Crankshafts after machining shall undergo 100% safety test of crankshaft body on bending fatigue performance and magnetic flaw detection to guarantee its high safety factor and reliable quality. Safety test of crankshaft body on bending fatigue performance shall ensure safety factor of iron crankshaft higher than 1.6 and of steel crankshaft higher than 1.8. The product employs exquisite thermal treatment technique for overall tempering of steel crankshaft, normalizing treatment of iron crankshaft and quenching or nitriding treatment of crankshaft surface. 100% magnetic flaw detection is required for the crankshaft after machining, followed by demagnetization treatment. It is required that magnetic strength shall be ≤5 gauss.
The cylinder body is mainly made of gray cast iron and vermicular graphite cast iron with use of strict technical control in the production process to make sure deformation on the upper plane of the cylinder body is no more than 0.05mm within every 50mm. For cast iron cylinder body, error of six-cylinder engine throughout its total length shall not exceed 0.30mm and that of four-cylinder engine not exceed 0.20mm, and for aluminum alloy cylinder body, error of six-cylinder engine shall not exceed 0.50mm and that of four-cylinder engine not exceed 0.30mm. Cooling spray shot test is carried out to further improve its reliability. Reinforcing rib built inside the cylinder body guarantees its strength and properly arranged coolant way and lubricant way ensures proper cooling and lubrication.
The cylinder head is mainly made of nodular cast iron. In terms of quality control, the cylinder head employs nodular cast iron to guarantee its strength and hardness and applies process measures of forced convection and opening of unloading groove to improve thermal load of cylinder body. In terms of precision control, the production process is inspected from 6 different directions with precise ruler and thickness gauge. The maximum warping of the lower plane is 0.05mm or smaller and the application limit is 0.02mm to maximize sealing tightness.
The starter is endurable and can be started continuously for more than 35,000 times, with outstanding features of extremely low temperature start, large torque and low power consumption. The product applies high-performance one-way clutch with large transmission torque (up to 500N.m) to guarantee high success rate of one-time start; due to its strong resistance to high temperature and extreme cold, the engine can be started at the low temperature of -40℃; with use of fully-enclosed integral electromagnetic switch, it has higher sealing performance; drive gear of one-way clutch and reducing mechanism is applied with cold extrusion technique to render higher strength.
Yuchai exclusive quality components are manufactured by the same line for manufacture of main engine products, same from the source to keep their consistency. Precise fit dimension brings about high reliability, low fuel consumption, low noise, low emission and easy and fast maintenance of accessories, which is time-saving and worry-saving.
Yuchai series engine oil filters with use of advanced process technology may provide sufficient clean engine oil even under substantial temperature change in order to ensure proper oil pressure under various working conditions, guarantee effective application mileage and make sure the filter accuracy meets the requirement of protecting engine and reducing wear. The product is applicable to the environment of high engine oil temperature and corrosion and is able to filter all particles >30 um.
Yuchai series generators in strict consistency with the entire vehicle load feature sufficient power generation and strong resistance to high temperature and severe cold, able to generate power properly at the rated speed in case of the low temperature of -40℃; regulators with stable properties can meet the power demand of the entire vehicle at idle speed.
Yuchai series diesel oil filters apply the engine filter system used for aviation industry and calibration technique of “particle counting method” for filtering efficiency of filter system to obtain scientific, accurate and objective measurement of core performance parameters of filter products and make the original filtering efficiency of filters not lower than 90%. Filters with sealing reinforcement shall not leak at the pressure of 98kPa(1kg/cm2), which shall undergo vibration and internal cold and heat reliability test.