JPS6067285A - Cradle type frame of car - 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] Regarding ladle type frames.

The tank rail or main pipe extending rearward from the steering head pipe, and the rear ends of the left and right down tubes extending rearward and downward below the tank rail, are connected in a circular manner by a forged bracket, and these tank rails, down tubes, and brackets are connected in a circular manner by a forged bracket. In a cradle-type frame where the engine is mounted in the space surrounded by the frame, the engine is held in place by the frame, so in consideration of the ease of attaching and detaching the engine, it is known that one of the down tubes is detachable. It is being

In this case, the down tube on the removable side has a front end part on the steering head pipe side that is removably divided, and a rear end part that is removably connected to the bracket. Is it possible to weld joint members made of forged products to these mutually connecting ends, respectively, and then overlap these inner joint members? Lutop Shuhiroishi F Keito kFrh Tag L Isuke.

However, this structure requires two joint members for each connection between the bracket and the down tube, which complicates the structure and increases the number of parts, resulting in an increase in weight and cost.

The present invention was made based on these circumstances, and
The purpose of the present invention is to provide a cradle-type frame for a vehicle that can simplify the connecting part between a down tube and a connecting member and reduce the number of parts.

That is, in order to achieve the above-mentioned object, the present invention is characterized in that a connecting member connecting detachable down tubes is integrally provided with a joint portion that connects and holds the connecting ends of the down tubes.

An embodiment of the present invention will be described below based on drawings in which the present invention is applied to a motorcycle.

1 in the figure is a cradle-type frame made of aluminum alloy.
The steering head pipe 2 located at the front end has
A front fork 4 with a front wheel 3 is pivotally supported.

As shown in FIGS. 2 to 4, the steering head pipe 2 of this embodiment includes a hollow cylindrical pipe portion 5, and an ij ring 6 located at the upper end of the pipe portion 5. and a lower ring 7 located at the lower end of the i9 ignition part 5. A bracket 8 is provided on the circumferential surface of the Atsunokling 6, and a stopper 9 is provided on the circumferential surface of the lower ring 7 to determine the steering angle. Each is installed protrudingly. Both rings 6.7 are made by extruding aluminum alloy into a planar shape as shown in Figs. The bracket 8 and the stopper 9 are integrally formed by cutting the bracket 8 and the stopper 9, and are welded to the upper and lower openings of the rib portion 5 so as to be coaxially overlapped with each other. Therefore, according to the steering head and the steering head 2, the bracket 8 and the stone/J that protrude outward in the radial direction
? 9 is integrated, so separate brackets, stones, and 6
It is not necessary to weld the parts, and the decrease in strength due to welding can be prevented.

The steering head and the steering head 2 are equipped with frame members extending rearward, such as left and right tank rails 10,
10 and left and right down tubes 11.12 extending rearward and downward below these tank rails 10.10 are welded.

Tank rails 10, 10 and down tube 11.1
2 uses a hollow tube made of aluminum alloy with a square cross section, and the rear ends of the tank rail 10゜10 and down tube 11.12 are connected to each other by a plate-shaped connecting member, that is, a forged aluminum They are connected in an annular manner by alloy brackets 13 and 14. Left and right seat rails 15.15 extending rearward are welded to the middle of the tank rails 1θ, 10, and a backstay 16.16 is installed between these seat rails 15115 and the brackets 73.14. Note that the seat rails 15.15 and backstays 16.16 also have lower ends of the brackets 13 and 14 made of aluminum alloy and having a rectangular cross section connected to the cross member 7.
These brackets 13.14
A front end portion of a rear arm 18 is interposed between them, and is pivotally supported by a bidet shaft 19. The rear arm 18 is constituted by a hollow A-beam made of aluminum alloy and having a rectangular cross section, and a rear wheel 20 is supported at its rear end.

An engine 21 is mounted in a space surrounded by the tank rails 10, 10, down tubes 11, 12, and brackets 13.degree. 14. The engine 21 of this embodiment is a water-cooled V-shaped engine 2 having a front cylinder 23 that extends substantially horizontally forward from the front surface of the crankcase 22, and a rear cylinder 24 that extends obliquely upward from the top surface of the crankcase 22. It is a cycle 4-cylinder engine, and the front part of the front cylinder 23 fits between the down tubes 11 and 12, and the upper part of the rear cylinder 24 fits between the tank rails Io and 1o.71≧-Aζ -It is mounted in a state where it is held against the shoe 211r + frame 1.

In this case, the down tube 12 located on the right side in the traveling direction is detachably attached to the frame 1 for convenience of attaching and detaching the engine 21, as shown in FIG. That is, the down tube 12 is connected to the fixed tube 25 at the upper end on the steering head pipe 2 side.
The fixed tube 25 is divided into two parts, and the upper end of the fixed tube 25 is welded to the steering head pipe f2. One end of a joint bracket 27, 2B made of a forged aluminum alloy product is fitted into the opposing openings of the fixed tube 25 and the detachable tube 26, and is fixed by welding. These joint brackets 27 and 28 are abutted from the left and right sides, and 12 nuts 29 and 29 are inserted into the abutting portions of the joint brackets 27 and 28, and the nuts 30
．． 30, the detachable tube 26 and the fixed tube 25 are removably connected. The rear end of the single-sided fixing tube 25 is connected to the lower end of the bracket 14 located on the right side. This connection structure 1c will be explained with reference to FIGS. 8 to 10.
One end of a joint bracket 31 similar to that described above is fitted into the rear end opening of the fixed tube 25 and fixed by welding. A joint portion 32 extending forward with a reduced wall thickness is integrally formed at the lower end front portion of the bracket 14 when the bracket 14 is forged.

A joint bracket 31 is abutted on the outer surface of the joint part 32, and bolts 3.9 and 33 are attached to this abutment part.
By inserting and tightening with nuts 34 and 34,
The detachable tube 26 and the bracket 14 are removably connected. In this case, a protrusion 35 is provided on the abutment surface of the joint portion 32 over the entire length, and a recess 36 into which the protrusion 75 fits is formed on the abutment surface of the joint bracket 31. When the nuts 34 and 34 are tightened, the upper and lower surfaces of the protrusion 35 and the recess 36 come into close contact, thereby substantially increasing the abutting area. Also, such a protrusion 3
5 and recess 36 are also formed on the abutment surfaces of the joint brackets 28 and 29, although not shown in detail.

In addition, in FIG. 1, reference numeral 37 is a fuel tank, 38 is a seat,
39 is a radiator, and 40 is a cowling that covers the front area.

According to such a configuration, when one down tube 12 is made detachable from the frame 1, the joint bracket 3 on the down tube 12 side is tightened to the bracket 14 to which this down tube 12 is connected. Since the joint portion 32 to which the attachment is fixed is integrally formed, there is no need to provide a separate joint member between the down tube 12 and the bracket 14 as in the conventional case. Therefore, the number of parts can be reduced, and troublesome welding work for installation can also be omitted, making it possible to reduce costs and weight.

For example, it may be made of general steel, and it can also be implemented on a tricycle.

According to the present invention described in detail above, there is no need to provide separate joint members at the connection points between the down tube and the connection member partner, and the structure of the connection portion can be simplified. Therefore, the number of parts can be reduced and special installation work can also be omitted, making it possible to reduce costs.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, with FIG. 1 being a side view of a motorcycle, and FIG. 2 being a sectional view of a steering head pipe.
Figure 3 is a view taken in the direction of the arrow in Figure 2, Figure 4 is a view taken in the direction of [V <a] in Figure 2, Figure 5 is a left side view of the frame, and Figure 6 is a view of the frame. Right side view, Figure 7 is X- in Figure 9
Fig. 8 is a view taken along the line Mll-■ in Fig. 6, Fig. 9 is a sectional view of the connecting portion, and Fig. 10 is taken along the line X-X in Fig. 9. This is a view of one place. 2... Steering head pike, 4... Front fork, 1θ... Frame member (tank rail),
11.12... Down cheap, 13.14... Connecting member (bracket), 21... Engine, 32...
・Joint part. Applicant's agent Patent attorney Takehiko Suzue Figure 7 Figure 8 Figure 1 Takashi 3 Figure 9 Figure 10

Claims (1)

[Scope of Claims] A frame member extending rearward from the steering head/zobe that pivotally supports the front fork, and the rear ends of left and right down tubes extending rearward and downward below the frame member are connected to each other on the left and right sides, respectively. In a vehicle in which an engine is mounted in a space surrounded by a frame member, a down tube, and a connecting member, at least one of the down tubes is removably attached to a steering head pipe and a connecting member. A cradle-type frame for a vehicle, characterized in that the connection member connected to the down tube on the attachment/detachment side is integrally provided with a joint portion for connecting the connection end of the down tube.