JPS6353405B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a boot of a sliding support portion of a pin slide type disc brake.

In general, pin slide type disc brakes consist of a support fixed to the edge of the rotor, and a pad such as a hydraulic cylinder device installed in a leg on one side of the rotor that straddles the rotor. It is equipped with a caliper that has the ability to operate a pressing mechanism and slide in the rotor axial direction, and a pair of opposing friction pads that are pressed against the rotor by the caliper, and the caliper has sliding properties in the rotor axial direction. Since the sliding support part configured to obtain mobility can be constructed by sliding a slide pin fixed to one side of the support or caliper and an opening formed in the other side, the sliding part can be sealed from the outside air. It is known as having the feature that it can be relatively easily assembled by attaching boots, etc.

Also, looking at the sliding support part of such a pin type disc brake from another perspective, it is common to have a pair of pin slide mechanisms on the left and right to support the caliper. It is necessary to take into consideration problems such as deviation in parallelism of the opening, pitch error, etc. Therefore, a rubber bushing is often interposed on the sliding surface of the slide pin and the opening.

In response to recent demands for weight reduction of vehicle tower-mounted equipment or structural simplification, many types of slide pins are fixed on the support side in a cantilevered manner. Efforts have also been made to reduce the number of parts by integrating the boots.

By the way, the bellows structure of such a boot effectively protects the sliding part between the slide pin fixed to one side of the support or caliper and the opening formed in the other side from the outside air, taking into consideration the sliding movement of the caliper in the rotor axial direction. Furthermore, this sliding joint is expandable and contractable so that it can absorb a certain amount of relative movement from when the friction pad is new to when it reaches its limit of wear as the pad lining wears out. However, if the wall is too thin, it will have poor durability and will be vulnerable to flying stones from the outside, so it is common to use an elastic body with a certain thickness.

However, in such a configuration, since the peaks and valleys of the bellows are at acute angles, an elastic repulsion force is generated against elongation or contraction beyond a certain level, and the elasticity is smaller than the total length in its natural state. There was a problem that the effective length of expansion and contraction without generating a large repulsive force was not very large. In other words, if this elastic repulsive force becomes large, it will adversely affect the sliding of the caliper or the securing of the stationary position.

The present invention has been made with the aim of reducing such problems as much as possible, and the crests and troughs of the bellows part of the boot are formed into thick walls that extend approximately in the axial direction, and the part that connects them is made of a thick wall. By providing a relatively thin wall and making the connection between the connecting part and the thick part at an obtuse angle, the elastic repulsion force at the time of extension is made as small as possible. Specifically, the rotor edge a support fixed to the support and a slide pin fixed to one side of the caliper that operates to straddle the rotor edge and press the pair of friction pads against the rotor; an opening that supports the caliper so as to be movable in the rotor axial direction by slidingly engaging with the slide pin; and an opening extending from the edge of the opening to the outer periphery of the slide pin;
In a pin-type disc brake equipped with these slide pins and a boot that seals the sliding portion of the opening from the outside air, the boot has a bellows-like body that provides elasticity in the axial direction and has a fixed length in the axial direction. It has thick crests and troughs, and relatively thin connecting parts that connect these crests and troughs, and the continuous shape of these crests and troughs and the connecting part has a gentle slope in its natural state. This is a pin-type disc brake boot that is characterized by its configuration.

The present invention will be explained below with reference to an embodiment shown as a boot integrated with a bushing in a pin type disc brake equipped with a cantilevered slide pin.

In the figure, 1 is a boot with an integrated bushing, 1 is a bushing part that is fitted into a through opening of a caliper (not shown), a groove 2 is formed on its outer periphery, and a support is provided on its inner periphery. Vertical grooves 3, 3, . . . for air venting in the axial direction are formed on the sliding surface of the slide pin (not shown) fixed in a cantilevered manner.

4 is a first boot portion that seals the free end side of the slide pin from the outside air.

Reference numeral 5 designates a second boot portion extending from the bush portion 1 to the opposite side of the first boot portion 4, and the enlarged tip portion 7 of the bellows-like trunk portion 6 is configured to tightly fit around the outer periphery of the slide pin. It is provided.

The feature of this example is that the shape of the bellows-like body part 6 of the second boot part 5 is characteristic, and the peaks 6a and troughs 6b of the body part 6, which has a wavy cross section as shown in the figure, are constant in the axial direction. The connecting portion 6c that connects the peak portion 6a and the valley portion 6b is provided with a relatively thin wall, and the connection shape between the peak portion 6a and the valley portion 6b is an obtuse angle. (In other words, it is set so as to form a gentle slope).

According to such a configuration, the connecting portions 6c, 6c...
is relatively thin, so the repulsive force against deformation is small, and since there are thick peaks 6a or troughs 6b between the connecting parts 6c, 6c, etc., the structure is such that deformation is difficult to be transmitted to other parts. Therefore, the problem of adverse effects during expansion and contraction is greatly reduced, and there is an advantage that it can be suitably handled even when the relative sliding amount between the slide pin and the opening is relatively large. In addition to the effect that there is less risk of damaging the sealing performance of the tightening engagement, the diameter of the boot crest is not too large compared to conventional ones, and elasticity can be secured, so the volume of the mounting part is secured. It has the advantage of being excellent in terms of durability and damage prevention because the thick portion is located sufficiently long in the axial direction.

As described above, the present invention allows for orderly deformation and a corresponding reduction in elastic repulsion by varying the thickness of the bellows-shaped body of the boot, thereby expanding the effective range of expansion and contraction. , its usefulness is extremely great.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a boot showing an embodiment of the present invention, and FIG. 2 is an enlarged view of the same part. 1...butsuzu, 2...concave groove, 3...vertical groove, 4
...First boot section, 5...Second boot section, 6...
Bellows-shaped trunk, 6a...crest, 6b...trough, 6c
... Connecting part, 7... Ampulla.

Claims (1)

[Claims] 1. A support fixed to the rotor edge, a slide pin fixed to one side of the caliper that straddles the rotor edge and operates to press a pair of friction pads against the rotor, and a slide pin formed on the other side of the support and caliper. and an opening that supports the caliper so as to be movable in the axial direction of the rotor by slidingly fitting with the slide pin, and an opening extending from the edge of the opening to the outer periphery of the slide pin to seal the sliding portion of the slide pin and the opening from outside air. In a pin type disc brake equipped with a stopping boot,
The boot has a bellows-like body that provides elasticity in the axial direction, and has thick crests and troughs of a certain length extending in the axial direction, and a relatively thin connecting portion that connects these crests and troughs. A pin type disc brake boot characterized in that the continuous shape of these peaks, valleys, and connecting parts forms a gentle slope in a natural state.