JPH10196358A - Exhaust pipe device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust pipe device for an internal combustion engine to prevent a twist from being applied on a vibration cut-off mechanism. SOLUTION: An exhaust pipe device 1 for an internal combustion engine comprises exhaust pipes 7, 8, and 9 connected to a transversely mounted internal combustion engine 13 and having a bend 15 obliquely bending in the direction of the width of a vehicle, and vibration cut-off mechanism 12 and 9 arranged midway of an exhaust system. The vibration cut-off mechanisms 12 and 9 are arranged on or right in the vicinity of the inertia main shaft 11 of the exhaust pipe device 1, and the axial directions of the vibration cut-off mechanism 12 and 9 are made to approximately coincide with a position within a vertical surface containing an internal main shaft 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an exhaust pipe device for a horizontal internal combustion engine.

[0002]

2. Description of the Related Art Japanese Unexamined Utility Model Publication No. 2-103119 discloses an exhaust pipe device of a vertical internal combustion engine (an internal combustion engine mounted on a vehicle with the longitudinal direction of the internal combustion engine being the vehicle front-rear direction), as shown in FIG. The engine shaft 2 of the exhaust pipe 22
3, a flexible tube 24 is arranged in the same direction as the portion 22a extending in the vehicle width direction, and the torsion of the flexible tube 24 is hardly accompanied by the roll vibration of the vertical internal combustion engine 21 ( An exhaust pipe device that absorbs the roll direction (indicated by reference numeral 25) is disclosed.

[0003]

However, when the conventional vibration absorbing device is applied to an exhaust pipe device of a horizontal internal combustion engine (an internal combustion engine mounted on a vehicle with the longitudinal direction of the internal combustion engine mounted on the vehicle), FIG. As shown in FIG. 6, when the internal combustion engine 26 vibrates in the roll (the roll direction is indicated by reference numeral 27), the exhaust pipe 22
Among them, in addition to bending, the portion 22a extending in the vehicle width direction is twisted (torsion having the same angle as the roll vibration angle of the internal combustion engine), and the flexible tube 24 is twisted. Although the flexible tube 24 is flexible for bending and can release bending vibration, it is rigid for torsion and has no vibration blocking effect, so that the vibration reducing effect of the exhaust pipe is reduced and the durability of the flexible tube 24 itself is reduced. Is reduced. An object of the present invention is to provide an exhaust pipe device for a horizontal internal combustion engine that can absorb the vibration of an exhaust system during roll vibration of the internal combustion engine without substantially twisting the vibration isolation mechanism.

[0004]

The present invention that achieves the above objects or objects is as follows. An exhaust pipe device for an internal combustion engine, comprising: an exhaust pipe connected to a horizontal internal combustion engine and having a bend that bends obliquely in the vehicle width direction; and a vibration isolation mechanism disposed in the middle of an exhaust system. An exhaust pipe device for an internal combustion engine in which a mechanism is disposed on or in the immediate vicinity of an inertia main axis of the exhaust pipe device in a plan view, and an axial direction of the vibration isolation mechanism is substantially aligned with an inward direction in a vertical plane including the inertia main axis. .

When a horizontal internal combustion engine undergoes roll vibration (rotational vibration about the longitudinal axis of the engine), the exhaust pipe apparatus as a whole undergoes bending vibration in a vertical plane including the inertia main axis, and torsional vibration about the inertia main axis. Rarely happens. Therefore, the vibration isolation mechanism, which is arranged on or in the immediate vicinity of the inertia main axis of the exhaust pipe device and whose vibration absorption direction is substantially aligned with the vertical plane extending in the vehicle front-rear direction, has a torsion during the roll vibration of the horizontal internal combustion engine. And the vibration cut-off mechanism can effectively absorb the bending vibration of the exhaust pipe device during the roll vibration of the internal combustion engine. In addition, the durability of the vibration isolation mechanism itself is also improved due to little torsion.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An exhaust pipe device for an internal combustion engine according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2
As shown in FIG. 1, an exhaust pipe device 1 for an internal combustion engine according to an embodiment of the present invention.
Are exhaust pipes 7, 8, and 9 connected to a horizontal internal combustion engine 13 of an FF vehicle (front engine front drive vehicle) and having a bend 15 that bends obliquely in the vehicle width direction, and a vibration disposed in the middle of the exhaust system. It has shutoff mechanisms 12 and 5 (first vibration shutoff mechanism 12, second vibration shutoff mechanism 5), and masses 3, 4, and 6 provided in the exhaust system. The vibration isolation mechanisms 12 and 5 are disposed on the main axis of inertia (the main axis of the moment of inertia and extending substantially in the vehicle longitudinal direction) 11 of the exhaust pipe device 1 or in the immediate vicinity of the main axis of inertia 11 in plan view of FIG. . The axial direction of the vibration isolating mechanisms 12 and 5 is the inertia main shaft 1.
1 are almost aligned in the vertical direction.

[0007] The exhaust pipe device 1 includes an exhaust manifold a.
And a front assembly b and a tail pipe assembly c. The front assembly b is connected to an exhaust manifold a of the internal combustion engine 13 by a connection flange 2. The first vibration isolation mechanism 12 is provided immediately below the connection flange 2. Second vibration isolation mechanism 5
Is provided at a connection portion between the front assembly b and the tail pipe assembly c.

The front assembly b includes a catalytic converter 3, a sub-muffler 4, and exhaust pipes 7, 8, and 9 connecting these. The tail pipe assembly c includes a main muffler 6 and a tail pipe 10. Catalytic converter 3, sub muffler 4, main muffler 6
Is heavier than other parts and constitutes a mass (mass body) of the exhaust system. The exhaust pipes 7, 8, and 9 have an offset design of d in the range of the front assembly b and the tail pipe assembly c due to restrictions on mounting on the vehicle, and are bent obliquely in the vehicle width direction due to the offset. 15. In FIGS. 1 and 2, the exhaust manifold a and the exhaust pipes 7, 8, and 9 are each indicated by one line.

The vibration isolating mechanisms 12 and 5 are mechanisms capable of absorbing (releasing) bending vibration of the system, and use a flexible joint or a ball joint. A flexible joint is used for the first vibration isolation mechanism 12 on the front side, and a ball joint is used for the second vibration isolation mechanism 5 on the rear side.

As shown in FIG. 3, the flexible joint constituting the first vibration isolation mechanism 12 includes two pipe elements 1
The ball joints 2a and 12b are hermetically connected by bellows 12c. As shown in FIG. 4, the ball joint constituting the second vibration isolating mechanism 5 includes two tube elements 5a and 5b sandwiching a spherical gasket 5c. Bolt 5e, nut 5f
And a spring 5d arranged around the bolt 5e.

The first vibration isolating mechanism 12 composed of a flexible joint has its axial direction oriented in the vertical direction, and the internal combustion engine performs roll vibration (the direction of roll vibration is indicated by reference numeral 14).
The vertical displacement generated in the vertically extending portion of the exhaust pipe 7 is absorbed (released) by the axial tension compression of the bellows 12c.

The second vibration isolating mechanism 5 composed of a ball joint has its axial direction substantially aligned with the direction of the inertia main shaft 11, and when the internal combustion engine rolls vibrates, the spring-mass system of the exhaust pipe 9 and the main muffler 6 swings back. The vertical bending vibration generated in the exhaust pipe 9 when the vibration of the entire exhaust system is amplified is absorbed (released) by the bending of the ball joint 5 in the bending direction.

Next, the operation will be described. When the roll vibration of the horizontal internal combustion engine 13 (the direction of the roll vibration is indicated by reference numeral 14) is applied to the exhaust pipe device 1, the bellows 12 c
By virtue of the axial tension and compression, vibration is effectively absorbed and the transmission of vibration to the rear is reduced. Therefore, the vibration amplitude at the rear of the first vibration isolation mechanism 12 becomes smaller.

When the roll vibration of the internal combustion engine 13 is large, the mass (main muffler 6),
Is also affected. In particular, the swing of the spring-mass system of the exhaust pipe 9 and the main muffler 6 amplifies the vibration of the entire exhaust system. The second vibration cut-off mechanism 5 absorbs the swing vibration and suppresses the vibration amplification.

In the above-described vibration absorption, the entire exhaust system tends to bend and vibrate in a vertical plane including the inertia main shaft 11,
Since the first vibration isolating mechanism 12 and the second vibration isolating mechanism 5 are located on or close to the inertia main shaft 11, the first vibration isolating mechanism 12,
The second vibration isolating mechanism 5 is not twisted or hardly twisted, and mainly bends or compresses. First
The vibration isolating mechanism 12 and the second vibration isolating mechanism 5 are composed of a flexible joint and a ball joint, and both joints flexibly absorb bending and tension, so that the vibration of the entire exhaust system is effectively reduced. The flexible joint and the ball joint are rigid against torsion and have almost no vibration absorbing effect, and the durability decreases when torsion is applied. However, the first vibration isolating mechanism 12 and the second vibration isolating mechanism 5
Since almost no torsion is applied, the durability is also improved.

[0016]

According to the exhaust pipe device for an internal combustion engine of the present invention, the vibration isolating mechanism is disposed on or near the inertia main axis of the exhaust pipe device, and the vibration isolating mechanism extends vertically in the vehicle longitudinal direction. Since it was arranged almost in the plane,
When the roll of the horizontal internal combustion engine vibrates, the vibration isolating mechanism is hardly twisted, and the vibration isolating mechanism can effectively absorb the bending vibration of the exhaust pipe device when the internal combustion engine roll vibrates. In addition, the durability of the vibration isolation mechanism itself can be improved by little torsion.

[Brief description of the drawings]

FIG. 1 is a plan view of an exhaust pipe device for an internal combustion engine according to an embodiment of the present invention.

FIG. 2 is a side view of the exhaust pipe device for an internal combustion engine of FIG. 1;

FIG. 3 is a sectional view of a flexible joint used as a first vibration isolation mechanism of the apparatus of FIG.

FIG. 4 is a half sectional side view of a ball joint used as a second vibration isolation mechanism of the apparatus of FIG. 1;

FIG. 5 is a plan view of a conventional exhaust pipe device of a vertical internal combustion engine.

FIG. 6 is a plan view of a virtual exhaust pipe device in a case where a vibration isolating mechanism arrangement in a conventional exhaust pipe device of a vertical internal combustion engine is applied to an exhaust pipe device of a horizontal internal combustion engine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Exhaust pipe device 2 Fastening flange 3 Catalytic converter 4 Sub muffler 5 Second vibration isolation mechanism (Ball joint) 6 Main muffler 7, 8, 9 Exhaust pipe 11 Inertia main shaft 12 First vibration isolation mechanism (Flexible joint) 13 Internal combustion engine 14 Roll Vibration direction 15 Bend

Claims (1)

[Claims] 1. An exhaust pipe device for an internal combustion engine, comprising: an exhaust pipe connected to a horizontal internal combustion engine and having a bend that bends obliquely in the vehicle width direction; and a vibration isolation mechanism disposed in the exhaust system. The vibration isolating mechanism is disposed on or in the immediate vicinity of the inertia main axis of the exhaust pipe device in plan view, and the axial direction of the vibration isolating mechanism is substantially aligned with the inward vertical plane including the inertia main axis. Exhaust pipe device for an internal combustion engine.