JPH0612961B2 - Forward / reverse rotary tiller - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a forward / reverse rotary tilling device that can be switched between downcut (normal tillage) and upper cut (reverse tillage).

(Prior art) A tilling claw that has a forward rotation (down cut) blade portion and a reverse rotation (upper cut) blade portion on both sides in the direction of rotation on a claw shaft that can be rotated in the forward and reverse directions, and also has a rake portion at the tip portion. Installation,
A forward / reverse rotary tilling device capable of performing forward and reverse tilling by switching the direction of rotation of the pawl shaft is known from, for example, Japanese Utility Model Publication No. 43-7843.

This cultivating device has a pawl that has a downcut blade portion and an uppercut blade portion and has a rake portion formed at a tip at a position biased to the uppercut blade portion, which can be switched between forward and reverse rotation. It was fixed on the shaft.

(Problem to be Solved by the Invention) Since the cultivating device disclosed in the above publication forms the rake portion at a position biased to the upper cutting blade portion, it is rotated prior to the upper cutting blade portion and the crushed soil effect is obtained. The digging resistance in the upper cut becomes abnormally high, and because the plowing nail is fixed to the nail shaft, the rake part is either down cut or upper cut. On the other hand, there was a problem of sacrifice.

In addition, if the cutting angle of the rake part is the same for forward and reverse rotation, the required horsepower during reverse culturing is about 15 to 20% higher than that during normal culturing, including the increase in traction resistance due to reverse culturing. It was This is because the rake part simply discharges the cultivated soil rearward during normal tillage, while it reverses because the rake part discharges the cultivated soil from the front side of the pawl shaft to the rear side during reverse tillage. This is because at the time of plowing, the section where the plowing claw and the soil interfere becomes longer.

(Means for Solving the Problem) The present invention is provided for the purpose of solving such a conventional problem, and as a specific means therefor, a downcut blade portion is provided on both sides in the rotation direction. A forward / reverse rotary tiller which pivotally mounts a tiller claw 10 having a cutting portion 29 for upper cutting and a scooping portion 31 for both cuts at a tip end thereof on a claw shaft 8 capable of switching between forward and reverse rotation. And the cutting angle α _{2 of the} rake portion 31 at the time of upper cutting
Is characterized in that a tilling claw 10 having a cutting angle α ₁ of the rake portion 31 at the time of downcut is smaller than the cutting angle α ₁ is pivotally attached to the claw shaft 8 so that the posture can be freely changed between uppercut and downcut. Is.

(Operation) During normal tillage (down cut), the contact portion 33 is brought into contact with the stopper portion 24 as shown by the solid line in FIG. 1 to bring the tiller pawl 10 into the normal tilling posture D, and the pawl shaft 8 is set to the first position. Rotate in the direction of arrow a in the figure.

At the time of this down cut, the blade part for the down cut of the plowing nail 10
29 is driven into the rice field from the upper front, the soil is vertically cut, the soil is cut into a wedge shape by the rake portion 31 at the tip, and the cultivated soil is released rearward as the soil rotates.

On the other hand, in order to make the upper cut, the pawl shaft 8 is set to b in FIG.
When the tiller 10 is rotated in the direction of the arrow, the tiller 10 swings around a pivot (color) 26 as a fulcrum, the contact portion 34 is brought into contact with the stopper 25, and the tiller 10 is switched to the reverse tilling posture U.

At the time of this upper cut plowing, the reversing blade of the plowing claw 10
30 is driven in from the upper rear, cuts the soil vertically, cuts the soil in a wedge shape with the rake portion 31 at the tip, and then scrapes the cultivated soil upward from the front of the nail shaft 8 to the rear. And throw it away.

In such forward cultivating and reverse cultivating, since the tilling claw 10 is swung about the pivot 26 to change the posture, the rake portion 31 becomes the optimum posture in both the upper cut and the down cut. While the wedge-shaped cutting is ensured, the cutting angle α ₂ of the rake portion 31 at the time of upper cutting is smaller than the cutting angle α ₁ at the time of down-cuting, so the cutting resistance for cutting the soil in a wedge shape is It is smaller than that at the time of down-cutting, and the scraping amount by which the rake portion 31 scrapes up the tilling soil becomes small.

Therefore, in the past, the horsepower consumed during the upper cut was higher than that during the downcut, but the resistance during the upper cut was reduced to reduce the difference in the horsepower consumed during forward / reverse rotation, or equivalently. It can be a degree.
In addition, the traction resistance against the tractor during reverse tillage is also reduced.

(Example) Hereinafter, the present invention will be described in detail with reference to the illustrated example.
The figure illustrates a tractor-mounted side-drive type forward / reverse rotary tiller. In FIG. 3, reference numeral 1 denotes a rotary machine, which comprises an input gear case 2, a support arm 3, etc., a chain case 4 and side frames 5 at the left and right ends of the support arm 3, respectively, and a three-point link mechanism behind the tractor. It is mounted so that it can be raised and lowered via 6. 7 is a rotary tiller, which is a chain case 4 and a side frame 5
It consists of a pawl shaft 8 rotatably supported between the lower ends of and, and a large number of tillage pawls 10 mounted on a mounting bracket 9 fixed to the pawl shaft 8. The pawl shaft 8 is an input of the gear case 2. Axis 1
1, forward / reverse switching mechanism, transmission shaft 12 in the support arm 3,
It is switched and driven in the forward and reverse directions by the PTO shaft of the tractor via the chain transmission mechanism in the chain case 4.

Reference numeral 13 denotes a rotary cover for covering the rotary tillage part 7, which includes a main cover 14, a rear cover 15, a front side cover 16, and a rear side cover.
Composed of 17. Reference numeral 18 is a comb-shaped rake, and 19 is a lowering mechanism for lowering the rear cover 15 downward. Reference numeral 20 denotes a pair of left and right gauge wheels, which are attached to the rotary machine body 1 via a supporting rod 21 so as to be vertically adjustable.

As shown in FIGS. 1 and 2, the mounting bracket 9 has a pair of left and right bracket bodies 22 and 23, and stopper portions 24 and 25 are provided between the bracket bodies 22 and 23. The mounting base on the base side of the tiller claw 10 is inserted between the pair of bracket bodies 22 and 23, and is fixed by tightening it together with the disc spring 27 by the collar 26 with a collar, etc. By switching to, the body is swung around the collar (pivot) 26 and the posture can be freely changed between the stopper portions 24 and 25.

As shown in FIG. 4, the plowing nail 10 includes a pair of bracket bodies 2
Mounting base 28 sandwiched between 2, 23, downcut blade 29 and uppercut blade 30 formed on both sides in the rotation direction.
And a rake portion 31 formed by bending on the tip side, and a hole portion 32 is formed in a central portion surrounded by these.

The blade edge curves of the downcut blade portion 29 and the uppercut blade portion 30 have a substantially symmetrical shape from the mounting base portion 28 to the vicinity of the rake portion 31, and each stopper portion 24, 25 on the mounting base portion 28 side.
The angles θ ₁ and θ ₂ of the contact portions 33 and 34 facing each other are the same, and therefore, the inclination angles γ ₁ and γ ₂ when the tiller 10 is rotated in the forward and reverse directions are the same.

The scooping portion 31 of the tilling claw 10 is asymmetric and is formed so that the cutting angle α ₂ at the time of reverse tillage is smaller than the cutting angle α ₁ at the time of forward tillage as shown in FIG. Namely folding curve segments 35 of the scoop section 31, the angle between the angular segment _{O-P 1, O-P} 2, i.e. bending angle beta _1, beta ₂ is reverse rotation relative to the forward side corner beta ₁ The rake portion 31 is bent in a curved shape along the fold line 35 so that the angle β ₂ of the rake becomes large. The line segments O-P ₁ and O-P ₂ are line segments that connect the intersection points P ₁ and P ₂ between the folding curve segment 31 and the blade portions 29 and 30 and the rotation center O point of the pawl shaft 8. is there. Cutting angle α ₁ is 30-40 °, cutting angle α ₂ is 20-30
Around ゜ is desirable.

In addition, in the above-mentioned embodiment, the blade edge curves of the down-cutting blade portion 29 and the upper-cutting blade portion 30 are illustrated as being substantially symmetrical, but the present invention is not limited to this, and is shown in FIG. 5, for example. As shown in FIG. 6, the asymmetrical tilling claw 10 may be configured such that the blade edge curve of the upper cutting blade portion 30 rises more than the blade edge curve of the down cutting blade portion 29 in the tilling state. Can be implemented. In this way, by making the blade edge curve of the upper cutting blade portion 30 stand up more than that of the down cutting blade portion 29, it is possible to reduce the horsepower consumption during reverse tillage, and this and the cutting angle α ₁ described above. , Α ₂
You may use together with the size of.

(Effect of the invention) According to the present invention, the cutting angle α ₂ of the rake portion at the time of upper-cut cultivating is set to be smaller than the cutting angle α ₁ at the time of down-cut cultivating. The resistance to scrape upwards is reduced, and the horsepower consumption and traction resistance during uppercut tillage can be reduced.

In addition, a tilling claw that has a downcut blade part and an uppercut blade part and a rake part at the tip is not fixed to the claw shaft as in the conventional example, but the posture can be freely changed to uppercut and downcut on the claw shaft. By being pivotally attached, there is no difference in tillage (plow depth) in both the upper and down cuts, and wedge-shaped cutting by the rake is optimized for both without sacrificing one .

[Brief description of drawings]

FIG. 1 is a sectional side view of an essential part showing an embodiment of the present invention, FIG. 2 is a sectional rear view thereof, FIG. 3 is a sectional side view thereof, and FIG. 4 is a front view of the plowing claws thereof. FIG. 6 is a front view of a tilling claw showing another embodiment, and FIG. 6 is a sectional side view of the relevant part. 8 ... Claw shaft, 10 ... Tilling claw, 29 ... Downcut blade, 30 ... Uppercut blade, 31 ... Rake, α
₁ , α ₂ …… Cutting angle, β ₁ , β ₂ …… Bending angle.

Claims (1)

[Claims] 1. Down cutting blades (29) on both sides in the direction of rotation
And a plowing claw (10) having a cutting portion (31) for upper cutting and a cutting portion (31) for both cuttings, which has a blade portion (30) for upper cutting,
A forward / reverse rotary cultivator pivotally mounted on a pawl shaft (8) capable of switching to forward / reverse rotation, wherein the cutting angle (α ₂ ) of the rake portion (31) at the time of upper cutting is the rake at the time of downcutting. The plunge claw (10) having a cutting angle (α ₁ ) smaller than that of the part (31) is attached to the claw shaft.
(8) A forward / reverse rotary tiller, which is pivotally attached to the upper cut and the down cut so that the posture can be freely changed.