Mechanic and hydraulic hybrid type power transmission system and control method

Abstract

The invention relates to a mechanic and hydraulic hybrid type power transmission system and a control method. The power transmission system is characterized in that a hydraulic pump / motor (12) is in rigid connection between an internal-combustion engine (2) and a clutch (11); a high-pressure oil port of the hydraulic pump / motor (12) is connected to a two-position three-way valve A (4) and connected to a high-pressure accumulator (5) by a hydraulic control one-way valve (7); a low-pressure oil port of the hydraulic pump / motor (12) is connected to a low-pressure accumulator (13); the hydraulic pump / motor (12) is further connected to the hydraulic control one-way valve (7) by a two-position three-way valve B (8); a pressure sensor (6) of the high-pressure accumulator (5), a brake pedal position sensor (15), an accelerating pedal position sensor (16) and an internal-combustion engine starting key position sensor (17) are connected to a hybrid power control unit (9) by electric cables; thehybrid power control unit (9) is connected to the hydraulic pump / motor (12) by a pump / motor discharge electric hydraulic control device (14). The system has simple structure, convenient operation andlow cost. The system can be applied to transforming the in-use vehicle or a new vehicle.

Description

technical field [0001] The invention provides a machine-hydraulic hybrid power transmission system and a control method, and specifically relates to energy utilization, conversion and storage of motor vehicle power and transmission systems. The purpose of the invention is to realize the energy saving and emission reduction of motor vehicles. Background technique [0002] With the rapid growth of the number of motor vehicles, oil consumption is increasing year by year, and the tail gas emitted by motor vehicles has caused serious air pollution. Studies have shown that for vehicles powered by internal combustion engines, only 15-25% of the fuel energy is used to drive the vehicle, and the rest of the fuel energy is consumed by rolling resistance, wind resistance, acceleration, and braking during vehicle driving. In order to reduce energy consumption and emissions of motor vehicles, traditional methods include improving the efficiency of the internal combustion engine, improvi...

AI Technical Summary

Problems solved by technology

Due to the inherent charging and discharging characteristics of the battery, its power density is low, and it is impossible to store or release a large amount of energy in a short time

Therefore, when the braking time of the vehicle is very short and the braking energy density is extremely high, it is difficult for the battery-generator type braking energy recovery system to effectively recover the huge kinetic energy generated at the moment of braking, resulting in low braking energy recovery efficiency.

However, vehicles such as buses and taxis that often operate in cities need to be started and braked frequently, the efficiency of internal combustion engines is extremely low, and the requirements for brakes are extremely high.

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