JPS604870Y2 - Motorcycle front body structure - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a vehicle body front structure which is a steering support section of a motorcycle.

Conventionally, the steering support part of a motorcycle, that is, the front structure of the vehicle body, is generally made of a pipe material to form a head tube, to which the front end of a frame component such as a backbone frame is joined, and the front end of a down tube is joined to this. The steering stem, which extends above the front fork, is inserted into the head tube to provide steering support.

Such conventional steering support parts and frame structures require large strength and rigidity because they support the load concentrated around the head tube structure, that is, at the joint between the head tube, backbone frame, and down tube. Extremely high-precision welding is required, the number of parts increases, and furthermore, adjustment of the shaft support of the steering stem is troublesome and complicated, and improvements are desired.

The inventors devised this invention in order to improve the above-mentioned problems with the front body structure of motorcycles. Each member forms a part of the frame and supports the engine, which simplifies the structure of the head tube, simplifies the structure of the frame, and improves the effective structure of the engine. It is an object of the present invention to provide a motorcycle body front structure that can be used as a member, and can also be manufactured easily and lightweight.

Next, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a longitudinal sectional side view of the assembled state, and FIG. 2 is an exploded perspective view of the constituent members.

In FIG. 1, reference numeral 1 denotes an upper member, and as is clear from FIG.
A shaft hole 3 is provided vertically in the center of the bottom 2a, and a ring-shaped raised wall 2b is formed around the bottom 2a.

Then, a main body 4 extends rearward from the pivot support 2 so as to be wide in plane and side, the main body 4 has a cross member part 4a in the middle part, an upper surface 4b is closed, and a side surface 4c. The rear surface 4d is bent and suspended so as to surround the periphery, and is formed integrally with the shaft support 2.

Attachment boss portions 4e are provided on the side surface 4C and rear surface 4d of this main body 4.
In the illustrated example, they extend at two locations on the side surface and at one location on the rear surface, and mounting holes 4f are formed in the boss portion 4e.

In the illustrated example, two positioning recesses 2c are formed on the outer bottom of the bottom 2a of the shaft support 2 described above.

Reference numeral 5 designates a lower member, which has a cylindrical boss-shaped shaft support 6 in the front part similar to that described above, a shaft hole 7 vertically provided in the center of the bottom 6a, and a shaft hole 7 around the bottom 6a. A cylindrical raised wall 6b is formed,
In the illustrated example, two positioning recesses 6c are formed on the bottom 6a.

A main body 8 extends behind this pivot support 6, and the main body 8 consists of left and right parts 8a, 8a, opens rearward in a V-shape in plane, and has a frame shape with horizontal triangular sides and a cross part etc. arranged in the middle. In order to reduce the weight by cutting out the weight, each vertical frame part 8b at each rear end is formed with an outward mounting boss part 8C, and the boss part 8c has two mounting holes 8d above and below in the illustrated example. It is formed.

The above-mentioned shaft support 6 and main body 8 are integrally molded.

Reference numeral 9 denotes a collar long in the axial direction, and the upper and lower ends of the collar 9 have engaging protrusions, and in the illustrated example, two protrusions 9 are provided spaced apart in the circumferential direction.
A is formed respectively.

In the above, the collar 9 is interposed vertically between the shaft supports 2.6 of the upper and lower members 1 and 5, and the engaging protrusions 9a projected on the upper and lower peripheral edges of the collar 9 are connected to the shaft supports 2.6. It engages with the recesses 2c and 6c formed on the opposing surfaces.

This positions the collar 9 and the upper and lower members and prevents the collar 9 from rotating.

In this way, the collar 9 is interposed between the front parts, and the rear parts of the upper and lower members 1 and 5 to which the steering stem (to be described later) is connected are connected to the engine 10 via bolts or the like.

That is, the upper part of the engine 10 is faced below the upper member 4,
The two upper left and right parts of the engine 10 and the rear part are connected via bolts and boss parts.

On the other hand, the left and right boss portions 8c of the rear end of the main body of the lower member 5 are abutted against the front left and right sides of the middle and upper portions of the engine 10, and the engine 10 and the lower member 5 are connected through the mounting holes 8d and bolts. conclude.

When connecting the engine 10 and the members 1.5, the mounting holes 4f of the upper member 1 are made into elongated holes, etc., and when the engine and the members 1, 5 are connected, the lower member 5 is first screwed. By attaching the upper member 1 and then screwing the upper member 1, assembly errors can be absorbed.

Then, the steering stem 12, which is installed upward at the center of the upper end of the front fork 11, is passed through the shaft hole 7 of the lower member 5, the inner diameter of the collar 9, and the shaft hole 3 of the upper member 1 from below, and the stem 12 is inserted into the shoulder of the lower part of the stem 12. The inner race 13a of the lower bearing 13 is applied to the part 12a, the outer race 13b is applied to the concave outer bottom 6a of the lower surface of the shaft support of the lower member 5, and the outer race 14b of the bearing 14 is applied to the concave outer bottom 2a of the upper surface of the shaft support of the sumo wrestler member. In addition, the inner race 14a is placed on the stem 12 and the nut 15, and the nut 15 is screwed into the threaded portion 12b provided on the stem 12 and tightened.

In this way, the bearings 13 and 14 are tightened, and the tightened side is connected to the upper member 1.
Therefore, even if the member is connected to the engine after inserting the stem 12, the axial center adjustment allowance will be in the upper member, and the upper and lower bearings 13,
14 can be easily and reliably adjusted.

Thereafter, the lock nut 16 is placed on the nut 15, and the lock nut 16 is locked after adjustment and tightening.

FIG. 3 shows a specific example of the front structure of a motorcycle in which the above-mentioned structure is implemented. is provided with a handle 20, a meter unit 21, etc., and 22 is a headlight.

In the above explanation, it was assumed that the upper member, collar, lower member, and steering stem 12 were assembled and the engine was installed.
This may be done at the same time or in different orders.

As is clear from the above, according to the present invention, the conventional Herad tube section is divided into upper and lower members, a collar is interposed between each member to support the steering stem, and each member is directly connected to the engine. Firstly, since the engine is made part of the upper and lower parts, the structure and manufacturing of the head tube part is simplified, and the steering stem support part is integrated with the frame, so making the engine part of this part also makes it easier. The steering support section of conventional motorcycles can be made simpler, lighter, have fewer parts, and more compact, as well as provide sufficient strength and rigidity. Adjustment is easy, which is favorable for assembly and adjustment work, and furthermore, since the engine is used as a strength member of the frame, there are many advantages such as no need for a large frame body.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a longitudinal sectional side view of a motorcycle steering section, FIG. 2 is an exploded perspective view, and FIG. 3 is a side view of the front part of the motorcycle. In the drawings, 1 is an upper member, 2 is a shaft support, 4 is a main body, 5 is a lower member, 6 is a shaft support, 8 is a main body, 10 is an engine, 12 is a steering stem, 13 and 14 are bearings, and 12b. 15 is a screwing means.

Claims (1)

[Scope of utility model registration request] An upper member that supports a part of the engine at the rear and includes a shaft support through which the steering stem is inserted and supported at the front; and an upper member that supports a part of the engine at the rear and has a shaft support through which the steering stem is inserted and supported at the front. A front body structure for a motorcycle, comprising a lower member and a collar interposed between upper and lower shaft supports and arranged to surround the outer periphery of a steering stem.