JP2008309319A - Brake lining and disk brake for railroad vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively disperse heat energy in brake operation. <P>SOLUTION: This brake lining 1 for a railroad vehicle is pressed by a brake caliper, to a disk body installed on a wheel shaft or a sliding surface 2a of an aluminum group composite material brake disk 2 fastened by a bolt to a wheel by a fastening hole part provided on the inner peripheral side from the sliding surface 2a, and has friction members 1aa and 1ab pressed to the sliding surface 2a of the brake disk 2 and a back board 1b installed in the brake caliper and supporting the friction members 1aa and 1ab. The friction members 1aa and 1ab are arranged to be divided into two pieces or more in the radial direction of the brake disk 2, and a pressing load acting on the brake lining 1 from the brake caliper is increased on the inner peripheral side than the outer peripheral side of the friction members 1aa and 1ab. The highest temperature of the aluminum group composite material brake disk is effectively reduced, and the occurrence of thermal deformation and a crack of the brake disk is reduced. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention particularly relates to a brake lining for a railway vehicle that can effectively disperse thermal energy due to friction between an aluminum matrix composite brake disc and a brake lining, thereby improving the durability of both, and the brake lining. It is related with the disc brake provided with.

  In land transport machines such as railway vehicles, automobiles, and motorcycles, disk brakes are increasingly used as braking devices with the increase in speed and size of vehicles.

  The disc brake is a device that obtains braking force by friction between the brake disc and the brake lining, and obtains braking force by pressing the brake lining against the sliding surface of the brake disc attached to the axle or wheel by the brake caliper. The speed of the vehicle is controlled by braking the rotation of the axle or wheel.

  At that time, the temperature of the contact surface between the brake lining and the brake disc rises due to frictional heat, but the brake load increases and the temperature at the contact surface tends to increase as the vehicle speed increases or the vehicle weight increases.

  FIG. 4 shows a brake lining and a brake disc as a conventional disc brake for a railway vehicle. 4A is a plan view of the brake lining as viewed from the friction member side, and FIG. 4B is a cross-sectional view taken along the line AB of FIG.

  The brake lining 1 has a configuration in which a friction member 1a that comes into contact with the sliding surface 2a of the brake disk 2 is attached to the back plate 1b by a rivet (not shown). The brake lining 1 is attached to a brake caliper (not shown).

  The brake caliper is a device for obtaining a braking force by pressing the brake lining 1 against the brake disc 2, and includes a hydraulic type and a pneumatic type. The pressing force applied to the brake lining 1 from the brake caliper does not act on the entire brake lining 1 due to the structure of the mounting portion, but acts on a specific portion. For example, in the case of a hydraulic caliper, there are two center positions 3 of the pressing load as shown in FIG. 4, and the pressing load is applied to substantially the same position even in the case of a pneumatic caliper.

  As described above, in the conventional disc brake, the pressing force from the brake caliper acts only on a part of the brake lining 1 because of its structure. For this reason, in the contact surface of the brake lining 1 and the brake disc 2, the difference between the high portion and the low portion of the contact surface pressure becomes large, and immediately below the pressing force from the brake caliper acts, The contact surface pressure tends to increase.

  In the portion where the contact surface pressure is high, more heat energy is generated due to friction, and particularly in a high-speed vehicle such as a Shinkansen, there is a possibility that the temperature rise during the brake operation becomes excessive. When the contact surface pressure increases and the temperature rises, it may cause thermal deformation of the brake disk 2, generation of cracks, increase in wear amount of the brake lining 1 and the brake disk 2, and the like. Therefore, in order to ensure the durability of the brake lining 1 and the brake disc 2, it is important to efficiently disperse the thermal energy due to friction between the two during the brake operation.

In particular, in recent years, various brake discs tend to be used as the vehicle speed increases.
For example, Patent Document 1 discloses a brake disk made of an aluminum-based composite material.
JP 2002-364686 A

  However, aluminum has a high thermal conductivity, and depending on the distribution of thermal energy due to friction, the maximum temperature of the brake disc varies greatly, so it is necessary to disperse the thermal energy due to friction more effectively than that of conventional forged steel. is there.

Patent Document 2 has been proposed for the purpose of improving the durability of the brake disc and brake lining. In this patent document 2, the friction member is divided into a plurality of parts, and the contact surface pressure between the brake lining and the brake disc is reduced by a structure in which the pressing force from the brake caliper is equally applied to each friction member. .
Japanese National Patent Publication No. 10-507250

  However, in the method of Patent Document 2, the same thermal energy is applied to the portion where the brake disk is thick and the heat capacity is large and the portion where the thickness is thin and the heat capacity is small. Therefore, in a brake disk having a high thermal conductivity such as a brake disk made of an aluminum-based composite material, the temperature of a portion having a small heat capacity is increased. In other words, the technique of Patent Document 2 cannot always realize a thermal energy distribution that can suppress the temperature rise of the brake disk made of aluminum-based composite material.

  The problem to be solved by the present invention is that, in the case of a brake disc made of an aluminum-based composite material, the conventional technology effectively distributes the thermal energy due to friction to improve the durability of the brake disc and brake lining. Is difficult.

The brake lining for railway vehicles of the present invention is
A fastening hole is provided on the inner peripheral side of the sliding surface, and is pressed by the brake caliper on the sliding surface of the disc body attached to the axle at the fastening hole portion or the aluminum-based composite brake disc that is bolted to the wheel. A railway vehicle brake lining,
A friction member pressed against the sliding surface of the brake disc;
A back plate attached to the brake caliper and supporting the friction member;
The friction member is
It is divided into two or more pieces in the radial direction of the brake disc,
The most important feature is that the pressing load acting on the brake lining from the brake caliper is larger on the inner circumferential side of the friction member divided in the radial direction than on the outer circumferential side.

  The brake lining for a railway vehicle according to the present invention can effectively disperse the thermal energy due to friction during brake operation by giving more thermal energy due to friction to a portion having a large thickness and a large heat capacity.

In the brake lining for a railway vehicle of the present invention, the pressing load acting on the brake lining from the brake caliper is larger on the inner peripheral side than on the outer peripheral side of the friction member divided in the radial direction of the brake disc. to do so,
For example, when the radial length of the sliding surface of the brake disk is T, and the distance between the center position of the pressing load acting on the brake lining from the brake caliper and the innermost peripheral position of the sliding surface of the brake disk is P. , P / T may be configured to be 0.20 to 0.47.

  At that time, among the divided friction members, the distance between the radial center line of the friction member disposed at a position facing the inner peripheral side of the brake disc and the innermost peripheral position of the sliding surface of the brake disc If M is set so that M / T is 0.2 to 0.3, M can be more effectively dispersed.

  In the brake lining for a railway vehicle of the present invention, when the friction member is divided and arranged in two or more in the circumferential direction of the brake disc, it is further effective that the contact surface pressure of the friction member is locally increased. Can be avoided.

The disc brake for railway vehicles of the present invention is
A brake disc made of an aluminum-based composite material provided with a fastening hole on the inner peripheral side from the sliding surface, and a bolt attached to a disc body or a wheel attached to the axle at the fastening hole portion;
The most important feature is that the brake lining for a railway vehicle of the present invention attached to a brake caliper is provided.

  In the railway vehicle disc brake of the present invention, heat energy generated by friction during brake operation can be evenly distributed, so that sufficient durability can be ensured for both the brake disc and the brake lining made of an aluminum-based composite material. .

  According to the present invention, the thermal energy generated by friction during brake operation is evenly distributed and the maximum temperature of the aluminum-based composite brake disc having a high thermal conductivity is effectively reduced. The occurrence of cracks can be reduced.

  Furthermore, since the contact surface pressure between the brake lining and the brake disc is reduced, wear of the brake lining and the brake disc can be reduced.

  As a result, the durability of the brake lining and the brake disc made of the aluminum-based composite material is improved, and it is possible to cope with the increase in speed and size of the railway vehicle.

  Hereinafter, the best mode for carrying out the present invention will be described together with the process from the idea of the present invention to the solution of the problem.

  In brake discs made of a material with high thermal conductivity such as aluminum matrix composite, if the thermal energy due to friction is increased in the part with large heat capacity (thick part), the brake disk temperature during brake operation Can be effectively reduced.

  In particular, in the case of a brake disc (side disc) attached to the side surface of the wheel, the thickness of the outer peripheral portion is reduced due to shape restrictions and the heat capacity is reduced. Therefore, it is preferable to increase the heat energy at the inner peripheral portion.

  Also, even when there is no shape restriction, such as a brake disc (shaft mount disc) fastened to the disc body attached to the axle, the peripheral speed during rotation is faster on the outer peripheral side than on the inner peripheral side, When the contact surface pressure between the brake disc and the brake lining is the same, the thermal energy of the outer peripheral portion tends to be larger.

  From the above, it is considered that the brake disk temperature during braking can be reduced by intentionally increasing the contact surface pressure of the inner peripheral portion as compared with the outer peripheral portion. However, if the thermal energy of a specific part becomes too large, the temperature of the specific part will increase excessively.

  Therefore, it is necessary to consider the arrangement of the friction member of the brake lining and the pressing position loaded on the brake lining from the brake caliper so that the thermal energy can be dispersed to some extent. A structure in which the friction member moves following the thermal deformation of the brake disk is also effective.

  Based on the above concept, the inventors conducted a finite element analysis in order to evaluate the thermal energy due to friction between the brake disc and the brake lining during brake operation.

  In the finite element analysis, the brake lining and brake disc were modeled with elastic bodies, and a load equivalent to the pressing force from the brake caliper was applied from the back side of the brake lining. At that time, the pressing position applied to the brake lining was changed.

  1A and 1B are diagrams for explaining a brake lining of an example of an invention in which finite element analysis is performed. FIG. 1A is a plan view of the brake lining as viewed from the friction member side, and FIG. 1B is a cross-sectional view taken along line AB in FIG. is there.

The structure of the brake lining 1 of this invention example is defined as follows.
・ Pressing position from the brake caliper The length of the sliding surface 2a of the brake disc 2 in the radial direction is T, the center position 3 of the pressing load acting on the brake lining 1 from the brake caliper, and the sliding surface 2a of the brake disc 2 Let P be the distance from the inner circumferential position.

Arrangement position of the friction members 1aa and 1ab The center line 4 in the radial direction of the friction member 1aa disposed on the back plate 1b at a position facing the inner peripheral side of the brake disk 2 and the innermost side of the sliding surface 2a of the brake disk 2 The distance M from the circumferential position was set to 35 mm.

  Further, at the position of the back plate 1b facing the outer peripheral side of the brake disc 2, the friction member 1aa disposed at a position relative to the inner peripheral side and the radial center line 5 of the sliding surface 2a of the brake disc 2 are arranged. The friction member 1ab is arranged so as to be symmetrical with the line.

-Size and number of friction members 1aa, 1ab The length L in the radial direction of the friction members 1aa, 1ab was set to 50 mm. Further, the number of divisions in the radial direction of the friction members 1aa and 1ab is 2, and the number of divisions in the circumferential direction is 5 on the inner peripheral side and 7 on the outer peripheral side.

A structure for attaching the friction members 1aa, 1ab to the back plate 1b A spring component 1c (a disc spring or a radially arched plate spring) is inserted between the friction members 1aa, 1ab and the back plate 1b.

  The brake lining 1 of the invention example having the above structure was subjected to finite element analysis for various dimensions shown in Table 1 below. For comparison, finite element analysis was also performed for conventional brake linings and brake linings that receive heat almost uniformly over the entire sliding surface. In these comparative examples, not only a brake disc made of an aluminum-based composite material but also a brake disc made of forged steel was targeted. The brake disc model was assumed to be a brake disc having a structure in which bolts are fastened on the inner peripheral side of the sliding portion.

  The invention example and the comparative example in which the finite element analysis was performed commonly target the Shinkansen brake lining 1, and the length of the brake lining 1 in the longitudinal direction was 400 mm and the length in the width direction was 130 mm. As for the material constituting the brake lining 1, the back plate 1b was a steel material, and the friction members 1a, 1aa and 1ab were a copper sintered alloy. The braking conditions were equivalent to emergency braking from 300 km / h, and the pressing force was 20 kN.

  The brake disc 2 used for the finite element analysis is made of aluminum-based composite material and forged steel. The inner diameter is 310 mm and the outer diameter is 720 mm. It is. The inner peripheral side is an area for fastening bolts. The thinnest position (thinnest position) on the sliding surface 2a of the brake disk 2 is the outermost peripheral position, and the position farthest from the thinnest position is the innermost peripheral position of the sliding surface 2a. The distance T is 127.5 mm.

  An object of the present invention is to improve the durability of the brake disc 2 and the brake lining 1.

  Therefore, the inventors calculate the average thermal energy per unit area due to friction from the contact surface pressure distribution of the brake lining 1 and the brake disk 2 of the invention example and the comparative example obtained by finite element analysis, The maximum temperature of the brake disc 2 was evaluated. Moreover, since the wear of the brake disc 2 and the brake lining 1 has a correlation with the contact surface pressure of both, the maximum contact surface pressure during the brake operation was evaluated. The durability of the brake disc 2 and the brake lining 1 is improved as the maximum temperature of the brake disc 2 is lower and the maximum contact surface pressure is smaller. In particular, it is important to suppress the maximum temperature of the brake disk 2 in order to reduce thermal deformation and cracking of the brake disk 2 that greatly affect durability.

  Table 2 below shows the maximum temperature and the maximum contact surface pressure of the brake disc 2 of the invention example and the comparative example, respectively.

  From Table 2, all of the invention examples are compared with Comparative Example 11 in which the pressing load on the outer peripheral side is increased, Comparative Example 12 which is a conventional brake lining, and Comparative Example 13 in which heat is input almost evenly over the entire sliding surface. It can be seen that the maximum temperature of the brake disc is lowered, the occurrence of thermal deformation and cracking of the brake disc is reduced, and durability is improved. Further, in the inventive example, the maximum contact surface pressure is also lower than that of the comparative example 12 which is a conventional brake lining, and it becomes possible to reduce the wear of the brake lining and the brake disc.

  Further, as shown in the results of Comparative Examples 14 to 19 in Table 2, for the forged steel brake disk having a relatively low thermal conductivity, the maximum temperature of the brake disk can be changed even if the pressing position is changed as in the invention example. It can be seen that there is no significant effect on

  FIG. 2 shows the relationship between the maximum brake disc temperature and P / T for Invention Examples 1 to 5 (circles) and Comparative Example 11 (circles). Since the strength of the aluminum-based composite material greatly decreases when the temperature exceeds 400 ° C., it is difficult to ensure the durability of the brake disc. Therefore, it can be seen from FIG. 2 that when P / T is 0.20 to 0.47, the maximum temperature of the brake disk can be reduced from 400 ° C., particularly when P / T is 0.3 to 0.4. I understand that

  The present invention was made on the basis of the results obtained from the above finite element analysis performed by the inventors. The aluminum base composite having a fastening hole on the inner peripheral side of the sliding surface 2a and having a high thermal conductivity. The brake lining 1 of the present invention pressed against the brake disc 2 using a material is configured as follows.

  That is, the brake lining 1 for a railway vehicle according to the present invention includes a friction member that presses against the sliding surface 2a of the brake disk 2 and a back plate 1b that is attached to a brake caliper and supports the friction member.

  In the present invention, the friction member is divided into two or more in the radial direction of the brake disk 2, and the pressing load acting on the brake lining 1 from the brake caliper is applied to the divided friction member. The inner circumference side is larger than the outer circumference side.

  Specifically, the friction member divided and arranged in two or more in the radial direction of the brake disk 2 is configured and arranged as follows, for example.

-Pressing position from the brake caliper The radial length T of the sliding surface 2a of the brake disc 2, the center position 3 of the pressing load acting on the brake lining 1 from the brake caliper, and the maximum of the sliding surface 2a of the brake disc 2 The ratio P / T with respect to the distance P from the inner circumferential position is set to 0.20 to 0.47, preferably 0.3 to 0.4.

  By making P / T within this range, heat energy is reliably given to the inner peripheral side of the brake disk 2 having a large heat capacity, and the temperature of the brake disk 2 can be reduced.

  The center position 3 of the pressing load is preferably two or more in the circumferential direction, and in this case, it is preferable that the center positions 3 are on the same radius.

  Further, there may be a plurality of center positions 3 of the pressing load in the radial direction as shown in FIG. In this case, the distance P between the center position 3 of the pressing load and the innermost peripheral position of the sliding surface 2a of the brake disk 2 is defined as follows.

  For example, when there are k center positions 3 of the pressing load (k = 6 in FIG. 3), the distance between each center position and the innermost peripheral position of the sliding surface 2a of the brake disk 2 is Pi, and each center position 3 When the load value is Qi, the relationship of the following formula 1 is established among P, Pi, and Qi.

  Therefore, if P / T obtained by dividing P obtained by Equation 1 by T is smaller than 0.5, the pressing load is larger on the inner peripheral side than on the outer peripheral side, and the temperature of the brake disk 2 is reduced. It becomes possible.

-Arrangement of friction member In order to give a large thermal energy to the inner peripheral side of the sliding surface 2a of the brake disk 2 having a large heat capacity, it is necessary to consider the position of the friction member arranged on the inner peripheral side. At this time, if the distance between the radial center line 4 of the friction member 1aa arranged on the inner peripheral side and the innermost peripheral position of the sliding surface 2a of the brake disk 2 is M, the sliding surface 2a of the brake disk 2 is surely obtained. In order to give heat energy strongly to the inner peripheral side of the film, it is preferable to set M / T to 0.2 to 0.3.

  That is, if M / T is less than 0.2, excessively large heat energy is applied to the inner peripheral side, and the temperature on the inner peripheral side of the brake disk 2 may increase excessively. Further, if M / T exceeds 0.3, there is a possibility that heat energy cannot be applied strongly to the inner peripheral side of the sliding surface 2a of the brake disk 2.

  In this case, the outer peripheral friction member 1ab is preferably arranged so as to be symmetric with respect to the radial center line of the sliding surface 2a of the brake disk 2. Further, it is preferable to arrange a plurality in the circumferential direction.

-Size of friction member Since the contact area with the brake disk 2 cannot be sufficiently secured if the friction members 1aa and 1ab are too small, the radial length L of the friction members 1aa and 1ab is preferably 40 mm or more. The circumferential lengths of the friction members 1aa and 1ab are preferably substantially equal to the radial length L.

A structure in which the friction member is attached to the back plate In order for the friction members 1aa and 1ab to move following the deformation of the brake disc 2, a disc spring or a radially arched shape is provided between the friction members 1aa and 1ab and the back plate 1b. It is preferable to insert a spring part 1c such as a leaf spring. In order for the friction members 1aa and 1ab to move sufficiently, the spring constant is preferably 6 to 12 kN / mm. If the spring constant is smaller than 6 kN / mm, the durability of the spring cannot be secured sufficiently, and if it is larger than 12 kN / mm, the friction member cannot move sufficiently. More preferably, the spring constant is 8 to 10 kN / mm.

Note that generally used sintered materials and resin materials can be applied to the friction members 1aa and 1ab of the brake lining 1 of the present invention.
In addition, the brake caliper applied to the railway vehicle disc brake of the present invention having the brake disc 2 and the brake lining 1 of the present invention attached to the brake caliper can be applied to various types such as a hydraulic type and a pneumatic type. It is.

  The present invention is not limited to the above example, and it goes without saying that the embodiments may be changed as appropriate within the scope of the technical idea described in each claim.

  The present invention described above is not limited to a brake disk for a railway vehicle, but can be applied to a brake disk for an automobile, a motorcycle, or the like.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows one Embodiment of the brake lining of this invention, (a) is the top view which looked at the brake lining from the friction member side, (b) is AB sectional drawing of (a) figure. It is the figure showing the relationship of the maximum temperature of a brake disc obtained by finite element analysis, and P / T about the brake lining of the example of this invention shown in FIG. It is a figure similar to Fig.1 (a) which shows other embodiment of the brake lining of this invention, and is explanatory drawing in case there exist multiple pressing loads in a radial direction. It is the figure which showed the brake lining and brake disc which comprise the conventional disc brake for rail vehicles, (a) is the top view which looked at the brake lining from the friction member side, (b) is AB sectional drawing of (a) figure FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Brake lining 1a, 1aa, 1ab Friction member 1b Back plate 1c Spring member 2 Brake disk 2a Sliding surface 3 Center position of pressing load 4 Radial center line of inner peripheral side friction member

Claims (5)

A fastening hole is provided on the inner peripheral side of the sliding surface, and is pressed by the brake caliper on the sliding surface of the disc body attached to the axle at the fastening hole portion or the aluminum-based composite brake disc that is bolted to the wheel. A railway vehicle brake lining,
A friction member pressed against the sliding surface of the brake disc;
A back plate attached to the brake caliper and supporting the friction member;
The friction member is
It is divided into two or more pieces in the radial direction of the brake disc,
A brake lining for a railway vehicle, wherein a pressing load acting on a brake lining from a brake caliper is larger on an inner peripheral side of the friction member divided in the radial direction than on an outer peripheral side. The radial length of the sliding surface of the brake disc is T,
When the distance between the center position of the pressing load acting on the brake lining from the brake caliper and the innermost peripheral position of the sliding surface of the brake disk is P,
By configuring so that P / T is 0.20 to 0.47, the pressing load acting on the brake lining from the brake caliper is larger on the inner circumference than on the outer circumference side of the friction member divided in the radial direction. 2. The brake lining for a railway vehicle according to claim 1, wherein the side is made larger. When the distance between the center line in the radial direction of the friction member arranged at a position facing the inner peripheral side of the brake disc and the innermost peripheral position of the sliding surface of the brake disc among the divided friction members is M In addition,
The brake lining for a railway vehicle according to claim 2, wherein the M / T is configured to be 0.2 to 0.3. The friction member is
The brake lining for a railway vehicle according to any one of claims 1 to 3, wherein the brake lining is divided into two or more pieces in a circumferential direction of the brake disc. A brake disc made of an aluminum-based composite material provided with a fastening hole on the inner peripheral side from the sliding surface, and a bolt attached to a disc body or a wheel attached to the axle at the fastening hole portion;
A disc brake for a railway vehicle, comprising the brake lining according to any one of claims 1 to 4 attached to a brake caliper.

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