Mower Cutter Blade

Abstract

To provide a desired cutter blade capable of suppressing rotation resistance with simple machining.SOLUTION: The cutter blade 20 arranged inside a housing of a mower and rotation driven about a vertical rotation axis includes a blade body 40, a cutting part 51 arranged to at least a part of a front end in the rotation direction of the blade body 40, and a wind creating part 52 arranged to at least a part of a rear end in the rotation direction of the blade body 40 and extending upward than the cutting part 51. The thickness of the rear end in the rotation direction of the wind creating part 52 is thinner than the other part of the wind creating part 52.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a cutter blade for a mower that is driven to rotate about an axis extending vertically within a housing. [Background technology]

[0002] The above-mentioned cutter blade includes a blade section and a wind raising section, and the blade section cuts grass, and the wind raising section generates wind in the housing, which makes the grass stand up so that it is easier to cut, and transports the cut grass. The wind raising section is formed by bending the cutter blade body, which has a thickness, upward. By increasing the size of the wind raising section, the amount of wind generated can be increased, and the ability to stand up the grass and transport the cut grass can be improved. On the other hand, in this type of cutter blade, negative pressure may be generated on the lower surface side of the wind raising section (the rear side in the rotation direction of the cutter blade). When negative pressure is generated, a vortex is generated in the negative pressure part, which causes the air flow to become turbulent, causing an increase in the rotation resistance of the cutter blade. The larger the wind raising section, the greater the turbulence of the air flow caused by the negative pressure, and the greater the rotation resistance tends to be.

[0003] Conventionally, cutter blades described in, for example, cited documents 1 and 2 are used as configurations for preventing negative pressure from being generated on the back side of the wind generating part. That is, patent documents 1 and 2 disclose cutter blades in which holes are provided in the wind generating part, connecting the upper side (the front side in the direction of rotation of the cutter blade) and the lower side of the wind generating part. In these cutter blades, the air flows from the front side to the back side of the wind generating part through the holes formed in the wind generating part, thereby enlarging the wind generating part and eliminating noise associated with negative pressure. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2002-315418 A [Patent Document 2] JP 2005-312396 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the cutter blades described in Patent Documents 1 and 2, it was necessary to form holes. Since it was necessary to form the holes in specific positions and shapes, the formation of the holes required precision and was time-consuming.

[0006] In view of the above problems, an object of the present invention is to provide a cutter blade that can reduce rotational resistance through simple processing. [Means for solving the problem]

[0007] The cutter blade of the present invention is a cutter blade that is provided inside a housing of a mower and is driven to rotate around an axis that faces up and down, and includes a blade body, a blade portion provided on at least a part of a front end portion of the blade body in the rotational direction, and a wind-raising portion provided on at least a part of a rear end portion of the blade body in the rotational direction and extending upward beyond the blade portion. At least a part of an underside of the blade body, an underside of the blade portion, and an underside of the wind-raising portion include high-strength portions made of a material stronger than the material of the blade body, and the blade body is provided with a first portion located in the center, and the wind generating section has a second section located on both sides of the first section and having a blade section and a wind generating section formed thereon, and a third section located between the first section and the second section, the height of the first section is set to be higher than the height of the second section, and the third section is inclined to become lower from the first section toward the second section, the wind generating section is provided on the upper surface section and has a tapered section that extends upward from a position a predetermined distance away from the rear end section in the rotation direction and has an inclined surface that gradually becomes thinner toward the rear end section in the rotation direction of the wind generating section, and the inclined surface is formed by trimming the rear end section in the rotation direction on the upper surface side of the wind generating section, an upper end portion of the inclined surface is constituted by the high strength portion,The blade portion is inclined so as to approach the lower surface portion of the blade portion as it approaches the front end portion in the rotation direction.

[0008] According to this invention, the thickness of the rear end of the wind generating part in the rotation direction is thin, so that the negative pressure generated on the rear side of the cutter blade in the rotation direction is small, and the generation of vortexes and turbulent air flow caused by the generation of negative pressure can be suppressed. As a result, the rotational resistance of the cutter blade caused by vortexes and turbulent air flow can be suppressed. According to the present invention, a high-strength material having a higher strength than the material of the blade body is provided on the underside of the cutter blade, and an inclined surface for suppressing the rotational resistance of the cutter blade is formed on the upper side of the wind-raising part. By providing a high-strength material on the underside of the cutter blade, durability is improved, damage caused by cut grass and pebbles during mowing work can be reduced, and the service life of the cutter blade can be extended. On the other hand, for example, when forming an inclined surface on the underside of the wind-raising part, it is necessary to trim the high-strength material to form the inclined surface. However, since high-strength materials are relatively difficult to process, it is difficult to form the inclined surface, and even if the high-strength material can be processed, a part of the high-strength material is removed to form the inclined surface, which causes the inconvenience of not being able to improve durability by the high-strength material at the processed portion. On the other hand, when forming an inclined surface on the upper side of the wind-raising part, it is not necessary to form an inclined surface on the high-strength material, so the above-mentioned inconvenience can be prevented.

[0009] In the present invention, it is preferable that the wind generating section has a tapered section having an inclined surface which gradually becomes thinner from a position a predetermined distance away from the rear end in the rotation direction towards the rear end in the rotation direction of the wind generating section.

[0010] According to this invention, the wind raising portion is configured to become gradually thinner toward the rear end in the rotation direction, so that the air flowing on the upper and lower surfaces of the cutter blade smoothly merges with the air flowing on the lower surface of the cutter blade. As a result, it is possible to suppress the generation of vortexes and turbulent air on the rear side of the rotation direction of the cutter blade, and therefore it is possible to suitably suppress the rotational resistance of the cutter blade.

[0011] In the present invention, it is preferable that the inclined surface is a flat surface or a curved surface.

[0012] According to this invention, when forming an inclined surface, for example, the wind-raising portion is formed by a conventional forming method (such as bending), and then the rear end portion of this wind-raising portion in the rotational direction is trimmed, so that the inclined surface can be formed in a simple process without requiring precision.

[0013] In the present invention, it is preferable that the inclined surface is provided on the lower surface of the wind generating section.

[0014] According to this invention, by providing an inclined surface on the lower surface of the wind raising part, it is possible to prevent the height of the wind raising part in the vertical direction from decreasing. When an inclined surface is provided on the upper surface of the wind raising part, the height of the wind raising part in the vertical direction is decreased, and the wind raising part becomes smaller. When the wind raising part becomes smaller, the volume of the wind generated by the wind raising part decreases, and the ability to make the grass stand up and transport the cut grass decreases. In order to prevent this, it is necessary to further increase the height of the wind raising part to increase the volume of the wind, which is inconvenient in that a design change is required to change the height of the wind raising part in the vertical direction. Therefore, by providing an inclined surface on the lower surface of the wind raising part, it is possible to prevent the height of the wind raising part in the vertical direction from decreasing, that is, the wind raising part from becoming smaller, and therefore it is possible to prevent the volume of the wind generated by the wind raising part from decreasing without the above-mentioned design change.

[0015]

[0016]

[0017] In the present invention, it is preferable that the blade body, the cutting edge portion and the wind generating portion are integrally formed.

[0018] According to this invention, since processes such as welding are not required, the amount of labor can be reduced compared to when the blade body, cutting edge and wind-raising portion are constructed separately, and therefore the cutter blade can be formed more easily. [Brief description of the drawings]

[0019] [Figure 1] 1 is a side view showing an example of an electric grass cutter to which the cutter blade of the mower of the present invention can be applied. [Diagram 2] FIG. 2 is a partial cross-sectional view of a mower unit. [Diagram 3] FIG. [Figure 4] FIG. 2 is a top view of the cutter blade. [Diagram 5] FIG. 4 is an enlarged view showing the wind raising portion of the cutter blade. [Figure 6] FIG. 13 is a diagram showing a cutter blade according to another embodiment. [Figure 7] FIG. 13 is a diagram showing a cutter blade according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, the mower is a mid-mounted electric riding mower, and FIG. 1 is a side view of the mower. Here, unless otherwise specified, "front" means forward in the fore-and-aft direction (traveling direction) of the machine body, and "rear" means rearward in the fore-and-aft direction (traveling direction) of the machine body. Furthermore, left-right or lateral direction means the transverse direction of the machine body (machine body width direction) perpendicular to the fore-and-aft direction of the machine body. "Up" or "down" refers to the positional relationship in the vertical direction (perpendicular direction) of the machine body, and indicates the relationship in height above the ground.

[0021] As shown in FIG. 1, this grass cutter comprises a front wheel unit 1 consisting of rotatable caster-type left front wheel 1a and right front wheel 1b, a drive wheel unit 2 consisting of a left rear wheel 2a and a right rear wheel 2b, a body frame 10 supported by the front wheel unit 1 and the drive wheel unit 2, a battery 7 arranged at the rear of the body frame 10, a driver's seat 11 arranged in front of the battery 7, a tip-over protection frame 12 erected behind the driver's seat 11, and a mower unit 3 suspended from the body frame 10 between the front wheel unit 1 and the drive wheel unit 2 in the space below the body frame 10 via a lifting link mechanism 13 so as to be able to be raised and lowered.

[0022] A floor plate 14, which is a place for the driver to place his / her feet, is provided in front of the driver's seat 11, from which protrudes a brake pedal 16. On either side of the driver's seat 11, there are disposed steering units 15 consisting of a left steering lever 15a and a right steering lever 15b which swing about a horizontal swing axis in the transverse direction of the vehicle body.

[0023] FIG. 2 is a partial cross-sectional view of the mower unit 3. As shown in FIG. 2, the mower unit 3 is provided with a mower housing 30 and two rotatable cutter blades 20. The left cutter blade 20 and the right cutter blade 20 are arranged side by side in the vehicle body transverse direction. The mower housing 30 includes a top plate 31 and a front side plate 32 and a rear side plate 33 extending downward from the outer periphery of the top plate 31. The front side plate 32 is connected to the front outer periphery of the top plate 31, and the rear side plate 33 is connected to the rear outer periphery. The right end regions of the front side plate 32 and the rear side plate 33 are missing, creating a grass clipping discharge port 35 covered with a cover 34. Each cutter blade 20 is disposed in an internal space of the mower housing 30 created by the top plate 31, the front side plate 32, and the rear side plate 33.

[0024] A rotating shaft 21 that penetrates through a top plate 31 of the mower housing 30 and extends downward is rotatably supported on the top plate 31 by a bearing unit (not shown). Each cutter blade 20 is replaceably fastened and fixed by a mounting bolt at the lower end of the rotating shaft 21 that extends vertically. An input pulley 22 is attached to the upper end of the rotating shaft 21.

[0025] 2, the mower motor 80 that supplies power to the cutter blade 20 is mounted on a mounting base 36 that protrudes rearward from the rear side plate 33. An output shaft 81 of the mower motor 80 is rotatably supported in a motor housing 82 via bearings in a vertical position, and its upper end protrudes from the motor housing 82. An output pulley 24 is attached to the protruding portion of the output shaft 81.

[0026] A belt 25 is wound around the input pulley 22 attached to the two rotating shafts 21, the output pulley 24 attached to the output shaft 81 of the mower motor 80, and the tension pulley unit 23 attached to the mower housing 30. When the mower motor 80 is driven, each cutter blade 20 is rotated around an axis extending vertically via the output pulley 24, the input pulley 22, and the rotating shaft 21.

[0027] As shown in Figs. 2 to 4, in this embodiment, the blade body 40 of the cutter blade 20 is in the shape of a long plate, and a cutting edge portion 51 and a wind raising portion 52 are formed at both ends in the longitudinal direction. During grass cutting, the cutter blade 20 rotates while the grass cutter travels, and the grass clippings cut by the blade portion 51 are guided by the conveying wind generated by the wind raising portion 52 of the cutter blade 20 to the baffle plate inside the mower housing 30, pass through the inside of the mower housing 30, and are discharged from the grass clippings discharge port 35 to the outside side of the mower housing 30.

[0028] 3 and 4, the blade body 40 of the cutter blade 20 has, along the longitudinal direction, a first portion 41 in which a hole 41a in which the rotation shaft 21 is provided is formed at the center of the blade body 40, a second portion 42 in which a blade portion 51 and a wind raising portion 52 are formed on both sides of the first portion 41, and a third portion 43 between the first portion 41 and the second portion 42. The height position of the first portion 41 is set higher than the height position of the second portion 42, and the third portion 43 is inclined so as to become lower from the first portion 41 toward the second portion 42.

[0029] At both longitudinal ends of the blade body 40, each second portion 42 has a blade portion 51 formed at its front end in the rotational direction, and a wind raising portion 52 formed at its rear end in the rotational direction.

[0030] As shown in Figures 3 and 5, each wind-raising portion 52 is formed by bending a part of the second portion 42 and raising it so as to extend upward beyond the blade portion 51 and rearward in the direction of rotation.

[0031] The cutter blade 20 is formed, for example, by punching a steel plate, and in this embodiment, the blade body 40, the blade section 51, and the wind generating section 52 are integrally formed. With this configuration, compared to the case where the blade body 40, the blade section 51, and the wind generating section 52 are formed separately, no process such as welding is required, so the number of steps can be reduced, and the cutter blade can be formed more easily.

[0032] As shown in FIG. 5, in this embodiment, each wind generating part 52 of the blade body 40 (see FIG. 4) is formed so that the thickness T2 of the rear end in the rotation direction is thinner than the thickness T1 of the other part of the wind generating part 52. Specifically, in the wind generating part 52, a tapered part 52a is formed having an inclined surface 52b that gradually becomes thinner from a position a predetermined distance away from the rear end in the rotation direction toward the rear end in the rotation direction of the wind generating part 52. In this embodiment, the inclined surface 52b is formed as a flat surface or a curved surface. The formation of this tapered part 52a is not particularly limited, but is formed, for example, by trimming the rear end in the rotation direction of the wind generating part 52. Of course, it may be formed by a method other than trimming, such as pressing.

[0033] As shown in Figs. 3 and 5, in this embodiment, the lower surface of the wind generating part 52 is provided with an inclined surface 52b. Here, if an inclined surface is provided on the upper surface of the wind generating part 52, the height of the wind generating part 52 in the vertical direction will be lowered, and the wind generating part 52 will be smaller. If the wind generating part 52 becomes smaller, the amount of wind generated by the wind generating part 52 will decrease, and the ability to make the grass stand up and transport the cut grass will decrease. In order to prevent this, it is necessary to increase the height of the wind generating part 52 to increase the amount of wind, which is inconvenient because it requires a design change to change the height of the wind generating part 52 in the vertical direction. Therefore, by providing the inclined surface 52b on the lower surface of the wind generating part 52, it is possible to prevent the height of the wind generating part 52 in the vertical direction from being lowered, that is, the wind generating part 52 from being smaller, and therefore it is possible to prevent the amount of wind generated by the wind generating part 52 from being reduced without the above-mentioned design change.

[0034] [Another embodiment] The following are examples of other embodiments that are modified from the above embodiment. The following other embodiments may be combined and applied to the above embodiment as long as no contradiction occurs. Note that the scope of the present invention is not limited to the contents of each embodiment.

[0035] (1) In the above embodiment, an example was described in which the blade body 40 has the blade portion 51 formed at the front end portion in the rotational direction of both longitudinal ends of the blade body 40. However, it is sufficient that the blade portion 51 is formed on at least a portion of the front end portion in the rotational direction of the blade body 40, and the blade portion 51 may be provided, for example, at a position closer to the center than both ends of the blade body 40.

[0036] (2) In the above embodiment, an example was described in which the blade body 40 has a wind-generating portion 52 formed at the rear end in the rotational direction of both longitudinal ends of the blade body 40. However, it is sufficient that the wind-generating portion 52 is formed in at least a portion of the rear end in the rotational direction of the blade body 40, and it may be provided, for example, at a position closer to the center than both ends of the blade body 40.

[0037] (3) In the above embodiment, each wind-generating portion 52 of the blade body 40 is described as being formed so that the overall thickness of its rotational rear end is thinner than other portions of the wind-generating portion 52. However, it is sufficient that the wind-generating portion 52 is formed so that only a portion of its rotational rear end is thinner than other portions. For example, as shown in Figure 6, the wind-generating portion 52 may be formed so that only a portion of its rotational rear end, which is on the longitudinal end side of the blade body 40 (see Figure 4), is thinner than other portions.

[0038] (4) In the above embodiment, the inclined surface 52b is formed on the lower surface of the wind generating section 52. However, the inclined surface 52b may be formed on the upper surface of the wind generating section 52.

[0039] (5) As shown in FIG. 7, at least a part of the lower surface of the blade body 40 (see FIG. 4), the lower surface of the blade portion 51, and the lower surface of the wind generating portion 52 may be provided with a high-strength portion 60 made of a material stronger than the material of the blade body 40 (see FIG. 4). In this case, by forming an inclined surface 52b on the upper surface of the wind generating portion 52, which is the surface opposite to the surface on which the high-strength portion 60 is provided, it becomes unnecessary to form the inclined surface 52b on the high-strength material constituting the high-strength portion 60. Here, since high-strength materials are relatively difficult to process, it becomes difficult to form the inclined surface 52b. Even if the high-strength material can be processed, a part of the high-strength material is removed to form the inclined surface 52b, which causes the inconvenience of not being able to improve durability by the high-strength material at the processing location. On the other hand, when the inclined surface 52b is formed on the upper surface of the wind generating portion 52, it becomes unnecessary to form the inclined surface 52b on the high-strength material, so that the above-mentioned inconvenience can be prevented.

[0040] (6) In the above embodiment, a rear discharge type grass cutter having two cutter blades 20 has been described as an example, but the present invention is not limited to the above embodiment. For example, the present invention can be applied to grass cutters other than those described above, such as grass cutters having three cutter blades 20 or grass cutters having one cutter blade 20. Furthermore, the present invention is not limited to rear discharge type grass cutters, and can be applied to grass cutters other than those described above, such as side discharge type grass cutters and mulching type grass cutters.

[0041] (7) In the above embodiment, a mid-mounted riding electric grass cutter has been described as an example, but the present invention is not limited to the above embodiment. For example, the present invention can be applied to grass cutters other than those described above, such as a front-mounted riding grass cutter. In addition, the driving unit may be a grass cutter that uses an internal combustion engine instead of an electric motor. [Industrial Applicability]

[0042] The present invention is applicable to cutter blades for mowers. [Explanation of symbols]

[0043] 20: Cutter blade 30:Moore Housing (Housing) 40: Blade body 41 :1st part 42:Second part 43: 3rd part 51:Blade 52:Okifubu 52a: Tapered section 52b: Inclined surface 60: High strength part R: Traveling device

Claims

1. A cutter blade is provided inside a housing of a mower and is driven to rotate around an axis extending in an up-down direction, A blade body; a cutting edge provided on at least a portion of a front end of the blade body in a rotational direction; a wind raising portion provided on at least a part of the rear end portion of the blade body in the rotation direction and extending above the cutting edge, a high-strength portion is provided on at least a portion of the underside of the blade body, the underside of the cutting edge, and the underside of the wind-raising portion, the high-strength portion being made of a material stronger than the material of the blade body; The blade body has a first portion located at a center, second portions located on both sides of the first portion and having a blade portion and a wind raising portion formed therein, and a third portion located between the first portion and the second portion, the height of the first portion is set higher than the height of the second portion, and the third portion is inclined so as to become lower from the first portion toward the second portion, The wind-generating section is provided on the upper surface, extends upward from a position a predetermined distance away from the rear end in the rotation direction, and has a tapered section with an inclined surface that gradually becomes thinner toward the rear end in the rotation direction of the wind-generating section, the inclined surface being formed by trimming the rear end in the rotation direction on the upper surface side of the wind-generating section, the upper end of the inclined surface being composed of the high-strength section, and the blade portion is inclined so as to approach the lower surface portion of the blade portion as it approaches the front end in the rotation direction.

2. 2. The cutter blade according to claim 1, wherein the inclined surface is a flat surface or a curved surface.

3. 3. A cutter blade according to claim 1, wherein the blade body, the cutting edge and the wind raising portion are integrally formed.

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