JP3393294B2 - Exhaust pipe support device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a muffler for an automobile, that is, an exhaust pipe support device for supporting an exhaust pipe on a vehicle body in a vibration-proof manner.

[0002]

2. Description of the Related Art Conventionally, as a supporting device for supporting an exhaust pipe on a vehicle body in a vibration-proof manner, it is integrally formed of an elastic material such as rubber. A first holding part having a through hole to be inserted;
A second holding portion having a through hole into which a support member on the exhaust pipe side is inserted is connected by left and right side wall portions so as to face each other at a vertical interval, and is configured to have a substantially annular shape as a whole. It is known that the vibration is absorbed by the. Usually, the supporting devices are arranged at a plurality of positions in the longitudinal direction of the exhaust pipe at a required interval, and the exhaust pipe is supported by the vehicle body through these supporting devices.

Further, in order to extend the effect of suppressing the vibration transmission to a high frequency range, the left and right side wall parts are connected to an intermediate position between the first and second holding parts so that the horizontal vibration is generated. It has been proposed that a central damping unit that suppresses the above is arranged (for example, Japanese Patent No. 2585805).

The present applicants also consider the temperature rise during traveling, and for the purpose of further improving the effect of suppressing vibration transmission, the central part of the central vibration damping part is a mass part and extends from the mass part. A supporting device has been proposed in which both side portions are branched into two forks, and a central vibration damping portion connected to both side wall portions is provided (Japanese Patent No. 2863910).

FIG. 10 shows the proposed supporting device, in which (101) is a first holding part and (102) is a second holding part.
Each has through holes (111) (121) for inserting a support material. (103) (103) are both the 1st and 2nd holding parts (101)
Both side wall portions connecting (121), (105) shows a central vibration damping portion having the center as a mass portion (105a), and both side portions are bifurcated into a substantially X shape.

However, in the case of the supporting device provided with the central vibration damping portion (105) having the above-mentioned approximately X shape, it is particularly preferable that the supporting device is 300 to 40.
Although the effect of suppressing vibration transmission in the frequency range of 0 Hz is improved, in the high frequency range of 600 Hz or higher, the dynamic absolute spring constant is high, the vibration noise of the vehicle is high, and noise prevention is not sufficiently satisfactory. However, the effect of suppressing noise, especially at high speed rotation, was not sufficiently obtained.

The present invention has been made in view of the above, and as an exhaust pipe supporting device of this type, the dynamic absolute spring constant can be lowered not only in the frequency range of 600 Hz or lower but also in the frequency range of 600 Hz or higher. , It is possible to reduce the dynamic absolute spring constant over a wide frequency range,
It effectively prevents noise when the engine rotates at high speed and contributes to the quietness of the vehicle.

[0008]

Means and Actions for Solving the Problems First of the Invention
The exhaust pipe supporting device is integrally formed of an elastic material and has a first holding portion having a through hole into which a vehicle body side supporting member is inserted and a through hole into which an exhaust pipe side supporting member is inserted. A second holding portion; a pair of side wall portions that connect the first holding portion and the second holding portion on both sides thereof with a space therebetween;
An exhaust pipe support device having a central damping part that is arranged at an intermediate position between the two holding parts and integrally connected to the both side wall parts, the first holding part and the second holding part. Are separated by a portion between the both side wall portions.

According to the exhaust pipe supporting device having the above-described structure, the first holding portion in which the support material on the vehicle body side is inserted and the second holding portion in which the support material on the exhaust pipe side is inserted relatively vibrate. However, for example, when oscillating and displacing in the perspective direction, the rigidity of both side wall portions connecting the first and second holding portions is appropriately increased by the central damping portion, and the rigidity in the lateral direction is also increased. Coupled with the resonance action of the central vibration damping unit, the fluctuation, that is, the vibration of both the holding units is effectively damped and suppressed.

In particular, since the first and second holding portions are partly separated from each other, the vibration load exerted from the support member by the separated parts is appropriately moderated during vibration in a high frequency range. The dynamic absolute spring constant is reduced in a wide frequency range as compared with the case of the conventional holding portion which acts so as to escape and thus completely holds the entire circumference of the support member. In particular, the dynamic absolute spring constant is lowered even in a high frequency range exceeding 600 Hz.

In the above exhaust pipe support material, it is particularly preferable that the cut portion is formed so as to have a gap of 0.5 mm or more between the cut end surfaces. That is, when the gap between the cut-off portions is less than 0.5 mm, the action of releasing the vibration load is reduced, so that it is preferable to set as described above.

In the exhaust pipe supporting device of each of the above inventions,
The first holding portion and the second holding portion, those in other portions except the disconnection unit fraction, formed by forming a support member which is inserted into the through hole so as to embrace at least 1/2 of the entire circumference Is preferred. That is, other portions except the disconnection unit content is less than the effect of holding the support member is reduced,
On the contrary, rattling tends to occur, which is not preferable.

In the exhaust pipe supporting device of each of the above inventions,
The central damping portion has a central portion formed as a mass portion and both side portions extending from the mass portion, the mass portion is formed to have a larger mass than each of the both side portions, and each of the both side portions is bifurcated. It is preferable that it is formed into a branched shape and is connected to the both side wall portions.

As a result, the rigidity of the central damping portion in the oblique direction is increased, the ambient temperature of the supporting device is increased, and the elastic material such as rubber is softened to lower the rigidity of the entire device. As the side wall extends due to the weight of the exhaust pipe or the like, the bifurcated portion also extends and the Young's modulus of the branched portion rises, which corresponds to the mass distribution due to the central portion being the mass portion. In addition, the vibration of the central damping unit can be effectively dampened, and the frequency characteristic can be prevented from shifting to the low frequency side due to the temperature rise, which is stable against temperature changes. The frequency characteristics can be maintained.

The present invention also provides a supporting device having the same basic structure as that of the first invention, that is, an exhaust pipe provided with a first holding portion and a second holding portion, a pair of side wall portions and a central damping portion similar to the above. In the supporting device, the central damping portion may be provided with a cutout portion or a thin portion in a part thereof.

In this case, the central vibration damping portion has a central portion formed as a mass portion and both side portions extending from the mass portion, and the both side portions are branched into a bifurcated shape to form the both sides. In the case of being connected to the wall portion, it is preferable that the cut portion or the thin portion is formed on one of the bifurcated portions on at least one side of the both side portions.

In the case of the present invention, the peak of the dynamic absolute spring constant appears due to the resonance due to the bending of the central damping part.
In the frequency range of 500 Hz, the absolute spring constant can be effectively reduced.

[0018] Incidentally, the In either case, the width of the recess to form a gap or thin portion of the separating portion of the good that is set to more than 0.5 mm.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described based on an embodiment shown in the drawings.

FIG. 1 is a perspective view showing an embodiment of an exhaust pipe supporting device according to the first invention, FIG. 2 is a front view, and FIG. 3 is a front view X.
-X line sectional drawing, and FIG. 4 is the same YY line sectional drawing.

As shown in the drawing, the supporting device (A) of this embodiment has an overall elliptical shape with its major axis in the vertical direction when viewed from the front, and is made of an elastic material, that is, rubber. The material is vulcanized and molded to be integrally formed, and is configured as follows.

In the upper part of the supporting device (A), a supporting member (not shown) mainly on the vehicle body side is inserted in the front-rear direction (thickness direction).
A first holding part (1) having a through hole (11) is formed at a lower position opposite to the first holding part (1) with a required space (usually 10 to 15 mm). A second holding portion (2) having a through hole (21) in the front-rear direction (thickness direction) into which a support member (not shown) on the exhaust pipe side is inserted is formed.

The first holding portion (1) and the second holding portion (2) are connected to each other by arch-shaped left and right side portions (3) and (3) whose both ends are connected to the left and right sides of the first and second holding portions, respectively. Is formed in a substantially elliptical annular shape that is symmetrical vertically and horizontally. That is, when viewed from the front, it is formed in a substantially elliptical annular shape whose major axis is a line passing through both axial centers of the upper and lower first and second holding portions (1) and (2).

The both side walls (3) and (3) have the first
And a slight gap (4) (4) between the two holding parts (1) and (2) at an intermediate position between the two holding parts (1) and (2).
Are arranged so as to hold both ends and both side walls (3)
It is connected by the central damping section (5) connected to the inner surface of (3).

The central damping section (5) and both holding sections (1)
The gaps (4) and (4) between (2) and (2) have a central damping part (5) at the center of the both holding parts (1) during large-amplitude vibration.
The interval is set so as to serve as a stopper that restricts excessive deformation by contacting the inner surface of (2).

In the supporting device (A) having the above-mentioned structure, the first and second holding portions (1) and (2) are respectively provided between the side wall portions (3) and (3). The part is separated by a dividing line substantially parallel to the axial centers of the through holes (11) and (21) so as to have a gap that hardly affects the vibration characteristics in the low frequency range. It is preferable that the cut portion (6) is cut and formed so that a gap of 0.5 mm or more is retained between the cut end surfaces, and the cut portion (6) is formed as shown in FIG. 5, for example. It is also possible to cut and form) so that approximately half of the through hole is opened. In this case, the support material can be easily inserted into the through hole.

However, if the gap between the cut-off portions (6) becomes too large, the vibration characteristics in the low frequency range will be affected, and a support material to be inserted into the through holes (11) (21) will be removed. Since the holding effect is reduced, it is preferable to form at least half of the entire circumference of the support member by the other portion excluding the cut portion (6).

As shown in FIGS. 2 and 5, the cut-off portion (6) is provided on the opposite sides with the central damping portion (5) interposed therebetween, and as shown in FIG. It is also possible to provide on the side portions of 1) and 2).

It should be noted, in any case of Examples above, as the elastic material used, a rubber hardness (Japanese Industrial Standards of J
In order to ensure the required strength and static spring constant by using a rubber material having a rubber hardness test specified in IS K-6301A) of 50 degrees or more, particularly preferably 55 to 70 degrees. Preferably.

In the supporting device (A) of the present invention constructed as described above, the supporting member on the vehicle body side is inserted and fixed in the through hole (11) of the upper first holding portion (1), and The support member on the exhaust pipe side is inserted and fixed in the through hole (21) of the second holding portion (2) on the side of the exhaust pipe, and the exhaust pipe is arranged at a plurality of positions at a predetermined interval in the longitudinal direction of the exhaust pipe. Support and use.

In this usage state, the vibration transmitted from the exhaust pipe side and the vibration transmitted from the vehicle body side due to the engine drive are absorbed by the support device to prevent noise and vibration in the vehicle interior from being deteriorated.

In the case of the present invention, the first damping unit (5) for connecting the left and right side wall portions (3) and (3) between the first and second holding portions (1) and (2) allows the first And the second
Both side wall parts (3) connecting both holding parts (1) and (2)
The rigidity of (3) is moderately increased, and the rigidity in the lateral direction is also higher than that without the central damping portion. Therefore, when the first holding portion (1) and the second holding portion (2) vibrate relative to each other, for example, when the vibration is displaced in the perspective direction, the rigidity is high. In combination with the resonance action of (5), it is possible to effectively damp and suppress the fluctuation, that is, the vibration, of both holding portions (1) and (2).

Furthermore, since the first and second holding portions (1) and (2 ) are provided with the cut-off portion (6 ), the holding portion (1) is vibrated in the high frequency range. )
Separating portion (2) (6), will act to moderately release the load due to vibration displacement of the support, as a result, the ratio in the case of the conventional holder for holding the entire periphery supporting member As a result, the dynamic absolute spring constant decreases in a wide frequency range. Especially, the dynamic absolute spring constant is lowered even in a high frequency range exceeding 600 Hz or 800 Hz.

[0034] In the embodiment of a light emitting described above, the central damping unit (5) includes a central portion of the columnar formed as parts by weight (5a), side portions extending from the mass portion (5a) ( 5b) and (5b), and the mass part (5a) is formed to have a larger mass than both side parts (5b) and (5b). Further, both side portions (5b) (5b) are branched and formed into a bifurcated shape, and the branched portions (5c) (5c), (5c)
(5c) are respectively connected to the both side wall portions (3) and (3), and have a substantially X shape.

With this structure, the rigidity of the central damping section (5) in the oblique direction is increased, the ambient temperature of the supporting device (A) is increased, and the elastic material such as rubber is softened. When the rigidity of the entire device is reduced, the bifurcated branch portions (5c) and (5c) also expand as the side walls (3) and (3) on both sides expand due to the weight of the exhaust pipe or the like. The Young's modulus of the branched portions (5c) (5c) is increased, and this is combined with the mass distribution due to the central portion being the mass portion (5a), so that the vibration is effectively caused by the resonance action of the central vibration damping portion. In addition to the attenuation, it is possible to prevent the frequency characteristic from shifting to the low frequency side due to the temperature increase, and it is possible to maintain the stable frequency characteristic against the temperature change.

Mass part (5a) of the central damping part (5)
Is formed in a rectangular column shape by increasing the thickness in the vertical direction as shown in the figure, and the maximum dimension in the front-rear direction of the other parts excluding the mass part (5a), that is, the first and second holding parts ( It is also possible to extend longer than the dimension in the front-back direction of 1) and (2) to have a larger mass. By appropriately setting the length and the position of the center of gravity, it is possible to provide a mass suitable for the purpose and further widen the frequency range in which the absolute spring constant can be reduced. In addition, this mass part (5a)
It is also possible to embed a metal having a large specific gravity, such as iron, to give a large mass.

Further, branch portions on both sides of the central vibration damping portion (5)
The minutes (5c) and (5c) are formed in a thin plate shape so that the combined thickness of both legs does not become larger than the thickness dimension of the mass part (5a) in the vertical direction, but the branch angle (α) is 30 ° -60 °, its thickness (t) and length (L)
The ratio (t / L) is preferably set in the range of 0.1 to 0.5 from the viewpoint of the vibration suppressing effect.

In the present invention, as shown in FIG. 7 , the central vibration damping part (5) is also laid across the both side wall parts (3) and (3) in a horizontal line shape. Similarly to form a separating portion (6) can be real Hodokosuru. In this case as well, in a wide frequency range as described above, for example, 600H
Even in high frequency range over z or 800Hz,
The dynamic absolute spring constant can be reduced.

In order to confirm the effect of the above-mentioned supporting device of the present invention, the cut-off portion (6) is provided on both the first and second holding portions.
1 to 4 in which the gap is provided between the cut-off portions (6) of 1.5 mm (Example 1), and the cut-off portions obtained by cutting approximately half the circumference of the through hole ( embodiment examples product shown in FIG. 5 in which a 6) (example 2), 10
The relationship between the vibration frequency and the dynamic spring constant was measured and compared with the comparative example product (comparative example) having the conventional structure shown in FIG. The result is shown in FIG .

In each of the example product and the comparative example product, the total length (H) in the vertical direction (longitudinal direction) is 65 mm, the width (W) is 55 mm, and the dimension of the first holding portion (1) in the thickness direction is set. (T) is 25 mm, and the dimension of the side wall portion (3) in the thickness direction (T
1) is 20 mm, the dimension (W1) in the same width direction is 10 mm,
The rubber hardness is 55 degrees, the branch angle (α) of the branch portions (5c) and (5c) is 40 °, and the ratio of the thickness to the length is 0.3.
And

The above-mentioned dynamic absolute spring constant was measured by using a dynamic characteristic determination tester (KC-V type) manufactured by Sagimiya Seisakusho, and rod-shaped support metal fittings inserted into the first holding portion and the second holding portion of the supporting device. Fixed to the jig of the above-mentioned dynamic characteristic tester by statically applying a predetermined load (5 kgf), and applying a predetermined vibration (acceleration 5G constant) by a vibration exciter, and the movement when swept from 100 Hz to 1000 Hz. The load / dynamic displacement (deflection) and its phase angle were measured, and the absolute spring constant was calculated by a predetermined calculation method. The absolute spring constant referred to in the present invention is an average value of the values obtained by dividing the dynamic displacement generated by the vibration frequency by the dynamic load in the above measuring method.

As is apparent from FIG . 8 , in the comparative example which is a conventional product, the absolute spring constant is gradually increased in the high frequency region where the frequency exceeds 600 Hz, and the effect of reducing vibration and noise during high speed engine rotation is small. However, in the case of the example of the present invention, in the region where the frequency is 600 Hz or higher,
It was found that the absolute spring constant was significantly lower than that of the comparative example product, and that it was further effective in suppressing vibration transmission and preventing noise.

FIG . 9 shows an embodiment of the second invention.

The supporting device (A) of this embodiment has basically the same structure as that of the above-mentioned embodiment, that is, the first holding portion (1) and the second holding portion (2) and the pair of side wall portions (3). (3)
And a central damping section (5) as a basic configuration.
In the case of this supporting device (A), a cut-off portion (61) is provided in a part of the central vibration damping portion (5).

As shown in the figure, in the cut-off portion (61), the central damping section (5) extends from the central section formed as the mass section (5a) and the mass section (5a). Both side portions (5b) and (5b), and the both side portions (5b)
(5b) is bifurcated to form a bifurcated portion (5c)
(5c), (5c) and (5c) are respectively connected to the both side wall portions (3) and (3) to form a substantially X shape, at least one side of the both side portions (5b) and (5b) ( In the case of the drawing, it is preferable to form it on one of the bifurcated branch portions (5c) (5c) on both sides.

That is, in the case of the supporting device provided with the central damping section (5) having the above-mentioned X-shape, the second peak of the dynamic absolute spring constant is the resonance caused by the bending of the central damping section (5). Although it appears in the vicinity of the frequency range of 450 to 500 Hz, by providing the cut-off part (61) in a part of the central vibration damping part (5) as described above,
It is possible to suppress the decrease of the peak and to effectively reduce the absolute spring constant even in the frequency range of 400 to 500 Hz. In particular, when this is implemented together with the above-described first or second invention, the effect becomes large.

Incidentally, a part of the central vibration damping part (5) may be provided with a thin part formed by forming a recess instead of the cut part (not shown). Also in this case, the same effect as described above can be obtained. Further, not only in the supporting device having the above-described central X-shaped vibration damping portion, but also in a supporting device having the lateral one-letter-shaped central vibration damping portion, the same cut-off portion and thin-walled portion are provided. Can be implemented, 400-500Hz
It is possible to reduce the second peak of the second absolute spring constant in the frequency region of.

The cut-off portion (61) in this embodiment
Of the width of the gap or recess to form a thinned portion it may have to the 0.5mm or more, have the preferred to the particular less than 1.0mm.

[0049]

As described above, according to the exhaust pipe supporting device of the present invention, not only the frequency region of 600 Hz or less,
The absolute spring constant can be set low even in the frequency range of 600 Hz or higher, the absolute spring constant can be reduced over an extremely wide frequency range, noise can be effectively prevented at the time of high-speed engine rotation, and the vehicle can be kept quiet. It can contribute to the improvement of sex.

[Brief description of drawings]

FIG. 1 is a perspective view showing an exhaust pipe support device of a first embodiment of the first invention.

FIG. 2 is a front view of the same k support device.

FIG. 3 is a cross-sectional side view taken along line XX in the previous figure.

FIG. 4 is a sectional view taken along line YY of FIG.

FIG. 5 is a partial front view showing another embodiment of the supporting device of the above.

FIG. 6 is a partial front view showing still another embodiment of the same supporting device.

FIG. 7 is a front view showing still another embodiment of the above exhaust pipe supporting device.

FIG. 8 is a graph showing the relationship between frequency and dynamic absolute spring constant.

FIG. 9 is a front view showing still another embodiment of the exhaust pipe supporting device of the present invention.

FIG. 10 is a front view illustrating a conventional supporting device.

[Explanation of symbols]

(A) Exhaust pipe support device (1) First holding part (11) Through hole (2) Second holding part (21) Through hole (3) (3) Left and right side wall parts (4) Void (5) Center Damping part (5a) Mass part (5b) (5b) Both side parts (5c) (5c) Branch part (6) (61) Separation part (H) Vertical total length (W) Width (T) First and Thickness of second holding portion (T1) Thickness of side wall portion (W1) Width of side wall portion

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B60K 13/04 F16F 15/08

Claims (5)

(57) [Claims] 1. A first holding portion integrally formed of an elastic material and having a through hole into which a support member on the vehicle body side is inserted, and a second holding portion having a through hole into which a support material on the exhaust pipe side is inserted.
A holding portion, a pair of side wall portions that connect the first holding portion and the second holding portion on both sides thereof with a space therebetween, and the both side walls arranged at an intermediate position between the first and second holding portions. An exhaust pipe supporting device having a central damping part integrally connected to a part, wherein the first holding part and the second holding part are separated from each other at a part between the both side wall parts. An exhaust pipe support device characterized by the following. 2. The cut portion is 0.5 mm between the cut end faces.
The exhaust pipe support device according to claim 1, wherein the exhaust pipe support device is formed so as to be separated so as to retain the above gap. Wherein said first holding portion and the second holding portion, at least half of the support material its entire periphery to be inserted into the through-hole in the other portion excluding the disconnection unit content to embrace The exhaust pipe support device according to claim 1, which is formed. 4. The central vibration damping part has a central part formed as a mass part and both side parts extending from the mass part.
The mass portion is formed mass is greater than the respective both side portions and said side portions are Re Izu <br/> of claims 1 to 3 formed by connected to the side wall portions are branching bifurcated respectively The exhaust pipe support device according to item 1. 5. A first holding part integrally formed of an elastic material and having a through hole into which a support member on the vehicle body side is inserted, and a second holding part having a through hole into which a support material on the exhaust pipe side is inserted.
A holding portion, a pair of side wall portions that connect the first holding portion and the second holding portion on both sides thereof with a space therebetween, and the both side walls arranged at an intermediate position between the first and second holding portions. An exhaust pipe supporting device having a central damping portion integrally connected to a portion, wherein a cutout portion or a thin portion is provided in a part of the central damping portion. Exhaust pipe support device.