JP2011055823A - Rotary blade for mowing grass, and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary blade for mowing grass which is capable of satisfactory grasping a sense of distance to the ground surface, prolonging life of the rotary blade by preventing chipping of the blade edge, etc., and getting a sufficient mowing performance by suppressing vibration etc., and excellent in safety, and to provide a method for producing the same. <P>SOLUTION: The rotary blade for mowing includes a disk shaped base metal with a mounting hole formed on the center and having many tooth edges installed on the outer periphery with a predetermined interval, and is integrally formed with a plurality of discontinuous recesses recessing on the back surface side of the base metal on equal positions of a concentric circular between the mounting hole of the base metal and the tooth edge, and the part excluding the recesses of the base metal is formed on the same flat plane as the flange surface the mower. The recess is formed in a shape close to a hemispherical recess, and set on the outer peripheral edge side than the intermediate position of the radius of the base metal. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rotary blade for mowing used when cutting weeds, weeds, and the like with a cutting edge provided on the outer peripheral edge of a base metal, and a method for manufacturing the same.

  In general, most of the mowers for mowing use a rotating blade that rotates counterclockwise and swings the rotating blade from right to left, so that weeds are removed with the sharpness and rotational force of the blade. It has become. Since the cutting edge of the rotary blade is put in the weeds at the time of the mowing work, it is difficult to make an appropriate interval between the cutting edge and the root of the weeds. Further, the rotary blade for mowing functions as a cutting edge for cutting away weeds and the like by cutting a cemented carbide chip onto a heat-treated steel plate, and the cutting edge cuts only the weed. As long as you are working, wear is low and slowing down is slow. However, in an actual mowing operation, weeds cannot be eradicated by mowing, but workers often aim for grazing on the ground so that mowing from near the root of the weeds.

  The mowing work behavior with such a thought is that the left hand inevitably falls down, the distance between the blade edge and the ground is not understood, and the work is based on the operator's sense, The cutting edge easily comes into contact with the ground. In addition, since the cutting edge entering the weed is invisible to the operator and it is left to the operator to determine whether the cutting edge hits the ground, the chip as the cutting edge collides with pebbles on the ground. Then the chip is easily missing. In addition, when there are many small pebbles on the work site, such as a slope or riverbed slope boundary, the operator should be careful not to lift the rotary blade as much as possible and hit the pebbles etc. In this case, the sense of distance from the ground often tends to be distorted, and the cutting edge is brought into contact with the ground such as a paved surface or applied to a pebble or the like, and the life of the rotary blade is shortened by lacking the cutting edge.

  Therefore, in order to eliminate such problems, a mowing rotary blade 101 (referred to as the rotary blade 101) as shown in FIGS. 7 and 8 is used. In the rotary blade 101, a large number of galettes 106 and tips 108 (blade tips) are provided at regular intervals along the circumferential direction on the outer peripheral edge portion 102a of a base metal 102 made of a steel plate, and the tips 108 are formed on the base metal 102. Each of the chip fixing portions 107 is fixed by brazing. In addition, a mounting hole 104 to the brush cutter 5 (see FIG. 9) is formed at the center position of the base metal 102, and a number of lightweight holes 103 are formed to reduce the weight of the rotary blade 101. Yes. Further, on the outer side of the attachment hole 104 of the base metal 102, a concavity 109 that is recessed concentrically (annularly) is formed on the back surface side (the lower surface side in FIG. 8) of the base metal 102. In addition, the rotary blade for mowing provided with the chip | tip is disclosed by patent document 1, for example.

Japanese Patent No. 4168164

  However, in such a rotating blade 101, a number of light-weight holes 103 are provided in the base metal 102 for weight reduction, and the chips 108 are brazed and fixed to the heat-treated base metal 102, respectively, and then polished, and then concentrically formed by pressing. Since the dent 109 is formed in a shape, as shown in FIG. 9, the distance from the ground 11 can be measured by the height dimension of the dent 109, and the cutting edge (tip 108) is prevented from touching the ground 11 directly. Give me. However, due to the characteristics of processing the recess 109 by press working, the blade edge is at an angle with respect to the mounting surface 10a (flange surface) of the flange 10 for mounting the brush cutter 5, that is, the blade edge portion is in the outer circumferential upward direction. It will be in a state of warping. As a result, the cutting edge of the rotary blade 101 is inclined so as not to enter a substantially right angle with respect to the weeds 12 to be cut off, and the weeds 12 are chopped without being cut. It is difficult.

  Further, since the brush cutter 5 to which the rotary blade 101 is attached is used at a high speed (use range 4500-6500 R / M), a large centrifugal force acts on the blade edge, and the blade edge is not flat but warped. In this case, the rotary blade 101 is easily shaken and difficult to work. This is because as the number of rotations of the brush cutter 5 is increased so as to obtain sufficient brush cutting performance, the vibration becomes more noticeable and the work becomes more difficult. Furthermore, since the lightweight hole 103 is provided in the dent 109 portion, pebbles or the like that have entered the lightweight hole 103 during operation may be skipped, which is inferior in terms of safety in mowing work. In addition, in the case of a work site such as a dredging or a riverbed, the base metal 102 is likely to be worn, so that the strength of the base metal 102 is reduced because the entire concentric recess 109 is thinned by wear. In the case of the brush cutter 5 used at a high speed rotation, the above-described vibration becomes more noticeable, and there is a possibility that an unexpected situation may occur because the rotary blade 101 is divided at the recess 109 portion.

  The present invention has been made in view of such circumstances, and its purpose is to be able to capture a good sense of distance from the ground, to prevent chipping of the blade edge and extend the life of the rotary blade. Another object of the present invention is to provide a rotary blade for mowing that is capable of suppressing vibration and obtaining sufficient cutting performance and is excellent in safety. Another object of the present invention is to provide a method for manufacturing a rotary blade for mowing that can easily manufacture a rotary blade of the above-mentioned purpose and that can easily obtain an inexpensive and high-quality rotary blade. It is in.

  In order to achieve such an object, the invention according to claim 1 of the present invention has a large number of cutting edges on the outer peripheral edge of a disk-shaped base metal having a mounting hole for a brush cutter at the center. A rotary blade for mowing provided at intervals, and a plurality of discontinuous recesses recessed on the back side of the base metal are integrally formed in concentric uniform positions between the mounting hole of the base metal and the cutting edge. In addition, the portion excluding the recessed portion of the base metal is formed by a plane that is flush with the flange surface of the brush cutter.

  The invention according to claim 2 is characterized in that the recess is formed as a substantially hemispherical recess. Furthermore, the invention described in claim 3 is characterized in that the dent is provided closer to the outer peripheral edge side than the intermediate position of the radius of the base metal.

  According to a fourth aspect of the present invention, there is provided a rotary blade for mowing in which a large number of cutting edges are provided at predetermined intervals on the outer peripheral edge portion of a disk-shaped base metal having a mounting hole for a brush cutter at the center. A step of integrally forming a plurality of discontinuous recesses recessed on the back side of the base metal at concentric equal positions between the mounting hole and the blade edge of the base metal material, It comprises a step of heat-treating the base metal material obtained in the step and a step of processing the cutting edge after the step.

  Further, in the invention according to claim 5, the heat treatment step includes a step of quenching the base metal material using a dedicated jig, and a step of tempering the base metal material after the quenching. It is characterized by that.

  According to the invention described in claim 1 of the present invention, a plurality of discontinuous dents recessed on the back side of the base metal between the base metal mounting hole and the cutting edge are integrated in a concentric uniform position. Since the portion excluding the recessed portion of the base metal is formed by a flat surface that is flush with the flange surface of the brush cutter, it is possible to obtain a good sense of distance from the ground by the recess, and the cutting edge The cutting edge can be prevented and the life of the rotary blade can be extended, and the cutting edge of the same surface as the base metal can be used to suppress the vibration of the base metal, and the cutting edge can be put at right angles to weeds etc. Payment performance can be obtained. Further, the discontinuous dent can prevent an unexpected situation when the dent is worn, and the safety of the rotary blade for mowing can be improved.

  Further, according to the invention described in claim 2, in addition to the effect of the invention described in claim 1, since the dent is formed of a substantially hemispherical dent, the contact surface with the dent pebble or the like can be reduced. Thus, scattering of pebbles and the like can be reliably prevented, and the inner diameter of the recess can be set to a predetermined value, so that a rotary blade that can be used at various work sites can be easily handled.

  Furthermore, according to the invention described in claim 3, in addition to the effect of the invention described in claim 1 or 2, since the recess is provided closer to the outer peripheral edge side than the intermediate position of the radius of the base metal, The distance between the blade edge and the blade edge can be set optimally so that the blade edge can be surely applied to the root of the weed, and the efficiency of the mowing work can be improved.

  According to the invention of claim 4, a plurality of discontinuous recesses recessed on the back side of the base metal are integrally formed at concentric uniform positions between the mounting hole of the base metal material and the cutting edge. A process of heat-treating the base metal material, and a process of processing the blade edge, so that the heat treatment of the base metal material and the processing of the blade edge can be performed after forming the recess at the stage of the base metal material. In addition, the formation of the recess, the heat treatment and the cutting edge processing can be easily performed, and the rotary blade according to claim 1 can be manufactured at low cost and with high quality.

  According to the invention described in claim 5, in addition to the effect of the invention described in claim 4, the heat treatment step includes a step of quenching the base metal material using a dedicated jig and a base metal after quenching. The process of tempering the material, so that the internal stress in the dents can be well distributed, and the flatness of the base metal can be ensured by using a dedicated jig, resulting in higher quality. A rotating blade can be obtained.

  The top view which shows one Embodiment of the rotary blade for mowing concerning this invention   Sectional view along the AA line of FIG.   Explanatory drawing of the mounting state to the brush cutter   Process drawing which shows an example of the manufacturing method of the rotary blade for the same mowing   Top view of the dedicated jig   The top view which shows the modification of the rotary blade for the same mowing   Plan view showing a conventional rotary blade for mowing   Sectional drawing along the BB line of FIG.   Explanatory drawing of the mounting state to the brush cutter

The best mode for carrying out the present invention will be described below in detail with reference to the drawings.
1 to 5 show an embodiment of a rotary blade for mowing according to the present invention. As shown in FIG. 1, the rotary blade 1 for mowing (referred to as the rotary blade 1) is disk-shaped and has a number of lightweight holes 3 for weight reduction, and is centered on the brush cutter 5 (see FIG. 3). The base metal 2 having the mounting holes 4 is formed.

  A large number of galettes 6 (blade chambers) and chip fixing portions 7 are formed at regular intervals on the outer peripheral edge portion 2a of the base metal 2, and each chip fixing portion 6 is made of a cemented carbide formed in the same shape. Chips 8 as cutting edges are fixed by brazing. Further, between the mounting hole 4 and the tip 8 (cutting edge) of the base metal 2, there are six in a circumferentially discontinuous state, closer to the outer peripheral edge 2 a side than the intermediate position of the base metal 2 radius. The recess 9 is integrally formed.

  The dent 9 is formed in a substantially hemispherical shape in consideration of impact resistance and workability, and its curvature is set to about 1/4 to 1/2 of the total spherical outer diameter, as shown in FIG. For example, when the diameter of the base metal 2 is 230 mm, the base metal 2 is provided in a state where the dimension h1 is recessed by 6.0 mm on the back surface side (the lower surface side in FIG. 2). In addition, the recess 9 is set such that the inner diameter is φ = 30 mm, the outer radius is R1 = 2.95 mm, the inner radius is R2 = 21.75 mm, and the six recesses 9 are evenly concentrically. The rotary blade 1 is set to be able to rotate in a well-balanced manner by reducing the eccentric weight. In addition, as shown in FIGS. 1-3, all the site | parts except the said dent 9 of the base metal 2 are formed as the same surface.

  As shown in FIG. 3, the mounting hole 4 of the rotary blade 1 is attached to the brush cutter 5 by a flange 10. At this time, the lower surface 10b of the flange 10 is set so as not to come into contact with the ground surface 11 during the brushing operation, depending on the setting of the height h1 of the recess 9 and the distance of the base metal 2 of the recess 9 from the chip 8. If the height h1 of the dent 9 is too high or the position of the dent 9 is too close to the tip 8, the cutting edge (tip 8) of the rotary blade 1 may not reach the root of the weed 12 and the height h1 or tip The distance from 8 is preferably set so that the lower surface 10 b of the flange 10 is slightly lifted from the ground 11.

  Further, the mounting surface 10a (flange surface) of the flange 10 and the outer peripheral edge 2a excluding the recess 9 of the rotary blade 1 and the outer portion of the mounting hole 4 are set on the same plane as described above. Thus, when the weed 12 is trimmed with the brush cutter 5 to which the rotary blade 1 is attached, the cutting edge of the rotary blade 1 enters the root of the weed 12 at a substantially right angle while the dent 9 is in contact with the ground 11. It has become. Moreover, since the dent 9 is formed in a substantially hemispherical shape and the contact surface with the ground surface 11 is a curved surface, the contact surface with the pebbles on the ground surface 11 becomes small, and the pebbles and the like are scattered during the brushing operation. Can be prevented.

  Next, an example of a method for manufacturing the rotary blade 1 will be described with reference to FIGS. As shown in FIG. 4, the rotary blade 1 first presses (draws) a disk-shaped base metal material made of a steel plate to process the depression 9 in the base metal material (K1). The base metal material in which the recess 9 is formed by this processing is quenched (K2) at a predetermined temperature, and then tempered (K3) at a predetermined temperature. During the heat treatment by quenching and tempering, the flat jig 13 (die) shown in FIG. 5A is brought into contact with the surface side of the base metal material, and the back side of the base metal material is shown in FIG. 5B. This is performed by bringing a jig 14 (mold) provided with an opening 14 a into contact with a position corresponding to the recess 9.

  By the heat treatment using the pair of jigs 13 and 14, the flatness of the portion other than the recess 9 of the base metal 2 is secured, and the internal stress of the recess 9 is dispersed. Then, the tip 8 is brazed and fixed to the chip fixing recess 7 of the outer peripheral edge 2a of the base metal material thus heat-treated, and the cutting edge processing (K4) for polishing the chip 8 is performed. Thereby, the rotary blade 1 is manufactured. By performing this cutting edge processing K4 in the final step, the accuracy of the tip 8 (cutting edge) is linked to the sharpness of the rotary blade 1. That is, the rotary blade 1 forms (processes) the recess 9 at the stage of the base metal material, heats the base metal material on which the recess 9 is formed, and then performs cutting edge processing. It is no longer necessary to form a dent by machining the product after the cutting edge processing, and the dent 9 can be easily processed.

  The shape of the recess 9 provided in the base metal 2 is not limited to the above example. For example, as shown in FIG. 6, when the diameter of the base metal 2 is 255 mm, the inner diameter of the recess 9 is φ1. = 34 mm. Further, the number of the recesses 9 and the form such as the curvature are set in accordance with the use form of the rotary blade 1. That is, for example, in the case of the rotary blade 1 used in Tabata, the curvature of the dent 9 is increased and the number thereof is reduced, and if there is a stone or the like, the rotary blade 1 is lightly jumped up by the impact. Inform the operator that something lacking the blade edge (stones, etc.) is hidden, and call attention to the work.

  Further, in the case of the rotary blade 1 that is continuous and used in a place with a lot of pebbles or the like, the dents 9 that are contact portions are worn abruptly, and therefore, a large number of dents 9 having a small curvature are arranged in a concentric manner. In this case, even if the dent 9 is worn, finally, the dent 9 portion has the same form as a general rotary blade that functions as a lightweight hole. As a result, unlike the conventional example, the base metal shape that promotes the wear of the dent 101 portion is not formed, and all the dents 9 are not worn at the same time, and the lightweight hole 103 of the dent 109 portion is not formed. The pebbles will not fly away in contact with the ground 11, and the safety of the brushing work by the rotary blade 1 will not be significantly impaired.

  As described above, according to the rotary blade 1, the discontinuous plurality of recesses 9 that are recessed on the back surface side of the base metal 2 between the mounting hole 4 of the base metal 2 and the chip 8 are arranged in a concentric uniform position. Therefore, the dent 9 makes it possible to capture a sense of distance from the ground 11 and to suppress chipping of the tip 8, thereby extending the life of the rotary blade 1. In particular, when the dent 9 hits a stone or the like on the ground 11 during the mowing operation, the base metal 2 is lifted up by an impact, so that the operator can work while sensing invisible stones or the like due to weeds. The chip 8 can be prevented from being chipped, and the life of the rotary blade 1 can be further extended.

  Further, since the tip 8 is fixed on the same surface as the base metal 2 of the rotary blade 1, the vibration of the base metal 2 at the time of the brushing operation can be suppressed and the operator is not burdened by the vibration. The cutting operation can be performed satisfactorily, and the tip 8 can be inserted into the root portion of the weeds 12 and the like at a substantially right angle without slashing the weeds 12 like the conventional rotary blade 101. A sufficient cutting performance for the rotary blade 1 can be easily obtained, for example, the weeds 12 can be cleaned clearly.

  Further, since the recess 9 is formed of a substantially hemispherical discontinuous recess 9 and the surface excluding the recess 9 is the same surface as the mounting surface 10a of the flange 10 of the brush cutter 5, It is possible to improve the safety of the rotary blade 1 by making the contact surface as small as possible so as to surely prevent scattering of pebbles and the like and to prevent the occurrence of unforeseen circumstances when the dent 9 is worn. it can. Further, by setting the radius R1 and R2 of the substantially hemispherical recess 9 to a predetermined value, the contact of the recess 9 with the ground 11 becomes smooth, and the sense of distance between the chip 8 and the ground 11 can be stably captured. At the same time, since the recess 9 is provided closer to the outer peripheral edge 2 a side than the intermediate position of the radius of the base metal 2, the distance between the recess 9 and the tip 8 is set optimally to ensure that the tip 8 is at the root of the weed 12. This makes it possible to improve the efficiency of the mowing work.

  Moreover, according to the manufacturing method of the rotary blade 1 of the present invention, a step of integrally forming a plurality of discontinuous recesses 9 at the concentric uniform positions between the mounting hole 4 of the base metal material and the chip 8; A step of heat-treating the base metal material and a step of processing the cutting edge. After the recess 9 is formed at the stage of the base metal material, the base metal material is heat-treated and the chip 8 is processed. Heat treatment and cutting edge processing can be easily performed, and the rotary blade 1 can be manufactured inexpensively and with high quality.

  In particular, the heat treatment step includes a step of quenching the base metal material using the jigs 13 and 14 and a step of tempering the base metal material after quenching. In this way, the internal stress in the recess 9 can be well dispersed while ensuring a good flatness, and the rotary blade 1 with higher quality can be easily manufactured. In addition, since the cutting edge processing consisting of brazing and polishing of the tip 8 is the final step, the processing accuracy of the tip 8 can be linked to the sharpness of the rotary blade 1, and the rotary blade 1 with excellent sharpness can be manufactured. become. Moreover, since the dent 9 is formed by pressing the base metal material, the inner diameter of the dent 9 can be easily set to a predetermined dimension, and the rotary blade 1 corresponding to various work sites can be easily obtained. it can.

  In the above embodiment, the number and shape of the chip fixing portions 7 of the base metal 2, the shape of the chip 8, the size and position of the lightweight hole 3, the shape and number of the recesses 9, the shape of the jigs 13 and 14, etc. For example, the light-weight hole 3 is formed as shown in FIG. 6, for example, and the R1 and R2 of the substantially hemispherical recess 9 are increased on the outer peripheral edge side and the mounting hole side, for example, on the outer peripheral edge side. An appropriate configuration can be employed without departing from the gist of the present invention, such as making it different or making the shape of the recess 9 itself a semi-elliptical shape.

  The present invention can be applied not only to a rotary blade in which a tip as a blade tip is brazed and fixed to the outer peripheral edge of the base metal but also to a rotary blade for mowing in which a blade tip corresponding to the tip is integrally formed on the base metal.

  DESCRIPTION OF SYMBOLS 1 ... Tip saw, 2 ... Base metal, 2a ... Outer peripheral edge part, 3 ... Lightweight hole, 4 ... Mounting hole, 5 ... Brush cutter, 6 ... Galette (blade Chamber), 7 ... tip fixing part, 8 ... tip (blade edge), 9 ... dent, 10 ... flange, 10a ... mounting surface (flange surface), 10b ... bottom surface, 11 ... ground, 12 ... weed, 13, 14 ... jig, 14a ... opening.

Claims (5)

A rotary blade for mowing provided with a large number of cutting edges at predetermined intervals on the outer peripheral edge of a disc-shaped base metal in which a mounting hole to a brush cutter is formed at the center,
Between the mounting hole of the base metal and the cutting edge, a plurality of discontinuous recesses recessed on the back side of the base metal are integrally formed at concentric and equal positions, and a portion excluding the concave portion of the base metal Is formed on a plane that is flush with the flange surface of the brush cutter.   The rotary blade for mowing according to claim 1, wherein the recess is formed as a substantially hemispherical recess.   3. The rotary blade for mowing according to claim 1, wherein the dent is provided closer to the outer peripheral edge side than an intermediate position of a base metal radius. 4. A method for manufacturing a rotary blade for mowing in which a large number of cutting edges are provided at predetermined intervals on the outer peripheral edge of a disk-shaped base metal in which a mounting hole to a brush cutter is formed at the center,
A step of integrally forming a plurality of discontinuous recesses recessed on the back side of the base metal between the mounting hole and the blade edge of the base metal material in a concentric uniform position, and the base metal obtained in the step The manufacturing method of the rotary blade for mowing characterized by including the process of heat-processing a raw material, and the process of processing the said blade edge | tip after this process.   5. The heat treatment step according to claim 4, wherein the heat treatment step includes a step of quenching the base metal material using a dedicated jig and a step of tempering the base metal material after the quenching. A method for manufacturing a rotary blade for mowing.

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