Method and system for directional stress finishing of steel back of brake pad of bullet train

Abstract

The embodiment of the application provides a motor train brake block steel back multi-section directional stress finishing method and system, and belongs to the technical field of metal material plasticity processing. The method comprises the following steps: obtaining initial state information of a motor train brake block steel back to be processed, and establishing a steel back processing datum based on the initial state information; dividing the motor train brake block steel back into multiple steel back sections along the length direction, and determining a section stress regulation target corresponding to the face pressure stability under the braking condition for each steel back section; sequentially performing overall flattening treatment and section directional stress regulation treatment on the motor train brake block steel back, so as to form a residual stress distribution state meeting the section stress regulation target; performing detection and judgment on the motor train brake block steel back, and outputting a steel back finished product when it is judged that the preset condition is met. The scheme realizes the sectional directional stress regulation of the motor train brake block steel back along the length direction, so that the stable face pressure distribution matching the braking condition is obtained.

Description

Technical Field

[0001] This invention relates to the field of metal material plastic processing technology, specifically to a method and system for multi-segment directional stress finishing of high-speed train brake pad steel backing. Background Technology

[0002] As a key component of the braking system of rail transit vehicles, the steel back of the brake pad is used to support the friction material and form a stable contact interface with the brake caliper. During actual braking, the steel back of the brake pad needs to work under the combined action of high-frequency braking, cyclic thermal loads, and complex mechanical loads. Its overall morphology and residual stress distribution directly affect the uniformity of pressure distribution under braking conditions and the service stability of the brake pad.

[0003] The steel backing of existing high-speed train brake pads typically employs a processing technique where sheet metal is formed followed by leveling to eliminate overall warping or localized morphological deviations that occur during the forming process. This leveling process primarily focuses on overall straightening or leveling, with the main objective being to improve the macroscopic flatness of the steel backing. However, after the steel backing undergoes previous processes such as stamping, forming, or heat treatment, non-uniformly distributed residual stresses are often unavoidably generated within it. While these residual stresses may be redistributed during the overall leveling process, they are difficult to control specifically.

[0004] Under braking conditions, the steel backing of brake pads typically corresponds to different stress conditions along its length, resulting in variations in surface pressure transmission, deformation response, and stress evolution behavior at different locations. If the steel backing is uniformly treated solely through an overall leveling process, the residual stress state in some sections may not match the actual braking conditions, leading to problems such as uneven surface pressure distribution, localized abnormal wear, or decreased service stability during use.

[0005] To address the aforementioned issues, some existing technologies attempt to introduce additional correction steps after the leveling process, or to repeatedly level local areas using empirical methods. However, such methods typically lack a systematic consideration of the internal stress state of the steel backing, and have not developed a processing method based on the stress characteristics of different sections of the steel backing for targeted control. This makes it difficult to effectively guide the distribution of residual stress while ensuring the overall shape requirements.

[0006] Therefore, how to control the residual stress state in a targeted manner, based on the stress characteristics of different sections of the steel backing along the length direction, without introducing cutting processes, to meet the requirements of pressure stability under braking conditions, remains an urgent technical problem to be solved in the finishing of steel backing for high-speed train brake pads. Summary of the Invention

[0007] The purpose of this invention is to provide a method for multi-segment directional stress finishing of the steel backing of high-speed train brake pads, so as to at least solve the problem that the existing overall flattening process of the steel backing is difficult to control the residual stress according to the stress characteristics of different segments.

[0008] To achieve the above objectives, the first aspect of the present invention provides a method for multi-segment directional stress finishing of the steel backing of a high-speed train brake pad. The method includes: acquiring initial state information of the steel backing of the high-speed train brake pad to be processed, and establishing a steel backing processing benchmark based on the initial state information; dividing the steel backing of the high-speed train brake pad into multiple steel backing segments along the length direction based on the steel backing processing benchmark, and determining segment stress control targets corresponding to the compressive stability under braking conditions for each steel backing segment; performing overall leveling and segment directional stress control processing sequentially on the steel backing of the high-speed train brake pad based on the segment stress control targets to form a residual stress distribution state that satisfies the segment stress control targets; performing detection and judgment on the high-speed train brake pad steel backing after the segment directional stress control processing is completed, and outputting the finished steel backing product when the judgment meets preset conditions.

[0009] Optionally, the initial state information of the steel backing of the train brake pad to be processed is obtained, and a processing benchmark for the steel backing is established based on the initial state information. This includes: collecting the flatness information, thickness distribution information, and residual stress distribution characterization information of the steel backing of the train brake pad as initial state information; determining the overall shape deviation of the steel backing based on the flatness information, and correcting the flatness information in the thickness direction based on the thickness distribution information to obtain corrected flatness data corresponding to the actual stress state of the steel backing; determining the initial stress state at different positions of the steel backing based on the residual stress distribution characterization information, and spatially associating the initial stress state with the corrected flatness data; and establishing a processing benchmark for the steel backing to uniformly describe the geometric positional relationship and stress distribution relationship of the steel backing based on the spatial association result between the corrected flatness data and the initial stress state.

[0010] Optionally, determining the initial stress state at different locations on the steel backing based on the residual stress distribution characterization information, and spatially associating the initial stress state with the corrected flatness data, includes: extracting corresponding residual stress characterization values ​​at different locations on the steel backing of the EMU brake pad along the steel backing processing datum based on the residual stress distribution characterization information to form an initial stress state distribution that corresponds one-to-one with the spatial location of the steel backing; mapping the initial stress state distribution to the spatial location corresponding to the corrected flatness data according to the steel backing processing datum to construct a joint characterization result of the morphological deviation and initial stress state at each location on the steel backing; and based on the joint characterization result, identifying the spatial correspondence between the morphological deviation and initial stress state at different locations on the steel backing, and forming a spatial association result reflecting the coupling characteristics of the morphological deviation and stress state at each location.

[0011] Optionally, based on the steel backing processing datum, the steel backing of the train brake pad is divided into multiple steel backing segments along its length. For each steel backing segment, a segment stress control target corresponding to the compressive stability under braking conditions is determined. This includes: based on the steel backing processing datum, identifying locations where morphological deviation characteristics and initial stress state characteristics change along the length of the train brake pad steel backing, and using these determined change locations as the dividing boundaries of the steel backing segments to divide the train brake pad steel backing into multiple continuous steel backing segments; for each steel backing segment, summarizing the morphological deviation characteristics and initial stress state characteristics within that segment to form a segment stress characteristic description; based on the segment stress characteristic description and combined with the compressive stability requirements under braking conditions, determining the segment stress corresponding to each steel backing segment to limit the control direction and degree of residual stress control within that steel backing segment.

[0012] Optionally, based on the description of the stress characteristics of the sections, the corresponding section stress of each steel backing section is determined as a control target to limit the direction and degree of control of the residual stress within the steel backing section. This includes: for each steel backing section, based on the corresponding section stress characteristic description, a comparative analysis is performed on the morphological deviation characteristics and initial stress state characteristics within the steel backing section; if the comparative analysis results indicate that the morphological deviation characteristics within the steel backing section need to be compensated and adjusted first, a section stress control target guided by morphological compensation is determined; if the comparative analysis results indicate that the initial stress state within the steel backing section needs to be redistributed first, a section stress control target guided by residual stress redistribution is determined; if the comparative analysis results indicate that both the morphological deviation characteristics and the initial stress state within the steel backing section need to be controlled, a composite section stress control target that simultaneously includes morphological compensation guidance and residual stress redistribution guidance is determined.

[0013] Optionally, based on the stress control targets corresponding to each steel backing section, the steel backing of the EMU brake pads is sequentially subjected to overall leveling and section-oriented stress control to form a residual stress distribution state that satisfies the section stress control targets. This includes: determining the steel backing sections that need to undergo section-oriented stress control and their corresponding control sequence based on the stress control targets corresponding to each steel backing section; performing section-oriented stress control on each steel backing section according to the control sequence to directionally control the residual stress state within the corresponding steel backing section while maintaining the overall flatness of the steel backing; and after completing the section-oriented stress control on all steel backing sections, forming a residual stress distribution state that matches the stress control targets corresponding to each steel backing section.

[0014] Optionally, before performing overall leveling and section directional stress control on the steel back of the EMU brake pads, the method further includes: based on the steel back processing reference, applying an overall leveling load sequentially along the length direction to level the shape of the steel back within its entire range; during the application of the overall leveling load, applying loads sequentially to different positions of the steel back according to a preset leveling sequence, and verifying the shape of the steel back after each load application to complete the overall leveling process; and using the EMU brake pad steel back after the overall leveling process as the processing input for section directional stress control.

[0015] Optionally, according to the control sequence, segment-oriented stress control processing is performed on each steel back section, including: based on the control sequence, sequentially selecting the corresponding steel back section as the current control section, and applying segment-oriented control load within the length range of the current control section; when applying the segment-oriented control load to the current control section, controlling the position of the segment-oriented control load to be limited to the current control section, and controlling the application direction of the segment-oriented control load to correspond to the segment stress control target, until the control of the current steel back section is completed.

[0016] A second aspect of the present invention provides a multi-segment directional stress finishing system for the steel backing of high-speed train brake pads. The system is used to execute the aforementioned multi-segment directional stress finishing method for the steel backing of high-speed train brake pads. The system includes: an information acquisition unit, used to acquire initial state information of the steel backing of the high-speed train brake pad to be processed, and to establish a steel backing processing benchmark based on the initial state information; a target generation unit, used to divide the steel backing of the high-speed train brake pad into multiple steel backing segments along its length direction based on the steel backing processing benchmark, and to determine a segment stress control target corresponding to the compressive stability under braking conditions for each steel backing segment; a control execution unit, used to sequentially perform overall leveling treatment and segment directional stress control treatment on the steel backing of the high-speed train brake pad based on the segment stress control target corresponding to each steel backing segment, so as to form a residual stress distribution state that satisfies the segment stress control target; and a detection unit, used to perform detection and judgment on the steel backing of the high-speed train brake pad after the segment directional stress control treatment is completed, and to output the finished steel backing product when the judgment meets preset conditions.

[0017] Through the above technical solution, the present invention obtains the initial state information of the steel backing of the train brake pads before processing and establishes a unified processing benchmark for the steel backing. This allows the geometric morphology information and residual stress state of the steel backing to be described under the same processing benchmark, providing a consistent reference basis for subsequent processing steps. Based on this, the steel backing is divided into multiple steel backing segments along its length, and stress control targets are determined for each segment according to its stress characteristics. This enables the steel backing processing to reflect the segmental differences in pressure distribution under braking conditions.

[0018] Furthermore, by performing directional stress control treatment in a segmented sequence after overall leveling, the overall shape adjustment of the steel backing and the residual stress control of each segment are systematically linked, thereby ensuring the overall shape requirements of the steel backing while providing targeted guidance for the residual stress state of different segments. By inspecting and judging the processed steel backing, a finished product is output only when preset conditions are met, providing a clear basis for judging the processing results.

[0019] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0020] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings:

[0021] Figure 1 This is a flowchart of the steps of a method for multi-segment directional stress finishing of the steel backing of high-speed train brake pads according to one embodiment of the present invention;

[0022] Figure 2 This is a detailed flowchart of step S10 of the multi-segment directional stress finishing method for the steel backing of high-speed train brake pads provided in one embodiment of the present invention;

[0023] Figure 3 This is a detailed flowchart of step S30 of the multi-segment directional stress finishing method for the steel backing of high-speed train brake pads provided in one embodiment of the present invention;

[0024] Figure 4 This is a system structure diagram of a multi-segment directional stress finishing system for the steel backing of high-speed train brake pads provided in one embodiment of the present invention. Detailed Implementation

[0025] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0026] like Figure 1 As shown, this invention provides a method for multi-segment directional stress finishing of the steel backing of high-speed train brake pads, the method comprising:

[0027] Step S10: Obtain the initial state information of the steel backing of the brake pad to be processed, and establish a processing reference for the steel backing based on the initial state information.

[0028] Specifically, by acquiring the initial state information of the steel backing of the brake pads to be processed, and establishing a processing benchmark based on this initial state information, subsequent processing steps have a unified reference basis. The initial state information reflects the geometric morphology and stress distribution characteristics of the steel backing before finishing. By organizing and associating this information, a processing benchmark is formed that simultaneously describes the spatial position and stress state of the steel backing. This processing benchmark supports the segmentation of the steel backing along its length and the determination of segment stress control targets, ensuring that subsequent leveling and segment-oriented stress control are performed under the same processing benchmark. This avoids inconsistencies in reference conditions between different processing steps, guaranteeing the continuity and feasibility of the processing flow. Specifically, such as... Figure 2 Step S10 includes the following steps:

[0029] Step S101: Collect the flatness information, thickness distribution information and residual stress distribution characterization information of the steel back of the train brake pad as initial state information.

[0030] Specifically, step S101 is used to obtain the initial state information of the steel backing of the train brake pads before entering the finishing process. The initial state information includes at least the flatness information, thickness distribution information, and residual stress distribution characterization information of the steel backing, which are used to comprehensively reflect the geometric shape and internal stress state of the steel backing.

[0031] In the specific implementation process, the steel backing of the train brake pads to be processed can be placed in a stable support position, allowing the steel backing to be measured in a natural state without external load interference. Flatness information can be collected by setting multiple measurement paths along the length and width directions of the steel backing. By sampling the height or displacement at multiple discrete positions on the surface of the steel backing, a set of flatness data reflecting the overall undulation of the steel backing's shape can be formed. Thickness distribution information can be collected by corresponding to the above measurement paths, measuring the thickness of the steel backing at the same or adjacent positions to obtain the thickness variation along the length and width directions. By corresponding the thickness distribution information with the flatness information, the stress influence caused by thickness differences can be avoided by relying solely on surface morphology for judgment.

[0032] Residual stress distribution characterization information is used to reflect the stress state formed inside the steel backing during the preceding forming or processing. Multiple measurement locations can be selected along the length of the steel backing to obtain characteristic data that characterizes the residual stress level. After the above three types of information are collected, they are uniformly numbered and recorded according to the actual geometric position of the steel backing to form a complete set of initial state information, which serves as the basis for establishing the steel backing processing benchmark.

[0033] Step S102: Determine the overall shape deviation of the steel backing based on the flatness information, and correct the flatness information in the thickness direction based on the thickness distribution information to obtain corrected flatness data corresponding to the actual stress state of the steel backing.

[0034] Specifically, based on the flatness information obtained in step S101, the overall morphological deviation of the steel backing of the train brake pads is first identified. Specifically, by comparing and analyzing the height or displacement data at each measurement position in the flatness information, the overall bending, warping, or local undulation characteristics of the steel backing relative to the ideal straight state are determined, thereby obtaining the original flatness data reflecting the overall morphological deviation of the steel backing.

[0035] Based on this, thickness distribution information is introduced to correct the flatness information in the thickness direction. Since thickness differences at different locations on the steel backing affect its stiffness and stress response under external loads, judging the overall deviation solely based on surface morphology is prone to error. Therefore, in this embodiment, by associating flatness data with thickness data at corresponding locations, the flatness data is corrected according to thickness variations, enabling the corrected flatness data to more accurately reflect the morphological characteristics of the steel backing under actual stress.

[0036] In practice, for each measurement location on the steel backing, the corresponding flatness data can be weighted or corrected based on the thickness information at that location, thereby eliminating morphological judgment bias caused by uneven thickness. After the above processing, corrected flatness data corresponding to the actual stress state of the steel backing is generated, providing a more reliable geometric basis for subsequent stress state analysis and spatial correlation.

[0037] Step S103: Determine the initial stress state at different locations on the steel backing based on the residual stress distribution characterization information, and spatially correlate the initial stress state with the corrected flatness data.

[0038] Specifically, based on the residual stress distribution characterization information, corresponding residual stress characterization values ​​are extracted at different positions of the steel back of the train brake pad along the steel back processing reference to form an initial stress state distribution that corresponds one-to-one with the spatial position of the steel back; the initial stress state distribution is mapped to the spatial position corresponding to the corrected flatness data according to the steel back processing reference to construct a joint characterization result of the morphological deviation and initial stress state at each position of the steel back; based on the joint characterization result, the spatial correspondence between the morphological deviation and initial stress state at different positions of the steel back is identified, and a spatial correlation result reflecting the coupling characteristics of the morphological deviation and stress state at each position is formed.

[0039] Specifically, in step S103, the initial stress state at different locations on the steel back is determined based on the residual stress distribution characterization information, and the initial stress state is spatially correlated with the corrected flatness data obtained in step S102.

[0040] Specifically, residual stress characterization values ​​can be extracted from multiple locations along the length of the steel backing along the spatial coordinates corresponding to the steel backing machining datum. Each stress characterization value corresponds one-to-one with a specific spatial location on the steel backing, thus forming distribution data reflecting the initial stress state at different locations on the steel backing. During this process, it should be ensured that the extraction locations of the stress characterization values ​​have a clear spatial correspondence with the flatness and thickness measurement locations to facilitate subsequent data correlation.

[0041] Subsequently, the initial stress state distribution is mapped to the spatial location corresponding to the corrected flatness data, so that the same location on the steel back simultaneously possesses both morphological deviation information and stress state information. Through this mapping process, a joint characterization result of morphological deviation and initial stress state at various locations on the steel back can be constructed.

[0042] Based on this, the joint characterization results are analyzed to identify the correspondence between the morphological deviation characteristics and the initial stress state characteristics at different locations on the steel backing, and to form spatial correlation results reflecting the coupling characteristics of morphological deviation and stress state at each location. These spatial correlation results are used to characterize the comprehensive features of the geometric shape and stress state of the steel backing at different locations before entering the finishing process.

[0043] Step S104: Based on the spatial correlation results between the corrected flatness data and the initial stress state, establish a steel back machining datum for uniformly describing the geometric position relationship and stress distribution relationship of the steel back.

[0044] Specifically, based on the corrected flatness data obtained in step S102 and the spatial correlation results formed in step S103, a steel back processing datum is established to uniformly describe the geometric position relationship and stress distribution relationship of the steel back.

[0045] In practice, the corrected flatness data can be used as the basic data to describe the geometry of the steel backing, and the spatial correlation results can be used as supplementary information to describe the stress state at different positions of the steel backing and its relationship with the shape. By uniformly organizing and numbering the above data, a steel backing machining datum is formed. This steel backing machining datum is used to describe the geometric state and initial stress state of the steel backing at various positions along the length direction under the same reference system.

[0046] In subsequent processing, the steel backing processing datum serves as a unified reference, used for dividing the steel backing sections, describing the stress characteristics of each section, and determining the stress control targets for each section. By establishing this processing datum before processing, it can be ensured that subsequent overall leveling and section-specific stress control processes are performed based on consistent reference conditions, thereby avoiding processing deviations caused by inconsistent reference systems.

[0047] In one specific embodiment, a steel backing for train brake pads is selected as the object to be processed. The steel backing is generally elongated, with a length of approximately 320 mm, a width of approximately 75 mm, and a nominal thickness of 8 mm. After completing the preliminary stamping and heat treatment processes, the steel backing enters the finishing stage.

[0048] In step S101, the steel backing is placed on a testing station without external load constraints. Sixteen measurement sections are selected at equal intervals along the length of the steel backing, and three measurement points are selected along the width direction on each section, forming a total of 48 measurement positions. Height sampling is performed at each measurement position to obtain the flatness information of the steel backing. The test results show that the steel backing has an upward arching trend in the middle of its length, with a maximum height deviation of approximately 0.42 mm. Simultaneously, the thickness distribution information of the steel backing is collected at the above measurement positions. The test results show that the thickness of the steel backing varies between 7.85 mm and 8.10 mm, and the thickness distribution is slightly uneven along the length direction. Furthermore, residual stress distribution characterization information is obtained at the corresponding 16 section positions. The results show that the residual tensile stress level in the middle region of the steel backing is significantly higher than that in the two end regions.

[0049] In step S102, the overall morphological deviation of the steel backing is first identified based on the flatness information, and the central arched area is marked as the main morphological deviation area. Subsequently, thickness distribution information is introduced to correct the flatness data. For example, the flatness data corresponding to measurement locations with a thickness less than 7.9 mm is weighted and adjusted so that the corrected flatness data can reflect the morphological response of that location under actual stress conditions. After correction, the effective morphological deviation value of the central region of the steel backing is re-evaluated, providing a more accurate geometric basis for subsequent analysis.

[0050] In step S103, the residual stress characterization values ​​are spatially mapped to the aforementioned corrected flatness data along the length of the steel backing, ensuring that each measured section simultaneously possesses corresponding morphological deviation data and initial stress state data. By processing the joint characterization results, it can be identified that several sections in the middle of the steel backing exhibit both large morphological deviations and high residual tensile stress, while sections near both ends mainly show smaller morphological deviations and lower residual stress levels. Based on this joint characterization result, a spatial correlation result reflecting the coupling relationship between the morphological deviation and stress state of the steel backing along its length is formed.

[0051] In step S104, based on the aforementioned corrected flatness data and spatial correlation results, each measurement section of the steel backing is uniformly numbered and positioned to establish a steel backing processing benchmark for describing the geometric positional relationship and stress distribution relationship of the steel backing. This processing benchmark provides a unified reference for subsequent steel backing segment division and the determination of segment stress control targets, enabling subsequent processing to proceed based on a consistent data foundation.

[0052] Step S20: Based on the steel back processing reference, the steel back of the EMU brake pad is divided into multiple steel back sections along the length direction, and stress control targets corresponding to the compressive stability under braking conditions are determined for each steel back section.

[0053] Specifically, based on the steel backing processing benchmark, the locations where changes in morphological deviation characteristics and initial stress state characteristics occur along the length direction of the EMU brake pad steel backing are identified, and the determined change locations are used as the dividing boundaries of the steel backing segments to divide the EMU brake pad steel backing into multiple continuous steel backing segments. For each steel backing segment, the morphological deviation characteristics and initial stress state characteristics within that segment are summarized to form a segment stress characteristic description for the corresponding steel backing segment. Based on the segment stress characteristic description and combined with the requirements for pressure stability under braking conditions, the segment stress corresponding to each steel backing segment is determined to limit the control direction and control degree of residual stress within that steel backing segment.

[0054] Furthermore, based on the description of the stress characteristics of the aforementioned sections, the corresponding section stress of each steel backing section is determined as a control target to limit the direction and degree of control of the residual stress within that steel backing section. This includes: for each steel backing section, based on the corresponding section stress characteristic description, a comparative analysis is performed on the morphological deviation characteristics and initial stress state characteristics within that steel backing section; if the comparative analysis results indicate that the morphological deviation characteristics within that steel backing section need to be compensated and adjusted first, a section stress control target guided by morphological compensation is determined; if the comparative analysis results indicate that the initial stress state within that steel backing section needs to be redistributed first, a section stress control target guided by residual stress redistribution is determined; if the comparative analysis results indicate that both the morphological deviation characteristics and the initial stress state within that steel backing section need to be controlled, a composite section stress control target that simultaneously includes morphological compensation guidance and residual stress redistribution guidance is determined.

[0055] In this embodiment of the invention, after establishing the steel backing processing benchmark, the steel backing of the train brake pad is divided into sections along its length based on the steel backing processing benchmark, and the stress control target corresponding to each steel backing section is further determined. The steel backing processing benchmark has uniformly described the spatial correlation between the corrected flatness data and the initial stress state at each position of the steel backing, providing a data basis for subsequent section division and target determination.

[0056] Specifically, during the section division process, the morphological deviation characteristics and initial stress state characteristics recorded in the steel backing of the train brake pads are first sequentially scanned along the length direction of the steel backing. Let the length direction of the steel backing be... In the axial direction, the steel back is discretized along the length direction as follows: Each sampling location has a continuous sampling position. Corresponding to a set of morphological deviation characteristic values and initial stress state eigenvalues .

[0057] To identify the locations where changes occur in morphological deviation characteristics and initial stress state characteristics, a joint change index function is introduced in this embodiment. Its definition is as follows:

[0058]

[0059] in: Indicates the position of the steel back. Corrected flatness deviation value at the location; Indicates the position of the steel back. The characteristic value of the initial stress state at the location; Indicates the distance between adjacent sampling locations; and This is a weighting coefficient used to balance the influence of morphological deviation changes and stress state changes on the segmentation process.

[0060] When joint change indicators When a significant trend of change occurs between adjacent locations, it indicates that the morphological deviation characteristics and initial stress state characteristics of the steel backing near that location are changing synchronously or asynchronously. In this embodiment, sampling locations that meet the preset change criteria are selected. As the dividing boundary for the steel backing sections, the steel backing of the train brake pads is divided into multiple continuous steel backing sections along its length. The steel backing sections obtained in this way can reflect the differences in stress and morphological state at different locations on the steel backing at the data level.

[0061] Furthermore, after completing the segmentation, for each steel backing segment... The morphological deviation characteristics and initial stress state characteristics within the segment are summarized to form a description of the segment's stress characteristics. Specifically, in the segment... Length range Within this, statistical processing is performed on the morphological deviation characteristics and stress state characteristics respectively. In this embodiment, the section... The morphological deviation characteristics can be expressed as:

[0062]

[0063] And section The stress state characteristics can be expressed as:

[0064]

[0065] in: Indicates a section The number of internal sampling locations; Indicates a section The average morphological deviation characteristic value; Indicates a section The average initial stress state characteristic value. The above description of the stress characteristics of the section not only reflects the morphological state and stress state of the steel backing at the section scale, but also provides a quantitative basis for comparing the stress differences between different sections.

[0066] After obtaining the stress characteristics of each steel backing section, the stress control target for each steel backing section is determined by further considering the requirements for surface pressure stability under braking conditions. In this embodiment, the requirement for surface pressure stability under braking conditions is regarded as a constraint on the uniformity of load transfer of the steel backing during braking. This constraint can be indirectly characterized by the influence of section morphological deviation and section stress state on surface pressure transfer.

[0067] Therefore, within each steel backing section, the morphological deviation characteristics are... Characteristics of stress state A comparative analysis is conducted. Specifically, a segment discrimination function is introduced. :

[0068]

[0069] in: This represents the reference morphological deviation value used for normalization. This represents the reference stress state value used for normalization. and , which is a weighting coefficient used to reflect the relative influence of morphological deviation and stress state on the compressive stability under braking conditions.

[0070] When segment discrimination function When the proportion of the component contributed by morphological deviation characteristics is higher, it indicates that the morphological deviation characteristics in the steel back section have a more prominent impact on surface pressure stability. In this case, the section stress control target for the steel back section is determined to be a control target guided by morphological compensation. When the proportion of the component contributed by stress state characteristics is higher, the section stress control target for the steel back section is determined to be a control target guided by residual stress redistribution. When both types of components are at a high level, the section stress control target for the steel back section is determined to be a composite control target that includes both morphological compensation guidance and residual stress redistribution guidance.

[0071] In this way, the stress control target for each section is no longer a uniform overall target, but is determined separately based on the differences in stress characteristics of different sections of the steel backing, thus providing a clear direction and control degree basis for subsequent directional stress control treatment of each section.

[0072] In another possible implementation, after dividing the steel backing sections based on the steel backing processing datum, instead of directly performing numerical comparative analysis on the stress characteristics of the sections, the equivalent bending stiffness characteristics of the sections are introduced as an intermediate criterion for determining the stress control target of the sections. Specifically, based on the corrected flatness data, thickness distribution information, and initial stress state characteristics recorded in the steel backing processing datum, the equivalent bending stiffness parameters of each steel backing section are calculated to characterize the deformation response capability of the section under the downward pressure of braking conditions.

[0073] Furthermore, the equivalent bending stiffness parameters of each steel backing section are compared along the length to identify sections where the equivalent bending stiffness changes abruptly or discontinuously. For steel backing sections with low equivalent bending stiffness, a stress control target aimed at improving the bending response of that section is determined. For steel backing sections with high equivalent bending stiffness but concentrated initial stress levels, a stress control target aimed at redistributing residual stress is determined. By introducing the equivalent bending stiffness of the section as an intermediate characterization parameter, the determination of the stress control target no longer depends solely on geometric deviations or stress values ​​themselves, but rather distinguishes the control needs of different steel backing sections from the perspective of structural response.

[0074] Step S30: Based on the stress control target of each steel backing section, perform overall leveling and section-oriented stress control treatment on the steel backing of the EMU brake pads in sequence to form a residual stress distribution state that meets the stress control target of the section.

[0075] Specifically, after dividing the steel backing into sections and determining the corresponding stress control targets for each section, the steel backing of the EMU brake pads is subjected to overall leveling and section-oriented stress control treatment sequentially based on these targets. The overall leveling process is used to uniformly adjust the overall shape of the steel backing at the initial stage of processing, ensuring consistent starting conditions across the entire structure, thus providing a stable foundation for subsequent section-level processing. Subsequently, based on the overall leveling process, section-oriented stress control treatment is performed on different sections of the steel backing according to the predetermined stress control targets and sequence, guiding the residual stress state within each section according to the corresponding control direction and degree. By combining the overall leveling and section-oriented stress control treatment sequentially, the overall shape adjustment of the steel backing and the section residual stress control are seamlessly integrated, avoiding interference between different processing steps. Ultimately, through the above processing, while meeting the overall morphological requirements of the steel backing, the residual stress distribution in different sections along the length of the steel backing is made consistent with the corresponding stress control targets, providing a stable and controllable basis for subsequent testing and judgment. Specifically, such as... Figure 3 Step S30 includes the following steps:

[0076] Step S301: Based on the steel back processing reference, apply an overall leveling load sequentially along the length direction to the steel back of the train brake pad to level the shape of the steel back within its entire range.

[0077] Specifically, during the application of the overall leveling load, loads are applied sequentially to different positions of the steel back according to the preset leveling sequence, and the shape of the steel back is checked after each load is applied to complete the overall leveling process; the steel back of the train brake pad after the overall leveling process is used as the processing input for the section directional stress control process.

[0078] Specifically, step S301 is used to perform overall leveling on the steel back of the train brake pads before the section-oriented stress control treatment. This step is based on the steel back processing benchmark established above, and its purpose is to uniformly process the overall shape of the steel back without distinguishing specific sections of the steel back, so that the steel back has a consistent processing starting state before entering the section-level control.

[0079] In practice, the steel backing of the train brake pads to be processed is placed in the overall leveling station. Based on the geometric position information recorded in the steel backing processing reference, multiple load application positions are set along the length of the steel backing. The overall leveling load is applied sequentially along the length of the steel backing, with a preset spacing between each load application position to cover the entire length range of the steel backing. During the load application process, loads are applied to different positions sequentially according to a preset leveling sequence. This leveling sequence can be set according to the overall shape deviation distribution reflected in the steel backing processing reference. For example, loads can be applied first to areas with more concentrated overall shape deviations, and then gradually extended to both ends.

[0080] After each overall leveling load is applied, the current shape of the steel backing is checked. This check can be based on the flatness description method corresponding to the steel backing processing datum to confirm the changes in the overall shape of the steel backing caused by the current load application. If the check results show that there are still unprocessed overall shape deviations, then the overall leveling load is applied to the corresponding positions according to the leveling sequence. Through the alternating execution of multiple load applications and shape checks, the leveling process of the overall shape of the steel backing is gradually completed.

[0081] After the overall leveling process is completed, the steel back of the EMU brake pads, which has undergone overall leveling, is used as the processing input for the section directional stress control process and proceeds to the next step.

[0082] Step S302: Based on the stress control target of each steel back section, determine the steel back sections that need to be subjected to directional stress control treatment and their corresponding control sequence.

[0083] Specifically, based on the stress control targets corresponding to each steel backing section, the steel backing sections requiring directional stress control treatment and their corresponding control sequence are determined. This step clarifies the targets and order of subsequent section-level control after the overall leveling process is completed.

[0084] Specifically, firstly, based on the steel backing section division results recorded in the steel backing processing datum, multiple steel backing sections along the length direction of the EMU brake pad steel backing are obtained, and the stress control target corresponding to each steel backing section is read. Subsequently, the stress control targets of each steel backing section are summarized and compared to identify the differences in the control direction and degree of different sections.

[0085] Based on this, the control sequence of each steel backing section is determined according to the preset control strategy rules. For example, the steel backing section with a higher degree of control among the stress control targets can be selected as the first control section, or the control process can be performed sequentially from one end to the other according to the spatial relationship of the steel backing sections in the length direction. The control sequence is not limited to a single rule, but is determined according to the relationship between the stress control targets of the sections.

[0086] After determining the control sequence, each steel backing section and its corresponding execution sequence are numbered and recorded, forming a control sequence table to guide subsequent section directional stress control treatments. This control sequence table serves as a crucial basis for subsequent steps, ensuring that the section directional stress control treatments are carried out sequentially according to the predetermined order.

[0087] Step S303: According to the control sequence, perform segment-oriented stress control treatment on each steel back section to control the residual stress state in the corresponding steel back section while maintaining the overall straightness of the steel back.

[0088] Specifically, based on the control sequence, corresponding steel back sections are selected sequentially as the current control sections, and section-oriented control loads are applied within the length range of the current control sections. When applying the section-oriented control load to the current control section, the position of the section-oriented control load is controlled to be limited to the current control section, and the direction of application of the section-oriented control load is controlled to correspond to the stress control target of the section, until the control of the current steel back section is completed.

[0089] Specifically, following the control sequence determined in step S302, sectional directional stress control treatment is performed on each steel backing section. This step is carried out after the overall leveling treatment is completed, and is used to specifically control the residual stress state in different sections of the steel backing.

[0090] In practice, according to the control sequence, the corresponding steel backing sections are selected sequentially as the current control sections, and a section-oriented control load is applied within the length range of the current control section. The application location of the section-oriented control load is limited to the spatial range corresponding to the current control section to avoid unnecessary impact on non-current control sections.

[0091] When applying a load to the current control section, the direction of the directional control load is controlled according to the stress control target corresponding to the steel backing section, ensuring that the load direction is consistent with the control direction defined by the stress control target. Simultaneously, the number of applications or the order of applications of the directional control load can be controlled according to the degree of control defined in the stress control target.

[0092] After completing the sectional directional stress control treatment for the current steel backing section, an intermediate check can be performed on the stress state within that section to confirm that the control treatment for the current section has been completed. Subsequently, following the control sequence table, switch to the next steel backing section and repeat the above operation until all steel backing sections have completed the corresponding sectional directional stress control treatment.

[0093] Step S304: After completing the sectional directional stress control treatment of all steel back sections, a residual stress distribution state matching the sectional stress control target of each steel back section is formed.

[0094] Specifically, after completing the segment-oriented stress control treatment for all steel back sections, a residual stress distribution state matching the segment stress control target for each steel back section is formed. This step is used to periodically conclude the execution results of the aforementioned overall leveling treatment and segment-oriented stress control treatment.

[0095] Specifically, after the directional stress control treatment of all steel backing sections is completed, the residual stress state of the steel backing as a whole and within each section has been adjusted according to the corresponding section stress control target. At this time, the residual stress distribution state in different sections of the steel backing along the length direction is consistent with its corresponding control direction and control degree, forming a residual stress distribution state corresponding to the steel backing processing reference and section stress control target.

[0096] The residual stress distribution, as the output of the section-oriented stress control treatment stage, will be used in subsequent inspection and judgment steps to determine whether the steel backing of the train brake pads meets the preset conditions and to decide whether to output the finished steel backing. Through the above steps, the overall leveling treatment and the section-oriented stress control treatment are fully connected in the process, providing a clear basis for subsequent quality judgment.

[0097] Step S40: Perform testing and judgment on the steel backing of the EMU brake pads after the section directional stress adjustment treatment is completed, and output the finished steel backing when the judgment meets the preset conditions.

[0098] Specifically, after the section-oriented stress control treatment is completed, the final inspection status information of the EMU brake pad steel backing is collected. The final inspection status information includes at least the steel backing flatness detection information and the steel backing residual stress distribution detection information. Based on the final inspection status information, the consistency judgment of the EMU brake pad steel backing with the corresponding section stress control target is performed to obtain the judgment result. If the judgment result meets the preset conditions, the EMU brake pad steel backing is marked as a finished steel backing product and output.

[0099] In this embodiment of the invention, after completing the section-oriented stress control treatment of all steel backing sections, a detection and judgment step is performed on the steel backing of the train brake pads to confirm whether the processing results meet preset conditions and to determine whether to output the finished steel backing product. The detection and judgment are based on the final inspection status information, which includes at least the steel backing flatness detection information and the steel backing residual stress distribution detection information.

[0100] In practice, final inspection data is collected on the steel backing after the directional stress control treatment of the completed sections. Flatness inspection information reflects the morphological state of the steel backing on both overall and sectional scales, and its acquisition location is consistent with the position recorded in the steel backing processing datum. Residual stress distribution inspection information reflects the stress state within each steel backing section along its length, and its detection location has a one-to-one correspondence with the corresponding section stress control target. Through these methods, a set of final inspection status information corresponding to each section of the steel backing is formed.

[0101] Furthermore, based on the final inspection status information, a consistency determination is performed on the steel backing of the train brake pads and the corresponding section stress control target. In this embodiment, a section consistency evaluation function is introduced. , used for the first The final inspection result of each steel back section is determined by the following expression:

[0102]

[0103] in, Indicates the first The final inspection flatness characteristic value of each steel back section, Indicates the first The final residual stress characteristic value of each steel back section; and They represent the first The flatness reference value and stress state reference value specified in the stress control target of each steel back section; and This is a weighting coefficient used to balance the influence of morphological state and stress state on consistency determination.

[0104] When the segment consistency evaluation function corresponding to each steel back section If all preset judgment conditions are met, the steel back of the train brake pad is marked as a finished steel back and output; otherwise, it is not output as a finished product, thus completing the detection and judgment process of this step.

[0105] In another possible implementation, after completing the segment-oriented stress control process, instead of directly determining consistency based on the numerical deviation between the final inspection status information and the segment stress control target, the segment stress continuity maintenance characteristics are introduced as an auxiliary basis for judging the finished steel backing product. Specifically, after collecting steel backing flatness detection information and steel backing residual stress distribution detection information, based on the steel backing processing benchmark, the residual stress change characteristics at the junctions of adjacent steel backing segments are extracted sequentially along the length of the steel backing to construct the stress continuity description results between segments. Subsequently, the stress continuity description results of each adjacent steel backing segment are analyzed to determine whether there are abnormally abrupt residual stress gradients at the segment junctions.

[0106] If the stress control target for the corresponding section is met within the steel backing section, and the residual stress change between adjacent sections remains continuous, then the overall stress distribution of the steel backing is considered to match the underbody stability requirements under braking conditions. Conversely, if a significant discontinuous stress change occurs at the section boundary, then the steel backing is considered not to meet the output conditions for the finished product. By introducing the continuity of stress between sections as a criterion, the output determination of the finished steel backing no longer relies solely on indicators within a single section, but rather on a comprehensive evaluation of the processing results from the perspective of section synergy.

[0107] like Figure 4 As shown, this invention provides a multi-segment directional stress finishing system for the steel backing of high-speed train brake pads. The system is used to execute the aforementioned multi-segment directional stress finishing method for the steel backing of high-speed train brake pads. The system includes: an information acquisition unit, used to acquire initial state information of the steel backing of the high-speed train brake pad to be processed, and to establish a steel backing processing benchmark based on the initial state information; a target generation unit, used to divide the steel backing of the high-speed train brake pad into multiple steel backing segments along its length direction based on the steel backing processing benchmark, and to determine a segment stress control target corresponding to the compressive stability under braking conditions for each steel backing segment; a control execution unit, used to sequentially perform overall leveling and segment directional stress control processing on the steel backing of the high-speed train brake pad based on the segment stress control target corresponding to each steel backing segment, so as to form a residual stress distribution state that satisfies the segment stress control target; and a detection unit, used to perform detection and judgment on the steel backing of the high-speed train brake pad after the segment directional stress control processing is completed, and to output the finished steel backing product when the judgment meets preset conditions.

[0108] Those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. This program is stored in a storage medium and includes several instructions to cause a microcontroller, chip, or processor to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0109] The optional embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details described above. Within the scope of the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all fall within the protection scope of the embodiments of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the embodiments of the present invention will not further describe the various possible combinations.

[0110] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the embodiments of the present invention, they should also be regarded as the content disclosed by the embodiments of the present invention.

Claims

1. A method for multi-segment directional stress finishing of the steel backing of high-speed train brake pads, characterized in that, The method includes: Obtain the initial state information of the steel backing of the brake pad to be processed for the high-speed train, and establish a processing benchmark for the steel backing based on the initial state information; Based on the aforementioned steel backing processing datum, the steel backing of the train brake pad is divided into multiple steel backing sections along its length, and stress control targets corresponding to the compressive stability under braking conditions are determined for each steel backing section; including: Based on the steel backing processing benchmark, the locations where changes in morphological deviation characteristics and initial stress state characteristics occur along the length direction of the steel backing of the EMU brake pad are identified, and the determined change locations are used as the dividing boundaries of the steel backing sections to divide the EMU brake pad steel backing into multiple continuous steel backing sections. For each steel backing section, the morphological deviation characteristics and initial stress state characteristics within that section are summarized to form a section stress characteristic description of the corresponding steel backing section. Based on the section stress characteristic description and combined with the requirements for pressure stability under braking conditions, the section stress corresponding to each steel backing section is determined to limit the control direction and control degree of residual stress within that steel backing section. Based on the description of the stress characteristics of the aforementioned sections and in conjunction with the requirements for underbody stability under braking conditions, the stress corresponding to each steel back section is determined as a control target to limit the direction and degree of residual stress control within that steel back section. This includes: for each steel back section, based on the corresponding section stress characteristic description, a comparative analysis is performed on the morphological deviation characteristics and initial stress state characteristics within that steel back section; if the comparative analysis results indicate that the morphological deviation characteristics within the steel back section require priority compensation and adjustment, a section stress control target guided by morphological compensation is determined; if the comparative analysis results indicate that the initial stress state within the steel back section requires priority redistribution adjustment, a section stress control target guided by residual stress redistribution is determined; if the comparative analysis results indicate that both the morphological deviation characteristics and the initial stress state within the steel back section require control, a composite section stress control target that simultaneously includes morphological compensation guidance and residual stress redistribution guidance is determined. Based on the stress control targets of each steel backing section, the steel backing of the EMU brake pads is subjected to overall leveling and section-oriented stress control treatment in sequence to form a residual stress distribution state that meets the stress control targets of the section. After the section directional stress control treatment is completed, the steel backing of the EMU brake pads is tested and judged, and the finished steel backing is output when the judgment meets the preset conditions.

2. The method for multi-segment directional stress finishing of the steel backing of high-speed train brake pads according to claim 1, characterized in that, Obtain the initial state information of the steel backing of the brake pad to be processed, and establish a processing reference for the steel backing based on the initial state information, including: The flatness information, thickness distribution information, and residual stress distribution characterization information of the steel backing of the train brake pads are collected as initial state information; Based on the flatness information, the overall shape deviation of the steel back is determined, and the thickness distribution information is used to correct the flatness information in the thickness direction to obtain corrected flatness data corresponding to the actual stress state of the steel back. Based on the residual stress distribution characterization information, the initial stress state at different locations on the steel back is determined, and the initial stress state is spatially correlated with the corrected flatness data. Based on the spatial correlation between the corrected flatness data and the initial stress state, a steel back machining datum is established to uniformly describe the geometric position relationship and stress distribution relationship of the steel back.

3. The method for multi-segment directional stress finishing of the steel backing of high-speed train brake pads according to claim 2, characterized in that, Based on the residual stress distribution characterization information, the initial stress state at different locations on the steel back is determined, and the initial stress state is spatially correlated with the corrected flatness data, including: Based on the residual stress distribution characterization information, the corresponding residual stress characterization values ​​are extracted at different positions of the steel back of the EMU brake pad along the steel back processing reference to form an initial stress state distribution that corresponds one-to-one with the spatial position of the steel back. The initial stress state distribution is mapped to the spatial position corresponding to the corrected flatness data according to the steel back processing reference, so as to construct a joint characterization result of the morphological deviation and initial stress state at each position of the steel back; Based on the joint characterization results, the spatial correspondence between the morphological deviations and the initial stress state at different locations on the steel back is identified, and spatial correlation results reflecting the coupling characteristics of the morphological deviations and stress states at each location are formed.

4. The method for multi-segment directional stress finishing of the steel backing of high-speed train brake pads according to claim 1, characterized in that, Based on the stress control targets corresponding to each steel backing section, the steel backing of the EMU brake pads is sequentially subjected to overall leveling and section-oriented stress control treatment to form a residual stress distribution state that satisfies the aforementioned section stress control targets, including: Based on the stress control target of each steel back section, the steel back sections that need to be subjected to directional stress control treatment and their corresponding control sequence are determined. According to the control sequence, sectional directional stress control treatment is performed on each steel back section to directionally control the residual stress state in the corresponding steel back section while maintaining the overall straightness of the steel back. After completing the sectional directional stress control treatment of all steel back sections, a residual stress distribution state matching the sectional stress control target of each steel back section is formed.

5. The method for multi-segment directional stress finishing of the steel backing of high-speed train brake pads according to claim 4, characterized in that, According to the aforementioned control sequence, sectional directional stress control treatment is performed on each steel back section, including: Based on the control sequence, the corresponding steel back section is selected as the current control section in sequence, and the section-oriented control load is applied within the length range of the current control section. When applying the segment-oriented control load to the current control segment, the position of the segment-oriented control load is limited to the current control segment, and the direction of application of the segment-oriented control load is controlled to correspond to the stress control target of the segment, until the control of the current steel back segment is completed.

6. The method for multi-segment directional stress finishing of the steel backing of high-speed train brake pads according to claim 1, characterized in that, After the section-specific stress adjustment treatment is completed, the steel backing of the EMU brake pads is inspected and judged, and when the judgment meets the preset conditions, the finished steel backing is output, including: The final inspection status information of the steel back of the EMU brake pad after the section directional stress control treatment is completed is collected. The final inspection status information includes at least the steel back flatness detection information and the steel back residual stress distribution detection information. Based on the final inspection status information, a consistency determination is performed on the steel back of the EMU brake pad and the corresponding section stress control target to obtain the determination result. If the determination result meets the preset conditions, the steel back of the train brake pad is marked as a finished steel back and output.

7. A multi-segment directional stress finishing system for the steel backing of high-speed train brake pads, characterized in that, The system is used to perform the multi-segment directional stress finishing method for the steel backing of high-speed train brake pads as described in any one of claims 1-6, and the system includes: The information acquisition unit is used to acquire the initial state information of the steel backing of the brake pad to be processed for the high-speed train, and to establish a steel backing processing reference based on the initial state information. The target generation unit is used to divide the steel back of the EMU brake pad into multiple steel back sections along the length direction based on the steel back processing reference, and to determine the section stress control target corresponding to the compressive stability under braking conditions for each steel back section. The control execution unit is used to perform overall leveling and section-oriented stress control treatment on the steel back of the EMU brake pads in sequence, based on the section stress control target corresponding to each steel back section, so as to form a residual stress distribution state that meets the section stress control target. The detection unit is used to detect and judge the steel backing of the EMU brake pads after the section directional stress adjustment treatment is completed, and outputs the finished steel backing when the judgment meets the preset conditions.

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