A power downshift control method for high-horsepower tractors considering the characteristics of diesel engine speed regulation

Abstract

The invention discloses a high-horsepower tractor down-shift control method considering the speed regulation characteristic of a diesel engine. The high-horsepower tractor down-shift control method considering the speed regulation characteristic of the diesel engine comprises the steps that firstly, the power down-shift control parameter of a tractor is determined; and secondly, the power down-shift control process of the tractor is divided into a shift preparation stage, a rotation speed synchronizing stage, a gear overlapping stage and an engaging strengthening stage, then the purpose that in the power down-shift process, a variable-speed transmission system always keeps a large output torque is achieved, and meanwhile it is guaranteed that the diesel engine avoids flameout. In this way, the tractor can be adapted to change of work resistance and continuously operate, and the operation efficiency is guaranteed.

Description

technical field [0001] The invention belongs to the field of high-horsepower tractor power transmission system control, and specifically relates to a downshift control method for a multi-clutch high-horsepower tractor power transmission system. Background technique [0002] Tractor work has the following characteristics: (1) Affected by agronomy and implement carrying capacity, it generally moves at a constant speed; (2) In order to improve productivity, the throttle opening is generally above 80%; (3) The working resistance will fluctuate, which is difficult for traditional manual transmissions. To adapt to changes in working resistance, it is necessary to stop and change gears; in view of the operating characteristics of tractors, a 'Power Shift' (power shift) transmission system has been proposed abroad, and the cost of tractors equipped with this transmission system is also relatively high. The transmission system effectively expands the working resistance range of the t...

AI Technical Summary

Problems solved by technology

In the process of power downshifting, it is necessary to reasonably control the actuating pressure of the disengagement and engagement clutches. Since the diesel engine generally works in the speed regulation area, when the diesel engine speed decreases due to the increase of the load, the torque of the diesel engine increases, and when the torque of the diesel engine increases Large, the speed of the diesel engine rises, if the shift control is unreasonable, it will cause excessive power loss or the diesel engine stalls

[0004] In the process of clutch pressure control, it is especially necessary to avoid the generation of parasitic power, which is also called circulating power. In addition to causing unnecessary energy loss, this power will also cause great damage to the components of the transmission system.

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