JPH0239913Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an exhaust passage mounting structure for a motorcycle using a step bar.

The exhaust system in a motorcycle has its front end connected in communication with an exhaust port formed on the front side of the engine cylinder, and reaches the rear of the vehicle body through a curved exhaust pipe that constitutes an exhaust passage, and the rear end of the exhaust passage is communicates with the atmosphere.

On the other hand, to install the exhaust passage, the front end, that is, the front end of the exhaust pipe, is connected and fixed to the front side of the engine cylinder, and the middle part is fixed by bolting a stay fixed to the muffler to the vehicle body frame. ing.

By the way, especially in the case where the exhaust passage is formed by separate exhaust pipes and a muffler connected to the rear end of the exhaust pipe, and the two are connected at a joint via a gasket, the exhaust pipe and the muffler are connected at one point each as described above. This serves as a support and a load such as the weight of the muffler is applied to the joint portion. As a result, insufficient rigidity tends to occur, and it is desirable to securely fix the muffler to prevent exhaust leakage at the joint portion.

Therefore, in this type of exhaust passage, it is necessary to provide the muffler with at least one other fixing point to the vehicle body.

However, simply adding a fixing point requires installing a fixing bracket via a mounting part provided on the frame or engine body, which requires additional processing and shape changes, and space is limited. In the case of a two-wheeled motor vehicle, the installation space is naturally limited, and this is undesirable because it increases the cost of parts and deteriorates the appearance design.

SUMMARY OF THE INVENTION Therefore, the present invention aims to provide an exhaust passage mounting structure for a motorcycle that is low in cost and has additional fixing points for the exhaust passage to the vehicle body without impairing the design.

In order to achieve this purpose, the present invention is applied to the exhaust passage of a motorcycle, especially a muffler that is formed separately from the exhaust pipe and connected with a joint, and its main component is a muffler that protrudes to the side of the vehicle body. Using an existing step bar, a stay is installed inside the step bar that is curved downward, the side part of the muffler is attached to the outside of the stay, and the muffler is installed inside the bulge of the step bar. It is characterized by the fact that it is made to be carried out.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

In the drawings, Fig. 1 is a side view of a motorcycle to which the exhaust passage mounting structure according to the present invention is applied, Fig. 2 is a main part configuration diagram taken along the line A-A in Fig. 1, and Fig. 3 2 respectively represent views taken in the direction of arrow B in FIG.

First, in order to clarify the present invention, the general structure of a motorcycle will be explained with reference to FIG. 1. The motorcycle designated by reference numeral 1 in the figure has a body frame 3 whose front part is attached to a head tube 2. A front form 5 supporting a front wheel 4 is attached to the head tube 2 via both top and bottom bridges 6 and 7. pivot. On the other hand, an engine unit 8 is mounted on the lower part of the body frame 3, and a rear fork 1 supporting a rear wheel 9 is mounted on the rear lower part of the body frame 3.
0 pivotably extends rearward, and a shock absorber 11 is interposed between the rear fork 10 and the vehicle body frame 3. In addition, a fuel tank 12 is provided at the upper front part of the vehicle body frame 3.
, and a seat 13 is attached to the rear thereof.

On the other hand, the engine unit 8 is connected to the fuel tank 1.
2, and consists of a crankcase 8a, an engine cylinder 8b, an auxiliary equipment system 8c, etc. Also,
A step bar 14 that protrudes to both sides of the vehicle body using the lower part of the vehicle body frame 3 is attached to approximately the rear lower portion of the crankcase 8a.
Steps 14a are attached to both ends of the 4.

Further, the front end of the engine cylinder 8b is connected to the tip of an exhaust pipe 15 that communicates with an exhaust port formed in the engine cylinder 8b, and the exhaust pipe 15 is curved so as to extend from below to the rear. The rear end of the muffler 15 is connected in communication with the front end of a linear muffler 16. As mentioned above, the exhaust pipe 15 and the muffler 16 are connected to the joint 17 through a gasket, for example.
The front part of the muffler 16 intersects above the step bar 14 and is fixed by the mounting structure P according to the present invention, and the rear end reaches the rear of the vehicle body and communicates with the atmosphere. Further, a stay 18 is fixedly installed at the middle upper part of the muffler 16, and the stay 18 is fastened to the vehicle body frame 3 with, for example, bolts 19.

In addition, the other code 20 is the front fork 5.
The handle attached to the top, 21 is a headlight,
22 and 23 indicate front and rear fenders, respectively.

Next, the mounting structure P of the muffler 16 according to the present invention will be specifically explained with reference to FIGS. 2 and 3. Note that the same parts are given the same reference numerals throughout all the drawings to clarify their configurations.

In FIG. 2, a lower part of the vehicle body frame 3 includes, for example, a pair of left and right frame bodies 3a and 3b, and a cross member 3c is installed between them. Then, step bar mounting stays 26 and 27 are fixedly attached to the lower portions of, for example, gusset plates 24 and 25 attached to both sides of the frame bodies 3a and 3b, and the stays 26 and 27 are attached to the ends of the stays 26 and 27, respectively. The intermediate portion of the step bar 14 is attached by welding or the like.

The step bar 14 is straight when viewed from the plane as shown in Figure 3, but when viewed from the forward direction, the left side (right side in Figure 2) has a step so that the tip is located slightly upward. A step 14b made of rubber, for example, is fitted and attached to the straight part of the tip, and the other right side (left side in FIG. 2) is curved downward to form a bulge part 29, and the tip is bent approximately horizontally. At least the step 14a is fitted onto the outside. Therefore, the steps 14a and 14b have substantially the same height and are located substantially horizontally.

Further, the bulging part 29 is formed into a bulge so that the muffler 16 shown in cross section in FIG. For example, as shown in FIG. 3, a stay 31 having an L-shaped planar shape in consideration of reinforcement is welded or otherwise erected so as to be substantially vertical.

On the other hand, the muffler 1 facing the stay 31
For example, as shown in FIG. 2, a bracket 32 having a U-shaped cross section is attached to the outer wall of the vehicle body side of No.
and tighten with nut 34. As is clear from FIG. 2, the upper end of the stay 31 is formed so as not to protrude from the upper end of the muffler 16 in consideration of appearance.

As described above, the exhaust passage mounting structure according to the present invention can reliably fix the exhaust passage in which, for example, a muffler and an exhaust pipe are connected by a joint, and also ensure reliable sealing. Furthermore, even if the exhaust pipe and muffler are integrated by welding, etc., in addition to the basic effect of dramatically increasing the mounting support strength, the following excellent effects can be obtained. .

First, since the existing step bar is used, and the exhaust passage is placed in an intersecting manner at the top of the step bar, the stay can be made smaller, and additional machining and shape changes to other parts are minimized, which reduces component costs. The step bar can also be implemented at extremely low cost, and the step bar can also be used as a protection member from flying stones from the road surface or tread surface, improving durability.

Second, since the muffler is attached to the stays set up on the inside of the step bar, the stays are also not noticeable from the outside and do not cause any discomfort. Therefore, the external design is not impaired in any way. In particular, if the step bar is made to bulge downward and an exhaust passage is arranged inside this bulge, or if the side of the exhaust passage on the vehicle body side is attached to the stay, the appearance can be further improved. can.

Note that the present invention can be similarly applied to other similar vehicle types such as motorcycles and tricycles.

[Brief explanation of the drawing]

Figure 1 is a side view of a motorcycle to which the exhaust passage mounting structure according to the present invention is applied, and Figure 2 is A-A in Figure 1.
Main part configuration diagram showing the arrow direction of A line, Fig. 3 is B in Fig. 2
It is a directional view. In the drawings, 14 is a step bar, 16 is a muffler, 18 is a stay, and 29 is a protrusion.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In a motorcycle equipped with an exhaust passage arranged to intersect with a step bar protruding to the side of the vehicle body, the step bar is made to bulge downward, and the inside of the bulged part is 1. An exhaust passage mounting structure for a motorcycle, characterized in that said exhaust passage is disposed in said step bar, and said exhaust passage is supported and fixed to a stay raised inside said step bar. (2) The exhaust passage mounting structure for a motorcycle according to claim (1), wherein the exhaust passage has a side portion of the exhaust passage on the vehicle body side supported and fixed to the stay.