JPH026745Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotating blade of a rotary mower.

Prior Art The rotary blade of a rotary mower is usually in the shape of a rectangular flat plate, and the blade part formed on one side end in the direction of rotation cuts grass such as lawns, and the blade part formed on the other side end part. The upwardly rising part blows away the cut grass. Conventionally, such rotary blades have been designed with a focus on mowing and evacuation performance, with little consideration given to noise, and therefore have the drawback of high noise caused by wind noise during rotation. Recently, particularly in foreign countries, noise regulations have become stricter regarding such mowers, and there are demands for noise reduction.

For example, FIGS. 1 to 3 show the state and shape of a rotary blade of this kind that has been conventionally used on a tractor. In FIGS. 2 and 3, in a rotary blade that has a mounting shaft hole 1 in its center and rotates horizontally around this shaft hole 1, the rotational direction of the flat blade body 2 is shown. Blade parts 4, 4 which are shaved down in an inclined manner are formed along the end direction at the front end of the blade part 4, and furthermore, on the opposite side of the blade part 4, that is, at the rear end in the rotational direction, An upwardly rising portion 5 is formed that is bent with a line L oblique to the direction of the blade portion 4 as a boundary. In such a rotary blade having a conventional shape, the top surface 6 of the rising portion 5 is
As shown in FIG. 3, since it faces obliquely upward, when it rotates, air vortices are created in the rear part of the blade, resulting in poor discharge efficiency of cut grass and also being a source of noise.

As shown in FIG. 1, the blade A shaped as described above is attached to, for example, a mower deck 8 attached to the lower center of the tractor body 7 so as to protrude downward, and is attached to the mower deck 8 by a pulley 9, a belt 10, etc. It is designed to be driven by a power take-off section 11 at the front of the fuselage 7.

Purpose of the invention The present invention was devised in view of the above-mentioned drawbacks of the conventional technology, and its purpose is to prevent the generation of vortices behind the apex 6, thereby improving grass discharge efficiency and noise reduction effect. It is said that

Structure of the Device In order to achieve the above-mentioned object, in the present invention, the top surface of the raised portion is formed approximately parallel to the upper surface of the blade body, and the raised portion is bordered by a line approximately parallel to the longitudinal direction of the blade. The structure is bent, and its detailed structure will be explained below based on the illustrated embodiment.

Embodiment In FIGS. 4 and 5, first, a rectangular flat plate-shaped blade body 12 has a blade portion 14 that is shaved off in an inclined manner at the front side end in the rotation direction, as in the conventional case. formed along the edge. As shown in FIG. 4, the raised portion 15 formed on the opposite side of the blade portion 14, that is, on the rear side in the rotational direction, is diagonal with respect to a line _L2 substantially parallel to a line _L1 in the longitudinal direction of the blade portion 14. Although it is bent upward, its top surface 16 is
As shown in FIG. 5, the blade body 12 has a shape that is shaved off or pressed approximately parallel to the upper surface of the blade body 12, and this shape prevents the generation of vortices as in the conventional case. This made it possible to prevent noise, reduce noise, and improve discharge efficiency. Reference numeral 11 is a shaft hole for mounting to the rotating shaft as in the conventional case, and it has a symmetrical shape with the shaft hole 11 for mounting as the center, so only the left half thereof is shown here, and the other half is omitted. ing.

Effects Therefore, according to the present invention, since the top surface of the rising portion, which was a source of noise in the past, is shaped approximately parallel to the surface of the blade body, vortices are not generated behind this top portion. As a result, the efficiency of expelling grass clippings has been improved, and noise has also been reduced by more than 2 dB. In addition, as shown in this example, when forming the raised portion, it is bent at the line _L2 that is substantially parallel to the longitudinal direction of the blade length, which further improves the discharge efficiency and noise reduction effect. This has the advantage of forming the blade in this manner, and furthermore, by forming the blade in this manner, it is possible to obtain the effect that processing for forming the top surface parallel to the surface of the blade body is facilitated.

[Brief explanation of the drawing]

Figure 1 is an overall side view of a tractor with a mower attached, Figure 2 is a perspective view of a conventional blade, and Figure 3 is a perspective view of a conventional blade.
4 is a plan view of essential parts of the blade of the present invention, and FIG. 5 is an end view. 12...blade body, 14...blade portion, 15...
...Rising portion, 16...Top surface.

Claims (1)

[Scope of utility model registration request] In a rotary blade in which a blade portion is provided along the front end of a rectangular flat blade main body in the rotational direction, and a raised portion is formed by bending the rear end portion upward, the raised portion is A rotary mower characterized in that it is bent at an obtuse angle with respect to a line _L2 that is substantially parallel to the longitudinal direction of the blade, and that the top surface of the rising portion is formed substantially parallel to the surface of the blade body. rotating blade.