JPH0610148Y2 - Exhaust pipe structure of vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to the structure of an exhaust pipe connecting a vehicle engine and a muffler.

(Prior Art and its Problems) An engine of a vehicle is mounted on a chassis frame of the vehicle via an engine mount to reduce vibration of the chassis frame due to rotation of the engine. On the other hand, since the exhaust pipe, the muffler, and other members that are connected to the exhaust manifold of the engine to form an exhaust system are supported and fixed to the chassis frame (vehicle body) side, the engine and the exhaust pipe are opposed to each other. You will be exercising. In particular, an exhaust manifold provided on one side of an engine mounted between left and right side members of a chassis frame, such as a crane vehicle, and a muffler disposed and fixed on the upper part of the vehicle body, for example, the upper surface of a front fender. In a vehicle having a connection structure, it is indispensable to absorb the relative motion between the engine and the exhaust pipe.

Therefore, in a vehicle such as the crane vehicle, as shown in FIG. 5, a flexible pipe 51 is connected in the middle of an exhaust pipe 50 whose one end is connected to an exhaust manifold of an engine, and the other end of the exhaust pipe 50 is connected to a chassis frame. The exhaust pipe 53 is supported through the direction-changing box 52 that is supported and fixed to the exhaust pipe 53.
Of the exhaust pipe 53, and the other end of the exhaust pipe 53 is connected to a muffler arranged and fixed on the upper surface of the front fender.
Relative movements generated between the engine and the exhaust pipe, especially the relative movements in the upward and downward directions indicated by arrows A and B in FIG. 6 are absorbed.

However, since the flexible pipe 51 is formed of a metal member having heat resistance, it has poor elasticity and is weak in strength against displacement or twisting in the direction perpendicular to the axial direction. Particularly, as shown in FIG. 6, the flexible pipe 51 has both ends 51a and 51b connected to the exhaust pipe 50.
A stress larger than that in the intermediate portion is applied in the vicinity of, and the stress is repeatedly applied, so that the durability is significantly reduced. Further, in the box 52 that changes the direction of the exhaust gas, the high temperature exhaust gas collides with the wall surface 52c of the side wall 52a that faces the exhaust gas introduction port 52b, so that the deterioration of the portion is remarkable and the durability is poor. is there.

The present invention has been made to solve the above-mentioned problems, and is an exhaust pipe of a vehicle capable of absorbing the relative motion of the engine and the exhaust pipe well and smoothly changing the direction of the exhaust gas. It is intended to provide a structure.

(Means for Solving the Problems) In order to achieve the above object, according to the present invention, an exhaust gas that connects an exhaust manifold of an engine mounted on a main frame of a vehicle and a muffler disposed on the vehicle body side A pipe is formed in a substantially U shape and is arranged vertically between the exhaust manifold and the muffler with a curved portion facing downward, and a flexible pipe is provided in the middle of one side of the exhaust pipe connected to the exhaust manifold. The structure is such that it is connected in the vertical direction, the other side is connected to the muffler, and the curved portion is supported by the vehicle body via a cushion member.

(Operation) Relative displacement in the vertical direction caused by the rotation of the engine between the engine and the exhaust pipe is facilitated by expansion and contraction in the axial direction of the flexible pipe connected in the middle of the exhaust pipe arranged in the vertical direction. Is absorbed by. Further, the exhaust gas flowing in the exhaust pipe is smoothly changed in direction in the substantially U-shaped curved portion and flows into the muffler. This reduces the deterioration of the exhaust pipe due to the exhaust gas.

Embodiment An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a side view of an all-terrain crane vehicle to which the present invention is applied. An all-terrain crane vehicle 1 has a working frame (hereinafter referred to as a main frame) 2 extending over substantially the entire vehicle length,
A crane 5 is mounted via a turntable 4, and a carrier house 6 is provided on a front frame extending forward from the front end of the main frame 2, and a crane house 7 that rotates with the crane 5 is provided on the turntable 4. Therefore, it is possible to operate the mobile crane 1 in each of the houses 6 and 7.

At the time of suspending the crane 5, the front outriggers 8 and the rear outriggers 9 attached to the front and rear ends of the main frame 2 are laterally laterally extended to fix the main frame 2, and the suspending work is performed. Then, large single tires 10 and 11 are attached between the outriggers 8 and 9 and adjacent to the outriggers 8 and 9.

The output of the engine 20 mounted behind the carrier house 6 and between the left and right side members 2a of the main frame 2 is transmitted through the transmission, the rear side propeller shaft, and the final transmission (both not shown) to the rear wheels. 11 is transmitted to the front wheel 10 via the dog clutch, the front side propeller shaft, and the front side final transmission (both not shown) by engaging a dog clutch built in the transmission. Is also transmitted.

An exhaust manifold 21 is mounted horizontally on the side wall of the engine 20 along the front-rear direction as shown by a two-dot chain line in FIG.

The muffler 25 is the exhaust manifold 21 of the engine 20.
The same as the right side, for example, the right side, the front fender 12 of the front wheel 10 is disposed substantially vertically at the front end position of the upper surface 12a of the front fender 12.
As shown in the figure, the bottom surface is screwed to the upper surface 12a via a muffler bracket 26. Also, this muffler 25
A cylindrical muffler cover 27 is concentrically attached to the outer side of the muffler cover 27. The muffler cover 27 has an upper end fixed to the upper end surface of the muffler 25 via a plurality of arms 28 and a lower end integrally formed with the muffler cover 27. It is screwed to the muffler bracket 26 via a plurality of legs 27a formed on the.

The muffler 25 is provided with an exhaust gas introduction port at a lower position of a side wall facing the exhaust manifold 21 of the engine 20, so that the exhaust gas is introduced from the lower side wall. Further, the muffler cover 27 is provided with a hole having a diameter slightly larger than the inlet of the muffler 25 at a position facing the exhaust gas inlet. Further, the muffler 25 is provided with an exhaust gas exhaust port at the center of the upper end surface thereof, and an exhaust pipe 29 is attached substantially vertically to exhaust the exhaust gas upward.

The exhaust pipe 30 is connected to the engine 2 as shown in FIG. 3 and FIG.
0 and the right side member 2a and below the exhaust manifold 21 are arranged substantially vertically in the vertical direction.
The exhaust pipe 30 has a substantially U shape, and has both sides 30a and 30b.
Both are formed in a constricted shape by curving inward at the substantially center thereof. A flexible pipe 31 is vertically connected to the upper portion of the one side 30a of the exhaust pipe 30, and can be expanded and contracted by a predetermined length in the axial direction, that is, the vertical direction.

An upper end 30c of the one side 30a of the exhaust pipe 30 is opened to face upward, and is connected to an exhaust port 21a opened downward to face the center of the exhaust manifold 21 of the engine 20. The other side 30b of the exhaust pipe 30 is bent at a substantially right angle with the upper portion 30d facing outward, extends in the muffler 25 direction across the upper side member 2a, and extends toward the muffler 25 through the support member 32. Is supported and fixed to the upper surface 12a of the muffler 25, and the tip of the muffler cover 27 is loosely connected to the exhaust gas introduction port of the muffler 25. The exhaust pipe 30 has a curved portion 30e at the lower end.
The bracket 38 is welded to the upper surface 8a of the outrigger 8 through brackets 35 and 36 and cushion rubbers 37 and 37 at the substantially center thereof.

The operation will be described below.

Since the engine 20 is mounted between the left and right side members 2a via an engine mount, the engine 20 vibrates in the vertical direction due to rotation and is displaced in the vertical direction with respect to the side member 2a, while the muffler 25 is a front fender. Since they are arranged and fixed on the upper surface 12a of 12, both of them make relative movement in the vertical direction.

By the way, the exhaust pipe 30 has its one end 30a connected at its upper end to the exhaust manifold 21 of the engine 20 and fixed at its lower end 3.
0e is supported by the outrigger 8 and the upper portion 30 of the other side 30b
Since d is connected and fixed to the muffler 25, the flexible pipe 31 absorbs the relative movement. That is, this relative motion is displacement in the vertical direction, which is displacement in the axial direction of the flexible pipe 31, and the flexible pipe 31 expands and contracts favorably with respect to axial displacement, and absorbs the relative motion well. Also, the side member 2a
The vertical relative motion between the muffler 25 and the front fender 12 provided with the muffler 25 is absorbed by the cushion rubber 37 supporting the lower end 30e of the exhaust pipe 30. As a result, the space between the other side 30b of the exhaust pipe 30 and the muffler 25 is kept substantially stationary.

Further, the exhaust gas emitted from the engine 20 is exhausted by the exhaust pipe 3.
0 flows downward in one side 30a, is smoothly inverted by the curved portion 30e at the lower end, flows upward in the other side 30b, flows into the muffler 25, is silenced by the muffler 25, and is exhausted from the exhaust pipe 29 to the atmosphere. Is discharged. Since the lower end 30e of the exhaust pipe 30 is smoothly curved, the exhaust gas is exhausted from the lower end 30e.
It flows along the wall surface and is smoothly changed in direction. As a result, the lower end 30e of the exhaust pipe 30, that is, the direction change portion of the exhaust gas, is less deteriorated by the exhaust gas.

(Effect of the Invention) As described above, according to the present invention, the exhaust pipe connecting the exhaust manifold of the engine mounted on the main frame of the vehicle and the muffler arranged on the vehicle body has a substantially U shape. Formed and arranged in the up-down direction between the exhaust manifold and the muffler with the curved portion facing downward, and connecting a flexible pipe in the up-down direction in the middle of one side of the exhaust pipe connected to the exhaust manifold, Since the side is connected to the muffler and the curved portion is supported by the vehicle body through a cushion member, the flexible pipe favorably absorbs vertical displacement between the engine and the exhaust pipe. This makes it possible to significantly improve the durability of the flexible pipe. Further, since the exhaust gas flowing through the exhaust pipe is smoothly inverted by the curved portion, the flow becomes good, and the deterioration of the exhaust pipe due to the exhaust gas is reduced, and the durability is significantly improved.

[Brief description of drawings]

1 is a side view of an all-terrain crane vehicle to which an exhaust pipe of a vehicle according to the present invention is applied, FIG. 2 is a top view of the muffler and the exhaust pipe of FIG. 1, and FIG. 3 is an arrow line of FIG. A sectional view taken along the line III, FIG. 4 is a sectional view taken along the line IV-IV in FIG.
FIG. 6 is an explanatory view of a main part of an exhaust pipe of a conventional vehicle, and FIG. 6 is a diagram showing displacement of the exhaust pipe of FIG. 1 ... All-terrain mobile crane, 2 ... Main frame, 2
a ... Side member, 12 ... Front fender, 20 ... Engine, 21 ... Exhaust manifold, 25 ... Muffler, 30
... Exhaust pipe, 31 ... Flexible pipe, 35, 36, 3
8 ... Bracket, 37 ... Cushion rubber.

Claims (1)

[Scope of utility model registration request] 1. An exhaust pipe for connecting an exhaust manifold of an engine mounted on a main frame of a vehicle and a muffler arranged on a vehicle body is formed in a substantially U-shape so as to be provided between the exhaust manifold and the muffler. Is arranged in the vertical direction with the curved portion facing downward, and a flexible pipe is connected in the vertical direction in the middle of one side of the exhaust pipe connected to the exhaust manifold,
A structure of an exhaust pipe of a vehicle, wherein the other side is connected to the muffler, and the curved portion is supported by the vehicle body via a cushion member.