JPS6115699Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a lawn mower that cuts grass by coaxially overlapping an upper blade and a lower blade with a plurality of cutting blades protruding from the periphery and sliding both cutting blades against each other. Regarding improvements to the machine.

Conventional lawn mowers of this type have cutting blades shaped like saw blades or comb blades that protrude radially from the center of rotation. Grass could not be introduced smoothly into the cutting blade, and the cutting width was narrow, resulting in poor cutting efficiency. Moreover, if the upper and lower blade plates or cutting blades are made larger in order to widen the cutting width, the upper and lower blade plates will rotate, which naturally increases the size of the lawn mower itself, and also makes it difficult to manufacture the cutting blades. .

Furthermore, even if multiple cutter units are installed in an array, grass cannot be introduced smoothly to the cutting blade located perpendicular to the direction of movement of the lawn mower body, and each cutter unit There was a drawback that uncut areas tended to occur between the units.

In view of these drawbacks of conventional products, the present invention has been developed by arranging small-diameter cutter units in the left-right direction to increase the cutting width without increasing the size of the lawn mower. It is an object of the present invention to provide a lawn mower with high cutting efficiency that does not leave any uncut material.

Hereinafter, an example of the implementation of the present invention will be described based on the drawings. The cutter units B ₁ , B ₂ , B ₃ consist of an upper blade 1 and a lower blade 2, and are attached to the lower open part 10 of the lawn mower body A. Arrange and install on the same plane.

The upper blade 1 and the lower blade 2 are formed in a circular plate shape, with cutting edges 3 and 4 protruding from the peripheral edges 1' and 2', respectively. The two are overlapped coaxially, the upper blade 1 is attached to the lower end of a rotating shaft 12 linked to a prime mover (motor or engine) 11 so as to be freely rotatable, and the upper blade 2 is attached to a fixed shaft 12 fixed to a machine frame 13 so as to be coaxial with the rotating shaft 12.
The upper blade 1 is rotated in the direction of the arrow t, and the cutting edge 3 of the upper blade 1 and the cutting edge 4 of the lower blade 2 cut the grass with scissors, slicing it down.
The lower blade 2 may be unfixed, but may be attached to a separate rotating shaft arranged coaxially with the rotating shaft 12 of the upper blade 1 so as to be able to rotate in the opposite direction to the upper blade 1. Alternatively, contrary to the illustrated example, the rotating upper blade 1 may be positioned below the fixed lower blade 2 and overlapped coaxially.

The diameter _l3 of the upper blade 1 is the same as or slightly larger than the diameter _l4 of the lower blade 2, and its peripheral edge 1' and the root part 3' of the cutting edge 3 are in close sliding contact with the lower blade 2. Like upper blade 1
The entire body is pressed toward the lower blade 2 by a spring 15, and the outer side 16 of the cutting blade 3 (the side opposite to the cutting edge 5) is slightly bent upward to push the cutting edge 5 of the cutting blade 3 toward the lower blade 2.
Closely rub against the cutting edge 6 of the cutting blade 4.

The cutting edge 3 of the upper blade 1 is formed such that its cutting edge 5 is located forward in the rotational direction t of the upper blade 1 from a line a passing through the base end 7 of the cutting edge. That is, the cutting edge 3 is formed to protrude in a substantially sickle shape toward the direction t of the upper blade 1 at the peripheral edge 1' of the upper blade 1, and the cutting edge portion 5 is formed on the side opposite to the peripheral edge 1' of the upper blade. It is what it is.

The cutting edge 4 of the lower blade 2 has its cutting edge 6 formed on the opposite side from the peripheral edge 2' of the lower blade, and the intersection angle θ at which the cutting edge 4 and the cutting edge 6 of the upper blade 1 rub against each other is always 16° to 20°. Form it so that it is front and back. That is, the shape of the cutting edge part 6 of the cutting blade 4 is determined by the shape of the cutting edge part 5 of the upper blade 1, and is opposed to the cutting edge part 5 of the upper blade 1 like scissors. As shown in this example, the cutting edge part 5 of the upper blade 1 is formed into a straight line so that the cutting edge part 5 sequentially reaches the tip part 8 from the base end part 7 of the cutting edge part and rubs against each other at an intersection angle θ of about 16° to 20°. However, the cutting edge part 6 of the lower blade 2 is formed in a gentle arc shape, the cutting edge part 5 of the upper blade 1 is formed in a gentle arc shape, and the cutting edge part 6 of the lower blade is formed in a straight line shape, or both cutting edges are formed. The portions 5 and 6 are formed into a gentle arc shape. In addition, when the lower blade 2 and the upper blade 1 are installed in a fixed manner, that is, in a non-rotating manner, the cutting blade 4 is attached to the front part of the lower blade 2 (the front semicircular part facing the direction of movement of the lawn mower body). It may be arranged so that it protrudes only in the area.

The cutting edge 3 of the upper blade 1 has a length l ₁ from its leading edge 8 to the shaft center, which is the same as or longer than the length l ₂ from the cutting edge 9 of the lower blade 2 to the shaft center O. hand,
Grass is taken in by the cutting edge 3 of the upper blade 1 and brought to the cutting edge part 6 of the lower blade 2, and the grass is rubbed against the cutting edge part 6 of the lower blade 2 and the cutting edge part 5 sequentially from the base end 7 to the tip part 8. Cut the grass in a slicing motion.

Thus, a plurality of cutter units B ₁ , B ₂ ,
When arranging and installing B ₃ on the same plane in the lower open part 10 of the lawn mower main body A, the cutting blade 3 of the adjacent upper blade 1 and the cutting blade 4 of the lower blade 2 should be brought close to each other to the extent that they do not come into contact with each other. Adjacent upper blades 1 each have rotating shafts 12a,
Gears 17a, 17b attached to 12b, 12c,
The meshing of the parts 17c allows them to rotate synchronously and prevent them from coming into contact with each other.

Since the present invention is configured in this manner, it has the following advantages.

The cutting edge part 5 of the upper blade 1 is rubbed against the cutting edge part 6 of the lower blade 2 sequentially from the base end 7 to the tip part 8, and the cutting edge part 5 of the upper blade 1 takes in the grass and removes it to the lower blade 2. The cutting method is similar to that of a reel-type lawn mower, and the grass cutting edge and mowing marks are beautifully finished, and the lawn grass is cut continuously. Since there is little variation in load, the required power can also be reduced.

The cutting blade of the upper blade reliably captures the grass in the area perpendicular to the direction of movement of the lawnmower body, making it possible to cut the grass between each cutter unit without leaving anything uncut, improving cutting efficiency. can be greatly improved.

A required wide cutting width can be obtained without increasing the size of the lawn mower body, and the lawn mower can be made smaller and lighter.

In other words, in the past, to obtain a cutting width of 60 cm, the diameter
A cutter unit with a diameter of 60 cm is required, and the lawn mower itself must necessarily be formed to be more than 60 cm in size from front to back, left to right, but in the case of this invention, two cutter units are arranged in a cutter unit with a diameter of 80 cm. Alternatively, by arranging three cutter units with a diameter of 20 cm in the horizontal direction, a cutting width of 60 cm can be obtained without increasing the size of the lawnmower body in the front-back direction.

It is easy to bring the upper and lower cutting blades into close contact with each other and slide them together, and there is no fear that the cutting edges of the cutting blades will mesh with each other, resulting in good sharpness.

The upper and lower blades can be manufactured by press processing, and they can be easily replaced and the blade edges can be polished.Although the grass cutting method is similar to that of a relay-type lawn mower, it is more effective than the cutting blades of a relay-type lawn mower. Its manufacture and maintenance are extremely easy, and it can be provided at low cost.

[Brief explanation of the drawing]

The drawing shows one example of the implementation of the lawn mower of the present invention.
The figure is a partially cutaway front view, FIG. 2 is a bottom view, and FIGS. 3 and 4 are plan views illustrating the relationship between the upper blade and the lower blade. In the figure, 1 is the upper blade, 2 is the lower blade, 3 and 4 are the cutting blades,
5 and 6 are the cutting edge parts, 7 is the base end of the cutting edge part 5, 8 is the tip part of the cutting edge part 5, 9 is the tip part of the cutting blade 4, A is the lawn mower body, B ₁ , B ₂ , B ₃ are It is a cutter unit.

Claims (1)

[Scope of utility model registration request] The cutting edges 5, 6 of the cutting blades 3, 4 are made by coaxially overlapping the upper blade 1 and the lower blade 2, which have a plurality of cutting edges on the periphery.
In the cutter unit B, which is formed by rubbing the upper blades against each other, the cutting edge portion 5 of the cutting edge 3 of the upper blade 1 is positioned forward in the rotational direction t of the upper blade 1 from the line a passing through the base end portion 7 thereof. At the same time, the cutting edge part 5 of the upper blade 1 and the cutting edge part 6 of the lower blade 2 are formed so that the mutual sliding angle θ is always around 16° to 20°, and the cutter unit B is attached to the lawn mower body. A lawn mower characterized by having multiple pieces arranged in the same plane on the underside.