JPH0237673Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial field of application The present invention relates to an improvement of a three-wheeled bicycle in which the front frame can swing from side to side, and relates to a frame structure that firmly supports a swing shaft fixed to the rear frame. .

Structures of conventional examples and their problems Rocking tricycles are bicycles whose front frame can swing from side to side.This provides a sense of security for elderly people who are unable to ride a two-wheeled bicycle or who find it dangerous. It is designed so that it can be held and ridden, and the front frame can be tilted when turning a curve, just like a two-wheeled bicycle, but since it provides a certain return force, it feels stable when riding straight. ing.

Therefore, in this type of tricycle, it is necessary to tilt the front frame to the left and right with respect to the rear frame, and therefore, it is necessary to support the rear frame and the front frame with one bearing. In this case, most of them have a bearing housing at the rear end of the front frame, and a swing shaft is welded and fixed to a part of the rear frame.

According to this structure, the swing shaft is cantilevered, and all the bending force acting on this part must be supported at the base of the swing shaft. Despite choosing a strong material for the swing shaft, Accidents of cutting and damage often occurred.

Purpose of the invention The purpose of the invention is to improve the mounting structure of the rocking shaft, which is the weakest member of a rocking tricycle, and to realize a strong support structure with a simple structure.

Structure of the invention In the present invention, the swing shaft is not supported in a cantilever manner with respect to the rear frame, but is firmly supported at both ends.

That is, one end of the swing shaft is directly welded to a part of the rear frame, and the other end is joined to the other end of the rear frame via a metal fitting. This allows the swing shaft to be supported at both ends, resulting in a frame that is strong against bending forces.

DESCRIPTION OF EMBODIMENTS FIG. 1 shows an example of the structure of a rocking tricycle. 1
is a front frame, on which a front fork 2 and a handle 3 are rotatably supported. 4 is the front hawk 2
A front wheel 5 is rotatably supported by a shaft, and a saddle 5 is fixed to the front frame 1. 6 is the crank, 7
are gears, which are rotatably supported by the front frame 1, and the rotational force of the crank 6 is the first gear.
The signal is transmitted to the intermediate shaft gear A9 through the chain 8 to rotate the intermediate shaft gear B10 which rotates coaxially, and the freewheel 1 is transmitted through the second chain 11.
The rotational force transmitted to 2 rotates the left rear wheel 13a. 13b is the right rear wheel.

14 is an intermediate shaft bearing pipe, one of which is connected to the frame pipe of the rear frame 15, and the other to the swing shaft 16.
The intermediate shaft bearing 14 serves as a metal fitting that supports the swing shaft 16.

The front frame 1 has a bearing 17 at its rear end, and is pivotally attached to the rear frame 15 by the bearing 17, thereby allowing it to swing from side to side.

FIG. 2 shows the structure of the rear frame. In the present invention, the swing shaft 16 is welded to the rear frame 15 at a central portion A, and the other end is joined to one end of the intermediate shaft bearing 14 at a portion B. Further, one end of the intermediate shaft bearing 14 is connected to the rear frame 15.
Since the rear frame is welded and fixed to the frame pipe at C, the rear frame as a whole has an annular structure, and the swing axis 1 in the conventional example shown in FIG.
Compared to the 6' cantilevered structure, there is a significant difference in strength.

4 and 5 show the structure of the bearing 17 portion.

The swing shaft 16 fixed to the rear frame 15 has a square cross section, and Neidhardt rubber 18 with a triangular cross section is installed on each of its four sides, and a housing 19 surrounds it. A bearing is formed. The housing is divided into upper and lower parts, and the upper housing 19a is joined to the rear end of the front frame 1. The upper housing 19a and the lower housing 19b are connected by bolts 20 and nuts 21 at their left and right flanges. 22 is a spacer inserted between the flange portions, and 23 is a stop plate that prevents the housing and Neidhardt rubber from moving back and forth.

The rear part of the front frame 1 is composed of two parallel thin pipes 24, 24, and when the front frame swings left and right, the housing 19 is twisted left and right.
The rubber 18 is compressed and deformed.

Since the swing shaft 16 is integrally formed with the rear frame 15 and the intermediate shaft bearing 14 and has an annular shape, the housing cannot be made into a pipe shape and fit with the swing shaft, so it is divided into two parts. be.

However, since it is divided into two parts, it is easier to assemble. This is because, in order to prevent play between the Neidhardt rubber 18 and the housing 19, tight fitting tolerances must be provided, and in this case, assembly is difficult if the insertion method is used.

Effects of the invention (1) Since the swing shaft is supported at both ends, sufficient strength can be obtained to prevent the breakage accidents of the swing shaft that frequently occurred in the past.

(2) If an intermediate shaft bearing is used as a supporting metal fitting for the swing shaft, there is no need to use a separate metal fitting.
A simple structure allows for a cheap and strong frame.

(3) If the bearing housing is divided into upper and lower halves,
Assembly is easier than before.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing an embodiment of the tricycle of the present invention, Fig. 2 is a sketch showing the rear frame, Fig. 3 is a sketch showing the conventional rear frame, and Fig. 4 shows the bearing section of the invention. Right side view, Figure 5 is Figure 4-
6 is a sketch showing the rear end of the front frame. 1...Front frame, 14...Intermediate shaft bearing, 15
... Rear frame, 16 ... Swing shaft, 17 ... Bearing, 18 ... Neidhardt rubber, 19a, 19b
……housing.

Claims (1)

[Claims for Utility Model Registration] (1) A rear frame to which the rear end of the swing shaft is fixed, and a front frame having a housing forming a bearing for the swing shaft at the rear end, the extension,
A tricycle with a rocking front frame supported by metal fittings fixed to a part of the rear frame. (2) The front frame rocking three-wheeled bicycle according to claim 1, wherein the metal fitting is constituted by a bearing pipe of an intermediate shaft for driving a rear wheel. (3) The front frame rocking three-wheeled bicycle according to claim 1 or 2, wherein the housing is divided into two parts and assembled so as to wrap around the rocking shaft.