JP3828978B2 - Adjuster for disc brake device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adjuster to suppress size in the axial direction of a rotor, eliminate a need to locate a load plate between a piston and a friction pad, and be suitable for reduction of size and weight. SOLUTION: An adjuster for a disc brake device is formed such that a mechanism to rotate a ratchet by an adjuster lever 38 on an eccentric shaft 34 rotated integrally with an operation lever 36 is incorporated between a pair of pistons 15 and 16 to press the friction pad 6 of a disc brake device against a rotor 4, rotation of an adjuster gear 30 formed integrally with a ratchet is transmitted to transmission gears 27 and 28 engaged with an adjuster gear 30, adjuster screws 21 and 22 joined in a screwed-in state with transmission gears 27 and 28 are fed to the rotor side, and the pistons 15 and 16 fitted with the tip parts of the adjuster screws 21 and 22 are also pushed out to the rotor 4 side.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an adjuster that adjusts a gap between a rotor and a friction pad in a disc brake device, and more specifically, to an air-driven disc brake device that uses air pressure as a drive source of a friction pad during braking operation. The present invention relates to an adjuster suitable for use.
[0002]
[Prior art]
Up to now, as an adjuster used in an air-driven disc brake device, when the rotary drive is performed behind a pair of pressure pieces abutted against the back plate of the friction pad, a screw feed mechanism is used. An adjustment spindle that pushes the pressure piece toward the rotor, an operation lever for rotationally driving each adjustment spindle, a synchronization device that synchronizes the rotation of each adjustment spindle, and a post-adjustment device that adjusts the rotational torque acting on each adjustment spindle Have been proposed (see JP-T-8-508080).
[0003]
In addition, a male screw is engraved on the outer periphery, and a pair of pistons that are mounted so as to be movable in the axial direction of the rotor with the tip directed toward the rotor, and a male thread portion engraved on the outer periphery of each piston When a female screw portion is formed on the inner periphery and is driven to rotate, a pair of sleeves that cause the piston to advance and retreat along the rotor shaft, and a pair of transmissions that are coupled to the ends of the sleeves and rotate integrally with the sleeve. A gear, an adjuster gear mounted between the pair of transmission gears so as to mesh with the pair of transmission gears, a camshaft that rotates the operation lever by a turning operation, and the rotation of the camshaft An adjuster having a transmission mechanism for rotating the adjuster gear has also been proposed (see European Patent EP 0703379 A1).
[0004]
[Problems to be solved by the invention]
However, the former adjuster has a structure in which various mechanisms including the adjustment spindle are connected in the rotor axis direction, so the dimensions are large in the rotor axis direction, and it is necessary to secure a large accommodation space in the rotor axis direction. There was a problem that it was difficult to install in other vehicles.
In the case of the latter adjuster, the outer diameter of the piston is reduced because the pair of pistons that press the friction pad are screwed into the sleeve. For this reason, in order to stabilize the contact property with the friction pad, it is necessary to interpose a load plate having a large contact area with the friction pad. Occurs. Further, due to the weight of the load plate, the return operation of the piston at the time of releasing the brake is not smoothly performed, and there is a possibility that dragging occurs.
[0005]
Accordingly, an object of the present invention is to eliminate the above-mentioned problems, and can reduce the dimension in the rotor axial direction, can be easily mounted on a small vehicle, and has a large piston diameter for pressing the friction pad. Therefore, it is not necessary to interpose the load plate between the piston and the friction pad, and at the same time, the weight can be reduced, and at the same time, the return operation of the piston can be smoothly performed when the brake is released to prevent the occurrence of inconvenience such as dragging. An object of the present invention is to provide an adjuster for a disc brake device.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, an adjuster for a disc brake device according to a first aspect of the present invention includes a rotor that rotates integrally with a wheel, a pair of friction pads disposed opposite to the rotor, and one friction pad. A drive mechanism housing portion serving as a piston housing portion that presses against the rotor is provided at one end of the bridge portion straddling the rotor, and a claw that presses the back surface of the other friction pad on the other end side of the bridge portion. A disc brake device comprising: a caliper having a portion; and a support fixed to the vehicle body side and supported so as to be movable in the axial direction of the rotor. And adjusts the gap between the friction pad and the rotor, and has a headed cylindrical shape with one end open. A pair of pistons mounted so as to be movable only in the axial direction of the rotor with the other end side closed to the rotor side, and a distal end side slidably fitted to the inner periphery of the piston and a proximal end side A pair of adjuster screws formed with screw portions, and a screw portion that is rotatably supported by the drive mechanism housing portion and that engages with an end portion of the adjuster screw, and is rotated when driven. A pair of transmission gears for moving back and forth in the rotor axial direction; an adjuster gear provided between the pair of transmission gears so as to mesh with the pair of transmission gears; and coaxial with the adjuster gear and integral with the adjuster gear A ratchet that is rotatably mounted, an eccentric camshaft that is rotatably mounted between the pair of pistons with an axis line in a radial direction of the rotor, and an end of the eccentric camshaft An operation lever that is connected and rotates the eccentric cam shaft, and one end is connected to the eccentric cam shaft so as to rotate integrally with the eccentric cam shaft, and the other end engages with the pawl of the ratchet And an adjuster lever for rotating the ratchet according to the rotation of the eccentric cam shaft, and transmitting the rotation of the ratchet to a pair of transmission gears via an adjuster gear. Each piston is sent out to the rotor side by the adjuster screw moving to the side.
In order to achieve the above object, the adjuster of the present invention according to claim 2 is characterized in that the adjuster lever has flexibility and is elastically deformed when the rotation resistance of the adjuster gear is not less than a predetermined value. It is characterized by.
[0007]
According to the above configuration, when the operating lever is rotated, the eccentric cam shaft rotates integrally with the operating lever, and the adjuster lever provided on the eccentric cam shaft rotates the ratchet by a certain amount. . As a result, the adjuster gear integral with the ratchet rotates, and the rotation of the adjuster gear is caused by rotating the adjuster screw screwed into the inner periphery of each piston via each transmission gear meshed with the adjuster gear. The pistons are pushed out to the rotor side by pushing out the adjuster screws, and the friction pads in contact with the pistons are moved to the rotor side.
[0008]
In the above configuration, in order to move the piston to the rotor side, the components connected in the rotor axial direction are an adjuster screw and a transmission gear connected to the end of the adjuster screw. A ratchet mechanism or the like for transmitting the rotation is disposed in the space between the pair of pistons, and does not affect the dimension in the rotor axial direction.
That is, since there are few components connected in the rotor axial direction, the dimension in the rotor axial direction can be suppressed.
[0009]
Further, since the piston that presses the friction pad is fitted to the outer periphery of the adjuster screw, the piston diameter can be maximized within the dimensional limit on the caliper. Since the piston diameter can be increased, the contact between the piston and the friction pad is stabilized, and there is no need to interpose a load plate between the piston and the friction pad in order to stabilize the contact.
Also, the adjuster lever is elastic and is configured so that there is a preload in the assembled state, so it adjusts while no axial force is generated, and prevents breakage of the adjuster when the piston is locked with brake rigidity. be able to.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described with reference to illustrated embodiments.
1 to 4 show an embodiment of an adjuster of a disc brake device according to the present invention. FIG. 1 is an exploded perspective view of the adjuster 1 according to the embodiment. FIG. 2 is a disc brake incorporating the adjuster 1. FIG. 3 is a cross-sectional view taken along line AA in FIG. 2, and FIG. 4 is a cross-sectional view taken along line BB in FIG.
[0011]
As shown in FIG. 2, the disc brake device 2 equipped with the adjuster 1 according to this embodiment includes a disk-shaped rotor 4 that rotates integrally with a wheel, and a pair of friction pads that are arranged to face each other with the rotor 4 interposed therebetween. 6 and 7 and a drive mechanism accommodating portion 11c serving as a piston accommodating portion that pushes the back surface of one friction pad 6 toward the rotor 4 is provided at one end of the bridge portion 11a straddling the rotor 4 and A caliper 11 equipped with a claw portion 11b that presses the back surface of the other friction pad 7 on the other end side of the bridge portion 11a, is fixed to the vehicle body side, and the caliper 11 is movable in the axial direction of the rotor 4. The support 10 (see FIGS. 3 and 4) is supported, and the pair of friction pads 6 and 7 are attached to the rotor 4 by compressed air pressure during normal braking (service braking). Attach to, Ru der those for generating a predetermined braking force.
[0012]
Each of the aforementioned friction pads 6 and 7 is pressed against the surface of the rotor 4 to generate a predetermined frictional force, and a back plate 13 that is fixedly mounted on the back side of the lining 12 and functions as a mounting bracket or the like. It is composed of
[0013]
The adjuster 1 according to one embodiment pushes one friction pad 6 toward the rotor 4 by a pair of pistons 15 and 16 incorporated in the drive mechanism housing portion 11c of the caliper 11, and the friction pads 6 and 7 and the rotor Adjust the gap between the four.
[0014]
Specifically, as shown in FIGS. 1 and 2, the adjuster 1 is moved in the rotor axial direction by a piston support case 18 fixed to the drive mechanism housing portion 11 c of the caliper 11 and the piston support case 18. A pair of freely-supported pistons 15 and 16, and a pair of adjuster screws 21 having a distal end side slidably fitted to the inner periphery of the pistons 15 and 16 and a threaded portion 19 formed on the proximal end side, 22 and a pair of transmission gears 27 having a screw portion 24 that is rotatably supported by the drive mechanism housing portion 11c via the piston support case 18 and that is screwed into the screw portion 19 of the adjuster screws 21 and 22. , 28, and an adjuster gear 30 mounted between the pair of transmission gears 27, 28 so as to mesh with the pair of transmission gears 27, 28, and the adjuster A ratchet 32 that is coaxially mounted with the adjuster gear 30 so as to be rotatable integrally with the adjuster gear 30, and an eccentric camshaft that is rotatably mounted between the pair of pistons 15, 16 with the axis line directed in the radial direction of the rotor 4. 34, an operation lever 36 connected to the end of the eccentric camshaft 34 to rotate the eccentric camshaft 34, and one end of the eccentric camshaft so as to rotate integrally with the eccentric camshaft 34. 34 and an adjuster lever 38 that engages with a pawl of the ratchet 32 and rotates the ratchet 32 according to the rotation of the eccentric cam shaft 34.
[0015]
The piston support case 18 has a structure in which a shaft insertion hole 18b through which the eccentric cam shaft 34 is inserted is formed between a pair of cylindrical portions 18a and 18a that accommodate the pistons 15 and 16. Further, a gear support hole 18c for rotatably supporting the adjuster gear 30 and the ratchet 32 is provided so as to penetrate the center of the shaft insertion hole 18b.
[0016]
The pair of pistons 15, 16 has a headed cylindrical shape with one end open, and the other closed end faces toward the rotor 4 and is slidable on the cylindrical portion 18 a of the piston support case 18. It is mated. These pistons 15 and 16 move only in the axial direction of the rotor, and the front end surface of the friction pad 6 that contacts the back plate 13 is engaged so that the rotational movement in the piston support case 18 is restricted. A joint groove 40 is formed. The engagement grooves 40 engage with the protrusions formed on the back plate 13, so that the rotation of the pistons 15 and 16 is restricted.
[0017]
As shown in FIGS. 1 and 2, the adjuster screws 21 and 22 have a substantially cylindrical shape, and are screw portions (female screws) that are screwed into the screw portions (male screws) 24 of the transmission gears 27 and 28 described above. Is engraved on the inner periphery of the base end. Further, a flange portion 42 is formed on the outer peripheral portion near the base end of each adjuster screw 21, 22. The flange 42 abuts against the end surfaces of the pistons 15 and 16 and pushes the pistons 15 and 16 to the rotor side when receiving the rotational torque from the transmission gears 27 and 28 and moving to the rotor 4 side. Further, the flange portion 42 abuts on a protruding portion that bulges toward the inner diameter side of the proximal end of the cylindrical portion 18a of the piston support case 18, and the initial position on the transmission gears 27 and 28 side is determined.
[0018]
When the transmission gears 27 and 28 are rotationally driven, the adjuster screws 21 and 22 engaged with each other advance and retract in the rotor axial direction. At the center of each of the transmission gears 27 and 28, an opening is provided for inserting a return spring 44 that urges the pistons 15 and 16 in a direction to separate them from the friction pad 6.
[0019]
The return spring 44 includes a cylindrical portion 46a that passes through the transmission gears 27 and 28 and the adjuster screws 21 and 22, and a positioning piece 46b that protrudes from the base end of the cylindrical portion 46a and abuts against the end surfaces of the transmission gears 27 and 28. Are accommodated in a spring receiving sleeve 46 having
The return spring 44 accommodated in the spring receiving sleeve 46 is compressed by a spring receiving washer 49 mounted on a bolt 48 that is inserted through the center of the spring receiving sleeve 46 and screwed to the pistons 15, 16. The urging force in the direction is applied to the pistons 15 and 16.
The positioning piece 46b of the spring receiving sleeve 46 is clamped and fixed between the body cover 50 screwed to the drive mechanism accommodating portion 11c from the outside of the spring receiving sleeve 46 and the transmission gears 27 and 28. .
[0020]
The adjuster lever 38 is attached to the outer periphery of the eccentric cam shaft 34 via an auxiliary ring 52, and is fixed to the eccentric cam shaft 34 together with the auxiliary ring 52 by a screw member 56. There is a gap between the auxiliary ring 52 and the projecting portion 34a of the eccentric cam shaft 34, and drag is prevented by providing a non-adjustment range of a certain amount ΔX.
The upper end side of the eccentric camshaft 34 is rotatably supported by a retainer 54 screwed into a shaft insertion hole 11d opened at the upper part of the drive mechanism housing portion 11c. A spring 58 that biases the adjuster lever 38 is provided between the retainer 54 and the auxiliary ring 52 so as to keep the end of the adjuster lever 38 engaged with the ratchet 32.
[0021]
A manual release gear 60 is attached to the body cover 50 by a lever 61 so as to be rotatable. The gear 60 rotates when the lever 61 is rotated, pulls the adjuster lever 38 upward, disengages the adjuster lever 38 and the ratchet 32, and returns the gap adjustment to the initial state.
[0022]
In the adjuster 1 of the embodiment described above, when the operation lever 36 is rotated, the eccentric cam shaft 34 is rotated integrally with the operation lever 36, and the adjuster lever 38 provided on the eccentric cam shaft 34 is moved. 3, the ratchet 32 is rotated by a certain amount by moving in the direction of arrow (A) in FIG. As a result, the adjuster gear 30 integral with the ratchet 32 is rotated, and the rotation of the adjuster gear 30 is caused by the inner periphery of each piston 15, 16 via the respective transmission gears 27, 28 meshed with the adjuster gear 30. The fitted adjuster screws 21 and 22 are sent to the rotor side, and the pistons 15 and 16 are pushed out to the rotor 4 side by the feed of the adjuster screws 21 and 22 so that these pistons 15 and 16 come into contact with each other. The friction pads 6 are moved to the rotor 4 side, and the gaps between the rotor 4 and the friction pads 6 and 7 are reduced.
[0023]
In the adjuster 1 described above, in order to move the pistons 15 and 16 toward the rotor 4, the components connected in the axial direction of the rotor 4 are connected to the adjuster screws 21 and 22 and the end portions of the adjuster screws 21 and 22. A ratchet mechanism or the like for transmitting the rotation of the operation lever 36 to the transmission gears 27 and 28 is arranged in the space between the pair of pistons 15 and 16 by the transmission gears 27 and 28, and is arranged in the direction of the rotor 4 axis. Does not affect dimensions.
That is, since there are few components connected to the rotor 4 axial direction, the dimension of the rotor 4 axial direction can be suppressed, size reduction can be achieved, and mounting on a small vehicle or the like is facilitated.
[0024]
Further, since the pistons 15 and 16 that press the friction pads 6 and 7 are screwed to the outer periphery of the adjuster screws 21 and 22, the pair of pistons that press the friction pads are screwed into the sleeve. Compared with the conventional one, the diameters of the pistons 15 and 16 can be maximized within the dimensional limit on the caliper 11. Since the diameters of the pistons 15 and 16 can be increased, the contact between the pistons 15 and 16 and the friction pads 6 and 7 is stabilized, and the pistons 15 and 16 and the friction pads 6 and 7 are stabilized in order to stabilize the contact. There is no need to interpose a load plate between the two.
Therefore, the weight can be reduced as compared with the structure having a load plate, and the return operation of the pistons 15 and 16 at the time of releasing the brake is smoothed to prevent the occurrence of inconvenience such as dragging. can do.
[0025]
The adjuster 1 according to the embodiment described above is a forward operation type that operates when the operation lever 36 is rotated, but is changed to a return operation type that operates when the operation lever 36 returns. In this case, the component part 64 surrounded by the two-dot chain line in FIG. 1 may be replaced with the component part 66 surrounded by the broken line.
[0026]
Furthermore, although the adjuster 1 of the above-described embodiment is a positive type, as shown in FIG. 5, if the direction of the pawl of the ratchet 32 is changed and the contact direction of the adjuster lever 38 is changed, It can also be a negative type.
[0027]
【The invention's effect】
In the adjuster of the disc brake device of the present invention, in order to move the piston to the rotor side, the constituent members connected in the rotor axial direction are an adjuster screw and a transfer gear connected to the end of the adjuster screw. A ratchet mechanism or the like for transmitting the rotation of the operation lever is disposed in the space between the pair of pistons and does not affect the dimension in the rotor axial direction.
That is, since there are few constituent members connected in the rotor axial direction, the dimensions in the rotor axial direction can be suppressed, miniaturization can be achieved, and mounting on a small vehicle or the like is facilitated.
Further, since the piston that presses the friction pad is fitted to the outer periphery of the adjuster screw, the piston diameter can be maximized within the dimensional limit on the caliper. Since the piston diameter can be increased, the contact between the piston and the friction pad is stabilized, and there is no need to interpose a load plate between the piston and the friction pad in order to stabilize the contact.
Therefore, it is possible to reduce the weight as compared with the structure having a load plate, and to prevent the occurrence of inconvenience such as dragging by smoothly returning the piston when releasing the brake. it can.
The adjuster destruction prevention mechanism is simple and inexpensive because it is performed by the elasticity of the adjuster lever.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of an embodiment of an adjuster for a disc brake device according to the present invention.
FIG. 2 is a cross-sectional plan view of a part of a disc brake device incorporating an adjuster according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view taken along line AA in FIG.
4 is a cross-sectional view taken along line BB in FIG.
FIG. 5 is a sectional view of a disc brake device showing another embodiment of an adjuster according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Adjuster 2 Disc brake apparatus 4 Rotor 6, 7 Friction pad 11 Caliper 11c Drive mechanism accommodating part 15, 16 Piston 18 Piston support case 19 Screw part 21, 22 Adjuster screw 24, 25 Screw part 27, 28 Transmission gear 30 Adjuster gear 32 Ratchet 34 Eccentric camshaft 34a Protrusion 36 Operation lever 38 Adjuster lever 40 Engaging groove 44 Return spring 46 Spring receiving sleeve 48 Bolt 52 Auxiliary ring 54 Retainer 58 Spring 60 Release gear 61 Lever

Claims (2)

A rotor that integrally rotates with the wheel, a pair of friction pads that are arranged to face the rotor, and a bridge portion that spans the rotor with a drive mechanism housing portion that serves as a piston housing portion that presses one friction pad toward the rotor And a caliper that has a claw portion that presses the back surface of the other friction pad on the other end of the bridge portion, and is fixed to the vehicle body side and can move the caliper in the axial direction of the rotor. In the disc brake device comprising a supported support, an adjuster that adjusts a gap between the friction pad and the rotor by pushing one friction pad to the rotor side by the pair of pistons,
A pair of pistons with a headed cylinder shape with one end open and a closed other end side facing the rotor, which can be moved only in the axial direction of the rotor, and the tip side can slide on the inner circumference of the piston And a pair of adjuster screws having a threaded portion formed on the base end side, and a threaded portion that is rotatably supported by the drive mechanism housing portion and is screwed to the end of the adjuster screw. A pair of transmission gears that move the adjuster screw forward and backward in the rotor axial direction when driven to rotate, an adjuster gear provided between the pair of transmission gears so as to mesh with the pair of transmission gears, and the adjuster A ratchet mounted coaxially with the gear and so as to rotate integrally with the adjuster gear, and an eccentric camshaft rotatably mounted between the pair of pistons with the axis line directed in the radial direction of the rotor An operation lever connected to the end of the eccentric camshaft to rotate the eccentric camshaft, and one end connected to the eccentric camshaft so as to rotate integrally with the eccentric camshaft. An end that engages with the pawl of the ratchet and an adjuster lever that rotates the ratchet according to the rotation of the eccentric camshaft;
A disk brake device characterized in that the rotation of the ratchet is transmitted to a pair of transmission gears via an adjuster gear, and each piston is sent to the rotor side by the adjuster screw that moves to the rotor shaft side by the rotation of the transmission gear. Adjuster. 2. The adjuster of a disc brake device according to claim 1, wherein the adjuster lever is flexible and elastically deforms when the rotation resistance of the adjuster gear is equal to or greater than a predetermined value.

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