JPS61265012A - Production of cutter housing of lawn mower - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

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

(Prior Art) Lawn mowers are known that cut grass with a cutter that is driven by wheels and rotated in a horizontal plane by an engine.

In such lawn mowers, the cutter is covered with a skirt portion of the housing to protect the cutter.

(Technical Problem to be Solved by the Invention) In the following lawn mowers, the skirt part of the housing is of a type that completely covers the front part of the cutter, that is, the front part in the direction of movement of the lawn mower, and of a type that leaves this part open. When the cutter housing was put into practical use and the cutter housing was molded from synthetic resin to reduce weight and cost, two types of molds were prepared and molded: one with the front part of the skirt section cut off, and one with the front part. This increases the cost of the mold, which affects the cost of the product, which is undesirable.

The present invention has been made to solve the following two technical problems, and its purpose is to make it possible to mold both the long and short front parts of the skirt part with one mold. death,
An object of the present invention is to provide a method for manufacturing a power/interhousing for a lawn mower, which reduces manufacturing costs.

(Means for Solving the Technical Problems) The means for solving the following two technical problems include a cutter housing that is equipped with moving wheels and that is rotatably driven in a horizontal plane by an engine, and that surrounds the cutter. In a lawn mower equipped with a cutter housing, the cutter housing consists of a piece and a skirt part that hangs down from the piece and surrounds the cutter. The molding is performed by selecting an intermediate mold which is replaceably attached to the lower mold of the part corresponding to the front part of the skirt part.

(Effect of the above means) According to the above means, long or short lengths can be selectively molded by simply exchanging the intermediate mold of the part corresponding to the front part of the skirt between the upper and lower molds, and the mold itself can be molded. There is no need to prepare two types.

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

Figure 1 is a longitudinal cross-sectional view of the lawn mower (1), with the housing (2)
The housing (2) has a skirt part (201) that covers the circumference of the blade-shaped cutter (5) and a piece (202), and the rear part has wheels (3), (3) for moving the cutter. ”The cut grass outlet (203) is formed like two heads,
The housing is made of synthetic resin and all parts are integrally molded.

The engine (4) is mounted on the upper piece (202) of the housing (2).
), the engine (4) is a vertical engine with a vertical crankshaft in this embodiment, and the lower part of the crankshaft (401) is an output part (402).
A cutter (5) is fixed to the lower end of the output part (402) via a holder (501), and the cutter (5) is rotated in a horizontal plane. , perform lawn mowing work. The cylinder (403) of the engine (4) is oriented horizontally, and the upper part of the engine including these is covered with a cover (6). In the figure, (404) is a flywheel equipped with a cooling fan, and (405) is a recoil starter for starting. Also, reference numeral (7) is a handle whose base is fixed to both outer sides of the rear part of the housing and is provided so as to be tilted rearward.

In the above, the hanging skirt portion (201) of the housing (2) covers the entire circumference of the cutter (5),
The skirt portion (20+) in the embodiment shown in FIG. 1 has its lower end (201a) extending all around the lower surface (5
a) by a predetermined length Δh, covering the entire circumference including the front of the cutter (5) in the direction of movement with the same ground clearance, and
5) is located higher than the lower end of the skirt (201a) by a slight amount Δh. Therefore, when the lawn mower (1) moves to the left in Fig. 1 to perform lawn mowing work, the grass first moves to the skirt section (
201) 17) Front (20lb) (7) Lower end (20
The cutter (5) hits 1a), bends, and enters inside.
He was cut off at the scene. This creates resistance to the movement of the lawn mower during lawn mowing work, but on the other hand, the cutter (5) is completely covered by the skirt, preventing stones and other obstacles from coming into direct contact with the cutter during lawn mowing work. The cutter can be protected by contacting the skirt portion first.

However, according to the above, the lower end (201a) of the front part of the skirt part (201,b) comes into contact with the grass, which causes resistance, and the mowing height of the grass also increases, so it is desired to cut the grass lower. Depending on the time, the height of the front part of the skirt may be set to be 2" taller than the cutter.

This is shown in Figures 2 and 3, and the skirt part (21+)
Except for the front part (211b), the lower end thereof is lower than the lower surface (5a) of the cutter (5) as described above. The front part (211b) of the skirt part (211) is the lower end (211c)
is cut with respect to the lower end (211a) of the other part to make it higher than the lower surface (5a) of the cutter (5) by a predetermined amount Δh'.

The cut portion (A) is formed over a predetermined angle α at the front as shown in the bottom view of FIG. It is determined within the range that is compatible with the discharge function.

Therefore, according to this embodiment, the front part (2
11b) is cut so that the cutter is exposed, so the grass faces the cutter and is cut without being obstructed by the front part of the skirt. According to this embodiment, the mowing height of the grass can be lowered. This reduces resistance when mowing the lawn.

Incidentally, the housing (2) has the same structure except for the height of the front portion of the skirt portion. Therefore, the housing is molded as follows.

FIG. 4 and FIG. 5 show this, and (5o) is a molding die consisting of a mold (51) and a lower mold (52). ”-type (51
), the molding parts (5lb) and (52b) forming the molding cavity (a) of the two pieces (202) of the housing (2) are formed on the mold mating surfaces (51a) and (52a) of the lower mold (52). Four parts (52c) are provided at a predetermined angle in the portion of the lower mold (52) for forming the front part of the skirt part, and the intermediate mold (53A) is removably fitted therein. A four-step part (53a) having a predetermined length and the same length as the other skirt molding gap of the lower mold is formed on the front surface of the intermediate mold (53), and a gap between the front wall (52d) of the fourth part (52c) and the front wall (52d) is formed. A cavity (b) communicating with the upper piece cavity is formed. As a result, as shown in FIG. 1, a housing is formed in which the skirt portion is provided so as to cover the entire circumference of the cutter.

Figure 5 shows a four-part mold (52A) instead of the intermediate mold (53A) described above.
Another intermediate mold (53B) was set in c). Intermediate type (5
The dimension in the height direction of the four-step portion (53a) described above in 3B) is reduced to form a cavity (b') for molding the front part of the skirt part that communicates with the cavity (a) for molding the upper piece. In b'), since the recessed step part (53a') is short, the height from the upper piece cavity (a) is longer on one side (h).
and the other one is shorter than this (h').

By exchanging the intermediate molds (53A) and (53B) in this way, it is possible to mold a skirt with a long front part or a short skirt part with the front part cut.

(Effects of the invention) Two types of lawn mower cutter housings, one with a long front part and one with a short part, can be molded using a common mold.
Two types of products can be molded simply by replacing the intermediate mold set in the lower mold.

Therefore, since two types of dedicated molds are not required, the cost of molds can be reduced, the manufacturing cost of the housing can be reduced, and different types of lawn mowers can be provided at low cost for each country of destination.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and Fig. 1 is a longitudinal cross-sectional side view of a lawn mower, Fig. 2 is a diagram of the main parts of the embodiment of the same, and Fig. 3 is a side view of a lawn mower.
The figure is a bottom view of the housing of the same embodiment, and FIGS. 4 and 5 are explanatory views of the housing mold. In the drawings, (1) is the lawn mower, (2) is the housing, and (3) is the lawn mower.
), (4) are wheels, (20+), (211) are skirt parts, (50) are molds, (51), (52) are upper and lower molds,
(53) is an intermediate type.

Claims (1)

[Claims] In a lawn mower that is equipped with a cutter that is rotatably driven in a horizontal plane by an engine and has wheels for movement, and a cutter housing that surrounds the cutter, the cutter housing is composed of an upper piece and a skirt part hanging from the upper piece, The skirt part is integrally molded from synthetic resin, and the front part of the skirt part is molded between the upper and lower molds by selecting an intermediate mold that is replaceably attached to the lower part of the part corresponding to the front part of the skirt part. A method of manufacturing a cutter housing for a lawn mower.