1. Control Yoke is at an angle activated by the stepper motor
2. Front wheels are steered to the right. The small bevel gear is rotated in direction X by the rotation of the rear steering shaft. The small bevel gear, in turn, rotates the main bevel gear.
3. Rotation of the main bevel gear causes movement of the control rod toward the control valve.
4. Input rod of the control valve is pushed to the right, according to the degree of the control rod's movement (determined by the disposition of the swing arm), which is positioned to move in an upward direction, to the right. The rear wheels are thus steered to the left, in an opposite direction to the front wheels.
5. As the angle of the control yoke is increased in direction A as vehicle speed decreases, the rear-to-front steering ratio proportionately increases and the vehicle's steering lock tightens.
b. Same phase (direction) over 35km/h (22mph)
The operation of this phase is the reverse of the opposite phase one, because the control yoke is angled toward "positive" in this vehicle speed range, as illustrated. The phasing of the swing arm, yoke rod and bevel gear steers the rear wheels toward the right-the same direction as the front wheels.
c. Neutral phase, at 35km/h (22mph) The control yoke's angle is horizontal (neutral). Thus, the input rod is not affected, even if the control rod is moved with the rotation of the bevel gear unit. As a result, the rear wheels are not steered in this mode.
Power Cylinder
The movement of the input rod of the control valve unit is transmitted to the power cylinder's spool. The spool's displacement to the sleeve causes a pressure difference between the right and left side chambers in the hydraulic power cylinder. The pressure difference overcomes the output shaft load and initiates sleeve movement. The sleeve-power rod assembly is moved in the direction of the input rod by a proportionate degree. The output rod transmits steering action to the tie rod on either end of the rear wheel steering control-mechanism unit, thereby steering the rear wheels.
Fail-Safe Measures
The system automatically counteracts possible causes of failure, both electronic and hydraulic. In either case, the centering lock spring housed in the steering system unit returns the output rods in the "neutral" straightforward position, essentially alternating the entire steering system to a conventional 2WS principle.
Specifically, if a hydraulic defect should render a reduction in pressure level (by a movement malfunction or a broken driving belt), the rear wheel steering mechanism is automatically locked in a neutral position, activating a low-level warning light.
In the event of an electrical failure, such would be detected by a self-diagnostic circuit integrated within the 4WS control unit, which stimulates a solenoid valve and then neutralizes hydraulic pressure and return lines, thereby alternating the system again to that of a 2WS principle. Henceforth, the warning light referencing the 4WS system within the main instrument display is activated, indicating a system failure.
翻译:三十五年前,两个马自达设计师提出了一个远见的、有计算认为是相当革命性的结论。
他们在1962年10月26日日本汽车工程师学会技术会议上 Tadashi Okada博士和Toshiaki工程师总结了他们关于车辆动力学的辛勤研究如下:
1.基本特性差别在于过度转向与不足转向的量和时间上的延迟和响应。论文网
2.汽车在高速状态下应具备不足转向特点。
3.后方的稳定很大程度上反映出车轮和轮胎。
4.控制与稳定的一大进步,可预期的方式自动引导系统后车轮. 汽车转向节英文文献和中文翻译(3):http://www.751com.cn/fanyi/lunwen_15947.html