Design and development of school bus seats accordi

New regulations on the design and development of school bus seats

with the rapid development of China's economy and the continuous improvement of people's living standards, people pay more and more attention to life safety. In the face of the continuous school bus safety accidents, people are more aware that school bus safety must be solved. Recently, the state has continuously issued laws and regulations related to school bus safety. As an important part of school bus safety - school bus seat, which is an important part related to students' life safety, was proposed separately, and the compulsory regulation gb24406 was required to be implemented. Its version was also updated from the original 2009 to 2012. This standard regulation specifies the requirements that school bus seats should meet in terms of composition, installation, configuration, strength, etc. it is a rare piece of equipment to ensure that students can minimize injury in case of vehicle emergencies

according to the requirements of the new regulations, taking the structural design of a school bus seat for primary school students as an example, this paper introduces how to design and develop the school bus seat

1 comparative analysis of new and old regulations

the strength of special school bus student seat system and its vehicle fixings has been changed from GB 24406-2009 to GB 24406-201 2. Its significance has changed greatly. Originally, it only emphasized the strength and implemented the static test method, while the new standard requires the combination of dynamic and static to test the injury with the actual dynamic simulation collision. The specific differences are shown in the following points:

(1) the 2009 version of the regulations is applicable to the special primary school bus, while the 2012 version of the regulations is extended to the student school bus, including preschool school 3 There are contact buses, primary school buses, secondary school buses and other school buses used to transport students between the toothed bar pressing plate and the toothed bar

(the 2012 version of the national regulation adds the restraint partition installed in front of the seat on the school bus, which needs to perform the same dynamic test detection as the seat;

(3) the biggest difference between the two regulations is that 201 2 will produce a strange phenomenon. The version will verify the static test method of forward tilt performance and energy absorption characteristics of the back of the seat, The dynamic test method is modified. The experimental machine system can automatically switch different experimental conditions according to the experimental instructions transmitted by the superior computer. The dummy dynamic sled collision is adopted, and more attention is paid to the actual safety effect evaluation

the details are as follows:

the forward leaning performance of the 2009 seat. Apply force to the backrest according to the requirements of figure l to test its safety

2012 version requires simulating dynamic collision between seat and partition according to figure 2, and using a 6-year-old manikin conforming to GB 27887 and the internationally used mixed IIL 5th percentile manikin, a dynamic test is carried out respectively. Through the evaluation of the injury index after the test, whether the seat is qualified or not is judged, which is closer to the actual situation of traffic accidents and safer, but also puts forward higher requirements for the seat itself

2 state analysis of existing seats through a detailed analysis of the seats in the current production state and combined with the results of many tests, it can be determined that there are mainly the following two deficiencies:

(1) the strength of the seats in the current production state is very strong. Although the strength meets the national regulations, there are unreasonable design and excess strength, resulting in an increase in the total mass and cost of the whole vehicle. See Figure 3 for the specific structural form

(2) the seat frame in the current state uses square tubes, which does not meet the regulatory requirements in terms of the internal protrusions and the energy absorption characteristics of the back of the seat back