JP4155869B2 - Disc brake with parking mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a disk brake furnished with a parking mechanism, capable of lessening the number of constituent components of a parking brake mechanism, facilitating fabrication of the component parts, their management, and the assembling work, and reducing the cost of the disk brake. <P>SOLUTION: The disk brake furnished with the parking mechanism is structured so that balls 17 are moved to the shallower parts of cam grooves 18a and 18b in association with the rotation of a cam member 15a generated by a parking lever 19a so as to press a piston 6a through a rod 8a and an adjusting nut 42. The parking lever 19a is coupled with the cam member 15a between the rod 8a and an anchor member 12a coupled fast to calipers 4a, and thereby the required number of the components is reduced. <P>COPYRIGHT: (C)2005,JPO&amp;NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The disc brake with a parking mechanism according to the present invention is used for braking an automobile. In particular, the present invention simplifies the structure of a disc brake provided with a parking brake mechanism for keeping a vehicle in a stopped state, and realizes a low-cost structure.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, disc brakes having various structures have been known for braking automobiles. Various disc brakes with a parking mechanism have been proposed and used in practice as described in Patent Document 1, for example. 7 to 9 show a disc brake with a parking mechanism described in Patent Document 1. FIG. A pair of pads 2 a and 2 b are arranged on both sides of the rotor 1 that rotates together with the wheels while being supported by the support 3. A caliper 4 is supported on the support 3 so as to be displaceable in the axial direction of the rotor 1. Then, a piston 6 fitted in a cylinder 5 provided inside the inner side of the caliper 4 (the center side in the width direction when assembled to the vehicle, the right side in FIG. 8), and the outer side (vehicle of the caliper 4) The two pads 2a and 2b are clamped from both sides in the axial direction of the rotor 1 by the claw portion 7 provided on the outer side in the width direction in the assembled state to the left side in FIG.
[0003]
Also, a rod 8 for constituting a parking mechanism is provided in a state of penetrating liquid-tightly through a cylinder bottom 9 that partitions the inner end of the cylinder 5 of the caliper 4 and protruding out of the cylinder 5. The rod 8 presses the piston 6 against the inner side surface of the rotor 1 along with the axial movement in the direction approaching the rotor 1. In the illustrated example, the piston 6 and the rotor side of the rod 8 are coupled via a gap adjusting mechanism 10 formed by combining a plurality of components, whereby the linings 11 and 11 of the pads 2a and 2b are worn. Regardless of this, the gap between the linings 11 and 11 and the side surface of the rotor 1 is kept constant during non-braking.
[0004]
Further, a cam mechanism 13 for pressing the rod 8 against the piston 6 is provided between the anchor member 12 fixed to the outside of the cylinder bottom 9 of the caliper 4 and the rod 8. In order to constitute the cam mechanism 13, a rotary shaft portion 22 provided in the cam member 15 is rotatably inserted into a circular hole 14 provided concentrically with the rod 8 in the anchor member 12. A plurality (three in the illustrated example) of balls 17 and 17 are sandwiched between the cam plate 16 provided at the rotor side end of the cam member 15 and the anchor member 12. Cam grooves 18a and 18b in which the depth in the axial direction gradually changes in the circumferential direction are formed in the portion where the balls 17 and 17 are sandwiched between the opposing surfaces of the cam plate portion 16 and the anchor member 12. is doing. Further, a base end portion of the parking lever 19 is coupled and fixed to a portion of the rotating shaft portion 22 that protrudes from the anchor member 12 to the side opposite to the rotor.
[0005]
In the case of a disc brake with a parking mechanism configured as described above, when a service brake (a brake for decelerating or stopping a traveling vehicle) is used, this cylinder 5 is fed by feeding pressure oil into the cylinder 5. The piston 6 is protruded from. As a result, the caliper 4 is displaced toward the inner side of the support 3 at the same time as the piston 6 presses the inner pad 2 a against the inner side surface of the rotor 1. The claw portion 7 of the caliper 4 presses the outer side pad 2 b against the outer side surface of the rotor 1. As a result, the rotor 1 is strongly clamped from both sides by the pair of pads 2a and 2b, and braking is performed.
[0006]
On the other hand, at the time of parking brake, the cam member 15 is rotated via the parking lever 19 by pulling the parking cable 20. As a result, the balls 17 and 17 move while rolling to the shallow portions of the cam grooves 18a and 18b, and the cam plate portion 16 and the anchor member 12 formed with the cam grooves 18a and 18b. Increase the distance between the surfaces facing each other. The cam plate portion 16 is displaced toward the rotor side, and the cam plate portion 16 pushes the piston 6 toward the rotor side via the rod 8. As a result, as in the case where pressure oil is fed into the cylinder 5, the rotor 1 is strongly held from both sides by the pair of pads 2a and 2b, and braking is performed.
[0007]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-12518
[Problems to be solved by the invention]
In the case of the disc brake with a parking mechanism described in Patent Document 1 as described above, there are many components of the parking brake mechanism, and parts production, parts management, and assembly work are all cumbersome and it is possible to avoid an increase in cost. Absent. For example, in addition to using three bolts 21, 21 to fix the anchor member 12 to the caliper 4, in order to prevent the parking lever 19 from coming out of the rotating shaft portion 22 of the cam member 15, A nut 23 is screwed onto the male screw portion formed by the rotating shaft portion 22. Further, in order to transmit only the axial force between the cam plate portion 16 and the rod 8 that rotate relative to each other, a second ball 24 is provided at the center of the inner end surface of the rod 8. Furthermore, a dedicated member (independent of itself) is also used for the guide member 25 for guiding the parking cable 20 for rotating the parking lever 19.
[0009]
Considering these things, in order to reduce the cost of the disc brake with the parking mechanism, the number of components of the parking brake mechanism should be reduced to facilitate the production of parts, the management of parts, and the assembly work. Becomes important.
The disc brake with a parking mechanism of the present invention has been invented in view of such circumstances.
[0010]
[Means for solving the problems]
The disc brake with a parking mechanism according to the present invention includes a pair of pads, a caliper, a rod, a cam member, an anchor, and a disc brake with a parking mechanism described in Patent Document 1 and conventionally known. A member and a parking lever are provided.
Among these, a pair of pad is arrange | positioned at the both sides of the rotor which rotates with a wheel.
Further, the caliper presses both the pads against both axial sides of the rotor as the piston fitted in a cylinder provided therein is pushed out.
In addition, the rod penetrates the bottom of the cylinder in a liquid-tight manner by a part of the caliper and protrudes out of the cylinder, and presses the piston toward the rotor as it moves in the axial direction.
The cam member is rotatably provided around the central axis of the rod on the side opposite to the rotor (the side far from the rotor) from the rod, and presses the rod toward the piston with relative rotation with respect to the rod. .
The anchor member is for supporting a reaction force applied to the cam member as it is pressed by the cam member.
The parking lever is for rotating the cam member.
[0011]
In particular, in the disc brake with a parking mechanism of the present invention, the coupling portion between the base end portion of the parking lever and the cam member is disposed between the anchor member and the rod. Further, the base end portion of the parking lever is externally supported by the cam member so as to be able to transmit rotational force directly. Further, the anchor member is coupled and fixed to the caliper by a coupling member.
Further, preferably, as described in claim 2, the cam lever is rotated by pulling a parking cable coupled to a tip of the parking lever, and the rod is pressed toward the piston. A guide portion for guiding the parking cable is integral with the anchor member.
[0012]
[Action]
In the case of the disc brake with a parking mechanism of the present invention configured as described above, it is possible to reduce the number of components of the parking brake mechanism and to facilitate the manufacture of parts, the management of parts, and the assembly work.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
1 to 4 show an example of an embodiment of the present invention corresponding to all claims . The disc brake with a parking mechanism of this example includes a support 3a, a pair of pads 2a and 2b, and a caliper 4a.
Of these, the support 3a is fixed to the vehicle body (a suspension device such as a knuckle) while straddling the rotor 1 (see FIGS. 7 to 8) that rotates with the wheels. The pads 2a and 2b are disposed on both sides of the rotor 1 in a state where the pads 2a and 2b are supported by the support 3a so as to be capable of displacement in the axial direction of the rotor 1.
[0014]
The caliper 4a is integrally formed of cast iron or the like. For the support 3a, a pair of guide pins 26 and 26 provided on the caliper 4a side and a pair of guides provided on the support 3a side. Based on the engagement with the portions 27, 27, the rotor 1 is supported by being displaceable in the axial direction. Such a caliper 4a is provided on the outer side by abutting the front end surface (left end surface in FIG. 4) of the piston 6a fitted in the cylinder 5a provided inside the inner side against the back surface of the pad 2a on the inner side. The inner surface of the claw portion 7a is brought into contact with the back surface of the outer pad 2b. Such a caliper 4a presses both the pads 2a and 2b against both axial sides of the rotor 1 as the piston 6a is pushed out based on the pressure oil fed into the cylinder 5a. The above configuration is the same as that of a conventionally known floating caliper type disc brake.
[0015]
On the other hand, in the case of the disc brake with a parking mechanism of this example, a rod 8a, a cam member 15a, an anchor member 12a, and a parking lever 19a are provided to constitute the parking mechanism.
Among these, the rod 8a is provided in a state of liquid-tightly penetrating the cylinder bottom 9a that partitions the bottom end of the bottom of the cylinder 5a of the caliper 4a and protruding outside the cylinder 5a. Such a rod 8 a presses the piston 6 a toward the inner side surface of the rotor 1 through the adjusting nut 42 as the rod 8 a moves in a direction approaching the rotor 1. The piston 6a is provided with a gap adjusting mechanism 10a having a function of preventing over-adjustment (excessive gap adjustment generated at high hydraulic pressure) and comprising a plurality of parts including the adjusting nut 42. Regardless of the wear of the linings 11 and 11 of 2a and 2b, the gap between the linings 11 and 11 and the side surface of the rotor 1 is kept constant during non-braking.
[0016]
Note that such a gap adjusting mechanism 10a is inserted into the cylinder 5a from the rotor side opening in a state in which members other than the rod 8a such as the adjusting nut 42 are pre-assembled inside the piston 6a. Assembling is performed by engaging the rod 8a and the adjusting nut 42 while rotating the piston 6a. The structure and operation of the gap adjusting mechanism 10a assembled in this manner have been conventionally performed and are not related to the gist of the present invention.
[0017]
The cam member 15a is provided on the side opposite to the rotor from the rod 8a so as to be rotatable about the central axis of the rod 8a. In the case of this example, the pin part 29 formed in the center part of the rotor side end surface of the cam member 15a is inserted into the circular hole 28 formed in the center part of the rod 8a on the side opposite to the rotor. With this configuration, the rod 8a and the cam member 15a can be relatively rotated while the rod 8a and the cam member 15a are arranged concentrically. Such a cam member 15a presses the rod 8a toward the piston 6a with the relative rotation with respect to the rod 8a by the action of the cam mechanism 13a described below.
[0018]
Since the cam mechanism 13a is configured, the anchor member 12a prevents the cam member 15a from being displaced in the direction of retreating from the piston 6a (right direction in FIG. 4). The anchor member 12a is formed by punching and bending a metal plate having sufficient strength and rigidity, such as a steel plate, and has a U-shaped or U-shaped flat plate portion 30 and the substrate. The guide portion 39 is bent from the outer peripheral edge of the portion 30. Such an anchor member 12a is such that bolts 32, 32 inserted through through holes provided at both end portions of the substrate portion 30 are screwed into screw holes formed in the inner side wall end portion of the caliper 4a and further tightened. Thus, the caliper 4a is coupled and fixed. Then, the end surface on the side opposite to the rotor of the rotary shaft portion 22a provided at the center portion of the cam member 15a is abutted against the anchor plug 33 that is fitted and supported on the inner peripheral edge intermediate portion of the substrate portion 30. The abutting portion between the anchor plug 33 and the rotating shaft portion 22a is in an engaged state between the spherical concave surface and the spherical convex surface so that the sliding resistance of the abutting portion does not become excessive when the parking brake is operated.
[0019]
In addition, outwardly flanged cam plate portions 34 and 16a are formed at the opposite end of the rod 8a on the rotor side and the end of the cam member 15a on the rotor side, respectively. A plurality of (for example, three) balls 17 are sandwiched between the cam plate portions 34 and 16a. Cam grooves 18a and 18b in which the depth in the axial direction gradually changes in the circumferential direction are formed in the portion where the balls 17 are sandwiched between the surfaces of the cam plates 34 and 16a facing each other. Accordingly, by relatively rotating the two cam plate portions 34 and 16a, the distance between the two cam plate portions 34 and 16a can be changed.
[0020]
In the case of this example, convex portions 48, 48 formed on the outer peripheral edge portion of the cam plate portion 34 on the rod 8a side, and a guide groove 49 formed in the inner peripheral surface of the inner side end portion of the caliper 4a in the axial direction, 49, the cam plate 34 on the rod 8a side can be displaced only in the axial direction. Therefore, if the cam plate portion 16a on the cam member 15a side is rotated, the cam plate portion 16a and the cam plate portion 34 on the rod 8a side are rotated relative to each other, so that the cam plate portions 16a and 34 You can change the interval. In order to rotate the cam plate portion 16a on the cam member 15a side, the base end portion of the parking lever 19a is externally supported by the intermediate portion of the rotating shaft portion 22a of the cam member 15a. The fitting portion between the rotating shaft portion 22a and the parking lever 19a has a structure capable of transmitting rotational force by preventing relative rotation by serration engagement, fitting between non-circular shapes having flat portions, key engagement, and the like. It is said.
[0021]
A return spring 35 is provided between the parking lever 19a and the anchor member 12a to give the parking lever 19a elasticity in a direction to release the parking brake. In the illustrated example, the return spring 35 is a torsion coil spring, and a coil portion provided at the center thereof is disposed around a seal member 36 spanned between the rotary shaft portion 22a and the anchor plug 33. ing. Then, a pair of elastic pieces projecting radially outward from the coil portion to the opposite side in the axial direction are brought into contact with the anchor member 12a and the parking lever 19a so that the parking lever 19a is elastic in the above direction. Is granted. The seal member 36 prevents foreign matter from entering the abutting portion between the rotating shaft portion 22a and the anchor plug 33, and is formed by covering an elastic material such as rubber with a metal plate cover, The sealing member 36 keeps the two members 22a and 33 relatively rotatable. Preventing foreign matter from entering the engaging portions between the cam grooves 18a and 18b and the balls 17 is achieved by a boot 37 provided between the inner end of the caliper 4a and the rotating shaft portion 22a. .
[0022]
Further, the parking lever 19a is folded at the tip of the parking lever 19a in a U-shape, and U-shaped cutouts are formed in portions facing each other, thereby forming the parking cable 20 (FIG. 7). A locking portion 38 is provided for locking the end portion of the reference). In addition, a guide portion 39 for guiding the parking cable 20 is provided on a portion of the outer peripheral edge of the base plate portion 30 constituting the anchor member 12a so as to face the locking portion 38, and the anchor member 12a. It is provided integrally. The end portion of the parking cable 20 is locked to the locking portion 38 in a state in which the end portion of the guide portion 39 is inserted through the through hole 40.
[0023]
Further, a spring 41 is provided between the cam plate portion 34 on the rod 8a side and the cylinder bottom portion 9a, and this cam plate portion 34 is elastically pressed toward the cam plate portion 16a on the cam member 15a side. ing. The ball 17 is prevented from rattling between the cam grooves 18a, 18b when the parking mechanism is not operated, and the rod 8a is displaced by the piston 6a when the service brake is operated. This prevents the gap adjusting mechanism 10a from functioning.
[0024]
In the case of the disc brake with a parking mechanism of this example configured as described above, when the service brake is used, the piston 6a is protruded from the cylinder 5a by feeding pressure oil into the cylinder 5a. As a result, the piston 6 a presses the inner pad 2 a against the inner side surface of the rotor 1, and at the same time, the caliper 4 a is based on the sliding between the guide pins 26, 26 and the guide portions 27, 27. The support 3a is displaced toward the inner side. The claw portion 7a of the caliper 4a presses the outer pad 2b against the outer side surface of the rotor 1. As a result, the rotor 1 is strongly clamped from both sides by the pair of pads 2a and 2b, and braking is performed.
[0025]
On the other hand, at the time of parking brake, the cam member 15a is rotated via the parking lever 19a by pulling the parking cable 20. The parking cable 20 whose end is locked to the front end of the parking lever 19a in a state where the through hole 40 formed at the front end of the guide portion 39 is inserted is substantially at the rotation center of the cam member 15a. Since the cam member 15a is driven to rotate efficiently by the parking cable 20, the cam cable 15a is driven efficiently. As a result of the rotation of the cam member 15a, the balls 17 move to the shallow portions of the cam grooves 18a and 18b while rolling to form the cam members 15a formed with the cam grooves 18a and 18b. The space | interval of the mutually opposing surfaces of the cam plate part 16a on the side and the cam plate part 34 on the rod 8a side is widened. As a result, the rod 8a including the cam plate portion 34 is displaced to the rotor side and pushes the piston 6a to the rotor side through the adjusting nut 42 constituting the gap adjusting mechanism 10a. As a result, as in the case where pressure oil is fed into the cylinder 5a, the rotor 1 is strongly held from both sides by the pair of pads 2a and 2b, and braking is performed.
[0026]
In the case of the disc brake with a parking mechanism of the present example configured and operated as described above, the number of components of the parking brake mechanism portion can be reduced to facilitate the manufacture of parts, the management of parts, and the assembly work. Become. That is, the nut 23 and the second ball 24 incorporated in the conventional structure shown in FIGS. 7 to 9 are not necessary, and only two bolts are required to couple and fix the anchor member 12a to the caliper 4a. . Further, since the guide portion 39 for guiding the parking cable 20 is formed integrally with the anchor member 12a, the cost increase associated with the provision of the guide portion 39 can be minimized.
[0027]
Next, FIGS. 5-6 has shown one example of the reference example regarding this invention . In the case of the disc brake with a parking mechanism of the present reference example , the caliper 4b is formed by combining a caliper plate 43 made of a metal plate and a cylinder portion 44 that are separate from each other. Of these, the caliper plate 43 is formed into a flat plate shape having through holes 45 by punching a metal plate having sufficient strength and rigidity, such as a steel plate. The cylinder portion 44 is made of cast iron and is fixedly coupled to a part of the through hole 45 by bolts 47a and 47b. The caliper plate 43 supports the support 3b such that the caliper plate 43 can rotate about the pivot pin 50. An anchor plug 33a is attached to this part of the caliper plate 43 so that a part of the caliper plate 43 (right end in FIG. 5) that faces the bottom of the cylinder part 44 functions as an anchor member. Further, a guide bracket 46 is coupled and fixed to a part of the caliper plate 43 by bolts 47c. A through hole 40 is formed in the guide portion 39a provided at the distal end portion of the guide bracket 46 for inserting a parking cable having the end portion engaged with the distal end portion of the parking lever 19b. In the case of this reference example as well, as in the case of the above-described example of the embodiment, it is possible to reduce the number of component parts and facilitate the production of parts, the management of parts, and the assembly work. Become.
[0028]
【The invention's effect】
Since the present invention is configured and operates as described above, the cost can be reduced by simplifying the disc brake with a parking mechanism.
[Brief description of the drawings]
FIG. 1 is a view of a disc brake with a parking mechanism as viewed from the outside in the radial direction, showing an example of an embodiment of the present invention.
FIG. 2 is a view as seen from below in FIG.
FIG. 3 is a diagram viewed from the right side of FIG.
4 is a cross-sectional view taken along line AA in FIG.
FIG. 5 is a view of a disc brake with a parking mechanism as viewed from the outside in the radial direction, showing one example of a reference example relating to the present invention.
6 is a view from the right side of FIG.
FIG. 7 is a view similar to FIG. 3, showing an example of a conventional structure.
8 is a cross-sectional view taken along the line BB in FIG.
9 is a cross-sectional view taken along the line CC of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Rotor 2a, 2b Pad 3, 3a Support 4, 4a, 4b Caliper 5, 5a Cylinder 6, 6a Piston 7, 7a Claw part 8, 8a Rod 9, 9a Cylinder bottom part 10, 10a Gap adjustment mechanism 11 Lining 12, 12a Anchor Member 13, 13a Cam mechanism 14 Circular hole 15, 15a Cam member 16, 16a Cam plate part 17 Ball 18a, 18b Cam groove 19, 19a, 19b Parking lever 20 Parking cable 21 Bolt 22, 22a Rotating shaft part 23 Nut 24 Second Ball 25 Guide member 26 Guide pin 27 Guide portion 28 Circular hole 29 Pin portion 30 Substrate portion 32 Bolt 33, 33a Anchor plug 34 Cam plate portion 35 Return spring 36 Seal member 37 Boot 38 Locking portion 39, 39a Guide portion 40 Hole 41 Spring 42 Adjust nut 43 caliper plate 44 a cylinder portion 45 through hole 46 guide bracket 47a, 47b, 47c bolt 48 protrusions 49 guide groove 50 pivot pin

Claims (3)

A pair of pads arranged on both sides of the rotor that rotates together with the wheels, a caliper that presses these pads against both side surfaces in the axial direction of the rotor as a piston fitted in a cylinder provided therein, and the caliper A part of the cylinder that penetrates the bottom of the cylinder in a liquid-tight manner and protrudes out of the cylinder, and, in the axial direction, pushes the piston toward the rotor. A cam member that is rotatably provided around the center axis of the rod, and that presses the rod toward the piston as the rod rotates relative to the rod, and an anchor for supporting the reaction force applied to the cam member as the pressure is applied. In a disc brake with a parking mechanism having a member and a parking lever for rotating the cam member, A coupling portion between the base end portion of the grever and the cam member is installed between the anchor member and the rod, and the base end portion of the parking lever directly transmits the rotational force to the cam member. A disc brake with a parking mechanism, which is freely fitted and supported , and wherein the anchor member is coupled and fixed to the caliper by a coupling member .   The parking lever is configured to rotate the cam member by pulling a cable coupled to a distal end portion and press the rod against the piston, and a guide portion for guiding the cable is provided with the anchor. The disc brake with a parking mechanism according to claim 1, which is integral with the member. The disc brake with a parking mechanism according to any one of claims 1 and 2, wherein a contact portion between the cam member and the anchor member is blocked from outside air by a seal member .

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