Weichai Power Safety Brake System--WEVB is a patented technology that Weichai Power purchased from German company MAN. This technology is already a standard configuration for heavy trucks in developed countries and has become a mandatory structure for regulations. The main function of this organization is to increase the braking torque generated by the diesel engine when the truck needs to decelerate, so that the vehicle can continuously reduce or stabilize the vehicle speed, effectively improve the control performance of the vehicle, and can ensure the safety of the vehicle in the mountain downhill, reduce the brakes. The frequency of use of the system reduces the wear and tear of the brake system, lowers the operating cost of the entire vehicle, and improves the economical efficiency of use. Drivers can reduce or reduce the number of brakes and reduce the intensity of driving work by eliminating or reducing the need for watering and cooling tires on downhill roads. Increased ride comfort. The traditional exhaust brake device uses a butterfly valve switch to close the exhaust pipe passage, so that the piston receives the back pressure of the gas during the exhaust stroke, which prevents the engine from operating and generates a braking effect, thereby achieving the purpose of controlling the vehicle speed. WEVB exhaust valve braking is based on conventional butterfly valve exhaust assist brakes. When the butterfly throttle valve is closed, the diesel engine works like a compressor under the gravity drag of the car. The pressure of the exhaust gas in the exhaust passage rises sharply, and the pressure waves generated by the exhaust of the adjacent cylinders cause the suction stroke. The exhaust valve of the cylinder near the dead point opens uncontrolled. Exhaust valve braking device (EVB) is the phenomenon that the exhaust valve is automatically opened by the pressure wave during the braking process. By adding an actuator to control the stroke of the exhaust valve, the exhaust valve is achieved during engine braking. Keep a gap open to increase the braking efficiency of the engine. When the exhaust valve is opened by the pressure wave, the small piston in the exhaust valve brake mechanism moves downwards following the exhaust valve due to its own weight and spring action. At this time, the one-way valve opens, filling the cavity above the small piston. Oil, and because in the above-mentioned process and in the subsequent compression and power stroke, the sealing plane of the rocker arm of the exhaust valve is close to the sealing surface of the oil seal screw, and the oil discharge hole is closed, so the oil enclosed in the small piston is closed. The small piston cannot be retracted into the rocker arm, forcing the exhaust valve to open, maintaining a stroke of approximately 1-2 mm throughout the subsequent compression and power strokes. At the beginning of the exhaust stroke, the exhaust valve is fully opened by the motion of the rocker arm, and the oil discharge hole on the rocker arm of the exhaust valve is opened, and the lubricating oil is ejected, and the extended small piston returns to the position under the valve pressure. The above process is repeated in cycles, thereby increasing the braking power of the diesel engine. Suction Stroke Compression stroke Power stroke Exhaust stroke When the butterfly valve is closed, the exhaust valve is opened by a pressure wave from the exhaust pipe, and the check valve in the rocker arm of the exhaust valve opens, lubrication in the rocker oil hole The oil fills the cavity above the small piston, and the closed oil prevents the small piston from retracting into the rocker, forcing the opened exhaust valve to hold approximately 1-2 mm of opening. The gap is maintained and the compressed air is discharged into the exhaust pipe through the throttling action, so that the gas pressure in the cylinder is significantly reduced after the compression is completed. As the piston descends, the vacuum generated by the gas is drawn from the exhaust pipe into the cylinder. Because of the throttling effect, the pressure of the gas in the cylinder is further reduced, thereby avoiding the compression work to drive the engine to perform positive power. This stroke is caused by the exhaust valve being cammed. The shaft is opened, the drain hole at the top of the rocker arm is also opened, the oil is drained off, the small piston returns under the pressure of the valve, the open small gap is closed, and one cycle is completed. Red Pine Noodle Ukulele,Low G Tenor Ukulele,Flight Tenor Ukulele,Personalized Ukulele Shandong Changyun Musical Instruments Co., Ltd. , https://www.cyukulele.com