JPS625810B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is mainly typified by a small-sized garden management machine for home gardens, and more specifically, an output shaft in a downward position is mounted on the upper part of a transmission case containing a passive shaft for vertical impulse. fixedly connected to the output shaft in a state where the output shaft is located concentrically or almost concentrically with the passive shaft, and the passive shaft is interlocked with the output shaft via a planetary gear type reduction mechanism, The present invention relates to a working machine provided with a mechanism that can freely switch the planetary gear type reduction mechanism between a transmission state and a non-transmission state by locking and releasing a ring gear of the gear type reduction mechanism.

In such working machines, in order to improve the durability of the driving device, when a work load (overload) exceeding a certain level is applied to the passive shaft, the interlock between the passive shaft and the output shaft is automatically cut off. Normally, the switching mechanism is configured to prevent overload from being transmitted backwards to the prime mover. If the brake structure is configured so that it can be freely switched between the detented state and the detented state, when a rotational force above a certain level is applied to the ring gear because it is a friction type, the ring gear is caused to slip and rotate to ensure that the transmission is cut off. This is technically difficult, and therefore requires a separate slip clutch to be provided in the passive gear transmission mechanism, which has the disadvantage of complicating the structure and increasing costs.

An object of the present invention is to overcome the conventional drawbacks in terms of structure.

The present invention prevents rotation of the ring gear by elastic engagement, and when a rotational force of a certain level or more is applied to the ring gear in the non-rotation state, an engagement tool that automatically disengages from the engaged portion is operated to disengage. The above-mentioned switching operation mechanism was constructed by freely providing the switching operation mechanism.

Therefore, by having a switching operation mechanism, it can also be used as a slip clutch that disconnects the driven shaft from the output shaft when an overload is applied to the driven shaft. , The engagement force between the engaging tool and the engaged part can be made small compared to the rotational force of the output shaft, and ○C The engaging tool and the engaged part are located on the outer periphery of the planetary gear reduction mechanism. This has led to the following advantages:

In other words, when an overload is applied to the passive shaft, the above ○B can prevent the overload from being reversely transmitted to the prime mover, and the structure is simple and can be constructed at low cost. Although it is an engaging type, it suppresses deformation and damage of the engaging tool and the engaged part,
Sufficient durability can be obtained, and assembly is easy due to the above-mentioned ○C.

Hereinafter, embodiments of the present invention will be described based on the drawings. A passive shaft 1 in a vertical position is installed inside, and a weeding rotor, a tilling rotor, a rotary plow, a spike cultivating wheel, etc. are mounted and driven on the lower end thereof. An engine 4,
A prime mover 7 equipped with a fuel tank 5 and a recoil starter 6 for starting the engine is fixedly connected in such a manner that the engine crankshaft 7A as its output shaft is positioned downward and coaxially with the passive shaft 1. , a walking management work machine in which a steering handle 8 and a resistance rod 9 are attached to the mission case 3, and the passive shaft 1 is interlocked with the crankshaft 4A via a clutch, The case 3 and the driven shaft 1 are configured to be able to expand and contract up and down.
At the same time, a member 11 for inserting the cylindrical body 10 in the direction of expansion and contraction is integrally provided in the lower case 3B portion, and a set bolt 12 is attached to the cylindrical body 10 to fix the expansion and contraction steplessly. It is structured as follows.

The clutch includes a sun gear 13A that rotates integrally with the crankshaft 7A, a carrier 13B that rotates integrally with the passive shaft 1, and this carrier 13B.
A planetary gear reduction mechanism 13 comprising a sun gear 13A and a planetary gear 13D supported in mesh with the ring gear 13C is provided in the reduction mechanism 13, and the ring gear 13C of this reduction mechanism 13 is prevented from rotating and is released from rotation. It is constructed by providing a mechanism 14 that can freely switch the speed reduction mechanism 13 between a transmission state and a non-working state.

The switching operation mechanism 14 prevents the ring gear 13C from rotating by elastically engaging the recess 14a (engaged portion) formed in the transmission case 3 from the diametrical direction via the elastic force of the spring 14b. Further, the ring gear 13C is provided with a ball 14c that automatically detaches from the recess 14a when a rotational force of a certain level or more is applied to the ring gear 13C in the non-rotating state, and a pushing tool that can push the ball 14c out of the recess 14a. 14d and an operating lever 14e linked thereto.

A plurality of sets of the balls 14c and springs 14b are provided at appropriate intervals in the circumferential direction.

According to the configuration of the above embodiment, in the transmission state,
When the load applied to the passive shaft 1 exceeds a certain level and a rotational force of a certain level or more acts on the ring gear 13C, the ball 14c automatically disengages and prevents the load above the certain level from being transmitted to the prime mover 7 side. .

In the above embodiment, the ball 14c is elastically engaged with the recess 14a from the diametrical direction, but in the present invention, the ball 14c may be elastically engaged with the recess 14a from the axial direction. The recess 14a may be provided on the transmission case 3 side and the ring gear 13C side.

In addition, the engagement tool 13c does not need to be the ball described in the embodiment, and the output shaft 7A may be a shaft that is linked to the crankshaft.

[Brief explanation of the drawing]

FIG. 1 is a side view, FIG. 2 is an enlarged longitudinal sectional side view of the main part, and FIG. 3 is an enlarged cross-sectional plan view of the main part. 1... Passive shaft, 3... Mission case, 7A
. . . Output shaft, 7 . . . Power drive, 13 . . . Planetary gear reduction mechanism, 13C .

Claims (1)

[Claims] 1. A prime mover 7 equipped with an output shaft 7A in a downward position is placed on the upper part of a transmission case 3 containing a passive shaft 1 in a vertical position, and the output shaft 7A is located concentrically or almost concentrically with the passive shaft 1. The passive shaft 1 is interlocked with the output shaft 7A via the planetary gear reduction mechanism 13, and the ring gear 13C of the planetary gear reduction mechanism 13 is prevented from rotating and released from rotation. Planetary gear reduction mechanism 1
3 between a transmission state and a non-transmission state. The feature is that an engaging tool 14c that automatically disengages from the engaged portion 14a when a rotational force of a certain level or more is applied to the ring gear 13C in a non-rotating state is provided in a state where the disengagement operation is freely possible. work equipment.