JPS6344115B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a chain tensioning device for a chain-driven vehicle having two left and right drive wheels.

Chain-driven small tricycles and small four-wheeled vehicles have driving wheels at both ends of a single axle, and the axle is driven by an engine via a chain. To adjust the tension of the chain in this type of vehicle, the axle is supported by the left and right frames so that it can move back and forth.
Each of these frames is provided with a chain puller, and by operating each of these chain pullers to move the axle, the tension of the chain is ensured, and these chain pullers act as a stopper for the tension of the chain.

However, when adjusting the tension of the chain, there is a problem that the alignment of the axles will go awry unless the left and right chain plastics are adjusted by the same amount.Moreover, each chain plastic is installed inside the vehicle body rather than the drive wheels. The drive wheels get in the way and are difficult to operate. Therefore, chain tensioning work was extremely troublesome.

The present invention has been made based on the above circumstances, and an object thereof is to provide a chain tensioning device that does not cause misalignment of axles and that allows easy operation of a chain puller in a chain-driven vehicle.

An embodiment of the present invention will be described below based on the drawings.

Figure 1 shows a small-sized automatic tricycle, with one front wheel 1 as a steering wheel and a rear wheel 2 as a driving wheel.
It is equipped with two a and 2b. The body structure of the above-mentioned tricycle is shown in FIGS. 2a, b, and c. In other words, 3 is the main pipe, 4 is the down tube,
5, 5 indicates the seat rail, and 6, 6 indicates the lower tube. At the rear ends of the lower tubes 6, 6, support plates 7a, 7b are provided on the left and right sides. Each of these support plates 7a, 7b is formed with a notch 8a, 8b whose rear end edge is open. Each upper edge and lower edge of these notches 8a and 8b extend in the front-rear direction, and the sliding surfaces 9a, 9a, 9b, 9
It forms b. Further, above and below these notches 8a and 8b, long holes 10 are formed along the front and back direction.
a, 10a, 10b, and 10b are formed. Further, in front of the notches 8a, 8b, pivot holes 11a, 11b for a chain plastic, which will be described later, are formed.

A rear wheel hub 12 is supported by the support plates 7a and 7b. This rear wheel hub 12 rotatably holds a rear wheel axle 13 through bearings 14, 14. The aforementioned rear wheels 2a and 2b are integrally attached to both ends of the axle 13. Note that the rear wheels 2a and 2b have balloon tires. The axle 13 is integrally provided with a sprocket 15 on the left side when facing forward, and the sprocket 15 is connected to a sprocket 16 of an engine (not shown) by a chain 17. Further, a brake disc 18 is integrally connected to the right side of the axle 13. This brake disc 18 is braked by a caliper 19, which is not shown in detail. Note that the caliper 19 is provided in a mounting hole 20 opened in one of the support plates 7b. 21 is a case that covers the disk 18.

The rear wheel hub 12, which supports the axle 13 as described above, is fitted into the notches 8a and 8b. That is, the rear wheel hub 12
The sliding surfaces 9a, 9a, 9 of the notches 8a, 8b are
Guide fitting surfaces 22a, 22a, facing b, 9b,
22b, 22b are provided. Therefore, the hub 12 can be moved back and forth by sliding between these sliding surfaces and the guide fitting surface.

This rear wheel hub 12 has elongated holes 10a and 10 formed in the support plates 7a and 7b.
By inserting and screwing the bolts 23 into the support plates 7a, 7a, 10b, 10b, respectively, the support plates 7a, 7
It is fixed at b.

As shown in FIG. 5, the rear wheel 12 has protrusions 24, 2 at its front end spaced apart from each other on the left and right.
4 is formed. Chain pullers 25, 25 are in contact with these protrusions 24, 24, respectively. Each of the chain pullers 25, 25 has a cam surface formed on its rear surface, and this cam surface has a large number of engagement recesses 26 along the circumferential direction. As shown in FIG. 5, these chain pullers 25, 25 are integrally connected by a collar 27, and are also connected to each other by a substantially U-shaped operating lever 28. A support bolt 29 is inserted into the collar 27. The support bolt 29 is connected to the pivot hole 11a formed in the support plates 7a, 7b.
11b and is fixed with a nut 30. Therefore, the chain pullers 25, 25 can rotate together around the support bolt 29.

According to such a configuration, when slack occurs in the chain 17, the bolts 23 are first loosened so that the rear wheel hub 12 can freely slide within the notches 8a and 8b. After that, the operation lever 28
When the chain puller 25 is rotated in the direction of arrow A in FIG. 3, both chain pullers 25, 25 are rotated together in the same direction. Since the chain pullers 25, 25 contact the protrusions 24, 24 of the rear wheel hub 12 with their cam surfaces, they push both sides of the rear wheel hub 12 rearward with the above rotation. Therefore, the rear wheel hub 12
is moved rearward, so the chain 17 is stretched. When a predetermined tension is applied to the chain 17, the bolts 23 are tightened to fix the rear wheel hub 12. In this state, the protrusions 24, 24 of the rear wheel hub 12 are connected to the engagement recesses formed on the cam surfaces of the chain plastics 25, 25.
6..., the chain pullers 25, 25 are prevented from rotating, and the chain pullers 25, 25 prevent the rear wheel hub 12 from moving forward.

According to the embodiment described above, the chain pullers 25, 25 are integrally connected to each other by one operating lever 28, so that both chain pullers 25, 25 can be operated simultaneously by simply rotating the operating lever 28. It can be rotated by the same amount. Therefore, both the left and right ends of the rear wheel hub 12 are moved by the same amount, so there is no risk of the axle 13 becoming out of alignment. Therefore, there is no need to mutually adjust the operating amounts between the two chain plastics, making the operation extremely simple. In addition, in the case of the above embodiment, both chain plastics 2
Since one operating lever 28 is connected between 5 and 25, push this operating lever 28 from the rear of the vehicle in the direction of arrow A.
It can be pushed in any direction, and even if the wheels 2a, 2b and the support plates 7a, 7b are located on the left or right, the operation will not be hindered.

As detailed above, the present invention enables the axle to be moved in the front and rear directions relative to the left and right frames, each of these frames is provided with a chain puller for moving the axle in the front and rear direction, and these chain pullers are connected to each other. It is. Therefore, according to this product, when one chain puller is operated, the other chain puller is also operated at the same timing, and the axles are moved equally on the left and right sides, so there is no misalignment of the axles. Furthermore, since it is only necessary to operate one side or the connecting portion of both chain pullers, the chain puller can be operated very easily and the chain tensioning work can be carried out efficiently.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is a side view of a small motor tricycle, and Figs. 2 a, b, and c show its body structure, where a is a plan view and b is B in Fig. 2 a.
- Side view along B, c is C-C in Figure 2 a
3 is a cross-sectional view taken along line - in Figure 4, Figure 4 is a cross-sectional view taken along line - line in Figure 3, and Figure 5 is a cross-sectional view taken along line - line in Figure 3. FIG. 6 is a perspective view of the chain plastic. 2a, 2b... Drive wheel, 7a, 7b... Support plate (frame), 8a, 8b... Notch, 1
0a, 10b... Long hole, 12... Rear wheel hub, 13... Axle, 25, 25... Chain plastic, 28... Operation lever.

Claims (1)

[Claims] 1. In a vehicle in which an axle with drive wheels at both ends is supported by frames on both the left and right sides, and this axle is driven by a chain, the axle is movable in the front and rear directions relative to the frames on both the left and right sides, and these frames have a A chain tensioning device for a chain-driven vehicle, characterized in that a chain puller is provided for moving the axle in the front-rear direction, and the chain pullers are connected so as to interlock with each other.