JP2010025351A - Drum brake device having automatic shoe clearance adjuster - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a brake pad wear alarm device enabling probe bodies to be attached on rear plates of brake pads in one operation in association with existing parts without adding a novel part. <P>SOLUTION: The wear alarm device for the brake pads 11, 12 is characterized in that, in a disk brake device 10 having a wear detector 50 for electrically detecting the wear limit of the friction materials 14 of the brake pads 11, 12, a storage groove 15 is formed at the outer peripheral edge of each of the rear plates 13 of the brake pads 11, 12 opposed to an anti-rattle spring 40. The probe body 51 of the friction detector 50 is fitted into the storage groove 15 while limiting movement in the direction parallel to the axis of a rotor. The disengagement of the probe body 51 in the opening direction of the storage groove 15 is prevented by the anti-rattle spring 40. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a brake pad of a disk brake device that electrically detects that the remaining thickness of a friction material of a brake pad that brakes and engages with a disk rotor during braking is reached. The present invention relates to a wear alarm device, and relates to a structure for easily and reliably disposing a wear detector constituting the wear alarm device in a disc brake device.

  As a brake pad wear alarm device, for example, there are types described in Japanese Patent Application Laid-Open No. 12-220676 and Japanese Patent Application Laid-Open No. 5-248464 filed earlier by the applicant. In the prior art described in the above publication, the columnar probe body of a wear detector that electrically detects the wear of the brake pad is fitted into a through hole (mounting hole) formed in the back plate of the brake pad and protrudes therefrom. The U-shaped top portion of the insulated conducting wire is disposed at the wear limit position of the friction material. The columnar probe body allows the movement in the direction toward the disk rotor when fitted into the through hole of the back plate, but restricts the movement in the opposite direction. It is larger than the through hole and has a stepped shape. In addition, a slit (retainer locking groove) is formed in the intermediate portion in the axial direction of the small-diameter shaft portion, and the retainer is locked in the slit to restrict movement in the direction toward the disk rotor, To prevent it from coming off from the mounting hole). That is, the attachment of the columnar probe main body constituting the conventional wear alarm device to the brake pad is performed after the stepped columnar probe main body including the insulated conducting wire is inserted from the small-diameter shaft portion side into the through hole of the back plate. This is performed by attaching a retainer to a slit formed in the thin shaft portion.

JP-A-12-220676 JP-A-5-248464

The above-described conventional brake pad wear alarm device has the following problems.
<A> Since the columnar probe body of the wear detector that electrically detects the wear limit position must use a retainer to attach it to the back plate of the brake pad, the number of parts in the wear alarm device as a whole It will increase.

<B> In addition to the step of fitting a columnar probe body including a relatively long insulated wire into a through hole (mounting hole) formed in the back plate, a retainer is provided in a slit (retainer locking groove) formed in the columnar probe body. Two steps of the engaging step are required, and it takes time and effort to attach the columnar probe main body to the back plate.

  The present invention has been made in view of the above problems. The object of the present invention is to cooperate with existing parts without adding any new parts, and to attach the probe main body of the wear alarm device to the back plate of the brake pad. Another object of the present invention is to provide a brake pad wear warning device that can be attached in one step.

  As a means for solving the above-described problems, the invention according to claim 1 is directed to a pair of brake pads that press and brake the disk rotor from both sides in the axial direction, and the brake pads are directed toward the rotor center side. In a disc brake device comprising an anti-rattle spring that is energized and a wear detector that electrically detects the wear limit of the friction material of the brake pad, the disc brake device is housed in the outer peripheral edge of the back plate of the brake pad facing the anti-rattle spring A groove is formed, and the wear detector is inserted into the receiving groove while restricting movement in a direction parallel to the rotor axis, and the anti-rattle is removed from the probe in the opening direction of the receiving groove. The brake pad wear warning device is characterized by being configured to be prevented by a spring.

  The invention according to claim 2 is the brake pad wear alarm device according to claim 1, wherein the anti-rattle spring is a leaf spring.

  The invention according to claim 3 is the brake pad wear warning device according to claim 1, wherein the anti-rattle spring is a wire spring.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the probe main body is fitted in the receiving groove of the back plate in the middle portion of the probe main body in the direction parallel to the rotor axis, and cannot rotate. This is a brake pad wear alarm device characterized by integrally forming a groove.

Since the present invention has been described above, the following effects can be obtained.
<A> Using the existing anti-rattle spring, which is a component of the disc brake device, to prevent the wear detector fitted in the receiving groove of the back plate of the brake pad from coming off in the direction of the receiving groove opening. Therefore, it is not necessary to attach any new member as a means for preventing the detachment.

<B> The process of attaching the wear detector to the back plate of the brake pad is only one step of inserting the wear detector into the housing groove of the back plate, and it is only necessary to insert from the outer edge direction of the back plate. Therefore, assembly work is easy even in a wear detector including a relatively long insulated conductor.

The top view which showed the floating type disc brake apparatus provided with the wear warning apparatus of the brake pad in the Example of this invention, and showed the partial cross section Front view with a partial cross section of FIG. Rear view of FIG. IV-IV sectional view of FIG. The top view of the wire spring which shows the modification of the Example of this invention It is explanatory drawing of the wear detector of a wear alarm device, (A) is a front view of a probe main body, (B) is BB sectional drawing of a figure (A), (C) is a perspective view of a probe main body.

  Hereinafter, an example of a brake pad wear warning device according to the present invention will be described in detail with reference to the drawings. First, an embodiment of the present invention in which a brake pad wear warning device is applied to a floating disc brake device and a modification thereof will be described with reference to FIGS.

<A> Configuration of Disc Brake Device The floating disc brake device 10 includes a pair of brake pads 11 and 12, a carrier 20 that is a torque receiving member, and a floating caliper 30 that includes an actuator unit and a reaction unit described later. The main components are the anti-rattle spring 40, the wear detector 50, and the like.
Hereinafter, the above-described components will be described individually.

  Each of the pair of brake pads 11 and 12 is configured by integrally attaching a friction material 14 to a back plate 13 by fastening, tacking, or the like. In the back plate 13 of the inner brake pad 11 in this embodiment, a housing groove 15 is cut out at the outer peripheral side of the rotor and at the edge of the central portion in the rotor circumferential direction. The receiving groove 15 has a semicircular bottom as shown in FIG. 2 and preferably has a tapered shape that slightly expands toward the opening side, but is not limited thereto, and may be U-shaped, for example.

The carrier 20, which is a torque receiving member, has an attachment portion 21 that is attached to a stationary portion of the vehicle facing one side surface of the disc rotor 60 that rotates integrally with the wheel, and an attachment portion 21 that sandwiches the disc rotor 60. And a pair of bridge portions 23, 23 that both separate the two portions 21 and 22 in the circumferential direction of the rotor and are connected across the outer periphery of the rotor.
The bridge portion 23 on the side of the attachment portion 21 and the beam portion 22 is formed with L-shaped rail portions 24 that are separated from each other in the circumferential direction of the rotor. Both ends of the brake pads 11 and 12 in the circumferential direction of the brake are slidable in a direction parallel to the rotor axis and supported in the circumferential direction of the rotor.

The caliper 30 according to the present embodiment is a split type, and is arranged so as to straddle the outer periphery of the disc rotor 60 and the pair of brake pads 11 and 12.
One caliper member 31 facing one side surface of the disk rotor 60 includes a pair of actuator portions 32 and 32 arranged in parallel in the circumferential direction of the rotor and a pair of pin slide mechanism portions 33 disposed on both outer portions. 33, and the pistons 34, 34 (only one of which is shown in FIG. 1) of the actuator portions 32, 32 abut against the back plate 13 of the inner brake pad 11, respectively, and the pin slide mechanism portions 33, 33 are provided. The bottom holes 35 and 35 (only one is shown in FIG. 1) are slidably fitted to the guide pins 25 and 25 (only one is shown in FIG. 1) erected from the attachment portion 21 of the carrier 20 respectively. is doing.
The other caliper member 36 includes a reaction portion 37 that faces the actuator portions 32 and 32 and abuts against the back plate 13 of the outer brake pad 12, and a pair of bridges that are spaced apart in the rotor circumferential direction and cross over the outer periphery of the rotor. The bridge portions 38, 38 are integrally attached to one caliper member 31 with four bolts 39. The caliper members 31, 36 are integrally formed. The structure is also known.
As is clear from the configuration described above, the caliper 30 is guided in a direction parallel to the rotor axis with respect to the carrier 20 by the pair of pin slide mechanism portions 33 and 33, and the pair of brake pads 11 and 12 The caliper member 36 can be detached from the space defined by the bridge portions 38 and 38, the reaction portion 37, and the one caliper member 31.

The anti-rattle spring 40 made of a leaf spring extends along the outer periphery of the disk rotor 60 so as to cover the pair of brake pads 11 and 12, and the pair of brake pads 11 and 12 are attached to the carrier 20 which is a torque receiving member. It is a member that prevents backlash and dragging of the brake pads 11 and 12 by being elastically pressed onto the rail portions 24 and 24.
As shown in FIG. 2, the anti-rattle spring 40 of this example abuts both ends of the rotor in the circumferential direction on the inner surfaces of the inner bridge portions 23, 23 of the carrier 20 and elastically contacts the probe body 51, which will be described later. Or by elastically contacting the protrusions 16 and 16 of the brake pads 11 and 12 (only the inner brake pad 11 side is shown), the brake pads 11 and 12 are always urged toward the rotor center side. ing.
Incidentally, positioning of the anti-rattle spring 40 in the circumferential direction of the rotor is performed by using the protrusions 41 and 41 projecting from both ends in the width direction (direction parallel to the rotor axis) of the receiving grooves 15 and 15 of both brake pads 11 and 12. This is done by fitting into the mouth of the inner brake pad 11 side only (illustrated). Further, the anti-rattle spring 40 is appropriately provided with a peephole through which the remaining allowance of the friction materials 14 and 14 can be visually recognized, and a thinning for weight reduction.
The means for urging the brake pads 11 and 12 toward the rotor center side direction (on the rail portion 24 of the carrier 20) is not limited to this. A pin is passed between the caliper members 31 and 36, and the anti-rattle spring 40 is pressed by this pin, and both ends of the anti-rattle spring 40 are attached to the outer surfaces of the back plates 13 and 13 of both brake pads 11 and 12. It may be elastically contacted, and the anti-rattle spring 40 made of a leaf spring can be easily changed to an anti-rattle spring 42 made of a wire spring as shown in FIG.
The anti-rattle spring 42 shown in this plan view is made of a single wire, and the pair of central crank portions 43, 43 formed by folding back are elastically pressing the brake pads 11, 12. The left and right end portions 44 and 45 are portions that are hooked to the inner bridge portions 23 and 23 of the carrier 20. In short, it is only necessary to have a function of always urging both brake pads 11 and 12 on the rail portions 24 and 24 of the carrier 20 and a function of preventing the wear detector 50 to be removed, which will be described later.

<B> Brake Pad Wear Warning Device The brake pad wear warning device includes a wear detector 50 for electrically detecting the wear limit position W of the friction material 14 shown in FIG. , 12 is composed of an alarm device, etc., not shown in the figure that warns the replacement.
The wear detector 50 in this example is attached to the inner brake pad 11. As an example, the wear detector 50 including a probe main body and an insulated conductor, which will be described later, is shown in the enlarged view of FIG. 4 and FIG. The description will be given with reference.

<Probe body>
The probe main body 51 is an integrally molded member such as a thermosetting resin that can be worn with the friction material 14 without damaging the friction surface of the disk rotor 60.
The probe main body 51 has an outer shape in which a semicircular shape having a length of one side is connected to one side of a substantially square, and the receiving groove 15 of the inner brake pad 11 is formed in the middle portion in the thickness direction. A V-shaped U-shaped groove 52 formed so as to fit, and flange portions 53, 53 that form the U-shaped groove 52, and a gentle spherical surface portion 54 on the semicircular side of one plate surface side. Protrusions are formed. Here, if the taper angle of the two surfaces of the U-shaped groove 52 is set to be slightly larger than that of the receiving groove 15 of the inner brake pad 11, the U-shaped groove 52 can be securely fixed only by pushing. Further, in the vicinity of the top portion of the spherical surface portion 54, two parallel through holes 55, 55 are formed which are spaced apart in the direction of the symmetry axis of the outer shape of the probe main body 51 and penetrate in the plate thickness direction. A semicircular arc-shaped top portion 56 is formed between the through holes 55 and 55.

<Insulated conductor>
One insulated conducting wire 57 bent in a U-shape at the tip is composed of a conductor 58 that electrically detects disconnection and an insulator 59 that protects the conductor 58.
The insulated conductor 57 is inserted through the through holes 55 and 55 from the spherical surface 54 side of the probe main body 51, and the end thereof is connected to an alarm device (not shown). In this example, the U-shaped inner surface of the insulated conducting wire 57 is fitted on the insulated conducting wire 57 on the rear end side of the probe main body 51 under the state where the U-shaped inner surface of the probe main body 51 is in contact with the semicircular arc shaped top portion 56. Although the insulation tube 57 is positioned with respect to the probe main body 51 by contracting and fixing the contraction tube, it may be positioned at the time of wiring.
Alternatively, the U-shaped portion of the insulated conductor 57 may be embedded in the probe main body 51, or may be electrically conductive when contacted with the disk rotor 60, instead of a manner of electrically detecting disconnection. .

<C> Attachment Structure of Wear Detector As shown in FIGS. 2 and 4, the wear detector 50 is configured such that the probe body 51 is pushed into the receiving groove 15 of the back plate 13 of the inner brake pad 11 so that the tapered surface bites. As a result, the probe main body 51 is restricted from rotating by the fitting of the tapered surface.
Further, since the back plate 13 is fitted with the flange portions 53, 53 on both sides forming the U-shaped groove 52, the dropout in the direction parallel to the rotor axis is restricted, and the conductor 58 The inner surface of the U-shaped top portion 56 is set at the wear limit position W of the friction material 14.

Thus, the probe main body 51 in this example is prevented from coming off in the opening direction of the receiving groove 15 of the back plate 13 by the existing anti-rattle spring 40 or 42.
The protrusion 41 of the anti-rattle spring 40 and the central crank-shaped portion 43 of the anti-rattle spring 42 may be elastically contacted with the probe main body 51 or may be arranged with a slight gap. Good.
Therefore, as is apparent from the above description, the work of attaching the wear detector 50 to the inner brake pad 11 is merely an operation of fitting the pad 11 into the receiving groove 15 and is extremely simple.

<D> Brake operation Next, the brake operation in the above-described configuration will be briefly described.
Now, when the pistons 34 and 34 (only one is shown in FIG. 1) are advanced by the pressurized fluid, the friction material 14 of the inner brake pad 11 is frictionally engaged with one side surface of the disc rotor 60 and the reaction force The caliper 30 is guided and retracted by the pin slide mechanism portions 33, 33, and the reaction portion 37 of the other caliper member 36 presses the outer brake pad 12 so that the friction material 14 is moved to the other side of the disc rotor 60. To frictionally engage.
The friction members 14 and 14 rotate together in a state where the disc rotor 60 is clamped, and the side surfaces of the back plates 13 and 13 on the rotation direction side of the disc rotor 60 are supported by the rail portions 24 and 24 of the carrier 20. To generate braking force. When the friction material 14 of the inner brake pad 11 is gradually worn due to repeated braking over a long period of time, and finally the U-shaped top of the conductor 58 is disconnected, the driver brakes with a warning light or warning buzzer. A warning is given to the replacement of the pads 11 and 12.

  It should be noted that the present invention is not limited to the above-described embodiment, and various modifications such as mounting the wear detector 50 on the outer brake pad 12 or mounting both the brake pads 11 and 12 are possible. It is.

DESCRIPTION OF SYMBOLS 10 Floating type disc brake apparatus 11, 12 Brake pad 13 Back plate 14 Friction material 15 Housing groove 16 Protrusion 17 Opposite piston type disc brake apparatus 20 Carrier 21 Mounting part 22 Beam part 23 Bridge part 24 Rail part 25 Guide pin 30 Caliper 31 Caliper member 32 Actuator part 33 Pin slide mechanism part 34 Piston 35 Bottomed hole 36 Caliper member 37 Reaction part 38 Bridge part 39 Bolt 40 Anti-rattle spring (made by leaf spring)
41 Protrusion 42 Anti-Rattle Spring (made of wire spring)
43 Central crank-shaped portion 44 End portion 45 End portion 50 Wear detector 51 Probe main body 52 U-shaped groove 53 Flange portion 54 Spherical surface portion 55 Through hole 56 Top portion 57 Insulated lead wire 58 Conductor 59 Insulator 60 Disc rotor W Wear limit position

Claims (4)

A pair of brake pads that clamp and brake the disk rotor from both sides in the axial direction, an anti-rattle spring that biases the brake pad toward the rotor center side, and the wear limit of the friction material of the brake pad are electrically In a disc brake device provided with a wear detector for detecting the
Forming an accommodation groove on the outer peripheral edge of the back plate of the brake pad facing the anti-rattle spring;
Inserting the wear detector into the receiving groove while restricting movement in a direction parallel to the rotor axis,
The wear detector is configured to prevent the anti-rattle spring from escaping in the opening direction of the receiving groove.
Brake pad wear alarm device. The brake pad wear warning device according to claim 1, wherein the anti-rattle spring is a leaf spring. The brake pad wear warning device according to claim 1, wherein the anti-rattle spring is a wire spring. 4. The method according to claim 1, wherein a non-rotatable groove is integrally formed in the intermediate portion of the probe main body in a direction parallel to the rotor axis so as to fit into the receiving groove of the back plate. Brake pad wear warning device.

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