JP2021156317A - Torsional damper - Google Patents

Abstract

To provide a torsional damper which can be arranged in a front cover while maintaining quality.SOLUTION: A torsional damper 100 having a hub 110 attached to a crankshaft in a front cover, and an oscillation ring 120 arranged at the hub 110 coaxially therewith comprises: an annular case 140 in which the oscillation ring 120 is accommodated; an inner wall face of a case 140; and at least one rubbery elastic body (first rubbery elastic body 131) interposed between the oscillation ring 120 and an outer ring part. The case 140 is fittingly fixed to an internal peripheral face of a cylindrical part 112 arranged at the hub 110, and a clearance between the case 140 and the hub 110 is sealed by at least one seal ring (a first seal ring 151 and a second seal ring 152).SELECTED DRAWING: Figure 2

Description

The present invention relates to a torsional damper used to reduce torsional vibration generated in a crankshaft (rotary drive shaft) of an automobile engine.

A torsional damper is attached to the crankshaft of the engine to reduce its torsional vibration. An engine according to a conventional example will be described with reference to FIG. FIG. 6 is a cross-sectional view showing the vicinity of the torsional damper in the engine according to the conventional example.

A sprocket 530 (or rotor), a torsional damper 550, and the like are attached to the crankshaft 520 provided inside the front cover 510 of the engine. Further, an oil seal 560 for sealing an annular gap between the front cover 510 and the torsional damper 550 is provided. The torsional damper 550 is fixed to the crankshaft 520 by a bolt 540 having a shaft portion 541 screwed to the inner peripheral surface of the crankshaft 520 and a head portion 542 abutting on the end surface of the torsional damper 550. ..

The torsional damper 550 is provided with a pulley (not shown) for rotating the belt on the outer peripheral surface side thereof, and also plays a role of driving an auxiliary machine. Therefore, the torsional damper 550 is configured to protrude outward from the front cover 510. However, in recent years, in order to improve fuel efficiency, the hybridization of engines has progressed, and a belt for driving an auxiliary machine has become unnecessary. On the other hand, the structure itself in which the torsional damper protrudes to the outside of the front cover is the same as before.

Here, the longer the crankshaft, the easier it is to vibrate, so it is desirable that the crankshaft be as short as possible. Therefore, it can be considered that the crankshaft can be shortened and the vibration itself can be reduced if a structure in which the torsional damper is provided in the front cover can be adopted. However, ethylene propylene rubber (EPDM) or the like is widely used as an elastic material applied to a torsional damper, but such a material has a drawback of being inferior in oil resistance. Therefore, in the conventional torsional damper structure, there is a problem that it is not possible to adopt a configuration provided in the front cover.

Jitsufuku 7-21941 Japanese Unexamined Patent Publication No. 2005-299807

An object of the present invention is to provide a torsional damper that can be provided in a front cover while maintaining quality.

The present invention employs the following means to solve the above problems.

That is, the torsional damper of the present invention is
A torsional damper including a hub attached to a crankshaft and a vibrating ring provided concentrically with the hub in the front cover.
An annular case in which the vibrating ring is housed and
At least one rubber-like elastic body interposed between the inner wall surface of the case and the vibrating ring,
With
The case is fitted and fixed to the inner peripheral surface of a cylindrical portion provided on the hub, and the gap between the case and the hub is sealed by at least one seal ring. And.

According to the present invention, the vibrating ring and at least one rubber-like elastic body are housed in the case, and the gap between the case and the hub is sealed by at least one seal ring. The elastic body can be confined in a closed space. Therefore, even if the torsional damper is provided in the front cover, it is possible to prevent the rubber-like elastic body from being exposed to oil. Therefore, as a material for this rubber-like elastic body, for example, EPDM or the like, which is inferior in oil resistance but excellent as a damper material, can be adopted.

The case includes an inner ring portion, an outer ring portion that is provided concentrically with the inner ring portion and is fitted and fixed to the inner peripheral surface of the cylindrical portion, and one end portion of the inner ring portion and the outer ring portion. It is equipped with a connecting part that connects them to each other.
It is preferable that the vibrating ring and the at least one rubber-like elastic body are housed in the annular space portion formed by the inner ring portion, the outer ring portion, and the connecting portion.

The at least one seal ring includes a first seal ring provided on the inner ring portion side via the connecting portion and a second seal ring provided on the outer ring portion side via the connecting portion. It is good to be.

The at least one rubber-like elastic body may include an annular first rubber-like elastic body provided between the outer peripheral surface of the vibrating ring and the inner peripheral surface of the outer ring portion.

Further, the at least one rubber-like elastic body may include an annular second rubber-like elastic body provided between the inner peripheral surface of the vibrating ring and the outer peripheral surface of the inner ring portion.

Further, it is also preferable that the at least one rubber-like elastic body includes a plate-shaped third rubber-like elastic body provided between the end face of the vibrating ring and the connecting portion.

Further, the at least one rubber-like elastic body includes a first annular portion provided between the outer peripheral surface of the vibrating ring and the inner peripheral surface of the outer ring portion, and the inner peripheral surface and the inner peripheral surface of the vibrating ring. A fourth rubber integrally provided with at least one of the second annular portions provided between the outer peripheral surface of the ring portion and a plate-shaped portion provided between the end surface of the vibrating ring and the connecting portion. It is also preferable that a state elastic body is included.

In addition, each of the above configurations can be adopted in combination as much as possible.

As described above, according to the present invention, it is possible to provide the torsional damper in the front cover while maintaining the quality of the torsional damper.

FIG. 1 is a cross-sectional view showing the vicinity of a torsional damper in the engine according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view of the torsional damper according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view of the torsional damper according to the second embodiment of the present invention. FIG. 4 is a cross-sectional view of the torsional damper according to the third embodiment of the present invention. FIG. 5 is a cross-sectional view of the torsional damper according to the fourth embodiment of the present invention. FIG. 6 is a cross-sectional view showing the vicinity of the torsional damper in the engine according to the conventional example.

Hereinafter, embodiments for carrying out the present invention will be described in detail exemplarily based on examples with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in this embodiment are not intended to limit the scope of the present invention to those unless otherwise specified. ..

(Example 1)
The torsional damper according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a cross-sectional view showing the vicinity of a torsional damper in the engine according to the first embodiment of the present invention. Note that FIG. 1 shows a cross section obtained by cutting various members on a surface including the center of rotation of the crankshaft. Further, in FIG. 1, only a part of the torsional damper is shown. FIG. 2 is a cross-sectional view of the torsional damper according to the first embodiment of the present invention. The torsional damper has a rotationally symmetric shape, and FIG. 2 shows a cross section of the torsional damper cut along a surface including the central axis of the torsional damper.

<Engine>
An engine to which the torsional damper according to the present embodiment is applied will be described with reference to FIG. In this embodiment, a sprocket 30 (or rotor), a torsional damper 100, or the like is attached to the crankshaft 20 provided inside the front cover 10 of the engine. The torsional damper 100 is fixed to the crankshaft 20 by a bolt 40 having a shaft portion 41 screwed to the inner peripheral surface of the crankshaft 20 and a head portion 42 abutting on the end surface of the torsional damper 100. .. Then, in the case of this embodiment, the torsional damper 100 is provided in the front cover 10 (as a whole).

<Tortional damper>
The torsional damper 100 according to this embodiment will be described with reference to FIG. The torsional damper 100 according to this embodiment includes a hub 110 attached to the crankshaft 20 and a vibration ring 120 provided concentrically with the hub 110. Further, the torsional damper 100 according to the present embodiment includes an annular case 140 in which the vibrating ring 120 is housed, an inner wall surface of the case 140, and at least one rubber-like elastic body interposed between the vibrating ring 120. It has. In this embodiment, the only first rubber-like elastic body 131 is provided as at least one rubber-like elastic body.

The hub 110 is a metal annular member. The hub 110 according to this embodiment includes a cylindrical (cylindrical) attached portion 111 to be attached to the crankshaft 20. In this embodiment, the attached portion 111 of the hub 110 is directly attached to the crankshaft 20. However, the present invention also includes a case where the hub is indirectly attached to the crankshaft via, for example, a member such as a sleeve provided on the outer peripheral surface side of the crankshaft. Further, the hub 110 includes an outward flange portion 113 provided at the end of the attached portion 111, and a cylindrical portion 112 provided at the radial outer tip of the outward flange portion 113.

The vibrating ring 120 is a metal annular member. As shown in the figure, the vibrating ring 120 according to the present embodiment is composed of an annular member (cylindrical member) having a rectangular cross section, but the vibrating ring in the present invention always has a shape as shown in the figure. It doesn't have to be.

The case 140 is a metal annular member. The case 140 has a disk-shaped portion 141 with a hole, an inner ring portion 142 provided at the radial outer end of the disk-shaped portion 141, and an outer ring provided concentrically with the inner ring portion 142. A portion 143 and a connecting portion 144 that connects one end portions of the inner ring portion 142 and the outer ring portion 143 are provided. The outer ring portion 143 of the case 140 is fitted and fixed to the inner peripheral surface of the cylindrical portion 112 of the hub 110. Then, the vibrating ring 120 and the first rubber-like elastic body 131 are housed in the annular space portion formed by the inner ring portion 142, the outer ring portion 143, and the connecting portion 144 in the case 140.

The gap between the case 140 and the hub 110 is configured to be sealed by at least one seal ring. In this embodiment, the first seal ring 151 provided on the inner ring portion 142 side via the connecting portion 144 in the case 140 and the second seal ring 152 provided on the outer ring portion 143 side via the connecting portion 144 , The above gap is configured to be sealed. More specifically, the first seal ring 151 is configured to seal between the vicinity of the boundary portion of the disc-shaped portion 141 with the inner ring portion 142 and the outward flange portion 113 of the hub 110. There is. It is desirable that at least one of the disc-shaped portion 141 and the outward flange portion 113 is provided with an annular groove for mounting the first seal ring 151. Further, the second seal ring 152 is configured to seal between the tip surface of the outer ring portion 143 and the outward flange portion 113 of the hub 110. It is desirable to provide an annular groove for mounting the second seal ring 152 on at least one of the tip surface of the outer ring portion 143 and the outward flange portion 113. For the first seal ring 151 and the second seal ring 152, various known seal rings such as an O-ring having a circular cross-sectional shape and a square ring having a rectangular cross-sectional shape can be adopted. Further, the first seal ring 151 and the second seal ring 152 are both made of an elastic material having better oil resistance than the first rubber-like elastic body 131. As the material of the first seal ring 151 and the second seal ring 152, for example, NBR, HNBR, ACM, FKM, silicone rubber and the like can be preferably adopted. In this embodiment, the configuration in which two seal rings are arranged is shown, but a configuration in which three or more seal rings are arranged can also be adopted.

In this embodiment, the first rubber-like elastic body 131 is composed of an annular member. The first rubber-like elastic body 131 is provided in a state of being press-fitted between the outer peripheral surface of the vibrating ring 120 and the inner peripheral surface of the outer ring portion 143 of the case 140. The first rubber-like elastic body 131 is obtained by vulcanization molding. As the material of the first rubber-like elastic body 131 according to the present embodiment, ethylene propylene rubber (EPDM) or the like, which is inferior in oil resistance but excellent in durability, heat resistance, vibration reduction effect, etc., can be preferably used. ..

In the torsional damper 100, when vibration at a frequency at which the crankshaft 20 resonates is transmitted, the vibration ring 120 vibrates, thereby exerting a function of suppressing the resonance of the crankshaft 20. In the torsional damper 100 according to the present embodiment, the vibration ring 120 is designed so as to suppress the resonance of the crankshaft 20 with respect to the vibration in the rotation direction (twisting direction) of the crankshaft 20.

<Advantages of torsional dampers according to this example>
According to the torsional damper 100 according to the present embodiment, the vibrating ring 120 and the first rubber-like elastic body 131 are housed in the case 140, and the gap between the case 140 and the hub 110 is the first seal ring 151. And sealed by a second seal ring 152. Therefore, the vibrating ring 120 and the first rubber-like elastic body 131 can be confined in the closed space. Thereby, even if the torsional damper 100 is provided in the front cover 10, it is possible to prevent the first rubber-like elastic body 131 from being exposed to oil. Therefore, as the material of the first rubber-like elastic body 131, for example, EPDM or the like, which is inferior in oil resistance but excellent as a damper material, can be adopted.

As described above, according to the present embodiment, the torsional damper 100 can be provided in the front cover 10 while maintaining the quality of the torsional damper 100. As a result, the crankshaft 20 can be shortened as compared with the case where the torsional damper protrudes to the outside of the front cover 10, and the torsional damper itself does not require an oil seal sliding portion, so that the hub The width of the boss can be cut to reduce weight. That is, the portion corresponding to the range L in FIG. 6 described in the background technique can be cut. As a result, the vibration of the crankshaft 20 itself can be reduced.

In the torsional damper 100 according to the present embodiment, a component in which the vibrating ring 120 and the first rubber-like elastic body 131 are press-fitted into the case 140 can be handled as one component. Then, for example, the vibration ring 120 and the first rubber-like elastic body 131 are attached to the cylindrical portion 112 of the hub 110 with the first seal ring 151 and the second seal ring 152 attached to the hub 110. The torsional damper 100 can be assembled by fixing the case 140 by fitting.

(Example 2)
FIG. 3 shows Example 2 of the present invention. In this embodiment, the configuration of the rubber-like elastic body is different from that of the first embodiment. Since other configurations and operations are the same as those in the first embodiment, the same components are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 3 is a cross-sectional view of the torsional damper according to the second embodiment of the present invention. Note that FIG. 3 shows a cross section of the torsional damper cut along a surface including the central axis of the torsional damper, as in FIG. Further, since the engine to which the torsional damper is applied is as described in the first embodiment, the description thereof will be omitted.

In the torsional damper 100a according to the present embodiment, as in the case of the first embodiment, the hub 110, the vibrating ring 120, at least one rubber-like elastic body, the case 140, the first seal ring 151, and the like. It is provided with a second seal ring 152. Since the configurations of the hub 110, the vibrating ring 120, the case 140, the first seal ring 151, and the second seal ring 152 are the same as those shown in the first embodiment, the description thereof will be omitted.

In this embodiment, the first rubber-like elastic body 131 and the second rubber-like elastic body 132 are provided as at least one rubber-like elastic body. Since the first elastic elastic body 131 is as described in the first embodiment, the description thereof will be omitted.

The second rubber-like elastic body 132 is composed of an annular member. The second rubber-like elastic body 132 is provided in a state of being press-fitted between the inner peripheral surface of the vibrating ring 120 and the outer peripheral surface of the inner ring portion 142 of the case 140. The second rubber-like elastic body 132 is obtained by vulcanization molding. Similar to the first rubber-like elastic body 131, the material of the second rubber-like elastic body 132 according to the present embodiment is also inferior in oil resistance, but is excellent in durability, heat resistance, vibration reduction effect, and the like. Rubber (EPDM) or the like can be preferably used.

Needless to say, the torsional damper 100a according to the present embodiment configured as described above can also obtain the same effect as that of the first embodiment. Further, in this embodiment, since the second rubber-like elastic body 132 is in close contact with the inner ring portion 142 of the case 140, there is also an effect of suppressing the vibration of the inner ring portion 142. In this embodiment, a configuration including both the first rubber-like elastic body 131 and the second rubber-like elastic body 132 is shown. However, the present invention also includes a configuration in which only the second rubber-like elastic body 132 is provided and the first rubber-like elastic body 131 is not provided.

(Example 3)
FIG. 4 shows Example 3 of the present invention. In this embodiment, the configuration of the rubber-like elastic body is different from that of the first embodiment. Since other configurations and operations are the same as those in the first and second embodiments, the same components will be designated by the same reference numerals and the description thereof will be omitted.

FIG. 4 is a cross-sectional view of the torsional damper according to the third embodiment of the present invention. Note that FIG. 4 shows a cross section of the torsional damper cut along a surface including the central axis of the torsional damper, as in FIG. Further, since the engine to which the torsional damper is applied is as described in the first embodiment, the description thereof will be omitted.

In the torsional damper 100b according to the present embodiment, as in the case of the first and second embodiments, the hub 110, the vibrating ring 120, at least one rubber-like elastic body, the case 140, and the first It includes a seal ring 151 and a second seal ring 152. Since the configurations of the hub 110, the vibrating ring 120, the case 140, the first seal ring 151, and the second seal ring 152 are the same as those shown in the first embodiment, the description thereof will be omitted.

In this embodiment, the first rubber-like elastic body 131, the second rubber-like elastic body 132, and the third rubber-like elastic body 133 are provided as at least one rubber-like elastic body. Since the first rubber-like elastic body 131 is as described in the first embodiment and the second rubber-like elastic body 132 is as described in the second embodiment, the description thereof will be omitted.

The third rubber-like elastic body 133 is composed of a plate-shaped (disc-shaped with holes) member. The third rubber-like elastic body 133 is provided in a compressed state between the end face of the vibrating ring 120 and the connecting portion 144 in the case 140. The third rubber-like elastic body 133 is obtained by vulcanization molding. Similar to the first rubber-like elastic body 131 and the second rubber-like elastic body 132, the material of the third rubber-like elastic body 133 according to the present embodiment is also inferior in oil resistance, but has durability, heat resistance and vibration. Ethylene propylene rubber (EPDM), which has an excellent reduction effect, can be preferably used.

Needless to say, the torsional damper 100b according to the present embodiment configured as described above can also obtain the same effects as those of the first and second embodiments. Further, in this embodiment, since the third rubber-like elastic body 133 is provided, resonance can be suppressed not only for vibration in the rotational direction (twisting direction) but also for bending vibration. In this embodiment, a configuration including both the first rubber-like elastic body 131 and the second rubber-like elastic body 132 is shown. However, in the present invention, in the configuration of Example 3, a configuration in which only one of the first rubber-like elastic body 131 and the second rubber-like elastic body 132 is provided and the other is not provided is also included.

(Example 4)
FIG. 5 shows Example 4 of the present invention. In this embodiment, the configuration of the rubber-like elastic body is different from that of the first embodiment. Since other configurations and operations are the same as those in the embodiment, the same components are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 5 is a cross-sectional view of the torsional damper according to the fourth embodiment of the present invention. Note that FIG. 5 shows a cross section of the torsional damper cut along a surface including the central axis of the torsional damper, as in FIG. Further, since the engine to which the torsional damper is applied is as described in the first embodiment, the description thereof will be omitted.

In the torsional damper 100c according to the present embodiment, as in the case of each of the above embodiments, the hub 110, the vibrating ring 120, at least one rubber-like elastic body, the case 140, the first seal ring 151, and the first seal ring 151. It is provided with a second seal ring 152. Since the configurations of the hub 110, the vibrating ring 120, the case 140, the first seal ring 151, and the second seal ring 152 are the same as those shown in the first embodiment, the description thereof will be omitted.

Then, in this embodiment, the fourth rubber-like elastic body 134 is provided as at least one rubber-like elastic body. The fourth rubber-like elastic body 134 includes a first annular portion 134a provided between the outer peripheral surface of the vibrating ring 120 and the inner peripheral surface of the outer ring portion 143 of the case 140, and the inner peripheral surface and inner surface of the vibrating ring 120. A second annular portion 134b provided between the outer peripheral surface of the ring portion 142 and a plate-shaped portion 134c provided between the end surface of the vibrating ring 120 and the connecting portion 144 are integrally provided. The first annular portion 134a is provided in a state of being press-fitted between the outer peripheral surface of the vibrating ring 120 and the inner peripheral surface of the outer ring portion 143 in the case 140, and the second annular portion 134b is the inner circumference of the vibrating ring 120. The plate-shaped portion 134c is provided in a state of being press-fitted between the surface and the outer peripheral surface of the inner ring portion 142, and the plate-shaped portion 134c is provided in a state of being compressed between the end surface of the vibrating ring 120 and the connecting portion 144 in the case 140. ing. As described above, the fourth rubber-like elastic body 134 according to the present embodiment has the first rubber-like elastic body 131, the second rubber-like elastic body 132, and the third rubber-like elastic body in the configuration shown in the third embodiment. It is a configuration in which 133 is provided integrally with.

The fourth rubber-like elastic body 134 is obtained by vulcanization molding. As for the material of the fourth rubber-like elastic body 134 according to the present embodiment, ethylene propylene rubber (EPDM) or the like, which is inferior in oil resistance but excellent in durability, heat resistance, vibration reduction effect, etc., can be preferably used. can.

Needless to say, the torsional damper 100c according to the present embodiment configured as described above can also obtain the same effects as those of the above-mentioned Examples 1, 2, and 3. Further, in the present embodiment, since the plate-shaped portion 134c is provided on the fourth rubber-like elastic body 134, resonance is suppressed not only for vibration in the rotational direction (twisting direction) but also for bending vibration. Can be done. In this embodiment, the fourth rubber-like elastic body 134 shows a configuration including both the first annular portion 134a and the second annular portion 134b. However, in the present invention, the fourth rubber-like elastic body 134 includes a configuration in which only one of the first annular portion 134a and the second annular portion 134b is provided and the other is not provided.

10 Front cover 20 Crank shaft 30 Sprocket 40 Bolt 41 Shaft 42 Head 100, 100a, 100b, 100c Tortional damper 110 Hub 111 Attached part 112 Cylindrical part 113 Outward flange part 120 Vibration ring 131 First rubber elastic Body 132 2nd rubber-like elastic body 133 3rd rubber-like elastic body 134 4th rubber-like elastic body 134a 1st annular part 134b 2nd annular part 134c Plate-like part 140 Case 141 Disc-like part 142 Inner ring part 143 Outer ring Part 144 Connecting part 151 First seal ring 152 Second seal ring

Claims (7)

A torsional damper including a hub attached to a crankshaft and a vibrating ring provided concentrically with the hub in the front cover.
An annular case in which the vibrating ring is housed and
At least one rubber-like elastic body interposed between the inner wall surface of the case and the vibrating ring,
With
The case is fitted and fixed to the inner peripheral surface of a cylindrical portion provided on the hub, and the gap between the case and the hub is sealed by at least one seal ring. Tortional damper. The case includes an inner ring portion, an outer ring portion that is provided concentrically with the inner ring portion and is fitted and fixed to the inner peripheral surface of the cylindrical portion, and one end portion of the inner ring portion and the outer ring portion. It is equipped with a connecting part that connects them to each other.
The torsional according to claim 1, wherein the vibrating ring and at least one rubber-like elastic body are housed in an annular space portion formed by the inner ring portion, the outer ring portion, and the connecting portion. Damper. The at least one seal ring includes a first seal ring provided on the inner ring portion side via the connecting portion and a second seal ring provided on the outer ring portion side via the connecting portion. The torsional damper according to claim 2, wherein the torsional damper is provided. The at least one rubber-like elastic body includes an annular first rubber-like elastic body provided between the outer peripheral surface of the vibrating ring and the inner peripheral surface of the outer ring portion. The torsional damper according to 2 or 3. The at least one rubber-like elastic body includes an annular second rubber-like elastic body provided between the inner peripheral surface of the vibrating ring and the outer peripheral surface of the inner ring portion. The torsional damper according to 2, 3 or 4. The fourth or fifth aspect of the present invention, wherein the at least one rubber-like elastic body includes a plate-shaped third rubber-like elastic body provided between the end face of the vibrating ring and the connecting portion. Tortional damper. The at least one rubber-like elastic body includes a first annular portion provided between the outer peripheral surface of the vibrating ring and the inner peripheral surface of the outer ring portion, and the inner peripheral surface of the vibrating ring and the inner ring portion. A fourth rubber-like elasticity integrally provided with at least one of the second annular portions provided between the outer peripheral surface of the vibration ring and a plate-shaped portion provided between the end surface of the vibrating ring and the connecting portion. The torsional damper according to claim 2 or 3, wherein the body is included.

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