JPH07329814A - Rear wheel steering device for u-type frame vehicle - Google Patents

Abstract

PURPOSE:To steer a rear wheel in a U-type narrow frame by steering the rear wheel through a drag link which is branched off along the frames of both sides of a U-type frame and disposed in order in a vehicle in which the rear wheel is steered in synchronization with the steering of a front wheel. CONSTITUTION:A U-type frame vehicle in which the rear part has U-type structure and the rear wheel 2 has two axles is provided with an articulate steering device (vehicle body refracting type steering device). The movement of an arm 4 of a front wheel 1 side which is steered by a hydraulic cylinder 8 for steering is transmitted to right and left drag links 12, 13 through a drag link 5 and an L-type lever 11 and further is transmitted to drag links 7 (7a to 7c) through an L-type lever 15 and a steering valve 16. A lever 22 is operated by the propellent power of a hydraulic cylinder 19 and a knuckle arm 23 journalled to the other end of the drag link 7c is operated, thereby steering the rear wheel journalled to a king pin 24.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear wheel steering system which can be used in an articulated steering type vehicle equipped with a U-shaped frame.

[0002]

2. Description of the Related Art Conventionally, when a rear wheel of a U-type frame is a two-axle vehicle, when the vehicle travels on a curved road, unless the wheels in front of and behind the rear wheel of the two-axle are steerable wheels, a large skid between the vehicle and the road surface occurs. And the tire wear increases.

In particular, the articulated steering type vehicle has a large turning amount because the turning radius is small. In the case of cargo handling on the premises, the ratio of curved traveling to the total traveling distance is large, and skid wear determines the life of the tire.

As a countermeasure against this, as shown in FIG. 4, when the front wheel 1 is steered, the center pin 40, the arm 41,
One of the rear wheels 2 is rotatably supported by a king pin 47 via a drag link 42, a lever pin 43, an idle lever 44, a drag link 45, and a knuckle arm 46. I am trying to rotate around 47. Further, after passing through the knuckle arm 48, the tie rod 49, and the knuckle arm 50, the other rear wheel 2
Is rotated from the position of the solid line to the position of the virtual line.

As shown in FIG. 5, when the front wheel 1 is steered, the center pin 40, the arm 41, the drag link 42, the lever pin 43, the arm 51, the drag links 52, 52,
King pin 54, via the steering arms 53, 53
Both left and right rear wheels 2, 2 which are rotatably supported by 54,
King pin 5 from solid line to virtual line
It is designed to rotate around 4, 54.

[0006]

However, in the rear wheel steering device having the structure shown in FIG. 4, in the U-shaped frame vehicle, the tie rod is provided between the left and right rear wheels 2, 2.
Since it cannot pass through 49, it cannot be used for U-frame vehicles.

Further, in the structure as shown in FIG. 5, there is no space for arranging the arm 51, the drag link 52, etc., and the rear wheel 2 is a double wheel, so that the overall width of the vehicle becomes extremely large. , U-frame vehicles cannot be used.

Therefore, the present invention has been made for the purpose of providing a novel rear wheel steering device that can be used in a U-shaped frame vehicle.

[0009]

Therefore, the U of the present invention is used.
In a rear wheel steering system of a type frame vehicle, a front wheel 1 is provided with an articulated steering system, a rear part has a U-shaped structure, and a rear wheel 2 has two axes, and one of the two axes is used. In a vehicle in which the rear wheel 2 is steered in synchronization with the steering angle of the front wheel 1 when the front wheel 1 steers, an arm that rotates around the kingpin 3 that is the front wheel steering rotation axis when steering the front wheel 1. The drag link 5 connected to the No. 4 is arranged so as to be branched along the both side frames 6a, 6a of the U-shaped frame 6 so that the rear wheel 2 of one of the two shafts can be moved forward. It is designed to be able to steer in conjunction with the wheel 1.

[0010]

The rear wheel steering system of the U-shaped frame vehicle according to the present invention enables steering of the rear wheels of a U-shaped vehicle having a narrow frame width and extends the life of the tire.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of a rear wheel steering system for a U-shaped frame vehicle according to the present invention will be described below with reference to the drawings shown as embodiments.

The U-frame vehicle shown in the figure has front wheels 1
Is equipped with an articulated steering device, the rear part has a U-shaped structure, and the rear wheels 2 are biaxial.
Moreover, the rear wheel 2 of any of the two axles is a vehicle that is steered in synchronization with the steering angle of the front wheel 1 when the front wheel 1 steers.

The rear wheel steering system according to the present invention comprises, in the U-shaped frame vehicle, a drag link 5 connected to an arm 4 which rotates around a kingpin 3 which is a front wheel steering rotation shaft when the front wheel 1 is steered. The drag links 7 and 7 that are branched and arranged along both side frames 6a and 6a of the mold frame 6 enable the rear wheel 2 of any one of the two shafts to be steered in conjunction with the front wheel 1. There is.

1 and 2 show an embodiment in which the rear wheel 2 on the front axle side is used as a steering wheel, and FIG. 3 shows an embodiment in which the rear wheel 2 on the rear axle side is steered. ing.

In the figure, a front wheel 1 is constructed so that it can rotate around a kingpin 3 and is steered by hydraulic cylinders 8 for steering.
A drag link 5 is pivotally supported by a pin 9 on the side arm 4. Then, an L-shaped lever 11 attached to a lever shaft 10 is pivotally supported on the drag link 5, and a drag link 12 arranged on the front frame 6b of the U-shaped frame 6 is supported on the L-shaped lever 11.
13 is pivotally supported. In addition, these drag links 12, 13
L-shaped levers 15 and 15 are pivotally supported on the lever shafts 14 and 14 provided on the corners 6c of the U-shaped frame 6, respectively, and the steering valve 16 is attached to each of the L-shaped levers 15 and 15. , 16 are pivotally supported. Further, drag links 7a, 7a arranged along the insides of both side frames 6a, 6a of the U-shaped frame 6 are pivotally supported on the steering valves 16, 16, respectively. The drag links 7a, 7a are connected to the drag links 7b, 7b via levers 18, 18 pivotally supported by lever shafts 17, 17, respectively.

On the other hand, rods 20 and 20 of hydraulic cylinders 19 and 19 are connected to the levers 18 and 18, respectively. The hydraulic cylinders 19 and 19 are provided with hydraulic circuits (not shown) from the steering valves 16 and 16, respectively. The steering valves 16 and 16 are
The valve is the same as a normal separate linkage type power steering valve, and has a valve spool (not shown) at the center of the valve shaft.

Therefore, in the embodiment shown in FIGS. 1 and 2, each of the drag links 7b, 7b has a lever shaft 21,
The levers 22 and 22 pivotally supported on 21 are connected to each other,
Drag links 7c and 7c are pivotally supported on the respective 22. Further, the knuckle arms 23, 23 are pivotally supported by the drag links 7c, 7c, and the rear wheels 2 are pivotally supported by the king pins 24, 24 at the knuckle arms 23, 23 respectively.

Further, in the embodiment shown in FIG. 3, the knuckle arm 2 is directly attached to each of the drag links 7b and 7b.
3 and 23 are pivotally supported, and the rear wheels 2 are pivotally supported by king pins 24 and 24 on these knuckle arms 23 and 23, respectively.

In the rear wheel steering system of the U-shaped frame vehicle of the present invention constructed as described above, first, when the front wheel 2 is steered by the steering hydraulic cylinders 8, 8, the arm 4 of the front wheel 2 is moved. L-shaped lever 11 mounted on lever shaft 10 via drag link 5 supported by a shaft, and drag links 12, 13 arranged on front frame 6b of U-shaped frame 6 to lever provided on corner 6c of U-shaped frame 6. Axis 14,
L-shaped levers 15, 15 pivotally supported at one end of 14 are operated. As a result, the drag link 7 disposed along the inside of both side frames 6a, 6a of the U-shaped frame 6 via the steering valves 16, 16 pivotally supported on the other ends of the L-shaped levers 15, 15.
a, 7a actuated, lever 1 attached to lever shaft 17, 17
8 and 18 work.

On the other hand, the hydraulic pressures from the steering valves 16 and 16 are sent to the hydraulic cylinders 19 and 19 corresponding to the hydraulic pressures through the hydraulic circuits.

Therefore, in the embodiment shown in FIGS. 1 and 2, the thrusts of the hydraulic cylinders 19 and 19 operate the levers 22 and 22 rotatably attached to the lever shafts 21 and 21, respectively. Drag links 7c and 7c, one end of which is connected to 22
Works. Further, when the knuckle arms 23, 23 pivotally supported on the other ends of these drag links 7c, 7c are operated,
The rear wheels 2 pivotally supported by the kingpins 24, 24 are steered to the imaginary line position in the figure.

Further, in the embodiment shown in FIG. 3, the drag links 7b, 7 are directly driven by the thrust of the hydraulic cylinders 19, 19.
Activate b. And these drag links 7b, 7
When the knuckle arms 23, 23 pivotally supported on the other end of b are actuated, the kingpins 24, 24 are moved as in the embodiment shown in FIGS.
The rear wheel 2 pivotally supported by the vehicle is steered to the position of the virtual line in the figure.

After the valve spools of the steering valves 16 and 16 have moved by a required stroke, the drag links 7a and 7a are directly pushed and pulled, and the levers 18 and 18 and the drag links 7b and 7b are mechanically driven. Lever 22,
22 will be operated, and even if the hydraulic system fails, the rear wheels 2 will be steered in synchronization with the steering angle of the front wheels 1.

Since the hydraulic cylinders 19 and 19 are operated by separate valves, the drag links 7a and
Proper strength can be maintained without excessive thrust of the hydraulic cylinder acting on 7a, 7b, 7b, 7c, 7c and the like.

Further, in the embodiment shown in FIGS. 1 and 2, the bogie beam 25 can be swung around the bogie beam shaft 26 fixed to the frame 6a, so that the wheel loads of the rear two axes are equalized. I am trying to allocate it to. And the front-rear axis
Numeral 27 is fixed to the bogie beam 25, and a torque rod arm 28 is rotatably attached. The torque rod arm 28 supports the stationary member of the brake and serves as a member that shares the reaction force of the brake torque.

As shown in FIG. 2, the line connecting the bogie beam shaft 26, the rear front shaft 27, and the pins 29, 30 is formed into a parallelogram so that the pins 29, 30 are connected to each other. The torque rod 31 holds the torque rod arm 28 at a constant angle with respect to the frame 6a, and transmits the reaction force of the brake torque to the frame 6a. Therefore, the rear wheel 2 is moved by the rocking of the bogie beam 25 due to the unevenness of the road surface.
The angle (king pin angle) of the kingpins 24, 24 with respect to the frame 6a does not change even when the frame is moved up and down relative to the frame 6a.

[0027]

EFFECT OF THE INVENTION The rear wheel steering system of the U-shaped frame vehicle of the present invention is constructed as described above,
Since the rear wheels can be steered in a U-shaped vehicle with a narrow frame width, it does not have a complicated structure compared to the conventional rear wheel steering device, and is very suitable for use in U-shaped frame vehicles. It became a thing.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing an embodiment of a rear wheel steering system of a U-shaped frame vehicle of the present invention.

FIG. 2 is a schematic explanatory view showing a state of the rear wheel steering system shown in FIG. 1 when viewed from the side.

FIG. 3 is a schematic explanatory view showing another embodiment of the rear wheel steering system of the U-shaped frame vehicle of the present invention.

FIG. 4 is a schematic explanatory view showing an example of a rear wheel steering system of a conventional vehicle.

FIG. 5 is a schematic explanatory view showing another example of a rear wheel steering system of a conventional vehicle.

[Explanation of symbols]

 1 Front Wheel 2 Rear Wheel 3 King Pin 4 Arm 5 Drag Link 6 U Type Frame 6a Both Sides Frame 7 Drag Link

Claims (1)

[Claims] 1. The front wheel (1) is provided with an articulated steering device, the rear part has a U-shaped structure, and the rear wheel (2) is biaxial, and the rear wheel of any one of the biaxes is used. In a vehicle in which a wheel (2) is steered in synchronization with a steering angle of the front wheel (1) when the front wheel (1) steers, a kingpin that is a front wheel steering rotation axis when steering the front wheel (1). Drag links (5) connected to an arm (4) that rotates around (3) are branched and arranged along both side frames (6a) and (6a) of a U-shaped frame (6). 7) By means of (7), it is possible to steer the rear wheel (3) of any one of the two shafts in conjunction with the front wheel (1), and the rear wheel steering system for a U-shaped frame vehicle. .