JPS5842162Y2 - tractor front axle - Google Patents

Description

[Detailed Description of the Invention] The present invention mainly relates to a front axle structure having a rectangular cross section in an agricultural tractor.

Generally, the front axle of an agricultural tractor is swingably supported at its center by a center pin facing in the longitudinal direction of the tractor, and extends from there to the left and right (outward in the width direction of the vehicle), with left and right front wheels attached to the tips.

Considering the stress distribution, the cross-sectional shape, especially the shape of the front and rear walls, is changed so that the center part near the center pin is high, and from there it becomes low as you move left and right.

However, conventionally, as shown in Fig. 1, a rear wall (or front wall) 2 is fitted onto the inner surfaces of the upper and lower wall edges of a front axle main body 1 having a U-shaped cross section, and the joint with the main body 1 is welded by arc welding or the like. However, a comparatively thick (for example, 8 m thick) steel plate must be pressed using a drawing die, which requires a large amount of equipment and has the drawback of increasing manufacturing costs.

The present invention employs a main body with an inverted U-shaped cross section so that a front axle with a variable height can be obtained only by bending. Examples are shown in FIGS. 2 to 4.

In Fig. 3, a pair of side members (front axle brackets) 5 have their rear ends fastened to the left and right side walls of the engine with a plurality of bolts, and extend forward (toward this side in Fig. 3) from there. A center pin 7 facing in the longitudinal direction of the center of the tractor is fixed to the center of the cross member 6 welded at a location, and a cylindrical shaft 9 integral with the front axle 8 is rotatably supported by this center pin T. Therefore, the front axle 8 can swing by an angle α□ on the left and right sides of the center pin 7, respectively.

The center pin 7 has its front and rear ends (left and right ends in the figure) fitted into the holes 11 of the cross member 6 as shown in FIG. A wedge portion 16 is fitted between the tapered portion 15 at the front end and the hole 11, and the wedge portion 16 is tightened with a NAND 17 to fix the center pin 7 to the cross member 6.

The cylindrical shaft 9 is fitted onto the center pin 7 via a bush 18, and has a nipple 19 at the bottom for injecting grease.

The front axle 8 consists of the front and rear walls 20.21 of the main body, which consists of approximately vertical front and rear walls 20.21 and an upper wall 22 that connects the two.
The bottom plate 23 is fitted on the inner surface of the lower edge of the box, and the joint with the main body is welded by arc welding, spot welding, etc., and the hole 24 is made in the center of the front and rear walls 20, 21.
25 is passed through the tube shaft 9, and the angle between the tube shaft 9 and the front axle 8 is determined using a suitable jig, and the joint is arc welded to give a caster angle α2.

The front axle 8 has a height Hl in the left and right sections L□ near the center pin 7, and the height changes smoothly from H□ to H2 in the sections L2 on both left and right sides, as shown in Fig. 3. In the section L3 on both the left and right sides, the height is H2.

Since the mud wall of the front axle 8 has the same width over its entire length, the main body of the front axle 8 is made by punching out a steel plate on both sides of the band-shaped part that will become the upper wall 22, including the parts that will become the front and rear walls 20 and 21. By bending the front and rear walls by 90° from both edges, a main body with an inverted U-shaped cross section can be obtained.

The bottom plate 23 extends along the lower edge of the front and rear walls 20.21 in the section L1. L
3 is horizontal, but in the section L2 between them, it is bent in advance to be inclined and is sandwiched and welded between the front and rear walls of the main body as described above.

Extensions 27 having a box cross section are slidably fitted into sections L3 at both left and right ends of the front axle 8, and are fixed to the front axle 8 by two bolts 26 on each of the left and right sides.

The extension 27 is a generally horizontal earthen wall 28 (Figure 4)
and the front wall 29 and rear wall 30 bent at 90 degrees from both sides.
A pair of bottom walls 31.32 are provided by folding back the lower edges of these front and rear walls 29.30 by an angle α3 larger than 90°, and the end edges of the bottom walls 31.32 are abutted to the portion 33. The cross section of the box is closed by arc welding.

Since the angle α3 is slightly larger than 90°, welding part 3
3 occupies a position slightly N higher than the corner portions 34 and 35 of the extension 27, so this portion 33 does not contact the front axle bottom plate 23.

Reference numeral 36 denotes a reinforcing plate, both edges of which abut on the inner surface of the extension 27, and are spot welded at multiple locations.

At the left and right ends of the front axle 8, the front wall 20 is provided with two holes 38 into which the heads 37 of the bolts 26 are fitted, and the rear wall 21 is provided with two holes into which the bolts 26 are fitted at the positions of the holes 38 and Go. 39, while the extension 27 has a plurality of holes 40 in the front and rear walls 29, 30 into which the bolts 26 fit.

As is clear from FIG. 4, the pole HJ portion 37 hits the front wall 29 of the extension 27, and by screwing in the nut 10, the rear wall 30 of the extension 27 is fastened to the rear wall 21 of the front axle 8, and the extension 27 is tightened. is fixed.

A sleeve 742 that supports the king pin 41 is attached to the tip of the extension 27 that protrudes from the front axle 8, as shown in FIG.
A support shaft 44 of a front wheel 43 is fixed to the lower end of the wheel.

A knuckle arm 45 is attached to the upper end of the king pin 41, and steering force is transmitted from the knuckle arm 45 through the king pin 41 to the front wheels 43.

To change the distance between the left and right front wheels 43, remove the bolts 26 with one or both left and right front wheels jacked up, and attach the extension 27 to the tip cylindrical part inside the front axle 8 (
Slide it within section L3), align the holes 40 and 39 at appropriate positions, fit the bolt 26 again, and remove the extension 27.
It is sufficient to fasten it to the rear wall 21 of the front axle.

As explained above, in the present invention, the front axle 8 is formed of a main body with an inverted U-shaped cross section and a bottom plate 23 welded to the lower edges of its front and rear walls, and is high in the center and becomes lower as it goes left and right from there. Since the shapes of the front and rear walls 20, 21 are determined in this way, a front axle with a different height can be easily obtained by a simple bending process.

In addition, when embodying the present invention, the bottom plate 23 is replaced with the front and rear walls 20 and 21.
It looks better if it is fitted and welded to the inner surface of the lower edge of the bottom plate, but it can also be butt-welded to the lower end surfaces of the front and rear walls, which are both edges of the upper surface of the bottom plate.

The main body of the front axle 80 may be arranged in a U shape, but if it is in an inverted U shape as shown in the drawings, it will look better, and the position of most of the front axle can be kept as high as possible, making it easier to work. becomes easier.

[Brief explanation of the drawing]

Fig. 1 is a sectional view for explaining the conventional example, Fig. 2 is a vertical sectional view, Fig. 3 is a sectional view taken along ■-■ in Fig. 2, and Fig. 4 is a sectional view taken along
FIG. 8... Front axle, 20, 21...
...Front and rear walls, 23...Bottom plate.

Claims (1)

[Scope of utility model registration request] A front axle for a tractor, characterized in that a bottom plate is welded to the lower edge of the front and rear walls of a main body having an inverted U-shaped cross section, and the front and rear walls are shaped so that they are high in the center and become lower as they go left and right from there.