JPH071345Y2 - Operation link mechanism in power farm - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a steering link mechanism in a power agricultural machine in which a vertical load is always applied to wheels on the outside of the turning to improve the turning performance when a steering operation is performed. It is related to.

2. Description of the Related Art Generally, in a power farming machine such as a tractor in which a steering gear box is arranged in front of a swinging front axle, a steering link mechanism is formed by connecting a pitman arm provided in the steering gear box to a knuckle arm. As is known, in the conventional steering link mechanism, as shown in FIGS. 12 and 13, two tie rods b and c that cross the tip of a pitman arm a formed in a bifurcated shape are used. It is connected to the left and right knuckle arms d and e.

(Problems to be solved by the present invention) However, in the case where the pitman arm a and the left and right knuckle arms d and e are connected by the two tie rods b and c, the connection portion B between the tie rods b and c and the pitman arm a, Since B is a vertical relative position separated by l ₁ and l ₂ from the swing center A of the front axle, when turning left, the thrust P _L acting on the tie rod b causes the swing center A to swing in the direction of the arrow. if work is rotational moment of P _L · l ₁ from the swing center a of the distance to the wheel and L _1, the right wheel of the turning outer, 1/2 vertical load of _{(P L · l 1) /} L 1 is However, the thrust P _R acting on the tie rod C also makes a rotational moment P _R · l _{2 in the} same direction when turning to the right.
Is activated, and 1/2 (P _R ·
Since a vertical load of l ₂ ) / L ₁ is applied, the vertical load acts on the wheel inside the turning when turning right, and the turning performance becomes worse than when turning left, and therefore the same amount of turning is applied. Even when the operation was performed, there was a problem that the turning radius was different between the right turn and the left turn.

The present invention has been devised to solve the above-mentioned problems. Even when a turning operation is performed in any direction, a vertical load is always applied to wheels on the outside of the turning to improve turning performance. It is an object of the present invention to provide a steering link mechanism for a power farm machine that can be used.

(Means for Solving the Problems) In order to solve the above problems, a technical means taken by the present invention is to provide a pitman of the steering gear box in a power agricultural machine in which a steering gear box is arranged in front of a swinging front axle. The arm is connected to one of the knuckle arms that are interlocked with each other via a single tie rod to form a steering link, and the connecting portion between the tie rod and the pitman arm is located below the swing center of the front axle. It is characterized by being placed in.

(Effect of the Invention) Therefore, according to the present invention, the tie rod rotates the knuckle arm in conjunction with the pitman arm during the turning operation of the power farming machine, but a single tie rod that connects one of the pitman arm and the knuckle arm. Is applied with a force in the opposite direction between the right turn and the left turn. And since the rotational moment in the opposite direction acts on the front axle,
When the same amount of turning operation is performed, the turning radii are not different between the right turn and the left turn. Moreover, since the connecting portion between the pitman arm and the tie rod is located below the swing center of the front axle, the vertical load due to the rotation moment is always applied to the wheels on the outside of the turn, which further improves turning performance. To do.

(Embodiment) Next, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
Reference numeral 1 denotes a front axle equipped with a power farming machine such as a tractor. The front axle 1 is mounted on a lower surface of a machine body frame 2 so as to be swingable around a support shaft 3, and a king pin 4 provided at both ends of the front axle 1 has a wheel. Left and right front wheels 6, 6 are pivotally supported via a hub 5. Reference numerals 7 and 7 denote knuckle arms that rotate the front wheels 6 and 6, respectively.
The protruding ends of 7, 7 are connected to each other by a connecting rod 8 so as to interlock with each other.

Reference numeral 9 denotes a steering gear box, which is located in front of the front axle 1 and is mounted on the frame 2 of the machine body.
A pitman arm 11 that is mounted via the pitman arm 11 and rotates left and right in conjunction with the turning operation of a steering wheel (not shown) projects toward the front axle 1. An operation link mechanism for operating the front wheels 6,6 is formed by connecting the pitman arm 11 to one knuckle arm 7 that is interlocked and connected through a single tie rod 12. That is, the pitman arm side rod end 13 of the tie rod 12 is connected to the protruding end of the pitman arm 11, and the knuckle arm side rod end 14 is connected.
Is connected to a rotating arm 15 extending forward from the right knuckle arm 7. The connecting portion 16 between the pitman arm 11 and the tie rod 12 is arranged below the support shaft 3 that is the swing center of the front axle 1. In this embodiment, the tie rod 12 is shown connected to the right knuckle arm, but it goes without saying that it may be connected to the left knuckle arm.

In Fig. 3 and Fig. 4, the right cut stopper and the left cut stopper of the steering link mechanism are centrally provided on one knuckle arm side, and the thrust of the tie rod 12 is applied to the left and right knuckle arms 7 and 7 during stationary operation. It is designed so as not to act directly. That is, the stopper 17 is provided on the rotating arm 15, and the right cutting stopper 18 and the left cutting stopper 19 with which the stopper 17 abuts are provided on the front axle 1 side.

The one shown in FIG. 5 and FIG. 6 is the front axle 1
By providing a reinforcing frame 20 at the lowest ground clearance below and lowering the connecting portion 16 of the pitman arm 11 and the tie rod 12 to approximately the same position as the lower end of the reinforcing frame 20, the vertical load acting on the front wheels during turning can be minimized. It is a large one.

7 and 8 show a tread adjustable front axle which can be easily adjusted. Generally, a tread-adjustable front axle is composed of an axle center 21 and an axle outer 22 that slides on the axle center 21, and the tread can be adjusted by inserting and removing a bolt 23.
The end of the 21, the elastic body 25 to be fitted into the bolt hole 24 of the axle outer 22 is provided, the bolt hole spacing L _b of the axle outer 22 the distance L _a between the bolt holes 26 of the elastic member 25 and the axle center 21
By making it the same as, the holes of the bolts 23 can be easily aligned.

Further, as shown in FIGS. 9 to 11, the axle center 21
A rotatable link body 28 is provided on a boss 27 provided at the center of the left and right axle outers 22, 2
By connecting to 2 via the rods 29, 29, the left and right axle outers 22, 22 are simultaneously expanded and contracted to make it easier to align the holes of the bolts 23.

With the above structure, when turning right now, the pitman arm is linked with the operation of the steering wheel.
11 rotates, and the tie rod 12 pulls the rotating arm 15 to rotate the machine body. Since this time the thrust P _R acts on the tie rod 12, a rotation center 3 of the front axle 1, if the distance between the connecting portion 16 of the tie rod 12 and l _3, P _R · l ₃ becomes rotational moment arrow Work in the R direction. Therefore, if the distance from the center of rotation 3 to the front wheels is L ₁ , a vertical load of 1/2 (P _R · l ₃ ) / L ₁ acts on the left front wheel on the outside of the turn. Since acting thrust P _L in the opposite directions in a single tie rod 12 at the time of left turn, acts rotation moment P _L · l ₃ of the arrow L direction to the front axle 1, the vertical load on the right wheel of the turning outer 1 / 2
(P _L · l ₃ ) / L ₁ works. Therefore, no matter which direction you turn, the same vertical load is always applied to the front wheels on the outside of the turn, so the turning performance is improved and the turning radius does not differ between right turn and left turn, and you can operate smoothly. be able to.

The one shown in FIGS. 3 and 4 includes knuckle arms 7,7.
The large thrust force of the tie rod 12 does not directly act on the tie rod 12, and the strength of the knuckle arms 7, 7 does not need to be particularly increased. Further, as shown in FIGS. 5 and 6, the turning performance can be further improved by increasing the vertical load acting on the front wheels on the outside of the turning as much as possible.

In the structure shown in FIGS. 7 and 8, only by inserting the elastic body 25 into the bolt hole 24 of the axle outer 22, the bolt hole 26 of the axle center 21 and the bolt hole 24 of the axle outer 22 are aligned with each other. Therefore, the tread of the front axle 1 can be easily adjusted.
In the case shown in Fig. 11, the left and right axle outers 22 and 22 expand and contract at the same time, so it is possible to align the positions of the other holes only by aligning the holes of one bolt 23, and further adjusting the tread of the front axle 1. Can be done easily.

(Effect of the Invention) In short, the present invention is a power farming machine in which a steering gear box is arranged in front of a swinging front axle, and the pitman arm of the steering gear box is connected to one of the knuckle arms that are interlocked with each other. When forming a steering link by connecting through a single tie rod, when the connecting portion between the tie rod and the pitman arm is arranged below the swing center of the front axle, when turning the power agricultural machine to the right, When turning to the left, a single tie rod that connects one of the pitman arm and the knuckle arm is acted on by a force in the opposite direction, causing a rotational moment in the opposite direction to act on the front axle. In addition, the turning radius does not differ between left turning and left turning, and moreover, with the pitman arm Since the connecting portion with the tie rod is located below the swing center of the front axle, the vertical load due to the rotation moment can always be applied to the wheels on the outside of the turn, and the turning performance can be improved. .

[Brief description of drawings]

1 is a front view, FIG. 2 is a plan view, and FIG. 3 is a front axle having stoppers concentrated on one side. Plan view, FIG. 4 is a partially enlarged view of FIG. 3, and FIG.
The figure shows a front view of the link mechanism with the connecting portion at the minimum ground clearance, Fig. 6 is a sectional view taken along the line AA of Fig. 5, Fig. 7 is a front view of the tread adjustable front axle, and Fig. 8 is a view of Fig. 7. A partially enlarged plan view, FIG. 9 is a plan view of a front axle in which the left and right axle outers are simultaneously expanded and contracted, FIG. 10 is a partially enlarged front view of FIG. 9, and FIG. 11 is of FIG. AA cross section, No.
FIG. 12 is a front view showing a conventional example, and FIG. 13 is a plan view of the same. In the figure, 1 ... Front axle, 3 ... Spindle, 7 ... Knuckle arm, 9 ... Steering gear box, 11 ...
… Pitman arm, 12 …… tie rod, 16 …… connecting part.

Claims (1)

[Scope of utility model registration request] 1. A power farming machine in which a steering gear box is arranged in front of a swinging front axle,
Pitman arm of the above steering gear box,
One of the knuckle arms that are interlockingly connected to each other is connected via a single tie rod to form a steering link,
A steering link mechanism in a power farming machine, wherein a connecting portion between the tie rod and the pitman arm is arranged below a swing center of a front axle.