JPH06255529A - Steering system for trailer - Google Patents

Abstract

PURPOSE:To improve steering performance and lower a load-carrying platform by constituting a king pin in the load-carrying platform of a trailer connected to the coupler part of a tractor, in such a way as to be rotatable according to the rotation of the tractor, and transmitting the rotational displacement mechanically to a rear axle. CONSTITUTION:The front face lower part in the load-carrying platform 16 of a trailer 14 is protrusively provided with a king pin 18. The king pin 18 is fixed to a rotary plate 20 and a bevel gear 22 rotated on the horizontal plane. Accordingly, when the king pin 18 is engaged with the coupler part of a tractor 28, the rotary plate 20 and the bevel gear 22 are also rotated according to the rotation of the tractor 28, and the rotational displacement is transmitted to a bevel gear 24 rotated on the vertical plane. Since the rotational displace-ment transmitted to the bevel gear 24 is transmitted to a hydraulic control valve 26, oil pressure from a hydraulic drive source 30 is force-fed to a flow control valve 34 through hydraulic piping 32 and then force-fed to hydraulic cylinders 38 through hydraulic piping 36. As a result, wheels 46 are steered through a transmission means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a trailer steering device, and more particularly to a steering device for smoothly rotating a rear axle of a trailer in accordance with rotational displacement of a tractor towing the trailer. It is a thing.

[0002]

2. Description of the Related Art A steering device for displacing a rear axle of a trailer in accordance with rotational displacement of a tractor to rotate smoothly is disclosed in, for example, Japanese Patent Application Laid-Open No. 2-1795.
88 to transmit the rotational displacement of the tractor to the rear axle by using a link mechanism of a rod and a lever, and to rotational displacement of the tractor using a hydraulic cylinder as shown in Japanese Utility Model Laid-Open No. 3-52285. Various proposals have been made in the past, such as those that transmit power to the rear axle.

[0003]

In the case of using the link mechanism of the rod and the lever described above, the weight of the link mechanism increases the weight of the trailer itself, and the link is disconnected during traveling, so that the steering device operates normally. The one that does not work, and the one using a hydraulic cylinder inevitably raises the loader of the trailer because it is necessary to store a hydraulic cylinder of a considerably large diameter between the upper surface and the lower surface of the loader of the trailer. In some cases, oil leakage occurred inside the upper hydraulic cylinder and it did not operate correctly.

On the other hand, it is desirable that the weight of the trailer itself is as light as possible in order to load as much load as possible within the range of legal regulations, and the height of the upper surface of the loading platform is safe during traveling and loading on the loading platform. Needless to say, it is desirable that the steering device be operated normally, so that it is a little low so that the work can be done easily.

An object of the present invention is to reduce the height of the steering device itself, which is housed between the upper and lower surfaces of the bed of the trailer, to lower the height of the upper surface of the bed so that the trailer itself is running. It is an object of the present invention to provide a steering device that enhances safety, facilitates loading work on a loading platform, and operates more accurately.

[0006]

In order to achieve the above object, a trailer pivotally attached to a coupler of a tractor is detachably and rotatably mounted through a kingpin projecting downward from a lower surface of a front portion of a loading platform. A trailer steering device is characterized in that the kingpin is configured to rotate according to the rotation of the tractor, and the rotational displacement is transmitted to a rear axle using a mechanical gear mechanism.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of a steering system according to an embodiment of the present invention.
2 shows a mechanical gear mechanism to which the present invention is applied in a partially cutaway view of an enlarged portion A of FIG. 5, FIG. 3 shows the conventional structure of FIG. 2, and FIG. 4 shows the steering of this embodiment. FIG. 5 shows a state in which the rear wheels of the trailer are rotating as shown by a chain line by the device.
Shows a front view of the trailer.

A structure using a conventional hydraulic cylinder (for example, as shown in Japanese Utility Model Laid-Open No. 3-52285) is shown in FIG.
As shown in Fig. 5, since the hydraulic cylinder 10 must be a cylinder having a considerably large inner diameter, the height L2 of the bed is inevitably large, and the ground height of the top surface of the bed shown in FIG. H + L becomes large, and oil leakage may occur from the gap between the compartment disk 12 sliding inside the cylinder 10 and the inner surface of the cylinder 10 as shown in FIG.

In the present invention, as shown in FIGS. 1, 2 and 8, a kingpin 18 is provided so as to project downward from the lower surface of the front part of the luggage carrier 16 of the trailer 14 of this embodiment. Is fixed to a bevel gear 22 that rotates in a horizontal plane, and these are configured to rotate about the kingpin 18 as an axis.

When the kingpin 18 is engaged with the coupler portion (not shown) of the tractor, the rotary plate 20 is configured to be fixed to the coupler portion of the tractor (this is a known structure, so the description thereof is omitted). According to the rotation of the tractor, the rotating plate 20 and the bevel gear 22 rotating in the horizontal plane also rotate, and this rotational displacement is transmitted to the bevel gear 24 rotating in the vertical plane. Since the diameter can be arbitrarily determined by the design, the height dimension L1 of the luggage carrier 16 can be minimized.

The rotational displacement of the tractor transmitted to the bevel gear 24 is transmitted to the hydraulic control valve 26, which transmits the hydraulic pressure sent from the hydraulic drive source 30 provided on the tractor 28 side. The pressure is sent to the flow control valve 34 through the hydraulic pipes 32, 32 based on the rotational displacement thus determined,
Pressure is sent from the flow rate control valve 34 to hydraulic cylinders 38, 38 through hydraulic pipes 36, 36, and the hydraulic cylinders 38, 38 are, as shown in FIG.
40, and the rotation of the triangular levers 40, 40 rotates the levers 44, 44 through the connecting rods 42, 42 so that the wheels 46, 46 can bend as shown by the chain double-dashed line in FIG.

The present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the spirit thereof.

[0013]

As described above, the present invention uses the mechanical gear mechanism to transmit the rotational displacement of the steering device housed between the upper surface and the lower surface of the bed of the trailer. By lowering the height of the trailer, the height of the upper surface of the loading platform can be reduced, which increases the safety of the trailer itself while traveling and facilitates loading work on the loading platform, and steering of the trailer that operates more accurately. It became a device.

[0014]

[Brief description of drawings]

FIG. 1 is a plan view of a steering device according to an embodiment of the present invention.

FIG. 2 shows a mechanical gear mechanism to which the present invention is applied in a drawing in which a part A of FIG. 5 is enlarged and partially broken.

FIG. 3 shows the conventional structure of FIG.

FIG. 4 shows a state in which the rear wheels of the trailer are rotating as shown by a chain line by the steering system of this embodiment.

FIG. 5 shows a front view of the trailer.

[Explanation of Codes] 10 Cylinder 12 Compartment Disc 14 Trailer 16 Loading Platform 18 King Pin 20 Rotating Plate 22 Bevel Gear 24 Bevel Gear 26 Hydraulic Control Valve 28 Tractor 30 Hydraulic Drive Source 32 Hydraulic Piping 34 Flow Control Valve 36 Hydraulic Piping 38 Hydraulic Cylinder 40 triangular lever 42 connecting rod 44 lever 46 wheel

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[Procedure amendment]

[Submission date] February 1, 1994

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Added

[Correction content]

[Figure 1]

[Fig. 2]

[Figure 3]

[Figure 4]

[Figure 5]

Claims (1)

[Claims] 1. In a trailer which is detachably and rotatably connected to a coupler portion of a tractor through a king pin protruding downward from a lower surface of a front portion of a loading platform, the king pin rotates in accordance with rotation of the tractor. A steering device for a trailer configured as described above, wherein the rotational displacement is transmitted to a rear axle using a mechanical gear mechanism.