CN113833790B

CN113833790B - Friction plate for reducing MPU problem between friction pairs

Info

Publication number: CN113833790B
Application number: CN202111138734.2A
Authority: CN
Inventors: 林玮静; 刘朋; 孔卓; 马兵兵
Original assignee: China National Heavy Duty Truck Group Jinan Power Co Ltd
Current assignee: China National Heavy Duty Truck Group Jinan Power Co Ltd
Priority date: 2021-09-27
Filing date: 2021-09-27
Publication date: 2023-07-07
Anticipated expiration: 2041-09-27
Also published as: CN113833790A

Abstract

The invention provides a friction plate for reducing MPU problems between friction pairs, wherein 2-6 strip-shaped grooves are formed in the friction plate; the strip-shaped grooves are arranged in parallel, and a space is arranged between the strip-shaped grooves; the cross section shape of the strip-shaped groove is the same; the dimensions of the strip-shaped groove are as follows: the sum of the lengths of the strip-shaped grooves is smaller than the width of the friction plate and accounts for 85% -90% of the width of the whole friction plate. The friction plate can play a role of a cutter, in the braking process, as the brake drum rotates, the brake shoes are opened, and scrap iron and friction material abrasion substances adhered on the friction surface of the brake drum are peeled off by grooves formed in the surface of the friction plate, so that the surface of the friction plate is prevented from forming local hard spots due to the metal accumulation effect, and further generation of the MPU is restrained. Through specific bar groove arrangement mode and bar groove cross section shape for friction disc surface's stress condition is more even, has blocked the condition of producing that the metal was piled up, thereby can reduce MPU's production to a certain extent.

Description

Friction plate for reducing MPU problem between friction pairs

Technical Field

The invention relates to the field of vehicle friction plates, in particular to a friction plate for reducing MPU problems between friction pairs.

Background

With the rapid development of the automobile industry, the automobile maintenance amount is improved year by year, after a period of use, the automobile has NVH problems such as brake noise and the like caused by overgrinding (shown as brake drum pull grooves, surface scratches of brake discs and the like) among brake friction pairs due to MPU (Metal Pick-up) phenomenon, and the proportion of the after-sale problems is increased year by year, so that the maintenance cost is increased, and the public praise of products is damaged.

However, the current solutions to the problem of the MPU are mainly focused on: the proportion of the friction plate material is optimized and improved, so that the heat transfer and heat dissipation performance of the friction material are improved, the generation of local hard spot accumulation on the surface of the friction material is avoided, and the purpose of reducing the MPU is achieved. However, after the proportion of the friction plate material is optimized and improved, the problems of heat transfer and heat dissipation of the friction material are solved, but other performances of the friction material are reduced, and the use of the friction material is still affected. The problem that friction plate metal is accumulated cannot be fundamentally solved by optimizing and improving the proportion of friction plate materials, and further how to find a mode for inhibiting the MPU from the viewpoint of friction pairs of a drum brake is a technical problem to be solved currently.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides the friction plate for reducing the MPU problem between friction pairs, the friction plate can effectively reduce the occurrence probability of the MPU problem, and meanwhile, the friction plate is beneficial to prolonging the service life of parts, and the aims of reducing the after-sale cost can be achieved.

2-6 strip-shaped grooves are formed in the friction plate;

the strip-shaped grooves are arranged in parallel, and a space is arranged between the strip-shaped grooves;

the cross section shape of the strip-shaped groove is the same;

the dimensions of the strip-shaped groove are as follows: the sum of the lengths of the strip-shaped grooves is smaller than the width of the friction plate and accounts for 85% -90% of the width of the whole friction plate.

The depth of the strip-shaped groove is 1/3 to 1/2 of the thickness of the friction plate.

The area of the notch of the strip-shaped groove is larger than the area of the groove bottom.

The position of the strip-shaped groove is close to the end part of the friction plate.

It should be further noted that the friction plate is provided with a plurality of riveting holes arranged in a matrix;

and a space is arranged between the strip-shaped groove and the riveting hole.

It is further noted that the friction plate is provided with 3 strip-shaped grooves;

wherein 2 strip-shaped grooves are arranged at the end part of the friction plate, and 1 strip-shaped groove is arranged at the middle position of the friction plate in the width direction;

the sum of the lengths of the 3 strip-shaped grooves is smaller than the width of the friction plate.

It is further noted that the cross section of the bar-shaped groove is isosceles trapezoid, and the area of the notch is larger than the area of the groove bottom;

the depth of the strip-shaped groove is 1/2 of the thickness of the friction plate.

The angle formed by the two sides of the isosceles trapezoid is 60 degrees.

The two bar grooves provided at the end portions of the friction plate are arranged on the same straight line and are provided in parallel with the bar grooves provided at the intermediate positions in the width direction of the friction plate.

The 3 strip-shaped grooves are mutually parallel.

From the above technical scheme, the invention has the following advantages:

the friction plate with the surface grooves can play a role of a cutter, in the braking process, as the brake drum rotates, the brake shoes are opened, and the grooves formed in the surface of the friction plate strip scrap iron and friction material abrasion substances adhered on the friction surface of the brake drum, so that the surface of the friction plate is prevented from forming local hard spots due to metal accumulation, and further generation of MPU is inhibited.

According to the friction plate with the grooved surface, the stress condition of the friction plate surface is more uniform through the specific arrangement mode of the strip-shaped grooves and the cross-sectional shape of the strip-shaped grooves, so that the uneven abrasion phenomenon between friction pairs is avoided, the generation condition of metal accumulation is blocked, and the generation of MPU can be reduced to a certain extent.

The friction plate with the surface grooves can effectively reduce the occurrence probability of MPU problems, is beneficial to prolonging the service life of parts, and can achieve the purpose of reducing after-sale cost.

Drawings

In order to more clearly illustrate the technical solutions of the present invention, the drawings that are needed in the description will be briefly introduced below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a front view of the friction plate with surface grooves.

FIG. 2 is a side view of the friction plate with surface grooves.

FIG. 3 is a schematic diagram of the friction plate with surface grooves to solve MPU problem.

FIG. 4 is a schematic diagram of a friction plate simulation result acquisition point with/without grooves on the surface.

FIG. 5 is a friction plate with grooves on the surface.

FIG. 6 is a graph of comparative analysis of stress results at a collection point on a friction plate without grooves.

Table 1 shows the stress results at the collection points on the friction plate versus the results.

In the figure:

1-riveting holes; 2-slotting the friction plate; 3-friction plate; 4-abrasion substances.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The invention provides a friction plate for reducing MPU problems between friction pairs, as shown in figures 1 to 3, wherein 2 to 6 strip-shaped grooves are formed in the friction plate; the strip-shaped grooves are arranged in parallel, and a space is arranged between the strip-shaped grooves; the cross section shape of the strip-shaped groove is the same; the dimensions of the strip-shaped groove are as follows: the sum of the lengths of the strip-shaped grooves is smaller than the width of the friction plate and accounts for 85% -90% of the width of the whole friction plate. Wherein the depth of the strip-shaped groove is 1/3-1/2 of the thickness of the friction plate.

In the invention, the area of the notch of the strip-shaped groove is larger than the area of the groove bottom. I.e. the grooved cross section should meet the requirement that the grooved area at the friction surface location be relatively large and gradually decrease inwardly in the radial direction of the friction plate. The surface grooving of the strip-shaped groove is realized, the function of a full cutter is realized, and the problem of the MPU can be prevented and solved more efficiently.

The location of the grooves for the present invention is near the ends of the friction plate. In order to facilitate the discharge of scrap iron and friction material wearing substances adhered to the friction surface cut by the grooving, keep the cleanness in the grooving, ensure the effectiveness of the grooving in solving the problem of MPU, the grooving positions should be arranged at two ends of the friction plate along the width direction of the friction plate as much as possible, and the grooving is directly opened to the edge of the friction plate. In order to ensure uniform distribution of stress on the surface of the friction plate, grooves with corresponding sizes are arranged in the middle of the friction plate.

In the invention, a plurality of riveting holes 1 which are arranged in a matrix are arranged on a friction plate 3; a space is arranged between the strip-shaped groove 2 and the riveting hole 1. The arrangement position of the strip-shaped groove is a certain distance from the position of the riveting hole on the friction plate, and the shape and the arrangement mode of the groove with the optimal effect are determined by combining the stress distribution condition and the strength checking calculation of the surface of the friction plate through simulation calculation.

As one embodiment of the present invention, the number of friction plate strip grooves for reducing the problem of MPU between friction pairs is 3 pieces; the cross section shapes of the strip-shaped grooves are the same, but the lengths are different; the longer strip-shaped grooves are arranged independently and are positioned at the middle position of the width direction of the friction plate, and the two strip-shaped grooves with shorter lengths are symmetrically arranged at two ends of the friction plate and are arranged in parallel with the strip-shaped grooves with longer lengths; the stripe groove width meets the following conditions: the sum of the lengths of the three grooves is smaller than the width of the friction plate and accounts for about 85-90% of the width of the whole friction plate; the grooving section shape has the following characteristics: the cross section of the strip-shaped groove is similar to an isosceles trapezoid, the depth of the strip-shaped groove is about 1/2 of the thickness of the friction plate, the shorter bottom edge of the trapezoid is positioned in the friction plate, the longer bottom edge of the trapezoid is positioned on the surface of the friction plate, and the angle formed by the two sides of the trapezoid is 60 degrees.

As shown in fig. 3, the friction plate according to the present invention can act as a "cutter", and during braking, as the brake drum rotates, the brake shoes open, and the grooves formed in the surface of the friction plate strip away the iron filings and friction material abrasion substances 4 adhered to the friction surface of the brake drum, and the stripped abrasion substances 4 are separated from the friction plate along the grooves at the two sides of the friction plate, thereby preventing the friction plate surface from forming local hard spots due to metal accumulation, and thus inhibiting the generation of MPU;

as shown in fig. 4 to 6, the brake assembly with and without the friction plate according to the present invention was subjected to finite element analysis by the finite element analysis software Abaqus, data acquisition points were selected at the same positions on the surface thereof, as shown in table 1 and fig. 6,

as can be seen by comparing the stress values at the corresponding acquisition points, the friction plate for reducing the MPU phenomenon between the friction pairs has more uniform stress distribution and smaller stress values at the same positions compared with the friction plate without the strip-shaped grooves, thereby avoiding the occurrence of uneven abrasion phenomenon between the friction pairs, blocking the generation condition of metal accumulation and further reducing the generation of the MPU to a certain extent; and the stress values of the surfaces of the materials are smaller than the yield limit of the materials, so that the strength checking requirement is met.

When a friction plate provided by the invention for reducing MPU problems between friction pairs is referred to as being "on" or "connected" or "coupled" to another element or layer, it may be directly on or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly connected to" or "directly coupled to" another element or layer, there are no intervening elements or layers present. Like numbers refer to like elements throughout. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The friction plate provided by the present invention for reducing the problem of the MPU between friction pairs may use spatially relative terms such as "under" … "," below "," lower "," above "," over "etc. to describe the relationship of one element or feature to another as shown in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "under" or "beneath" other elements or features would then be oriented "over" the other elements or features. Thus, the exemplary term "below" may include both an orientation above and below. Other orientations of the device (90 degrees or other orientations) are possible, and spatially relative descriptors used herein interpreted accordingly.

The terminology used in the friction plate for reducing the problem of the MPU between friction pairs provided in the present invention is used only for describing specific embodiments and is not intended to limit the expressions in this document. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The friction plate for reducing the problem of the MPU between the friction pairs is characterized in that 3 strip-shaped grooves are formed in the friction plate;

the depth of the strip-shaped groove is 1/2 of the thickness of the friction plate;

the 3 strip-shaped grooves are arranged in parallel, and a space is arranged between the strip-shaped grooves;

the cross section shape of the strip-shaped groove is the same;

the dimensions of the strip-shaped groove are as follows: the sum of the lengths of the 3 strip-shaped grooves is smaller than the width of the friction plate and accounts for 85% -90% of the width of the whole friction plate;

the cross section of the strip-shaped groove is isosceles trapezoid, and the area of the notch is larger than the area of the groove bottom;

the angle formed by two sides of the isosceles trapezoid is 60 degrees;

the two bar grooves arranged at the end positions of the friction plate are arranged on the same straight line and are respectively arranged in parallel with the bar grooves arranged at the middle positions of the width direction of the friction plate.

2. The friction plate for reducing the problem of the MPU between friction pairs according to claim 1, wherein,

the friction plate is provided with a plurality of riveting holes which are arranged in a matrix;

and a space is arranged between the strip-shaped groove and the riveting hole.