peripheral surface of the hub on the inner peripheral side thereof, the pair of elastic bodies have a curved portion and a protruding portion arranged to sandwich the convex portion from both sides in the axial direction of the vibration ring, the sleeve is cylindrical and has a cylindrical portion constituting an inner cylindrical surface parallel to the axial direction and a flange portion protruding toward the outer peripheral side from one end portion of the cylindrical portion, and the end portions on the inner and outer diameter sides of the curved portion in the elastic bodies are each fixed only to the inner cylindrical surface.)

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 clamp the convex portion of the vibration ring from both axial sides, 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 cylindrical and has a cylindrical portion constituting an inner cylindrical surface parallel to an axial direction and a flange portion protruding from one end portion of the cylindrical portion toward an outer circumferential side, and ends on an inner diameter side and an outer diameter side of the bent portion in the elastic body are each fixed only to the inner cylindrical surface in the sleeve.

2. The dynamic damper of claim 1,

the flange portion in the sleeve has a guide portion.

3. A manufacturing method of a dynamic damper, which method results in the dynamic damper of claim 1 or 2, the manufacturing method comprising:

a fixing step of fixing end portions of the bent portions in the elastic body only to the inner cylindrical surfaces of the two sleeves disposed on the inner diameter side and the outer diameter side, respectively, to obtain a sleeve-equipped elastic body;

a first press-fitting step of disposing the elastic body with a sleeve on a jig that supports at least a part of a stress applied to the cylindrical portion from below via the flange portion, with the inner cylindrical surface being in a vertical direction and the flange portion being in a lower side state;

a second press-fitting step of fitting the hub into the sleeve on the inner peripheral side of the elastic body with a sleeve disposed on the jig in the first press-fitting step from above, and fitting the vibration ring into the sleeve on the outer peripheral side of the elastic body with a sleeve from above; and

a third press-fitting step of press-fitting the other sleeve-equipped elastic body between the hub and the vibration ring main body from above with the inner cylindrical surface in a vertical direction and the flange portion on the upper side, using a jig capable of applying stress to the cylindrical portion via the flange portion.

Technical Field

The present invention relates to a dynamic damper for absorbing torsional vibration generated in a rotary drive system such as a propeller shaft of an internal combustion engine, and a method for manufacturing the dynamic damper. 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 stoppers.

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

As shown in fig. 10, 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 periphery of the hub 20, each elastic body 40 is formed in a shape that is bent outward in the axial direction from the convex portion 32 from the hub 20 to the vibration ring 30, a protrusion 44 made of a rubber-like elastic material extending toward the convex portion 32 is integrally formed on a 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 radial space 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. Here, when the elastic body 40 is fitted so as to sandwich the convex portion 32 of the vibration ring 30 from both axial sides, fitting (press fitting) cannot be performed even if stress is applied to the elastic body 40, and therefore, both end portions of the bent portion 42 are fixed to the cylindrical sleeve 41, and then the sleeve 41 is fitted by applying stress.

However, as in the embodiment shown in fig. 10, when the end portion of the bent portion 42 is fixed to the end surface perpendicular to the shaft of the sleeve 41, the end surface cannot be fitted (press-fitted) by applying stress thereto. This is because there is a possibility that the end portion of the bent portion 42 may be broken. When the end portion of the bent portion 42 is broken, the elastic body 40 hardly exhibits a predetermined performance, and as a result, the torsional load to the elastic body 40 cannot be reduced, and in addition, the stopper function of the protrusion 44 is hardly 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 and a manufacturing method thereof, which can suppress damage to an elastic body and deformation of a sleeve.

Means for solving the technical problem

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

The present invention is (1) to (3) below.

(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,

a pair of the elastic bodies: a bending portion configured to clamp the convex portion of the vibration ring from both axial sides, 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,

wherein the content of the first and second substances,

the sleeve is cylindrical and has a cylindrical portion constituting an inner cylindrical surface parallel to an axial direction and a flange portion protruding from one end portion of the cylindrical portion toward an outer circumferential side, and ends on an inner diameter side and an outer diameter side of the bent portion in the elastic body are each fixed only to the inner cylindrical surface in the sleeve.

(2) The dynamic damper according to the above (1), wherein the flange portion in the sleeve has a guide portion.

(3) A manufacturing method of a dynamic damper, which obtains the dynamic damper of (1) or (2), the manufacturing method comprising:

a fixing step of fixing each of end portions of the bent portion in the elastic body only to the inner cylindrical surface of each of the two sleeves disposed on the inner diameter side and the outer diameter side to obtain a sleeve-equipped elastic body;

a first press-fitting step of disposing the elastic body with a sleeve on a jig that supports at least a part of a stress applied to the cylindrical portion from below via the flange portion, with the inner cylindrical surface being in a vertical direction and the flange portion being in a lower side state;

a second press-fitting step of fitting the hub into the sleeve on the inner peripheral side of the elastic body with a sleeve disposed on the jig in the first press-fitting step from above, and fitting the vibration ring into the sleeve on the outer peripheral side of the elastic body with a sleeve from above; and

a third press-fitting step of press-fitting the other sleeve-equipped elastic body between the hub and the vibration ring main body from above with the inner cylindrical surface in a vertical direction and the flange portion on the upper side, using a jig capable of applying stress to the cylindrical portion via the flange portion.

Effects of the invention

According to the present invention, it is possible to provide a dynamic damper capable of suppressing breakage of an elastic body and deformation of a sleeve, and a method for manufacturing the dynamic damper.

Drawings

Fig. 1 is a schematic cross-sectional view in the axial direction of a dynamic damper of the present invention.

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

Fig. 3 is a schematic sectional perspective view of the sleeve 41a on the outer diameter side and the sleeve 41b on the inner diameter side.

Fig. 4 is a schematic sectional perspective view showing a state in which the elastic body 40 is fixed to the two sleeves shown in fig. 3.

Fig. 5 is a schematic perspective view showing a preferred example of the jig used in the first press-fitting step.

Fig. 6 is a schematic partial sectional view for explaining the first press-fitting step.

Fig. 7 is a schematic partial sectional view for explaining the second press-fitting step.

Fig. 8 is a schematic perspective view showing a preferred example of the jig used in the third press-fitting step.

Fig. 9 is a schematic partial sectional view for explaining the third press-fitting step.

Fig. 10 is a schematic cross-sectional view in the axial direction of a conventional dynamic damper.

Detailed Description

The present invention will be explained.

The present invention is a dynamic damper including a hub, an oscillation ring, a pair of elastic bodies, a bearing, and a sleeve, the oscillation ring being disposed on an outer peripheral side of the hub and having 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, the pair of elastic bodies including: a bending portion configured to clamp the convex portion of the vibration ring from both axial sides, 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 bent portion toward the protrusion portion, wherein the bearing is disposed between the protrusion portion and the hub, the sleeve is cylindrical and has a cylindrical portion constituting an inner cylindrical surface parallel to an axial direction and a flange portion protruding from one end portion of the cylindrical portion toward an outer circumferential side, and ends of the elastic body on an inner diameter side and an outer diameter side of the bent portion are fixed only to the inner cylindrical surface in the sleeve.

Such a dynamic damper is hereinafter also referred to as "dynamic damper of the present invention".

In addition, the present invention is a method for manufacturing a dynamic damper, which can obtain the dynamic damper of the present invention, including: a fixing step of fixing end portions of the bent portions in the elastic body only to the inner cylindrical surfaces of the two sleeves disposed on the inner diameter side and the outer diameter side, respectively, to obtain a sleeve-equipped elastic body; a first press-fitting step of disposing the sleeve-attached elastic body on a jig that supports at least a part of a stress applied to the tube portion from below via the flange portion in a state where the inner tube surface is in a vertical direction and the flange portion is positioned on a lower side; a second press-fitting step of fitting the hub into the sleeve on the inner peripheral side of the elastic body with a sleeve disposed on the jig in the first press-fitting step from above, and fitting the vibration ring into the sleeve on the outer peripheral side of the elastic body with a sleeve from above; and a third press-fitting step of press-fitting the other sleeve-equipped elastic body between the hub and the vibration ring main body from above with the inner cylindrical surface in a vertical direction and the flange portion on the upper side, using a jig capable of applying stress to the cylindrical portion via the flange portion.

The method of manufacturing such a dynamic damper is hereinafter also referred to as "the method of manufacturing the present invention".

The dynamic damper of the present invention can be obtained by the manufacturing method of the present invention.

The dynamic damper of the present invention is preferably manufactured by the manufacturing method of the present invention.

A preferred embodiment of the dynamic damper according to the present invention will be described with reference to fig. 1 to 4. Fig. 1 is a schematic cross-sectional view in the axial direction of a dynamic damper according to the present invention in a preferred embodiment, and fig. 2 is a schematic plan view in the direction perpendicular to the axis of the dynamic damper according to the present invention shown in fig. 1. Fig. 3 is a schematic cross-sectional perspective view of the outer diameter side sleeve 41a and the inner diameter side sleeve 41b, and fig. 4 is a schematic cross-sectional perspective view showing a state in which the elastic body 40 is fixed to both the sleeves shown in fig. 3.

Fig. 1 to 4 and fig. 5 to 9 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 9. 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 connected 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 the sleeves 41(41a, 41b) and the 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 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 slight gap C1 is provided between the tip of the projection 44 and the convex portion 32. The clearance C1 is approximately 1-2 mm.

As shown in fig. 1 and 4, the end 42a on the outer diameter side and the end 42b on the inner diameter side of the bent portion 42 in the elastic body 40 are fixed to the cylindrical sleeves 41a and 41 b.

Here, as shown in fig. 3 and 4, the sleeve 41aHaving an inner cylindrical surface X formed parallel to the axial direction₁And a flange portion β protruding from one end portion of the tube portion α toward the outer peripheral side. Here, the flange portion β preferably has a guide portion γ. The flange β is coupled to the tube portion α at one end, and preferably coupled to the guide portion γ at the other end of the flange β. As shown in fig. 3 and 4, the guide portion γ preferably extends in a direction parallel to the axial direction.

When the flange portion β has the guide portion γ, positioning of the jig becomes easy in the manufacturing process, which contributes to improvement of work efficiency in the manufacturing process.

The end 42a of the elastic body 40 on the outer diameter side of the bent portion 42 is fixed only to the inner cylindrical surface X parallel to the axis of the cylindrical portion α₁. Here, as shown in fig. 4, the end portion 42a does not contact the pressing surface X of the flange portion β₂Are connected with each other.

In this manner, the sleeve 41a is bonded to the bent portion 42 in the elastic body 40. The sleeve 41a is fitted and fixed to the inner circumferential surface of the vibration ring main body 31. That is, the end 42a on the outer diameter side of the bent portion 42 is connected to the vibration ring main body 31 via the sleeve 41 a.

The same applies to the sleeve 41 b. As shown in FIGS. 3 and 4, the sleeve 41b has an inner cylindrical surface Y parallel to the axis₁And a flange portion epsilon protruding from one end of the cylinder portion delta toward the inner periphery. Here, the flange portion ∈ preferably has a guide portion ζ. The flange part ∈ is joined to the cylindrical part δ at one end, and preferably joined to the guide part ζ at the other end of the flange part ∈. As shown in fig. 3 and 4, the guide section ζ preferably extends in a direction parallel to the axial direction.

When the flange part ∈ has the guide part ζ, positioning of the jig becomes easy in the manufacturing process, and work efficiency in the manufacturing process is improved.

The end 42b of the elastic body 40 on the inner diameter side of the bent portion 42 is fixed only to the inner cylindrical surface Y of the cylindrical portion δ parallel to the axis₁. Here, as shown in fig. 4, the end portion 42b does not contact the pressing surface Y of the flange portion ∈₂Are connected with each other.

In this manner, the sleeve 41b is bonded to the bent portion 42 in the elastic body 40. The sleeve 41b is fitted and fixed to the outer peripheral surface of the hub 20. That is, the end 42b on the inner diameter side of the bent portion 42 is coupled to the hub 20 via the sleeve 41 b.

The bent portion 42 can be fixed to the sleeve 41(41a, 41b) 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.

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 with the rubber block 43 as the center, 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 embodiment shown in fig. 1 to 4, when the vibration ring 30 is displaced in the torsional direction X with respect to the hub 20, the curved portion 42 having a curved 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 relative displacement of the vibration ring 30 is improved, and the range of the vibration reduction effect against 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 rotation speed of the propeller shaft increases, the bent portion 42 is stretched, so that the clearance C1 between the protrusion 44 and the protrusion 32 decreases, and the protrusion 44 comes into contact with the protrusion 32. When the protrusion 44 contacts the convex portion 32, the amount of attenuation of the vibration in the torsional direction X is increased. 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.

Next, a manufacturing method of the present invention will be explained.

The dynamic damper of the present invention can be obtained by the manufacturing method of the present invention.

The manufacturing method of the present invention includes a fixing step, a first press-fitting step, a second press-fitting step, and a third press-fitting step described below.

< immobilization step >

The fixing step included in the manufacturing method of the present invention will be described.

In the fixing step, the elastic body 40, the sleeve 41a on the outer diameter side, and the sleeve 41b on the inner diameter side as shown in fig. 1 and 4 are prepared first.

The elastic body 40 can be manufactured by a conventionally known method using a conventionally known material, for example. For example, the material may be selected from rubbery elastic materials such as Natural Rubber (NR), Ethylene Propylene Diene Monomer (EPDM), butyl rubber, fluororubber, nitrile rubber, chloroprene, and the like, and thermoplastic elastomers such as polyester elastomers, thermoplastic polyurethanes, and the like, depending on the intended use. Such a material is poured into a mold to mold the elastic body 40.

The outer diameter side sleeve 41a and the inner diameter side sleeve 41b are similarly obtained by a conventionally known method using a conventionally known material, for example. For example, the sleeve 41a and the sleeve 41b can be obtained by press working a plate-shaped metal (preferably cold-rolled steel).

The end 42a of the bent portion 42 of the elastic body 40 is fixed only to the inner cylindrical surface X of the sleeve 41a disposed on the outer diameter side₁. That is, the contact with the pressing surface X is avoided also in a part of the end portion 42a₂Are connected with each other. Here, as in the method described in patent document 1, the pressing surface X is formed on the pressing surface X₂When the end portion 42a of the bent portion 42 is present, the end portion 42a of the bent portion 42 is sandwiched between the jig and the pressing surface X when the hub and the vibration ring are fitted to the elastic body with the sleeve disposed on the jig in the second press-fitting step described later₂This causes breakage of the end portion 42a of the bent portion 42.

In addition, the end 42b of the bent portion 42 in the elastic body 40 is fixed only to the inner cylindrical surface Y of the sleeve 41b disposed on the inner diameter side₁. That is, the contact with the pressing surface Y is avoided also in a part of the end portion 42b₂Are connected with each other. Here, as in the method described in patent document 1, the pressing surface Y is provided with a concave portion₂When the end portion 42b of the bent portion 42 is present, the pressing surface X in the elastic body with the sleeve is pressed from above by using a jig in a third press-fitting step to be described later₂、Y₂When the pressing is performed, the end 42b of the bent portion 42 is clamped between the jig and the pressing surface Y₂This causes breakage of the end portion 42b of the bent portion 42.

In this way, the end 42a of the bent portion 42 in the elastic body 40 is fixed only to the inner cylindrical surface X in the sleeve 41a disposed on the outer diameter side₁In addition, the end 42b of the bent portion 42 in the elastic body 40 is fixed only to the inner cylindrical surface Y of the sleeve 41b disposed on the inner diameter side₁Accordingly, in the second press-fitting step described later, when the boss and the vibration ring are fitted to the elastic body with the sleeve disposed on the jig, the end portion of the bent portion 42 is not damaged, and in the third press-fitting step described later, the pressing surface X in the elastic body with the sleeve is pressed from above by using the jig₂、Y₂This prevents the end of the bent portion 42 from being damaged even if the hub 20 and the vibration ring body 32 are pushed in.

When the end portion of the bent portion 42 is broken, the elastic body 40 hardly exhibits a predetermined performance, and as a result, the torsional load on the elastic body 40 cannot be reduced, and in addition, the stopper function of the protrusion 44 is hardly exhibited.

The fixation of the sleeves 41a, 41b to the end portions 42a, 42b of the bent portion 42 can be achieved by, for example, welding, vulcanization adhesion, or adhesion using an adhesive.

In this manner, the elastic body with a sleeve 50 as shown in fig. 4 can be obtained.

< first Press-fitting step >

The first press-fitting step included in the manufacturing method of the present invention will be described with reference to fig. 5 and 6.

Fig. 5 is a schematic perspective view showing a preferred example of the jig used in the first press-fitting step, and fig. 6 is a schematic partial sectional view for explaining the first press-fitting step.

As shown in fig. 6, in the first press-fitting step, the elastic body with a sleeve 50 obtained in the fixing step is placed on a jig 60. That is, the elastic body with sleeve 50 is disposed on the jig 60 such that the inner ring 62 supports the inner sleeve 41b from below and the outer ring 64 supports the outer sleeve 41a from below.

The jig 60 is used, for example, by being disposed on a table so that the bottom 66 is horizontal.

As shown in fig. 5, the two rings (62, 64) are concentrically arranged on the jig 60 and fixed to a plate-shaped bottom portion 66. The rings (62, 64) are both cylindrical and have the same width (height protruding from the bottom 66).

In addition, the radial distance t between the two rings in the jig 60 and the inner cylindrical surface X of the sleeve 41a₁And an inner cylindrical surface Y in the sleeve 41b₁Are approximately equal.

The width of the ring 62 itself is preferably larger than the width of the cylindrical portion δ of the sleeve 41b, and is preferably larger than the pressing surface Y of the flange portion ∈₂Has a small radial length.

The width of the outer ring 64 itself is preferably larger than the width of the cylindrical portion α of the sleeve 41a, and preferably larger than the pressing surface X of the flange portion β₂Has a small radial length.

This is because, in such a case, the jig 60 can support at least part of the stress applied to the tube portions α and δ of the sleeve-attached elastic body 50 from below via the flange portions β and ∈.

Here, when the flange portions β, ∈ have the guide portions γ, ζ, positioning with respect to the jig 70 during the manufacturing process becomes easy, which contributes to improvement of work efficiency during the manufacturing process.

The jig 60 can be obtained by a conventionally known method using a conventionally known material, for example. For example, it can be obtained by cutting a metal (preferably SS400 or the like).

As shown in FIG. 6, has an inner cylindrical surface X₁、Y₁The elastic body with a sleeve 50 is disposed on the jig 60 with the flange portions β, ∈ being located below in the vertical direction.

< second Press-fitting step >

The second press-fitting step included in the manufacturing method of the present invention will be described with reference to fig. 7.

Fig. 7 is a schematic partial sectional view for explaining the second press-fitting step.

The hub 20 is fitted from above to the inner peripheral sleeve 41b of the elastic sleeve with bushing 50 disposed above the jig 60 in the first press-fitting step, and the vibration ring 30 is fitted from above to the outer peripheral sleeve 41a of the elastic sleeve with bushing 50.

Here, the hub 20 may be fitted after the vibration ring 30 is fitted.

It is preferable that the dry bearing 33 is fitted to the vibration ring 30 and then fitted to the elastic body with sleeve 50.

The method of fitting the hub 20 and the vibration ring 30 to the elastic body with sleeve 50 is not particularly limited. By applying stress to the hub 20 or the vibration ring 30 from above, these members can be fitted into the elastic body with sleeve 50.

< third Press-fitting step >

The third press-fitting step included in the manufacturing method of the present invention will be described with reference to fig. 8 and 9.

Fig. 8 is a schematic perspective view showing a preferred example of the jig used in the third press-fitting step, and fig. 9 is a schematic partial sectional view for explaining the third press-fitting step.

In the third press-fitting step, another bush-fitted elastic body 52 is press-fitted between the boss 20 and the vibration ring main body 32 from above.

As shown in fig. 8 and 9, in the third press-fitting step, a jig 70 is used, and the jig 70 can apply stress to the tube portions α and δ through the flange portions β and ∈ of the elastic body with sleeve 52.

The jig 70 may have the same structure as the aforementioned jig 60, in which only two rings (72, 74) have a high height. This will be specifically explained.

As shown in fig. 8, the two rings (72, 74) are disposed concentrically in the jig 70 and fixed to a plate-shaped bottom portion 76. The rings (72, 74) are both cylindrical and have the same width (height protruding from the bottom portion 76).

In addition, the distance in the radial direction of the two rings in the clip 70 is detachable from the inner tube surface X of the sleeve 41a₁And an inner cylindrical surface Y in the sleeve 41b₁Are approximately equal.

The width of the inner ring 72 itself is preferably larger than the width of the cylindrical portion δ of the sleeve 41b, and preferably larger than the pressing surface Y of the flange portion ∈₂Has a small radial length.

The width of the outer ring 74 itself is preferably larger than the width of the cylindrical portion α of the sleeve 41a, and preferably larger than the pressing surface X of the flange portion β₂Has a small radial length.

This is because, in such a case, stress can be applied to the tube portions α, δ in the elastic body with sleeve 52, and therefore, deformation of the sleeve can be suppressed. If the stress from the jig 70 is hard to be applied to the tube portions α, δ, the flange portions β, ∈ may be deformed.

Here, when the flange portions β, ∈ have the guide portions γ, ζ, positioning with respect to the jig 70 during the manufacturing process becomes easy, which contributes to improvement of work efficiency during the manufacturing process.

The jig 70 is fixed to the bottom 76 so as to be horizontally used.

The jig 70 can be obtained by a conventionally known method using a conventionally known material, for example. For example, it can be obtained by cutting a metal (preferably SS400 or the like).

Using such a jig 70, the other elastic body 52 with a sleeve is put on its inner cylindrical surface X₁、Y₁In a state of being parallel to the vertical direction, the vibration ring is pressed from above between the boss 20 and the vibration ring main body 32. Here, the flange portions β, ∈ are pressed against the pressing surface X by the jig 70 in a state of being located on the upper side₂、Y₂To perform the fitting.

The dynamic damper of the present invention can be obtained by the manufacturing method of the present invention.

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

50. 52 with sleeve elastomer

60. 70 clamp

62. 72 inner ring

64. 74 outside ring

C1 gap

Direction of X torsion

t distance of inner and outer rings

X₁、Y₁Inner tube surface

X₂、Y₂Pressing surface

Alpha, delta cylinder part

Beta, epsilon flange part

Gamma, zeta guiding part

This application claims priority based on Japanese application laid-open at 11/20/2019, application No. 2019-209885, the disclosure of which is hereby incorporated by reference in its entirety.