Hydraulic plunger variable duplex pump total power control method and system

Abstract

The invention discloses a method and system for controlling the total power of a hydraulic plunger variable duplex pump, and the method comprises the steps: connecting a first throttling plug and a second throttling plug at the outlet pressure oil positions of a first pump and a second pump of the hydraulic plunger variable duplex pump in series; the average pressure of first pump outlet pressure oil and second pump outlet pressure oil is obtained, the average pressure acts on a constant power control valve of a corresponding hydraulic plunger variable duplex pump total power control valve, so that the output flow of the first pump and the output flow of the second pump are decreased or increased, and the total power of the first pump and the total power of the second pump are kept constant. And the total power control of the hydraulic plunger variable duplex pump is realized. The integral control oil way is simple, machining is easy, and the size of parts is small. In conclusion, the invention has the characteristics of simplifying the oil path, reducing the processing difficulty and reducing the cost.

Description

technical field [0001] The invention relates to a hydraulic plunger variable displacement duplex pump, in particular to a hydraulic plunger variable displacement duplex pump total power control method and system. Background technique [0002] Among the hydraulic plunger pumps used in construction machinery, constant power control is widely used. The hydraulic plunger variable pump with constant power control can make the output flow of the hydraulic plunger variable pump follow the The change of load pressure is automatically adjusted to maximize the output power of the engine. [0003] For the hydraulic plunger variable single pump, the constant power control can be realized relatively simply through the joint action of the hydraulic plunger variable pump's own outlet pressure signal and the control valve. However, current construction machinery, such as excavators, cranes, etc., often use hydraulic plunger variable duplex pumps, that is, two hydraulic plunger variable pum...

AI Technical Summary

Problems solved by technology

[0004] In order to solve the above problems, the total power control of the hydraulic plunger variable duplex pumps currently on the market mostly adopts the constant power linkage control of the first pump and the second pump, and the outlet pressure signal of the first pump acts on its own power control valve at the same time. , also acts on the constant power control valve of the second pump, and at the same time, the outlet pressure signal of the second pump acts on its own power control valve, and also acts on the constant power control valve of the first pump. The total power control valve adopts a three-step control spool. The constant power control spool is usually matched with the constant power control valve sleeve. The coaxiality of the three-step diameter of the constant power control spool is relatively high. The coaxiality requirement of the inner hole is also high, otherwise the power control spool is subjected to the hydraulic clamping force, causing the movement of the power control spool to be stuck or even stuck, the total power control becomes invalid, and the engine speed drops or even stalls

The processing of the power control spool valve sleeve is a big challenge, and the outlet pressure oil of the first pump and the second pump needs to be cross-guided to the step of the constant power control spool of the other party, the oil circuit is complicated, the oil circuit layout and processing Both are more difficult, and may also lead to an increase in the volume of parts with oil passages

Therefore, the existing technology has the problems of complex oil circuit and difficult processing

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