JPH0437681B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a cutter housing for a power lawn mower.

(Prior Art) A power lawn mower is in practical use, which is equipped with a cutter blade that rotates in a horizontal plane within a cutter housing, has four wheels, and has the cutter blades and wheels driven by an engine.

A conventional cutter housing 50 is as shown in FIG. 5, and includes a circular peripheral wall 51 and an upper wall 52, and a scroll-shaped guide portion 53 is formed so as to tilt upward and backward from a portion near one side of the upper wall 52. The guide part 53 is connected to the duct part 54 at the rear, and a part 55 of the duct part 54 on the opposite side from the guide part 53 is provided with a partition wall 58 tilted forward and downward at a steep slope in order to merge with the flat upper wall 52. A nearly right-angled bent portion 57 is formed between the partition wall 56 and the upper wall 52.

(Problems to be Solved by the Invention) In the above conventional technology, a bent portion 57 is formed in a part of the upper wall 52 to form a duct and a guide portion for discharging grass, and a sudden cross-sectional change occurs at this portion. If the housing is made of metal such as a light alloy, there is no problem in practical use as the material itself has high rigidity and strength, but if the housing is made of synthetic resin, the material itself is more rigid than metal. It is inferior in terms of rigidity and strength, and stress is concentrated at the bent portion 56, which may result in insufficient rigidity and bending. To prevent this, the wall thickness of the housing is increased. In this case, the weight increases, which goes against the request for weight reduction.

The present invention has been made to solve the above technical problems.

(Objective of the Invention) The object of the present invention is to provide a power lawn mower that is advantageous in terms of rigidity and strength, and has excellent functionality, since when the cutter housing is molded with synthetic resin, there is no brittle part due to sudden cross-sectional changes. The machine is provided with a katsuta housing.

(Means for solving the problem) A power type mowing system that is equipped with an engine above the central part of the cutter housing, and has a cutter blade inside the cutter housing that is driven to rotate in a horizontal plane by the engine. In the cutter housing of a lawn mower, the cutter housing is made of synthetic resin, and the left and right parts of the upper wall of the cutter housing are formed continuously at approximately the same height so as to tilt rearward upward, and the upper wall rear part is formed continuously at approximately the same height. A partition wall for defining a discharge duct is installed vertically in the middle part of the lower surface in the left-right direction, and the rear walls of the left and right cutter housings of this discharge duct are approximately the same in height, and symmetrical handles are attached to the rear walls. It was installed by extending it from top to bottom.

(Effect of the above means) According to the above, the upper wall of the cutter housing is flat on both the left and right sides as if tilted backward and upward, and has approximately the same height, one side is low and the other is high, due to the difference in level between the low part and the rear part. There are no bends in the front-rear direction, and on the other hand, by installing the partition wall vertically, a discharge duct can be formed, and by making the heights of the side walls of the left and right cutter housings of this discharge duct approximately the same, The rigidity and strength of the cutter housing have been improved, allowing the symmetrical handle to be firmly and securely fixed across the top and bottom of the housing side wall, improving the rigidity of this side wall and reducing vibrations from the engine to the handle. Although the housing is molded from synthetic resin, it is possible to obtain a housing that is advantageous in terms of rigidity and strength, and is also excellent in functionality.

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

FIG. 1 is a perspective view showing the external appearance of a power-type core trimmer 1. Four wheels, left and right front wheels 3 and rear wheels 4 are provided at the four corners of a cutter housing 2 molded from synthetic resin, and a cutter housing 2 is provided with four wheels, ie, a left and right front wheel 3 and a rear wheel 4, in the center of the cutter housing 2. is equipped with an engine 5, which is surrounded by an engine cover 6. A handle 7 is extended rearward and upwardly from the rear left and right sides of the cutter housing 2, and a grass bag 8 for storing cut grass is attached to the rear of the housing 2.

The cutter housing described above is as shown in FIGS. 2 and 3, and the cutter housing 2 is equipped with a circular peripheral wall 201, the peripheral wall 201 is opened downward, and the upper end of the peripheral wall 201 is equipped with an upper wall 202, and the upper wall 202 The central part 203 is formed into a lower circular shape, and the output part 502 of the vertical crankshaft 501 of the vertical engine 5 mounted above is connected to the circular opening 204.
A cutter blade 9 is fixed to the lower end of the output section 502, and a discharge fan 10 is fixed coaxially thereon, and the fan 10 is surrounded by an inner cylindrical section 205. In the engine 5, a cylinder 503 is oriented horizontally, a crankshaft 501 is oriented vertically, a cooling fan 504 is fixed to the upper end of the crankshaft 501, the engine is covered with a cover 6, and a recoil star is mounted on the center of the cover 6. A tapuri 11 is provided. The hanging output section 502 of the engine 5 rotates the cutter blade 8 in a horizontal plane to perform lawn mowing work, and also rotates the coaxial fan 10.
A discharge wind for discharging the grass is generated, and the air is drawn into the inner cylinder part 205 from the opening 204 and is then passed through the discharge duct part 20 at the rear of the cutter housing 2.
Transfer the cut grass to 6. In the figure, 506 is an intermediate shaft for driving the rear wheels 4 driven by the crankshaft 501.

The upper wall 202 of the cutter housing 2 has a circular shape with a central portion 203 that is lower than the central portion 203. The opening 204 described above is formed in the central portion of the upper wall 202 of the cutter housing 2. is formed. Left and right portions 208, 20 of the top wall 202
9 are flat and formed at approximately the same height so as to be inclined rearward and upward, and continue to the upper end of the raised wall portion 207 and continue in the width direction to the rear portion 201 at the highest position.

The peripheral wall 201 has a circular shape, as shown in the bottom view of FIG. is bulkhead 21
1 is provided diagonally, an extension part 213 of this is formed in the tangential direction of the central part, the inside of the peripheral wall 201 is formed in a scroll shape, and a guide part 214 is formed on one side,
The cutter blade 9 rotates counterclockwise in the figure.
The guide section 21 guides the grass cut by the fan 10 described above.
4. The grass is fed into the duct 212 and discharged and stored in the grass bag 8. The rear side walls 217 of the left and right cutter housings 2 are formed with this discharge duct 212 and are continuous with the above-mentioned peripheral wall 201 and rear part 210.
are formed to have substantially the same height. Attachment portions 218, 218 are provided at the upper and lower portions of the rear wall 217 for attaching the handle column A of the symmetrical handle column A and upper handle B of the handle 7 described above. Further, at the upper part of the handle column A, a mounting part 219 is provided for mounting the handle B, which is also located at the upper part, so that the handle 7 can be made longer, making it easier to handle the handle 7. FIG. 3 shows a specific example of a cutter housing, in which reference numeral 215 indicates a front rib;
6,216 are ribs on both sides.

(Effects of the Invention) As is clear from the above, according to the present invention, one of the left and right upper walls of the cutter housing is lower than the conventional one.
The other side is higher, and there is no bend due to a step between the lower part and the rear part, and the left and right sides are flat as if tilted upward, and are continuous with the rear part at approximately the same height, so there are no weak parts, and the bulkhead By vertically installing the cutter housing, a discharge duct can be formed, and by making the side walls of the left and right cutter housings of this discharge duct almost the same height, even if the cutter housing is molded from synthetic resin, the rigidity and strength can be improved. The improved, left-right symmetrical handle can be firmly and reliably fixed across the top and bottom of the housing side wall, improving the rigidity of this side wall and reducing vibrations from the engine to the handle. Since a scroll-shaped guide part can also be formed, sufficient functionality can be obtained.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a perspective view showing the external appearance of a power lawn mower, FIG. 2 is a perspective view schematically showing the external appearance of a cutter housing,
Fig. 3 is a bottom view showing a specific example of a cutter housing, Fig. 4 is a vertical side view showing an example of a lawn mower,
FIG. 5 is an external perspective view of a conventional cutter housing. In addition, 1 in the drawing is a lawn mower, 2 is a cutter housing,
201 is a peripheral wall, 202 is an upper wall, 208, 209 are left and right parts, 210 is a rear part, and 211 is a partition wall.

Claims (1)

[Claims] 1. A cutter housing for a power lawn mower, which is equipped with an engine above the center of the cutter housing, and has a cutter blade rotatably driven in a horizontal plane within the cutter housing to mow lawns, wherein the cutter housing are made of synthetic resin, and the left and right parts of the upper wall of the cutter housing are formed continuously at approximately the same height so as to be tilted backwards and upwards, and a discharge duct is provided at the middle part in the left and right direction of the lower surface at the rear of the upper wall. The height of the rear walls of the left and right cutter housings of this discharge duct were approximately the same, and a symmetrical handle was installed by extending vertically across the rear walls. Katsuta housing for power lawn mowers is characterized by: