JPH0725266B2 - Walk-behind lawn mower - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention provides an exhaust duct provided with an engine for driving a cutting blade and wheels, and cutting grass sown by the cutting blade on one side of an upper part in a housing. The present invention relates to a walk-behind lawnmower that is configured to discharge through.

[Conventional technology]

As a conventional walking lawn mower, there is a conventional one configured to drive a pair of left and right rear wheels (03) directly from an engine (01) through a belt type continuously variable transmission (02) as shown in FIG. .

[Problems to be solved by the invention]

The above-mentioned conventional example simply switches the vehicle speed between high and low speeds via the belt type continuously variable transmission, so that the wheels cannot be reversed and the front and rear of the machine body that is forced to mow the grass around the standing tree. During repeated work, the transmission of the belt-type continuously variable transmission must be cut off to free the wheels to move backwards.The power of the belt-type continuously variable transmission must also be maintained when the aircraft changes direction. It had to be cut off and the direction changed, which made the work inefficient.

Further, since one end of the belt type continuously variable transmission is wound around an axle positioned at a low position, when the grass after rain is harvested, water drops adhere to the belt and the pulley, causing slipping. May occur easily, and reliable transmission may not be possible. Needless to say, such a problem can be solved by covering the belt type continuously variable transmission with a cover case, but this causes the structure to be complicated, which leads to cost increase and is disadvantageous to maintenance.

It is an object of the present invention to solve the above-mentioned drawbacks by devising a transmission structure and to obtain a structure therefor from a compact structure.

[Means for solving problems]

A characteristic configuration for achieving the above-mentioned object is to provide a disc type continuously variable transmission for switching the rotation of wheels to forward / reverse and high / low speed, and a differential device, and to provide the disc type continuously variable transmission and the differential device. A differential device arranged in a space formed on a side portion of the exhaust duct in a state where the disc type continuously variable transmission is located above the differential device, and at the bottom of the disc type continuously variable transmission device. Is configured to be movable up and down and fixed around a horizontal axis with respect to the housing, the wheels are supported by the differential device, and the output shaft of the disc type continuously variable transmission and the input shaft of the differential device are further supported. The point is that they are linked together by a gear.

[Work]

Since a continuously variable transmission that can switch forward and backward and high and low speeds is provided, the belt type continuously variable transmission can be changed by switching the transmission to reverse when repeating forward and backward movements of the aircraft that are forced to mow grass around standing trees. There is no need to cut off the power transmission of the device to free the wheels to back the machine, and when changing the direction of the machine, it is possible to smoothly make a small turn by using the differential device. It is not necessary to cut off the power transmission of the and free the wheels to make a small turn.

Further, since the continuously variable transmission is a disc type, it can be compactly stored and arranged at a high position in a narrow space such as the lateral side of the exhaust duct, and water droplets can be placed on the friction transmission surface of the transmission. It is possible to reliably perform speed change transmission without sticking.

〔The invention's effect〕

Therefore, the lawn mowing work around the standing tree can be performed dramatically more efficiently than before, and moreover, the adhesion of water droplets to the transmission can be prevented without using a special cover structure. Even when mowing leaked grass after raining, the work can be performed well without slipping the transmission.

Moreover, by arranging the disk type continuously variable transmission and the differential gear side by side in the dead space on the lateral side of the exhaust duct, the empty space can be effectively used to make the whole compact.

Furthermore, since the differential equipped with wheels can move up and down around the horizontal axis with respect to the housing, the disc type continuously variable transmission and the differential can be moved up and down integrally to increase the cutting height. The cutting height can be changed more easily than when changing the cutting height.

〔Example〕

FIG. 3 is a side view showing the whole of a walk-behind lawnmower.
The cutting blade (3) in the housing (16) is driven through the vertical engine (1) and the cutter clutch (2), the bevel gear (4), the universal joint (5), and the extendable spline shaft (7). Shaft transmission mechanism (8) and disk type continuously variable transmission (9), and V as a transmission tool
The rear wheel (12) is configured to be driven via the belt (10) and the differential device (11).

The cutter clutch (2) and the continuously variable transmission (9)
Is configured to be operated by a cutter clutch operating lever (14) and a gear shift operating lever (15) provided on the steering handle (13), respectively.

At the rear of the housing (16), a grass container (18 is attached and detached for collecting cut grass that is discharged through an exhaust duct (17) provided on one lateral side of the upper part of the housing (16). It is provided freely.

As shown in FIG. 4, the continuously variable transmission (9) is arranged in the high position space (A) on the lateral side of the discharge duct (17), and is shown in FIGS. As shown in, the driven disk (9B) is frictionally transmitted to the drive disk (9A), and the driven disk (9A) is driven to the driven disk (9A).
B) is configured so that low speed transmission is performed by locating it radially inward, and high speed transmission is performed by locating it radially outward. By moving to the right or left at the boundary, it is possible to switch between forward and reverse, that is, forward / backward switching is also possible.

The drive disk (9A) is constantly pressed against the driven disk (9B) by the spring (19), and the spring (19)
The transmission is configured to be cut off by being separated from the urging force of the vehicle, and is configured to be turned on and off by operating the traveling clutch lever (20) provided on the steering handle (13). .

The differential device (11) is swingably fixed vertically below the disc type continuously variable transmission (9) about the axis (X) of the input shaft (21) of the V-belt (10). The height position of the rear wheel (12) is adjustable with respect to the housing (16) provided. That is, as shown in FIG. 3, a pair of left and right L-shaped operation levers (22), (22) are concentric with the input shaft (21) of the differential device (11) in the housing (16). Is pivotally attached in a circular shape, and the axle (23) of the rear wheel (12) is rotatably mounted on the other end side of the levers (22) and (22), and the lever (22) is operated to raise the axle. The position is adjustable and fixed.

Further, the height of the front wheels is adjusted by swinging and adjusting a lever (26) fixed to a crankshaft (25) that supports the front wheels (24) in a freely rotatable manner.

The output shaft (9b) of the driven disk (9B) and the differential device (1
1) Input shaft (21) and transmission belt (1
0) is kept in a predetermined tension state by a tension pulley (29) whose position is adjustable via a bolt (27) and an elongated hole (28).

[Other Embodiments] In the above embodiments, the V-belt was illustrated as the transmission tool (10), but a toothed belt having meshing teeth on the inner peripheral surface, or a winding transmission tool such as a chain may be used. It is good. Further, power transmission can be performed by a gear or a transmission tool that is a combination of a bevel gear and a transmission shaft.

In the above-described embodiment, the drive disk (9A) of the continuously variable transmission (9) is separated from the driven disk (9B) as the traveling clutch, but as shown in FIG. 29) The swing arm (3) is swung by the traveling clutch lever (20).
It is also possible to mount it on 0) to construct a belt tension clutch type traveling clutch.

[Brief description of drawings]

The drawings show an embodiment of a walk-behind lawnmower according to the present invention.
The figure shows a vertical side view showing the main part, Fig. 2 a partially cutaway vertical rear view showing the main part, Fig. 3 a side view showing the entire lawn mower, and Fig. 4 a partial cutout of the cutter cover. FIG. 5 is a plan view, FIG. 5 is a vertical cross-sectional side view of an essential part showing another embodiment, and FIG. 6 is a schematic view showing a conventional structure. (1) ...... Engine, (3) ...... Cutting blade, (9) ...... Disc type continuously variable transmission, (9b) ...... Output shaft, (10) ...... Winding transmission, (11) ...... Actuator, (12) …… Wheels,
(16) …… Housing, (17) …… Exhaust duct, (A)
……space.

Claims (2)

[Claims] 1. An engine (1) for driving a cutting blade (3) and a wheel (12) is provided, and cutting grass cut by the cutting blade (3) is provided on one side of an upper part in a housing (16). In a walk-behind lawnmower configured to discharge through a discharge duct (17), a disc type continuously variable transmission (9) for switching the rotation of the wheel (12) between forward and reverse as well as high and low speeds. And a drive device (11), and the disk type continuously variable transmission (9) and the differential device (11) are provided in the space (A) formed on the lateral side of the exhaust duct (17). The stage transmission (9) is arranged in a state of being located above the differential device (11), and the differential device (11) disposed below the disc type continuously variable transmission (9) is provided with a housing ( 16) is configured so that it can be moved vertically and fixed around the horizontal axis (X), and the wheels (12) are attached to this differential device (11). In addition, further, the output shaft (9b) of the disk type continuously variable transmission (9) and the input shaft (21) of the differential device (11) are interlocked by a transmission tool (10). A characteristic walking lawn mower. 2. The walk-behind lawnmower according to claim 1, wherein the transmission tool (10) is a winding transmission tool.