JPH09187135A - Mulching lawn mower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mulching lawn mower, having a relatively small-sized and lightweight cutter housing simple in structure and capable of uniformly dispersing cut lawn grass in all the area under the cutter housing. SOLUTION: This mulching lawn mower is capable of rotating two sets of cutter blades (24a) and (24b) in mutual opposite directions, respectively passing each of sidewall parts (36a) and (36b) along tip rotation loci (35a) and (35b) of the corresponding cutter blades (24h) and (24b) with a slight interval kept therebetween, connecting mutual fronts (36af) and (36bf) of the respective sidewall parts (36a) and (36b) through front and rear surrounding parts 37 and 38 prepared by connecting left and right circular arc parts (37a), (37b), (38a) and (38b), hung from the undersurface of the upper wall 19 of a cutter housing 5 and passing along the tip rotation loci (35a) and (35b) of the cutter blades (24a) and (24b) with a slight interval kept therefrom at the centers (37c) and (38c) to mutual rears (36ar) and (36br) of the respective sidewall parts (36a) and (36b) and forming a gourd-shaped surrounding wall completely surrounding the outer peripheral part of the connected tip rotation foci (35a) and (35b) of the left and right cutter blades (24a) and (24b) with left and right sidewall parts (36a) and (36b) and the front and rear surrounding wall parts 37 and 38.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary lawnmower in which two sets of cutter blades that rotate in a substantially horizontal direction are provided in a cutter housing, and in particular, the lawn mower left near the tip of the cutter blade is eliminated. The present invention relates to a mulching lawn mower, which cuts grass cut by a cutter blade into small pieces, discharges the cut grass, and sinks the cut grass under the surface of the cut grass to cover the roots.

[0002]

2. Description of the Related Art Conventionally, there is known a lawn mower in which two sets of cutter blades that rotate substantially horizontally are arranged side by side in a cutter housing that opens downward.
-75445 publication.

In the lawn mower disclosed in the above publication, the left and right cutter blades are displaced in the front-rear direction, and their respective loci of rotation are arranged so as to overlap the lateral center line of the cutter housing. In addition, the rotation direction of the cutter blade on the right side in the traveling direction is clockwise in plan view, and the rotation direction of the cutter blade on the left side in the traveling direction is counterclockwise in plan view. The blade allows for reliable cutting.

This lawnmower is a rear discharge type lawnmower, and has a discharge opening at the rear wall of the cutter housing. In order to independently guide grass cut by the left and right cutter blades to the discharge opening. A discharge scroll guide plate is provided in the cutter housing. The cut grass is either stored in the glass bag from the discharge port through the shooter or discharged directly to the rear cutting mark.In the former case, the cut grass in the glass bag is thrown to an appropriate place. In the latter case, the released mowing grass will fall unevenly on the mowing trace, and the appearance of the mowing trace will deteriorate, and the air circulation will be poor in the part where the mowing turf is piled up, and the turf will easily die. .

On the other hand, in the mulching lawn mower,
The cut grass shredded by the cutter blade is discharged relatively evenly from above to the cut mark directly below the cutter housing and sinks below the surface of the cut trace grass, thus avoiding the above problems.

In US Pat. No. 5,133,176, a plurality of cutter blades that rotate substantially horizontally are arranged side by side in a cutter housing that opens downward, as in the rear discharge lawnmower. Fig. 5 shows a lawn mower in which the left and right cutter blades adjacent to each other are displaced in the front-rear direction so that the respective rotation loci overlap slightly when viewed in the front-rear direction. And described in the text.

In this mulching lawnmower, a side wall is provided vertically along a peripheral edge of the cutter housing, and
A shroud that surrounds each of the three side-by-side cutter blades to form a circular cutting chamber is hung, and these shrouds are connected to each other through an opening so that the circular cutting chambers communicate with each other. The three cutter blades are collectively formed as an enclosing wall that completely surrounds the outer peripheral portion thereof.

In this surrounding wall, all three cutter blades arranged in parallel rotate in the same direction, and in each of the cutting chambers, a kicker projects from the lower surface of the upper wall of the cutter housing. The cut grass, which is cut by the cutter blade and circulates in the cutting chamber, is directed downward by the kicker and discharged to the cut mark directly below.

[0009]

In the above-mentioned conventional mulching lawn mower, since a plurality of cutter blades must be collectively formed in the cutter housing, the surrounding wall that completely surrounds the outer peripheral portion must be formed independently. The cutter housing becomes larger than the rotation range of the cutter blade, and the weight also increases.

Further, since each cutter blade rotates in the same direction, the cut grass is apt to be biased to one of the left and right sides within the surrounding wall enclosing these cutter blades collectively, and the grass is evenly distributed over the entire lower part of the cutter housing. In order to ensure even distribution, it is necessary to provide a kicker for each cutter blade and drop the grass cut by a blade to the bottom of that blade. , The structure becomes complicated.

Therefore, according to the present invention, the cutter housing can be made relatively small, lightweight and simple in structure, and the cutting grass can be evenly dispersed and discharged over the entire area below the cutting housing. Is to provide a machine.

[0012]

Therefore, in the present invention, in the present invention, a mulching lawn mower is formed by horizontally arranging two sets of cutter blades that rotate substantially horizontally in a cutter housing that opens downward. In the machine, each of the cutter blades is rotated in the opposite directions so that the tip moves from the front to the rear on the outer side in the left-right direction of the lawn mower, and the side wall portions on the outer side in the left-right direction of the cutter housing are respectively corresponding Along the tip rotation locus with a slight distance, the front and rear portions of the side wall portions are vertically installed on the lower surface of the upper wall of the cutter housing, and are slightly spaced along the tip rotation loci of the left and right cutter blades. The left and right side walls are connected to each other through front and rear surrounding wall parts formed by connecting left and right arc-shaped parts that are separated from each other at the center. By the minute and the front and rear enclosure part,
A gourd-shaped enclosure wall is formed that completely surrounds the outer peripheral portion of the left and right cutter blades, which links the rotation paths of the tips of the blades.

This mulching lawn mower has two sets of cutter blades arranged side by side, and the two sets of cutter blades are arranged so that their tip rotation loci slightly overlap when viewed in the front-rear direction. Therefore, it is possible to mow the grass over a wide width without leaving uncut residue in the center, but since the above-mentioned two sets of cutter blades are completely surrounded by the surrounding wall, the outer peripheral part that links their tip rotation loci is surrounded. The cut grass cut by the cutter blade is confined in the enclosure wall, further shredded, and then discharged directly below from the lower opening of the enclosure wall and sunk between the cut grasses (mulch mulch). ).

In the present invention, the surrounding wall has a gourd shape in which two circular portions surrounding the outer circumference of each cutter blade are connected to each other. Since the lawn is cut while rotating outward in the left-right direction in the front part, the cut lawn hardly stays in the circular portion on the side of the cutter blade that cut it and moves into the other circular portion. It is discharged below the cutter blade. Therefore, even without providing a kicker for directing the cut grass downward, the cut grass is uniformly dispersed and dropped over the entire cutting mark below the portion surrounded by the surrounding wall, and a good mulching action can be obtained.

Further, since each cutter blade rotates on the outside of the lawn mower in the left-right direction from the front to the rear, that is, so as to raise the turf tilted in the traveling direction by the front tire, the footprint of the front tire also It can be cut well.

Further, the surrounding walls surrounding both cutter blades are not provided separately in the cutter housing, but both side portions thereof are formed by utilizing side wall portions on the outside in the left-right direction of the cutter housing, and The cutter housings are small, lightweight and have a simple structure because they are provided with the surrounding wall portions of simple shapes.

If the cutter housing is opened even toward the rear and the surrounding wall portion of the rear part is detachable from the cutter housing, this mulching lawn mower can be easily converted into a rear discharge type lawnmower if necessary. can do.

[0018]

1 is a side view showing an example of a riding mulching lawnmower to which the present invention is applied. This lawnmower 1
Respectively, a cutter housing 5 is suspended and supported so as to be able to move up and down at the lower center of a body frame 4 supported by a pair of left and right front wheels 2, 2 and rear wheels 3, 3. FIG. 2 is a plan view of relevant parts showing the cutter housing 5 and its vicinity.

An engine 6 is provided on the front portion of the body frame 4.
Is mounted, a seat 7 is provided in the rear portion, and a handle 8 is disposed between the two. Then, the rear wheels 3 are driven by the engine 6, and the front wheels 2 are steered by the steering wheel 8.

The cutter housing 5 includes front and rear links 9 and 10.
It is suspended and supported by the vehicle body frame 4 via. In more detail, the front link 9 is a plate-shaped link piece whose rear end is pivotally supported by a shaft 9a between a pair of left and right brackets 11a, 11a protruding from the front end surface of the cutter housing 5. 9b, and rod-shaped link portions 9c and 9c pivotally supported by a pair of left and right brackets 11b and 11b, which are welded to both sides of the front end of the link portion 9b and whose front ends are vertically attached to the front end of the vehicle body frame 4, respectively. Made of. The rear link 10 is also composed of a pair of left and right link parts, and its front end is pivotally supported by the brackets 11c, 11c on the vehicle body frame 4 side and the rear end near brackets 11d, 11d protruding on the upper surface of the cutter housing 5, respectively. . These links 10 further project rearward from the bracket 11d, and are pivotally attached to the lower end of the lifting rod 12 at the rear end. The upper ends of the left and right elevating rods 12 are engaged with pins 14 and 14 which are laterally projected to the rocking part pieces 13 and 13, respectively.
The rotary shafts 15 traversing each other are fixed to both ends and connected to each other. An elevating lever 16 is fixed to the swinging piece 13 on the left side and projects forward.

Therefore, when the elevating lever 16 is swung up and down about the rotary shaft 15, the left and right links 10, 10 are swung uniformly around the pivot point of the bracket 11c. Since the link 9 also swings around the pivot point with the bracket 11b, the cutter housing 5 moves up and down while maintaining the parallel relationship with the vehicle body frame 4.

Rollers 17, 17 are rotatably supported by brackets 18, 18 on the left and right sides of the front of the cutter housing 5, respectively. The roller 17 is mounted on the bracket 18 so that its height can be adjusted. By adjusting the height of the roller 17, the lowest position of the cutter housing 5, that is, the cutting height of the lawn can be appropriately set.

FIG. 3 is a cross-sectional view of the cutter housing 5 substantially along the line III-III in FIG. 2, and FIG.
It is the top view which looked at the inside of a from the bottom.

As shown in FIGS. 1 to 4, the cutter housing 5 has a flat upper wall 19 and a side wall 20 provided along the periphery of the flat upper wall 19 and is open downward. The inside of the cutter housing 5 is also opened rearward through an opening 21 formed in the rear end surface portion of the side wall 20.

In the cutter housing 5, two left and right cutter shafts 22a and 22b are vertically arranged. These cutter shafts 22a and 22b rotatably pass through the upper wall 19 via bearings 23a and 23b mounted on the upper wall 19, and the cutter housing 5
Cutter blades 24a and 24b are fixed to the lower end of the inside, and driven pulleys 25a and 25a are attached to the upper end protruding upward from the upper wall 19.
25b is fixed. Each of the cutter blades 24a and 24b is configured by vertically arranging _two blades 26 ₁ and 26 ₂ of the same shape, which will be described in detail later.

The cutter shafts 22a and 22b are driven by the engine 6. Therefore, as shown in FIGS. 1 and 2, the power take-off shaft 27 of the engine 6 extends below the front part of the vehicle body frame 4, and a drive pulley 28 is provided at the lower end thereof, and the drive pulley 28 and the driven pulley 28 are provided. 25 and winding transmission device 29
Are connected by The winding transmission device 29 has a tension roller 31 and an idle roller 32 biased by a spring 30 in addition to the above-mentioned pulleys, and a belt 33 having a hexagonal cross section is wound around these pulleys. As shown by an arrow a in FIG. 2, the power take-off shaft 27 and the drive pulley 28 rotate clockwise when viewed from above, and the belt 33 wound in this direction from the drive pulley 28 is a tension roller.
After passing through 31, the driven pulley 25b on the right side is reached, the driven pulley 25b is wound clockwise, and then the vehicle is moved to the left side of the vehicle body. Then, the idle roller 32 is reached to the driven pulley 25a on the left side. Then, it engages with the surface opposite to the engaging surface with the driven pulley 25b, winds this in the counterclockwise direction, and then returns to the drive pulley 28.

Since each of the pulleys 25a, 25b, 31, 32 is arranged on the flat upper surface of the upper wall 19 of the cutter housing 5 in parallel with and at the same height as the upper surface, the pulleys 25a, 25b, 31, 32 are provided with respect to these pulleys. It is easy to wrap the belt 33 and
The entire winding transmission device 29 becomes compact and reliable transmission operation can be obtained. Therefore, the cutter shaft 22 of the upper wall 19
The portions where a and 22b penetrate through the bearings 23a and 23b are circular recesses 34 and 34, and the heights of the driven pulleys 25a and 25b are made low, but these recesses 34 also form the upper wall 19. Has a reinforcing effect.

Thus, the left and right cutter blades 24a, 24b
4, as shown by arrow a in FIG. 4, that is, during half rotation forward of the traveling direction (mainly at this time, lawn mowing is performed), rotate in opposite directions so as to move from the inside to the outside in the left-right direction. To do. Therefore, the tip portions of the cutter blades 24a and 24b also move from the front to the rear in the traveling direction on the outer side in the left-right direction.

Left and right two-dot chain circles 35a, 35 in FIG.
b b) is a rotation locus of the tips of the cutter blades 24a and 24b, respectively. As shown, these tip rotation trajectories 35a,
Although 35b are in contact with each other, the cutter shaft 22a and the cutter shaft 22
b is offset by x in the front-back direction, so the tip rotation locus
35a and the tip rotation locus 35b overlap by y when viewed in the front-rear direction. With such arrangement of the tip rotation loci 35a and 35b, the lawn mower 1 advances the lawn mowing over the entire width of the cutter housing 5 by the left and right cutter blades 24a and 24b without leaving uncut matter in the middle. You can go.

The side wall portions 36a, 36b of the cutter housing 5 on the outer side in the left-right direction of the side wall 20 have the tip rotation locus 35.
The outer surfaces of the a and 35b are spaced apart from each other by a short distance, and extend along the outer side of the a and 35b for almost half a circumference. And these side wall portions 36a,
Front end portions 36af, 36bf which start to separate from the outer peripheral portions of the tip end rotation loci 35a, 35b of 36b are connected by a front surrounding wall portion 37. The front surrounding wall portion 37 includes an arcuate portion 37a extending inward from the front end portion 36af of the side wall portion 36a along the tip rotation locus 35a with a slight distance therebetween, and a side wall portion.
An arcuate portion 37b extending inward from the front end portion 36bf of the 36b along the tip rotation locus 35b with a slight distance therebetween,
It consists of a seagull-shaped piece formed by smoothly connecting the inner side, that is, the central portion 37c, where they approach each other (Fig. 5).
The upper end surface 37d is welded to the lower surface of the upper wall 19 of the cutter housing 5 and hangs down from the lower surface. The front surrounding wall portion 37 may be detachably attached to the cutter housing 5 with bolts, nuts or the like, which facilitates cleaning of the lower front portion of the cutter housing 5.

Tip rotation locus 35 of the side wall portions 36a and 36b
Rear end portions 36ar, 36b which start to separate from the outer peripheral portions of a, 35b
The r parts are connected by a rear surrounding wall portion 38.
Similarly to the front surrounding wall portion 37, the rear surrounding wall portion 38 also comprises a seagull-shaped piece formed by connecting arcuate portions 38a and 38b on both sides at a central portion 38c (FIG. 6). The portion 38 is detachably attached to the lower surface of the upper wall 19. Therefore, the rear end portion 36ar and the rear end portion of the side wall portion 36b are provided at both ends of the rear surrounding wall portion 38, respectively.
Mounting pieces 39a, 39a along the 36br are projected (FIG. 6), and L-shaped mounting pieces 39b, 39b are respectively projected on the arc-shaped portions 38a, 38b by welding one side to the side surface. (FIG. 7) Further, the central portion 38c is provided with a mounting piece 39c (FIG. 8) in which the bent portions at both ends are welded to the side surfaces on the side of the arc-shaped portions 38a and 38b, respectively, and straddle both portions. Pieces 39a, 39a at the rear ends of the side wall portions 36a, 36b,
By screwing the mounting pieces 39b, 39b and the mounting piece 39c to the upper wall 19 of the cutter housing 5, the rear surrounding wall portion 38
Is detachably attached to the lower surface of the upper wall 19.

The side wall portions 36a, 36b, the front surrounding wall portion 37, and the rear surrounding wall portion 38 on both sides are the left and right cutter blades.
A continuous surrounding wall that completely surrounds the outer peripheral portions of 24a and 24b is formed, and this surrounding wall is the central portion of each of the front and rear surrounding wall portions 37 and 38.
Most of the blades except 37c and 38c are cutter blades 24
Along the tip rotation loci 35a, 35b of a, 24b, the shape of a gourd is constricted in the central portions 37c, 38c.
Within this enclosure, the cutter blades 24a, 24b are located in the central portion
In most of the rotation angle range except between 37c and 38c, the tip rotates in a state where the tip approaches the inner surface of the surrounding wall.

As described above, each cutter blade 24a, 24b
Is configured by arranging _two blades 26 ₁ and 26 _{2 respectively} on the upper and lower sides. The blades 26 ₁ and 26 ₂ have substantially the same shape, each having a blade portion 40 at a front edge portion in a rotational direction of a radially outer portion and a blade portion 41 standing obliquely upward at a rear edge portion, As shown in FIG. 10, the upper blade 26 ₁ is attached to the cutter shaft 22 while being displaced from the lower blade 26 _{2 in the} rotational direction by an angle α. Therefore, when the cutter blade 24 rotates, the grass 42 in front of the cutter blade 24 is first mowed by the upper blade 26 _{1 for a} relatively long period of time and then cut short by the lower blade 26 ₂ of the cutter blade 24. The cut grass 43 is obtained. Since the periphery of the cutter blades 24 are surrounded by the surrounding wall, the cut grass 43 stays for a while該囲wall is further shredded strikes the blades 26 _1, 26 ₂ of the blade section 40 during this time.

Inside the wall surrounding the cutter blade 24, air pulsation occurs due to the wind generated by the blade portions 41 of the rotating blades 26 ₁ and 26 ₂ , and the cut grass 43
While being trapped and scattered in the surrounding wall, the pulsation causes the pulsation to be discharged from the lower open portion, drop to the cut mark, and sink below the surface of the lawn.

By the way, the surrounding wall is formed by each cutter blade.
Two circular portions respectively surrounding the outer circumferences of 24a and 24b, that is, the left side surrounded by the side wall portion 36a, the arcuate portion 37a of the front surrounding wall portion 37 and the arcuate portion 38a of the rear surrounding wall portion 38 (the left side in the traveling direction, The same shall apply hereinafter) and the right side circular portion surrounded by the side wall portion 36b, the arcuate portion 37b of the front surrounding wall portion 37 and the arcuate portion 38b of the rear surrounding wall portion 38 are connected to each other to eliminate the gourd shape. , The cutter blades 24a and 24b rotate in opposite directions to each other, and the grass 42 is cut while rotating outward in the left-right direction in the front part of each circular portion. The cutter blade rarely stays in one part and moves into the other circular part.
It is discharged below 24. Therefore, even if a kicker for directing the cut grass downward is not provided and the inner surface of the upper wall 19 of the cutter housing 5 is made substantially flat, the cut grass 43 is evenly distributed over the entire cut mark below the portion surrounded by the surrounding wall. It is dispersed and dropped, and a good mulching effect is obtained with a simple structure.

In the illustrated embodiment, a ring 44 surrounds the cutter shaft 22 and surrounds the cutter shaft 22 on the lower surfaces of the left and right recesses 34 formed in the cutter housing upper wall 19 where the cutter shaft 22 penetrates. The distal end of the separator piece 45 that is provided and extends tangentially from the outer peripheral surface of the ring 44 is the rear surrounding wall portion.
38 reaches the vicinity of the central portion 38c. By providing such a separator piece 45, the surrounding wall portion
In the portion between the central portions 37c and 38c of the 37 and 38, a particularly large amount of grass is prevented from falling to the cut mark, and uniform discharge is obtained. The ring 44 and the separator piece 45 are of course provided only above the cutter blade 24 and on the upper wall 19 side.

Further, since the side wall 20 of the cutter housing 5 has the opening 21 at the rear side, the detachable rear surrounding wall portion 38.
This mulching lawn mower can be easily converted to a rear discharge type lawnmower by removing the turf, and at this time, the separator part 45 is used for cutting grass on the cutter blade 24a side and cutting blade on the cutter blade 24b side. It works to smoothly guide the grass to the opening 21 without interfering with each other.

The left and right cutter blades 24a, 24b move forward and backward at the outer ends of the lawnmower 1 in the left-right direction, so that when the lawnmower 1 advances, the cutter blades 24a, 24b are stepped on the tires of the front wheels 2 in advance. The cutter blades 24a, 24b approach from the front to the turf that has been towed down by the blades and made it difficult to mow while raising it. Therefore, the trails of the front tires can be finished and cut well.

The surrounding walls surrounding both cutter blades 24a and 24b are not provided separately in the cutter housing 5 surrounded by the side wall 20, and both side portions thereof are located outside the cutter housing 5 in the left-right direction. Side wall portions 36a, 36
Since the front surrounding wall portion 37 and the rear surrounding wall portion 38 each having a simple shape are formed on the front and rear sides, the plane shape of the cutter housing 5 is substantially equal to the rotation range of the cutter blade 24. As a result, the size of the cutter housing 5 can be reduced, and the cutter housing 5 can be made lightweight and have a simple structure.

[Brief description of the drawings]

FIG. 1 is a side view showing an example of a riding mulching lawn mower to which the present invention is applied.

FIG. 2 is a main part plan view showing a cutter housing of the lawnmower and its vicinity.

FIG. 3 is a cross-sectional view of the cutter housing substantially along the line III-III in FIG.

FIG. 4 is a plan view of the inside of the cutter housing as viewed from below.

FIG. 5 is a perspective view of a front surrounding wall portion.

FIG. 6 is a perspective view of a rear surrounding wall portion.

7 is an enlarged cross-sectional view taken along the line VII-VII of FIG.

FIG. 8 is a partial front view of a part of FIG. 4 viewed in the direction of arrow VIII.

FIG. 9 is a perspective view of a ring and a separator piece.

FIG. 10 is a schematic perspective view showing a state of lawn mowing with a cutter blade.

[Explanation of symbols]

1 ... Lawn mower, 2 ... Front wheels, 3 ... Rear wheels, 4 ... Body frame,
5 ... Cutter housing, 6 ... Engine, 7 ... Seat, 8 ...
Handle, 9 ... Link, 10 ... Link, 11 ... Bracket,
12 ... Lifting rod, 13 ... Oscillating piece, 14 ... Pin, 15 ... Rotating shaft, 16 ... Lifting lever, 17 ... Roller, 18 ... Bracket, 19
… Top wall, 20… Side wall, 21… Opening, 22… Cutter shaft, 23… Bearing, 24… Cutter blade, 25… Driven pulley, 26… Blade, 27… Power extraction shaft, 28… Drive pulley, 29… Winding Hanging device, 30 ... Spring, 31 ... Tension roller, 32 ... Idle roller, 33 ... Belt, 34 ... Recessed portion, 35 ... Tip rotation locus, 36 ... Side wall portion, 37 ... Front surrounding wall portion, 38 ... Rear surrounding wall portion, 39 … Mounting piece, 40… Blade part, 41… Blade part, 42… Lawn, 43…
Cut grass, 44 ... Ring, 45 ... Separator part.

Claims (5)

[Claims] 1. A mulching lawn mower in which two sets of cutter blades that rotate substantially horizontally are arranged side by side in a cutter housing that opens downward, and each cutter blade has a tip at the left and right of the lawn mower. In order to move from the front to the rear on the outer side in the direction, they are rotated in opposite directions, and the side wall portions on the outer side in the left-right direction of the cutter housing are made to follow the tip rotation loci of the corresponding cutter blades at a slight interval, The front and rear portions of each of the side wall portions are connected to each other at the center of the left and right arc-shaped portions that are vertically provided on the lower surface of the upper wall of the cutter housing and that extend along the tip rotation trajectories of the left and right cutter blades with a slight interval. Connected through the surrounding wall parts before and after,
A mulching lawn mower characterized in that the left and right side wall portions and the front and rear surrounding wall portions form a gourd-shaped surrounding wall that completely surrounds an outer peripheral portion in which the tip rotation trajectories of the left and right cutter blades are connected. 2. The mulching lawn mower according to claim 1, wherein the cutter housing is opened even when facing rearward, and the surrounding wall portion of the rear portion is detachable from the cutter housing. 3. The cutter blades of each set are composed of two blades arranged one above the other.
Or 2 mulching lawn mower. 4. The front end of the cutter blade rotationally moves from the front to the rear at the rear position of the front tire.
Or 3 mulching lawn mowers. 5. The mulching lawn mower according to claim 1, 2 or 3, wherein the inner surface of the upper wall of the cutter housing is substantially flat.