A method, system and device for detecting the out-of-roundness of a brake drum

Abstract

The application discloses a brake drum roundness detection method, system and detection device. First, basic detection parameters are collected and a three-dimensional polar coordinate system is constructed, then detection distance parameters of each detection point on the brake drum to be detected are obtained, and polar coordinate sets of each detection point are calculated according to the basic detection parameters and the detection distance parameters, then an actual outer circular surface model of the brake drum to be detected is generated according to the polar coordinate sets, finally, a standard outer circular surface model and the actual outer circular surface model are compared to determine whether the brake drum to be detected is qualified. The application can simultaneously perform multi-point synchronous detection on the brake drum to be detected in the height direction, is more efficient, simultaneously realizes 360-degree dead angle-free measurement on the brake drum to be detected, forms a plurality of sampling points arranged once in the axial direction, and thus the entire outer peripheral surface of the brake drum to be detected is covered, that is, the height of the detection device does not need to be adjusted in a detection period, and the detection efficiency is further improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of roundness detection equipment, in particular to a brake drum roundness detection method, system and detection device. BACKGROUND

[0002] The automobile brake drum is an important equipment for ensuring driving safety. In the prior art, the brake drum needs to be detected in roundness after production. In the prior art, the detection is generally performed manually by using a micrometer and the like. However, the contact surface between the detection equipment and the brake drum is limited, and in order to ensure accuracy, detection needs to be performed at different heights. The detection efficiency is low, and the detection data is fragmented, so that the roundness of the brake drum cannot be effectively evaluated, and the detection precision is low. SUMMARY

[0003] The main purpose of the application is to provide a brake drum roundness detection method, system and detection device, and to solve the problem of low detection precision in the prior art.

[0004] The application achieves the above purpose by the following technical solutions:

[0005] A brake drum roundness detection method comprises the following steps:

[0006] Collecting basic detection parameters and constructing a three-dimensional polar coordinate system;

[0007] Obtaining detection distance parameters of each detection point on the brake drum to be detected;

[0008] Calculating a polar coordinate set of each detection point according to the basic detection parameters and the detection distance parameters;

[0009] Generating an actual outer circular surface model of the brake drum to be detected by fitting in the three-dimensional polar coordinate system according to the polar coordinate set;

[0010] Calling a standard outer circular surface model of the brake drum to be detected, comparing the standard outer circular surface model with the actual outer circular surface model, and determining whether the brake drum to be detected is qualified.

[0011] Optionally, the basic detection parameters include a sampling period T, a rotation angular velocity omega, an initial distance H and a polar angle set {beta1, beta2,..., beta n}, and the expression of the polar angle is wherein n represents the number of detection modules, and h n represents the installation height of the detection module.

[0012] Optionally, calculating a polar coordinate set of each detection point according to the basic detection parameters and the detection distance parameters comprises the following steps:

[0013] obtaining a polar angle set {β1, β2,..., β n} according to the sampling period T and the initial distance;

[0014] generating an azimuth angle set {θ 11 , θ 12 ,..., θ 1M , θ 21 , θ 22 ,..., θ 2M ,..., θ n1 , θ n2 ,..., θ nM} according to the sampling period T and the rotation angular velocity ω; wherein M represents the total sampling number, and n represents the number of detection modules;

[0015] generating a radial distance set {r 11 , r 12 ,..., r 1M , r 21 , r 22 ,..., r 2M ,..., r n1 , r n2 ,..., r nM} according to the detection distance parameter and the initial distance;

[0016] integrating the polar angle set, the azimuth angle set and the radial distance set to generate a polar coordinate set {(r 11 , θ 11 , β1), (r 12 , θ 12 , β1),..., (r 1M , θ 1M , β1), (r 21 , θ 21 , β2), (r 22 , θ 22 , β2),..., (r 2M , θ 2M , β2),..., (r n1 , θ n1 , β n ), (r n2 , θ n2 , β n ),..., (r nM , θ nM , β n}.

[0017] Optionally, the expression of the azimuth angle θ nM is θ nm = (m-1)Tω; wherein m represents the sampling number, and m is a positive integer not greater than M; the radial distance rnM The expression is r nM =Hh nM ; The total number of sampling times M satisfies M=2π / ωT,h nM Indicates the detection distance parameter.

[0018] Optionally, generating an actual outer circular surface model of the brake drum to be inspected by fitting the polar coordinate set in the three-dimensional polar coordinate system comprises the following steps:

[0019] Get polar coordinates set;

[0020] calibrating a plurality of fitting points in the three-dimensional polar coordinate system according to the polar coordinate set;

[0021] Divide each fitting point into several radial fitting point sets according to the polar angle, and each fitting point in the same radial fitting point set has the same polar angle;

[0022] Generating a plurality of radial fitting curves according to the radial fitting point sets;

[0023] Divide each fitting point into several axial fitting point sets according to the azimuth angle, and each fitting point in the same axial fitting point set has the same azimuth angle;

[0024] generating a plurality of axial fitting curves according to the axial fitting point sets;

[0025] The radial fitting curves and the axial fitting curves are fitted and connected in series to generate an actual outer circular surface model.

[0026] Optionally, calling a standard outer cylindrical surface model of the brake drum to be tested, comparing the standard outer cylindrical surface model with the actual outer cylindrical surface model, and determining whether the brake drum to be tested is qualified includes the following steps:

[0027] Automatically retrieve the standard outer circular surface model according to the specification parameters to be tested;

[0028] Generate a standard outer circular surface comparison module according to the quality control parameters and the standard outer circular surface model;

[0029] Importing the standard outer circular surface comparison module and the actual outer circular surface model into the three-dimensional polar coordinate system;

[0030] If the standard outer circular surface comparison module completely wraps the actual outer circular surface model, the outer circularity of the brake drum to be tested is qualified; otherwise, it is judged to be unqualified.

[0031] Optionally, generating a standard outer circular surface comparison module according to the quality control parameters and the standard outer circular surface model includes the following steps:

[0032] Obtaining a quality control parameter, the quality control parameter including an upper deviation and a lower deviation of an outer diameter;

[0033] Generating an upper deviation standard model according to the upper deviation and the standard model;

[0034] Generating a lower deviation standard model according to the lower deviation and the standard model;

[0035] Integrating the upper deviation standard model and the lower deviation standard model into a standard outer diameter surface comparison module.

[0036] Correspondingly, the application also discloses a detection system based on the outer diameter detection method, which comprises

[0037] A parameter setting module is configured to collect basic detection parameters and construct a three-dimensional polar coordinate system;

[0038] A parameter obtaining module is configured to obtain detection distance parameters of each detection point on the brake drum to be detected;

[0039] A data calculation module is configured to calculate a polar coordinate set of each detection point according to the basic detection parameters and the detection distance parameters;

[0040] A model generating module is configured to generate an actual outer diameter surface model of the brake drum to be detected by fitting in the three-dimensional polar coordinate system according to the polar coordinate set;

[0041] A comparison and determination module is configured to call a standard outer diameter surface model of the brake drum to be detected, compare the standard outer diameter surface model with the actual outer diameter surface model, and determine whether the brake drum to be detected is qualified.

[0042] A brake drum outer diameter detection device comprises a rack;

[0043] A rotating detection table is rotationally arranged on the rack, and a fixing seat adapted to the brake drum to be detected is arranged on the rotating table;

[0044] A driving module is arranged on the rack, and the rotating table is connected with the driving module in power;

[0045] A support is arranged on the rack, and a plurality of detection modules are sequentially arranged on the support in the height direction, and each detection module is configured to measure point distribution parameters on the surface of the brake drum to be detected;

[0046] A control module is electrically connected with the driving module and each detection module, and the control module is configured to determine whether the outer diameter of the brake drum to be processed meets the requirements according to the point distribution parameters collected by each detection module.

[0047] Optionally, the detection module comprises sliding seats and infrared distance sensors connected with each other, and each sliding seat is arranged along the height direction of the support in sequence; the support is provided with a plurality of limiting plates, and each sliding seat is provided with a plug-in slot matched with the limiting plate.

[0048] Compared with the prior art, the present application has the following beneficial effects:

[0049] The present application first collects basic detection parameters and constructs a three-dimensional polar coordinate system, then obtains detection distance parameters of each detection point on the brake drum to be detected, and calculates a polar coordinate set of each detection point according to the basic detection parameters and the detection distance parameters, and then generates an actual cylindrical surface model of the brake drum to be detected according to the polar coordinate set, and finally combines the standard cylindrical surface model of the brake drum to be detected, compares the standard cylindrical surface model and the actual cylindrical surface model, and determines whether the brake drum to be detected is qualified.

[0050] Correspondingly, the present application also discloses a detection device based on the above detection method, which comprises a rack and a rotating workbench rotatingly arranged on the rack, the rotating workbench is provided with a fixing seat matched with the brake drum to be detected, and the rack is also provided with a support along the height direction, and a plurality of detection modules are sequentially arranged on the support along the height direction, and each detection module is used for measuring point distribution parameters on the surface of the brake drum to be detected.

[0051] Compared with the prior art, the present application can simultaneously perform multi-point synchronous detection on the brake drum to be detected in the height direction, which can effectively improve the detection efficiency on the one hand, and can realize 360° dead angle-free measurement of the brake drum to be detected by rotating the brake drum, and form a plurality of sampling points arranged once in the axial direction, so that the entire outer periphery of the brake drum to be detected is covered, that is, the height of the detection device does not need to be adjusted in a detection cycle, and the detection efficiency is further improved.

[0052] Secondly, compared with the traditional runout detection method, the present application can densely sample on the entire outer periphery of the brake drum to be detected, and finally generate an actual cylindrical surface model of the brake drum to be detected through fitting, which can effectively avoid the detection blind area, thereby improving the detection precision. BRIEF DESCRIPTION OF DRAWINGS

[0053] Figure 1 A structure schematic view of a brake drum roundness detection device provided by the present application embodiment is provided;

[0054] Figure 2 A connection structure diagram of the support and the detection module is provided;

[0055] Figure 3 A structure schematic view of a brake drum roundness detection system provided by the present application embodiment is provided;

[0056] Figure 4 A flow chart of a brake drum roundness detection method provided for the embodiment of the present application is shown in the figure;

[0057] Figure 5 A calculation principle diagram for the polar angle is shown in the figure;

[0058] Figure 6 A fitting principle diagram for the actual roundness curved surface model is shown in the figure;

[0059] Figure 7 A comparison principle diagram along the axis direction of the hub to be detected is shown in the figure;

[0060] The figure shows the reference signs: 1-frame, 2-rotary table, 3-fixed seat, 4-driving module, 5-bracket, 6-detection module, 601-sliding seat, 602-infrared distance sensor, 603-limiting plate, 604-limiting groove.

[0061] The object implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0062] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present application.

[0063] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications also change accordingly.

[0064] In the present application, unless otherwise explicitly specified and limited, the terms "connection", "fixation" and the like should be understood in a broad sense, for example, "fixation" can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be direct connection, or indirect connection through an intermediate medium; can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0065] In addition, if the description of "first", "second" and the like is involved in the embodiments of the present application, the description of "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can be explicitly or implicitly included at least one of the features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes. For example, "A and / or B" includes A scheme, or B scheme, or A and B scheme. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of the ordinary skilled in the art. When the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope required by the present application.

[0066] Embodiment 1

[0067] Referring to Figure 1 and Figure 2 The present embodiment discloses a brake drum roundness detection device, which comprises a rack 1, a rotary detection table is rotatably connected to the rack 1 through a thrust ball bearing, a fixed seat 3 is arranged on the top of the rotary detection table, and the fixed seat 3 is connected with a brake drum to be detected through a plurality of connecting bolts or special clamps.

[0068] A driving module 4 is further arranged on the rack 1, the driving module 4 comprises a driving motor, preferably a servo motor, and the output shaft of the driving motor is connected with the rotary detection table in power through a shaft coupling.

[0069] Meanwhile, a support 5 is further arranged on the rack 1, the support 5 is in an L-shaped structure as a whole, the horizontal end of the support 5 is connected with the rack 1, and the vertical end of the support 5 is in a free state.

[0070] A plurality of detection modules 6 are further arranged on the support 5, a plurality of limiting plates 603 are sequentially arranged on the vertical end of the support 5 along the height direction of the support 5, the detection module 6 comprises a sliding seat 601, an infrared distance sensor 602 is installed on the sliding seat 601, a plug-in slot is further arranged on the sliding seat 601, the limiting plate 603 is inserted into the plug-in slot, and a connecting bolt is further arranged between the sliding seat 601 and the support 5.

[0071] Through the cooperation of the limiting plate 603 and the plug-in slot, not only the stability of the installation of the detection module 6 can be improved, but also the installation position of the detection module 6 can be accurately limited, so as to accurately control the height of each infrared distance sensor 602, facilitate the calculation of the polar angle of each infrared distance sensor 602, and improve the accuracy of data calculation.

[0072] Further, a stepped hole is arranged on the slide 601 and matched with the infrared distance sensor 602, the infrared distance sensor 602 is inserted into the stepped hole, and the end face of the infrared distance sensor 602 abuts against the stepped face of the stepped hole.

[0073] The installation position of the infrared distance sensor 602 can be accurately limited by the stepped hole, so that the accuracy of the installation position is ensured, the polar angle of each infrared distance sensor 602 is calculated, and the accuracy of data calculation is improved.

[0074] Further, the detection device further comprises a control module, the control module is electrically connected with the driving module 4 and each detection module 6 respectively; the control module judges whether the outer roundness of the brake drum to be processed meets the requirements according to the point position distribution parameters collected by each detection module 6.

[0075] With reference to Figure 3 , the embodiment further discloses a brake drum outer roundness detection system, which comprises a parameter setting module, a parameter acquisition module and a data calculation module, wherein the input end of the data calculation module is connected with the parameter setting module and the parameter acquisition module to acquire corresponding parameters, the output end of the data calculation module is connected with a model generation module, and the output end of the model generation module is connected with a comparison and judgment module.

[0076] Embodiment 2

[0077] With reference to Figure 4 , the embodiment discloses a brake drum outer roundness detection method, which comprises the following steps.

[0078] S1, collecting basic detection parameters and constructing a three-dimensional polar coordinate system;

[0079] The basic detection parameters comprise a sampling period T, a rotation angular velocity ω, an initial distance H and a polar angle set {β1, β2,..., βn} of the detection module, and the expression of the polar angle is n wherein n represents the number of the detection module, h n represents the installation height of the detection module;

[0080] It should be noted that the sampling period T and the rotation angular velocity ω are set by the staff according to the detection requirements, that is, the more the detection points are, the shorter the sampling period is, and the smaller the rotation angular velocity is;

[0081] Meanwhile, the initial distance H is determined by adjusting the position of the support, and the initial distance refers to the distance between the measurement starting point of the detection module and the rotation shaft of the rotation detection table, and the above parameters are determined after the detection modules are installed.

[0082] The h n ​Indicates the installation height of the detection module, that is, the distance between the detection point of the infrared distance sensor and the frame plane; it should be noted that the top surface of the frame is flush with the top surface of the rotary detection table to ensure the consistency of various parameters;

[0083] After each infrared distance sensor is installed in place, its installation height has been determined, i.e. h1, h2, ..., h n At the same time, due to the initial distance H, the polar angle set {β1, β2, ..., β n}, for specific calculation principles, refer to Figure 5 ;

[0084] At the same time, a three-dimensional polar coordinate system is constructed, wherein the origin of the three-dimensional polar coordinate system is the intersection of the rotation axis of the rotation detection platform and the top surface of the fixed seat;

[0085] During use, the brake drum to be tested is mounted on the fixing seat and is coaxial with the fixing seat, that is, coaxial with the rotating testing platform.

[0086] At the same time, corresponding coordinate axes are constructed respectively using the line connecting the origin and the bracket and the vertical upward direction;

[0087] S2. Obtaining detection distance parameters of each detection point on the brake drum to be detected;

[0088] Control the infrared distance sensor to perform sampling according to the sampling period T, and control the rotation of the rotary table according to the rotation angular velocity ω;

[0089] After completing a rotation cycle, the infrared distance sensor will obtain several detection distance parameters h 11 , h 12 ,...,h 1M , h 21 , h 22 ,...,h 2M , h n1 , h n2 ,...,h nM ;

[0090] S3. Calculate the polar coordinate set of each detection point according to the basic detection parameters and the detection distance parameters;

[0091] S31, obtain the polar angle set {β1, β2, ..., β n};

[0092] Retrieve the polar angle set {β1, β2, ..., β n};

[0093] S32, generating an azimuth angle set {θ11 ,θ 12 ,...,θ 1M ,θ 21 ,θ 22 ,...,θ 2M ,...,θ n1 ,θ n2 ,...,θ nM}; where M represents the total number of sampling times, and n represents the number of the detection module;

[0094] According to the sampling period T and the rotation angular velocity ω, the rotation angle of the brake drum to be tested within a sampling period can be calculated to be Tω. At the same time, considering that the rotation angle of the first sampling is 0, the subsequent sampling is increased by an integer multiple of Tω, so the azimuth angle θ nM The expression for θ is nm =(m-1)Tω; where m represents the number of sampling times, and m is a positive integer not greater than M; M represents the total number of sampling times, which satisfies M=2π / ωT;

[0095] Secondly, it should be pointed out that at the same sampling time point, the azimuth angles of all infrared distance sensors are equal, that is, θ 11 =θ 21 =...=θ n1 ;

[0096] S33, generating a radial distance set {r 11 , r 12 ,...,r 1M , r 21 , r 22 ,...,r 2M ,...,r n1 , r n2 ,...,r nM};

[0097] Combined with the attached figure, it can be seen that the initial distance H is the sum of the outer diameter of the brake drum to be tested and the detection distance parameter, and the outer diameter of the brake drum to be tested is the radial distance, so the radial distance r nM The expression is r nM =Hh nM ;

[0098] Combined with the detection distance parameter h 11 , h 12 ,...,h 1M , h 21 , h 22 ,...,h 2M , h n1 , h n2 ,...,h nMThe radial distance set {r 11 , r 12 ,..., r 1M , r 21 , r 22 ,..., r 2M ,..., r n1 , r n2 ,..., r nM} can be calculated according to the initial distance H.

[0099] S34, integrating the polar angle set, the azimuth angle set and the radial distance set to generate a polar coordinate set {(r 11 , θ 11 , β1), (r 12 , θ 12 , β1),..., (r 1M , θ 1M , β1), (r 21 , θ 21 , β2), (r 22 , θ 22 , β2),..., (r 2M , θ 2M , β2),..., (r n1 , θ n1 , β n ), (r n2 , θ n2 , β n ),..., (r nM , θ nM , β n}.

[0100] All parameters obtained in steps S31 to S33 are called, and all parameters are classified and collected according to the detection point position, that is, the polar angle, the azimuth angle and the radial distance of the same detection point position are collected, such as (r 11 , θ 11 , β1) represents the three-dimensional polar coordinates of the detection point position determined by the infrared distance sensor numbered 1 at the first sampling time; specifically, the expression of the three-dimensional polar coordinates is (H-h 11 , 0, arccot(h n / H)).

[0101] It should be noted that at least two groups of detection modules can also be arranged on the rack, and each group of detection modules includes a plurality of infrared distance sensors, and the infrared distance sensors in each group are arranged in a staggered manner in the height direction.

[0102] That is, due to the volume limitation of the infrared distance sensor itself, the number of infrared distance sensors that can be arranged in the height direction is limited, thereby resulting in a limited total number of detection points. Through the above arrangement, the density of the detection points can be effectively improved, thereby improving the final detection quality and avoiding missed detection.

[0103] S4, fitting an actual outer circular surface model of the brake drum to be detected in the three-dimensional polar coordinate system according to the polar coordinate set;

[0104] S41, acquiring a polar coordinate set;

[0105] S42, calibrating a plurality of fitting points in the three-dimensional polar coordinate system according to the polar coordinate set;

[0106] acquiring a polar coordinate set {(r 11 , θ 11 , β1), (r 12 , θ 12 , β1),..., (r 1M , θ 1M , β1), (r 21 , θ 21 , β2), (r 22 , θ 22 , β2),..., (r 2M , θ 2M , β2),..., (r n1 , θ n1 , β n ), (r n2 , θ n2 , β n ),..., (r nM , θ nM , β n )};

[0107] Then, a plurality of fitting points are calibrated in the three-dimensional polar coordinate system according to the polar coordinate set.

[0108] S43, dividing each fitting point into a plurality of radial fitting point sets according to the polar angle, each fitting point in the same radial fitting point set having the same polar angle;

[0109] According to the polar angle, each fitting point is divided into a plurality of radial fitting point sets, each fitting point in the same radial fitting point set having the same polar angle, that is, each fitting point is divided into a plurality of groups in the axial direction through the polar angle, each group corresponding to a radial fitting point set, and each fitting point in the same group is enclosed in a circular shape and uniformly distributed on the outer surface of the brake drum to be detected.

[0110] S44, fitting a plurality of radial fitting curves according to each radial fitting point set;

[0111] According to the division fitting in step S43, a plurality of radial fitting curves are generated, each of which is a closed torus curve, and each of the radial fitting curves is uniformly arranged in the axial direction;

[0112] S45, according to the azimuth angle, each fitting point is divided into a plurality of axial fitting point sets, and each fitting point in the same axial fitting point set has the same azimuth angle;

[0113] According to the azimuth angle, each fitting point is divided into a plurality of axial fitting point sets, and each fitting point in the same axial fitting point set has the same azimuth angle, which can be divided into several groups in the direction around the rotation axis, each fitting point corresponds to an axial fitting point set, and each fitting point in the same axial fitting point set is arranged in the axial direction. The connecting line is a vertically arranged curve;

[0114] Through the above division, a plurality of curves can be formed in the direction around the rotation axis;

[0115] S46, according to each of the axial fitting point sets, a plurality of axial fitting curves are fitted;

[0116] S47, fitting each of the radial fitting curves and each of the axial fitting curves to generate an actual outer circular surface model.

[0117] Through steps S44 to S46, a longitudinal and transverse intersecting curve network can be formed in the axial and direction around the rotation axis. The above network constitutes the outer surface of the brake drum to be detected. The actual outer circular surface model of the brake drum to be detected is generated by computer fitting based on the above curve network. For details, see Figure 6 ;

[0118] S5, calling a standard outer circular surface model of the brake drum to be detected, comparing the standard outer circular surface model with the actual outer circular surface model, and determining whether the brake drum to be detected is qualified.

[0119] S51, calling a standard outer circular surface model according to the specification parameters of the automatic detection;

[0120] S52, generating a standard outer circular surface comparison module according to the quality control parameters and the standard outer circular surface model;

[0121] S521, obtaining quality control parameters, the quality control parameters including an upper deviation and a lower deviation of the outer diameter;

[0122] Obtain the outer diameter tolerance of the brake drum, such as the upper deviation of +0.5mm and the lower deviation of -0.5mm;

[0123] S522, generating an upper deviation standard model according to the upper deviation and the standard model;

[0124] Along the radial direction of the standard outer circular surface model, the upper deviation value is extended outwardly in the direction away from the axis to generate an upper deviation standard model;

[0125] S523, generating a lower deviation standard model according to the lower deviation and the standard model;

[0126] Along the radial direction of the standard outer circular surface model, the lower deviation value is retracted in the direction pointing to the axis to generate an upper deviation standard model;

[0127] S524, integrating the upper deviation standard model and the lower deviation standard model into a standard outer circular surface comparison module.

[0128] The axis of the upper deviation standard model and the lower deviation standard model is overlapped to obtain the standard outer circular surface comparison module.

[0129] S53, importing the standard outer circular surface comparison module and the actual outer circular surface model into the three-dimensional polar coordinate system;

[0130] S54, if the standard outer circular surface comparison module completely wraps the actual outer circular surface model, the outer roundness of the brake drum to be detected is qualified; otherwise, it is determined to be unqualified.

[0131] Reference Figure 7 If the standard outer circular surface comparison module completely wraps the actual outer circular surface model, the outer roundness of the brake drum to be detected is qualified; otherwise, it is determined to be unqualified.

[0132] Compared with the prior art, the application can simultaneously detect the brake drum to be detected in the height direction, which can effectively improve the detection efficiency. On the other hand, by rotating the brake drum, 360° non-blind angle measurement of the brake drum to be detected can be realized, and a plurality of sampling points arranged once in the axial direction are formed, so that the entire outer periphery of the brake drum to be detected is covered, that is, in a detection cycle, the height of the detection device no longer needs to be adjusted, and the detection efficiency is further improved.

[0133] Secondly, compared with the traditional runout detection method, the application can densely sample the entire outer periphery of the brake drum to be detected, and finally generate the actual outer circular surface model of the brake drum to be detected by fitting, which can effectively avoid the detection blind area, thereby improving the detection accuracy.

[0134] The above is only a preferred embodiment of the application, and does not limit the patent scope of the application. Any equivalent structure or equivalent process transformation using the content of the specification and drawings, or direct or indirect application in other related technical fields, is also included in the patent protection scope of the application.

Claims

1. A method for detecting the outer roundness of a brake drum, characterized in that: The following steps are involved: Collect basic detection parameters and construct a three-dimensional polar coordinate system; Obtain the detection distance parameters of each detection point on the brake drum to be detected; Calculate the polar coordinate set of each detection point according to the basic detection parameters and the detection distance parameters; Get polar coordinates set; calibrating a plurality of fitting points in the three-dimensional polar coordinate system according to the polar coordinate set; Divide each fitting point into several radial fitting point sets according to the polar angle, and each fitting point in the same radial fitting point set has the same polar angle; Generating a plurality of radial fitting curves according to the radial fitting point sets; Divide each fitting point into several axial fitting point sets according to the azimuth angle, and each fitting point in the same axial fitting point set has the same azimuth angle; generating a plurality of axial fitting curves according to the axial fitting point sets; Fitting and connecting the radial fitting curves and the axial fitting curves in series to generate an actual outer circular surface model; The standard outer cylindrical surface model of the brake drum to be tested is called, and the standard outer cylindrical surface model is compared with the actual outer cylindrical surface model to determine whether the brake drum to be tested is qualified.

2. A brake drum outer roundness detection method according to claim 1, characterized in that: The basic detection parameters include sampling period T, rotation angular velocity ω, initial distance H and polar angle set {β1, β2, ..., β n }, the expression of the polar angle is , where n represents the number of the detection module, Indicates the installation height of the detection module.

3. A brake drum outer roundness detection method according to claim 2, characterized in that: The method of calculating the polar coordinate set of each detection point according to the basic detection parameters and the detection distance parameters includes the following steps: Get the polar angle set {β1, β2, ..., β n }; Generate an azimuth angle set {θ 11 ,θ 12 ,...,θ 1M ,θ 21 ,θ 22 ,...,θ 2M ,...,θ n1 ,θ n2 ,...,θ nM }; where M represents the total number of sampling times, and n represents the number of the detection module; Generate a radial distance set {r 11 , r 12 ,...,r 1M , r 21 , r 22 ,...,r 2M ,...,r n1 , r n2 ,...,r nM }; The polar angle set, the azimuth angle set and the radial distance set are integrated to generate a polar coordinate set {(r 11 ,θ 11 ,β1)(r 12 ,θ 12 ,β1),...,(r 1M ,θ 1M ,β1)(r 21 ,θ 21 ,β2)(r 22 ,θ 22 ,β2),...,(r 2M ,θ 2M ,β2),...,(r n1 ,θ n1 , β n ), (r n2 ,θ n2 , β n ),...,(r nM ,θ nM , β n )}.

4. A brake drum outer roundness detection method according to claim 3, characterized in that: The azimuth angle θ nM The expression for θ is nm = (m-1)Tω; Where m represents the number of sampling times, and m is a positive integer not greater than M; the radial distance r nM The expression is r nM =Hh nM ; The total number of sampling times M satisfies M=2π / ωT,h nM Indicates the detection distance parameter.

5. The method for detecting outer roundness of a brake drum according to claim 1, characterized in that: The method of calling a standard outer cylindrical surface model of the brake drum to be tested, comparing the standard outer cylindrical surface model with the actual outer cylindrical surface model, and determining whether the brake drum to be tested is qualified comprises the following steps: Automatically retrieve the standard outer circular surface model according to the specification parameters to be tested; Generate a standard outer circular surface comparison module according to the quality control parameters and the standard outer circular surface model; Importing the standard outer circular surface comparison module and the actual outer circular surface model into the three-dimensional polar coordinate system; If the standard outer circular surface comparison module completely wraps the actual outer circular surface model, the outer circularity of the brake drum to be tested is qualified; otherwise, it is judged to be unqualified.

6. A brake drum outer roundness detection method according to claim 5, characterized in that: The method of generating a standard outer circular surface comparison module according to the quality control parameters and the standard outer circular surface model comprises the following steps: Acquiring quality control parameters, wherein the quality control parameters include an upper deviation and a lower deviation of an outer roundness; Generate an upper deviation standard model according to the upper deviation and the standard outer circular surface model; Generate a lower deviation standard model according to the lower deviation and the standard outer circular surface model; The upper deviation standard model and the lower deviation standard model are integrated into a standard outer circular surface comparison module.

7. A detection system based on the brake drum outer roundness detection method according to any one of claims 1 to 6, characterized in that: include: Parameter setting module, used to collect basic detection parameters and construct a three-dimensional polar coordinate system; A parameter acquisition module is used to obtain the detection distance parameters of each detection point on the brake drum to be detected; A data calculation module, configured to calculate a polar coordinate set of each detection point based on the basic detection parameters and the detection distance parameters; A model generation module, configured to generate an actual outer circular surface model of the brake drum to be tested by fitting in the three-dimensional polar coordinate system according to the polar coordinate set; The comparison and determination module is used to call the standard outer cylindrical surface model of the brake drum to be tested, compare the standard outer cylindrical surface model with the actual outer cylindrical surface model, and determine whether the brake drum to be tested is qualified.

8. A detection device based on the brake drum outer roundness detection method according to any one of claims 1 to 6, comprising a frame (1); A rotary testing platform, the rotary testing platform being rotatably mounted on the frame (1), and the rotary testing platform (2) being further provided with a fixing seat (3) adapted to the brake drum to be tested; A driving module (4), the driving module (4) being arranged on the frame (1), and the rotating detection platform (2) being dynamically connected to the driving module (4); A bracket (5), the bracket (5) is arranged on the frame (1), and a plurality of detection modules (6) are sequentially arranged on the bracket (5) along the height direction, each detection module (6) is used to measure the point distribution parameters of the brake drum surface to be detected; A control module is electrically connected to the drive module (4) and each of the detection modules (6) respectively; the control module determines whether the outer roundness of the brake drum to be processed meets the requirements based on the point distribution parameters collected by each of the detection modules (6).

9. The detection device according to claim 8, characterized in that The detection module (6) comprises a slide (601) and an infrared distance sensor (602) connected to each other, and each of the slides (601) is arranged in sequence along the height direction of the bracket (5); a plurality of limit plates (603) are provided on the bracket (5), and each of the slides (601) is provided with a plug-in slot adapted to the limit plates (603).

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