JPS6340534Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a trench excavator for excavating drainage ditches in rice fields.

2. Description of the Related Art A trench excavator shown in FIG. 1 is known as a trench excavator that excavates a relatively shallow drainage ditch on the surface of a rice field in order to promote drainage of the rice field. This trench excavator has a connecting part 2 connected to a tractor (not shown) via a three-point link hitch at the front of a main body 1, and has a rotating shaft 3 protruding vertically downward from the main body 1. A spiral blade 5 is attached to the outer periphery of the rotating shaft 3 via a support member 4, and a guide chamber 6 attached to the lower part of the main body 1 is provided above the spiral blade 5. is provided with a discharge port (not shown) that opens toward one side of the fuselage, and is operated by a discharge blade 7 attached to the base of the rotating shaft 3 in the guide chamber 6.
The soil excavated and lifted up by the spiral blade 5 is discharged from the discharge port to the side of the machine body. Also,
A shaping plate 8 supported at the rear of the main body 1 is provided behind the rotating shaft 3 and the spiral blade 5, and is configured to dredge the soil in the groove excavated by the spiral blade 5 to shape the groove. I have to.

The spiral blade 5 of the conventionally known trench excavator configured in this manner has its cutting edge 5a substantially horizontal with respect to the direction of rotation, and gradually rises with a predetermined curvature toward the rear while moving around the outer periphery of the rotating shaft 3. is rotating, but
When digging trenches, the cutting edge 5a comes into contact with the soil and excavates, so this part is subject to severe wear.Also, if a hard object such as a stone hits the horizontal part, the impact is large, causing wear and tear in a short period of time, resulting in frequent wear. In addition, when there was only one spiral blade, the bottom surface of the groove was not flat, and even when shaped with the shaping plate 8, a good groove could not be formed. Therefore, there are some helical blades 5 (indicated by imaginary lines) with the cutting edges 180 degrees out of phase with respect to the rotation axis 3, but in this case, the bottom of the groove is flatter than with one. However, the wear of the cutting edge,
Issues such as impact still remained.

The present invention was developed in consideration of the above circumstances, and provides a trench excavator that prevents wear and tear, especially at the cutting edge of the spiral blade, increases durability, shapes the bottom of the trench, and can form a good trench. This is what I am trying to do.

For this purpose, the present invention provides a shaping blade located on the front side in the rotational direction of the lower end cutting edge of the spiral blade and on the outer periphery of the rotating shaft, and this shaping blade has a predetermined rake angle in the rotational direction with respect to the horizontal plane. It is characterized in that it is inclined forward, the tip side is curved with a relief angle rearward with respect to the rotation direction, and the tip part is bent upward at a predetermined bending angle. It is.

Hereinafter, the present invention will be explained with reference to FIGS. 2 to 4. Note that the same parts as in the conventional example explained in FIG. 1 are given the same reference numerals, and the explanation will be omitted.

As shown in FIG. 3, the cutting edge 5b of the spiral blade 5 is inclined upward with a rake angle γ with respect to the horizontal plane. At the front side of this cutting edge 5b in the rotational direction, the rotation axis 3
A mounting box 9 is provided at the lower end of the cutting edge 5b to protrude in the circumferential direction at approximately the same level as the cutting edge 5b, and a shaping blade 11 is mounted to this mounting box 9 via a bolt nut 10. This shaping blade 11 has a horizontal cutting portion 11 that is curved backward in the rotational direction from the mounting base 11a with a relief angle α relative to the rotational radius r.
b, and the tip of this horizontal cutting part 11b is bent at a bending angle β
and a molded part 11c bent diagonally upward at
The entire shaping blade 11 is inclined at the same rake angle γ as the rake angle γ of the cutting edge 5b so that the entire shaping blade 11 descends in the rotation direction.

Next, the operation of the trench excavator according to the present invention constructed as described above will be explained.

When the rotating shaft 3 rotates clockwise as shown in FIG. 4, the shaping blade 11 comes into contact with the soil first, and then the cutting edge 5b of the spiral blade 5 comes into contact with the soil. Then, the shaping blade 11 rotates horizontally to cut the soil slightly downward to a predetermined thickness, and in the horizontal cutting part 11b it is horizontal by the length of the blade, and in the shaping part 11c it is tilted slightly diagonally outward. Shape the outer edge of the groove with. The soil cut by the forming blade 11 rises from the cutting edge 5b of the spiral blade 5 along the inclined spiral surface and is brought into the guide chamber 6, where it is fed by the discharge blade 7 and is delivered to the discharge port. It is ejected to the side of the aircraft and digs a trench. This dug groove is shaped by a shaping plate 8.

If there is a hard substance such as a stone in the soil during such trench digging work, it will first collide with the shaping blade 11, but since the shaping blade 11 is inclined at a rake angle γ, the impact with the stone etc. It reduces the impact force by reducing the impact force, and since it is curved with a clearance angle α, it reduces the cutting resistance and cuts the bottom surface horizontally. Furthermore, in the forming part, the shape of the lower ends on both sides of the groove is clearly defined, and the groove The finish is good. Furthermore, the torque of the rotary shaft 3 is constant, and vibration of the machine body is reduced, which also has a favorable effect on the tractor that transmits the rotary power.

Note that the number of shaping blades 11 is not limited to one as in the above embodiment, and a plurality of shaping blades may be provided.

As explained above, according to the groove digging machine of the present invention, the shaping blade 11 is provided on the front side in the rotational direction of the cutting edge portion 5b of the spiral blade 5, and the shaping blade 11 has a rake angle γ and is tilted forward. Since it is curved at a clearance angle α and the tip is bent upward at a bending angle β, it reduces the impact with hard parts such as stones in the soil, reducing wear and impact on the spiral blade. In addition, the bottom surface of the groove can be flattened and the lower side edges of the groove can be shaped to create a clean groove. moreover,
The torque of the rotating shaft is also stable, reducing the vibration of the aircraft,
It also has a positive effect on the tractor that transmits power to the trench excavator.

[Brief explanation of drawings]

FIG. 1 is a side view of a conventional trench excavator, FIG. 2 is a side view of the trench excavator of the present invention, FIG. 3 is a side view of the main parts, and FIG. 4 is a plan view of the trench excavator. DESCRIPTION OF SYMBOLS 1... Main body of trench excavator, 2... Connecting portion, 3... Rotating shaft, 4... Supporting member, 5... Spiral blade, 5a, 5
b...Blade tip, 6...Guide chamber, 7...Discharge blade, 9...
... shaping plate, 9... mounting box, 10... bolt nut, 11... shaping blade, 11a... mounting base,
11b...Horizontal cutting part, 11c...Forming part, α...
...Relief angle, β...Bending angle, γ...Ripping angle, r...
turning radius.

Claims (1)

[Scope of utility model registration request] A helical blade is provided on the outer periphery of a rotating shaft that protrudes almost vertically downward from the machine body and rotates in the horizontal direction, and a shaped blade is located on the front side in the rotational direction of the lower end cutting edge of the spiral blade and is provided on the outer periphery of the rotating shaft. The shaping blade has a predetermined rake angle in the direction of rotation with respect to the horizontal plane and is inclined forward, and the tip side is curved with a clearance angle backward in the direction of rotation, and the tip side is curved with a clearance angle backward in the direction of rotation. A trench excavator characterized by being bent upward at a predetermined bending angle.