JPH0537017U - Cutting blade for brush cutter - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a cutting blade for a brush cutter, which can continue light cutting work with good sharpness for a long time and which can be easily attached to a blade. [Structure] In a brush cutter for brushing off weeds, grasses and the like by relative reciprocating motions of an upper blade 10 and a lower blade 20, blade-shaped inclined portions 17 and 27 form a mountain-shaped blade edge 70 and are adjacent to each other. The cutting edge bottom 73 that connects the cutting edges 70, 70 is located inside the upper support guide 40 and the lower support guide 50. [Effect] Upper support guide 40 and lower support guide 50
Is blocked by the side surfaces of the blades, and weeds and the like are not caught between the upper blade 10 and the lower blade 20. Further, since the upper blade 10 and the lower blade 20 are sandwiched by the wide upper support guide 40 and the lower support guide 50, the gap between the upper blade 10 and the lower blade 20 is also constant. The cutting edge 70 includes the inclined portions 17 and 2 with blades.
Since it is composed of 7, it becomes easy to blade and sharpen.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a cutting blade for a brush cutter, which maintains good sharpness for a long period of time without leaving uncut residue.

[0002]

[Prior Art]

 A shoulder-type brush cutter is equipped with a cutting blade unit at one end of the operating main rod, and the cutting blade unit is driven by a power source such as an engine provided at the other end of the operating main rod. The cutting blade unit includes a reciprocating type in which two upper and lower cutting blades move relative to each other, and a rotating blade type in which weeds and grass are cut by a cutting blade that rotates at high speed. As a larger bush cutter, a hand-operated type with a power source such as an engine lowered to the ground is also used.

For example, in a brush cutter having a reciprocating type cutting blade, as shown in FIG. 1, the output from the engine 1 is transmitted to the front by a drive shaft rotatably inserted in the operating main rod 2. At the front end of the operating main rod 2, a housing 3 is provided which has a crank rod for converting the rotational movement of the drive shaft into a linear movement. A pair of upper and lower cutting blades 4 are provided on the front side of the housing 3 so as to be capable of reciprocating.

The applicant of the present invention has introduced the structure shown in FIG. 2 as a drive mechanism for the cutting blade 4 in this cutting blade in Japanese Patent Application No. 63-235. That is, the bevel gear 5a is fixed to the drive shaft 5 rotatably provided inside the housing 3, and the bevel gear 6a meshing with the bevel gear 5a is fixed to the main shaft 6. The cams 7a and 7b with different phases are attached to the cam 7 near the end of the main shaft 6, and the long holes provided in the crank rods 8a and 8b of the upper blade 8u and the lower blade 8d are attached to the respective cam portions 7a and 7b. It is fitted.

When the main shaft 6 rotates by receiving power from the engine 1, the rotational motion of the main shaft 6 is converted into a linear motion between the cam portions 7a and 7b and the crank rods 8a and 8b. Then, the upper blade 8u and the lower blade 8d alternately reciprocate in the opposite directions to weed and the like. At this time, in order to move the upper blade 8u and the lower blade 8d along a constant locus, the upper blade 8u and the lower blade 8d are arranged along the support guides 9u and 9d. The support guides 9u and 9d enable the reciprocating motion of the upper blade 8u and the lower blade 8d by tightening a bolt 9a penetrating the guide holes of the upper blade 8u and the lower blade 8d with a nut 9b.

Further, as a driving method of the cutting blade, in addition to the method of reciprocating both the upper blade 8u and the lower blade 8d shown in FIG. 2, either the upper blade or the lower blade is reciprocated, A method of fixing the other is also adopted.

[0007]

[Problems to be solved by the device]

 When weeding and weeding is done using a reciprocating type cutting blade, the cutting quality is good and the cutting weeds do not become clogged due to biting. It is important for making the light.

In order to improve the sharpness, in the conventional cutting blade, the top side and the inclined side of the trapezoidal cutting edges provided on both sides of the upper blade and the lower blade are bladed. However, it is difficult to attach the blade to the bottom located between the blade and the tip, and incomplete cutting of weeds and the like is unavoidable at this portion. Moreover, since both the top side and the slanted side are bladed, the blade mounting operation itself becomes troublesome.

[0009] Furthermore, when weeds, grasses, etc. that have been cut are caught between the upper blade and the lower blade, the cutting blade cannot smoothly reciprocate, and the gap between the upper blade and the lower blade opens, and It also hinders itself. In this respect, the support guides 9u and 9d press the upper blade 8u and the lower blade 8d from above and below to prevent the gap between them from opening, while keeping the reciprocating locus of the upper blade 8u and the lower blade 8d constant. It has an effective function. However, simply providing the support guides 9u and 9d inevitably causes biting of weeds and the like in the gap between the upper blade 8u and the lower blade 8d.

The present invention has been devised to solve such a problem, and by improving the cutting edge shape of the cutting blade and the relationship of the support guides for the upper blade and the lower blade, excellent cutting is achieved. The purpose is to prevent biting of weeds, etc. while ensuring the taste and to perform light cutting work.

[0011]

[Means for Solving the Problems]

 In order to achieve the object, the cutting blade for a brush cutter according to the present invention has an upper blade and a lower blade, at least one of which is capable of reciprocating movement, and a bolt inserted through a guide hole formed in the upper blade and the lower blade. A plurality of cutting edges that are connected and that have an upper support guide and a lower support guide that sandwich the upper blade and the lower blade, and that are composed of a pair of bladed inclined surfaces are provided on both sides of the upper blade and the lower blade. It is characterized in that an unbladed portion which is formed along the direction and which is between adjacent blade tips is located between the upper support guide and the lower support guide.

[0012]

【Example】

 Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. As shown in FIG. 3, the cutting blade of this embodiment has a configuration in which both the upper blade 10 and the lower blade 20 reciprocate with respect to each other. A connecting member 11 is fixed to the base end side of the upper blade 10, and a fitting hole 12 is formed in the connecting member 11. Further, the lower blade 20 also has a connecting member 21 similarly having a fitting hole 23 formed therein, which is fixed to the base end side. Further, both the upper blade 10 and the lower blade 20 are provided with a plurality of guide holes 13 and 23 extending in the longitudinal direction.

On both sides of the upper blade 10 and the lower blade 20, a plurality of blade edges are formed along the longitudinal direction. As shown in FIG. 4, the cutting edge 70 has a mountain shape composed of a pair of inclined portions 71 and 72 protruding laterally from the blade base portions 14 and 24. Further, a slanting portion 71 of one cutting edge 70 and a slanting portion 72 of the adjacent cutting edge 70 are connected to each other by a cutting edge bottom portion 73. A bladed surface 74 is provided on the inclined portions 71 and 72, but the blade tip bottom portion 73 is not bladed.

The power of the engine (see FIG. 1) is transmitted to the main shaft 30 via the drive shaft in the operating main rod. The upper and lower ends of the main shaft 30 are pivotally supported by the inner wall of the housing (see FIG. 2). The seat plate 31, the driven gear 32, and the seat plate 33 are fitted into the main shaft 30. The driven gear 32 has a gear surface on its peripheral surface that meshes with a drive-side gear (corresponding to the bevel gear 5a in FIG. 2).

On the upper surface side of the driven gear 32, a cylindrical cam projection 34 into which the fitting hole 12 of the connecting member 11 is fitted is formed at an eccentric position of the driven gear 32. On the other hand, the columnar cam projection 35 formed on the lower surface side of the driven gear 32 is formed at a position eccentric to the center of the driven gear 32 in the direction opposite to the cam projection 34. The fitting hole 22 formed in the connecting member 21 of the lower blade 20 is fitted to the cam projection 35.

An upper support guide 40 and a lower support guide 50 are provided so as to sandwich the upper blade 10 and the lower blade 20. The base end portions of the support guides 40 and 50 are fixed to predetermined positions of the housing by mounting bolts 41 and 51. Further, a plurality of connection holes 42, 52 are formed along the longitudinal direction of the support guides 40, 50.

The bolt 60 inserted into the connecting hole 52 via the washer 61 is inserted into the guide holes 13 and 23 of the upper blade 10 and the lower blade 20, and projects from the upper surface of the upper support guide 40. By screwing the nut 62 onto the protruding bolt 60, the upper blade 10 and the lower blade 20 are sandwiched between the upper and lower support guides 40, 50 so as to be capable of reciprocating.

The upper and lower support guides 40, 50 are wider than conventional support guides. Then, as shown in FIGS. 5 and 6, the side portions of the upper blade 10 and the lower blade 20 on which the blades are attached are partially covered by the support guides 40 and 50. That is, the distance from the blade tip bottom 73 on one side of the upper blade 10 and the lower blade 20 to the blade tip bottom 73 on the other side, that is, the width W of the blade bases 14 and 24.₁ The width W of the upper and lower support guides 40, 50 ₂ It is set smaller than. As a result, the blade tip bottom 73 is positioned in a state of being sandwiched between the upper and lower support guides 40 and 50, and only the bladed inclined portions 71 and 72 project from the lateral sides of the upper and lower support guides 40 and 50.

When mowing weeds or the like using the cutting blade that partially covers the cutting edge as described above, only the cutting surface 74 comes into contact with the weeds to be cut, and the uncut cutting edge bottom portion 7 3 Does not come into contact with weeds. Then, weeds or the like that reach the cutting edge bottom portion 73 are obstructed by the upper and lower support guides 40 and 50 and do not reach the cutting edge bottom portion 73 through the gap between the support guides 40 and 50. Therefore, only the inclined portions 71, 72 having the sharp bladed surface 74 act on the weeds and the like to be mowed, and the weeds and the like are not caught between the blade tip bottoms 73 which are not bladed. As a result, smooth cutting work will be performed.

Further, the blade attaching operation is also performed relatively easily on the two surfaces of the inclined portions 71 and 72. The ease of blade cutting is also advantageous when re-sharpening a blade that has been dull by use, which improves the usability of the blade.

On the other hand, in the conventional cutting edge 70, as shown in FIG. 7, a pair of inclined portions 71 and 72 are provided from the top portion 75 to the blade edge bottom portion 73, and the blade portions are provided on the top portion 75 and the inclined portions 71 and 72. The attachment surface 74 is formed. Therefore, it is necessary to attach the blade to the blade tip 70 from three directions, which makes the blade attaching work troublesome. Further, the sharpness of the cutting blade is dominated by the relatively short and sharply pointed apex 75, and is likely to decrease in a relatively short time. Therefore, a blade attaching operation that reduces complicated steps is frequently required.

Moreover, in the conventional cutting blade, as shown in FIG. 8, the upper support guide 40 and the lower support guide 50 that are narrower than the blade bases 14, 24 of the upper blade 10 and the lower blade 20 are used. ing. Therefore, the incompletely bladed bottom 73 is exposed to the side of the upper and lower support guides 40 and 50. With such a cutting blade, a piece of weed or the like, which has been incompletely cut by the blade tip bottom portion 73, is likely to be caught between the upper blade 10 and the lower blade 20. Therefore, it is necessary to interrupt the mowing work and remove the broken pieces of weeds that have been bitten.

[0023]

[Effect of the device]

 As described above, in the present invention, the blade tip is formed by the pair of bladed inclined portions, and the non-blade tip bottom is positioned inside the upper and lower support guides to perform the blade attaching operation. The simplification and the sharpness are ensured. In addition, weeds that are to be cut are prevented from being caught between the upper and lower blades, enabling a light cutting work. Moreover, since the upper and lower blades are sandwiched by the upper support guide and the lower support guide that are wider than in the conventional case, the gap between the upper and lower blades is kept constant, and the weeds themselves are cut. It is done smoothly.

[Brief description of drawings]

FIG. 1 is a perspective view showing a shoulder type brush cutter.

FIG. 2 is a sectional view showing a power transmission section of the brush cutter.

FIG. 3 is an exploded view of a cutting blade according to an embodiment of the present invention

FIG. 4 is a perspective view showing a cutting edge of a cutting blade according to an embodiment of the present invention.

FIG. 5 is a longitudinal sectional view showing the relationship between the cutting blade and the support guide.

FIG. 6 is a plan view showing the relationship between the cutting blade and the support guide.

FIG. 7 is a perspective view showing a cutting edge of a cutting blade in a conventional brush cutter.

FIG. 8 is a plan view showing a relationship between a cutting blade and a support guide in a conventional brush cutter.

[Explanation of symbols]

10 Upper blade 20 Lower blade 1
3,23 Guide hole 14,24 Blade base 40 Upper support guide 50
Lower support guide 70 Blade edge 71, 72 Inclined portion 73
Blade tip bottom 74 Blade mounting surface W ₁ Blade base width (distance between blade tip bottoms on both sides) W ₂ Width of upper support guide and lower support guide

Claims (1)

[Scope of utility model registration request] 1. An upper blade and a lower blade, at least one of which can be reciprocated, and a upper blade and a lower blade, which are connected to each other by bolts inserted into guide holes formed in the upper blade and the lower blade, and which sandwich the upper blade and the lower blade. An upper support guide and a lower support guide are provided, and a plurality of blade edges formed by a pair of bladed inclined surfaces are formed along the longitudinal direction on both sides of the upper blade and the lower blade, and are between adjacent blade edges. A cutting blade for a brush cutter, wherein an unbladed portion is located between the upper support guide and the lower support guide.