JP7828086B2 - Rotary grass cutting blade - Google Patents

Description

The present invention relates to a rotary grass cutting blade that is attached to the rotating tip of a brush cutter to efficiently cut vines and tall weeds entangled in grass.

Traditionally, plants such as vines and tall grass spread easily, and when they grow in fields or agricultural soil, they interfere with farming and other work, so they are cut down and removed with brush cutters to clear the land.

These brush cutters use a rotatable, disk-shaped blade attached to an output shaft of a drive source such as an engine to cut weeds, vines, etc.

Such a grass cutting blade has a blade section protruding from the periphery of the disk-shaped metal grass cutting blade body, and when rotated, the cutting blade body attached to the edge of the blade cuts vines and tall weeds.

However, when using a brush cutter to cut weeds with its blade in areas overgrown with tall weeds or vines, the length of the cut weeds increases by the height of the weeds, resulting in the inconvenience of having to spend a great deal of effort cleaning up the vacant lot after cutting and disposing of the piled up weeds. Furthermore, depending on the type of weed being cut, the strength of the stems and vines can cause the long cut weeds to become wrapped around the output shaft of the brush cutter, negatively impacting work efficiency.

The grass cutting blades of such brush cutters are typically called chip saws, and chip saws are replaced as part of maintenance. When the chip saw blade described above deteriorates, it is replaced with a new chip saw. During replacement, weeds that have been cut and become entangled around the output shaft are removed. However, many brush cutters are designed to prevent weeds from getting entangled in advance, such as the one described in Patent Document 1.

In other words, when cut weeds attempt to wrap around the output shaft of the brush cutter, the cutting blade on the outside of the output shaft cuts the weeds.

Japanese Patent Application Laid-Open No. 2005-110531

However, the weeds cut by the brush cutter are long and require further processing, even if they are disposed of as general waste or industrial waste, or mixed with soil to be used as fertilizer, which is cumbersome.

These inconveniences are primarily due to the long cutting length of weeds by the mower blade. Because the cut weeds are so long, they tend to become tangled and form clumps, which requires the weeds to be separated, potentially making the processing work even more labor-intensive.

The present invention was made in consideration of the above-mentioned problems, and aims to provide a brush cutting blade that is a tip saw that can be modified in a certain way, i.e., the peripheral cutting edge can be deformed in various ways, such as pointing downward, upward, or horizontally, to cut overgrown weeds and vines as short as possible, scattering the cut weeds widely and shallowly across the ground to prevent them from becoming tangled and forming clumps, making it easier to dispose of the weeds after cutting (transporting and bagging), and also preventing weeds from getting tangled around the output shaft of the brush cutter.

In order to solve the above-mentioned problems of the conventional method, the present invention features a disk-shaped grass cutting blade body with a number of roughly uneven cutting blades formed on the periphery, in which the number of adjacent cutting blades formed on the periphery of the grass cutting blade body are formed in an alternating pattern of downwardly inclined lower cutting blades and horizontally extending horizontal cutting blades.

Another feature is the formation of an upwardly inclined upper cutting blade midway between the lower cutting blade and the horizontal cutting blade at the periphery of the grass cutting blade body.

According to this invention, by rotating two types of blades (a lower blade and a horizontal blade) or three types including an upper blade, the cutting length of weeds can be shortened, and by scattering short weeds thinly over a wide area, the weeds can be easily disposed of after cutting without requiring a great deal of labor. For example, tasks such as transporting the weeds and bagging them for storage can be easily performed, and furthermore, the short cutting length of the weeds prevents them from getting tangled around the output shaft of the brush cutter.

1 is a perspective view showing a state in which a rotary grass-cutting blade according to the present invention is attached to a brush cutter. FIG. 2 is an exploded perspective view illustrating a method for attaching the rotary grass-cutting blade of the present invention to a brush cutter. FIG. 2 is a bottom view illustrating the configuration of the rotary grass cutting blade according to the first embodiment of the present invention. FIG. 10 is an end view illustrating a lower cutting blade and a horizontal cutting blade of a rotary grass cutting blade according to the first and third embodiments of the present invention. FIG. 10 is a bottom view illustrating the configuration of a rotary grass cutting blade according to a second embodiment of the present invention. FIG. 10 is an end view illustrating a lower cutting blade, a horizontal cutting blade, and an upper cutting blade of a rotary grass cutting blade according to a second embodiment of the present invention. FIG. 10 is a bottom view illustrating the configuration of a rotary grass cutting blade according to a third embodiment of the present invention.

The gist of this invention is that the disk-shaped grass-cutting blade body has a number of roughly uneven cutting blades formed on its periphery, and the number of adjacent cutting blades formed on the periphery of the grass-cutting blade body is formed in an alternating pattern of downwardly inclined lower cutting blades and horizontally extending horizontal cutting blades.

Another feature is the formation of an upwardly inclined upper cutting blade midway between the lower cutting blade and the horizontal cutting blade at the periphery of the grass cutting blade body.

Embodiments of the rotary grass cutting blade M according to the present invention will now be described in detail with reference to the accompanying drawings. FIG. 1 is a perspective view showing the rotary grass cutting blade M according to the present invention attached to a brush cutter 40, with the arrow at the top of the figure indicating the direction of rotation of the rotary grass cutting blade M. FIG. 2 is an exploded view illustrating a method for attaching the rotary grass cutting blade M according to the present invention to a brush cutter 40. FIG. 3 is a bottom view of the rotary grass cutting blade M according to the first embodiment. FIG. 4 is an end view of the rotary grass cutting blade M according to the first and third embodiments, with (A) showing the A-A end view in FIG. 1 and the F-F end view in FIG. 7, and (B) showing the B-B end view in FIG. 1 and the G-G end view in FIG. 7. FIG. 5 is a bottom view of the rotary grass cutting blade M according to the second embodiment. Figure 6 shows end views of the rotary grass cutting blade M according to the second embodiment, with (A) showing the CC end view, (B) showing the DD end view, and (C) showing the EE end view. Figure 7 is a bottom view of the rotary grass cutting blade M according to the third embodiment.

The following mainly describes the first embodiment of the present invention, with the second and third embodiments also described in relation to this. The rotary grass cutting blade M of the present invention is used to cut and remove weeds, vines, etc., and is attached to the output shaft 41 of a brush cutter 40, as shown in Figures 1 and 2.

It is attached to the output shaft 41 of a drive source such as an engine and cuts weeds into small pieces as it rotates. As shown in Figure 2, the main components of the mounting portion of the brush cutter 40 are the output shaft 41 with a threaded groove at the tip of the rod, an output shaft cover 42 that covers the output shaft 41, a mounting bolt 43 that corresponds to the threaded groove of the output shaft 41, and a bracket 44 that is interposed between the output shaft 41 and the mounting bolt 43.

As described above, the output shaft 41 rotates due to the driving force from the drive source of the brush cutter 40. The output shaft 41 is cylindrical near its lower end, and has a threaded groove formed inside it into which the mounting bolt 43 can be threaded.

The bracket 44 is a circular member with an area larger than the diameter of the mounting hole 12 of the rotary grass cutting blade M, and has a through-hole drilled in the center through which the mounting bolt 43 can be inserted.

As shown in Figures 3, 5, and 7, the rotary grass cutting blade M consists of a grass cutting blade body 10, which is a base disk body that holds the cutting blade 20, and the cutting blade 20 formed on the peripheral edge 11 of the grass cutting blade body 10.

The blade body 10 and cutting blade 20 that make up the rotary grass cutting blade M are made from metal plate-shaped components such as steel plates, and have the same thickness as a regular chip saw. Therefore, when a certain amount of wear and tear occurs due to usage, it is replaced with the rotary grass cutting blade M of this invention that has been stored in advance, and so-called chip saw replacement work is performed as maintenance.

The grass cutting blade body 10 is configured in a roughly circular plate shape, with a mounting hole 12 at the center for fixing it to the output shaft 41 of the brush cutter 40.

As shown in Figure 2, the blade is attached to the brush cutter 40 by inserting the output shaft 41 through the mounting hole 12 from above, and then threading the mounting bolt 43 into the threaded groove of the output shaft 41 while holding the blade body down from below with the bracket 44. In other words, it can be attached to the output shaft 41 of the brush cutter 40 in the same way as a conventional brush cutter.

The output shaft 41 of the brush cutter 40 is connected to the drive source of the brush cutter 40, receives rotational power, and functions as the rotation output shaft of the rotary grass cutting blade M. In other words, the grass cutting blade body 10 attached to the output shaft 41 of the brush cutter 40 rotates counterclockwise as shown in Figure 1 (the direction of the arrow shown in Figure 1, hereinafter referred to as the "blade rotation direction").

In addition, the grass cutting blade body 10 has a number of lightening holes 13 drilled outside the mounting holes 12, separate from the mounting holes 12. These lightening holes 13 are provided to reduce the weight of the rotary grass cutting blade M.

The specific configuration of the cutting blade 20, which is the gist of the present invention, is described in detail below. Specifically, the basic configuration of the cutting blade 20 is such that a large number of uneven cutting blades 20 are formed on the peripheral edge 11 of the blade body 10. The numerous cutting blades 20 formed on the peripheral edge 11 of the blade body 10 alternate between lower cutting blades 20a that are inclined downward in side view and horizontal cutting blades 20b that extend horizontally. In a second embodiment, an upper cutting blade 20c that is inclined further upward is formed midway between the lower cutting blades 20a and horizontal cutting blades 20b on the peripheral edge 11 of the blade body 10.

As described above, the various types of blades 20 are formed in an uneven pattern on the extended peripheral edge 11 of the blade body 10. Because the blades 20 are protruded from the peripheral edge 11 of the blade body 10 in an uneven pattern at regular intervals, recessed spaces 30 are formed between adjacent blades 20. These recessed spaces 30 function as weed collection spaces when cutting weeds; weed stems and leaves are collected into these spaces and then cut by the blade 20 located on the upstream side of the rotation. Therefore, in actual cutting operations with the present invention, rather than horizontal cutting movements back and forth and side to side as in conventional cutting operations with flat blades, a vertical lifting movement is used; that is, the blade body 10 is pressed against the weeds from above, collecting the cut weeds into the recessed spaces 30 and cutting them as they come into contact with the blade 20.

This working style is achieved by the vertically inclined shape of the cutting blade 20 of the present invention, and this cutting style allows tall weeds to be chopped into short, fine pieces.

In addition, as a second embodiment, the multiple cutting blades 20 formed on the peripheral edge 11 of the blade body 10 can be configured as six cutting blades 20, as shown in Figures 5 and 6, with three types of cutting blades 20 being alternately combined: an upwardly inclined upper cutting blade 20c, a downwardly inclined lower cutting blade 20a, and a horizontally extending horizontal cutting blade 20b. This complex combination of three types of cutting blades 20 can shred weeds more efficiently, and is particularly ideal for cutting large volumes of material to be cut, such as intricately tangled vines.

As described above, in the second embodiment, an upper cutting blade 20c that is inclined upward is formed between the lower cutting blade 20a and the horizontal cutting blade 20b on the peripheral edge 11 of the grass cutting blade body 10, as shown in Figure 6, resulting in a configuration of six cutting blades 20.

Specifically, the cutting blades 20 are formed alternately with downwardly inclined lower cutting blades 20a and horizontal cutting blades 20b formed horizontally from the blade body 10. There are two lower cutting blades 20a and two horizontal cutting blades 20b, for a total of four cutting blades 20, and an upper cutting blade 20c is formed in the middle, resulting in a rotary grass cutting blade M with six cutting blades 20. The corners of the recessed space 30 are formed as curved cutting blades 21.

Furthermore, three to five chip blade bodies 22 are formed on the upper part of the above-mentioned cutting blade 20, and the chip blade bodies 22 have an uneven shape with a height that is half to one-third of the height of the cutting blade 20, and a long cutting blade 21 is formed at the tip of the cutting blade 20 that contacts the recessed space 30 of the cutting blade 20.

As shown in Figures 3, 5, and 7, the cutting blade 21 is formed on the peripheral edge 11 of the grass cutting blade body 10 and is configured as a downwardly sloping surface. The cutting blade 21 formed on the upper edge of the tip blade body 22 has a small hard piece called a tip 23.

In the first embodiment, as shown in Figure 3, when there are four cutting blades 20, each cutting blade 20 is formed with four to five tip blade bodies 22. In the second embodiment, as shown in Figure 5, when there are six cutting blades 20, four tip blade bodies 22 are formed. In the third embodiment, as shown in Figure 7, when there are eight cutting blades 20, three tip blade bodies 22 are formed. Note that, as shown in Figures 4 and 7, the third embodiment is similar to the rotary grass cutting blade M of the first embodiment, in that the lower cutting blades 20a and horizontal cutting blades 20b are arranged alternately.

In this way, as the number of cutting blades 20 increases, the number of tip blade bodies 22 formed on each cutting blade 20 decreases. This prevents a large difference in the overall number of cutting blades 21 formed on the peripheral edge 11 of the grass-cutting blade body 10. As a result, there is no large difference in the weed-cutting function regardless of the number of cutting blades 20 and the number of tip blade bodies 22, and the cutting blade 20 that is appropriate for the characteristics and propagation pattern of the weeds to be cut can be selected.

In this way, when two types of cutting blades 20, the horizontal cutting blade 20b and the lower cutting blade 20a, are provided, for example, when cutting tall weeds, two locations are cut: the stem near the base and the middle of the stem. In particular, by placing the cutting blade 20 over the weed and pressing down from above during cutting, the downward-facing lower cutting blade 20a cuts long weed stems into small pieces. This means that weeds can be cut into shorter, finer pieces than with conventional cutting blades, making it easier to transport and bag the weeds for post-processing. Furthermore, when cutting tall weeds or vines using conventional cutting blades, the long cutting length of the weeds can easily cause the stems to wrap around the output shaft 41 of the brush cutter 40. In contrast, the rotary cutting blade M can cut weeds and vines into short pieces, preventing the stems from wrapping around the output shaft 41 of the brush cutter 40.

As shown in Figures 4 and 6, the angles α and β of the lower cutting blade 20a and the upper cutting blade 20c relative to the grass cutting blade body 10 are set to be equal to or greater than 90 degrees and less than 180 degrees, and it is preferable that both angles α and β are in the range of 120 degrees to 160 degrees. In this embodiment, angles α and β are set to be approximately 135 degrees, which is considered to be the most preferable. Furthermore, angles α and β may be within the above-mentioned angle range, and angles α and β do not necessarily have to be the same.

In this way, the six cutting blades 20 in the rotary grass cutting blade M according to the second embodiment are provided in three configurations: the horizontal cutting blade 20b, the lower cutting blade 20a, and the upper cutting blade 20c, so that when cutting weeds, it is possible to cut the stems near the base and at three points midway through the stems, resulting in a total of four or more chopped stems . In other words, when cutting a large, complexly tangled object such as a vine, the second embodiment, which has six cutting blades 20, is more suitable for cutting weeds more efficiently, as it cuts them to a shorter length than the rotary grass cutting blades M according to the first and third embodiments.

Of the three types of cutting blades 20 provided, namely the horizontal cutting blade 20b, the lower cutting blade 20a, and the upper cutting blade 20c, the lower cutting blade 20a in particular faces downward. Therefore, when cutting weed stems, the cut pieces of weeds are scattered diagonally downward in a wide area along the downward cutting direction of the cutting blade 20, scattering thinly over a wide area around the cut area and scattering in a roughly horizontal state around the cutting point.

This eliminates the labor-intensive process of removing cut weeds that are piled up one on top of the other, as occurs with conventional horizontal cutting blades.

At the same time, because the cut grass is not cut into long pieces but into short-cut stems, it is easier to transport, store, and dry in the sun, which simplifies the process of weed disposal during weeding, making a significant contribution to the efficiency and energy savings of weeding operations.

M Rotary grass cutting blade 10 Grass cutting blade body 11 Peripheral edge portion 12 Mounting hole 13 Lightweight hole 20 Cutting blade 20a Lower cutting blade 20b Horizontal cutting blade 20c Upper cutting blade 21 Cutting blade 22 Tip blade body 23 Tip 30 Recessed space 40 Brush cutter 41 Output shaft 42 Output shaft cover 43 Mounting bolt 44 Bracket

Claims (2)

A disk-shaped grass cutting blade body,
A plurality of cutting blades are formed on the periphery of the grass cutting blade body so as to form recessed spaces between each other together with the grass cutting blade body,
The cutting blade has three to five tip blade bodies formed on the tip side so as to have an uneven shape with a height that is one-half to one-third of the height of the cutting blade ,
The plurality of cutting blades include:
A lower cutting blade inclined downward to form an obtuse angle of 120 to 160 degrees with respect to the grass cutting blade body;
horizontal cutting blades extending horizontally relative to the grass cutting blade body, and horizontal cutting blades are formed alternately in the circumferential direction of the grass cutting blade body ,
Each tip blade has a small, hard tip at its tip.
A rotary grass cutting blade characterized by: The rotary grass cutting blade according to claim 1, characterized in that the multiple cutting blades include an upper cutting blade that is formed midway between the lower cutting blade and the horizontal cutting blade in the circumferential direction and is inclined upward at an obtuse angle relative to the grass cutting blade body.