JPH0436644B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to improvements in powered lawn mowers.

(Prior Art) A power lawn mower that uses engine power to drive the cutter and move the cutter has been put into practical use. Equipped with.

In order to simplify and downsize such a lawn mower, if the mowed lawn (grass) is discharged to one side from the discharge section provided in the body housing as in the past, the structure of the housing becomes complicated, and There is a risk that the structure of the lawn mower will become more complicated and larger, such as requiring a discharge fan.

(Technical problem to be solved by the invention) Therefore, if the front and rear of the housing are opened and the cut grass is left behind in the direction of movement and discharged, the structure of the housing can be simplified and a discharge fan is not required. Therefore, it can be further simplified and downsized.

By the way, when the front and back of the housing are opened, the drive part of the cutter protrudes downward in the middle part, so it is necessary to smoothly infiltrate and cut the grass up to the cutter in the housing. Because of this, it is possible to force the grass into the cutter from both the front and rear directions.Therefore, if the grass can be moved in both the front and rear directions, mowing work can be conveniently performed in a reciprocating motion without having to change direction. If such a configuration is adopted and the inner and rear wheels of the front and rear wheels are driven, the front opening can be set large because the front wheels are rolling wheels and do not have a drive or transmission mechanism. Because of the drive and transmission mechanism, the ground clearance is inevitably low, and there is a risk that the rear opening may become small. When mowing is performed by moving the lawn mower, if the grass is higher than the rear opening, the grass will fall down more and the mowing height will vary, which is not preferable for smooth mowing.

The present invention has been made to solve the above-mentioned technical problems, and its purpose is to provide a lawn mower with open front and rear ends that can be moved forward and backward, to smoothly discharge lawn mowings.
To provide a power lawn mower designed to facilitate mowing work during backward mowing.

(Means for solving the technical problems) The means for solving the above technical problems are equipped with wheels on the front and rear left and right, and between the front and rear wheels a cutter that is rotationally driven in a horizontal plane by engine power. In a power lawn mower that can move in either the front or back direction by driving its wheels, the front, rear and lower parts of the body housing are open, side pieces are provided on both sides, and the front wheels can rotate independently on both the left and right sides. In addition to being rotatably supported, both left and right rear wheels are independently supported, and the rear wheel drive shaft is disposed above and in front of the rear wheel support shaft.

(Effects of the above means) According to the above means, since the front wheels of the housing are each independently pivotally supported, and the drive and
Since there is no transmission system, the open area can be set large, while the rear wheels are each independently pivoted.
Since the drive shaft of this is disposed above and in front of the support shaft, the part that covers this part of the housing is less likely to protrude high and rearward, and the rear opening can be set large, and from this part The grass (grass) can be guided and discharged smoothly, and taller grass (grass) than in the open part is less likely to fall down, and the mowing height is the same as that of a cutter, allowing smooth and accurate mowing.

(Embodiment) Next, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a lawn mower, and the lawn mower 1 has two front wheels 3, which are rollers, on the left and right sides of the front of the machine body 2, and two rear wheels 4, which are drive wheels, on the left and right rear parts. An engine 5 is provided on the fuselage 2, and a handle 6 is provided at the rear so as to tilt backward and upward.

As shown in FIGS. 2 and 3, the fuselage 2 consists of a frame 7 and a housing 8, and an engine 5 is mounted on the frame 2. The engine is a vertical engine with a vertical crankshaft, and a clutch mechanism 9 is attached to the lower end of an output shaft 501. A vertical cutter drive shaft 101 is fixedly fixed to the outer 902 below, and the lower half of the shaft 101 extends downward from the boss portion 702 of the container-shaped main body 701 of the frame 7. The cutter 10 is fixed to the lower end, and the main body 701 is surrounded by a bowl-shaped middle part 801 of the housing 8.

The wheels 3, 3 are supported by two arms 70 provided at the front of the frame 7 so as to be spaced apart laterally and inclined upward.
3,703, the middle part is horizontally supported between 11, both ends 111, 111, and the rear upper base 121, 121
The support shaft 301 of the front wheels 3, 3 is attached to the tips 122, 122 of the stays 12, 12, which hang down so as to be tilted forward and downward.
301, thereby supporting the front wheels, the left and right front wheels are supported independently, and the support shafts 301, 3
01 does not protrude inside the left and right support stays. Therefore, the space between the left and right front wheels 3, 3 is completely open. The rear wheels 4, 4 are supported by two arms 704, 705 provided at the rear left and right sides of the frame 7 at the base 13.
Reduction case 13 with 1,141 bound together,
14 via support shafts 401, 401. The reduction cases 13 and 14 are formed so that the respective rear end portions 704a and 705a of the arms 704 and 705 expand obliquely outward in a plan view and are tilted upward so that there is a sufficient gap between them. Bases 131, 14 of reduction cases 13, 14
1 is positioned above and behind the clutch mechanism 9 described above.

Between the base parts 131 and 141 which are the upper parts of the reduction cases 13 and 14, an intermediate transmission shaft 15 serving as a drive shaft is horizontally mounted, and both ends of the intermediate transmission shaft 15 are rotatably supported by bearings 16.
The final drive shaft 18 is supported horizontally between the boss portions 132 and 142 at the intermediate portions of the reduction cases 13 and 14, and the one end portion 151 is extended and the sprocket 17 is fixed thereto. is rotatably supported by a bearing 19, and pinions 20 are fixedly installed on both ends 181, 181 of the shaft, and meshed with internal gears 402, 402 provided on the inner surfaces of the rear wheels 4, 4,
Rotation of the shaft 18 causes a pinion 20 to rotationally drive the rear wheels 4, 4, and the shaft 18 is connected to a cylindrical holding member 2 horizontally fixed between the opposing inner end surfaces of the boss portions 132, 142.
It passes through 1. A sprocket 22 is fixedly installed in front of the pinion 20 at one end 181 of the shaft 18,
This is connected to the sprocket 17 via a chain 23, and the output of the shaft 15 is transmitted to the shaft 18.

In the embodiment of the boss portions 132, 142 of the reduction cases 13, 14 that support the drive shaft 18 described above, the reduction cases are provided at bent portions because the side surfaces are approximately inverted L-shaped as shown in the second figure. Part 13
2, 142 is horizontally mounted behind the high-level power transmission shaft 15 supported between the bases 131, 141 and at a slightly lower and higher position. Further, shaft support boss portions 134, 144 are provided in the intermediate portions of the hanging portions 133, 143 of the reduction cases 13, 14 to project outwardly, and the above-mentioned support shafts 40 are provided on the boss portions 134, 144.
1,401 fixed, the hub part 403 of the rear wheels 4, 4,
403 is supported via bearings 404, 404.
Due to this wheel support structure, the support shafts 401, 401 are located in the reduction case 13, which is sufficiently spaced left and right.
14 and does not protrude inside the support shaft 40.
1,401 is below, whereas the wheel drive shaft 18
As is clear from FIGS. 2 and 3, it is arranged at an upper level and faces forward from the vertical extension line N of the support shafts 401, 401. The holding member 21 has flange portions 211, 211 at both ends connected to the boss portions 132, 142 of the left and right reduction cases 13, 14, and also functions as a cross member therebetween.

A pair of friction disks 24 and 25 are arranged on the intermediate portion of the intermediate transmission shaft 15, spaced apart in the axial direction, and are rotatable together with the shaft 15 via cylindrical boss portions 241 and 251, and are slidable in the axial direction. provided, boss part 2
A return spring 26 is compressed around the shaft between opposing ends of the shafts 41 and 251, and the spring 26 is covered with a dust boot 27 to prevent dust.

A pulley 28 having a friction roller 29 in its upper portion is disposed below between the peripheral friction portions 242, 252 of the friction disks 24, 25.

The pulley 28 is rotatably supported via a support shaft 281 provided on the rear end of an arm portion 706 extending rearward from the rear intermediate portion of the frame 7. Since the roller 29 faces between the high friction disks 24 and 25, it is disposed above the frame. On the other hand, a drive pulley 30 is provided above the clutch mechanism 9 of the output shaft 501 of the engine 5, a belt 31 is stretched between the pulleys 30 and 28, and the rotation of the output shaft 501 is controlled by the clutch outer 902.
is transmitted to the pulley 30 via the belt 31, and is transmitted to the pulley 28 and friction roller 29 via the belt 31, and the shaft 15 is rotated to one side by the frictional engagement of one of the discs 24 and 25 with the roller 29. , the sprocket 17, the chain 23, and the sprocket 22 rotate the drive shaft 18, and the wheels 4, 4 are driven by the meshing of the pinions 20, 20 and the internal gears 402, 402, thereby turning the vehicle forward and backward. By the way, a clutch roller 32 is provided inside the middle part of the belt 31, and when the belt 31 is tightened and loosened, the pulley 3
Power transmission between 0 and 28 is disconnected. 3 in Figure 3
3 and 33 are switching mechanisms for sliding the disks 24 and 25 on the shaft 15 and selectively engaging the disks with the roller 29.

By the way, the housing 8 has left and right side pieces 802, 8.
The sides are closed with 02, but the front and back are open 803, 8
04, and is also opened downward, and the side pieces 802, 8
The lower edge 802a of the cutter 02 is slightly lower than the cutter 10. The upper piece 806 of the front part 805 of the housing 8 is tilted forward and upward to open 803, and is connected to the bowl-shaped intermediate part 801 by tilting backward and downward from the front end so as to surround the main body 701 of the frame 7 in which the clutch mechanism 9 is housed. The housing rear part 807 is tilted upward and backward from the rear part of the bowl-shaped intermediate part 801, and the front part 808 of the rear part 807 approaches the arm 706 and pulley 28 mentioned above and faces the upper part, and the rear part 808 is tilted at a steep angle. The shaft 18 is tilted rearward and upward to approach the holding member 21, and the rear end portion 810 stands vertically upward. and side piece 802,
The front part 802b and the rear part 802c of 802 are the wheels 3,
Facing between 3 and 4, 4, middle part 802d, 80
2d bulges outward symmetrically in an arc shape.

In the above, if the left side in Figure 2 is forward movement,
As the lawn mower 1 moves, the grass enters between the side pieces 802 and 802 from the open part 803 and is cut by the cutter 10. In this case, since the front end of the front part 805 is at a high level, the open part 803 Since it is sufficiently large, grass can enter smoothly and the mowing operation can be carried out smoothly and reliably. The cut grass moves backwards as the mower moves forward, but the rear part 807 is high.
In addition, as described above, the rear opening portion 804 can be set large, so that it can be smoothly discharged to the rear.

On the other hand, assuming that the handlebar 6 is turned halfway and mowing work is performed while moving backward, the grass will enter the interior through the rear opening 804 by moving to the right in FIG. 2, and in this case, the shaft 18 will be Since it is at a high position, the portion 809 is also at a high position, and the open portion 804 can be made large. Therefore, the invasion of grass is done smoothly. By the way, in the case of grass that is taller than the open part 804, the upper end a of the open part 804 touches the grass and falls down, and the base touches the rear end b of the rotational trajectory of the cutter 10 and is cut, causing the grass to fall down. is as shown by the dashed line N1 in Figure 2, and since the shaft 18 is in front of and above the wheel 401 at the upper end a, the angle of inclination θ is small, and therefore the grass does not fall in the direction of movement, and the mowing is less. The height difference is not much different from the height of the cutter 10.

(Effects of the Invention) As is clear from the above, according to the present invention, since the opening at the front of the housing can be set large, the grass can be mowed smoothly when moving forward, and the cut grass can also be discharged from the rear. On the other hand, at the rear, each rear wheel is supported independently, and the drive shaft for this is located above and behind the rear wheel support shaft, so the part of the housing that covers this part is placed at a high level. It does not protrude rearward, and the rear opening can be set large, so that grass (grass) can be removed from this part.
Guide and discharge can be performed smoothly, taller grass (grass) falls less than in the rear open part, and the mowing height is no different from that of a stubble, allowing smooth and accurate mowing.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, in which Fig. 1 is a schematic side view of a lawn mower, Fig. 2 is a longitudinal sectional side view of the main parts thereof, Fig. 3 is a longitudinal sectional view of the rear wheel drive mechanism, and Fig. 3 is a longitudinal sectional view of the rear wheel drive mechanism. 4
The figure is a cutaway plan view of the same essential parts.

Claims (1)

[Claims] 1. A power lawn mower that is equipped with wheels on both the front and rear, and a cutter that is rotatably driven in a horizontal plane by engine power between the front and rear wheels, and that is capable of running in either the front or rear direction by driving the rear wheels. , the front, rear and lower sides of the fuselage housing are open, side pieces are provided on both sides, the front wheels are pivoted so that they can roll independently on both the left and right, and the rear wheels are also pivoted independently on the left and right, allowing for rear wheel drive. A power lawn mower characterized in that the shaft is disposed above and in front of the rear wheel support shaft.