JPH03295782A - Frame for motorcycle - Google Patents

Abstract

PURPOSE:To prevent the output reduction of an engine caused by lack of the intake quantity by positively discharging the air guided into a bridge member from the air guide port of tank rail sections to the air intake section of the engine from air discharge holes formed on the bridge member. CONSTITUTION:The frame 10 of a motorcycle has a pair of the right and left tank rail sections 30 (30R, 30L) connected to a head pipe 20 at their tips, and a bridge member 70 is suspended across rear end sections of the tank rail sections 30. An air intake port 33 is formed above the tip sections of the tank rail sections 30, and many air discharge holes 71 are formed on the lower face of the bridge member 70 formed into a flat duct structure. Many air feed holes 36 are bored on the inside faces of the tank rail sections 30 located at the connection position of the bridge member 70 and the tank rail sections 30. When air is guided from the air intake port 33, this air is discharged from the air discharge holes 71 and fed to the periphery of the intake port of a carburetor 61.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a frame for a motorcycle, and more particularly to a frame equipped with means for supplying intake air to an engine.

[Conventional technology]

In racing motorcycles, almost the entire body frame is covered by a fairing in order to reduce air resistance during running.

[Problems to be Solved by the Invention] In such motorcycles, it is difficult to introduce sufficient air into the air intake portion of the engine when the motorcycle is running, and as a result, the amount of intake air is insufficient and the output of the engine sometimes decreases.

In view of the above circumstances, an object of the present invention is to provide a frame for a motorcycle that can prevent a decrease in engine output due to insufficient intake air.

[Means to solve the problem]

In the present invention, a pair of left and right tank rail sections having a duct structure and whose tips are joined to a head pipe, a pair of left and right body frame sections extending downward from the rear ends of these tank rail sections, and a tank rail are provided. In a frame for a motorcycle, the frame has a pair of left and right down tube sections interposed between a distal end section of the down tube section and a lower end section of the body frame section,
A duct structure bridge with an air inlet opening at the front end of the tank rail section, one end and the other end connected to the rear end of the left and right tank rail sections, respectively, and an air release hole provided on the bottom surface. and an air supply hole provided at a joint portion of the bridge member in the left and right tank rails to allow air introduced from the air inlet to flow into the bridge member via the tank rail portion. It is being

[Effect]

Air introduced from the air inlet flows into the bridge and joint members through the tank rail portion. Then, the air flowing into the bridge member is released from the air release hole formed in the bridge member.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a racing motorcycle equipped with a frame 10 according to the present invention.

As shown in the enlarged view of FIG. 2, the frame 10 of this embodiment includes a pair of left and right tank rail portions 30L, each of which is joined to the head vibrator 20 at its tip end.

30R, a pair of left and right body frame parts 40L and 40R extending downward from the rear ends of these tank rail parts 30L and 30R, and tank rail parts 30L and 30R.
A pair of left and right down tube parts 50L, 50 interposed between the tip of the body frame parts 40L, 40R and the lower ends of the body frame parts 40L, 40R.
It is equipped with R.

Above tank rail parts 30L, 30R, body frame parts 4OL, 40R and down tube parts 50L, 50R
forms a loop that goes around the engine 60 (in this embodiment, a parallel four cylinder) on the side of the motorcycle shown in FIG.

A bridge member 70 is provided between the rear end portions of the tank rail portions 30L and 30R, and a bridge member 70 is also provided between the rear end portions of the tank rail portions 30L and 30R.
Bridge members 80 and 90 are disposed horizontally between the intermediate portions and between the lower end portions of the down tube portions 50L and 50R, and a bridge member 100 is provided horizontally between the intermediate portions of the down tube portions 50L and 50R.

Note that the upper end of a rear suspension (not shown) is hooked to the center portion of the bridge member 80.

As shown in FIG. 1, the tank rail portion 30L.

30R is positioned approximately horizontally, and a fuel tank 110 is placed above them. The distance W1 (see FIG. 3) between the outer surfaces of these cylinders is set to be narrower than the distance W2 between the outer surfaces of the cylinders located on both sides of the engine 60 in order to reduce the knee grip width. has been done.

In this embodiment, the tank rail portions 30L, 30
R, and the upper half of the body frame portions 40L and 40R, specifically, the body frame portion 40L.

The parts 40L-1 and 4OR-1 above the joining position of the bridge member 80 at 40R are both formed of pressed sheet metal (aluminum plate, steel plate, etc.).

That is, for example, the tank rail portion 30R is made of an external member 3 as shown in FIG. 4 which is press-formed in advance to have a U-shaped cross section.
1 and an internal member 32 are connected to each other (see FIGS. 6 and 7).

The other tank rail portion 30L has a similar structure, and the upper half portion 40L-1°4OR-1 of the body frame portion also has a structure in which an external material and an internal material, which are press-formed to have a U-shaped cross section, are joined to each other. have

The inner material of the tank rail portion and the upper half of the body frame portion are integrally molded, and the outer material of the tank rail portion and the upper half of the body frame portion are integrally molded.

On the other hand, the lower half portions 40L-2 and 4OR-2 of the body frame including the joint portion of the bridge member 80 are formed by forging, casting, or machining. This lower half 40
L-2, 4OR-2 may have a duct structure, but in consideration of strength and ease of mounting parts, it is desirable to have a solid structure.

The body frame lower half portions 40L-2, 4OR-2 are the body frame upper half portions 40L-1, 4OR-2, respectively.
-1 by welding, and in FIG. 2, the weld line at their joint is indicated by the symbol g.

Note that the above welding is performed after the upper ends of the lower half parts 40L-2, 4OR-2 are fitted into the upper half parts 40L-1, 4OR-1.

The tip portions of the tank rail portions 30L and 30R are formed with a large vertical width in order to ensure strength and rigidity around the head pipe 20, and the intermediate portions are formed to have a large vertical width to ensure the strength and rigidity around the head pipe 20, and the intermediate portions are formed to accommodate the cylinders of the engine 60, the upper profile of the carburetor 61, and the fuel tank 110. - is formed to follow the lower profile of.

FIG. 4 shows a portion corresponding to the intermediate section L (see FIG. 2) of this tank rail portion 30R.

As shown in the figure, the external member 31 located at this location
A lateral reinforcing plate 33 is provided along the longitudinal direction between the inner member 32 and the inner member 32, and longitudinal reinforcing plates 34 and 35 are provided in such a manner that they intersect one end and the other end of the lateral reinforcing plate 33. It is provided.

The base of the lateral reinforcing plate 33 is welded to the inner surface of the outer member 31 before the outer member 31 and the inner member 32 are joined together. On the other hand, the longitudinal reinforcing plate 34 has a slit 33a provided therein, and a slit 33a provided in the longitudinal reinforcing plate 34.
It is inserted into the horizontal reinforcing plate 33 using the slit 33a provided in the outer member 3, and then joined to the inner surface of the reinforcing plate 33 and the outer member 31 by welding.

Note that the other vertical reinforcing plate 35 is also attached in advance to the horizontal reinforcing plate 33 side using a similar method.

An edge 33b of the lateral reinforcing plate 33 is provided on the side surface of the internal member 32.
A slit 32a is formed at a portion opposite to the edge 34b of the longitudinal reinforcing plate 34,35.

A slit 32b is provided at a portion opposite to 35b.

32c is formed.

Therefore, when the outer material 31 and the inner material 32 are joined,
As shown in FIG. 5, a reinforcing plate 33 is inserted into the slit 32a.
The edges 33b of the reinforcing plates 34, 35 are fitted into the slits 32b, 32c, respectively.

After the outer material 31 and the inner material 32 are joined, the slit 32
Welding is performed at portions a, 32b and 32c, thereby fixing the reinforcing plates 33, 34 and 35 also to the internal member 32. Note that the point image in FIG. 5 shows the range of the above-mentioned welding.

The middle area of tank rail #30L is also the tank rail part 3.
Similar to 0R, reinforcing plates are arranged vertically and horizontally.

As shown in FIG. 3, the tank rail portion 30L.

An air intake port 33 is formed above the tip of each member 30R, and as shown in FIG. 4, a ventilation hole 34c is provided in the vertical reinforcing plate 33, 35.

35c are formed respectively. Therefore, when air is introduced from the air intake port 33, this air passes through the tank rail portions 30L and 30R.

In addition, at the lower end of the body frame parts 40L and 4OR,
A pivot bearing 41 is provided for pivotally supporting the swing arm 120 shown in FIG.

As shown in FIG. 2, the down tube portion 50L,
50R, its upper end is the tank rail part 30L, 30R
The lower ends of the body frame parts 40L and 40R are respectively fastened with bolts 130 to the lower ends thereof, and the lower ends of the body frames 40L and 40R are fastened with bolts 140, respectively. Therefore, the down tube parts 50L and 50R are connected to the tank rail part 3.
0L.

30R and body frame parts 40L and 40R, respectively.

Note that the down tube portions 5OL and 50R are formed of extruded material (pipe).

Next, the bridge member 70 will be explained. 8th
As shown in the figure, this bridge member 70 has a flat duct structure with a substantially triangular cross section, and a number of air discharge holes 71 are formed through the lower surface thereof. One end and the other end of this bridge member 70 are joined by welding to the inner surfaces of the tank rail portions 30L and 30R, respectively, and the joining portions are shown by dashed-dotted lines in FIG. 8.

On the other hand, a large number of air supply holes 36 are formed through the inner surface of the tank rail portion located at the joint location. Therefore, when air is introduced from the air intake port 33 protruding from the tank rail portions 30L, 30R, this air passes through the tank rail portions 30L, 30R, and then blows out from the air supply hole 36 and bridges the tank rail portions 30L, 30R. It flows into the member 7o. The air that has flowed into the bridge member 70 is discharged from the air discharge hole 71 and is supplied around the intake port of the carburetor 61 shown in FIG.

By the way, since the fuel tank 110, left and right side fairings, etc. are present near the intake port of the carburetor 61, sufficient air may not be supplied to the intake port when the motorcycle is running.

As in the above embodiment, the air release hole 7 of the bridge member 7o
If air is supplied to the vicinity of the intake port of the carburetor 61 from the engine 1, sufficient fresh air will be supplied to the engine, so that the engine can be operated efficiently.

In addition, in order to prevent the air that has passed through the tank rail parts 30L and 30R from flowing into the lower side of the body frame parts 40L and 40R, the body frame parts 40L and 40R are
A partition (not shown) is provided within the upper end of R.

Although not shown, it is also possible to provide a suitable enclosure around the carburetor 61 and open the air discharge hole 71 of the bridge member 70 within this enclosure.

Furthermore, it is also possible to connect a flexible tube to the air intake port 33 of the tank rail portions 30L and 30R, and open the tip of this tube at an appropriate location on the front of the fairing 1-7o, allowing fresh air to flow in more efficiently. can be introduced.

Furthermore, as shown in FIG. 9, the tank rail section 30
By covering the inner and lower surfaces of L and 30R with a heat shield sheet, the temperature of the air introduced into these tank rail parts 30L and 3QR is suppressed from increasing due to heat radiation from the engine 60 as much as possible. This further increases engine operating efficiency.

FIG. 10 shows the front lower surface of the frame 1o, and dotted lines in the figure indicate welding lines.

The above embodiment frame 1o has tank rail parts 30L, 3
0R and upper half of body frame 4゜L-1,4OR
-1 are formed by pressing sheet metal, so they have a high degree of freedom in shape and are lightweight.

Note that electric components such as ignition coils are arranged in the six 37 formed at the front ends of the tank rail parts 30L and 30R, and a wire harness is inserted into the hole 38 provided near the six 37.

In the above embodiment, the outer member 31 and the inner member 32 of the tank rail parts 30L and 30R are joined in the manner shown in FIG. , 4OR-1 external material and internal material as the first
It is also possible to join in the manner illustrated in FIGS. 1(a) to 1(e). Of course, in this case, it is necessary for the outer material and the inner material to have cross-sectional shapes that are compatible with these joining methods.

Further, in the above embodiment, the tank rail portion 30L.

30R and upper half of body frame 40L-1°4O
Although the outer and inner members of R-1 are molded by pressing, it is also possible to mold them by casting.

It is also possible to form one of the external material and internal material by pressing, and to form the other by casting or forging.

Although the above embodiment is applied to a racing motorcycle without an air cleaner, this embodiment can of course be effectively applied to a general motorcycle equipped with an air cleaner.

〔Effect of the invention〕

According to the motorcycle frame according to the present invention, air introduced from the air inlet of the tank rail portion flows into the bridge member via the tank rail portion. Then, the air flowing into the bridge member is actively discharged from the air discharge hole formed in the bridge member to the air intake portion of the engine.

Therefore, it is possible to prevent a decrease in engine output due to insufficient intake air amount.

[Brief explanation of drawings]

FIG. 1 is a side view conceptually showing an embodiment of the frame according to the present invention, FIG. 2 is an enlarged perspective view of the frame according to this embodiment, and FIG. 3 is a frame according to this embodiment. Fig. 4 is a perspective view showing how the reinforcing plate is attached to the tank rail part, and Fig. 5 shows how the reinforcing plate is fitted into the slit provided in the internal material of the tank rail part. 6 and 7 are conceptual diagrams showing the
8 is a perspective view showing the structure of the bridge member; FIG. 9 is a sectional view showing a state in which a heat shield sheet is provided on the tank rail; 10th
The figure is a perspective view showing the position of the welding line on the lower surface of the front end of the frame, and FIG. 11 is a cross-sectional view showing another joining mode of the outer member and the inner member. 20... Head vibe, 30L, 30R... Tank rail part, 31... External material, 32... Internal material, 33
...Air inlet, 36...Air supply hole, 40L, 4
0R...Body frame part, 40L-1, 4OR-1
...upper half, 40L-2,4OR-2...lower half,
50L, 50R...down chineave part, 60...engine, 70...bridge member, 71...air release hole. Figure 6 (a) Figure 5 Figure 10 (b) (e) Figure 11 (C) Figure 8 2 Figure procedural amendment (method) Relationship between patent applicant Suzuki Motor Co., Ltd. June 29, 1990 (Shipping date: July 31, 1990) 6゜ Name of invention column in the specification subject to amendment

Claims (1)

[Scope of Claims] A pair of left and right tank rail portions having a duct structure and having their tips joined to a head pipe, and a pair of left and right body frame portions extending downward from the rear ends of these tank rail portions; In a motorcycle frame having a pair of left and right down tube sections interposed between a distal end of a tank rail section and a lower end of a body frame section, an air inlet opening opened at a front end of the tank rail section; A bridge member with a duct structure is connected at one end and the other end to the rear ends of the left and right tank rail sections, respectively, and has an air release hole on the bottom surface, and the air introduced from the air inlet is connected to the tank rail. and an air supply hole provided at a joint portion of the bridge member in the left and right tank rails so as to allow air to flow into the bridge member through the air supply hole.