JP2013202020A - Lawn mower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lawn mower allowing the adjustment of a height of a wheel as the need arises.SOLUTION: This lawn mower 1 includes a rotary blade 5a provided in a body 2 including a wheel 3a. When a rotation plane of the rotary blade 5a is horizontal, the wheel 3a can be adjusted between a first height at which the vertical-direction downmost point is positioned below the rotation plane and a second height at which the vertical-direction downmost point is positioned above the rotation plane.

Description

  The present invention relates to a lawn mower in which a rotary blade is provided on a main body having wheels.

  It has a handle extending from the back of the main body with a rotary blade and wheels, and grabs the lawn with the rotary blade while moving the main body by pushing and pulling the handle by grasping the grip provided on the handle Lawn mowers configured to be able to do so are known. In a lawn mower having such a basic configuration, wheels are rotatably supported by axles protruding from both side surfaces of the main body (Patent Document 1).

  Further, in the conventional lawn mower, the handle may be rotatably attached to the main body. In such a lawn mower, the support shaft of the handle often serves as the wheel axle. Specifically, the wheels are often rotatably supported by both ends of a support shaft that passes through the handle.

JP 2004-159621 A

  If there are walls or fences on the turf-grown land or paving stones are placed on the lawn mower along these walls, fences or paving stones (hereinafter collectively referred to as “obstacles”) Even if you drive, you may not be able to mow the lawn that is growing in the case of obstacles. In such a case, instead of running the lawn mower, the lawn mower may be cut more efficiently if the lawn mower is moved sideways or obliquely along the obstacle. For example, it may be easier to mow the lawn if the lawn mower is swung left and right like a brush cutter.

  However, if the lawn mower is moved in a direction crossing the predetermined traveling direction, the wheel in contact with the ground becomes a resistance. In other words, in order to move the lawn mower in the direction intersecting the traveling direction, it was necessary to forcibly slide the wheels. However, a large force is required to move the lawn mower sideways or diagonally by forcibly sliding the wheels, and it is not easy to move the lawn mower as intended. Furthermore, an excessive force is applied to the wheels and axles, which may cause damage or deformation.

  The objective of this invention is providing the lawn mower which can adjust the height of a wheel as needed.

  The lawn mower of the present invention is a lawn mower in which a rotary blade is provided on a main body provided with wheels, and the wheel has a vertical lowest point when the rotation plane of the rotary blade is horizontal. The height can be adjusted to a first height located below the rotation plane and a second height where the vertical lowest point is located above the rotation plane.

  The lawn mower according to the present invention has an axle with a fixed position relative to the main body, and the height of the wheel is changed to the first height or the second height by changing the fixed position of the axle. Adjusted to.

  The lawn mower according to the present invention is a long hole into which the axle is inserted, and has a long hole extending along a vertical direction, and the axle has the main body at at least two points along the longitudinal direction of the long hole. It can be fixed to.

  The lawn mower of the present invention has a handle rotatably attached to the main body via a support shaft, and when the height of the wheel is adjusted to the first height, the axle and the The support shaft is arranged on the same straight line.

  The lawn mower according to the present invention is a support member that is variable in distance from the rotation plane, has a support member that contacts the ground and adjusts the height of the rotation plane relative to the ground, and the first height The lowermost point in the vertical direction of the wheel adjusted to be positioned above the lowermost point in the vertical direction of the support member when the distance is minimum.

  ADVANTAGE OF THE INVENTION According to this invention, the lawn mower which can adjust the height of a wheel as needed is implement | achieved.

It is sectional drawing which shows the whole structure of a lawn mower. It is a top view of a lawn mower partially omitted. It is a side view of the lawn mower partially omitted. (A)-(c) is a side view of the lawn mower set to different cutting height. It is a fragmentary sectional view of a lawn mower. (A) is a partial side view showing the wheel adjusted to the first height, (b) is a partial side view showing the wheel adjusted to the second height. (A), (b) is a side view which shows the relationship between the height of a wheel and the height of a pad.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings. As shown in FIGS. 1 to 3, the lawn mower 1 includes a main body 2, wheels 3 a and 3 b (FIG. 2) provided on the main body 2, a handle 4, a lawn mowing means 5, and a cutting height adjusting mechanism 6 (FIG. 2). (Not shown).

  The handle 4 is made of reinforced plastic. As shown in FIG. 1, the handle 4 extends upward from the rear of the main body 2 and can be rotated in the direction of the arrow in the figure. Further, a main grip 10 is provided at the upper end of the handle 4, an auxiliary grip 11 is provided in the middle of the handle 4, and a grass collection box in which cut grass is collected between the auxiliary grip 11 and the main body 2. 12 is provided.

  The position of the main grip 10 can be changed stepwise along the longitudinal direction of the handle 4, and the position of the main grip 10 can be adjusted according to the height of the operator. In other words, the entire length of the handle 4 including the main grip 10 can be expanded and contracted by changing the position of the main grip 10. Further, a power cord 14 provided with an outlet 13 connected to a commercial power source extends from the main grip 10.

  The main body 2 incorporates an electric motor (disc motor 20) as a drive source for the lawn mowing means 5. The output shaft 20a of the disk motor 20 is hollow, and is rotatably held by bearings at two locations in the axial direction. A substantially disc-shaped rotary blade (hereinafter referred to as “rotary blade 5a”) constituting the lawn mowing means 5 is attached to one end (lower end) of the output shaft 20a so as to be integrally rotatable. In addition, a substantially disk-shaped fixed blade (hereinafter referred to as “fixed blade 5b”) that constitutes the lawn mowing means 5 together with the rotary blade 5a is disposed below the rotary blade 5a. That is, the fixed blade 5b and the rotating blade 5a are laminated in this order, and when the rotating blade 5a rotates, the turf is sandwiched between the rotating blade 5a and the fixed blade 5b and cut. The main grip 10 is provided with a trigger switch 15, and when the operator operates the trigger switch 15, via the power cord 14 and electric wiring (not shown) provided inside the handle 4. Electric power is supplied to the disk motor 20 to drive the disk motor 20. On the other hand, when the operation of the trigger switch 15 by the operator is released, the power supply to the disk motor 20 is cut off and the disk motor 20 stops.

  A rotating shaft 30 is provided in the main body 2 in parallel with the output shaft 20a of the disk motor 20, and a fan 31 is provided at one end (lower end) of the rotating shaft 30 so as to be integrally rotatable. The output shaft 20a of the disk motor 20 and the rotary shaft 30 are connected via a power transmission mechanism. The power transmission mechanism is applied to a drive pulley 32 provided at one end (upper end) of the output shaft 20 a of the disk motor 20, a driven pulley 33 provided at one end (upper end) of the rotary shaft 30, and the pulleys 32, 33. The drive belt 34 is rotated. Therefore, when the disk motor 20 is driven, the rotational driving force is transmitted to the rotary shaft 30 via the power transmission mechanism, and the fan 31 rotates together with the rotary shaft 30. That is, the disk motor 20 also functions as a drive source for the fan 31. The turf cut by the lawn mowing means 5 composed of the rotating blade 5a and the fixed blade 5b is sent to the grass collection box 12 via the conveyance path formed inside the handle 4 by the wind generated by the rotating fan 31. It is done. The grass collection box 12 is detachable from the handle 4 and is detached from the handle 4 as necessary. For example, when the grass collection box 12 is filled with the cut grass, the grass collection box 12 is removed from the handle 4 and the grass collected in the grass collection box 12 is discarded.

  A shaft 40 constituting the cutting height adjusting mechanism 6 is inserted inside the output shaft 20 a of the disk motor 20. One end (upper end) of the shaft 40 protrudes from the upper surface of the main body 2, and the other end (lower end) passes through the centers of the blades 5 a and 5 b and protrudes below the main body 2. A knob 41 is provided at the upper end of the shaft 40, and a pad 42 as a support member is attached to the lower end of the shaft 40. The operator can pick up the knob 41 and raise and lower the shaft 40 in the axial direction. When the shaft 40 is lifted and lowered in the axial direction, the lowermost vertical direction of the pad 42 from the rotation plane of the rotary blade 5a. The distance to the point (hereinafter referred to as “projection length”) changes. Therefore, when the shaft 40 is moved up and down to change the protrusion length, the distance (height) from the ground to the rotation plane of the rotary blade 5a changes, and the lawn cutting height is changed.

  In the present embodiment, the protruding length of the pad 42 can be changed in seven stages so that the cutting height is changed every 5 mm within a range of 10 mm to 40 mm. Specifically, the cutting height is set to 10 mm when the protrusion length of the pad 42 is minimum, and the cutting height is set to 40 mm when it is maximum. 4 (a) to 4 (c) show the lawn mowers 1 whose cutting heights are set to 40 mm, 25 mm, and 10 mm, respectively. As shown in these drawings, the lawn mower 1 is normally supported by three points of two wheels 3 a and 3 b (only the wheel 3 a is shown in FIG. 4) and a pad 42. Then, when the handle 4 is pushed by the operator who holds the grip 10 shown in FIG. 1, the lawn is mowed while traveling from the right side to the left side in FIG. Thus, when the lawnmower 1 travels, the wheels 3a and 3b roll on the ground or the lawn growing on the ground, and the pad 42 slides on the ground or the lawn growing on the ground. Note that the lower surface of the pad 42 is formed in a spherical shape so that the pad 42 can slide smoothly. In this case, the protrusion length of the pad 42 means the vertical distance from the rotation plane of the rotary blade 5a to the apex of the lower surface of the pad.

  As shown in FIGS. 4A to 4C, in the present embodiment, when the protruding length of the pad 42 is set so that the cutting height is 40 mm, the main body 2 rises forward (FIG. 4 ( a)) When the protruding length of the pad 42 is set so that the cutting height is 10 mm, the main body 2 is lowered forward (FIG. 4C). Further, when the protruding length of the pad 42 is set so that the cutting height is 25 mm, the main body 2 becomes horizontal (FIG. 4B).

  Refer to FIG. 1 again. The lower end of the handle 4 shown in the figure is fixed to the main body 2 via a support shaft so that the handle 4 can be rotated in the direction of the arrow in the figure. As shown in FIG. 5, a pair of arms 4a and 4b are integrally formed at the lower end of the handle 4, and a nut 50 is inserted into each of the arms 4a and 4b. On the other hand, a block-shaped protrusion 51 is integrally formed behind the main body 2. Further, plate-like handle holding portions 52a and 52b are integrally formed on the rear side of the main body 2 and on both outer sides of the protruding portion 51. The handle holding portions 52a and 52b are respectively connected to the arms 4a and 4b. A through hole (not shown) communicating with the inserted nut 50 is formed. The arms 4a and 4b of the handle 4 are respectively inserted into gaps 53 between the outer side surface of the projecting portion 51 and the inner side surfaces of the handle holding portions 52a and 52b, and the nut 50 passes through the through holes of the handle holding portions 52a and 52b. It is fixed to the main body 2 by a bolt 54 screwed to the main body 2. That is, the shaft portion of the bolt 54 is a support shaft that rotatably attaches the handle 4 to the main body 2.

  Further, as shown in FIGS. 5 and 6A and 6B, plate-like wheel holding portions 55a and 55b are integrated with the rear of the main body 2 and outside the handle holding portions 52a and 52b. Molded. Further, as shown in FIGS. 6A and 6B, the outer surfaces of the wheel holding portions 55a and 55b (only the wheel holding portion 55a is shown in FIG. 6) extend along the vertical direction. A substantially gourd-shaped guide 56 is formed by connecting substantially circular concave portions 56a and 56b arranged through a constricted portion 56c, and a vertical direction is formed inside the guide 56 across the two concave portions 56a and 56b. A long hole 57 is formed extending in the direction. On the other hand, as shown in FIG. 5, substantially cylindrical protrusions 58 that are selectively fitted into the two recesses 56a and 56b (FIG. 6) of the guide 56 are formed on the inner surfaces of the wheels 3a and 3b. In the center of the wheels 3a and 3b, a round hole 59 communicating with the long hole 57 (FIG. 6) formed in the wheel holding portions 55a and 55b is formed.

  As shown in FIG. 5, a bolt 60 is inserted into the communicating round hole 59 and elongated hole 57 (FIG. 6), and the tip of the bolt 60 is connected to the outer surface of the handle holding portions 52a and 52b and the wheel holding. A gap is formed between the inner surfaces of the portions 55a and 55b. A washer 61 having a diameter larger than the width of the long hole 57 (FIG. 6) is attached to the tip of the bolt 60 protruding into the gap, and a nut 62 is screwed from the outside of the washer 61. That is, the shaft portion of the bolt 60 is an axle that rotatably supports the wheels 3a and 3b.

  In the lawn mower 1 according to the present embodiment, the bolt 60 and the nut 62 shown in FIG. 5 are loosened and the bolt 60 and the nut 62 are moved along the longitudinal direction of the long hole 57 (FIG. 6). That is, the height of the wheels 3a and 3b can be adjusted by moving the axle in the vertical direction. Specifically, the wheel 3a, the height (first height) shown in FIG. 6 (a) and the height (second height) shown in FIG. 6 (b). The height of 3b can be adjusted (changed). 6 (a) and 6 (b) show only one wheel 3a, the two wheels 3a and 3b shown in FIGS. 2 and 5 are adjusted to the same height. The Therefore, in order to avoid redundant description, the following description will mainly describe the height of the wheel 3a.

  The first height shown in FIG. 6A is the height of the wheel 3a shown by a solid line in FIG. Specifically, when the rotation plane of the rotary blade 5a is horizontal, the vertical lowest point of the wheel 3a is a height located below the rotation plane. This first height is a height that is selected when the lawn mower 1 is supported by the three points of the two wheels 3a and 3b and the pad 42. The first height is suitable for mowing the lawn while the lawn mower 1 is driven by the wheels 3a and 3b.

  When the height of the wheel 3a is adjusted to the first height, the bolt 60 (FIG. 5) that is the axle of the wheel 3a and the bolt 54 (FIG. 5) that is the support shaft of the handle 4 are on the same straight line. Be placed. Therefore, when the handle 4 shown in FIG. 1 is pushed to run the lawn mower 1, no unnecessary moment is generated, and the lawn mower 1 can be smoothly run.

  On the other hand, the second height shown in FIG. 6B is the height of the wheel 3a shown by the phantom line in FIG. Specifically, when the rotation plane of the rotary blade 5a is horizontal, the vertical lowest point of the wheel 3a is a height located above the rotation plane. The second height is a height selected when the two wheels 3a and 3b are lifted from the ground and the lawn mower 1 is supported by the pad 42 only at one point. If the wheels 3a and 3b are lifted from the ground and the lawn mower 1 is supported only by the pad 42, the wheels 3a and 3b will not become resistance when the lawn mower 1 is moved in a direction crossing a predetermined traveling direction. . Therefore, the second height is suitable for mowing the lawn growing on the obstacle by moving the lawn mower 1 sideways or diagonally along the obstacle existing on the land where the lawn grows. It is height.

  As shown in FIG. 7A, when the height of the wheel 3a is adjusted to the second height, the lowest point in the vertical direction of the wheel 3a is the vertical direction of the pad 42 when the protrusion length is minimum. It is located above the lowest point (the apex of the lower surface of the pad). This positional relationship is maintained even if the protruding length of the pad 42 is extended. For example, in the lawn mower 1 shown in FIG. 7B, the protruding length of the pad 42 is set so that the cutting height is 25 mm, and the height of the wheel 3a is adjusted to the second height. ing. That is, the protruding length of the pad 42 shown in FIG. 7B is longer than the protruding length of the pad 42 shown in FIG. However, even in the state shown in FIG. 7B, the vertical lowest point of the wheel 3 a is located above the vertical lowest point of the pad 42.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.

DESCRIPTION OF SYMBOLS 1 Lawn mower 2 Main body 3a, 3b Wheel 4 Handle 5a Rotating blade 42 Pad 57 Long hole 54, 60 Bolt

Claims (5)

A lawn mower in which a rotary blade is provided on a main body with wheels,
When the rotation plane of the rotary blade is horizontal, the wheel has a first height in which a vertical lowest point is located below the rotation plane, and a vertical lowest point is higher than the rotation plane. A lawn mower characterized in that the height can be adjusted to a second height located at the position. Having an axle with a fixed position relative to the body;
The lawn mower according to claim 1, wherein a height of the wheel is adjusted to the first height or the second height by changing a fixed position of the axle. A long hole into which the axle is inserted, and has a long hole extending along the vertical direction;
The lawn mower according to claim 2, wherein the axle can be fixed to the main body at at least two points along a longitudinal direction of the long hole. A handle rotatably attached to the main body via a support shaft;
The lawn mower according to claim 2 or 3, wherein when the height of the wheel is adjusted to the first height, the axle and the support shaft are arranged on the same straight line. Machine. A support member having a variable distance from the rotation plane, the support member contacting the ground and adjusting the height of the rotation plane relative to the ground;
The vertical lowest point of the wheel adjusted to the first height is located above the lowest vertical point of the support member when the distance is minimum. The lawn mower according to any one of claims 1 to 4.

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