Precision spring use maintenance common sense

1. Valve spring

The valve spring is subjected to high temperature and periodic high-frequency alternating force, which will produce wear and plastic deformation after use for a period of time, weakening the elasticity, resulting in loose valve closure, reduced engine power, black smoke exhaust, difficult to start and other failures. Therefore. Check the valve spring elasticity regularly. A small piece of iron sheet can be placed between the old spring and the new spring, and the pressure is compared on the vice to see the degree of shortening. When the new spring is compressed to 2/3 of the original length, if the old spring is 2mm shorter than the new spring, it should be replaced. If there is no spare part for a while, a flat washer of about 2mm can be padded on the old spring to make up for its lack of elasticity. Under normal circumstances, the valve spring should be replaced after using 2500 ~ 3000h.

2. Plunger spring of fuel injection pump

The plunger spring of fuel injection pump will also be worn and deformed by the action of periodic high frequency alternating force, so that its free length is shortened and the elasticity is weakened. After the elasticity is weakened, the return speed of the plunger slows down. Aye. When the engine is running at high speed, the reciprocating motion of the plunger cannot be coordinated with the high-speed rotating motion of the oil pump CAM, thus reducing the lift of the plunger. The amount of fuel supplied is reduced accordingly, resulting in a decrease in engine power. Therefore, when the plunger spring is used 3600 ~ 4500h, it should be replaced in time.

3. Outlet valve spring

After the spring elasticity of the oil outlet valve is weakened. It will cause serious leakage of high pressure oil, reduce the remaining pressure in the high pressure oil pipe, and the oil valve is not set quickly, resulting in reduced oil supply and instability, and the engine is weak and "traveling". In addition, it will make the injector start to spray weak, the oil is not completely cut off, and the phenomenon of post-drip appears. This causes combustion to worsen, the engine to overheat, and the exhaust to emit black smoke. Therefore, the oil valve spring should be replaced after 3600-4500h, if there is bending deformation, it should be replaced in time.

4. Speed regulating spring

Small diesel engine speed spring should pay attention to the following points.

(1) After the diesel engine stops and shuts down, the speed control handle should be placed in the stop position to avoid the speed control spring in a long-term tensile state, resulting in weak elasticity.

(2) Parts such as speed spring should be cleaned frequently to avoid dust and debris blocking, causing gridlock and affecting the normal operation of the governor.

(3) Do not use the method of "tying" the speed regulating spring to increase the engine speed, otherwise it may cause serious consequences.

(4) Speed regulating spring due to long-term use after the elastic change, will make the diesel engine can not reach the due speed, then the adjustment screw can be adjusted. When adjusting the adjustment screws, the engine speed must be measured with a tachometer.

5. Clutch spring

Most of the time the clutch spring is subjected to static pressure, when the use of time is too long, plastic deformation will occur, the free length is shortened, and the elasticity is weakened. After the clutch spring's elasticity is weakened. The torque transmitted by the clutch will be reduced, and the power of the engine will not be fully exerted, resulting in the locomotive's inability to work. When it is found that the elasticity of the clutch spring is weakened, it can be adjusted by adding the appropriate thickness of the gasket in the pit of the part in contact with the spring. When adding gaskets, it should be noted that the free length of each spring on the same clutch assembly (including the thickness of the gasket) should be consistent. If the spring can not recover the original elasticity after adding the gasket, a new set of springs should be replaced. Under normal circumstances, when the spring is used for 2500 ~ 3000h, a gasket of 1 ~ 2mm thickness should be added to adjust the pressure; After 5000h, all springs should be replaced at the same time.

6. Hand tractor steering spring

When installing a steering spring, first identify the left or right hand spring. The left side should be equipped with a right-handed spring, and the right side should be equipped with a left-handed spring. If the left and right springs are installed incorrectly, when the tractor turns, the steering spring will be subjected to a reverse torsion force, which will deform the spring, or even break the spring, or the internal step of the steering gear will be damaged by scraping. Once the spring breaks and the steering handle relaxes, the steering gear loses thrust. The inlaid teeth cannot be repositioned, which may cause serious accidents. The identification method of left and right spring: hold the spring with the left hand, the thumb is up, and the other 4 fingers are in the same direction as the steel wire: the opposite is the right spring.

In addition, insufficient steering spring elasticity may cause the walking tractor to lose its handling stability. Therefore, the steering spring should be checked regularly. The inspection and adjustment method is the same as that of the valve spring, but flat washers of the same thickness should be placed on both sides. Generally about 4 years to check and adjust once.

7. Spring with adjustable elasticity

When the pressure regulator spring of the injector is weakened. Fuel injection atomization is poor, combustion deteriorates, engine power decreases, fuel consumption increases; When the spring elasticity of the governor is weakened, the engine speed decreases. Power decline, but also produce a "car" phenomenon: lubrication system pressure spring and hydraulic safety valve spring elasticity weakened, will cause parts accelerated wear, engine technical state deterioration; When the spring spring of the shift fork is weakened, the gear of the transmission can not be positioned, and the phenomenon of automatic jump gear and random gear will occur. Therefore, the pressure of the adjustable spring should be adjusted in time.