JP3125631U - Automobile exhaust system - Google Patents

Abstract

The present invention provides a vehicle having a structure in which an exhaust silencer is sufficiently invisible and the exhaust resistance is small, the structure is simple, the number of parts, processing, assembly man-hours are reduced, and the cost is reduced so that the exhaust silencer cannot be seen from the outside of the bumper. An automobile exhaust system that improves the aesthetics of the vehicle is provided.
In an automobile in which an exhaust silencer 10 is disposed inside a bumper 1, the exhaust silencer is configured as a horizontally long exhaust silencer that extends in the vehicle width direction and does not use a pipe member. A volumetric inlet expansion chamber 12 and a volumetric outlet expansion chamber 13 having an exhaust port 15 formed therein are partitioned by a partition member 14, and an upstream expansion chamber and a downstream expansion chamber of the partition member are provided. The exhaust port is formed in a substantially rectangular shape or a substantially oval shape whose length in the vehicle width direction is greater than that in the perpendicular direction, and is opened downward or obliquely downward. In addition, the open end is positioned inside the bumper.
[Selection] Figure 2

Description

  The present invention relates to an automobile exhaust system in which an exhaust system including an exhaust silencer is disposed inside a bumper.

In an automobile, an exhaust silencer is usually installed by shifting it to either the right or left side in the vehicle width direction inside the bumper, and the exhaust port to the atmosphere of the exhaust gas passing through the exhaust silencer has a circular or rectangular shape. Formed and opened at the back of the bumper.
On the other hand, a horizontally long exhaust silencer in which the exhaust silencer is provided over the entire vehicle width direction inside the bumper has also been proposed, one of which is the technique disclosed in Japanese Patent Laid-Open No. 10-238331. .
In this technology, the interior of the horizontally long exhaust silencer provided across the entire vehicle width direction inside the bumper is divided into a front chamber and a rear chamber in which a heat insulating material is sealed by a partition member formed with a number of louvers. The partition member is provided with an intake tube connected to the engine exhaust pipe and an outflow tube connected to the exhaust port extending in the vehicle width direction so as to face the front chamber side and the rear chamber side. The member is fixed to the member with a flange, and both are connected inside, and the exhaust port is formed in a circular shape so as to be exposed to the outside of the bumper from the outflow tube and open to the atmosphere.
Japanese Patent Laid-Open No. 10-238331

However, in the technique of Patent Document 1, the interior of the horizontally long exhaust silencer provided over the entire vehicle width direction inside the bumper is divided into a front chamber and a rear chamber in which a heat insulating material is enclosed. A complicated structure in which a partition member in which a large number of louvers are formed, a suction tube and an outflow tube that are fixed to the partition member by a flange and are provided so as to extend in the vehicle width direction, and the like are installed. The number of assembly steps is increased and the cost is increased.
Moreover, in the technique of the said patent document 1, since it has the form which exposed the circular exhaust port outside the bumper and opened in air | atmosphere, exhaust resistance is large and the beauty | look is impaired. In general, there are more opportunities for automobiles to see the rear part during traveling than the opportunity to see from the front side when the vehicle is stopped, and the shape of the rear part greatly affects the aesthetics of the car. The shape of the circular exhaust port exposed to the outside of the bumper, as in the ordinary car, greatly impairs the aesthetics of the car.
In particular, if a car with a small displacement exposes a circular exhaust port consisting of a single small-diameter pipe to the outside of the bumper, it reveals the small engine capacity of the car, so-called “cheap car”. It is seen and wins.
Have problems such as.

In view of the problems of the prior art, the present invention has an exhaust silencer function as an exhaust silencer and has a low exhaust resistance, a simple structure, a reduced number of parts, processing and assembly steps, and a low cost. The purpose is to provide a silencer.
The second object of the present invention is to maintain a sufficient exhaust silencer function, and to make the exhaust silencer exhaust port into a smart shape without any special processing and assembly man-hours. It is an object of the present invention to provide an automobile exhaust system that improves the above.

  The present invention achieves such an object, and in an automobile in which an exhaust device including an exhaust silencer is disposed inside a bumper, the exhaust silencer is provided inside the bumper and extends in the vehicle width direction. In addition, the silencer body has one or more volumetric inlet expansion chambers connected to the engine side exhaust pipe and one or more exhaust ports for exhaust gas to the atmosphere. The volumetric outlet expansion chamber provided is partitioned by a partition member having a gas passage, and the exhaust port has a substantially rectangular shape or a substantially oval shape whose length in the vehicle width direction is larger than the length in the direction perpendicular thereto. It has a shape of either a shape or an ellipse, is processed and formed by drawing processing integrated with the silencer body, and is opened downward or obliquely downward (Claim 1).

In this device, the following configuration is preferable.
(1) The exhaust port is provided such that an end portion thereof is positioned in front of the vehicle body above the lower end portion of the bumper and above the lower end portion of the bumper.
(2) The partition member is formed with a large number of small hole passages communicating the inlet expansion chamber and the outlet expansion chamber, and between the both end portions of the partition member and the inner wall surface of the silencer body. A side gas passage is formed (claim 3).
(3) An air passage is formed between the outer surface of the side wall of the silencer body and the inner surface of the side of the bumper, through which air passing through the inner side of the vehicle body flows, and the air flowing through the air passage The exhaust silencer is configured to be cooled (Claim 4).

  Further, the present invention is characterized in that either one or both of the inlet expansion chamber and the outlet expansion chamber is loaded with either an oxidation catalyst or a reduction catalyst (Claim 5).

  According to the first to fourth aspects of the present invention, the shape of the exhaust port to the atmosphere formed integrally with the silencer body is substantially rectangular or oval with a vehicle width direction length larger than a perpendicular direction length. Alternatively, the exhaust port may have any shape of an ellipse, and preferably the exhaust port is provided such that the end of the exhaust port is located in front of the lower end of the bumper and above the lower end of the bumper. Therefore, in the so-called back view as seen from the rear of the automobile, the exhaust port is hidden in the lower edge of the bumper so that the exhaust port does not protrude downward from the lower edge of the bumper. In this case, even if the exhaust port is slightly visually observed, the exhaust port is formed in a substantially rectangular shape, a substantially oval shape, or an elliptical shape, and the lower edge and the upper edge are substantially parallel to the lower edge of the bumper. Sometimes invisible in the exhaust Since the Jo, the prior art such as, in comparison with those having an open circular outlet into the atmosphere is exposed to the bumper outside, aesthetics in the back view is greatly improved.

  In addition, according to the present invention, the silencer body of the horizontally long exhaust silencer extending in the vehicle width direction is formed in a thin plate structure that does not use a pipe, and the exhaust port to the atmosphere is drawn with the silencer body. Because it is integrally formed, the exhaust silencer can be manufactured by interweaving thin plate bending and drawing processes, and there are fewer welded parts than the silencer body using pipe material for the exhaust port etc. like the conventional one. As a result, the structure is simplified, the processing is simplified, the number of processing steps is reduced, and the manufacturing cost of the exhaust silencer can be reduced.

Further, according to this device, the exhaust silencer provided on the inside of the bumper is configured as a horizontally long exhaust silencer that extends in the vehicle width direction and does not use pipe material, and the engine-side exhaust pipe is provided in the silencer body. A volumetric inlet expansion chamber connected to a volumetric outlet expansion chamber having an exhaust port for exhaust gas to the atmosphere, preferably a gas such as a plurality of small hole passages and side gas passages as in claim 3. Since it is provided by partitioning with a partition member having a passage, the volume of the volumetric inlet expansion chamber and outlet expansion chamber formed inside the silencer main body can be formed sufficiently large, and the exhaust gas from the engine has a volume. The first stage of the sound is silenced by volume expansion in the shape of the inlet expansion chamber, and then passes through gas passages such as a small hole passage and a side gas passage of a partition member communicating between the inlet expansion chamber and the outlet expansion chamber. Due to the passage resistance of the gas passage The second stage is silenced, and the volume expansion is further performed in the volumetric outlet expansion chamber, so that the third stage is silenced. By performing three-stage noise reduction, exhaust gas can be completely silenced and released into the atmosphere from a wide exhaust port.
In addition, since a large-volume inlet expansion chamber is connected to the engine-side exhaust inlet, the exhaust resistance is small, and therefore the increase in the back pressure on the engine side due to noise reduction is reduced, and the reduction in engine output due to noise reduction can be reduced. .

  In addition, according to such a device, a configuration in which a horizontally long exhaust silencer that extends in the vehicle width direction by effectively utilizing the space inside the bumper is installed, and the length in the vehicle width direction is integrally formed with the silencer body. And a volume shape formed inside the silencer main body by combining the configuration of the exhaust port to the atmosphere with a substantially rectangular shape, a substantially oval shape, or an elliptical shape that is larger than the length in the perpendicular direction. Even if the passage area of the exhaust port is increased by forming the exhaust port in a substantially rectangular shape, a substantially oval shape, or an elliptical shape, the volume of the inlet expansion chamber and the outlet expansion chamber of the Thus, the volume of the inlet and outlet expansion chambers can be made sufficiently large, so that the exhaust gas completely silenced without being affected by the increase in the passage area of the exhaust port can be sent to the atmosphere through the exhaust port. It is possible to output with can maintain a low noise, can exhibit a silencing function to hold further reduce the back pressure rises by a passage area increasing of the exhaust port.

  In addition, according to such a device, since the horizontally long exhaust silencer extending in the vehicle width direction is installed inside the bumper, the volume of the exhaust silencer can be effectively utilized by utilizing the space inside the bumper, which has conventionally had a lot of space. As a result, the noise reduction effect of the exhaust gas can be further improved without increasing the back pressure on the engine side.

  In addition, according to such a device, as described above, the exhaust silencer is configured as a horizontally long exhaust silencer, so that it can be installed so as to fill the space in the vehicle width direction inside the bumper. Sometimes, the horizontally long exhaust silencer can perform the same buffer function as the bumper, and the double bumper function of the bumper and the horizontally long exhaust silencer improves the impact mitigation function at the time of collision.

  According to the fourth aspect of the present invention, an air passage is formed between the outer surface of the side wall of the silencer body and the inner surface of the side of the bumper, through which air passing through the inner side of the vehicle body flows. Since the exhaust silencer is cooled by the air flowing therethrough, the air passing through the passage between the side portion inside the vehicle body, that is, the outer side surface of the rear wheel, and the wheel cover when the automobile is running. The exhaust silencer can be cooled by using the scoop action caused by the running of the automobile, which flows through the air passage between the outer side wall of the silencer body and the inner side surface of the bumper, and a special device is provided. Therefore, the cooling effect of the exhaust silencer can be improved.

  According to the invention of claim 5, since either one or both of the large-volume inlet expansion chamber and the outlet expansion chamber can be loaded with either the oxidation catalyst or the reduction catalyst, the large-volume catalyst with a simple structure. A charge silencer can be constructed, the catalytic action of the oxidation catalyst or reduction catalyst can be activated, and the exhaust gas purification effect can be improved.

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.
FIG. 1 is a rear side view including a partial cross section of an automobile provided with an exhaust device according to first and second embodiments of the present invention.
In FIG. 1, 100 is a vehicle body, 1 is a bumper installed at the rear of the vehicle, 101 is a rear wheel, and 102 is a road surface.
Reference numeral 10 denotes an exhaust silencer (details will be described later) mounted inside the bumper 1, and includes an inlet expansion chamber 12, an outlet expansion chamber 13, an exhaust port 15, and the like.
An engine side exhaust pipe 103 connects an engine exhaust port (not shown) and the inlet expansion chamber 12 of the exhaust silencer 10. The engine-side exhaust pipe 103 is fixed to the silencer body 11 by tightening the inlet flange 103a via the gasket 16 with a plurality of bolts 17, as shown in FIG.

First embodiment

2A is a cross-sectional view in the vehicle front-rear direction of the exhaust silencer in the first embodiment of the present invention and in second and third embodiments to be described later (cross-sectional view taken along line BB in FIG. 3 and C- in FIG. 4). C line sectional drawing and DD line sectional drawing (figure which abbreviate | omitted the catalyst) of FIG. 5, (B) is a Z arrow directional view in (A).
3A is a cross-sectional view taken along line AA in FIG. 2 in the first embodiment, and FIG. 3B is a cross-sectional view taken along line EE in FIG.
2 and 3, reference numeral 1 denotes a bumper, and 10 denotes an exhaust silencer mounted inside the bumper 1. The exhaust silencer extends in the vehicle width direction and does not use a pipe material. It is configured as follows. In FIG. 3, the Y arrow indicates the front of the vehicle.
Reference numeral 11 denotes a silencer body made of a heat-resistant plate material such as a steel plate, and the silencer body 11 is made of a heat-resistant plate material and is fixed by a partition member 14 extending in the vehicle width direction and the vertical direction (vehicle height direction). It is divided into a volumetric inlet expansion chamber 12 and a fixed volume outlet expansion chamber 13. Each corner 11a, 11b of the inlet expansion chamber 12 and the outlet expansion chamber 13 has a rounded shape (with R) so that the exhaust gas flows smoothly with a small resistance.
As shown in FIG. 2, the silencer body 11 includes the partition between the end flange of the inlet side member 12 z constituting the inlet expansion chamber 12 and the end flange of the outlet side member 13 z constituting the outlet expansion chamber 13. The end of the member 14 is inserted and joined by seal welding for sealing the exhaust gas. 11v is a seal welding part.

The silencer body 11 extends in the vehicle width direction with a width A as shown in FIG. 3 (A), and in the vertical direction (vehicle height direction) with a height D as shown in FIG. 2 (A). It extends in the longitudinal direction of the vehicle and extends in the longitudinal direction of the vehicle, and is configured as a horizontally long silencer body that does not use a pipe. And the width A of the silencer body 11 is formed in a horizontally long shape in the vehicle width direction which is larger than the length E and the height D in the vehicle front-rear direction, and exhausts the space space in the width direction inside the bumper 1. It is effectively used for the sound deadening volume.
3A and 3B, mounting flanges 31 project from both side surfaces of the silencer body 11, and the mounting flanges 31 are mounted on flanges 32 projecting from both inner surfaces of the bumper 1. The silencer body 11 is fixed to the vehicle body 100 by tightening with bolts 30 from below (or from above).

As shown in FIG. 3, the partition member 14 has a plurality of small hole passages 14 b communicating with the inlet expansion chamber 12 and the outlet expansion chamber 13. Further, a side gas passage 18 that connects the inlet expansion chamber 12 and the outlet expansion chamber 13 is formed between both side ends 14a, 14a of the partition member 14 and the inner surface of the silencer body 11, and The side ends 14a are curved toward the outlet expansion chamber 13 to reduce the flow resistance of the exhaust gas.
Therefore, the exhaust gas in the inlet expansion chamber 12 flows out into the outlet expansion chamber 13 through both the small hole passage 14 b of the partition member 14 and the side gas passage 18.
Further, the total passage area of the small hole passage 14b, that is, the diameter and the number of the small hole passages 14b is determined by the ratio of the total passage area of the small hole passage 14b and the total passage area of the side gas passage 18 being a silencing effect. Is set based on simulation analysis or experimental results so that the pressure loss of exhaust gas is minimized and the pressure loss of exhaust gas is minimized.

An exhaust port 15 opens from the outlet expansion chamber 13 obliquely rearward (or may be downward), and without using any pipe material as in the prior art, the outlet expansion chamber 13 of the silencer body 11. The rear lower part is processed and formed with a smooth connection portion 15a having a low resistance to the exhaust gas flow by a drawing process integrated with the silencer body 11.
As shown in FIG. 3, the exhaust port 15 is disposed substantially at the center of the silencer body 11 in the vehicle width direction, and the vehicle width direction length B is perpendicular to the vehicle width direction as shown in FIG. The straight portion 15c and the curved portion 15d larger than the length (width) H are formed into a substantially rectangular shape, a substantially oval shape, or an elliptical shape.

Further, as shown in FIG. 2A, the exhaust port 15 has a lower end edge 15f above the lower end edge 1a of the rear wall 1b of the bumper 1 by C and a rear end edge 15e at the lower end edge of the bumper 1. It is positioned in front of the vehicle by L rather than 1a, is formed inside the bumper 1 so that the exhaust port 15 is not visible from the rear of the vehicle, and the exhaust gas flow from the exhaust port 15 is the lower end of the bumper 1. It does not hit the edge 1a.
As a result, even if the exhaust port 1 is provided so as not to be seen from the rear of the vehicle as described above, the exhaust gas flow discharged from the exhaust port 15 hits the lower end edge 1a of the bumper 1 to cause flow drift and noise. The occurrence of is not seen.

Further, as shown in FIG. 3A, an air passage 19 through which air passing through the inner side of the vehicle body flows between the outer side wall 11z of the silencer body 11 and the side inner surface 1s of the bumper 1 is provided. 2A, an air passage 19a and an air passage 19c are formed between the upper wall outer surface 11y and the rear wall inner surface 11w of the silencer body 11 and the inner surface of the bumper 1, as shown in FIG. An air passage 19b is also formed below the lower wall outer surface 11x of the silencer body 11, and the exhaust silencer 10 is cooled by the air flowing through the air passage 19 and the air passages 19a, 19b, 19c. It is configured.
That is, with this configuration, as shown in FIG. 3 (A), when the vehicle travels, it passes through the passage inside the side of the vehicle body, that is, the passage 104 between the outer side surface of the rear wheel 101 and the wheel cover. The exhaust silencer 10 can be cooled by a scoop action caused by traveling of the automobile, in which air flows through the air passage 19 between the outer side wall of the silencer body 11 and the inner side surface of the bumper 1. The cooling effect of the silencer 10 can be improved.

In the first embodiment, the exhaust gas from the engine flows from the engine side exhaust pipe 103 as indicated by the arrow, is introduced into the inlet expansion chamber 12 of the exhaust silencer 10, and expands in the inlet expansion chamber 12, thereby causing the first. The stage is muted. In this case, since the volume of the inlet expansion chamber 12 is extremely large with respect to the passage area S of the engine side exhaust pipe 103, the exhaust gas from the engine side exhaust pipe 103 rapidly expands in the inlet expansion chamber 12, and the exhaust gas is exhausted. Pulsation is reduced at once.
The exhaust gas that has undergone primary expansion in the inlet expansion chamber 12 flows as indicated by the arrows in the figure, one of which flows into the outlet expansion chamber 13 through the side gas passage 18 and the rest is the partition. It flows into the outlet expansion chamber 13 through a large number of small hole passages 14 b provided in the member 14.
In this case, the ratio of the passage area of the side gas passage 18 to the total passage area of the small hole passage 14b is simulated so that a required silencing effect can be obtained while suppressing the pressure loss in the small hole passage 14b to a constant value. Set by calculation.

The exhaust gas flowing into the outlet expansion chamber 13 through the side gas passage 18 and the many small hole passages 14b is further expanded in volume in the outlet expansion chamber 13, and the exhaust pulsation is further relaxed. And is discharged from the exhaust port 15 into the atmosphere.
Therefore, the exhaust gas is volume-expanded in the volumetric inlet expansion chamber 12 to be silenced in the first stage, and then the side gas passage 18 or the partition member communicating between the inlet expansion chamber 12 and the outlet expansion chamber 13. The second stage is silenced by the passage resistance of the gas passage while passing through the gas passage formed by the small-hole passage 14b perforated in the number 14, and further volume-expanded in the volumetric outlet expansion chamber 14 to the third stage. Is silenced in three stages in the order of sandwiching the one-stage passage resistance during the two-stage volume expansion of the two-stage volume expansion, so that the exhaust gas is completely silenced and the wide exhaust port 15 From the atmosphere.
In addition, since the large-capacity inlet expansion chamber 12 is connected to the engine-side exhaust pipe 103, the exhaust resistance is small. Therefore, the increase in the back pressure on the engine side due to noise reduction is reduced, and the reduction in engine output due to noise reduction can be reduced. Become.

  According to this embodiment, the shape of the exhaust port 15 to the atmosphere integrally formed with the silencer body 11 is substantially rectangular or substantially longer in the vehicle width direction length B than the length H in the direction perpendicular thereto. The exhaust port 15 has either a circular shape or an elliptical shape, and the end 15f of the exhaust port 15 is in front of the vehicle body from the lower end 1a of the bumper 1 and only C from the lower end 1a of the bumper 1 (see FIG. 2). In the so-called back view as viewed from the rear of the automobile, the exhaust port 15 is hidden in the lower edge of the bumper 1 so that the exhaust port 15 extends downward from the lower edge of the bumper 1. Even if the exhaust port 15 is slightly viewed when viewed from obliquely below, the exhaust port 15 is formed in a substantially rectangular shape, a substantially oval shape, or an elliptical shape and has a lower edge and an upper portion. The edge is under bumper 1 It is almost parallel to the exhaust port 15 at first glance, so compared with the conventional technology, the circular exhaust port is exposed to the outside of the bumper and opened to the atmosphere. The beauty of the view is greatly improved.

  In addition, according to this embodiment, the silencer body 11 of the horizontally long exhaust silencer extending in the vehicle width direction is formed in a thin plate structure that does not use a pipe material, and the exhaust port 15 to the atmosphere is formed in the silencer body. 11 is integrally formed by drawing, so that the exhaust silencer 10 can be manufactured by interweaving bending and drawing of a thin plate, as compared to a silencer body using a pipe material for an exhaust port or the like as in the conventional case. The number of welded portions is reduced, the structure is simplified, the processing is simplified, the number of processing steps is reduced, and the manufacturing cost of the exhaust silencer 10 can be reduced.

Further, according to this embodiment, the exhaust silencer 10 provided inside the bumper 1 is configured as a horizontally long exhaust silencer that extends in the vehicle width direction and does not use a pipe, and the silencer body 11 includes an engine. A large number of small hole passages 14b and side gas passages 18 form a positive displacement inlet expansion chamber 12 connected to the side exhaust pipe and a positive displacement outlet expansion chamber 13 having an exhaust port 15 for exhaust gas to the atmosphere. Since the partition member 14 is provided so as to be partitioned, the volume of the volumetric inlet expansion chamber 12 and outlet expansion chamber 13 formed inside the silencer body 11 can be formed sufficiently large, and as described above, Exhaust gas from the engine is volume-expanded in the volumetric inlet expansion chamber 12 to be silenced in the first stage, and then the small hole passage of the partition member 14 communicating between the inlet expansion chamber 12 and the outlet expansion chamber 13. 14b and side While passing through the gas passage 18, the second stage noise is silenced by the passage resistance of the gas passages 14 b and 18, and further, the volume expansion is performed in the volumetric outlet expansion chamber 13 and the third stage noise is silenced. By performing the three-stage noise reduction in the order of sandwiching the one-stage passage resistance during the volume expansion of the exhaust gas, the exhaust gas can be completely silenced and released from the wide exhaust port 15 into the atmosphere.
In addition, since the large-capacity inlet expansion chamber 12 is connected to the engine-side exhaust inlet, the exhaust resistance is small, so that the increase in the back pressure on the engine side due to noise reduction is reduced, and the reduction in engine output due to noise reduction can be reduced. Become.

  Moreover, according to this embodiment, the structure which installs the horizontal elongate exhaust silencer extended in the vehicle width direction using the space inside the bumper 1 effectively, and the vehicle width direction length formed integrally with the silencer main body 11. In combination with the configuration of the exhaust port 15 to the atmosphere having a substantially rectangular shape, a substantially oval shape, or an elliptical shape, the length of which is greater than the length in the perpendicular direction, The volumes of the formed volumetric inlet expansion chamber 12 and outlet expansion chamber 13 can be formed sufficiently large, and the exhaust port 15 is formed in a substantially rectangular shape, a substantially oval shape, or an elliptical shape. Even if the passage area is increased, the volume of the inlet and outlet expansion chambers 12 and 13 can be sufficiently increased as described above, so that the passage area of the exhaust port 15 is not affected by the increase. The exhaust gas completely silenced can be discharged to the atmosphere through the exhaust port 15 to maintain low noise, and the noise reduction function can be achieved by keeping the back pressure rise smaller by increasing the passage area of the exhaust port 15. Can be demonstrated.

  In addition, according to this embodiment, since the horizontally long exhaust silencer extending in the vehicle width direction is installed inside the bumper 1, the exhaust silencer can be effectively used by utilizing the space inside the bumper 1 that has a lot of conventional space. The volume of 10 can be increased, and the noise reduction effect of the exhaust gas can be further improved without increasing the back pressure on the engine side.

  Further, according to this embodiment, as described above, the exhaust silencer 10 is configured as a horizontally long exhaust silencer, so that it can be installed to fill the space in the vehicle width direction inside the bumper 1. When the vehicle collides, the horizontally long exhaust silencer 10 can perform a buffer function similar to that of a bumper. The double bumper function of the bumper 1 and the horizontally long exhaust silencer 10 provides a shock mitigation function at the time of collision. improves.

  Further, according to such an embodiment, the air passage 19 or the like through which the air passing through the inner side of the vehicle body flows is formed between the outer side wall of the silencer main body 11 and the inner side surface of the bumper 1. Since the exhaust silencer 10 is configured to be cooled by the air flowing through the air passage 19 and the like, when the automobile is running, a passage on the inner side of the vehicle body, that is, between the outer side surface of the rear wheel 101 and the wheel cover. A scoop by traveling of an automobile in which the air passing through the passage 104 flows as shown by the arrow in FIG. 3 and flows through the air passage 19 between the outer side wall of the silencer body 11 and the inner side surface of the bumper. The exhaust silencer 10 can be cooled by utilizing the action, and the cooling effect of the exhaust silencer 10 can be improved without providing a special device.

Second embodiment

FIG. 4 is a view corresponding to FIG. 3 showing an exhaust silencer according to the second embodiment of the present invention.
In the second embodiment, two exhaust ports 15 connected to the outlet expansion chamber 13 are arranged side by side in the vehicle width direction. The two exhaust ports 15 have the same shape, and the vehicle width direction length B1 is set in consideration of the silencing effect. Note that three or more exhaust ports 15 can be provided in consideration of the silencing effect.
Other configurations and operational effects are the same as those of the first embodiment, and the same members are denoted by the same reference numerals.

Third embodiment

FIG. 5 is a cross-sectional view taken along line AA of FIG. 2 showing the structure of the exhaust silencer according to the third embodiment of the present invention.
In the third embodiment, in addition to the first embodiment, either the oxidation catalyst or the reduction catalyst is loaded in the inlet expansion chamber 12 on the high temperature side. Reference numeral 40 denotes a catalyst layer of the oxidation catalyst or reduction catalyst.
Note that the catalyst layer 40 of the oxidation catalyst or the reduction catalyst may be provided in both the inlet expansion chamber 12 and the outlet expansion chamber 13, or may be provided only in the outlet expansion chamber 13.
According to the third embodiment, since either one or both of the large-capacity inlet expansion chamber 12 and the outlet expansion chamber 13 can be formed with the catalyst layer 40 loaded with either the oxidation catalyst or the reduction catalyst, it is easy. A large-volume catalyst-loaded silencer can be constructed with a simple structure, the catalytic action of the oxidation catalyst or reduction catalyst can be activated, and the exhaust gas purification effect can be improved.
Other configurations and operational effects are the same as those of the first embodiment, and the same members are denoted by the same reference numerals.

  According to the present invention, it is possible to provide an exhaust silencer that has a sufficient exhaust silencer function as an exhaust silencer, has a low exhaust resistance, has a simple structure, reduces the number of parts, processing, and assembly steps, and is low in cost. In addition, while maintaining a sufficient exhaust silencer function, the exhaust port of the exhaust silencer is made into a smart shape without requiring special processing and assembly man-hours, and the appearance of the car as a structure that can not be seen from the outside of the bumper An improved automobile exhaust system can be provided.

1 is a rear side view including a partial cross section of an automobile equipped with an exhaust device according to a first embodiment of the present invention. (A) is a vehicle longitudinal cross-sectional view of the exhaust silencer in the first, second, and third embodiments (cross-sectional view taken along the line BB in FIG. 1, the cross-sectional view taken along the line CC in FIG. 4, and D in FIG. 5). -D line sectional drawing (figure which omitted the catalyst)), (B) is the Z arrow figure in (A). (A) is the sectional view on the AA line of FIG. 1 in the said 1st Embodiment, (B) is the EE sectional view taken on the line in (A). FIG. 4 is a view corresponding to FIG. 3 showing an exhaust silencer according to a second embodiment of the present invention. FIG. 6 is a view corresponding to FIG. 3 illustrating an exhaust silencer according to a third embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bumper 10 Exhaust silencer 11 Silencer main body 12 Inlet expansion chamber 13 Outlet expansion chamber 14 Partition member 14b Small hole passage 15 Exhaust port 18 Side gas passage 19 Air passage 40 Catalyst layer 100 Car body 103 Engine side exhaust pipe

Claims (5)

  In an automobile in which an exhaust device including an exhaust silencer is disposed inside a bumper, the exhaust silencer is configured as a horizontally long exhaust silencer that is provided inside the bumper and extends in the vehicle width direction and does not use a pipe. In addition, a volumetric inlet expansion chamber connected to the engine side exhaust pipe and a volumetric outlet expansion chamber provided with one or a plurality of exhaust ports to the atmosphere of the exhaust gas are gas passages in the silencer body. The exhaust port has a substantially rectangular shape, a substantially oval shape, or an elliptical shape whose length in the vehicle width direction is longer than the length in the direction perpendicular to the vehicle width direction. An exhaust system for an automobile, wherein the exhaust apparatus is processed and formed by a drawing process integrated with the silencer body and is opened downward or obliquely downward.   2. The exhaust system for an automobile according to claim 1, wherein an end portion of the exhaust port is provided in front of the lower body of the bumper and above the lower end of the bumper.   The partition member is formed with a plurality of small hole passages communicating the inlet expansion chamber and the outlet expansion chamber, and a side portion is provided between both side ends of the partition member and the inner wall surface of the silencer body. 2. An automobile exhaust system according to claim 1, wherein a gas passage is formed.   An air passage is formed between the outer surface of the side wall of the silencer body and the inner surface of the side portion of the bumper. 2. An automobile exhaust system according to claim 1, wherein the exhaust is cooled.   2. An automobile exhaust system according to claim 1, wherein either one or both of the inlet expansion chamber and the outlet expansion chamber is loaded with either an oxidation catalyst or a reduction catalyst.

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