JPH11230262A - Exhaust pipe support device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lower the total dynamic spring constant of an exhaust pipe support device by dividing its frequency band that causes surging into two or more. SOLUTION: A rubber hanger 1 with a constant thickness is integrally formed out of an elastic rubber body with upper end utilized as a first mounting part 11 and lower end as a second mounting part 12. The first mounting part is perforated with a first mounting hole 2a inserted with a support member on a car body, and the second mounting part is perforated with a second mounting hole 2b inserted with a support member on an exhaust pipe. Between the first and second mounting holes, perforations 51 to 57 of various shapes and grooves 61 and 62 are made to define connecting spring parts 71 to 78 of eight routes which connect the first and second mounting holes with their different lengths and cross-sectional areas leading to different natural frequencies. The resonance frequency band that causes surging is thus divided into plurality corresponding to the several types of natural frequency of those connecting spring parts to thereby reduce the resonance energy of reduce the jump of each dynamic spring by the resonance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust pipe supporting device used for suspending and supporting an exhaust pipe connected to a vibration source such as a prime mover with respect to a supported body such as a vehicle body.

[0002]

2. Description of the Related Art Conventionally, as this kind of exhaust pipe supporting device, for example, the one shown in FIG. 6 is known (for example, Japanese Utility Model Laid-Open No. 2-24028, Japanese Utility Model Laid-Open No. 4-84711).
Reference). This has a first mounting portion having a first mounting hole 2a into which a support member on the vehicle body side as a supported body is fitted, and a second mounting portion having a second mounting hole 2b into which a support member of an exhaust pipe is fitted. And a pair of connecting spring portions 70 connecting the first mounting portion and the second mounting portion to each other at both side positions thereof.
Reference numerals 0 and 700 are formed integrally and at least symmetrically by a rubber elastic body having the same thickness (the thickness in the direction perpendicular to the plane of FIG. 6).

[0003]

However, in the above-described conventional exhaust pipe supporting device, the pair of connecting spring portions 70 are provided.
0,700 are formed in a symmetrical shape and have the same mass and spring constant.
The natural frequencies at which 00 and 700 generate natural vibrations are the same. For this reason, as illustrated in FIG. 8 or FIG. 9, phase inversion occurs in one specific high-frequency region (each frequency region around 500 Hz in the example) determined by the mass and the spring constant, and the pair of coupling springs Part 70
At 0,700, resonance (surging) occurs irrespective of the movement of the upper and lower vehicle bodies and the exhaust pipe. As a result of this resonance, a jump (rapid increase) of the dynamic spring constant occurs, and the value increases, leading to a deterioration in the transmission rate of vibration. Area (for example, 30
(0 to 400 Hz), an increase in muffled sound or the like is caused.

The present invention has been made in view of such circumstances, and an object of the present invention is to disperse the frequency range in which surging occurs into two or more to reduce the overall dynamic spring. is there.

[0005]

In order to achieve the above object, the present invention provides an exhaust pipe for suspending and supporting an exhaust pipe 40 (see FIG. 1) with respect to a supported member 30. On the premise of a supporting device, a first mounting portion 110 provided on the upper end side and mounted on the supported body 30 side, a second mounting portion 120 provided on the lower end side and mounted on the exhaust pipe 40 side, The first mounting portion 110 and the second mounting portion 120
And two or more connecting spring portions 70 formed so as to have different natural frequencies from each other.
a, 70b, and 70c are specified as basic matters.

Here, the exhaust pipe 40 is connected to a prime mover which is a vibration source to transmit vibration from the prime mover, and includes a muffler and the like communicated with the exhaust pipe main body in addition to the exhaust pipe main body. It is a thing. Further, the supported body 30 may be a fixed installation object other than the vehicle body on which the prime mover is mounted. First attachment portion 110 or second attachment portion 12
Even if the mounting member is provided with a mounting hole into which the support member from the supported body 30 or the exhaust pipe 40 is inserted, 0 is used for the mounting supported on the mounting hole of the supported body 30 or the exhaust pipe 40. It may have a unit. The first mounting portion 110, the second mounting portion 120, and each connecting spring portion 7
Oa, 70b, and 70c may be formed integrally with each other by, for example, rubber, or may be formed separately from each other and connected. As the number of the connection spring portions, at least two having natural frequencies different from each other may be sufficient, and preferably three or more, or four or more. Note that the above “two” or “three” has different natural frequencies equivalent to “two” or “three”. Further, each of the connecting spring portions 70a, 70b, 70c may be formed by an individual mass member and a spring member. In this case, a weight as a mass member is provided in a rubber elastic body as a spring member. The connecting spring portion may be configured by being embedded. Then, by setting the mass of the mass member and the spring constant of the spring member so as to change at each connection spring portion, the respective natural frequencies may be changed. On the other hand, each connecting spring portion 70a, 70b,
When 70c is formed of a rubber elastic body,
As described above, by setting one or both of the length and the cross-sectional area to be different from each other, the natural frequencies of the respective connection spring portions can be made different from each other.

In the configuration of the present invention described above, since two or more connecting spring portions for connecting the first mounting portion and the second mounting portion to each other have different natural frequencies, the frequency range in which surging occurs is also limited. It will be distributed to two or more. Since the energy of the phase inversion in each of the dispersed surging regions is smaller than that in the case where surging occurs only in one frequency region, the degree of jump of the absolute spring constant in each surging region is also surging only in the one frequency region. Is smaller than in the conventional case in which is caused, and a low dynamic spring (reduction of the absolute spring constant) is achieved as a whole.

In the present invention, when each connecting spring portion is formed of a rubber elastic body, a path connecting the first mounting portion and the second mounting portion of both adjacent connecting spring portions as described in claim 3. If two connecting spring portions having a part in common with each other are formed by making a portion of the first connecting portion common, the first mounting portion and the first connecting portion can be apparently formed of two connecting spring portions. It becomes possible to provide four paths connecting the two mounting portions, and accordingly, it becomes possible to provide four types of natural frequencies.

Further, in the above invention, the first mounting portion, the second mounting portion, and each connecting spring portion are integrally formed by a rubber elastic body, and the two connecting spring portions adjacent to each other are formed. By disposing the inner peripheral surface between the two connecting spring portions so as to be separated by a smoothly curved through hole, it is advantageous in avoiding local stress concentration.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 shows a hanger rubber 1 as an exhaust pipe support device according to an embodiment of the present invention. The hanger rubber 1 has a uniform thickness and is formed in a substantially elliptical or substantially elliptical shape having a constant thickness and a vertically long shape by a uniform rubber elastic body. This hanger rubber 1 has a first
It has a first mounting portion 11 in which a mounting hole 2a is formed, and a second mounting portion 12 in which a second mounting hole 2b is formed in a lower end portion. A support member 3a on the vehicle body 3 side as a supported body is inserted into the first mounting hole 2a, and a support member 4a on the exhaust pipe 4 side is inserted into the second mounting hole 2b. Thus, the exhaust pipe 4 is suspended and supported on the vehicle body 3 via the hanger rubber 1.

FIGS. 3 to 5 show specific shapes of the hanger rubber 1. FIG. The first of the hanger rubber 1
A plurality of (seven in the illustrated example) through-holes 51 to 57 of various shapes are provided between the two mounting holes 2a and 2b in the thickness direction of the hanger rubber 1 (see FIGS. 3 and 5). A plurality of (two in the illustrated example) concave grooves 61 and 62 are formed so as to penetrate in the direction perpendicular to the paper surface and cut inward from both the left and right sides and extend in the thickness direction. A plurality (eight in the illustrated example) of connecting the first and second mounting holes 2a and 2b to each other in the vertical direction by portions defined by the through holes 51 to 57 and the concave grooves 61 and 62. Connection spring portions 71 to 78 are formed.

Each of the through holes 51 to 57 and each of the grooves 61 and 62 are provided.
Has a circular arc surface and a smoothly curved shape, and the through holes 51 to 57 and the concave grooves 6
Each of the connection spring portions 71 to 78 partitioned by
Is smoothly bent and extends between the mounting holes 2a and 2b.

The first to eighth eight connecting spring portions 71 to 71 are provided.
Reference numeral 78 is formed so that the length and cross-sectional area of the path (see the two-dot chain line in FIGS. 3 and 5) connecting the mounting holes 2a and 2b are different from each other, and a part of the path is partway along the path. The common parts overlap each other. Hereinafter, the paths of the first to eighth connection spring portions 71 to 78 will be described in detail. For convenience of explanation, a route starting from the second mounting hole 2b and ending at the first mounting hole 2a will be described with reference to FIG.

The first connecting spring portion 71 includes a portion 81 defined by the first through hole 51 and the second through hole 52 and the right side surface 13 from the second mounting hole 2b, a second through hole 52 and the first groove. 61, a portion 83 defined by the fifth through-hole 55 and the first groove 61, and a fifth through-hole 5
5 through a portion 84 defined by the right side 13 and the first side.
It reaches the mounting hole 2a.

The second connecting spring portion 72 includes a portion 85 defined by the first through hole 51 and the second through hole 52 from the same starting point as the first connecting spring portion 71, and the second through hole 52 and the third through hole 52. Hole 53
, A portion 87 defined by the second through hole 52 and the fourth through hole 54, a portion 88 defined by the second through hole 55 and the fifth through hole 55, 5
The first mounting hole 2a is reached via the portions 83 and 84 defined by the through hole 55, the first groove 61 and the right side surface 13.

The third connecting spring portion 73 is connected to the second through hole 52 and the third through hole 53 through a portion 89 defined by the first through hole 51 and the third through hole 53 from the second mounting hole 2b. Merges with the second connection spring portion 72 at a portion 86 defined by
Thereafter, it reaches the first mounting hole 2a via the same path as the second connection spring portion 72.

The fourth connecting spring portion 74 extends from the second mounting hole 2b to the portion 9 defined by the third through hole 53 and the left side surface 14.
0, a portion 91 defined by the third through hole 53 and the second concave groove 62, a portion 92 defined by the third through hole 53 and the fifth through hole 55, and a third portion 53 defined by the third through hole 53 and the fourth through hole 55. Through a portion 93 defined by the through hole 54, a portion 87 defined by the second through hole 52 and the fourth through hole 54 merges with the second or third connecting spring portion 72, 73. Through the same path as the second or third connecting spring portions 72 and 73, the first
It reaches the mounting hole 2a.

In the fifth connecting spring portion 75, only the portion 93 of the fourth connecting spring portion 74 is replaced by a portion 94 defined by the fourth through hole 54 and the fifth through hole 55, and the other portions except for this portion are the same as those of the fifth connecting spring portion 75. Through the same path as the four connection spring portions 74, the second connection hole 2b reaches the first attachment hole 2a.

The sixth connection spring portion 76 passes through the same starting point and portion 90 as the fourth or fifth connection spring portions 74 and 75, and passes through a portion 95 defined by the second concave groove 62 and the fifth through hole 55. And a portion 96 defined by the fifth through-hole 55 and the sixth through-hole 56 from this portion 95, and a fifth through-hole 5
The first mounting hole 2a is reached through a portion 97 defined by the fifth and seventh through holes 57.

The seventh connecting spring portion 77 passes through the same path as the sixth connecting spring portion 76 from the second mounting hole 2b, and
6 and the sixth through hole 56 and the seventh through hole 5
7 and diverges into a portion 98 defined by the first through hole 57 and the first mounting hole 2a via a portion 100 defined by the seventh through hole 57 and the left side surface 14.

The eighth connecting spring portion 78 reaches the bottom portion 95 of the second groove 62 from the second mounting hole 2b through the same path as the sixth or seventh connecting spring portion 76, 77. The first mounting hole 2 branches from a portion 99 defined by the sixth through hole 56 and the second concave groove 62 through a portion 100 defined by the sixth and seventh through holes 57 and the left side surface 14.
to a.

Each of the connecting spring portions 71 to 71 formed as described above
Reference numeral 78 denotes a path whose length is different from each other. In addition, although the wall thickness is constant, the distance between the adjacent through holes and the distance between each of the concave grooves 61 and 62 and the adjacent through hole are provided. The spacing, that is, the spacing between the left or right side surface 13, 14 and each of the adjacent through holes is variously changed so that each portion 8
The widths of 1 to 100 are different, and the cross-sectional areas of the respective paths are different from each other.

In the case of the hanger rubber 1 constructed as described above, since the masses and spring constants of the connecting spring portions 71 to 78 are different from each other, the connecting spring portions 71 to 78 are different.
Have different natural frequencies. Therefore, when high-frequency vibration is input from the exhaust pipe 4 side or the vehicle body 3 side, the frequency ranges in which the connection spring portions 71 to 78 resonate are different from each other, and the generated surging is caused by the connection spring portions 71 to 78. 78 will be distributed. That is, the surging is dispersed into two or more corresponding to two or more connection spring portions having different natural frequencies, and in addition, each one of the connection spring portions 71 to 78 in this case is provided.
The mass of each book is smaller than that of the conventional case (see FIG. 6) in which the first and second mounting holes 2a and 2b are connected to each other by two connecting springs having the same length and cross-sectional area. Therefore, the resonance energy in each of the two or more dispersed surgings becomes small. As a result, an increase in the dynamic spring constant in each surging can be suppressed, and the overall dynamic spring can be reduced.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Using the embodiment shown in FIGS. 3 to 5 and the conventional example shown in FIG. 6, a first mounting hole 2a and a second mounting hole 2b are used.
Excitation test to input vertical vibration between and
Dynamic spring characteristics for vertical vibration were compared.

The results are shown in FIGS. 7 to 9 with the frequency (Hz) on the horizontal axis and the absolute spring constant (kgf / mm) and phase (degree) on the vertical axis. 7 shows the dynamic spring characteristics of the above embodiment, FIG. 8 shows the dynamic spring characteristics of the conventional example having substantially the same size as the above embodiment, and FIG. 9 shows the dynamic spring characteristics of the conventional example having a size larger than that of FIG. The spring characteristics are shown respectively. 7 to 9, the solid line indicates a change in the absolute spring constant, and the dashed line indicates a change in the phase.

In the case of the conventional example shown in FIG. 8 or FIG. 9, phase inversion occurs and resonance occurs in a frequency range of 500 Hz slightly in FIG. 8 and in a frequency range slightly before 500 Hz in FIG. As a result,
A jump in the dynamic spring has occurred. That is, in the conventional example, since the pair of connecting spring portions 700 and 700 (see FIG. 6) have the same length and cross-sectional area and the same mass and spring constant, even if there are two connecting spring portions, Each has the same natural frequency. As a result, phase inversion and resonance occur in the same frequency range, and the degree of jump of the dynamic spring due to the resonance also increases.

On the other hand, in the case of the embodiment shown in FIG. 7, since there are a plurality of connecting spring portions having different natural frequencies from each other, a frequency range in which phase inversion and resonance occur correspondingly. Are occurring multiple times. And
Since the mass of each of the eight connecting spring portions of the embodiment is smaller than that of a case where one phase inversion is generated based on the two connecting spring portions of the conventional example, the phase inversion is performed. The resulting resonance energy in each resonance frequency range is smaller than in the conventional example. For this reason, the degree to which the absolute spring constant jumps due to the resonance in the respective resonance frequency ranges is smaller than in the case of the conventional example. In other words, if the frequency region where the phase inversion occurs is dispersed into two or more, the jump degree of the absolute spring constant based on the resonance in each frequency region is smaller than the conventional case where the phase inversion occurs only in one frequency region. Become. As a result, a lower dynamic spring is achieved as a whole than in the conventional example.

[0029]

As described above, according to the exhaust pipe support device of the present invention as set forth in any one of claims 1 to 4, the resonance frequency range in which surging occurs can be dispersed to two or more. The degree of jump of the absolute spring constant in the resonance frequency range can be made smaller than in the conventional case where surging occurs only in one frequency range. As a result, a low dynamic spring can be achieved as a whole.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing the principle of the present invention.

FIG. 2 is a perspective view showing a use state of the embodiment.

FIG. 3 is a front view of the hanger rubber of FIG. 2;

FIG. 4 is a cross-sectional view taken along line AA of FIG.

FIG. 5 is a sectional view taken along line BB in FIG. 4;

FIG. 6 is a front view showing a conventional exhaust pipe support device.

FIG. 7 is a dynamic spring characteristic diagram illustrating a relationship between a frequency, an absolute spring constant, and a phase according to the embodiment.

8 is a dynamic spring characteristic diagram showing the relationship between the frequency, the absolute spring constant, and the phase in the conventional example of FIG.

FIG. 9 is a dynamic spring characteristic diagram showing the relationship between the frequency, the absolute spring constant, and the phase of the conventional example whose size is larger than that of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hanger rubber (exhaust pipe support apparatus) 3 Body (supported body) 4,40 Exhaust pipe 11,110 1st mounting part 12,120 2nd mounting part 30 Supported body 51-57 Through-hole 70a, 70b, 70c Connection Spring part 71-78 Connecting spring part

Claims (4)

[Claims] 1. An exhaust pipe supporting device for suspending and supporting an exhaust pipe with respect to a supported body, a first mounting portion provided on an upper end side and mounted on the supported body side, and a first mounting portion provided on a lower end side. The second attached to the exhaust pipe side
It is characterized by comprising: a mounting portion; and two or more connecting spring portions for connecting the first mounting portion and the second mounting portion to each other and having different natural frequencies from each other. Exhaust pipe support device. 2. The exhaust pipe supporting device according to claim 1, wherein each connecting spring portion is formed of a rubber elastic body so that one or both of a length and a cross-sectional area are different from each other. 3. The exhaust pipe support according to claim 2, wherein the connecting spring portions adjacent to each other share a part of a path connecting the first mounting portion and the second mounting portion. apparatus. 4. The connecting spring according to claim 2, wherein the first mounting part, the second mounting part, and the connecting springs are integrally formed by a rubber elastic body, and the two connecting springs adjacent to each other are connected to the two connecting springs. An exhaust pipe support device, which is disposed between the parts and has an inner peripheral surface separated by a smoothly curved through hole.