What is the plunger pump?

What is the plunger pump? How does the plunger pump work? Axial piston pump is the use of the plunger parallel to the shaft reciprocating motion in the plunger hole volume changes to work. Due to the plunger and plunger hole are round parts, machining can achieve high precision with the volume of high efficiency, smooth operation, flow uniformity, low noise, high working pressure, but the hydraulic oil pollution More sensitive, the structure is more complex, higher cost. MCY14-1B: quantitative piston pump SCY14-1B: manual variable piston pump YCY14-1B: pressure variable piston pump BCY14-1B: electro-hydraulic control piston pump PCY14-1B: constant pressure variable displacement piston pump piston pump The pumping mechanism consists of two sets of precision couplings: plunger + barrel to make plunger and barrel assembly (Figure 5-11), delivery valve and oil out Delivery valve seat The delivery valve assembly is a pair of precision couplings that, after being mated, are not interchangeable and require high precision and finish and good wear resistance Of the radial clearance of 0.002 ~ 0.003mm Cylindrical head of the plunger cut a chute, and through the radial hole, the axial hole and the top of the same, its purpose is to change the cycle of fuel supply; plunger sleeve system The inlet and outlet holes are connected to the low-pressure oil chamber on the pump, and the plunger sleeve is installed on the upper body of the pump, and the positioning screw is used to locate the position of the chute head and the method of changing the oil supply amount is also different. Out valve and the valve seat is a pair of precision couplings, matching grinding Not interchangeable, with the gap of 0.01mm. Outlet valve is a one-way valve, under the action of spring pressure, the valve conical surface and the valve seat closely with the role of stop feeding, the high-pressure tubing and plunger The upper end of the cavity isolated to prevent the high-pressure tubing back into the fuel injection pump. The lower part of the oil valve was cross-section, both guide, but also through the diesel. Out of the valve cone under a small cylindrical surface, said For the decompression zone, its role is in the end of the oil supply, so that the hydraulic pressure within the high-pressure tubing rapidly decreased to avoid drip hole at the Department of the phenomenon.When the ring into the valve seat will make the top volume quickly increased Large, the pressure decreases rapidly, stop spraying quickly.Working, the camshaft in the fuel injection pump camshaft and plunger spring under the action of forcing the plunger for the upper and lower reciprocating motion, thus completing the pump oil task, the pump process can be Divided into the following three stages. Intake process When the convex part of the cam turn, under the action of the spring force, the plunger moves downward, the upper space of the plunger (called pump oil chamber) produces a vacuum, when the column Plug the plunger into the end face On the oil hole is opened, full of oil in the upper body of the oil in the oil passage into the pump oil chamber, the piston moves to the bottom dead center, the oil into the end of the process when the camshaft turn to the convex part of the cam When the roller body is lifted, the plunger spring is compressed, the plunger moves upwards, the fuel is pressurized, and a part of the fuel flows back to the upper oil chamber of the injection pump through the oil hole. When the top surface of the plunger covers the upper edge of the oil inlet hole on the sleeve , Due to the small clearance between the plunger and the sleeve (0.0015-0.0025mm), the pump oil chamber at the top of the plunger becomes a sealed oil chamber, the plunger continues to rise, the pressure in the pump oil chamber rapidly increases, and the pump oil Pressure> When the valve spring force + residual pressure of high-pressure tubing, push out the valve, high-pressure diesel through the valve into the high-pressure tubing, injected into the combustion chamber through the injector. Oil return process up the plunger, when up to the plunger on the chute (stop for the side) and the sleeve on the return hole, the pump chamber low pressure oil and the plunger head of the hole and the hole Radial hole and chute communication, a sudden drop in oil pressure, the oil valve in the spring force quickly shut down, stop the fuel supply. After the plunger has to go up, when the convex part of the cam turn, under the action of the spring, the plunger down again. At this point they started the next cycle. Conclusion: From the above discussion, the following conclusions can be drawn: â‘  The total stroke L of plunger reciprocation is constant and depends on the lift of the cam. (2) The amount of fuel supplied by the plunger per cycle depends on the fuel supply stroke, and the fuel supply stroke is variable regardless of the camshaft control. â‘¢ fuel supply start time does not change with the change of fuel stroke. â‘£ Turn the plunger can change the fuel supply end time, thus changing the fuel supply. 3. Domestic series plunger pump Domestic series plunger pump are A, B, P, Z and â… , â…¡, â…¢ and other series. Series is based on the power range of single cylinder diesel engine for different fuel requirements, based on plunger stroke, pump cylinder center distance and structure type, and then with different sizes of plunger diameter, composed of several in a work cycle Internal fuel supply ranging from fuel injection pump to meet the needs of various diesel engines. Domestic series injection pump working principle and structure of the same type to A-type pump as an example to introduce the structure and working principle plunger pump. Piston pump consists of four major components: sub-pump, fuel regulating mechanism, transmission and pump body.