JPS6349525A - Steering mechanism for working vehicle - Google Patents

Abstract

PURPOSE:To protect the side parts of front wheels and simplify constitution by installing a steering gear box in tunable ways around a king pin which is also used as a power transmission shaft, for a fixed side gear box, and arranging a steering wheel directly under the king pin. CONSTITUTION:A steering mechanism which is suitable for the front wheels of a lawn mowing working vehicle is equipped with a fixed side gear box 22 having a front wheel input shaft 34 onto which the power supplied from a transmission case is transmitted and a steering gear box 20 onto which the power is transmitted through bevel gear trains 34a and 35a. The steering gear box 20 can turn freely for the fixed gear box, around a king pin 35 which constitutes the turning center shaft for the front wheels. A sprocket shaft 36 is turned through the bevel gear trains by the turn of the king pin 35, and said turn is transmitted to the front wheels 1 arranged directly under the king pin 35 through a chain laid onto the sprockets 36b and 37b which are arranged in a steering transmission case 20a.

Description

[Detailed Description of the Invention] (a) Field of Industrial Application The present invention relates to a configuration that performs both power transmission and steering rotation in the case where steering wheels are also driven in a traveling work vehicle. .

(B) Prior art The steering mechanism in a conventional steering wheel drive vehicle is, for example, the technology described in Japanese Utility Model Publication No. 60-9105.
The kingpin is disposed on the side of the steering wheel, and the ground contact portion of the steering wheel is located on an extension of the kingpin. However, when the steering wheel has a camber angle as in the case of the conventional configuration, such a configuration can be obtained, but when there is only one steering wheel and no camber angle is provided, this configuration can be obtained. Therefore, it is not possible to offset the king pin and steering wheel.

(c) Problems to be Solved by the Invention The present invention uses one steering wheel and attempts to drive the one steering wheel. In the conventional configuration, the technique of rotating the steering wheel while driving the two front steering wheels is known, but there was no technique of driving one steering wheel.

In the case of a single wheel, the steering wheel does not have a camber angle and stands upright when viewed from the front, so the kingpin must be located above the steering wheel, and the kingpin 35 above the steering wheel must be positioned above the steering wheel.
Therefore, it was necessary to provide a structure for transmitting power to the steering wheels.

The present invention achieves the above objects.

(d) Means for Solving the Problems The objects of the present invention are as described above. Next, the configuration for achieving the objects will be explained.

The steering gearbox is rotatable with respect to the stationary gearbox around a kingpin that also serves as a power transmission shaft, and the steering gearbox, steering transmission gauge, and steering axle form a mouth-shaped power transmission path. , the steering wheel is placed directly below the kingpin.

Further, the steering transmission case is constituted by a bevel gear and a bevel gear shaft, and the lower end of the steering transmission case is inclined inward to fit inside the rim of the steering wheel.

(E) Embodiment The object and structure of the present invention are as described above. Next, the structure of the embodiment shown in the attached drawings will be explained.

Fig. 1 is a side sectional view of a radio-controlled lawn mowing vehicle equipped with the present invention, Fig. 2 is a side view of the support portion of the front wheel 1 which is the steering wheel, and Fig. 3 is a front sectional view of the drive portion of the front wheel l. 4 is a side sectional view, and FIG. 5 is a plan view showing the rotation angle of the knuckle arm 21 and the steering gear box 20. FIG. 6 is a steering transmission case composed of a bevel gear and a bevel gear shaft. FIG. 3 is a front sectional view of the embodiment.

The overall configuration will be explained with reference to FIGS. 1 and 2.

The mower device is composed of a mower deck 3 and a rotating reaping blade 4. A deck frame 5 is arranged on the upper surface of the mower deck 3. An engine E is placed in the rear part above the deck frame 5, a transmission case M is placed in the center part, and a pantry 13 is placed in the front part. Engine E
A shaft that transmits power into the mission case M and drives the rotary reaping blade 4 from the mission case M is projected from the mission case M into the mower deck 3 as a working machine drive shaft 23. A universal joint shaft 9 is also interposed to drive the front wheels 1, which are steering wheels, thereby transmitting power to the stationary gearbox 22. A steering gearbox 20 is disposed below the stationary gearbox 22.

Parallel links 11 and 12 that move the stationary side gearbox 22 up and down to adjust the cutting height are interposed between the mission case M and the stationary side gearbox 22.

Further, a steering drive mechanism 14 for steering and turning the front wheels 1, which are the steering wheels, is also pivotally supported at its base to the transmission case M by a joint. The steering drive mechanism 14 is composed of a forward/reverse motor, a screw rod, etc., and the telescopic cylinder 3
0 is extendable and retractable, and the tip of the telescopic cylinder 30 is pivotally connected to the arm 21a at the other end of the knuckle arm 21, which is configured in a bell crank shape, by means of a pivot pin 29.

The knuckle arm 21 has its rear end pivotally supported by a knuckle arm shaft 28 to a pivot part 22b formed as a part of the stationary gearbox 22, and its front end is a rotary arm 32 that protrudes from the steering gearbox 20. The rotating arm pin 33 is engaged in the elongated hole 21b. Since the knuckle arm shaft 28 and the center of the king pin, which is the center of rotation of the steering gear box 20, do not coincide with each other, the long hole 21b provided at the tip of the knuckle arm 21 and the rotation arm pin 33
While absorbing the eccentric portion, the steering gear box 2
0 is being steered and rotated.

Moreover, between the moadetsuki 3 and the parallel links 11 and 12,
A cutting height adjustment rod 16 and a cutting height adjustment vibrator 15 are interposed, and the cutting height of the front wheels is adjusted by changing the interval between the two using a bin.

Further, the rear wheels 2 are provided on the left and right, and the rear axle cases 18 and 19 of the rear wheels 2 connect the front end to the transmission case M.
The rear end can be adjusted and fixed in a five-stage adjustment hole drilled in the cutting height adjustment bracket 17 using a pin.

The cutting height of the mower device can be adjusted by adjusting the front wheels 1 using the cutting height adjustment vibrator 15 and the cutting height adjustment rod 16, and by adjusting the vertical position of the rear axle cases 18 and 19 with respect to the cutting height adjustment bracket 17. This is what is being done.

Also, bumper guards 6 and 7 are installed in front and behind the deck frame 5.
is installed protrudingly. The front bumper guard 6 surrounds the hood and covers the front part including the front wheel 1, which is one steering wheel. The bumper guard 6 can also be used as a safety frame.

The overall configuration as described above is covered by the bonnet 8. A warning light 10 for radio control is attached to the top of the bonnet 8.

In Figures 3, 4, and 5, the front wheel 1, which is the steering wheel,
Let me explain about the drive and steering mechanism.

As shown in FIG. 4, the stationary gearbox 22 is bent in a shape, and a universal joint 9 is connected to the rear end of a front import force shaft 34 that projects rearward. The bevel gear 34a at the front end of the core import force shaft 34 is connected to the upper bevel gear 35 of the king pin 35.
It meshes with a. The king pin 35 is the front wheel 1
It forms the central axis of rotation of the engine, and also serves as a power transmission axis. That is, the lower bevel gear 35b of the king pin 35 meshes with the bevel gear 36a of the sprocket shaft 36, and the other end is inserted into the steering transmission case 2Oa. A chain is wound from the sprocket 36b at the other end of the sprocket shaft 36 to the sprocket 37a of the front axle 37, and the core axle 37 supports the front wheel 1.
is supported. The steering gear box 20, which is rotatably arranged at the bottom of the fixed side gear box 22 configured in the shape of ``, has a bent configuration in the shape of ``'', and the steering gear box 20 is transmitted to the tip of the steering gear box 20 in the shape of ``''. This is because the case 20a is fixedly installed.

In the embodiments shown in FIGS. 3 and 4, the steering transmission case 20a is constituted by a chain case.
In the illustrated embodiment, the steering transmission case 40 is constituted by a bevel gear case.

”-shaped steering gear box 20 has a steering transmission case 4 at the tip of the steering gear box 20.
However, inside the steering transmission case 40, a bevel gear shaft 41 and bevel gears 41a and 41b above and below it are arranged, and the bevel gear 36c of the shaft 36 meshes with the bevel gear 41a. Furthermore, the bevel gear 41b is configured to mesh with the bevel gear 37b of the front axle 37.

The steering transmission case 40 is configured such that its lower end is fitted into the rim of the front wheel 1, which is the inner steering wheel, and has an inwardly inclined structure.

The front wheel 1, which is the steering wheel, is a single wheel, and although it does not constitute a camber angle, it does constitute a caster angle in the longitudinal direction. The front end of the case is at a distance of X1 from the ground, and the rear end of the chain case, whose rear is tilted low due to the caster angle, is close to the ground at a distance of X3 from the ground, potentially causing scratches on the grass surface. There is a nature.

As shown in FIG. 6 (by constructing the steering transmission case 40 by the bevel gear shaft 41 and the bevel gear, the diameter of the internal bevel gear is also reduced, and the distance X2 from the ground surface can be configured to be small.

In this configuration as well, the steering gear box 20, the steering transmission case 40, and the front axle 37 are configured in the shape of a mouth, so that the center of steering rotation of the front wheel 1 is located just below the center of the king pin 35. It is composed of

As mentioned above, the knuckle arm shaft 28 , which is the center of rotation of the knuckle arm 21 , is located at the rear of the stationary gearbox 22 .
A king pin 35 is provided at a position away from the center line of the front wheel human power shaft 34 and is the center of steering rotation of the front wheel 1.
is located at the front, so the rotation center 01 of the knuckle arm 21 and the rotation center 02 of the king pin 35 do not coincide.

In the conventional technology, it was common sense that the rotation center 01 of the knuckle arm 21 and the rotation center 02 of the king pin 35 coincided.

If they match, the rotation angle of the knuckle arm 21 becomes the steering rotation angle of the front wheel 1, so it is necessary to rotate the knuckle arm 21 by a large amount of about 180 degrees.

In particular, in the case of the radio-controlled lawn mowing vehicle of the present invention, it is necessary to rotate approximately 180 degrees in order to make a small turn. It is necessary to increase the stroke of the cylinder 30, which makes the configuration difficult.

In order to solve this problem, the present invention provides a knuckle arm 21.
By intentionally making the rotation center 01 of the rotation center 01 and the rotation center 02 of the king pin 35 not coincide with each other, the rotation angle of the knuckle arm 21 is made small and the rotation angle of the king pin 35 is made large.

As a result, the knuckle arm 21 and the steering gear box 2
Since a deviation in the rotation angle occurs between the rotation angle and the rotation angle, the elongated hole 21b is formed in the knuckle arm 21 in order to absorb this deviation.

A rotating arm pin 33 of a rotating arm 32 protruding from the steering gear box 20 is fitted into the elongated hole 21b, and the rotating arm pin 33 slides within the elongated hole 21b to avoid the deviation. It is absorbed by

In FIG. 5, the steering gearbox 20 is configured so that it does not rotate by an angle θ2 with respect to the rotation angle θ1 of the knuckle arm 21, and the relationship between θ1 and θ2 is configured such that θ2>θ1. That's what I'm doing.

In addition, in FIG. 5, the rotation center 01, which is the center of the knuckle arm shaft 28, and the center 03 of the pin hole at the tip of the arm 21a, which is the pivotal connection part of the knuckle arm 21 with the telescopic cylinder 30 side, are connected. The arm 21a is positioned forward by an angle θ3 with respect to the line, and due to this configuration, when the arm 21a is pushed from the connection part with the telescopic cylinder 30, the arm 21a moves forward or backward. Dead points, which are branching points, no longer occur.

(F) Effects of the Invention Since the present invention is constructed as described above, it has the following effects.

First, by driving the front steering wheel of a moving vehicle such as a lawnmower, when turning, the steering wheel can slide across the lawn and damage the lawn, unlike non-driven steering wheels. There isn't.

Second, a steering transmission case 2 is installed on the side of the front wheel 1, which is the steering wheel.
Since 0a is arranged in the shape of a mouth, the steering transmission case 2
Oa allows the sides of the front wheel 1, which is a steering wheel, to be held and protected, and the durability of the front wheel 1 can be improved.

Thirdly, by constructing the redirection transmission case 40 using a bevel gear shaft and a bevel gear, the distance between the case and the ground surface can be increased, and contact with obstacles on the ground surface can be lost. Further, the lower end of the steering transmission case 40 can be housed inside the rim 1a of the front wheel 1.

[Brief explanation of drawings]

Fig. 1 is a side sectional view of a radio-controlled lawn mowing vehicle according to an embodiment of the present invention, Fig. 2 is a side view of the support portion of the front wheel 1, which is the inner wheel a, and Fig. 3 is a front view of the drive portion of the front wheel 1. A sectional view, FIG. 4 is a side sectional view, and FIG. 5 is a knuckle arm 21.
FIG. 6 is a front sectional view of an embodiment in which the steering transmission case is composed of a bevel gear and a bevel gear shaft. 1... Front wheel 1a which is a steering wheel...Rim 14...Steering drive mechanism 20...Steering gearbox 20a, 40...Steering transmission case 22...Fixed side gearbox 28 ...Knuckle arm shaft 35...King pin 37...Front axle E...Engine M...Mission case

Claims (2)

[Claims] (1) The steering gearbox is rotatable with respect to the fixed side gearbox around a kingpin that also serves as a power transmission shaft, and the steering gearbox, steering transmission case, and steering axle form a ■-shaped A steering mechanism for a work vehicle, comprising a power transmission path and a steering wheel placed directly below a kingpin. (2) The steering transmission case according to claim 1 is constituted by a bevel gear and a bevel gear shaft, and the lower end of the steering transmission case is inclined inward so as to fit inside the rim of the steering wheel. A steering mechanism for a work vehicle characterized by: