Automobile cylinder sleeve air tightness detection device

Abstract

The invention discloses an air tightness detection device for an automobile cylinder sleeve. The air tightness detection device comprises an operation table, the supporting assembly is arranged on the operation table, slides in the length direction of the operation table and is used for containing a cylinder sleeve. The driving assembly is arranged on the operation table and the supporting assembly and used for driving the supporting assembly to slide on the operation table. The sealing assembly comprises an upper sealing unit arranged on the operation table and a lower sealing unit arranged on the supporting assembly, and the upper sealing unit and the lower sealing unit are matched to seal the cylinder sleeve. And the pressure detection assembly comprises a pressure sensor and a flow sensor, the pressure sensor is arranged in the cylinder sleeve and used for detecting the pressure change in the cylinder sleeve, and the flow sensor is installed on the air pipe between the inflation assembly and the external air source and used for detecting the flow of inflated air. The device has the advantages that the detection efficiency is improved, the production quality of the automobile cylinder sleeve is guaranteed, the production cost is reduced, the cylinder sleeve is effectively protected, operation is convenient, replacement and maintenance are convenient, and the detection precision is high.

Description

Technical Field

[0001] The present invention relates to the field of vehicle detection, and more particularly, to an airtightness detection device for an automotive cylinder liner. Background Art

[0002] As a core component of an engine, the airtightness of an automotive cylinder liner plays a decisive role in the performance of the engine. During the operation of the engine, the interior of the cylinder liner is subject to repeated impacts of high-temperature and high-pressure combustion gas. Good airtightness can ensure that the combustion gas burns fully in the combustion chamber, providing strong power for the engine. If there is a problem with the airtightness of the cylinder liner, the combustion gas will leak, which will not only reduce the combustion efficiency, resulting in a significant decrease in the engine power, but also cause waste of fuel and a remarkable increase in fuel consumption. Taking a certain type of engine as an example, due to slight air leakage in the cylinder liner, the power output decreased by 15% and the fuel consumption per 100 kilometers increased by 2L. More seriously, long-term gas leakage will cause the internal components of the engine to bear abnormal pressure, accelerate component wear, trigger serious mechanical failures such as piston ring fracture and cylinder block scoring, greatly shortening the service life of the engine, increasing maintenance costs and safety hazards. Currently, the airtightness detection of automotive cylinder liners mainly adopts two methods: manual detection and traditional equipment detection. Manual detection relies on the experience and sensory judgment of the detection personnel. Usually, soapy water is applied and bubbles are observed, or a simple tool is used for pressure testing. In actual operation, the detection personnel need to evenly apply soapy water on the surface of the cylinder liner, and then fill a certain pressure of gas into the cylinder liner, and judge the airtightness by observing whether bubbles are generated on the surface of the soapy water. This method is greatly affected by the subjective judgment of the detection personnel. Different personnel have different judgment criteria for the size and quantity of bubbles, resulting in the lack of consistency and accuracy of the detection results. Moreover, the efficiency of manual detection is extremely low. Skilled workers can only detect 5-8 cylinder liners per hour, which is difficult to meet the detection requirements of large-scale production. In view of the many problems existing in the existing detection methods, those skilled in the art are committed to providing an airtightness detection device with a simple structure, accurate detection, low cost and effective protection of the cylinder liner, which can not only improve the production quality of automotive cylinder liners, ensure the stable performance of the engine, but also reduce the production cost of enterprises and improve production efficiency, and is of great significance to the development of the automotive manufacturing industry. Summary of the Invention

[0003] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to provide an airtightness detection device for an automotive cylinder liner that can effectively solve the above technical problems.

[0004] To achieve the above object, the present invention provides an airtightness detection device for an automotive cylinder liner, including an operation table; A support assembly, arranged on the operation table and sliding along the length direction of the operation table for placing the cylinder liner; A driving component, which is arranged on the operation table and the support component, and is used to drive the support component to slide on the operation table; A sealing component, which includes an upper sealing unit arranged on the operation table and a lower sealing unit arranged on the support component, and seals the cylinder liner through the cooperation of the upper sealing unit and the lower sealing unit; An inflation component, which is arranged on the operation table and is connected to an external air source through an air pipe, and is used to fill the inside of the sealed cylinder liner with a detection gas; A pressure detection component, which includes a pressure sensor and a flow sensor. The pressure sensor is arranged inside the cylinder liner and is used to detect the pressure change inside the cylinder liner. The flow sensor is installed on the air pipe between the inflation component and the external air source and is used to detect the flow rate of the filled gas; A control unit, which is used to receive the data transmitted by the pressure sensor and the flow sensor, and analyze and process the data according to a preset detection program to judge whether the air tightness of the automobile cylinder liner is qualified.

[0005] Furthermore, the operation table includes a table body, a channel penetrating the table body is opened along the length direction of the table body, and end plates for closing the channel are arranged at both ends of the table body; Guide grooves are arranged on both sides of the channel and are opened at the upper end of the table body. The support component is slidably arranged on the table body through the guide grooves.

[0006] Furthermore, the support component includes a support seat, two parallel guide rails are arranged at the lower end of the support seat, and each guide rail is slidably arranged in each guide groove; Limit cylinders are arranged on both sides of the support seat, and rubber - made limit heads are arranged at the output ends of each limit cylinder.

[0007] Furthermore, the driving component includes a positioning frame. The positioning frame is located between the two guide rails and is connected to the lower end of the support seat. A driving motor is arranged on the positioning frame. The output end of the driving motor rotates with the lower end of the support seat. A driving gear is sleeved on the output end of the driving motor. The driving gear meshes with a rack, and both ends of the rack are detachably connected to the respective end plates.

[0008] Furthermore, the positioning frame includes two extension columns. Limit columns with cross - sections smaller than those of the extension columns are arranged at the lower ends of each extension column. The two sides of the upper half of each extension column are respectively connected to the inner sides of each extension rod. The outer sides of each extension rod are respectively sleeved on each positioning rod and are locked by each first locking nut. The upper ends of each positioning rod are simultaneously connected to the lower end of the support seat; The driving motor is arranged on the support plate. Each of the limiting columns is respectively passed through the support plate. A pull rod is arranged at the lower end of each of the extension rods. Each of the pull rods passes through the support plate and is locked by a second locking nut.

[0009] Furthermore, the upper sealing unit includes a downward pressing air cylinder arranged on the top plate. The two sides of the top plate are respectively connected to the two sides of the table body through a plurality of columns. A lower pressing plate connected to the output end of the downward pressing air cylinder is arranged below the top plate. The four corners of the upper end of the lower pressing plate are respectively connected to each guiding rod. Each of the guiding rods is slidably passed through the top plate. A sealing head and a plurality of sealing rods are arranged at the lower end of the lower pressing plate. The lower ends of each of the sealing rods and the sealing head are both provided with a sealing layer made of an elastic material.

[0010] Furthermore, a U-shaped guiding frame is arranged at the lower end of the top plate. The inner side of the U-shaped guiding frame is spaced from the two sides of the lower pressing plate. An opening is formed on the U-shaped guiding frame. The sealing head extends downward through the opening. The upper half sections of each of the sealing rods are slidably passed through the U-shaped guiding frame. The upper ends of each of the sealing rods are detachably connected to the lower pressing plate through nuts.

[0011] Furthermore, the lower sealing unit includes a lower sealing plate detachably arranged on the support seat. A plurality of positioning holes are formed on the lower sealing plate and are located between the two limiting air cylinders. An elastic sealing material layer is arranged on the lower sealing plate. The elastic sealing material layer is detachably connected to the lower sealing plate through a plurality of positioning holes. An operation panel is arranged on the column. A display screen is arranged on the operation panel. Furthermore, the inflation assembly includes two positioning plates. The outer sides of each of the positioning plates are respectively connected to the inner sides of each of the columns. A weight-reducing opening is formed on each of the positioning plates. A plurality of strengthening blocks are arranged at the included angle between each of the positioning plates and each of the columns. Sliders are arranged on the inner sides of each of the positioning plates. An installation fixing plate is arranged between each of the positioning plates. A displacement air cylinder is arranged on the installation fixing plate. The output end of the displacement air cylinder is connected to a U-shaped member. Chutes are arranged on both sides of the U-shaped member. Each of the sliders is respectively slidably arranged in each of the chutes. Both sides of the U-shaped member are respectively sleeved on each of the positioning columns. The upper ends of each of the positioning columns are connected to the lower end of the top plate. The lower ends of each of the positioning columns are respectively connected to the upper ends of each of the positioning plates. A telescopic air cylinder is arranged at the outer end of the U-shaped member. The output end of the telescopic air cylinder is connected to the outer end of a positioning block. An inflation head is arranged at the inner end of the positioning block. The inflation head is connected to an external air source through an air pipe and is used for filling the inside of the sealed cylinder sleeve with detection gas. The upper end of the positioning block is slidably connected to the lower end of the U-shaped member.

[0012] Furthermore, the pressure sensor is a piezoresistive sensor. During the detection process, the pressure sensor converts the sensed pressure signal into an electrical signal to capture the pressure fluctuation; The flow sensor installed on the air pipe between the inflation component and the external air source adopts a thermal gas mass flow sensor. Based on the heat conduction effect, the gas flow is calculated by measuring the rate at which the gas takes away heat. During the inflation process, the flow sensor monitors the flow of the gas in real time and transmits the data to the control unit to help the control unit understand the speed and total amount of gas entering the cylinder liner, and then analyze the air tightness of the cylinder liner. The control unit uses a microcontroller, which is connected to the pressure sensor and the flow sensor through a data transmission interface. After receiving the data, the control unit performs preprocessing operations on the data to remove noise and interference signals in the data. At the same time, the control unit performs in-depth analysis on the processed data according to a preset algorithm to calculate the pressure change rate and flow stability. The control unit stores a preset detection program and standard threshold value. After receiving and processing the pressure and flow data, the control unit compares the calculated parameters with the preset standard threshold value. If the pressure change is within the specified range and the flow is stable and meets the preset air tightness standard, the air tightness of the automobile cylinder liner is determined to be qualified; if the pressure change is abnormal, the air tightness of the cylinder liner is determined to be unqualified. The control unit controls the inflation speed and pressure of the inflation component, as well as the actions of the drive component and the sealing component according to the detection requirements.

[0013] The beneficial effects of the present invention are: The automobile cylinder liner air tightness detection device provided by the present invention has many beneficial effects, which are as follows: 1. Compared with manual inspection, the device has a high degree of automation and greatly improves the inspection efficiency. It can meet the inspection needs of large-scale production, effectively guarantee the production quality of automobile cylinder liners, ensure stable engine performance, and reduce the production cost of enterprises; 2. The control unit can control the inflation speed and pressure of the inflation component according to the detection requirements. When it is detected that the internal pressure of the cylinder liner is close to the preset upper limit, the inflation component can be adjusted in time to reduce the inflation speed to avoid damage to the cylinder liner caused by excessive pressure, which can effectively protect the cylinder liner; 3. The control unit intuitively feeds back the test results to the operator through the display screen on the operation panel, making it convenient for the operator to understand the test progress and results, making the operation convenient and the feedback more intuitive; 4. The two ends of the rack in the drive assembly are detachably connected to the end plates at both ends of the operating table, which facilitates subsequent maintenance and replacement of components; the components such as the extension columns, limit columns, extension rods, and positioning rods of the positioning frame are provided, which not only realizes the drive of the support seat, but also facilitates its disassembly and assembly, ensuring the stable operation of the drive assembly; the lower sealing plate of the lower sealing unit is detachably arranged on the support seat, and the elastic sealing material layer is detachably connected to the lower sealing plate through the positioning holes, which is convenient for replacement and maintenance; 5. A piezoresistive pressure sensor is adopted, with a fast response speed and a measurement accuracy of up to ±0.1% FS full-scale accuracy, which can accurately capture extremely small pressure changes inside the cylinder liner; the thermal gas mass flow sensor is not affected by changes in gas temperature, pressure, and composition, with a measurement accuracy of up to ±1% reading and a wide measurement range, which can meet the detection requirements of different specifications of cylinder liners. The control unit performs preprocessing such as filtering and amplification on the sensor data, and deeply analyzes and calculates key parameters such as the pressure change rate and flow stability through a preset algorithm, compares them with the preset standard thresholds, accurately judges the airtightness of the cylinder liner, and can also preliminarily judge the leakage position or cause according to data anomalies, with high detection accuracy. Description of the Drawings

[0014] Figure 1 It is a schematic structural diagram of a specific embodiment of the present invention.

[0015] Figure 2 It is a schematic structural diagram of components such as a drive assembly arranged on the table body.

[0016] Figure 3 It is a schematic structural diagram of a channel and a guide groove opened on the table body.

[0017] Figure 4 It is a schematic structural diagram of components such as a support assembly.

[0018] Figure 5 It is a schematic structural diagram of the drive assembly in the present invention.

[0019] Figure 6 It is a schematic structural diagram with a limit column arranged at the lower end of the extension column.

[0020] Figure 7 It is a schematic structural diagram of the upper sealing unit arranged on the top plate.

[0021] Figure 8 It is Figure 7 The partial enlarged structural diagram at position A in

[0022] Figure 9 It is a schematic structural diagram of the inflation assembly slidably arranged on the positioning column.

[0023] Figure 10 It is Figure 9 The partial enlarged structural diagram at position B in

[0024] Figure 11 It is a schematic structural diagram of the cooperation between a U-shaped part and a telescopic cylinder.

[0025] Figure 12 It is a schematic structural diagram of a sealing rod sliding on a U-shaped guide frame.

[0026] Figure 13 It is a schematic bottom view structural diagram of components such as a U-shaped guide frame.

[0027] Figure 14 It is a schematic structural diagram of the cooperation between a lower pressing plate and a U-shaped guide frame. Specific implementation mode

[0028] The present invention will be further described below in conjunction with the accompanying drawings and embodiments: In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0029] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "setting", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0030] As Figures 1 to 14 shown, an airtightness detection device for an automobile cylinder liner includes an operation table 1; A support assembly 2 is arranged on the operation table 1 and slides along the length direction of the operation table 1 for placing the cylinder liner; A driving assembly 3 is arranged on the operation table 1 and the support assembly 2 for driving the support assembly 2 to slide on the operation table 1; A sealing assembly 5 includes an upper sealing unit 6 arranged on the operation table 1 and a lower sealing unit 7 arranged on the support assembly 2, and the cylinder liner is sealed through the cooperation of the upper sealing unit 6 and the lower sealing unit 7; An inflation component 8 is arranged on the operation table 1 and is connected to an external air source through an air pipe, and is used to inflate the inside of the sealed cylinder sleeve with a detection gas; A pressure detection component, including a pressure sensor and a flow sensor. The pressure sensor is arranged inside the cylinder sleeve and is used to detect the pressure change inside the cylinder sleeve. The flow sensor is installed on the air pipe between the inflation component 8 and the external air source and is used to detect the flow rate of the inflated gas; A control unit is used to receive the data transmitted by the pressure sensor and the flow sensor, and analyze and process the data according to a preset detection program to determine whether the air tightness of the automotive cylinder sleeve is qualified.

[0031] The operation table 1 includes a table body 9. A channel 10 penetrating the table body 9 is opened along the length direction of the table body 9. End plates 11 for closing the channel 10 are arranged at both ends of the table body 9; Guide grooves 12 are arranged on both sides of the channel 10 and are opened at the upper end of the table body 9. The support component 2 is slidably arranged on the table body 9 through the guide grooves 12.

[0032] The support component 2 includes a support seat 13. Two mutually parallel guide rails 15 are arranged at the lower end of the support seat 13. Each guide rail 15 is slidably arranged in each guide groove 12. In the present invention, preferably, the guide rails 15 at the lower end of the support seat 13 are made of wear-resistant and high-strength alloy steel material, such as 42CrMo alloy steel, with a Rockwell hardness HRC between 40-45, a tensile strength of not less than 1080 MPa, and the surface of the guide rail is subjected to precision grinding treatment, and the roughness Ra can reach 0.8 μm. When cooperating with the guide groove, the friction coefficient is about 0.1-0.15, so that the support component slides smoothly, reduces energy loss and component wear, and effectively extends the service life of the device.

[0033] Limit cylinders 16 are arranged on both sides of the support seat 13. Limiting heads 17 made of rubber material are arranged at the output ends of the limit cylinders 16. The limit cylinders 16 are of the CDQ2 series high-precision cylinders, and their positioning accuracy can reach ±0.1 mm. The limiting heads 17 are made of nitrile rubber material with a Shore A60 hardness, which not only has good elasticity, can closely fit the surface of the cylinder sleeve, but also has a certain anti-slip performance. In actual detection, through precise stroke control of the limit cylinders 16, the positioning error of the cylinder sleeve can be controlled within the range of ±0.1 mm, ensuring the consistency of the cylinder sleeve position during each detection and improving the reliability of the detection result.

[0034] The driving assembly 3 includes a positioning frame 18 which is located between two guide rails 15 and connected to the lower end of the support seat 13. A driving motor 19 is arranged on the positioning frame 18. The output end of the driving motor 19 rotates with the lower end of the support seat 13. A driving gear 20 is sleeved on the output end of the driving motor 19. The driving gear 20 meshes with a rack 21. Two ends of the rack 21 are respectively detachably connected to the end plates 11. In the present invention, the driving motor 19 is a three-phase asynchronous motor with the model of Y90L-4, its rated power is 1.5 kW, the rated speed is 1400 r / min, and the starting torque can reach 2.2 times of the rated torque. When driving the sliding of the support assembly 2, the motor can quickly respond to the control signal and provide a stable driving force to ensure the smooth and rapid movement of the support seat 13 in the guide groove 12; In addition, the extension columns 22 and positioning rods 27 of the positioning frame 18 are made of 6061 aluminum alloy and manufactured by precision casting process. The density of 6061 aluminum alloy is about 2.7 g / cm³, and the tensile strength is not less than 205 MPa. The surfaces of the extension columns 22 and positioning rods 27 are treated by anodic oxidation, and the thickness of the oxide film is about 10-15 μm, which enhances the corrosion resistance and wear resistance. The extension rod 26 and the positioning rod 27 are connected by a first locking nut 28 of M8, and the tightening torque is controlled at 20-25 N·m, which is convenient for installation and disassembly, and can accurately control the structural dimensions of the positioning frame 18 to ensure the installation accuracy and operation stability of the driving assembly 3.

[0035] The positioning frame 18 includes two extension columns 22. The lower end of each extension column 22 is provided with a limit column 23 whose cross-section is smaller than that of the extension column 22. The two sides of the upper half of each extension column 22 are respectively connected to the inner sides of the extension rods 26. The outer sides of the extension rods 26 are respectively sleeved on the positioning rods 27 and locked by the first locking nuts 28. The upper ends of the positioning rods 27 are simultaneously connected to the lower end of the support seat 13; The driving motor 19 is arranged on a support plate 29. The limit columns 23 respectively pass through the support plate 29. A pull rod 30 is arranged at the lower end of each extension rod 26. The pull rods 30 respectively pass through the support plate 29 and are locked by second locking nuts 31.

[0036] The upper sealing unit 6 includes a downward pressing air cylinder 50 which is arranged on a top plate 51. Two sides of the top plate 51 are respectively connected to two sides of the table body 9 through a plurality of columns 53; A lower pressing plate 52 connected to the output end of the lower pressing cylinder 50 is arranged below the top plate 51. The upper ends of the four corners of the lower pressing plate 52 are respectively connected to the guiding rods 55. Each of the guiding rods 55 is slidably arranged through the top plate 51. A sealing head 56 and a plurality of sealing rods 57 are arranged at the lower end of the lower pressing plate 52. The lower ends of each of the sealing rods 57 and the sealing head 56 are both provided with a sealing layer made of an elastic material.

[0037] A U-shaped guiding frame 58 is arranged at the lower end of the top plate 51. The inner side of the U-shaped guiding frame 58 is spaced from both sides of the lower pressing plate 52. An opening 59 is formed on the U-shaped guiding frame 58. The sealing head 56 extends downward through the opening 59. The upper half sections of each of the sealing rods 57 are slidably arranged through the U-shaped guiding frame 58. The upper ends of each of the sealing rods 57 are detachably connected to the lower pressing plate 52 through nuts.

[0038] In the present invention, in the upper sealing unit 6, the elastic sealing layer is made of DuPont Viton fluororubber material with high temperature resistance and wear resistance. Its hardness is Shore A70 degrees, and its elastic modulus is 3 - 5 MPa. The bottom of the sealing head 56 is a circular arc with a radius of 15 mm, having a large and uniform contact area with the top of the cylinder liner. Three sealing lips are designed at the lower end of the sealing rod 57, and the width of each lip is 2 mm, enhancing the sealing effect.

[0039] The lower sealing unit 7 includes a lower sealing plate 60 detachably arranged on the support seat 13. A plurality of positioning holes 61 are formed on the lower sealing plate 60 and are located between the two limiting cylinders 16. An elastic sealing material layer is arranged on the lower sealing plate 60. The elastic sealing material layer is detachably connected to the lower sealing plate 60 through the plurality of positioning holes 61. An operation panel 62 is arranged on the column 53. A display screen is arranged on the operation panel 62. The elastic sealing material layer of the lower sealing unit 7 is made of polyurethane rubber with a hardness of Shore A80 and a tear resistance of not less than 30 kN / m. The diameter of the positioning holes 61 on the lower sealing plate 60 is 8 mm and they are evenly distributed, which not only facilitates the installation and disassembly of the elastic sealing material layer but also aids in positioning, making the elastic sealing material layer fit more closely to the bottom of the cylinder liner and improving the sealing performance.

[0040] The inflation assembly 8 includes two positioning plates 63. The outer sides of each of the positioning plates 63 are respectively connected to the inner sides of each of the columns 53. A weight reduction opening 65 is formed on each of the positioning plates 63. A plurality of reinforcing blocks 66 are arranged at the angles between each of the positioning plates 63 and each of the columns 53. Sliders 67 are arranged on the inner sides of each of the positioning plates 63. There is a mounting fixed plate 68 between each of the positioning plates 63. A displacement cylinder 69 is arranged on the mounting fixed plate 68. The output end of the displacement cylinder 69 is connected to a U-shaped member 70. Slide grooves 71 are arranged on both sides of the U-shaped member 70. Each of the sliders 67 is respectively arranged to slide in each of the slide grooves 71. Both sides of the U-shaped member 70 are respectively sleeved on each positioning post 72. The upper ends of each of the positioning posts 72 are connected to the lower end of the top plate 51. The lower ends of each of the positioning posts 72 are respectively connected to the upper ends of each of the positioning plates 63; The displacement cylinder 69 selects a DGC series cylinder, with a working pressure range of 0.4 - 0.8 MPa and a stroke accuracy of up to ±0.05 mm; the telescopic cylinder 73 selects an MBB series cylinder, with a working pressure range of 0.3 - 0.7 MPa and a stroke accuracy of up to ±0.03 mm. During the inflation process, the displacement cylinder 69 accurately controls the moving position of the U-shaped member 70 to make the inflation head 76 accurately align with the cylinder sleeve inflation port; the telescopic cylinder 73 accurately controls the insertion depth of the inflation head 76 to ensure good sealing between the inflation head 76 and the cylinder sleeve inflation port and avoid gas leakage.

[0041] A telescopic cylinder 73 is arranged at the outer end of the U-shaped member 70. The output end of the telescopic cylinder 73 is connected to the outer end of a positioning block 75. An inflation head 76 is arranged at the inner end of the positioning block 75. The inflation head 76 is connected to an external air source through an air pipe and is used to fill the sealed cylinder sleeve with detection gas; the upper end of the positioning block 75 is slidably connected to the lower end of the U-shaped member 70.

[0042] The inflation head 76 is made of 304 stainless steel. The inlet pipe diameter of the internal gas flow channel is 10 mm, and the outlet pipe diameter is 6 mm, showing a tapered design. This design forms a pressure difference of about 0.1 - 0.2 MPa when the gas enters the cylinder sleeve, promoting the gas to evenly fill the inside of the cylinder sleeve and improving the inflation efficiency and detection accuracy.

[0043] In the present invention, the pressure sensor is a piezoresistive sensor. During the detection process, the pressure sensor converts the sensed pressure signal into an electrical signal, with an extremely fast response speed to capture the pressure fluctuations; moreover, the measurement accuracy of this sensor is as high as ±0.1% FS full-scale accuracy, which means that even if there is an extremely small change in the internal pressure of the cylinder sleeve, it can be accurately detected, providing key data support for subsequent airtightness judgment.

[0044] The flow sensor installed on the air pipe between the inflation component and the external gas source adopts a thermal gas mass flow sensor. Based on the heat conduction effect, it calculates the gas flow by measuring the rate at which the gas takes away heat. This sensor is not affected by changes in gas temperature, pressure and composition, and has extremely high measurement accuracy and reliability. It has a wide measurement range and can meet the monitoring needs of gas flow when testing cylinder liners of different specifications, with an accuracy of up to ±1% of the reading. During the inflation process, the flow sensor monitors the flow of the filling gas in real time and transmits the data to the control unit to help the control unit understand the speed and total amount of gas entering the cylinder liner, and then analyze the air tightness of the cylinder liner; The control unit adopts a microcontroller with powerful data processing capabilities. The controller adopts STMicroelectronics' STM32F407ZGT6 chip, whose core frequency is up to 168MHz, and integrates 1MB of flash memory and 192KB of SRAM. In the data processing process, the Kalman filter algorithm is used to reduce the noise of the data collected by the pressure sensor and flow sensor by 30%-50%, and improve the data accuracy and stability.

[0045] It is connected to the pressure sensor and flow sensor through the data transmission interface, and can receive the pressure and flow data from the sensor in real time and stably. After receiving the data, the control unit performs pre-processing operations such as filtering and amplification on the data to remove noise and interference signals in the data to ensure the accuracy and reliability of the data. At the same time, the control unit will conduct in-depth analysis of the processed data according to the preset algorithm to calculate key parameters such as pressure change rate and flow stability; The control unit stores preset detection programs and standard thresholds. After receiving and processing the pressure and flow data, the control unit compares the calculated parameters with the preset standard thresholds. If the pressure change is within the specified range and the flow is stable and meets the preset air tightness standard, the automobile cylinder liner is judged to be airtight. If the pressure change is abnormal, such as the pressure drops too fast or the flow fluctuates abnormally, the cylinder liner is judged to be unqualified. In addition, the control unit can also perform intelligent analysis based on the abnormal data, preliminarily determine the location or cause of the possible leakage, and provide a reference for subsequent maintenance and improvement.

[0046] The control unit can not only determine the air tightness of the cylinder liner, but also has the function of controlling the entire detection device. During the detection process, it can control the inflation speed and pressure of the inflation component, as well as the actions of the drive component and the sealing component according to the detection requirements; for example, when it is detected that the internal pressure of the cylinder liner is close to the preset upper limit, the control unit will adjust the inflation component in time to reduce the inflation speed to avoid damage to the cylinder liner caused by excessive pressure. At the same time, the control unit can also intuitively feedback the test results to the operator through the display screen on the operation panel, making it convenient for the operator to understand the progress and results of the test; The algorithm preset by the control unit adopts a machine learning algorithm based on Support Vector Machine (SVM). After learning and training with 1000 sets of cylinder liner detection data with known airtightness states, an accurate airtightness judgment model is established. In actual detection, the error of the algorithm in calculating parameters such as the pressure change rate and flow stability does not exceed ±5%. Compared with the preset standard threshold, the accuracy and reliability of airtightness judgment are greatly improved. In addition, the control unit has a fault diagnosis function. When abnormal data is detected, it can initially judge the cause and location of the fault within 5s according to the preset fault diagnosis rules, and prompt the operator to handle it through the indicator light or display screen on the operation panel 62.

[0047] The optimal working principle of the present invention is as follows: First, place the cylinder liner on the support assembly 2. The driving assembly 3 drives the support assembly 2 to slide to the specified detection position. The upper sealing unit 6 and the lower sealing unit 7 of the sealing assembly 5 cooperate to seal the cylinder liner. The inflation assembly 8 fills in the detection gas. The pressure sensor and flow sensor of the pressure detection assembly respectively monitor the internal pressure change of the cylinder liner and the flow rate of the filled gas. The control unit receives and processes the data and judges the airtightness of the cylinder liner. More specifically: Place the automotive cylinder liner on the support seat 13 of the support assembly 2. The lower end of the support seat 13 slides in the guide groove 12 on the table body 9 of the operating table 1 through the driving motor 19, so as to realize the movement of the support assembly 2 along the length direction of the operating table 1. The limiting air cylinders 16 on both sides of the support seat 13 extend, and position the cylinder liner through the limiting heads 17 made of rubber material to prevent its displacement during the detection process; start the driving motor 19 of the driving assembly 3. The driving gear 20 at the output end of the driving motor 19 meshes with the rack 21. Both ends of the rack 21 are detachably connected to the end plates 11 at both ends of the operating table 1, which is convenient for subsequent maintenance and replacement of parts. When the driving gear 20 rotates, it drives the support seat 13 to slide along the guide groove 12, so that the cylinder liner reaches the appropriate detection position. The settings of components such as the extension column 22, the limiting column 23, the extension rod 26, the positioning rod 27 and the driving motor 19 of the positioning frame 18 can not only drive the support seat 13, but also facilitate its disassembly and assembly to ensure the stable operation of the driving assembly 3; start the pressing air cylinder 50 of the upper sealing unit 6 to push the lower pressing plate 52 to move downward. The lower pressing plate 52 slides on the top plate 51 through the guide rod 55 to ensure the smoothness of the pressing process. The sealing head 56 and the sealing rod 57 at the lower end of the lower pressing plate 52 descend, and the elastic sealing layer at the lower ends of the sealing head 56 and the sealing rod 57 contacts and seals the top of the cylinder liner. At the same time, the elastic sealing material layer on the lower sealing plate 60 of the lower sealing unit 7 contacts and seals the bottom of the cylinder liner to realize the overall sealing of the cylinder liner. The U-shaped guide frame 58 plays a guiding role for the sealing rod 57 to ensure the sealing effect; the displacement air cylinder 69 of the inflation assembly 8 acts to push the U-shaped part 70 to move, so that the inflation head 76 is aligned with the inflation port of the cylinder liner. The telescopic air cylinder 73 extends to drive the positioning block 75 and the inflation head 76 to insert into the inflation port of the cylinder liner. The external air source fills the sealed cylinder liner with detection gas through the inflation head 76 via the air pipe. The pressure sensor is installed inside the cylinder liner to monitor the internal pressure change of the cylinder liner in real time and convert the pressure signal into an electrical signal and transmit it to the control unit; the flow sensor is installed on the air pipe between the inflation assembly 8 and the external air source to measure the flow rate of the inflated gas based on the heat conduction effect and transmit the flow rate data to the control unit; the control unit adopts a high-performance microcontroller, receives the data transmitted by the pressure sensor and the flow sensor through the high-speed data transmission interface, performs preprocessing operations such as filtering and amplifying on the data, and then calculates key parameters such as the pressure change rate and the flow stability according to the preset algorithm. Compare the calculated parameters with the preset standard thresholds. If the pressure change is within the specified range and the flow rate is stable, it is determined that the air tightness of the automotive cylinder liner is qualified; otherwise, it is determined to be unqualified. The control unit can also preliminarily judge the leakage position or cause according to the data anomaly; the control unit controls the inflation speed and pressure of the inflation assembly 8 and the actions of components such as the driving assembly 3 and the sealing assembly 5 according to the detection requirements. For example, when it is detected that the internal pressure of the cylinder liner is close to the preset upper limit, the control unit adjusts the inflation assembly 8 to reduce the inflation speed.The test results are fed back to the operator through the display screen on the operation panel 62, facilitating the understanding of the test progress and results.

[0048] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations based on the concept of the present invention without creative work. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field of the present invention through logical analysis, reasoning, or limited experiments based on the concept of the present invention on the basis of the prior art should fall within the protection scope determined by the claims.

Claims

1. An airtightness detection device for an automobile cylinder liner, characterized in that, Comprising an operating platform (1); A support assembly (2), arranged on the operating platform (1) and sliding along the length direction of the operating platform (1), for placing a cylinder liner; A driving assembly (3), arranged on the operating platform (1) and the support assembly (2), for driving the support assembly (2) to slide on the operating platform (1); A sealing assembly (5), including an upper sealing unit (6) arranged on the operating platform (1) and a lower sealing unit (7) arranged on the support assembly (2), realizing the sealing of the cylinder liner through the cooperation of the upper sealing unit (6) and the lower sealing unit (7); An inflation assembly (8), arranged on the operating platform (1), connected to an external gas source through a gas pipe, for filling the sealed cylinder liner with a detection gas; A pressure detection assembly, including a pressure sensor and a flow sensor, the pressure sensor is arranged inside the cylinder liner for detecting the pressure change inside the cylinder liner, and the flow sensor is installed on the gas pipe between the inflation assembly (8) and the external gas source for detecting the flow rate of the filled gas; A control unit, for receiving the data transmitted by the pressure sensor and the flow sensor, and analyzing and processing the data according to a preset detection program to judge whether the air tightness of the automotive cylinder liner is qualified.

2. The airtightness detection device for an automobile cylinder liner according to claim 1, characterized in that, The operating platform (1) includes a platform body (9), a channel (10) penetrating the platform body (9) is opened along the length direction of the platform body (9), and end plates (11) for closing the channel (10) are arranged at both ends of the platform body (9); Guide grooves (12) are arranged on both sides of the channel (10) and opened at the upper end of the platform body (9), and the support assembly (2) is slidably arranged on the platform body (9) through the guide grooves (12).

3. The airtightness detection device for an automotive cylinder liner according to claim 2, characterized in that, The support assembly (2) includes a support seat (13), two parallel guide rails (15) are arranged at the lower end of the support seat (13), and each guide rail (15) is respectively slidably arranged in each guide groove (12); Limit cylinders (16) are arranged on both sides of the support seat (13), and limit heads (17) made of rubber are arranged at the output ends of the limit cylinders (16).

4. The airtightness detection device for an automotive cylinder liner according to claim 3, characterized in that, The driving assembly (3) includes a positioning frame (18), the positioning frame (18) is located between the two guide rails (15) and is connected to the lower end of the support seat (13), a driving motor (19) is arranged on the positioning frame (18), the output end of the driving motor (19) rotates with the lower end of the support seat (13), a driving gear (20) is sleeved on the output end of the driving motor (19), the driving gear (20) meshes with a rack (21), and both ends of the rack (21) are detachably connected to the end plates (11).

5. The airtightness detection device for an automobile cylinder liner according to claim 4, characterized in that, The positioning frame (18) includes two extension columns (22). At the lower end of each extension column (22), a limit column (23) with a cross-section smaller than that of the extension column (22) is provided. On both sides of the upper half of each extension column (22), they are respectively connected to the inner sides of the extension rods (26). The outer sides of the extension rods (26) are respectively sleeved on the positioning rods (27) and locked by the first locking nuts (28). The upper ends of the positioning rods (27) are simultaneously connected to the lower end of the support seat (13). The driving motor (19) is arranged on the support plate (29). Each limit column (23) passes through the support plate (29). At the lower end of each extension rod (26), a pull rod (30) is provided. Each pull rod (30) passes through the support plate (29) and is locked by the second locking nut (31).

6. The airtightness detection device for an automotive cylinder liner according to claim 5, characterized in that, The upper sealing unit (6) includes a downward pressing air cylinder (50). The downward pressing air cylinder (50) is arranged on the top plate (51). Both sides of the top plate (51) are respectively connected to both sides of the table body (9) through a plurality of columns (53). Below the top plate (51), a lower pressing plate (52) connected to the output end of the downward pressing air cylinder (50) is provided. The four corners of the upper end of the lower pressing plate (52) are respectively connected to the guide rods (55). Each guide rod (55) slidably passes through the top plate (51). At the lower end of the lower pressing plate (52), a sealing head (56) and a plurality of sealing rods (57) are provided. The lower ends of the sealing rods (57) and the sealing head (56) are both provided with a sealing layer made of elastic material.

7. The airtightness detection device for the automotive cylinder liner according to claim 6, wherein, At the lower end of the top plate (51), a U-shaped guide frame (58) is provided. The inner side of the U-shaped guide frame (58) is spaced from both sides of the lower pressing plate (52). An opening (59) is formed on the U-shaped guide frame (58). The sealing head (56) extends downward through the opening (59). The upper half of each sealing rod (57) slidably passes through the U-shaped guide frame (58). The upper ends of the sealing rods (57) are detachably connected to the lower pressing plate (52) through nuts.

8. The airtightness detection device for an automotive cylinder liner according to claim 7, wherein, The lower sealing unit (7) includes a lower sealing plate (60) detachably arranged on the support seat (13). A plurality of positioning holes (61) are formed on the lower sealing plate (60) and are located between the two limit air cylinders (16). An elastic sealing material layer is arranged on the lower sealing plate (60). The elastic sealing material layer is detachably connected to the lower sealing plate (60) through the plurality of positioning holes (61). An operation panel (62) is arranged on the column (53). A display screen is arranged on the operation panel (62).

9. The airtightness detection device for an automotive cylinder liner according to claim 8, characterized in that, The inflatable assembly (8) comprises two positioning plates (63), the outer sides of each positioning plate (63) are respectively connected to the inner sides of each upright column (53), each positioning plate (63) is provided with a weight-reducing opening (65), a plurality of reinforcing blocks (66) are provided at the angle between each positioning plate (63) and each upright column (53), and a sliding block (67) is provided on the inner side of each positioning plate (63); A mounting plate (68) is provided between each of the positioning plates (63), and a displacement cylinder (69) is provided on the mounting plate (68). The output end of the displacement cylinder (69) is connected to a U-shaped member (70), and both sides of the U-shaped member (70) are provided with a slide groove (71). Each of the sliders (67) is slidably arranged in each of the slide grooves (71), and both sides of the U-shaped member (70) are respectively sleeved on each of the positioning columns (72), and the upper end of each of the positioning columns (72) is connected to the lower end of the top plate (51), and the lower end of each of the positioning columns (72) is respectively connected to the upper end of each of the positioning plates (63); The outer end of the U-shaped member (70) is provided with a telescopic cylinder (73), the output end of the telescopic cylinder (73) is connected to the outer end of the positioning block (75), the inner end of the positioning block (75) is provided with an air charging head (76), the air charging head (76) is connected to an external air source via an air pipe, and is used to charge the inside of the sealed cylinder sleeve with detection gas; the upper end of the positioning block (75) is slidably connected to the lower end of the U-shaped member (70).

10. The automobile cylinder liner air tightness detection device according to claim 9, characterized in that: The pressure sensor is a piezoresistive sensor. During the detection process, the pressure sensor converts the sensed pressure signal into an electrical signal to capture the pressure fluctuation; The flow sensor installed on the air pipe between the inflation component and the external air source adopts a thermal gas mass flow sensor. Based on the heat conduction effect, the gas flow is calculated by measuring the rate at which the gas takes away heat. During the inflation process, the flow sensor monitors the flow of the gas in real time and transmits the data to the control unit to help the control unit understand the speed and total amount of gas entering the cylinder liner, and then analyze the air tightness of the cylinder liner. The control unit uses a microcontroller, which is connected to the pressure sensor and the flow sensor through a data transmission interface. After receiving the data, the control unit performs preprocessing operations on the data to remove noise and interference signals in the data. At the same time, the control unit performs in-depth analysis on the processed data according to a preset algorithm to calculate the pressure change rate and flow stability. The control unit stores a preset detection program and standard threshold value. After receiving and processing the pressure and flow data, the control unit compares the calculated parameters with the preset standard threshold value. If the pressure change is within the specified range and the flow is stable and meets the preset air tightness standard, the air tightness of the automobile cylinder liner is determined to be qualified; if the pressure change is abnormal, the air tightness of the cylinder liner is determined to be unqualified. The control unit controls the inflation speed and pressure of the inflation component, as well as the actions of the drive component and the sealing component according to the detection requirements.

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