JPH09177887A - Hanger rubber for exhaust system member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrict surging and improve durability by forming mounting holes through which support members are to be inserted respectively at the upper and lower end parts of a hanger rubber for hanging an automobile exhaust system members from a vehicle body and providing a side rubber at an intermediate part and a coupling rubber between both-side rubbers, respectively. SOLUTION: A hanger rubber 1 is thick and is disk-shaped, a first mounting hole through which a support member on the vehicle side is to be inserted into the upper end part thereof is formed, and a second mounting hole 5 through which a support member on the silencer side being an exhaust member is to be inserted into the lower end part thereof is formed. A number of through holes 6 is formed at the intermediate part greatly expanding in an arc shape, of the hunger rubber, and the right and left of an arc shaped circumferential walls of their specified thickness are a pair of side rubbers 7, 7 oppositely faced in the direction connecting the upper and lower end parts thereof and vertical to both mounting holes 3 and 5. The right and left side rubbers 7, 7 are coupled together by means of a coupling rubber 8 at the center part formed by being bored with a number of through holes 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hanger rubber for suspending a vehicle silencer and other exhaust system members on a vehicle body.

[0002]

2. Description of the Related Art An example of a hanger rubber for a vehicle exhaust system member is disclosed in Japanese Patent Laid-Open No. 3-6695. As shown in FIG. 14, it has a first holding portion b having a first through hole a into which a vehicle body side supporting member is inserted, and a second through hole c having a second through hole c into which an exhaust system member supporting member is inserted. 2 holding part d
And a pair of side portions e connecting the first holding portion b and the second holding portion d on both sides thereof, and one central connecting portion f connecting the both side portions e, e left and right. It is a type of hanger rubber g. This θ type hanger rubber g shifts the resonance frequency to the high frequency side by the central connecting portion f to reduce the vibration transmission force in the low frequency region, and the pair of side portions e,
It is intended to suppress surging in which e swings to the left and right in opposite phases.

Japanese Utility Model Laid-Open No. 52-82611 discloses a ring-shaped hanger rubber having therein a cross beam having a through hole formed at an intersection of a vertical beam portion and a horizontal beam portion. This is intended to prevent the vertical swing portion and the horizontal swing portion from increasing the vertical amplitude of the hanger rubber when there is a large vertical vibration input.

[0004]

However, in the case of the θ type hanger rubber, there is a problem that the central connecting portion is bent when the vibration frequency becomes high.
The resonance frequency appears near 00 Hz, and the expected surging suppression effect becomes insufficient. Moreover, stress is likely to be concentrated between the connecting point where the central connecting portion of the side portion is connected and the first or second holding portion, and there is a problem in terms of durability. Further, in the case of the hanger rubber having the cross beam, it is advantageous in preventing the vertical amplitude from increasing, but it is not sufficient to suppress surging.

[0005]

Means for Solving the Problems The present inventor has conducted various experiments and studies on the suppression of surging of the hanger rubber, and has made a plurality of opposing side rubbers (side portions or peripheral walls in the above-mentioned prior art). It was found that it is effective to suppress the surging described above and that the durability can be improved by connecting the portions with a connecting rubber having a crossing portion that meshes in a net shape, and the present invention has been completed. is there. Hereinafter, the invention according to each claim will be specifically described.

<Invention of Claim 1> The present invention is an exhaust system member hanger rubber for suspending an exhaust system member of an automobile on a vehicle body. A vehicle body side support member is inserted into an upper end portion of the hanger rubber. A mounting hole is formed, and a second mounting hole is formed at a lower end portion of the exhaust system member side so as to be inserted therein in parallel with the first mounting hole, and an intermediate portion thereof has the one end portion and the other end portion, respectively. Is provided with a pair of side rubbers that connect to each other and that face each other in a direction perpendicular to the mounting hole, and connect a plurality of portions of each of the both side rubbers to each other and form a crossover portion in the middle. It is characterized by including a connecting rubber having.

(Operation) In the present invention, since the plurality of opposite side rubbers are connected to each other by the connecting rubbers, the rigidity of the both side rubbers is increased to increase the resonance frequency of the hanger rubber. It is advantageous to shift it to the side. Further, since the connecting rubber is provided with the crossing portion, it is advantageous in distributing the load applied to the both side rubbers to the entire hanger rubber by the connecting rubber, and local stress concentration can be avoided. .

<Invention of Claim 2> In the hanger rubber for an exhaust system member according to claim 1, the connecting rubbers are opposite to each other with respect to the direction connecting the both mounting holes. It is characterized in that it is formed in a mesh shape in which a plurality of slanted connecting bars cross each other.

(Operation) In the case of the present invention, since the connecting rubber is formed in a net shape, it is advantageous in obtaining the operation of the invention according to claim 1. Further, since the connecting bar which constitutes the connecting rubber extends obliquely with respect to the direction connecting the both mounting holes, it receives the tensile force in the vertical direction by the deformation in which the extension is bent. It will be.

<Invention of Claim 3> The present invention is characterized in that, in the hanger rubber for exhaust system members described in claim 2, the mesh of the connecting rubber is circular.

(Operation) In the case of the present invention, since the mesh of the connecting rubber is circular, it is advantageous in avoiding stress concentration.

[0012]

According to the invention of claim 1, between the pair of side rubbers facing each other, there is provided a connecting rubber that connects a plurality of points of each of the side rubbers and has an intersection in the middle. Therefore, it becomes easy to shift the resonance frequency of the hanger rubber to the high frequency side and suppress the surging in the low frequency region, and improve the durability by avoiding the local concentration of stress on both side rubbers. be able to.

According to the second aspect of the invention, in the exhaust system member hanger rubber according to the first aspect, the connecting rubber is diagonally opposite to each other with respect to the direction connecting the both mounting holes. Since it is formed in a mesh shape in which a plurality of connecting bars that have become crossed with each other, it is possible to support a tensile load in the up-and-down direction not by simple extension of the connecting bars but by deformation caused by bending. While performing the function of shifting the resonance frequency of the side rubber to the high frequency side,
It is advantageous in obtaining durability.

According to the invention of claim 3, in the hanger rubber for exhaust system member according to claim 2, the mesh of the connecting rubber is circular, which is advantageous in avoiding stress concentration. , Durability is improved.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

<Shape of Hanger Rubber> -Example 1-As shown in FIG. 1, the hanger rubber 1 is a thick-walled disc-shaped member, and is a first attachment for inserting the support member 2 on the vehicle body side into the upper end portion thereof. A hole 3 is formed, and a second mounting hole 5 into which a silencer-side support member 4 as an exhaust system member is inserted is formed at a lower end portion. A large number of through holes 6 are formed in the middle of the hanger rubber 1.

2 and 3 show the specific shape of the hanger rubber 1. The upper and lower surfaces of the hanger rubber 1 bulge in a circular arc shape, and the left and right surfaces largely bulge in an arc shape. First mounting hole 3 and second
Each of the mounting holes 5 is a circular hole arranged concentrically with each of the arcs of the upper surface and the lower surface. The through hole 6 is a circular hole provided on the inner side of the arcuate peripheral wall having a predetermined thickness left and right. As shown in FIG. 3, the mounting holes 3 and 5 and the through hole 6 are provided.
Extend in the plate thickness direction of the hanger rubber 1 and are parallel to each other.

The left and right arcuate peripheral walls having a predetermined thickness connect the upper end portion where the first mounting hole 3 is formed and the lower end portion where the second mounting hole 5 is formed, and are perpendicular to the both mounting holes 3, 5. Forming a pair of side rubbers 7, 7 facing each other.
The left and right side rubbers 7, 7 are connected by a central connecting rubber 8 formed by forming the above-described large number of through holes 6.

In the case of this example, the number of the through holes 6 is 17, and a total of 1 in each of the "V" shape along the respective left and right peripheral walls.
Zero through holes 6 are arranged, and seven through holes 6 are arranged inside thereof. Therefore, the connecting rubber 8 has a space 7a in the circumferential direction of each of the left and right side rubbers 7, 7.
It is a net-like body that connects four places of ~ 7d. Also,
In the case of this example, the closest through holes 6, 6 are the above-mentioned mounting holes 3,
There is a positional relationship in which one of the oblique directions is aligned with the direction connecting the five, or the other oblique direction. Therefore, the net-shaped connecting rubber 8
Is composed of a plurality of connecting bars 8a, 8a ... And connecting bars 8b, 8b ..

Example 2 FIG. 4 shows a hanger rubber 11 of this example. The hanger rubber 11 is provided with through holes 6 similar to those of the first embodiment in the first, third, and fifth steps from the top, and the left and right sides of the second and fourth steps in the left-right direction. Long through holes 12,1
The side rubbers 13 and 13 and the connecting rubber 14 are formed by drilling 2.
Is the same as

Example 3 FIG. 5 shows a hanger rubber 15 of this example. The hanger rubber 15 has a diamond-shaped thick plate whose corners are cut off at the upper end thereof with a first mounting hole 3 and at the lower end thereof with a second mounting hole 3.
The mounting hole 5 is drilled and the upper part of the middle part is 3
The side rubbers 17, 17 are formed by arranging three through holes 6 on the left and right, four in the middle, and three in the lower.
And a connection rubber 18 is formed.

Example 4 FIG. 6 shows a hanger rubber 21 of this example. This hanger rubber 21 has two elliptical through holes 22 formed between the first mounting hole 3 and the second mounting hole 5 in the upper stage, three in the middle stage, and two in the lower stage to form side rubber. 23, 2
3 and the connection rubber 24 are formed, and the others are the same as in the third embodiment.

<Internal Stress in Static Deformation of Hanger Rubber> Regarding the hanger rubber 1 of the first embodiment, a supporting member is inserted and fixed in the second mounting hole 5 thereof, while the supporting member is supported in the first mounting hole 3. The distribution of internal stress was investigated when the support member was inserted and the support member was displaced upward by a certain distance. The hanger rubber 1 used for the test has a height of 64 mm in a free state, a maximum width of 56 mm, and a center-to-center distance between the mounting holes 3 and 5 of 34 mm. The amount of displacement of the support member is 3
mm. The stress distribution is shown in FIG.

In the figure, the shape indicated by the chain double-dashed line indicates the original position, and the stress in each region represented by the diagonal lines is as follows.

Area of diagonal line to the left; 0 kgf / mm ^{2 to} 2.320 × 10 ^-3 kgf / mm ² Area of diagonal line to the right; 2.320 × 10 ^-3 kgf / mm ^{2 to} 4.288 × 10 ^-3 kgf / mm ² Vertical line Area ； 4.288 × 10 ^-3 kgf / mm ² 〜1.216 × 10 ^-2 kgf / mm ² Area of diagonal grid ； 1.216 × 10 ^-2 kgf / mm ² 〜1.806 × 10 ^-2 kgf / mm ²

FIG. 8 shows the result of similarly examining the stress distribution of the θ type hanger rubber shown in FIG. The spring constant of the hanger rubber in the vertical direction is the same as that in the first embodiment, and the displacement amount is also the same.

Area of diagonal down left: 0 kgf / mm ^{2 to} 2.994 × 10 ^-3 kgf / mm ² Area of diagonal down right: 2.994 × 10 ^-3 kgf / mm ^{2 to} 5.363 × 10 ^-3 kgf / mm ² Vertical line Area ； 5.363 × 10 ^-3 kgf / mm ² 〜1.484 × 10 ^-2 kgf / mm ² Area of diagonal grid ； 1.484 × 10 ^-2 kgf / mm ² 〜2.194 × 10 ^-2 kgf / mm ²

Further, FIG. 9 shows the result of similarly examining the stress distribution for a conventional type hanger rubber having no central connecting portion. The spring constant of the hanger rubber in the vertical direction is the same as that in the first embodiment, and the displacement amount is also the same.

Area of diagonal down left: 0 kgf / mm ^{2 to} 2.104 × 10 ^-3 kgf / mm ² Area of diagonal down right: 2.104 × 10 ^-3 kgf / mm ^{2 to} 4.196 × 10 ^-3 kgf / mm ² Vertical line Area ； 4.196 × 10 ^-3 kgf / mm ² 〜1.256 × 10 ^-2 kgf / mm ² Area of diagonal grid ； 1.256 × 10 ^-2 kgf / mm ² 〜1.884 × 10 ^-2 kgf / mm ²

In the case of the hanger rubber 1 of the first embodiment (FIG. 7), the stress of the connecting rubber 8 is 4.28 over almost the whole.
8 × 10 ^-3 kgf / mm ^{2 to} 1.806 × 10 ^-2 kgf / mm ^{2 which} is relatively high, while the stress on the side rubber 7 is lower than that (0 kgf / mm ^{2 to} 4.288 × 10 ^-3 kgf / mm ² ).
On the other hand, in the case of the θ type hanger rubber (Fig. 8), the stress at the central connecting part is low (0 kgf / mm ^{2 to} 2.994 × 10
^-3 kgf / mm ² ) and the stress on the side rubber part is high (5.363 × 10 ^-3 kgf / mm ^{2 to} 2.194 × 10 ^-2 kgf / mm ² ).
Also in the conventional type (FIG. 9), the stress on the side rubber portion is high.

Thus, the hanger rubber 1 of Example 1
Then, since the side rubbers 7, 7 are connected by the connecting rubber 8 having a net-like structure, the stress is dispersed by the connecting rubber 8, and the stress is reduced as a whole, which is advantageous in durability. That is, the hanger rubber 1 of Example 1
Comparing the maximum stress (1.806 × 10 ^-2 kgf / mm ² ) with the θ type maximum stress (2.194 × 10 ^-2 kgf / mm ² ), the stress value in Example 1 is about 18% lower. . Since it is known from experience that the durability of rubber is proportional to the fourth power of the stress, in the case of Example 1, the life is extended about twice as long as that of the θ type by the reduction of the stress. .

In the case of the first embodiment, the side rubber 7
The stress of the part is lower than that of the connecting rubber 8. Therefore, even if a large load acts on the hanger rubber 1, the connecting rubber 8 is cut first and the side rubber 7 is prevented from being cut, which is advantageous in preventing the exhaust system member from falling. Become.

<Relationship between Frequency of Hanger Rubber and Vibration Transmission Force> For each of the θ type and conventional type hanger rubbers of the above-mentioned Example 1, the frequency and the vibration transmission force (absolute spring constant) were compared by a dynamic characteristic testing device. I investigated the relationship. The results are shown in FIG.

According to the figure, in the conventional type, 300H
When it becomes z or more, the vibration transmission force becomes considerably large,
The peak appears near 380 Hz. It can be said that the θ type has a lower vibration transmission force than the conventional type as a whole, but around 270 Hz and 470 Hz
The peak of the vibration transmission force due to resonance appears in two nearby places.

On the other hand, in the first embodiment, 450 Hz
Although a resonance peak appears in the vicinity, the vibration transmission force is low in a lower frequency region, and there is no resonance peak in the vicinity of 200 to 300 Hz as in the θ type.
From this, it can be said that in the hanger rubber 1 of Example 1, the supporting rubber of the side rubbers 7, 7 was increased by the connecting rubber 8 having the mesh structure, and the resonance frequency could be increased.

<Analysis of Vibration Mode of Hanger Rubber> For each of the above Example 1 and θ type hanger rubber,
The vibration mode at resonance was analyzed. The results are shown in FIG. 11 for Example 1 and in FIG. 12 for the θ type. In each of FIG. 11 and FIG. 12, the two-dot chain line indicates the original position, the area of the diagonal line to the left is small displacement, the area of the diagonal to the right is small displacement, the region of the vertical line is displacing, and the diagonal grid region is displacing. Is large. Here, the resonance frequency of the hanger rubber 1 of Example 1 was 470 Hz, and the resonance frequency of the θ type hanger rubber was 439 Hz. Regarding this resonance frequency, the results of FIG. 10 and FIGS.
Although there is some deviation from the result of (1), in any case, it can be said that the coupling rubber 8 as in Example 1 has a high resonance frequency.

<Relationship between Supporting Rigidity of Coupling Rubber and Resonant Frequency of Hanger Rubber> For each hanger rubber of Example 1 and Example 2, the relationship between the frequency and vibration transmission force (absolute spring constant) was examined. The results shown in FIG. 13 were obtained. The hanger rubber of the second embodiment has lower supporting rigidity in the left-right direction by the connecting rubber than the hanger rubber of the first embodiment. The spring constants in the vertical direction were the same in Examples 1 and 2.

According to FIG. 13, the frequency at which the resonance peak appears is lower in the second embodiment. Therefore, it can be seen that increasing the lateral support rigidity of the connecting rubber is effective for increasing the resonance frequency.

<Summary> As described above, by connecting a plurality of places on the left and right side rubbers with a net-like connecting rubber, stress distribution from the left and right side rubbers to the connecting rubber is achieved and the durability of the hanger rubber is enhanced. It is possible,
Moreover, the support rigidity in the left-right direction can be increased to increase the resonance frequency of the hanger rubber.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a mode of use of a hanger rubber according to a first embodiment.

FIG. 2 is a front view of the hanger rubber according to the first embodiment.

FIG. 3 is a sectional view of the hanger rubber according to the first embodiment in a central vertical direction.

FIG. 4 is a front view of a hanger rubber according to a second embodiment.

FIG. 5 is a front view of a hanger rubber according to a third embodiment.

FIG. 6 is a front view of a hanger rubber according to a fourth embodiment.

FIG. 7 is a stress distribution diagram of the hanger rubber of Example 1.

FIG. 8 is a stress distribution diagram of a θ type hanger rubber.

FIG. 9 is a stress distribution diagram of a conventional type hanger rubber.

FIG. 10 is a vibration characteristic diagram showing the relationship between the frequency and the absolute spring constant of each hanger rubber of Example 1, θ type and conventional type.

FIG. 11 is a vibration mode diagram of the hanger rubber according to the first embodiment.

FIG. 12 is a vibration mode diagram of a θ type hanger rubber.

FIG. 13 is a diagram comparing the vibration characteristics of both hanger rubbers of Examples 1 and 2.

FIG. 14 is a front view of a θ type hanger rubber.

[Explanation of symbols]

 1,11,15,21 Hanger rubber 2 Car body side support member 3 First mounting hole 4 Silencer side support member 5 Second mounting hole 6,12,22 Through hole 7,13,17,23 Side rubber 7a to 7d Connection point 8, 14, 18, 24 Connection rubber 8a, 8b Connection rail

Claims (3)

[Claims] 1. A hanger rubber for an exhaust system member for suspending an exhaust system member of an automobile on a vehicle body, wherein a first mounting hole into which a support member on the vehicle body side is inserted is formed at an upper end portion, and a lower end portion is formed at a lower end portion. A second mounting hole, into which the support member on the exhaust system member side is inserted, is formed in parallel with the first mounting hole, and the middle portion connects the one end and the other end and is perpendicular to the mounting hole. In addition to having a pair of side rubbers facing each other in a different direction, a connection rubber is provided between the side rubbers that connects a plurality of locations of the side rubbers and has a crossing portion in the middle. A characteristic hanger rubber for exhaust system members. 2. The exhaust system member hanger rubber according to claim 1, wherein the connecting rubber has a plurality of connecting bars that are inclined in directions opposite to each other with respect to a direction connecting the both mounting holes. A hanger rubber for exhaust system members, which is formed in a mesh shape by crossing. 3. The hanger rubber for an exhaust system member according to claim 2, wherein the mesh of the connecting rubber is circular.