A tractor complete machine assembly quality evaluation method and detection device

Abstract

The invention discloses a method and a detection device for evaluating the assembly quality of a tractor as a whole. Aiming at the demand for rapid detection of assembly quality during the final inspection of the tractor, the invention takes the vibration characteristics of the whole tractor as the starting point, adopts a method of comparing the vibration characteristics of the whole tractor with a qualified sample benchmark, and simultaneously quickly realizes the qualification detection, and provides the positioning of potential defects and fault types based on the vibration characteristics. The invention is suitable for rapid detection and evaluation of the quality of the whole machine and its assembly during the final inspection of the tractor enterprise before it is assembled off the line and shipped out of the factory, so as to make up for the shortcomings of the lack of, incomplete and overly subjective detection means for the quality of the whole machine assembly in the final inspection link, and the difficulty in pre-discovery of potential faults. At the same time, the detection device adopts a magnetic MEMS multi-axis acceleration sensor, which has a light structure, low cost, and simple test operation, and meets the requirements of the rapid detection rhythm of the detection line.

Description

Technical Field

[0001] The invention relates to the technical field of rapid detection of tractor complete machine assembly quality, and in particular to a tractor complete machine assembly quality evaluation method and detection device. Background Art

[0002] The final inspection before the tractor is assembled is the last important inspection link to ensure the long-term reliable operation of the tractor during the after-sales use process. Tractor assembly plants at home and abroad will design and implement a variety of functional and performance-based inspection contents for the final inspection before leaving the factory, and this inspection project has far exceeded the factory inspection index requirements stipulated in the relevant national standards. However, compared with the online inspection of vehicles before leaving the factory, due to the differences in the structural characteristics of tractors and the production and quality requirements, the rhythm, effectiveness and real-time performance of the online inspection implemented on the tractor assembly line are not perfect. As far as the assembly quality of the tractor is concerned, it includes the connection between the engine and the gearbox, the installation of the gear set inside the gearbox, the connection and installation of the front and rear axles, the installation of the cockpit and the hood. These assembly and installation will cause resonance at the least, and affect the power output at the worst, and even affect the normal operation of the tractor and shorten its service life.

[0003] At present, the main methods for evaluating the assembly quality of tractors are: 1) using performance indicators to evaluate the power output of the engine, gearbox, and rear axle, and indirectly judging the assembly quality of the main components by testing the power output indicators, smoothness, and other performance of the engine, gearbox, and rear axle; 2) using subjective human observation methods to evaluate the assembly quality by checking the loose bolts, abnormal vibration, noise, and leakage at the joints of accessories such as the car, hood, exhaust pipe, and fuel tank. These conventional testing methods have the disadvantages of excessive subjectivity of testers, long implementation cycles, and unclear testing targets.

[0004] As an online detection technology, mechanical fault vibration diagnosis technology has been widely used in various mechanical fault diagnosis with the development of sensor and computer technology. As a power machine, the tractor generates mechanical vibration during operation and transmits it through the rigid body. In addition to the excitation vibration caused by the operation of the engine and gearbox itself, the whole machine vibration contains a lot of transmission information due to the assembly connection of the parts. At present, online vibration detection methods are used in the fields of gearboxes, fans, cable cars, generator sets, etc. From the characteristics of vibration intensity, vibration spectrum frequency distribution, etc., it can be implemented to obtain the operating status of the mechanical mechanism and even discover potential fault hazards. The defects of the parts themselves, assembly quality, design defects, abnormal working conditions, etc. in the mechanical equipment will be reflected in the vibration of the whole machine.

[0005] The present invention aims at the characteristics of the rigid structure of the tractor body, and refers to the mechanical vibration intensity index to establish an evaluation index for the vibration characteristics of the tractor as a whole, so as to constrain the quality standard of the tractor assembly and achieve the goal of assembly consistency; and uses the comparison of the frequency distribution characteristics of the vibration spectrum to quickly evaluate and judge the potential defects and fault types of the tractor assembly. The present invention aims to provide a fast and simple assembly quality evaluation method and detection device for tractor manufacturers, so as to improve the detection level of tractor manufacturers as a whole, improve the factory standards, and improve the quality level of enterprise products. Summary of the invention

[0006] Aiming at the demand for rapid detection of assembly quality during the final inspection of tractors, the present invention takes the vibration characteristics of the tractor as the starting point and proposes a tractor whole machine assembly quality evaluation method and detection device, which is suitable for rapid detection and evaluation of the whole machine and assembly quality during the final inspection of tractor enterprises before they are assembled off the line and shipped out of the factory, so as to make up for the shortcomings of the whole machine assembly quality detection means in the final inspection link, such as lack, incompleteness, excessive subjectivity, and difficulty in pre-detection of potential faults.

[0007] The technical solution adopted by the present invention to solve the technical problem is as follows:

[0008] The present invention first provides a method for evaluating the assembly quality of a complete tractor, which is implemented by taking the following steps based on the vibration characteristics of the complete tractor:

[0009] S1, using a vibration sensor to obtain a vibration signal under specific excitation conditions at a specific position of the tractor;

[0010] S2. The vibration characteristics of the tractor are converted into vibration severity by the data receiving and analyzing unit, and the vibration severity value range of the tractor benchmark database is compared to evaluate the vibration intensity of the tractor as a whole, give the over-limit range, and give the working quality status index of the tractor as a whole;

[0011] S3. Another channel of vibration signal is subjected to fast Fourier transform (FFT) to obtain the vibration spectrum and frequency distribution characteristics of the tractor. The potential mechanical fault type can be quickly located by comparing it with the tractor benchmark database and the vibration spectrum diagram of typical mechanical faults.

[0012] Furthermore, the tractor benchmark database is established by statistics of actual test data of a large number of tractor models to be tested, and the specific method is as follows: according to the type and specific model of the tractor to be tested, the position on the rigid body of the tractor that is convenient for pasting the vibration sensor is pre-determined, and the vibration characteristics under different excitation conditions are collected, and the vibration characteristic correlation function between the positions is established, which is a characteristic relationship for the quality of the whole machine assembly; based on the statistics of a large number of vibration characteristic data of tractors of the same model, a vibration intensity evaluation index range is established, and a frequency distribution comparison database of the spectrum of characteristic parts is established, which is used as a comparison benchmark for the vibration intensity and spectrum analysis of the tractor to be tested; using a typical mechanical fault vibration spectrum characteristic comparison table, the mechanical defect or fault type of the tractor whole machine assembly is obtained by comparing the tractor vibration spectrum frequency distribution characteristics;

[0013] Furthermore, the excitation condition is at the engine idle speed;

[0014] Furthermore, the vibration sensor is mounted on the rigid body of the tractor by magnetic attraction;

[0015] Furthermore, the vibration sensor adopts a small MEMS three-axis sensor;

[0016] Furthermore, the data receiving and analyzing unit adopts MCU;

[0017] Another object of the present invention is to provide a whole machine assembly quality detection device, comprising: a vibration sensor, a data receiving and analyzing unit and a data display unit;

[0018] The vibration sensor adopts a small MEMS three-axis sensor, which is used to collect vibration parameters of the whole machine within the range of 10 to 2000 Hz, and is connected to the data receiving and analyzing unit in a wireless or wired manner;

[0019] The data receiving and analyzing unit adopts MCU, which is used to issue collection instructions to the sensor and obtain the vibration information of the whole machine, and calculate the vibration intensity of the whole machine according to the received vibration parameters, and obtain the frequency distribution and characteristics of the vibration spectrum of the whole machine through FFT analysis, and finally compare it with the benchmark database and the comparison table of the frequency spectrum of typical mechanical faults to provide the test results;

[0020] The data display unit is connected to the data receiving and analyzing unit and is used to display operation instructions, tractor status, real-time test data and test results;

[0021] Furthermore, the vibration sensor is provided with a magnetic suction head;

[0022] Further, the whole machine is a power machinery whole machine with rigid connection;

[0023] Further, the whole machine is a tractor;

[0024] In addition, the present invention also provides a whole machine assembly quality detection device for use in a tractor whole machine assembly quality evaluation method test steps, including:

[0025] 1) The tractor to be tested enters the test station, and the tester enters the tractor model code in the test system;

[0026] 2) Install the vibration sensor at the designated location on the tractor according to the instructions on the system display unit;

[0027] 3) The tester starts the tractor and completes the operation at different speeds under idle speed according to the instructions of the system display unit;

[0028] 4) During the test, the display unit shows vehicle information, current operation and final test results;

[0029] 5) After the vibration information is processed and compared, the vibration evaluation results of the tractor are output:

[0030] The vibration characteristics are determined to be qualified within the allowable range and released;

[0031] If the vibration characteristics exceed the allowable range, the over-limit index, fault type, possible fault location and other information will be displayed, and the product will be guided to the repair process.

[0032] 6) After completing the test, the experimenter removes the sensor, confirms the end and waits for the next tractor test.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The tractor whole machine assembly quality evaluation method of the present invention adopts the method of comparing the vibration characteristics of the whole machine with the qualified sample benchmark, which can quickly realize the qualification detection and provide the location of potential defects and fault types based on the vibration characteristics. The whole machine assembly quality detection device of the present invention adopts a magnetic MEMS multi-axis acceleration sensor based on the vibration transmission characteristics of the rigid connection, which has a light structure, low cost, and simple test operation, and meets the requirements of the rapid detection rhythm of the detection line. The method and detection device of the present invention can be used for the rapid evaluation of the whole machine assembly quality of power machinery such as tractors with rigid connections such as engines, gearboxes, and rear axles. Under the condition of engine idle excitation, the abnormal vibration level of the tractor whole machine is evaluated, and the fault type that causes the abnormal vibration is found, meeting the demand for rapid detection of assembly quality during the final inspection. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a schematic diagram of the connection structure between the detection device and the tractor provided by an embodiment of the present invention;

[0036] Figure 2is a schematic diagram of the structure of an acceleration sensor provided by an embodiment of the present invention;

[0037] Figure 3 It is a schematic diagram of the detection principle provided by an embodiment of the present invention.

[0038] Description of reference numerals:

[0039] 1-tractor; 11-vibration characteristic collection point;

[0040] 2-vibration sensor; 21-magnetic head; 22-MEMS three-axis acceleration sensor; 23-MCU and accessories; 24-sensor housing;

[0041] 3-data receiving and analyzing unit; 31-signal receiving module; 32-vibration intensity data processing module; 33-FFT processing module; 34-reference database storage module; 35-control module; 36-comparison analysis and decision-making module;

[0042] 4-Data display unit;

[0043] 5- Connect the cables. DETAILED DESCRIPTION

[0044] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0045] Example 1

[0046] like Figure 1 The whole machine assembly quality detection device shown includes: a vibration sensor 2, a data receiving and analyzing unit 3 (host computer) and a data display unit 4, and the data receiving and analyzing unit 3 is connected to the display unit 4 and the vibration sensor 2 through a connecting cable 5.

[0047] The vibration sensor 2, such as Figure 2 As shown, a small MEMS three-axis sensor 22 is used, including a magnetic head 21, an MCU and accessories 23 for data acquisition and conversion, as well as electronic circuits such as data transmission components, battery components, and a sensor housing 24. According to the requirements of on-site operations, the sensor can be connected to the data receiving and analysis unit by wireless or wired communication. According to the mechanical vibration characteristics of the tractor, the vibration acquisition frequency range is 10 to 2000Hz, and the acquisition rate is ≥2000Hz. It is installed on the rigid body of the tractor by magnetic attraction.

[0048] The data receiving and analyzing unit 3 has the functions of data receiving, data conversion, feature comparison, display and recording, etc. Figure 3As shown, the data receiving and analyzing unit 3 adopts MCU, including a signal receiving module 31, a vibration intensity data processing module 32, an FFT processing module 33, a reference database storage module 34, a control module 35, and a comparative analysis and decision module 36, which are used to issue acquisition instructions to the sensor and obtain the vibration information of the whole machine, and calculate the vibration intensity of the whole machine according to the received vibration parameters, and obtain the frequency distribution and characteristics of the whole machine vibration spectrum through FFT analysis, and finally compare with the reference database and the typical mechanical fault spectrum frequency comparison table to provide the test results. Among them, the signal receiving module 31 can select a wired interface or a wireless interface according to the type of the vibration sensor 2.

[0049] The data display unit 4 is composed of an electronic display screen, connected to the data receiving and analyzing unit 3, and is used to display operation instructions, tractor status, real-time test data and test results. The electronic display screen can be installed in the visual range of the test operator on the upper side of the tractor to be tested.

[0050] The whole machine assembly quality detection device can be used for the rapid evaluation of the whole machine assembly quality of power machinery such as tractors with rigidly connected engines, gearboxes, rear axles, etc. Based on the vibration transmission characteristics of the rigid connection and with engine idle excitation as the condition, it evaluates the abnormal vibration level of the tractor and discovers the type of fault that causes the abnormal vibration.

[0051] Example 2

[0052] The tractor assembly quality evaluation method provided by the present invention is as follows: Figure 3 As shown, based on the vibration characteristics of the tractor, the following steps are taken to achieve:

[0053] S1. Using the vibration sensor 2 to obtain the vibration signal under specific excitation conditions at a specific position of the tractor (vibration feature collection point 11), and input it into the data receiving and analyzing unit 3.

[0054] S2, the vibration signal is processed in two ways by the data receiving and analyzing unit 3. One way is to integrate the spatial vibration acceleration in the x, y, and z directions to obtain the vibration velocity of each axis, and further integrate to obtain the spatial vibration intensity (vibration velocity intensity) and the x, y, and z direction component intensity ratio, which is used for the whole machine vibration intensity evaluation (jitter) and x, y, and z direction component abnormality judgment, and finally combined with the standard tractor benchmark vibration intensity and component ratio comparison to quickly evaluate the overall vibration state of the tractor.

[0055] S3, another vibration acceleration signal, after filtering and fast Fourier transform FFT, obtains the spectrum diagram. The frequency characteristics of the standard tractor vibration spectrum and the typical mechanical fault diagnosis spectrum characteristics are compared with the obtained tractor vibration spectrum characteristics to quickly determine the tractor abnormality and the abnormal fault type classification, providing guidance for quickly locating the fault point.

[0056] The method of the invention relies on a large number of test data of the tractor model to be tested to establish a reference data comparison library, so it is suitable for application on the off-line inspection line of the tractor manufacturing plant to achieve the consistency of assembly quality through the consistency of the vibration of the whole machine. In order to realize the establishment of a reference library of vibration characteristics of the tractor as a whole, a large number of vibration collections are performed on multiple feature points on the rigid matrix of the tractor model to be tested in the evaluation method disclosed by the present invention, and the vibration feature association between the feature points is established, and the vibration collection point with the richest feature information is sought to establish a reference database for the vibration characteristics of the whole machine. The specific method is: according to the type and specific model of the tractor to be tested, the position on the rigid body of the tractor that is convenient for pasting the vibration sensor is pre-determined, the vibration feature collection under different excitation conditions is performed, and the vibration feature correlation function between the positions is established, which is a characteristic relationship for the characterization of the assembly quality of the whole machine; based on the statistics of a large number of vibration feature data of tractors of the same model, a vibration intensity evaluation index range is established, and a reference database for the frequency distribution of the spectrum of the characteristic parts is established, which is used for the reference benchmark of the vibration intensity and spectrum analysis of the tractor to be tested; using the comparison table of the vibration spectrum characteristics of typical mechanical faults, the mechanical defects or fault types of the tractor assembly are obtained by comparing the frequency distribution characteristics of the tractor vibration spectrum.

[0057] Example 3

[0058] The specific test steps of using the whole machine assembly quality detection device for the tractor whole machine assembly quality evaluation method are as follows:

[0059] 1) The tractor to be tested enters the test station, and the tester enters the tractor model code in the test system; the benchmark library information established in the system contains the location information of the typical optimal vibration collection points of each model of tractor, the vibration intensity of the vibration measurement point under specific idle excitation, the frequency distribution characteristics of the vibration spectrum, and other information;

[0060] 2) Install the vibration sensor at the designated position of the tractor according to the instructions of the system display unit; specifically, the system determines the vibration sensor pasting position for the tester in the real unit according to the input tractor model code; the tester completes the sensor positioning according to the instructions;

[0061] 3) The tester starts the tractor and completes the operation at different speeds under idle speed according to the instructions of the system display unit; specifically, the tester starts the tractor, and the display unit will display the tractor engine speed status and vibration implementation status; after the initialization is completed, the system requires the tester to adjust the idle speed and maintain it according to the benchmark database test parameter conditions through the display unit, so that the vibration sensor can fully obtain the vibration information of the tractor under the speed condition;

[0062] 4) During the test, the display unit displays vehicle information, current operation, and final test results; specifically, the display unit is based on the benchmark database test condition strategy, so the test unit is required to change the idle speed and supplement the tractor vibration characteristics under various idle conditions, so as to obtain more tractor vibration characteristics under more excitation conditions and obtain more assembly quality information;

[0063] 5) After the vibration information is processed and compared, the vibration evaluation results of the tractor are output:

[0064] The vibration characteristics are determined to be qualified within the allowable range and released;

[0065] If the vibration characteristics exceed the allowable range, the over-limit index, fault type, possible fault location and other information will be displayed, and the product will be guided to the rework process.

[0066] 6) After completing the test, the experimenter removes the sensor, confirms the end and waits for the next tractor test.

[0067] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and the embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily realized. Therefore, without departing from the general concept defined by the claims and equivalent scope, the present invention is not limited to the specific details and the illustrations shown and described here.

Claims

1. A method for evaluating the assembly quality of a tractor, characterized in that: Testing is performed using a tractor complete machine assembly quality testing device, the tractor complete machine assembly quality testing device comprising: a vibration sensor (2), a data receiving and analyzing unit (3) and a data display unit (4); The vibration sensor (2) adopts a small MEMS three-axis sensor, which is used to collect vibration parameters of the tractor (1) within a range of 10 to 2000 Hz, and is connected to the data receiving and analyzing unit in a wireless or wired manner; The data receiving and analyzing unit (3) uses an MCU to issue collection instructions to the sensor and obtain vibration information of the tractor (1), and calculate the vibration intensity of the tractor (1) based on the received vibration parameters, and at the same time obtain the frequency distribution and characteristics of the vibration spectrum of the tractor (1) through FFT analysis, and finally compare it with the benchmark database and the typical mechanical fault frequency spectrum comparison table to provide a test result; The data display unit (4) is connected to the data receiving and analyzing unit (3) and is used to display operation instructions, tractor status, real-time test data and test results; The vibration sensor (2) is provided with a magnetic suction head (21); The tractor complete machine (1) is a power machinery complete machine with a rigid connection; Based on the vibration characteristics of the tractor, the following steps are taken to achieve: S1, using a vibration sensor (2) to obtain a vibration signal under specific excitation conditions at a specific position of the tractor; S2, through the data receiving and analyzing unit (3), the vibration signal is converted into vibration intensity for the vibration characteristics of the tractor, and the vibration intensity value range of the tractor benchmark database is compared to evaluate the vibration intensity of the tractor as a whole, give the over-limit range, and give the working quality status index of the tractor as a whole; S3, perform fast Fourier transform (FFT) on another vibration signal to obtain the vibration spectrum and frequency distribution characteristics of the tractor, and quickly locate the potential mechanical fault type by comparing it with the tractor benchmark database and the vibration spectrum diagram of typical mechanical faults; The tractor benchmark database is established by statistics of actual test data of a large number of tractor models to be tested. The specific method is as follows: according to the type and specific model of the tractor to be tested, the position on the rigid body of the tractor that is convenient for pasting the vibration sensor is pre-determined, vibration characteristics under different excitation conditions are collected, and the vibration characteristic correlation function between the positions is established, which characterizes the characteristic relationship of the assembly quality of the whole machine; based on the statistics of a large number of vibration characteristic data of tractors of the same model, a vibration intensity evaluation index range is established, and a frequency distribution comparison database of the spectrum of characteristic parts is established, which is used as a comparison benchmark for the vibration intensity and spectrum analysis of the tractor to be tested; using a typical mechanical fault vibration spectrum characteristic comparison table, the mechanical defect or fault type of the tractor whole machine assembly is obtained by comparing the tractor vibration spectrum frequency distribution characteristics; The excitation condition is at the engine idle speed; The vibration sensor (2) is mounted on the rigid body of the tractor by means of magnetic attraction; The vibration sensor (2) adopts a small MEMS three-axis sensor; The data receiving and analyzing unit (3) adopts MCU.

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