JPH03100330A - Exhaust system supporting device for transversely placed v-engine - Google Patents

Abstract

PURPOSE:To surely suppress a resonance phenomenon of vibration of an exhaust pipe with that of an engine by rigidity-coupling the joined exhaust pipes to the side of the engine in a location where extension lengths of exhaust pipe are equal to each other from front and rear cylinder blocks. CONSTITUTION:In a V-engine 6, in a location where extension length of a front exhaust pipe 2 from a front part cylinder block 1 and that of a rear exhaust pipe 4 from a rear part cylinder block 3 are obtained equal, both the exhaust pipes 2, 4 are grasp-tightened by a clamp 9 which is mounted by a bolt 11 to a bracket 10 provided in a transaxle 7, and the exhaust pipes 2, 4 are rigidity-connected to an engine side in the above described location. During operation of the engine 6, the joined exhaust pipes 2, 4 tend to swivel in a longitudinal direction (right and left directions in the drawing) with a cylinder side mounting part serving as the center. However, this swivel action is suppressed by the bracket 10 through the clamp 9, and the swivel action is prevented from vibration-exciting a car body through an exhaust mount and from transmitting an internal noise to the inside of a car room, by a resonance phenomenon with the engine 6.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an exhaust system support device for a ■-shaped engine mounted laterally on a vehicle.

(Prior Art) In order to improve exhaust efficiency, this horizontal type engine has a front exhaust pipe 2 extending from a front cylinder block 1 at the front of the vehicle body, and a rear cylinder block 3 at the rear of the vehicle body, as shown in FIG.
Normally, the rear exhaust pipe 4 extending from the rear exhaust pipe is merged with the rear exhaust pipe 4 at the bottom of the engine.

However, in this case, the front and rear exhaust pipes 2 and 4 swing together in the longitudinal direction of the vehicle body, as shown by a in FIG. 3, about the engine-side mounting portion. This vibration causes a resonance phenomenon that resonates with the vibrations of the engine, causing the vehicle body to vibrate from the mount that suspends the exhaust system on the vehicle body, and transmitting muffled noise into the vehicle interior, reducing the commercial value of the vehicle.

On the other hand, the front and rear exhaust pipes 2.4 are heated by exhaust gas during engine operation and swell in the axial direction, deforming as shown by dotted lines in FIG. This deformation causes stress to be concentrated at a location designed to absorb this deformation, and this location is quickly damaged by repeated heating and cooling. For this purpose, the exhaust pipe is connected to the engine using a stay as shown in 5 in Fig. 3, which is described in Japanese Patent Application Laid-Open No. 6050216.
Techniques for dispersing the above stress in the engine have previously been proposed.

Although this stay is installed for a different purpose, it can help suppress the above-mentioned resonance phenomenon.

(Problem to be solved by the invention) However, in light of the purpose of its installation, it is necessary to reduce the rigidity of the Menghai stay in the longitudinal direction of the vehicle body, and the vibration of the exhaust pipe in the same direction is suppressed to prevent the above-mentioned resonance phenomenon. cannot be expected to have a significant effect on suppressing

In addition, since the lengths of the exhaust pipes from the support point A of the exhaust pipe by the stay to the front and rear cylinder blocks 1.3 are different, the support point A is different from B when heated, based on the difference in the amount of expansion caused by the difference between the two. point and returns to the original position upon cooling, which inevitably causes thermal strain (thermal stress) δ. 20 Thermal strain not only significantly impairs the durability of the stay, but can even damage the exhaust pipe itself at its weak points.

An object of the present invention is to provide an exhaust system support device that can reliably suppress the resonance phenomenon of the exhaust pipe without causing such problems.

(Means for Solving the Problems) For this purpose, the present invention provides exhaust pipes extending from the front cylinder block and the rear cylinder block of a ■-shaped engine mounted laterally on the vehicle body, so that the exhaust pipes are of approximately equal length at the bottom of the engine. In the vehicle, the merged exhaust pipes are rigidly connected to the engine side at a point where the lengths extending from the front and rear cylinder blocks are approximately equal.

(Function) During operation of the V-type engine, exhaust gas generated in the front cylinder block and the rear cylinder block is discharged through exhaust pipes extending from the corresponding cylinder blocks.

These exhaust pipes are merged at the bottom of the engine so that they have approximately the same length, but since the merged exhaust pipes are rigidly connected to the engine side at a point where the extension length from the front and rear cylinder blocks is approximately equal, the exhaust The vibration of the pipe can be prevented to avoid the above-mentioned resonance phenomenon, and the generation of thermal strain at the rigid connection point of the exhaust pipe can be prevented to increase the durability of the joint and avoid damage to the weak part of the exhaust pipe. be able to.

(Example) Embodiments of the present invention will be described in detail below with reference to the drawings.

1 and 2 show an embodiment of the present invention, in which the same parts as in FIG. 3 are designated by the same reference numerals.

A ■-shaped engine 6 comprising a front cylinder block l and a rear cylinder block 3 is arranged in the lateral direction of the vehicle body (in the direction perpendicular to the drawing in FIG. 1), and engine power is transmitted through a transaxle 7 provided in tandem with the ■-shaped engine 6. It is assumed that the output is distributed to the front two wheels to drive the vehicle.

A front exhaust pipe 2 extending from the front cylinder block 1 located at the front of the vehicle body of the ■ type engine 6 is extended to the rear of the vehicle body by crossing the lower part of the oil pan 8, and extends from the rear cylinder block 3 located at the rear of the vehicle body. It merges with the existing rear exhaust pipe 4 so that it has the same length.

Then, the exhaust pipes that have been merged in this way are clamped with a clamp 9 at a point where the extension lengths from the front and rear cylinder blocks 1.3 are equal (usually the V-angle bisecting surface of a ■-shaped engine),
This clamp is attached to the bracket 10 provided on the transaxle 7 with a bolt 11, and the exhaust pipe is rigidly connected to the engine side at the above-mentioned location.

The operation of the above embodiment will be explained next.

While the V-type engine 6 is in operation, its output is distributed to the front two wheels via the transaxle 7, driving these wheels to drive the vehicle. During this operation, both cylinder blocks 1
．． The exhaust gas discharged from every third cylinder chamber passes through the corresponding exhaust pipe 2.4 and then joins together and is led to the outside.

Note that during the operation, the merged front and rear exhaust pipes 24 tend to swing integrally in the longitudinal direction of the vehicle body (the left-right direction in FIG. 1) centering on the cylinder-side mounting portion. However, the swinging of the lever is suppressed by the bracket 10 via the clamp 9, and this swinging causes a resonance phenomenon with the engine, causing the vehicle body to vibrate through the exhaust system mount, or transmitting muffled noise into the passenger compartment. can be prevented from occurring.

On the other hand, when the exhaust pipe thermally expands during engine operation, since the lengths of the exhaust pipes from the clamp 9 to both cylinder blocks 1.3 are the same, the expansion types of these exhaust pipes are also the same. Therefore, the position of the clamp 9 does not change due to thermal expansion of the exhaust pipe, and it is possible to avoid thermal strain occurring in the exhaust pipe support devices 9 to 11, thereby preventing damage to the durability of the exhaust pipe support device. Troubles such as damage to weak parts of the exhaust pipe can be eliminated.

(Effects of the Invention) As described above, the exhaust system support device of the present invention rigidly connects the merged front and rear exhaust pipes to the engine side at points where their extension lengths from the front and rear cylinder blocks are equal. without causing the problem of thermal distortion at times,
The resonance phenomenon can be reliably prevented.

[Brief explanation of drawings]

Fig. 1 is a front view of a ■-shaped engine showing one embodiment of the exhaust system support device of the present invention, Fig. 2 is a sectional view taken along the line nn in Fig. 1, and Fig. 3 is a conventional exhaust system support device. FIG. 2 is a front view of the engine. l...Front cylinder block 2...Front exhaust pipe 3...Rear cylinder block 4...Rear exhaust pipe 6...■ type engine 7.
...Transaxle 8...Oil pan 9...Clamp 10...Bracket 11...Bolt Figure 1 Figure 3 Figure 2

Claims (1)

[Scope of Claims] 1. In a vehicle in which exhaust pipes extending from a front cylinder block and a rear cylinder block of a V-type engine mounted laterally on the vehicle body are merged to have approximately equal lengths at the bottom of the engine, An exhaust system support device for a horizontal V-type engine, characterized in that merged exhaust pipes are rigidly connected to the engine side at locations where their extension lengths from the front and rear cylinder blocks are approximately equal.