JPH07107837A - Mowing device - Google Patents

Abstract

PURPOSE:To provide a mowing device capable of rotating rotary blades at a low speed and simultaneously cutting grasses in a good cutting state by disposing the two superposed rotary blades in a state capable of being reciprocatively rotated in mutually reverse directions and disposing a speed-reducing mechanism in the power transmission route. CONSTITUTION:Two superposed rotary blades 43, 45 are pivotally supported in a transmission case 47 in a state capable of being reciprocatively rotated in mutually reverse directions, and circular cam plates 81, 83 and a large gear 79 engaged with a small gear 73 to reduce the rotation speed are fixed to a cam shaft 75 through a bearing ring 85.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mowing device for performing mowing work such as mowing grass on the ground by a rotary blade driven by a prime mover such as an engine.

[0002]

2. Description of the Related Art In a conventional mowing device, such as a brush cutter, a bearing body for pivotally supporting a rotary blade and an engine are connected by a connecting rod, and an operator holds a grip provided on the connecting rod with both hands. The grass was mowed with the rotating rotary blade. That is, in FIG.
In FIG. 5, a disk-shaped rotary blade 3 having a saw-shaped blade portion 1 on its outer periphery is axially supported by a bearing case 5, and is driven by an engine 9 that is connected to the bearing case 5 via a connecting rod 7. It is rotationally driven via a transmission shaft 11 penetrating the connecting rod 7. A grip 13 and a handle 15 are provided in the middle of the connecting rod 7, and a grip 17 is fixed to the handle 15. A rotating shaft 21 is vertically supported in the bearing case 5 via a bearing 19, and a bevel gear 23 fixed to the upper end of the rotating shaft 21 is engaged with the tip of the transmission shaft 11 by a bearing 25. Bevel gear 2 supported by
It meshes with 7. The lower end of the rotary shaft 21 is clamped by the upper and lower washers 31 and 33 engaging with the spline 29 on the outer periphery, and the disc-shaped rotary blade 3 having the saw blade-shaped blade portion 1 on the outer periphery is clamped and fixed by the nut 35 on the lower end. ing.

An operator carries out a mowing operation in which the grips 13 and 17 are held by both hands and the rotary blade 3 which is rotated at high speed by driving the engine 9 cuts off grass and the like on the ground.

[0004]

In this case, since the rotary blade 3 rotates at a high speed, it is dangerous to bounce off small stones or the like, and when cutting soft grass, it may be blown down by the centrifugal wind and mowed. I could not do it, and it was a cause of uncut.

In particular, since the conventional rotary blade has a sharp blade portion with a serrated tip on the outer periphery and rotates at a high speed, it causes a large scratch when touching the trunk of a plant or the like, and touches the leg of another person. There was a danger of a big accident.

In order to eliminate this danger, the rotation speed should be reduced, but this has not been implemented because of the following problems.

(1) When the speed is slowed down, one rotary blade cannot cut, and it is necessary to overlap two rotary blades and cut them like scissors.

(2) When one of the two rotary blades is fixed, the tip of the fixed blade hits a twig or the like, and the entire rotary blade cannot be pushed forward, and the twig does not enter between the blades, so cutting cannot be performed.

(3) If the two rotary blades are rotated in mutually opposite directions, the blade tip will not hit the twigs,
Therefore, the pushing of the rotary blade is not obstructed, but the rotary blade rotates at a slow speed, the centrifugal force is reduced, and the grass is wrapped around the rotary blade, which makes removal difficult.

[0010]

SUMMARY OF THE INVENTION The present invention provides two overlapping
Let's solve the above-mentioned problems by supporting the rotary blades in a mutually reciprocating manner in opposite directions and providing a reduction mechanism in the transmission path from the engine for driving the rotary blades to the rotary blades. It is what

[0011]

[Function] Although two grass blades are scissored by two rotary blades which respectively reciprocally rotate in opposite directions, the rotation speed is slowed to improve work safety, and it is possible to prevent grass pieces from being caught. Become.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. That is, in FIGS.
Two disk-shaped upper and lower rotary blades 43 and 45 having blade portions 41 and 42 on their outer circumferences are axially supported by being superposed on a transmission case 47 and connected to the transmission case 47 via a connecting rod 49. When the engine 51 is driven, they are reciprocally rotatable in opposite directions via a transmission shaft 53 that penetrates the connecting rod 49. In the middle of the connecting rod 49, the grip 5
5 and a handle 57 are provided, and a grip 59 is fixed to the handle 57. One end of a connecting rod 49 is obliquely fixed to the transmission case 47, and an angular shaft 61 at the tip of a transmission shaft 53 that penetrates the inside of the connecting rod 49 is supported by a bevel gear 47 on the transmission case 47 via a bearing 63. 65 is engaged. An intermediate shaft 67 is vertically supported by the transmission case 47 via bearings 69, 69. A bevel gear 71 that engages with the bevel gear 65 is fixed to the upper portion of the intermediate shaft 67. A small gear 73 is fixed to the lower part of the intermediate shaft 67. A vertical cam shaft 75 is supported on the transmission case 47 by bearings 77, 77.
A large gear 79 that meshes with the small gear 73 to reduce the speed and two circular cam plates 81 and 83 are fixed to the cam shaft 75 via a bearing ring 85. 2 cam plates 8
Numerals 1 and 83 are provided above and below the large gear 79, respectively, so as to be eccentrically arranged in symmetry with respect to the center of the cam shaft 75.
Connecting rods 89, 87 are provided on the outer periphery through bearing rings 85, 87, respectively.
One end of 91 is fitted. A vertical rotating shaft 93 is rotatably supported by the transmission case 47 via bearings 95 and 97, and an upper end of the rotating shaft 93 is integrally provided with the other end of the connecting rod 89 and an arm 101 pivotally attached by a pin 99. Stuck,
A support plate 105 that engages with the square shaft 103 formed at the lower end is fixed by a nut 107. The lower rotary blade 45 is fixed to the support plate 105 with bolts 109. A rotary cylinder 111 is rotatably fitted to the outer periphery of the rotary shaft 93, and the other end of an arm 113 integrally fixed to the rotary cylinder 111 is pivotally attached to the other end of a connecting rod 91 by a pin 115. Support plate 117 integrally fixed to the lower end of the rotary cylinder 111
The rotary blade 43 superposed on the rotary blade 45 has a bolt 1
It is fixed by 19.

In the above embodiment, when the engine 51 is rotated, power is transmitted from the transmission shaft 53 to the bevel gears 65 and 7.
It is transmitted to the intermediate shaft 67 via 1 and rotates the cam shaft 75 via the small gear 73 and the large gear 79. With the rotation of the cam shaft 75, the two cam plates 81 and 83 rotate while maintaining symmetrical positions with each other, so that the arms 101 and 113 are swung in opposite directions via the connecting rods 89 and 91. Therefore, the rotary blades 43 and 45 that are integrally fixed to the arms 101 and 113 relatively reciprocally rotate,
The blades 41, 42 are used to cut grass or the like. An operator holds the grips 55 and 59 with both hands and cuts grass or the like with the rotary blades 43 and 45 that reciprocally rotate.

[0014]

The present invention has the following effects because it has the structure as described in the claims.
(1) Since the rotary blade can rotate at low speed, there is no danger of splashing pebbles and the like, and even if it comes into contact with a plant or the leg of another person, it is not important. (2) Since it is cut between two rotary blades, it has good sharpness and can cut soft grass without leaving uncut residue. (3) Moreover, since the blades are arranged in a disk shape,
It can be cut in any direction, can be swung right and left like a brush cutter, and can be used for reciprocating grass cutting, and it can also cut complicated shapes.

According to the present invention, the transmission case is connected to the engine through the connecting rod in the above-described embodiment, but the connecting rod is eliminated and the transmitting case and the prime mover such as the engine are directly integrated. You may connect and form compactly, and may be used for trimming garden trees.

[Brief description of drawings]

FIG. 1 is an explanatory perspective view of an embodiment of the present invention.

FIG. 2 is a plan sectional view of a main part.

FIG. 3 is a developed side sectional view taken along line III-III in FIG.

FIG. 4 is a perspective explanatory view of a conventional example.

FIG. 5 is a side sectional view of the main part.

[Explanation of symbols]

 43, 45 rotary blade 47 transmission case 51 engine

Claims (1)

[Claims] 1. A transmission case 47 is provided with two superposed rotary blades 43, 45 axially supported so as to be reciprocally rotatable in opposite directions, and a reduction mechanism is interposed in a power system path. A mowing device characterized by being provided.