JPH07236331A - Mower - Google Patents

Abstract

PURPOSE:To provide a mower capable of providing both buffer effect and dustproof effect by simple constitution. CONSTITUTION:A rotary edge 8 is loosely engaged into the cylindrical part 10a of an inner flange 10 fitted monolithically to a spindle 6 projected from a motor housing 2, and the tip of the spindle 6 is screwed with a lock nut 9 holding the rotary edge 8 together with the inner flange 10. Between the rotary edge 8 and the flange part 10b of the inner flange 10, a countersunk spring 12 pressing the rotary edge 8 toward the lock nut 9 side, with its tip in proximity to the step 2a of the motor housing 2 and a raising part 11 provided so as to enclose the gap between the rotary edge 8 and the motor housing 2, is set up. This spring 12 exhibits buffer effect through serving as the clutch for the rotary edge 8, while the raising part 11 exhibits dustproof effect between the rotary edge 8 and the step 2a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mower in which rotary blades are mounted orthogonally on a spindle protruding from a motor housing.

[0002]

2. Description of the Related Art In the above mower, the rotary blade is clamped between an inner flange and an outer flange and fixed to a spindle with a bolt, or directly fixed to a mounting seat provided on the spindle with a bolt or the like. It is integrated with the spindle. For example, a mower disclosed in Japanese Utility Model Publication No. 46-4822 has a structure in which a mounting shaft portion provided on a spindle is inserted into a mounting hole at the center of a rotary blade and the rotary blade is fixed by a washer and a bolt. Interposes a disc spring between the rotary blade and the washer, and when the rotary blade collides with a stone, a standing tree, etc. during mowing work, the rotary blade is slipped, and its cushioning action prevents the motor etc. A configuration that tries to prevent the influence is adopted.

[0003]

In a normal mowing operation, there is a risk that the grass may be caught in the spindle or minute dusts may enter the inside of the main body to cause malfunction. Therefore, as is well known from Japanese Utility Model Publication No. 62-45546, a cover attached to the main body is used to prevent the involvement of grass, but it still does not prevent the intrusion of minute dust, No significant dustproof effect is obtained. On the other hand, in the former publication, of course, no dust-proof measures are taken, and the buffer mechanism is also
When the rotary blade slips due to an external force, the external force in the tightening direction is transmitted to the washer (outer flange) that supports the disc spring, and the bolts and washers are too tight, which makes removal of the rotary blade troublesome. .

[0004]

In view of the above, the present invention has a simple structure and not only provides a dustproof effect in addition to the cushioning effect described above, but also the slip of the rotary blade for obtaining the cushioning is caused by the rotation blade and the spindle. The lawn mower does not have any effect on the mounting structure of the motor.The structure is such that the rotary blade is loosely fitted orthogonally to the spindle protruding from the motor housing, and the rotary blade does not come out at the tip of the spindle. On the motor housing side of the rotary blade, a spring member for pressing the rotary blade toward the retaining member side is arranged while fixing the stopper member, and the spring member surrounds the periphery of the gap between the motor housing and the rotary blade. The rising portion is integrally formed. In addition to the above configuration, an eave portion may be integrally provided around the rising portion of the motor housing.

[0005]

Since the rotary blade is pressed against the retaining member by the spring member, the rotary blade normally rotates integrally with the spindle, and when an external force exceeding the pressing force of the spring member is applied to the rotary blade, the spring member acts as a clutch. It allows the rotary blade to slip and absorbs external force. Further, since the rotary blade is free from the spindle, slipping of the rotary blade does not affect the coupling between the spindle and the retaining member, and the retaining member can be easily removed. Further, since the gap between the motor housing and the rotary blade is substantially closed by the rising portion of the spring member, there is no entanglement of grass and dust and the like do not enter the motor housing. In particular, if the eave portion is integrally provided around the rising portion of the motor housing, it is more effective in preventing the grass from being entangled from above.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partial cross-sectional view of a mower. The mower comprises a motor-driven rotary blade 8 on a main body 1 connected to a handle portion (not shown) equipped with a power switch via a long pipe. is there. In the main body 1, a motor shaft 4 of a motor 3 built in a motor housing 2 is connected to a spindle 6 via a gear 5, and the spindle 6 is axially supported by a ball bearing 7 and protrudes below the main body 1. The rotary blade 8 is composed of a lock nut 9 screwed to a screw portion 6a formed at the tip of the spindle 6 and an inner flange 10 above the lock nut 9 and integrally fitted to the spindle 6. It is pinched. For details, refer to the cylindrical nut portion 9 of the lock nut 9.
By fitting the cylindrical portion 10a of the inner flange 10 that is provided so as to be opposed to the outer periphery of the a, a space S is generated between the flange portion 9b of the lock nut 9 and the flange portion 10b of the inner flange 10, The circular mounting hole 8a at the center of the rotary blade 8 is inserted into the cylindrical portion 10a of the inner flange 10 within the space S. The diameter of the mounting hole 8a is set larger than the outer diameter of the cylindrical portion 10a. Further, between the rotary blade 8 and the flange portion 10b of the inner flange 10 at the interval S, a mortar-shaped disc spring 1 is provided around the rising portion 11 parallel to the axis of the spindle 6.
2 is a rotary blade 8 on the large diameter side in which the rising portion 11 is bent and formed.
, And the mounting hole 12a provided in the center of the rotary blade 8 is inserted into the cylindrical portion 10a of the inner flange 10 and is vertically pressed. Furthermore, this disc spring 1
As shown in FIG. 2, the mounting hole 12a of No. 2 is inserted in a shape matching the outer shape of the cylindrical portion 10a formed by chamfering. Therefore, in the state of FIG. 1, the disc spring 12 is integrated with the inner flange 10. The rotary blade 8 is pressed toward the flange portion 9b side of the lock nut 9 by the pressing force in the vertical direction while rotating in the direction of 0.
Is free in the direction of rotation, but is configured to be integrated with the disc spring 12 and the lock nut 9 by the pressing force of the disc spring 12. The leading end of the rising portion 11 of the disc spring 12 has a stepped portion 2a provided around the leading end of the motor housing 2.
Is close to, leaving a slight gap between them, and surrounds the circumference between the stepped portion 2a and the rotary blade 8 to substantially close the gap. By this rising portion 11, grass and minute dust are generated from the rising portion 11. Prevents intrusion to the center side. On the other hand, an eaves portion 2b that prevents the grass from being entangled from above is also provided around the step portion 2a of the motor housing 2. 13
Is a safety cover.

In the mower constructed as described above, when the spindle 6 is rotated clockwise by the motor drive (in the direction from the motor 3 side), the inner flange 10 integral with the spindle 6 and the lock nut 9 are also rotated. The rotary blade 8 also rotates integrally with the spindle 6 by the pressing force of the disc spring 12 which is integral with the inner flange 10. When the rotary blade 8 comes into contact with a stone, a standing tree, or the like during the mowing work, an external force exceeding the pressing force of the disc spring 12 is applied to the rotary blade 8, and the rotary blade 8 is braked. Belleville spring 1
Since it slips between 2 and the flange portion 9b of the lock nut 9 and absorbs the shock, the rotation of the spindle 6 is not affected, and the shock is not transmitted to the inside of the main body 1 such as the gear 5 and the motor 3. Further, at this time, the lock nut 9 screwed to the spindle 6 receives almost no external force even if the rotary blade 8 slips, so the screwing with the spindle 6 is not affected, and the rotary blade 8 is replaced. Therefore, the lock nut 9 can be easily removed. On the other hand, since the space between the rotary blade 8 and the motor housing 2 is substantially closed by the rising portion 11 of the disc spring 12, it is possible to almost completely prevent grass entanglement and dust from entering the motor housing 2. Further motor housing 2
The eaves 2b on the upper side can prevent the grass from being entangled from above the rising portion 11, which is more effective.

In the above embodiment, the disc spring 12 is integrated with the spindle 6 via the inner flange 10.
The shape of the inner flange 10 and the locking structure with the disc spring 12 are not limited to those in the above embodiments, and the design can be changed as appropriate. The inner flange 10 is eliminated, and the disc spring 12 is fixed directly to the spindle 6 to fix the rotary blade 8. It may be pressed.
Further, the rising portion 11 of the disc spring 12 is not parallel to the axial direction of the spindle 6 and its angle may be changed arbitrarily, and the other disc springs 12 may be turned upside down or raised. It is also possible to widen the vertical width of the portion 11 so as to cover the front end portion of the motor housing 2 more widely.
Furthermore, although the disc spring 12 rotates integrally with the spindle 6 in the above-described embodiment, it may be loosely fitted to the spindle as a separate rotation like the rotary blade. In addition, the eaves portion 2b of the motor housing 2 can also be provided in a downwardly projecting manner so as to cover the gap between the motor housing and the rising portion outside, in addition to the horizontal direction, but the eaves portion 2b can be eliminated. However, it goes without saying that the dustproof effect can be maintained.

[0009]

As described above, according to the present invention, not only the conventional cushioning effect but also the effective dustproof effect and the effect of preventing the entanglement of grass can be obtained only by the constituent parts of the spring member, and the cost can be reduced. , Very effective in maintaining the performance of the mower. Also, since the slip of the rotary blade and the mounting structure of the rotary blade are not linked, the retaining member is not affected and the workability of removing the rotary blade is not affected. Furthermore, if the motor housing is provided with an eaves portion, grass entanglement can be prevented more effectively.

[Brief description of drawings]

FIG. 1 is an explanatory view of a mower of the present invention.

FIG. 2 is an enlarged sectional view taken along line AA.

[Explanation of symbols]

1 ... Main body, 2 ... Motor housing, 3 ... Motor,
4 ... Motor shaft, 5 ... Gear, 6 ... Spindle, 7 ...
・ Ball bearings, 8 ・ ・ Rotating blades, 9 ・ ・ Lock nuts, 10 ・ ・ Inner flanges, 11 ・ ・ Rising parts,
12 ... Disc spring, 13 ... Safety cover

Claims (2)

[Claims] 1. A rotary blade is loosely fitted orthogonally to a spindle protruding from a motor housing, and a retaining member for the rotary blade is fixed to the tip of the spindle, while the rotary blade is attached to the motor housing side of the rotary blade. A mower characterized in that a spring member that is pressed toward the retaining member is arranged, and a rising portion that surrounds a gap between the motor housing and the rotary blade is integrally formed on the spring member. 2. The mower according to claim 1, wherein an eave portion is integrally provided around the rising portion of the motor housing.