Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
  • B62D—MOTOR VEHICLES; TRAILERS
  • B62D15/00—Steering not otherwise provided for
  • B62D15/02—Steering position indicators ; Steering position determination; Steering aids
  • B62D15/021—Determination of steering angle
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
  • B62D—MOTOR VEHICLES; TRAILERS
  • B62D5/00—Power-assisted or power-driven steering
  • B62D5/06—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle
  • B62D5/062—Details, component parts
  • B62D5/064—Pump driven independently from vehicle engine, e.g. electric driven pump
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
  • B62D—MOTOR VEHICLES; TRAILERS
  • B62D5/00—Power-assisted or power-driven steering
  • B62D5/06—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle
  • B62D5/08—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle characterised by type of steering valve used
  • B62D5/081—Seat valves
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
  • B62D—MOTOR VEHICLES; TRAILERS
  • B62D5/00—Power-assisted or power-driven steering
  • B62D5/06—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle
  • B62D5/10—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle characterised by type of power unit
  • B62D5/12—Piston and cylinder
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
  • B62D—MOTOR VEHICLES; TRAILERS
  • B62D7/00—Steering linkage; Stub axles or their mountings
  • B62D7/06—Steering linkage; Stub axles or their mountings for individually-pivoted wheels, e.g. on king-pins
  • B62D7/14—Steering linkage; Stub axles or their mountings for individually-pivoted wheels, e.g. on king-pins the pivotal axes being situated in more than one plane transverse to the longitudinal centre line of the vehicle, e.g. all-wheel steering
  • B62D7/142—Steering linkage; Stub axles or their mountings for individually-pivoted wheels, e.g. on king-pins the pivotal axes being situated in more than one plane transverse to the longitudinal centre line of the vehicle, e.g. all-wheel steering specially adapted for particular vehicles, e.g. tractors, carts, earth-moving vehicles, trucks
  • B62D7/144—Steering linkage; Stub axles or their mountings for individually-pivoted wheels, e.g. on king-pins the pivotal axes being situated in more than one plane transverse to the longitudinal centre line of the vehicle, e.g. all-wheel steering specially adapted for particular vehicles, e.g. tractors, carts, earth-moving vehicles, trucks for vehicles with more than two axles

Definitions

• NLA trailing axles
• NLA active steering of the NLA is desired only at low speeds. At higher vehicle speeds, no steering of the NLA is desired, as this negatively affects stable driving.
• the NLA must be fixed at a certain vehicle-dependent speed, so as not to cause an unstable driving condition.
• the state of the art is that the NLA is articulated via a hydraulic cylinder.
• the oil is pumped into one or the other cylinder chamber via a pump that is driven by the internal combustion engine, depending on how the valves are switched. Therefore, especially in the straight-ahead driving, in which the vehicle is a long time, the hydraulic pump would be constantly driven, although this is not required. In this operating condition, the hydraulics generate losses that are not countered by added value. This is contrary to the demand for a lower fuel consumption of the vehicle.
• the problem is solved by the steering pump is not driven by the internal combustion engine, but via an electric motor. Since the electric motor can drive equally in both directions, one or the other can with a reversible pump depending on the direction of rotation
• Cylinder space are acted upon.
• German patent DE 4414161 C1 a multi-axle steering system is described, in which a master cylinder is controlled. Depending on the position of the master cylinder on the front axle, the slave cylinder reacts on the rear axle.
• a disadvantage of this system is the direct dependence on the respective position of the master cylinder. Thus, there is no possibility of a speed-dependent influence on the rear axle with this system.
• DE 103 51 482 A1 shows a steering system in which a hydraulic
• hinged vehicle rear axle is held with an additional locking device in the current position or hinged back adhesion-deflected in a central position and then locked.
• this requires more components, requires additional space and is therefore expensive.
• Steering axle is applied, if this is also active - so when steering lock - is needed.
• this system can only be implemented with great effort for a rear-axle steering, which is to be locked in straight ahead driving from a certain speed range.
• DE 10 2012 105 976 A1 discloses a steering system for a
• a valve In the fluid connection between the center bore and pump, a valve is connected, which prevents a fluid flow there in the working position.
• the valve is de-energized in the event of a fault and then allows a fluid flow.
• This valve is designed as a slide valve.
• Gate valves are however dirt susceptible. For example, metal particles floating around in the hydraulic fluid in the steering system may jam the piston.
• the pump is each with a connecting line with the two
• Hydraulic fluid is virtually always pushed back and forth in the circuit. This causes several disadvantages, since air pockets in the circuit.
• Hydraulic fluid can not be routed out. Especially at the first filling, the system can be poorly vented. Furthermore, in the circuit no filter for filtering out dirt from the
• Hydraulic fluid to be installed, since the hydraulic fluid flows in both directions.
• the object of the present invention is to provide a steering system for a
• the object is achieved in that instead of a slide valve several seat valves are used. These have the advantage that metal particles in the Hydraulic fluid can not affect the function of the valve, but be washed out again.
• the poppet valves are installed in the housing and connected to the cylinder via solid, solid lines. These solid lines may be drilled oil channels in the housing or metal tubes running on the housing. As a result, a failure of the system is prevented by line break, which in previous systems in which the
• Fig. 1 shows a functional diagram of a vehicle.
• a steering angle sensor S a For detecting a steering angle of wheels of a front axle here is a steering angle sensor S a , and for detecting a vehicle speed v a
• FIG. 2 shows the hydraulic circuit diagram of the entire steering system.
• the data obtained by a steering angle sensor which measures the steering angle at the front axle and data obtained from a vehicle speed sensor are input to a controller 1 .1.
• the control unit 1 .1 calculates from the data a caster angle of wheels on the trailing axle of the vehicle and controls accordingly an electric motor 1 .2.
• Fluid connection between the center bore and the oil tank is connected, and which releases a fluid flow between the center bore of the working cylinder and the oil tank in a basic position, and which prevents a fluid flow between the center bore of the working cylinder and the oil tank in a working position, and wherein the control unit for Recognizing malfunctions and in the event of a malfunction for switching the valve is formed in its normal position, so that the piston is driven adhesion driven to its center position, in which the piston closes the central bore, and the wheels of the trailing axle are blocked in a straight-ahead position.
• the pump can be the system by appropriate switching of the valve in a safe state to be transferred. While the valve is e.g.
• the control unit can be designed to switch the motor off when a predeterminable vehicle speed is exceeded.
• the trailing axle is thus - automatically from a certain presettable speed - i. driven by adhesion in their center position and held there, so that their wheels are in straight-ahead driving position. Since this center position can be maintained without further energy consumption, the power consumption of the system is minimal.
• the pump is designed as a reversibly operable pump or as a combination of a one-way operable pump with a valve block.
• a reversibly operable pump is the least Requirements for the space requirement of the steering system, while a one-way operable pump requires a simpler electric drive.
• Each cylinder chamber 1 1 .1, 1 1 .2 is associated with a return valve 10, 10.1, which is closed when filling the cylinder chamber 1 1 .1, 1 1 .2.
• the return valve 10, 10.1 of the other cylinder chamber 1 1 .1, 1 1 .2 is opened and thereby the
• Reflux from the other cylinder chamber 1 1 .1, 1 1 .2 through the filter 5 to the tank 6 allows.
• the mid-position valve 12 has a defined flow area for the open switch position, whereby the return speed of the
• the axle can be actively held by the motor here, but energy is consumed.
• the axis is held by trapped in the cylinder 1 1 oil.
• the axis is actively returned from the engine to the straight ahead driving position and then the steering system is switched passive, ie the mid-position valve 12 is closed and thus blocks together with the Check valves 9 and 9.1, the cylinder space.
• the advantage here is that no more energy is needed by the engine.
• Active steering low driving speed
• the steering angle of the front axle is detected metrologically and transmitted to the control unit 1 .1 of the rear axle steering.
• the vehicle speed of the setpoint of the rear axle is calculated and the motor 1 .2 driven by the control unit 1 .1.
• the actual value is detected and the
• Mid-position valve 12 is in its normal position and the axis is returned via the wheel forces and the desired damping via the center bore 1 1 .3 in the straight-ahead position, i. safe condition. There, the axis is held as explained below.
• Middle position valve 12 de-energized, whereby it assumes its basic position. If the piston is in the straight-ahead position, it can not be moved any further - thus the axle remains held.
• the axis is deflected, it is not possible to actively bring the axis into the middle position in the case of many errors.
• the currentless switching of the mid-position valve 12 prevents the axle from being deflected further than it is at that moment.
• the Achsrepstell rule try to move the cylinder in the direction of straight travel, this movement is made possible by the center position hole 1 1 .3 in the cylinder until the piston reaches the center position. After reaching the center position, the axis is held in this position, since the piston closes the middle position hole 1 1 .3.
• the speed of the axis movement in the event of failure can be adjusted so that no critical driving condition arises.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• Steering-Linkage Mechanisms And Four-Wheel Steering (AREA)
• Power Steering Mechanism (AREA)
• Steering Control In Accordance With Driving Conditions (AREA)
• Vehicle Body Suspensions (AREA)

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• 2014
  • 2014-09-25 DE DE102014113880.5A patent/DE102014113880B4/de active Active
• 2015
  • 2015-08-26 BR BR112017005965-7A patent/BR112017005965B1/pt active IP Right Grant
  • 2015-08-26 WO PCT/EP2015/069495 patent/WO2016045896A1/de not_active Ceased
  • 2015-08-26 JP JP2017516364A patent/JP6522744B2/ja active Active
  • 2015-08-26 US US15/514,547 patent/US10370027B2/en active Active
  • 2015-08-26 CN CN201580051267.6A patent/CN106687360B/zh active Active

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