JP2003237668A - Vehicular body frame for scooter type motorcycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily exchange a pipe member in which engine cooling water flows, and to lower a center gravity position of a vehicular body. <P>SOLUTION: An upper frame 23 extending from a head pipe 21 to a rear end portion of a vehicular body is provided. A lower frame 23 composed of the pipes 51, 52 in which the engine cooling water flows and downwardly extending from the upper frame 23 is provided. The lower frame 24 is detachably attached to the upper frame 23, and a radiator 67 is supported by the lower frame 24. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle body frame of a scooter type motorcycle in which a cooling water passage is formed by a pipe member.

[0002]

2. Description of the Related Art A conventional scooter type motorcycle of this type is disclosed in, for example, Japanese Patent Laid-Open No. 2000-225980. The body frame of a scooter type motorcycle disclosed in this publication is assembled by welding a plurality of pipe members, and engine cooling water flows through a pair of left and right pipe members extending in the front-rear direction of the vehicle body above a footrest plate. Has been done.

This pipe member has front ends welded to the lower ends of a pair of left and right front down tubes extending rearward and downward from the head pipe to above the front side of the footrest plate, and passes above the footrest plate. And extends linearly below the seat. A cooling water inlet and a cooling water outlet of the radiator are connected to the openings at the front ends of these pipe members via a joint. The radiator is disposed between the front wheel and the body frame and is supported by the body frame.

The cooling water outlet of the engine is connected via a cooling water hose to the rear end of the pipe member to which the cooling water inlet of the radiator is connected, and the rear of the pipe member connected to the cooling water outlet of the radiator. The cooling water inlet of the engine is connected to the end portion via a cooling water hose. That is, the engine cooling water is guided from the engine to the radiator through one pipe member, cooled by the radiator, and then returned to the engine through the other pipe member.

Lower pipes extending downward are respectively welded to the pair of left and right pipe members through which the engine cooling water flows. These lower pipes are formed in a mountain shape that protrudes downward when viewed from the side of the vehicle body so that the lowest part is positioned below the footrest plate. The rear upper end is welded to the front end and the rear end of the pipe member. A unit swing type power unit is swingably connected in the vertical direction to the rear end of the lower pipe.

[0006]

In the conventional scooter type motorcycle constructed as described above, since the pipe member through which the engine cooling water flows is welded to another pipe member, it can be used for a long period of time. If corroded by engine cooling water, the entire body frame must be replaced. Further, the pipe member through which the engine cooling water flows has a heavy weight because the inside thereof is always filled with the engine cooling water, and the pipe member is disposed at a relatively high position above the footrest plate. There was also the problem that the position of the center of gravity of the robot would become high.

The present invention has been made in order to solve such a problem. When the pipe member through which the engine cooling water flows is corroded, only the pipe member can be replaced and the center of gravity of the vehicle body is low. An object of the present invention is to provide a body frame of a scooter type motorcycle.

[0008]

In order to achieve this object, a vehicle body frame of a scooter type motorcycle according to the present invention comprises an upper frame extending from a head pipe to a rear end portion of a vehicle body, and the pipe member. A lower frame extending downward from the upper frame, the lower frame being detachably attached to the upper frame, and the radiator being supported by the lower frame.

According to the present invention, when the pipe member (lower frame) is corroded by cooling water, the pipe member can be removed from the upper frame member and replaced. The radiator can be detached from the vehicle body together with the pipe member, and can be detached from the pipe member without being blocked by other members, for example, on a workbench. Further, since the inside is constantly filled with the cooling water, the pipe member having a relatively heavy weight is positioned at a lower position of the vehicle body.

A vehicle body frame for a scooter type motorcycle according to a second aspect of the present invention is the vehicle body frame for a scooter type motorcycle according to the first aspect,
The lower frame is formed in a mountain shape that is convex downward in a side view. According to the present invention, since the lower frame has both end portions in the front-rear direction of the vehicle body higher than the central portion, it is possible to prevent the cooling water from leaking from the both end portions when the lower frame is removed from the upper frame.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a frame of a scooter type motorcycle according to the present invention will be described below with reference to FIGS.
It will be described in detail by. 1 is a side view of a scooter type motorcycle using a frame of a scooter type motorcycle according to the present invention, FIG. 2 is a plan view of a frame according to the present invention, FIG.
Is a side view of the front half of the upper frame, and FIG. 4 is a plan view of the same. 5 is a side view of the rear half of the upper frame, and FIG. 6 is a plan view of the same. FIG. 7 is a side view of the lower frame, and FIG. 8 is a plan view of the same. 9 is a sectional view taken along the line IX-IX of the left down frame in FIG. 3, and FIG. 10 is a sectional view taken along the line XX of the front-rear extension portion on the left side of the vehicle body in FIG.
5 is a sectional view taken along the line XI-XI of the front-rear direction extending portion on the left side of the vehicle body in FIG. 5, and FIG. 12 is a perspective view of the vehicle body frame according to the present invention.

In these drawings, reference numeral 1 indicates a scooter type motorcycle according to this embodiment (hereinafter, simply referred to as a scooter). This scooter 1
The vehicle body frame 2 according to the present invention is used. In FIG. 1, 3 is a front wheel, 4 is a front fork, 5 is a steering handle, 6 is a seat, 7 is a power unit for driving a rear wheel 8, and 9 is a vehicle body cover. The power unit 7 is a unit swing type which is well known in the related art, and an engine 10 and a transmission case 11 are integrally formed to support a rear wheel 8 at a rear end thereof. V-belt type automatic transmission installed inside (not shown)
Power is transmitted from the engine 10 to the rear wheels 8 via the. In FIG. 1, the reference numeral 12 provided above the transmission case 11 is an air cleaner of the engine 10.

The vehicle body frame 2 is an upper frame that extends from a head pipe 21 that rotatably supports the front fork 4 and the steering handle 5 to a rear end portion of the vehicle body, passing under a footrest portion 22 and a seat 6. 23 and a lower frame 24 extending downward from the middle of the upper frame 23. The upper frame 2
3 is made of an aluminum alloy, and the lower frame 24 is made of an iron-based alloy.

The upper frame 23 is the head pipe 2
A front half portion 25 extending from 1 to the footrest portion 22 and a rear half portion 26 welded to the rear end portion of the front half portion 25 and extending to the rear end portion of the vehicle body are separately formed. As shown in FIGS. 3 and 4, the front half portion 25 includes a head pipe 21, a pair of left and right down frames 27 extending rearward and downward from the head pipe 21, and an interposition between the down frames 27. Two cross members 28,
29 and is formed by so-called gravity casting to integrally form the above-mentioned respective parts. The gravity casting is a casting method in which a molten metal is filled in a mold by gravity.

As shown in FIG. 9, the down frame 27 is formed in a box shape having a closed cross section. Further, of the two cross members 28 and 29, the front cross member 28 located on the head pipe 21 side is shown in FIG.
As shown in, the vertical cross section is formed to have a closed shape,
The rear cross member 29 is formed in a V shape in cross section. A mounting seat 30 for mounting a front end portion of a lower frame 24, which will be described later, is provided in the vicinity of the rear cross member 29 in each of the down frames 27, 27.

The rear half 26 of the upper frame 23 is shown in FIG.
As shown in FIG. 6 and FIG. 6, a left front-rear extending portion 31 and a right front-rear extending portion 32 extending in the front-rear direction of the vehicle body at both end portions in the vehicle width direction, and these front-rear extending portions 3 are formed.
1, 32 are composed of first to third cross members 33 to 35 connecting the front end portion, the central portion, and the rear end portion to each other, and are formed by a vacuum die casting method to integrally form the respective portions. Has been done.

The left and right extending portions 31, 32 in the front-rear direction are
The front portion of the power unit 7 is vertically swingably connected to the center portion of the vehicle body in the front-rear direction via brackets 36 and 37 (see FIG. 6) for supporting the power unit, and extends in the front-rear direction on the left side of the vehicle body. The upper end of the rear cushion unit 38 is connected to the rear end of the portion 31. Further, as shown in FIGS. 1 and 5, a bracket 39 for supporting an intermediate portion of the lower frame 24, which will be described later, is provided at the front ends of the front-rear extending portions 31, 32 so as to project downward. ing.

The two brackets 36 and 37 for supporting the power unit are provided so as to extend rearward and downward inside the vehicle body of the longitudinally extending portions 31 and 32. Cylindrical bosses 41 and 4 provided in pairs
2 (see FIG. 5) is elastically supported via a damper rubber (not shown). Further, as shown in FIG. 6, a connecting rod 43 is horizontally provided at the lower end portions of the brackets 36 and 37, and the power unit 7 can be swung in the vertical direction via the connecting rod 43. To support. The connecting portion between the connecting rod 43 and the power unit 7 has a cylindrical boss 44 (see FIG. 2).
And FIG. 6) are provided so as to be separated from each other in the vehicle width direction and located on the same axis line.
4 is passed through the connecting rod 43, and the connecting rod 4
The structure is such that the boss 44 rotates with respect to 3.

The first to third cross members 3 connecting the left front-rear extending portion 31 and the right front-rear extending portion 32.
The first cross member 33 that connects the front end portions of the front-rear direction extending portions 31 and 32 and the second cross member 34 that connects the central portions among the items 3 to 35 accommodate the helmet between them. It is formed so that a possible large storage box (not shown) can be mounted. That is, the rear surface of the first cross member 33 is formed so as to be gradually positioned forward as it goes to the central portion in the vehicle width direction, and the front surface of the second cross member 34 has both ends in the central portion in the vehicle width direction. It is formed so as to be located behind the part. The storage box has a structure similar to that of a conventional scooter, and the opening of the upper end is opened and closed by the seat 6.

As shown in FIG. 12, the third cross member 35 connecting the rear end portions of the left and right extending portions 31 and 32 is formed in a box shape opening upward. In this embodiment, the third cross member 35 is
It is formed to function as a battery storage box for storing a battery (not shown).

The rear half 2 comprising the left and right front and rear extending portions 31 and 32 and the first to third cross members 33 to 35.
6 is molded by using different molds for the front part in the range indicated by the symbol A in FIG. 5 and the rear part in the range indicated by the symbol B in FIG. The front part of the rear half part 26 is formed by a mold that divides in the vehicle width direction, and the rear part is formed by a mold that divides in the vertical direction. For this reason, the front portions of the left and right front-back direction extending portions 31 and 32 are formed in a U shape that opens to the side as shown in FIG. 10, and the rear portions are
As shown in FIG. 11, it is formed in a U-shape that opens downward.

By molding the rear half portion 26 with the dies having different dividing directions in this way, the extending portion 3 in the front-rear direction is formed.
It is possible to improve the lateral rigidity of the front portions of the Nos. 1 and 32 and the longitudinal rigidity of the rear portions. The lateral rigidity of the front portions of the front-rear extending portions 31 and 32 is improved because the front portions are the front half portions 2.
This is because it is connected to the two down frames 27 and 26 of No. 5 and the front portion of the power unit 7 is connected, and a load is mainly applied in the lateral direction during cornering or the like.

The down frame 27 of the front half portion 25 connected to the front portions of the front-rear extending portions 31 and 32 extends rearward and downward, and the down frame 27 causes front ends of the front-rear extending portions 31 and 32. Is firmly supported in the vertical direction, the upper frame 2 having high rigidity in the torsional direction is welded to the front half 25 and the rear half 26 by welding.
3 can be formed. In this embodiment, in order to increase the rigidity in the torsional direction only in the front-rear direction extending portions 31 and 32, inside the U-shape in the front portion having the U-shaped cross section, the X-shape in a side view is formed. The reinforcing rib 45 (see FIGS. 1, 3, 10, and 12) is integrally formed.

The longitudinal rigidity of the rear portions of the front and rear extending portions 31 and 32 is improved because a cushion reaction force is applied from the rear cushion unit 38 to the rear portions. As a result, the allowable value of the cushion reaction force applied from the rear cushion unit 38 to the rear half portion 26 can be increased, so that even if the vehicle weight increases with the increase in size of the vehicle body, the vehicle body can be reliably removed. Can be supported. In this embodiment, vertical walls 47 and 48 are provided so as to form grooves 46 (see FIG. 11) on the upper surfaces of the rear portions of the longitudinally extending portions 31 and 32. The groove 46 can further improve the rigidity in the vertical direction, and the groove 46 can accommodate a cable 49 to be connected to another electric component such as a battery or a tail lamp.

The lower frame 24 is shown in FIGS.
As shown in FIG. 5, a pair of left and right pipes 51 and 52 extending in the front-rear direction below the upper frame 23, and first to fourth cross members 53 to 56 which are laterally bridged between the pipes 51 and 52. It consists of and. As shown in FIG. 7, the pipes 51 and 52 are formed in a mountain shape that is convex downward, and the front end portion is fixed to the front half portion 25 of the upper frame 23 by a fixing bolt 57, and the rear end portions are fixed. The portion is fixed to the rear half portion 26 of the upper frame 23 via a connecting bracket 58. The connecting bracket 58 is formed of a ferrous alloy equivalent to the pipes 51 and 52 in a box shape, the lower end portion is welded to the pipes 51 and 52, and the upper end portion is fixed to the rear half portion 26 by a fixing bolt 59 ( (See FIG. 1).

Further, both pipes 51, 52 are subjected to corrosion resistance treatment on the entire inner surfaces thereof because engine cooling water is flowed therein as described later. This anticorrosion treatment is performed by coating the inner surface of the pipe with a paint for anticorrosion or by plating. A front end portion of a lower portion of each of the pipes 51 and 52 extending in the front-rear direction is provided so that the connecting plate 60 extends upward.
A bracket 39 provided so as to extend downward at the front end of the rear half portion 26 and a fixing bolt 61 as shown in FIG.
It is supported by the upper frame 23 by being fastened.

Further, the left and right pipes 51 and 52 are provided with stays 62 to 64 for supporting the lower portion of the vehicle body cover 9,
The side stand supporting stay 65 and the like are welded, and as shown in FIG. 7, a radiator 67 is attached via a bracket 66. The stays 62 to 6
5 is also made of an iron-based alloy that is equivalent to the pipes 51 and 52, and by supporting the side stand (not shown) on the side stand supporting stay 65, it is possible to reduce wear resistance and impact resistance. Absent.

As shown in FIGS. 1 and 7, the radiator 67 is disposed below the front end portion of the pipes 51, 52 extending rearward and downward, and is inclined so as to be directed forward and upward. By inclining the radiator 67 in this manner, the traveling wind whose flow direction is changed by hitting the front surface 25a of the front half portion 25 of the upper frame 23 (an inclined surface inclined rearward and downward) flows into the radiator 67.
Therefore, the cooling efficiency of the radiator 67 can be improved.

Further, the radiator 67 is of a lateral water flow type similar to that well known in the prior art, and as shown in FIG. 8, it is below the pipes 51 and 52 in the vehicle width direction as seen from above. The size is such that the cooling water tanks 67a, 67b at both ends are located. Both tanks 67
The cooling water passages connecting the a and 67b to the engine are formed by the pipes 51 and 52 of the lower frame 24 and the cooling water hoses 68 to 71 which will be described later and are connected to these pipes.

That is, in the vehicle body frame 2, the front ends of the pipes 51 and 52 are the front side cooling water hoses 68 and 6.
9 is connected to both tanks 67a and 67b of the radiator 67, and the rear ends of both pipes 51 and 52 are connected to the cooling water inlet / cooling water outlet of the engine 10 by rear side cooling water hoses 70 and 71. Each cooling water hose 68-
71 and the pipes 51, 52 are connected by the pipes 51, 52.
A hose joint (not shown) is welded to and is performed through this joint.

The cooling water system of the engine 10 is the engine 10
The relatively high temperature cooling water flowing out of the radiator 67 is guided to the radiator 67 through the pipe 52 on the right side of the vehicle body, and the cooling water cooled by the radiator 67 is guided to the engine 10 through the pipe 51 on the left side of the vehicle body. Both pipes 5
1, 52 are provided with plug members 72 (see FIG. 7) in the vicinity of the portions connecting the cooling water hoses 68 to 71 so that the cooling water does not leak from the openings at both ends or the bolt holes. .

The plug member 72 has a structure in which the cylindrical sealing rubber fitted in the pipes 51 and 52 is expanded by a bolt provided in the shaft center portion. The bolt is operated by a tool inserted into the pipe through openings at both ends of both pipes 51 and 52. In addition,
When the openings at both ends of both pipes 51 and 52 are closed by a lid member or the like, the plug member 72 is unnecessary. In the case of adopting this structure, a pipe penetrating the pipes 51 and 52 is provided so that the cooling water does not leak from the penetrating portion of the bolt 57 that fixes the front ends of the pipes 51 and 52 to the upper frame 23. Without inserting the bolt 57 into the pipe or using the bolt 57, the pipe 51,
It is also possible to adopt a structure in which the outer peripheral portion of 52 is clamped and fastened to the upper frame 23.

Both pipes 51, 5 of the lower frame 24
First to fourth cross members 53 to 5 that connect the two together
Of the six, the first to third cross members 53 to 55 are formed of steel plates, and the fourth cross member 56 is formed of a pipe. Also, the third cross member 5
As shown in FIG. 8, 5 is formed in an X shape in a plan view, and is welded to both pipes 51 and 52 at four positions, front, rear, left and right. A fuel tank 73 is supported by the third cross member 55 as shown in FIG. The fuel tank 73 is housed in a space above the third cross member 55 and formed between the fuel tank 73 and the housing box. Lower frame 24 made of iron-based alloy
Since the fuel tank 73 is mounted on the lower end of the fuel tank 73, the fuel tank 73 can be firmly protected by the lower frame 24.

The fourth cross member 56 is formed in a mountain shape protruding downward as viewed from the rear of the vehicle body, and a main stand bracket 74 is welded to the central portion in the vehicle width direction. The bracket 74 is also made of an iron-based alloy, and the main stand (not shown) attached to the bracket 74 can firmly support the vehicle body, and the abrasion resistance of the portion pivotally supporting the main stand can be improved. Can be improved.

In order to manufacture the vehicle body frame 2 constructed as described above, first, the front half portion 25 and the rear half portion 26 of the upper frame 23 are molded by a mold, respectively.
The front and rear extending portions 31, 32 of the rear half portion 26 are welded to the down frame 27 of the front half portion 25. At the same time, the lower frame 24 is assembled, and the stays and brackets are welded to the lower frame 24. Also, at this time,
The radiator 67 and the fuel tank 73 are attached to the lower frame 24.

The power unit 7 is connected to the lower frame 24 via cooling water hoses 68 to 71, a fuel hose (not shown), etc. to form an assembly consisting of the lower frame 24 and the power unit 7. . Next, the lower frame 24 is attached to the upper frame 23 with the fixing bolts 57, 59, 61, and the power unit 7 is attached with the power unit supporting brackets 36, 37. In addition, the rear end of the power unit 7 and the upper frame 23
A rear cushion unit 38 is provided between the rear cushion unit 38 and the rear end portion.

In the scooter 1 using the vehicle body frame 2 assembled in this way, engine cooling water circulates through the pipes 51 and 52 of the lower frame 24 during engine operation. The pipes 51 and 52 are made of an iron-based alloy, and when the scooter 1 is used for a long period of time, it may be corroded by engine cooling water. When the pipes 51 and 52 corrode in this way,
The lower frame 24 can be replaced with a new one by loosening the fixing bolts 57 and 59 and removing the lower frame 24 from the upper frame 23.

At the time of replacement, the radiator 67 is removed from the vehicle body together with the lower frame 24, and may be blocked by other members by placing the lower frame 24 on a workbench (not shown), for example. It can be removed from the lower frame 24 without it. Therefore, it becomes easy to remove the radiator 67 from the lower frame 24 during the replacement. Further, since the radiator 67 is supported by the lower frame 24, an assembly formed by attaching the radiator 67 to the lower frame 24 is used as the upper frame 2.
The radiator 67 can be attached to the vehicle body frame 2 by attaching the radiator 67 to the vehicle body frame 2.

Since the lower frame 24 of the vehicle body frame 2 is constantly filled with cooling water, the relatively heavy pipes 51 and 52 are positioned at a lower position of the vehicle body. By using 2, the center of gravity of the scooter 1 can be positioned low. Particularly, in the vehicle body frame 2 according to this embodiment, the upper frame 23 is made of aluminum alloy, and the weight of the upper portion of the vehicle body frame is reduced as compared with the conventional one, so that the center of gravity can be remarkably lowered. By using the vehicle body frame 2, traveling stability is further improved.

Further, in this vehicle body frame 2, since the lower frame 24 is formed in a mountain shape which is convex downward in a side view, both end portions of the lower frame 24 in the front-rear direction of the vehicle body are closer to the central portion. Get higher Therefore, even if the engine cooling water leaks to the outside through the space between the plug member 72 and the pipes 51 and 52, the lower frame 24
It is possible to prevent engine cooling water from leaking from both ends when the engine is removed from the upper frame 24.

[0041]

As described above, according to the present invention, when the pipe member is corroded by the cooling water, the pipe member can be removed from the upper frame and replaced, so that the maintenance cost can be reduced. be able to. Further, since the radiator is also removed from the vehicle body together with the pipe member, and the radiator can be removed from the pipe member without being blocked by other members, for example, on a workbench, the above-described replacement work is easy. become.

Further, since the pipe member, which is relatively heavy, is positioned at a lower position of the vehicle body because the inside is constantly filled with cooling water, the scooter-type automatic vehicle having a low center of gravity position is used by using this vehicle body frame. Motorcycles can be manufactured.

According to the second aspect of the invention, it is possible to prevent the cooling water from leaking from both ends of the lower frame with the lower frame removed from the upper frame.
The replacement work can be performed more easily.

[Brief description of drawings]

FIG. 1 is a side view of a scooter type motorcycle using a frame of the scooter type motorcycle according to the present invention.

FIG. 2 is a plan view of a frame according to the present invention.

FIG. 3 is a side view of a front half of the upper frame.

FIG. 4 is a plan view of the front half of the upper frame.

FIG. 5 is a side view of the rear half of the upper frame.

FIG. 6 is a plan view of the rear half of the upper frame.

FIG. 7 is a side view of the lower frame.

FIG. 8 is a plan view of a lower frame.

9 is a sectional view taken along line IX-IX of the left down frame in FIG.

FIG. 10 shows a front-rear extending portion on the left side of the vehicle body in FIG.
It is a XX sectional view.

FIG. 11 shows a front-rear extending portion on the left side of the vehicle body in FIG.
It is a XI-XI line sectional view.

FIG. 12 is a perspective view of a vehicle body frame according to the present invention.

[Explanation of symbols]

1 ... scooter, 2 ... vehicle body frame, 7 ... power unit,
10 ... Engine, 21 ... Head pipe, 23 ... Upper frame, 24 ... Lower frame, 51, 52 ... Pipe, 67
… Radiators, 68-71… Cooling water hoses.

Claims (2)

[Claims] 1. A vehicle body frame of a scooter type motorcycle in which a cooling water passage is formed by a pipe member, and an upper frame extending from a head pipe to a rear end portion of the vehicle body.
A lower frame configured by the pipe member and extending downward from the upper frame, and the lower frame is detachably attached to the upper frame,
A body frame of a scooter type motorcycle in which a radiator is supported by the lower frame. 2. The vehicle body frame of the scooter type motorcycle according to claim 1, wherein the lower frame is formed in a mountain shape that is convex downward in a side view.