Specification
Title of the invention: Brake linings for railway vehicles, disc brake systems for railway vehicles using the same, and sintered friction materials used for brake linings for railway vehicles.
Technical field
[0001]
　The present disclosure relates to a brake lining for a railroad vehicle, a disc brake system for a railroad vehicle using the brake lining, and a sintered friction material used for a brake lining for a railroad vehicle.
Background technology
[0002]
　Railway vehicles such as the Shinkansen are becoming faster and larger. A disc brake system is adopted as one of the braking devices for these railway vehicles.
[0003]
　Disc brake systems for railroad vehicles are classified as adhesive mechanical braking devices. The disc brake system for railroad vehicles includes a brake disc and a brake caliper. Brake discs are attached to the wheels or axles of railroad vehicles. The brake caliper is attached to a bogie, which is a running device. The brake caliper includes a brake lining, a caliper arm to which the brake lining is attached, and a pneumatic or hydraulic pressing mechanism for moving the caliper arm to press the brake lining against the brake disc. When braking, the pressing mechanism presses the brake lining against the sliding surface of the brake disc. At this time, the disc brake system for railroad vehicles brakes the rotation of wheels or axles by the frictional force generated between the brake disc and the brake lining, and decelerates or stops the railroad vehicle.
[0004]
　The brake lining includes a substrate that can be attached to the caliper arm of the brake caliper, a friction material, and a friction material support mechanism. The friction material support mechanism is arranged between the substrate and the friction material and supports the friction material. The friction material support mechanism may include, for example, an elastic member typified by a disc spring. The friction material support mechanism in the brake lining supports the friction material so as to be movable in the plate thickness direction of the substrate. Therefore, during braking, the friction material can be moved in the plate thickness direction of the substrate according to the unevenness of the brake disc, and the contact area of ​​the friction material with the brake disc can be increased. Therefore, it is easy to make the contact pressure distribution of the friction material uniform during braking. As a result, the temperature distribution of the brake disc can be made uniform, and uneven wear of the friction material can be suppressed.
[0005]
　By the way, in the brake lining including the friction material support mechanism, noise called "brake squeal" is likely to be generated at the time of braking. Brake squeal is thought to occur when the frictional force generated between the brake disc and the brake lining causes self-excited vibration in the entire rail vehicle disc brake system. Self-excited vibration is a phenomenon in which steady (non-vibration) energy from the outside is converted into vibration energy inside the system, and the vibration amplitude increases by vibrating itself.
[0006]
　Techniques for suppressing brake squeal of a brake lining including a friction material support mechanism are JP-A-2011-214629 (Patent Document 1), JP-A-2015-218808 (Patent Document 2), and JP-A-2014-122313. It is proposed in Gazette (Patent Document 3).
[0007]
　The technique of Patent Document 1 defines the rigidity of the support mechanism of the friction member as "support rigidity", and by controlling this support rigidity, the brake squeal is reduced. Specifically, the brake lining for a railway vehicle disclosed in Patent Document 1 includes a friction member and a substrate that supports the friction member. Then, in the state where the brake lining is arranged on the carriage, the support rigidity of the friction member in the portion other than the center line H portion is made larger than the support rigidity of the friction member existing in the vertical center line H portion of the brake lining.
[0008]
　The technique of Patent Document 2 reduces brake squeal by imparting damping (damping ability) to the friction material. Specifically, the friction material for lining disclosed in Patent Document 2 includes polytetrafluoroethylene and acrylic rubber-modified phenol resin.
[0009]
　The technique of Patent Document 3 reduces brake squeal by stabilizing the friction coefficient of the friction material. Specifically, the friction material disclosed in Patent Document 3 includes a fiber base material, a friction adjusting material and a binder, and further contains two or more kinds of non-whisker-like titanium acid compounds. The two or more non-whisker-like titanic compounds contain at least non-whisker-like lithium potassium titanate and do not contain a copper component.
Prior art literature
Patent documents
[0010]
Patent Document 1: Japanese Patent Application Laid-Open No. 2011-214629
Patent Document 2: Japanese Patent Application Laid-Open No. 2015-218808
Patent Document 3: Japanese Patent Application Laid-Open No. 2014-122313
Non-patent literature
[0011]
Non-Patent Document 1: Journal of the Japan Society of Mechanical Engineers, Vol. 71, No. 709, Paper No. 03-1224
Outline of the invention
Problems to be solved by the invention
[0012]
　As described above, in Patent Document 1, the rigidity (support rigidity) of the support mechanism of the friction member is controlled to suppress the brake squeal. Further, in Patent Document 2, a damping function is provided to the friction material to suppress brake squeal. In Patent Document 3, brake squeal is suppressed by stabilizing the friction coefficient of the friction material. However, the method of suppressing the brake squeal in the disc brake system for railway vehicles is not limited to the above, and other methods may be used.
[0013]
　An object of the present disclosure is to use a brake lining for a railway vehicle capable of suppressing brake squeal when braking a railway vehicle, a disc brake system for a railway vehicle using the brake lining for the railway vehicle, and a brake lining for a railway vehicle. It is to provide a sintered friction material that can be used.
Means to solve problems
[0014]
　The brake lining for a railroad vehicle according to the present disclosure is a brake lining for a railroad vehicle used in a disc brake system for a railroad vehicle,
　and includes a substrate, a
　sintered friction material in which a plurality of powder particles are sintered, and the
　substrate. It is provided with a friction material support mechanism that is arranged between the sintered friction material and supports the
　sintered friction material, and the Young ratio of the sintered friction material is 35.0 GPa or more.
[0015]
　The disc brake system for a railroad vehicle according to the present disclosure includes a
　brake disc attached to a wheel or axle of the
　railroad vehicle and a brake caliper attached to a bogie of the railroad vehicle, and the
　brake caliper is a
　brake for the railroad vehicle described above. It includes a lining, a
　caliper arm to which the railroad vehicle brake lining is attached, and
　a pressing mechanism capable of pressing the railroad vehicle brake lining against the brake disc.
[0016]
　The sintered friction material according to the present disclosure is used for brake linings for railway vehicles.
Effect of the invention
[0017]
　The brake lining for railway vehicles, the disc brake system for railway vehicles using the brake lining for railway vehicles, and the sintered friction material used for the brake lining for railway vehicles according to the present disclosure cause brake squeal when braking the railway vehicle. Can be suppressed.
A brief description of the drawing
[0018]
FIG. 1 is a diagram showing the relationship between the Young's modulus of a sintered friction material and the maximum squeal index obtained from the brake squeal analysis result using an opposed disc brake system.
FIG. 2 is a diagram showing the relationship between the Young's modulus of the sintered friction material and the maximum squeal index obtained from the brake squeal analysis result using the floating disc brake system.
FIG. 3 is a schematic diagram of a disc brake system for a railway vehicle according to the present embodiment.
[Fig. 4A] Fig. 4A is a schematic view of a floating type disc brake system for railway vehicles.
FIG. 4B is a schematic diagram for explaining the braking operation of a floating type disc brake system for a railway vehicle.
FIG. 5 is a schematic diagram of a rail vehicle disc brake system, which is different from FIGS. 4A and 4B.
[Fig. 6] Fig. 6 is a schematic view of an opposed type disc brake system for railway vehicles.
FIG. 7 is a front view of a railroad vehicle brake lining when the railroad vehicle brake lining is viewed from the brake disc side.
FIG. 8 is a cross-sectional view taken along the line segment VIII-VIII in FIG.
FIG. 9 is a front view of another railroad vehicle brake lining different from FIG. 7.
FIG. 10 is a diagram showing the relationship between the porosity and Young's modulus of the sintered friction material.
Mode for carrying out the invention
[0019]
　First, the present inventors investigated and investigated the cause of brake squeal in a disc brake system for a railroad vehicle including a brake lining for a railroad vehicle having a friction material support mechanism.
[0020]
　There are mainly two types of disc brake systems for railway vehicles, a floating system and an opposed system. The brake caliper of a floating type disc brake system for railroad vehicles is provided with a pressing mechanism for pressing the brake lining against the brake disc on one of the pair of caliper arms supporting the pair of brake linings. In the floating method, the pressing mechanism pushes the brake lining attached to one of the pair of caliper arms toward the brake disc and presses it against the brake disc. At this time, the brake caliper slides in the direction opposite to the pressing direction of the brake lining of the pressing mechanism due to the reaction force of the brake lining against the pressing force on the brake disc. As a result, a pair of brake linings sandwich a brake disc attached to a wheel or an axle to perform a braking operation. The pressing mechanism includes a well-known piston and / or diaphragm and the like. The brake calipers of an opposed rail vehicle disc brake system are equipped with pressing mechanisms on both the pair of caliper arms that support the pair of brake linings. Both the floating system and the opposed system are used for the disc brake system for railway vehicles. Therefore, it is preferable that the brake squeal can be suppressed in both the floating method and the opposed method.
[0021]
　The present inventors have focused on a sintered friction material, which is a configuration applicable to both a floating system and an opposed system among the configurations of a disc brake system for a railway vehicle. Then, if the brake squeal can be suppressed by the mechanical characteristics of the sintered friction material, the present inventors can suppress the brake squeal in any type of brake caliper-equipped disc brake system for railway vehicles. I thought.
[0022]
　By the way, a high-speed railway vehicle in which a disc brake system for a railway vehicle is used may travel in a high-speed range of 260 km / hour or more. When a railroad vehicle is braked by a disc brake system in such a high speed range, the coefficient of friction between the brake disc and the sintered friction material of the brake lining changes depending on the speed of the railroad vehicle at the start of braking. In the case of high-speed railway vehicles that may travel even in the high-speed range of 260 km / hour or more, the coefficient of friction between the brake disc and the sintered friction material of the brake lining is 0.2 to 0 depending on the speed during travel. It changes widely to 0.6. Therefore, in the brake lining of a disc brake system applied to a railroad vehicle, it is desired that the brake squeal can be suppressed in a friction coefficient in the range of 0.2 to 0.6.
[0023]
　Therefore, the present inventors have a range of 0.2 to 0.6 in the sintered friction material used for the brake lining of the disc brake system for railway vehicles, which may travel in a high speed range of 260 km / hour or more. We investigated and examined the relationship between the mechanical characteristics of the friction coefficient and the brake squeal. As a result, it was found that among various mechanical properties of the sintered friction material, Young's modulus shows a negative correlation with brake squeal. Therefore, as a result of examining the relationship between the Young's modulus and the brake squeal in more detail by the present inventors, if the Young's modulus of the sintered friction material is 35.0 GPa or more, the range is 0.2 to 0.6. For the first time, it was found that the brake squeal can be sufficiently suppressed in terms of friction coefficient. This point will be described in detail below.
[0024]
　FIG. 1 is a diagram showing the relationship between the Young's modulus (GPa) of a sintered friction material and the maximum squeal index obtained by brake squeal analysis using an opposed disc brake system. FIG. 2 is a diagram showing the relationship between the Young's modulus (GPa) of the sintered friction material and the maximum squeal index obtained by brake squeal analysis using a floating disc brake system. 1 and 2 were obtained by complex eigenvalue analysis by the finite element method (FEM). Here, the maximum squeal index was defined by the following method. In the complex eigenvalue analysis by the finite element method (FEM), the natural frequency and the damping ratio can be obtained by performing the complex eigenvalue analysis by changing the Young's modulus of the sintered friction material. If the obtained attenuation ratio is negative, it is determined that the mode is unstable. The sum of each 1/3 octave band frequency of the absolute value of the attenuation ratio in the unstable mode is defined as a "squeal index". Of the obtained squeal indexes, the maximum squeal index is defined as the "maximum squeal index".
[0025]
　As a result of accumulating complex eigenvalue analysis by FEM and experiments, the present inventors have determined that if the maximum squeal index is lowered to the target value (2.0) or less, the brake squeal can be sufficiently suppressed.
[0026]
　The numerical value written next to each mark shown in the upper part of FIGS. 1 and 2 is the coefficient of friction at the corresponding mark. With reference to FIGS. 1 and 2, in any of the methods (FIG. 1: opposed method, FIG. 2: floating method), the Young's modulus of the sintered friction material is in the range of 0.2 to 0.6. When was 35.0 GPa or more, the maximum squeal index was 2.0 or less, and the brake squeal could be sufficiently suppressed. Therefore, when the Young's modulus of the sintered friction material is 35.0 GPa or more, the brake squeal can be sufficiently suppressed during braking of the railway vehicle in the brake lining for a railway vehicle having a friction material support mechanism.
[0027]
　In the friction coefficient in the range of 0.2 to 0.6, when the Young's modulus of the sintered friction material is up to 100.0 GPa, the maximum squeal index monotonically decreases as the Young's modulus of the sintered friction material is increased. On the other hand, if Young's modulus exceeds 100.0 GPa, the maximum squeal index does not decrease so much even if Young's modulus is increased further, especially when the friction coefficient is high (friction coefficient is 0.5, 0.6, etc.). , The maximum squeal index becomes almost constant. That is, in the relationship between the Young's modulus of the sintered friction material and the maximum squeal index, there is an inflection point near Young's modulus = 100.0 GPa. Therefore, when the Cu content in the sintered friction material is 40.0% or more, the preferable upper limit of the Young's modulus of the sintered friction material is 100.0 GPa.
[0028]
　The mechanism by which the brake squeal can be suppressed by increasing the Young's modulus of the sintered friction material is considered as follows.
[0029]
　The self-excited vibration generated when braking a railroad vehicle is the vibration in the pressing direction of the sintered friction material and the vibration in the sliding direction of the brake disc and the sintered friction material in the contact state between the brake disc and the sintered friction material. It is thought that this occurs when and are coupled. When the Young's modulus of the sintered friction material is increased, it is considered that self-excited vibration is less likely to occur because the vibration in the pressing direction and the vibration in the sliding direction are less likely to be coupled.
[0030]
　Based on the above study results, the present inventors say that in the brake lining for railroad vehicles, the young ratio of the sintered friction material is set to 35.0 GPa or more to suppress the brake squeal during braking of the railroad vehicle. , The present invention has been completed based on a technical idea different from the conventional one.
[0031]
　The brake lining for railway vehicles according to the present embodiment completed based on the above findings has the following configurations.
[0032]
　The brake lining for railroad vehicles according to [1] is a brake lining for railroad vehicles used in a disc brake system for railroad vehicles,
　and is a substrate, a
　sintered friction material in which a plurality of powder particles are sintered, and the
　substrate. It is provided with a friction material support mechanism that is arranged between the sintered friction material and the sintered friction material and supports the
　sintered friction material, and the Young ratio of the sintered friction material is 35.0 GPa or more.
[0033]
　The brake lining for a railroad vehicle of [1] may be used for a floating type disc brake system for a railroad vehicle, or may be used for an opposed type disc brake system for a railroad vehicle. In the brake lining for railway vehicles of the present embodiment, the Young's modulus of the sintered friction material is 35.0 GPa or more. Therefore, even when the brake lining for a railway vehicle of the present embodiment is applied to a railway vehicle that is expected to travel in a high speed range of 260 km / hour or more, the friction coefficient is 0.2 to 0. Brake squeal can be suppressed in a wide range of 6.6.
[0034]
　The brake lining for railroad vehicles according to [2] is the brake lining for railroad vehicles according to [1], and the
　sintered friction material contains 40.00% or more of Cu in mass% and is
　sintered. The porosity of the friction material is 12.0% or less.
[0035]
　The brake lining for railroad vehicles according to [3] is the brake lining for railroad vehicles according to [1] or [2], and
　the Young's modulus of the sintered friction material is 100.0 GPa or less.
[0036]
　The brake lining for a railroad vehicle according to [4] is the brake lining for a railroad vehicle according to any one of [1] to [3], and the
　friction material support mechanism is the
　substrate and the sintered friction material. Includes elastic members placed between and.
[0037]
　Here, the elastic member is, for example, a spring, a resin, or the like. The spring is, for example, a disc spring, a leaf spring, a wire spring, or the like. The resin is, for example, natural rubber, synthetic rubber, or the like.
[0038]
　The disc brake system for a railroad vehicle according to [5] includes a
　brake disc attached to a wheel or axle of the
　railroad vehicle and a brake caliper attached to a carriage of the railroad vehicle, and the
　brake caliper is
　described in the above [1] to The brake lining for a railroad vehicle according to any one of [4], a
　caliper arm to which the brake lining for a railroad vehicle is attached, and
　a pressing mechanism capable of pressing the brake lining for a railroad vehicle against the brake disc are provided. ..
[0039]
　The railway vehicle disc brake system of the present embodiment may be a floating type railway vehicle disc brake system or an opposed type railway vehicle disc brake system. Both floating and opposed rail vehicle disc brake systems include the brake discs described above and brake calipers. In the disc brake system for railway vehicles of the present embodiment, the Young's modulus of the sintered friction material is 35.0 GPa or more. Therefore, even when the brake lining for a railway vehicle of the present embodiment is applied to a railway vehicle that is expected to travel in a high speed range of 260 km / hour or more, the friction coefficient is 0.2 to 0. Brake squeal can be suppressed in a wide range of 6.6.
[0040]
　The sintered friction material of [6] is used for the brake lining for railway vehicles according to any one of the above [1] to [4].
[0041]
　Hereinafter, the brake lining for a railroad vehicle according to the present embodiment, the disc brake system for a railroad vehicle using the brake lining, and the sintered friction material used for the brake lining for a railroad vehicle will be described.
[0042]
　[Structure of Disc Brake System for Railway Vehicles and Brake Lining for Railway Vehicles]
　[Disc Brake System for Railway Vehicles]
　FIG. 3 is a schematic diagram of a disc brake system for railway vehicles according to the present embodiment. With reference to FIG. 3, the disc brake system for rolling stock is a disc brake device, comprising a brake disc 201 and a brake caliper 202. The brake disc 201 is attached to a wheel or axle (described later) of a railway vehicle. The brake caliper 202 is attached to a bogie (described later) which is a running device. The brake caliper 202 includes a brake lining 10, a caliper arm 203 to which the brake lining 10 is attached, and a pressing mechanism 204. The pressing mechanism 204 presses the brake lining 10 against the brake disc 201 during braking. The pressing mechanism 204 is, for example, a piston and / or a diaphragm. The pressing mechanism 204 may be a pneumatic type or a hydraulic type. The pressing mechanism 204 presses the brake lining 10 against the brake disc 201, generates a frictional force between the brake lining 10 and the brake disc 201, suppresses the rotation of the wheels or axles, and brakes the railway vehicle. The disc brake system for a railway vehicle of the present embodiment may be an opposed system or a floating system.
[0043]
　FIG. 4A is a schematic view of a floating type disc brake system for railway vehicles. With reference to FIG. 4A, the floating disc brake system for rail vehicles includes brake discs 201 (201A and 201B) and brake calipers 202, as in FIG. In FIG. 4A, the wheels 300 are arranged between the pair of brake discs 201A and 201B. The brake discs 201A and 201B are fixed to the wheels 300. The brake caliper 202 is attached to the carriage 400, which is a running device. Specifically, the brake caliper 202 of the floating type disc brake system for railroad vehicles is attached to the bogie 400 so as to be slidable in the thickness direction of the wheels 300 (direction perpendicular to the radial direction of the wheels 300).
[0044]
　The brake caliper 202 includes a pair of caliper arms 203A and 203B, a pressing mechanism 204, and a pair of brake linings 10. Each of the caliper arms 203A and 203B includes a brake lining 10. The brake lining 10 attached to the caliper arm 203A is arranged so as to face the brake disc 201A attached to the wheel 300. The brake lining 10 attached to the caliper arm 203B is arranged so as to face the brake disc 201B attached to the wheel. The pressing mechanism 204 is attached to the caliper arm 203A, and the brake lining 10 of the caliper arm 203A can be pressed against the brake disc 201A.
[0045]
　The braking operation of the floating type disc brake system for railway vehicles is shown in FIG. 4B. The pressing mechanism 204 pushes the brake lining 10 of the caliper arm 203A forward and presses it against the brake disc 201A of the wheel 300. At this time, due to the reaction force of the brake lining 10 against the pressing force of the brake disc 201A, the brake caliper 202 including the pair of caliper arms 203A and 203B slides in the direction opposite to the pressing direction of the brake lining 10 by the pressing mechanism 204. As a result, the pair of brake linings 10 sandwich the brake discs 201A and 201B together with the wheels 300 to brake the wheels 300.
[0046]
　In addition, in FIG. 4A and FIG. 4B, the pressing mechanism 204 is attached to the caliper arm 203A, and is not attached to the caliper arm 203B. However, the pressing mechanism 204 may be attached to the caliper arm 203B and may be attached to the caliper arm 203A. Further, FIGS. 4A and 4B show a floating type disc brake system for railway vehicles in which brake discs 201 (201A and 201B) are attached to wheels 300. However, in the floating type disc brake system for railway vehicles, the brake disc 201 may be attached to the axle 500 as shown in FIG. In this case, the brake disc 201 is mounted on the axle 500 coaxially with the axle 500.
[0047]
　FIG. 6 is a schematic view of an opposed type disc brake system for railway vehicles. With reference to FIG. 6, the opposed type disc brake system for railway vehicles includes brake discs 201 (201A and 201B) and brake calipers 202, as in FIG. In FIG. 6, the wheels 300 are arranged between the pair of brake discs 201A and 201B. The brake caliper 202 is attached to the carriage 400, which is a running device. Specifically, the brake caliper 202 of the floating type disc brake system for railway vehicles is fixed to the bogie 400.
[0048]
　The brake caliper 202 includes a pair of caliper arms 203A and 203B, a pair of pressing mechanisms 204, and a pair of brake linings 10. Each of the caliper arms 203A and 203B includes a brake lining 10. The brake lining 10 attached to the caliper arm 203A is arranged so as to face the brake disc 201A attached to the wheel 300. The brake lining 10 attached to the caliper arm 203B is arranged so as to face the brake disc 201B attached to the wheel 300.
[0049]
　In the opposed type disc brake system for railway vehicles, the pressing mechanism 204 is further attached to the caliper arms 203A and 203B. The pressing mechanism 204 attached to the caliper arm 203A can press the brake lining 10 of the caliper arm 203A against the brake disc 201A. The pressing mechanism 204 attached to the caliper arm 203B can press the brake lining 10 of the caliper arm 203B against the brake disc 201B. In an opposed rail vehicle disc brake system, the pressing mechanisms 204 attached to the caliper arms 203A and 204B each press the corresponding brake lining 10 against the brake disc 201 (201A or 201B) to brake the wheels 300.
[0050]
　In short, the floating type disc brake system for rolling stock uses one pressing mechanism 204 to perform the braking operation, whereas the opposed type disc brake system for rail vehicles uses two pressing mechanisms 204. Perform braking operation. Note that FIG. 6 shows an opposed type disc brake system for railway vehicles in which brake discs 201 (201A and 201B) are attached to wheels 300. However, in the opposed type disc brake system for railway vehicles, the brake disc 201 may be attached to the axle instead of the wheel 300. In this case, the brake disc 201 is mounted on the axle coaxially with the axle.
[0051]
　[Structure of Brake Lining 10]
　FIG. 7 is a front view of the brake lining 10 facing the surface of the brake disc 201 in the disc brake system for railway vehicles shown in FIGS. 3 to 6. FIG. 8 is a cross-sectional view of the line segments VIII-VIII in FIG.
[0052]
　With reference to FIGS. 7 and 8, the brake lining 10 includes a plurality of sintered friction materials 20, a friction material support mechanism 30, and a substrate 40.
[0053]
　The substrate 40 is attached to the caliper arm 203 of the brake caliper 202 (see FIG. 3). The friction material support mechanism 30 is arranged between the sintered friction material 20 and the substrate 40, and is attached to the substrate 40. The friction material support mechanism 30 further supports the sintered friction material 20. The friction material support mechanism 30 is connected to the substrate 40 and the sintered friction material. The friction material support mechanism preferably supports the sintered friction material 20 so as to be movable at least in the thickness direction of the substrate 40. Here, the thickness direction of the substrate 40 means a direction perpendicular to the main surface of the substrate 40 (the surface having the largest area among the surfaces of the substrate 40).
[0054]
　The configuration of the friction material support mechanism 30 is not particularly limited. The friction material support mechanism 30 includes, for example, a mounting member 31, an elastic member 32, and a back metal 33. Of the surface of the sintered friction material 20, the surface (back surface) opposite to the surface of the brake disc 201 facing the sliding surface 200 is fixed to the back metal 33. The mounting member 31 mounts the back metal 33 on the substrate 40 so as to be movable in the thickness direction of the substrate 40. The mounting member 31 is, for example, a rivet, but is not limited thereto. The mounting member 31 may be a bolt and a nut, or may have another configuration.
[0055]
　The elastic member 32 is arranged between the sintered friction material 20 and the substrate 40. In FIG. 8, the elastic member 32 is arranged between the back metal 33 and the substrate 40. The elastic member 32 may be, for example, a spring typified by a disc spring, or a resin such as rubber.
[0056]
　The friction material support mechanism 30 supports the sintered friction material 20 movably in at least the thickness direction of the substrate 40 by the elastic member 32. As a result, the sintered friction material 20 is likely to come into uniform contact with the sliding surface 200 of the brake disc 201, the temperature distribution of the brake disc 201 is made uniform, and uneven wear of the sintered friction material 20 is suppressed.
[0057]
　The friction material support mechanism 30 does not have to include the elastic member 32. The structure and mechanism of the friction material support mechanism 30 are not particularly limited as long as the sintered friction material 20 can be movably supported at least in the thickness direction of the substrate 40.
[0058]
　In FIGS. 7 and 8, a plurality of sintered friction material units in which a plurality of sintered friction materials 20 are fixed to one back metal 33 are arranged on the substrate 40. As described above, the brake lining 10 including the plurality of sintered friction material units is also referred to as the brake lining 10 having an isobaric structure. The brake lining 10 having an isobaric structure makes the contact between the brake lining 10 and the brake disc 201 equal surface pressure by uniformly contacting each sintered friction material unit with the brake disc 201. However, the brake lining 10 of the present embodiment is not limited to the isobaric structure.
[0059]
　In FIG. 7, the sintered friction material 20 has a disk shape, but the shape of the sintered friction material 20 is not particularly limited. As shown in FIG. 9, the sintered friction material 20 may be a rectangular plate material, or may have another shape such as a polygonal shape.
[0060]
　As described above, in FIGS. 7 and 9, the brake lining 10 includes a plurality of sintered friction materials 20, but the brake lining 10 may include one sintered friction material 20 or a plurality of baked friction materials 20. The friction material 20 may be provided. The brake lining 10 may include at least one sintered friction material 20.
[0061]
　As described above, in the present embodiment, the Young's modulus of the sintered friction material 20 is 35.0 GPa or more. As shown in the graphs of FIG. 1 (opposed method) and FIG. 2 (floating method), the Young's modulus of the sintered friction material 20 is in the range of 0.2 to 0.6 in the friction coefficient during braking in both methods. When is 35.0 GPa or more, the maximum squeal index becomes 2.0 or less, and the brake squeal can be sufficiently suppressed. Therefore, the Young's modulus of the sintered friction material 20 is 35.0 GPa or more. The upper limit of the Young's modulus of the sintered friction material 20 is not particularly limited, but as shown in FIGS. 1 and 2, when the Young's modulus of the sintered friction material 20 exceeds 100.0 GPa, the effect is saturated. Therefore, the upper limit of the preferred Young's modulus of the sintered friction material 20 is 100.0 GPa. The Young's modulus of the sintered friction material can be measured by a dynamic elastic modulus test method (bending resonance method) based on JIS R 1602 (1995).
[0062]
　[Example of Chemical Composition of
　Sintered Friction Material ] The chemical composition of the sintered friction material is not particularly limited as long as the Young's modulus is 35.0 GPa or more. The sintered friction material is preferably a sintered material made of a Cu-based alloy. The sintered friction material is formed by sintering a plurality of powder particles. The particle size of each particle of the powder particles is not particularly limited, but the particle size of each particle of the powder particles is, for example, 1 to 1000 μm. Hereinafter, an example of the chemical composition of the sintered friction material will be described, but as described above, the chemical composition of the sintered friction material is not limited to this. In addition, "%" regarding the composition of the sintered friction material means mass%.
[0063]
　[About the raw material of the sintered friction material]
　The raw material powder which is the raw material of the sintered friction material is composed of the above-mentioned plurality of powder particles. Specifically, the raw material powder contains Cu and a dispersant.
[0064]
　The preferred Cu content in the raw material powder is as follows.
[0065]
　Cu: 40.00% or more
　Copper (Cu) functions as a matrix (base material) of the sintered friction material. Cu has high thermal conductivity. Therefore, it is possible to suppress an increase in the interface temperature between the braking target (brake disc or the like) and the sintered friction material during braking (friction), and it is possible to suppress the occurrence of excessive seizure. Therefore, the wear resistance of the sintered friction material is increased. Cu, which is a matrix, further retains a dispersant (lubricant, hard particles) described later contained in the matrix. When the Cu content in the raw material powder is 40.00% or more, the above effect can be obtained more effectively. The preferred lower limit of the Cu content is 45.00%, more preferably 50.00%, still more preferably 55.00%.
[0066]
　The upper limit of the Cu content is not particularly limited. The preferable upper limit of the Cu content is 75.00%. When the Cu content is 75.00% or less, the friction due to adhesion to the sliding surface of the brake disc to be braked is effectively suppressed, and the wear resistance of the sintered friction material is more effectively enhanced. Therefore, the preferable range of the Cu content in the raw material powder is 40.00 to 75.00%.
[0067]
　The above-mentioned raw material powder may contain other metal particles (Ni, Zn, Sn, Fe, etc.) in addition to the powder particles made of Cu. These metal particles are a well-known raw material for sintered friction materials.
[0068]
　[Dispersant]
　The raw material powder used as the raw material of the sintered friction material 20 may further contain at least one or more dispersants selected from the following groups (1) to (7). More specifically, the raw material of the sintered friction material 20 contains Cu of 40.00% or more in mass% and one or more dispersants selected from the group consisting of (1) to (7). You may. The raw material powder does not have to contain a dispersant.
　(1) Graphite
　(2) One or more selected from the group consisting of magnesia, zircon sand, silica, zirconia, mulite and silicon nitride
　(3) One or more selected from the group consisting of W and Mo
　(4) Ferrochrome , ferro tungsten, ferro molybdenum, and, one or more selected from the group consisting of stainless steel
　(5) below (a) ~ (d) one or more selected from the group consisting of
　　　(a) hexagonal boron nitride
　　　( b) Molybdenum disulfide
　　　(c) Mica
　　　(d) One or more selected from iron sulfide, copper sulfide and copper mat
　(6) vanadium carbide
　(7) Fe
　or less, the dispersants of (1) to (7) will be described. To do.
[0069]
　(1) Graphite
　The graphite referred to in the present specification may be natural graphite or artificial graphite. In the sintered friction material after pressure sintering, graphite is contained in the matrix as particles. Graphite functions as a lubricant, stabilizes the coefficient of friction, and reduces the amount of wear of the sintered friction material. That is, graphite enhances the wear resistance of the sintered friction material. The preferable graphite content in the raw material powder is 5.00 to 15.00%.
[0070]
　(2) One or more selected from the group consisting of magnesia, zircone sand, silica, zirconia, mulite and silicon nitride.
　Magnesia (MgO), zircone sand (ZrSiO 4 ), silica (SiO 2 ), zirconia (ZrO 2 ), mullite (3Al 2 O 3 · 2SiO 2 ~ 2Al 2 O 3 · SiO 2 ), and silicon nitride (Si 3 N 4 ) are both a ceramic, and functions as the hard particles. In the sintered friction material after pressure sintering, these ceramics are contained in the matrix as particles. All of these ceramics remove the oxide film formed on the sliding surface by scratching the sliding surface of the braking target (brake disc or the like), and stably generate adhesion. As a result, it is possible to suppress a decrease in the friction coefficient of the sintered friction material with respect to the braking target (brake disc or the like), and excellent friction characteristics can be obtained. The preferable total content of one or more selected from the group consisting of these ceramics in the raw material powder is 1.50 to 15.00%.
[0071]
　(3) One or more types of
　tungsten (W) and molybdenum (Mo) selected from the group consisting of W and Mo all function as hard particles. W and Mo are contained in the matrix as particles without being dissolved in Cu in the matrix. Both W and Mo enhance the wear resistance of the sintered friction material. If W and / or Mo is contained together with the Fe-based alloy particles described later, the wear resistance of the sintered friction material is further enhanced. The preferred total content of one or more selected from the group consisting of W and Mo is 3.0 to 30.0%.
[0072]
　(4) One or more
　ferrochrome (FeCr), ferrotungsten (FeW), ferromolybdenum (FeMo) and stainless steel selected from the group consisting of ferrochrome, ferrotungsten, ferromolybdenum and stainless steel are all included in the matrix. It is contained in the matrix as particles without being solidified in. In the present specification, ferrochrome, ferrotungsten, ferromolybdenum, and stainless steel are collectively referred to as Fe-based alloy particles. All of these Fe-based alloy particles enhance the wear resistance of the sintered friction material. The reason is not clear, but the following reasons can be considered.
[0073]
　The hardness of the Fe-based alloy particles is higher than that of the matrix (Cu). Further, the Fe-based alloy particles have a higher affinity with the matrix and are less likely to be peeled off from the matrix as compared with the above-mentioned ceramics (magnesia, zircon sand, silica, zirconia, mullite and silicon nitride). Therefore, the Fe-based alloy particles enhance the wear resistance of the sintered friction material. The preferable total content of Fe-based alloy particles in the raw material powder is 2.0 to 20.0%.
[0074]
　In the present specification, the ferrochrome is one or more of high carbon ferrochrome (FCrH0 to FCrH5), medium carbon ferrochrome (FCrM3, FCrM4), and low carbon ferrochrome (FCrL1 to FCrL4) specified in JIS G 2303 (1998). Including.
[0075]
　As used herein, ferrotungsten means ferrotungsten (FW) having the chemical composition specified in JIS G 2306 (1998).
[0076]
　In the present specification, ferromolybdenum includes one or more of high carbon ferromolybdenum (FMOH) and low carbon ferromolybdenum (FMOL) specified in JIS G 2307 (1998).
[0077]
　In the present specification, stainless steel means an alloy steel containing 50.0% or more of Fe and 10.5% or more of Cr in mass%, and more preferably defined in JIS G 4304 (2012). Means stainless steel. The stainless steel in the present specification may be, for example, martensitic stainless steel represented by SUS403 and SUS420 specified in the above JIS standard, or ferritic stainless steel represented by SUS430. Austenitic stainless steel typified by SUS304, SUS316, and SUS316L may be used. Duplex stainless steel typified by SUS329J1 may be used. Precipitation hardening stainless steel typified by SUS630 may be used.
[0078]
　(5) One or more selected from the group consisting of the following (a) to (d)
　　(a) Hexagonal boron nitride
　　(b) Molybdenum disulfide
　　(c) Mica
　　(d) From iron sulfide, copper sulfide and copper matte One or more selected
　Hexagonal boron nitride (h-BN), molybdenum disulfide (MoS 2 ), mica (mica) and iron sulfide, copper sulfide and one or more selected from copper mats are all lubricants. Functions as. Similar to graphite, these lubricants stabilize the coefficient of friction of the sintered friction material and obtain excellent friction characteristics.
[0079]
　The copper mat is described in JIS H 0500 (1998), copper product term No. 5400, and is mainly composed of iron sulfide and copper sulfide. Iron sulfide and copper sulfide each act independently as a lubricant. Further, iron sulfide and copper sulfide may be mixed and used. The above-mentioned copper mat can be used as a mixture of iron sulfide and copper sulfide, and is inexpensive, which is advantageous from an economical point of view. Preferably, the content of hexagonal boron nitride is more than 0% and less than 3.0% by mass, the content of molybdenum disulfide is more than 0% and less than 3.0% by mass, and the content of mica. Is more than 0% and 3.0% or less in mass%, and the total content of one or more selected from iron sulfide, copper sulfide and copper mat is more than 0% and 1.0% or less in mass%.
[0080]
　(6) Vanadium Carbide
　Vanadium carbide (VC) is hard particles and is contained as particles in the matrix. Vanadium carbide further enhances the wear resistance of the sintered friction material due to the synergistic effect with W. However, if the content of vanadium carbide is too high, the sinterability of the sintered friction material is lowered, and the wear resistance is lowered. The preferable content of vanadium carbide is more than 0% and 5.00% or less in mass%.
[0081]
　(7) Fe
　iron (Fe) is contained in the sintered friction material as particles or aggregates in the matrix of the sintered friction material. Fe increases the strength of the matrix and enhances the wear resistance of the sintered friction material. Fe further increases the coefficient of friction of the sintered friction material by seizure. The preferable content of Fe in the raw material powder is more than 0% and 20.0% or less in mass%.
[0082]
　The balance of the raw material powder for the sintered friction material is impurities. Here, the impurities are those that are mixed from the raw material or the manufacturing environment when the raw material powder is industrially manufactured, and are allowed as long as they do not adversely affect the sintered friction material of the present embodiment. Means things.
[0083]
　The sintered friction material is formed, for example, by pressure-sintering the above-mentioned raw material powder at 800 to 1000 ° C. as described later.
[0084]
　[Method of specifying the chemical composition of the
　sintered friction material ] When the sintered friction material is formed by sintering the above-mentioned raw material powder, the chemical composition of the sintered friction material after molding is 40 by mass%. Contains 0.00% or more Cu. Preferably, the Cu content of the sintered friction material is 40.00 to 75.00% Cu.
[0085]
　[Porosity of
　Sintered Friction Material ] The preferable porosity of the sintered friction material is 12.0% or less. FIG. 10 is a diagram showing the relationship between the porosity (%) and Young's modulus (GPa) of the sintered friction material produced from the raw material powder shown in Examples described later, which is within the range of the above-mentioned raw material powder. is there. With reference to FIG. 10, in the sintered friction material, the porosity and Young's modulus show a negative correlation. Specifically, as the porosity of the sintered friction material decreases, the Young's modulus of the sintered friction material increases. When the Cu content of the sintered friction material formed by sintering the above-mentioned raw material powder is 40.00% or more in mass% (preferably 40.00 to 75.00%), the porosity If is 12.0% or less, the Young's modulus is 35.0 GPa or more. The preferred porosity is 10.0% or less, more preferably 9.5% or less, still more preferably 9.0% or less.
[0086]
　Here, the porosity is measured based on JIS Z 2501 (2000). As shown in FIG. 10, the lower the porosity, the higher the Young's modulus. Therefore, it is preferable that the porosity is low. However, an extreme reduction in porosity increases manufacturing costs. Therefore, when industrial production is taken into consideration, the preferable lower limit of the porosity is 0.1%.
[0087]
　[Example of Manufacturing Method of Sintered Friction Material] The
　above-mentioned sintered friction material is manufactured by, for example, the following manufacturing method. An example of a method for producing a sintered friction material includes a raw material powder manufacturing step, a molding step, and a pressure sintering step. Hereinafter, each step will be described.
[0088]
　[Raw material powder manufacturing process] The
　Cu powder particles described above and a dispersant, if necessary, are prepared. The prepared powder particles and the dispersant are mixed (mixed) using a well-known mixer to produce a raw material powder. Well-known mixers are, for example, ball mills and V-type mixers.
[0089]
　[Molding process] The
　produced raw material powder is molded into a predetermined shape to produce a green compact. A well-known molding method may be applied to the molding of the raw material powder. For example, the green compact is produced by a press forming method. Specifically, a mold (die) for forming a predetermined shape is prepared. The raw material powder is filled in the mold. The powder or granular material filled in the mold is pressed by a press machine at a well-known pressure to be formed into a green compact. The molding pressure in the press is, for example, 1.0 to 10.0 ton / cm 2 . Molding should be done in the atmosphere.
[0090]
　[Pressure Sintering Step] A
　well-known pressure sintering method is carried out on the produced green compact to produce a sintered friction material. For example, the green compact is placed on a graphite plate in a pressure sintering apparatus. After that, graphite plates on which the raw material powder is arranged are stacked and stored in a housing-shaped frame in which the high-frequency heating coil is arranged on the inner peripheral surface. Then, while applying pressure to the uppermost graphite plate to pressurize the green compact, sintering is performed at a predetermined sintering temperature in a sintering atmosphere.
[0091]
　It suffices to carry out pressure sintering under well-known conditions. The sintering temperature during pressure sintering is, for example, 800 to 1000 ° C. The pressure applied to the green compact during pressure sintering is, for example, 2.0 to 20.0 kgf / cm 2 . The holding time at the above sintering temperature during pressure sintering is 60 to 120 minutes. The atmosphere at the time of pressure sintering is a well-known atmosphere, for example, a mixed gas of 5 to 20% or less of H 2 gas and N 2 gas, or Ar gas.
[0092]
　By the pressure sintering, a neck is formed at the contact portion of the powder or granular material in the green compact, and the above-mentioned sintered friction material is manufactured. By adjusting the molding pressure of the press machine in the molding step, the pressure and the temperature in the pressure sintering step, the porosity of the sintered friction material changes. Therefore, the porosity is adjusted by adjusting the molding pressure of the press machine in the molding step, the pressure and the temperature in the pressure sintering step, and the Young ratio of the sintered friction material is set to 35.0 GPa or more. Preferably, in the chemical composition of the sintered friction material, when the Cu content is 40.00% or more (that is, when the Cu content in the raw material powder is 40.00% or more), the pores of the sintered friction material The molding pressure of the press machine in the molding step, the pressure and the temperature in the pressure sintering step are adjusted so that the ratio becomes 12.0%. As a result, the Young's modulus of the sintered friction material becomes 35.0 GPa or more. The porosity of the sintered friction material is reduced to 12.0% or less by adjusting the molding pressure of the press machine in the molding process and the pressure and temperature in the pressure sintering process according to the composition of the raw material powder. The young rate can be 35.0 GPa or more.
[0093]
　[Other Steps]
　The manufacturing step may further include a well-known coining step and / or a well-known cutting step.
[0094]
　[Coining Step] The
　coining step may be carried out after the pressure sintering step. In the coining step, the sintered friction material after the pressure sintering step is coldly pressed to adjust the shape of the sintered friction material.
[0095]
　[Cutting process] The
　cutting process may be performed after the pressure sintering process or the coining process. In the cutting process, the sintered friction material is cut to obtain a desired shape.
[0096]
　The sintered friction material according to the present embodiment is manufactured by the above manufacturing process.
[0097]
　The chemical composition of the sintered friction material according to the present embodiment is not limited to the above composition. The Young's modulus of the sintered friction material can be adjusted by the chemical composition and the porosity. Therefore, as long as the Young's modulus of the sintered friction material of the present embodiment is 35.0 GPa or more, its chemical composition and porosity are not particularly limited.
[0098]
　[Manufacturing method of brake lining for railroad vehicle]
　One or a plurality of sintered friction materials manufactured by the above-mentioned manufacturing process are attached to a substrate via a friction material support mechanism. For example, as shown in FIGS. 7 and 8, the friction material support mechanism 30 is used to connect the sintered friction material 20 and the substrate 40 to support the sintered friction material 20. The brake lining 10 for railway vehicles is manufactured by the above manufacturing process.
Example
[0099]
　An attempt was made to produce a friction material having a Young's modulus of 35.0 GPa or more. Raw material powders having the chemical compositions shown in Table 1 were prepared.
[0100]
[table 1]

[0101]
　Blanks in Table 1 indicate that the corresponding composition was not contained. The raw materials of each test number were put into a V-type mixer and then mixed at a rotation speed of 20 to 40 rpm for 20 to 100 minutes to produce a raw material powder. Using the raw material powder of each test number , a green compact was produced by molding at the molding pressure (ton / cm 2 ) shown in Table 1 by a press molding method . The produced green compact was pressure-sintered to produce a sintered friction material having each test number.
[0102]
　Specifically, the green compact was placed on the graphite plate. After that, graphite plates on which the green compact was arranged were stacked and stored in a housing-shaped frame in which the high-frequency heating coil was arranged on the inner peripheral surface. Heat the green compact at the heating temperature (° C.) shown in Table 1 for 60 minutes, and pressurize the green compact at the pressure (kgf / cm 2 ) shown in Table 1 to sintered the green compact to obtain a sintered friction material. Manufactured. The atmosphere in the frame during pressure sintering was a mixed gas of 5 to 10% H 2 gas and N 2 gas. A sintered friction material was manufactured by the above manufacturing process.
[0103]
　Porosity, density, and Young's modulus were measured for the produced sintered friction material. Porosity was measured by a method according to JIS Z 2501 (2000). Young's modulus was measured by a dynamic elastic modulus test method (bending resonance method) according to JIS R 1602 (1995).
[0104]
　The measurement results are shown in Table 1. As shown in Table 1, the Young's modulus of the sintered friction material was 35.0 GPa or more by setting the porosity to 12.0% or less. Therefore, as shown in FIGS. 1 and 2, it was considered that the brake squeal could be sufficiently suppressed in the test numbers 1, 5, 7 and 8 in which the Young's modulus was 35.0 GPa or more.
[0105]
　The embodiments of the present invention have been described above. However, the embodiments described above are merely examples for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiment, and the above-described embodiment can be appropriately modified and implemented without departing from the spirit of the present invention.
Code description
[0106]
　10 Brake lining
　20 Sintered friction material
　30 Friction material support mechanism
　40 Board
　201 Brake disc
　202 Brake caliper
　203 Caliper arm
　204 Pressing mechanism
The scope of the claims
[Claim 1]
　A railway brake lining for a vehicle for use in a disc brake system for a railway vehicle,
　a substrate,
　a plurality of powder particles sintered by being sintered friction material,
　disposed between the substrate and the sintered friction material A 　brake lining for
　a
railway vehicle , which comprises a friction material support mechanism for supporting the sintered friction material, and has a Young rate of 35.0 GPa or more of the sintered friction material .
[Claim 2]
　The brake lining for a railroad vehicle according to claim 1,
　wherein the sintered friction material contains 40.00% or more of Cu in mass%, and
　the porosity of the sintered friction material is 12.0% or less. in it,
　brake lining for railway vehicles.
[Claim 3]
　The brake lining for a railroad vehicle according to claim 1 or 2,
　wherein the Young's modulus of the sintered friction material is 100.0 GPa or less
　.
[Claim 4]
　The brake lining for a railroad vehicle according to any one of claims 1 to 3,
　wherein the friction material support mechanism includes
　an elastic member arranged between the substrate and the sintered friction material. ,
　Brake linings for railcars.
[Claim 5]
　A disc brake system for a railroad vehicle,
　comprising a brake disc attached to a wheel or axle of the
　railroad vehicle and a brake caliper attached to a bogie of the railroad vehicle,
　wherein the brake caliper is
　claimed 1 to 4. a brake lining for a railway vehicle according to any one of
　the caliper arm the railway vehicle brake linings is attached,
　and a possible pressing mechanism pressing the brake lining for the railway vehicle to the brake disc,
　a railway vehicle For disc brake system.
[Claim 6]
　A sintered friction material used for the brake lining for railway vehicles according to any one of claims 1 to 4.