Front structure of motorcycle

A load receiving pipe extends from a separate frame and has a closed portion at the extremity thereof. A meter unit is disposed immediately behind the closed portion. Accordingly, the meter unit can be accommodated in a limited space in front of a handle post cover and behind the load receiving pipe, and the probability that a load on the load receiving pipe comes into contact with the meter unit can be avoided. Therefore, the appearance of the front portion of a vehicle body can be improved while improving the load receiving capacity at the front of the vehicle body.

CROSS-REFERENCE TO RELATED APPLICATIONS

This nonprovisional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 2003-195663, filed in Japan on Jul. 11, 2003, the entirety of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an improvement of a front structure of a motorcycle.

2. Description of Background Art

In the background art, various types of motorcycles are in practical use. For example, Japanese Utility Model Application Laid-open No. Sho. 59-42771 discloses a motorcycle according to the background art. Referring toFIG. 10of the present invention,FIG. 1of the JP 59-42771 document is reproduced.FIG. 10of the present invention illustrates a motorcycle1including an exposed head pipe2. A meter unit (not identified by a reference numeral) is disposed upwardly of the head pipe2. A main frame21is supported by a lower supporting arm24and an upper supporting arm26extending from the vehicle body frame at a front thereof. Supporting the main frame21in this manner allows a load to be supported by the main frame21.

However, in a mid-sized motorcycle or larger, the situation occurs where the meter unit is disposed forwardly of the head pipe, and not above the head pipe, due to the position of the rider. In order to dispose the meter unit forward in this manner, it is necessary to avoid interference between the main frame21and the meter unit.

However, when providing an additional guard member to avoid interference, an increase in the number of components occurs, and maintaining the appearance of the motorcycle must be taken into account. While covering the exposed head pipe with a cover in order to improve the appearance is possible, there is a limit in the external shape or layout of the main frame or the meter unit.

SUMMARY OF THE INVENTION

It is an object of the present invention to ensure a sufficient loading capacity, to dispose a meter unit at an optimal position, and to improve the appearance of a motorcycle in which a load can be placed at the front thereof.

In order to achieve the above described object, a first aspect of the present invention is directed to a front structure of a motorcycle including a head pipe at the front of a vehicle body frame, which is covered by a handle post cover. A closed portion of a separate frame of substantially U-shape in plan view protrudes forward from the vehicle body frame. A load receiving pipe of inverted U-shape in front view extends upward from the separate frame along the front surface of the handle post cover. Furthermore, the closed portion of the load receiving pipe passes around the front portion of a meter unit.

The appearance can be improved by covering the head pipe with the handle post cover. The appearance can be improved by integrating the load receiving pipe with the separate frame, and forming the separate frame and the load receiving pipe into a substantially U-shape so that the integrated member is formed into a combination of a straight line and a curved line.

By passing the load receiving pipe around the front portion of the meter unit, the probability that the load comes into contact with the meter unit can be avoided. Therefore, according to the first aspect of the present invention, the appearance of the front portion of the vehicle body can be improved while improving the load receiving capacity of the front portion of the vehicle body.

According to a second aspect of the present invention, the closed portion of the inverted U-shaped load receiving pipe is bent frontward of the vehicle body so as to pass around the front portion of the meter unit, so that the load receiving pipe and the front portion of the separate frame form an angular C-shape in side view.

A load may be placed on the portion of the angular C-shape in side view formed by the load receiving pipe and the front portion of the separate frame. Since it is formed into an angular C-shape, a cord or a rope for fixing the load can easily be tied. In addition, downward movement of the load can be received by the separate frame, and lifting or the rearward movement of the load can be received by the load receiving pipe.

According to a third aspect of the present invention, the front surface of the handle post cover is a flat surface extending along a lower leg, which constitutes the lower portion of the load receiving pipe. By forming the front surface of the handle post cover into a flat surface, the load can be received with a surface together with the load receiving pipe.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the attached drawings, an embodiment of the present invention will be described. The drawings are to be viewed so that the reference numerals are oriented in an upright manner.

In the present embodiment, a low-deck vehicle is described, taking a scooter-type vehicle as an example. However, it should be noted that the low-deck vehicle according to the present invention may be a two, three or four wheel vehicle. Specifically, the low deck vehicle may be of any type, as long as a front wheel and a rear wheel are provided at the front and the rear of a vehicle body frame, and a main frame of the vehicle body frame, which extends rearward from a head pipe, is formed into a V- or U-shape in side view, so that the rider can easily straddle the main frame.

FIG. 1is a side view of a scooter-type vehicle according to the present invention. A scooter-type vehicle10is basically constructed by steerably attaching a steering handle13to a head pipe12at the front of a vehicle body frame11, and mounting a front wheel15and a front fender16to a front fork14connected to the steering handle13.

The scooter-type vehicle is a light-weight, two-seater vehicle including a separate frame18attached to the vehicle body frame11. A head lamp19and turn signal lamps21are mounted to the separate frame18. Steps22are mounted to down tubes17. A power unit23is mounted at the rear of the vehicle body frame11so as to be capable of vertical swinging motion. A rear wheel24is mounted at the rear of the power unit23. A rider's seat25is provided forwardly and obliquely upwardly of the rear wheel24. Furthermore, a passenger's seat26, which also serves as a seat back, is provided above the rear wheel24.

Reference numeral27in the drawing designates a handle post cover, reference numeral28designates a side cover, reference numeral29designates a rear cushion, reference numeral31designates a stand, and reference numeral32designates a grab rail.

FIG. 2is a side view of the scooter-type vehicle according to the present invention, which is modified into a single-seat mode. Since the basic structure is the same asFIG. 1, a description of the elements that are in common withFIG. 1will be omitted.FIG. 2illustrates the passenger's seat26, which serves as the seat back, moved to the upright position to form a backrest for a rider M, i.e., modified into a seatback.FIG. 2also illustrates that a load33such as a tent is placed at the front of the separate frame18. InFIG. 2, reference numeral87designates a rear load-carrying platform, and reference numeral132designates an air cleaner. In addition, the steering handle13, the grab rails32, the separate frame18, the down tube17, a lower pipe34and a rear frame35extending from the down tube17are exposed.

In the scooter-type vehicle in the background art, normally, the vehicle body frame is covered by the vehicle body cover, and most of the parts of the vehicle body frame are not exposed. In contrast, according to the present invention, most of the parts of the vehicle body frame are exposed so that an unnatural appearance is demonstrated.

FIG. 3is an exploded view of the vehicle body frame of the scooter-type vehicle according to the present invention. The vehicle body frame11includes a main frame43extending from the head pipe12and formed into the V- or U-shape in side view. A rear frame35constitutes the rear portion of the main frame43and extends rearward. A down tube17extends downward from the head pipe12. A lower pipe34extends substantially horizontally from the down tube17. A center frame44extends upward from the rear end of the lower pipe34. Furthermore, a stay45connects the center frame44and the rear frame35. The lower pipe34is provided with cover securing plates46,46.

The separate frame18illustrated inFIG. 3has a simple structure. The separate frame18will be described below. In addition, the vehicle body frame11will be described below in conjunction withFIG. 7.

The separate frame18includes a load receiving pipe47provided on the upper surface of the front portion thereof. A lamp supporting bracket48and a loading hook49are provided on the lower surface of the front portion of the frame18. Cover securing plates51,51are provided on the lower surface of the frame18. A bracket53is provided on the upper surface of the front portion of the frame18. The bracket53includes holes52,52formed therethrough. Furthermore, a U-shaped bracket54is provided on the lower surface of the rear portion of the frame18.

On the other hand, the head pipe12includes a front plate57on the front surface thereof. The front plate57has holes56,56formed therethrough. In addition, the rear frame35includes a rear plate59on the upper surface of the front portion thereof. The rear plate59has a hole58formed therethrough.

The rear plate59is disposed in the vicinity of a joint55between the main frame43and the rear frame35. The joint55is a portion where the one main frame43and the two rear frames35converge. In view of this, the joint55has a high-rigidity. By providing a rear plate59in the vicinity (rearwardly thereof in the embodiment) of the joint55, it is advantageous in terms of strength for supporting the separate bracket18.

The separate frame18can be integrated with the head pipe12and the main frame43by fastening the bracket53to the front plate57with bolts or other separable fasteners and fastening the U-shaped bracket54to the rear plate59with bolts or other separable fasteners. The shape of the frames after integration will be described in conjunction withFIG. 5.

FIG. 4is an explanatory drawing showing the operation of the separate frame according to the present invention. The separate frame18is a pipe frame formed into a U-shape in plan view. The separate frame18is configured in such a manner that the turn signal lamps21,21and the head lamp19can be mounted to the lamp supporting bracket48. In addition, parking brake levers63can be mounted to the right side of the bracket53via a stay62.

It is also possible to reduce the time required for assembly in an assembly line, for example, by assembling the vehicle components such as the turn signal lamps21, the head lamp19, a meter unit61, and the parking brake levers63to the separate frame18in advance (referred to as sub-assembly). It is then possible to assemble the sub-assembly (the assembly shown inFIG. 4as a whole) to the head pipe12and the main frame43shown inFIG. 3.

FIG. 5is a side view of the vehicle body frame of the scooter-type vehicle according to the present invention, showing that the separate frame18is mounted to the head pipe12and the rear frame35. A center cover portion64including the integrally formed handle post cover27is covered on the separate frame18. The center cover portion64covers between the opposing legs of the separate frame18. The side cover28is mounted between the separate frame18and the lower pipe34with bolts or other separable fasteners65. Furthermore, a step22L is mounted to the lower pipe34.

As shown inFIG. 5, a structure is employed in which the front surface of the handle post cover27is a flat surface so that a front load-carrying space can be sufficiently obtained. A shelf portion27a, which is taken one step downward, is formed at the rear on top of the handle post cover27. Furthermore, combi-lock device70can be mounted on the shelf portion27a.

In the present invention, the so-called combi-lock device70, which is a combination switch including a handle lock mechanism integrated therein, is employed. Since most of the parts of the combi-lock device70are covered by the handle post cover27, the combi-lock device70is in no danger of being damaged due to mischief.

FIG. 6is a cross-sectional view taken along the line6-6inFIG. 5, showing that the center cover portion64is attached to cover securing plates66,66provided on the separate frame18with bolts or other separable fasteners67,67. In addition, the side covers28,28are attached to the cover securing plates51,51with the bolts or other separable fasteners65,65. When an attempt is made to secure the center cover portion64and the side covers28,28to the main frame43with bolts or other separable fasteners, a large scale cover mounting bracket is required.

Further to the above, the present invention includes separate frames18,18(although the separate frame18is a single piece, it is represented by two reference numerals for convenience) disposed above the left and the right lower pipes34,34. The center cover portion64and the side covers28,28are mounted by skillfully handling the separate frames18,18.

As a consequence, the separate frames18,18can be used for fixing the load. In addition, since the center cover portion64and the side covers28,28(these members are referred to as the vehicle body cover) are disposed inside the separate frames18,18and the left and the right lower pipes34,34, the vehicle body cover can be downsized as a whole. Hence, a light-weight and reduced cost vehicle body cover can be obtained.

In addition, since the box-shaped vehicle body cover is surrounded by the separate frames18,18and the lower pipes34,34, the container-like outline formed by the pipe frame is formed as a whole. Accordingly, the appearance is improved. In addition, as is clear fromFIG. 6, a large scale cover mounting bracket is not necessary. Therefore, a reduction in the manufacturing cost of the vehicle body frame can be achieved.

FIG. 7is a perspective view of the vehicle body frame according to the present invention, showing that the main frame43extends from the head pipe12. In addition, the two rear frames35,35, which are normally referred to as seat rails, extend from the main frame43. Reference numeral147designates a fuel tank to be mounted to the vehicle body frame11.

FIG. 8is a perspective view showing the front structure of the motorcycle according to the present invention. Referring toFIG. 8, the head pipe12is surrounded by the handle post cover27. In addition, the separate frame18is of substantially U-shape in plan view and protrudes toward the front so that a closed portion18afaces toward the front.

In addition,FIG. 8illustrates that the load receiving pipe47of inverted U-shape in front view extends from the separate frame18along a front surface27bof the handle post cover27(in the embodiment, the front surface27bof a protruded portion27cof the post cover mounted to the handle post cover27) with a closed portion47bthereof oriented upward to allow the load to be placed in front of the load receiving pipe47. In addition, the closed portion47bof the load receiving pipe47passes around the front portion of the meter unit61so that the meter unit61is guarded by the closed portion47b.

The protruded portion27cof the post cover is a portion constituting part of the handle post cover27. Therefore, the handle post cover27may be formed either by integrally attaching the protruded portion27cof the post cover afterwards, or by molding integrally with the protruded portion27cof the post cover during the stage of resin molding.

The appearance may be improved by surrounding the head pipe12by the handle post cover27. The appearance may also be improved by integrating the load receiving pipe47with the separate frame18and forming both of the separate frame18and the load receiving pipe47into a substantially U-shape so as to form the integrated member into a combination of a straight line and a curved line.

In addition, the load receiving pipe47includes left and right legs47a,47a(the47aon the far side is hidden and hence cannot be seen) extending upward from the separate frame18and the closed portion47bconnecting the ends of the legs47a,47a. In addition, the leg47ais sectionalized into a lower leg47clocated on the lower side and an upper leg47dlocated on the upper side and is bent forwardly at a boundary47ebetween the upper and lower legs47c,47d. In view of this, the separate frame18, the lower leg47cand the upper leg47dform an angular C-shape in side view.

The load can be placed on the portion of the angular C-shape in side view formed by the separate frame18, the lower leg47cand the upper leg47d. Since it is formed into the angular C-shape, a cord or a rope for fixing the load can easily be tied. In addition, downward movement of the load can be received by the separate frame18, lifting of the load can be held by the upper leg47d, and the rearward movement of the load can be held by the lower leg47c.

Furthermore, the handle post cover27includes the front surface27bthereof forming a flat surface27dextending along the lower leg47c, and a flat surface27eextending substantially along the upper leg47d. By forming the front surface27bof the handle post cover27into the flat surfaces27d,27e, the load can be received with a surface together with the load receiving pipe47.

FIG. 9is a plan view showing the front structure of the motorcycle according to the present invention. Referring toFIG. 9, the separate frame18is a member of substantially U-shape in front view having a closed portion18aat the extremity thereof. The load receiving pipe47extending from the separate frame18also includes the closed potion47bat the extremity thereof.

The closed portion47bis then passed around the front portion of the meter unit61. Accordingly, the meter unit61can be accommodated in the limited space formed in front of the handle post cover27and behind the load receiving pipe47. Therefore, the probability that the load comes into contact with the meter unit61can be avoided. In addition, the appearance of the front portion of the vehicle body can be improved while improving the load receiving capacity at the front of the vehicle body.

The separate frame according to the present invention must only be a member that can be mounted to an existing main frame or the main frame and the rear frame afterwards with bolts or other separable fasteners. The shape of the separate frame is arbitrary. The vehicle components to be mounted to the separate frame may be selected as desired.

With the arrangement described above, the present invention demonstrates the following effects.

According to the first aspect of the present invention, the appearance can be improved by covering the head pipe with the handle post cover. The appearance can be improved by integrating the load receiving pipe with the separate frame, and forming the separate frame and the load receiving pipe into the substantially U-shape so that the integrated member is formed into a combination of a straight line and a curved line.

By passing the load receiving pipe around the front portion of the meter unit, the probability that the load comes into contact with the meter unit can be avoided. Therefore, according to the first aspect of the present invention, the appearance of the front portion of the vehicle body may be improved while improving the load receiving capacity at the front of the vehicle body.

According to the second aspect of the present invention, the closed portion of the inverted U-shaped load receiving pipe is bent frontward of the vehicle body so as to pass around the front portion of the meter unit, so that the load receiving pipe and the front portion of the separate frame form an angular C-shape in side view.

A load may be placed on the portion of the angular C-shape in side view formed by the load receiving pipe and the front portion of the separate frame. Since it is formed into the angular C-shape, a cord or a rope for fixing the load can easily be tied. In addition, downward movement of the load can be received by the separate frame, and lifting or the rearward movement of the load can be received by the load receiving pipe.

According to the third aspect of the present invention, the front surface of the handle post cover is a flat surface extending along a lower leg, which constitutes the lower portion of the load receiving pipe. By forming the front surface of the handle post cover into the flat surface, the load can be received with a surface together with the load receiving pipe.