JP2014171470A - Mowing rotary blade - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mowing rotary blade that can smoothly perform replacement work of the rotary blade to a mowing machine, and stabilize a contact position of the blade part to the ground, thereby preventing the chipping or the like of a cutting edge, and extending the life of the rotary blade, and can reduce a work load to a worker to thereby improve efficiency of work.SOLUTION: A mowing rotary blade includes a mounting flat part with a mounting hole to a mowing machine formed in a central position, and a blade part annularly formed on an outer circumference side of the mounting flat part and provided with a cutting edge on the outer circumferential edge. The blade part is formed in a curved surface shape protruding to a back side of a base metal from the outer circumferential edge of the mounting flat part to the cutting edge. The deepest depth dimension is set larger than the projecting dimension of a mounting bolt when the mowing machine is mounted on the surface side of the mounting flat part with the mounting bolt, and the cutting edge is positioned on the back side of the base metal apart from the mounting flat part for a predetermined dimension .

Description

  The present invention relates to a rotary blade for brush cutting that is attached to a brush cutter and used when cutting weeds and the like.

  Conventionally, a rotary blade for brush cutting is disclosed in, for example, Patent Document 1. As shown in FIG. 6, the rotary blade (tip saw) includes a mounting flat portion 23 in which a mounting hole 24 to a brush cutter (not shown) is formed in the center portion of the base metal 22, and an outer peripheral side of the mounting flat portion 23. The inclined surface portion 25 formed in a state of projecting to the anti-brusher side (the back surface side of the base metal 22), and parallel to the mounting flat portion 23 toward the edge of the base metal 22 on the outer peripheral side of the inclined surface portion 25. And a flat blade portion 26 having a tip 27 fixed thereto by brazing at the tip thereof, and the height of the inclined surface portion 25 is set when the mounting flat portion 23 is attached to the brush cutter with the mounting bolt. It is set to be larger than the protruding dimension.

JP 2011-217712 A

  However, in such a rotary blade 21, the concave portion formed on the back surface of the mounting flat portion 23 protects the mounting bolts for mounting the brush cutter and suppresses head wear and the like. However, the following problems were clarified in the mowing work for weeds and the like.

  That is, the flat blade portion 26 is parallel to the mounting flat portion 23 and the tip 27 is brazed and fixed to the tip thereof, and the tip of the rake face of the tip 27 is located at the outermost peripheral edge of the rotary blade 21 (base metal 22). In a normal mowing operation, as shown by a two-dot chain line in FIG. 6, the rotary blade 21 is slightly inclined with respect to the ground 14 and the tip 27 is directed toward the root of weeds or the like. Therefore, the tip 27 easily comes into contact with the ground 14 first, and chipping of the tip 27 occurs due to contact with pebbles or the like on the ground 14, and the cutting ability of the rotary blade 21 is likely to be lowered.

  At the same time, when weeding the weeds and the like neatly, it is necessary to make the positional relationship between the tip 27 and the ground 14 at the position of the handle of the brush cutter, that is, the position of the operator's arm. In practice, it is practically difficult for the worker to always keep the arm position in the same state, which increases the work burden on the worker and also inferior the mowing work efficiency.

  The present invention has been made in view of such circumstances. The purpose of the present invention is to stabilize the contact position of the blade portion with respect to the ground while smoothly exchanging the rotary blade with respect to the brush cutter. It is an object of the present invention to provide a rotary blade for brush cutting that can suppress chipping and the like and extend the life of the rotary blade and reduce the work burden on the operator and improve the work efficiency.

  In order to achieve such an object, the invention according to claim 1 of the present invention includes a mounting flat portion in which a mounting hole for a brush cutter is formed in a central portion, and an annular shape on the outer peripheral side of the mounting flat portion. A blade portion having a blade edge formed on the outer peripheral edge thereof, and the blade portion is formed in a curved shape that bulges from the outer peripheral edge of the mounting flat portion to the blade edge on the back surface side of the base metal, The depth dimension of the deepest part is set larger than the projecting dimension of the mounting bolt when the brush cutter is mounted on the surface side of the mounting flat part with the mounting bolt, and the cutting edge is predetermined from the mounting flat part. It is located in the back surface side of a dimension metal plate.

  Further, in the invention according to claim 2, the blade portion has an inclined surface portion inclined in a planar shape outward from the outer peripheral edge of the mounting flat portion, and a predetermined radius is outward from the outer peripheral edge of the inclined surface portion. And having a curved surface provided in a curved surface state.

  According to the first aspect of the present invention, the blade portion formed on the outer peripheral edge of the mounting flat portion is formed in a curved shape that bulges to the back side of the base metal, and the depth dimension of the deepest portion thereof. Is set larger than the protruding dimension of the mounting bolt, and the cutting edge is located on the back side of the base metal with a predetermined dimension from the position of the mounting flat part, so that the head of the mounting bolt can be protected with the bulging blade part, The cutting blade can be brushed while making the replacement of the rotary blade to the brush cutter smooth, while the deepest part of the blade is in light contact with the ground, and the life of the rotary blade can be extended by suppressing chipping etc. At the same time, it is possible to reduce the work burden on the worker and improve the work efficiency.

  According to the invention described in claim 2, in addition to the effect of the invention described in claim 1, the blade portion has an inclined surface portion inclined in a flat shape outward from the outer peripheral edge of the mounting flat portion, and the inclination. Since it is formed with a curved surface provided in a curved state with a rounded outward from the outer peripheral edge of the surface portion, a curved shape is formed on the outer peripheral side of the flat inclined surface portion by annealing or press molding of the base metal The blade portion can be molded, and the blade portion having a predetermined shape can be easily formed, and the manufacturing cost of the rotary blade can be reduced.

  The top view which shows the rotary blade for brush cutting concerning this invention   The AA line arrow figure   Enlarged view of the main part of Fig. 2   The figure which shows the adhering state of the same chip   Illustration of the manufacturing method   Plan view showing a conventional rotary blade for brush cutting

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.
1 to 5 show an embodiment of a rotary blade for brush cutting according to the present invention. As shown in FIGS. 1 and 2, the brushing rotary blade 1 (referred to as the rotary blade 1) is formed in a disc shape as a whole, and a mounting flat portion 3 is formed at the center portion. The base metal 2 in which the blade part 4 was formed in the outer peripheral side is included.

  The mounting flat part 3 is formed in an annular shape in a plan view (surface view) by forming a circular mounting hole 5 at the center position, and on the surface side of the mounting flat part 3, a brush cutter (not shown) is formed. The mounting portion is adapted to be mounted by mounting bolts 6 (see FIG. 3). In addition, the blade portion 4 includes a flat inclined surface portion 4a extending outwardly from the outer peripheral edge of the mounting flat portion 3 and a rounded radius R described later on the outer peripheral edge of the inclined surface portion 4a. The curved surface portion 4b is provided and extended. A recessed portion 7 for accommodating the head of the mounting bolt 6 is formed on the back surface side of the mounting flat portion 3 by the inclined surface portion 4 a of the blade portion 4.

  Further, as shown in FIG. 3, the curved surface portion 4 b of the blade portion 4 is extended and provided with a connecting portion 8 having the radius R (rear surface side) = 4 mm on the outer peripheral edge of the inclined surface portion 4 a. The shape is curved from 8 to the tip 9 which is the tip of the tip, and the tip 9 is set to be closest to the mounting flat portion 3 side. Thereby, the curved surface portion 4b is formed in an annular shape and a substantially conical shape in plan view, and the blade portion 4 positioned on the outer peripheral side of the mounting flat portion 3 of the disk-shaped base metal 2 is mounted flat on the tip 9 side as a whole. It has a substantially dish shape that is warped by a predetermined amount in the direction of part 3.

  Further, the deepest portion S that is recessed (bulged) in the direction of the most anti-mounting flat portion 3 of the blade portion 4 is the connecting portion 8 of the inclined surface portion 4a and the curved surface portion 4b, and the connecting portion 8 and the mounting flat portion 3 When the height dimension h1 (for example, h1 = 19 mm) of the connecting portion 8 (the deepest portion S) shown in FIG. The height (projection) dimension h2 of the head of the bolt 6 is set to be larger (h1> h2).

  Further, the height dimension h3 of the tip 9 provided at the tip of the curved surface portion 4b with respect to the deepest portion S (connecting portion 8) is, for example, 14 mm or less (preferably 5 to 14 mm) when the diameter of the rotary blade 1 is 255 mm. When the diameter of the rotary blade 1 is 230 mm, it is set to 10 mm or less (preferably 4 to 10 mm). As shown in FIG. 1, the circular curved surface portion 4 b of the blade portion 4 is provided with a plurality of circular lightweight holes 10 in a row of annular shapes (for example, 16 lightweight holes 10 having a diameter of 20 mm). ing.

  The tip 9 provided at the tip of the blade portion 4 is formed of, for example, a cemented carbide tip, and as shown in FIG. 1, rotation of the blade chamber 12 formed at regular intervals on the outer peripheral edge of the blade portion 4 of the base metal 2. Each is fixed to the chip fixing portion 13 on the rear side in the direction A by brazing. As shown in FIG. 4A, each chip 9 includes a rake face 9a having a predetermined angle with respect to the rotation direction A of the base metal 2, and a tip face 9b connected to the tip of the rake face 9a. Etc., and the rake faces 9a of all the chips 9 are fixed so as to be in the same direction (the same state) with respect to the rotation direction A of the base metal 2. When the tip 9 is a rake face 9a having no angle, each tip 9 is fixed by brazing to the tip fixing portion 13 of the blade portion 4 as shown in FIG. 4B.

  Next, an example of the manufacturing method of such a rotary blade 1 is demonstrated based on FIG. First, a raw material such as a carbon steel plate is pressed to process a base metal material having the blade chamber 12 and the chip fixing portion 13, and the mounting flat portion 3 and the blade portion 4 are processed by pressing the base metal material. The base metal 2 having the shape is molded (K01). The base metal 2 molded at this time has the blade portion 4 in parallel with the mounting flat portion 3. Then, the base metal 2 is set to a hardness of, for example, about HRC45 by the first heat treatment (K02) of quenching and annealing by induction heating while using a predetermined die. The warp and distortion of the base metal 2 are removed by this first heat treatment.

  When the base metal 2 is set to a predetermined hardness by the first heat treatment, the second heat treatment is performed by the same method as the first heat treatment, and the hardness of the base metal 2 is set to about HRC30, for example. The curved surface portion 4b is formed on the blade portion 4 of the base metal 2 (K03) by using a die having a shape corresponding to the curved surface portion 4b different from the above. During the second heat treatment and curved surface molding, the hardness of the base metal 2 is set to a low value, and a predetermined number of lightweight holes 10 are formed in the curved surface portion 4b, so that the curved surface portion 4b can be favorably bent. In addition, it is possible to obtain a stable curved surface state in the blade portion 4 by suppressing the restoring force of the curved surface portion 4b.

  And the rotary blade 1 manufactured in this way is rotatably attached to the brush cutter by attaching the mounting flat portion 3 to the mounting portion of the brush cutter with the mounting bolt 6. At the time of attachment to the brush cutter, the head of the attachment bolt 6 is accommodated in the recess 7 on the back surface side of the attachment flat portion 3, and the head is outside the blade portion 4, that is, the ground 14 (see FIG. 3). Since it does not protrude (expose) to the side, the head of the mounting bolt 6 does not come into contact with the ground 14 or the like during the brushing operation, and wear is prevented.

  Further, when performing the brushing work, the blade portion 4 of the rotary blade 1 is directed toward the roots of weeds and the like in a slightly oblique state with respect to the ground 14 as shown by a two-dot chain line in FIG. Since the tip 9 is warped in the direction of the mounting flat portion 3, the back surface of the curved surface portion 4 b of the blade portion 4 is first in contact with the ground 14, and the tip 9 is prevented from contacting the ground 14 first. Can do. As a result, chipping of the chip 9 is suppressed, and the operator only needs to perform the brushing operation as if the back surface of the curved surface portion 4b of the blade portion 4 is in light contact with the ground surface 14.

  Thus, according to the rotary blade 1, the blade portion 4 formed on the outer peripheral edge of the mounting flat portion 3 is formed in a curved shape that bulges to the back surface side of the base metal 2, and the depth of the deepest portion S thereof. Since the dimension h1 is set larger than the protruding dimension h2 of the mounting bolt 6 and the tip 9 is positioned on the back side of the base metal 2 with a predetermined dimension from the position of the mounting flat part 3, it is formed by the bulging blade part 4. The recessed portion 7 can protect the head of the mounting bolt 6, smoothly perform the replacement operation of the rotary blade 1 with respect to the brush cutter, and can work while making the deepest portion S of the blade portion 4 lightly contact the ground 14. The chip 9 can be prevented from being chipped and the life of the rotary blade 1 can be extended, and the work efficiency for the operator can be reduced and the work efficiency can be improved.

  Further, the blade portion 4 is provided in a curved surface state having an inclined surface portion 4a inclined in a planar shape outward from the outer peripheral edge of the mounting flat portion 3 and a rounded radius R outward from the outer peripheral edge of the inclined surface portion 4a. The curved curved surface portion 4b can be formed on the outer side of the flat inclined surface portion 4a by annealing the base metal 2 and press molding or the like, so that the blade portion 4 having a predetermined curved surface shape is formed. It can be formed easily and the manufacturing cost of the rotary blade 1 can be reduced.

  In addition, the cutting edge of the blade portion 4 is composed of a large number of tips 9, and the tip of the rake face 9a of each tip 9 is set in the same direction rather than alternately with respect to the rotational direction A as in the prior art. Even when pebbles or the like on the ground 14 come into contact with the chip 9 during the mowing work, the scattering direction can be set to the anti-worker direction, and the work safety due to the blade 4 being warped toward the worker side. As a result, the rotary blade 1 having excellent sharpness and usability can be obtained, and the work efficiency of the mowing work can be further improved. Moreover, since the blade part 4 has the curved surface part 4b, the rigidity of the rotary blade 1 itself can be increased, the rotational runout of the rotary blade 1 during the brush cutting work can be prevented, and a safer brush cutting work can be performed. It can be carried out.

  Furthermore, the base metal 2 is provided with the mounting flat part 3 and the blade part 4, and when the depth dimension h1 of the deepest part S of the blade part 4 is attached to the brush cutter with the mounting bolt 6 when the mounting flat part 3 is mounted. Since it is set larger than the protruding dimension h2 of the bolt 6, the head of the mounting bolt 6 can be reliably accommodated in the recess 7 on the back surface of the mounting flat portion 3, and the head can be prevented from being worn or deformed. . As a result, a member such as a dedicated cover for protecting the mounting bolt 6 is not required, and the mounting bolt 6 can be favorably rotated when the rotary blade 1 is attached to or removed from the brush cutter. Exchange work can be performed smoothly.

  In the embodiment, the blade portion 4 is formed by the inclined surface portion 4a and the curved surface portion 4b, and the connecting portion 8 between the inclined surface portion 4a and the curved surface portion 4b is formed to be the deepest portion S. For example, as shown by a two-dot chain line in FIG. 3, the inclined surface portion 4 a may be omitted and the curved surface portion 4 b may be provided continuously from the outer peripheral edge of the mounting flat portion 3. In this case, the deepest portion S is located on the outer peripheral side from the position of the connecting portion 8. Further, the shape of the curved surface portion 4b itself is not limited to the illustrated example. For example, the curved surface portion 4b is combined with an appropriate flat surface portion, and the chip 9 is located on the mounting flat portion 3 side and has an appropriate curved shape as a whole. Can be adopted.

  Moreover, in the said embodiment, although the case where the direction (state) of the rake face 9a of the chip | tip 9 was all the same with respect to the rotation direction of the base metal 2 was demonstrated, the direction of the rake face 9a is alternated like the past. You may make it set to. Furthermore, in the above-described embodiment, the case where the rotary blade 1 is a tip saw in which the tip 9 as the blade tip is brazed and fixed to the tip of the blade portion 4 has been described. However, the tip-shaped blade tip is integrally formed on the base metal 2 itself. The rotary blade 1 may be used, and the lightweight holes 10 are not limited to the configuration in which one row is provided in an annular shape, but may be configured in a plurality of rows.

  INDUSTRIAL APPLICABILITY The present invention can be used for all rotary blades for brush cutting that have a cutting edge provided at the tip of a blade portion of a disk-shaped base metal and are used for cutting grass such as weeds.

  DESCRIPTION OF SYMBOLS 1 ... Rotary blade for brush cutting, 2 ... Base metal, 3 ... Mounting flat part, 4 ... Blade part, 4a ... Inclined surface part, 4b ... Curved surface part, 5 ... Mounting hole, 6 ... Mounting bolt, 7 ... Recess, 8 ... Connecting part, 9 ... Chip, 9a ... Rake face, 7b ... Tip face, 10 ... Lightweight hole, 12 ... blade chamber, 13 ... tip fixing part, 14 ... ground, S ... deepest part, R ... round.

Claims (2)

A mounting flat portion in which a mounting hole to the brush cutter is formed in the central portion, and a blade portion formed in an annular shape on the outer peripheral side of the mounting flat portion and provided with a blade edge on the outer peripheral edge thereof,
The blade portion is formed in a curved shape that bulges from the outer peripheral edge of the mounting flat portion to the blade edge on the back surface side of the base metal, and the depth dimension of the deepest portion is on the surface side of the mounting flat portion. Rotation for mowing, characterized in that, when the dispenser is mounted with a mounting bolt, the cutting edge is set to be larger than the protruding dimension of the mounting bolt, and the cutting edge is positioned on the back side of the base metal with a predetermined dimension from the mounting flat portion. blade.   The blade portion is an inclined surface portion that is inclined in a flat shape outward from the outer peripheral edge of the mounting flat portion, and a curved surface portion that is provided in a curved state with a predetermined radius outward from the outer peripheral edge of the inclined surface portion. The rotary blade for brush cutting according to claim 1, wherein

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