Commercial vehicle chassis air spring multi-project combination detection test method

Abstract

A commercial vehicle chassis air spring multi-project combination detection test method comprises the steps that air spring multifunctional general test tools are installed on the upper portion and the lower portion of a to-be-detected air spring respectively, and then the to-be-detected air springs with the multifunctional general test tools are sequentially placed on test equipment according to test requirements; an air spring air tightness test, an elastic characteristic test, a destructive test and a rack fatigue test are sequentially and respectively performed on the test equipment. According to the invention, the upper and lower parts of the to-be-detected air spring are respectively provided with a set of air spring multifunctional general test tool, and then the to-be-detected air spring with the multifunctional general test tool is used for testing the air spring, so that the problems of long auxiliary operation time and inconvenient operation of the air spring test can be effectively solved, and the test efficiency is improved.

Description

Technical Field

[0001] The present invention relates to a detection and testing method for automobile parts, and in particular to a multi-item combined detection and testing method for a commercial vehicle chassis air spring. The multi-item combined detection and testing method for a commercial vehicle chassis air spring can reduce auxiliary operation time during various tests and effectively improve operating efficiency during the tests. The invention belongs to the technical field of automobile parts detection and testing. Background Art

[0002] With the development of automobile manufacturing technology and the improvement of people's requirements for travel comfort, air springs are now used more and more in automobiles, and more and more commercial vehicle chassis adopt air springs; commercial vehicle air springs have become the core components of automobile air suspension systems, and they improve vehicle driving stability and comfort by adjusting vehicle body height, damping and stiffness, and are widely used in the commercial vehicle field.

[0003] On the other hand, as air springs have become the core components of automobile air suspension systems, the requirements for passenger car air springs are becoming increasingly higher. Commercial vehicle air springs are elastic elements that use compressed air as a medium and utilize the compressibility of gas to achieve elastic action. In order to ensure the safety and reliability of their operation, they need to undergo multiple tests before use, including: 1. Air tightness test: Check the air tightness of the air spring to ensure that there will be no gas leakage when it is under pressure. Usually, the method of inflation and pressure maintenance is adopted. After the air spring is inflated to a certain pressure, the air inlet valve is closed and the pressure change is observed over a period of time. If the pressure is stable, the air tightness is good. Otherwise, the leak point needs to be found and repaired.

[0004] 2. Dynamic elastic characteristics test: Set the air spring length at a specific height, set the amplitude, frequency, loading cycle, and pressure, and record the load-displacement curve of each cycle. The deviation is required to be within the specified range.

[0005] 3. Isothermal variable pressure characteristic test: Set the length of the air spring at a specific height, set the amplitude, frequency, loading cycle, and pressure, and record the load-deformation curve and internal pressure-deformation curve under each gradient pressure. The deviation is required to be within the specified range.

[0006] 4. Isothermal and isobaric characteristic test: Set the air spring length at the initial height, set the initial air pressure value, reduce the fixed pressure value each time (keep the air source connected to keep the pressure stable after the pressure is established), compress it to the specified height and stay for a certain time, then stretch it to the specified height at a certain speed, record the load-deformation curve and internal pressure-deformation curve under each gradient pressure, and require the deviation to be within the specified range.

[0007] 5. Destructive test (water burst test): Determine the maximum pressure that the air spring can withstand, that is, the bursting pressure, to ensure its safety and reliability in actual use, and avoid rupture and failure of the air spring due to excessive pressure.

[0008] 6. Bench Fatigue Test: Air springs are subjected to long-term, high-frequency, low-amplitude fatigue tests to simulate the vibrations experienced during long-term vehicle use, accelerating aging and wear of the air springs and thereby predicting their fatigue life. During the fatigue test, changes in the air spring's performance, such as stiffness loss and leakage, must be monitored in real time.

[0009] And these tests need to be completed on different testing equipment respectively, that is, the commercial vehicle air spring to be tested needs to be disassembled and installed on different testing equipment for different performance tests after multiple times of disassembly and assembly; since the air spring installation platforms of various testing equipment are different, different test fixtures need to be configured according to different testing equipment. When conducting detection tests on different testing equipment, test fixtures with different configurations need to be installed on the air spring to be tested in order to carry out different tests; however, this requires multiple installations of test fixtures, which not only increases the auxiliary operation time, but also easily causes damage to the air spring to be tested due to multiple disassembly and assembly, so it is very necessary to improve this.

[0010] To find the same technical reports through query retrieval, only technical literature in related fields is available, and the closest ones are the following: 1. Patent application number CN202311541765.1, entitled "An Air Spring Test Monitoring Device and Application Method," is filed by China First Automobile Group Co., Ltd. The invention patent application discloses an air spring test monitoring device and application method, comprising an air compressor, a three-way pipe, an air spring, an air pressure sensor, an ammeter, multiple indicator lights, a vibration sensor, a relay, and a power supply, which supplies power to all electrical components. The air compressor, air spring, and air pressure sensor are interconnected by a three-way pipe. The air compressor is used to inflate and deflate the air spring. The air pressure sensor is connected to the relay, which is used to identify the gas pressure value in the air spring, convert the gas pressure value into an electrical signal, and transmit it to the ammeter via the relay. The identified air pressure and current signal can be displayed on the ammeter, and the circuit operation can be monitored by the second indicator light. A vibration sensor is provided on the air spring, which is connected to the relay. The operation of the air spring is detected by the first indicator light. This technical solution only targets the detection of a single device and does not involve the detection of multiple stations and multiple devices, so the aforementioned problems do not exist.

[0011] 2. Patent document CN110779708A discloses a durability test method for air springs, comprising the following steps: Step S1, taking at least three groups of air springs in a single batch, setting three ambient temperatures of low temperature, normal temperature, and high temperature for the three groups of air springs, and separating the test environments of the three groups of air springs from each other, and further separating each air spring; Step S2, fixing the upper end of each air spring along its extension direction; driving and compressing multiple air springs at once through cam transmission, and achieving compression of different amplitudes and frequencies of the air springs by changing the shape of the cam piece, simulating the extrusion of the springs in the driving environment, and testing the low-temperature and high-temperature resistance of the air springs by setting separate temperature environments. The technical solution disclosed in this patent also only involves a single stiffness and fatigue resistance test, and does not involve the operation of multiple devices, and therefore does not involve the problems mentioned above.

[0012] 3. Patent publication number CN108801622B discloses a three-way composite loading fatigue test device and method for an air spring, comprising a support, a transverse loading assembly for applying a transverse dynamic load to the air spring, a vertical loading assembly for applying a vertical dynamic load to the air spring, and a longitudinal biasing assembly for causing the air spring to deform longitudinally. The transverse loading assembly is mounted on the support along the front-to-back direction of the air spring, the longitudinal braiding assembly is mounted on the transverse loading assembly and its positioning on the transverse loading assembly is adjustable, the air spring is mounted on the longitudinal biasing assembly, and the vertical loading assembly is mounted vertically directly above the air spring and in contact with the air spring. This patent document also refers to the detection of a single device, and does not involve the detection of multiple devices.

[0013] The above patents all involve the detection of air springs, but the current detection only considers the detection of a single device, without considering the problem of multiple devices. With the development of detection technology, more and more air spring detection projects are required. How to reduce the auxiliary operation time of detection has also become a pain point for improving the detection effect; therefore, further research and improvement are still needed. Summary of the Invention

[0014] The technical problem to be solved by the present invention is to provide a multi-item combined detection test method for chassis air springs of commercial vehicles, which aims to address the shortcomings of existing multi-item combined detection tests of chassis air springs of commercial vehicles, such as the need to replace test tooling multiple times, long auxiliary operation time, and easy damage to the air springs to be tested. The multi-item combined detection test method for chassis air springs of commercial vehicles can use a set of tooling to meet the tooling requirements of various test equipment at the same time, effectively shorten the auxiliary operation time, and avoid multiple disassembly and assembly of the air springs to be tested.

[0015] The present invention is mainly achieved through the following technical solutions: a multi-item combined detection test method for commercial vehicle chassis air springs, in which multifunctional universal test fixtures for air springs are respectively installed above and below the air spring to be tested, and then the air spring to be tested with the multifunctional universal test fixture is placed on the test equipment in sequence according to the test requirements, and the air spring air tightness test, elastic property test, destructive test and bench fatigue test are carried out on the test equipment in sequence.

[0016] Furthermore, the multifunctional universal test fixture for air springs to be tested is respectively installed on the upper and lower covers of the air spring to be tested, and the upper universal test fixture and the lower universal test fixture are respectively installed on the upper and lower covers of the air spring to be tested, and the upper universal test fixture and the lower universal test fixture are respectively connected to the upper and lower covers of the air spring to be tested, and at the same time, the upper universal test fixture and the lower universal test fixture are respectively connected to the test equipment; a replaceable joint is provided on the upper universal test fixture and / or the lower universal test fixture; during the test, the connection method of the replaceable joint and the test equipment is changed to select the connection of the loading air source or water source, and then the air spring to be tested is subjected to air tightness test, dynamic elastic characteristic test, isothermal variable pressure characteristic test, isothermal isobaric characteristic test, destructive test and bench fatigue test according to the test equipment.

[0017] Furthermore, the method of selecting the connection of the loading air source or water source by changing the connection mode of the replaceable joint and the test equipment is to make the upper universal test fixture and / or the lower universal test fixture into a connector with a double-layer plate structure, wherein one layer is an air spring connecting layer plate connected to the upper and lower cover plates of the air spring to be tested, and the other layer is an equipment connecting layer plate connected to the test equipment; the air spring connecting layer plate and the equipment connecting layer plate are connected by a connecting column, and an operating cavity is formed between the air spring connecting layer plate and the equipment connecting layer plate through the support of the connecting column; an air spring connecting layer plate connected to the air spring to be tested is provided in the operating cavity A stud clearance hole and a replaceable joint mounting hole are provided. The stud clearance hole is used to avoid the bolt position on the upper and lower cover plates of the air spring to be tested, so that the air spring connecting layer can be completely closed and fixed to the upper and lower cover plates of the air spring to be tested, and the replaceable joint mounting hole is set at the air inlet position of the air spring to be tested; during the test, according to the needs of the test, the replaceable joint is installed on the replaceable joint mounting hole, and the operating air source or water source of the test equipment is connected through the replaceable joint to carry out air spring air tightness test, elastic property test, destructive test and bench fatigue test respectively; the replaceable joint mounting hole that is not used during the test is blocked by a plug.

[0018] Furthermore, the operating air source or water source of the test equipment is connected through a replaceable joint, and the replaceable joint is directly screwed to the air inlet of the air spring to be tested through the replaceable joint mounting hole, and then connected to the outlet pipeline of the operating air source or water source of the testing equipment through the air source or water source connecting joint, forming a channel for the air or liquid to enter and exit the air spring to be tested during the testing process; the testing equipment provides the testing gas or liquid to the air spring to be tested through the replaceable joint.

[0019] Furthermore, the gas source or water source connection joint is a multi-channel joint, which is a "T"-shaped tube structure and includes 3 outlets; the "T"-shaped long tube outlet is connected to the replaceable joint, and the other two "T"-shaped short tube outlets are symmetrically arranged and distributed up and down, one is a water source or gas source input pipe, and the other is a water source or gas source discharge pipe, which are respectively connected to the water source or gas source output pipe of the test equipment and the water source or gas source discharge pipe or pressure sensor of the test equipment.

[0020] Furthermore, the upper universal test fixture and the lower universal test fixture are respectively connected to the test equipment by having a plurality of long "U"-shaped grooves on the equipment connection plates of the upper universal test fixture and the lower universal test fixture. The distribution of the long "U"-shaped grooves matches the screw holes or bolt positions of the upper and lower working platforms on the test equipment. During the test, the bolts are inserted into the long "U"-shaped grooves to connect the equipment connection plates of the upper universal test fixture and the lower universal test fixture to the upper and lower working platforms of the test equipment.

[0021] Furthermore, the number of the long "U"-shaped grooves matches the screw holes or bolts of the upper and lower working platforms on the test equipment, and the plane centers of the equipment connection layers of the upper universal test fixture and the lower universal test fixture are arranged radially.

[0022] Furthermore, the number of the long "U"-shaped grooves is 12, corresponding to screw holes or bolts that are multiples of 4 or 6 on the upper and lower working platforms on the test equipment.

[0023] Furthermore, the multi-item combined test of the commercial vehicle chassis air spring includes an air tightness test, a dynamic elastic property test, an isothermal variable pressure property test, an isothermal isobaric property test, a bench fatigue test, and a destructive test (water burst test), and is carried out in a step-by-step test method, including the following steps: (1) First clean the upper and lower surfaces of the air spring to be tested, and then install the air spring connecting plates of the upper universal test fixture and the lower universal test fixture on the upper and lower cover plates of the air spring to be tested respectively; during installation, care should be taken to avoid contact between the air spring connecting plates and the bolts in the upper and lower cover plates of the air spring to be tested, and avoid this by using the stud holes in the air spring connecting plates so that the air spring connecting plates of the upper universal test fixture and the lower universal test fixture can fit tightly on the air spring connecting plates of the upper universal test fixture and the lower universal test fixture; set a sealing gasket or apply sealant between the air spring connecting plates and the upper and lower cover plates of the air spring to be tested for sealing; (2) Carry out an air tightness test: directly place the air spring to be tested with the upper universal test fixture and the lower universal test fixture installed on the air tightness test platform, press the upper and lower working platforms of the air tightness test equipment on the equipment connecting plates of the upper universal test fixture and the lower universal test fixture, insert the compression bolts into the long "U"-shaped grooves of the equipment connecting plates to fix the equipment connecting plates on the upper and lower working platforms of the air tightness test equipment, and then directly insert the air source air pipe of the air tightness test equipment into the replaceable joint of the upper universal test fixture, tighten it, and then introduce compressed gas, and plug all the replaceable joint mounting holes on the other air spring connecting plates with plugs, start the air tightness test equipment, and carry out an air tightness test; after the air tightness test is completed, loosen the compression bolts on the upper and lower working platforms, and remove the upper and lower working platforms of the air tightness test equipment; take out the air spring to be tested with the upper and lower universal test fixtures after the test and place it on the transfer vehicle to be sent to the next process for testing; (3) Conducting elastic property test: directly place the air spring to be tested that has passed the air tightness test together with the upper universal test fixture and the lower universal test fixture on the test bench of the elastic property test equipment, and move the upper and lower working platforms of the test bench of the elastic property test equipment downward relative to each other, pressing the upper universal test fixture and the lower universal test fixture on the air spring to be tested. Insert the clamping bolts into the long "U"-shaped groove of the equipment connection layer to fix the equipment connection layer on the upper and lower working platforms of the elastic property test equipment. Then directly insert the air source pipe of the elastic property test into the replaceable joint of the upper universal test fixture, tighten it, and then introduce compressed gas. All the replaceable joint mounting holes on the other air spring connection layers are blocked with plugs. Start the elastic property test equipment and conduct the elastic property test. After the elastic property test is completed, loosen the clamping bolts on the upper and lower working platforms, and remove the upper and lower working platforms of the elastic property test equipment. Take out the air spring to be tested with the upper and lower universal test fixtures after the test and place them on the transfer vehicle for delivery to the next process for inspection.

[0024] (4) Perform bench fatigue test: The air spring to be tested that has directly undergone the elastic property test is placed on the test bench of the bench fatigue test equipment together with the upper universal test fixture and the lower universal test fixture, and the upper and lower working platforms of the bench fatigue test equipment are connected to the equipment connection layers of the upper universal test fixture and the lower universal test fixture respectively; then, the equipment connection layers are fixed to the upper and lower working platforms of the bench fatigue test equipment by inserting the compression bolts into the long "U"-shaped grooves of the equipment connection layers, and then the replaceable joints are installed on the air spring connection layers of the upper universal test fixture. Install the replaceable joint in the mounting hole, and directly insert the test air source pipe into the replaceable joint of the upper universal test fixture. After tightening, introduce compressed gas, and plug all the replaceable joint mounting holes on other air spring connection plates with plugs. Start the bench fatigue test equipment and conduct the bench fatigue test. After the bench fatigue test is completed, loosen the clamping bolts on the upper and lower working platforms, and remove the upper and lower working platforms of the bench fatigue test equipment. Take out the tested air spring with the upper and lower universal test fixtures and place it on the transfer vehicle to be sent to the next process for testing. (5) Conduct destructive test: directly place the air spring to be tested that has passed the bench fatigue test, together with the upper universal test fixture and the lower universal test fixture, on the test platform of the water explosion test equipment, and connect the upper and lower working platforms of the water explosion test equipment to the equipment connection plates of the upper universal test fixture and the lower universal test fixture respectively; then insert the compression bolts into the long strip "U" groove of the equipment connection plate to fix the equipment connection plate on the upper and lower working platforms of the water explosion test equipment, and then install the replaceable joint in the installation hole of the air spring connection plate of the lower universal test fixture. Install the replaceable joint and screw the multi-channel joint into the replaceable joint. Then connect the water inlet and outlet pipes of the water burst test equipment to the water inlet and outlet of the multi-channel joint respectively. At the same time, plug all the replaceable joint installation holes on the other air spring connection plates with plugs, start the water burst test equipment, and conduct the water burst test. After the water burst test is completed, loosen the clamping bolts on the upper and lower working platforms, and remove the upper and lower working platforms of the water burst test equipment. Place the tested air spring with the upper and lower universal test fixtures on the transfer vehicle and send it to the next process for testing. (6) Disassembling the upper universal test fixture and the lower universal test fixture: After the water burst test, the air spring to be tested is disassembled from the upper universal test fixture and the lower universal test fixture, thereby completing the performance test of the entire air spring to be tested.

[0025] Furthermore, the replaceable joint mounting hole of the air spring connecting layer plate is arranged at the air inlet position of the detection air spring; wherein, the replaceable joint mounting hole of the air spring connecting layer plate on the lower universal test tool is arranged at the center position of the air spring connecting layer plate; the replaceable joint mounting hole of the air spring connecting layer plate on the upper universal test tool plate is arranged at the eccentric air inlet position of the air spring connecting layer plate.

[0026] Beneficial effects of the present invention: The present invention pre-installs a set of universal test fixtures on the upper and lower end surface connection plates of the test air spring. The universal test fixture can adapt to the testing requirements of various testing equipment, which can greatly shorten the auxiliary Ouye time and improve the testing efficiency. It has the following advantages: 1. The present invention installs universal testing fixtures on the upper and lower parts of the air spring to be tested, so that the air spring to be tested does not need to be tested on multiple different test equipment without installing additional auxiliary fixtures. All air spring testing tests can be completed with one set of fixtures, which can save a lot of auxiliary operation time, manpower and material resources; 2. The universal test fixture of the present invention adopts a double-layer structure, forming a working space above and below the air spring to be tested and the test work platform, which facilitates the installation of the air or water source inlet and outlet interfaces for various tests; all operations are concentrated on the equipment connection layer in the working space, which is both convenient and safe. 3. The present invention adopts an air source or water source connection joint to lead out the water source and air source access port from the double-layer working cavity, which is more convenient for operators to operate the connection and simplifies the installation of the inlet and outlet pipelines. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the overall structure of the commercial vehicle air spring involved in the present invention; Figure 2 Schematic diagram of the three-dimensional structure of the universal detection and testing tool of the present invention; Figure 3 This is a schematic diagram of the connection between the universal testing fixture and the air spring of the present invention; Figure 4 This is a schematic diagram of the three-dimensional structure of the universal detection and testing tooling and the test equipment combined installation of the present invention; Figure 5 This is a schematic diagram of the three-dimensional structure of the universal detection and testing tool of the present invention from another direction; Figure 6 This is a schematic diagram of the overall structure of the universal test tool of the present invention; Figure 7 This is a schematic diagram of the overall structure of the universal test tool of the present invention; Figure 8This is a schematic diagram of the structure of the multi-channel connector of the present invention; Figure 9 This is a schematic diagram of the replaceable joint structure of the present invention; Figure 10 This is a schematic diagram of the structure for the top installation of a multi-channel connector; Figure 11 This is a schematic diagram of the structure for the bottom installation of the multi-channel connector.

[0028] Explanation of the accompanying numbers: 1. Air spring to be tested; 2. Test equipment; 3. Multifunctional universal test fixture for air spring; 4. Upper universal test fixture; 5. Lower universal test fixture; 6. Upper cover plate; 7. Lower cover plate; 8. Replaceable joint; 9. Air spring connection layer; 10. Equipment connection layer; 11. Operation cavity; 12. Stud clearance hole; 13. Replaceable joint mounting hole; 14. Air or water source connection joint; 15. Connecting column; 16. Water or air source input pipe; 17. Water or air source discharge pipe; 18. Upper and lower working platforms; 19. Countersunk screw hole; 20. Countersunk screw; 21. Air inlet; 22. Bolt; 23. Air spring mounting hole; 24. External connection hole; 25. Plug; 26. Long "U"-shaped groove; 27. "T"-shaped long pipe outlet; 28. External connection hole. DETAILED DESCRIPTION

[0029] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] A multi-item combined detection test method for a commercial vehicle chassis air spring, wherein an air spring 1 to be detected of the commercial vehicle chassis air spring comprises an upper cover plate 6 and a lower cover plate 7; an air inlet 21 and a bolt 22, as well as an air spring mounting hole 23, are provided on the upper and lower covers 8 and / or the lower covers 7; a multifunctional universal test fixture 3 for an air spring is respectively installed above and below the air spring 1 to be detected; the air spring 1 to be detected with the multifunctional universal test fixture 3 is then placed on a test device 2 for an air tightness test, an elastic property test, a destructive test, and a bench fatigue test in accordance with test requirements; and the air spring air tightness test, elastic property test, destructive test, and bench fatigue test are respectively performed on the test device 2 in sequence.

[0031] Among them, the multifunctional universal test fixture 3 for the air spring to be tested is respectively installed on the upper and lower covers 6 and the lower covers 7 of the air spring 1 to be tested, and the air spring connecting layer 9 on the upper universal test fixture 4 and the lower universal test fixture 5 is provided with a countersunk screw hole 19 matching the air spring 1 to be tested, and the countersunk screw hole 19 corresponds to the external connection hole 24 on the air spring 1 to be tested, and the air spring connecting layer 9 on the upper universal test fixture 4 and the lower universal test fixture 5 is respectively connected to the upper cover 6 and the lower cover 7 of the air spring 1 to be tested by the countersunk screw 20. When installing, the countersunk screws must be kept lower than the outer plane of the air spring connection layer 9 so that no bulge will be formed when placed on the working platform of the test equipment. At the same time, the upper universal test fixture 4 and the lower universal test fixture 5 are respectively connected to the test equipment 2. A replaceable joint 8 is provided on the upper universal test fixture 4 and / or the lower universal test fixture 5. During the test, the connection method of the replaceable joint 8 and the test equipment 2 is changed to select the connection of the loading air source or water source, and then the air spring 1 to be tested is subjected to air tightness test, dynamic elasticity characteristic test, isothermal variable pressure characteristic test, isothermal isobaric characteristic test, destructive test and bench fatigue test respectively according to the test equipment 2. That is, according to the characteristics of the test equipment 2, different methods are adopted to connect the loading air source or water source of the test equipment to the replaceable joint 8, so that it can meet the requirements of various test equipment.

[0032] The method of selecting the connection of the loading air source or water source by changing the connection mode of the replaceable joint 8 with the test equipment is to make the upper universal test fixture 4 and / or the lower universal test fixture 5 into a connector with a double-layer plate structure, wherein one layer is an air spring connection layer plate 9 connected to the upper cover plate 6 and the lower cover plate 7 of the air spring 1 to be tested, and the other layer is an equipment connection layer plate 10 connected to the test equipment; the air spring connection layer plate 9 and the equipment connection layer plate 10 are connected by a connecting column 15, and an operating cavity 11 is formed between the air spring connection layer plate 9 and the equipment connection layer plate 10 by supporting the connecting column 15; a stud is provided on the air spring connection layer plate 9 connected to the air spring 1 to be tested in the operating cavity 11 The stud hole 12 and the replaceable joint mounting hole 13 avoid the bolt position on the upper cover plate 6 and the lower cover plate 7 of the air spring 1 to be tested through the stud hole 12, so that the air spring connecting layer 9 can be completely closed and fixed to the upper cover plate 6 and the lower cover plate 7 of the air spring 1 to be tested, and the replaceable joint 8 mounting hole is set at the air inlet position of the air spring 1 to be tested; during the test, according to the needs of the test, the replaceable joint 8 is installed on the replaceable joint mounting hole 13, and the operating air source or water source of the test equipment is connected through the replaceable joint 8 to carry out the air spring air tightness test, elastic property test, destructive test and bench fatigue test respectively; the replaceable joint mounting hole 13 not used in the test is blocked by the plug 25 (such as the attached Figure 5 shown).

[0033] The said connection of the working air source or water source of the test equipment through the replaceable joint 8 is to screw the replaceable joint 8 directly to the air inlet of the air spring 1 to be tested through the replaceable joint mounting hole 13. The replaceable joint 8 is also provided with an external connection hole 28. The external connection hole 28 is a convertible joint hole. It is connected to the air source or water source connection joint 14 through the external connection hole 28, and then connected to the outlet pipeline of the working air source or water source of the testing equipment 2 through the air source or water source connection joint 14 (drawn in the figure), forming a channel for the air or liquid to enter and exit the air spring 1 to be tested during the testing process; the testing equipment provides the testing gas or liquid to the air spring 1 to be tested through the replaceable joint 8. The replaceable joint 8 is connected to the working air source or water source of the test equipment, including a variety of connection methods such as connection through the upper universal test fixture 4 and / or connection through the lower universal test fixture 5, to facilitate the connection of different test equipment; wherein Figure 9 For the above general test fixture 4 connection methods; Figure 10 It is a universal test fixture 5 connection method.

[0034] The air or water source connection joint 14 is a multi-channel joint with a T-shaped tube structure and includes three outlets. The long T-shaped tube outlet 27 connects to the external connection hole 28 of the replaceable joint 8. The other two short T-shaped tube outlets are symmetrically arranged, one for the water or air source input pipe 16 and the other for the water or air source discharge pipe 17, which are connected to the test equipment water or air source output pipe and the test equipment water or air source discharge pipe (not shown in the figure). If the test equipment water or air source discharge pipe does not have a discharge pipe, a pressure sensor can be installed at the end of the water or air source discharge pipe 17 or it can be directly blocked with a plug. This allows for flexible connection according to the needs of the test and the specific conditions of the equipment, facilitating various test operations.

[0035] The upper universal test fixture 4 and the lower universal test fixture 5 are respectively connected to the test equipment in that a plurality of long "U"-shaped grooves 26 are opened on the equipment connection layer 10 of the upper universal test fixture 4 and the lower universal test fixture 4. The distribution of the long "U"-shaped grooves 26 matches the screw holes or bolt positions of the upper and lower working platforms 18 on the test equipment. During the test, the bolts are inserted into the long "U"-shaped grooves to connect the equipment connection layer 10 of the upper universal test fixture 4 and the lower universal test fixture 4 to the upper and lower working platforms 18 of the test equipment.

[0036] The number of the long U-shaped grooves 26 matches the screw holes or bolts of the upper and lower working platforms 18 on the test equipment, and the plane centers of the equipment connection layers 10 of the upper universal test fixture 4 and the lower universal test fixture 4 are arranged radially.

[0037] There are 12 long U-shaped grooves 26 , which respectively correspond to screw holes or bolts of an integral multiple of 4 or 6 on the upper and lower working platforms 18 of the test equipment.

[0038] The replaceable joint mounting hole 13 of the air spring connecting layer plate 9 is set at the air inlet position of the detection air spring; wherein, the replaceable joint mounting hole 13 of the air spring connecting layer plate 9 on the lower universal test tooling 4 is set at the center position of the air spring connecting layer plate 9; the replaceable joint mounting hole 13 of the air spring connecting layer plate 9 on the upper universal test tooling 4 is set at the eccentric air inlet position of the air spring connecting layer plate 9.

[0039] The multi-item combined test for commercial vehicle chassis air springs includes an air tightness test, a dynamic elastic properties test, an isothermal variable pressure properties test, an isothermal isobaric properties test, a bench fatigue test, and a destructive test (water burst test). The test is conducted in a step-by-step manner, including the following steps: (1) First clean the upper and lower surfaces of the air spring 1 to be tested, and then install the air spring connecting layer plates 9 of the upper universal test fixture 4 and the lower universal test fixture 4 on the upper cover plate 6 and the lower cover plate 7 of the air spring 1 to be tested respectively; during installation, it is necessary to pay attention to the installation of the countersunk screws 20, and at the same time avoid the air spring connecting layer plates 9 from contacting the bolts in the upper cover plate 6 and the lower cover plate 7 of the air spring 1 to be tested, and avoid this by setting the stud clearance holes 12 in the air spring connecting layer plates 9, so that the air spring connecting layer plates 9 of the upper universal test fixture 4 and the lower universal test fixture 4 can fit tightly on the air spring connecting layer plates 9 of the upper universal test fixture 4 and the lower universal test fixture 4; set a sealing gasket or apply sealant between the equipment connecting layer plates 9 and the upper cover plate 6 and the lower cover plate 7 of the air spring 1 to be tested for sealing; (2) Carry out air tightness test: directly place the air spring 1 to be tested with the upper universal test fixture 4 and the lower universal test fixture 4 installed on the air tightness test platform, press the upper and lower working platforms 18 of the air tightness test equipment on the equipment connection layer 10 of the upper universal test fixture 4 and the lower universal test fixture 4, insert the compression bolts into the long "U"-shaped groove of the equipment connection layer 10 to fix the equipment connection layer 10 on the upper and lower working platforms 18 of the air tightness test equipment, and then directly connect the air source pipe of the air tightness test equipment to the upper and lower working platforms 18 of the air tightness test equipment. Insert the replaceable joint 8 into the upper universal test fixture 4, tighten it, and then introduce compressed air. Plug all the replaceable joint mounting holes 13 on the other air spring connection plates 9 with plugs. Start the air tightness test equipment and conduct an air tightness test. After the air tightness test is completed, loosen the clamping bolts on the upper and lower working platforms 18, and remove the upper and lower working platforms 18 of the air tightness test equipment. Take out the tested air spring 1 with the upper and lower universal test fixtures 4 and the lower universal test fixtures 4, place them on a transfer vehicle, and send them to the next process for testing. (3) Conduct elastic property test: directly place the air spring 1 to be tested that has passed the air tightness test, together with the upper universal test fixture 4 and the lower universal test fixture 4, on the test bench of the elastic property test equipment, and move the upper and lower working platforms 18 of the test bench of the elastic property test equipment downward relative to each other, pressing on the equipment connecting layer 10 of the upper and lower universal test fixtures 4 on the air spring 1 to be tested, and insert the tightening bolts into the long "U"-shaped groove of the equipment connecting layer 10 to fix the equipment connecting layer 10 on the upper and lower working platforms 18 of the elastic property test equipment. Then, insert the air source pipe for the elastic characteristic test directly into the replaceable joint 8 of the upper universal test fixture 4, tighten it, and introduce compressed gas, and plug all the replaceable joint mounting holes 13 on the other air spring connection layers 9 with plugs, start the elastic characteristic test equipment, and conduct the elastic characteristic test; after the elastic characteristic test is completed, loosen the tightening bolts on the upper and lower working platforms 18, and remove the upper and lower working platforms 18 of the elastic characteristic test equipment; take out the tested air spring 1 with the upper universal test fixture 4 and the lower universal test fixture 4, put it on the transfer vehicle and send it to the next process for inspection.

[0040] (4) Perform bench fatigue test: put the air spring 1 to be tested that has directly undergone the elastic property test on the test bench of the bench fatigue test equipment together with the upper universal test fixture 4 and the lower universal test fixture 4, and connect the upper and lower working platforms 18 of the bench fatigue test equipment to the equipment connection layers 10 of the upper universal test fixture 4 and the lower universal test fixture 4 respectively; then, insert the compression bolts into the long strip "U"-shaped groove of the equipment connection layer 10 to fix the equipment connection layer 10 on the upper and lower working platforms 18 of the bench fatigue test equipment, and then replace the joints on the air spring connection layer 9 of the upper universal test fixture 4. Install the replaceable joint 8 in the mounting hole 13, and directly insert the test air source pipe into the replaceable joint 8 of the upper universal test fixture 4, and then tighten it to introduce compressed gas. All the replaceable joint mounting holes 13 on the other air spring connection plates 9 are plugged with plugs, and the bench fatigue test equipment is started to conduct the bench fatigue test. After the bench fatigue test is completed, the clamping bolts on the upper and lower working platforms 18 are loosened, and the upper and lower working platforms 18 of the bench fatigue test equipment are removed. The air spring 1 to be tested with the upper and lower universal test fixtures 4 and the lower universal test fixtures 4 is taken out and placed on a transfer vehicle for the next process test. (5) Conduct destructive test: directly place the air spring 1 to be tested that has passed the bench fatigue test, together with the upper universal test fixture 4 and the lower universal test fixture 4, on the test platform of the water explosion test equipment, and connect the upper and lower working platforms 18 of the water explosion test equipment to the equipment connection layer 9 of the upper universal test fixture 4 and the lower universal test fixture 4 respectively; then, insert the compression bolts into the long strip "U"-shaped groove of the equipment connection layer 10 to fix the equipment connection layer 10 on the upper and lower working platforms 18 of the water explosion test equipment, and then replace the joint mounting hole 1 on the air spring connection layer 9 of the lower universal test fixture 4. 3, install the replaceable joint 8, and screw the multi-channel joint into the replaceable joint 8, then connect the water inlet and outlet pipes of the water explosion test equipment to the water inlet and outlet of the multi-channel joint respectively; at the same time, plug all the replaceable joint installation holes 13 on the other air spring connection layer plates 9 with plugs, start the water explosion test equipment, and conduct the water explosion test; after the water explosion test is completed, loosen the clamping bolts on the upper and lower working platforms 18, and remove the upper and lower working platforms 18 of the water explosion test equipment; place the tested air spring 1 with the upper and lower universal test fixtures 4 on the transfer vehicle and send it to the next process for testing; (6) Disassembling the upper universal test fixture 4 and the lower universal test fixture 4: After the water burst test, the air spring 1 to be tested is disassembled from the upper universal test fixture 4 and the lower universal test fixture 4, thereby completing the performance test of the entire air spring 1 to be tested.

[0041] Beneficial effects of the present invention: The present invention pre-installs a set of universal test fixtures on the upper and lower end surface connection plates of the test air spring. The universal test fixture can adapt to the testing requirements of various testing equipment, which can greatly shorten the auxiliary Ouye time and improve the testing efficiency. It has the following advantages: 1. The present invention installs universal testing fixtures on the upper and lower parts of the air spring to be tested, so that the air spring to be tested does not need to be tested on multiple different test equipment without installing additional auxiliary fixtures. All air spring testing tests can be completed with one set of fixtures, which can save a lot of auxiliary operation time, manpower and material resources; 2. The universal test fixture of the present invention adopts a double-layer structure, forming a working space above and below the air spring to be tested and the test work platform, which facilitates the installation of the air or water source inlet and outlet interfaces for various tests; all operations are concentrated on the equipment connection layer in the working space, which is both convenient and safe. 3. The present invention adopts an air source or water source connection joint to lead out the water source and air source access port from the double-layer working cavity, which is more convenient for operators to operate the connection and simplifies the installation of the inlet and outlet pipelines.

[0042] It should be noted that the above-mentioned embodiments are only used to clearly and completely describe the technical solutions of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments, and the terms such as "upper", "lower", "front", "back", "middle" and so on quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be considered as the scope of the implementation of the present invention without substantially changing the technical content. At the same time, the structures, proportions, sizes, etc. illustrated in the drawings of the specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they have no technical significance. Any modification of the structure, change in the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the efficacy and purpose that can be achieved by the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

Claims

1. A multi-item combined test method for commercial vehicle chassis air springs, characterized by: The multifunctional universal test fixtures for air springs are installed on the upper and lower parts of the air spring to be tested. The air spring to be tested with the multifunctional universal test fixtures is then placed on the test equipment in sequence according to the test requirements. The air spring air tightness test, elastic property test, destructive test and bench fatigue test are carried out on the test equipment in sequence.

2. The multi-item combined detection test method for commercial vehicle chassis air springs according to claim 1, characterized in that: The multifunctional universal test fixture for air springs to be tested is respectively installed on the upper and lower covers of the air spring to be tested, and the upper universal test fixture and the lower universal test fixture are respectively installed on the upper and lower covers of the air spring to be tested, and the upper universal test fixture and the lower universal test fixture are respectively connected to the upper and lower covers of the air spring to be tested, and at the same time, the upper universal test fixture and the lower universal test fixture are respectively connected to the test equipment; a replaceable joint is provided on the upper universal test fixture and / or the lower universal test fixture; during the test, the connection method of the replaceable joint and the test equipment is changed to select the connection of the loading air source or water source, and then the air spring air tightness test, elastic property test, destructive test and bench fatigue test are respectively performed on the air spring to be tested.

3. The multi-item combined testing method for commercial vehicle chassis air springs according to claim 2, characterized in that: The method of selecting the connection of the loading air source or water source by changing the connection mode of the replaceable joint and the test equipment is to make the upper universal test fixture and / or the lower universal test fixture into a connector with a double-layer plate structure, wherein one layer is an air spring connection layer plate connected to the upper and lower cover plates of the air spring to be tested, and the other layer is an equipment connection layer plate connected to the test equipment; the air spring connection layer plate and the equipment connection layer plate are connected by a connecting column, and an operating cavity is formed between the air spring connection layer plate and the equipment connection layer plate through support by the connecting column; a screw is provided on the air spring connection layer plate connected to the air spring to be tested in the operating cavity The column clearance hole and the replaceable joint mounting hole avoid the bolt position on the upper and lower cover plates of the air spring to be tested through the stud clearance hole, so that the air spring connecting layer can be completely closed and fixed to the upper and lower cover plates of the air spring, and the replaceable joint mounting hole is set at the air inlet position of the air spring to be tested; during the test, according to the needs of the test, the replaceable joint is installed on the replaceable joint mounting hole, and the operating air source or water source of the test equipment is connected through the replaceable joint to carry out air spring air tightness test, elastic property test, destructive test and bench fatigue test respectively; the replaceable joint mounting holes that are not used during the test are blocked by plugs.

4. The multi-item combined testing method for commercial vehicle chassis air springs according to claim 3, characterized in that: The working air source or water source of the test equipment is connected to the replaceable joint by screwing the replaceable joint directly to the air inlet of the air spring to be tested through the replaceable joint mounting hole, and then connected to the outlet pipeline of the working air source or water source of the testing equipment through the air source or water source connecting joint, forming a channel for the air or liquid to enter and exit the air spring to be tested during the testing process; the testing equipment provides the testing gas or liquid to the air spring to be tested through the replaceable joint.

5. The multi-item combined testing method for commercial vehicle chassis air springs according to claim 4, characterized in that: The gas source or water source connection joint is a multi-channel joint, which is a "T"-shaped tube structure and includes three outlets; the "T"-shaped long tube outlet is connected to the replaceable joint, and the other two "T"-shaped short tube outlets are symmetrically arranged, distributed up and down, one is the water source or gas source input pipe, and the other is the water source or gas source discharge pipe, which are respectively connected to the water source or gas source output pipe of the test equipment and the water source or gas source discharge pipe or pressure sensor of the test equipment.

6. The multi-item combined detection test method for commercial vehicle chassis air springs according to claim 2 or 3, characterized in that: The upper universal test fixture and the lower universal test fixture are respectively connected to the test equipment by having multiple long "U"-shaped grooves on the equipment connection plates of the upper universal test fixture and the lower universal test fixture. The distribution of the long "U"-shaped grooves matches the screw holes or bolt positions of the upper and lower working platforms on the test equipment. During the test, the bolts are inserted into the long "U"-shaped grooves to connect the equipment connection plates of the upper universal test fixture and the lower universal test fixture to the upper and lower working platforms of the test equipment.

7. The multi-item combined testing method for commercial vehicle chassis air springs according to claim 6, characterized in that: The number of the long "U"-shaped grooves matches the screw holes or bolts on the upper and lower working platforms on the test equipment, and the plane centers of the equipment connection layers of the upper universal test fixture and the lower universal test fixture are arranged radially.

8. The multi-item combined testing method for commercial vehicle chassis air springs according to claim 6, characterized in that: The number of the long "U"-shaped grooves is 12, corresponding to the screw holes or bolts of 4 or 6 integral multiples on the upper and lower working platforms of the test equipment.

9. The multi-item combined testing method for commercial vehicle chassis air springs according to any one of claims 1, characterized in that: The multi-item combined test of the commercial vehicle chassis air spring includes an air spring air tightness test, an elastic property test, a destructive test, and a bench fatigue test. It is carried out in a step-by-step test method and includes the following steps: (1) First clean the upper and lower surfaces of the air spring to be tested, and then install the air spring connecting plates of the upper universal test fixture and the lower universal test fixture on the upper and lower cover plates of the air spring to be tested respectively; during installation, care should be taken to avoid contact between the air spring connecting plates and the bolts in the upper and lower cover plates of the air spring to be tested, and avoid this by using the stud holes in the air spring connecting plates so that the air spring connecting plates of the upper universal test fixture and the lower universal test fixture can fit tightly on the air spring connecting plates of the upper universal test fixture and the lower universal test fixture; set a sealing gasket or apply sealant between the air spring connecting plates and the upper and lower cover plates of the air spring to be tested for sealing; (2) Carry out an air tightness test: directly place the air spring to be tested with the upper universal test fixture and the lower universal test fixture installed on the air tightness test platform, press the upper and lower working platforms of the air tightness test equipment on the equipment connection layer plates of the upper universal test fixture and the lower universal test fixture, insert the compression bolts into the long "U"-shaped grooves of the equipment connection layer plates to fix the equipment connection layer plates on the upper and lower working platforms of the air tightness test equipment, and then directly insert the air source air pipe of the air tightness test equipment into the replaceable joint of the upper universal test fixture, tighten it, and then introduce compressed gas, and plug all the replaceable joint installation holes on other equipment connection layers with plugs, start the air tightness test equipment, and carry out an air tightness test; after the air tightness test is completed, loosen the compression bolts on the upper and lower working platforms, and remove the upper and lower working platforms of the air tightness test equipment; take out the air spring to be tested with the upper and lower universal test fixtures after the test, place it on the transfer vehicle and send it to the next process for testing; (3) Conducting elastic property test: directly place the air spring to be tested that has passed the air tightness test, together with the upper universal test fixture and the lower universal test fixture, on the test bench of the elastic property test equipment, and move the upper and lower working platforms of the test bench of the elastic property test equipment downward relative to each other, pressing the upper universal test fixture and the lower universal test fixture on the air spring to be tested. Insert the compression bolts into the long "U"-shaped groove of the equipment connection layer to fix the equipment connection layer on the upper and lower working platforms of the elastic property test equipment. Then directly insert the air source pipe of the elastic property test into the replaceable joint of the upper universal test fixture, tighten it, and then introduce compressed gas. All the replaceable joint mounting holes on other equipment connection layers are blocked with plugs, start the elastic property test equipment, and conduct the elastic property test. After the elastic property test is completed, loosen the compression bolts on the upper and lower working platforms, and remove the upper and lower working platforms of the elastic property test equipment. Take out the air spring to be tested with the upper and lower universal test fixtures after the test and place it on the transfer vehicle for delivery to the next process for inspection. (4) Perform bench fatigue test: The air spring to be tested that has directly undergone the elastic property test is placed on the test bench of the bench fatigue test equipment together with the upper universal test fixture and the lower universal test fixture, and the upper and lower working platforms of the bench fatigue test equipment are connected to the equipment connection layers of the upper universal test fixture and the lower universal test fixture respectively; then, the equipment connection layers are fixed to the upper and lower working platforms of the bench fatigue test equipment by inserting the compression bolts into the long "U"-shaped grooves of the equipment connection layers, and then the replaceable joints are installed on the air spring connection layers of the upper universal test fixture. Install the replaceable joint in the mounting hole, and directly insert the test air source pipe into the replaceable joint of the upper universal test fixture. After tightening, introduce compressed gas, and plug all the replaceable joint mounting holes on other air spring connection plates with plugs. Start the bench fatigue test equipment and conduct the bench fatigue test. After the bench fatigue test is completed, loosen the clamping bolts on the upper and lower working platforms, and remove the upper and lower working platforms of the bench fatigue test equipment. Take out the tested air spring with the upper and lower universal test fixtures and place it on the transfer vehicle to be sent to the next process for testing. (5) Conduct destructive test: directly place the air spring to be tested that has passed the bench fatigue test, together with the upper universal test fixture and the lower universal test fixture, on the test platform of the water explosion test equipment, and connect the upper and lower working platforms of the water explosion test equipment to the equipment connection plates of the upper universal test fixture and the lower universal test fixture respectively; then insert the compression bolts into the long "U"-shaped grooves of the equipment connection plates to fix the equipment connection plates on the upper and lower working platforms of the water explosion test equipment, and then install the replaceable joints in the installation holes of the air spring connection plates of the lower universal test fixture. Install the replaceable joint and screw the multi-channel joint into the replaceable joint. Then connect the water inlet and outlet pipes of the water burst test equipment to the water inlet and outlet of the multi-channel joint respectively. At the same time, plug all the replaceable joint installation holes on the other air spring connection plates with plugs, start the water burst test equipment, and conduct the water burst test. After the water burst test is completed, loosen the clamping bolts on the upper and lower working platforms, and remove the upper and lower working platforms of the water burst test equipment. Place the tested air spring with the upper and lower universal test fixtures on the transfer vehicle and send it to the next process for testing. (6) Disassembling the upper universal test fixture and the lower universal test fixture: After the water burst test, the air spring to be tested is disassembled from the upper universal test fixture and the lower universal test fixture, thereby completing the performance test of the entire air spring to be tested.

10. The multi-item combined testing method for commercial vehicle chassis air springs according to claim 9, characterized in that: The replaceable joint mounting hole of the air spring connecting layer plate is arranged at the air inlet position of the detection air spring; wherein, the replaceable joint mounting hole of the air spring connecting layer plate on the lower universal test tool is arranged at the center position of the air spring connecting layer plate; the replaceable joint mounting hole of the air spring connecting layer plate on the upper universal test tool plate is arranged at the eccentric air inlet position of the air spring connecting layer plate.

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