A trolley side impact test method for child restraint systems

Abstract

The present invention provides a trolley side impact test method for a child restraint system, comprising the following steps: S1. Fabricating a test door with side impact characteristics consistent with the door of the vehicle to be tested; S2. Dividing the test door into three sub-doors, corresponding to the head, chest, and pelvis of a child dummy; and S3. Subjecting the three sub-doors to side impact tests at different accelerations. The present invention has the beneficial effect of dividing the test door into an upper sub-door, a middle sub-door, and a lower sub-door, and subjecting the three sub-doors to side impact tests at different accelerations, simulating the intrusion of different door sections during a real vehicle collision, resulting in more realistic, accurate, and objective test results.

Description

Technical Field

[0001] The present invention belongs to the technical field of automobile side collision testing, and in particular relates to a trolley side collision testing method for a child restraint system. Background Art

[0002] In the design and development of automotive crash safety performance, trolley testing is a crucial testing method. Compared to full-vehicle testing, it can effectively shorten development cycles and reduce costs. Recent traffic accident statistics indicate that the fatality rate for child passengers in side impacts exceeds 30%. Hospital data indicates that 41% of AIS2+ injuries to child passengers occur in side impacts. The European Union has incorporated side impact testing for child restraint systems (CRS) into its standard regulations. However, my country currently has no side impact regulations or evaluation methods for CRS. Door panel intrusion is a key factor in side impact injuries. However, in current international CRS side impact testing regulations, there are two main approaches to addressing door panel intrusion: the first utilizes a non-intrusive fixed door structure, which cannot simulate intrusion in side impact testing; the second utilizes a dual-trolley system to achieve relative motion between the door panel and the seat, but only involves translation of the entire door panel, resulting in a single degree of freedom intrusion, which cannot simulate the intrusion of different door sections in real-world crash conditions. Summary of the Invention

[0003] In view of this, the present invention aims to propose a trolley side impact test method for a child restraint system to solve the problem that the current side impact test cannot simulate the intrusion of different parts of the vehicle door.

[0004] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0005] A method for testing a trolley side impact of a child restraint system comprises the following steps:

[0006] S1. Make a test door with the same side impact characteristics as the door of the vehicle to be tested;

[0007] S2. Divide the test door into three sub-doors, corresponding to the head, chest, and pelvis of the child dummy;

[0008] S3. Perform side impact tests on the three sub-doors at different accelerations.

[0009] Furthermore, the step S1 includes the following steps:

[0010] S11. Analyze the side impact characteristics of the door of the vehicle to be tested;

[0011] S12. Manufacturing a test door according to the side impact characteristics of the door of the vehicle to be tested;

[0012] S13. Verify the side impact characteristics of the test vehicle door.

[0013] Furthermore, the specific content of step S11 is as follows:

[0014] Perform drop tests on different positions of the vehicle door to be tested, obtain the acceleration at different positions at each moment, and calculate the average acceleration a. The calculation formula is as follows:

[0015]

[0016] Where: a1, a2, ..., a n is the drop test acceleration of different parts of different doors, and a is the average drop test acceleration;

[0017] Calculate the standard deviation of acceleration using the following formula:

[0018]

[0019] Where: a is the average value of acceleration, σ is the standard deviation of acceleration;

[0020] The upper and lower limits of the side impact characteristic acceleration are calculated using the average value and standard deviation of the acceleration. The calculation formula is as follows:

[0021] a upper =a+σ

[0022] a lower =a+σ

[0023] Where: a upper is the upper limit of acceleration; a lower As the lower limit of acceleration, plot a upper Curve and a lower curve.

[0024] Furthermore, the specific content of step S13 is as follows:

[0025] Perform drop tests on different positions of the test door to obtain the acceleration of the test door at different positions at each moment, calculate the average acceleration of the test door at each moment, draw the acceleration curve of the test door, and verify whether the acceleration curve of the test door is within a upper Curve and a lowerq between the curves;

[0026] If the acceleration curve of the test door is at a upper Curve and a lowerq If the acceleration curve of the test door is not between a upper Curve and a lowerqIf the test door panel is between the two curves, the process returns to step S12 to reselect the material for making the test door panel.

[0027] Furthermore, the specific steps of the drop test are as follows: a hemispherical drop model is used to perform a drop test on the door of the vehicle to be tested, wherein the drop model has a diameter of 150 mm, a mass of 6 kg ± 0.1 kg, and an impact speed of 4 m / s ± 0.1 m / s.

[0028] Furthermore, in step S2, the test doors are divided into upper sub-doors, middle sub-doors, and lower sub-doors according to the structure of the child restraint system, corresponding to the head, chest, and pelvis of the child dummy, respectively;

[0029] Set the test door height to 480mm-520mm and length to 800mm-850mm. The alignment point at the bottom of the test door should correspond to the CR point of the rear seat. The distance between the alignment point and the front end of the test door should be 580mm-620mm, and the distance between the alignment point and the rear end of the test door should be 220mm-230mm.

[0030] The height of the upper door is 50mm-60mm, the height of the middle door is 180mm-200mm, and the height of the lower door is 230mm-240mm.

[0031] Furthermore, the specific content of step S3 is as follows: the child dummy is fixed to the seat through the child restraint system, the seat is mounted on the pulley, and the pulley is fixed with a side impact trolley hydraulic accelerator, so that the upper sub-door, the middle sub-door, and the lower sub-door correspond to the head, chest, and pelvis of the child dummy respectively, the main piston of the main trolley hydraulic accelerator corresponds to the pulley, and the side impact trolley hydraulic accelerator is provided with an upper side impact piston, a middle side impact piston, and a lower side impact piston, which correspond to the upper sub-door, the middle sub-door, and the lower sub-door respectively;

[0032] The acceleration curve of the main piston is the acceleration curve of the B-pillar on the non-collision side in a real car side collision. main ;

[0033] The acceleration curve of the upper side impact piston is the acceleration curve a of the upper door panel in the actual vehicle side impact sled1 ;

[0034] The acceleration curve of the middle side collision piston is the acceleration curve of the middle part of the door panel in the side collision of the actual vehicle. sled2 ;

[0035] The acceleration curve of the lower side impact piston is the acceleration curve of the lower part of the door panel in the actual vehicle side collision. sled3 .

[0036] Compared with the prior art, the trolley side impact test method for a child restraint system described in the present invention has the following beneficial effects:

[0037] (1) The present invention provides a trolley side impact test method for a child restraint system, which divides the test door into an upper sub-door, a middle sub-door, and a lower sub-door, and performs side impact tests on the three sub-doors at different accelerations. This method can simulate the intrusion of different parts of the door during a real vehicle collision, making the test results more realistic, accurate, and objective.

[0038] (2) The trolley side impact test method for a child restraint system described in the present invention reduces test costs and improves test efficiency by analyzing the side impact characteristics of the vehicle door to be tested and making a test door that matches the side impact characteristics of the vehicle door to be tested. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0040] Figure 1 This is a flow chart of the testing method according to an embodiment of the present invention;

[0041] Figure 2 This is a schematic diagram of the test door structure according to an embodiment of the present invention;

[0042] Figure 3 a described in the embodiment of the present invention upper Curve and a lower Schematic diagram of the curve;

[0043] Figure 4 This is a schematic structural diagram of the side impact test bench according to an embodiment of the present invention. DETAILED DESCRIPTION

[0044] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0045] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0046] like Figures 1 to 4 As shown, a trolley side impact test method for a child restraint system is shown, comprising the following steps:

[0047] S1. Make a test door with the same side impact characteristics as the door of the vehicle to be tested;

[0048] S2. Divide the test door into three sub-doors, corresponding to the head, chest, and pelvis of the child dummy;

[0049] S3. Perform side impact tests on the three sub-doors at different accelerations.

[0050] Step S1 includes the following steps:

[0051] S11. Analyze the side impact characteristics of the door of the vehicle to be tested;

[0052] S12. Manufacturing a test door according to the side impact characteristics of the door of the vehicle to be tested;

[0053] S13. Verify the side impact characteristics of the test vehicle door.

[0054] Furthermore, the specific content of step S11 is as follows:

[0055] Perform drop tests on different positions of the vehicle door to be tested, obtain the acceleration at different positions at each moment, and calculate the average acceleration a. The calculation formula is as follows:

[0056]

[0057] Where: a1, a2, ..., a n is the drop test acceleration of different parts of different doors, and a is the average drop test acceleration;

[0058] Calculate the standard deviation of acceleration using the following formula:

[0059]

[0060] Where: a is the average value of acceleration, σ is the standard deviation of acceleration;

[0061] The upper and lower limits of the side impact characteristic acceleration are calculated using the average value and standard deviation of the acceleration. The calculation formula is as follows:

[0062] a upper =a+σ

[0063] a lower =a+σ

[0064] Where: a upper is the upper limit of acceleration; a lower As the lower limit of acceleration, plot a upper Curve and a lower Curve (such as Figure 3 As shown, the horizontal axis is time in ms, the vertical axis is acceleration in g, and the dark upper limit line in the figure is a upper The curve is simplified, and the light lower limit line is a lower The curve is simplified).

[0065] The specific content of step S13 is as follows:

[0066] Perform drop tests on different positions of the test door to obtain the acceleration of the test door at different positions at each moment, calculate the average acceleration of the test door at each moment, draw the acceleration curve of the test door, and verify whether the acceleration curve of the test door is within a upper Curve and a lowerq between the curves;

[0067] If the acceleration curve of the test door is at a upper Curve and a lowerq If the acceleration curve of the test door is not between a upper Curve and a lowerq If the test door panel is between the two curves, the process returns to step S12 to reselect the material for making the test door panel.

[0068] The specific steps of the drop test are as follows: a hemispherical drop model is used to perform a drop test on the door of the test vehicle. The diameter of the drop model is 150 mm, the mass is 6 kg, and the impact speed is 4 m / s.

[0069] In step S2, according to the child restraint system ( Figure 4 The test door is divided into upper, middle and lower sub-doors, which correspond to the head, chest and pelvis of the child dummy respectively;

[0070] Based on the position and size of the rear doors of various models, the test door is set to a height of 500mm and a length of 933mm. The alignment point at the bottom of the test door corresponds to the CR point of the rear seat. The distance between the alignment point and the front end of the test door is 600mm, and the distance between the alignment point and the rear end of the test door is 233mm.

[0071] The height of the upper door is 55mm, the height of the middle door is 190mm, and the height of the lower door is 235mm. The distance between the upper door, the middle door and the lower door is 10mm.

[0072] The specific contents of step S3 are as follows: the child dummy is fixed to the seat through the child restraint system, and the seat is mounted on the pulley. The pulley is fixed with a side impact trolley hydraulic accelerator, so that the upper door, middle door, and lower door correspond to the child dummy's head, chest, and pelvis respectively. The main piston of the main trolley hydraulic accelerator corresponds to the pulley. The side impact trolley hydraulic accelerator is equipped with an upper side impact piston, a middle side impact piston, and a lower side impact piston, which correspond to the upper door, middle door, and lower door respectively.

[0073] The acceleration curve of the main piston is the acceleration curve of the B-pillar on the non-collision side in a real car side collision. main ;

[0074] The acceleration curve of the upper side impact piston is the acceleration curve a of the upper door panel in the actual vehicle side impactsled1 ;

[0075] The acceleration curve of the middle side collision piston is the acceleration curve of the middle part of the door panel in the side collision of the actual vehicle. sled2 ;

[0076] The acceleration curve of the lower side impact piston is the acceleration curve of the lower part of the door panel in the actual vehicle side collision. sled3 .

[0077] By analyzing the side impact characteristics of the door of the vehicle to be tested and manufacturing a test door that matches the side impact characteristics of the door of the vehicle to be tested, the test cost is reduced and the test efficiency is improved.

[0078] The test door is divided into an upper sub-door, a middle sub-door and a lower sub-door, and side impact tests are performed on the three sub-doors at different accelerations. This can simulate the intrusion of different parts of the door during a real vehicle collision, making the test results more realistic, accurate and objective.

[0079] Those skilled in the art will appreciate that the units and method steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the components and steps of each example according to their functions. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0080] In the several embodiments provided in this application, it should be understood that the disclosed methods and systems can be implemented in other ways. For example, the division of the units described above is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. The above-mentioned units may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the embodiment of the present invention.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.

[0082] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A trolley side impact test method for a child restraint system, characterized by: The following steps are involved: S1. Make a test door with the same side impact characteristics as the door of the vehicle to be tested; S2. Divide the test door into three sub-doors, corresponding to the head, chest, and pelvis of the child dummy; S3, performing side impact tests on the three sub-doors at different accelerations; Step S1 includes the following steps: S11. Analyze the side impact characteristics of the door of the vehicle to be tested; S12. Manufacturing a test door according to the side impact characteristics of the door of the vehicle to be tested; S13. Verify the side impact characteristics of the test vehicle door; The specific content of step S11 is as follows: Perform drop tests on different positions of the vehicle door to be tested, obtain the acceleration at different positions at each moment, and calculate the average acceleration a. The calculation formula is as follows: Where: a1, a2, ..., a n is the drop test acceleration of different parts of different doors, and a is the average drop test acceleration; Calculate the standard deviation of acceleration using the following formula: Where: a is the average value of acceleration, σ is the standard deviation of acceleration; The upper and lower limits of the side impact characteristic acceleration are calculated using the average value and standard deviation of the acceleration. The calculation formula is as follows: a upper =a+σ a lower =a+σ Where: a upper is the upper limit of acceleration; a lower As the lower limit of acceleration, plot a upper Curve and a lower curve; The specific content of step S13 is as follows: Perform drop tests on different positions of the test door to obtain the acceleration of the test door at different positions at each moment, calculate the average acceleration of the test door at each moment, draw the acceleration curve of the test door, and verify whether the acceleration curve of the test door is within a upper Curve and a lowerq between the curves; If the acceleration curve of the test door is at a upper Curve and a lowerq If the acceleration curve of the test door is not between a upper Curve and a lowerq If the test door panel is between the two curves, the process returns to step S12 and reselects the material to make the test door panel; In step S2, based on the structure of the child restraint system, the test doors are divided into upper, middle, and lower sub-doors, corresponding to the head, chest, and pelvis of the child dummy, respectively; Set the test door height to 480mm-520mm and length to 800mm-850mm. The alignment point at the bottom of the test door should correspond to the CR point of the rear seat. The distance between the alignment point and the front end of the test door should be 580mm-620mm, and the distance between the alignment point and the rear end of the test door should be 220mm-230mm. The height of the upper door is 50mm-60mm, the height of the middle door is 180mm-200mm, and the height of the lower door is 230mm-240mm; The specific contents of step S3 are as follows: the child dummy is fixed to the seat through the child restraint system, and the seat is mounted on the pulley. The pulley is fixed with a side impact trolley hydraulic accelerator, so that the upper door, middle door, and lower door correspond to the child dummy's head, chest, and pelvis respectively. The main piston of the main trolley hydraulic accelerator corresponds to the pulley. The side impact trolley hydraulic accelerator is equipped with an upper side impact piston, a middle side impact piston, and a lower side impact piston, which correspond to the upper door, middle door, and lower door respectively. The acceleration curve of the main piston is the acceleration curve of the B-pillar on the non-collision side in a real car side collision. main ; The acceleration curve of the upper side impact piston is the acceleration curve a of the upper door panel in the actual vehicle side impact sled1 ; The acceleration curve of the middle side collision piston is the acceleration curve of the middle part of the door panel in the side collision of the actual vehicle. sled2 ; The acceleration curve of the lower side impact piston is the acceleration curve of the lower part of the door panel in the actual vehicle side collision. sled3 .

2. A trolley side impact test method for a child restraint system according to claim 1, characterized in that: The specific steps of the drop test are as follows: a hemispherical drop model is used to perform a drop test on the door of the test vehicle. The diameter of the drop model is 150 mm, the mass is 6 kg ± 0.1 kg, and the impact speed is 4 m / s ± 0.1 m / s.

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