JPH0636267Y2 - Exhaust device for vertical engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an exhaust system for a vertical engine, in which an exhaust passage is branched, and a catalytic converter is provided in each branch exhaust passage. Regarding

(Prior Art) In recent years, the demand for higher engine power has increased,
In order to respond to this, it is necessary to reduce exhaust resistance during high-speed operation and increase the size of the catalytic converter. Then, in order to increase the size of the catalytic converter without increasing the exhaust resistance, the passage cross section of the catalytic converter must be enlarged, but if the passage cross section of the catalytic converter is made too large, the flow of exhaust gas in the catalytic converter However, there was a problem in that the emission performance became poor and the emission performance deteriorated.

Therefore, a so-called dual catalyst type exhaust device has been proposed in which the common exhaust passage is branched into two branched exhaust passages at a branch portion, and a catalytic converter is provided in each of the branched exhaust passages (for example, actual opening). (See Japanese Patent Publication No. 57-53013). Then, in such an exhaust device, the common exhaust passage is extended to the rear of the oil pan while avoiding the oil pan of the transmission, and the Y-shaped joint is used at the rear position of the oil pan to divide the common exhaust passage into the left and right. It is designed to branch into two branch exhaust passages.

(Problems to be solved by the invention) However, in the above-mentioned conventional dual catalyst type exhaust device, the Y-shaped joint occupies a considerable space in the front-rear direction of the vehicle body and is provided in each branch exhaust passage downstream of the Y-shaped joint. Since the position of the interposed catalytic converter is closer to the rear of the vehicle body, there is a problem that the temperature of the exhaust gas flowing into the catalytic converter is lowered and the emission performance is lowered.

In addition, the position of the catalytic converter is closer to the rear, and it is located just inside the tunnel-shaped floor panel below the foot of the rear seat, so the tunnel-shaped floor panel becomes large near the foot of the rear seat. As it protrudes into the car, there is a problem that space is poor.

The present invention has been made in view of the conventional problems described above, and effectively prevents a decrease in exhaust gas temperature, improves the emission performance of the catalytic converter, and improves the space in the vehicle. An object is to provide an exhaust system for a stationary engine.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides an exhaust system for a vertical engine having two branched exhaust passages branched from a common exhaust passage toward a downstream side. At a position near the rear end of the oil pan and below the extension housing at the rear of the transmission, the common exhaust passage serving as the first branch exhaust passage. The first branch exhaust passage is branched to the second branch exhaust passage, and the first branch exhaust passage is arranged so as to extend rearward from the branch portion in the vicinity of the extension line of the common exhaust passage, while the second branch exhaust passage is extended from the branch portion. Bend it and extend it along the rear end face of the oil pan to the specified position in the engine width direction, and then bend it further to extend it rearward. Provided is an exhaust system for a vertical engine, in which a catalytic converter is provided at a position below the housing in a portion extending in the front-rear direction of the first branch exhaust passage and the second branch exhaust passage, respectively.

According to the present invention, the first branch exhaust passage extends rearward from the branch portion near the rear end face of the oil pan near the extension line of the common exhaust passage, while the second branch exhaust passage extends. Since the exhaust passage also extends along the rear end surface of the oil pan to a predetermined position in the engine width direction and then extends rearward immediately, the first branch exhaust passage and the second branch exhaust passage are connected to the oil pan. It extends rearward from the position near the rear end face almost in parallel. For this reason, the catalytic converters provided in the first and second branch exhaust passages, respectively, should be arranged at a considerably forward position as compared with the conventional dual catalyst type exhaust device using a Y-shaped joint. You can

Therefore, the path length of the exhaust system between the engine body and the catalytic converter can be shortened, so that the temperature drop of the exhaust gas can be prevented and the emission performance can be improved.

In addition, the catalytic converter can be placed in the tunnel-shaped floor panel below the front seat by utilizing a space that is a dead space, which is conventionally a dead space, below the extension housing of the transmission. It is possible to arrange a large-scale catalytic converter that can handle high power without impairing the space inside the vehicle.

Further, the common exhaust passage can be compactly arranged without interfering with the oil pan.

That is, the exhaust system can have a compact layout in the vertical direction around the floor, can also have a compact layout in the front-rear direction, and can further dispose the catalytic converter at the front position. Emission performance can be improved while maintaining a compact structure.

(Example) Hereinafter, an example of the present invention will be specifically described.

As shown in FIG. 1 and FIG. 2, a transmission 2 is connected to the rear side of the vertical engine 1, and the output of the engine 1 is transmitted to the transmission 2 via a clutch (not shown). , And is transmitted at a predetermined gear ratio to drive wheels (not shown). Further, an oil pan 3 for storing lubricating oil for lubricating a lubrication-required portion in the transmission 2 is provided below the transmission 2.

Then, in order to discharge the exhaust gas discharged from each cylinder of the engine 1, the independent exhaust passages 5, 5, 5,
5 are provided, and these independent exhaust passages 5,5,5,5 are gathering parts 6
Are collected in one common exhaust passage 7. The common exhaust passage 7 extends obliquely downward from the collecting portion 6 rearward, and at the front end position of the oil pan 3 when viewed in the longitudinal direction of the vehicle body,
It has almost the same height as the oil pan 3. from here,
The common exhaust passage 7 extends rearward along the right side wall (upper side in FIG. 1) of the oil pan 3 at approximately the same height as the rear side wall of the oil pan 3 at the rear end portion of the oil pan 3. Curved. The common exhaust passage 7 is branched into a first branched exhaust passage 9 and a second branched exhaust passage 10 at a branch portion 8 located slightly closer to the center in the vehicle width direction from the right side of the rear wall of the oil pan 3.

The first branch exhaust passage 9 extends rearward in the vehicle longitudinal direction from the branch portion 8, while the second branch exhaust passage 10 includes the oil pan 3
It extends leftward in the vehicle width direction from the branch portion 8 along the rear wall of the vehicle, and curves rearward in the vehicle body longitudinal direction at a position symmetrical to the branch portion 8 with respect to the vehicle body longitudinal centerline (OBL). The first branch exhaust passage 9 extends substantially parallel to the rear in the longitudinal direction.

Then, at positions as close as possible to the rear end of the oil pan 3, first and second catalytic converters 11 and 12 using a three-way catalyst are provided in the first and second branch exhaust passages 9 and 10, respectively. Has been done. Since the first and second branch exhaust passages 9 and 10 extend rearward in parallel with each other from positions close to the rear end of the oil pan 3, the first and second catalytic converters 11 and 12 are
Compared to the conventional exhaust device in which the branch exhaust passage is connected by using a Y-shaped joint, it is arranged far forward. Therefore, the first and second catalytic converters 11 and 12 are located slightly below the extension housing 2a of the transmission 2 in the tunnel-shaped floor panel 16 at a position below the front seat 15. It was dead space. It is stored in the space 17. Therefore, since the arrangement of the rear seat 18 is not affected at all, there is no reduction in space on the rear seat side unlike the conventional exhaust device described in the related art.

Further, since the first and second catalytic converters 11 and 12 are arranged far ahead of the conventional exhaust device, the temperature of the exhaust gas flowing into the first and second catalytic converters 11 and 12 is kept high. Therefore, the emission performance can be improved.

Then, downstream of the first and second catalytic converters 11 and 12, in the first and second branch exhaust passages 9 and 10, in order from the upstream, a sound absorbing material such as glass wool is used to reduce particularly high frequency sound. The second pre-silencers 21 and 22 and the expansion and contraction type first and second main silencers 23 and 24 that reduce exhaust noise by gradually expanding the exhaust gas are provided.
Then, the exhaust gas is discharged into the atmosphere through the first and second tail pipes 25 and 26.

Further, the exhaust system on the side of the first branch exhaust passage 9 and the exhaust system on the side of the second branch exhaust passage 10 are arranged in the longitudinal center line (OBL) of the vehicle body.
It is formed symmetrically with respect to. Therefore, since the weights of the two exhaust systems are balanced and the runout phase difference between them is eliminated, uneven stress due to vibration does not occur in the exhaust system, and the durability of the exhaust system can be improved. .

[Brief description of drawings]

FIG. 1 is a plan view of an exhaust system showing an embodiment of the present invention. FIG. 2 is a side view of the exhaust device shown in FIG. 1 ... Engine, 2 ... Transmission, 3 ... Oil pan, 7 ... Common exhaust passage, 8 ... Branch part, 9,10 ... First and second branch exhaust passages,
11,12 ... First and second catalytic converters.

Continuation of the front page (72) Creator Go Ogawa 3-1, Shinchi Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd. (56) Bibliography Application for Japanese Patent Application No. 48-83204 Photographing the contents of the attached specifications and drawings Microfilm (JP, U) Filmed the contents of the specifications and drawings attached to the application for Japanese Patent Application No. 55-130519 (No. 57-53013) Microfilm (JP, U) Practical Application Microfilm (JP, U) Practical Application in which the detailed description and drawings attached to the application for Sho 48-61771 (Saikai Sho 50-10921) were photographed Microfilm (JP, U) Actual application No. 55-136081 (Actual exploitation No. 57-) which was photographed of the contents and drawings attached to the application for Sho 61-10259 (Actual exploitation No. Sho 62-124216) No. 59915) Microfilm (JP, U) Actual Application Sho 61-80524 (in which details and drawings attached to the application are photographed Micro film (JP, U) of the detailed description and drawings attached to the application of Japanese Utility Model Publication No. Sho 62-191532)

Claims (1)

[Scope of utility model registration request] 1. An exhaust system for a vertical engine provided with two branch exhaust passages branched from a common exhaust passage toward a downstream side, wherein the common exhaust passage is rearward along a side surface of an oil pan of a transmission. The common exhaust passage is branched to the first branch exhaust passage and the second branch exhaust passage at a position near the rear end of the oil pan and below the extension housing at the rear of the transmission by extending the first exhaust branch. The passage is arranged so as to extend rearward from the branch portion in the vicinity of the extension line of the common exhaust passage, while the second branch exhaust passage is curved from the branch portion to extend along the rear end surface of the oil pan in the engine width direction. After being extended to a predetermined position, it is further curved and arranged so as to extend rearward. At a position below the extension housing, the first branch exhaust passage and An exhaust system for a vertical engine, wherein a catalytic converter is provided in each of the portions extending in the front-rear direction of the second branch exhaust passage.