One-minute entry: Evolution of the Bosch Common Rail System
[Hubei Cheng Li original] In 1892, the German engineer Rudolf Christian Karl Diesel invented the world's first diesel engine. In the following 30 years, diesel engines were used in ships, submarines, industries, generators and other fields. ◠ High pressure air supply Early diesel engines were huge and the process of diesel injection was completed with compressed air. In the era of steam engines, huge cylinders seemed to have become commonplace. However, the huge body can not be installed on land transport tools to solve the problem of high-pressure diesel injection and become the key to the application of diesel engines for vehicles. ◠ Mechanical plunger injection fuel In 1920, the society generally favored the future application of diesel engines. In 1922, Bosch officially started the development of diesel fuel injection pump. Thanks to its past experience in developing lubrication pumps, the developed high-pressure fuel injection pump can provide accurate quantities of liquid pressure. The unprecedented reduction in the volume of new high-pressure oil pumps has broken through the bottleneck in the application of automotive diesel engines. In 1923, at the Berlin Motor Show, Mercedes-Benz exhibited a 45-hp OB 2 diesel engine fitted with a Bosch fuel injection pump. The following year, the world’s first diesel-engined truck was born in Germany and was accepted by customers. In 1927, Bosch's fuel injection pumps began production and paved the way for the use of automotive diesel engines, changing the world. Mechanical oil pumps have been produced so far, and the pressure on the plunger has basically not changed much, but its drawbacks have also been fully exposed. The oil supply pressure is controlled by the engine speed. Accurate fuel injection at low speed is subject to many restrictions. Low pressure fuel injection is bound to result in poor atomization of diesel oil. The mechanical oil pump has completed its historical mission and cannot adapt to higher environmental protection and engine technical performance. ◠ Common rail system for oil supply The diesel engine is rude, has great vibration and noise, emits black smoke, and is difficult to start when it is cold in winter. Due to the above characteristics, engineers are constantly improving the technical performance of diesel engines. In 1945, the high pressure common rail system was first applied. However, due to the constraints of precision electronic technology at that time, reliability and control methods were not completely broken. Until the late 1990s, high pressure common rail technology was fully applied to diesel engines. The common rail fuel injection system consists of a high-pressure oil pump, a common oil supply pipe, an injector, an electronic control unit (ECU), and some pipeline pressure sensors. Each injector in the system passes through its own high-pressure fuel pipe and public oil supply. The pipes are connected and the common oil supply pipe acts as a hydraulic pressure accumulator for the injector. During operation, the high-pressure oil pump delivers fuel to the common oil supply pipe at high pressure. The high-pressure oil pump, pressure sensor and ECU form a closed-loop work to achieve precise control of the oil pressure in the common oil supply pipe and completely change the oil supply pressure as the engine speed changes. phenomenon. ◠Interesting oil supply system In order to be able to distinguish the difference between the two, you can simply make an analogy. Mechanical pump oil supply is similar to pressure wells. Common rail system oil supply is like a tap. Customization Of Chillers,Customization Of Open Chillers,Customized Laser Small Chiller,Air-Cooled Modular Chiller DONGGUAN CARNO MACHINERY CO., LTD. , https://www.kainuochiller.com
