Application of nylon hose in automobile brake pipe

Because of its easy assembly, cleanness, anti-aging and corrosion resistance, nylon tubes are widely used by various auto manufacturers around the world. The second automaker has applied nylon 11 pressure pipes on several models, such as the EQ4090F5D and ED1118R series, and also used some nylon tubes on the EQ1902F model. In the future new models, all the traditional steel pipes are gradually adopted. Replaced with nylon tubes.

1 Experimental of the brake system using nylon tube

In order to achieve safe driving, the car must have good braking performance, so the parts of the braking system are also called "security parts." Since the requirements for nylon tubes used in automotive brake systems are very high, they must undergo rigorous experimental and research measurements before they can be applied to automobiles. In accordance with this requirement, pressure pipes supplied by Ato Chemical China Co., Ltd., and Yada Plastic Products Co., Ltd. were tested. After the experiment, it is concluded that the performance of the nylon tube provided by the former is completely up to standard. In the experiment, the experimental conditions were not standard, so the experiment was not carried out according to the original standard. The final result is that all the other aspects are in compliance with the standard except that the sample has a relatively large bending radius (the result meets Japanese standards). Therefore, the car's brake system can use this quality product.

2 nylon pipe joints

The installation of nylon tubes for automotive brake systems also has strict requirements: it must have good sealing performance, and it must be easy to disassemble, but also adapt to various weather and environment, and good anti-vibration effects. When designing the joint of nylon pipe, the following two principles must be met: (1) Under the specified conditions, the pipe joint should have good sealing, and the joint of the pipe should conform to the strength when the pipe is unplugged; (2) The joint should be simple, the process is good, the cost is low, the size is small, and the disassembly and maintenance are convenient. The pipe joints of nylon pipes mainly have three structural forms: (1) card sleeve type; (2) single head card

Socket; (3) flange type. The edge of the ferrule type pipe joint is sharp, which is easy to cause damage to the nylon so that the strength of the detachment is low, so it is not suitable for use on a nylon tube.

When the device is connected to the nut, some of the nylon tubes at the joint will rotate as the nut rotates. This phenomenon is caused by the same force at both ends of the structure and the opposite direction. It is subjected to the force of the backing core and the pipe to integrate the pipe. When the external force causes the friction of one end of the nut to be greater than the end of the joint, the pipe will be forced to rotate. In view of this, the best method is to use a single-head ferrule fitting.

Because the sealing angles of the nut end and the joint end are not the same, this causes the nut end to ensure that the friction torque of the joint end is greater than the friction torque of the nut end, which effectively prevents the nut from rotating when the nut is tightened. Not only that, but the inner edge of the ferrule is also eliminated, the outer side of the nylon tube is no longer damaged, and the pull-out strength is not weakened.

3 Nylon tube position and fastening method

The position of the nylon tube should be noted in the following principles: try to avoid erosion by the battery acid; (2) away from the exhaust, compressor and all other heat sources; (3) to ensure that it is not subjected to any blow, friction, damage, distortion, etc. Also, try to avoid contact with sharp objects and avoid tube damage; (4) minimize the fatigue value of the pipe, and pay attention to the fact that the length of the pipe itself should not change when the pipe changes in the ambient temperature or its own temperature. Therefore, the phenomenon of pulling and breaking is avoided; (5) The shelf for fixing the pipe is considered to be adapted to the change of the length of the pipe during installation, and the pipe is not damaged during the installation.

Refer to the air brake systems of European-made BMWs and Volvos. The brake systems of these cars are made of nylon tubes, which are bundled into a protective cylinder fixed to the frame. The advantage of this approach is to prevent the nylon tube from being damaged by other components and to be aesthetically pleasing. But the disadvantage is that the cost is relatively high, and it is difficult to assemble and maintain.

China's heavy-duty trucks, such as Jiefang brand tractors, use spiral protection tubes to protect parts in stages. Before installation, it has a strict dispensing process, which is very time-consuming in mass production, even if nylon tubes are used. 11, the cost is not low. Therefore, this type of device is more suitable for vehicles with more valves and more distributed distribution. Japan's RV32PXUM passenger car and China's Steyr type car use a tube-type nylon tube, the spacing of the clip is between 250mm-350mm, it is arranged along the inside of the beam, with its protection, It can effectively prevent the invasion of sand, dust or other debris. This method is relatively simple, and the cost is not high, and the device (assembly) and maintenance are also relatively easy.

4 Advantages of using nylon tube

4.1 Improved sealing of the brake system

The use of a nylon tube allows the car to use less than half of the intermediate link of the tube, and the nylon tube itself has a high degree of sealing, thereby reducing the possibility of air leakage.

4.2 Improve the reliability and safety of the brake system

The air in the coastal area is humid, it is easy to rust the steel pipe, and the nylon pipe has good corrosion resistance, effectively avoiding problems with parts such as the valve, the corrosion of the steel pipe is easy to pose a threat to the car, and the nylon pipe is completely unnecessary to worry, thereby ensuring The reliability and safety of the brake system.

4.3 Shorten the intake and exhaust time and improve efficiency

The nylon tube has a smooth interior, a large curved diameter, and smooth airflow. In the same environment, the nylon tube can run faster than the steel tube and saves time.

4.4 Conducive to standardized production of products

Nylon tube

5 Nylon tube cost calculation

The experiment used nylon tubes and steel tubes for evaluation and research. According to the following content, the price of nylon tubes should be much lower than that of steel tubes. The reasons are as follows: (1) The total arrangement length is gradually reduced after the nylon tube is used; (2) Nylon tube can be used in signal circuit, working circuit, gas source circuit and other systems; (3) nylon tube has no molding process; (4) steel tube has no high utilization rate of nylon tube; according to investigation, currently sold steel pipe on the market Each car is 28 yuan higher than the nylon tube. After the nylon tube is used, the number and variety of the pipe joints used by the car are much reduced, and the cost per vehicle can be reduced by another 45 yuan.

6 Conclusion

After the car brake system uses nylon tube, although the price of nylon tube and steel tube is almost the same (should be different), there are still much economics in the current enterprise that cannot be statistically economical, such as assembly and reserve transportation. In terms of aspects, reducing workload and simplifying the production process, reducing the failure rate and compensation rate, this is undoubtedly indicating that the economic benefits of using nylon tubes are better (since many are unable to calculate economic benefits, how can they get Is the economic benefit of the nylon tube better?). Therefore, the use of nylon tubes can promote the automotive pipeline technology to a higher level and improve the braking performance of the vehicle.