JP2009106257A - Cutter disk for mowing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutter disk for a mowing machine which avoids collision with a rotary driving shaft of a mowing machine and reduce risk of breaking a cutter or the like, when the cutter is retreated by collision with a material hard to cut, such as stone or hard tree. <P>SOLUTION: In the cutter disk for the mowing machine, the rotary driving shaft is attached to the center part of a rotary disk 2 and the cutters 11 are rotatably mounted to the circumferential part of the rotary disk 2 by mounting shafts 12, the cutter radially projects from the outer periphery of the rotary disk while rotating together with the rotary disk, grass is cut when the cutter collides with grass, and the cutter is retreated to the central part side of the rotary disk by rotating around the mounting shaft when the cutter collides with the material hard to cut, the rotary disk is provided with receiving pieces 5 each for avoiding collision of the back of the cutter retreated to a central part side of the rotary disk with the rotary driving shaft. The receiving piece 5 is configured so that a surface 14 of the ridge of the cutter collides with a receiving surface 6 by surface contact. The receiving surface and the surface of the ridge of the cutter are formed into a flat surface. The receiving surface 6 is formed as a buffer surface. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a tool board that is detachably attached to a rotary drive shaft of a mower.

  A cutter blade of a mower attached to the body of an operator is provided with a mounting hole at the center of the rotating disk, and a rotary drive shaft at the tip of the mower is attached to the mounting hole. The turntable is mounted with blades rotatably at the equidistant positions on the outer peripheral portion by an attachment shaft.

  This cutter board is attached to the rotary drive shaft at the tip of the mower, and is rotated by driving the prime mover of the mower. Then, the strip-shaped blade protrudes in the radial direction from the outer periphery of the rotating disk by centrifugal force while rotating together with the rotating disk. When the blade collides with the grass while rotating around the rotation center of the turntable, the blade cuts down the grass. When it collides with a difficult-to-cut object such as a stone or hard wood, it moves backward, rotates around the mounting shaft, and retracts toward the center of the rotating disk.

  Further, the blade board shown in FIG. 10 of Patent Document 2 is provided with steady rests on both sides in the vicinity of the blade in order to narrow the swing range of the blade when the blade collides with a difficult-to-cut object.

Japanese Utility Model Publication No. 5-20529 Japanese Patent Laid-Open No. 58-9612 (FIG. 10)

[Issues of background technology]
In a blade for a mower, if the length of the blade protruding from the outer periphery of the rotating disk is increased, the range of cutting the grass is increased and the efficiency of cutting is increased. However, the blade board becomes longer and larger in size. When the outer diameter of the turntable is reduced, the blade board becomes smaller.

  Therefore, in order to increase the mowing efficiency with a small size, the blade is lengthened and the rotating disk is reduced in diameter. Then, during the mowing, when the cutting tool collides with the difficult-to-cut object and moves backward and enters the center of the rotating disk, the cutting tool collides with the rotary drive shaft of the mowing machine. The rotary drive shaft of the mower has a risk of breaking during rotation because the blade will collide every time the blade collides with a difficult-to-cut object.

[Idea for solving problems]
When the cutting tool collides with a difficult-to-cut object and retreats toward the center of the turntable, the cutting tool is received before the cutting tool collides with the rotary drive shaft of the mower. The blade was prevented from colliding with the rotary drive shaft. The rotating disk is provided with a receiving piece that hits the wing of the retreated blade on the center side.

  In addition, when the receiving piece is configured to receive a strip-shaped cutter with a circular plate or a column on the outer peripheral cylindrical surface, the cylindrical surface and the ridge and back of the cutter collide by line contact or point contact, and the collision pressure is Get higher. Therefore, the receiving piece is configured to receive the surface of the blade ridge by surface contact with the surface. The surface of the receiving piece and the surface of the blade ridge collide in surface contact, and the collision pressure is lowered. The risk of damage to the receiving piece and the blade is reduced.

1) The rotary drive shaft of the mower is attached to the center of the rotating disk, and the blade is rotatably mounted on the outer periphery of the rotating disk with the mounting shaft. The blade rotates while rotating together with the rotating disk. The grass that protrudes radially from the outer periphery of the panel, cuts the grass when it collides with the grass, and cuts around the mounting shaft when it collides with a difficult-to-cut object such as a stone or hard tree, and then retreats toward the center of the rotating disk In the machine tool board,
The rotating disk is provided with a receiving piece for avoiding the wing of the blade retracted to the center side of the rotating disk from colliding with the rotation drive shaft.
The receiving piece is characterized in that the surface of the ridge of the blade collides with the receiving surface by surface contact.
2) In the above mower cutter,
The receiving piece has a flat receiving surface,
The blade is characterized in that the surface of the ridge that collides with the receiving surface of the receiving piece is flat.
3) In the above mower cutter,
For example, the receiving surface of the receiving piece is a surface of an elastic material, or a buffer sheet is pasted to form a buffer surface.

  Even if the cutter is lengthened and the turntable has a small diameter, the receiving piece prevents the cutter from colliding with the rotary drive shaft when the cutter collides with a difficult-to-cut object and moves backward. It is small and can increase the mowing efficiency.

  Further, the receiving piece collides with the blade ridge in surface contact, and the collision pressure is lowered. There is little risk of damage to the receiving piece or blade.

[First example (see FIGS. 1 to 5)]
This example is a cutter blade of a mower used by an operator attached to the body. As shown in FIG. 1 to FIG. 4, this blade board has two rotating disks 1 and 2 and is arranged vertically. The upper rotating disk 1 and the lower rotating disk 2 are discs and pass through the mounting holes 3 and 4 in the center. The upper and lower rotating disks 1 and 2 have the same outer diameter. The mounting hole 3 of the upper rotating disk 1 has a smaller diameter than the mounting hole 4 of the lower rotating disk 2.

  As shown in FIG. 5, the two rotary plates 1 and 2 are attached to the attachment portion 51 at the tip of the mower. The rotation drive shaft 52 in the attachment portion 51 passes through the attachment holes 3 and 4 and is connected to the central portion of the turntables 1 and 2. With the rotation of the rotary drive shaft 52, the two rotary disks 1 and 2 rotate in the direction of the arrow R shown in FIG.

  A plurality of receiving pieces 5 are sandwiched and fixed between the upper and lower rotary plates 1 and 2. The receiving piece 5 doubles as a gap holding piece and a connecting piece of the two rotary plates 1 and 2. Both rotary disks 1 and 2 are connected concentrically in parallel. The receiving piece 5 has a rectangular parallelepiped shape or a rectangular plate shape, and has an upper surface fixed to the upper rotating disk 1 and a lower surface fixed to the lower rotating disk 2. Both the rotary plates 1 and 2 and the receiving piece 5 are made of metal and welded. The plurality of receiving pieces 5 are arranged at equal intervals on the inner peripheral portions of the two rotary plates 1 and 2. The rectangular parallelepiped receiving piece 5 is arranged with its longitudinal direction along the circumferential direction of the two rotating disks 1 and 2, and serves as a receiving surface for the outer side surface 6 and the outer surface 6 of the rotating disks 1 and 2. The receiving surface 6 is flat.

  A blade 11 is rotatably mounted on the mounting shaft 12 between the rotary plates 1 and 2. The number of blades 11 is the same as the number of receiving pieces 5. The plurality of blades 11 are arranged at equal intervals on the outer peripheral portions of the two rotary disks 1 and 2. The mounting shaft 12 passes through the shaft holes of the upper rotating disk 1, the washer, the blade 11, the washer and the lower rotating disk 2 in order. The upper end portion of the mounting shaft 12 protrudes above the upper rotating disk 1 and has a large diameter. The lower end portion of the mounting shaft 12 protrudes below the lower rotating disk 2 and has a large diameter. The upper and lower projecting ends of the mounting shaft 12 have a dome shape, and have a smooth shape that does not easily catch grass and vines. A bush of a cylindrical bearing is fitted into the shaft hole of the blade 11. The mounting shaft 12 is a rivet.

  The blade 11 is a strip-shaped or rectangular plate, and most of the blade 11 except the end through which the mounting shaft 12 penetrates protrudes outward from between the two rotary disks 1 and 2. As the rotating disks 1 and 2 rotate, the blade 11 protrudes radially from the outer periphery of the rotating disks 1 and 2 as shown in FIGS. The strip-shaped blade 11 has a long side edge on the front side when the turntables 1 and 2 are rotated as a blade 13, and a long side edge on the rear side and a rear surface 14 of the ridge are used as collision surfaces. The collision surface 14 is a flat surface.

  When the cutter 11 rotates around the mounting shaft 12 in the direction of the arrow S as shown by a chain line in FIG. 3, the collision surface 14 of the ridge of the cutter 11 hits the receiving surface 6 of the receiving piece 5. , 6 are parallel to each other, and the receiving surface 6 is arranged in the direction of surface contact.

  When the blade 13 of the blade 11 collides with a difficult-to-cut object such as a stone or hard wood while the turntables 1 and 2 are rotating, the blade 11 is moved around the mounting shaft 12 by an arrow as shown by a chain line in FIG. It rotates in the direction of S and moves backward. The blade 11 is retracted to the center part side of the rotating disks 1 and 2. Then, the ridge of the blade 11 collides with the receiving piece 5. The cutter 11 is stopped by the receiving piece 5 toward the rotational drive shaft 52. It is avoided that the blade 11 collides with the rotary drive shaft 52.

  The collision between the ridge of the blade 11 and the receiving piece 5 is performed by surface contact between the collision surface 14 of the ridge of the blade 11 and the receiving surface 6 of the receiving piece 5. The flat collision surface 14 and the flat receiving surface 6 come into contact with each other and collide with each other. Impact pressure is low.

[Second example (see FIG. 6)]
In the grass cutter for this example, as shown in FIG. 6, the receiving piece 5 has a triangular prism shape or a triangular plate shape. The blade 11 has an earlier short side edge inclined with respect to the longer side edge, and the front long side edge when the rotating disks 1 and 2 are rotated is shorter than the rear long side edge. Is the blade 13 in the same manner as the front long edge. Other points are the same as in the previous example.

[Modification]
1) In the above embodiment, the receiving surface 6 of the receiving piece 5 is a metal surface, but it is a surface of an elastic material such as rubber or synthetic resin to be a buffer surface. Alternatively, a buffer sheet is attached to the metal surface to form a buffer surface.
2) In the above embodiment, the rotating disks 1 and 2, the receiving piece 5 and the blade 11 are made of metal, but are made of synthetic resin.
3) In the above embodiment, the means for fixing the receiving piece 5 to the rotary disks 1 and 2 is welded, but other fixing means are used.
4) In the above embodiment, the rotating disks 1 and 2 are two, but they are one.
5) In the above embodiment, the mounting shaft 12 is a rivet, but is a bolt, nut, pin or the like.

The top view of the cutting board for mowers in the 1st example of embodiment of this invention. The front view of the cutter blade for the same mower. FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. FIG. 3 is an end view taken along line BB in FIG. 1. The front view of the state which attached the cutter blade for the mower to the attachment part of the mower. It is a figure of the cutting board for mowers in the 2nd example of embodiment, and is sectional drawing similar to FIG.

Explanation of symbols

1, 2 Rotating disk 1 Upper rotating disk 2 Lower rotating disk 3 Upper rotating disk mounting hole 4 Lower rotating disk mounting hole 5 Receiving piece, spacing holding piece and connecting piece 6 of both rotating disks, outer surface of the receiving piece, Receiving surface, plane R Arrow 11 indicating direction of rotation of rotating disk 11 Cutting tool 12 Mounting shaft, rivet 13 Blade 14 of blade Cutting surface, impact surface, plane S Arrow 51 indicating direction of rotation of cutting tool Mounting part 52 of the rotary drive shaft in the mounting part

Claims (3)

The rotary drive shaft of the mower is attached to the center of the turntable, and the cutter is attached to the outer periphery of the turntable so that it can be rotated by the attachment shaft. In the cutter blade for a mower that protrudes radially from the outer periphery, collides with the grass, cuts the grass, and collides with a difficult-to-cut object, rotates around the mounting shaft and moves back to the center side of the turntable.
The rotating disk is provided with a receiving piece for avoiding the wing of the blade retracted to the center side of the rotating disk from colliding with the rotation drive shaft.
The cutting piece for a mowing machine, wherein the receiving piece is configured such that the surface of the ridge of the cutter collides with the receiving surface by surface contact. The receiving piece has a flat receiving surface,
2. The blade for a mower according to claim 1, wherein the blade has a flat surface that collides with the receiving surface of the receiving piece.   The cutter blade for a mower according to claim 1 or 2, wherein the receiving surface of the receiving piece is a buffer surface.

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