JP2517627Y2 - Exhaust pipe support structure for motorcycles - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention forms an exhaust expansion portion which is curved in a substantially horizontal direction at the other end of an exhaust pipe having one end attached to an exhaust port of an engine and which passes under a crankcase and in front of a rear wheel. At the same time, it relates to an exhaust pipe support structure for a motorcycle mounted on a vehicle body through a support bracket mounted on the exhaust expansion portion.

[0002]

2. Description of the Related Art An engine mounted on a motorcycle is equipped with an exhaust pipe for exhausting burnt gas in a cylinder. The exhaust pipe has one end connected to the exhaust port of the cylinder, and the other end has a large-diameter exhaust expansion part formed.
The burnt gas is appropriately expanded and silenced inside and then released into the atmosphere.

Usually, in a motorcycle equipped with this kind of exhaust pipe, the above-mentioned large-diameter exhaust expansion portion is made to pass through the lower region of the crankcase to make effective use of the space.

On the other hand, the engine mounted on a motorcycle has conventionally been provided with hoses as engine accessories in the vicinity thereof in order to guide the fluid discharged from each part to a required portion. For example, in the crankcase, a breather hose for discharging the breather gas in the crankcase to the outside is extended downward, and when the liquid stored in the reservoir tank or carburetor overflows. Overflow hoses for discharging this to the outside are extended downward, and breather gas and liquid discharged from the crankcase, reservoir tank and carburetor are guided to the lower area of the engine and discharged to the outside. I am trying to do it.

[0005]

By the way, when the engine is in a driving state or when the motorcycle is in a running state, the motorcycle and the engine constantly vibrate or shake.

Therefore, in the motorcycle as described above, a situation may occur in which the exhaust expansion portion passing through the lower region of the crankcase and the hoses extending downward of the engine come into contact with each other. There is.

Since the above-mentioned hoses are usually molded from resin such as rubber, when they come into contact with the exhaust expansion portion, the heat of the exhaust expansion portion in a high temperature condition may cause damage such as deformation and damage. Will be done.

In view of the above situation, an object of the present invention is to provide an exhaust pipe support structure for a motorcycle capable of preventing damage to hoses as an engine auxiliary machine without reducing space utilization efficiency. Especially.

[0009]

According to the present invention, at the other end of an exhaust pipe, one end of which is attached to an exhaust port of an engine, is provided an exhaust expansion portion which passes under a crankcase and which is curved in a substantially horizontal direction in front of a rear wheel. In an exhaust pipe support structure for a motorcycle, which is formed and attached to a vehicle body through a support bracket attached to the exhaust expansion portion, both ends of the support bracket are provided with curved portions curved in a substantially horizontal direction of the exhaust expansion portion. A holding portion is welded to the outer wall of the exhaust expansion portion so as to be short-circuited, and a holding portion for holding hoses as an engine accessory is formed at a substantially middle portion of the support bracket in a plan view.

[0010]

According to the above construction, the hoses as engine accessories are held by the holding portion formed on the support bracket to prevent contact between the hoses and the exhaust pipe.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings showing one embodiment. 2 and 3 show an embodiment of a motorcycle according to the present invention, which illustrates a motorcycle equipped with a two-cycle engine. As shown in FIG. 3, an engine 1 mounted on this motorcycle has a V-shaped engine 2 in which the cylinder axes a and b are vertically inclined from the horizontal position toward the front of the vehicle (to the left in FIG. 3). It is a cylinder and has exhaust ports 2a and 3a on the lower surface side of each cylinder block 2 and 3, respectively.

As clearly shown in FIG. 2, these exhaust ports 2
One end of each exhaust pipe 4, 5 is attached to each of a and 3a. Each of the exhaust pipes 4, 5 has a large diameter expansion chamber (exhaust gas expansion portion) 4a formed at the other end,
5a are arranged in parallel with each other in such a manner that they sequentially pass through the lower region of the crankcase 6 and the lower region of the vehicle, and from there extend to both sides of the vehicle so as to surround the rear wheel 7. It opens toward the rear of.

As is clear from the figure, the cylinder block 3 has one end inclined downward with the cylinder axis b.
The exhaust pipe 5 attached to the exhaust port 3a has a central portion of the expansion chamber 5a that is largely curved in the substantially horizontal direction toward the inside of the vehicle, and its length is substantially the same as the other exhaust pipe 4. Is configured. Note that reference numerals 8 and 9 in FIG. 2 denote silencers attached to the end portions of the individual exhaust pipes 4 and 5. The exhaust pipes 4 and 5 are attached to the silencers 8 and 9 described above by mounting brackets 10 and 1 respectively.
The rear footrest brackets 12 and 13 extending from the vehicle body, for example, the frame F, are held via the mounting brackets 10 and 11.

Further, as shown in FIG. 2, the exhaust pipes 4 and 5 are provided with connecting brackets 14 at positions facing each other in the expansion chambers 4a and 5a, respectively. As shown in FIGS. 1 and 4, the coupling bracket 14 has an L-shape having fitting holes 14a in one of the respective portions, and means such as welding is provided at a position where the fitting holes 14a face each other. Are fixedly installed, and rubber cushion materials 15 are provided between them. The cushion material 15 has a fitting hole 14a for the coupling bracket 14.
Buffer portion 15a formed to have a larger diameter than
A shaft portion 15b formed from both end surfaces of a to have an outer diameter substantially the same as that of the fitting hole 14a, and a head bulged outward from the free end portion of each shaft portion 15b in the radial direction of the shaft portion 15b. A state in which each of the shaft portions 15b is located in the fitting hole 14a of the coupling bracket 14 and a constant gap W is secured between the exhaust pipes 4 and 5 arranged in parallel with each other. The exhaust pipes 4 and 5 are connected to each other.

Further, a connecting bracket 16 and a support bracket 17 are welded to the other ends of the exhaust pipes 4 and 5, respectively.

As shown in FIG. 3, the connecting bracket 16 welded to one of the exhaust pipes 4 is provided so as to project upward from the upper surface of the outer wall of the expansion chamber 4a in the exhaust pipe 4, and the vehicle is provided at the upper end thereof. Front footrest bracket 18 extending from the body, eg frame F
It has a connecting portion 16a.

The supporting bracket 17 welded to the other exhaust pipe 5 is constructed by stacking a pair of plate-shaped members A and B on each other, as is apparent from FIGS. 1 and 2. As shown, a mode in which the curved proximal ends of the expansion chamber 5a in the exhaust pipe 5 are laid so as to short-circuit, and a space having a substantially triangular shape in plan view is defined between the curved proximal ends. And projects upward from the upper surface of the outer wall of the expansion chamber 5a,
An insertion hole (holding portion) 17a is provided at a substantially middle portion thereof, and a mounting hole 17b is provided at a rear end portion thereof.

The insertion hole 17a of the support bracket 17 is formed by bending the other plate member B so as to define a rectangular space between the plate member A and the plate member A. A resin overflow hose 19 hung from a reservoir tank or a carburetor (not shown) as an engine accessory and a resin breather hose 20 hung from the crankcase 6 are sandwiched between the two. I am holding it.

The mounting hole 17b of the support bracket 17 is opened in the left-right direction of the vehicle, and is connected to a vehicle body, for example, a front footrest bracket (not shown) extending from the frame F inside. A mounting bolt (not shown) is inserted and fastened.

In the motorcycle constructed as described above, since the portions of the exhaust pipes 4 and 5 arranged in parallel with each other are connected by the cushion member 15, the engine 1 is in operation or the motorcycle is Even in the running state, the exhaust pipes 4 and 5 do not collide with each other due to the influence of vibration or shaking.

Moreover, even when the exhaust pipes 4 and 5 are previously joined by the cushion material 15, the cushion material 15 is appropriately deformed to change the positions and the postures of the exhaust pipes 4 and 5 while being assembled. Since the attachment work can be performed, the connecting portions with the exhaust ports 2a and 3a and the connecting portions 10 with the vehicle body in the exhaust pipes 4 and 5 that are arranged side by side at the time of processing,
High dimensional accuracy is not required for relative positioning of 11, 16, and 17.

According to the motorcycle, the exhaust pipe 5
Using a support bracket 17 for attaching the vehicle to the vehicle body, hoses attached as an auxiliary machine of the engine 1, that is, the overflow hose 19 hung from the above-mentioned reservoir tank and carburetor, and the breather hung from the crankcase 6. Since the hoses 20 are sandwiched and held in the insertion holes 17a of the support bracket 17, the expansion chamber 5a in which the hoses 19 and 20 are curved without increasing the number of parts.
The hose can be maintained in the substantially central part of the space defined by the above, and the dead space of the vehicle can be effectively used, and these hoses due to vibration and shaking when the engine 1 is in operation or during traveling. It is possible to prevent contact between the exhaust pipes 4 and 5 and the exhaust pipes 4 and 5, and to prevent the hoses 19 and 20 from being damaged by the heat of the exhaust pipes 4 and 5 in a high temperature state.

Further, in the above-mentioned motorcycle, the above-mentioned support bracket 17 is welded to the exhaust pipe 5 while straddling the curved expansion chamber 5a so as to short-circuit between the base end portions thereof, that is, the support bracket 17. Is welded to the expansion chamber 5a at two locations, which is not only advantageous in terms of strength, but also equivalent to the exhaust pipe 5 being attached to the vehicle body at two locations. 5 also has the effect of suppressing the vibration and shaking.

In the above embodiment, the motorcycle equipped with the V-type two-cylinder engine is exemplified, but it is of course applicable to the motorcycle equipped with the engine of a different type. In this case, the motorcycle does not necessarily have to have a plurality of exhaust pipes.

Further, in the above embodiment, when a plurality of exhaust pipes are provided, the exhaust pipes arranged side by side are connected to each other by the cushion member, so that they can be prevented from colliding with each other and vibrate. And, it is possible to suppress the occurrence of shaking, but it is not always necessary to combine both.

[0026]

As described above, according to the present invention,
Since the support bracket for attaching the exhaust pipe to the vehicle body is used and the hoses are held by the holding portion formed on the support bracket, the hose and the exhaust pipe are not increased without increasing the number of parts. Since contact with the hose is blocked, it is possible to prevent damage to hoses due to the influence of heat without reducing the space utilization efficiency while leaving the exhaust expansion part in the lower area of the crankcase. Becomes

In addition, since the support bracket is welded to the exhaust pipe so as to short-circuit between the base ends of the curved exhaust expansion portion, it is not only advantageous in terms of strength, but also the exhaust pipe is mounted on the vehicle. This is substantially equivalent to being attached to the main body at two places, and it becomes possible to suppress vibration and shaking of the exhaust pipe.

[Brief description of drawings]

FIG. 1 is a perspective view conceptually showing a main part of an exhaust pipe support structure for a motorcycle according to the present invention.

FIG. 2 is a bottom view conceptually showing a motorcycle to which the exhaust pipe support structure according to the present invention is applied.

FIG. 3 is a side view of the motorcycle shown in FIG.

4 is an enlarged sectional view taken along line IV-IV in FIG.

[Explanation of symbols]

 1 ... 2-cycle engine 4,5 Exhaust pipes 4a, 5a ... Expansion chamber 6 ... Crankcase 12, 13 ... Rear footrest bracket 17 ... Support bracket 17a ... Insertion hole 17b ... Mounting hole 19 ... Overflow hose 20 ... Breather hose A, B ... Plate-shaped member F ... Frame

Claims (2)

(57) [Scope of utility model registration request] 1. An exhaust expansion part, which has one end attached to an exhaust port of an engine and which is curved in a substantially horizontal direction in front of a rear wheel and below a crankcase, is formed at the other end of the exhaust pipe. In an exhaust pipe support structure for a motorcycle mounted on a vehicle body through a support bracket attached to the exhaust pipe, the exhaust gas is straddled over both ends of the support bracket so as to short-circuit a curved portion of the exhaust expansion portion that is curved in a substantially horizontal direction. An exhaust pipe support structure for a motorcycle, characterized in that a holding portion, which is welded to the outer wall of the inflated portion and holds a hose as an engine auxiliary machine, is formed in a substantially middle portion of the support bracket in a plan view. 2. The support bracket is composed of a pair of plate-shaped members that are overlapped with each other, the holding portion is formed between the pair of plate-shaped members, and the hoses are held by the holding portion. The exhaust pipe support structure for a motorcycle according to claim 1, wherein: