Hydrostatic driving movement gear shifting control method and system

Abstract

The invention discloses a hydrostatic driving movement gear shifting control method which comprises the steps of load reduction, neutral gear switching, synchronous control and target gear switching, wherein in the step of the load reduction, when gear shifting is required, differential pressure delta p between the high-pressure side and the low-pressure side of a motor is reduced; in the step of the neutral gear switching, a gear shifting actuator is switched to a neutral gear state when the delta p is reduced to preset differential pressure; in the step of the synchronous control, a rotating speed of the motor is controlled, and a rotating speed of an input shaft of a gearbox and a rotating speed of an output shaft of the gearbox are synchronized based on a target gear transmission ratio; and in the step of the target gear switching, the gear shifting actuator is switched to a target gear. The gearbox used in the hydrostatic driving movement gear shifting control method is not provided with a clutch or a synchronizer, is simple and universal in structure and low in cost, and has the comparative cost advantage in a hydrostatic driving solution, the whole gear shifting process can be realized completely automatically, the gear shifting time can be controlled within 500-800ms, and the gear shifting rapidity and the velocity smoothness in the gear shifting process are ensured. The invention further discloses a hydrostatic driving movement gear shifting control system.

Description

technical field [0001] The present invention relates to the technical field of hydrostatic transmission, and more specifically relates to a method and system for controlling shifting of hydrostatic transmission. Background technique [0002] The hydrostatic drive is a hydraulic drive transmission system consisting of a hydraulic pump and a hydraulic motor in a closed circuit. The hydraulic pump absorbs the power of the engine and converts it into hydraulic energy, and the hydraulic motor converts the hydraulic energy into kinetic energy and drives the vehicle or crawler through the transmission device. [0003] Hydrostatic drive has the absolute advantages of simple structure, low noise, large starting torque, high reliability and high operating comfort, and it is mainly used in the field of mobile machinery (construction machinery, agricultural machinery, municipal machinery and some special vehicles, etc.). In some applications that require speeds exceeding 20Km / h, such a...

AI Technical Summary

Problems solved by technology

[0037] (1) First of all, in terms of system composition, this technology requires a gearbox with a synchronizer. Compared with a gearbox without a synchronizer, its disadvantages are high price and high failure rate

[0038] (2) During the shifting process, the control system needs to adjust the displacement of the motor to 0 first, and the displacement of the pump to 0 at the same time, otherwise the hydraulic oil output by the pump will quickly cause the overflow of the system, resulting in engine failure. heavy load

In this case, on the one hand, a certain overflow and energy loss will inevitably be caused during the shifting process; on the other hand, special pumps need to be selected, and the system applicability is poor

[0039] (3) The steps of upshifting and downshifting are different. In the process of downshifting, in order to meet the requirements of synchronization, the motor needs to be quickly adjusted from 0 displacement to 60% of the maximum displacement, and then returned to 0. The process Complexity puts forward higher requirements for software design

At the same time, due to the response characteristics of the motor's own adjustment, from 0 to 60%, it takes about 200ms in theory, which increases the total time required for gear shifting

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