JPS5976632A - Press forming method of housing for lawn mower - Google Patents

Abstract

PURPOSE:To improve mowing performance by press-forming a housing from the direction intersecting approximately orthogonally with the inclined direction of a box part extending diagonally backward and upward thereby increasing the height in the box part and increasing the sectional area of a passage for blowing out lawn. CONSTITUTION:A top die 14 and a bottom die 15 are formed horizontally with parts 14a, 15a corresponding to the base in a box part inclinding backward and upward with respect to the base in a blade containing part in such a way that the base in said box part serves as a reference plane. A blank 13 set on a blank holder 16 is grasped between said holder and the die 14 by the downward movement of the die 14 and in this state the blank is pressed, whereby a press formed article 1' is obtd. The article 1' is then subjected to trimming, punching of each part including an engine mount part and further bulging at the bottom edge of housing, whereby the housing is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for press molding a lawn mower housing.
More specifically, the present invention relates to a method of press-molding a lawn mower housing, which is provided with a tall bulge extending diagonally rearward and upward, forming a grass blowing passage, on the rear side of a blade accommodating portion having a generally circular planar shape with an open bottom surface.

Conventionally, this type of lawn mower housing has generally been molded by casting, but it is desirable to be able to make it lightweight and inexpensive by press molding SP material or the like.

In this case, the conventionally generally adopted method is to use the upper die (a) and the lower die (b) to form the nozzle (0) as shown in Figure 1.
This is a method of pressing from a direction perpendicular to the bottom surface of the blade accommodating section (d) as a reference plane, but in this case, the aperture height A of the box section (,) from the bottom surface of the blade accommodating section (d) is The limit is about 200 mm, and the box part (
The height dimension B perpendicular to the inclination direction of , ) is limited to about 150wm, making it impossible to secure a sufficient cross-sectional area of the grass blowing passage formed within the box part (θ), resulting in poor grass cooking performance. .

It is an object of the present invention to provide a press forming method that eliminates such inconveniences.The present invention has been made to provide a press forming method that eliminates such inconveniences. The present invention is based on the drawings in a press-molding method for a lawn mower housing having a box portion with a long and extending height, characterized in that the housing is press-molded from a direction substantially perpendicular to the inclination or diagonal direction of the box portion. I will explain.

FIG. 2 shows a lawn mower using a housing 1) obtained by the method of the present invention. A long box part (1b) extending obliquely rearward and upward is provided on the rear side of the blade accommodating part (1a), which has a generally circular plane.
) is attached to the bottom frame (3), and a lateral direction extending rearward and upwardly along the inclination direction of the box part (1b) partitioned by the partition plate (3a) is installed inside the box part (1b). −
A grass blowing passageway (4) on one side and a mission chamber (5) on the other side are formed, and a passageway from the mission chamber (5) side to the grass blowing passageway (4) is formed in the blade accommodating portion (1a). A scroll-shaped air guide channel (6) was formed. The back of the box part (1b) was opened in the form of a gate, and a lid plate (forced) was attached to this to cover the mission chamber (5).

The lawn mower blade (2) is mounted on an engine (1c) mounted on a mount (1c) on the upper surface of the blade housing (1a).
The blade (2) shall be rotationally driven by
The cut grass is blown out from the air guide passageway (6) through the blowout passageway (4) into the grass storage bag (9) located behind it.

In the drawing, (10) is the front protrusion (10) of the housing (1).
1d) and the box (1b), respectively.
) with a swinging arm (11), the rear wheel 00) is connected to the engine (8).
), the transmission is driven via a mission mechanism (not shown) housed in the mission chamber (5).

In the drawings, α indicates a partition plate provided at the front side of the blade accommodating portion (1a) where the projecting portion (1j) is formed.

Here, according to the present invention, the housing (1) is formed by forming the box part (1b) by using a blank 0 made of sp material etc. with an upper mold 04) and a lower mold 09, as shown in FIG. It is molded by pressing from a direction approximately perpendicular to the direction of inclination.
To explain this in more detail, for the upper mold 051 and the lower mold 051, the reference plane is the bottom surface of the box portion (1b) that is inclined rearward and upward with respect to the bottom surface of the blade accommodating portion (1a). The blank α■ set on the blank holder (16) is moved to the holder (L6) by the negative drive of the upper die (+4). ) is pressed in the vertical direction with the molded product (11) shown in FIG. The holes in each part including 1C) are machined, and the lower edge of the housing (1) is bulged to obtain the housing resistance as shown in FIGS. 2 to 4.

Here, the box part (1b) is formed into a fourth part during press molding.
As shown by the arrow X in the figure, the blade is narrowed down from a direction substantially perpendicular to the direction of inclination, and the height B of the box part (1b) perpendicular to the direction of inclination is about 200 + lIn, and the blade housing part (1a) is The box part (1
It is now possible to make the height A of b) about 250+lI, and these heights A and B are 200+lI and 150+lI, respectively.
Compared to the above-mentioned conventional method in which the number of turf blowouts is n, it is possible to form a turf blowing passage (4) with a larger cross-sectional area within the box portion (1b).

As described above, according to the present invention, the housing is press-formed from a direction substantially perpendicular to the inclination direction of the box portion extending diagonally rearward and upward, and the height dimension of the box portion is increased, and the housing is formed within the box portion. It is possible to increase the cross-sectional area of the grass blowing passage, which improves the grass blowing performance through the passage, and has the effect of improving the grass cutting performance accordingly.

[Brief explanation of the drawing]

Fig. 1 is a diagram explaining the conventional method, Fig. 2 is a perspective view of a lawn mower using a housing obtained by the method of the present invention, Fig. 3 is a plan view of the housing, and Fig. 4 is the same as Fig. 3. IV
-IV line sectional side view FIG. 5 is a process diagram of one example of the method of the present invention, and FIG. 6 is a perspective view of a press-formed product obtained in this process. (1)...Housing (1a)...Blade accommodating part (1b)...2 people outside the box part

Claims (1)

[Claims] On the back side of the blade storage part, which has a planar approximately circular shape with an open bottom,
A press molding method for a lawn mower housing having a tall box portion extending obliquely rearward and upward constituting a grass blowing passage, characterized in that the housing is press molded from a direction substantially perpendicular to the direction of inclination of the box portion. A press-forming method for lawn mower fittings.