The brake failure of new energy vehicles some time ago caused many people to turn their attention to the brake system of the vehicle. For vehicles, the brake system is also the brake system. In the relevant vehicle standards, the vehicle’s braking response time There are strict requirements. After all, on high-speed roads, the response time of the braking system is 1 second slow, and the time for the vehicle to travel forward cannot be estimated. Therefore, various automobile manufacturers and vehicle inspection centers will measure the braking response time. How to measure the braking response time of a vehicle? The following editor of Naiou will give you a detailed introduction to the detection method of vehicle braking response time and the vehicle's braking response time requirements for your reference.
1. The definition of vehicle braking response time
The indexes for evaluating the braking performance of a vehicle are mainly braking distance and braking deceleration. The length of the braking response time directly affects the braking distance. The braking response time of a vehicle refers to the most unfavorable starting from the action of the brake pedal. The time required for the pressure in the brake chamber to reach 75% of its steady-state value. According to relevant regulations, for vehicles whose service brake system depends entirely or partly on other energy sources other than the driver's physical strength, the vehicle's braking response time should not exceed 0.6s during emergency braking.
2. Measuring method of braking response time
Generally, the braking response time of a vehicle is measured by various sensors plus a test system. For example, the braking response time test system produced by Naiou Electric is to install pressure sensors and brake motion sensing sensors on the relevant parts of the vehicle's braking system. , And then monitor the braking response time through the test host, the specific operations are as follows:
1. The response time of the braking system is measured under the stationary condition of the vehicle. The air pressure sensors are installed on the left and right air chambers of the front and rear axles respectively, and transition pipe joints are installed at suitable positions in the control pipelines of the front and rear axles to install the air pressure. sensor;
2. The stroke of each brake chamber must be adjusted according to the manufacturer's specified value, or the stroke equivalent to the lower limit of the brake adjustment gap;
3. For heavy-duty vehicles equipped with trailer brake joints, it is also necessary to connect a hose with a length of 2.5m and an inner diameter of 13mm at the joints of the trailer control pipeline and the supply pipeline respectively, and install a three-pass crossover joint at the end of the hose. , The air pressure sensor is installed on the transition joint;
4. For vehicles equipped with load sensing device, the load sensing device should be adjusted to the full load state.
3. vehicle braking response time requirements
In a number of related standards, the response time of commercial vehicles and trailer braking systems is clearly specified, as follows:
1. During emergency braking, the time from when the control device is activated to when the braking force on the most unfavorable axle reaches the corresponding prescribed braking performance should not exceed 0.6s;
2. For trailers equipped with air pressure control pipelines, the time from when the pressure provided by the simulation device to the control pipeline reaches 0.65 MPa to when the pressure in the trailer brake chamber reaches 75% of its steady-state value is not Should exceed 0.4s;
3. The pressure of the energy supply pipeline should be 0,65 MPa;
4. When the simulation device is connected to a gas cylinder with a volume of 385±5 mL, the time required for the pressure to rise from 0.065 MPa to 0.49 MPa is 0.2±0.01s; if a cylinder with a volume of 1125±15 mL is used, the pressure will increase The time is 0.38±0.02 s, and the rising law of the pressure from 0.065 MPa to 0.49 MPa should be approximately linear.
Regarding how to measure the braking response time, the above is the specific measurement method and time requirements compiled by the Naiou editor for everyone. I hope it can be helpful to everyone. Luoyang Naiou Electric Co., Ltd. is a high-tech enterprise focusing on the research, design and manufacture of automobile road test instruments and test system equipment. The products include brake response time test systems and related peripheral sensors, etc., if necessary, you can visit us Leave a message on the website, or call the customer service phone for detailed consultation.