JPH0396616A - Mounting structure for muffler for motor cycle - Google Patents

Abstract

PURPOSE:To enhance heat radiating effect as well as to prevent a seat cowl from being thermally deformed by laterally bridging a cross member between both side sections of the seat cowl made of resin in a portal shape in cross section which is opened downward. CONSTITUTION:Among mufflers connected with a V-type 4 cylinder engine 4, one connected with a lower cylinder 4a is extended from the lower side of the engine 4 to the right rear section of a car body so as to be mounted. and one connected with an upper cylinder 4b is extended from the lower side of a fuel tank 3 upward to a rear wheel 12 so as to be mounted. And a cross member 25 to support the rear section of a muffler 14 is mounted on the rear section of a forward seat cowl 19 with a mounting bolt 26. Namely, the cross member 25 is laterally bridged between both of the side sections of the forward seat cowl 19 in rear of a seat 17 for the forward set cowl 19. This thereby permits heat in the muffler 14 to be transferred to the seat cowl 19 through the cross member 15, thereby enhancing heat radiating effect with a heat transfer route extended.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a mounting structure for a muffler for a motorcycle, in which a muffler is mounted within a synthetic resin seat cowl.

[Conventional technology]

In recent years, from the viewpoint of aerodynamic characteristics, motorcycles have been equipped with a seat cowl that is integrated with a seat and covers the upper part of the rear part of the vehicle body in addition to a front cowl that covers the front part of the vehicle body. A conventional seat cowl of this type is disclosed in, for example, Japanese Patent Laid-Open No. 1-109185.

This is a seat cowl for a motorcycle equipped with a 4-cycle engine, and the seat cowl body is made of aluminum and has a generally gate-shaped cross section that opens downward. It is integrally formed of aluminum alloy or composite resin such as carbon fiber reinforced plastic. This seat cowl was constructed so that it could be attached directly to the vehicle body without using a seat rail. In addition, some motorcycles equipped with a two-stroke engine have a muffler that extends in a substantially straight line from the engine to the rear, and the seat cowl used for such motorcycles has a muffler placed inside it. The structure was

[Problem to be solved by the invention]

However, since the seat cowl is a member that bears the weight of the driver and must be formed strongly, if the seat cowl body is made of aluminum or aluminum alloy as a single piece as described above, it will be heavy. turn into.

For this reason, seat cowls made of aluminum or aluminum alloy could not be used in road racing motorcycles that aim to reduce the weight of the vehicle. In order to reduce the weight, the seat cowl body may be made of synthetic resin such as carbon fiber reinforced plastic. However, when such a seat cowl made of synthetic resin is used for a motorcycle equipped with a two-stroke engine in which the muffler extends approximately in a straight line from the engine to the rear, the large-diameter muffler of the two-stroke engine is attached to the seat cowl. Must be attached directly to the cowl. If this is done, a problem arises in that the portion of the seat cowl where the muffler is attached is deformed by the heat conducted from the muffler.

[Means to solve the problem]

The mounting structure for a muffler for a motorcycle according to the present invention is such that a cross member is horizontally suspended between both sides of a resin seat cowl formed in a gate-shaped cross section that opens downward, and the muffler is mounted on this cross member. It is something.

[For production]

Since the heat of the muffler is transferred to the seat cowl via the cross member, the heat transfer path is extended, and most of the heat is radiated during that time, so that almost no heat is transferred to the seat cowl.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIGS. 1 to 4.

FIG. 1 is a side view showing a motorcycle to which a motorcycle seat cowl according to the present invention is attached, and FIGS. 2(a) to (c)
) are views showing the seat cowl for a motorcycle according to the present invention, in which (a) is a plan view, (b) is a front view, and (c) is a front view.
) is an enlarged sectional view showing the cross section taken along line nn in the figure (b). Figure 3 is a sectional view taken along the line ■■ in Figure 1, Figure 4 (a),
(b) is an enlarged view showing the main part of the frame to which the seat cowl according to the present invention is attached, where (a) is a plan view of the attachment part, and (b) is a front view. In these figures, 1 indicates a frame of a motorcycle to which a motorcycle seat cowl according to the present invention is attached, and this frame 1 is connected to a belly button pipe 2 and this head pipe 2, and has a fuel tank 3 and a V-type 4 cylinder. A pair of left and right main frames 5 that support the engine 4, and both left and right main frames 5.
It consists of a backstay 6 installed between them to form a cross member, a rear arm bracket 7 connected to the lower part of the main frame 5, and the like. A front fork 9 for suspending the front fork 8 and a handle 10 for operating the front fork 9 are rotatably supported on the hemlock pipe 2 of the frame 1. Further, a bracket I-6a for fixing a seat cowl, which will be described later, is provided on the backstay 6 of the frame I so as to protrude toward the rear of the vehicle body. 11 is a rear arm swingably supported by the rear arm bracket 7 of the frame 1; 12 is a rear wheel supported by the rear arm 11; 13 is a rear arm between the rear arm 11 and the back stay 6 of the frame 1; This is an interposed cushion unit. 14 is a muffler connected to the V-type four-cylinder engine 4, and the muffler 14 connected to the lower cylinder 4a of the engine 4 is connected to the engine 4.
The one that extends from the bottom to the right rear part of the vehicle body and is connected to the upper cylinder 4b is connected to the rear wheel 1 from the bottom of the fuel tank 3.
2, and a silencer 14a is attached to the rear end of each muffler l4.

Reference numeral 15 denotes a front cowling for reducing air resistance and protecting the driver from wind pressure, and is supported by the frame 1 via a bracket (not shown) or the like.

16 is a seat cowl used when implementing the motorcycle muffler mounting structure according to the present invention, and this seat cowl 16 is arranged above and on both sides of the two mufflers l4 arranged above the rear wheel 12. The front seat cowl 19 has a substantially gate-shaped cross section so as to cover the front seat cowl 19, to which the seat l7 is attached and is fixed to the bracket 6a of the frame l with a mounting bolt 18.
A rear seat cowl 21 is detachably attached to the rear of the seat 9 via a locking portion 20. The dividing line dividing the front and rear seat cowls 19 and 21 connects both sides of the seat cowl 16 from the rear of the seat 17 to the exhaust pipe 1.
It is set so that it cuts diagonally across the front, avoiding the thickest part of No. 4. That is, by dividing the seat cowl 16 from the above-mentioned dividing line, the front seat cowl 19 acts as a cantilever beam having a substantially triangular shape when viewed from the side. It can be shaped with limited dimensions.

The front seat cowl 19 is indicated by the two-dot chain line A in FIG. 2(b).
In other words, the portion shown by , in other words, the portion shaped like a triangular gate in side view, including the portion through which the mounting bolt 18 is inserted from the front end of the front seat cowl 19 to the backrest portion, is made of aramid fiber-reinforced plastic. 19a is sandwiched between carbon fiber reinforced plastics 19b to form a three-layer laminated structure, and the other parts are made of a single layer structure such as carbon fiber reinforced plastics to support the weight of the driver. It is strongly formed to allow for

Further, a cross member, which will be described later, is horizontally suspended behind the seat l7 in the front seat cowl 19. A reinforcing plate 19c is integrally buried in a portion of the front seat cowl 19 through which the mounting bolt 18 is inserted, and is attached to the bracket 6a of the frame 1 via a spacer 22 and a pusher 23. Furthermore, a fuel tank fixing member 24 is provided at a portion of the front seat cowl 19 that corresponds to the front portion of the seat 17.

The rear seat cowl 21 is integrally formed of carbon fiber reinforced plastic with a one-layer structure, and has a silencer opening 21a bored in its rear end. Additionally, the rear seat cowl 21 is formed to have lower rigidity than the front seat cowl 19, and is designed to avoid interference with the large diameter portion of the muffler when it is attached to and removed from the front seat cowl 19. The locking portion 20 can be attached and detached by bending the front portion.

25 is a cross member for supporting the rear part of the muffler 14, and this cross member 25 is connected to the seat cowl 1.
It is attached to the rear of 9 by an attachment port 26. This cross member 25 is shown in FIG. 2(b). As shown in (c), there is a cross member main body 25a which is made of a tube with a rectangular cross section and spans in the vehicle width direction within the front seat cowl 19, and the cross member main body 25a is provided at both ends of the cross member main body 25a. Mounting plate 2 onto which mounting bolts 26 are screwed
5b, and a muffler support stay 25c that is erected toward the rear of the vehicle body on the cross member main body 25a and connected to the bracket l4b of the muffler l4. It is located at the rear of I7 and is suspended horizontally between both sides of the front seat cowling 9. In addition, 27 in Fig. 2(c) is a reinforcing wasosha,
Front seat cowl l9 cross member mounting bolt 2
6 is integrally buried in the portion through which it is inserted.

In the motorcycle employing the motorcycle muffler mounting structure according to the present invention, the muffler 14 can be attached or detached by removing the rear seat cowl 21 and exposing the connecting portion between the cross member 25 and the muffler 14. done in the state. The rear seat cowl 21 is removed by bending its front portion to release the locking state of the locking portion 20 and pulling it away toward the rear of the vehicle body. The rear seat cowl 21 is attached by bringing it close to the front seat cowl 19 from the rear of the vehicle so as to cover the muffler 14, and by bending the front portion of the cowl and locking the locking portion 20.

Therefore, when the muffler 14 is attached to the cross member 25 as described above, the heat of the muffler 14 is sequentially conducted from the bracket 14b to the muffler support stay 25c, the cross member body 25a, and the mounting plate 25b to the front seat cowl. Since the heat is transferred to the front seat cowl 19, the heat transfer path is extended, and most of the heat is radiated during that time, so almost no heat is transferred to the front seat cowl 19.

Furthermore, when the cross member 25 is provided at the rear of the seat 17 in the front seat cowl 19 as shown in this embodiment, this portion is connected to both sides, the upper part, and the backrest stepped portion of the front seat cowl 19. Since it is a strong part and corresponds to the thickest part of the muffler 14, it can reliably support the muffler 14. Furthermore, in this embodiment, since the rear seat cowl 21 is formed to have lower rigidity than the front seat cowl l9, the side portions of the seat cowl 16 are shaped along the contour of the muffler 14 so that the gap between the seat cowl 16 and the muffler 14 is small. Even if the rear seat cowl 21 is formed with a rounded shape, the rear seat cowl 21 can be easily bent, so the lower open end should be expanded along the vehicle width direction to widen the gap with the muffler 14 before attachment and detachment. I can do it.

In this embodiment, an example was shown in which the cross member body 25a of the cross member 25 was formed of a tube material having a rectangular cross section, but as shown in FIG. 5(a). It can also be shaped by attaching a plate to the cross member main body 25a as shown in FIG. 3(b). In this way, the rigidity of the cross member 25 can be increased by using the plate material, and it is also possible to mount vehicle cargo such as a control unit on the cross member main body 25a when damping force electronic control suspension is adopted for the cushion unit l3. can. Further, the member for mounting the cargo on the vehicle is not limited to the above-mentioned plate material, and its shape, method of attachment to the cross member 25, etc. can be changed as appropriate.

Figure 5(a). (b) is a diagram showing another embodiment, in which (a) is a side view of the seat cowl, and (b) is a cross-sectional view showing a main part thereof. Figure 5 (a), (b)
In the figure, 3l indicates a plate attached to the cross member main body 25a, and 32 indicates a vehicle cargo such as the control unit. In addition, Fig. 5(a). In FIG. 2(b), the same members as those explained in FIGS. 2(b) and 2(c) are designated by the same reference numerals, and detailed explanation thereof will be omitted.

Furthermore, although this embodiment shows an example in which the rear seat cowl 2 is made of carbon fiber reinforced plastic, the rear seat cowl 21 is not a member that requires high rigidity like the front seat cowl 19, so it is made of carbon fiber reinforced plastic. It is also possible to use a plastic material that is not reinforced by the material, and the thickness can also be made thinner than that of the front seat cowl 19. Also,
The portion of the front seat cowl 19 having a three-layer structure is not limited to the range shown in the above embodiment, and the portion where the cross member 25 is attached may also have a three-layer structure. In this way, the mounting portion of the cross member 25 can also be strongly shaped. Furthermore, in this embodiment, a front seat cowl 19 and a rear seat cowl 21 are provided.
Although an example has been shown in which the locking portion 20 is provided at the connecting portion, it goes without saying that both the front and rear seat cowls may be connected by a fastening member such as a screw.

〔Effect of the invention〕

As explained above, according to the present invention, a cross member is installed horizontally between both sides of a resin seat cowl formed in a gate-shaped cross section that opens downward, and a muffler is attached to this cross member. Since heat is transferred to the seat cowl via the cross member, the heat transfer path is extended, and most of the heat is radiated during that time, so that almost no heat is transferred to the seat cowl. Therefore, when the motorcycle muffler mounting structure according to the present invention is adopted, the seat cowl can be reliably prevented from being deformed by the heat of the muffler, and the reliability of the seat cowl can be improved. In addition, by horizontally suspending a cross member on the seat cowl, the seat cowl can be reinforced by this cross member, so the seat cowl can be reliably prevented from twisting or bending. It's also effective.

[Brief explanation of drawings]

FIG. 1 is a side view showing a motorcycle to which a motorcycle seat cowl according to the present invention is attached, and FIGS. 2(a) to (c)
) are views showing the seat cowl for a motorcycle according to the present invention, in which (a) is a plan view, (b) is a front view, and (c) is a front view.
) is an enlarged sectional view showing the cross section taken along line nn in the figure (b). Figure 3 is a sectional view taken along line ■-- in Figure l, Figure 4 (a)
, (b) is an enlarged view showing the main part of the frame to which the seat cowl according to the present invention is attached, where (a) is a plan view of the attachment part, and (b) is a front view. Figure 5 (
a) and (b) are diagrams showing other embodiments;
1 is a side view of the seat cowl, and FIG. 14...Muffler l6...Seat cowl, 1
7. ...Seat, 19...Front seat cowl, 2
1..・．． Rear seat cowl. 25...Cross member, 25a...Cross member body.

Claims (1)

[Claims] A mounting structure for a muffler for a motorcycle, characterized in that a cross member is horizontally suspended between both sides of a resin seat cowl formed in a gate-shaped cross section that opens downward, and a muffler is attached to the cross member.