Static pressure driving system of vehicle and control method for static pressure driving system

Abstract

The invention discloses a static pressure driving system of a vehicle and a control method for the static pressure driving system. The static pressure driving system comprises a closed pump and a hydraulic motor, and further comprises an energy storage module; the closed pump and the hydraulic motor are connected through an oil supply pipeline and an oil return pipeline to form a closed loop; and the energy storage module comprises the following components, namely an accelerator pedal displacement detection element, an energy storage pipeline, a first pressure detection element, a second pressure detection element and a high-pressure selection valve, wherein the accelerator pedal displacement detection element is used for detecting the displacement of an accelerator pedal, in addition, the accelerator pedal displacement detection element is connected to a controller, the energy storage pipeline is connected with an energy storage device and an on-off valve, the first pressure detection element and the second pressure detection element are connected to the energy storage pipeline, the first pressure detection element and the energy storage device are located on the same side of the on-off valve, the second pressure detection element is located on the other side of the on-off valve, the first pressure detection element and the second pressure detection element are both connected to the controller, the high-pressure selection valve is used for enabling high-pressure pipelines in the oil supply pipeline and the oil return pipeline to be connected to the energy storage pipeline, and when the controller controls the on-off valve to be opened, the energy storage device can work in an energy storage state or an energy release state.

Description

technical field [0001] The invention relates to a hydraulic system, in particular to a closed circuit hydraulic system for driving a vehicle and a control method thereof. Background technique [0002] The closed circuit is a hydraulic system in which the hydraulic medium is closed and circulated in the pipeline formed by the end-to-end connection of the hydraulic pump and the hydraulic motor. In the closed circuit, the circulating hydraulic medium does not pass through the oil tank. Closed loops have been widely used in the driving systems of agricultural machinery, engineering machinery, special vehicles and other vehicles. During the acceleration process of the vehicle driven by the closed loop, due to the displacement adjustment speed of the closed pump and the depressing speed of the accelerator pedal There is a lag between them, which makes the vehicle acceleration insensitive; during the deceleration process, the displacement of the closed pump decreases, and the funct...

AI Technical Summary

Problems solved by technology

Closed loops have been widely used in the driving systems of agricultural machinery, engineering machinery, special vehicles and other vehicles. During the acceleration process of the vehicle driven by the closed loop, due to the displacement adjustment speed of the closed pump and the depressing speed of the accelerator pedal There is a lag between them, which makes the vehicle acceleration insensitive; during the deceleration process, the displacement of the closed pump decreases, and the functions of the closed pump and the hydraulic motor are interchanged. Due to the large inertia of the vehicle, high pressure will be generated on the oil inlet side of the closed pump. In order to promote the deceleration of the vehicle, it is very easy to cause the engine driving the closed pump to overspeed at this time. In order to relieve the high pressure on the oil inlet side of the closed pump, in the prior art, a high-pressure relief valve is generally installed on the oil inlet pipe of the closed pump to make the inlet Part of the high-pressure oil in the oil pipe returns to the oil tank through the high-pressure relief valve, which will cause the temperature of the oil in the oil tank to rise and increase energy consumption

[0003] Due to the existing closed-circuit hydrostatic drive system, the acceleration of the vehicle is not sensitive during the startup acceleration process, which affects the user experience; and the excessive heat generated during the braking deceleration process causes the oil temperature to rise, which affects the static pressure drive. Both the system and the lubrication system can have a negative impact

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