JPH01301410A - Exhauster of automobile engine - Google Patents

Abstract

PURPOSE:To improve the exhaust gas purification performance by inclining a cylinder rearward to form a space between the back face of the cylinder and a dash panel and placing an exhaust manifold having a catalyst device. CONSTITUTION:A cylinder block 6c is inclined rearward to form a space approximately triangle in the side view between the block 6c and a dash panel 5. An exhaust manifold 32 is placed in said space, extend downward to from a cylinder head 6d and is connected to an exhaust pipe 33. A catalyst device 35 is connected to the exhaust pipe 33 via a flexible pipe 34. In such constitution exhaust from an engine is purified by the catalyst so that the purification performance may be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an exhaust system for an automobile engine equipped with a catalyst device.

[Conventional technology]

In recent years, automobile engines have come to be mounted in such a way that the axis of the crankshaft extends in the vehicle width direction. This type of engine is a cross-flow type engine in which the intake air flows across the cylinders, and is configured so that intake air is taken in from the rear of the cylinder, which is supported in an approximately vertical direction, and exhaust air is directed to the front of the cylinder. ing. After the exhaust gas is rendered harmless by a catalyst device, it is discharged into the atmosphere through a tailpipe at the rear of the vehicle.

[Problem to be solved by the invention]

However, in such a structure, the exhaust gas is cooled by the running wind flowing into the engine compartment, and the temperature at which the exhaust gas flows into the catalyst device becomes low. Therefore, there are cases where the temperature at which the catalyst is activated cannot necessarily be obtained, and there is a risk that the exhaust gas purification performance cannot be improved.

The present invention was made in view of the above circumstances, and it is an object of the present invention to provide an exhaust system for an automobile engine that can improve the exhaust gas purification performance of a catalyst device.

[Means to solve the problem]

The exhaust system for an automobile engine according to the present invention tilts the cylinders of an in-line engine disposed in the vehicle width direction rearward to form a generally triangular space in side view between the rear surface of the cylinders and the dash panel. An exhaust manifold connected to the cylinder is disposed in this space, and an exhaust pipe provided with a catalyst device is connected to the exhaust manifold.

[Effect]

In the present invention, the distance from the cylinder to the catalyst device is shortened, and the exhaust manifold is prevented from being exposed to running wind, so that the temperature of the exhaust gas is prevented from decreasing before it flows into the catalyst device.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. Fig. 1 is a side view showing an exhaust system for an automobile engine according to the present invention, and Fig. 2 is a plan view of the same. A horizontal engine unit 3 for driving the front wheels 2 is mounted in the engine compartment 1 so that the axis of the crankshaft extends in the vehicle width direction. 4 is an engine hood that covers the upper part of the engine compartment 1, and 5 is a dash panel that defines the engine compartment 1 and the vehicle compartment.

The engine unit 3 is an integral combination of an engine 6, a transmission 7, and a differential gear device 9 provided on a rear front axle 8. The differential gear device 9 is arranged behind the engine 6. ing. The transmission 7 is disposed on the side of the engine 6 and connects the engine 6 and the differential gear device 9.

11 is a clutch interposed between the engine 6 and the transmission 7.

The engine 6 is a 6-cylinder plane engine, and includes a crankshaft 6b that is supported in the vehicle width direction between a crankcase 6a that is divided into an upper and lower part, and a crankshaft that extends rearwardly from the crankcase 6a. Cylinder block 6C having a cylinder that holds a piston connected to the shaft 6b
The cylinder head 6d closes the upper part of the combustion chamber and forms a combustion chamber together with the piston and the cylinder block 6C. The cylinder head 6d has an intake valve 12.
The exhaust valves 13 are held movably up and down, and camshafts 14, 14 for driving these valves are pivotally supported. 1
Reference numeral 5 denotes an output output shaft that takes out the output of the crankshaft 6b.

This output output shaft 15 is located in front of the crankshaft 6b, is supported in parallel with the crankshaft 6b, and is connected to the crankshaft 6b via a gear (not shown), and the clutch 11 is attached to the left end. There is.

21 is an intake device connected to the front side of the cylinder head 6d. This intake device 21 includes an intake manifold 22 forming each intake passage extending forward from the cylinder head 6d, a throttle device 23 connected to the upstream side of this intake manifold 22, and each throttle device 23 connected to each other. It consists of a communicating surge tank 24 and the like, and the surge tank 24 is connected to an air cleaner 25 disposed on the left side of the engine 6.

31 is an exhaust device connected to the rear side of the cylinder head 6d. The exhaust device 31 includes an exhaust manifold 32 connected to the back surface of the cylinder head 6d, an exhaust pipe 33 connected to the downstream side of the exhaust manifold 32, and the like.

The exhaust manifold 32 is disposed in a generally triangular space in side view formed between the rear surface of the cylinder block 6C and the dash panel 5 by tilting the cylinder block 6C backward, and extends downward from the cylinder head 6d. has been done. The exhaust pipe 33 is bent rearward below the exhaust manifold, and is connected to a catalyst device 35 via a flexible pipe 34.

The catalyst device 35 is a well-known device that forms a reaction chamber filled with a catalyst in the middle of an exhaust passage, and the exhaust pipe 33 connected to the downstream side is opened to the atmosphere through a muffler (not shown). Note that 36 is a radiator disposed in front of the engine 6.

In the automobile engine configured in this way, when the engine is started, intake air passes from the air cleaner 25 through the surge tank 24, and after the flow rate is restricted by the throttle device 23, it enters the combustion chamber from the front of the cylinder head 6d. . On the other hand, the exhaust gas is pushed out from the rear side of the cylinder head 6d to the exhaust manifold 32, flows through the exhaust pipe 33, and is discharged into the atmosphere after harmful substances are removed by the catalyst device 35.

Here, since the cylinder head 6d is disposed at the rear and the exhaust manifold 32 is disposed below it, the distance from the cylinder head 6d to the catalyst device 35 is reduced by a structure in which exhaust gas is discharged from the front side of the cylinder head 6d. compared to
Can be shortened.

In other words, the cylinder head 6d and the catalyst device 35 can be connected through the geometrically shortest distance. In addition, the cylinder blocks the running wind, and the exhaust manifold 32
Not only can this prevent wind from hitting the engine while driving, but it can also prevent exhaust heat from escaping through the cylinders and dash panel 5, allowing the exhaust gas to reach the catalytic converter 3.
It is possible to suppress the temperature from decreasing before the water flows into the water.

Therefore, even when the exhaust temperature is low, such as during low-load, low-speed operation, it is possible to easily maintain the exhaust gas temperature at the inlet of the catalyst device above the temperature at which the catalyst is activated, and to start the engine. Even immediately after this, the exhaust gas temperature can be raised quickly to reach a temperature at which the catalyst is activated in a short period of time. As a result, the proportion of time during which the catalyst is not activated can be reduced compared to when the engine is operating.

Furthermore, the rearwardly inclined cylinder prevents the exhaust heat dissipated from the exhaust manifold 32 from being transmitted to the upper part of the engine compartment 1, thereby preventing the upper part of the dash panel 5 and the passenger compartment from being heated. can.

〔Effect of the invention〕

As explained above, according to the present invention, the cylinders of the in-line engine arranged in the vehicle width direction are tilted rearward to form a generally triangular space in side view between the rear surface of the cylinder and the dash panel, Since an exhaust manifold connected to the cylinder is disposed in this space, and an exhaust pipe equipped with a catalyst device is connected to this exhaust manifold, the distance from the cylinder to the catalyst device can be shortened, and the exhaust gas It is possible to prevent the wind from hitting the manifold.

Therefore, it is possible to suppress the temperature drop before the exhaust gas flows into the catalyst device, and when the engine is running,
Since the proportion of time during which the catalyst is not activated can be relatively reduced, the exhaust purification performance of the catalyst device can be improved. Additionally, as a secondary effect, the rearwardly tilted cylinder prevents exhaust heat from being transferred to the upper part of the engine compartment, which prevents the upper part of the dash panel and the passenger compartment from heating up. It is possible to protect electrical equipment installed in the area from heat damage.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an exhaust system for an automobile engine according to the present invention, and FIG. 2 is a plan view thereof. 1...Engine compartment, 5...Dash panel, 6
C... Cylinder block, 32... Exhaust manifold, 33... Exhaust pipe, 35... Catalyst device. Patent applicant Yamaha Motor Co., Ltd.

Claims (1)

[Claims] In an automobile engine in which an in-line engine is arranged in the engine compartment at the front of the vehicle body so that the axis of the crankshaft extends in the vehicle width direction, the cylinder is tilted rearward and the side surface is installed between the back of the cylinder and the dash panel. An exhaust system for an automobile engine, comprising a space having a substantially triangular shape in view, an exhaust manifold connected to the cylinder being disposed in the space, and an exhaust pipe provided with a catalyst device being connected to the exhaust manifold. .