High and low temperature flexural fatigue test method and test bench for air brake hoses

Abstract

The present invention relates to the field of braking technology, and in particular to a high- and low-temperature flexural fatigue test method for an air brake hose and its test bench. The method comprises extracting the full stroke of the vehicle's suspension up and down jumps and the full stroke of the steering left and right turns based on the motion characteristics of the vehicle's front and rear axles, fixing one end of the hose to be tested to the fixed end of a flexural circulation device on a test stand and connecting it to a pressure circulation device, and connecting the other end to a movable end and sealing it, and placing the entire test stand in a temperature-controlled test chamber. After the test parameters are set, the test is started, and the flexural circulation device, pressure circulation device, and temperature-controlled test chamber are started synchronously. When the number of working cycles of the flexural circulation device reaches a target preset value, the high- and low-temperature flexural fatigue test of the air brake hose is terminated. The present invention fully considers the bending conditions and high and low-temperature environments of the vehicle's air brake hose, shortens the vehicle verification cycle and verification costs, and is conducive to improving the design quality of the air brake hose.

Description

Technical Field

[0001] The invention relates to the field of brake technology, in particular to a high-low temperature flexural fatigue test method for an air brake hose and a test bench thereof. Background Art

[0002] Trucks and some buses widely use pneumatic brake systems, controlling and transmitting brake energy from the point of application via a pneumatic transmission device. Air brake hoses transmit air pressure to the brake chambers. They also need to adapt to front wheel steering, oscillation, and rear axle oscillation, requiring sufficient flexibility. Currently, the flexural fatigue performance of air brake hoses is primarily verified according to GB16897.

[0003] Current flexure fatigue testing, on the one hand, operates in a single direction of motion and cannot simulate the actual motion of a vehicle. Bench testing results are questionable and require full vehicle durability support. On the other hand, bench testing is set at room temperature (25°C-32°C), while the actual operating temperature of hoses ranges from -40°C to 100°C. Current flexure fatigue testing cannot fully verify the flexure fatigue performance of hoses under different temperature conditions.

[0004] The existing air brake hose bending fatigue test is quite different from the actual test conditions of the whole vehicle, which often results in the air brake hose passing the bench test but breaking, leaking and other faults under the whole vehicle test, affecting the safety of the whole vehicle. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a high- and low-temperature flexural fatigue test method for air brake hoses and a test bench thereof.

[0006] The high and low temperature flexural fatigue test method for an air brake hose according to the first embodiment of the present invention comprises:

[0007] Step S100: Based on the motion characteristics of the front and rear axles of the vehicle, extract the full travel of the vehicle's suspension up and down jumps and the full travel of the steering left and right turns;

[0008] Step S200: Establishing a high- and low-temperature flexural fatigue test scenario for an air brake hose of a complete vehicle, wherein one end of the hose to be tested is fixed to the fixed end of a flexural circulation device on a test stand and connected to a pressure circulation device. The other end of the hose to be tested is connected to the movable end of the flexural circulation device and sealed. The test stand containing the hose to be tested and the flexural circulation device is placed in a temperature-controlled test chamber within the high- and low-temperature flexural fatigue test scenario for the air brake hose.

[0009] Step S300: setting test parameters, including full-stroke parameter settings for the flex cycle device, parameter settings for the pressure cycle device, and parameter settings for the temperature control test chamber. The flex cycle device, the pressure cycle device, and the temperature control test chamber operate synchronously to simulate the actual operating environment of the vehicle.

[0010] Step S400: The high-low temperature flexing fatigue test of the air brake hose is started. The flexing cycle device, the pressure cycle device, and the temperature control test chamber are started simultaneously. When the number of working cycles of the flexing cycle device reaches the target preset value, the high-low temperature flexing fatigue test of the air brake hose is completed.

[0011] According to the high- and low-temperature flexural fatigue test method for air brake hoses of an embodiment of the present invention, the full up and down suspension jump stroke and the full left and right steering stroke of the vehicle are extracted based on the movement characteristics of the front and rear axles of the vehicle, and a high- and low-temperature flexural fatigue test scenario for the air brake hoses of the vehicle is established based on the full suspension stroke of the vehicle. The flexural cycle device, the pressure cycle device and the temperature control test chamber work synchronously to simulate the actual movement conditions of the vehicle, fully considering the bending conditions and high and low temperature environments of the air brake hoses of the vehicle, thereby shortening the vehicle verification cycle and verification costs, and being conducive to improving the design quality of the air brake hoses.

[0012] According to some embodiments of the present invention, the full-stroke parameter setting of the flexion cycle device includes selecting the full stroke of the up and down jump test in the flexion cycle device to be 88% of the full up and down jump stroke of the whole vehicle suspension, and performing the full-stroke test of the up and down jump at a frequency of 90 cycles per minute, and selecting the full stroke of steering and left and right turns in the flexion cycle device to be 88% of the full stroke of steering and left and right turns of the whole vehicle, and performing the full stroke test of steering and left and right turns at a frequency of 12 cycles per minute.

[0013] According to some embodiments of the present invention, parameter settings of the pressure cycling device include increasing the sample air pressure of the hose to be tested from 0 MPa to a target pressure for 30 seconds, and then decreasing the target pressure to 0 MPa for 30 seconds in a cycle of 60 seconds.

[0014] According to some embodiments of the present invention, the parameter setting of the temperature-controlled test chamber includes setting the test temperature into three groups, with the low temperature set to -40°C, the room temperature set to 25°C, and the high temperature set to 100°C, which correspond to the low temperature mode, room temperature mode and high temperature mode of the temperature-controlled test chamber respectively.

[0015] According to some embodiments of the present invention, the target pressure is 1 MPa, which is used to simulate the actual pressure environment of the air brake hose when the vehicle is running.

[0016] According to some embodiments of the present invention, the pressure increasing and reducing processes of the pressure cycle device last less than 1 second, making it more in line with actual working conditions.

[0017] According to some embodiments of the present invention, the target preset value of the number of working cycles of the flexure cycle device is 1 million times; based on the 1 million working cycles of the flexure cycle device, the temperature-controlled test chamber is set to operate in high temperature mode, room temperature mode and low temperature mode in sequence to complete the high and low temperature flexure fatigue test of the air brake hose, wherein the flexure cycle device works 200,000 times in high temperature mode, 500,000 times in room temperature mode, and 300,000 times in low temperature mode.

[0018] According to a second embodiment of the present invention, a high-low temperature flexural fatigue test bench for air brake hoses is applied to the above-mentioned method to perform high-low temperature flexural fatigue tests on air brake hoses, comprising:

[0019] A flexing circulation device is used to perform a flexing cycle test on a hose to be tested, wherein the flexing circulation device includes a fixed bracket, a front-to-back displacement circulation device, a vertical displacement circulation device, and a horizontal displacement circulation device. The fixed bracket is mounted on an actuating end of the horizontal displacement circulation device. The vertical displacement circulation device is mounted on the fixed bracket. The actuating end of the vertical displacement circulation device is connected to the front-to-back displacement circulation device. The actuating end of the front-to-back displacement circulation device is fixedly mounted with the hose to be tested.

[0020] A pressure circulation device, the pressure circulation device comprising a pipeline connected to an air pump, the pipeline being connected to one end of a hose to be tested, the pipeline being equipped with an inflation solenoid valve and a release solenoid valve;

[0021] A temperature-controlled test chamber is provided with a regulating device for regulating the internal temperature of the temperature-controlled test chamber, a temperature sensor and a temperature display. The temperature sensor is electrically connected to the temperature display and is used for temperature environment monitoring of high and low temperature flexural fatigue tests of air brake hoses.

[0022] According to some embodiments of the present invention, the displacement strokes of the front-to-back displacement circulation device, the up-down displacement circulation device, and the left-to-right displacement circulation device are all 0 to 100 mm, so as to adapt to the actual working conditions of the entire vehicle.

[0023] The high and low temperature flexural fatigue test method for air brake hoses and its test bench can effectively simulate the bending conditions and high and low temperature environments of the air brake hoses of the entire vehicle, shortening the vehicle verification cycle and verification costs, and helping to improve the design quality of the air brake hoses.

[0024] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 4 is a flow chart of a high and low temperature flexural fatigue test method for an air brake hose according to an embodiment of the present invention. DETAILED DESCRIPTION

[0027] The embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0028] It should be noted that when an element is referred to as being “fixed to” another element, it may be directly on the other element or there may be an intermediate element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or there may be an intermediate element.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0030] Example 1

[0031] See Figure 1 As shown, this embodiment provides a high and low temperature flexural fatigue test method for an air brake hose, which includes:

[0032] Step S100: Based on the motion characteristics of the front and rear axles of the vehicle, extract the full travel of the vehicle's suspension up and down jumps and the full travel of the steering left and right turns;

[0033] Step S200: Establish a high- and low-temperature flexural fatigue test scenario for the air brake hose of the entire vehicle, wherein one end of the hose to be tested is fixed to the fixed end of the flexural circulation device on the test stand and connected to the pressure circulation device, and the other end of the hose to be tested is connected to the movable end of the flexural circulation device and sealed, and the test stand containing the hose to be tested and the flexural circulation device is placed in a temperature-controlled test chamber in the high- and low-temperature flexural fatigue test scenario for the air brake hose, wherein the full-stroke parameter setting of the flexural circulation device includes selecting the full up-and-down jump test stroke in the flexural circulation device to be 88% of the full up-and-down jump stroke of the vehicle suspension, and performing up-and-down jumps at a frequency of 90 cycles per minute. For the full-stroke test, the full left and right turning stroke of the flexion cycle device is selected as 88% of the full left and right turning stroke of the vehicle, and the full-stroke test of the steering and left and right turns is carried out at a frequency of 12 cycles per minute; the parameter setting of the pressure cycle device includes raising the sample air pressure of the hose to be tested from 0MPa to a target pressure in a cycle of 60s, maintaining it for 30s, and then reducing it from the target pressure to 0MPa and maintaining it for 30s; the parameter setting of the temperature control test chamber includes setting the test temperature into three groups, with the low temperature setting at -40℃, the room temperature setting at 25℃, and the high temperature setting at 100℃, which correspond to the low temperature mode, room temperature mode and high temperature mode of the temperature control test chamber respectively.

[0034] Step S300: setting test parameters, including full-stroke parameter settings for the flex cycle device, parameter settings for the pressure cycle device, and parameter settings for the temperature control test chamber. The flex cycle device, the pressure cycle device, and the temperature control test chamber operate synchronously to simulate the actual operating environment of the vehicle.

[0035] Step S400: The high- and low-temperature flexural fatigue test of the air brake hose is started. The flexural cycle device, the pressure cycle device, and the temperature control test chamber are simultaneously started. When the number of working cycles of the flexural cycle device reaches the target preset value, the high- and low-temperature flexural fatigue test of the air brake hose is completed. The air brake hose after the test is removed and the flexural fatigue performance is evaluated.

[0036] According to the high- and low-temperature flexural fatigue test method for air brake hoses of an embodiment of the present invention, the full up and down suspension jump stroke and the full left and right steering stroke of the vehicle are extracted based on the movement characteristics of the front and rear axles of the vehicle, and a high- and low-temperature flexural fatigue test scenario for the air brake hoses of the vehicle is established based on the full suspension stroke of the vehicle. The flexural cycle device, the pressure cycle device and the temperature control test chamber work synchronously to simulate the actual movement conditions of the vehicle, fully considering the bending conditions and high and low temperature environments of the air brake hoses of the vehicle, thereby shortening the vehicle verification cycle and verification costs, and being conducive to improving the design quality of the air brake hoses.

[0037] Specifically, the target pressure is 1 MPa, which is used to simulate the actual pressure environment of the air brake hose when the vehicle is running.

[0038] Specifically, the pressure increasing and reducing processes of the pressure circulation device last less than 1 second, making it more in line with actual working conditions.

[0039] In this embodiment, a target preset value for the number of working cycles of the flexion cycle device is 1 million times. Based on the 1 million working cycles of the flexion cycle device, the temperature-controlled test chamber is set to operate in high-temperature mode, room-temperature mode, and low-temperature mode in sequence to complete the high- and low-temperature flexural fatigue test of the air brake hose, wherein the flexion cycle device operates 200,000 times in the high-temperature mode, 500,000 times in the room-temperature mode, and 300,000 times in the low-temperature mode.

[0040] Example 2

[0041] According to a second embodiment of the present invention, a high-low temperature flexural fatigue test bench for air brake hoses is applied to the above-mentioned method to perform high-low temperature flexural fatigue tests on air brake hoses, comprising:

[0042] A flexing circulation device is used to perform a flexing cycle test on a hose to be tested, wherein the flexing circulation device includes a fixed bracket, a front-to-back displacement circulation device, a vertical displacement circulation device, and a horizontal displacement circulation device. The fixed bracket is mounted on an actuating end of the horizontal displacement circulation device. The vertical displacement circulation device is mounted on the fixed bracket. The actuating end of the vertical displacement circulation device is connected to the front-to-back displacement circulation device. The actuating end of the front-to-back displacement circulation device is fixedly mounted with the hose to be tested.

[0043] A pressure circulation device, the pressure circulation device comprising a pipeline connected to an air pump, the pipeline being connected to one end of a hose to be tested, the pipeline being equipped with an inflation solenoid valve and a release solenoid valve;

[0044] A temperature-controlled test chamber is provided with a regulating device for regulating the internal temperature of the temperature-controlled test chamber, a temperature sensor and a temperature display. The temperature sensor is electrically connected to the temperature display and is used for temperature environment monitoring of high and low temperature flexural fatigue tests of air brake hoses.

[0045] Specifically, the displacement strokes of the front-to-back displacement circulation device, the up-down displacement circulation device, and the left-to-right displacement circulation device are all 0 to 100 mm, so as to adapt to the actual working conditions of the entire vehicle.

[0046] The high and low temperature flexural fatigue test method for air brake hoses and its test bench can effectively simulate the bending conditions and high and low temperature environments of the air brake hoses of the entire vehicle, shortening the vehicle verification cycle and verification costs, and helping to improve the design quality of the air brake hoses.

[0047] Example 3

[0048] Based on the above embodiment, this embodiment provides a specific practical case:

[0049] Take a single batch of 100 hoses to be tested with a length of 500mm. Fix one end of the hose to the actuating end of the forward and backward displacement cycle device on the high and low temperature flexural fatigue test bench of the air brake hose, and connect the other end to the pressure cycle device. Both ends of the hose to be tested are connected to the air circuit.

[0050] The flexion cycle device, pressure cycle device and temperature control test chamber are started simultaneously. The flexion cycle device is tested in the following order: front-to-back direction (0 to 100 mm), up-to-down direction (0 to 100 mm), left-to-right direction (0 to 100 mm), left-to-right direction (0 to 100 mm), up-to-down direction (0 to 100 mm), and front-to-back direction (0 to 100 mm). This completes one cycle, and the total test cycle is 1 million.

[0051] During this process, the hose to be tested is inflated synchronously. The inflation process is as follows: the air pressure is 0 MPa from 0 to 30 seconds, and the air pressure is 1 MPa from 30 to 60 seconds. This is a 60-second cycle, and the duration of the pressure increase and decrease process is less than 1 second.

[0052] Based on the 1 million working cycles of the flexure cycle device, the temperature-controlled test chamber was set to operate in high-temperature mode, room-temperature mode, and low-temperature mode in sequence to complete the high- and low-temperature flexure fatigue test of the air brake hose. The flexure cycle device worked 200,000 times in high-temperature mode, 500,000 times in room-temperature mode, and 300,000 times in low-temperature mode.

[0053] After the high and low temperature flexural fatigue tests on the air brake hoses were completed, the hoses were removed for flexural fatigue performance evaluation. The verification efficiency and results of this batch of hoses to be tested met expectations, which is conducive to improving the design quality of the air brake hoses.

[0054] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as a limitation to the invention.

[0055] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "example," "specific example," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0056] Obviously, the described embodiments are only some of the embodiments of the present application, rather than all of the embodiments. Mentioning "embodiment" in this article means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present embodiment application. The appearance of this phrase in various positions in the specification does not necessarily mean that they are all the same embodiments, nor are they independent or alternative embodiments that are mutually exclusive with other embodiments. It can be understood explicitly and implicitly by those skilled in the art that the embodiments described herein can be combined with other embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of this application.

[0057] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A high and low temperature flexural fatigue test method for air brake hoses, characterized in that: include: Step S100: Based on the motion characteristics of the front and rear axles of the vehicle, extract the full travel of the vehicle's suspension up and down jumps and the full travel of the steering left and right turns; Step S200: Establishing a high- and low-temperature flexural fatigue test scenario for an air brake hose of a complete vehicle, wherein one end of the hose to be tested is fixed to the fixed end of a flexural circulation device on a test stand and connected to a pressure circulation device. The other end of the hose to be tested is connected to the movable end of the flexural circulation device and sealed. The test stand containing the hose to be tested and the flexural circulation device is placed in a temperature-controlled test chamber within the high- and low-temperature flexural fatigue test scenario for the air brake hose. Step S300: Test parameter setting, including full stroke parameter setting of the flex cycle device, parameter setting of the pressure cycle device, and parameter setting of the temperature control test chamber. The flex cycle device, pressure cycle device, and temperature control test chamber are operated synchronously to simulate the real environment of the vehicle during operation. The full stroke parameter setting of the flexion cycle device includes selecting the full stroke of the up and down jump test in the flexion cycle device to be 88% of the full stroke of the up and down jump of the vehicle suspension, and performing the full stroke test of the up and down jump at a frequency of 90 cycles per minute; selecting the full stroke of the steering and left and right turns in the flexion cycle device to be 88% of the full stroke of the steering and left and right turns of the vehicle, and performing the full stroke test of the steering and left and right turns at a frequency of 12 cycles per minute; The parameter setting of the pressure cycle device includes increasing the sample pressure of the hose to be tested from 0 MPa to a target pressure in a cycle of 60 seconds, maintaining it for 30 seconds, and then decreasing it from the target pressure to 0 MPa and maintaining it for 30 seconds; The parameter setting of the temperature control test chamber includes setting the test temperature into three groups: low temperature setting at -40℃, room temperature setting at 25℃, and high temperature setting at 100℃, which correspond to the low temperature mode, room temperature mode, and high temperature mode of the temperature control test chamber respectively; Step S400: The high-low temperature flexing fatigue test of the air brake hose is started. The flexing cycle device, the pressure cycle device, and the temperature control test chamber are started simultaneously. When the number of working cycles of the flexing cycle device reaches the target preset value, the high-low temperature flexing fatigue test of the air brake hose is completed.

2. The high and low temperature flexural fatigue test method for air brake hose according to claim 1, characterized in that: The target pressure is 1 MPa.

3. The high and low temperature flexural fatigue test method for air brake hose according to claim 1, characterized in that: The duration of the pressure increasing and reducing process of the pressure circulation device is less than 1 second.

4. The high and low temperature flexural fatigue test method for air brake hose according to claim 1, characterized in that: The target preset value of the number of working cycles of the flexion cycle device is 1 million times.

5. The high and low temperature flexural fatigue test method for air brake hose according to claim 4, characterized in that: Based on the 1 million working cycles of the flexure cycle device, the temperature-controlled test chamber was set to operate in high-temperature mode, room-temperature mode, and low-temperature mode in sequence to complete the high- and low-temperature flexure fatigue test of the air brake hose. The flexure cycle device worked 200,000 times in high-temperature mode, 500,000 times in room-temperature mode, and 300,000 times in low-temperature mode.

6. A high- and low-temperature flexural fatigue test bench for air brake hoses, used to perform high- and low-temperature flexural fatigue tests on air brake hoses according to the method described in any one of claims 1 to 5, comprising: A flexing circulation device is used to perform a flexing cycle test on a hose to be tested, wherein the flexing circulation device includes a fixed bracket, a front-to-back displacement circulation device, a vertical displacement circulation device, and a horizontal displacement circulation device. The fixed bracket is mounted on an actuating end of the horizontal displacement circulation device. The vertical displacement circulation device is mounted on the fixed bracket. The actuating end of the vertical displacement circulation device is connected to the front-to-back displacement circulation device. The actuating end of the front-to-back displacement circulation device is fixedly mounted with the hose to be tested. A pressure circulation device, the pressure circulation device comprising a pipeline connected to an air pump, the pipeline being connected to one end of a hose to be tested, the pipeline being equipped with an inflation solenoid valve and a release solenoid valve; A temperature-controlled test chamber is provided with a regulating device for regulating the internal temperature of the temperature-controlled test chamber, a temperature sensor and a temperature display. The temperature sensor is electrically connected to the temperature display and is used for temperature environment monitoring of high and low temperature flexural fatigue tests of air brake hoses.

7. The high and low temperature flexural fatigue test bench for air brake hoses according to claim 6, characterized in that: The displacement strokes of the front-to-back displacement circulation device, the up-down displacement circulation device, and the left-to-right displacement circulation device are all 0 to 100 mm to adapt to the actual working conditions of the vehicle.

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