JPS6226178A - Steering head for 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 steering head used for vehicles such as motorcycles and tricycles, in which the connecting portion between the head pipe and the vehicle body frame is formed by integral extrusion molding of light metal. It is something.

(Prior Art) As already proposed, a frame structure in which the body frame of a motorcycle is made of a light alloy, and the steering head connected thereto, the head pipe, and the connection part are formed by integral extrusion molding of a light alloy has been proposed. It is. (Special request, No. 160186/1986, No. 179213, No. 38/1983)
No. 405, etc.).

In these, the main frame and down tube, which are vehicle body frame members, were connected and fixed to the upper and lower surfaces of the connection part.

(Problem to be solved by the invention) Generally speaking, the conventional technology described above has an engine unit mounted inside a closed-loop body frame surrounded by a main frame and a down tube, and a fuel tank placed on the second side of the main frame. .

On the other hand, a so-called backbone type vehicle body frame is known, in which one or two main frames extend behind the head pipe, an engine unit is suspended and supported below the main frames, and a fuel tank is disposed above. According to this, since the main frame is integrated by welding directly to the head pipe, the joints are arcuate, and thermal distortion during welding is likely to occur (problems in terms of accuracy and quality). However, welding is difficult due to shape limitations.

The technical problem of the present invention is to eliminate the above-mentioned method of directly connecting the main frame to the head pipe, making it easier to weld (and improving the strength and accuracy of the connection between the main frame and the head pipe, thereby making it possible to improve the stability of the steering head). The aim is to improve mass productivity and bonding accuracy.

(Means for solving the technical problems) The means taken to solve the above technical problems is a steering head in which the head pipe and the connecting part are integrally extruded, and the rear end part of the connecting part is A joint part with a square cross section is integrally provided, and a vehicle body frame member with a square cross section is inserted and fitted to the outside using this joint part as a guide, and the contact parts at the rear parts are welded, screwed, riveted, glued, etc.・・・・・・
The gist is that it is integrated with the steering head via fixing means such as .

(Embodiment) A preferred embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

Fig. 1 is a perspective view of the steering head and body frame of a motorcycle obtained by the present invention, Fig. 2 is a plan view showing the method of assembling the steering head and the body frame and their relationship, and Fig. 3 is a side view. A similar diagram is shown in .

In the figure, reference numeral 1 denotes a head pipe, which has a thick cylindrical shape and has a plate-shaped mounting portion 2 protruding toward the front for mounting auxiliary equipment.

Further, on both sides of the head pipe 1, connecting portions 4 having appropriate reinforcing ribs 3 on the inside extend rearward in a substantially eight-shape shape when viewed from above with the head pipe 1 as the center.

As shown in FIG. 4(A), the connecting portion 4 is formed as a pair of left-right symmetrical outer walls 5 and inner walls 6, and is surrounded by an outer wall 5 and an inner wall 6.
The head pipe 1 is curved at a radius [gamma] so as to form a space S inside through a reinforcing rib 3' at the rear of the head pipe 1. The terminal portion of each connecting portion 4 is closed with a reinforcing rib 8, and furthermore, the rear portion thereof is connected to the connecting portion 4 and has a rectangular closed cross-sectional shape formed in a narrower width L2. For example, a joint part 10 having an X-shaped reinforcing rib 9.
to protrude.

The effective total length of this joint 10 is tl.The tip is provided with an inclined surface with an angle θ1 as appropriate to serve as a guide when fitting the vehicle body frame member, and the base is provided with a welding groove 7 with an angle θ2.
will be established.

The above cross-sectional shape is formed by pressing a light alloy material such as an aluminum alloy, connecting them all together through a die, and forming the steering head 1 as shown in Fig. 3 (a). The connecting portion 4 and the joint portion 10 having a length L3 are formed by cutting at the length LO and then cutting off the upper and lower surfaces of the connecting portion 4 while leaving the head pipe 1 intact.

Note that 20 and 21 indicate bearing fitting seats provided at both ends of the head pipe 1.

The vehicle body frame member 15 connected to the steering head 10 is shown in FIGS. The outer shape has a rectangular closed cross-sectional shape, the ratio of width T1 to height Hl is at least 11 or 1:2 or more, and the inside thereof is partitioned by one or more partition walls 16,
To the above-mentioned steering wheel.

It is integrally extruded using the same material.

The inner width T2 of the vehicle body frame member 15 is set to be the same as or slightly smaller than the width L2 of the joint portion 10, and the inner height H2 and the length L3 of the joint portion 10 are also set in the same manner.

Further, the partition wall 16 of this vehicle body frame member 15 is connected to the joint portion 10.
The effective total length t] is equal to or slightly less than B+.

The front ends of the vehicle body frame members 15 are press-fitted or statically fitted into the joint portions 10 as shown by arrows P, respectively.

Note that adhesive bonding can be achieved by applying an adhesive to the fitting surface 14 of the joint portion 10.

In addition, the fitting surfaces 14 have an expanded range of tIXL3, and these are interposed on four surfaces in the pair of left and right joints 10, so that extremely strong bonding force and high precision mounting and bonding accuracy can be obtained without using a jig or the like. .

The vehicle body frame member 15 press-fitted to the steering head to side in this manner is brought into contact with the groove 7 that is the base of the joint portion 10, and a weld bead is drawn on the groove 7 so that they can be joined together. In the above, the width L1 of the connecting part 4
By making the width T1 the same as the width T1 of the vehicle body frame member 15, a smooth side appearance with no steps can be obtained, and an excellent design effect can be obtained.

Furthermore, the upper and lower surfaces of the connecting portion 4 are covered with lids 30 and 31 having the shape shown in the figure.
2 and 3, and the mutual contact surfaces are integrally joined by welding.

Note that the arc R+ at the rear of the lid is the steering head l.
By making the dimension larger than the same γ1 of o, and making this an arc connecting the bases of the left and right joint parts 10 as shown by the chain line in FIG. By closing the upper and lower surfaces, this portion can be formed into a hollow, box-like shape, thereby further strengthening the torsional and bending rigidity of the steering head IO.

Moreover, by making the plate thickness H4 of the lid body 30.31 and the plate thickness H3 of the vehicle body frame member 15 the same or approximately the same, it is possible to eliminate the step-up of the joining surface, thereby improving the appearance. It is also possible to improve the product's marketability.

In addition, when the total length of the steering head lo is set to L3 as shown in Fig. 3 (a), the bearing fitting seats 20' and 2
1' does not protrude at both ends as shown by the dashed line in the figure, so both ends may be flat (cut surfaces), and the lid body 30.3
Only the plate thickness H4 of 1 may be made to protrude.

Next, FIG. 4 shows another embodiment, in which a vehicle body frame member 40
Therefore, the connecting part 42 and the joint part 43 that form the head pipe 41 and the steering head 44 are one piece and extend rearward along the center line of the vehicle body frame. In accordance with the above-described embodiment, the vehicle body frame member 40 is integrally connected.

Further, FIG. 5(A) shows another embodiment of the joint portion between the joint portion and the vehicle body frame member and the shape of the corresponding lid. According to this, each joint portion 11 (or The welding allowance can be extended and the fitting area can be increased by creating a wedge-shaped or chain-angled cross-sectional shape when viewed from above.

Furthermore, in FIG. 6 (a), a hollow cylindrical portion 50° 51 is attached to the joint portion 12.
was integrally extruded in the longitudinal direction of the head pipe 1, and the inside thereof was made into a bolt hole for connection.

Then, as shown in the same figure (b), the front ends of the vehicle body frame 15 are fitted into the mounting holes 53 on the vehicle body frame 15 side as shown by the arrows.
．． 54, a fixing bolt 52 was inserted vertically, and a nut 55 was used to connect the fixing bolt 52 by threading.

Further, on the right side of the figure, another embodiment is shown, in which the above-mentioned screwing means is arranged to cross the vehicle body frame member 15', and instead of the above-mentioned hollow cylindrical part 50.degree. Integral extrusion molding (resulting in the formation of 56.57 ref.
A side bolt fastening method is adopted in which the fixing bolt 52 is passed through the side wall of the vehicle body frame member 15 via the ribs 56 and 57.

By fitting the end of the body frame member 15' into the joint part 12 and making a screw connection, a high-precision, high-rigidity car body frame free from thermal distortion can be obtained. Therefore, special jigs and the like can be omitted.

Incidentally, the above-mentioned screwing method can further improve the bonding strength if the illustrated embodiments are used in combination at the same time.

Also, similar results can be obtained by using a rivet fastening method instead of bolts.

(Specific Effects of the Invention) The present invention produces the following specific effects. That is, in a steering head in which the head pipe and the connection part are integrally extruded, a joint part for fitting the vehicle body frame is provided at the rear of the connection part by integral extrusion molding together with the head pipe and the connection part, and the joint part is integrally extruded together with the head pipe and the connection part. Since the front end of the vehicle body frame is fitted to the front end of the body frame, the mating area is wide, and therefore the connection strength is excellent and the rigidity around the head pipe can be improved.By improving the connection precision, the precision of the entire vehicle body frame is improved. Since the joint is located far away from the head pipe, there is little effect of welding heat around the head pipe, screwing, and adhesion.

The vehicle body frame and steering head can be integrated and simplified by being able to be connected with rivets.

In addition, it is possible to further improve the strength by covering the top and bottom surfaces of the connection part with a lid body, which allows the top and bottom cross sections of the connection part and ribs to be closed in the longitudinal direction of the extruded molded part. This part is formed into a hollow box-like so-called monocoque shape, which has many advantages such as further improved torsion and bending rigidity around the head pipe, making it ideal for use as a steering head for motorcycles.

Of course, the same effect can be obtained even if it is applied to other vehicles such as automatic tricycles, tricycles, etc.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a perspective view of a steering head and a vehicle body frame, FIG. 2 is a plan view showing a method of assembling the steering head and a vehicle body frame and their relationship, and FIG. 4 is a perspective view of a steering head and a vehicle body frame in another embodiment, and FIGS. 5 and 6 are an assembly relationship between a steering head and a vehicle body frame in another embodiment. FIG. In the figure, 1 is the head pipe, 10 is the steering head, 3 is the reinforcing rib, 4 is the connection part, 1o is the joint part, 1
5 is a vehicle body frame member, and 3o and 31 are lid bodies.

Claims (8)

[Claims] (1) In a steering head in which a connection part with a head pipe and reinforcing ribs is formed by integral extrusion molding of a light alloy, a joint part formed by extrusion molding integrally with the connection part is provided protruding from the rear of the connection part. A steering head for a motorcycle, characterized in that a body frame member is fitted and fixed to the joint, and the top and bottom surfaces of the joint are sealed with a lid. (2) A steering head for a motorcycle according to claim (1), wherein the connecting portion has a rectangular shape when viewed from the rear, or a rectangular shape that is elongated in the vertical direction. (3) A steering head for a motorcycle according to claim (1), wherein the joint portion is narrower than the connecting portion. (4) A steering head for a motorcycle as set forth in claim (1), wherein the connecting portion and the body frame are configured such that there is no step on the joining surface after they are fixed. (5) A steering head for a motorcycle as set forth in claim (1), wherein the tip of the joint portion is provided with a guiding slope. (6) The connection portion and the joint portion are configured in a substantially eight-shape shape in plan view with the head pipe as the center.
) The steering head of the motorcycle described in item 2. (7) A steering head for a motorcycle as set forth in claim (1), wherein the joint portion includes a hollow cylindrical portion for a bolt hole. (8) A steering head for a motorcycle according to claim (1), wherein the cross-sectional shape of the joint portion is wedge-shaped or acute-angled.