JPH09123972A - Motor cycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a main frame formed into a box shape from coming into contact with the knees of an occupant to decrease air resistance by extending a main frame extending rearwards and downwards from a head pipe so that an upper end may almost direct the upper end of an engine crank case when viewed from side. SOLUTION: A main frame 6, whose front end is welded to a head pipe 7, extends so as to pass above a cylinder 12 from the head pipe 7 and incline rearwards and downwards, and the front part and rear part of a rear end part are fixed on the top of an upper crank case 5 by fixing bolts. Inclining the main frame 6 downwards and rearwards is carried out with the upper end of a tank rail almost directing the upper end of the upper crank case 5 when a vehicle body is viewed from side. A fuel tank 23 is fixed on the top of a tank rail. The tank rail on the left side of the vehicle body is formed so that the end of the vehicle body may not interfere with detaching work of a cassette type transmission.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motorcycle having a structure in which a main frame of a vehicle body frame extends rearward and downward from a head pipe.

[0002]

2. Description of the Related Art Conventionally, as a vehicle body frame of a motorcycle, in order to obtain high rigidity while achieving weight reduction, a main frame extending rearward and downward from a head pipe is formed into a substantially rectangular shape whose longitudinal section is vertically long. There is a box-shaped aluminum alloy made of aluminum alloy. This main frame extends so that the lower edge of the main frame is oriented near the upper end of the crankcase of the engine when the vehicle body is viewed from the side, and the rear arm bracket is joined to the rear end.

[0003]

However, if the main frame is formed in a box shape as described above, the knees of the occupant are likely to hit the upper edge portion of the main frame. Must. When both legs of the occupant are spread in this way, the front projection area is increased by the amount of the knee protruding laterally, and the air resistance is increased.

Conventionally, a concave portion is formed in the main frame in order to prevent the knees of an occupant from hitting the main frame. However, if the recess is formed deep over a wide area, the rigidity of the main frame will be reduced, so that the air resistance cannot be significantly reduced.

The present invention has been made to solve such problems, and an object thereof is to reduce air resistance by preventing a box-shaped main frame from hitting an occupant's knees.

[0006]

In the motorcycle according to the first aspect of the present invention, the main frame is extended so that the upper edge thereof is oriented near the upper end of the crankcase of the engine in a side view. Therefore, since the rear portion of the main frame is positioned close to the crankcase and positioned at a low position, a space above the main frame where the occupant's knees face can be obtained.

A motorcycle according to a second aspect of the present invention is the motorcycle according to the first aspect, wherein the cylinder of the engine is arranged below the main frame in a side view. Therefore, the dimension of the main frame in the vehicle width direction can be made as narrow as possible while avoiding interference with the cylinder.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION

First Embodiment Hereinafter, an example of an embodiment of a motorcycle according to the present invention will be described in detail with reference to FIGS. 1 to 6. FIG. 1 is a side view of a motorcycle according to the present invention, and FIG. 2 is a side view of a main part. In the figure, a footrest part is omitted. 3 is a sectional view taken along line III-III in FIG. 2, FIG. 4 is a side view showing a footrest portion of the motorcycle according to the present invention, and FIG. 5 is a sectional view taken along line VV of the configuration of the shift lever in FIG. 6 is a plan view showing a schematic configuration of a body frame.

In these figures, reference numeral 1 denotes a motorcycle according to this embodiment. This motorcycle 1 has front wheels 2
The engine 4 is arranged between the rear wheel 3 and the rear wheel 3.
A head pipe 7 is connected to the upper crankcase 5 of the vehicle through a main frame 6 described later to support the front fork 8 on the head pipe 7 in a steerable manner.
A rear arm 10 is vertically swingably connected to the upper crankcase 5 via a pivot shaft 9.

The engine 4 is of a water-cooled 4-cycle 4-cylinder type, and a crankcase is formed by the upper crankcase 6 and a lower crankcase 11 closing a lower end opening of the upper crankcase 6. The upper crankcase 5 is configured so that it can be divided in the vertical direction.
The cylinder 12 is attached to. This cylinder 12
The axis is configured to incline forward, and the intake device 13 is connected to the rear surface that faces the upper rear of the vehicle body, and the exhaust pipe 14 is connected to the front surface that directs the lower front. Further, a radiator 15 is arranged between the cylinder 12 and the front wheel 2. The radiator 15 is supported on the main frame 6 by a stay or the like (not shown).

As shown in FIGS. 1 and 2, the intake device 13 has a throttle valve device 13a connected to the upper end of an intake pipe extending right above the cylinder 12 and a fuel injection device 13b.
And the air cleaner 1 which the upper end of the throttle valve device 13a faces
3c and the like. The throttle valve device 13a and the fuel injection device 13b are provided for each cylinder, as shown in FIG.

The exhaust pipe 14 is provided for each cylinder and is assembled under the engine 4. As shown in FIGS. 1 and 2, an exhaust control valve device 14a is provided in this collecting portion. The exhaust control valve device 14a is for enhancing the exhaust efficiency by utilizing the pressure wave of the exhaust, and has a conventionally known structure that increases or decreases the passage cross-sectional area of the exhaust passage for each cylinder according to the engine operating state. Has become.

The upper crankcase 5 has a structure in which the crankshaft 17 is rotatably supported together with the lower crankcase 11, and the cassette type mission 1 is provided at a rear portion thereof.
I am wearing 8. This cassette type mission 18
The upper crankcase 5 is attached to the right side portion of the vehicle body so as to be detachable along the left-right direction of the vehicle body. When the crankshaft 17 drives the drive shaft 18a, the output sprocket 19 on the driven shaft 18b rotates. It has a conventionally known structure. A rear wheel drive chain, designated by reference numeral 20 in FIGS. 1 and 2, is wound around the output sprocket 19.

The lower crankcase 11 has a crank web rotating space formed in the inner front portion thereof, and an oil tank 21 arranged in the inner rear portion thereof. The lubrication device for the engine 4 employs a so-called dry sump lubrication device that pumps oil from the oil tank 21 to the lubricated portion.

As shown in FIG. 6, the main frame 6 has a pair of left and right tank rails 6a, 6a having front ends connected to the head pipe 7, and these tank rails 6
It is formed from a reinforcing member 6b that connects the front end portions of a and 6a. In this embodiment, the tank rail 6a is formed of an aluminum alloy into a box-like shape having a vertically long vertical cross section. Further, the tank rail 6a is bent by pressing so that the portion above the cylinder is projected to the side of the vehicle body. The intake device 13 is faced inside the bent portions of the left and right tank rails 6a, 6a.

When the four throttle valve devices 13a are arranged between the bent parts, the throttle valve devices 13a are arranged near the center in the left-right direction of the vehicle body and the bent parts of the tank rail 6a are arranged. The cam chain (not shown) of the engine 4 is arranged at one end in the left-right direction of the vehicle body, not between the cylinders, so that the amount of protrusion of the vehicle to the side of the vehicle body becomes as small as possible.

Main frame 6 formed as described above
Is welded at its front end to the head pipe 7 and extends from the head pipe 7 so as to incline rearward and downward, passing above the cylinder 12, and fixing the front and rear portions of the rear end to the fixing bolts 22. By the upper crankcase 5
Is fixed at the top of the When inclining the main frame 6 rearward and downward, as shown in FIGS. 1 and 2, when the vehicle body is viewed from the side, the upper edge of the tank rail 6a is directed near the upper end of the upper crankcase 5. Have been to. Then, as shown in FIG. 1, the fuel tank 23 is fixed to the upper portions of the tank rails 6a, 6a. In addition, the tank rail 6a positioned on the left side of the vehicle body
The rear end of the vehicle body is formed as shown by a broken line 6c in FIG. 2 in order to prevent it from interfering with the attachment / detachment work of the cassette type mission.

As shown in FIG. 6, the rear arm 10 includes front arm portions 10a, 1a provided on both sides of the vehicle body in the left-right direction.
0a is pivotally supported on the pivot shaft 9 and, as shown in FIG.
And is connected to the lower end of the cushion unit 26 via a link mechanism 25 pivotally attached to the connecting member 24.
A chain hole 10b is formed in the lower portion of the rear arm 10 for passing the rear wheel drive chain 20.

In the link mechanism 25, a part of the joint is pivotally attached to a bracket 11a integrally formed at an end of the lower crankcase 11 on the rear side of the vehicle body. In this embodiment, the upper end of the cushion unit 26 is fixed to a pair of left and right cushion unit brackets that are fixed to the rear end of the upper crankcase 5 as shown in FIGS. 2 and 6. It is pivoted to 27.

The pivot shaft 9 is, as shown in FIG.
A boss portion 5a formed integrally with a rear end portion of the vehicle body at a lower portion of the upper crankcase 5 is supported while penetrating therethrough. The front arm portions 10a, 10a of the rear arm 10 are rotatably supported by bearings 28 at the portions of the pivot shaft 9 that project from the boss portion 5a. Also, at the shaft end of the pivot shaft 9,
A pair of left and right footrest brackets 30 for supporting the footrest 29 (FIG. 1) are supported.

As shown in FIGS. 1 and 4, the footrest bracket 30 has a holding plate 29a of a footrest 29 attached to the rear end of the vehicle body so as to be supported by the pivot shaft 9 and to the front end of the vehicle body. The parts are fixed to the upper crankcase 5 and the lower crankcase 11. That is, the footrest 29 has the holding plate 29.
a, footrest bracket 30 and pivot shaft 9
It is supported by the crankcase of the engine 4 via the above. Note that the footrest bracket 30 positioned on the left side of the vehicle body has a front end portion of the vehicle body shown in FIG.
It is formed as shown by a chain double-dashed line 30a.

An occupant who is riding with the foot resting on the footrest 29 is indicated by reference character A in FIG. The seat on which the occupant A sits is integrally provided on the rear cowling 31. The rear cowling 31 is supported by the upper crankcase 5 of the engine 4 via a rear cowling frame 32.

The shift pedal operated by the left foot of the occupant A is indicated by reference numeral 33 in FIGS. 4 and 5. The shift pedal 33 is provided on the holding plate 29a of the footrest 29.
It is swingably supported by and is connected to a shift arm 35 of the upper crankcase 5 via a shift rod 34.
In this embodiment, as shown in FIG. 5, the shift rod 34 is inside the vehicle body with respect to the footrest bracket 30 and includes the rear arm 10 and the rear wheel drive chain 20.
It goes through a part that is more outside the vehicle. By adopting this configuration, it is possible to prevent the foot of the occupant from hitting the shift rod 34.

The motorcycle 1 constructed in this way has the main frame 6 extending rearward and downward from the head pipe 7.
When the vehicle body is viewed from the side, the upper edge is the upper crankcase 5
Since it extends so as to be oriented near the upper end of the main frame 6, the rear portion of the main frame 6 approaches the crankcase and is positioned at a low position. Therefore, the occupant A is attached to the motorcycle 1.
When the passenger gets on, the knees of the occupant A come to face above the main frame 6 as shown in FIG.

Further, in this motorcycle 1, the cylinder 12 of the engine 4 is arranged below the main frame 6 when viewed from the side. Therefore, the dimension of the main frame 6 in the vehicle width direction is the same as the cylinder 12. It can be made as narrow as possible while avoiding interference. Therefore, the main frame 6 itself is also positioned inside the vehicle body. With this configuration, the main frame 6 is unlikely to get in the way when the cylinder head 12a (FIGS. 1 and 2) is attached to and detached from the cylinder 12 during maintenance.

Further, in this embodiment, since the rear end portion of the main frame 6 does not extend from the upper portion of the upper crankcase 5 to the rear side of the vehicle body, the side portion of the vehicle body should be disposed so as to avoid the side wall of the upper crankcase 5. No need to bulge. With this configuration, it is possible to prevent the dimension of the main frame 6 in the vehicle width direction from increasing.

Second Embodiment As shown in FIG. 7, the main frame may be configured to support the rear arm. FIG. 7 is a side view showing another embodiment of the main frame, in which the same or equivalent members as those described in FIGS. 1 to 6 are designated by the same reference numerals and detailed description thereof will be omitted.
The buffer mechanism of the rear arm is omitted in FIG. 7 because it has the same structure as in the first embodiment.

In the main frame 6 shown in FIG. 7, the tank rails 6a, 6a are extended to the rear side of the vehicle body from the one shown in the first embodiment, and the upper part of the upper crankcase 5 is seen from the side. Is configured to traverse along the front-rear direction of the vehicle body, and the rear arm 10 is attached to the rear end through the pivot shaft 9.
Is swingably supported. When extending the tank rail 6a, the upper edge of the main frame 6 is oriented near the upper end of the upper crankcase 5 when the vehicle body is viewed from the side, as in the first embodiment. .

The engine 4 used in this embodiment
Since the cassette type mission 18 is removed to the right of the vehicle body, the tank rail 6a positioned on the right side of the vehicle body in the main frame 6 has a portion that covers the lateral side of the cassette type mission 18 from other portions. It has a separable structure.

That is, the tank rail 6 on the right side of the vehicle body
The letter a is formed so as to extend in the front-rear direction of the vehicle body with the connecting member 41 interposed at a portion facing the cassette type transmission 18. The connecting member 41 is fixed to the tank rail constituent members on the front side and the rear side of the vehicle body with connecting bolts 42, and connects the front and rear tank rail constituent members. The tank rail constituent member on the front side of the vehicle body with respect to the connecting member 41 is fixed to the upper crankcase 5 by a fixing bolt 22, and the tank rail constituent member on the rear side of the vehicle body is fixed to the upper crankcase 5 by a fixing bolt 22. The lower part is fixed to the lower crankcase 11 by fixing bolts 43.

In this embodiment, the holding plate 29a of the footrest 29 is supported on the rear end of the main frame 6. The shift rod 24 that connects the shift pedal 33 swingably provided to the holding plate 2a and the shift arm 35 on the crankcase side is inside the vehicle body with respect to the main frame 6 on the left side of the vehicle body and the holding plate 29a, and the rear arm. 10 and the rear wheel drive chain 20 pass through the outside of the vehicle body.

Even with this structure, since the rear portion of the main frame 6 is located at a low position close to the crankcase, a space above the main frame 6 where the knees of the occupant can face is obtained.

[0033]

As described above, in the motorcycle according to the first aspect of the present invention, the main frame is extended so that the upper edge thereof is oriented near the upper end of the crankcase of the engine in a side view, and therefore the rear portion of the main frame is provided. Is located at a low position close to the crankcase, so that a space over which the occupant's knee faces can be obtained above the main frame.

Therefore, the knees of the occupant do not hit the main frame, and the occupant can be positioned inside the vehicle body to reduce the front projected area during traveling and reduce the air resistance.

A motorcycle according to a second aspect of the present invention is the motorcycle according to the first aspect, in which the engine cylinder is arranged below the main frame in a side view.
The dimension of the main frame in the vehicle width direction can be made as narrow as possible while avoiding interference with the cylinder.

Therefore, since the main frame itself is also positioned inside the vehicle body, the front projected area is further reduced and the air resistance is further reduced in combination with the knees of the occupant not protruding laterally of the vehicle body.

[Brief description of the drawings]

FIG. 1 is a side view of a motorcycle according to the present invention.

FIG. 2 is a side view of a main part of the motorcycle according to the present invention.

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is a side view showing a footrest portion of the motorcycle according to the present invention.

5 is a V-V showing the configuration of the shift lever in FIG.
It is a line sectional view.

FIG. 6 is a plan view showing a schematic configuration of a body frame.

FIG. 7 is a side view showing another embodiment of the main frame.

[Explanation of symbols]

4 ... Engine, 5 ... Upper side crankcase, 6 ... Main frame, 7 ... Head pipe, 9 ... Pivot shaft, 10 ... Rear arm, 12 ... Cylinder.

Claims (2)

[Claims] 1. A motorcycle according to claim 1, wherein a main frame extending rearward and downward from the head pipe is provided so that an upper edge thereof is oriented near an upper end of a crankcase of the engine in a side view. 2. The motorcycle according to claim 1, wherein the engine cylinder is arranged below the main frame in a side view.