JPH0224423Y2 - - Google Patents

Description

[Detailed explanation of the idea] (Industrial application field) The present invention relates to 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.

In the above-mentioned lawn mowers, it is desired that the cutter housing be made of synthetic resin in order to reduce costs such as weight reduction, ease of molding, and reduction in material costs.

(Problem that the invention aims to solve) By the way, when the cutter housing is molded from synthetic resin, it tends to lack rigidity compared to metal, and the front part of the circular cutter housing is in the direction of movement, so it cannot be easily moved in the direction of movement during lawn mowing work. There is a possibility of hitting a certain tree or other obstacle, and there is a risk that the front part of the cutter housing may be slightly deformed due to the collision with the obstacle.
As a result, if the gap between the cutter blade rotating inside the housing and the front inner wall of the cutter housing is constant as in the past, the gap at the front becomes smaller, and there is a possibility that interference may occur in some cases. .

The present invention has been made to solve the above-mentioned technical problems of a synthetic resin cutter housing.

(Purpose of the invention) The purpose of the invention is to provide a power lawn mower whose cutter housing is made of synthetic resin, so that even if the front part of the housing, which is located at the frontmost part in the direction of travel, hits an obstacle, the deformation is small and the deformation is small. To provide a power lawn mower in which a cutter blade and a front inner wall of a housing do not interfere with the blade even if the blade is heated.

(Means for Solving the Problems) In order to solve the above technical problems, the present invention offsets the center of the front half of the peripheral wall of the cutter housing forward to reduce the clearance between the front part of the peripheral wall of the cutter housing and the cutter blade. The clearance between the cutter housing and the peripheral wall is larger than that of the cutter housing, and a rib projecting forward is formed integrally with the housing at the front part of the cutter housing peripheral wall.

(Effects of the above means) According to the above means, the rigidity of the front part of the housing is increased by the ribs, and deformation in the event of a collision is prevented. Even if deformation occurs, the clearance between the front part and the cutter blade is large, so the blade No interference occurs between the front inner wall and the front inner wall.

(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 lawn mower 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 an engine is located in the center of the housing 2. 5, which is covered with an engine cover 6. Handles 7 extend upwardly from the rear left and right sides of the housing 2, and a grass bag 11 for storing cut grass is attached to the rear of the housing 2.

As shown in FIGS. 2 and 3, the cutter housing 2 has a circular peripheral wall 2.
01, the peripheral wall 201 is opened downward, and the peripheral wall 2
01 upper end portion includes a top wall 202, the center portion 203 of the top wall 202 is molded one step lower, and the vertical crankshaft 50 of the vertical engine 5 mounted above
1's output section 502 is suspended through a circular opening 204, a cutter blade 8 is fixed to the lower end of the output section 502, a discharging fan 9 is coaxially fixed on the cutter blade 8, and is covered with an inner cylinder part 205. Engine 5 has 50 cylinders
3 is horizontal, and the crankshaft 501 is vertical, and a cooling fan 5 is installed at the upper end of the crankshaft 501.
04 is fixedly installed, the engine is covered with a cover 6, and a recoil starter pulley 10 is provided on the center of the cover 6. 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 9 to generate a discharging wind for discharging the grass. The cut grass is drawn into the inner cylinder part 205 from the part 204 and transferred to the discharge duct part 206 at the rear of the housing 2. In addition, 506 in the figure is the crankshaft 5
This is an intermediate shaft for driving 4 rear wheels driven by 01.

In the above, the peripheral wall 201 of the housing 2 has a circular shape, surrounds the cutter blade 8, and
The front part 207 of 01 is bulged forward, and the locus a of the outer end of the cutter blade 8 and the inner wall 208 of the front part 207 are
The clearance S between the inner wall 210 of the other portion 209 is set larger than that of the inner wall 210 of the other portion 209. And the surrounding wall 201
An extending piece 211 whose front part faces downward is provided forward from the upper end of the front part 207, and both sides of the extending piece 211 are continuous with both side pieces 212 which protrude forward from the upper left and right halves of the front part 207. The extending piece 211 and the side piece 212 are molded integrally with the housing 2, and constitute a front rib.

FIG. 4 shows a longitudinal cross-sectional view showing only the front part for ease of understanding, and FIG. By offsetting the front part 207 as shown in b and c, the front part 207 bulges forward, and a larger clearance S is formed between it and the locus a of the cutter blade 8 than in other parts. Become.

(Effects of the invention) As is clear from the above, according to the invention, when the cutter housing is molded from synthetic resin, the front part of the housing facing the frontmost part in the direction of travel is reinforced with ribs and therefore has high rigidity. Even if it collides with an obstacle during mowing work, there is very little deformation.
Even if deformed, the clearance between the cutter blade and the front part is large, so there will be no interference between the blade and the inner wall of the front part, allowing smooth lawn mowing work. Furthermore, since the center of the front portion of the cutter housing peripheral wall is offset forward, the entire front portion of the cutter housing peripheral wall is oriented forward. Therefore, even if the front portion of the cutter housing hits an obstacle and the cutter housing is displaced rearward as a whole, contact between the front half of the cutter housing peripheral wall and the cutter blade can be prevented.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is an external perspective view of a lawn mower, Fig. 2 is a vertical side view of the main parts of the cutter housing, Fig. 3 is a bottom view of only the cutter housing, and Fig. 4 is a bottom view of only the cutter housing. The figure is an explanatory vertical sectional view of only the front part of the cutter housing, and FIG. 5 is an explanatory bottom view of the same. In addition, in the drawing, 1 is a power lawn mower, 2 is a cutter housing, 207 is a front part, 211, 212 are ribs,
8 is a cutter blade.

Claims (1)

[Scope of Claim for Utility Model Registration] A power lawn mower in which a cutter housing that is substantially circular in plan view surrounding a cutter blade is formed of synthetic resin, wherein the center of the front half of the circumferential wall of the cutter housing is offset forward. The clearance between the front part of the peripheral wall of the cutter housing and the cutter blade is larger than the clearance between the peripheral walls of other parts, and the front part of the peripheral wall of the cutter housing has a rib that projects forwardly formed integrally with the housing. Powered lawn mower.