JPH0738809Y2 - Wear detecting device for friction material in braking device - Google Patents

Description

[Detailed Description of the Invention] A. Purpose of the Invention (1) Field of Industrial Application The present invention relates to a braking wheel, a brake element provided with a friction material facing the braking wheel, and the friction material pressed against the braking wheel. As described above, the present invention relates to a friction material wear detecting device in a braking device including a pressing device capable of pressing the brake element toward a braking wheel, and more particularly to a device for optically detecting the wear of the friction material.

(2) Related Art In the wear detecting device of the above type, a light emitting portion of a light emitting optical fiber cable for irradiating light from a light source toward a braking wheel and a light emitting portion irradiated from this light emitting portion and reflected by the braking wheel. The light receiving part of the light receiving optical fiber cable for receiving light is embedded in the friction material, and when the friction material reaches a certain wear limit, the light emitting part and the light receiving part appear in front of the friction material and It has been publicly known that a light is transmitted to a lens and a wear alarm is issued by this light.
-11902).

(3) Problems to be Solved by the Invention In the above-described conventional device, since only one light receiving portion of the light receiving optical fiber cable is provided, even if it can be detected that the friction material has reached a certain wear limit. The specific degree of progress of the wear cannot be detected, and if only one light receiving portion is covered with dust or the like, the wear cannot be detected at all.

The present invention has been proposed in view of the above, and an object thereof is to provide a wear detecting device for a friction material in a braking device, which is capable of solving the above-mentioned problems of the conventional device.

B. Configuration of the Invention (1) Means for Solving the Problems In order to achieve the above-mentioned object, the present invention provides a light emitting unit of a plurality of light emitting optical fiber cables capable of emitting light from a light source toward a braking wheel. And a light-receiving portion of a plurality of light-receiving optical fiber cables through which light emitted from the light-emitting portion and reflected by the braking wheel can enter, the light-emitting portion and the light-receiving portion are formed of the friction material as the wear of the friction material progresses. It is characterized in that it is directly embedded in the friction material so as to appear on the surface facing the braking wheel, respectively, and integrated, and the light receiving optical fiber cable is connected to a detector for detecting the light receiving state of these cables. And

(2) Action As the wear of the friction material progresses, each of the plurality of light emitting portions and the light receiving portion appears one after another on the surface of the brake element facing the braking wheel, and as a result, the plurality of light receiving optical fiber cables have the above Since the light emitted from the light emitting portion and reflected by the braking wheel can be sequentially received, it is possible to detect the change in the light receiving state by the detector to specifically know the degree of progress of the wear.

Further, in particular, the light emitting portion and the light receiving portion are directly embedded in the friction material so as to be integrated, so that the friction material itself causes relative vibration in the friction material and wobbles, causing damage or displacement. It can be effectively prevented.

(3) Embodiment Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 6, a vehicle disc brake device B as a braking device includes a brake disc D that rotates integrally with wheels,
It is composed of first and second friction pads P ₁ and P ₂ that are opposed to each other with the brake disc D in between, and a brake caliper C that can press these friction pads P ₁ and P ₂ toward the brake disc D. , Brake caliper C and friction pads
P ₁ and P ₂ are supported by a body frame (not shown) so as to be movable only in the axial direction of the brake disc D by a suitable supporting means.

The brake caliper C is the _{first one} that straddles the friction pads P ₁ and P ₂ .
It has a first arm portion 1 and a second arm portion 2, and a hydraulic cylinder 3 is formed in the first arm portion 1, and a piston 4 fitted therein is in contact with the back surface of the first friction pad P ₁ . The lower part of the second arm portion 2 is branched into a pair of arm pieces 2a, 2a.
Contacts the back surface of the second friction pad P ₂ .

The friction pads P ₁ and P ₂ are opposed to the brake disc D and have friction materials 5 ₁ and 5 ₂ having a constant thickness, and the friction materials 5 ₁ and 5 _2.
And a metal backing plate 6 ₁ , 6 ₂ adhered to the back surface of the friction member 5 _{2. In} particular, the second friction pad P ₂ is provided with a wear detecting device A capable of detecting the wear state of the friction material 5 _2. It

The wear detecting device A uses a halogen lamp H as a light source.
And a plurality of optical fiber cables for light emission 7 _{1 to} 7 ₆ for irradiating the light from the lamp H toward the metal surface of the brake disc D, and the metal surface of the brake disc D emitted from these cables. The same number of light-receiving optical fiber cables 8 ₁ to 8 ₆ as the light-emitting optical fiber cables for receiving the reflected light, and a detector S that detects the light-receiving state of the light-receiving optical fiber cables 8 ₁ to 8 ₆ The intermediate portions of the optical fiber cables 7 _{1 to} 7 ₆ and 8 ₁ to 8 ₆ are bundled together and covered with a cable cover 9 as shown in FIGS.

The light emitting respective optical fiber cable 7 _{1-7 6} extending from one end of the cable cover 9, the caliper of the pair of arm pieces 2a of the second arm section 2 through the inter-2a and the second back of the friction pad P ₂ Board 6 ₂
Through the, each end or the light-emitting unit 7a ₁ ~7a ₆ friction material 5 ₂
Each of the optical fiber cables for light reception 8 ₁ to 8 which are directly embedded in and integrated with each other and extend from one end of the cable cover 9
Numeral 8 ₆ passes between the pair of arm pieces 2a, 2a of the caliper second arm portion ₂ and penetrates the back plate 62 of the second friction pad P ₂ , and its end portions, that is, the light receiving portions 8a _{1 to} 8a. ₆ is a gap without direct implantation fixed in the friction material 5 _2. As shown in FIGS. 3 to 5, the optical fiber cables at the embedded portions are arranged in the circumferential direction of the disk in such a manner that different types of cables 7 ₁ , 8 ₁ ; ...; 7 ₆ , 8 ₆ are substantially parallel to each other. and allogeneic cable between 7 _{1-7 6;} emission portion 7a ₁ ~7a ₆ of 8 _{1-8 6} has parallel to each one row in the radial direction of the disk, in particular light-emitting optical fiber cable 7 _{1-7 6} , and the light receiving unit 8a ₁ ~8a ₆ of the light-receiving optical fiber cable 8 _{1-8 6,} their respective buried depth for friction material 5 ₂ front is set to be deeper as those of the inner disk radial direction ing. Therefore, as the wear amount of the friction material 5 ₂ increases, sequentially it becomes to appear in front of the friction member 5 ₂ from the first light emitting part 7 ₁ and the first light receiving portion 8 ₁ of the disk radially outward.

The optical fiber cable extending from the other end of the cable cover 9 is branched into a light emitting optical fiber cable group 9a and a light receiving optical fiber cable group 9b as shown in FIG. Is disposed opposite to the halogen lamp H, and the latter is connected to the detector S.

The detector S is provided with a housing 10 placed in a place where it can be easily visually recognized by a driver or maintenance personnel, and a plurality of light receiving optical fiber cables 8 ₁ to 8 ₆ provided in the housing 10. It is composed of a plurality of detection systems 11 _{1 to} 11 ₆ for independently detecting the state. Of these detection systems 11 ₁ to 11 _6, the first detecting system 11 ₁ for detecting a first light receiving state of the receiving optical fiber cable ₈₁ having a friction material 5 ₂ the nearest to the front the first light receiving portion 8a ₁ The structure will be described with reference to FIG. 6. The structure is that a light receiving element 12 ₁ that faces the end face of the first light receiving optical fiber cable 8 ₁ and generates a current when receiving light, and a base is connected to the output side of this light receiving element 12 _1. the transistors T ₁ that, the power supply circuit 13 ₁ to be opened and closed by the transistors T _1, the power supply circuit 13 ₁ lamp interposed, the light emitter 14 ₁ such as a light emitting diode (the illustrated example the light emitting diode) is composed more and It Therefore, when the first light receiving optical fiber cable 8 ₁ enters the light receiving state, the light receiving element 12 ₁ generates a current, so that the transistor T ₁ is turned on to close the power supply circuit 13 ₁ and cause the light emitting body 14 ₁ to emit light. .

The structures of the detection systems 11 _{2 to} 11 ₆ other than the first detection system 11 ₁ are the same, and thus the description thereof will be omitted. Thus each detection system 11 ₁
To 11 the light emitter 14 _{1-14 6 6} have been arranged in a line as shown in FIG. 1 in the display panel of the device housing 10, so that can be observed simultaneously.

In FIG. 6, reference numeral 15 is a switch for controlling energization of the halogen lamp H as a light source.

Next, the operation of the above embodiment will be described. When pressure oil is supplied to the hydraulic cylinder 3 during braking, the first friction pad P ₁ is pushed by the piston 4 and moves forward to press the right side surface of the brake disc D, and the reaction thereof moves the brake caliper C to the right. The second friction pad P ₂ to the brake disc D
Since it comes into pressure contact with the left side surface, the braking force is applied to the brake disc D from both pads P ₁ and P ₂ .

However when the second friction pad P ₂ is the thickness of the friction material 5 ₂ is enough as shown in Figure 3 the solid line in the unused state, the light receiving portion 8a ₁ ~8a ₆ of the light-receiving optical fiber cables are all friction material 5 ₂
Since it is buried inside, even if the switch 15 is closed and the halogen lamp H is turned on, the light is not transmitted to the respective light-receiving optical fiber cables 8 ₁ to 8 ₆ and the light emitters of the respective detection systems 11 _{1 to} 11 ₆ 14 ₁
To 14 ₆ it does not emit light.

Thus to progressing wear of the friction material 5 ₂ by the braking action described above, when the wear amount reaches a predetermined amount as shown in FIG. 3 dashed line a (may not be wear limit amount), first Light receiving part 8a ₁
And, the first light emitting portion 7a ₁ adjacent thereto appears on the front surface of the friction material 5 ₂ . If the halogen lamp H is turned on in this state,
The light of the first light-emitting optical fiber cable 7 ₁ emitting portion 7a ₁
Is radiated toward the brake disc D from the light source, reflects on the metal surface of the disc D, and enters the first light receiving portion 8a ₁ .
The first light receiving optical fiber cable 8 ₁ enters the light receiving state, and the light emitter 14 _{1 of} the first detection system 11 ₁ emits light.

The wear amount wear further advances the friction material 5 ₂ Figure 3 the chain line b
Further more, as shown in, the first light emitting portion 7a ₁ and the first
The second light-emitting unit 7a ₂ and the second light receiving portion 8a ₂ respectively adjacent to the light receiving portion 8a ₁ also to appear on the front surface of the friction material 5 _2. If the halogen lamp H is turned on in this state, the second light receiving portion 8a ₂
Since the second is emitted from the light emitting portion 7a ₂ receives the light reflected by the metal surface of the brake disc D, also emits light emitter 14 ₂ of the second detection system 11 _2.

Thereafter, a similar effect because repeated one after another as the wear progresses of the friction material 5 _2, also sequentially emitting remaining emitters in accordance with the amount of wear. Thus if you look at the driver or crew an emission state of each light emitter 14 _{1-14 6,} since without each time disassembling the brake device B can know specifically the degree of progress of the wear, the treatment for the abrasion Can be done quickly and accurately.

Next, a second embodiment of the present invention will be described with reference to FIG. This embodiment differs from the first embodiment only in the number of optical fiber cables used and the structure in which they are embedded in the friction pad P ₂ . That is, in this embodiment, is buried in the friction member 5 _2, each end of the light-emitting optical fiber cable 7 _{1-7 4} and the respective end portions of the light-receiving optical fiber cable 8 _{1-8 4,}
As shown in FIG. 7, they are symmetrically arranged with respect to a reference line 1 orthogonal to the brake disc D and are inclined at a predetermined angle α with respect to the reference line 1. According to this inclination, the friction member 5 to the total amount of light emitted from the _second light-emitting portions 7a ₁ ~7a ₄ of the light-emitting optical fiber cable 7 _{1-7 4} during wear, the light-receiving optical fiber by reflecting the brake disc D the proportion of the received light amount that reaches the cable 8a ₁ ~8a ₄ is increased, there is an effect that it is possible to reduce the output of the halogen lamp H as a light source. And, such an effect becomes more remarkable when the inclination angle α is set to 45 ° or more as shown in FIG.

In the above embodiment, the brake disc D, the second friction pad P ₂ and the brake caliper C respectively constitute the braking wheel, the brake element and the pressing device of the present invention.

Although the present invention is applied to the disc brake device for a vehicle in the above embodiment, it is needless to say that the present invention may be applied to the drum brake device.

Although the detector S detects the light receiving state of the light receiving optical fiber cable and causes the light emitting body to emit light in the above-described embodiment, the light emitting body is detected by detecting the light receiving state. Of course, the emission of light may be stopped.

C. Effect of the Invention As described above, according to the present invention, the light emitting portions of a plurality of light emitting fiber optic cables capable of emitting light from the light source toward the braking wheel and the light emitting portions of the optical fiber cables for reflecting the braking wheel. A plurality of light receiving portions of the optical fiber cable for receiving light, the light emitting portion and the light receiving portion being sequentially exposed on the surface of the friction material facing the braking wheel as the wear of the friction material progresses. Since it was embedded in the friction material and the fiber optic cable for light reception was connected to the detector that detects the light receiving state of these cables, as the friction material wears, the multiple light emitting parts and light receiving parts are rubbed one after another. By exposing it to the surface of the material facing the braking wheel, the plurality of light-receiving optical fiber cables can sequentially receive the reflected light from the braking wheel. Because you can know It can cope precisely with respect to its wear. Further, since there are a plurality of light emitting units and a plurality of light receiving units, even if a part of them is covered with dust,
The degree of wear can be generally known from the light receiving state of the remaining portion.

Further, in particular, since the light-emitting portion of each of the plurality of light-emitting optical fiber cables and the light-receiving portion of the light-receiving optical fiber cable are directly embedded in the friction material to be integrated, the light-emitting portion and the light-receiving portion are included in the friction material. The friction material itself can effectively prevent relative vibrations and wobbles and damage or displacement.
It is possible to expose each of the plurality of light emitting portions and the light receiving portions in a highly accurate and sequential manner only in accordance with the degree of progress of wear of the friction material itself, so that the state of progress of wear of the friction material can be detected extremely accurately. Moreover, the friction material itself, which is a basic functional component of the brake element, can also be used as it is as a holding means for accurately fixing and holding the plurality of optical fiber cable light-emitting parts and light-receiving parts in fixed positions. This can contribute to cost reduction by simplifying and reducing the number of parts.

[Brief description of drawings]

1 to 6 show a first embodiment of the present invention. FIG. 1 is an overall view in which a part of a disc brake is broken, FIG. 2 is a view taken along the line II-II in FIG. 3 is an enlarged sectional view taken along the line III-III in FIG. 2, FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3,
FIG. 5 is a sectional view taken along the line VV in FIG. 3, FIG. 6 is a circuit diagram of the detector, and FIG. 7 is an enlarged sectional view of a friction pad showing a second embodiment of the device of the present invention. . C ...... brake caliper as a pressing device, a brake disk as D ...... braking wheels, halogen lamp as H ...... light source, a second friction pad as P ₂ ...... brake shoe, S
…… Detector 5 ₂ …… Friction material, 7 _{1 to} 7 ₆ …… Optical fiber cable for light emission,
7a _{1 to} 7a ₆ ...... Emitting section, 8 ₁ to 8 ₆ ...... Receiving optical fiber cable, 8a _{1 to} 8a ₆ ...... Receiving section

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-56-8524 (JP, A) JP-A-57-144402 (JP, A) Actual opening 55-92934 (JP, U) Actual opening 60- 151996 (JP, U) Actually open 51-111601 (JP, U) Actually public 50-11902 (JP, Y1)

Claims (1)

[Scope of utility model registration request] And 1. A braking wheel (D), the friction material facing the brake wheel (D) (5 ₂₎ and brake shoe (P ₂₎ comprising said friction member (5 ₂₎ a braking wheel (D) A friction material wear detecting device in a braking device, comprising a pressing device (C) capable of pressing the brake element (P ₂ ) toward the braking wheel (D) so as to be pressed against the light source (H). a plurality of light-emitting optical fiber cable a light can irradiate towards the brake wheel (D) (7 ₁ ~
7 ₆ ) light emitting parts (7a _{1 to} 7a ₆ ) and those light emitting parts (7a _{1 to} 7a 7
receiving portion of the obtained contains the light reflected by the braking wheel (D) out of a ₆₎ a plurality of light-receiving optical fiber cable (8 ₁ ~8 ₆₎ (8a
The _{1 ~8a 6)} and the braking thereof emitting portion (7a ₁ ~7a ₆₎ and a light receiving portion (8a _{1 ~8a 6)} said friction member (5 ₂₎ the friction material with the wear progression (5 ₂₎ wheel (D) respectively appear sequentially as the friction material on the facing surface (5 ₂₎ and integrated with embedded directly into,
Further the light-receiving optical fiber cable (8 _{1-8 6),} characterized in that connected to them cable (8 _{1-8 6)} detector for detecting a receiving state of the (S), the friction in the brake device material Wear detector.