JP2849089B2 - Front structure of scooter-type motorcycles and tricycles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a scooter-type motorcycle having a low-floor footrest plate between a steering axle barrel and a seat. For a front structure for supporting with a cylinder and covering the supporting portion with an inner fender and a leg shield,
In particular, the present invention relates to an improvement in the shape of a front fork that can sufficiently secure a footrest space. [Prior art] Conventionally, in a scooter type motorcycle or three-wheeled vehicle, a body frame is bent downward to form a low-floor footrest portion between a seat and a steering axle barrel that supports a front fork for a front wheel. doing.
And the front fork is telescopic left,
In many cases, the upper ends of the right forks are connected by an under bracket, a steering shaft is fixed to the center of the under bracket, and the steering shaft is supported by the steering shaft tube (for example, a real steering shaft). See JP-A-52-178358). [Problems to be Solved by the Invention] In recent motorcycles and tricycles, there is also a demand for a model with high terrain running ability such that it can run on uneven terrain as a sport, and even scooter type motorcycles and tricycles have irregular terrain. A model with improved driving performance is desired. In order to improve the ability to travel on uneven terrain, it is conceivable to make the front and rear wheels larger and wider than the wheels in the conventional scooter type motorcycles and tricycles. However, if this wide front wheel is supported by the front fork having the structure described in the above-mentioned publication, the left,
As the distance between the right forks and, consequently, the left and right lengths of the under bracket become longer, the rotation area becomes wider, so that the leg shield bulges to the footrest side to avoid interference with the under bracket, and as a result, There is a risk that the footrest space will be compressed. The present invention has been made in consideration of the above-described conventional circumstances, and has a front structure of a scooter-type motorcycle that can suppress a bulge outward of a leg shield as much as possible even when a wide front wheel is mounted and can secure a sufficient footrest space. It is intended to provide. [Means for Solving the Problems] In the present invention, the upper brackets of telescopic left and right fork pipes 15 and 15 each having an inner cylinder 15b inserted into a linear outer cylinder 15a are connected by an under bracket 16. , The under bracket
A front fork 4 having a steering shaft 17 fixed to the center of 16 is tilted rearward to one main pipe 9 of the vehicle body frame, and is pivotally supported in a rearwardly tilted state by the steering shaft tube 3 fixed thereto. The lower end of the front fork 4 supports the front wheel 5, and an inner fender 18 shaped to cover the rotation area of the front wheel 5 and the under bracket 16 is fixed to the lower end of the steering shaft barrel 3. An inclined portion 9a obliquely downward and rearward of the cylinder 3 and the main pipe 9 described above.
In the front structure of a scooter-type motorcycle having a low-floor footrest between the leg shield 8c and the seat, the under bracket 16 is traversed by a steel plate. A steering shaft fixing portion 16b which is formed in a U-shape and is bent so as to open rearward and downward, and extends substantially horizontally in the vehicle width direction and is fixed to the steering shaft 17; A fork pipe fixing portion 16 extending substantially horizontally outwardly in the vehicle width direction from the outer end of each of the inclined portions 16c;
a, 16a and the left and right fork pipes 1
The outer cylinders 15a, 15a are arranged above the inner cylinder 15b, the outer cylinders 15a, 15a are fixed to the fork pipe fixing portions 16a, 16a of the under bracket 16, and the inner fender 18 is formed of a resin-integrated product. The wall 18k that covers the upper part of the rotation area of the under bracket 16 and the under bracket 16
Peripheral wall 18l covering the periphery of the rotation area of
The upper surface wall 18k is disposed close to a flat upper surface of the steering shaft fixing portion 16b of the under bracket 16, and has a through hole 18e through which the steering shaft 17 and the steering shaft tube 3 penetrate. A central wall 18a extending substantially horizontally in the width direction and extending above the inclined portion 16c;
An outer edge wall 18c extending substantially horizontally in the vehicle width direction in the vicinity of 6a and located below the central wall 18a;
It has a slanted wall 18d that extends inclining outwardly downward from a and connects the center wall 18a and the outer edge wall 18c, so that the upper wall 18k avoids interference with the main pipe 9. The escape recess 18 is formed and the central wall is formed.
A cylindrical wall 18f extending upwardly along the periphery of the through-hole 18e of the through-hole 18e so as to surround the steering shaft barrel 3. The inclined portion of the under bracket 16 is formed from the through-hole 18e on the lower surface of the central wall 18a. A vertical wall 18h extending substantially vertically downward is formed at a position outwardly separated to the vicinity of the outer end portion of 16c. [Operation] In the front structure of the scooter type motorcycle according to the present invention, the under bracket 16 is formed by opening a steel plate with a U-shaped cross section toward the lower rear and is substantially horizontal in the vehicle width direction. The steering shaft fixing portion 16b, the inclined portion 16c extending outward and downward from both ends thereof, and the fork pipe fixing portion 16a extending substantially horizontally in the vehicle width direction from the steering shaft fixing portion 16b are provided. It is easy to incline the portion 16c at a relatively steep angle, so that the fork pipe fixing portion 16a of the under bracket 16, that is, the outer peripheral portion of the rotation region can be lowered, and thereby the outer peripheral portion of the inner fender 18 As a result, the amount of bulging of the leg shield covering the rear portion of the inner fender 18 toward the footrest plate can be reduced to secure a footrest space. Also, the outer cylinder 15a of the left and right fork pipes 15,15 is connected to the inner cylinder 15
b, and the outer cylinders 15a, 15a are fixed to the fork pipe fixing portions 16a, 16a of the under bracket 16, so that a large joint area between the fork pipe 15 and the under bracket 16 can be secured, Even if 16 is not large, the support rigidity of fork pipe 15 can be secured. Also, the outer cylinder 15a, not the inner cylinder 15b, is under-bracketed.
Since it is fixed to the fork 16, the vertical thickness of the fork pipe fixing portion 16a can be made thicker downward, and the fork pipe support rigidity can be increased. In this case, since the fork pipe fixing portion 16a is fixed to the outer cylinder 15a, the cushion stroke is not shortened even if the fork pipe fixing portion 16a is made thicker downward. Incidentally, when the inner cylinder 15b is arranged on the upper side and the fork pipe fixing portion 16a is fixed to the inner cylinder 15b, if the fork pipe fixing portion 16a is made thicker downward, the cushion stroke becomes shorter accordingly. In this way, the support rigidity of the fork pipe can be increased without increasing the rotation space of the under bracket 16, and also in this respect, the leg shield can be prevented from bulging to the footrest plate side, and the footrest space is secured. it can. Furthermore, the inner fender 18 and the under bracket
An upper surface wall 18k covering the upper part of the rotation area 16 and a peripheral wall 18l covering the periphery are provided, and the upper surface wall 18k is a central wall 18 that covers the steering shaft fixing portion 16b and has a through hole 18e.
a and an outer peripheral wall along the fork pipe fixing portion 18a
18c, and an inclined wall 18d that obliquely connects the central wall 18a and the outer edge wall 18c, and further includes a cylindrical wall 18f surrounding the steering shaft cylinder 3 at a peripheral edge of a through hole 18e on the upper surface of the central wall 18a. And the vertical wall 18h extending downward is formed on the lower surface.
By f, muddy water and the like coming along the lower surface are blocked by the vertical wall 18h, and muddy water and the like that has invaded to the inside of the vertical wall 18h easily fall because the lower surface of the central wall 18a is horizontal, As a result, it is possible to prevent muddy water or the like that winds up the front wheel from entering the sliding portion between the steering shaft and the steering shaft cylinder. In this case, since the vertical wall 18h is formed in the vicinity of the outer end of the inclined portion 16c of the under bracket 16, the vertical wall 18h can be set to be long downward, whereby the muddy water and the like can be more reliably blocked. In addition, since there is only one main pipe 9, the escape recess 18d 'for avoiding interference with the main pipe 9 in the inner fender 18 can be made small, and from this point also, intrusion of muddy water and the like can be prevented. In addition, since the through hole 18e is disposed close to the upper surface of the steering shaft fixing portion 16b of the under bracket 16, muddy water and the like hardly reach the above-mentioned sliding portion from this point, so that muddy water and the like enter the sliding portion more. Can be reduced. Also, since the under bracket 16 has a U-shaped cross section and is opened downward and rearward, muddy water and the like rolled up along the rear edge of the front wheel are scraped by the upper and lower walls of the U-shape. From this point, it is difficult to reach the sliding portion from this point, and muddy water or the like that has entered the U-shaped space of the under bracket is not discharged and accumulated satisfactorily by opening the rear downward direction. Embodiment An embodiment of the present invention will be described below with reference to the drawings. 1 to 4 are views for explaining a front structure of a scooter type motorcycle according to one embodiment of the present invention. In the figure, reference numeral 1 denotes a scooter type motorcycle, and a main pipe 9 of a body frame 2 of the motorcycle 1 has a front rising portion 9a extending obliquely downward and rearward from a steering shaft tube 3 fixed to a front end thereof. It comprises a main support 9b extending rearward substantially horizontally from the lower end thereof. Side support portions 10a of a pair of side pipes 10 are disposed on the left and right sides of the main support portion 9b, and the front ends of the side support portions 10a are fixed slightly above the bent portions of the main pipe 9. Have been. A footrest plate 19a is mounted on the upper side of the main and side support portions 9b and 10a, and an under cowl 19b is mounted on the lower side. At the rear end of the side support portion 10a of the side pipe 10, there is formed a rear rising portion 10b which extends obliquely rearward and upward, and further has a seat rail portion 10c. And this seat rail part 1
A seat 11 is mounted above 0c, and a lower portion of the seat 11 is surrounded by a rear cover 12. Below the rear cover 12, an engine unit 13 in which an engine 13a and a transmission case 13b are integrated is arranged. A rear wheel 14 on which a large-diameter and wide tire 14a is mounted is supported at the rear end of the transmission case 13b,
The front end is pivotally supported by a support bracket 17 fixed to the rear rising portion 10b. In addition, the large diameter of this embodiment,
A wide tire is a tire used for a conventional scooter type motorcycle with a displacement of about 50 cc, which is about 400 mm in diameter × about 75 mm in width, while a tire with the same displacement is 490 mm in diameter ×
It is about 120mm wide. A front fork 4 is rotatably supported by the steering shaft barrel 3. The front fork 4 connects the upper ends of the left and right fork pipes 15, 15 with an under bracket 16,
A lower end of the steering shaft 17 is fixed to the center of the under bracket 16. The left and right fork pipes 15 are outer cylinders
It is a telescopic type in which an inner cylinder 15b is inserted into the inner cylinder 15b so as to be extendable and retractable, and the upper end of the outer cylinder 15a is inserted into both ends of the under bracket 16 and fixed by welding. The steering shaft 17 is made of a copper tube, and its lower end is inserted into the center of the under bracket 16, and is also fixed by welding. The under bracket 16 is formed by bending a steel plate into a U-shape in cross section. The under bracket 16 extends substantially horizontally in the vehicle width direction and is fixed to the steering shaft 17.
And an inclined portion 16c which is inclined to be located outwardly downward from both ends of the steering shaft fixing portion 16b, and a fork pipe which extends substantially horizontally outward in the vehicle width direction from the outer end of each of the inclined portions 16c. Fifteen
And a fork pipe fixing portion 16a, 16a to which the upper end is fixed. As a result, the fixed portion 1 of the left and right forks 15, 15
6a and 16a are located below the fixed portion 16b of the steering shaft 17. Between the lower ends of the left and right fork pipes 15 of the front fork 4, a large-diameter and wide tire 5a of the same size as the rear wheel 14 is provided.
Is rotatably supported on the front wheel 5. An inner fender 18 is attached to the lower end of the steering barrel 3. The inner fender 18 is for covering the upper region of the front wheel 5 and the rotation region of the front fork 4. The upper wall 18 k covers the upper region of the rotation region of the under bracket 16 and the rotation of the under bracket 16. It has a peripheral wall 18l covering the periphery of the movement area, and a fender 18b extending forward from the upper surface wall 18k. The upper surface wall 18k is adjacent to the steering shaft fixing portion 16b of the under bracket 16, has a through hole 18e through which the steering shaft 17 and the steering shaft tube 3 penetrate, and is substantially horizontal in the vehicle width direction. A central wall 18a extending above the inclined portion 16c, and an outer edge wall 18c extending substantially horizontally in the vehicle width direction in proximity to the fork pipe fixing portion 16a and located below the central wall 18a. The outer wall 1a and the outer edge wall 1
8c. At the periphery of the through hole 18e of the central wall 18a, a cylindrical wall 18f extending upward along the steering shaft tube 3 is formed so as to surround the steering shaft tube 3, and is outside the through hole 18e on the lower surface of the central wall 18a. A vertical wall 18h extending substantially vertically downward is formed at a position separated from the vertical wall 18h. In addition, at the center rear of the inner fender 18, there is an escape portion for avoiding interference with the main pipe 9.
18d is recessed. A front cover 8 is mounted on the front side of the steering shaft barrel 3. The front cover 8 includes a front leg shield portion 8 a that covers the front side of the steering barrel 3, and the inner fender 18.
Fender section 8b and front fender section 8 covering above front wheel 5
b is integrally formed of resin. Further, on the rear side of the main pipe 9, a rear leg shield 8c is provided.
Is installed. The rear leg shield 8c covers the steering shaft barrel 3, the front rising portion 9a of the main pipe 9, and mainly the upper wall 18a of the inner fender 18. Next, the operation and effect of this embodiment will be described. In the motorcycle 1 according to the present embodiment, the large and wide front and rear wheels are used.
5, 14 was installed to improve the running performance on uneven terrain, but when such a wide tire is attached, the rotation area of the under bracket is widened as described above, and the leg shield foot mounting There is a concern that the swelling amount to the side of the part becomes large and the footrest space is pressed. In this embodiment, the under bracket 16 is a steel plate having a U-shaped cross section and opened rearward and downward, and a steering shaft fixing portion 16b that is substantially horizontal in the vehicle width direction, and is provided with an outer portion from both ends thereof. Since it is provided with the inclined portion 16c extending downward and the fork pipe fixing portion 16a extending substantially horizontally in the vehicle width direction from the inclined portion 16c, it is easy to incline the inclined portion 16c at a relatively steep angle. And therefore the under bracket 16
Fork pipe fixing portion 16a, that is, the outer peripheral portion of the rotation region can be lowered, whereby the outer peripheral portion of the inner fender 18 can be located below, as a result, the leg covering the rear portion of the inner fender 18 The footing space can be secured by reducing the amount of bulging of the shield to the footrest plate side. Also, the outer cylinder 15a of the left and right fork pipes 15,15 is connected to the inner cylinder 15
b, and the outer cylinders 15a, 15a are fixed to the fork pipe fixing portions 16a, 16a of the under bracket 16, so that a large joint area between the fork pipe 15 and the under bracket 16 can be secured, Even if 16 is not large, the support rigidity of fork pipe 15 can be secured. Also, the outer cylinder 15a, not the inner cylinder 15b, is under-bracketed.
Since it is fixed to the fork 16, the vertical thickness of the fork pipe fixing portion 16a can be made thicker downward, and the fork pipe support rigidity can be increased. In this case, since the fork pipe fixing portion 16a is fixed to the outer cylinder 15a, the cushion stroke is not shortened even if the fork pipe fixing portion 16a is made thicker downward. Incidentally, when the inner cylinder 15b is arranged on the upper side and the fork pipe fixing portion 16a is fixed to the inner cylinder 15b, if the fork pipe fixing portion 16a is made thicker downward, the cushion stroke becomes shorter accordingly. In this way, the support rigidity of the fork pipe can be increased without increasing the rotation space of the under bracket 16, and also in this respect, the leg shield can be prevented from bulging to the footrest plate side, and the footrest space is secured. it can. Here, when the conventional structure is adopted in the shape of the present embodiment, the inner fender 18 swells outward as shown by the two-dot chain line in FIG. 2, and the leg shield also swells toward the footrest side. As a result, the footrest space is compressed. On the other hand, when the both sides of the under bracket 16 are lowered as in the present embodiment, muddy water or the like that winds up the front wheels causes
There is a concern that it may easily enter the sliding portion between the steering shaft cylinder 3 and the steering shaft barrel 3. However, in this embodiment, the through hole 18e of the inner fender 18
Is formed on the periphery of the inner wall of the inner fender 18 so that muddy water or the like that travels along the upper surface of the inner fender 18 is not covered by the cylindrical wall 18f.
Thereby, intrusion into the sliding portion is prevented. Further, since the vertical wall 18h is formed to extend downward on the lower surface of the inner fender 18, intrusion of muddy water and the like guided along the lower surface does not occur.
h, and muddy water and the like that has entered the inside of the vertical wall 18h easily fall because the lower surface of the central wall 18a of the inner fender 18 is horizontal. Can be prevented from invading. In this case, since the vertical wall 18h is formed in the vicinity of the outer end of the inclined portion 16c of the under bracket 16, the vertical wall 18h can be set to be long downward, whereby the muddy water and the like can be more reliably blocked. In addition, since there is only one main pipe 9, the escape recess 18d 'for avoiding interference with the main pipe 9 in the inner fender 18 can be made small, and from this point also, intrusion of muddy water and the like can be prevented. In addition, since the through hole 18e is disposed close to the upper surface of the steering shaft fixing portion 16b of the under bracket 16, muddy water and the like hardly reach the above-mentioned sliding portion from this point, so that muddy water and the like enter the sliding portion more. Can be reduced. Furthermore, since the under bracket 16 has a U-shaped cross section and is opened downward and rearward, muddy water and the like rolled up along the rear edge of the front wheel can be removed by the upper and lower walls. It is hard to reach the sliding portion from this point, and muddy water or the like that has entered the U-shaped space of the under bracket is not drained and accumulated satisfactorily by opening it backward and downward. Although the above embodiment is an example of a scooter type motorcycle, the present invention can be applied to a scooter type motorcycle. [Effects of the Invention] As described above, according to the front structure of the scooter-type motorcycle according to the present invention, the under bracket is formed by bending a steel plate into a U-shaped cross section. Can be inclined at a relatively steep angle, so that the outer peripheral portion of the rotation area is lowered to reduce the amount of bulging of the leg shield covering the rear portion of the inner fender to the footrest plate side. Has the effect of being able to secure Also, since the large-diameter outer cylinder is fixed to the fork pipe fixing portion, a large joint area between the fork pipe and the under bracket can be secured, and the support rigidity of the fork pipe can be secured even if the under bracket is not large. Also, since the outer cylinder is fixed to the under bracket, the vertical thickness of the fork pipe fixing part can be increased downward to increase the fork pipe support rigidity. There is an effect that bulging to the footrest plate side can be suppressed, and a footrest space can be secured. Furthermore, since a cylindrical wall is formed on the upper surface of the central wall of the inner fender and a vertical wall is formed on the lower surface, muddy water transmitted along the upper surface of the inner fender is prevented from flowing along the lower surface by the cylindrical wall. Is blocked by the vertical wall, and muddy water and the like that has penetrated into the inside of the vertical wall are easy to fall because the lower surface of the central wall is horizontal, and as a result, muddy water and the like that wind up the front wheel are controlled by the steering shaft. This has the effect of preventing entry into the sliding part with the countershaft cylinder, and the through hole is located close to the upper surface of the steering shaft fixing part of the under bracket. It is difficult to reach the sliding portion, and it is possible to further reduce intrusion of muddy water and the like into the sliding portion. In this case, since the vertical wall is formed in the vicinity of the outer end of the inclined portion of the under bracket, the vertical wall can be set to be long downward, whereby the muddy water and the like can be more reliably blocked. Also, since there is only one main pipe, the escape recess for avoiding interference with the main pipe in the inner fender can be made small, and from this point too, it is possible to prevent infiltration of muddy water and the like. In addition, since the under bracket has a U-shaped cross section and is opened downward and rearward, muddy water and the like rolled up along the rear edge of the front wheel are scraped off by the upper and lower walls of the U-shape. It is difficult to reach the sliding part from this point,
In addition, muddy water and the like that have entered the U-shaped space of the under bracket are well discharged by the rear downward opening and do not accumulate.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 to 4 are views for explaining a front structure of a scooter type motorcycle according to an embodiment of the present invention, FIG. 1 is a plan view thereof, and FIG. FIG. 3 is a sectional front view, FIG. 3 is a sectional side view, and FIG. 4 is a side view of a scooter type motorcycle to which the structure of the embodiment is applied. In the drawing, 1 is a scooter type motorcycle, 2 is a body frame, 3 is a steering axle, 4 is a front fork, 5 is a front wheel, 8c is a rear leg shield, 9 is a main pipe, and 9a is a front rising portion (main). 15 is the left and right fork pipes, 16a is the fork pipe fixing part, 16b is the steering shaft fixing part, 16c is the inclined part, 17 is the steering shaft, 18 is the inner fender, 1
8a is a central wall, 18c is an outer edge wall, 18d is an inclined wall, 18e is a through hole, 18f is a cylindrical wall, 18h is a vertical wall, 18k is a top wall, and 18l is a peripheral wall.

Claims (1)

(57) [Claims] The upper fork of the telescopic left and right fork pipes in which an inner cylinder is inserted into a straight outer cylinder is connected with an under bracket, and a front fork having a steering shaft fixed to the center of the under bracket is attached to the vehicle body. The steering wheel barrel is fixed to one main pipe of the frame by being tilted rearward and supported in a rearwardly tilted state, and the front wheel is supported at the lower end of the front fork.
An inner fender shaped to cover the rotation area of the front wheel and the under bracket is fixed to a lower end of the steering barrel, and a rear portion of the steering barrel and the main pipe is inclined rearward and obliquely downward. In the front structure of a scooter-type motorcycle or tricycle having a low-floor footrest between the leg shield and the seat while covering with a shield, A steering shaft fixing portion that is bent so as to open and extends substantially horizontally in the vehicle width direction and is fixed to a floor control shaft; And a fork pipe fixing portion extending substantially horizontally outward in the vehicle width direction from an outer end of each of the inclined portions so that the outer cylinders of the left and right fork pipes are provided inside. While placing it on the upper side of the cylinder, A top wall that is fixed to a fork pipe fixing portion of the under bracket, and that is formed of a resin-integrated resin and that covers the rotation area of the under bracket; The upper surface wall is disposed close to the flat upper surface of the steering shaft fixing portion of the under bracket, and has a through hole in the center through which the steering shaft and the steering shaft tube penetrate, A central wall extending substantially horizontally in the vehicle width direction and extending above the inclined portion; and an outer edge wall extending substantially horizontally in the vehicle width direction near the fork pipe fixing portion and located below the central wall. And an inclined wall extending from the center wall so as to be located further downward toward the outside, and having an inclined wall connecting the center wall and the outer edge wall, so that the upper wall does not interfere with the main pipe. In addition to forming an escape recess, a cylindrical wall extending upwardly along the periphery of the through hole of the central wall so as to surround the steering shaft cylinder, and forming the under bracket from the through hole on the lower surface of the central wall. A front wall structure for a scooter-type motorcycle, wherein a vertical wall extending substantially vertically downward is formed at a position outwardly separated to a position near an outer end of the inclined portion.