JPH07257200A - Installation structure of exhaust system in automobile - Google Patents

Abstract

PURPOSE:To suppress the cooling of the exhaust gas due to the running air by providing the exhaust system in an extending manner rearward of a vehicle body from the upper rear surface of the engine body between a board and the engine body partitioning the engine room and the cabin to effectively prevent the running air from blowing by a power unit. CONSTITUTION:In a vehicle V of FF type, the exhaust system 11 to be connected to a transversely-mounted engine body 2 is provided with an exhaust manifold 12, a flexible tube 13 to be connected to the downstream end of the exhaust manifold 12, a catalyst converter 14 to be connected to the rear end of the flexible tube 13, and a muffler, and extended toward the rear part of the vehicle body from the rear end surface of the upper part of the engine body 2. The exhaust manifold 12 is extended downward along the rear part of the engine body 2 through the clearance between the inclined rear surface of the engine body 2 in the forward tilted condition and a forward tilted toe board 16 as the board to partition the engine room 1 and the cabin 15, and the running air is prevented from blowing by the engine body 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has an engine room, which is covered with a bonnet at the front, and is connected to the engine body and the crankshaft of the engine body in the engine room. A vehicle in which a power unit including a transmission and a drive shaft connected to the left and right front wheels and a differential device interposed between the transmission is mounted so that a crankshaft of an engine body is arranged along a lateral direction of a vehicle body. Regarding the installation structure of the exhaust system.

In this specification, "front and rear" means front and rear with respect to a vehicle body, and "left and right" means left and right with respect to the vehicle body.

[0003]

2. Description of the Related Art Generally, an exhaust system in a vehicle described above extends from the front surface of the upper part of the engine body to the front side of the vehicle body, and then reverses backward so as to bypass the horizontally long power unit. It is designed to extend to the rear side of the vehicle body via the bottom of the vehicle body floor.

[0004]

In such a conventional vehicle, when a catalytic converter for purifying exhaust gas is provided in the middle of the exhaust system, the exhaust system takes a relatively long front side of the horizontally long power unit. Due to the rotation, the exhaust pipe length on the upstream side of the catalytic converter inevitably becomes long,
Moreover, traveling wind is likely to hit the front half of the upstream exhaust pipe. Therefore, the exhaust gas from the engine body to the catalytic converter is likely to be cooled on the way, and there is a problem that the desired purification performance of the converter cannot be sufficiently exhibited due to the decrease of the exhaust gas inflow temperature to the catalytic converter.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a structure for installing an exhaust system in a vehicle, which can solve the above problems with a simple structure.

[0006]

In order to achieve the above object, according to the first feature of the present invention, the exhaust system of the engine body is a board which partitions the engine room and the vehicle compartment from the upper rear surface of the body. And a rear surface of the engine body, and extends to the rear side of the vehicle body, and a catalytic converter is provided in the middle of the exhaust system. According to a second aspect of the present invention, in addition to the above characteristics, an exhaust gas that is connected to a plurality of exhaust ports of the engine main body between the board and a rear surface of the engine main body and forms a part of the exhaust system. A manifold is provided.

[0007]

[Operation] According to the first feature described above,
Since the exhaust system with a catalytic converter extends from the upper rear surface of the engine body to the rear side of the vehicle body between the board partitioning the engine room and the vehicle interior and the rear surface of the engine body, the exhaust gas from the engine body to the catalytic converter The portion of the system that passes between the rear surface of the engine body and the board effectively blocks the traveling wind from hitting it with a horizontally long power unit, and the exhaust air cooling due to the traveling wind is suppressed as much as possible. Since the exhaust pipe length between the catalytic converter and the engine body is shortened compared to the structure in which the exhaust system is extended from the upper front surface of the engine body to the front side of the vehicle body, the exhaust gas inflow temperature to the catalytic converter as a whole is reduced. Reduction is effectively suppressed.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a plan view of a front portion of an automobile showing a first embodiment of the present invention, FIG. 2 is a vertical sectional side view of the first embodiment, and FIG. 3 shows a second embodiment of the present invention, corresponding to FIG. Plan view, Figure 4
[Fig. 6] is a vertical sectional side view of the second embodiment corresponding to Fig. 2.

1 and 2 showing the first embodiment of the present invention, the vehicle V is a so-called FF type vehicle of a front engine / front drive, which is arranged in the front part of the vehicle V and has an upper bonnet. The power unit P is mounted in the engine room 1 covered with.

The power unit P includes an engine body 2 and
Transmission 3 connected to crankshaft 2a of engine body 2
And a differential device 4 interposed between the drive shafts 5 and 5 connected to the left and right front wheels Wfl and Wfr of the vehicle V and the transmission 3. The power unit P is arranged in a so-called horizontal type in the engine room 1 so that the crankshaft 2a of the engine body 2 is along the width direction of the vehicle V (that is, the left-right direction). The center of gravity G of the engine is located on the rear side of the vehicle body (that is, on the rear side in the vehicle traveling direction 6 in FIGS. 1 and 2) with respect to the drive shafts 5 and 5 extending from the differential device 4 to the left and right front wheels Wfl and Wfr. It is located in room 1.

The transmission 3 is connected to the left and right ends of the engine body 2, and the differential 4 is connected to the front of the transmission 3 so as to be connected to the drive shaft 5. Moreover, the power unit P is arranged in the engine room 1 in a forward leaning state in which the power unit P leans forward toward the vehicle body as it goes upward.

An intake system 7 for supplying the air-fuel mixture to the engine body 2 includes an air cleaner 8, an intake manifold 9 connecting a plurality of intake ports (not shown) of the engine body 2 and the air cleaner 8, and an air cleaner 8. A fuel injection valve 10 for injecting fuel toward the intake port 8 in order to inject the fuel into the air that has passed through and is supplied to each intake port. The engine main body 2 is extended from the front end face toward the front of the vehicle body.

An exhaust system 11 for exhausting exhaust gas from the engine body 2 is connected to an exhaust manifold 12 connected to a plurality of exhaust ports (not shown) of the engine body 2 and a downstream end of the exhaust manifold 12. Flexible tube 13
And the catalytic converter 1 connected to the rear end of the flexible tube 13.
4 and a muffler (not shown) that is further connected to the catalytic converter 14, and extends from the rear end surface of the upper part of the engine body 2 toward the rear of the vehicle body. Moreover, the exhaust manifold 1
2 has a length that enables the output of the engine body 2 to be improved, and a tilted rear surface of the engine body 2 in a forward tilted state,
A flexible pipe that extends downward along the rear part of the engine body 2 via a gap between the engine room 1 and the forward tilt toe board 16 as a board for partitioning the compartment 15 and is connected to the exhaust manifold 12. 13 is bent to bend the exhaust direction toward the rear of the vehicle body, and its downstream side extends rearward along the vehicle body floor.

By adopting such a structure, as compared with the conventional structure in which the exhaust system is extended from the upper part of the engine body to the front side of the vehicle body (then, it is inverted and extended to the rear side of the vehicle body), the catalytic converter 14 Can be arranged as close as possible to the engine body 2 (that is, the exhaust pipe length between the converter 14 and the engine body 2 can be made as short as possible), and the exhaust system 11 must be arranged at the rear of the vehicle body of the power unit P. Since the traveling wind is blocked by the power unit P and the traveling wind is prevented from hitting the exhaust system 11, the exhaust system 1
It is possible to suppress the temperature decrease of the exhaust gas that flows through 1 to reach the catalytic converter 14, and the exhaust gas purification function of the catalytic converter 14 can be effectively and sufficiently exhibited. For example, even when the exhaust gas temperature is low, such as a region (lean burn region) where the air-fuel mixture concentration is reduced to burn in order to reduce fuel consumption, the exhaust gas inflow temperature to the catalytic converter 14 is set to a sufficient level. It is possible to maintain the value higher than that required to achieve the above.

A common leaf spring 17 which is relatively long in the left-right direction is used as a suspension for suspending the left and right front wheels Wfl and Wfr on a vehicle body (not shown). The leaf spring 17 is used for the drive shafts 5 and 5 of the power unit P. The side opposite to the center of gravity G, that is, the power unit P
And the drive shafts 5, 5 are arranged on the front side of the vehicle body, and are supported by the vehicle body by the support portions 18 at a plurality of places (for example, two places) spaced apart in the vehicle body left-right direction, and both ends thereof are attached to the left and right front wheels Wfl, Wfr. Be connected. Moreover, in order to correspond to the forward extension of the differential device 4 in the power unit P, the leaf spring 17 is displaced so that the central portion in the longitudinal direction, that is, the central portion along the width direction of the vehicle V is deviated to the vehicle body front side from both ends. A convex curve is formed on the front side of the vehicle body.

A steering gear box 19 for steering the left and right front wheels Wfl, Wfr is arranged on the front side of the vehicle body with respect to the drive shafts 5, 5 and above the leaf spring 17. The steering gear box 19 is formed to be relatively long in the left-right direction of the vehicle body so as to extend substantially along the drive shafts 5 and 5, and inside thereof, as is well known in the art, the left and right front wheels Wfl and Wfr are provided in accordance with a steering operation. An operating mechanism including a rack rod (not shown) that moves left and right in the box 19 for steering and driving is disposed and supported, and the left and right tie rods 20 and 20 connected to the rack rod are connected to the ball joint 2
Via 1 and 21, the hub carriers 22 and 22 of the left and right front wheels Wfl and Wfr are connected.

A steering shaft 24 connected to a steering wheel 23 arranged in the vehicle compartment 14 corresponding to a driver's seat is connected to a pinion (not shown) in a steering gear box 19 via a steering joint 25. The pinion meshes with the rack rod. Moreover, the steering shaft 24 and the steering joint 25 are respectively arranged on the side of the engine body 2 and above the transmission 3.

Next, the operation of this embodiment will be described. The center of gravity G of the power unit P is set to the left and right front wheels Wfl, W.
By arranging the fr on the rear side of the vehicle body with respect to the drive shafts 5 and 5, the weight distribution of the weight of the power unit P to the left and right front wheels Wfl and Wfr and the left and right rear wheels (not shown) can be made closer to each other, so that It is possible to improve the exercise characteristics of.

Further, the intake system 8 is arranged on the front side of the engine body 2 and the exhaust system 11 is arranged on the rear side of the engine main body 2, so that the intake and exhaust efficiencies can be improved and the output can be improved. Moreover, by tilting the power unit P forward, the intake ports of the engine body 2 can be arranged in a substantially straight line, the intake resistance can be suppressed low, and the height of the bonnet covering the upper part of the engine room 1 can be reduced. The height can be made as low as possible to contribute to improving the visibility from the driver's seat. Further, as described above, the center of gravity G of the power unit P is on the rear side of the vehicle body with respect to the drive shaft 5, and the unit P is arranged in the engine room 1 toward the rear side of the vehicle body, that is, near the toe board 16, but the engine is not disposed. By tilting the main body 2 forward, a space between the rear surface of the main body 2 and the toe board 16 can be secured as wide as possible, and the exhaust system 11 can be easily and easily arranged therein. Further, an exhaust system 11 that extends to the rear side of the vehicle body and needs to be routed to a relatively low position is located behind the upper rear surface of the engine body 2, and an intake system 7 that does not need to be routed to such a low position is an engine. Arrangement of the drive shafts 5, 5, the steering gear box 19, and the leaf spring 17, which should be installed in a relatively low position in the engine room 1 on the front side of the power unit P, because they extend from the upper front surface of the main body 2 to the front side thereof. Can be easily performed without being disturbed by any of the intake and exhaust systems 7 and 11.

The steering gear box 19 is disposed on the front side of the vehicle body with respect to the drive shafts 5 and 5, and the leaf spring 1 is provided below the steering gear box 19.
Since 7 is arranged, it becomes possible to arrange the power unit P behind the drive shafts 5 and 5 without difficulty. Moreover, since the leaf spring 17 is bent in a convex manner toward the front of the vehicle body so that the center portion in the longitudinal direction thereof is displaced to the front side of the vehicle rather than both left and right ends, it is possible to avoid interference with the power unit P and sufficiently It is possible to secure stroke and leveling.

Further, since the steering gear box 19 is located in front of the drive shafts 5 and 5, the steering shaft 24 and the steering gear box 19 can be connected easily and the design can be facilitated.

FIGS. 3 and 4 show a second embodiment of the present invention, in which parts corresponding to those of the above embodiment are designated by the same reference numerals.

In this embodiment, it should be noted that the motor 26, which operates by the operation amount according to the turning angle by the steering operation of the steering wheel 23, operates the steering gear box 19.
The steering handle 23 and the steering gear box 19 are not directly connected to each other. That is, the motor 26 is connected to the steering gear box 19 via the electric steering gear box 27, and the rack rod in the steering gear box 19 is driven to the left or right according to the operation amount of the motor 26.
Further, the steering wheel 23 has an input angle sensor 2
8, a reaction force motor 29 and a steering angle sensor 30 are attached, and the motor 26 is operated by the output from the steering angle sensor 30.

According to this embodiment, the steering gear box 19 and the steering handle 23 are not directly connected to each other in addition to the effects of the above-described embodiment, so that support of the connecting portion is unnecessary and the weight is reduced. In addition, regardless of the arrangement of the power unit P, the steering handle 23 can be arranged on either the left or right side.

Although the front wheel drive vehicle has been described in the above embodiment, the present invention is also applicable to a four wheel drive vehicle.

[0026]

As described above, according to the present invention, the exhaust system is provided on the rear side of the vehicle body from the upper rear surface of the engine main body through the board separating the engine room and the vehicle compartment and the rear surface of the engine main body. Since the catalytic converter is installed in the middle of the exhaust system, the portion of the exhaust system extending from the engine body to the catalytic converter that passes between the rear surface of the engine body and the board is exposed to traveling wind. It is possible to effectively prevent the exhaust air from being cooled by the running wind by using the horizontally long power unit, and moreover, compared with the structure in which the exhaust system is extended from the upper front surface of the engine body to the front side of the vehicle body. Since the length of the exhaust pipe between the catalytic converter and the engine body can be shortened, the overall decrease in the temperature of the exhaust gas flowing into the catalytic converter can be effectively suppressed, which results in a catalytic converter. Can contribute to improved performance of the converter can be exhibited efficiently exhaust purification function.

[Brief description of drawings]

FIG. 1 is a plan view of a front portion of an automobile showing a first embodiment of the present invention.

FIG. 2 is a vertical sectional side view of the first embodiment.

FIG. 3 is a plan view corresponding to FIG. 1, showing a second embodiment of the present invention.

FIG. 4 is a vertical sectional side view of the second embodiment corresponding to FIG.

[Explanation of symbols]

 2 ... Engine body 2a ... Crank shaft 3 ... Transmission 4 ... Differential device 5 ... ... Drive shaft 11 ... Exhaust system 14 ... Catalytic converter 16 ... To board as a board P ... Power unit V ... .... Vehicles Wfl, Wfr ... Left and right front wheels

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kenichi Nagahiro 1-4-1 Chuo, Wako-shi, Saitama, Ltd. Inside Honda R & D Co., Ltd.

Claims (2)

[Claims] 1. An engine room (1) whose upper part is covered with a bonnet is arranged in the front part of a vehicle (V), and an engine body (2) and an engine body (1) are provided in the engine room (1). The transmission (3) connected to the crankshaft (2a) of 2), the drive shaft (5) connected to the left and right front wheels (Wfl, Wfr), and the differential device (4) provided between the transmission (3). )
The power unit (P) including and the engine body (2)
The exhaust system (11) of the engine body (2) is mounted so that the crankshaft (2a) of the engine is mounted along the left-right direction of the vehicle body.
From the rear of the upper part of the engine room (1) and the passenger compartment (1
5) The exhaust system (1) is extended to the rear side of the vehicle body via the board (16) for partitioning the space and the rear surface of the engine body (2).
An installation structure of an exhaust system in a vehicle, characterized in that a catalytic converter (14) is interposed in the middle of 1). 2. An exhaust manifold that is connected to a plurality of exhaust ports of the engine body (2) and forms a part of the exhaust system (11) between the board (16) and the rear surface of the engine body (2). The installation structure of an exhaust system in a vehicle according to claim 1, wherein (12) is provided.