JPS6326582Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an adjustment device for adjusting the gap between the lining and the drum to an optimum state when the brake is not activated in a uniservo drum brake for a bicycle.

FIG. 1 shows the main parts of a conventional uniservo type drum brake. 1 is a board, 2 is a cam for pushing and expanding the first shoe, and the shaft 3 of the cam 2 is rotatably attached to the board 1, and is rotated in the direction of arrow X in the figure by a crank that is linked to a brake wire (not shown). do.

4 is a first shoe with a lining layer 5 provided on its outer surface; 6 is a second shoe with a lining layer 7 provided on its outer surface; one end of the first shoe 4 is in contact with the flat part 2a of the cam 2; One end is in contact with the cam shaft 3, and the other end of the shoes 4, 6 is in contact with a concave contact surface 8.
and the convex abutment surface 9 are fitted into each other.

Reference numeral 10 denotes a spring tensioned between the first shoe 4 and the second shoe 6 so as to draw them together;
One end of the second shoe 6 is brought into contact with the flat surface 2a of the cam 2, and one end of the second shoe 6 is brought into contact with the shaft 3 of the cam. 11 is a protruding piece 12 cut and raised from the substrate 1
A spring tensioned between the second shoe 6 and the second shoe 6 urges the other end of the second shoe 6 toward the first shoe.

Reference numeral 13 denotes a stop cam for adjusting the gap between the lining layer and a brake drum (not shown) disposed outside the lining layer, and its shaft 14 is rotatably attached to the base plate 1, and a second shoe is attached to the cam surface. The abutting pin 15 is in contact with it.

To adjust the gap between the lining layer and the drum, the shaft 14 of the abutment cam 13 is rotated from the outside of the substrate 1 to change the position of the cam that abuts the abutment pin 15, and the second shoe 6 is brought into contact with the abutment pin 15. This is done by adjusting the position.

Conventional examples with such a configuration have the following drawbacks.

1 When trying to adjust the rotation angle of the cam by operating the camshaft 14, the camshaft is close to the center of the drum and parallel to the direction of the drum axis, so in the case of a bicycle, the frame or stand may become an obstacle. , It is difficult to insert tools and make adjustments.

2. Due to the contact by the cam 13, the cam is rotated in the opposite direction due to the reaction force of the contact, and the adjusted position becomes incorrect.

3. It is necessary to provide the stopper pin 15 on the second shoe, which increases the number of parts and increases the number of man-hours required for machining operations such as caulking the pin. Furthermore, since a cam is used, machining the cam is difficult.

In addition, the ends of the first shoe and the second shoe are connected by a pin, and a screw threaded onto the exterior member of the brake is brought into contact with the extension of the pin, and the lining gap is adjusted by moving the screw forward and backward. There is also a known structure (Japanese Utility Model Publication No. 56-34185).

According to this structure, the adjustment of the lining gap is
This can be done by adjusting screws in a direction perpendicular to the center axis of the drum, and the workability is good. However, it has the following drawbacks.

1. Since the pin is inevitably cylindrical in structure,
When the shoe is expanded by the cam, the tip of the screw does not always come into contact with the outer periphery of the pin at right angles, which poses problems in accuracy and durability.

2. Since the pin is rotatably inserted into the hole in the shoe, the pin structurally requires room for movement in the radial direction within the hole. Therefore, the movement of the pin makes the screw contact uncertain, and the pin Rotation and deformation occur, making precise adjustment of the lining gap impossible.

3. There are many parts, processing precision and strength are required, and the manufacturing cost is high.

The present invention solves the above-mentioned conventional inconveniences by bending and raising a part of the first shoe or the second shoe to form an abutting part that protrudes outward from the board, and at the same time is bent and raised to form a support portion for the screw parallel to the contact portion, and the screw held by this support portion is brought into contact with the contact portion.

According to the present invention, the lining gap can be easily adjusted by moving the screw forward and backward from outside the board. In addition, since the contact part and the screw support part are formed by bending and raising the shoe and the board, there is no need to attach other parts, and since the contact part of the screw can be made larger, the screw can be screwed regardless of the movement of the shoe. can be brought into reliable contact with the abutting part, and can be manufactured easily and inexpensively without requiring high machining precision. Further, by providing the abutting portion at a position away from the axis of the cam that pushes and spreads the first shoe, fine adjustment is also possible.

Hereinafter, the present invention will be explained in more detail with reference to FIGS. 2 and 3.

In FIG. 2, the same reference numerals as in FIG. 1 represent the same elements. That is, the spring 10
It has the role of drawing the shoe 4 and the second shoe 6 together and pressing the end faces of both against the flat portion 2a of the cam 2 or the shaft 3.

The cam 2 is rotatable around a camshaft 3, and the camshaft 3 is operated from outside the brake body by a lever (not shown). Since the cam 2 has a flat part 2a, by rotating, the first shoe 4
Push open.

The first shoe 4 transmits the force pushed by the cam 2 to the second shoe 6 at the other end, but since an extremely large pressure is generated at the contact area of both shoes during operation, it is better to make contact over as wide an area as possible. , Therefore, the first shoe 4 has a concave contact surface 8,
The second shoe 6 is provided with a convex abutment surface 8. However, even if this part does not have this configuration, instead of creating an abutting surface for both shoes, the ends of both shoes are overlapped and rotatably supported with a pin, and the first shoe 4 to the second shoe 6 The pressure may be transmitted by the pin.

Next, the adjustment of the gap between the lining and the drum will be described.

First, the second shoe 6 is pulled toward the first shoe 4 by the spring 11, and biased to ensure a gap between the second lining 7 and a drum (not shown).
One end of the spring 11 is fixed to a hole provided in the second shoe 6, and the other end is locked to a raised cut 12 provided in the substrate 1.

Since the second shoe 6 pushes the first shoe 4 due to the biasing force of the spring 11, the gap between the first lining 5 and the drum becomes smaller. In order to fix this movement and support the shoe, for example, bend and raise a part of the sheet metal member of the first shoe 4 (or the second shoe) and guide it out of the brake body through the hole 16 provided in the base plate 1. forming part 17;
Further, a member is bent up by bending from the substrate 1, and is erected parallel to the abutment part 17, and is located on the opposite side of the second shoe 6 when viewed from the abutment part 17, and a screw support part 18 is provided. Support part 18
By passing a screw 19 through and bringing the tip of the screw 19 into contact with the contact portion 17, the biasing force of the second shoe 6 described above is received.

When screw 19 is tightened, screw 1 will be attached to contact part 17.
Since the tip of the drum 9 makes contact quickly, the gap between the first lining 7 and the drum becomes wider. Conversely, when the screw 19 is returned, the gap between the first lining 5 and the drum becomes narrower, and the gap between the second lining 7 and the drum becomes wider.

20 is a lock nut for fixing the rotation of the screw 19.

As described above, according to the present invention, the gap between the left and right linings can be easily adjusted. That is, since the center axis of the adjusting screw 19 is perpendicular to the center axis of the drum, that is, facing toward the outer circumferential direction of the brake body, this is convenient when operating with a tool. This is because in the case of a car, the brake body is embedded in the wheel, and there is no space around the outer circumference of the brake, so it is easier to operate if the adjustment part is in the axial direction of the drum, but in the case of a bicycle, the drum brake is located outside the wheel and is mounted between the frame and the wheel, so there is space in the outer circumferential direction, but the frame, stand, and other metal fittings become obstacles in the direction of the drum axis. The structure makes it difficult to insert tools.

In addition, since the contact part is formed by using a part of the sheet metal forming the first shoe, and the support part of the screw by the board is also formed by bending and raising the sheet metal forming the board, there is no need to attach extra parts. It has the advantage of having fewer parts and fewer parts.

[Brief explanation of the drawing]

Fig. 1 is a side view showing the main parts of a conventional drum type brake, Fig. 2 is a side view showing the main parts of the drum type brake according to the present invention, and Fig. 3 is Fig. 2-'
FIG. 1... Board, 2... Cam, 4... First shoe,
6...Second shoe, 10, 11...Spring, 17...
...Attaching part, 18...Screw support part, 19...Screw.

Claims (1)

[Scope of utility model registration request] a base plate that supports the brake body; a cam rotatably supported by the base plate for pushing open the first shoe; and a first shoe that has one end in contact with the cam and the other end that transmits a pressing force to the second shoe. a second shoe that receives pressure from the first shoe at one end and is supported by the shaft of the cam at the other end; and a spring that biases the second shoe toward the first shoe. , 1st
A part of the shoe or the second shoe is bent and raised to protrude from the base plate to the outside of the brake body to form a contact part, and a part of the base board is bent and raised to form a support part for the screw parallel to the contact part. and a lining gap adjustment device for a drum type brake in which a screw held by the support part is brought into contact with the contact part.