US-12617454-B2 - Agricultural tractor

US12617454B2US 12617454 B2US12617454 B2US 12617454B2US-12617454-B2

Abstract

The present disclosure is directed to an agricultural tractor. In an agricultural tractor according to the present disclosure, a steering unit is coupled to a coupling target in a power supply room. According to the present disclosure, the efficiency of the assembly of a cabin and a transmission is maintained, and also vibration and noise are reduced in a boarding space.

Inventors

Tae Ho Eom
Taek Seong KIM
Seung Tae LEE

Assignees

LS MTRON LTD.

Dates

Publication Date: 20260505
Application Date: 20250325
Priority Date: 20221005

Claims (11)

1 . An agricultural tractor comprising: a power generator located in a power supply room, and configured to generate power; an advance/retreat device including drive wheels configured to generate advance/retreat force by rotating in conjunction with operation of the power generator, and steer wheels configured to adjust an advance/retreat direction; a transmission configured to convert revolutions per minute based on the operation of the power generator and input a converted revolutions per minute to the drive wheels; a cabin disposed behind the power supply room and above the transmission, and configured to form a boarding space where a driver rides; and a steering system configured to adjust a traveling direction by controlling the steer wheels; wherein the steering system comprises: a handle configured to be rotated and manipulated by the driver in the boarding space to control a direction of the steer wheels; a steering unit configured to contribute to changing the direction of the steer wheels by using the driver's rotational force applied to the handle; and a transmission unit configured to transmit rotational force of the handle to the steering unit, and provided with a plurality of rotation shafts that are interconnected to each other; wherein one side of the transmission unit is coupled to the handle and an other side of the transmission unit is coupled to the steering unit; and wherein a coupling target to which the steering unit is coupled is located within the power supply room; wherein the coupling target is the power generator, wherein the agricultural tractor further comprises a mounting bracket configured to couple and install the steering unit to the power generator, and wherein the steering unit is spaced apart from the transmission while being coupled to the power generator via the mounting bracket.
2 . The agricultural tractor of claim 1 , wherein the plurality of rotation shafts comprise: a first rotation shaft coupled to the handle on one side thereof, and configured to rotate together with the handle; a second rotation shaft coupled to the steering unit on an other side thereof, and configured to rotate in conjunction with rotation of the first rotation shaft; a third rotation shaft disposed between the first rotation shaft and the second rotation shaft, and configured to rotate in conjunction with the first rotation shaft and transmit rotational force of the first rotation shaft to the second rotation shaft; a first universal joint configured to connect an other side of the first rotation shaft and one side of the third rotation shaft; and a second universal joint configured to connect one side of the second rotation shaft and an other side of the third rotation shaft.
3 . The agricultural tractor of claim 2 , wherein at least one of a first angle formed by the first rotation shaft and a vertical line, a second angle formed by the second rotation shaft and a vertical line, and a third angle formed by the third rotation shaft and a vertical line has a different angle.
4 . The agricultural tractor of claim 1 , wherein the mounting bracket has a form that secures a separation space so that the steering unit is coupled to the power generator with a separation space therebetween.
5 . The agricultural tractor of claim 4 , wherein the mounting bracket comprises: a first coupling portion coupled to the power generator; a second coupling portion formed to face the first coupling portion with the separation space interposed therebetween, and configured such that the steering unit is coupled thereto; and a separation portion configured to connect the first coupling portion and the second coupling portion so that they are spaced apart from each other.
6 . The agricultural tractor of claim 5 , wherein: the separation space is located between the power generator and the steering unit; and the second coupling portion and the separation portion have an angle greater than 0 degrees and less than 90 degrees.
7 . The agricultural tractor of claim 5 , wherein the second coupling portion and the separation portion have an angle greater than 90 degrees.
8 . The agricultural tractor of claim 4 , wherein the steering unit is disposed in the separation space.
9 . The agricultural tractor of claim 8 , wherein: the second coupling portion has a shaft through hole; and the transmission unit is coupled to the steering unit via the shaft through hole.
10 . The agricultural tractor of claim 8 , wherein the mounting bracket further comprises a guide portion configured to guide the steering unit and the transmission unit through coupling to each other.
11 . The agricultural tractor of claim 5 , wherein the mounting bracket has an approximately inverted “U” shape that is open downward when viewed from one side.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application is a Continuation Application of International Application No. PCT/KR2023/013261 filed on Sep. 5, 2023, which claims priority to and the benefit of Korean Patent Application No. 10-2022-0127117, filed on Oct. 5, 2022, and Korean Patent Application No. 10-2023-0115966, filed on Sep. 1, 2023, the disclosures of which are incorporated herein by reference in its entirety. FIELD The present disclosure relates to an agricultural tractor, and more particularly, to a steering structure. BACKGROUND Agricultural tractors are work machines (or vehicles) that are used for various purposes through the attachment and detachment of implements having different functions. Agricultural tractors are moved forward and backward by the power generated by power generators (mainly internal combustion engines), like general automobiles, so that steering systems need to be installed to change the direction of movement. Generally, such a steering system includes a handle, a steering unit, etc. The steering unit is implemented to change the direction of steer wheels by converting the rotational force of the handle, manipulated by a driver, into linear movement force. The main usage areas of agricultural tractors are workspaces, so that the contact surfaces between steer wheels and a ground surface are considerably uneven. This makes it difficult for a driver to manipulate the handle. Accordingly, the steering unit requires a mechanism that adds separate assistance force when the driver wants to turn the handle. Unlike general automobiles, agricultural tractors mainly use hydraulic pressure as the assistance force. In this case, a hydraulic pump is operated to provide assistance force to the steering unit, so that a hydraulic line needs to be installed between the hydraulic pump and the steering unit. Usually, the steering unit is disposed inside the boarding space of a cabin, and the hydraulic pump is disposed on an engine or transmission side. Furthermore, the hydraulic line connects the hydraulic pump and the steering unit in order to take charge of the movement of the working fluid from the hydraulic pump to the steering unit. However, this arrangement has some problems. First, the vibration and noise of an engine and the hydraulic pump are directly transmitted to the driver in the boarding space of the cabin through the hydraulic line. Unlike airborne noise or the vibration and noise coming through a cabin frame, it is considerably difficult to reduce the vibration and noise coming through the hydraulic line. Second, when the cabin is separated from or coupled to the transmission, separate hydraulic line disassembly or connection work needs to be performed. In this case, a work space is significantly narrow, making it difficult to disassemble or connect the hydraulic line. For this reason, there have been various proposals to separate a steering unit from a driver. However, existing proposals have problems in that it is difficulty to secure space and perform design, and increase the manufacturing cost by increasing the material cost. For reference, Korean Patent Application Publication No. 10-2009-0090510 (Title of the disclosure: Steering System for Tractor Cabin with Noise and Vibration Prevention Function) (hereinafter referred to as ‘conventional art’), which is one of the existing proposals, is discussed below. According to the conventional art, a steering unit (called a ‘power steering unit’ in the conventional art) is disposed under the cabin. Accordingly, the conventional art has the advantage of reducing noise and vibration coming to a driver through the hydraulic line. Nevertheless, the conventional art still has the following various difficulties. First, there is provided a structure in which the transmission is generally disposed under the cabin and the cabin is coupled to the transmission. However, in order to apply the conventional art, the design of the location and structure of the transmission needs to be changed somewhat as the steering unit is disposed under the cabin. Furthermore, there is a need for a change in the design of a power transmission structure between an engine and the transmission. Moreover, these changes significantly increase the initial cost in terms of the new design of a power transmission structure and the verification of stability. Second, the steering unit in the conventional art is directly coupled to the bottom plate of the cabin, so that the cabin may not be completely free from the vibration and noise coming from the steering unit. It is obvious that the conventional art attempts to minimize vibration and noise by spacing the cabin and the steering unit apart from each other and disposing a buffer material. However, even with this structure, two problems are still not overcome. One of them is that the buffer material also functions to some extent as a medium for transmitting vibration and noise, so that there is a limitation to th