JPH0614B2 - Power transmission structure for walking type lawnmower - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is directed to an engine which is positioned on the rear side of a cutting blade housing portion of a machine body and has a height-adjustable drive axle mounted thereon, and which transmits power to the drive axle. The present invention relates to a traveling transmission structure for a walk-behind lawnmower that is arranged above a cutting blade storage portion and that is provided with a transmission for the drive axle.

[Conventional technology]

In such a walk-behind lawnmower, the cutting height is adjusted by adjusting the mounting height of the drive axle.

In this kind of lawn mower, the conventional application is Japanese Utility Model Application 60-1572.
Like the one proposed in No. 82, the transmission and the drive axle are interlocked with each other by the transmission belt, and the change in the distance between the two caused by the height adjustment of the drive axle is absorbed by the flexion and extension of the transmission belt. It is placed at a higher level than the cutting blade storage part of the so that the transmission system from the engine to the transmission can have a transmission distance that is as short as possible and that the influence of the height adjustment of the drive axle does not reach as much as possible. It was

[Problems to be solved by the invention]

However, in the above-described configuration, there is room for improvement because there is a possibility that a transmission failure due to lawn debris may occur, such as lawn debris that scatters with the work being entangled with the belt and slipping between the belt and the pulley.

An object of the present invention is to enable the transmission system from the engine to the transmission to be advantageous as described above, and also to prevent transmission troubles due to lawn debris from occurring easily.

[Means for solving problems]

According to a characteristic configuration of the present invention, in the traveling power transmission structure of the walk-behind lawnmower described above, the transmission is arranged above the drive axle at a position higher than the cutting blade storage portion, and The output part of the device and the input part of the drive axle are connected by a rotary shaft whose connection interval can be freely changed, and the operation and effect are as follows.

[Action]

That is, even if the transmission is fixed so that it does not move at a position higher than the accommodating portion of the cutting blade, or if it is installed in a state close to being fixed so that it does not move much, the transmission shaft of the rotary shaft does not move. The change in the gap between the drive axle and the transmission due to the height adjustment is absorbed by the function that can change the connection gap, and even if grass dust is entangled, it is transmitted to the drive axle without being adversely affected as much as the transmission belt. .

〔The invention's effect〕

Therefore, the rotation axis absorbs the gap change,
The transmission can be fixed or almost fixed at a position located at a higher level than the cutting blade storage part, and the transmission system from the engine to the transmission can be made compact and simple as much as possible, which is advantageous in terms of economy and design. It became a thing.

Moreover, since the rotating shaft is less likely to be adversely affected by the scattered grass scraps than the transmission belt, troubles such as a transmission failure due to the scattered grass scraps are less likely to occur and the malfunction is less likely to occur.

〔Example〕

As shown in FIG. 12, a cutting blade which is provided with a pair of left and right front wheels (1), (1) and a pair of left and right driven rear wheels (2), (2), and which is rotatable about a longitudinal axis. The engine (5) is attached to the machine body having the cutting blade housing (4) as the cutting blade housing portion containing (3), with the engine (5) positioned above the cutting blade housing (4). Output the cutting blade via the cutting blade clutch (6)
At the same time as transmitting to (3), a part of the engine output is transmitted to the rear wheels (2), (2) via the power transmission shaft (7) and the friction type continuously variable transmission (8). In addition, the control handle (13) and the grass collection container (14) are attached to the rear part of the machine body to form a walk-behind lawnmower.

As shown in FIGS. 1 to 3, the friction type continuously variable transmission unit
(8) and a second output shaft (10) in a direction in which the first output shaft (9) of the friction type continuously variable transmission unit (8) is orthogonal to the first output shaft (9). The output transmission unit (11) directly connected to the shaft (9) constitutes a transmission (A) for the drive axle (23) of the rear wheels (2), (2). The transmission (A) is located above the drive axle (23) and at a position higher than the cutting blade housing (4).

Explaining the transmission (A) in detail, the drive transmission shaft
The drive rotor (18) is integrally rotatably attached to the input shaft (16) that is interlockingly connected (7) via the universal joint (15) via the cylinder shaft (17). 18) Boss part (1
8A), the drive side disk (19) is attached to the drive rotating body (18) so as to rotate integrally by the cam mechanism (B), and the outer peripheral portion contacts the side surface of the drive side disk (19),
In addition, while the sliding operation is performed with respect to the drive side disk (19), the passive side disk (20) is integrally rotatably and slidably attached to the first output shaft (9), and Gear shifting section
(8), and the cylindrical second output shaft (10) supported by the output mission unit (11) on the first output shaft (9).
Are interlockingly coupled via a bevel gear mechanism (21), and a third output shaft (2
2) and the drive axle (23) are interlockingly connected via a bevel gear mechanism (12), so that the output shifted by the continuously variable transmission (8) is output to the first output shaft (9) and the second output shaft ( 10), 3rd output shaft (22),
Also, the rear wheels (2), (2) are driven by being transmitted to the drive shaft (23) via the bevel gear mechanism (12).

The front wheels (1), (1) and the rear wheels (2), (2) are provided so that their heights can be adjusted with respect to the machine body so that the cutting height of lawn can be adjusted. As shown in FIGS. 1 and 2, the second output shaft (10) serving as the output portion of the transmission (A) is integrally rotatable and slidably attached to the drive axle ( 23) The third output shaft (22) as a rotary shaft protruding upward from the bevel gear mechanism (12) as an input part of the second output shaft (22) is fitted in the bevel gear portion (22A) of the third output shaft (22). And bevel gear (35) integrally rotatably attached to the drive axle (23) in a state of being meshed with the bevel gear portion (22A) and the bevel gear mechanism (12) are mounted in the mission case (36) of the bevel gear mechanism (12), 3rd output shaft (22) to 2nd output shaft
The height of the drive axle (23) can be adjusted by sliding the second output shaft (10) and the bevel gear mechanism (12) by sliding it against the (10). .

A structure for sliding the third output shaft (22) will be described. As shown in FIGS. 4 to 7, the drive axle (23)
The forward and backward movements of the vehicle with respect to
(23) a guide rod (37) in the machine vertical direction fixed to the machine so as to allow vertical movement with respect to the machine, and one end side of which is slidably fitted on the guide rod (37) and the other end A guide mechanism (39) consisting of a guide member (38) whose side is fitted to the drive axle (23) so as to be relatively rotatable is provided, and the boss portion (38A) of the guide member (38) has the boss portion (38). 38A), a long hole (4 mm) formed to allow relative movement in the machine longitudinal direction.
The axle support member (40) provided with (0a) is externally fitted, and thus the drive axle raising / lowering lever (4) connected to the axle support member (40).
By swinging 1), the axle support member (40) is vertically swung with respect to the machine body, and the boss portion (38A) of the guide member (38).
By moving the long hole (40a), the drive axle (23) is moved up and down, and the height of the rear wheels (2) and (2) can be adjusted. In addition, by locking the lever (41) with the lever guide (42) attached to the machine side, the rear wheel
The positions (2) and (2) can be fixed at the desired height.

Further, as shown in FIG. 12, the front wheels (1) and (1) are mounted on a front axle (43) on which the front wheels (1) and (1) are rotatably supported, and the front axle is lifted and lowered. The height can be adjusted by swinging the operating lever (44).

When adjusting the heights of the rear wheels (2) and (2) one by one, the second output shaft (10) and the third output shaft (10) are inclined by tilting the vehicle body with respect to the drive axle (23). The output mission unit (11) is provided so that its attitude can be changed with respect to the machine body in order to avoid twisting between the unit and the unit (22). That is, the first
As shown in FIG. 2, FIG. 8, FIG. 8 and FIG. 9, a pair of boss parts (11) provided on the upper part of the output mission part (11).
A) and (11B) are fitted onto a bracket (45) bolted to the machine body through arcuate slots (45a) and (45b) formed in the bracket (45), and the back part of the output mission section (11) is fitted. A bracket (46) fixed to the body is externally fitted to a pair of bolts (47) and (48) fixed to the machine body through an arc-shaped long hole (46a) formed in the bracket (46). After adjusting the height of the rear wheel (2) on one side, the boss (11A), (11
B) moves in the long holes (45a) and (45b), respectively, and the bracket (46) moves through the long holes (46a), so that the output mission unit (11) moves in the tilt direction of the airframe. Is inclined in the opposite direction and the output mission unit (11) can always be maintained in a predetermined posture with respect to the drive axle (23), and twisting between the second output shaft (10) and the third output shaft (22) is possible. I try not to occur.

The structure for sliding the passive side disc (20) will be described. As shown in FIGS. 10 and 11, the passive side disc (20) slides on the first output shaft (9). The shift fork (24) to be operated is fixed to the shift fork shaft (26) slidably fitted and supported by the bosses (25a) and (25b) provided on the rear surface of the output mission (11). The pin (27) protruding through the shift fork shaft (26) has a bifurcated first portion.
The rocking arm (28) is provided with a long hole (28
While a) and (28a) are locked at both ends, they are fixed to a support shaft (29) supported at the lower end of the output mission section (11) in the machine longitudinal direction, and the first swing arm (28 ) The second swing arm fixed to the support shaft (29) opposite to the side where the
(30) and the operating lever (31) provided on the steering handle (13) are linked by a push-pull wire (32), and by operating the operating lever (31), the second swing arm (30) is moved. The support shaft (29) is swung to rotate the support shaft (29), and the support shaft (29) is rotated.
The first swing arm (28) is swung along with the rotation of the shift fork to slide the shift fork shaft (26), and further the shift fork is moved.
Passive disk (20) through drive disk (19) through (24)
The gears are slidably moved in the radial direction of the gear shift operation.

The cam mechanism (B) drives the drive rotor (18) so that the drive rotor (18) and the drive disc (19) rotate relative to each other when the drive rotor (18) is driven. A spring (33) for initial pressure contact that presses and urges the passive side disc (20) side, the drive rotating body (18) and the drive side disc.
A plurality of balls (34) arranged in the plurality of V-shaped grooves (18a) ··· and (19) ··· formed along the circumferential direction on each inscribed surface of (19) .. and the cam surface (18a) so that the pressing contact force of the drive side disk (19) to the passive side disk (20) increases as the drive load of the passive side disk (20) increases.・ Ball (34) ・ ・
Automatically moves to the lower side of the rotation direction.

[Another embodiment]

In the embodiment, the rotary shaft (22) is slidably connected to the second output shaft (10), but the rotary shaft (22) is connected to the bevel gear mechanism (12) as the input part of the drive axle (23). You may connect slidably.

[Brief description of drawings]

The drawings show an embodiment of a transmission structure for traveling of a walk-behind lawnmower according to the present invention. Fig. 1 is a vertical sectional side view showing a transmission structure of a drive axle, and Fig. 2 is a longitudinal rear view showing a transmission structure of a drive axle. FIG. 3 is a cross-sectional plan view showing a power transmission structure for traveling, FIGS. 4 and 5 are side views with partially cutaway showing a structure for raising and lowering a drive axle, and FIG. 6 is a lever for raising and lowering a drive axle. FIG. 7 is a longitudinal sectional rear view showing the mounting structure, FIG. 7 is a transverse sectional view showing the swing structure of the drive axle, and FIGS. 8 and 9 are views showing the shape of a bracket for swinging and guiding the output mission portion. Is a rear view showing the support structure of the shift fork shaft, FIG. 11 is a schematic view showing the gear shift operation structure, and FIG. 12 is a side view of the walking type lawnmower. (4) …… Cutting blade storage part, (5) …… Engine, (10) …… Output part, (12) …… Input part, (22) …… Rotating shaft, (23) …… Drive axle, ( A) ... Transmission.

Claims (2)

[Claims] 1. A drive axle (23) is attached to a rear portion of a cutting blade housing portion (4) of the machine body so that the height of the drive axle can be adjusted.
(23) an engine (5) for transmission to the cutting blade storage portion (4) is arranged above, and a transmission structure for traveling of a walk-type lawn mower provided with a transmission (A) for the drive axle (23). The transmission (A) is arranged above the drive axle (23) at a position higher than the cutting blade storage portion (4), and the output of the transmission (A) ( 10) and said drive axle (23)
Rotating shaft (22) whose input section (12) and can be freely connected
A transmission structure for running a walk-type lawn mower that is linked and linked by. 2. The transmission structure for traveling according to claim 1, wherein the rotating shaft (22) is slidably connected to the output portion (10) for changing a connection interval.