JPS6229482A - Motorcycle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a motorcycle (including a tricycle) in which an arm extending forward from the center of the vehicle body is connected to a steering arm that supports a front wheel.

(Prior Art) For the purpose of reducing vehicle weight and lowering the center of gravity, a motorcycle in which a conventional front fork is abolished has been proposed as Japanese Patent Publication No. 58-49435.

This motorcycle uses an engine as part of a frame, a connecting plate is fixed to the engine, and the rear ends of an upper arm and a lower arm are pivotally supported on this connecting plate so as to be able to swing vertically. The tip of the arm is attached to a steering plate that supports the front wheels, and a shock absorber is interposed between one of the upper or lower arms and the connecting plate.

(Problems to be Solved by the Invention) In the above-mentioned motorcycle, the pivot points of the upper arm and the lower arm relative to the steering plate are both located inside the outer periphery of the front wheel when viewed from the side.

By the way, when the frame and the front wheels are connected by horizontal arms, in order to ensure a sufficient steering angle for the front wheels, move each arm outward so that the upper and lower arms do not interfere with the front wheels when they are turned. It must be greatly curved in the opposite direction.

As a result, the total length of the arm becomes longer, which also causes an increase in weight.

(Means for Solving the Problems) In order to solve the above problems, the present invention extends an upper arm and a lower arm so as to be able to swing forward, and connects the front ends of the upper arm and the lower arm to a steering arm. In particular, extend the steering arm upward so that its upper end is outside the outer periphery of the front wheel, and make sure that the connection point between the upper arm and the steering arm is outside the outer periphery of the front wheel. The lower arm was placed upward.

(Function) Since the upper arm and the front wheel do not overlap when viewed from the side, there is no need to curve the upper arm outward to avoid interference when the front wheel is steered. Furthermore, since the lower arm can also be positioned above where the most side part can escape when the front wheels are steered, tire escape in the lateral direction can be reduced.

(Example) An example in which the present invention is applied to a motorcycle will be described below based on the accompanying drawings.

FIG. 1 is an overall side view of a motorcycle according to the present invention, FIG. 2 is an enlarged side view of the front part of the motorcycle, and FIG. 3 is an enlarged plan view of the front part of the motorcycle.

A motorcycle (1) has a frame (2) arranged at the center of the vehicle body. This frame (2) is the engine unit (3)
It consists of a lower frame (4) and an engine unit (
3) consists of a ■-type engine (5) consisting of a front cylinder (5a) that tilts forward and a rear cylinder that tilts backward, and a transmission case (6) installed at the rear of this engine, and the lower frame (4) is made of steel plate, It is constructed of an aluminum alloy monolithic cast product or a laminated product of an aluminum alloy plate and a fiber-reinforced panel, and its shape is a boat bottom shape when viewed from the front, with the left and right side walls continuous at the bottom wall. It has a U-shape in side view with the front and rear ends being upright parts (7) and (8), and the front upright part (7) is tilted backwards and its upper end is connected to the front cylinder (5).
Face the valley between a) and rear cylinder (5b), and also stand up front and rear! Between (7) and (8), the engine 22-y (
3), the rigidity of the frame (2) itself is increased.

Further, as shown in FIGS. 2 and 3, there are shafts (9) between the upper and lower parts of the left and right standing parts (7), (7).

(lO), the rear end of the upper arm (11) is rotatably connected to the shaft (8) via a bearing, and the shaft (1
The rear end of the lower arm (12) is rotatably connected to the upper arm (11) and the lower arm (12) through a bearing.

The arm (12) is configured to swing up and down about the connection point.

The upper arm (11) has a truss structure in a V-shape or U-shape in plan view, with left and right members (lla) and (Ila) made of aluminum alloy or the like expanding toward the rear, which helps distribute the load to the left and right. Efforts are being made to increase rigidity and reduce weight.

The lower arm (12) is made of a hollow aluminum alloy casting or forging, and its shape is similar to that of the rear half (12a).
) is wide, and the front half (12b) is narrow and curved and bulges out on one side of the vehicle body (in the example, the left side), forming a space (S) for the front wheels (13) to steer inside. . The lower arm (12) has a shape in which the center part is bent upward when viewed from the side, and by having such a shape, when the front wheel (13) is steered, the front wheel (13), which has the largest amount of movement, By avoiding the rear end, the overall length of the lower arm (12) is shortened, and the rigidity and clearance from the road surface are increased.

Further, the axle (13a) of the front wheel (13) is rotatably supported at the lower end of the steering arm (10), and this steering arm (14) is tilted upward and rearward, and its intermediate portion is integral with the vehicle body. The upper end of the steering arm (14) is curved and bulged to the side.
13), and the front end of the upper arm (11) is connected to the upper end via a joint member (15). Also, the steering arm (14
) is integrally formed with a boss portion (16) that bulges rearward, and a joint member (17) is formed on this boss portion (16).
) is connected to the front end of the lower arm (12). In addition, the boss part (18) is not provided, and a separate member is fixed to the lower end of the steering arm (14), and the front end of the lower arm (12) is connected to this separate member to improve the ease of assembly. You can also do this. The steering arm (14) rotates around an axis connecting the front end connection points of the upper arm (11) and lower arm (12) by operating the steering system, which will be described later, and this rotation causes the front wheels to rotate. The steering (13) is performed.

Here, the front end connection point of the upper arm (11) is connected to the front wheel (13).
), and the front end connection point of the lower arm (12) is located inside the rim outer circumference of the front wheel (13), specifically at the rear of the axle (13a) and above the axle (13a), Further, an upper arm (11) and a lower arm (1
The lines connecting the front and rear connection points of 2) form a quadrilateral, especially a parallelogram. In this way, ``two-part arm (
By configuring the lower arm (11) and the lower arm (12) to have the same length and to be parallel, the caster angle does not change and bump steer can be effectively prevented. Furthermore, in this embodiment, the upper arm (11) and the lower arm (12) are connected in a line state.
) and tilt upward toward the front, so that the front wheels (
Even if the front wheel (13) rides on a convex portion, the front wheel can escape upwards smoothly, improving riding comfort.

Further, a bracket (1B) is provided on the front side of the steering arm (14), and a brake caliper (20) that clamps the brake disc (19) during braking is attached to this bracket (18). The brake caliper (20) is attached to the rear side of the steering arm (14) or the lower arm (1), as shown in FIG.
2) may be installed.

On the other hand, a backwardly inclined through hole (21) is formed in the rear half (12a) of the lower arm (12), and an I 7 bar (22) is disposed within this through hole (21). The upper end of this damper (22) is pivotally supported by a bracket (23) provided on the upright part (7) of the lower frame (0), and the rear end of the lower end is rotatably supported by the lower frame (4). The link (24) is pivotally supported at the front end of the link (24).
) and the lower arm (12) is a link (25).
) are connected. Thus, the front wheel suspension mechanism composed of the lower arm (12), damper (22), links (24) and (25) exhibits progressive characteristics.

Further, each cylinder (5a), (5
b) The fuel tank (26) is equipped with a fuel tank (26) bracket (27).
and attach the bracket (28) to this fuel tank (26).
) is attached to the steering pivot (29). The steering pivot (29) is supported by extending the stay from the engine (5) or lower frame (4).
A steering stem (30) may be inserted into the steering arm (29) as shown in FIG. fix it,
The upper end of a steering rod (33) is connected to the lower end of the steering stem (30) via a joint arm (32), and the lower end of the steering rod (33) is connected to the upright part (7) of the lower frame (4). ) The swing arm (34) has a joint (3
5), connect the rear end of the link rod (36) to this joint (35), and connect the rear end of the link rod (36) to this joint (35).
3B) is connected to a lever (37) provided in the middle of the steering arm (14). Since this lever (37) is provided at the outermost portion of the steering arm (14), it is possible to reduce the steering load and increase the rigidity. Then, when you turn the handle (31),
The steering stem (30) rotates, and this rotation is transmitted to the steering rod (3) via the joint arm (32).
3) as a linear motion, and this linear motion is transmitted to the link rod (36) as a longitudinal motion via the joint (35), and as the link rod (36) moves longitudinally, the steering arm (14) (37), the front wheels (13) are rotated about the axis (see). Note that the hole (34) formed in the swing arm (34)
a) is for adjusting the mounting position of the joint (35), and in the embodiment, one joint is installed in the same hole (34a).
) and the ends of the link rod (36) are connected, but each rod (33) and (3B) may be connected to separate holes (34a).

Note that the present invention is not limited to the above-described steering structure; for example, the steering stem (30) may be extended downward, and the upper end of the steering arm (14) may be directly connected to the lower end of the steering stem (30). Or by spline fitting through other members, the rotation of the handlebar (31) is transmitted directly from the steering stem (30) to the steering arm (14) without going through the steering rod and link rod, and the The vertical movement of the steering arm may be absorbed by the spline fitting portion.

Further, the front end of a rear swing arm (38) is pivotably supported on the rear upright portion (8) of the lower frame (4), and the rear end of this swing arm (38) ring(
39) is rotatably supported, and the lower end of a damper (41) is supported on the front end of a bell-shaped link (40) rotatably attached to the middle part of the swing arm (38). The upper end is supported by the upper end of the upright part (8),
Furthermore, a bar-shaped link (42) connects the middle part of the bell-shaped link (40) and the rear end of the lower frame (4). Therefore, the swing arm (38), damper (4)
1), links (40), and (42). The rear suspension mechanism also exhibits progressive characteristics.

Additionally, an air cleaner case (
43), a seat (40) may be provided above the air cleaner case (43), and the side surface of the vehicle body may be further covered with a cover (45).

In the embodiment, a motorcycle has been described, but a three-wheeled motorcycle having the same front structure may also be used.

(Effects of the Invention) As explained above, according to the present invention, since the line connecting the front and rear connection points of the upper arm and the lower arm forms a quadrilateral, bump steer etc. can be prevented, and furthermore, the front end connection of the upper arm can be prevented. Since the point is outside the outer circumference of the front wheels, there is no interference when the front wheels are steered, and as a result, the steering angle of the front wheels can be increased, and the upper arm can be made almost straight, which increases rigidity. It is advantageous in terms of weight and weight, and since the lower arm is also oriented upward toward the front, the length can be shortened and steering of the front wheels can be avoided, making it possible to achieve light weight and high rigidity, etc. Demonstrates the effect of

[Brief explanation of the drawing]

FIG. 1 is an overall side view of a motorcycle showing an embodiment of the present invention, FIG. 2 is a side view of the front of the motorcycle, FIG. 3 is a plan view of the front of the motorcycle, and FIG. 4 is a side view of the front of the motorcycle. FIG. 2 is a perspective view showing the steering system. In the drawing, (2) is the if frame, (3) is the engine unit, (4) is the lower frame, (7), (8)
is the upright part of the lower frame, (11) is the upper arm, (
12) is the lower arm, (13) is the front wheel, (14) is the steering arm, (20) is the brake caliper 1 (2)
2) is the damper, (29) is the steering pivot, (
30) is the steering stem, (31) is the steering wheel, (
33) is a steering rod, (34) is a swing arm,
(3B) is a link rod.

Claims (1)

[Claims] The front ends of the upper arm and the lower arm, which swingably extend forward from the center of the vehicle body, are connected to a steering arm that rotatably supports the front wheel, and the line connecting the connection points of the upper arm and the lower arm forms a quadrilateral. In addition, the front end connection point of the upper arm is located outside the outer periphery of the front wheel, the front end connection point of the lower arm is located inside the outer periphery of the front wheel rim when viewed from the side, and the upper and lower arms are both raised forward. A motorcycle characterized by: