JPH08177978A - Torsional damper - Google Patents

Abstract

PURPOSE: To provide a torsional damper having an elastic body layer adhesively fixed between two inner and outer rigid cylindrical members with excellent reliability. CONSTITUTION: Between an inside rigid cylindrical member 11 and an outside rigid cylindrical member 20 disposed concentrically outside the inside rigid cylindrical member 11 in the diametral direction and spaced by a predetermined distance from the member 11, an elastic body layer 24 previously compressed and bonded fixedly to both members is interposed. Two inner and outer surfaces of the elastic body layer 24 opposed to the rigid cylindrical members 11, 20 are provided respectively with a plurality of recessed grooves 26 extending circumferentially continuously.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torsion damper, and in particular, an elastic layer having a predetermined thickness is interposed between an inner rigid cylindrical member and an outer rigid cylindrical member in a pre-compressed state. The present invention relates to a torsional damper that is adhesively fixed with reliability.

[0002]

BACKGROUND ART Generally, when a crankshaft of an internal combustion engine is rotated, complicated torsional vibrations are inevitably generated, which causes damage to the crankshaft and vibrations and noises of the internal combustion engine. There is a risk that

Therefore, conventionally, in a vehicle engine or the like, a torsional damper is attached to a crankshaft in order to avoid such a fear. That is, this torsional damper has an inner rigid cylindrical member fixed to the crankshaft and an outer member as a damper mass, which is concentrically arranged at a predetermined distance radially outside the inner rigid cylindrical member. A rigid cylindrical member of
An elastic body layer is interposed between the inner and outer rigid cylindrical members and elastically connects and supports them, and the elastic body layer causes torsional vibration around the axis of the crankshaft. Therefore, the problems such as the damage of the crankshaft, the vibration of the engine, the noise, etc. as described above can be advantageously solved.

By the way, in a torsional damper having such a structure, in general, in order to improve the durability in use, the elastic layers are subjected to a predetermined adhesion treatment on the inner and outer surfaces thereof. After being press-fitted between two rigid cylindrical members and subjected to pre-compression, secondary vulcanization is performed so that they can be adhesively fixed, especially after adhesive fixation to two rigid cylindrical members inside and outside. In order to maintain a good compressed state of the elastic layer, the pre-compression rate of the elastic layer is usually about 20 to 30%, that is, between the two rigid cylindrical members inside and outside. The change amount of the thickness of the elastic body layer after the press-fitting is configured to be about 20 to 30% of the thickness of the elastic body layer before the press-fitting.

However, in such a conventional torsional damper, the elastic layer can be easily elastically deformed in the axial direction when the elastic layer is press-fitted between the two rigid cylindrical members inside and outside. Therefore, the internal stress generated based on the restoring force at the time of elastic deformation of the elastic body layer reduces the pressure exerted on the adhesive surface of the elastic body layer to the two rigid cylindrical members inside and outside. In view of such pressure, it was unavoidable that the elastic layer had a pre-compression rate of about several percent in practice. The secondary vulcanization accompanied by a heating operation is performed below, and since the elastic body layer is adhered and fixed between the two rigid cylindrical members inside and outside, heat generated during the secondary vulcanization is performed. By the elastic layer Tarrying occurs, and as a result, not only the compressed state of the elastic layer is almost eliminated, but also tensile stress is generated at the bonding surface between the two rigid cylindrical members inside and outside, depending on the part. .

Therefore, in the conventional torsional damper, although the elastic body layer is press-fitted between the inner and outer rigid cylindrical members at the time of assembly, the elastic body layer is in a product state. On the adhesive surface for two rigid cylindrical members inside and outside
Tensile strain of about 1 to 0% occurs, which causes the reliability of the adhesion between the elastic layer and the two rigid cylindrical members inside and outside to be extremely poor.

[0007]

The present invention has been made in view of the above circumstances, and the problem to be solved by the present invention is to provide a structure between an inner rigid cylindrical member and an outer rigid cylindrical member. Even if the elastic body layer interposed under the pre-compression state is adhered and fixed to the two rigid cylindrical members inside and outside, the compression state can be more effectively ensured, thereby It is an object of the present invention to provide an improved structure of a torsion damper in which reliability of adhesion of the elastic layer to the two rigid cylindrical members inside and outside can be advantageously improved.

[0008]

In order to solve the above problems, the present invention concentrically arranges an inner rigid cylindrical member and a radially outer side of the inner rigid cylindrical member at a predetermined distance. And a rigid outer cylindrical member, and an elastic body layer having a predetermined thickness, which is interposed between the inner and outer rigid cylindrical members in a pre-compressed state and is adhesively fixed. The elastic layer is characterized in that a plurality of concave grooves extending continuously along the circumferential direction are respectively provided on the surface of the elastic layer facing the two rigid cylindrical members inside and outside.

According to one preferred mode of the torsional damper according to the present invention, the elastic layer is interposed between the inner rigid cylindrical member and the outer rigid cylindrical member. In the former mode, the axial length is 80 to 90% of the axial length of the gap formed between the inner and outer rigid cylindrical members, and the axial length of the inner and outer rigid cylindrical members is 80% to 90%. 60-80 for the distance between
%, And the thickness of the remaining portion excluding the depth of the recessed groove so that a plurality of the recessed grooves are formed at intervals of 3 to 8 mm in the axial direction of the elastic layer. The Rukoto.

[0010]

In other words, in the torsional damper according to the present invention as described above, concave grooves that continuously extend along the circumferential direction are respectively formed on the surfaces of the elastic layer facing the two rigid cylindrical members inside and outside. , Because there are multiple,
When the elastic layer is press-fitted between the inner rigid cylindrical member and the outer rigid cylindrical member, the portions between the adjacent concave grooves in the elastic layer are formed by the inner and outer rigid cylindrical members. , Respectively, which can be crushed and elastically deformed so as to fill the space in the groove, whereby the axial extension of such a part is advantageously absorbed by the space in the groove. As a result, the amount of elastic deformation of the entire elastic layer in the axial direction, that is, the difference in the axial length of the elastic layer before and after the press-fitting was such that the surface facing the two rigid cylindrical members inside and outside was a flat surface. , It can be advantageously made smaller than that used in conventional torsion dampers.

Therefore, in such a torsional damper, the internal stress of the elastic layer caused by the elastic deformation in the axial direction can be effectively reduced, whereby the internal stress caused by such internal stress can be reduced. Inside and outside the elastic layer 2
The reduction of the pressure exerted on the adhesive surfaces to the two rigid cylindrical members can be effectively suppressed.

Therefore, in the torsional damper according to the present invention, the compressed state of the elastic layer is effectively secured even after the elastic layer is bonded and fixed to the two rigid cylindrical members inside and outside by secondary vulcanization. As a result, the reliability of adhesion between the elastic layer and the two rigid cylindrical members inside and outside can be effectively improved, and as a result, the durability of use can be improved very effectively. That will be the case.

When the structure according to the preferred embodiment of the present invention described above is adopted, the elastic layer is easily bent or deformed in accordance with the formation of the groove. It can be advantageously prevented that the handleability of the elastic body layer during press-fitting work between the inner rigid cylindrical member and the outer rigid cylindrical member is impaired, and good assembling can be ensured. Further, the axial extension of the entire elastic body layer in the compressed state can be suppressed more effectively, and the reliability of the adhesion between the elastic body layer and the two rigid cylindrical members inside and outside can be improved more effectively. .

[0014]

[Specific Configuration / Examples] In order to more specifically clarify the present invention, typical examples of the present invention will be described below.
A detailed description will be given with reference to the drawings.

First, FIGS. 1 and 2 show a damper pulley 10 as an example of a torsional damper according to the present invention.
Are shown schematically. In this figure, 11
Is a pulley body as an inner rigid cylindrical member,
At the center thereof, there is a small-diameter cylindrical boss portion 14 provided with a key groove 12 on the inner peripheral surface. In addition, in the pulley main body 11, a cylindrical portion 16 having a large-diameter cylindrical shape, the outer peripheral surface of which is a cylindrical surface, is arranged radially outward of the boss portion 14.
Is positioned concentrically with a predetermined distance in the radial direction, and the boss portion 14 and the cylindrical portion 16 are positioned between them, and by the annular plate-shaped connecting portion 18, They are connected together.

On the outer side in the radial direction of the cylindrical portion 16 constituting the pulley main body 11, the inner peripheral surface is a smooth cylindrical surface, which has a thick cylindrical shape as a whole, and on the outer peripheral surface,
Two V-grooves 2 extending in the circumferential direction around which the V-belt is wound
Damper mass 20 as an outer rigid cylindrical member, which is integrally provided with 2 and 22, is concentrically arranged at a predetermined distance. The cylindrical portion 16 of the pulley body 11 and the damper mass 20 are integrally connected by the rubber elastic body 24 interposed between them.

Thus, in the damper pulley 10 configured as described above, the boss portion 14 of the pulley body 11 is used.
In addition, while being attached to a crankshaft of a predetermined internal combustion engine (not shown) and being rotated integrally therewith, the V-grooves 22, 2 provided in the damper mass 20 are
A predetermined V-belt (not shown) is wound around 2, so that it is used as a V-belt driving pulley that transmits the driving force from the crankshaft to a predetermined succeeding member. In such a mounted state, since the damper mass 20 is elastically adhered and fixed to the pulley body 11 via the rubber elastic body 24, the damper mass 20 and the rubber elastic body 24 exert a force. With respect to the torsional vibration of the crankshaft to which the pulley body 11 is attached, one vibration system that can function as a dynamic vibration absorber (damper mechanism) is configured.

By the way, in the present embodiment, in particular, the rubber elastic body 24 having a shape as shown in FIGS. 3 and 4 is used. More specifically, the rubber elastic body 24 has a substantially thick band plate shape as a whole, and has a predetermined depth and a length on two surfaces facing each other in the thickness direction. A plurality of (five in this case) recessed grooves 26 having a substantially semicircular cross section that continuously extend in the direction are formed at equal intervals in parallel with each other. In addition, the rubber elastic body 24
In this case, the plurality of recessed grooves 26 are formed in the rubber elastic body 2
In the two surfaces facing each other in the thickness direction of 4, respectively,
It is formed symmetrically.

Although the shape and dimensions of the rubber elastic body 24 are not particularly limited, here, the pulley body 11 is used.
The rubber elastic body 24 is prevented from partially protruding from the cylindrical gap formed between the cylindrical portion 16 and the damper mass 20, and the rubber elastic body 2 is described below.
In order to easily perform the press-fitting operation into the gap 4, the rubber elastic body 24 can cause a space to exist at the axial end portion of the gap in the pre-compression state as in the conventional case. The thickness and width are such that the preliminary compression ratio (compressibility in the thickness direction) is about 25% so that the volume (cross-sectional area) is about 95%.

Further, in the rubber elastic body 24,
Advantageously, the width (dimension n ₁ in FIG. 4) corresponds to the axial length (dimension n ₂ in FIG. 2) of the gap formed between the cylindrical portion 16 of the pulley body 11 and the damper mass 20. The thickness of the remaining portion excluding the depth of the concave groove 26 (dimension m ₁ in FIG. 4) is a cylinder of the pulley body 11 while being configured to have a size of about 80 to 90%. Part 1
6 and the damper mass 20 (m ₂ in FIG. ₂₎
Dimension), in other words, the width of the gap formed between the cylindrical portion 16 of the pulley body 11 and the damper mass 20 is about 60 to 80%. .

This is because the width of the rubber elastic body 24 is less than 80% of the axial length of the gap between the cylindrical portion 16 of the pulley body 11 and the damper mass 20, or the concave groove 26.
If the thickness of the remaining portion excluding the depth of the groove exceeds 80% of the width of the gap, the groove 26 should be made small in order to maintain the volume and the preliminary compression rate as described above. This is because it becomes unavoidable that it becomes difficult to effectively enjoy the effect obtained by forming the concave groove 26. If the width of the rubber elastic body 24 exceeds 90% of the axial length of the gap between the cylindrical portion 16 of the pulley body 11 and the damper mass 20, the concave groove 26 must be enlarged. If the thickness of the remaining portion is less than 60% of the width of the gap,
The remaining portion excluding the depth of the recessed groove 26 becomes too thin, and the rubber elastic body 24 is easily bent or deformed in any case, so that the cylindrical portion of the pulley body 11 is easily deformed. This is because the press-fitting operation between the 16 and the damper mass 20 will be hindered.

The shape and size of the concave groove 26 formed in the rubber elastic body 24 are not particularly limited, but the groove width is preferably about 1 to 5 mm. , And more preferably, the interval between the concave grooves 26 in the axial direction of the rubber elastic body 24 (dimension p in FIG. 4).
Is about 3 to 8 mm. Although it is related to the initial compression rate and the depth of the concave groove 26, if the groove width of the concave groove 26 is too wide, the concave groove 26 becomes large, and as a result, the cylinder of the pulley main body 11 of the rubber elastic body 24. This is because it becomes difficult to press fit between the portion 16 and the damper mass 20, or the space inside the recessed groove 26 is not filled by the deformation of the rubber elastic body 24 itself, and the adhesive area becomes small. On the other hand, if the groove 26 is too narrow, the groove 26 becomes small and the meaning of providing the groove 26 is lost. The groove 26
However, when the gaps are formed wider than 8 mm, the groove 26
When the size of each of the grooves is increased, and the grooves are formed at intervals smaller than 3 mm, the concave grooves 26 become small, and the above-mentioned problems are similarly caused.

Then, as shown in FIG. 5, the rubber elastic body 24 having such a structure and shape has the cylindrical portion 16 of the pulley body 11 and the damper mass 20 on the surface where the plurality of concave grooves 26 are formed. And the damper mass 20 are interposed between the cylindrical portion 16 of the pulley body 11 and the damper mass 20 so as to be opposed to. At that time, in the rubber elastic body 24, the portions between the adjacent grooves 26 are crushed and elastically deformed so as to fill the space in the grooves 26. As a result, the axial extension of such a portion under the pre-compression state is advantageously absorbed by the space in the groove 26, and the axial extension of the entire rubber elastic body 26 is reduced to the conventional plate. It can be advantageously made smaller than the shape. Then, under such a state, by being subjected to secondary vulcanization,
The rubber elastic body 24 is bonded and fixed to the cylindrical portion 16 of the pulley body 11 and the damper mass 20 to form the damper pulley 10.

Therefore, the damper pulley 1 according to the present embodiment.
At 0, the internal stress of the rubber elastic body 24, which is caused by the axial extension accompanying the precompression, can be advantageously made small, and the cylinder of the pulley main body 11 of the rubber elastic body 24 caused by the internal stress can be reduced. The reduction of the pressure exerted on the adhesive surface of the portion 16 and the damper mass 20 can be effectively suppressed, whereby the rubber elastic body 24 by the secondary vulcanization can be suppressed.
Of the pulley main body 11 and the damper mass 2
Even after the adhesive fixing to 0, the compressed state of the rubber elastic body 24 can be effectively ensured.

Therefore, in such a damper pulley 10, the rubber elastic body 24 is attached to the cylindrical portion 16 of the pulley body 11.
With this, it is possible to bond them to the damper mass 20 with excellent reliability, and as a result, the durability of use can be improved very effectively.

Further, the damper pulley 10 according to the present embodiment.
In the above, since the width of the rubber elastic body 24, the thickness of the remaining portion excluding the depth of the concave groove 24, and the arrangement interval of the concave groove 24 are defined in a specific range, the rubber elastic body 2
4 is a cylindrical portion 16 of the pulley body 11 and a damper mass 20.
It is possible to effectively prevent bending deformation or bending deformation during press-fitting into the space between and, and it is possible to advantageously prevent a decrease in workability during press-fitting work. The axial extension of the entire rubber elastic body 24 under the state can be suppressed more effectively, and the rubber elastic body 24
Therefore, the reliability of the adhesion of the pulley body 11 to the cylindrical portion 16 and the damper mass 20 can be improved more effectively.

Incidentally, the fact that the damper pulley 10 has the excellent characteristics as described above is confirmed by the experiments conducted by the present inventors as follows.
It is clearly recognized.

That is, first, as a rubber elastic body which is interposed between the cylindrical portion 16 of the pulley main body 11 and the damper mass 20 and is fixed by adhesion, as shown in FIGS. 3 and 4, in the thickness direction, A plurality of concave grooves 2 are provided on two facing surfaces.
As shown in FIG. 6, a damper pulley 10 (test product 1) using a rubber elastic body 24 provided in contrast with No. 4 and a plurality of recessed grooves are formed in a stepped state on these two surfaces. For comparison with the damper pulley 10 (test product 2) in which the rubber elastic body 28 formed in FIG.
Using a conventional damper pulley (conventional product) in which two surfaces facing each other in the thickness direction of the rubber elastic body are flat surfaces,
While fixing the pulley body side of these three types of damper pulleys, a constant tensile load was applied to the damper mass in the direction perpendicular to the axis, and in that state, they were left in a high temperature atmosphere. Then, in each damper pulley, the time at which the adhesion of the rubber elastic body to the pulley main body and the damper mass was peeled off was examined, and at the same time, the residual adhesive force when the peeling occurred was measured. The results are also shown in Table 1 below. The residual adhesive strength was evaluated by tensile in a normal temperature atmosphere.

[0029]

Next, in order to examine the adhesive strength of each rubber elastic body to the pulley main body and the damper mass in the above-mentioned three types of damper pulleys (test product 1, test product 2, conventional product) under no stress load, Each of the three types of damper pulleys was left in a temperature environment of 150 ° C. for 300 hours, after which the residual adhesive force of the rubber elastic body to each pulley body and the damper mass was measured in the same manner as the above test. At the same time, the broken state of the rubber elastic body was observed. The results are also shown in Table 2.

[0031]

As is clear from the results shown in Tables 1 and 2, Test Article 1 and Test Article 2 each having the structure according to the present invention.
In a high temperature environment, the adhesion of the rubber elastic body to the pulley body and the damper mass may peel off even when a predetermined load is applied and no stress load is applied. It can be prevented over time, yet good adhesion can be maintained in good condition. On the other hand, in the conventional product, not only adhesion peeling occurs in an extremely short time under such an environment, but also the adhesive strength is significantly reduced. This is because the damper pulley 10 having the structure according to the present invention is extremely superior to the conventional one in the reliability of adhesion between the rubber elastic bodies 24, 28 and the pulley body 11 and the damper mass 20. It really shows something.

Although the representative embodiments of the present invention have been described in detail above, this is a literal example and the present invention is not construed as being limited to such specific embodiments. Needless to say.

For example, in the above-described embodiment, the rubber elastic body 24 as the elastic body layer is formed in a substantially thick band plate shape, but the shape of such an elastic body layer is not limited to this. Any shape, such as one integrally molded in a ring shape, as long as it has a shape that can correspond to the gap formed between the inner rigid cylindrical member and the outer rigid cylindrical member. The same can be adopted.

Further, in the above-described embodiment, a plurality of concave grooves 24 having a substantially semicircular cross section are provided on two surfaces of the rubber elastic body 24 facing each other in the thickness direction, and are parallel to each other at a predetermined distance. Although the grooves are formed separately, the shape and the form of the concave groove are not limited to this. For example, the cross-sectional shape is V-shaped, W-shaped, or rectangular. It may be configured so that

Further, in the above-mentioned embodiment, the concave groove 24 is formed so as to be symmetrical or stepped on each of the two surfaces, but the arrangement of such concave groove on each surface. However, it goes without saying that the invention is not limited to this.

Needless to say, the number and intervals of formation of such concave grooves are not limited to those in the above embodiment.

Further, in the above-mentioned embodiment, the elastic layer is composed of the rubber elastic body 24, but the material for providing the elastic layer is not particularly limited to this.

In addition, in the above-described embodiment, a specific example of the present invention applied to a damper pulley around which a V-belt is wound is shown. Any of them can be similarly applied to the damper and the like.

Although not listed one by one, the present invention is
Based on the knowledge of those skilled in the art, it can be implemented in various modified, modified, and improved modes, and
It goes without saying that all such embodiments are included within the scope of the present invention, without departing from the spirit of the present invention.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of a torsional damper according to the present invention.

FIG. 2 is a cross-sectional view taken along the line AA in FIG.

FIG. 3 is an explanatory plan view showing an example of an elastic layer attached to the torsion damper shown in FIG.

FIG. 4 is an end face explanatory view of the elastic layer shown in FIG.

5 is an enlarged cross-sectional explanatory view of a main part of the torsional damper shown in FIG.

FIG. 6 is a view corresponding to FIG. 4, showing another example of an elastic layer attached to the torsion damper shown in FIG. 1.

[Explanation of symbols]

 10 Damper Pulley 11 Pulley Main Body 12 Key Groove 14 Boss Section 16 Cylindrical Section 18 Connecting Section 20 Damper Mass 22 V Groove 24, 28 Rubber Elastic Body 26 Recessed Groove

Claims (2)

[Claims] 1. An inner rigid cylindrical member, an outer rigid cylindrical member which is concentrically arranged at a predetermined radial outer side of the inner rigid cylindrical member, and two rigid cylindrical members inside and outside of the rigid cylindrical member. A torsion damper comprising an elastic body layer having a predetermined thickness, which is interposed and pre-compressed between the elastic body layer, and the elastic body layer is provided on a surface facing the two rigid cylindrical members inside and outside. , A torsional damper having a plurality of recessed grooves extending continuously along the circumferential direction. 2. The elastic layer is formed between two inner and outer rigid cylindrical members in a form before being interposed between the inner rigid cylindrical member and the outer rigid cylindrical member. The axial length is 80 to 90% with respect to the axial length of the gap, and the concave portion is 60 to 80% with respect to the distance between the two rigid cylindrical members inside and outside. The thickness of the remaining portion excluding the depth of the groove is formed, and a plurality of the recessed grooves are formed at intervals of 3 to 8 mm in the axial direction of the elastic layer. Torsional damper.