JPH0133128B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention provides a mechanism for rotating a cutter mounted on a shaft at the tip of a hollow frame at high speed by a motor (engine or motor) attached or linked to the other end of the cutter, which is driven by a shaft passing through the frame. Regarding the brush cutter,
Relating to a brush cutter in which a frame and a transmission shaft are joined together near the middle in a bendable and elastic manner, and the brush cutting frame on the cutter side is levered at a low speed by a high reduction gear device installed near the joint to perform automatic brush cutting motion. .

Conventionally, portable brush cutters that cut vegetation with a cutter that rotates at high speed have become rapidly popular in recent years because they are lightweight and easy to operate. However, with conventional brush cutters, the mowing motion must be done manually, which is physically tiring, and the user must firmly grip the frame and handle to swing the machine around, which can lead to numbness in the hands and fingers due to vibrations.
It was impossible to continue mowing the grass for a long time. There is a strong demand for a safe brush cutter, as there is a risk of developing white wax, which has already been caused by chain saw work and has become a social problem.

The present invention was made in response to this demand, and the fuselage frame on the prime mover side, which is bent and retractable, is stationary and carried, and the brush cutting frame has a support that is fixed to it and provided in parallel. The transmission shaft, which is the input member of the high reduction gear device installed at the front or rear of the joint, is strongly supported by a crank that rotates at an output perpendicular to the transmission shaft, and the other end of the support is connected to the fuselage frame. The mowing frame is supported by a pair of links, forming a crank-lever-bending motion mechanism, and the mowing frame is moved left and right by the crank, which moves in a slightly straight line, thereby mitigating the reaction and automatically mowing the grass. The worker can cut a wide area by simply walking naturally while lightly supporting the handle, which is fully vibration-proofed, and the vibrations and slight recoil that occur during cutting are eliminated by the inertia of the stationary machine frame. The idea is to improve safety by eliminating the problem of numbness in hands and fingers by eliminating recoil and drastically reducing physical fatigue.

Conventional brush cutters have been improved with anti-vibration measures, but the machine body absorbs the cutting vibrations of the cutter and is manually swung around to cut the grass, causing severe fatigue, and although the machine body is lightweight, , since the prime mover and cutter attached to both ends of the long frame rotate at high speed and move from side to side, inertia increases, and therefore it is necessary to firmly grasp the frame and handle.
After hours of continuous mowing, my hands and fingers became numb, making it difficult to use chopsticks or a pen.

In order to solve this problem, the present invention provides a high-reduction brush cutter configured with a crank-lever-bending movement mechanism, in which the output shaft is provided in the front or rear part of the bending/expanding joint, and the output shaft moves linearly as a crank. The feature is that the gear device performs lever movement to automatically perform the mowing motion, and since the crank motion is expanded by the lever ratio to perform the mowing motion, the high reduction gear device can be made smaller. The machine body can be configured to have the same weight as the conventional one, and the mowing frame section moves left and right in front of the operator to perform the mowing operation, making it easy to get used to and operate.

The automatic bending brush cutter of the present invention performs brush cutting by supporting the brush cutting frame portion, which is a lever, on the body frame at two points, by the fulcrum of the lever and the crankshaft, which is the output shaft of a high reduction gear device, which is a crank. However, when a person practices swinging a long stick with both hands, he or she moves the hand grip in front of him back and forth and swings it up and down. When the blade is drawn and levered, the cutter at the tip of the cutting section moves in a large circular arc, making it possible to greatly adjust the cutting width by slightly changing the length of the two-point support receiver or the length of the crank arm. The aim is to ensure safety by bending and stretching the mower to suit the task. Also, by replacing the bellows 16 with a pipe, the cylindrical part 6 of the gearbox 5
A spherical bearing 49 is attached to the other end, and the fulcrum part 4 is attached to the lightning bend part of the fixed column of the fuselage frame 1.
By providing 9 and 50, the support 11 can be removed and the weight can be reduced.

First, to explain the configuration of the linear/elliptic motion gear device of the present invention, a planetary gear is meshed with a fixed internal gear, and the gear ratio of both gears is set to 2:1. When the planetary gear rotates on its axis, the axial center moves in a circle (revolutions), but if both gears are standard gears, the fixed point on the pitch circle of the planetary gear moves in a straight line and follows the same trajectory. If the fixed point is slightly away from the axis, the locus of motion will become an elongated ellipse, and if the crank arm is fixed to the planetary gear and the distance from the axis is greater than the meshing center distance, the movement will be elliptical. However, since the elliptical or linear motion also makes one revolution while the planetary gear makes one revolution, this gear train itself does not undergo deceleration motion. For example, if this gear train is composed of standard gears, the pitch circle of the planetary gears will pass through the axis of the internal gear, so the sun gear cannot be directly meshed with this gear train. Therefore, increase/reducer gears consisting of meshing standard gears are the most common and widely used gears, but single-row planetary gears that also move linearly or ellipically have never appeared. .
The present invention is characterized in that the meshing center distance is increased and the sun gear is meshed with this gear train to form a special single planetary gear device to obtain a high reduction ratio with linear motion or elliptical motion. It is a thing,
Calculate the amount of increase and the number of teeth of the sun gear using the shifted gear calculation formula described later.In order to achieve high deceleration, it is necessary to reduce the number of teeth.If the amount of increase increases, the meshing ratio will deteriorate, so repeat the experiment. This is to ensure smooth engagement.

Next, the structure of the first embodiment of the present invention will be explained with reference to FIGS. The other end is inserted into the cylindrical portion 6 of the gearbox 5 and fixed with the screw 7. 2 is a brush cutting frame consisting of a pipe, and the upper end is attached to a support 1.
The cylindrical part 14 of the bevel gear box 13 penetrates and is fixed to the pipe part 12 of the bevel gear box 13, and the other end is attached to the cutter 15.
Insert it into place and fix it. Both frames 1 and 2 constitute a bendable and expandable body by connecting the ends of the cylindrical part 6 of the gearbox 5 and the pipe part 12 of the support 11 with bellows 16. The bevel gear box 13 bears a driven bevel gear provided on the shaft of the cutter 15 and a driving gear directly connected to the end of the transmission shaft 4 passing through the brush cutting frame 2 so that the shaft angles form an obtuse angle. The transmission shaft 4, which is provided through the brush cutting frame 2, is prevented from swinging by a bushing metal built into the pipe 2, and the transmission shaft 4 is
The transmission shaft 3 is screwed into the boss part of the internal gear 19 of the gear coupling ring having a bearing 17 at the end of the pipe part 12 of the transmission shaft 3, and is provided through the fuselage frame 1, with one end built into the housing 8. The other end is screwed into the spline shaft 23 which has bearings 22 at both ends inside the cylindrical part 6 of the gearbox 5, and the middle part is connected to the drum of the centrifugal clutch which is supported by the pipe 1.
The built-in button metal prevents swinging. One end of this spline shaft 23 is screwed into the boss portion of the internal gear 18 of another set of gear couplings, and both gear couplings 18, 19, 2
0 and 21 are respective external gears 20,
21, a spline hollow shaft 24 and a spline shaft 25 are connected to each other so as to be slidable in the axial direction, thereby forming a bending and retractable joint. The gear coupling springs 18, 19, 20, and 21 are configured with tooth profiles to form a large displacement angle, and the external gears 20,
21 to allow spherical movement and snap the snap spring 2.
6, and therefore the transmission shafts 3 and 4 are
The same rotation can be performed smoothly even during bending, stretching, and contracting movements. A cylindrical gear (input gear) 27 splined to the shaft 23 meshes with either the larger or smaller gears 29 and 30 forming a right-angled shaft by operating the shifter 28, thereby forming a two-speed front reduction section. Both gears 2
9 and 30 constitute the same rotating body as the sun gear 31, and the shaft 31-S of the sun gear 31 passes through the hollow shaft part 39 of the planetary carrier 40 vertically supported by the central boss part 36 of the internal gear 32. Both ends are supported by bearings 34. The internal gear 32 has a gear blank (material before gear cutting) in the shape of a bell, and its upper flange is fixed to the lower end of the vertical shaft cylindrical part 37 of the gear box 5 with a screw 38, and the spline shaft 23 and the orthogonal shaft are fixed. It sticks like an eggplant. The planetary carrier 40 freely rotates on a hollow shaft 39 with a bearing 42 concentric with the internal gear 32, and the upper end of the hollow shaft 39 is fixed with a round screw 43 to receive thrust. Flange portion 4 of planetary carrier 40
1, a planetary gear 33 and a crank 46 are attached to a spline 4 on a planetary pin 45 bearing a bearing 44 so as to rotate in reverse.
7 and fastened with screws 48 to form the same rotating body. The sun gear 31 passes through the hollow shaft 39 of the planetary carrier 40 and has its upper end connected to the cylindrical portion 6 of the gearbox 5.
The lower end of the planetary gear 33 is mounted on a disc 80 with both end bearings 34, and therefore the planetary gear 33 meshes with the internal gear 32 and the sun gear 31 simultaneously to form a single planetary gear unit. The disc 80 that seals the opening on the lower side of the internal gear 32 has a window hole at the engagement center distance A position to allow the planet pin 45 to pass through, and is an egg-shaped disc that is integrated with the hollow shaft 39 of the planetary carrier 40. This cover is fixed to the lower surface of the large circular portion of the flange portion 41 with stud screws 54 and rotates together with the carrier 40. The crank 46 is inserted into and fixed to the spline portion 47 of the planetary pin 45 that protrudes through the disk 80, has several mounting holes 51 lined up in the arm portion 46, and has a crankshaft that is rotatably supported on the support 11. 52
is fixed with a screw 53 to form a crank 46, which supports and receives the brush cutting frame 2 and adjusts the cutting width by changing the mounting hole 51. The tip of the pillar 11 is the link 5
The lower end of 0 and the spherical bearing 49 are paired, and the link 50
The upper end is fixed to a joint 56 with a pin 57 so as to swing in the axial direction of the body frame 1, forming a fulcrum part to support and receive the brush cutting frame. The joint 56 is vibration-proofed with rubber 58 and attached to the fuselage frame 1.
Attach to. The U-shaped handle 60 has a joint 56 so that its angle can be adjusted in the axial direction of the fuselage frame 1.
When the rope starter 65 of the engine 10 is installed, it serves as a stand when the aircraft is turned over. The throttle lever 61 is the handle 60
A stand 62 attached to the handle of the engine 10 and fixed to the engine 10 also serves as a safety guide. The engine 10 rotates to the left when viewed from the transmission shaft 3 side, and therefore the cutter 1
5 rotates to the left when viewed from the top.

Next, the configuration of the second embodiment will be explained.
The engine 10 attached to the backpack 66 is connected to the V pulley 67 of the drum shaft of the centrifugal clutch built into the housing 8 and bearing, and the V pulley 67 of the flexible transmission device 68 connected to the fuselage frame 1 and directly connected to the transmission shaft 3.
The power is transmitted by connecting a pulley 69 to a V-belt 70. Therefore, the rotation direction of the transmission shaft 3 is opposite to that in the first embodiment, and the cutter 15 is directly driven and rotated to the left. The brush cutting frame 2 has one end bent at an obtuse angle, and the cutter 15 is directly supported at the tip for flexible transmission.In place of the transmission shaft 4 of the first embodiment, a flexible shaft passing through the brush cutting frame 2 has one end. It is directly connected to the shaft of the cutter 15, and the other end is directly connected to the spline shaft 23. Therefore, the bevel gears of the gear coupling portion and the cutter portion are unnecessary, and the other configurations are the same as those of the first embodiment.

To explain in detail the configuration of the single planetary gear device of the embodiment, as described above, the fixed internal gear 32
The number of teeth of the planetary gear 33 is set to 2:1, and the planetary pin 4
The position of 5 is increased from the standard gear engagement center distance to mesh the sun gear 31, and the module of each gear 31, 32, 33 is m, the number of teeth is sun gear Z ₁ , planet gear Z ₂ , Assuming fixed internal gear Z ₃ ,
Standard mesh center distance of sun gear Z ₁ and planet gear Z ₂ A ₁₂₀
is A ₁₂₀ = (Z ₁ + Z ₂ ) m/2, and the standard meshing center distance A ₂₃₀ between fixed internal gear Z ₃ and planetary gear Z ₂ is, A ₂₃₀ =
(Z ₃ - Z ₂ ) m/2, and if the meshing center distance when increased due to dislocation is A, then the increase coefficient of both meshing rows is
Y ₁₂₀・Y ₂₃₀ is Y ₁₂₀ = (A-A ₁₂₀ )/m, Y ₂₃₀ =
The relationship is (A-A ₂₃₀ )/m, and when the meshing pressure angles α ₁₂₀ and α ₂₃₀ are calculated using the following formula, Bu (α ₁₂₀ )=2・Y ₁₂₀ /
(Z ₁ + Z ₂ ), cosα ₁₂₀ = cosαh/Bu (α ₁₂₀ ), Bu
(α ₂₃₀ ) = 2・Y ₂₃₀ / (Z ₃ − Z ₂ ), cos α ₂₃₀ =
The relationship is cosαh/Bu (α ₂₃₀ ). As a result, the meshing pressure angle α ₁₂₀ between the sun gear 31 and the planetary gear 33 tends to approach the tool pressure angle αh, and the meshing pressure angle α ₂₃₀ between the planetary gear 33 and the fixed internal gear 32 tends to be a high pressure angle. The calculation formula above is for the case where the back gap of the mesh is set to zero. Therefore, in the former mesh row, the back clearance is given and recalculated to cut the vertical displacement, and in the latter mesh row, the back clearance is reduced. Calculate zero and cut into vertical dislocation,
Smooth meshing can be achieved by re-cutting only the internal gear 32 at the transverse displacement to provide a back clearance. The amount of increase in the meshing center distance depends on the number of teeth of the sun gear 31, and in the example, Z ₁ =5 to 7. Also, the reduction ratio i of this gear device is j=Z ₁ /(Z ₂ +Z ₃ )=Z ₁ /(Z ₁
+2Z ₂ ), and if the tooth profile and strength are satisfied, a high reduction ratio can be obtained by decreasing the number of teeth of the sun gear 31 and increasing the number of teeth of the internal gear 32. This gear device has the characteristic that the transmission efficiency improves as the reduction ratio increases, and the internal gear 3
2 and the planetary gear 33 mesh with each other with uneven tooth surfaces, so the allowable tooth surface pressure is high. Moreover, the cycle of mowing motion is 30~
60r.pm, and the planetary gear 33 rotates at a low speed of 60 to 120r.pm, so the internal gear 32 can be made of light alloy or plastic to reduce weight, and the tooth profile can be made of cast iron to reduce cost.

Next, the motion locus of the single planetary gear device of the embodiment will be explained. As mentioned above, the planetary gear 33 meshing with the fixed internal gear 32 rotates and revolves due to meshing with the sun gear 31. A crankshaft 52 distant from the axis of the planetary gear 33 makes a crank motion drawing a straight line or an elliptical locus. The planetary gear 33 of the embodiment revolves around the engagement center distance A, which is increased from the standard, as a radius, and since the pitch circle does not pass through the axis of the internal gear 32, if the crankshaft 52 is installed on the pitch circle radius, the trajectory will change. is not a straight line but an oblong ellipse. The crankshaft 52 of the mounting hole 51, which is formed at a distance A from the axis of the planetary gear 33 on the crank 46 fixed to the planetary gear 33, moves linearly, and when the crankshaft 52 is slightly shifted to adjust the cutting width. The trajectory of motion is not a straight line but a hyperellipse. If the mounting position of the crankshaft 52 is made much larger than the engagement center distance A, the cutting width will be expanded, but the length of extension and contraction of the transmission will increase, and the sliding surface will tend to generate heat, reducing transmission efficiency. In this embodiment, in order to strengthen the attachment between the fuselage frame 1 and the gearbox 5, the cylindrical gear 27 of the front reduction section and both gears 2 are used.
Move the meshing position of 9 and 30 from the axis to the brush cutting frame 2.
I put it on my side. Therefore, the sun gear 31 is viewed from above,
The first embodiment rotates to the left, and the second embodiment rotates to the right.
reversed against. Normally, the brush cutter moves from the right side to the left, and the cutter 15 moves in a large circular arc locus while rotating to the left, along with the fan-shaped movement of the brush cutting frame 2. The bearing 49 only moves back and forth slightly. Then, by slightly shifting the crankshaft 52, the cutting width increases or decreases,
The longitudinal movement of the spherical bearing 49 increases by twice the amount of displacement. If the length of the fulcrum from the crankshaft 52 to the spherical bearing 49 is changed, the cutting width will greatly increase or decrease, and the longitudinal motion will change slightly. However, if the ratio of the number of teeth between the fixed internal gear and the planetary gear is set to something other than 2:1, for example, linear or elliptical motion will occur, but the locus of motion will be different for each revolution, creating a petal pattern, which cannot be applied to brush cutters. It is.

Next, the mowing action of the example will be explained.
First, to adjust the cutting width and cutting speed according to the work conditions, select the mounting position of the crankshaft 52,
The shifter 28 is operated to mesh the cylindrical gear 27 with either the large 29 or small 30 face gear. When mowing grass on a footpath, use a small mowing width and a fast mowing speed; when mowing hard grass such as mowing undergrowth in a mountain forest, use a medium mowing width and slow the mowing speed; When mowing, increase the cutting width and increase the mowing speed to increase work efficiency. Next, in order to prepare for starting the engine 10, the aircraft bodies 1 and 2 are turned over and stood on the handle 60. In the case of the first embodiment, the engine 10 stands upright on the stand 62 with the pipe section 9 of the housing 8 rotating freely, and in the case of the second embodiment, the joint between the flexible transmission device 68 and the fuselage frame 1 freely rotates. Therefore, keep the backpack 66 upright and place it on the ground. After confirming safety, start the rope starter 6.
5 and rotate the engine 10 at low speed. At low speed rotation, the centrifugal clutch of the engine 10 is released and the cutter 15 and brush cutting frame 2 are stopped, and after confirming this, the machine is carried. In the first embodiment, the one-touch hook 64 is hooked onto the shoulder band 63 that has been carried over the shoulder in the front, and in the second embodiment, the backpack carrier 66 is carried on the back, the body is returned to its normal position, and the handle 60 is grasped to take the mowing position. Take. After fully confirming safety, open the throttle lever 61 and start engine 1.
Increase 0 rotation. The centrifugal clutch of the small engine 10 normally operates at about 3000 rpm, and with this operation, the cutter 15 begins to bend and extend from side to side while rotating. That is, in the first embodiment, the transmission shaft 34 is connected to the gear couplings 18, 19,
20 and 21 are jointed and rotate to the left when viewed from the axial direction, and rotate in reverse due to the meshing of the bevel gear 13, so that the cutter 1
5 is rotated to the left when viewed from above (the same applies to plane rotating bodies below). On the other hand, the face gears 29 and 30, which are in mesh with the cylindrical gear 27 that rotates at the same time as the transmission shaft 3, are integrated with the sun gear 31 and rotate counterclockwise to achieve forward reduction (relative speed reduction).
I ₂₉ and I ₃₀ ) and rotate the planetary gear 33 to the right. Planetary gear 3 with an idling shaft mounted on a planetary carrier 40
3 rotates and meshes with the fixed internal gear 32, revolves in the left direction, and rotates at a low speed according to the overall reduction ratio I ₂₉ Xi or I ₃₀ Xi. Therefore, the crank 46, which rotates at the same time as the planetary gear 33, rotates clockwise while reciprocating the crankshaft 52 to the left and right of the machine frame 1 to make a linear or elliptical motion, and as a result, the brush cutting frame 2 is levered. At the same time, the spherical bearing 49 of the support column 11, which serves as a fulcrum, moves back and forth in the axial direction of the fuselage frame 1 by the link 50, and at the same time the blow 16 and the gear couplings 18, 19, 2
0 and 21 and the spline parts 23 and 24 bend and extend. At that time, gear coupling springs 18, 19, 20,
21 smoothly transmits power while making a two-stage bending movement in the displacement region of the lever movement, and therefore, the cutter 15 moves at a high speed while mowing the grass in a large arc locus expanded laterally by the lever movement of the grass cutting frame 2. This mowing motion locus is not similar to the motion locus of the crankshaft 52, but the mowing motion follows a fan-shaped circular arc formed by the spherical bearing 49 that moves back and forth. In addition, in the second embodiment, the gear couplers 18, 19, 20, 21 and the flexible transmission shaft replaced with the transmission shaft 4 rotate clockwise, and the cutter 15 directly connected and transmitted thereto rotates counterclockwise when viewed from the top. The gear trains 27, 29, 30, 31, 32, 33, 40 rotate in the opposite direction to the first embodiment. Therefore, planetary gear 3
The crank 46, which rotates at the same time as the first
As in the embodiment, the mowing motion is performed while rotating counterclockwise. At this time, the flexible transmission shaft bends and expands in two stages within the bellows 16 to transmit the transmission. Therefore, it is more effective to make the crank motion a linear or oblong locus because the rate of bending and stretching is small. In both embodiments, even when the crankshaft 52 moves linearly or elliptically, the fulcrum 49 moves back and forth, so the cutter 15 moves in a large circular arc to cut the grass. Further, in the first embodiment, the gear couplings 18, 19, 20, 21 and the splines 24, 25 are replaced with flexible transmission joints and a bending and retractable joint is constructed and interlocked with each other in the same manner as in the second embodiment.

Moreover, if the shifter 28 is set to the neutral position, the meshing between the cylindrical gear 27 and both gears 29 and 30 is released, and at the same time, the brush cutting frame 2 is made concentric with the body frame 1 and the crank 46 is fixed to the support 11, Both frames 1 and 2 are made into straight rods and can be operated like a conventional brush cutter, making it convenient for cutting vegetation in narrow terrain.
At this time, if an excessive external force is applied to the cutter 15, the meshing points of the planetary gear trains 31, 32, and 33 are locked, so it is safe. Also, even if an excessive external force is applied during the mowing motion, a similar effect occurs, and the sun gear 31 is decelerated to a high speed and then rotates at a constant speed, so there is no possibility of reverse rotation or acceleration due to being caught. be. Furthermore, when the throttle lever 61 is closed, the engine speed rapidly decreases by 10 rpm, the centrifugal clutch is released, and the rotation of the cutter 15 and the mowing motion are simultaneously stopped. Stop.

To explain in detail the mowing action of the example,
Based on a conventional brush cutter, the brush cutter frame 2
The weight of the fuselage frame 1 including the engine 10 is
This can be configured to less than 1/3 of the fuselage frame 1, and because it is levered by the crankshaft 52 that reciprocates linearly, and because it moves at a low speed of 30 to 60 revolutions per minute, there is little reaction. It can be held stationary and carried for mowing work. However, if, for example, the spherical bearing 49 becomes jammed or the bearing portion of the crankshaft 52 has a large play, the reaction will resonate and increase, making it difficult to cut the grass. This is because the force that automatically bends and stretches the two parts of the brush cutter frame to change its posture is internal to the brush cutter system.
Depending on how the second part of the brush cutting frame is driven, the reaction may similarly increase. In the automatic bending and stretching motion of the present invention, the moment of inertia of the entire brush cutting section is maximum at the center where the spherical bearing 49 moves back and forth and the driving force of the crankshaft 52 acts at right angles to the brush cutting frame 2.
On the left and right sides that act at an acute angle, the moment of inertia of the oblique shadow that acts when the posture of the cutting section becomes small becomes smaller. Therefore, due to the moment of inertia that reacts against the driving force of the high deceleration, linear, and elliptical motion gear system, the increase in angular acceleration of the crankshaft 52, which cranks at an inconstant speed, is softened and the reaction is reduced, and the back and forth motion of the bending and stretching motion is reduced. The angular momentum in the direction is extremely small, and the inertial mass of the engine 10 and the body frame 1 part cancels out the recoil that still occurs, making it recoilless. According to experiments, recoil tends to occur at the dead center in the deceleration bending/extending direction at an appropriate mowing speed. However, if the overall reduction ratio of the gear system is adjusted to the appropriate speed, the engine 1
Even when rotating 0 at full speed with no load, there is no recoil. In the single planetary gear device of the embodiment, the planetary gear 33 meshes with the sun gear 31 and the fixed internal gear 32 at two points on the inside and outside to perform a braking action (locking action), thereby eliminating recoil. make a target In other words, the cutter 15 rotating at high speed moves forward while drawing a small arc on the right side of the movement trajectory, accelerates and cuts the mowing while increasing the amount of cutting in front of the large arc, and in the latter half decelerates while mowing the standing grass. It cuts the grass in a manner that wraps around the grass, and on the left side, it moves in a small circular arc to release the cut vegetation. After being released, the cutter 15 moves backward while slightly floating and moves back along the rear surface of the large arc, accelerating in the first half and decelerating in the second half. Therefore cutter 15
Since the mower moves away from the standing grass and moves back, there is no need to mow twice, and the operator can carry out the mowing work simply by lightly supporting the handle 60 and walking naturally. With conventional brush cutters, it was necessary to pull the machine body back and forth in each mowing cycle, or twist the machine body to perform a release motion, but in the present invention, the rotation plane of the cutter 15 is slightly moved relative to the mowing plane. By attaching it tilted to the left, it is possible to perform mowing and release motions without causing the cut plants to scatter. Moreover, the recoil caused by the automatic mowing movement is small, and the machine frame 1
The stationary inertia of the cutter 15 cancels out the vibrations and reaction that occur in the cutter 15 during reaping, allowing the operator to cut the grass easily.

Next, other embodiments of the linear/elliptic motion gear device will be described.
In the combination of 32 and 33, when an internal gear is provided on the inner surface of the planetary gear 33 and the sun gear 31 is internally meshed with the internal gear, the planetary gear 33 will revolve in the opposite direction. In this case, the pitch circle radius of the planetary gear 33 is larger than the meshing center distance A, so that the crankshaft 52 can be directly attached to the planetary gear 33 for linear or elliptical movement. This gear system requires attention because the input and output shafts move in opposite directions, causing a loss unique to planetary gear systems (planetary loss). Next, if the planetary gear 33 that meshes with the fixed internal gear 32 is provided with a concentric variable-diameter external gear, and the sun gear 31 and the meshing gear train are made into a double row, the internal gear trains 32 and 33 are replaced with standard gears. It is possible to form an interlocking configuration. In this gear device, a loss (planetary loss) occurs because the planetary gears mesh with different diameters.
If both planetary gear units have the same size as the planetary gear unit described above, the reduction ratio will be small.

Next, as another example, instead of the fixed internal gear 32, a fixed external gear with twice the number of teeth of the planetary gear 33 is provided at the center so that the external teeth mesh with each other, and when the planetary carrier 40 is rotated, the planetary gear 33 A point passing through the center of the fixed external gear of the crank 46 that rotates in the same direction and fixed to the same gear 33 moves linearly, and a point away from the axis moves elliptically. When these two gears are replaced with sprocket gears and chained, and the planetary carrier 40 is rotated, the sprocket planetary gears rotate in the opposite direction, and the crankshaft 52 similarly moves linearly or elliptically.

Also, to explain an example in which the output member of the gear device rotates in a circular locus and performs mowing motion, when the support column 11 of the embodiment is directly attached to the planetary pin 45 and moves in a circular motion (revolutionary motion), the locus of motion of the cutter 15 is as follows. On one axis of the body frame, the diameter of the circular motion forms the short axis, and the mowing motion is performed in a large arc-shaped approximate ellipse extending left and right. In this embodiment, the degree of elongation in the longitudinal direction is small, and in order to obtain a large cutting width, it is necessary to lengthen the cutting frame 2 and increase the leverage ratio.In order to adjust the cutting width according to the work, the support 11 It is necessary to change the mounting position of the link 55 and at the same time change the fixing position of the link 55.

Also, even if the gear device is installed on the brush cutting frame side,
As before, the mowing motion is performed in a large arc. This embodiment will be explained with reference to FIGS. 6 and 3. In this embodiment, a gear device built into a gear box 5 and a set of bendable telescoping joints are installed with the orientation changed by 180 degrees. 19, 21, 24,
25 is attached to the tip of the fuselage frame 1 and the transmission shaft 3
The gearbox 5 at the front is directly connected to the cylindrical part 6.
The upper end of the brush cutting frame 2 is extended and inserted, and the screw 7 is fixed, and the spline shaft 23 is directly connected to the transmission shaft 4, thereby forming a brush cutting section in which the gear device moves in a bending and stretching manner integrally with the brush cutting frame 2. do. Therefore, the pillar 11
Since it is not necessary to support and receive the gearbox 5 by the crankshaft 52, the entire gear unit of the gearbox 5 is installed upside down and the tip of the lightning-shaped fixed support 1-11 newly installed at the front upper part of the fuselage frame 1. The cylindrical part 6 on the side bearing the cylindrical gear 27 of the gearbox 5 is extended and the sphere of the spherical bearing 49 is fixed to the tip thereof, and the link 50 is suspended and supported by the crankshaft 52. -11, and forms the aforementioned fulcrum parts 49 and 50 to support and receive the brush cutting part at two points. Then, the inside of the cylindrical portion 6 to which the sphere of the spherical bearing 49 is fixed is inserted into the gear coupling 1.
8, 19, 20, 21 or a flexible transmission 68 to be connected to the centrifugal clutch drum of the engine 10, thereby forming a bending/extending transmission. Therefore,
When the engine 10 rotates the transmission shafts 3 and 4,
Each gear train 27, 29, 31, 33 rotates in the opposite direction to the previous embodiment, and the gear train is connected to the brush cutting frame 2.
The fulcrum portions 49, 50 move as one body to swing left and right around the crankshaft 52.
moves back and forth and bends and stretches. As in the previous embodiment, the cutting width can be increased or decreased by changing the position of the mounting hole 51 of the crank 46 or by changing the length from the crankshaft 52 to the fulcrum. However, although the weight of the gear device is added to the second part of the brush cutting frame, the moment of inertia only increases slightly because it is close to the bending/extending joint and the center of equilibrium when the two are integrated is on the gear device. Recoil is prevented by making it recoilless.

As is clear from the above explanation, the present invention includes:
This is an automatic retractable brush cutter in which the retractable and retractable jointed mower body is supported and levered by a gear system in which the output member is cranked, and the fuselage part can be configured to have the same weight as conventional models. It is strongly supported by the crank part and the fulcrum part, and the cutting width is expanded by levering and bending/extending movements, so the gear system can be simplified, made smaller, and lighter.

The present invention provides a small and lightweight automatic bending brush cutter that can be carried with the body frame that forms the prime mover stationary, and can be cut by simply grasping the handle lightly, thereby eliminating the problem of numbness in the hands and fingers. Furthermore, since the ideal mowing motion is automatic with no reaction, there is less fatigue during work, and the mowing blade can be easily adjusted to suit the work, so safety can be ensured.

Moreover, in addition to being portable, simple wheels 81 can be attached to and removed from one part of the body frame, and even an inexperienced person can easily cut the grass by using it as a hand-held type.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the entire first embodiment of the present invention, FIG. 2 is a perspective view showing the entire second embodiment, and FIG. 4 is a plan view of FIG. 3, FIG. 5 is an exploded perspective view of the configuration of FIG. 3, and FIG. 6 is a cross-sectional view showing the gear device.
The figure is a perspective view of an embodiment equipped with wheels. In addition, in the drawing, 1... Aircraft frame, 2... Brush cutting frame, 3
...Transmission shaft, 4...Transmission shaft, 5...Gear box, 6...Cylindrical part, 7...Screw, 8...Clutch housing, 9...Boss part, 10...Engine, 1
1... Support column, 1-11... Fixed support column, 12... Pipe section, 13... Bevel gear box, 14... Cylindrical section,
15... Cutter, 16... Bellow, 17... Bearing, 18... Internal gear, 19... Internal gear, 20... External gear, 21
...External gear, 22...Bearing, 23...
... Spline shaft, 24 ... Spline hollow shaft, 2
5...Spline shaft, 26...Snat spring,
27...Cylindrical gear, 28...Sictor, 29...
Face gear, 30... Face gear, 31... Sun gear, 3
1-S...Sun gear shaft, 32...Internal gear, 3
3... Planetary gear, 34... Bearing, 36...
Center boss part, 37...Vertical shaft cylindrical part, 38...Screw, 39...Hollow shaft, 40...Planetary carrier, 4
1...Flange part, 42...Bearing, 43...Round screw, 44...Bearing, 45...Planet pin, 46...
Crank, 47...spline, 48...screw,
49... Spherical bearing, 50... Link, 51... Mounting hole, 52... Crankshaft, 53... Screw, 54
...Studded screw, 56...Joint, 57...
...Pin, 58...Rubber, 60...Handle, 61
... Throttle lever, 62 ... Stand, 63
...Jewel band, 65...Rope starter, 66...Backpack, 67...V pulley, 68
... Flexible transmission device, 69 ... V pulley, 70 ... V belt, 80 ... Disc, 81 ...
Wheel.

Claims (1)

[Claims] 1. Two power transmission shafts that connect the other end of the machine frame with the prime mover attached or linked to one end and the other end of the brush cutting frame with the cutter mounted on one end in a bendable and telescopic manner, and that are provided through both frames respectively. A gear box with a built-in high reduction gear unit, which is linked by a bendable telescopic joint in the joint part, and a front reduction part meshing with an input gear directly connected to a transmission shaft and a right angle shaft, and a high reduction gear unit directly connected by the shaft of a sun gear. Attach the joint to one of the frames at the front or rear of the joint, receive the crank bearing on the other frame, and link the fulcrum of the brush cutter frame to the machine frame to connect the crank.
A lever bending/extending movement mechanism is constructed, and the crank constitutes the same rotating body as the planetary gear that meshes with the sun gear of the high reduction gear device, and the length of the arm of the crank or the length from the crank shaft to the fulcrum is changed. Automatic bending brush cutter that adjusts the cutting width.