JPS624736Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is applicable to automobiles, agricultural tractors, industrial machinery,
This article relates to a ball cam type disc brake suitable for construction machinery, etc.

Conventionally, when this type of disc brake is mounted on a rear axle protruding from a differential case, for example, a guide part is provided in the bearing case that supports the bearing of the differential part, and the pressure plate can be rotated and slid on the guide part. was supporting. However, if the pressure plate is guided by the bearing case of the differential part, there are restrictions on where the brake can be installed, and it is not possible to install the brake in a place where there is no bearing case. There were cases where it was not possible to install it in the correct position.

In order to solve the above problem, it is possible to adopt a structure as shown in FIG. 1.

In FIG. 1, which is a schematic longitudinal cross-sectional view, a ring-shaped ball guide 3 is attached to a bolt (not shown) inserted into a hole 4 on the outer surface of a differential housing 2 from which a rear axle 1 protrudes outward (to the right in the figure). ) is tightened. The ball guide 3 is positioned concentrically with the axle 1 by a knock pin 9 shown in FIG. 2, which is a partial sectional view taken in the direction of the arrows in FIG. As shown in Fig. 1, the ball guide 3 is moved from the inner circumference to
It includes a cylindrical guide portion 5 that protrudes to the side (right side in the figure),
An annular pressure plate 6 is fitted onto the outer peripheral surface of the guide portion 5 so as to be rotatable and slidable in the axial direction. The plate 6 and the ball guide 3 are provided with holes 7 and 8 facing each other, and a ball 10 is fitted into the holes 7 and 8 so as to be able to freely roll. The illustrated brake has eight balls 10 arranged in the circumferential direction as shown in FIG. The bottom surfaces of the holes 7 and 8 extend in opposite directions. As shown in FIG. 1, the outer periphery of the brake disc 11 faces the plate 6, and
A spline hub 13 on the inner circumference is slidably spline fitted to the axle 1. Reference numeral 15 denotes an annular plate fixed to the inner surface of the brake case 16 in a non-rotatable manner. The case 16 is fastened to the housing 2 with a plurality of bolts (not shown).
The case 16 is filled with oil.

As shown in FIG. 2, the pressure plate 6 has a bifurcated protrusion 17 projecting outward in the radial direction, and a pin 20 parallel to the axle 1 is provided in the recess 18 of the protrusion 17.
are mated. As shown in FIG.
The lever 21 protrudes from the pin 20 side toward the housing 2 side and is fitted and fixed in the hole of the lever 21, and the lever 21 extends outward in the brake radial direction from the pin 20 side, and its outer end is connected to the pin 2.
It is fixed to a pin 22 parallel to 0. pin 22
The middle part of is rotatably supported by the housing 2,
The end opposite to the lever 21 is fixed to one end of the lever 23. The other end of the lever 23 is connected to a brake pedal via a link mechanism (not shown).

When the brake pedal is depressed, the lever 23 rotates in the direction of arrow Q in FIG. 2, the lever 21 rotates in the direction of arrow F, and the pressure plate 6 is rotated in the direction of arrow F via the pin 20. It will be done. plate 6
When the ball 10 rotates, the ball 10 rolls and pushes the plate 6 toward the opposite side of the housing 2, and the plate 6 presses the disk 11 against the plate 15, so that a braking force is applied from the disk 11 to the axle 1. When the brake pedal is released, each part operates in the opposite manner to the above-described operation, and the braking force on the axle 1 is released.
In this case, the plate 6 reliably returns to the housing 2 side due to the repulsive force of the return spring 30 (tension coil spring: Figs. 2 and 2a) arranged on the inner circumferential portion of the plate 6 and the inner circumferential portion of the guide 3.

According to the structure explained above, the guide 3 that guides and supports the plate 6 is a dedicated part, and unlike the conventional structure, the pressure plate is guided and supported using, for example, a bearing case of the differential part. The brake can be easily installed in locations where a bearing case cannot be used.
The brake can be mounted in any desired position.

The above structure can also be applied to a multi-plate disc brake as shown in FIGS. 3 and 4. For example, in FIG. disks 11, 11 and annular plates 15, 1
5 are arranged alternately.

As shown in FIG. 3, the connecting pin 22a between the levers 21a and 23a can be arranged radially inward from the pin 20, and as shown in FIG.
23b may be positioned on the disk 11 side with respect to the pressure plate 6, and the lever connecting pin 22b may be rotatably supported by the brake case 16.

However, according to the above structure, since the guide part 5 and the pressure plate 6 are in surface contact with each other, the resistance when the two rotate or slide relative to each other becomes large, which makes it difficult to operate the brake lightly. The problem is that it is difficult to do.

This invention solves the above-mentioned problems, and the fifth
It is constructed as shown in FIG.

That is, in the present invention, a plurality of guide pins 25 which are parallel to the braked shaft (rear axle 1 in FIG. 1) are fixed to the inner circumferential portion of the ball guide 3 in a state protruding toward the pressure plate side. The inner periphery of the plate 6 is rotatably and slidably supported by the guide pin 25 in a line contact state.

In the structure shown in FIG. 5, the pin 25 is in direct contact with the inner periphery of the pressure plate 6, and in the structure shown in FIG. and is in contact with the pressure plate 6.

The disc brake of the present invention has a structure similar to that of the brake shown in FIGS. 1 to 4 except for the structure described above.

As explained above, according to the present invention, pin 25
Since the pressure plate 6 is supported in a line-contact state by utilizing the pressure plate 6, the plate 6 rotates and slides smoothly, and the brake can be operated easily.

In particular, when the bush 26 is used as shown in FIG. 6, the brake can be operated extremely smoothly, and the durability of the brake can be improved by preventing wear of the pin 25 and plate 6.

[Brief explanation of the drawing]

Fig. 1 is a schematic longitudinal cross-sectional view of a structure different from the present invention that can solve the problems of general conventional products, and Fig.
Figure 2a is a partial cross-sectional view taken along the line a-a in Figure 2, and Figures 3 and 4 are longitudinal cross-sections of a multi-plate brake employing the pressure plate support structure shown in Figure 1. 5 and 6 are schematic longitudinal cross-sectional views of different embodiments of the present invention. 1... Rear axle (braked shaft), 2... Housing, 3... Ball guide, 6... Pressure plate, 10... Ball, 11... Brake disc, 16... Brake case, 20, 21
...Pin and lever (part of the rotation mechanism), 25...
pin.

Claims (1)

[Scope of utility model registration request] An annular ball guide is fixed concentrically with the braked shaft to the housing from which the braked shaft protrudes, and an annular pressure plate is arranged concentrically with the braked shaft so as to face the ball guide. A plurality of guide pins parallel to the braked shaft are fixed to the periphery in a state protruding toward the pressure plate side, and the inner periphery of the pressure plate is rotated and slid in line contact with the guide pins. A ball cam mechanism is provided between the pressure plate and the ball guide, a rotation mechanism for rotating the plate is connected to the pressure plate, and a brake disc is spline-fitted to the shaft to be braked. 1. A disc brake characterized in that a ball cam mechanism is provided between a pressure plate and a brake case so that rotation of the pressure plate causes a ball cam mechanism to press the plate toward the brake disc.