JPH08310422A - Hydraulic steering device for vehicle - Google Patents

Abstract

PURPOSE: To provide a low-priced hydraulic steering device for vehicle which can obtain steering reaction without feeling physical disorder. CONSTITUTION: In a vehicle provided with a plurality of steering wheels which can be steered independently respectively by oil pressure, a totally hydraulic type steering valve 12 which supplies oil quantity corresponding to a steering wheel angle to one steering wheel 2a is fitted onto a steering wheel shaft 11, and an angle sensor 7 for measuring steering angle is mounted onto one steering wheel 2a. There are also provided a controller 15 for computing a steering command value to steer another steering wheel 2b based on the steering angle of one steering wheel 2a detected by the angle sensor 7, and a steering valve 16 which supplies oil quantity corresponding to the steering command value obtained by the controller 15 to another steering wheel 2b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle hydraulic steering system. More specifically, the present invention relates to a device for steering each steered wheel in a vehicle having a large number of steered wheels.

[0002]

2. Description of the Related Art For example, in a shipyard, a hull carrier for carrying a block of a ship or a heavy goods carrier (dolly) for carrying a part of a bridge in construction work is operated by a large number of independently steered vehicles. Have a ring. In such a vehicle, the steered wheels can be steered in the same direction by the same angle, or the front steered wheels and the rear steered wheels can be cut in opposite phases to reduce the turning radius.

Here, as a method of steering a large number of steered wheels, generally, a hydraulic cylinder for turning each steered wheel by hydraulic pressure is provided, while an angle sensor such as a rotary encoder or a potentiometer is attached to a round handle to handle a steering wheel angle. Is detected and pressure oil is supplied to the hydraulic cylinder in accordance with the handle angle. In addition, since a proper steering reaction force is not generated simply by mounting a rotary encoder or the like on the round handle in this way, even if the steered wheels are not steered to the angle of the command value, only the steering wheel should be cut further. The driver may not be able to steer according to the driver's intentions.

Therefore, as shown in FIG. 8, the handle 01
An electromagnetic clutch 02 and a powder brake 03 are installed on the
It has been devised to generate an appropriate steering reaction force. still,
In the figure, reference numeral 04 is an encoder.

[0005]

In the above-mentioned prior art, it is necessary to attach an angle sensor to the steering wheel in order to steer a large number of steered wheels, and in order to obtain an appropriate steering reaction force, a powder is applied to the steering wheel. Since a brake or an electromagnetic clutch is required, there is a problem that the number of mounting steps increases and the manufacturing cost increases. The present invention has been made in view of the above prior art, and an object of the present invention is to provide an inexpensive hydraulic steering system for a vehicle that can obtain a steering reaction force without a feeling of strangeness.

[0006]

The structure according to the hydraulic steering system for a vehicle according to the present invention that achieves the above object is a vehicle having a plurality of steerable wheels that can be independently steered by hydraulic pressure, and the steering angle is changed according to the steering wheel angle. An all-hydraulic steering valve that supplies the amount of oil to one steering wheel is attached to the handle shaft, and an angle sensor that measures the steering angle is provided on the one steering wheel.
Further, a controller is provided which calculates a steering command value to be steered by the other steered wheels based on the steering angle of the one steered wheel measured by the angle sensor, and further the steering command value obtained by the controller. Is provided with a steering valve that supplies the amount of oil corresponding to the other steering wheel to the other steered wheels.

Here, the amount of power source oil to the full hydraulic steering valve is throttled by a reaction force proportional control valve, and the reaction force proportional control valve controls the steering angle of the other steering wheel. It is characterized in that the larger the deviation between the steering angle command value to be steered by the steering wheel and the steering wheel command value, the more the power source oil amount is reduced. Furthermore,
A mechanical power steering that supplies an oil amount corresponding to a steering wheel angle to one steering wheel is used instead of the all-hydraulic steering valve.

[0008]

[Operation] Of the many steered wheels, only one wheel is steered by the fully hydraulic steering valve, the steering angle is measured by the angle sensor, and the steering command value for the other steered wheels is generated by the controller. It is possible to steer by supplying the amount of oil corresponding to the value to other steered wheels through the steering valve.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in the drawings. FIG. 1 shows a hydraulic steering system for a vehicle according to an embodiment of the present invention. The present embodiment is applied to a hull carriage 1 having a large number of electro-hydraulic control type steering wheels. As shown in FIGS. 2 and 3, the hull cart 1 is provided with 10 rows of steered wheels 2 on the left and right respectively. As shown in FIG. 4, each steered wheel 2 is supported so as to be freely turnable and height adjustable.

That is, the outer frame of the turntable bearing 3 is fixed to a frame (not shown) of the vehicle body, and the bracket 4 is rotatably attached to the inner frame of the turntable bearing 3, and the bracket 4 has an arm. 5 is swingably connected. A double tire type steering wheel 2 is attached to the arm 5, while a suspension cylinder 6 is interposed between the bracket 4 and the arm 5.

Further, one end of a steering cylinder 7 is connected to the inner frame of the turntable bearing 3, and a steering angle sensor 8 for measuring a steering angle by the steering cylinder 7 is provided. As the steering angle sensor 8, a known potentiometer, encoder or the like can be used.

Therefore, the vehicle height of the hull carriage 1 can be adjusted by supplying / discharging pressure oil to / from the suspension cylinder 6 from a hydraulic source (not shown) and expanding / contracting the suspension cylinder 6. Therefore, as shown in FIG. 3, the vehicle height of the hull trolley 1 is lowered to dive under the block 10 placed on the turret 9, and thereafter the vehicle height of the hull trolley 1 is increased to increase the block 10 Can be lifted and transported.

Further, pressure oil is supplied to and discharged from the steering cylinder 7 from a hydraulic source (not shown), and together with the inner frame of the turntable bearing 3, the bracket 4, the arm 5 and the steered wheels 2 are provided.
The steering angle of each steered wheel 2 by the steering cylinder 7 is measured by the steering angle sensor 8. The measured steering angles are input to the controller 15, respectively. No link mechanism exists between the steered wheels 2, and the steered wheels 2 can be independently steered by hydraulic pressure.

Therefore, as shown in FIG. 5 (a), all the steered wheels 2 can be steered in the same direction to cause the hull carriage 1 to skew, and as shown in FIG. 5 (b). In addition, the front steering wheel 2 and the rear steering wheel 2 can be cut in opposite phases to reduce the turning radius so that one certain turning center can be specified. If there is no skew mode and only turning is performed, the left and right steered wheels 2 may be mechanically connected by tie rods 17 and steered at the same angle, as shown in FIG.

On the other hand, as shown in FIG. 6, the handle shaft 11
An all-hydraulic steering valve 12 called an orbit roll (registered trademark) is mounted on the. The all-hydraulic steering valve 12 supplies and discharges a turning angle of the steering wheel shaft 11, that is, an amount of oil corresponding to the steering wheel angle, to the steering cylinder 7 for one steering wheel 2.

The one steered wheel 2 is an arbitrary one of the many steered wheels 2. In this embodiment, the steering wheel 2 on the left side of the front row closest to the driver's seat is used. As shown in FIG.
This is because the steering angle is the largest when turning. In the following description, in order to distinguish one steered wheel 2 from the other steered wheels 2, it is called a master side steered wheel 2a.
Is referred to as the slave side steering wheel 2b.

Further, the full hydraulic steering valve 12 is connected to a pump 14 serving as a hydraulic pressure source via a reaction force proportional control valve 13. The reaction force proportional control valve 13 includes a controller 15
The amount of oil supplied from the pump 14 to the all-hydraulic steering valve 12 is continuously reduced in accordance with the command value from.
The controller 15 obtains the deviation of the steering angle between the master side steered wheel 2a and the slave side steered wheel 2b, and outputs a command value proportional to the deviation to the reaction force proportional control valve 13.

Therefore, the larger the deviation of the steering angle between the master side steered wheel 2a and the slave side steered wheel 2b, the larger the flow rate throttled by the reaction force proportional control valve 13 and the supply to the full hydraulic steering valve 12. Since the amount of oil decreases, a large steering reaction force is generated on the handle shaft 11.
That is, the reaction force proportional control valve 13 is connected to the slave side steering wheel 2
In a state where b is not steered to the steering command value, the supply of hydraulic oil to the full hydraulic steering valve 12 is limited to make the steering force of the steering wheel shaft 11 heavy, and how to turn the steering wheel to the driver. Informs you that it is too early.

For example, when the handle shaft 11 is suddenly cut, as shown in FIG. 1, the reaction force proportional control valve 13 stops the supply of hydraulic pressure, and the handle shaft 11 becomes heavy and cannot rotate. When the operating speed of the handle shaft 11 is assumed to be relatively low, a command value proportional to the engine speed is given to the reaction force proportional control valve 13 regardless of the deviation of the steering angle. good.

While the controller 15 outputs the command value to the reaction force proportional control valve 13 as described above, as shown in FIG. 7, according to the condition of "skew" or "turn", the master side steered wheels are controlled. A steering angle command value for steering the slave side steered wheels 2b is calculated based on the steering angle of 2a (hereinafter referred to as the master axis angle). The calculated steering angle command value is applied to the slave shaft steering valve 1 for each slave side steering wheel 2b.
Given to 6.

The slave shaft steering valve 16 supplies the oil amount corresponding to the steering angle command value obtained by the controller 15 to the steering cylinder 7 for the slave side steering wheel 2b. Therefore, when the condition of "skew" is given to the controller 15, the steering angle command value equal to the master axis angle is calculated by the controller 15, and the oil amount corresponding to this steering angle command value is given by the slave axis steering valve 16 to It is supplied to the steering cylinder 7 for each slave side steered wheel 2b.

When the controller 15 is given a "turning" condition, the front steering wheel 2 and the rear steering wheel 2 are arranged so that the controller 15 can specify a certain turning center according to the master axis angle. A steering angle command value is calculated so that 2 is reversed, and an oil amount corresponding to this steering angle command value is supplied to the steering cylinder 7 for each slave side steered wheel 2b by the slave shaft steering valve 16. It

Here, in principle, the controller 15 calculates the steering angle command value for steering the slave side steered wheels 2b according to the master axis angle, but exceptionally, the master axis angle is increased. The steering angle command value may be calculated according to the value. For example, when two hull carriages 1 are connected and turned, the steering angle of the master-side steered wheels 2a must be set to 50 ° in order to specify the turning center. In some cases, the steering angle of the steered wheels 2a may actually be limited to 45 °.

In such a case, the master side steering wheel 2a
Is cut to 50 °, that is, a value obtained by increasing the actual master axis angle is obtained, and the steering angle command value for steering the slave side steering wheel 2b is calculated. With this configuration, the master-side steered wheel 2a can slide while the master-side steered wheel 2a is swung by the slave-side steered wheel 2b with a relatively small turning radius around a certain turning center. You can do it.

Although the present embodiment is applied to the hull carriage 1, the present invention is not limited to this and can also be applied to a heavy load carrier (dolly) in construction work. Further, although the all-hydraulic steering valve 12 is used in the above embodiment, the present invention is not limited to this, and a mechanical power steering that steers one steered wheel at a steering angle according to the steering wheel angle may be used. good.

[0026]

As described above in detail with reference to the embodiments, in the present invention, the steering angle of one steered wheel is detected to obtain the steering command value to the other steered wheels. For,
It is no longer necessary to attach a rotary encoder, potentiometer, or other angle sensor to the handle. Also, since the hydraulic oil supplied to the all-hydraulic steering valve provided on the steering wheel is throttled by the reaction force proportional control valve, an appropriate steering reaction force can be obtained, so there is no need to attach a powder brake or electromagnetic clutch to the steering wheel. It was

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a hydraulic steering system according to an embodiment of the present invention.

FIG. 2 is a side view of a boat carriage.

FIG. 3 is an explanatory diagram of a traveling state of the boat carriage.

FIG. 4 is an explanatory diagram of a steering wheel steering method.

FIG. 5 is an explanatory diagram of a steering aspect of the boat carriage.

FIG. 6 is an explanatory diagram of a full hydraulic steering valve.

FIG. 7 is an explanatory diagram of a controller.

FIG. 8 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

 1 Ship Shell Cart 2 Steering Wheel 2a Master Side Steering Wheel 2b Slave Side Steering Wheel 3 Turntable Bearing 4 Bracket 5 Arm 6 Suspension Cylinder 7 Steering Cylinder 8 Steering Angle Sensor 9 Turret 10 Block 11 Handle Shaft 12 Full Hydraulic Steering Valve 13 Reversal Force proportional control valve 14 Pump 15 Controller 16 Slave shaft steering valve 17 Tie rod

Claims (4)

[Claims] 1. In a vehicle having a plurality of steered wheels that can be steered independently by hydraulic pressure, a steering wheel shaft is equipped with a fully hydraulic steering valve that supplies an amount of oil corresponding to a steering wheel angle to one steered wheel. In addition, an angle sensor for measuring a steering angle is provided on the one steered wheel, and based on the steering angle of the one steered wheel measured by the angle sensor, a steering command value to be steered by another steered wheel. A hydraulic steering system for a vehicle, further comprising: a controller for calculating the above, and a steering valve for supplying an oil amount corresponding to the steering command value obtained by the controller to the other steered wheels. 2. The reaction source proportional control valve is used to throttle the amount of power source oil to the full hydraulic steering valve.
A hydraulic steering system for a vehicle as described above. 3. The reaction force proportional control valve is configured to reduce the power source oil amount as the deviation between the steering angle of the other steered wheel and the steering angle command value to be steered by the steered wheel increases. The hydraulic steering system for a vehicle according to claim 2, wherein the hydraulic steering system is for a vehicle. 4. A mechanical power steering that steers one steered wheel at a steering angle according to a steering wheel angle is used in place of the all-hydraulic steering valve.
2. The vehicle hydraulic steering system according to 2 or 3.