Proportional steering valve, proportional steering hydraulic circuit, proportional steering system and vehicle

Abstract

A proportional steering valve comprises a reserving valve and a proportional throttle valve (4). The reversing valve is provided with an oil inlet port (10), an oil return port (11), a first working port (12) and a second working port (13), an output port (14) of the proportional throttle valve is communicated with the oil inlet port (10), and an input port (15) of the proportional throttle valve is connected with one end of an internal oil inlet channel (23). The invention further provides a proportional steering hydraulic circuit comprising the proportional steering valve and provides a proportional steering system and a vehicle. Functions of flow control and reversing are achieved by the aid of the proportional throttle valve and an electronic control valve respectively, and accordingly, steering is realized by combined control, response speed is increased conveniently, and flexibility in steering is improved remarkably. In addition, cost is low and pollution resistance capacity is strong due to utilization of common hydraulic elements.

Description

technical field [0001] The invention relates to a hydraulic valve used in a hydraulic steering system of a wheeled vehicle, in particular to a proportional steering valve. Further, the present invention relates to a proportional steering hydraulic circuit comprising the proportional steering valve. Furthermore, the present invention also relates to a proportional steering system comprising the proportional steering hydraulic circuit and a vehicle. Background technique [0002] Wheeled vehicles, such as truck cranes, all-terrain cranes, etc., need to use corresponding steering systems to realize the steering of the wheels. Steering systems currently applied to wheeled vehicles are roughly divided into three categories: rod-based steering systems, rod-based steering systems plus proportional steering systems, and rod-based steering systems plus servo steering systems. [0003] Generally speaking, the linkage steering system controls the steering of the wheels through the roc...

AI Technical Summary

Problems solved by technology

[0004] However, the steering system of the above-mentioned prior art has the following defects: First, the above-mentioned rod-system steering system is limited by the structure of the rod system, which has defects such as inconvenient layout, laborious operation, and large turning radius. Second, the above-mentioned proportional steering system generally adopts a three-position four-way electromagnetic proportional reversing valve. Due to the limitation of the structure of the proportional electromagnetic reversing valve itself, the valve core needs to move a predetermined distance during the reversing to realize the oil circuit. That is to say, there is a certain dead zone and hysteresis in the reversing itself through the movement of the spool. In the prior art, after the steering is started, the drive of the electromagnetic proportional directional valve is generally set in the controller. The step function setting value of the current increase is used to compensate the reversing dead zone and hysteresis of the electromagnetic proportional reversing valve, so as to ensure the steering coordination between the bridges. The technical proportional steering system obviously has a series of problems such as poor dynamic characteristics and lagging response; thirdly, the above-mentioned servo steering system generally uses a servo valve, because the servo valve itself has zero dead zone and fast response characteristics, so it can get better Dynamic characteristics and faster response

However, the servo valve is sensitive to the cleanliness of hydraulic oil, has poor anti-pollution ability, is prone to defects such as jamming, and is expensive, which increases the cost of the whole vehicle

In addition, it is known that there is a large functional loss △P between the spools of the servo valve, which makes the hydraulic system seriously heated, which makes the servo steering system extremely prone to failure

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