Control system and control method for automatic gear shifting of loader

Abstract

Disclosed are a control system and a control method for automatic gear shifting of a loader. The control system is characterized by being provided with a microprocessor. The microprocessor is used for receiving signals of engine speed, torque converter turbine speed, loader speed, operation hydraulic system pressure, braking pressure, gears and a steering handle. The microprocessor is provided with a driver's intention judgment controller, a gear operation controller and a gear shifting time controller. The control system has the advantages that three control links are provided, input signals are analyzed first to judge a driver's intention so as to decide shifting gear or not, the control links are selected via gear shifting strategies to select a proper gear shifting process, and finally, gear shifting time of former-gear disengaging and later-gear engaging is determined through the gear shifting time control link, so that gear shifting smoothness, power continuity and oil consumption reduction are guaranteed, and comfortable, energy-saving and efficient control is realized.

Description

technical field [0001] The invention relates to an automatic speed change control system and a control method for a loader. Background technique [0002] At present, the automatic variable speed control system of loaders produced or used at home and abroad is to obtain the current input speed and the current machine driving speed by checking the input gear speed and output gear speed of the gearbox, and rely on the vehicle speed as the basis for automatic speed change control. [0003] In traditional variable speed controllers, usually with attached Figure 1 Shift control is performed at the indicated vehicle speed shift points. From attached Figure 1 From the above, in order to make the vehicle shift smoothly, the general shift point selects two intersection points of each gear, that is, A, B, and C points. When the I gear is changed to the II gear, it is the A point, and the II gear is changed to the III gear to be the B point. Shifting from gear III to gear IV is point...

AI Technical Summary

Problems solved by technology

[0006] 2. This shifting method only considers the smoothness of the vehicle speed, and does not consider the traction demand of the loader. When the driving resistance of the loader changes, such as going uphill, downhill, or lifting the bucket while driving, it cannot be guaranteed Continuity of power when changing gears

[0007] 3. The impact on machine efficiency when shifting gears is not considered. In order to solve the impact of traveling load, loaders generally use hydraulic torque converters as the coupler of the engine and gearbox. Figure II is the working characteristic of the torque converter

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