阅读说明：本技术 摩擦构件、盘式制动器制动衬块和车 (Friction member, disc brake pad and vehicle ) 是由 海野光朗 高桥良尚 豊田一 于 2018-06-14 设计创作，主要内容包括：本发明提供通过背板的轻质化而实现摩擦构件(盘式制动器制动衬块等)的轻质化、与此同时反复制动后的耐久性也得到了改善的摩擦构件。作为上述摩擦构件,具体而言,其是在含有比重比钢轻的原材料的背板的一个面上配置摩擦材料而得到的摩擦构件,其中,上述摩擦材料的厚度方向的热传导率为0.40W/m·K以下。(The invention provides a friction member which realizes the weight reduction of a friction member (a disc brake pad and the like) through the weight reduction of a back plate and simultaneously improves the durability after repeated braking. Specifically, the friction member is a friction member in which a friction material is disposed on one surface of a back plate made of a material having a weight smaller than that of steel, and the thermal conductivity of the friction material in the thickness direction is 0.40W/m · K or less.)

1. A friction member comprising a friction material disposed on one surface of a back plate made of a material having a weight smaller than that of steel, wherein the coefficient of thermal conductivity in the thickness direction of the friction material is 0.40W/m.K or less.

2. The friction member according to claim 1, wherein a thermal conductivity coefficient in a thickness direction of the friction material is 0.35W/m-K or less.

3. A friction member in which a friction material is disposed on one surface of a back plate made of a material having a weight smaller than that of steel, with an intermediate layer interposed therebetween, wherein at least one of the intermediate layer and the friction material has a thermal conductivity coefficient in the thickness direction of 0.40W/m.K or less.

4. The friction member according to claim 3, wherein a thermal conductivity coefficient in a thickness direction of at least one of the intermediate layer and the friction material is 0.35W/m-K or less.

5. The friction member according to claim 3 or 4, wherein the thickness of the intermediate layer is 1mm or more.

6. The friction member according to any one of claims 1 to 5, wherein the specific gravity of the raw material contained in the back sheet is 5Mg/m³The following.

7. The friction member according to any one of claims 1 to 6, wherein the back sheet contains at least 1 selected from the group consisting of (1) a fiber-reinforced resin, (2-1) an aluminum alloy, (2-2) an aluminum composite material in which ceramic particles are dispersed in aluminum or an aluminum alloy, (3-1) a magnesium alloy, and (3-2) a magnesium composite material in which ceramic particles are dispersed in magnesium or a magnesium alloy.

8. The friction member according to claim 7, wherein the back plate contains the (1) fiber-reinforced resin, the reinforcing fibers of which are glass fibers or carbon fibers, and the resin of which is a thermosetting resin.

9. A friction member according to any one of claims 1 to 8, wherein the thermal conductivity in the thickness direction of the back plate is 0.4W/m-K or more.

10. A friction member comprising a back plate and a friction material disposed on one surface of the back plate, wherein the back plate contains at least 1 selected from the group consisting of (1) a fiber-reinforced resin, (2-1) an aluminum alloy, (2-2) an aluminum composite material in which ceramic particles are dispersed in aluminum or an aluminum alloy, (3-1) a magnesium alloy, and (3-2) a magnesium composite material in which ceramic particles are dispersed in magnesium or a magnesium alloy, and the friction material has a thermal conductivity of 0.40W/m.K or less in the thickness direction.

11. The friction member according to claim 10, wherein a thermal conductivity coefficient in a thickness direction of the friction material is 0.35W/m-K or less.

12. A friction member comprising a back sheet and a friction material disposed on one surface of the back sheet with an intermediate layer interposed therebetween, wherein the back sheet contains at least 1 member selected from the group consisting of (1) a fiber-reinforced resin, (2-1) an aluminum alloy, (2-2) an aluminum composite material in which ceramic particles are dispersed in aluminum or an aluminum alloy, (3-1) a magnesium alloy, and (3-2) a magnesium composite material in which ceramic particles are dispersed in magnesium or a magnesium alloy, and the intermediate layer and/or the friction material have a thermal conductivity coefficient in the thickness direction of 0.40W/m.K or less.

13. The friction member according to claim 12, wherein a thermal conductivity coefficient in a thickness direction of at least one of the intermediate layer and the friction material is 0.35W/m-K or less.

14. A disc brake pad comprising the friction member of any one of claims 1 to 13.

15. A vehicle on which the friction member according to any one of claims 1 to 13 is mounted.

Technical Field

The invention relates to a friction member, a disc brake pad and a vehicle.

Background

Fig. 1 and 2 show an example of a disc brake pad as a friction member for braking mounted on a two-wheeled vehicle, a four-wheeled vehicle, or the like. Fig. 1 is a plan view of a brake pad of a disc brake, and fig. 2 is an example of a cross-sectional view taken along line a-a of fig. 1. In this example, the disc brake pad is composed of a backing plate 1 and a friction material 2, and the friction material 2 is directly bonded to one face 11 of the backing plate 1 (here, the upper face of the backing plate 1). The friction material 2 is made of a so-called resin molding material formed of, for example, a binder, an organic filler, an inorganic filler, and a fiber base material. Such a disc brake pad as described above may be manufactured by the steps of: a preliminary molded body of a friction material composed of a binder, an organic filler, an inorganic filler, and a fiber base material is previously stacked on one surface of the back sheet 1, and is thermally press-molded to be integrally bonded, followed by surface processing.

Another example of a disc brake pad is shown in fig. 3. Fig. 3 is another example of a cross-sectional view taken along line a-a of fig. 1. The disc brake pad of fig. 3 is composed of a backing plate 1, a friction material 2, and an intermediate layer 3, and is obtained by bonding the friction material 2 to one surface 11 of the backing plate 1 (here, the upper surface of the backing plate 1) via the intermediate layer 3. In this case, the disc brake pad may be manufactured by the steps of: a pre-molded body of a friction material composed of a binder, an organic filler, an inorganic filler and a fiber base material and an intermediate layer is previously stacked on one surface of the back sheet 1, and is thermally press-molded to be integrally bonded, followed by surface processing.

In recent years, with the progress of environmental adaptation and fuel efficiency reduction of automobiles, weight reduction of each part of automobiles has been studied and implemented. In general, the components of the materials for automobiles are half or more of the metal materials, but the amount of the metal materials used tends to decrease year by year in order to reduce the weight of the automobile body. In addition, in recent years, when the vehicle body is reduced in weight, use of aluminum (aluminum alloy or aluminum composite) or resin as a raw material tends to increase. The specific gravity of the steel sheet is about 7.8Mg/m³In comparison with aluminum, the specific gravity is about 2.7Mg/m³The specific gravity of the resin is about 1Mg/m³Since the vehicle body is light, it is expected that the vehicle body can be reduced in weight by 50% or less by using a material such as aluminum or resin. In the process of weight reduction as described above, the demand for weight reduction of not only the vehicle body and the vehicle body but also the respective elements constituting the vehicle is increasing.

The demand for weight reduction of the vehicle body as described above is also increasing for a disc brake pad, which is one of the components of a brake system used for braking a vehicle. Specifically, conventionally, a back plate made of a steel plate material has been used as a disc brake pad, and recently, a resin back plate has been proposed, and for example, a product obtained by compression molding a phenol resin containing about 0.1 to 10mm of glass fiber has been proposed (see, for example, patent documents 1 and 2).

Disclosure of Invention

Problems to be solved by the invention

The present inventors have studied changing the conventional steel backing plate to a lightweight material such as resin or aluminum in order to achieve weight reduction of the disc brake pad, and as a result, have found that: these lightweight materials have insufficient durability as compared with conventional steel back sheets.

In view of the above circumstances, an object of the present invention is to provide a friction member in which weight reduction of a friction member (such as a disc brake pad) is achieved by weight reduction of a back plate, and durability after repeated braking is improved.

Means for solving the problems

The present inventors have conducted intensive studies to solve the above problems, and as a result, have found that the durability of a back plate is improved when the back plate is reduced in weight by adjusting the thermal conductivity of a friction material, and even that the durability of a friction member can be improved, thereby completing the present invention. The present invention has been completed based on this knowledge.

The present invention relates to the following [1] to [15 ].

[1] A friction member comprising a friction material disposed on one surface of a back plate made of a material having a weight smaller than that of steel, wherein the thermal conductivity of the friction material in the thickness direction is 0.40W/m.K or less.

[2] The friction member according to the above [1], wherein the thermal conductivity in the thickness direction of the friction material is 0.35W/m.K or less.

[3] A friction member in which a friction material is disposed on one surface of a back plate made of a material having a weight smaller than that of steel, with an intermediate layer interposed therebetween, wherein the thermal conductivity in the thickness direction of at least one of the intermediate layer and the friction material is 0.40W/m.K or less.

[4] The friction member according to item [3] above, wherein the thermal conductivity in the thickness direction of at least one of the intermediate layer and the friction material is 0.35W/m.K or less.

[5] The friction member according to the above [3] or [4], wherein the thickness of the intermediate layer is 1mm or more.

[6]According to the above [1]～[5]The friction member according to any one of the preceding claims, wherein the specific gravity of the raw material contained in the back sheet is 5Mg/m³The following.

[7] The friction member according to any one of the above [1] to [6], wherein the back plate contains at least 1 selected from (1) a fiber-reinforced resin, (2-1) an aluminum alloy, (2-2) an aluminum composite material in which ceramic particles are dispersed in aluminum or an aluminum alloy, (3-1) a magnesium alloy, and (3-2) a magnesium composite material in which ceramic particles are dispersed in magnesium or a magnesium alloy.

[8] The friction member according to the above [7], wherein the back plate contains the (1) fiber-reinforced resin, the reinforcing fiber of the fiber-reinforced resin is a glass fiber or a carbon fiber, and the resin of the fiber-reinforced resin is a thermosetting resin.

[9] The friction member according to any one of the above [1] to [8], wherein a thermal conductivity in a thickness direction of the back plate is 0.4W/mK or more.

[10] A friction member comprising a back plate and a friction material disposed on one surface of the back plate, wherein the back plate contains at least 1 selected from the group consisting of (1) a fiber-reinforced resin, (2-1) an aluminum alloy, (2-2) an aluminum composite material in which ceramic particles are dispersed in aluminum or an aluminum alloy, (3-1) a magnesium alloy, and (3-2) a magnesium composite material in which ceramic particles are dispersed in magnesium or a magnesium alloy, and the friction material has a thermal conductivity in the thickness direction of 0.40W/m.K or less.

[11] The friction member according to item [10] above, wherein the thermal conductivity of the friction material in the thickness direction is 0.35W/m.K or less.

[12] A friction member comprising a back sheet and a friction material disposed on one surface of the back sheet with an intermediate layer interposed therebetween, wherein the back sheet contains at least 1 selected from the group consisting of (1) a fiber-reinforced resin, (2-1) an aluminum alloy, (2-2) an aluminum composite material in which ceramic particles are dispersed in aluminum or an aluminum alloy, (3-1) a magnesium alloy, and (3-2) a magnesium composite material in which ceramic particles are dispersed in magnesium or a magnesium alloy, and the thermal conductivity in the thickness direction of at least one of the intermediate layer and the friction material is 0.40W/m.K or less.

[13] The friction member according to item [12] above, wherein the thermal conductivity in the thickness direction of at least one of the intermediate layer and the friction material is 0.35W/m.K or less.

[14] A disc brake pad comprising the friction member according to any one of claims [1] to [13 ].

[15] A vehicle on which the friction member according to any one of [1] to [13] above is mounted.

Effects of the invention

According to the present invention, it is possible to provide a friction member in which the weight of the back plate is reduced, thereby reducing the weight of the friction member (such as a disc brake pad) and, at the same time, durability after repeated braking is improved. Further, since the backplate has a lower specific gravity than steel, it is advantageous to reduce the weight of the vehicle body of a two-wheeled vehicle, a four-wheeled vehicle, or the like by reducing the weight of the friction member such as a disc brake pad.

Drawings

Fig. 1 is a schematic view (plan view) showing a friction member (disc brake pad).

Fig. 2 is a schematic view of a cross section a-a in fig. 1 of a friction member (disc brake pad) in which a friction material is directly disposed on one surface of a back plate.

Fig. 3 is a schematic view of a cross section a-a in fig. 1 of a friction member (disc brake pad) in which a friction material is disposed on one surface of a back plate with an intermediate layer interposed therebetween.

Detailed Description

The present invention will be described in detail below. However, in the following embodiments, the constituent elements thereof are not essential unless otherwise specified. The same applies to values and ranges, and is not intended to limit the invention.

In the numerical range described in the present specification, the upper limit or the lower limit of the numerical range may be replaced with the values shown in the examples. In the present specification, the content of each component in the friction material composition refers to the total content of a plurality of substances present in the friction material composition unless otherwise specified, when there are a plurality of substances corresponding to each component.

In addition, the present invention includes an embodiment in which the items described in the present specification are arbitrarily combined.

One mode (first mode) of the present invention is described with reference to, for example, fig. 2, which is a friction member in which a friction material 2 is disposed on one surface of a back plate 1 made of a material having a weight smaller than that of steel, wherein the thermal conductivity of the friction material 2 in the thickness direction is 0.40W/m · K or less.

Another aspect (second aspect) of the present invention is a friction member obtained by disposing a friction material 2 on one surface of a back sheet 1 made of a material having a weight smaller than that of steel, with an intermediate layer 3 interposed therebetween, wherein the thermal conductivity in the thickness direction of at least one of the intermediate layer 3 and the friction material 2 is 0.40W/m · K or less, as described with reference to fig. 3, for example.

In the present invention, the thickness direction refers to a direction from the surface of the friction material slidably connected to the target material toward the back plate, and the thermal conductivity refers to a thermal conductivity measured by a temperature gradient method at room temperature (25 ℃). Here, the temperature gradient method is a method of measuring the thermal conductivity of a sample from the thermal flux and the sample temperature when the sample in contact with 2 objects having a temperature difference reaches a steady state, and the thermal conductivity measured by the temperature gradient method can be measured using a commercially available measuring apparatus. The thermal conductivity measured by the temperature gradient method is, specifically, the thermal conductivity measured by the method described in examples.

As a result of the studies by the present inventors, if braking is repeated, the brake temperature is increased by frictional heat, and the surface temperature of the friction material may reach about 600 ℃ or higher, and particularly, when the friction material is worn and the remaining thickness of the friction material is reduced, the back plate may be heated to 200 ℃ or higher. It has also been found that: in the case of a back sheet made of a fiber-reinforced resin among lightweight materials, if the temperature of the back sheet is increased to the heat-resistant temperature of the resin or higher, the resin is thermally decomposed, the strength of the back sheet is significantly reduced, and defects such as cracks and fractures are likely to occur. A back sheet made of a lightweight material such as an aluminum alloy, an aluminum composite material, a magnesium alloy, or a magnesium composite material has a remarkably low strength and elastic modulus at 200 ℃. However, according to the above aspect 1 or 2, the temperature rise of the back plate 1 made of a lightweight material is suppressed, and even when the surface temperature of the friction material reaches 600 ℃.

Hereinafter, the back plate and the friction material of the friction member will be described in order.

[ Back plate ]

The back sheet contains a raw material having a weight lower than that of steel, and if preferred, is formed of a raw material having a weight lower than that of steel. The raw material having a lighter specific gravity than steel is preferably 5Mg/m in specific gravity³The following raw materials, more preferably 3Mg/m in specific gravity³The following raw materials, more preferably 2Mg/m in specific gravity³The following raw materials were used. Further, the specific gravity of the back sheet is preferably 5Mg/m³Less than, more preferably 3Mg/m³Hereinafter, more preferably 2Mg/m³The following.

Examples of the material having a lighter specific gravity than steel include (1) fiber-reinforced resin, (2-1) aluminum alloy, (2-2) aluminum composite material in which ceramic particles are dispersed in aluminum or aluminum alloy, (3-1) magnesium alloy, and (3-2) magnesium composite material in which ceramic particles are dispersed in magnesium or magnesium alloy. That is, the back sheet may contain at least 1 kind selected from the above-mentioned raw materials (1), (2-2), (3-1) and (3-2), or may be made of at least 1 kind selected from the above-mentioned raw materials (1), (2-2), (3-1) and (3-2).

((1) fiber-reinforced resin)

The fiber-reinforced resin is a composite material of fibers and a resin, which is a composite product of fibers and a resin. Since the specific gravity of the fiber-reinforced resin is about 1Mg/m³Therefore, it is suitable as a material for weight reduction.

As the fibers used for the fiber-reinforced resin, for example, inorganic fibers selected from glass fibers, alumina fibers such as α -alumina type and γ -alumina type, boron fibers, and the like; aramid fibers such as para-aramid fibers and meta-aramid fibers; at least 1 kind of carbon fiber selected from cellulose fiber, nanometer cellulose fiber, PBO (poly-p-phenylene benzobisoxazole) fiber, flame retardant fiber, pitch system carbon fiber, PAN (polyacrylonitrile) system carbon fiber, etc. In particular, when used as a back sheet, glass fibers and carbon fibers are preferable from the viewpoint of strength and rigidity; from the viewpoint of high thermal conductivity, carbon fiber is more preferable. By using carbon fibers, the thermal conductivity of the back plate can be further improved, and when the brake temperature is raised by frictional heat due to repeated braking, the temperature distribution in the back plate can be made uniform, and local temperature rise can be prevented, and cracks and fractures caused by thermal decomposition and strength reduction of the resin can be easily prevented.

The fiber length of the fibers used in the fiber-reinforced resin is not particularly limited, and is preferably a fiber length of 1mm or more, and more preferably a long fiber of 10mm or more, from the viewpoint of strength. The upper limit of the fiber length of the fiber is not particularly limited, and may be 100mm or less, or 70mm or less, or 50mm or less, or 35mm or less.

As the fibers used for the fiber-reinforced resin, nonwoven fabrics such as felts, papermaking products, woven fabrics such as woven fabrics, knitted fabrics, and interwoven fabrics made of continuous fibers can be used.

The resin used for the fiber-reinforced resin is preferably a thermosetting resin from the viewpoint of heat resistance, and is preferably a phenol resin, an epoxy resin, or a polyimide resin from the viewpoint of heat resistance and strength. The phenol resin and the epoxy resin are preferably used in combination with a curing agent. The resin used for the fiber-reinforced resin may be used alone in 1 kind, or may be used in combination in 2 or more kinds. As the phenol resin, commercially available products can be used, or they can be synthesized by a conventional method.

Examples of the phenol resin include resol-type phenol resins, novolak-type phenol resins, aralkyl-modified phenol resins, elastomer-modified phenol resins modified with an acrylic elastomer, a silicone elastomer, and the like. From the viewpoint of heat resistance, the phenol resin is preferably a novolak-type phenol resin or a resol-type phenol resin.

The epoxy resin may be commercially available or synthesized by a conventional method. The epoxy resin is preferably an epoxy resin having an aromatic ring from the viewpoint of strength and heat resistance. Specifically, phenol novolac type epoxy resins, cresol novolac type epoxy resins, naphthalene type epoxy resins, and the like can be preferably used. Epoxy resins modified with polysiloxane, acrylonitrile, butadiene, isopropyl rubber, polyamide resins, and the like can also be used.

In addition, other additives may be added to the fiber-reinforced resin in addition to the fibers and the resin. Examples of the other additives include inorganic fillers, organic fillers, and metal powders. The other additives may be used alone in 1 kind, or in combination of 2 or more kinds. The inorganic filler, the organic filler, and the metal powder are preferably in the form of particles, and the particles are preferably smaller in particle size in order to disperse the particles in the fiber aggregate. Specifically, from the viewpoint of improving the sliding property, graphite, molybdenum disulfide, tungsten sulfide, fluorine resin, coke, and the like can be cited, from the viewpoint of improving the flame retardancy, magnesium hydroxide, aluminum hydroxide, antimony compound, and the like can be cited, from the viewpoint of reducing the weight, hollow inorganic particles, and the like can be cited, from the viewpoint of improving the curing rate of the resin, calcium oxide, calcium hydroxide, and the like can be cited, and from the viewpoint of improving the thermal conductivity, metal powder, graphite, magnesium oxide, zinc oxide, and the like can be cited.

In order to prevent a local temperature rise in the backsheet, the thermal conductivity in the thickness direction of the fiber-reinforced resin is preferably 0.4W/mK or more, more preferably 0.45W/mK or more, and still more preferably 1.0W/mK or more. Examples of the method for setting the thermal conductivity in the thickness direction of the fiber-reinforced resin to the above range include a method in which an additive having high thermal conductivity such as the metal powder, graphite, magnesium oxide, and zinc oxide is added to the fiber-reinforced resin, a method in which a fiber having high thermal conductivity such as carbon fiber is used as a fiber of the fiber-reinforced resin, and the like, and fiber-reinforced resins obtained by using 1 kind of the above methods alone or 2 or more kinds of the above methods in combination can be used.

In the case where the above fiber reinforced resin is used for the back sheet, the above friction member may be manufactured by the following steps: the friction member is manufactured by molding a fiber-reinforced resin and, if necessary, shaping the molded product to produce a fiber-reinforced resin back sheet, and then using the fiber-reinforced resin back sheet instead of a conventional steel back sheet. That is, after a friction material composition that is preformed as necessary is inserted into a die hole of a thermoforming mold for friction material, a product obtained by previously applying an adhesive to a back sheet made of the fiber-reinforced resin is disposed so as to be in contact with the preform. Then, the friction material composition is thermoformed to form the friction material, whereby the fiber-reinforced resin and the friction material can be integrated to form the friction member. According to the above steps, since the back sheet made of the fiber-reinforced resin is subjected to thermoforming and the friction material is subjected to thermoforming, respectively, energy efficiency is not necessarily good. Therefore, by simultaneously performing the thermoforming of the back sheet made of the fiber reinforced resin and the thermoforming of the friction material, it is also possible to improve the energy efficiency. That is, the fiber-reinforced resin in a state before thermosetting and the friction material composition preformed as necessary are inserted and simultaneously thermoformed, and the thermosetting resin in the fiber-reinforced resin and the thermosetting resin in the friction material are melted and cured in the thermoforming step, whereby integration can be performed without an adhesive.

(aluminum, aluminum alloy)

Since the specific gravity of the aluminum is about 2.7Mg/m³And is relatively small, and therefore suitable as a lightweight material, but from the viewpoint of strength, it is preferable to use an aluminum alloy for the back sheet. As the aluminum alloy, there can be used deformation aluminum alloys such as 2XXX series (Al-Cu series), 3XXX series (Al-Mn series), 4XXX series (Al-Si series), 5XXX series (Al-Mg series), 6XXX series (Al-Mg-Si series), 7XXX series (Al-Zn series); aluminum for casting such as AC1C (Al-Cu system), AC1B (Al-Cu system), AC2A (Al-Cu-Si system), AC2B (Al-Cu-Si system), AC3A (Al-Si system), AC4A, AC4C (Al-Si-Mg system), AC4B (Al-Si-Cu system), AC4D (Al-Si-Cu-Mg system), AC5A (Al-Cu-Ni-Mg system), AC7A (Al-Mg system), AC8A (Al-Si-Cu-Ni-Mg system), AC8B (Al-Si-Cu-Ni-Mg system), AC9A (Al-Si-Cu-Mg system), AC9B (Al-Si-Cu-Mg system)Alloying; ADC1(Al-Si system), ADC3(Al-Si-Mg system), ADC5(Al-Mg system), ADC6(Al-Mg-Mn system), ADC10(Al-Si-Cu system), ADC12(Al-Si-Cu system), and ADC14(Al-Si-Cu-Mg system). Further, those subjected to heat treatment (aging treatment) and the like and subjected to thermal refining may be used.

(aluminum composite Material)

An aluminum composite material (ceramic particle-reinforced aluminum-based composite material) in which ceramic particles are dispersed in aluminum or the aluminum alloy has a higher young's modulus than an aluminum alloy, and therefore, if used as a back plate, the rigidity of a brake pad can be improved, which is preferable. As the dispersion-strengthened ceramic particles, Al can be used₂O₃、TiO₂、SiO₂、ZrO₂Oxide-based ceramics such as SiC and TiC, and nitride-based ceramics such as TiN.

(magnesium, magnesium alloy)

The specific gravity of magnesium is 1.74Mg/m³And is relatively small, and therefore suitable as a lightweight material, but from the viewpoint of strength, it is preferable to use a magnesium alloy as the back sheet. As the magnesium alloy, various casting magnesium alloys and processing magnesium alloys such as M1(Mg-Mn alloy), AZ series (Mg-Al-Zn alloy) such as AZ61 and AZ91, ZK series (Mg-Zn-Zr alloy) such as ZK51 and ZK60, ZH series (Mg-Zn-Zr alloy) such as ZH62, EK series (Mg-rare earth element alloy) such as EK30, HK series (Mg-Th series alloy) such as HK31, and K1(Mg-Zr alloy) can be used. In addition, a flame-retardant magnesium alloy to which several percent of calcium is added may be used.

(magnesium composite Material)

A magnesium composite material (ceramic particle-reinforced magnesium-based composite material) in which ceramic particles are dispersed in magnesium or the magnesium alloy has a higher young's modulus than a magnesium alloy, and therefore, if used as a back plate, the rigidity of a brake pad can be improved, which is preferable. As the dispersion-strengthened ceramic particles, Al can be used₂O₃、TiO₂、SiO₂、ZrO₂Oxide-based ceramics such as SiC and TiC, and nitride-based ceramics such as TiN.

Further, by increasing the thermal conductivity in the thickness direction of the back plate, when the brake is repeatedly applied and the brake temperature rises due to frictional heat, the temperature distribution in the back plate can be made uniform, local temperature rise can be prevented, and cracks and fractures due to thermal decomposition of the resin and strength reduction can be easily prevented. From this viewpoint, the thermal conductivity in the thickness direction of the back sheet is preferably 0.4W/mK or more, more preferably 0.45W/mK or more, and still more preferably 1.0W/mK or more. The upper limit of the thermal conductivity in the thickness direction of the back sheet is not particularly limited, and may be 400W/m.K or less, or may be 250W/m.K or less.

[ Friction Material ]

As the friction material, for example, a friction material formed of a friction material composition containing a binder material, an organic filler material, an inorganic filler material and a fiber base material is preferable. The friction material can be formed by overlaying the above-described friction material composition or the preform of the friction material composition with a back plate, followed by hot press molding, and then heat treatment to cure the thermosetting resin as the binder.

In the above aspect 1, the thermal conductivity in the thickness direction of the friction material 2 is 0.40W/m · K or less, preferably 0.35W/m · K or less, as described with reference to fig. 2. The lower limit of the thermal conductivity of the friction material 2 in the thickness direction is not particularly limited, and may be 0.05W/mK or more, or may be 0.1W/mK or more.

In the above embodiment 2, the thermal conductivity in the thickness direction of at least one of the intermediate layer 3 and the friction material 2, which will be described later, is 0.40W/m · K or less, preferably 0.35W/m · K or less, with reference to fig. 3. The lower limit of the thermal conductivity is not particularly limited, and may be 0.05W/mK or more, or may be 0.1W/mK or more.

Here, as a method of setting the thermal conductivity in the thickness direction of the friction material to the above range, for example, 0.40W/m · K or less (preferably 0.35W/m · K or less), there are, for example, (a) a method of increasing the porosity of the friction material, (B) a method of reducing the content of a material having high thermal conductivity such as graphite and metal fibers in the friction material, (C) a method of increasing the content of a resin in the friction material, and the like, and by using 1 kind of these methods alone or 2 or more in combination, a friction material having a thermal conductivity of 0.40W/m · K or less (preferably 0.35W/m · K or less) can be set.

From the viewpoint of durability, the thickness of the friction material is preferably 4 to 15mm, more preferably 6 to 15mm, and still more preferably 7 to 13 mm.

[ intermediate layer ]

In the above embodiment 2, the friction member 2 is formed on the back plate via the intermediate layer 3, as described with reference to fig. 3. As the intermediate layer 3, for example, a friction material formed of a friction material composition containing a binder, an organic filler, an inorganic filler and a fiber base material is a preferable embodiment. When the friction material 2 is fixed to the back plate 1 with the intermediate layer 3 interposed therebetween, a preform of the friction material composition and the intermediate layer composition or the friction material composition and the intermediate layer composition is overlapped with the back plate 1, and then hot-pressed, and then heat-treated to cure a thermosetting resin as a binder, thereby forming the intermediate layer 3.

As described above, the thermal conductivity in the thickness direction of at least one of the intermediate layer 3 and the friction material 2 is not particularly limited as long as it is 0.40W/m · K or less (preferably 0.35W/m · K or less), and if the thermal conductivity in the thickness direction of the friction material 2 is 0.40W/m · K or less, the thermal conductivity in the thickness direction of the intermediate layer 3 is not particularly limited, whereas if the thermal conductivity in the thickness direction of the friction material 2 exceeds 0.40W/m · K, the thermal conductivity in the thickness direction of the intermediate layer 3 is set to 0.40W/m · K or less (preferably 0.35W/m · K or less). By setting in this way, even when the surface temperature of the friction material becomes 600 ℃ or higher, the back plate can be prevented from cracking or breaking, and the friction member having excellent durability can be obtained. This is presumably because the temperature rise of the back sheet made of a lightweight material is effectively suppressed.

Here, as a method of setting the thermal conductivity in the thickness direction of the intermediate layer 3 to the above range, for example, 0.40W/m · K or less (preferably 0.35W/m · K or less), for example, (a) a method of increasing the porosity of the friction material, (B) a method of reducing the content of a material having high thermal conductivity such as graphite and metal fiber in the intermediate layer, (C) a method of increasing the content of a resin in the intermediate layer, and the like, and by using 1 kind alone or 2 or more kinds in combination of these methods, an intermediate layer of 0.40W/m · K or less (preferably 0.35W/m · K or less) can be produced.

The thickness of the intermediate layer is preferably 1mm or more. When the thermal conductivity of the intermediate layer 3 in the thickness direction is 0.40W/m · K or less, the thickness of the intermediate layer is set to 1mm or more, so that the heat insulating effect between the friction material and the back plate is increased, and cracks and fractures of the back plate can be effectively suppressed. The thickness of the intermediate layer is more preferably 1 to 5mm, still more preferably 1 to 3mm, and particularly preferably 1 to 2 mm.

Further, it is preferable that the back sheet 1 contains a fiber-reinforced resin, and the thermosetting resin contained in the friction material 2 is set to a combination of chemical components capable of forming a chemical bond with each other by thermosetting with the thermosetting resin used for the back sheet 1. By setting in this way, the back plate 1 and the friction member 2 can be integrally molded by hot press molding without using an adhesive, and it is preferable not only to improve the strength and toughness of the brake pad 1 but also to simplify the manufacturing process.

Further, it is preferable that the back sheet 1 contains a fiber-reinforced resin, and the thermosetting resin contained in the friction material 2 and the intermediate layer 3 is set to a combination of chemical components capable of forming a chemical bond with each other by thermosetting with the thermosetting resin used for the back sheet 1 when the intermediate layer 3 is provided. By setting in this way, the back plate 1, the intermediate layer 3, and the friction member 2 can be integrally molded by hot press molding without using an adhesive, and it is preferable not only to improve the strength of the brake pad 1 but also to simplify the manufacturing process.

Further, when the backsheet 1 contains an aluminum alloy containing Cu, Zn, or the like, or an aluminum composite material based on the aluminum alloy, the aging precipitation treatment may be performed simultaneously at the time of hot press forming and the heat treatment. In this case, it is preferable not only to improve the strength of the brake pad 1 but also to simplify the manufacturing process.

[ vehicle ]

The invention also provides a vehicle carrying the friction member of the invention. Examples of the friction member include vehicles using the friction member of the present invention for a disc brake pad, a brake shoe, a clutch disk, an electromagnetic brake, a parking brake, and the like. Examples of the vehicle include large-sized vehicles, medium-sized vehicles, general-purpose vehicles, large-sized special vehicles, small-sized special vehicles, large-sized motorcycles, general motorcycles, and the like.