JP3003986U - Weeding prevention device for brush cutter - Google Patents

Abstract

(57) [Abstract] [Purpose] To prevent grass and vines cut by the cutting blade from winding around the cutting blade itself and its rotary bearing. [Structure] A rectangular elastic seat plate in plan view whose long side is biased upward in a convex shape from ribbon steel, and both short sides of the elastic seat plate are bent ridge lines and bent upward at an acute angle. The elastic seat plate of the weeding blade, which is shaped into a generally parallelogram in plan view with the inclined winglets of a substantially right triangle in plan view, is attached to the rotary spindle of the mowing blade in a pair of upper and lower split bosses. And the front edge of each of the inclined blades in the direction of rotation is used as a blade for cutting grass, and a part of the long side of the elastic seat plate continuous to the front is used as a blade for preventing grass invasion. Polished.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 TECHNICAL FIELD The present invention relates to a grass curl prevention device for a brush cutter.

[0002]

[Prior art]

 Separate and small weeding blades are fitted in a stack in the central part of the mowing blade that is driven to rotate by the engine mounted on the main rod, and integrated so that the mowed grass and vines are transferred to the transmission box and other rotary bearing parts. A mowing machine which prevents the wrapping by its weeding blade is known from Japanese Utility Model Publication No. 52-30256 and Japanese Utility Model Publication No. 57-3239 which can be said to be an improved invention.

[0003]

[Problems to be solved by the device]

 However, the jump piece (8) of Japanese Utility Model Publication No. 52-30256 is obtained by simply bending and bending the projection piece (b) from the substrate (a) by sheet metal press working. Since it is not sharpened with a sharp edge, it is difficult to aggressively remove grass and vines, and the effect of preventing wrapping is still poor.

Further, the substrate (a) of the jumping piece (8) is in a simple joined state with the mowing blade (rotary blade) (5), and the substrate (a) is also subjected to polishing work as a sharp edge. Since it is not applied, the gripping force of the pair of upper and lower flanges (7) weakens over time, and if a slight gap is created in the joint surface between the substrate (a) and the mowing blade (5), the gap will be minute. There is a risk that vines will wind up due to repeated invasion of grass and the like.

In order to improve this problem, the auxiliary blade (3) of Japanese Utility Model Publication No. 57-3239 described above has a strip-shaped small blade from the non-bladed side of the right-angled triangular cutting blade (4). The claw (7) is cut and raised, and the small claw (7) is inserted into the engaging hole (8) of the mowing blade (rotary blade) (2) in a protruding state.

However, in this case, since it is necessary to form a special locking hole (8) in the mowing blade (2) as well, it can be used as it is for general mowing machines with various mowing blades on the market. There are restrictions that cannot be used interchangeably.

Further, since the hypotenuse of the right-angled triangle in the cutting blade (4) serves as a sawtooth-like portion for cutting grass and vines by scooping, sawtooth is engraved on the steel plate (B). In addition to this, the small nail (7) must also be specially cut and raised, which is complicated in processing and may cause the small nail (7) to break accidentally. Combined with the fact that the auxiliary blade (3) must be inserted into the locking hole (8), it is not possible for the user to quickly and safely replace and install the auxiliary blade (3).

[0008]

[Means for Solving the Problems]

 The present invention intends to improve such a problem, and in order to achieve this, a rotary shaft for a mowing blade driven by an engine equipped with a main rod is erected vertically to the tip of the main rod. , A small weeding blade and a separate small weeding blade that are stacked on the center of rotation of the mowing blade are fitted into the rotary support shaft from below in a state of being sandwiched by a pair of upper and lower split bosses.

The above weeding blade is made of ribbon steel, and a rectangular elastic seat plate in plan view whose long sides are biased upwardly in a convex shape, and both short sides of the elastic seat plate are bent ridge lines, An elastic seat plate of the weeding blade is shaped into a generally parallelogram in plan view with an inclined wing piece that is bent and raised at an acute angle and is a right-angled triangle in plan view. With the clamping force, it is pressed against the upper surface of the mowing blade to make it adhere closely, and the entire front side in the direction of rotation of each of the above-mentioned inclined blades is used as the blade tip for weeding, and a part of the long side of the elastic seat plate continuous to the front side is The cutting edge for preventing grass invasion is characterized by being sharply polished.

[0010]

According to the above configuration of the present invention, the weeding blade is formed of ribbon steel into a generally parallelogram in plan view, and the rectangular elastic seat plate is bent upward from both short sides to form an acute angle. Since the entire front side of the rotation direction in the inclined right-angled winglet is sharpened as a blade for cutting grass, the weeding blade rotates integrally with the cutting blade in the rotation direction. During use, the grass cutting edge can be used to grind grass and vines at the same time, and at the same time, the grass can be released to the outside, and the reliable effect of preventing winding can be achieved.

Further, the elastic seat plate of the weeding blade is biased in a pre-convex upward convex shape of its long side, and against the biasing force, the clamping force of the split boss is applied to the upper surface of the mowing blade. Since the clamping force of the split boss weakens over time because the elastic seat plate tries to float above the mowing blade, the elastic seat plate will not be pressed against the elastic seat plate. The bending ridgeline of the inclined winglet bent and bent from both short sides will bite and press firmly against the upper surface of the mowing blade by the above-mentioned biasing force, and the elastic seat plate and the mowing blade There is no risk of creating a gap on the stacking surface of.

Moreover, since a part of the long side of the elastic seat plate that rotates integrally with the mowing blade is sharply ground as a cutting edge for preventing grass invasion, which is continuous with the cutting edge for cutting grass of the inclined blade piece, Fine grass and the like that try to enter the gap can be surely eliminated, and an excellent effect of curling up can be obtained.

[0013]

【Example】

 The specific construction of the present invention will be described in detail below with reference to the illustrated embodiment. In FIG. 1 showing the assembled state of the main parts of the brush cutter, (10) is a main rod made of light metal, FRP or the like. An engine (not shown) is attached to its base end. Reference numeral (11) is a main shaft that is rotationally driven by the engine, and penetrates the inside of the main rod (10).

Reference numeral (12) is a rotary support shaft for a mowing blade, which is transmission-coupled to the tip of the main shaft (11) through a bevel gear mechanism (13), and stands upright in a state intersecting with the main shaft (11). It Reference numeral (14) is a transmission box (bevel gear box) fixedly attached to the tip of the main rod (10), and a plurality of bearings (15) and (16) enclosed therein allow the main shaft (11) to move. ) And the rotary spindle (12) for mowing blades are both rotatably supported by rotation.

The lower end of the rotary support shaft (12) is exposed from the transmission box (14), and the exposed lower end of the rotary support shaft (12) is detachably fitted so that the mowing blade (A) can rotate integrally. It is attached.

That is, a mounting hole (17) is opened at the center of rotation of the mowing blade (A), and the periphery thereof is sandwiched by a pair of upper and lower split bosses (18) and (19), and the boss is (18) and (19) are fitted onto the rotary support shaft (12) via splines (20) and keys. A fixing bolt (21) is screwed into the rotary support shaft (12) from below, thereby pressing the bosses (18) and (19) so as not to fall off.

However, the fixing bolt (21) and subsequently the bosses (18) and (19) are pulled out from the rotary support shaft (12), respectively, and the bosses (18) and (19) are disassembled to It is also possible to attach / detach and replace the mowing blade (A). It goes without saying that the spiral direction of the fixed bolt (21) is engraved in the direction opposite to the rotation direction of the mowing blade (A).

(22) is a bearing metal or bush inserted between the rotary support shaft (12) and the transmission box (14), (23) is a sealing material, and (24) is a lower part of the above. It is a stable ground plate that is clamped between the boss (19) and the large-diameter head of the fixing bolt (21), and rotates integrally with the mowing blade (A). By being depressed, the head of the fixing bolt (21) is sunk and the mowing blade (A) is kept in a floating state where it does not touch the ground.

Further, (25) is a bowl-shaped cover skirt that surrounds the upper boss (18), and is provided with screws (27) or the like from below to the projecting flange portion (26) of the transmission box (14). It is attached and fixed, and its lower end comes close to the upper surface of the mowing blade (A) to prevent grass and vines from entering.

In the illustrated embodiment, the mowing blade (A) is embodied by a circular saw having a plurality of cutting edges (28) engraved on its circumferential surface. However, a chip saw or other alternative The form may be adopted.

Further, (B) is interposed between the cover skirt (25) and the mowing blade (A) above and below each other, and is joined together by the split bosses (18) (19) of the mowing blade (A). The weeding blades are sandwiched, and are integrally rotated by the rotation support shaft (12) in the same direction as the mowing blade (A) (see arrow f in FIG. 5).

The weeding blade (B) is formed independently of the mowing blade (A) and formed into a substantially parallelogram in plan view smaller than the mowing blade (A) as shown in FIGS. There is.

That is, reference numeral (29) in FIGS. 2 to 6 denotes an elastic seat plate of the weeding blade (B) stacked on the upper surface of the mowing blade (A), which has a rectangular shape in plan view and is attached to the central portion thereof. Although it has a hole (30), its long side has a certain elasticity accumulated by being bent and biased in the upward convex shape in advance as shown in FIG. 3.

Reference numeral (31) is a pair of parallel reinforcing beads extending along both long sides of the elastic seat plate (29), and has a positional relationship that does not interfere with the split mold bosses (18) and (19). It protrudes upward from the elastic seat plate (29). By using the reinforcing beads (31), the elastic seat plate (29) is reinforced while the thin ribbon steel is used as a material, and the space between the elastic seat plate (29) and the upper boss (18) is blinded. It prevents the invasion of fine grass.

Further, (32) is a pair of inclined wing pieces bent and erected at an acute acute angle (α) with both short sides of the elastic seat plate (29) as bending ridgelines (33), both of which are flat. It has a nearly right-angled triangle.

Moreover, the front side of each inclined wing piece (32) in the rotational traveling direction (f) is in a straight line continuous with the long side of the elastic seat plate (29), but the entire front side thereof. Is sharpened at a constant angle (β) as a blade for cutting grass (a).

In that case, as shown in the plan view of FIG. 5, the bent ridgeline (33) of each inclined blade (32) is located at a relative position which is a tangent to the circular outer peripheral surface of the cover skirt (25). Is approaching. In other words, the long side of the elastic seat plate (29) is dimensioned so as to have a length substantially equal to the outer diameter of the cover skirt (25), whereby the grass cutting edge (a) is formed. Can be brought as close as possible to the outer peripheral surface of the cover skirt (25).

Further, when the sharp ridgeline of the grass cutting blade edge (a) is viewed from a plane, each of the inclined blade pieces (32) is bent at a bending point (X) which is bent and raised from the elastic seat plate (29). , The weeding blade (B) itself extends in a relational state intersecting an acute angle (γ) with respect to an imaginary radial line (r-r) connecting the rotation center (O) of the weeding blade (B) itself, and the acute angle (γ) As the so-called opening angle or clearance angle of the cutting edge (a), in combination with the centrifugal force of the weeding blade (B) itself, the grass and vines are surely ground and at the same time positively released to the outside. You can do it.

(B) is a state of continuous relation with the blade edge (a) for grass cutting of the inclined blade piece (32), in which a long side portion of the elastic seat plate (29) is sharply ground to prevent grass invasion It is a cutting edge, and its processing length (y) is dimensioned to be approximately equal to the distance between the bent ridgeline (33) of each inclined blade piece (32) and the circular outer peripheral surface of the cover skirt (25). . By the blade edge (b) for preventing grass invasion, between the elastic seat plate (29) of the weeding blade (B) and the mowing blade (A), and also between the elastic seat plate (29) and the cover skirt (25). It is designed to prevent the intrusion of fine grass and the like between the two.

When performing the mowing work using the weeding blade (B) having the above-described structure, the elastic seat plate (29) is moved to the center of rotation of the mowing blade (A) as shown in FIGS. The mounting holes (17) and (30) are stacked in a state where they match each other and clamped by a pair of upper and lower split bosses (18) and (19), and the elastic seat plate (29) is predicted by the clamping force. The blade is pressed against the upper surface of the mowing blade (A) so as to come into close contact with it while resisting the urging force of the blade.

Then, the split bosses (18) and (19) are fitted onto the rotary support shaft (12) for mowing blade from below, and the fixing bosses (21) are integrated so as not to fall off. By doing so, the two inclined blades (32) bent and raised from the weeding blade (B) face the circular outer peripheral surface of the cover skirt (25) by themselves and used for removing the grass from both the inclined blades (32). The blade cutting edge (b) of the blade edge (a) and the elastic seat plate (29) forming a ridge line continuous with the blade cutting edge (b) in the direction of arrow (f) in FIG. The grass and vines that have been mowed by A) will be surely cut off, and it will be positively released to the outside, and fine grass will be inserted between the weeding blade (B) and the mowing blade (A). It is possible to completely achieve the effect of preventing wrapping, without the risk of intrusion.

[0032]

[Effect of device]

 As described above, in the present invention, the rotary support shaft (12) for a mowing blade, which is driven by the engine mounted on the main rod (10), is erected by the tip of the main rod (10) in a standing state. The mowing blade (A) and a separate small weeding blade (B) stacked on the center of rotation thereof are sandwiched by a pair of upper and lower split bosses (18) and (19), and are attached to the rotary spindle (12) from below. In a mower that is fitted and integrated,

The weeding blade (B) is made of ribbon steel, and a rectangular elastic seat plate (29) in plan view is urged in such a manner that its long side is upwardly convexly curved, and the elastic seat plate (29). Bending both short sides of the ridge line (33), and including the inclined winglets (32) that are bent right at an acute acute angle (α) and have a substantially right-angled triangular shape in plan view Shaped into a shape, and the elastic seat plate (29) of the weeding blade (B) is pressed and closely attached to the upper surface of the mowing blade (A) by the clamping force of the split mold bosses (18) and (19). The entire front side of each inclined wing piece (32) in the rotation advancing direction (f) is used as a grass cutting edge (a), and a part of the long side of the elastic seat plate (29) continuous to the front side is prevented from invading grass. Since each of the cutting edges (b) is sharply polished, the problems of the prior art mentioned at the beginning are surely ensured. Can be good, there is the herbicidal blade (B) to be used with fitted as a general-purpose or interchangeably to the commercially available various cutting cutters effect.

That is, according to the above configuration of the present invention, the mowing blade (A) and the independent weeding blade (B) are formed from ribbon steel into a substantially parallelogram as a whole in plan view. The entire front side of the rotation advancing direction (f) in the substantially right-angled triangular inclined wing piece (32) bent and raised from both short sides of the rectangular elastic seat plate (29) to the acute angle (α) upwards is grass. Since the blade for sharpening (a) is sharply ground, the weeding blade (B) is rotated integrally with the mowing blade (A) in the direction of rotation (f) of the blade during use. By the point (a), grass and vines can be surely cut off, and by synergistic action with the rotating centrifugal force, it can be positively released to the outside, and the effect of preventing these wrapping is remarkable. Excel.

Further, the elastic seat plate (29) of the weeding blade (B) is biased in a pre-convex upward convex shape of its long side, and resists the biasing force of the grass cutting blade (A). The upper surface of the split bosses (18) (19) is pressed and closely attached by the clamping force of the split bosses (18), so that fine grass or the like may enter between the above weeding blade (B) and the mowing blade (A). Even if the gripping force of the split mold bosses (18) and (19) weakens over time and the elastic seat plate (29) tries to rise above the mowing blade (A) without fear, the more it does so. The bent ridgeline (33) of the inclined winglet (32) is more and more strongly bited and crimped onto the upper surface of the mowing blade (A) by the above-mentioned curved biasing force, resulting in the elastic seat plate (29). There is no risk of creating a gap in the stacking surface between the blade and the mowing blade (A), and permanent winding Therefore, the prevention effect can be maintained.

Furthermore, a part of the long side of the elastic seat plate (29) that is in close contact with the upper surface of the mowing blade (A) is used as a blade tip (b) for preventing grass invasion, and the direction of rotation (f ) Is sharpened at a constant angle (β) that is continuous with the cutting edge (a) that has been machined on the entire front side of). The preventive cutting edge (b) has the effect of reliably eliminating it.

Then, the weeding blade (B) can be punched out of the ribbon steel into an almost parallelogram as a whole in a plan view, and the grass cutting edge (a) and the grass penetrating under the developed flat plate state. Since the prevention blade edge (b) is continuously and integrally ground, and both inclined blade pieces (32) can be bent upward from the bending ridge line (33) to an acute acute angle (α), it is extremely easy to manufacture and process. Therefore, the mass production effect can be maximized.

If the construction of claim 2 is adopted, the strength of the elastic seat plate (29) is improved by providing a reinforcing bead (31) while using a thin ribbon steel as the weeding blade (B). In addition to this, a reasonably blind cover is provided between the elastic seat plate (29) of the weeding blade (B) and the upper boss (18) to achieve an effect of preventing intrusion of fine grass and the like. It is also possible to do.

In particular, if the structure of claim 3 is adopted, the cover skirt (25) prevents the upper boss (18) and the transmission box (14) for bearings from being entangled with grass or vines. In addition, the blade tip (a) for cutting off the grass of the inclined blade pieces (32) bent and raised from the elastic seat plate (29) and the blade tip (b) for preventing the grass invasion of the elastic seat plate (29). However, since both of them face the position close to the circular outer peripheral surface of the cover skirt (25), the two types of continuous cutting edges (a) and (b) have an effect of preventing wrapping of grass and vines. There is an advantage that can be improved.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an assembled state of a main part of a brush cutter according to the present invention.

FIG. 2 is a plan view showing an extracted weeding blade.

FIG. 3 is a front view of FIG.

4 is a sectional view taken along line 4-4 of FIG.

FIG. 5 is a plan view showing a mounting positional relationship between a mowing blade and a weeding blade.

6 is a partial enlarged cross-sectional view taken along the line 6-6 of FIG.

[Explanation of symbols]

 (10) -Main rod (12) -Rotating spindle (18) -Boss (19) -Boss (25) -Cover skirt (29) -Elastic seat plate (31) -Reinforcing bead (32) -Inclined wing piece ( 33) ・ Bending ridge (A) ・ Mowing blade (B) ・ Weeding blade (a) ・ Grass cutting edge (b) ・ Grass intrusion prevention edge (f) ・ Rotation direction (α) ・ Acute angle

Claims (3)

[Scope of utility model registration request] 1. A rotary shaft for a mowing blade (12) driven by an engine mounted on the main rod (10), comprising:
(0) is vertically supported by the tip of the mowing blade (A) and a separate small weeding blade (B) stacked on the center of rotation of the mowing blade (A).
The rotation support shaft (12) is clamped by (19).
In the brush cutter integrated by fitting from below to the above, the above weeding blade (B) is made of ribbon steel, and a rectangular elastic seat plate (29) in plan view is urged upward in a convex curved shape on the long side in advance.
And bend both short sides of the elastic seat plate (29) to the ridge line (3
3) while forming an approximately parallelogram in plan view as a whole with a slanted wing piece (32) in a plan view that is bent and raised at an acute angle (α) to form a weeding blade. The elastic seat plate (29) of (B) is pressed against and brought into close contact with the upper surface of the mowing blade (A) by the clamping force of the split mold bosses (18) and (19), and the rotation of each inclined blade piece (32) The entire front side in the traveling direction (f) is used as a blade for cutting grass (a), and a part of the long side of the elastic seat plate (29) continuous to the front side is used as a blade for preventing grass invasion (b), each sharply A device for preventing weeding of a mower, which is characterized by being polished. 2. A pair of reinforcing beads (31) which do not interfere with the split mold bosses (18) (19) are extended along both long sides of the elastic seat plate (29) of the weeding blade (B), and The grass winding prevention device for a brush cutter according to claim 1, characterized in that it is protruded upward from the elastic seat plate (29). 3. A bowl-shaped cover skirt (25) surrounding the upper boss (18) is integrally projected downward from the tip of the main rod (10), while an elastic seat plate for the weeding blade (B) is provided. The bent ridgeline (33) of each inclined blade piece (32) bent and raised from (29) is brought close to a relative position tangent to the circular outer peripheral surface of the cover skirt (25), and a grass intrusion prevention edge ( b) is a constant length (y) approaching the circular outer peripheral surface of the cover skirt (25) from the bent ridgeline (33) of each inclined blade piece (32), and a part of the long side of the elastic seat plate (29) The device for preventing weeding of a mowing machine according to claim 1, wherein the device is ground.