Friction member and friction member sensor

Abstract

To provide a friction member and a friction member sensor capable of continuously and accurately detecting a thickness of a friction material before the thickness of the friction member reaches a level that requires replacement.SOLUTION: A friction member 100 comprises a friction material 12 provided with a sensor unit 200, the sensor unit being composed of a first sensor unit 21 including a first resistance unit and a first electrode unit, and a second sensor unit 22 including a second resistance unit and a second electrode unit, and being surrounded by an insulating region that is at least a part of the friction material 12. A friction member sensor comprises the friction member 100 and a wear detection unit 400, measures resistance values of the first resistance unit and the second resistance unit, and calculates a thickness of the friction material 12 from the measurement result.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a friction member and a friction member sensor used in brake devices for automobiles, railways, industrial machines, and the like. [Background technology]

[0002] 2. Description of the Related Art Conventionally, disc brake devices and drum brake devices have been used as brake devices for automobiles, railways, industrial machines, and the like.

[0003] A disc brake device is a brake device that has brake pads with friction material attached to a back plate as the friction member and a disc rotor as the mating member, and brakes the wheels, etc. by pressing a pair of brake pads, which are provided on both sides of the disc rotor that rotates integrally with the wheels, etc., against the disc rotor.

[0004] A drum brake device is a brake device that has a brake shoe with a friction material attached to a shoe rim as a friction member, and a brake drum as a mating member, and brakes the wheels, etc. by pressing a pair of brake shoes provided on the inside of the brake drum, which rotates integrally with the wheels, etc., toward the brake drum.

[0005] Such friction members may be fitted with friction member sensors that detect the wear state of the friction material, and audible and electrical friction member sensors are known. An audible friction member sensor is configured to detect wear of the friction material by a metal fitting attached to the friction member coming into contact with a mating member and generating a sound when the friction material wears and becomes thinner (e.g., Patent Document 1). An electrical friction member sensor is configured to detect wear of the friction material by an electric wire embedded in the friction material becoming exposed and broken when the friction material wears and becomes thinner. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP2019-39511A Summary of the Invention [Problem to be solved by the invention]

[0007] As described above, conventional friction member sensors are designed to detect the wear state of a friction material that has become thin enough to require replacement due to the sound generated when a metal fitting comes into contact with a counter member or the breakage of an electric wire embedded in the friction material. Therefore, there is a problem in that the wear state cannot be detected unless the friction material reaches a specified thickness.

[0008] An object of the present invention is to provide a friction member and a friction member sensor that can continuously and accurately detect the thickness of a friction material before the friction material reaches a thickness that requires replacement when detecting wear of the friction material. [Means for solving the problem]

[0009] A friction member according to one aspect of the present invention is a friction member having a friction material that comes into contact with a counter member, the friction material having a sensor portion composed of a first sensor portion and a second sensor portion each surrounded by an insulating region that is at least a part of the friction material, the first sensor portion including a first resistor portion and a first electrode portion that measures a resistance value of the first resistor portion, and is disposed such that the resistance value of the first resistor portion changes as the surface of the friction material wears and the portion of the first resistor portion that is exposed on the surface wears, and the second sensor portion including a second resistor portion and a second electrode portion that measures a resistance value of the second resistor portion, and is disposed such that the second resistor portion is not exposed on the surface for a predetermined period of time after the resistance value of the first resistor portion changes as the friction material wears.

[0010] According to another aspect of the present invention, there is provided a friction member sensor including a friction member arranged by a support member so that the friction material can be brought into contact with a mating member, and a wear detection unit that calculates a thickness of the friction material, wherein the friction material is provided with a sensor unit composed of a first sensor unit and a second sensor unit, each of which is surrounded by an insulating region that is at least a part of the friction material, the first sensor unit includes a first resistor unit and a first electrode unit that measures a resistance value of the first resistor unit, and is arranged such that the resistance value of the first resistor unit changes as the surface of the friction material wears and a part of the first resistor unit that is exposed on the surface wears, the second sensor unit includes a second resistor unit and a second electrode unit that measures the resistance value of the second resistor unit, and is arranged such that the second resistor unit is not exposed on the surface for a predetermined period of time after the resistance value of the first resistor unit changes as the friction material wears, and the wear detection unit measures the resistance value of the first resistor unit by the first sensor unit and the resistance value of the second resistor unit by the second sensor unit, and calculates the thickness of the friction material from the resistance values ​​of the first resistor unit and the second resistor unit. Effect of the Invention

[0011] According to the friction member and friction member sensor of the present invention, the thickness of the friction material can be continuously detected before it reaches a thickness that requires replacement, and in particular, the thickness of the friction material can be accurately detected even when the temperature of the friction material is rising. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is an explanatory diagram of one embodiment (embodiment 1) of a friction member according to one aspect of the present invention. [Diagram 2] FIG. 3 is a partially enlarged view of a sensor portion of the friction member of the first embodiment. [Diagram 3] 4 is an explanatory diagram of a friction member in which the configuration of a sensor portion of the friction member of the first embodiment is modified. FIG. [Figure 4] FIG. 4 is an explanatory diagram of an embodiment (embodiment 2) of a friction member sensor which is another aspect of the present invention. [Diagram 5] 4 is an explanatory diagram of another embodiment (embodiment 3) of the friction member sensor of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] In this specification, "for a predetermined period of time after the resistance value of the first resistor changes with wear of the friction material" refers to the period during which exposure of the second resistor of the second sensor unit brings about disadvantages. The second sensor unit is provided to ensure the accuracy of the thickness of the friction material calculated from the measurement value by the first sensor unit, and usually, the value measured by the second sensor unit needs to be substantially unaffected by wear. When the second resistor of the second sensor unit is exposed to the surface of the friction material, the second resistor unit also wears with wear of the friction material, causing a change in its resistance value. Therefore, the resistance value of the first resistor of the first sensor unit changes with wear of the friction material, making it possible to detect changes in the thickness of the friction material, and the second sensor unit is arranged so that the second resistor unit is not exposed, at least until the friction material reaches a state where it is thin enough to require replacement of the friction member and detection of the thickness of the friction material becomes unnecessary. In other words, "a predetermined period of time after the resistance value of the first resistance part changes with wear of the friction material" means the period from when the resistance value of the first resistance part changes with wear of the friction material, that is, from when wear of the first resistance part begins, until wear of the friction material progresses and the friction material becomes thin enough to require replacement of the friction member.

[0014] The friction member and friction member sensor of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments, and the members, materials, etc. described below can be modified in various ways within the scope of the present invention. Furthermore, the same reference numerals in the drawings indicate equivalent or identical items, and the size and positional relationship between each component are for the sake of convenience and do not strictly reflect the actual situation.

[0015] (Embodiment 1) First, a friction member according to one aspect of the present invention will be described. FIG. 1 is an explanatory diagram of a friction member according to a first embodiment of the present invention. FIG. 2 is a partially enlarged view of a sensor portion of the friction member according to this embodiment. As shown in FIGS. 1 and 2, in the friction member 100 according to this embodiment, similar to a general friction member, a friction material 12 is attached to a back plate 11 constituting a part of a support member by an adhesive member. In the friction member 100, a surface 13 of the friction material 12 is pressed against a disc rotor or the like, thereby braking a wheel or the like.

[0016] A sensor section 200 is disposed on the friction material 12, and the sensor section 200 includes a first sensor section 21 having a height equivalent to the thickness of the friction material 12 and a second sensor section 22 having a height shorter than that of the first sensor section 21. As shown in FIG. 2, the first sensor section 21 includes first electrode sections 21E1 and 21E2 for measuring the resistance value of the first resistor section 21R, which are disposed on either side of the first resistor section 21R. The second sensor section 22 includes second electrode sections 22E1 and 22E2 for measuring the resistance value of the second resistor section 22R, which are disposed on either side of the second resistor section 22R. At least the regions of the friction material 12 surrounding the first sensor section 21 and the second sensor section 22 are insulating, and the resistance values ​​of the first resistor section 21R and the second resistor section 22R can be measured independently.

[0017] When the surface 13 of the friction material 12 is pressed against a disc rotor or the like, the surface 13 of the friction material 12 is worn. When the first sensor unit 21 is disposed as shown in FIG. 1, the surface of the first sensor unit 21 (first resistor unit) is exposed to the surface 13 of the friction material 12, and the surface of the first sensor unit 21 also wears together with the surface 13 of the friction material 12, so that the resistance value of the first resistor unit measured by the first sensor unit 21 changes according to the wear state. On the other hand, the second sensor unit 22 has a height in the thickness direction of the friction material 12 different from that of the first sensor unit 21 as shown in FIG. 2, and the end of the second sensor unit 22 on the surface 13 side of the friction material 12 is disposed farther from the surface 13 than the first sensor unit 21. Therefore, even if the surface of the first sensor unit 21 is worn due to the wear of the surface 13 of the friction material 12, the surface of the second sensor unit 22 is not exposed to the surface 13 of the friction material 12 unless the friction material 12 is worn to a thickness equivalent to the height of the second sensor unit 22, and as a result, the second sensor unit 22 (second resistor unit) is not worn. It is preferable that the wear of the surface 13 of the friction material 12 and the wear of the surface of the first sensor portion 21 progress simultaneously, and it is preferable that the friction material 12 and the first sensor portion 21 are made of the following materials.

[0018] The friction material 12 is made of materials that constitute general friction materials. Specifically, the friction material 12 is made of a composite material that includes, for example, a binder such as phenolic resin, a fiber base material such as aramid pulp, a lubricant such as graphite or molybdenum disulfide, an inorganic friction modifier such as zirconium oxide or zirconium silicate, an organic friction modifier such as cashew dust, and a filler such as barium sulfate, and is configured to be usable as a friction material and to be insulating. Here, the insulating property includes a state in which the first sensor unit 21 and the second sensor unit 22 are electrically separated from each other to such an extent that the resistance value of the first resistor unit 21R can be measured in the first sensor unit 21 and the resistance value of the second resistor unit 22R can be measured in the second sensor unit 22 when the friction material 12 is arranged around the first sensor unit 21 and the second sensor unit 22.

[0019] The first resistor portion 21R is made of a material having a higher electrical conductivity than the friction material 12, which is made by adding a conductive material, for example, graphite, to the composite material constituting the friction material 12. If the second resistor portion 22R is made of a material having the same composition as the first resistor portion 21R, the resistivity and temperature dependency of the second resistor portion 22R and the first resistor portion 21R become equal, which is preferable. Note that, when the first resistor portion 21R and the second resistor portion 22R are made of materials having different compositions, the first resistor portion 21R and the second resistor portion 22R may be made of materials whose respective resistivities and temperature characteristics are known, as described later.

[0020] The first electrode portions 21E1, 21E2 and the second electrode portions 22E1, 22E2 are also made of a material with high electrical conductivity that can be used as an electrode material, in which the composite material constituting the friction material 12 is mixed with a conductive material, such as graphite.

[0021] When the friction material 12 is made of the above-mentioned composite material and the first sensor section 21 and the second sensor section 22 are made of a material in which a conductive material has been added to the composite material constituting the friction material 12, the coefficient of linear expansion and the coefficient of wear of the friction material 12 and the sensor section 200 become approximately equal, which is preferable from the viewpoint of providing a configuration that satisfies the performance requirements of a friction material.

[0022] The resistance values ​​of the first resistor 21R and the second resistor 22R can be expressed as follows: As shown in Fig. 2, when the shape of the first resistor 21R of the first sensor unit 21 is width W, length L and height HL, and the resistivity is ρ(T), the resistance value RL of the first resistor 21R is RL = ρ(T) × (L / (W × HL)) When the surface of the first sensor portion 21 wears along with the wear of the surface 13 of the friction material 12, the height HL of the first resistor portion 21R decreases, and the resistance value of the first resistor portion 21R increases. Furthermore, when the temperature of the first resistor portion 21R changes, the resistance value of the first resistor portion 21R changes even if the height HL remains the same.

[0023] When the shape of the second resistor portion 22R of the second sensor portion 22 is width W, length L and height HS, and the resistivity is ρ(T), the resistance value RS of the second resistor portion 22R is given by RS = ρ(T) × (L / (W × HS)) In this way, when the surface 13 of the friction material 12 wears, unless the thickness of the friction material 12 becomes thin, for example, to about HS or less, to such an extent that the second sensor portion 22 is exposed from the surface 13 of the friction material 12, the second resistor portion 22R is not exposed on the surface 13 of the friction material 12, the surface of the second resistor portion 22R is not worn, and the resistance value of the second resistor portion 22R does not change. However, if the temperature of the second resistor portion 22R changes, the resistance value of the second resistor portion 22R will change.

[0024] The friction member 100 is configured as described above, and the friction member sensor of the present invention is configured to include the friction member 100 of this embodiment as described below, so that the thickness of the friction material 12 can be calculated by measuring the resistance values ​​RL and RS. Therefore, the width W and length L of the first resistor 21R are set so that the resistance value RL can be measured at least in the range from before the thickness of the friction material 12 reaches a thickness that requires replacement of the friction member 100 to when it reaches a thickness that requires replacement, and the change in the resistance value RL can be detected in this measurable range, along with the change in the thickness of the friction material 12 due to wear, and further in the temperature range of the friction material 12 when the brake device is used, for example, in the range where the temperature rises to about 200°C. The width W, length L and height HS of the second resistor 22R are set so that the change in the resistance value RS of the second resistor 22R can be detected as the temperature rises in the temperature range of the friction material 12, etc., when the brake device is used. Furthermore, the height HS of the second sensor portion 22 may be set so that the second resistance portion 22R is not exposed on the surface 13 of the friction material 12 and the surface of the second resistance portion 22R is surrounded by the insulating friction material 12 at least until the thickness of the friction material 12 reaches the thickness of the friction material 12 at which the friction member 100 needs to be replaced, and the height HS of the second sensor portion 22 should be set to be equal to or less than the thickness of the friction material 12 at which the friction member 100 needs to be replaced.

[0025] The resistance value of the first resistor 21R of the first sensor unit 21 is measured by measuring the current flowing between the first electrodes 21E1 and 21E2 arranged on either side of the first resistor 21R. The resistance value of the second resistor 22R of the second sensor unit 22 is measured by measuring the current flowing between the second electrodes 22E1 and 22E2 arranged on either side of the second resistor 22R. When making such measurements, in order to reduce the contact resistance between the measurement device and the first electrodes 21E1 and 21E2 and the second electrodes 22E1 and 22E2, metal pieces or metal rods may be connected to parts of the first electrodes 21E1 and 21E2 and the second electrodes 22E1 and 22E2.

[0026] The resistance values ​​of the first resistor portion and the second resistor portion measured by the first sensor portion and the second sensor portion, respectively, are used to calculate the thickness of the friction material 12 by a friction member sensor, which will be described later.

[0027] When the friction member 100 of this embodiment is used as a friction member sensor, it is not necessarily required to know the thickness of the friction material 12 in an unworn state or in a state where the wear is very small, as long as it can know that the thickness of the friction material 12 is approaching a thickness that requires replacement of the friction member 100, or has reached a thickness that requires replacement. Therefore, it is not necessarily required that the surface of the first resistor portion 21R of the first sensor portion 21 is exposed to the surface 13 of the friction material 12 as shown in Figures 1 and 2, and the surfaces of the first resistor portion 21R and the first electrode portions 21E1, 21E2 may be covered by the insulating friction material 12 when the surface 13 of the friction material 12 is not worn. In this case, even if the friction material 12 begins to wear, the resistance value of the first resistor 21R will not change initially as the friction material 12 wears. However, it is possible to measure the resistance value RL at least in the range from before the friction material 12 reaches a thickness that requires replacement of the friction member 100 until it reaches a thickness that requires replacement as the friction material 12 wears, and there is no problem as long as the resistance value RL is set so that the change in the resistance value RL can be detected along with the change in the thickness of the friction material 12 due to wear within this measurable range, and further so that the change in the resistance value RL can be detected within the predicted temperature range of the friction material 12.

[0028] The friction member of this embodiment can adopt a configuration in which the sensor portion and the friction material are integrally formed as shown in Figs. 1 and 2, but the sensor portion can also be formed as a separate member together with the insulating region surrounding the sensor portion, which is part of the friction material, and incorporated into the friction material. Fig. 3 shows an example of a friction member 101 including a friction material 12 with a modified sensor portion structure. In the friction member 101 shown in Fig. 3, instead of forming the first sensor portion 21, the second sensor portion 22, and the friction material 12 integrally, a member including the sensor portion 201 is formed by the sensor portion 201 composed of the first sensor portion 21 and the second sensor portion 22 and the friction material 12b (insulating region) surrounding them, and the member is fitted into a through hole formed in the friction material 12a. In this case, the friction material 12b and the friction material 12a are integrated to form the friction material 12. In this way, when the friction member 101 is formed by separately forming the friction material 12a and the member including the sensor portion 201, even if the friction material 12a does not have sufficient insulation to adjust the friction characteristics of the friction material 12, the resistance values ​​RL and RS can be measured by making the friction material 12b surrounding the first sensor portion 21 and the second sensor portion 22 insulating. The friction member 101 configured in this way can be formed by embedding the member including the sensor portion 201 in the friction material 12a, which is preferable because it simplifies the manufacturing process. Also, in the friction member 101 shown in FIG. 3, the surface of the first sensor portion 21 may be covered with the insulating friction material 12a or 12b when the surface 13 of the friction material 12a is not worn.

[0029] (Embodiment 2) Next, a friction member sensor according to another embodiment of the present invention will be described. Fig. 4 is an explanatory diagram of one embodiment (embodiment 2) of the friction member sensor of the present invention. The friction member sensor of this embodiment shown in Fig. 4 includes the friction member 100 shown in Figs. 1 and 2 described in embodiment 1 above, and is applied to a disc brake device.

[0030] As shown in Fig. 4, friction members 100 and 110 are pressed against disc rotor 300, which rotates integrally with a wheel or the like, from both sides of the disc rotor 300, thereby braking the wheel or the like. In the friction member 100, a friction material 12 is attached by an adhesive to a back plate 11, which constitutes a part of the support member. A sensor unit 200, which is composed of a first sensor unit 21 and a second sensor unit 22, is disposed on the friction material 12. In the friction member 110, the friction material 12 is attached by an adhesive to the back plate 11, which constitutes a part of the support member, and the friction member 110 is configured differently from the friction member 100 in that the friction material 12 is attached by an adhesive to the back plate 11, which constitutes a part of the support member, and the friction member 110 does not include the sensor unit 200.

[0031] 2, the first sensor unit 21 has first electrodes 21E1 and 21E2 for measuring the resistance value of the first resistor unit 21R, which are disposed on either side of the first resistor unit 21R. The second sensor unit 22 has second electrodes 22E1 and 22E2 for measuring the resistance value of the second resistor unit 22R, which are disposed on either side of the second resistor unit 22R.

[0032] In the friction member sensor of this embodiment, the wear detection unit 400 measures the resistance values ​​of the first resistor of the first sensor unit 21 and the second resistor of the second sensor unit 22 in a state in which the friction member 100 is not in contact with the disc rotor 300, and calculates the height HL of the first resistor of the first sensor unit 21. First, the resistance value measurement unit 41 of the wear detection unit 400 is connected to the first electrode units 21E1 and 21E2 of the first sensor unit 21 and the second electrode units 22E1 and 22E2 of the second sensor unit 22 described in FIG. 2, respectively, and the resistance value RL of the first resistor unit 21R and the resistance value RS of the second resistor unit 22R are measured independently. Specifically, the resistance value RL is measured by measuring the current flowing between the first electrode units 21E1 and 21E2 of the first sensor unit 21, and the resistance value RS is measured by measuring the current flowing between the second electrode units 22E1 and 22E2 of the second sensor unit 22.

[0033] In order to accurately measure the resistance value, the first sensor unit 21 is disposed such that the direction connecting the first electrode unit 21E1 and the first electrode unit 21E2 is different from the rotation direction of the disc rotor 300. This is to prevent a problem in which the resistance value of the first resistor unit 21R cannot be accurately measured because the first electrode units 21E1 and 21E2 wear due to wear of the friction material 12 and part of the worn conductive material gets between the first electrode units 21E1 and 21E2.

[0034] As described above, the resistance value RL of the first resistor 21R measured by the resistance value measuring unit 41 is RL = ρ(T) × (L / (W × HL)) And then, The resistance value RS of the second resistor 22R is RS = ρ(T) × (L / (W × HS)) It becomes.

[0035] Here, if the first resistor portion 21R and the second resistor portion 22R are made of the same material and have shapes that differ only in height, the resistivity and temperature dependence of the first resistor portion 21R and the second resistor portion 22R will be equal. Also, the height HS of the second resistor portion 22R shown in FIG. 2 is assumed to be known.

[0036] When the above conditions are satisfied, the ratio of resistance values ​​RS / RL calculated by the thickness calculation unit 42 of the wear detection unit 400 is RS / RL=HL / HS Therefore, the height HL of the first resistor portion 21R is HL = HS × (RS / RL) Thus, the height HL of the first resistance portion 21R, i.e., the thickness of the friction material 12, is calculated.

[0037] The detection signal of the height HL of the first resistance portion 21R, which corresponds to the thickness of the friction material 12 and is output from the wear detection unit 400, can also be output as a control signal for an alarm device that can notify the driver, etc. by a signal according to the alarm method, for example, by letters, sounds, etc., if the detection signal is to be made recognizable to the driver, etc. who is operating the brake device.

[0038] The height HL of the first resistor portion 21R, that is, the thickness of the friction material 12, can be calculated in the same manner by the wear detection unit 400 described above even when the friction member 100 has the configuration shown in FIG.

[0039] (Embodiment 3) Next, another embodiment (embodiment 3) of the friction member sensor of the present invention will be described. Fig. 5 is an explanatory diagram of the friction member sensor of this embodiment. The friction member sensor of this embodiment shown in Fig. 5 differs from the friction member sensor described in embodiment 2 above in the configurations of the sensor unit 202 and the wear detection unit 401.

[0040] The first sensor section 211 of this embodiment is the same as the first sensor section 21 and the second sensor section 22 described in FIG. 2 in that it is composed of a first resistor section and a first electrode section, and the second sensor section 221 is composed of a second resistor section and a second electrode section. On the other hand, the first resistor section constituting the first sensor section 211 and the second resistor section constituting the second sensor section 221 are different in that their resistivities and temperature characteristics are not equal. For example, even if the first resistor section and the second resistor section are made of the same material as described in the above embodiment 2, the resistivities and the like may vary due to the variation in the materials constituting the composite material. They may also be made of different composite materials. Even in such a case, the friction member sensor of this embodiment can calculate the height HL of the first resistor section, that is, the thickness of the friction material 12.

[0041] 5, the height HL of the first resistor of the first sensor unit 211 is calculated as follows. The resistance value measuring unit 41 of the wear detecting unit 401 is connected to the first electrode of the first sensor unit 211 and the second electrode of the second sensor unit 221, and the resistance value RL1 of the first resistor and the resistance value RS1 of the second resistor are measured independently. The resistance values ​​RL1 and RS1 are measured by the resistance value measuring unit 41 by measuring the current.

[0042] The resistance value RL1 of the first sensor portion 211 measured by the resistance value measuring portion 41 is input to the thickness calculating portion 421. On the other hand, the resistance value RS1 of the second sensor portion 221 measured by the resistance value measuring portion 41 is input to the temperature calculating portion 43. Under conditions in which the resistivity of the second resistor portion of the second sensor portion 221 and its temperature dependency are known, it is possible to calculate the temperature of the second resistor portion, i.e., the temperature of the friction material 12, from the resistance value RS1 input to the temperature calculating portion 43. A temperature detection signal is input to the thickness detecting portion 421.

[0043] In the thickness calculation unit 421, under conditions where the resistivity and temperature dependency of the first resistance part of the first sensor part 211 are known, the height HL of the first resistance part of the first sensor part 211 that has the resistance value RL1 at that temperature, i.e., the thickness of the friction material 12, is calculated from the resistance value RL1 input from the resistance value measurement unit 41 and the temperature detection signal input from the temperature calculation unit 43.

[0044] The detection signal of the height HL of the first resistance portion, which corresponds to the thickness of the friction material 12 and is output from the wear detection unit 401, can also be output as a control signal for an alarm device that can notify the driver, etc. by a signal according to the alarm method, for example, by letters, sounds, etc., if the detection signal is to be made recognizable to the driver, etc. who is operating the brake device.

[0045] In the present embodiment, the height HL of the first resistor portion, i.e., the thickness of the friction material 12, can be calculated by the wear detection unit 401 in the same manner even if the friction member 102 is the friction member 101 shown in FIG.

[0046] In this embodiment, the temperature is calculated in the temperature calculation unit 43 of the wear detection unit 401. The detection signal of this calculated temperature may be used simply to display the temperature of the friction member 102, but may also be used as a control signal for vehicle control that is affected by an increase in temperature of the friction material 12 or the friction member 102. For example, when used to display the temperature of the friction member 102, the temperature of the friction member 102 can be displayed on an alarm device to notify the driver of an increase in temperature of the friction member 102, and the temperature can be prevented from decreasing the braking performance due to the fade phenomenon, leading to a dangerous state. When used as a control signal for vehicle control, the detection signal can be used to control the brake oil pressure applied to the friction material 102 in response to a change in the temperature of the friction member 102.

[0047] In the above embodiment of the present invention, the case where the height HL of the first resistor portion, i.e., the detection signal related to the thickness of the friction material 12, is output from the thickness calculation unit 42, 421 has been described. However, as long as the driver or the like can recognize whether the friction member needs to be replaced or needs to be prepared for replacement, there may be cases where it is not necessary to know the exact thickness of the friction material 12. In such a case, the wear state may be detected from the thickness of the friction material 12. For example, a signal for indicating the level of the thickness of the friction material 12 or a signal for indicating the percentage (%) of the thickness compared to the state where the friction material 12 is not worn may be output, such as a state where the thickness of the friction material 12 is sufficiently thick and there is a sufficient margin before the friction members 102, etc. need to be replaced, a state where the thickness of the friction material 12 is somewhat thick and the friction members 102, etc. do not need to be replaced but it is preferable to prepare for replacement, and a state where the thickness of the friction material 12 is thin and the friction members 102, etc. need to be replaced.

[0048] Furthermore, in the above embodiment, the second sensor portion 22, 221 is not worn out in order to calculate the temperature. However, for example, the height HS of the second resistance portion of the second sensor portion 22, 221 may be set to a height equivalent to the thickness at which the friction members 100, 101, 102 require replacement, and the respective resistance values ​​RL and RS of the first sensor portion 21 and the second sensor portion 22 match, or the heights of the first sensor portion 211 and the second sensor portion 221 calculated from the respective resistance values ​​RL1 and RS1 of the first sensor portion 211 and the second sensor portion 221 match, thereby making it possible to know when to replace the friction members 100, 101, 102. In this case, the surface of the second sensor unit is not exposed on the surface of the friction material 12 until the thickness of the friction material 12 reaches a thickness that requires replacement of the friction members 100, 101, and 102 (a predetermined period) after the resistance value of the first resistor unit changes with wear of the friction material 12, that is, after wear of the first resistor unit starts, and the surface of the second sensor unit (second resistor unit) is exposed on the surface of the friction material 12 when the thickness of the friction material 12 reaches a thickness that requires replacement. In addition, by setting the height HS of the second electrode unit of the second sensor unit 22, 221 to a height that corresponds to the thickness of the friction members 100, 101, and 102 that requires replacement and confirming that a short circuit can be formed between the second electrode units, it is possible to know the time to replace the friction members 100, 101, and 102. In this case, when the resistance value of the second resistance part of the second sensor part 22, 221 is measured while the friction member 100 etc. is in contact with the conductive disc rotor 300, and it is confirmed that a short circuit (low resistance state) occurs between the second electrode parts, it is confirmed that the surface of the second sensor part (second electrode part) is exposed on the surface of the friction material 12.

[0049] In the above embodiment, an example in which the present invention is applied to a disk brake device has been described, but the present invention is not limited to this, and can also be applied to a drum brake device.

[0050] (summary) (1) One embodiment of a friction member according to the present invention is a friction member having a friction material that contacts a counter member, the friction material having a sensor portion including a first sensor portion and a second sensor portion each surrounded by an insulating region that is at least a part of the friction material, the first sensor portion including a first resistor portion and a first electrode portion that measures a resistance value of the first resistor portion, and is disposed such that the resistance value of the first resistor portion changes as the surface of the friction material wears and the portion of the first resistor portion that is exposed on the surface wears, and the second sensor portion including a second resistor portion and a second electrode portion that measures a resistance value of the second resistor portion, and is disposed such that the second resistor portion is not exposed on the surface for a predetermined period of time after the resistance value of the first resistor portion changes as the friction material wears.

[0051] (2) According to another embodiment, in the friction member of (1) above, the first resistance portion and the second resistance portion are made of a material obtained by adding a conductive material to a material constituting the friction material, which makes it easy to adjust the wear of the surface of the friction material and the wear of the surface of the first resistance portion of the first sensor portion so that they proceed simultaneously.

[0052] (3) One embodiment of a friction member sensor that is another aspect of the present invention is a friction member sensor including a friction member that is arranged by a support member so that the friction material can be brought into contact with a counter member, and a wear detection unit that calculates a thickness of the friction material, wherein the friction material is provided with a sensor unit composed of a first sensor unit and a second sensor unit, each of which is surrounded by an insulating region that is at least a part of the friction material, the first sensor unit includes a first resistor unit and a first electrode unit that measures a resistance value of the first resistor unit, and is arranged such that the resistance value of the first resistor unit changes as the surface of the friction material wears and the portion of the first resistor unit that is exposed on the surface wears, the second sensor unit includes a second resistor unit and a second electrode unit that measures a resistance value of the second resistor unit, and is arranged such that the second resistor unit is not exposed on the surface for a predetermined period of time after the resistance value of the first resistor unit changes as the friction material wears, and the wear detection unit measures the resistance value of the first resistor unit by the first sensor unit and the resistance value of the second resistor unit by the second sensor unit, and calculates the thickness of the friction material from the resistance values ​​of the first resistor unit and the second resistor unit.

[0053] (4) According to another embodiment, in the friction member sensor of (3) above, the first resistor and the second resistor are made of a material in which a conductive material is added to a material constituting the friction material, and the wear detection unit is configured to calculate the thickness of the friction material from the ratio of the resistance value of the first resistor to the resistance value of the second resistor. This makes it easy to adjust the wear of the surface of the friction material and the wear of the surface of the first resistor of the first sensor unit so that they progress simultaneously.

[0054] (5) According to another embodiment, in the friction member sensor of (3) above, the wear detection unit is configured to calculate the temperature of the friction material from the resistance value of the second resistor, and to calculate the thickness of the friction material from the temperature and the resistance value of the first resistor. This makes it possible to calculate the thickness of the friction material even if the resistivities and temperature characteristics of the first resistor and the second resistor are not equal to each other.

[0055] (6) According to still another embodiment, in the friction member sensor of (3) to (5) above, the wear detection unit is configured to detect the wear state of the friction material from the calculated thickness of the friction material, thereby making it possible to notify the driver or the like of information such as whether the friction member needs to be replaced or whether preparation for replacement is required. [Explanation of symbols]

[0056] 100, 101, 102, 110 Friction members 200, 201, 202 Sensor section 300 disc rotor 400, 401 Wear detection unit 11 Backplate 12, 12a, 12b Friction material 13 Surface 21, 211 First sensor section 21E1, 21E2 1st electrode part 21R 1st resistance section 22, 221 Second sensor section 22E1, 22E2 2nd electrode part 22R 2nd resistance section 41 Resistance measurement section 42, 421 Thickness calculation section 43 Temperature calculation section

Claims

1. A friction member having a friction material that contacts a counter member, The friction material is provided with a sensor unit including a first sensor unit and a second sensor unit, each of which is surrounded by an insulating region that is at least a part of the friction material; The first sensor unit is A first resistor and a first electrode for measuring a resistance value of the first resistor, a resistance value of the first resistor is changed by wear of a portion of the first resistor exposed on the surface of the friction material as the surface of the friction material wears, The second sensor unit is a second resistor and a second electrode for measuring a resistance value of the second resistor; The second resistor is disposed so as not to be exposed on the surface for a predetermined period of time after the resistance value of the first resistor changes with wear of the friction material. Friction material.

2. 2. The friction member according to claim 1, wherein the first resistance portion and the second resistance portion are made of a material in which a conductive material is added to a material constituting the friction material.

3. A friction member sensor including a friction member arranged to be in contact with a counter member by a support member, and a wear detection unit that calculates a thickness of the friction member, The friction material is provided with a sensor unit including a first sensor unit and a second sensor unit, each of which is surrounded by an insulating region that is at least a part of the friction material; The first sensor unit is A first resistor and a first electrode for measuring a resistance value of the first resistor, a resistance value of the first resistor is changed by wear of a portion of the first resistor exposed on the surface of the friction material as the surface of the friction material wears, The second sensor unit is a second resistor and a second electrode for measuring a resistance value of the second resistor; the second resistance portion is disposed so as not to be exposed on the surface for a predetermined period of time after a resistance value of the first resistance portion changes with wear of the friction material, The wear detection unit is measuring a resistance value of the first resistor section by the first sensor section and a resistance value of the second resistor section by the second sensor section; The thickness of the friction material is calculated from the resistance value of the first resistor and the resistance value of the second resistor. Friction member sensor.

4. the first resistor portion and the second resistor portion are made of a material in which a conductive material is added to a material constituting the friction material, The wear detection unit calculates a thickness of the friction material from a ratio of a resistance value of the first resistor to a resistance value of the second resistor.

4. The friction member sensor according to claim 3.

5. The wear detection unit is Calculating a temperature of the friction material from a resistance value of the second resistor; Calculating a thickness of the friction material from the temperature and the resistance value of the first resistor.

4. The friction member sensor according to claim 3.

6. The friction member sensor according to claim 3, wherein the wear detection section detects a wear state of the friction material from the calculated thickness of the friction material.

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