JPH057415A - Lawn mower - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a lawn mower that can easily perform spindle mounting work and can smoothly perform cutting height adjustment work. [Structure] The support shaft 17 is attached to the frame 2 in the width direction, and both ends thereof are integrally rotatable around the axis,
The arm member 11 is provided at each of the both ends of the support shaft 17,
11 are integrally provided so that each arm member 11 can swing around the support shaft 17. Also, this arm member 11
An axle 12a for rotatably supporting the wheel 12 is fixed parallel to and separated from the support shaft 17, thereby changing the vertical position of the wheel 12 with respect to the frame 2 and adjusting the cutting height of the lawn. In this case, spherical portions 17c are formed at both ends of the support shaft 17, and the support shaft 17 is attached to the frame 2 via a holding member 23 that holds the spherical portion 17c rotatably in all directions. Support.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lawn mower capable of adjusting a cutting height of lawn, and more particularly to improvement of a bearing portion of a support shaft which constitutes a cutting height adjusting mechanism.

[0002]

2. Description of the Related Art Conventionally, as a lawn mowing height adjusting mechanism used in lawn mowers, for example, there is a wheel raising / lowering type in which a vertical position of a wheel with respect to a frame is changed. As such a cutting height adjusting mechanism, for example, a support shaft is rotatably supported on a frame, arm members are fixed to both ends of the support shaft, and wheels are axially supported by axles fixed to the arm members. There is a structure. In this cutting height adjustment mechanism, the wheels, and thus the frame, are moved up and down by rotating the support shaft, whereby the cutting height of the lawn is adjusted.

[0003]

However, in the conventional lawnmower described above, when the positional accuracy of the mounting portion of the support shaft is low,
There is a problem that the adjustment work at the time of mounting the support shaft is troublesome. There is also a problem that an unreasonable force is applied between the support shaft and the bearing during the cutting height adjustment work, so that the wheels cannot be smoothly moved up or down, or the support shaft, and eventually the wheels are displaced in the axial direction. Therefore, conventionally, the design accuracy and the manufacturing accuracy have been made strict so as to avoid the above problems. The present invention has been made in view of the above conventional circumstances,
Provided is a lawn mower which can easily perform a spindle mounting work without making the above-mentioned design accuracy and manufacturing accuracy so severe, can smoothly perform cutting height adjustment work, and can prevent a wheel from being axially displaced. The purpose is to

[0004]

According to the present invention, the support shaft is attached to the frame in the width direction, and both ends are integrally or independently rotatable about the axis, and the both ends of the support shaft are attached. Arm members are integrally provided on the respective parts, the respective arm members are made swingable, and an axle for rotatably supporting a wheel is fixed to the respective arm members in parallel with and separated from the support shaft,
Change the vertical position of the wheel with respect to the frame,
In a lawnmower adapted to adjust the cutting height of lawn, spherical surfaces are formed at both ends of the support shaft, and the support shaft is supported via a holding member that rotatably holds the spherical surface in all directions. Is characterized in that the above frame is supported.

[0005]

According to the lawnmower of the present invention, when the arm is swung via the support shaft, the axle fixed to the arm,
As a result, the wheels move up and down, which changes the height of the frame, that is, the height of the cutter, and the cutting height of the grass is adjusted. At this time, since the bearing portion of the support shaft is configured as a so-called spherical bearing including a spherical portion and a holding member that holds the spherical portion so as to be rotatable in all directions, there is some error in the positional accuracy of the mounting portion. However, the error is automatically absorbed and the spindle can be attached without any trouble. Further, in the present invention, the above mounting error can be absorbed by the spherical portion of the support shaft and the holding member, and the cutting height can be adjusted smoothly without applying excessive force. Further, since the bearing portion of the support shaft is composed of the spherical surface portion and the holding member for holding the spherical surface portion, the movement of the support shaft in the axial direction is restricted, and rattling of the support shaft and the wheels can be reduced.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 6 are views for explaining a lawnmower according to an embodiment of the present invention. FIG. 1 is a plan sectional view of a main part, FIG. 2 is a plan sectional view of a rear part of the lawn mower, and FIG. III-III of 1
A sectional view, FIG. 4 is a perspective view of the lawnmower seen from the bottom, and FIGS. 5 and 6 are side views of the lawnmower.

In the figure, reference numeral 1 is a lawnmower equipped with a cutting height adjusting mechanism of the present embodiment, and a frame 2 of the lawnmower 1 is made of an aluminum alloy casting having a generally rectangular shape in plan view. An engine 3 is loaded on the upper surface of the frame 2, and a lawn mowing cutter 4 is fixed to an output shaft 2a protruding downward from the lower surface of the engine 3. A steering handle 5 is fixed to the rear end of the upper surface of the frame 2,
A collection box 8 for collecting cut grass is fixed to the rear wall.

Front wheel arms 9, 9 are arranged on both left and right sides of the front part of the frame 2. The arm 9 is a V-shaped plate-like member, and the base end portion thereof is rotatably supported by a pin 14. A front wheel 10 is rotatably supported on the lower portion of the front end of the front wheel arm 9, and the front end of a front link 13 is connected to the upper end of the front wheel 13 by a pin 13a. The rear end of the front link 13 is connected to the inner surface of the connecting portion 6a of the drive arm 6 via a pin 13b.
Is pivotally supported by the pin 6b on the rear left side surface of the frame 2. A grip portion 6c is formed on the drive arm 6 so as to extend forward, and a grip 28 is attached to the grip portion 6c. Further, a locking arm 7 is fixed to the outer surface of the drive arm 6, and the locking arm 7 is made of an elastic plate material that is deformable in the vehicle width direction. 7a can be engaged with and disengaged from the locking recess 27a of the locking plate 27 fixed to the frame 2.

At the rear end of the frame 2, the support shaft 1
7 are arranged in the vehicle width direction. The support shaft 17 is made of steel pipe and is divided into left and right support shafts 17a and 17b such that a transmission 18 described later is located between the left and right support shafts 17a and 17b. It is fastened by a bolt 21 via a connecting plate 20 formed so as to surround the rear surface of the transmission 18, and is thereby integrated.

A connecting arm 17 is attached to the left support shaft 17a.
e is fixed, and the arm 17e is connected to the outer surface of the connecting portion 6a of the drive arm 6 by the rear link 31 via the pin 13b. Furthermore, the rear end portions of the rear wheel arm 11 are fixed to the left and right end portions of the left support shaft 17a and the right support shaft 17b, respectively. An axle 12a is fixed to the front of each of the rear wheel arms 11 and 11, whereby the rear wheel 12 is rotatably supported.
Further, the drive shaft 15 is inserted into the support shaft 17, and the bearing 2
It is rotatably supported by 2. This drive shaft 15
The transmission 18 is installed in the middle of the
The casing is fixed to the support shaft 17. The driving force from the engine 3 is transmitted to the drive shaft 15 via the speed change gear 19 of the device 18. Drive shaft 1
A drive gear 16 is rotatably mounted on both ends of the gear 5, and a one-way clutch 26 is interposed between the drive shaft 15 and the drive gear 16. The drive gear 16 meshes with an internal gear 25 formed on the inner circumference of the rear wheel 12. The one-way clutch 26 is for transmitting only power in the forward direction from the drive shaft 15 to the drive gear 16. This facilitates conveyance when the engine is stopped and obtains an operation as a differential mechanism when changing directions.

The left and right support shafts 17a and 17b are integrally formed with spherical portions 17c and 17d, respectively, which are bulged so that their outer surfaces are spherical. Further, the inner surfaces of the spherical portions 17c and 17d are supported by resin holding members 23 and 24 formed in a spherical shape corresponding to the spherical portions 17c and 17d. This constitutes a spherical bearing that holds the spherical portions 17c and 17d so as to be rotatable in all directions. The holding members 23, 2
4 is fastened to the frame 2 with bolts 30 by means of stoppers 29a and 29b. Here, the left stopper 29a
While the flange portions 29c, 29c are arranged so as to be substantially vertical, the stopper 29b on the right side is arranged so that the flange portion 29d is slightly forward and downward with respect to the horizontal plane. That is, the left and right stops 29a and 29b are fixed on the planes of the frame 2 which are substantially orthogonal to each other.

Next, the function and effect of this embodiment will be described. In the lawnmower 1 of this embodiment, in order to adjust the cutting height of the lawn, the locking arm 7 is gripped on the handle 28 side and the locking pin 7a is held.
And the locking plate 27 are unlocked, and then the handle 28
Then, the drive arm 6 is pulled up to a predetermined position, and the locking arm 7 is loosened at this position so that the locking pin 7a of the driving arm 6 is locked in one of the locking recesses 27a of the locking plate 27. Then, according to the rotation of the drive arm 6, the front link 13 rotates the front wheel arm 9 in the clockwise direction in the drawing, whereby the height of the front wheel 10 with respect to the frame 2 changes. Further, the rotation of the drive arm 6 is transmitted to the support shaft 17 via the rear link 31, whereby the left and right rear wheel arms 11 rotate,
The height of the rear wheel 12 with respect to the frame 2 changes, and as a result, the vehicle height, and consequently the height of the cutter 4 with respect to the road surface, changes, and the cutting height of the lawn is adjusted.

When the support shaft 17 is mounted on the frame 2 in such a lawn mower 1, in the conventional device, if the positional accuracy of the mounting portion is low, for example, the mounting holes of the stoppers 29a and 29b are displaced. As it is, it is difficult to attach the spindle with high precision as it is, and therefore adjustment work is required. On the other hand, in the apparatus of this embodiment, the support shaft 17 is formed on the spherical surface portions 17c, 17d and the holding members 23, 2
Since the bearing of the support shaft 17 is a spherical bearing that can freely rotate in all directions, it is supported at the above mounting hole position. Even if there is an error, this error can be absorbed without performing the above adjustment work, and as a result, the support shaft 17 can be attached without any trouble. Further, even when the mounting accuracy of the support shaft 17 is low, the rear wheel arm 11 can be smoothly moved without applying an excessive force. Furthermore, since the bearing portion of the support shaft 17 is a spherical bearing, the position of the support shaft 17 in the axial direction can be regulated, and as a result, the support shaft 17 and thus the rear wheel 12 can be prevented from shifting in the axial direction.

Further, since the stoppers 29a and 29b for fixing the holding members 23 and 24 are fixed on the planes of the frame 2 which are substantially orthogonal to each other, the heights of the wheels 10 and 11 can be adjusted and the four wheels can be adjusted. It can be easily and surely positioned on the same plane. In this case, since the bearing of the support shaft 17 for the rear wheel 11 is a spherical bearing, there arises a problem that the support shaft 17 is twisted in the height adjustment without performing the adjustment work as in the conventional device described above. Not even.

In the above embodiment, the support shaft 17 is
The case where the right support shafts 17a and 17b are integrated by the connecting plate 20 has been described, but the support shaft of the present invention may have separate left and right parts. in this case,
It is desirable to dispose the bearings 22, 22 supporting the left and right support shafts 17a, 17b at intervals. Further, although the present invention is applied only to the rear wheel support shaft 17 in the above-described embodiment, a spherical member is formed on the axle of the front wheel 10 and a holding member for holding the spherical member rotatably in all directions. You may support it.

[0016]

As described above, according to the lawnmower of the present invention, the support shaft is provided with the spherical surface portion, and the spherical surface portion is held by the holding member rotatable in all directions. Since the bearing is a spherical bearing, there is an effect that the work of attaching the support shaft is easy and that the work of adjusting the cutting height can be performed smoothly, and that the wheel is prevented from being displaced in the axial direction.

[Brief description of drawings]

FIG. 1 is a cross-sectional plan view of a support shaft portion of a lawnmower according to an embodiment of the present invention.

FIG. 2 is a cross-sectional plan view of a rear portion of the lawnmower.

3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a perspective view of the lawnmower seen from the bottom.

FIG. 5 is a side view of the lawnmower.

FIG. 6 is a side view of the lawnmower.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lawn mower 2 Frame 11 Rear wheel arm (arm member) 12 Rear wheel (wheel) 12a Axle 17 Support shaft 17c, 17d Spherical part 23, 24 Holding member

Claims (1)

Claim: What is claimed is: 1. A support shaft is attached to a frame in a width direction, and both ends of the support shaft are integrally or independently rotatable about an axis, and the both ends of the support shaft are attached. Arm members are integrally provided on the respective parts, the arm members are swingable about the support shafts, and the axles for rotatably supporting the wheels on the arm members are parallel to and separated from the support shafts. In a lawn mower that is fixed and that adjusts the height of the lawn by changing the vertical position of the wheels with respect to the frame, forms spherical surfaces at both ends of the support shaft, and the spherical portions are provided in all directions. A lawn mower characterized in that the support shaft is supported on the frame via a holding member that is rotatably held by the frame.