JPH0749122Y2 - Walk-behind field cultivator - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a walk-behind field cultivator having a PTO system forward / reverse switching mechanism in a mission case having a traveling system gear shifting mechanism.

[Conventional technology]

Generally, the forward / reverse switching in the gear shift mechanism is performed by providing a back gear for reverse rotation as a separate shaft and allowing the meshing with the back gear to be switchable.

And, the transmission mechanism of the conventional walk-type cultivator also follows the above-mentioned configuration, and the PTO system forward / reverse rotation switching mechanism is equipped with a back shaft equipped with a back gear dedicated to this PTO system reverse rotation. .

[Problems to be solved by the device]

The walk-type cultivator, by its nature, is lighter and more compact so that the handleability is improved if the required functions are satisfied, so that the product value can be improved accordingly.

Therefore, efforts are being made to reduce the weight and size of the components by studying all the component configurations, and the demands for the mission case cannot be ignored.

Therefore, the present invention aims to promote the reduction in weight and size of the mission case as a whole by devising the structure of the speed change mechanism, especially the structure of the PTO forward / reverse switching mechanism.

[Means for Solving the Problems]

In order to achieve the above object, the present invention provides a PTO system first transmission shaft and a PTO.
A PTO system forward / reverse switching mechanism formed over the system second transmission shaft, and a traveling system gear speed change mechanism formed over the traveling system first transmission shaft traveling system second transmission shaft in the mission case. In the provided walk-type cultivator, the PTO system first transmission shaft is provided with the first and second drive gears in a state of integrally rotating therewith, and the traveling system first transmission shaft is engaged with the second drive gear. The drive system input gear for transmitting power to the drive system gear transmission mechanism is provided, and by the shift operation of the shift gear provided on the PTO system second transmission shaft, the shift gear meshes with the first drive gear. The first transmission shaft and the first transmission system of the traveling system, so that the state and the second transmission state of engaging the input gear of the traveling system and transmitting the power of the rotation reverse to the first transmission state can be revealed. The shaft and the PTO system second transmission shaft are linked to each other, and the traveling system input gear is made wide. It is characterized in that have configured the PTO reverse rotation switching mechanism and.

[Action]

According to the above configuration, the PTO system forward / reverse switching mechanism engages the shift gear with the traveling system input gear that is engaged with the second drive gear when the state in which the shift gear is engaged with the first drive gear is set to the forward rotation state. The reverse rotation state appears in the reverse rotation state, but since the reverse rotation state uses the traveling system input gear originally equipped for the traveling system, the back gear dedicated to the PTO system and the reverse Both the shaft can be omitted, and the bearing and the space inside the case can be omitted.

That is, by arranging the PTO system first transmission shaft, the traveling system first transmission shaft, and the PTO system second transmission shaft in an interlocking manner, and forming the traveling system input gear wide, the shift gear, the first drive gear, and The respective meshing of the shift gear and the input gear of the traveling system has become possible to appear.

[Effect of device]

As a result, by making the gear of the traveling system and its gear axis double as the PTO system by widening the gears and devising the shaft layout, the number of parts can be reduced, which reduces the assembly man-hours and the cost. The mission was made lighter and more compact by omitting the gear and back shaft dedicated to the reverse rotation switching mechanism.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 2, the horizontal shaft engine (3) is installed upright on the front frame (2) extending forward from the mission case (1),
A transmission mechanism (4) with a belt is installed over the engine (3) and the mission case (1), and a traveling system gear transmission mechanism (18) described later and a PTO system gear described later are provided in the mission case (1). A walk-behind cultivator with a speed change mechanism (19) is shown.

The mission case (1) has a traveling chain case (8) for transmitting power to traveling wheels (7) below the mission case (1), and a working device (9) provided behind the traveling wheels (7). ) Is attached to an auxiliary chain case (12) for transmitting power to a chain case (10) for driving.

As shown in FIG. 1, in the mission case (1),
Input pulley (13) that receives power from the engine (3)
Equipped with an input shaft (14), a traveling system output shaft [corresponding to the second traveling system transmission shaft] (15), a traveling system intermediate shaft (16), and a PTO system transmission shaft (17). , Each of these axes (1
4), (15), (16), (17) by the combination of the externally fitted gear group, the forward transmission two speeds, the reverse one speed and the traveling system transmission (18) that appears neutral, forward and reverse rotation, And a PTO transmission (19) that appears neutral.

Forward / reverse switching mechanism (22) in the PTO transmission (19)
Is equipped with a transmission shaft (17) of the PTO system in parallel with the input shaft (14), and a shift gear (24) provided on the transmission shaft (17),
Intermediate between a first drive gear (20A) fixed to the input shaft (14) and a second drive gear (20B) fixed to the input shaft (14) and a traveling system gear transmission mechanism (18) which is constantly rotated. The wide gear (21) pivotally supported by the shaft (16) can be selectively engaged with the wide gear (21) so that the transmission (19) for the PTO system is for the transmission (18) for the traveling system. The intermediate shaft (16) is partially shared.

That is, the input shaft (corresponding to the PTO system first transmission shaft) (14)
The first and second drive gears (20A) and (20B) so as to rotate integrally therewith, and the intermediate drive shaft (corresponding to the first transmission shaft of the traveling system) (16) and the second drive gear ( 20B) is provided with a wide gear (corresponding to a traveling system input gear) (21) for transmitting power to the traveling system gear transmission mechanism (18), and a shift gear provided on the PTO system second transmission shaft (17) By the shift operation of (24), the shift gear (24) engages the first drive gear (20A) in the first transmission state, and the wide gear (21) engages to transmit the power of rotation reverse to that in the first transmission state. So that the second transmission state can be realized, the input shaft (14) and the intermediate shaft (1
6) and the second transmission shaft (17) of the PTO system are linked to each other, and the wide gear (21) is a wide one that enables simultaneous engagement between the shift gear (24) and the second drive gear (20B). The PTO system forward / reverse switching mechanism (22) is formed. still,
Both drive gears (20A) and (20B) are formed as an integral structure with the input shaft (14).

As shown in FIG. 1, a PTO clutch mechanism (5) is constructed on the transmission shaft (17) of the PTO system. In this clutch mechanism (5), the PTO clutch mechanism is always in the clutch engaged state by pressing and urging the clutch body (6) with the spring (23), and the clutch body (6) is axially moved to the clutch fork (25). ) The clutch is disengaged by forcibly sliding it.

As shown in FIG. 3, the clutch fork (25) has a pin (2) that engages with the groove of the clutch body (6) on the fork shaft (26).
The frame body (28) with the 7) facing each other is fixed.

The pin (27) is arranged closer to the input pulley (13) side than the center of the frame body (28) in plan view to increase the wall thickness of the moving portion of the frame body (28) in the clutch disengagement direction. The frame body (28) can withstand the target cutting action.

It should be noted that reference numerals are added to the claims of the utility model for convenience of comparison with the drawings, but the present invention is not limited to the structure of the accompanying drawings by the entry.

[Brief description of drawings]

The drawings show an embodiment of a walk-behind cultivator according to the present invention.
The drawing is a horizontal and vertical cross-sectional view of the mission case, FIG. 2 is a side view, and FIG. 3 is a perspective view of the clutch fork portion. (1) …… Case, (14) …… PTO system first transmission shaft, (1
5) -Travel system second transmission shaft, (16) -Travel system first transmission shaft, (17) -PTO system second transmission shaft, (18) -Travel system gear speed change mechanism, (20A) ... … First drive gear, (20B) …… Second drive gear, (21) …… Running system input gear, (22) …… PT
O system forward / reverse switching mechanism, (24) …… Shift gear.

Claims (1)

[Scope of utility model registration request] 1. A traveling system gear transmission mechanism (1) formed over a traveling system first transmission shaft (16) and a traveling system second transmission shaft (15).
8), PTO system first transmission shaft (14) and PTO system second transmission shaft (1
A walk-type cultivator equipped with a PTO system forward / reverse switching mechanism (22) formed over 7) in a mission case (1), wherein the PTO system first transmission shaft (14) comprises: The first and second drive gears (20A) and (20B) are provided in a state of integrally rotating therewith, and the traveling system first transmission shaft (16) is engaged with the second drive gear (20B). A shift gear (24) provided with a travel system input gear (21) for transmitting power to the travel system gear speed change mechanism (18), and provided with the PTO system second transmission shaft (17)
The shift operation of the shift gear (24) engages the first drive gear (20A) in a first transmission state, and the traveling system input gear (21) engages in a reverse rotation from the first transmission state. The PTO system first transmission shaft (14), the traveling system first transmission shaft (16), and the PTO system second transmission shaft (17) so that the second transmission state for transmitting power can be revealed. And a traveling type input gear (21) having a wide width to form the PTO system forward / reverse switching mechanism (22).