JP3691559B2 - Motorcycle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a motorcycle having a structure in which a main frame of a body frame extends rearwardly downward from a head pipe.
[0002]
[Prior art]
Conventionally, as a 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 in a box shape in which the shape of the longitudinal section becomes a substantially rectangular shape in the vertical direction. Some of them are made of an aluminum alloy. The main frame extends so that the lower edge is directed to the vicinity of the upper end of the crankcase of the engine when the vehicle body is viewed from the side, and a rear arm bracket is coupled to the rear end.
[0003]
[Problems to be solved by the invention]
However, if the main frame is formed in a box shape as described above, it is easy for the occupant's knees to hit the upper edge, so the occupant must get on with both legs slightly extended. If the occupant's legs are spread in this manner, the front projection area is increased by the amount that the knee protrudes to the side, and the air resistance increases.
[0004]
Conventionally, in order to prevent the occupant's knees from hitting the main frame, a recess is formed in the main frame. However, if the concave portion is formed deeply over a wide area, the rigidity of the main frame is lowered, so that the air resistance cannot be significantly reduced.
[0005]
The present invention has been made to solve such problems, and an object of the present invention is to reduce air resistance by preventing a main frame formed in a box shape from hitting an occupant's knee.
[0006]
[Means for Solving the Problems]
A motorcycle according to a first aspect of the present invention is a motorcycle including a head pipe, a main frame extending rearwardly from the head pipe, an engine having a crankcase and a cylinder, and a footrest , wherein the main frame is The footrest is extended to face the upper surface of the crankcase in a side view and fixed to the upper end of the crankcase, and the footrest is supported by the crankcase via a footrest bracket and a holding plate, and the footrest The upper end edge of the bracket for use is formed so as to follow an extension line extending rearward from the upper end surface of the main frame in a side view.
Therefore, the rear part of the main frame is positioned at a low position close to the crankcase, so that a space where the occupant's knees face can be obtained above the main frame.
[0007]
The motorcycle according to the second invention is the motorcycle according to the first invention, wherein the cylinder of the engine is disposed below the main frame in a side view.
Therefore, the dimension of the main frame in the vehicle width direction can be reduced as much as possible while avoiding interference with the cylinder.
A motorcycle according to a third aspect of the invention is a motorcycle including a head pipe, a main frame extending rearwardly from the head pipe, an engine having a crankcase and a cylinder, and a footrest, wherein the main frame is And extending to face the upper surface of the crankcase in a side view and fixed to the upper end of the crankcase, and the footrest is supported by the main frame via a holding plate, and the upper edge of the holding plate Is formed along an extension line extending rearward from the upper end surface of the main frame in a side view.
Therefore, the rear part of the main frame is positioned at a low position close to the crankcase, so that a space where the occupant's knees face can be obtained above the main frame.
[0008]
DETAILED DESCRIPTION OF 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.
FIG. 1 is a side view of a motorcycle according to the present invention, FIG. 2 is a side view of an essential part, and the figure is drawn with a footrest part omitted. 3 is a sectional view taken along the line III-III in FIG. 2, FIG. 4 is a side view showing the footrest portion of the motorcycle according to the present invention, and FIG. 5 is a sectional view taken along the line V-V showing the structure of the shift lever in FIG. 6 is a plan view showing a schematic configuration of the body frame.
[0009]
In these drawings, reference numeral 1 denotes a motorcycle according to this embodiment. In the motorcycle 1, an engine 4 is disposed between a front wheel 2 and a rear wheel 3, and a head pipe 7 is connected to an upper crankcase 5 of the engine 4 via a main frame 6 described later. The front fork 8 is supported in a steerable manner, and the rear arm 10 is connected to the upper crankcase 5 via a pivot shaft 9 so as to be swingable in the vertical direction.
[0010]
The engine 4 is of a water-cooled 4-cycle 4-cylinder, and the upper crankcase 5 and the crankcase, in the vertical direction formed by the lower crankcase 11 for closing the lower end opening of the upper crankcase 5 The cylinder 12 is attached to the upper crankcase 5 so as to be divided. The cylinder 12 is configured such that its axis is inclined forward, and an intake device 13 is connected to a rear surface directed toward the rear upper side of the vehicle body, and an exhaust pipe 14 is connected to a front surface directed toward the lower front side. Further, a radiator 15 is disposed between the cylinder 12 and the front wheel 2. The radiator 15 is supported on the main frame 6 by a stay (not shown).
[0011]
As shown in FIGS. 1 and 2, the intake device 13 includes a throttle valve device 13a connected to an upper end of an intake pipe extending right above the cylinder 12, a fuel injection device 13b, and an upper end of the throttle valve device 13a. It consists of an air cleaner 13c that faces it. As shown in FIG. 6, the throttle valve device 13a and the fuel injection device 13b are provided for each cylinder.
[0012]
The exhaust pipe 14 is provided for each cylinder and is gathered below the engine 4. As shown in FIG. 1 and FIG. 2, an exhaust control valve device 14a is provided in this assembly portion. The exhaust control valve device 14a is for increasing the exhaust efficiency by utilizing the pressure wave of the exhaust, and has a conventionally known structure that increases or decreases the cross-sectional area of the exhaust passage for each cylinder according to the engine operating state. It has become.
[0013]
The upper crankcase 5 is structured to rotatably support the crankshaft 17 together with the lower crankcase 11, and a cassette type mission 18 is mounted on the rear part. This cassette type transmission 18 is attached to the right side of the vehicle body in the upper crankcase 5 so as to be detachable along the left-right direction of the vehicle body, and the crankshaft 17 drives the drive shaft 18a so that the driven shaft 18b The output sprocket 19 has a conventionally well-known structure. The output sprocket 19 is wound with a rear wheel drive chain indicated by reference numeral 20 in FIGS. 1 and 2.
[0014]
The lower crankcase 11 has a crank web rotation space at the inner front and an oil tank 21 at the inner rear. The engine 4 employs a so-called dry sump type lubrication device that pumps oil from the oil tank 21 to a portion to be lubricated.
[0015]
As shown in FIG. 6, the main frame 6 includes a pair of left and right tank rails 6a and 6a having a front end coupled to the head pipe 7, and a reinforcing member 6b that connects the front end portions of the tank rails 6a and 6a. And formed from. In this embodiment, the tank rail 6a is formed in a box shape whose longitudinal section is a rectangle that is long in the vertical direction by an aluminum alloy. Further, the tank rail 6a is bent so that a portion above the cylinder protrudes to the side of the vehicle body by pressing. The intake device 13 faces the bent portions of the left and right tank rails 6a, 6a.
[0016]
When the four throttle valve devices 13a are arranged between the bent portions, these throttle valve devices 13a are arranged near the center in the left-right direction of the vehicle body, and the vehicle rail side of the bent portion of the tank rail 6a. 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 in the direction becomes as small as possible.
[0017]
The main frame 6 formed as described above has a front end welded to the head pipe 7 and extends from the head pipe 7 so as to incline rearwardly downward from above the cylinder 12 to the front side of the rear end portion. The part and the rear part are fixed to the upper part of the upper crankcase 5 by fixing bolts 22. In tilting the main frame 6 downward, as shown in FIGS. 1 and 2, the upper edge of the tank rail 6a is directed near the upper end of the upper crankcase 5 when the vehicle body is viewed from the side. Is going to. And the fuel tank 23 is being fixed to the upper part of the tank rails 6a and 6a as shown in FIG. The tank rail 6a positioned on the left side of the vehicle body is formed with an end portion on the rear side of the vehicle body as shown by a broken line 6c in FIG. 2 in order to prevent it from interfering with the detaching operation of the cassette type transmission. .
[0018]
As shown in FIG. 6, the rear arm 10 has front arm portions 10a, 10a provided on both sides in the left-right direction of the vehicle body pivotally supported by the pivot shaft 9, and as shown in FIG. It is connected to the lower end portion of the cushion unit 26 via a protruding connecting member 24 and a link mechanism 25 pivotally attached to the connecting member 24. In addition, a chain hole 10b through which the rear wheel drive chain 20 is passed is provided in the lower portion of the rear arm 10.
[0019]
In the link mechanism 25, a part of a node is also pivotally attached to a bracket 11a formed integrally with the end of the lower crankcase 11 on the rear side of the vehicle body. Further, in this embodiment, as shown in FIGS. 2 and 6, the upper end portion of the cushion unit 26 is a pair of left and right cushion unit brackets fixed to the end of the upper crankcase 5 on the rear side of the vehicle body. 27 is pivotally supported.
[0020]
As shown in FIG. 3, the pivot shaft 9 is supported by a boss portion 5 a formed integrally with an end portion on the rear side of the vehicle body at the lower portion of the upper crankcase 5 so as to penetrate therethrough. Then, the front arm portions 10a and 10a of the rear arm 10 are rotatably supported via bearings 28 at portions of the pivot shaft 9 protruding from the boss portion 5a. Further, a pair of left and right footrest brackets 30 for supporting the footrest 29 (FIG. 1) is supported at the shaft end portion of the pivot shaft 9.
[0021]
As shown in FIGS. 1 and 4, the footrest bracket 30 has a holding plate 29a for the footrest 29 attached to an end portion on the rear side of the vehicle body, and is supported by the pivot shaft 9 and has an end portion on the front side of the vehicle body on the upper side. It is fixed to the crankcase 5 and the lower crankcase 11. That is, the footrest 29 is supported by the crankcase of the engine 4 through the holding plate 29a, the footrest bracket 30, the pivot shaft 9, and the like. In addition, the footrest bracket 30 positioned on the right side of the vehicle body is formed with an end portion on the front side of the vehicle body as shown by a two-dot chain line 30a in FIG. 2 in order to prevent it from interfering with the detaching operation of the cassette type mission. ing.
[0022]
An occupant in a state of getting on the footrest 29 with his / her foot on is indicated by a symbol A in FIG. The seat on which the occupant A is seated is provided integrally with 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.
[0023]
A shift pedal operated by the left foot of the occupant A is denoted by reference numeral 33 in FIGS. The shift pedal 33 is swingably supported by the holding plate 29 a of the footrest 29 and is connected to the 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 passes through a portion on the inner side of the footrest bracket 30 and on the outer side of the rear arm 10 and the rear wheel drive chain 20. By adopting this configuration, it is possible to prevent the occupant's feet from hitting the shift rod 34.
[0024]
In the motorcycle 1 configured as described above, the main frame 6 extending rearward and downward from the head pipe 7 is extended so that the upper edge is directed to the vicinity of the upper end of the upper crankcase 5 when the vehicle body is viewed from the side. The rear part of the main frame 6 approaches the crankcase and is positioned at a low position.
Therefore, when the occupant A gets on the motorcycle 1, the lap of the occupant A faces the upper side of the main frame 6 as shown in FIG.
[0025]
Further, in the motorcycle 1, since the cylinder 12 of the engine 4 is disposed below the main frame 6 when viewed from the side, the dimension of the main frame 6 in the vehicle width direction is avoided from interference with the cylinder 12. While narrowing as much as possible. For this reason, the main frame 6 itself is also positioned inside the vehicle body. If this configuration is adopted, the main frame 6 is unlikely to become an obstacle when the cylinder head 12a (FIGS. 1 and 2) is attached to and detached from the cylinder 12 during maintenance.
[0026]
Further, in this embodiment, since the rear end portion of the main frame 6 does not extend from the upper part of the upper crankcase 5 to the rear side of the vehicle body, the main frame 6 bulges to the side of the vehicle body so as to avoid the side wall of the upper crankcase 5. You don't have to. This configuration can also prevent the size of the main frame 6 in the vehicle width direction from increasing.
[0027]
Second Embodiment The main frame can also be configured to support the rear arm, as shown in FIG.
FIG. 7 is a side view showing another embodiment of the main frame. In FIG. 7, the same or equivalent members as those described in FIGS. 1 to 6 are given the same reference numerals, and detailed description thereof is omitted. The rear arm buffer mechanism has the same configuration as that of the first embodiment, and is omitted in FIG.
[0028]
The main frame 6 shown in FIG. 7 has tank rails 6a, 6a extending from the rear side of the vehicle body as shown in the first embodiment, and the upper part of the upper crankcase 5 is attached to the vehicle body when viewed from the side. The rear arm 10 is swingably supported at the rear end portion via a pivot shaft 9 so as to cross the longitudinal direction. When the tank rail 6a is extended, the upper edge of the main frame 6 is directed to the vicinity of the upper end of the upper crankcase 5 when the vehicle body is viewed from the side, as in the first embodiment. .
[0029]
Since the engine 4 used in this embodiment is also configured to remove the cassette type mission 18 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 The part covering the side is structured to be separable from other parts.
[0030]
That is, the tank rail 6a on the right side of the vehicle body 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 mission 18. The connecting member 41 is fixed to the tank rail constituent members on the front side of the vehicle body and the rear side of the vehicle body by connecting bolts 42 so as to connect the front and rear tank rail constituent members. The tank rail constituting member on the front side of the vehicle body from the connecting member 41 is fixed to the upper crankcase 5 by the fixing bolt 22, and the tank rail constituting member on the rear side of the vehicle body is fixed to the upper crankcase 5 by the fixing bolt 22. The lower part is fixed to the lower crankcase 11 with fixing bolts 43.
[0031]
In this embodiment, the holding plate 29a of the footrest 29 is supported at the rear end portion of the main frame 6. A shift rod 24 that connects a shift pedal 33 provided on the holding plate 2a so as to be swingable and a shift arm 35 on the crankcase side is located on the inner side of the main frame 6 on the left side of the vehicle body and the holding plate 29a. 10 and the rear wheel drive chain 20 pass through the outside of the vehicle body .
[0032]
Even if configured in this manner, the rear portion of the main frame 6 approaches the crankcase and is positioned at a low position, so that a space where the occupant's knees face above the main frame 6 is obtained.
[0033]
【The invention's effect】
As described above, the motorcycle according to the first invention is a motorcycle including a head pipe, a main frame extending rearwardly downward from the head pipe, an engine having a crankcase and a cylinder, and a footrest. The main frame is extended to face the upper surface of the crankcase in a side view and fixed to the upper end of the crankcase, and the footrest is connected to the crankcase via a footrest bracket and a holding plate. Since the upper end edge of the bracket for the footrest is formed to extend along the extension line extending rearward from the upper end surface of the main frame in a side view, the rear part of the main frame is close to the crankcase and is low Because it ’s positioned above the mainframe. Space facing the members of the knee can be obtained.
[0034]
Therefore, the occupant's knees do not hit the main frame and are positioned on the inner side of the vehicle body, so that the front projection area during travel is reduced and the air resistance is reduced.
[0035]
The motorcycle according to the second invention is the motorcycle according to the first invention, wherein the cylinder of the engine is arranged below the main frame in a side view, so that the dimension of the main frame in the vehicle width direction is avoided from interference with the cylinder. While narrowing as much as possible.
[0036]
For this reason, since the main frame itself is also positioned inside the vehicle body, coupled with the fact that the occupant's knees do not protrude to the side of the vehicle body, the front projection area is further reduced and the air resistance is further reduced.
A motorcycle according to a third aspect of the invention is a motorcycle including a head pipe, a main frame extending rearwardly from the head pipe, an engine having a crankcase and a cylinder, and a footrest, wherein the main frame is And extending to face the upper surface of the crankcase in a side view and fixed to the upper end of the crankcase, and the footrest is supported by the main frame via a holding plate, and the upper edge of the holding plate Is formed along an extension line extending rearward from the upper end surface of the main frame in a side view, and the rear portion of the main frame is positioned at a low position close to the crankcase. A space where the occupant's knees face upward is obtained.
[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 cross-sectional view taken along line III-III in FIG.
Fig. 4 is a side view showing a footrest portion of the motorcycle according to the present invention.
5 is a cross-sectional view taken along line VV showing the configuration of the shift lever in FIG. 4. FIG.
FIG. 6 is a plan view showing a schematic configuration of a vehicle body frame.
FIG. 7 is a side view showing another embodiment of the main frame.
[Explanation of symbols]
4 ... Engine, 5 ... Upper crankcase, 6 ... Main frame, 7 ... Head pipe, 9 ... Pivot shaft, 10 ... Rear arm, 12 ... Cylinder.

Claims (3)

A motorcycle including a head pipe, a main frame extending rearwardly downward from the head pipe, an engine having a crank case and a cylinder, and a footrest , wherein the main frame has a top surface of the crank case in a side view. And the footrest is supported on the crankcase via a footrest bracket and a holding plate, and the upper end edge of the footrest bracket is seen in a side view. The motorcycle according to claim 1, wherein the motorcycle is formed along an extension line extending rearward from an upper end surface of the main frame.   2. The motorcycle according to claim 1, wherein the cylinder of the engine is disposed below the main frame in a side view. A motorcycle including a head pipe, a main frame extending rearwardly downward from the head pipe, an engine having a crank case and a cylinder, and a footrest, wherein the main frame has a top surface of the crank case in a side view. And the footrest is supported by the main frame via a holding plate, and the upper end edge of the holding plate is located above the main frame in a side view. A motorcycle characterized by being formed so as to extend along an extended line with an end face extending backward.

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