JPS624738Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a disc brake, and more particularly, to a disc brake that incorporates a service brake mechanism and a parking brake mechanism, ensures that the rod arm is prevented from coming off, and is easy to maintain.

A disc brake that has a parking brake mechanism, that is, a parking lever is fixed to the end of a rod arm that is inserted into the caliper body of the disc brake, and a spindle that moves forward and backward as the rod arm rotates is linked to the main piston. In the case of a brake, when the rod arm is prevented from coming off by a torsion spring for reciprocating the parking lever, there is no need for a special prevention. However, in a type of disc brake in which an elastic restoring member for returning the spindle, such as a disc spring, is built into the caliper body, it is necessary to separately prevent the rod arm from coming off.

As an example of a retainer used in such a case, there is a known example in which the tip of the rod arm protrudes through the caliper body and a circlip is attached to the tip of the rod arm to prevent the rod arm from coming off. This type of disc brake has various problems, such as a decrease in the strength of the caliper body, an increase in the number of places where foreign matter can get into the caliper cylinder, and an increase in the number of tools required during disassembly and maintenance.

Another problem with disc brakes is the thinning of the canopy body and the maintenance of strength that can cope with the forces exerted by the parking mechanism inserted within the caniper body. This is noticeable when the carripa body is made of light alloy in order to further reduce weight. In other words, a carrier body made of light alloy has lower strength than a carrier body made of cast iron, especially when the caliper cylinder end is open and various parking mechanisms and adjusting mechanisms are built into the caliper cylinder as a housing. In this case, the parking mechanism drive section for transmitting the parking force to the parking mechanism applies a tensile force to the caliper body, and the caliper cylinder must be extended by a length that can withstand this tensile force. In terms of shape, the protruding portion becomes longer, which limits the mounting space for the disc brake, resulting in a shape that is difficult to install. Moreover, when sealing the rear end cylinder opening of the caliper body, simply using a rubber boot is not reliable and cannot sufficiently shut off dust, sand, salt water, etc. It is necessary to install a cap or cover plate with a

This idea was made in view of the above points,
The purpose is to slidably fit the piston 18 into the caliper cylinder 12 of the caliper body 10, provide a spindle 30 connected to the piston 18, and move the spindle 30 in the brake release backward direction with respect to the brake. A rod arm 36 is inserted into the rear position of the spindle 30 perpendicularly to the caliper cylinder 12, and the rod arm 36 is rotated by the spindle as the parking lever 66 rotates. The spindle 30 moves forward and backward in the direction of the cylinder axis.
In the parking brake mechanism of the disc brake connected to the cylinder 12, the outer curved surface of the connecting portion that connects the two upright walls of the U-shaped cross section has a U-shaped cross section with a constant depth, and the outer curved surface of the connecting portion has a curvature equal to the inner wall curved surface of the caliper cylinder 12. and a fixing part 40 having an arc-shaped notch 44 on one end side in the upright direction of both the upright walls and in a direction perpendicular to the upright direction of the upright walls; Cushion tongue portion 4 integrally provided on the other end side of both upstanding walls
An annular groove 37 corresponding to the notch 44 is provided on the outer periphery of the rod arm 36 so as to restrict the movement of the rod arm 36 in the axial direction. 40, and the connecting portion outer curved surface of the fixing portion 40 is fitted into the caliper cylinder 1.
2, and the cushion tongue 44' is connected to the bottom curved surface of the inner wall of the caliper cylinder 12, and the cushion tongue 44' is attached to a cover that covers the opening of the caliper cylinder 12 or to the inner wall of the caliper cylinder 12, so that the cutout portion 44 reliably contacts the annular groove 37. To provide a disc brake characterized in that it is locked to a locking part such as a concave and convex part of the disc brake.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

In the left side view of the carrier body 10 shown in FIG. 1 and the vertical longitudinal sectional view of the same left side shown in FIG.
Coaxial caliper cylinders 12a, 12b, and 12c are drilled through the inside of the cylinder 0 in the left-right direction. The caliper cylinder 12a has a large diameter and the bracket 14
A main piston 1 driven by hydraulic pressure to push the inner pad 16 supported by the main piston 1 to the left.
Interpolate 8. An outer pad 20 is disposed inside the reaction force piece of the caliper body 10 facing the inner pad 16, and presses both sides of the disc rotor 24. The caliper cylinder 12b following the caliper cylinder 12a has a small diameter and has a main piston 18.
The right half of the spindle 30 that abuts through the sub-piston 26 and an adjustment nut 28 press-fitted into the sub-piston 26 is inserted and supported. Inside the caliper cylinder 12c, which has a larger diameter than the caliper cylinder 12b and has a stepped portion between it and the caliper cylinder 12b on the left side, there is a spindle 30.
Cam follower 3 transmits parking force to the right end
2, and a rod arm 36 formed with a cam groove 34 through which the cam follower 32 is inserted. The rod arm 36 is orthogonal to the axis of the caliper cylinder 12c, and is inserted in the front-rear direction with the front side slightly upward.
8 and 38. Kyaripa body 1
The rod arm retaining member 39 for preventing the rod arm 36 from slipping out from the shaft has a U-shaped cross section, and has a connecting portion 4 that coincides with and contacts an arc formed on the inner wall of the caliper cylinder 10.
0, and U-shaped standing walls 42, 4 in FIG.
Each front end of the upper part of 2 is notched to form a 1/4 arc to form notches 44, 44;
44 engages with annular grooves 37, 37 formed on the outer periphery of the rod arm 36 in the rotational direction, respectively.
The connecting portion 40 and the notches 44 constitute a fixing portion. Cushion tongues 44', 44' are formed on the upper portions of the U-shaped upright walls 42, 42 of the rod arm retaining member 39, extending slightly rearward and gradually becoming parallel to the plane formed by the U-shape. The right end of the caliper cylinder 10 has a convex portion 46 that partially fits therein.
A thick metal cover plate 48 formed of
The cushion tongue 44' of the rod arm retaining member 39 is completely fixed to the main body of the carrier body 10 by three tightening bolts 50 extending in the axial direction of the carrier cylinder 12c. It comes into contact with the inner surface and exerts a resilient force on the rod arm 36.

To explain in more detail each component in the caliper body 10, the adjusting nut 28 and the male threaded portion 52 of the spindle 30 inserted therein are screwed together with a slight meshing play in the axial direction of the screw.
The sub-piston 26 into which the adjustment nut 28 is press-fitted is inserted into the main piston 18 and is connected to a bearing ball 54, a wave washer 56, and a circlip 58.
It is connected to the main piston 18 via. Regarding the spindle 30, the right portion of the spindle 30 is inserted into the caliper cylinder 12b, and an annular groove that goes around the spindle 36 is provided in the caliper cylinder 12b fitting portion of the spindle 30, and the seal ring 60 is inserted therein. A flange portion 62 is formed by expanding the diameter of the right end of the spindle 30, and disc springs 64 are alternately stacked between the left end surface of the flange portion 62 and a stepped portion formed between the caliper cylinders 12b and 12c. The elastic restoring member is compressed and the flange portion 6
A groove is formed on the right end surface of 2 to allow the left end of the cam follower 32 to pass therethrough. The fixing part of the parking lever 66 to the outer end of the rod arm 36 is formed by forming a prismatic part at the end of the rod arm 36, and fitting this prismatic part into the square hole of the parking lever 66. A retaining nut 68 is secured thereto. The upper end of the parking lever 66 passes through the bifurcated arms and is provided with a through hole 68' extending in the front-rear direction in FIG. A hook for the inner wire is inserted, the inner wire is inserted into the outer wire, and the end of the outer wire is extended forward from the lower part of the cover plate 70 as shown in FIG. The outer wire end holder is fixed to a guide hole 74 formed in the extending end 72, which acts as a guide hole 74, with a nut. This inner wire is subjected to tension by a parking brake (not shown).

The parking operation of the disc brake in the above configuration will be described. When the parking brake is pulled, the inner wire inside the outer wire is pulled downward in FIG. When pulled against the force, the rod arm 36 fixed to the parking lever 66 rotates clockwise, and the rod arm 3
The axial cam groove 34 cut at 6 presses the cam follower 32 to the left. This pressing force is applied to the spindle 30, adjustment nut 28 and sub-piston 26.
is transmitted to the main piston 18 via the rotor 2
Press 4 to perform the parking operation. The rod arm retaining member 39 is pressed in the direction of the rod arm 36 by its cushion tongue 44', and the notch 44 of the fixing portion is inserted into the annular grooves 37, 3 of the rod arm 36.
7, the rod arm 36 is reliably prevented from coming off, and the rotation of the rod arm 36 is not hindered at all.

In addition to the simple integrated retaining member made by press molding, the rod arm retaining member may be a separate molded elastic cushion member or a plurality of retaining members may be used to achieve the same effect. Any conventional means that can be used may be adopted. For example, it is easy to use not only a U-shaped retaining member but also an O-shaped retaining member having two arcuate cutouts.

In this way, according to the present invention, the curved surface of the rod arm retaining member comes into close contact with the inner surface of the caliper cylinder, making it easy and reliable to install, and as a result of being constantly pressed against the rod arm by the cushion tongue, it is resistant to vibrations. , there is no risk of it coming off the annular groove. Moreover, when a force is applied to the rod arm in the direction of pulling out the rod arm, the force in the pulling out direction is transmitted from the upper edge of the rod arm removal prevention member to the connecting part, and since the connecting part is in close contact with the inner surface of the caliper cylinder,
The reaction force is returned to the notch via the bottom of the shape, resulting in an increase in the pressing locking force. In addition, removal and replacement of the retaining member during disc brake maintenance and servicing can be done by simply removing the cover plate that the rod arm retaining member is in contact with, without the need for any tools, reducing the time and effort required for replacement. Minimal tools required. Furthermore, since the rod arm retaining member itself is located inside the caliper cylinder and is completely protected, there is almost no need for maintenance or replacement, and the reliability of the disc brake is improved by reducing the strength of the caliper body and reducing the chance of foreign matter getting in. Significantly improved.

Although the present invention has been variously explained above with reference to preferred embodiments, the present invention is not limited to these embodiments, and it goes without saying that many modifications can be made without departing from the spirit of the invention. It is.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention;
The figure is a left side view of the disc brake, a vertical cross-sectional view of the left side, and Figure 3 is a vertical cross-sectional view of the rod arm fixing part.
FIG. 4 is a perspective view of the rod arm retaining member, and FIG. 5 is a front view of the disc brake. 10... Caliper body, 12a, 12b, 1
2c...Caliper cylinder, 14...Bracket, 16...Inner pad, 18...Main piston, 20...Outer pad, 24...Disc rotor, 26...Sub piston, 28...Adjusting nut, 30...Spindle , 32...cam follower, 34...cam groove, 36...rod arm,
37...Annular groove, 38...Bearing, 39...
Rod arm removal prevention member, 40... Connection part, 42...
... U-shaped upper part, 44 ... Notch part, 44' ... Cushion tongue part, 46 ... Convex part, 48 ... Cover plate, 50 ... Tightening bolt, 52 ... Male thread part, 5
4... Bearing ball, 56... Wave washer, 58... Circlip, 60... Seal ring, 62... Flange portion, 64... Belleville spring, 6
6... Parking lever, 68... Locking nut,
68'...Through hole, 70...Cover plate, 72
...extending end, 74...guiding hole.

Claims (1)

[Scope of utility model registration request] A piston 18 is slidably inserted into the caliper cylinder 12 of the caliper body 10, and a spindle 30 is provided in conjunction with the piston 18, so that the spindle 30 is resiliently moved in the brake release backward direction in response to the brake. An elastic restoring member is provided, and a rod arm 36 is inserted at a rear position of the spindle 30 perpendicular to the caliper cylinder 12, and the rod arm 36 is moved forward and backward in the direction of the cylinder axis as the parking lever 66 rotates. In the parking brake mechanism of the disc brake connected to the spindle 30, the outer curved surface of the connecting portion that connects the two upright walls of the U-shaped cross section forms a U-shaped cross section with a constant depth. An arc-shaped notch 44 is provided at one end of each of the upright walls in a direction perpendicular to the upright direction, and which matches the curved surface of the inner wall in curvature. A rod arm retaining member 39 consisting of a fixing portion 40 and a cushion tongue portion 44' integrally provided on the other end side of both the upright walls is attached to the rod arm 36 so as to restrict movement of the rod arm 36 in the axial direction. An annular groove 37 corresponding to the notch 44 is provided on the outer periphery of the annular groove 37 , and the notches 44 of the fixing part 40 are respectively fitted into the annular groove 37 , and the outer curved surface of the connecting part of the fixing part 40 is connected to the bottom of the inner wall of the caliper cylinder 12 . A cover that covers the opening of the caliper cylinder 12 or a concave-convex portion of the inner wall of the caliper cylinder 12 is attached to the cushion tongue 44' so that the cutout portion 44 reliably contacts the annular groove 37. A disc brake characterized by being locked in a locking part of.