JP2007295850A - Cutting blade guard for brush cutter and brush cutter equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting blade guard for a brush cutter cutting relatively large weeds having a length not smaller than the comb pitch without bulking a tool and without being accompanied with complicated operation. <P>SOLUTION: The cutting blade guard for the brush cutter is equipped with a disk 2 fixed along the blade surface of a rotating blade 11 located at the tip of a holding rod 10 of the brush cutter 1 for lawn and having the larger outermost periphery than the rotating blade 11. The cutting blade guard is characterized as follows. The cutting blade guard is provided with comb parts 21 at a prescribed comb pitch 21p and a notched part 22 having a larger width than the comb pitch 21p over the outer periphery of the disk 2. The notched part 22 is installed within a partial prescribed range except the range provided with the comb parts 21 in the outer periphery of the disk 2. The width of the notched part is larger than the comb pitch 21p. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a cutting blade guard for a brush cutter that is attached to a brush cutter for cutting off a lawn and guards unnecessary cutting by a rotary blade of the brush cutter, and a lawn brush cutter provided with the same. .

  For example, there are cases where a plant and a lawn are arranged in a garden. In this case, the lawn needs to be mowed according to the growth in a state where the lawn and other than the lawn are intricate.

  In the above state, the lawn of a relatively wide flat area can be mowed using a large lawn mower having a plurality of blades. However, the large lawn mower cannot enter in a complicated area such as a planting area or on a slope. Therefore, in the region, it is necessary to cut using a relatively small brush cutter.

  In such a brush cutter, basically, a single high-speed rotary blade that rotates at high speed around an inclined axis is attached to the tip of an extended gripping rod. Then, the grass is mowed with the gripping bar directed obliquely downward and the rotary blade leveled. It has a relatively simple structure that does not have a lawn collection mechanism, tires, etc., is relatively lightweight, and is relatively easy to handle the rotating blades.

  However, the single blade brush cutter rotates at high speed while the rotary blade is exposed. For this reason, since the root exposed from the ground is hidden in the grown lawn, the root of the lawn may be damaged, or the stem of the plant may be damaged due to an operation mistake. If the workpiece other than the grass portion of the lawn is accidentally damaged in this way, the planted tree will die if it is bad.

In order to prevent such unnecessary laceration of the work piece other than the grass portion of the lawn, conventionally, the cutting blade is provided above or below the rotary blade of the brush cutter to prevent contact between the rotary blade and the work piece. There was a cutter blade guard (see Non-Patent Document 1, for example). This is a uniform comb shape around a disk larger than the rotary blade. This comb portion is formed by cutting the periphery of a disk larger than the rotary blade into a plurality of small U-shapes and protrudes to the periphery of the rotary blade. For example, like a clipper tooth, Guards against direct contact with the workpiece.
Kobayashi Iron Works Co., Ltd. “Safety cover for brush cutters, Anzen Cover-kun”, [online], 2005, [Searched on April 18, 2006], Internet URL <http: //www.kobayashi-tekkosho .co.jp / new / anzen1.jpg>

  However, in the above-described conventional brush blade guard for a brush cutter, the comb portions are provided at equal pitches and equally spaced comb pitches so as to uniformly guard the periphery of the rotary blades, and fit within this comb pitch. Only grass is mowed with a rotary blade. For this reason, it was impossible to mow a large grass larger than the comb pitch.

  On the other hand, it is possible to consider using a plurality of brush cutter guards with different comb pitches. In this case, however, it is necessary to replace the cutter blade guards with different comb pitches to the brush cutter. Alternatively, it is necessary to replace and use another brush cutter in which a brush guard for a brush cutter having a different comb pitch is attached in advance. In these, necessary tools are bulky, and work such as replacement becomes complicated.

  Accordingly, an object of the present invention is to provide a cutting blade guard for a brush cutter that can mow relatively large grass that is equal to or larger than the comb pitch, and that does not have a bulky tool and is not complicated.

  The present invention takes the following means in order to solve the above problems.

  (1) The cutting blade guard for a brush cutter according to the present invention is fixed along the blade surface of the rotary blade 11 at the tip of the gripping rod 10 of the brush cutter 1 and has an outermost periphery (comb portion) larger than the rotary blade 11. A disc 2 having a predetermined comb pitch 21p and a notch having a notch width 22w larger than the comb pitch 21p. The unit 22 is provided. The notch 22 is provided in a part of a predetermined range (preferably a rear position near the gripping rod) excluding the range where the comb portion 21 is provided on the outer periphery of the disk 2, and the notch width 22 w (length in the outer circumference direction). ) Is larger than the comb pitch 21p. Thereby, the weeds of the comb pitch 21p or more can be arbitrarily cut by contacting the weeds with the rotary blade 11 in the range provided with the notches 22.

  (2) Further, it is preferable that the notch portion 22 is provided in the range of less than 180 degrees in the periphery of the disk 2 and the comb portion 21 is provided in the remaining range of the periphery of the disk 2.

  In such a case, the comb part 21 occupies a range of more than half of the outer circumference of the disk 2, that is, the center angle of more than 180 degrees, so that the guard function by the comb part 21 can be more reliably performed. In other words, since the comb portion 21 on the outer periphery of the disk 2 covers the most part of the periphery of the blade portion 11B of the rotary blade 11 and more than half, only a small range portion with a central angle of less than 180 degrees of the notch portion 22 is recognized. Unnecessary lacerations can be prevented. On the other hand, the necessary range for cutting with a comb pitch of 21p or more is sufficiently secured by a range with a central angle of less than 180 degrees, and within the range of less than 180 degrees, a necessary portion for cutting is applied to any desired range. Can cut weeds of size.

  (3) Further, in the brush cutter guard for a brush cutter, it is preferable that a predetermined large opening 23 including a width of a comb pitch 21p and a comb length 21l is provided inside the disk 2. By setting it as such, a mowing grass is hard to be pinched | interposed between the rotary blade 11 and the (mowing blade guard for brush cutters), and a mowing grass can be discharged | emitted easily.

  In other words, the conventional blade guard causes the cut grass after the brush cutter 1 cuts the lawn to jump out of the blade by the centrifugal force of the blade, but when a comb-shaped guard is provided, The rotation of the rotary blade was suppressed by the mowing grass sandwiched between the guards, and as a result, cutting was impossible. On the other hand, the cutting blade guard for the brush cutter according to the present invention is capable of discharging the cut grass from a predetermined large opening provided inside the disk and suppressing the pinching of the temporary grass between the rotary blade and Become. At this time, since the opening of the blade is constantly open, the next workpiece can be touched and the blade can be continuously cut.

  (4) Further, the brush cutter 1 of the present invention includes at least a gripping rod 10 that is gripped and operated, and a substantially circular rotary blade 11 that is rotatably provided at the tip of the gripping rod 10, and this rotation. One of the brush cutter guards for a brush cutter is attached so as to be parallel to the blade surface of the blade 11. The cutout portion 22 on the outer periphery of the disk 2 is in a position close to the gripping rod 10 that fixes the rotary blade 11 in a state in which the cutter blade guard for the brush cutter is fixed to the brush cutter 1. .

  In such a case, the rotary blade 11 on the tip side of the brush cutter 1 is not exposed and is covered with the comb portion 21, and only a part of the rotary blade 11 on the side near the gripping rod 10 of the brush cutter 1 is covered. It will be exposed by the notch 22. Since the brush cutter 1 is normally used with the gripping rod 10 inclined forward and downward, the comb portion 21 exposes the blade portion 11B of the rotary blade 11 to the tip side far from the user during use. It can be reliably guarded. Since the distal end side far from the user is likely to cause an operation error or the visibility of the far portion is likely to deteriorate, the guard of the original rotary blade 11 is particularly necessary. Further, the necessity of cutting large grass having a comb pitch of 21p or more is usually limited to an arbitrary time. For this reason, it is preferable that the notch 22 is provided on the front side of the user, and that the guard function by the comb 21 is reliably exhibited in normal use. Note that the user's near side is close to the user's side, and the state of the turf can be confirmed more accurately. For this reason, even if the notch 22 is provided on the front side of the user, the probability of unnecessary laceration is not high.

  By adopting the above-described means, it is possible to provide a blade guard for a brush cutter that can mow relatively large grass that is equal to or greater than the comb pitch, is not bulky, and does not involve complicated operations.

  Embodiments of the present invention will be described together with respective drawings shown as examples of the present invention. 1 to 8 show the brush cutter 1 and the brush cutter guard for the brush cutter according to the first embodiment, and FIGS. 9 and 10 show the brush cutter 1 and the brush guard for the brush cutter according to the second embodiment. FIG.11 and FIG.12 shows the brush cutter 1 and the blade guard for brush cutters of Example 3. FIG.

  In any of the embodiments, the cutting blade guard for a brush cutter according to the present invention is basically a disk 2 having an outer shape (maximum diameter) larger than the rotary blade 11 and fixing for fixing to the brush cutter 1. Means. Further, the disk 2 includes a comb portion 21 provided in a part of the periphery, a notch portion 22 provided in the remaining portion of the periphery, and an opening 23 serving as a discharge hole for discharging the cut grass provided in the plate surface. It has.

  In any of the embodiments, the notch portion 22 is provided in a predetermined range (a rear position near the gripping rod 10) excluding the range in which the comb portion 21 is provided on the outer periphery of the disk 2. Further, it is preferable that the notch portion 22 is provided in the range of (at most) a central angle of less than 180 degrees in the periphery of the disk 2 and the comb portion 21 is provided in the remaining range of the outer periphery of the disk 2.

  Further, in the cutting blade guard for the brush cutter, a predetermined large opening 23 including a comb pitch 21p width and a comb length 21l is provided inside the disc 2, and the cut grass between the rotary blade 11 is sandwiched. It can be easily discharged without any problems. Hereinafter, the configuration in each embodiment will be described in detail.

  FIG. 1 and FIG. 2 are perspective partial explanatory views of the front end portion of the brush cutter 1 as viewed from obliquely downward and obliquely upward, respectively, with respect to the brush cutter 1 of Embodiment 1 to which the brush guard for brush cutter of the present invention is attached. Indicates. FIG. 3 is a partial sectional explanatory view in side view of the tip portion of the brush cutter 1 according to the first embodiment. FIG. 4 is an exploded perspective view of the front end portion of the brush cutter 1 according to the first embodiment obliquely from below.

  FIG. 5 is a perspective view, FIG. 6 is a plan view, FIG. 7 is a front view, and FIG. 8 is a cross-sectional view taken along line AA in FIG. Each figure is shown. The bottom view appears symmetrically with the plan view, and the left side view appears symmetrically with the front view. In both the right side view and the rear view, the notch portion 22 does not appear and the comb portion 21 appears in the width direction in the front view of FIG.

  The cutting blade guard for a brush cutter according to the first embodiment is provided with a partial fan-shaped notch 22 having a central angle of 40 degrees.

(Crusher 1)
The brush cutter 1 to be attached to which the cutting blade guard for a brush cutter according to the present invention is attached includes at least a gripping rod 10 and a rotary blade 11 provided rotatably at the tip of the gripping rod 10.

  The brush cutter 1 according to the first embodiment includes a gripping rod 10, a substantially circular rotary blade 11 that is rotatably provided at the tip of the gripping rod 10, a rotation mechanism 12 that rotates the rotary blade 11, and a rotary blade 11. It includes a safety cover 13 provided so as to intersect with the vicinity of the tip of the gripping rod 10 to prevent contact with the user, and does not include a lawn collecting mechanism or a self-propelled mechanism such as a tire.

  A brush cutter guard for the brush cutter is attached to the brush cutter 1 so as to overlap the circular surface of the rotary blade 11. When the cutting blade guard for the brush cutter is attached to the brush cutter 1, when the rotary blade 11 below the gripping rod 10 is opposed to the grass surface so as to face the substantially horizontal direction, the notch 22 is gripped. It is provided in the vicinity of the rod 10 and at a position near the left front side that is biased to the left side. In a state where the brush cutter guard for the brush cutter is attached, the notch portion 22 is in a position near the gripping rod 10 for fixing the rotary blade 11, that is, a position on the near side for the user.

(Grip bar 10)
The gripping rod 10 is a rod that has a gripping part for operation and extends. The rotating shaft 12S of the rotating mechanism 12 is attached to the lower end of the gripping rod 10, and a rotating blade is fixed to the rotating shaft 12S. The gripping rod 10 is used while being tilted so as to be positioned in front of the user.

(Rotating blade 11)
The rotary blade 11 is substantially circular, and a blade portion 11B is provided over the outer periphery thereof. It is rotatably attached to the tip of the gripping rod 10 together with the blade guard for the brush cutter through the packing 12P and the coupling 12C.

(Rotating mechanism 12)
The rotating mechanism 12 is a mechanism that rotates the rotary blade 11 at a high speed, and includes a rotating shaft 12S inclined at about 30 degrees with respect to the extending direction of the grasping rod 10 at the tip of the grasping rod 10, a coupling 12C that communicates therewith, And packing 12P. These hold and fix the rotary blade 11 and rotate at high speed by rotational power (not shown).
The inclination angle of the rotating shaft 12S is about 30 degrees.

(Safety cover 13)
The safety cover 13 is a horizontally long flat bent plate that is fixed so as to intersect the gripping rod 10 near the tip of the gripping rod 10. The curved plate is gently bent in a substantially arc shape along the periphery of the lower rotary blade 11, and the operator side of the rotary blade 11 is placed on the operator side of the rotary blade 11 for operational safety so that the rotary blade 11 does not tear the operator or the like. cover.

(Disc 2)
The cutting blade guard for a brush cutter according to the present invention includes a disk 2 fixed along the blade surface of the rotary blade 11 at the tip of the gripping rod 10 of the brush cutter 1. The disk 2 is overlapped with the rotary blade 11 along any surface of the rotary blade 11 at the tip of the brush cutter 1 by fixing means (the center fixing means 3 and the end fixing means 4) described later. Fixed in parallel with the rotary blade. The lower part of the rotary blade is guarded by being fixed substantially parallel to the blade surface. In the fixed state, the rotating shaft 12S of the rotary blade 11 and the center of the disk 2 are common. In order to guard an unnecessary laceration below the rotary blade 11, it is preferable to be fixed facing the lower surface of the rotary blade 11 as in the embodiment.

The disc 2 is provided with a comb portion 21 having a predetermined comb pitch 21p and a notch portion 22 having a width larger than the comb pitch 21p over the outer periphery of the disc 2. In addition, the disk 2 has the outermost periphery (the farthest distance between the tips of the comb portions 21) larger than that of the rotary blade 11 in the state where the comb portions 21 are provided.
The disk 2 is also provided with a comb part 21 and a notch part 22 over the entire periphery. As a result, the outermost contour of the disc 2 is the farthest distance between the tips of the comb portion 21, but the outermost contour of the disc 2 is larger than the rotary blade 11, and thereby the rotary blade is more outward than the outermost periphery of the disc 2. The eleven blade portions 11B do not protrude.

  The outer diameter of the disk is preferably about 200 to 300 mm, for example, 230 mm or 250 mm, and the thickness of the disk 2 is preferably 2.0 mm or less, for example, about 1.6 mm.

(Comb portion 21)
The comb portions 21 are provided radially in a direction from the center of the disk 2 toward the outer periphery. The range in which the comb portion 21 is provided is the remaining range excluding the predetermined range of the notch portion 22 on the outer periphery of the disk 2. In the embodiment, a plurality of semicircular arc-shaped cuts are equally applied at equal intervals around the circular outer shape disk 2 so as to reduce the diameter of the disk 2, so that a part of the circular outer periphery of the disk 2 is formed. Then, a comb surrounded by a three-way curve composed of the left and right arc curves is continuously formed around the disk 2.

  The comb pitch 21p needs to be smaller than the maximum width of the cross section of the part to be cut. Moreover, the comb needs to protrude from the blade.

  The semicircular arc-shaped cut depth is, for example, about 2.5 mm, that is, the radius of the semicircular arc is about 2.5 mm, which is slightly smaller than the radial length of the blade portion 11B of the rotary blade 11.

(Notch 22)
The notch 22 is provided by partially notching a predetermined range of the disk 2 along the periphery of the disk 2. In the predetermined range where the notch 22 is provided, the blade portion 11B of the overlapping rotary blade 11 is exposed. Specifically, the notch 22 is formed by a fan-shaped curve having a central angle near the center of the disk 2 and a radial straight line from both ends thereof toward the outer periphery of the disk 2.

  Regarding the predetermined range in which the notch 22 is provided, the width of the notch 22 (the notch width 22w, ie, the length along the circumference of the disk 2) is at least larger than the comb pitch 21p, and more specifically, the comb pitch 21p2 It is preferable that one portion (the space between two combs formed by three combs) is larger than the combined width, for example, in the range of two to five comb pitches 21p. In order for the cutting blade guard for a brush cutter of the present invention to maintain the guard function, it is preferable that a range of (at most) a central angle of less than 180 degrees within the periphery of the disk 2 be a predetermined range. In the first embodiment, the center is common to the disk 2 and has an arc having a central angle of 40 degrees, which is slightly smaller than the three blade portions 11B of the rotary blade 11.

  The notch depth 22l (the length in the direction along the radial direction of the disk 2) of the notch 22 is at least larger than the radial length of the blade 11B of the rotary blade 11.

  In addition, although the cutout portion 22 of the first embodiment is only one having a central angle of 40 degrees, two or more plural cutout portions may be provided as in the third embodiment. For example, if a plurality of cutout portions 22 having different central angles are provided around the disk 2, a comb pitch can be obtained by using the cutout portions 22 having an appropriate size according to the required cutting width. Safer trimming can be performed even in the trimming of a larger range than 21p.

(Position of notch 22)
In a state in which the brush cutter guard for the brush cutter is fixed to the brush cutter 1, the cutout portion 22 on the outer periphery of the disk 2 is located near the gripping rod 10 that fixes the rotary blade 11. In Example 1, it is the base end side of the gripping rod 10 and a position close to one side (left side). In Examples 2 and 3, it is the base end side of the gripping rod 10, and the left and right positions are centered on the gripping rod 10. In this way, by providing the notch 22 at the left and right positions with respect to the gripping rod 10, the operability is improved, for example, because the user does not have to move greatly to cut away the opposite side of the obstacle. .

  For example, when there is a large weed around the guardrail post, if there is only a large cutout 22 on one side, the user may move beyond the guardrail and cut away from the moved side. . On the other hand, if the two notches 22 are provided with the same length on both sides of the gripping rod 10 as in the second embodiment (or 3), the gripping rod 10 is operated and the rotary blade 11 is turned well. By indenting, the right and left sides of the guardrail post can be mowed on the near side and the far side with little movement of the user's feet.

(Opening 23)
The opening 23 is a hole for discharging the cut grass provided inside the disk 2, and a plurality (four in the embodiment) are provided symmetrically about the center of the disk 2. As long as the size includes at least the comb pitch 21p width and the comb length 21l, the opening shape may be any shape such as a circle, an oval, an ellipse, or a rectangle. In the embodiment, it has a partial fan shape in which the central angle side is removed from the fan shape by a circular arc curve of the same center. With respect to this opening shape, it is preferable that the outer peripheral side and the center side are surrounded by a circular arc curve as in the embodiment in order to discharge the cut grass coming out of the rotating rotary blade 11.

  When the opening shape is a partial fan shape, the central angle of the partial arc of the fan portion is 35 degrees to 40 degrees or more, further 45 degrees or more, or more, so that the cut grass is efficiently discharged by a larger hole. Is preferably about 90 degrees. However, it is preferable to secure the strength of the disk 2 that exhibits a guard function by providing a plurality of the central angles of about 120 degrees or less. In the embodiment, it is approximately 90 degrees.

  In addition, in addition to the opening 23, the disk 2 has a certain degree of bending elastic function, and an elastic member is interposed between the disk 2 and the rotary blade 11, so that the rotary blade 11 is interposed between the disk 2 and the rotary blade 11. When the cut grass is jammed, the space between the disk and the rotary blade may be widened by elastic deformation in the bending direction of the disk (not shown). At this time, it is preferable to use, for example, a cylindrical foam material that is coaxial with the rotating shaft 12S as the elastic member (both not shown).

  Alternatively, a cut-and-raised portion is provided in the rotary blade 11 in combination with the opening 23, and the cut-and-raised portion serves as a fin by the rotation of the rotary blade so that the cut grass is discharged out of the opening 23. It is also good. At this time, the cut-and-raised part is preferably composed of a curved ridge that folds and extends around the centroid of the opening 23 (both not shown).

(Fixing means)
The fixing means includes first and second connection holes for connecting the brush cutter 1 and the disk 2 through the first and second fixing holes 3H and 4H and the first and second fixing holes 3H and 4H, respectively. Tools 3C and 4C. Specifically, the center part fixing means 3 fixed at the center part of the disk 2 and the end part fixing means 4 fixed at the end part of the disk 2 are configured.

  First, the center fixing means 3 is a first fixing hole 3H provided in the center of the disk 2 and a first fixing hole 3H for connecting the gripping rod 10 of the brush cutter 1 and the disk 2 through the first fixing hole 3H. The connecting tool 3C. The center fixing means 3 also serves as a fixing means to the grasping holding rod.

  The first fixing hole 3H includes a large hole at the center of the disk 2 and four small holes provided at equal intervals around the large hole. The large hole is inserted into the rotary shaft 12S at the tip of the gripping rod 10 through the circular packing 12P and the rotary blade 11, and the upper side thereof is bolted by a cup member as the first fixture 3C. The cup member, which is the first fixture, can freely rotate at the outer peripheral portion integrally fixed with the disk 2 by the bearing 12B. Thereby, the disk 2 and the first fixing means are fixed, and the disk 2 and the first fixing means are fixed to the rotating shaft 12S so as to be freely rotatable in both the left and right directions.

  Next, the end fixing means 4 is connected to the safety cover 13 and the disk 2 of the brush cutter 1 through the second fixing hole 4H and the second fixing hole 4H provided near the end of the disk 2, respectively. And a second connector 4C for connecting the two.

  A plurality of second fixing holes 4 </ b> H are provided at positions close to the end portion away from the center of the disk 2. In the embodiment, near the outer periphery of the disk 2, two bolt holes are arranged in parallel on the diameter of the disk 2 in the center of the width of one of the four cross frames. The second connector 4C is formed of a bent plate bent at an angle of 90 degrees or more, and one end side thereof is bolted to the disk 2 by the second fixing hole 4H, and the multi-end side thereof is trimmed. It is bolted to the gripping rod 10 of the machine 1 or its accessory. In the embodiment, the bolts are indirectly bolted via a safety cover 13 which is an accessory of the brush cutter 1 and is fixed near the tip of the gripping rod 10. That is, in the first embodiment, the disk 2 can be freely rotated with respect to the rotating shaft 12S by the first fixing tool 3C, and the disk 2 is fixed in a non-rotatable state by the second fixing tool 4C.

  As described above, the safety cover 13 is composed of a substantially arc-shaped curved plate fixed along the periphery of the lower rotary blade 11 so that the rotary blade 11 does not tear the operator or the like. Therefore, the operator side of the rotary blade 11 is covered.

  The brush cutter 1 according to the second embodiment does not include the safety cover 13, is lighter, and has a good view of the safety cover 13, that is, near the gripping rod 10 (near side) of the rotary blade 11. In the brush cutter 1 of the second embodiment, the notch portion 22 of the brush cutter guard for the brush cutter is symmetrically arranged so that the gripping rod 10 is positioned at the center of the notch width 22w, near the user. Installed. Specifically, the second fixing hole 4H constituting the second fixing means is provided on the radius of the position where the central angle of the notch 22 is equally divided, and the cutting blade guard for the brush cutter is used as the brush cutter 1. In the attached state, the notches 22 are provided at equal positions on the left and right.

  The cutout portion 22 of the second embodiment is formed of a semi-ellipse cut-out line divided in the longitudinal direction, ie, a substantially flat U-shaped cut-out line that is divided in the longitudinal direction. . When considering the virtual circumference of the disk, the notch depth 22l becomes longer from both ends of the notch to the center. Thereby, it becomes a form which holds the mowing grass pushed out from a disk with a cutter, and becomes a thing with high cutting efficiency.

  Of the end fixing means 3 of the second embodiment, the second connector 3C is composed of a long plate bent once by 90 degrees, and one end is fixed through the second fixing hole 3H of the disk 2, Multiple ends are directly attached to the gripping rod 10 by inserting the vicinity of the tip of the gripping rod 10. As a result, the second connector 3C also serves as the safety cover 13 of the first embodiment, and the view on the front side of the rotary blade 11 as viewed from the user is not obstructed by the safety cover 13 or the like. This makes it easier to cut near the front.

  Other configurations not specifically mentioned are the same as those in the first embodiment.

  The brush cutter 1 according to the third embodiment does not include the safety cover 13 and the end fixing means 4 and is lighter in weight, and more easily cuts the near side. Further, the second connector 4C as in the first embodiment is not provided, and instead, as the first connector 3C, a rotary cup of a chevron-shaped cone is provided at the center lower portion of the disk 2 and the rotation shaft 12S. It is attached so that it can rotate in the reverse direction. Since the rotating cup as the first coupling tool 3C is fixed to the disk 2, when the rotating cup rotates relative to the rotating shaft 12S in the opposite direction, the disk 2 does not rotate.

  For example, such a rotating cup is provided with an external gear 31G that rotates coaxially around the rotary shaft 12S of the rotary blade 11, and an internal gear coaxial with the rotary shaft 12S via a planetary gear 31G meshing with the external gear 31G. It can also be established by fixing the tooth gear 33G in the rotary cup. Here, the disk is fixed to the rotating cup as the first connector 3C.

  When the rotary shaft 12S rotates at a high speed, the planetary gear 31G is rotationally driven by the rotary cup as the first connector 3C coming into contact with the ground, and the rotary cup is rotated in the same direction as the rotary shaft 12S with respect to the rotary shaft 12S. Rotates at the number of revolutions. Since the rotary blade 11 rotates relative to the non-rotating gripping rod and the rotary cup rotates in the opposite direction with respect to the rotary blade 11, only the rotary cup disk does not rotate. Here, when the rotating cup is brought into contact with the turf surface so as to make the rotating cup non-rotating, a traveling force that causes the rotating blade to travel is exerted by the gear resistance force of the planetary gear 32G. That is, when the rotating cup is in contact with the ground, a running force is exerted in the tangential direction of the contact point, which can be used for cutting power. The contact point changes depending on the inclination of the blade, and the traveling direction changes. Moreover, since there is a distance in the height direction from the contact point to the blade, there is an advantage that the cutting height can be maintained to some extent. This solves the problem that the weight to be supported increases and the cutting resistance increases by attaching the blade guard for the brush cutter of the present invention.

(Number and position of the notches 22)
In the third embodiment, two notches 22 having a central angle of 40 degrees are provided adjacent to each other. Each of these notches 2 is a position near the gripping rod 10 that fixes the disk rotary blade 11, and is a position that is equal to the right and left about the gripping rod 10.

  Other configurations not specifically mentioned are the same as those in the first embodiment.

  In addition, the present invention is not limited to the configurations of the above-described embodiments, and various modifications and combinations are possible without departing from the spirit of the present invention.

  The cutting blade guard for a brush cutter and the brush cutter 1 equipped with the same obtained in this way for cutting a weed or an unnecessary material having a comb pitch of 21p or more, or in a region having a comb pitch of 21p or more. It is possible to cut grass together and efficiently. For this reason, it is preferably used as a lawn remover for intricate areas and inclined surfaces, especially when plants or objects are placed in the lawn. It can be used as a lawn mower according to the situation.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective partial explanatory view from diagonally downward which shows the brush cutter 1 of Example 1 which attached the blade guard for brush cutters of this invention. It is a perspective partial explanatory view from diagonally upward of the brush cutter 1 shown in FIG. FIG. 2 is a partial cross-sectional explanatory view in side view of a tip portion of the brush cutter 1 shown in FIG. 1. It is a perspective exploded explanatory drawing from the slanting lower part of the front-end | tip part of the brush cutter 1 shown in FIG. It is a perspective view of the blade guard for brush cutters of Example 1 of the present invention. FIG. 6 is a plan view explanatory view of the cutting blade guard for a brush cutter according to the first embodiment shown in FIG. 5. It is front view explanatory drawing of the cutting blade guard for brush cutters of Example 1 shown in FIG. It is AA sectional drawing of the cutting blade guard for brush cutters of Example 1 shown in FIG. It is a perspective partial explanatory view from the slanting lower part which shows the brush cutter 1 of Example 2 which attached the blade guard for brush cutters of this invention. FIG. 10 is a partial cross-sectional explanatory view in side view of the tip portion of the brush cutter 1 shown in FIG. 9. It is a partial cross-sectional explanatory drawing of the front-end | tip part of the brush cutter 1 of Example 3 which attached the blade guard for brush cutters of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Brush cutter 10 Grasping rod 11 Rotary blade 11B Blade part 12 Rotating mechanism 12B Bearing 12S Rotary shaft 12C Coupling 12P Packing 13 Safety cover 2 Disc 21 Comb part 21p Comb pitch 21l Comb length 22 Notch part 22l Notch depth 22w Notch width 23 opening part 3 center part fixing means 3H first fixing hole 3C first connecting tool 31G external gear 32G planetary gear 33G inner gear 4 end fixing means 4H second fixing hole 4C second connecting tool

Claims (4)

  The outer peripheral disk larger than the rotary blade is fixed along the blade surface of the rotary blade at the tip of the brush cutter, and has a predetermined comb pitch around the disk. A cutting blade guard for a brush cutter, comprising a comb portion and a notch portion having a notch width larger than a comb pitch.   2. The cutting blade guard for a brush cutter according to claim 1, wherein the notch is provided in a range of a central angle of less than 180 degrees around the disk and the comb is provided in the remaining range around the disk.   The cutting blade guard for a brush cutter according to claim 1 or 2, wherein a predetermined large opening including a comb pitch width and a comb length is provided inside the disk. 4. A brush cutter according to claim 1, comprising a gripping rod and a substantially circular rotary blade rotatably provided at the tip of the gripping rod, and along the circular surface of the rotary blade. A brush cutter with a cutting blade guard attached, with the cutting blade guard for the brush cutter fixed to the brush cutter, the notch on the outer periphery of the disc is positioned closer to the gripping rod that fixes the rotary blade A brush cutter characterized by that.

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