JPS5855369B2 - Automatic brake adjustment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic shoe gap adjustment device for drum brakes used in two-wheeled vehicles, four-wheeled vehicles, and the like.

Various types of drum brake shoe gap automatic adjustment devices are already in practical use for four-wheeled vehicles, but since these are adjusted by operating the parking brake, it is difficult to use the parking brake device. For example, it could not be applied to two-wheeled vehicles that do not have the following.

An object of the present invention is to provide an automatic shoe gap adjustment device that is suitable for, for example, two-wheeled vehicles, regardless of the presence or absence of a parking brake device. In the actuated type, a transmission lever is provided that expands in conjunction with the brake operation part, and the transmission lever and the brake shoe are connected via a one-way clutch that transmits transmission in the expansion direction, and the brake shoe is connected to the transmission lever in the expansion direction. A one-way clutch is provided at the distal end of the opening to allow movement in the expansion direction.

One embodiment of the present invention will be explained with reference to FIGS. 1 to 4.

1 is a brake drum, 2, 2 are brake shoes whose one end is pivoted to pin 4, 3, 3 are these brake shoes 2, 2
Transmission levers are shown above each with one end pivotally connected to them by a pin 4', and a bridge body 5 that tilts in conjunction with the operation of the brake operating part 10 is shown between the tips of these transmission levers 3, 3. The transmission levers 3, 3 are expanded against the elasticity of a spring 11 that connects them by pressing the ends of the transmission levers 3, 3 to the left and right by tilting the transmission levers 3, 3.

7.7 indicates a first one-way clutch, and each one-way clutch 7 has a connecting rod 7a whose width gradually becomes narrower toward the tip, and a fourth one-way clutch.
As shown in the figure, it consists of a receiving body 7b having a recess 7 which becomes gradually shallower toward the tip, and a rolling element 1c such as a ball or roller interposed between the two, and a gap 7d in which the rolling element 7c intervenes.
was made to gradually become narrower toward the tip.

The root of the connecting rod 7a is pivotally connected 7e to the brake shoe 2, and the root of the receiver 7b is pivotally connected 7fL to the transmission lever 3, and a spring 7g is used to connect the ball 7c and the root of the receiver 7b. The elasticity of the spring 7g directs the rolling element 7c in the direction in which the gap 7d narrows.

Reference numerals 8 and 8 indicate second one-way clutches, and each one-way clutch 8 includes an upper movable body 8b having a receiving groove 8a opening upward and an inclined lower surface, and a lower fixed body 8c having a horizontal upper surface.
and a rolling element 8e that intervenes in a gap 8d that is formed between the inclined surface and the horizontal surface and gradually narrows toward the outside, and a spring 8f is connected to the upper movable body 8b. The elasticity of the upper movable body 8b causes the upper movable body 8b to turn inward, and the rolling body 8e also has a spring 8g.
The rolling elements 8e are bound together and their elasticity directs the rolling elements 8e outward, that is, in the direction in which the gap 8d becomes narrower.

A pin 8h protruding from the end of the brake shoe 2 faces the receiving groove 8a.

9 is the bottom surface of the brake housing, 6 is a spring tied between the brake shoes 2, and 7k.

These receptors 7b are provided at 7 in order to restrict the expansion of the receptors 7b, 7b around the pivot points 7r, 7t.

A claw piece integrally protruding from 7b, 71. ．． Is 7β a connecting rod? receptor 7b to facilitate mutual movement of a and γa,
7b shows rollers pivotally connected to each other.

Next, the operation will be described. When the driver operates the brake operation unit 10, the bridge body 5 tilts in conjunction with this operation and spreads the transmission levers 3, 3.

As these transmission levers 3, 3 are expanded, the upper one of the receivers 7b, 7b which are connected to each other 7f moves to the left in FIG. 2, and the lower one moves to the right. is the direction that narrows the gaps 7d, 7d, so the gaps 7d, 7
The upper connecting rod 7a moves to the left and the lower connecting rod 7a moves to the right via the rolling elements 7c and 7c located at d, respectively, and the brake shoes 1.1 are expanded and the brake drum 1 is moved.
Apply pressure to apply the brake.

There is no wear on the brake shoes 2, 2, and these shoes 2
, 2 and the drum 1, the pin 8h at the tip of each brake shoe 2 is allowed to move within the receiving groove 8a of the upper movable body 8b, and the above operation is repeated. When the gap becomes larger due to wear of the brake shoes 2, the brake shoes 2, 2 must be further expanded by strongly operating the brake operation unit 10 accordingly.

According to this further expansion, the pins 8ht8h of these brake shoes 2.2 press the inner surfaces 81 of the receiving grooves 8a, 8a, respectively, and the upper movable bodies 8b, 8b are pressed against the elasticity of the spring 8f. The rolling element 8e is moved outward against the
, 8e are moved outward by the elasticity of the spring 8g, and the upper movable body 8 is moved by the moving rolling elements 8e, 8e.
b, 8b are fixed in the new outer position.

Next, when the brake operation of the brake operation unit 10 is released, the transmission levers 3, 3 are pinched together, and the brake shoes 2, 2 are moved to the upper movable body 8b at the new fixed position as described above with the pins 8h, 8h. , 8b contact the inner surfaces 8J of the receiving grooves 8a, 8a, thereby preventing the brake shoes 2, 2 from getting caught, and thus the brake shoes 2, 2 stop in a slightly expanded state than before, and the brake shoes 2, 2 stop contacting the transmission levers 3, 3, respectively. The relative position of expands.

As the relative positions expand, the connecting rod 7a of each one-way clutch 7 projects a little outward from the receiver 7b, and the width of the connecting rod 7a at the location where the rolling element 7c exists becomes a little narrower, so that the gap 7d is created at that location. expands slightly.

In this way, the rolling element 7c is moved inward by the spring 7g to a position where the gap 7d is further reduced, and stops, and a new transmission relationship is established between the connecting rod 7a and the receiver 7b via the rolling element 7c at the stopped position. Form.

That is, by moving the rolling element 7c, the transmission relationship between the transmission lever 3 and the brake shoe 2 is adjusted in accordance with the expansion of their relative positions.

Note that this adjustment is achieved by the gap 7d and the rolling elements 7e, which gradually become narrower in the one-way clutch 7, so that continuous adjustment is possible.

The next braking operation is then performed in this adjusted state, and if the wear of the brake shoes 2.2 further progresses, the above-mentioned adjustment is repeated.

5 and 6 show another embodiment, in which the connecting rod 7a of each one-way clutch 7 and the receiver 7 are shown.
The surface facing the connecting rod 7a is formed into a serrated shape for engagement, and a leaf spring 71 is interposed between the connecting rods 7a, 7a.

Further, the opposing surfaces of the upper movable body 8b and the lower fixed body 8c of each one-way clutch 8 are formed into sawtooth shapes as in the case of the one-way clutch 7, and are engaged with each other.

Reference numeral 8 in the figure indicates a spring. The operation is substantially the same as in the previous embodiment, but the relative movement between the connecting rod 7a and the receiver 7b and the relative movement between the upper movable body 8b and the lower fixed body 8c largely resists the elasticity of the leaf spring 71 and the spring 8. This is accomplished by engagement with the next saw tooth, resulting in movement by tooth spacing.

As described above, according to the present invention, a one-way clutch is provided between the brake shoe that expands so as to come into pressure contact with the brake drum and the transmission lever that expands in conjunction with the operation of the brake operating section. A one-way clutch is also installed in the section to allow movement of the brake shoes in the direction of expansion of the brake shoes, so if the gap between the brake shoes and the drum widens due to wear of the brake shoes, it will be difficult to operate the brakes. Accordingly, the brake shoes are set slightly expanded according to the gap, and even in the expanded state, the brake operating force can be reliably transmitted from the transmission lever to the brake shinny, thus creating a two-wheeled vehicle without a parking brake. Also, it is possible to automatically adjust the interval between drum brakes, and the structure is simple.

[Brief explanation of drawings]

Fig. 1 is a front view of one example of the device of the present invention, Fig. 2 is an enlarged plan view with a part of its essential parts cut away, Fig. 3 is a cross-sectional view taken along I-1 [line], Fig. 4 is a FIG. 5 is an enlarged plan view of another example, and FIG. 6 is a cross-sectional view taken along the line v-v of the one-way clutch. 1... Brake drum, 2, 2... Brake shoe, 3, 3... Transmission lever, 7, 7
...One-way clutch, 8, 8... One-way clutch, 10... Brake operating section.

Claims (1)

[Claims] 1.For brakes that operate by pressing the inner wall of the brake drum by expanding the brake shoes,
Equipped with a transmission lever that expands in conjunction with the brake operating section,
A brake that connects the transmission lever and the brake shoe via a one-way clutch that transmits transmission in the expansion direction, and a one-way clutch that allows the distal end of the brake shoe to move in the expansion direction. automatic adjustment device.