JPH0769228A - Wheel steering device in riding-type agricultural machine - Google Patents

Abstract

PURPOSE:To reduce a motive power transmitting load, and lightly carry out steering operation by connecting a torque generator to a lower part of a steering shaft, and arranging input and output shafts of the torque generator and an upper connecting shaft of the an input shaft of a speed reduction mechanism almost in a straight line shape. CONSTITUTION:A front end upper corner part of a transmission 20 is formed in notched step shape constitution, and a bracket 38 is fixed here, and a torque generator 35 is fixed to the upper part in an exposure condition. The lower end of a steering column 31 where a steering shaft 30 is arranged penetratingly is fixed to an upper part of this torque generator 35. The bracket 38 is bent and formed in a U-shaped cross section, and the lower side of the torque generator 35 is fixed to an upper part of this bracket 38 by a bolt, and an input shaft 37 projecting to the upper part of this torque generator is connected to the upper end of an input shaft 41 pivotally supported in the vertical direction in the transmission 20 through a universal joint 40.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque steering type wheel steering device which can be applied to a riding type agricultural machine such as a tractor, a rice transplanter and a seeder. It is related to the configuration.

[0002]

2. Description of the Related Art Conventionally, a civil engineering work machine or an all-terrain vehicle using a torque generator as a power steering device is disclosed, for example, in Japanese Utility Model Laid-Open No. 54-50345.
Those described in JP-A-62-46788 and the like have been proposed. In all of these, the torque generator is directly provided on the steering shaft near the steering wheel.

[0003]

In the conventional device described above, the torque generator is located at the high position of the machine body, and
Since the position of the torque generator and the position of the lower speed reduction mechanism are displaced forward and backward, the output shaft of the torque generator and the input shaft of the speed reduction mechanism must be transmission-coupled in a state in which the output shaft of the torque generator is bent or biased. Since the input shaft of the mechanism also becomes long, there is a problem that high torque rotation from the torque generator to the speed reduction mechanism cannot be efficiently performed when the handle is operated. Therefore, the present invention was devised in order to solve the above-mentioned conventional problems. The torque generator is connected to the lower part of the steering shaft, and the input shaft, the output shaft of the torque generator and the upper part of the speed reduction mechanism are connected. An object of the present invention is to provide a wheel steering device in a riding-type agricultural machine that can solve the above-mentioned problems by arranging the connecting shafts in a substantially straight line shape, and that can improve the front-rear balance of the machine body and perform stable traveling. It is what

[0004]

[Means for Solving the Problems] A passenger traveling machine body and a working machine such as a planting part attached to the rear part of the vehicle are provided with a transmission for transmitting power from an engine to front and rear wheels of the riding machine body and the working machine. In a riding-type agricultural machine extending to the front, the lower end of a steering shaft having a steering wheel attached to the upper part is connected to an input shaft of a torque generator that generates a rotational force by hydraulic pressure, and the torque generator is connected to the front part of the mission. The output shaft of the torque generator is connected to the upper connecting shaft of the input shaft of the reduction mechanism housed in the front part of the transmission, and at least the input shaft of the torque generator, the torque generator, the output shaft of the torque generator, and the speed reducer. The upper connecting shaft of the mechanism input shaft is arranged in a substantially straight line, and the output shaft of the reduction mechanism is The provided Ttoman'amu, the pitman arm is characterized in that coupled to the knuckle arm of the front wheel support portion via a drag link.

[0005]

According to the present invention, the torque generator is configured as described above, and the torque generator is connected to the lower portion of the steering shaft, and the input / output shaft of the torque generator and the upper connecting shaft of the input shaft of the speed reduction mechanism are substantially straight. With this arrangement, the power transmission load from the torque generator to the reduction mechanism can be significantly reduced, high torque rotation transmission can be efficiently performed, and the maneuvering operation can be performed lightly. In addition, the fact that the power transmission load from the torque generator to the reduction mechanism can be remarkably reduced in this way also improves the durability of the torque generator.

Furthermore, by providing a heavy-duty torque generator on the front wheel shaft front extension portion side of the transmission, a weight balance is achieved with a speed reducer mechanism located at this portion as well as a working machine located at the rear of the machine body. It is possible to obtain a riding-type agricultural machine that is capable of stable traveling with good front-rear balance.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The drawings showing the present invention as an embodiment will be described in detail below. In FIG. 6, reference numeral 15 denotes a traveling machine body of the riding type rice transplanter, and a planting section 16 which is a working machine is connected to the rear of the traveling machine body 15 so as to be vertically movable. Two transmission belts 22 are alternately tensioned between a drive pulley 19 of an engine 17 mounted in front of the traveling machine body 15 and a driven pulley 21 of a different diameter of a transmission 20 arranged behind the drive pulley 19. Double tension mechanism 23
The double tension mechanism 23 drives the transmission 20 at high and low levels. The transmission casing 24 connected to the rear end of the transmission 20 is extended rearward and the rear end thereof has the left and right rear wheels 2.
5 is connected to a rear axle case 26 for driving the vehicle 5, and the left and right rear wheels 25 are driven. A rear wheel drive shaft 27 that is driven from the transmission 20 side is provided between the rear axle case 26 and the transmission 20. Further, front wheels 29 are provided on the left and right sides of the transmission 20 so as to be rotatable about a kingpin 36 via a rotating case 34. The transmission 20 has a structure extending forward from the axle of the front wheels 29.

As shown in detail in FIGS. 1 and 4,
The upper corner of the front end of the transmission 20 has a notched stepped structure, and a bracket 38 is fixed to this part, and a torque generator 35 is fixed above the bracket 38 in an exposed state. The lower end of the steering column 31 is fixed above 35. A fixed steering wheel 32 is provided above the steering column 31 and above a steering shaft 30 that penetrates through the column 31, and a driver seat 33 fixed to the machine body is provided below the steering wheel 32. .

The bracket 38 has a U-shaped cross section, and an input shaft 37 concentric with the axis of the steering shaft 30 is provided above the bracket 38.
The lower side of the torque generator 35 having the output shaft 39 and the output shaft 39 is fixed by bolts. In the torque generator 35, an input shaft 37 protruding upward is connected to a lower side of the steering shaft 30 via a universal joint 40, and an output shaft 39 protruding downward is vertically moved into the transmission 20 via the universal joint 40. Transmission 2 of input shaft 41 supported in the direction
It is adapted to be connected to the upper end of the upper connecting shaft 41a protruding outwardly from 0. The steering shaft 30, the torque generator 35, the input shaft 37, the output shaft 39 of the torque generator 35, the input shaft 41 of the speed reduction mechanism 48, and the upper connecting shaft 41a thereof are connected in a substantially straight line by the universal joint 40. It is arranged.

The input shaft 41 is the transmission 20.
It is connected to an output shaft 47 having a pitman arm 50 via a reduction gear mechanism 48 composed of a gear provided at the front end of the inside, and the details are as follows. That is, the pinion gear 43 fixed below the input shaft 41 is meshed with the large-diameter gear 45 fixed to the rotatable intermediate shaft 44 arranged vertically in the transmission 20, while the intermediate shaft 44 is fixed. The pinion gear 46 fixed to is meshed with the large diameter gear 49 fixed to the output shaft 47 arranged in the vertical direction (see FIG. 3 for the arrangement of each gear), so the input shaft is connected via the upper connecting shaft 41a. The power transmitted to the gear 41 is transmitted to the output shaft 47 after the torque is amplified by the speed reduction mechanism 48 including the series of gears. This output shaft 47
Is penetrated through the bottom wall of the transmission 20 and is projected downward, and the base end of the pitman arm 50 is fixed to the projecting portion 47 a of the output shaft 47.

As shown in FIGS. 4 to 5, the universal joint 40 is composed of a tubular portion 51, upper and lower connecting pins 52, 52, and a C pin 53 for preventing the connecting pin 52 from coming off. Long hole 51a with a phase difference of 90 degrees
Are provided on the upper and lower sides and the end face side is open.
A groove 51b for positioning is provided above and below the steering shaft 30 and the torque generator 35.
A hole into which the connecting pin 52 is fitted is provided above the input shaft 37 of the above, and the connecting pin 52 is fitted below the output shaft 39 of the torque generator 35 and above the upper connecting shaft 41a of the input shaft 41. Each hole is provided.

As shown in FIG. 1, the torque generator 35 is connected to a hydraulic pump 56 via an oil passage 55 and to a tank 20, that is, a transmission 20 also serving as a tank, via an oil passage 57. Although oil is supplied and discharged to operate, the hydraulic pressure generates a rotational force to amplify the torque, so that the steering wheel 32
It is possible to provide a power steering device in which the operation torque of is amplified by the torque generator 35. That is, in the torque generator 35, for example, the manual input torque of 0.3 Kgf-m can be amplified to the maximum torque of 8.1 Kgf-m at a rotation ratio of 1: 1.

2 to 3, the pitman arm 50 that swings (rotates) about the output shaft 47 is connected to the left and right rotating case 34 sides via a pair of left and right drag links 60. The knuckle arms 61 are pivotally connected to each other, and stoppers 62 are fixed to the left and right of the pitman arm 50, respectively.
The number 0 indicates that the stopper 62 swings up to the maximum steering angle at which it comes into contact with the regulating member 63 fixed below the transmission 20.

With this structure, in the case of a standard specification vehicle not equipped with the torque generator 35 as the power steering device, the torque generator 35 is provided between the lower portion of the steering shaft 30 and the upper connecting shaft 41a of the input shaft 41. By interposing a connecting shaft (not shown) corresponding to the input shaft 37 and the output shaft 39 arranged on the same shaft core, and connecting the upper and lower sides of the connecting shaft with the universal joint 40, the pitman arm 50 and the knuckle The relationship between the arm 61 and the drag link 60 can be changed to a standard specification vehicle without changing.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view showing a main part of a wheel steering system according to the present invention.

FIG. 2 is a plan view showing a relationship among a pitman arm, a drag link, and a knuckle arm.

FIG. 3 is an enlarged bottom view of the main part of FIG.

FIG. 4 is an enlarged partial cross-sectional side view showing a connected state of the torque generator with a part thereof broken.

FIG. 5 is a perspective view of a universal joint.

FIG. 6 is a side view of a riding rice transplanter.

[Explanation of symbols]

 20 Transmission 30 Steering Shaft 35 Torque Generator 37 Torque Generator Input Shaft 39 Torque Generator Output Shaft 41 Reduction Gear Input Shaft 47 Reduction Gear Output Shaft 48 Reduction Gear 50 Pitman Arm 60 Drag Link 61 Knuckle Arm

Claims (1)

[Claims] 1. A transmission, which comprises a riding traveling machine body and a working machine such as a planting part mounted on a rear portion thereof, and which extends a transmission for transmitting power from an engine to front and rear wheels of the riding traveling machine body and the working machine in front of a front wheel shaft. In the riding type agricultural machine, the lower end of the steering shaft with the steering wheel attached to the upper part is connected to the input shaft of a torque generator that generates a rotational force by hydraulic pressure, and the torque generator is positioned at the front of the mission. , The output shaft is connected to the upper connecting shaft of the input shaft of the reduction mechanism housed in the front part of the transmission, and at least the input shaft of the torque generator, the output shaft, and the upper connecting shaft of the input shaft of the reduction mechanism are connected. They are arranged in a substantially straight line, and a pitman arm is attached to the output shaft of the reduction mechanism. A wheel steering device for a riding-type agricultural machine, wherein the wheel steering device is connected to a knuckle arm of a front wheel support portion via a lug link.