System and method for starting a crane

Abstract

The invention relates to a system and a method for starting a crane. The starting system comprises a power system, a variable pump assembly and a main valve, wherein the variable pump assembly comprises a variable pump and a variable control structure; the power mechanism is used for supplying driving power for the variable pump assembly; a pilot oil opening is formed in the variable pump assembly and connected to the variable control structure; the system also comprises a pressure oil source; the pressure oil source is used for supplying pilot oil for the variable control structure and reducing the discharge capacity value of the variable pump to a predetermined discharge capacity value; the pressure oil source is connected to the pilot oil opening through a hydraulic oil channel. By virtue of the system, resistant torque of a hydraulic system is reduced to a maximum limit in a low-temperature environment, so that the cold start of an engine is realized, the low-temperature operation range is expanded and the low-temperature application range of products is expanded.

Description

technical field [0001] The invention relates to the field of engineering machinery, in particular to a crane starting system and method. Background technique [0002] Usually, at the ambient temperature where the hydraulic oil is suitable, the starting torque of the crane engine can overcome the instantaneous resistance torque caused by the displacement change of the variable pump at the moment of starting, and realize the smooth starting of the engine. attached figure 1 It shows an existing crane starting system, which includes a power system composed of an engine and a transfer case. The power system is connected with a variable displacement pump assembly for driving the variable displacement pump assembly, and then connected through a hydraulic oil circuit to the main valve, and then connect the main valve to the actuator through the hydraulic circuit. However, when the ambient temperature is low, especially below -20°C, the viscosity of the hydraulic oil increases, and...

AI Technical Summary

Problems solved by technology

However, when the ambient temperature is low, especially below -20°C, the viscosity of the hydraulic oil increases, and the resistance torque of the hydraulic system increases accordingly. When the resistance torque is greater than the starting torque of the engine itself, the engine cannot start normally

[0003] To solve this technical problem, the existing technical solutions usually improve the engine, but simply by increasing the engine starting torque to improve the cold start performance, the resistance torque to be overcome cannot be quantified, and the adaptability is poor

In addition, in the existing hydraulic system, the main valve with unloading function in the middle position is selected, resulting in dependence on the main valve components, and at the same time, the unloading of the main valve in the middle position limits the composite action of the system

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