JPS606827B2 - Steering device for agricultural tractors, etc. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a steering device for a vehicle such as an agricultural tractor, in which wheel steering is performed by rotating an axle housing movable part around a king pin with respect to a fixed part of the axle housing. .

Conventionally, in this type of steering device, the king pin constituting the pivot shaft of the movable part of the axle housing is generally supported at three points, upper and lower, and is prone to twisting or misalignment during steering operation.

In order to stably support the king pin with such a three-point support system, the vertical support length at one or more support points had to be increased, making the support structure complicated. . Therefore, in this invention, the kingpin is supported at four upper and lower points using a simple support structure, and the kingpin is supported extremely stably despite its simple structure. The new steering device of the type mentioned at the beginning has a large span that occupies almost the entire upper and lower part of the housing, and this also stabilizes the support.
This is what we are trying to provide.

The configuration of a steering device for an agricultural tractor or the like according to the present invention will be described with reference to the illustrated embodiment.This embodiment relates to an example in which the present invention is implemented in an agricultural tractor as shown in FIG.

The tractor has an engine 1 mounted on the front of the machine, and uses the engine 1 to forcibly drive the left and right rear wheels 3 via a transmission mechanism (not shown) in a mission case 2, and as needed. Accordingly, the left and right front wheels 4 are also forcibly driven via a transmission shaft 5 that extends forward from the mission case 2, and the pilot seated in the seat 6 steers the aircraft using the handlebar 7. This is done by turning the front wheels 4. As shown in FIGS. 2 and 3, the axle 4a of the front wheel 4, which is a steering wheel, is supported by a fixed part 8 of the front axle housing so as to be rotatable around a king pin 9. The movable part 10 is supported by bearings 11 and 12 through bearings 11 and 12, and the movable part 10 is rotatably displaced by a knuckle arm 14 which is rotatably displaced by a drag rod 13 which is moved forward and backward by the handle 7. In the steering device according to the present invention, the above-mentioned king pin 9 is particularly supported as follows.

That is, a pair of upper and lower bevel gears 28 and 27 for transmitting driving force to the axle shaft 4a are provided on the king pin 9 in the axle housing so as to rotate together with each other. A supporting arm portion 22 is integrally protruded from the kingpin 9 at a position below the bevel gear 27 on the lower side by an appropriate amount and facing toward the outer periphery of the kingpin 12.

As shown in FIG. 2, the support arm portion 22 has a bevel gear 30 facing inside at its base end so as to avoid the bevel gear 30, which will be described later, and allow the arm portion 22 to extend downward. A slot 36 is formed, and the tip of the support arm 22 is projected into a recess 37 on the inner surface of the post portion of the large bevel gear 26, which will be described later. And the above-mentioned lower bevel gear 2
The boss portion 27a of No. 7 extends upwardly on the kingpin 9, and the bevel gear 28 on the upper side of the kingpin 9 is provided on the kingpin 9 by loosening a spline on the boss portion 27a. 9 is connected to the upper end of the axle housing fixing part 8 via a ball bearing 32 that supports the boss part 27a on the upper surface side of the bevel gear 28, the boss part 27a, and a needle bearing inside the post part 27a, and also to the bush 23. The support arm portion 2 is connected to the sleeve 24 through
The extending ends of the two are supported rotatably. In other words, the king pin 9 is the axle housing fixing part 8
It is supported rotatably in two positions, upper and lower. On the other hand, near the lower end of the axle housing sog movable part 10, a support part 25 is integrally formed on the inner surface of the movable part 10 and extends in the direction of the king pin 12.

As shown in FIG. 2, the support section 25 includes the support arm section 2
2 and below the height of the front wheel axle 4a. The knuckle arm 14 is fixed to the upper surface of the axle housing movable part 10 outside the axle housing fixed part 8 and extends toward the inside of the machine and slightly upward. A support hole is formed in the middle of the knuckle arm 14. The upper end of the king pin 9 protruding upward from the upper surface of the axle housing fixing part 8 is supported and connected by a split pin 16, and the lower end of the king pin 9 is supported by the supporting part 25 in an iron-coupled manner. In other words, the king pin 9 includes the knuckle arm 14 and the support portion 25.
The axle housing 0 and the movable part 1 are supported at two positions above and below the movable part 10 through the movable part 10 so as to be immovable relative to the movable part 10. A thrust bearing 31 is disposed between the bevel gear 27 on the king pin 9 and the sleeve 24, and the lower end of the sleeve 24 is connected to the support portion 2 and 5.
I have received it. In Figures 2 and 3, 17 is a differential gear for the left and right front wheels 4, 18 is a differential housing rotatably supported by a bracket 20 on the underside of the fuselage around a horizontal support shaft 19 along the front and rear of the fuselage, and 21 is a differential gear. This is a transmission case between the housing 18 and the axle housing fixing part 8.

Further, 26 is a large bevel gear for deceleration iron-bonded to the inner end of the front wheel axle 4a, and is meshed with the bevel gear 27 on the lower side on the king pin 9, and 29 is provided inside the transmission case 21. A transmission shaft that transmits the front wheel drive force from the differential device 27 into the axle housing, and a bevel gear mounted on the end of the transmission shaft 29 to the upper bevel gear 28 on the king pin 9. The front wheel axle 4a is meshed with the front wheel axle 4a.
The transmission from the differential device 17 to the transmission shaft 29 and the bevel gear 30
, bevel gear 28, bevel gear 27, and bevel gear 26. Reference numeral 33 denotes a stop/gold bolt screwed onto the transmission case 21 so that it can be adjusted forward and backward.
The amount of rotation of the differential housing 19 around the front wheel 4 mechanism, and therefore the amount of rotation of the entire front wheel 4 mechanism, is restricted.

A tie rod 34 connects the left and right knuckle arms 14. The illustrated agricultural tractor is steered by operating the hand barrel 7, moving the knuckle arm 14 on one side via the drag rod 13, and then the tie rod 34.
This is accomplished by rotating the knuckle arm 14 on the other side together with the king pin 9 on that side, respectively, to rotate the left and right axle housing movable parts 10, and thus the left and Z right front wheels 4.

As is clear from the above description, in the steering device for an agricultural tractor or the like of the present invention, in the axle Z housing that houses the bevel gear transmission mechanism that transmits power to the axle 4a supported by the axle housing movable part 1, the axle housing A support arm part 22 having a slot 36 in which the bevel gear 30 at the end of the transmission shaft 29 transmitting power into the axle housing is exposed in the fixed part 8, and is fixedly installed on the inner end part of the axle shaft 4a. Large bevel gear 226 for reduction
The axle housing movable part 10 is integrally provided with a supporting arm part 22 that extends into the recess 37 on the inner surface of the boss.
The king pin 9 constituting the pivot axis of the axle housing fixing part 8 is attached to the upper and lower ends of the axle housing fixing part 8 and the extending end of the support arm part 22.
The supporting arm portion 22 is rotatably supported by the axle housing movable portion 10 near its lower end.
A support part 25 facing into the recess 37 below the height position of the axle 4a is integrally formed, and the above three king pins 9 are supported through the support part 25 on the lower end side, and on the upper end side. The axle housing movable part 1 is supported in a non-rotatable manner relative to the axle housing movable part 1 through a knuckle arm 14 which is placed outside the axle housing fixed part 8 and fixed to the upper surface of the axle housing movable part 10. It has the following advantages: That is, in the steering device of the present invention, (1) the king pin 9 is attached to the axle housing fixed part 8 at two points above and below the upper end of the fixed part 8 and the support arm part 22, and to the axle housing movable part 10. The king pin 9 is supported at two upper and lower points by support at the upper end side via the knuckle arm 14 and support at the lower end side via the support part 25, respectively, and by support at four points at the upper and lower sides. ■ The two-point support of the king pin 9 by the axle housing movable part 10 is supported by the axle housing fixed part 8 via the knuckle arm 14.
The support part 25 supporting the lower end side is formed near the lower end of the axle housing movable part 10 below the axle 4a position, so that the vertical spacing is large. ■ Also, regarding the two-point support of the king pin 9 by the axle housing fixing part 8,
A support arm portion 2 is formed with a slot 36 in which the bevel gear 30 faces inside so as to be able to extend downwardly avoiding the bevel gear 30 at the end of the transmission shaft 29 that transmits power into the axle housing.
2 extends to a lower level facing into the recess 37 on the inner surface side of the boss portion of the large reduction bevel gear 26 on the inner end of the axle 4a, and the king pin 9 is attached to the axle housing fixing portion 8.
Since it is supported by the upper end of the fixed part 8 and the extended end of the support arm part 22 which extends to a low vertical position as described above, it is supported at two points widely spaced vertically. ■ If the top and bottom of the axle housing are constant, the kingpin should have a large span that occupies the entire top and bottom of the axle housing as much as possible to support the kingpin and, by extension, the axle housing. The supporting arm part 22 on the inner surface of the axle housing fixed part 8 and the support part 25 on the inner surface of the axle housing movable part 10 stabilize the support of the moving part 10 and the wheel mechanism supported thereon. A king pin 9 is provided in the lower layer facing the recess 37 on the inner surface side of the boss portion of the upper large deceleration gear 26, and whose lower end side is supported by the support arm portion 22 and the support portion 25. Since the king pin 9 is made to have a large span extending as far downward as possible, the king pin 9 is supported extremely stably, and there is no twisting or misalignment of the pin 9.

In addition, since the support of the king pin 9 is stable as described above, the axle housing movable portion 1 of the king pin 9
01, for example, the split pin 1 shown in the example.
6, a coupling member that only prevents displacement of the king pin 9 in the sea bream direction is sufficient, and strong coupling means such as welding the lower end of the king pin 9 to the support portion 25 is not required. The support arm part 22 integral with the axle housing movable part 0 and the support part 25 integral with the axle housing movable part 0 can be integrally formed during casting of the fixed part 8 and the movable part 10, respectively, and the upper end side of the king pin 9 is connected to the axle housing movable part 0. 101 is supported using the knuckle arm 14 of the steering operation mechanism, the steering device of the present invention supports the king pin 9 extremely stably, but the supporting structure for this purpose is simple. This is what is said to be.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway side view of an agricultural tractor equipped with an embodiment of the present invention, Fig. 2 is a longitudinal cross-sectional view of the same main part, and Fig. 3
The figure is a plan view of the main parts. 4...Front wheel 4a...・Axle, 8...Axle housing fixing part, 9...
...King pin, 10...Axle housing movable part L Box 4...Knuckle arm, 16...Cotter pin, 22...Support arm part, 23...Futshu, 24...
Sleeve, 25...Support part, 27...Bevel gear, 27
a...Boss part, 32...Ball bearing. Figure 7 Figure 2 Figure 3

Claims (1)

[Claims] 1 Axle 4 supported by axle housing movable part 10
In the axle housing that houses the bevel gear transmission mechanism that transmits power to the axle housing, the bevel gear 30 at the end of the transmission shaft 29 that transmits power into the axle housing is attached to the axle housing fixing part 8.
The support arm portion 2 has a slot 36 facing inward.
2, a support arm portion 22 is integrally protruded and extends into a recess 37 on the inner surface side of the boss portion of the large deceleration bevel gear 26 fixedly installed on the inner end portion of the axle 4a. King pin 9 that constitutes the pivot axis of the housing movable part 10
is rotatably supported by the axle housing fixed part 8 at two positions above and below the upper end of the axle housing fixed part 8 and the extending end of the support arm part 22, and the lower end thereof is supported by the axle housing movable part 10. A support part 25 facing into the recess 37 below the support arm part 22 and below the height position of the axle 4a is integrally formed near the support arm part 22, and the king pin 9 is attached to the support part 25 at the lower end side of the support part 25. It is characterized in that it is supported in a relatively unrotatable manner on the axle housing movable part 10 via a knuckle arm 14 which is placed outside the axle housing fixed part 8 and fixed to the upper surface of the axle housing movable part 10 on the upper end side. A steering device for agricultural tractors, etc.