Axial pressure testing method for brake pipe sealing structure

Abstract

The invention discloses a method for testing the axial pressure of a brake pipe sealing structure, and the method comprises the following steps: S10, carrying out the horizontal cutting of a matching part in the radial direction, and forming an upper nut part and a lower pedestal part; s20, the lower base part is fixedly arranged in a concave cavity in the top of the torque column; s30, sequentially installing a pipe joint, an upper nut part and a fixing seat of the torque column; s40, sequentially installing an angle sensor and a torque wrench; s50, a brake fixing device is installed; s60, a torque wrench is driven to apply tightening torque to the pipe joint, and torque, rotation angle data and effective axial force when the tightening torque is the maximum value are obtained; s70, a torque wrench is driven to apply unscrewing torque to the pipe joint, and when the numerical value of the unscrewing torque reaches the maximum value of the tightening torque, the loosening torque is obtained; s80, the pipe joint is thoroughly loosened, and the torque and the axial load are both zero; and S90, reading the maximum rotation angle. According to the axial pressure testing method, the axial sealing pressure of the brake pipe sealing structure can be directly tested and evaluated.

Description

Technical Field

[0001] This invention relates to the field of automotive braking technology, and more specifically to a method for testing the axial pressure of a brake pipe sealing structure. Background Technology

[0002] Hydraulic fluid systems are widely used in motor vehicle braking systems. These systems contain several component interfaces that must maintain a high brake fluid pressure throughout their service life. Any leakage of hydraulic brake fluid can lead to reduced braking performance or complete brake failure, seriously jeopardizing driving safety and is therefore unacceptable.

[0003] In existing brake pipe sealing structures, the brake pipe sealing structure includes a matching component, a brake pipe section, and a pipe connector. The matching component has a fluid passage hole in its central axis, which includes a wide-diameter section, a conical section, and a narrow-diameter section connected in sequence. The inner wall of the wide-diameter section has internal threads. The brake pipe section includes a pipe body and an integrally coaxially mounted flared end cap at one end of the pipe body. The flared end cap is located inside the conical section. The end of the pipe body connected to the flared end cap is coaxially located inside the wide-diameter section. One end of the pipe connector has a nut, and the other end has external threads. The external threads of the pipe connector and the internal threads of the wide-diameter section are screwed together to compress and deform the flared end cap, so that the outer peripheral wall of the flared end cap and the inner peripheral wall of the conical section form a surface contact sealing fit. The reliability of this sealing structure depends on the tightening torque applied to the pipe connector during installation. If the torque is too small, sufficient sealing pressure cannot be formed, which may lead to leakage; if the torque is too large, the flared end cap may be excessively compressed, or even the threads may be damaged, which may also cause sealing failure or difficulty in disassembly and assembly. Therefore, accurately controlling and verifying the sealing performance of the sealing structure after tightening has become a key technical issue in this field.

[0004] Chinese patent (publication number CN108351055A) discloses a brake pipe connector and a brake pipe connector assembly. In this patent, to obtain the characteristics of the brake pipe connector, a digital model of the brake pipe connection was developed using the finite element code MSCMarc. This model aims to calculate the force and deformation in the brake pipe when torque is applied to the pipe connector. The specific analysis method includes: first, applying an axial force F to the pipe connector and the mating component, and measuring the torque TT generated by the rotating screw for a series of F values ​​to analyze the change in torque contribution with axial force; second, by fixing the mating component, simultaneously applying the axial force F and the torque TF to the pipe connector to determine the frictional force between the pipe connector and the brake pipe segment.

[0005] While the aforementioned digital modeling method provides a valuable reference for understanding the internal mechanical relationships of connectors, its analysis results heavily depend on the accuracy of the model boundary conditions, and the analysis process is complex, making it difficult to apply directly and quickly to online quality monitoring on production lines. Summary of the Invention

[0006] In view of this, the present invention proposes a method for testing the axial pressure of a brake pipe sealing structure, so as to directly test and evaluate the axial sealing pressure of the brake pipe sealing structure.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A method for testing the axial pressure of a brake pipe sealing structure, wherein the brake pipe sealing structure being tested includes:

[0009] A matching component, wherein a liquid passage hole is provided in the central axis of the matching component, the liquid passage hole comprising a wide diameter section, a conical section and a narrow diameter section connected in sequence, and the inner wall of the wide diameter section is provided with internal threads;

[0010] The braking pipe section includes a pipe body and an integrally coaxially arranged flared end cap at one end of the pipe body. The flared end cap is located within a conical section, and the pipe body is coaxially arranged within a wide-diameter section at the end connected to the flared end cap.

[0011] The pipe fitting has a nut at one end and an external thread at the other end. The external thread of the pipe fitting is screwed into the internal thread of the wide diameter section to compress and deform the flared end head, so that the outer peripheral wall of the flared end head and the inner peripheral wall of the conical section form a surface contact sealing fit.

[0012] The sealing structure axial pressure testing equipment includes a torque column, an angle sensor, a torque wrench, a pipeline fixing device, and a data processing unit. The torque column is equipped with a torque sensor and an axial force sensor, and the data processing unit is electrically connected to the angle sensor, the torque sensor, and the axial force sensor, respectively.

[0013] The axial pressure test method includes the following steps:

[0014] S10. The matching part is horizontally cut along its radial direction to form a separate upper nut part and lower base part, wherein the cut surface is located at the junction of the wide diameter section and the conical section;

[0015] S20. Place the lower base into the top recess of the torque column to fix it circumferentially;

[0016] S30. The pipe body is sequentially fitted into the center hole of the pipe connector, the pipe connector is fitted into the center hole of the torque column fixing seat, the upper nut is screwed onto the pipe connector, and the torque column fixing seat is fixedly pressed against the top cavity of the torque column, so that the torque column fixing seat is fixed.

[0017] S40. Install an angle sensor on the nut part of the pipe fitting, and install a torque wrench on the test nut of the angle sensor.

[0018] S50. A pipe fixing device for circumferentially fixing the pipe body is provided at the end of the pipe body away from the flared end.

[0019] S60: The drive torque wrench applies tightening torque to the nut part of the pipe fitting, causing the pipe fitting to rotate to the preset tightening endpoint. The data processing unit obtains the torque, rotation angle data, and effective axial force at the maximum tightening torque.

[0020] S70: The drive torque wrench applies loosening torque to the nut of the pipe fitting. When the value of the loosening torque reaches the maximum value of the tightening torque, the data processing unit obtains the loosening torque.

[0021] S80. Completely loosen the nut of the pipe fitting to reduce both torque and axial load to zero;

[0022] S90: The maximum rotation angle of the torque wrench is read from the rotation curve by the data processing unit.

[0023] To better achieve the above technical solution, the length of the brake tube segment may optionally be 150mm.

[0024] Optionally, in step S60, the torque wrench applies a tightening torque smoothly and uniformly to the nut of the pipe fitting, causing the pipe fitting to rotate to the preset tightening endpoint. During the tightening process, the angle sensor records the rotation angle data of the nut of the pipe fitting in real time, the torque sensor records the torque of the torque wrench in real time, and the axial force sensor records the axial load during the tightening process using the wrench in real time. The corresponding values ​​are plotted into a continuous curve by computer software, and the connection performance of the fitting is displayed accordingly.

[0025] The beneficial effects of this invention are:

[0026] The axial pressure testing method for the brake pipe sealing structure of the present invention involves cutting the matching part 10 to separate the upper nut part and the lower base part. This allows the axial force generated by tightening the pipe joint during the test, which directly acts on the sealing interface, to be accurately sensed and measured by the axial force sensor inside the torque column. This eliminates the force transmission loss of the intermediate structure, and the measurement results are direct and reliable. Attached Figure Description

[0027] Figure 1 This is a front view of a brake pipe section in the prior art;

[0028] Figure 2 This is a cross-sectional view of the brake pipe sealing structure in the prior art;

[0029] Figure 3 This is a cross-sectional view of the cut matching parts in an axial pressure test method for a brake pipe sealing structure according to an embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of the equipment required for an axial pressure testing method for a brake pipe sealing structure according to an embodiment of the present invention;

[0031] Figure 5 yes Figure 4 Enlarged view of point A in the middle;

[0032] Figure label:

[0033] Matching part 10, upper nut part 11, lower base part 12, wide diameter section 101, conical section 102, narrow diameter section 103, internal thread 104, brake pipe section 20, pipe body 21, flared end cap 22, pipe joint 30, nut part 31, external thread 32, torque column 40, torque sensor 401, axial force sensor 402, fixing seat 403, angle sensor 50, torque wrench 60, pipeline fixing device 70. Detailed Implementation

[0034] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. Identical components are indicated by the same reference numerals.

[0035] Please see Figures 1 to 5 This invention provides a method for testing the axial pressure of a brake pipe sealing structure, wherein the tested brake pipe sealing structure includes a matching part 10, a brake pipe section 20, and a pipe joint 30.

[0036] like Figure 1 and Figure 2 As shown, the matching part 10 has a fluid passage hole in its central axis. The fluid passage hole includes a wide diameter section 101, a conical section 102 and a narrow diameter section 103 connected in sequence. The inner wall of the wide diameter section 101 is provided with an internal thread 104. The brake pipe section 20 includes a pipe body 21 and an integrally coaxially disposed flared end cap 22 at one end of the pipe body 21. The flared end cap 22 is disposed inside the conical section 102. The end of the pipe body 21 connected to the flared end cap 22 is coaxially disposed inside the wide diameter section 101. One end of the pipe joint 30 is provided with a nut part 31 and the other end is provided with an external thread 32. By screwing the external thread 32 of the pipe joint 30 with the internal thread 104 of the wide diameter section 101 to compress the flared end cap 22 to cause it to deform, the outer peripheral wall of the flared end cap 22 and the inner peripheral wall of the conical section 102 form a surface contact sealing fit.

[0037] like Figure 4 and Figure 5As shown, the test equipment for implementing the axial pressure test method of the brake pipe sealing structure includes: a torque column 40, an angle sensor 50, a torque wrench 60, a pipe fixing device 70, and a data processing unit (not shown in the figure). The torque column 40 is equipped with a torque sensor 401 and an axial force sensor 402. The data processing unit is electrically connected to the angle sensor 50, the torque sensor 401, and the axial force sensor 402, respectively.

[0038] like Figures 3-5 As shown, the axial pressure test method includes the following steps:

[0039] S10. The matching part 10 is horizontally cut along its radial direction to form a separate upper nut part 11 and lower base part 12. The cut surface is located at the junction of the wide diameter section 101 and the conical section 102.

[0040] S20. Place the lower base portion 12 into the recessed cavity at the top of the torque column 40 to fix it circumferentially.

[0041] S30, the pipe body 21 is sequentially fitted into the central hole of the pipe connector 30, the pipe connector 30 is fitted into the central hole of the fixing seat of the torque column 40, the upper nut part 11 is screwed onto the pipe connector 30, and the fixing seat 403 of the torque column 40 is fixedly pressed against the top cavity of the torque column 40, so that the fixing seat 403 of the torque column 40 is fixed.

[0042] S40. Install an angle sensor 50 on the nut portion 31 of the pipe fitting 30, and then install a torque wrench 60 on the test nut of the angle sensor 50.

[0043] S50. A pipe fixing device 70 for circumferentially fixing the pipe body 21 is provided at the end of the pipe body 21 away from the flared end 22.

[0044] S60 and drive torque wrench 60 apply tightening torque to the nut part 31 of pipe joint 30, causing pipe joint 30 to rotate until the preset tightening endpoint is reached. The data processing unit obtains the torque, rotation angle data and effective axial force when the tightening torque is at its maximum value.

[0045] In step S60, the torque wrench 60 applies a tightening torque to the nut 31 of the pipe fitting 30 smoothly and at a constant speed to the specified value. During the tightening process, the angle sensor 50 records the rotation angle data of the nut 31 of the pipe fitting 30 in real time, the torque sensor 401 records the torque of the torque wrench 60 during the tightening process in real time, and the axial force sensor 402 records the axial load during the tightening process using the torque wrench 60 in real time. The corresponding values ​​are plotted into a continuous curve by computer software, and the connection performance of the fitting is displayed accordingly.

[0046] S70, the drive torque wrench 60 applies loosening torque to the nut part 31 of the pipe connector 30, and when the value of the loosening torque reaches the maximum value of the tightening torque, the data processing unit obtains the loosening torque.

[0047] S80. Completely loosen the nut 31 of the pipe fitting 30 to reduce both torque and axial load to zero.

[0048] S90: The maximum angle of torque wrench 60 is read from the angle curve by the data processing unit.

[0049] In a preferred embodiment of the present invention, the length of the brake tube segment 20 is 150 mm.

[0050] The performance evaluation of the test method in this invention embodiment can be based on relevant technical standards (such as TISPC600.018.0001 "Brake Tube Joint Mechanical Requirements"). This standard stipulates that the minimum loosening torque Ml of the pipe connector should be greater than 6 Nm (for M10×1 and M12×1 pipe joints), while the effective axial force Fax of a reliable pipe connection should be between 6 kN and 10 kN.

[0051] The axial pressure test method for the brake pipe sealing structure of the present invention involves cutting the matching part 10 to separate the upper nut part 11 and the lower base part 12. This allows the axial force generated by tightening the pipe joint 30 during the test, which directly acts on the sealing interface, to be accurately sensed and measured by the axial force sensor 402 inside the torque column 40. This eliminates the force transmission loss of the intermediate structure, and the measurement results are direct and reliable.

[0052] The technical solution of the present invention has been described in detail above with reference to specific embodiments. The specific embodiments described are used to help understand the concept of the present invention. Derivations and modifications made by those skilled in the art based on the specific embodiments of the present invention also fall within the scope of protection of the present invention.

Claims

1. A method for testing the axial pressure of a brake pipe sealing structure, wherein, The tested brake pipe sealing structure includes: Matching component (10), the matching component (10) has a liquid passage hole in the central axis, the liquid passage hole includes a wide diameter section (101), a conical section (102) and a narrow diameter section (103) connected in sequence, the inner wall of the wide diameter section (101) is provided with an internal thread (104). Braking pipe section (20), the braking pipe section (20) includes a pipe body (21) and an integrally coaxially disposed at one end of the pipe body (21). The flared end (22) is disposed in the conical section (102). The pipe body (21) is coaxially disposed in the wide diameter section (101) at the end connected to the flared end (22). The pipe fitting (30) has a nut (31) at one end and an external thread (32) at the other end. The external thread (32) of the pipe fitting (30) is screwed into the internal thread (104) of the wide diameter section (101) to compress and deform the flared end head (22), so that the outer peripheral wall of the flared end head (22) and the inner peripheral wall of the conical section (102) form a surface contact sealing fit. Its features are: The sealing structure axial pressure testing equipment includes a torque column (40), an angle sensor (50), a torque wrench (60), a pipeline fixing device (70), and a data processing unit. The torque column (40) is equipped with a torque sensor (401) and an axial force sensor (402). The data processing unit is electrically connected to the angle sensor (50), the torque sensor (401), and the axial force sensor (402), respectively. The axial pressure test method includes the following steps: S10. The matching part (10) is horizontally cut along its radial direction to form a separate upper nut part (11) and lower base part (12), the cut surface being located at the junction of the wide diameter section (101) and the conical section (102); S20. Place the lower base part (12) into the top cavity of the torque column (40) to fix it circumferentially; S30. The pipe body (21) is sequentially fitted into the center hole of the pipe connector (30), the pipe connector (30) is fitted into the center hole of the fixing seat (403) of the torque column (40), the upper nut (11) is screwed onto the pipe connector (30), and the fixing seat (403) of the torque column (40) is fixedly pressed against the top cavity of the torque column (40), so that the fixing seat (403) of the torque column (40) is fixed. S40. An angle sensor (50) is fitted onto the nut part (31) of the pipe fitting (30), and a torque wrench (60) is fitted onto the test nut of the angle sensor (50). S50. A pipe fixing device (70) for circumferentially fixing the pipe body (21) is provided at the end of the pipe body (21) away from the flared end (22). S60, the drive torque wrench (60) applies tightening torque to the nut part (31) of the pipe fitting (30), causing the pipe fitting (30) to rotate until the preset tightening endpoint is reached, and the torque, rotation angle data and effective axial force at the maximum tightening torque are obtained through the data processing unit; S70, the drive torque wrench (60) applies loosening torque to the nut part (31) of the pipe fitting (30), and when the value of the loosening torque reaches the maximum value of the tightening torque, the data processing unit obtains the loosening torque; S80. Completely loosen the nut (31) of the pipe fitting (30) to reduce both torque and axial load to zero; S90, read the maximum angle of torque wrench (60) from the angle curve through the data processing unit.

2. The method for testing the axial pressure of a brake pipe sealing structure according to claim 1, characterized in that, The length of the brake tube section (20) is 150 mm.

3. The method for testing the axial pressure of a brake pipe sealing structure according to claim 1, characterized in that, In step S60, the torque wrench (60) applies a tightening torque to the nut (31) of the pipe fitting (30) smoothly and at a constant speed, causing the pipe fitting (30) to rotate to the preset tightening endpoint. During the tightening process, the angle sensor (50) records the rotation angle data of the nut (31) of the pipe fitting (30) in real time, the torque sensor (401) records the torque during the tightening process of the torque wrench (60), and the axial force sensor (402) records the axial load during the tightening process using the wrench in real time. The corresponding values ​​are plotted into a continuous curve by computer software, and the connection performance of the fitting is displayed accordingly.

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