JP3127561B2 - Mower - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a riding type mowing machine suitable for mowing a large area of grass such as a park or a golf course.

[0002]

2. Description of the Related Art A front mower type riding mower in which a mower is mounted on a front portion of a four-wheeled vehicle in which rear wheels are steered wheels is widely used.

[0003]

In this type of mowing machine, for example, it is a major problem to minimize the minimum turning radius so that mowing can be performed by a single turning operation around a standing tree. .

[0004]

In order to solve the above problems, the present invention has the following arrangement. That is, the mowing machine according to the present invention is a mowing machine in which a front wheel is a non-steering type driving wheel, and a mower is attached to a front portion of a four-wheeled vehicle in which a rear wheel is a steering wheel. A differential device is provided, and when the steering angle of the rear wheels becomes greater than or equal to the predetermined angle α during traveling turning , the clutch of the rear inner wheel is disengaged and the left and right rear wheels roll freely.
And the steering angle of the rear wheels is increased to a certain angle.
When the degree exceeds β, it protrudes inward from the rear wheel differential device
Switching means for rotating the outer wheel at a high speed by braking the rear axle is provided.

[0005]

[Function] When the steering angle becomes equal to or larger than a predetermined angle α during turning,
The clutch of the rear inner wheel is disengaged and the left and right rear wheels roll freely.
It is possible to run, and the steering angle of the rear wheel is further increased and a certain angle
If it is more than β, the ribs protrude inward from the rear wheel differential device.
By braking the yaxle, the rear wheel on the outside of the turn rotates at a high speed, so that a turn with a small radius can be performed smoothly, and the grass is not damaged.

[0006]

Embodiment 1 FIGS. 1 and 2 are a side view and a plan view of a front mower type mower according to an embodiment of the present invention. In the mower 1, a mower 3 is provided in front of a main unit 2 which is a four-wheeled vehicle so as to be able to move up and down, and an operator sits on a cockpit 4 installed in the main unit 2 to operate.

The machine 2 has a pair of left and right front wheels 6, 6 and rear wheels 7, 7 as running wheels. As shown, the diameter of the front wheels 6, 6 is larger than that of the rear wheels 7, 7, and the rear wheels 7, 7 are larger.
Are the steering wheels. The cockpit 4 is installed facing forward at the front of the fuselage, and a steering handle 8 is provided in front of the cockpit. The rear wheels 7, 7 are supported by horizontally rotatable rear wheel support cases 9, 9, and a steering handle 8 is provided.
Turn left and right according to the operation of. An engine 10, a fuel tank 11, a radiator 12, and the like are provided behind the cockpit 4, and a transmission device is provided below the fuselage.

FIGS. 3 and 4 are sectional views of the transmission.

Reference numeral 15 denotes a main clutch. The rotational power of the engine 10 is transmitted to the inner shaft 16 and the outer shaft 17 which are fitted to each other via the main clutch. The rotational power of the inner shaft 16 is extracted as a traveling output to a traveling output shaft 19, and the rotational power of the outer shaft is extracted as a PTO output to a PTO output shaft 20. The main clutch 15 is configured such that the transmission to the inner shaft 16 and the transmission to the outer shaft 17 operate simultaneously, so that the traveling output and the PTO output are always turned on and off simultaneously. The main clutch 15 is operated by the shifter 23.

The traveling output taken out by the traveling output shaft 19 is shifted by a hydraulic continuously variable transmission (HST) 26 and a traveling mission 27. In the HST 26, the forward / backward switching and the speed change are performed steplessly by changing the swash plate angle. The traveling mission 27 is a gear transmission. When the gear is shifted to H, high-speed transmission is performed, when the gear is shifted to L, low-speed transmission is performed, and when the gear is shifted to N, the transmission is stopped. To adjust the traveling speed, the main transmission is performed in the HST 26 and the subtransmission is performed in the traveling mission 27.

The running output after shifting is separated into an output for driving the front wheels and an output for driving the rear wheels. The front wheel drive output rotationally drives the left and right front wheels 6, 6 via a front wheel differential device 28.
The rear wheel drive output is controlled by the rear wheel transmission shaft 29 and the rear case 30.
It is transmitted to. The one-way clutch 31 is provided on the rear wheel transmission shaft 29. If the rotation speed of the primary shaft 29a of the rear wheel transmission shaft 29 is higher than the rotation speed of the secondary shaft 29b, the one-way clutch 31 Power is transmitted to the secondary shaft 29b, but is not transmitted when the rotation speed of the secondary shaft 29b is higher than the rotation speed of the primary shaft 29a. For this reason, even if the front wheels 6, 6 slip, they are transmitted to the rear wheels 7, 7.

The inside of the rear case 30 is as shown in FIG. In the figure, reference numeral 40 denotes a rear wheel differential device, and rear axles 41 (L, R) protrude left and right from the rear wheel differential device. The rear wheel differential device 40 and the rear wheel transmission shaft 29 are drivingly connected by bevel gears 42 and 43, and the rotational power input to the rear case 30 is transmitted to the rear wheels 7 and 7 by the action of the rear wheel differential device 40. It is distributed and transmitted to the left and right rear axles 41 (L, R) at a ratio according to the applied load. Although omitted in the drawing, a plurality of transmission gears are provided between the rear axle 41 (L, R) and the rear wheels 7, 7. The bevel gear 44 is one of the transmission gears.

The transmission from the left rear axle 41 (L) to the bevel gear 44 is formed as a pawl clutch 46. Claw 47a of sliding cylinder 47 and claw 44 of bevel gear 44, which are slidably spline-fitted to rear axle 41 (L).
When a is engaged, the clutch is engaged, and when both claws are released, the clutch is disengaged.

A brake drum 51 having a lining 50 adhered to the inner peripheral surface thereof is integrally attached to the sliding cylinder 47, and an annular projecting portion 52 is formed on the inner peripheral portion of the housing correspondingly. Have been. The rear wheel brake device 54 is constituted by these components. The rear axle 41 (L) is formed by pressing the brake drum 51 against the annular overhang portion 52.
It is designed to brake.

An operating section for operating the claw clutch 46 and the rear wheel brake device 54 is configured as shown in FIGS. That is, the shifter 55 of the sliding cylinder 47 is attached to a shift arm 57 swingably supported by a support shaft 56, and a clutch lever 58 is integrally formed at an end of the support shaft 56 protruding outside the rear case 30. ing. A drive arm 61 driven by a cam 60 formed on the outer periphery of the rear wheel support case 9 is provided at the left end of the rear case 30. The shift arm 56 and the drive arm 61 are connected by a connecting rod 62.

When the left rear wheel 7 is disengaged to the left by a predetermined angle α or more, the clutch lever 58 is pulled and the pawl clutch 46 is disengaged. Further, when the rear wheel 7 is further turned to the left, and the turning angle becomes equal to or greater than the predetermined angle β, the rear wheel brake device 54
Hangs. When the left rear wheel 7 is turned to the front, the clutch lever 58 returns to the original position by the force of the spring 63, the rear wheel brake device 54 is released, and the pawl clutch 46 is engaged again.

The operating portion operates the claw clutch 46 and the rear wheel brake device 54 based on the turning angle of the rear wheel 7, and operates both based on the operation amount of the steering handle 8. You may do so.

The PTO output taken out by the PTO output shaft 20 is transmitted forward by a PTO transmission shaft 65 and is shifted by a PTO transmission 66. When the gear is shifted to H, high-speed transmission is performed, when the gear is shifted to L, low-speed transmission is performed, and when the gear is shifted to N, the transmission is stopped. The PTO output after the shift is transmitted to the mower 3 via the universal joint 67.

The mower 3, the rotary blade 71 of the triple type in the interior of the deck 70, has a ..., grass clippings were reaped by these rotating blades are discharged from the discharge exit 72 is formed on the right side of the deck 70 It has become. The mower 3 is attached to mounting links 74, 74 protruding forward from the machine 2, and is moved up and down by rotating the mounting links 74, 74 up and down by a hydraulic cylinder (not shown). At the time of work, it is supported by support wheels 75, 75 provided in front of the deck 70, and is in a state of rising to a certain height from the ground. By changing the mounting height of the support wheels 75, 75, the length of grass after cutting can be adjusted.
In addition, the rear part of the deck 70 is suspended from the attachment link 74 by a suspension link (not shown). Reference numerals 77 and 78 denote auxiliary rollers provided before and after the deck 70 to prevent the lower surface of the deck 70 from directly contacting the ground or the like when the mower 3 is removed from the mounting links 74 and 74.

When using the mower 1, the traveling mission 27 and the PTO mission 66 are shifted to a low speed or a high speed while the mower 3 is lowered to the working position, and the main clutch 15 is engaged. Then Moore 3
Operates to start mowing. Then, the HST 26 is operated to the forward side to start. The progress speed is adjusted by HST26. When the mower 3 was pushed up due to irregularities on the ground during the operation, the mower 3 was provided on the support portion by the mounting link 74.
Absorbed by slots .

When cutting grass around a standing tree or the like, this is done by turning left. The reason is that the discharge port 72 of the mower 3 is provided on the right side, and the cut grass is discharged to the grassland outside the turning. As shown in FIG. 8, the vehicle turns around the axis of the front wheels 6, 6. When the turning angle of the left rear wheel 7 (L) is equal to or larger than the 2WD switching angle α during the turn, the pawl clutch 46 is disengaged, and the rear wheels 7, 7 rotate freely. In this two-wheel drive state, the left and right rear wheels 7, 7 rotate at a speed corresponding to the turning radius of the body, so that turning can be performed smoothly. Also, since there is no gap between the wheel and the grass, the grass is not damaged. The steering amount is further increased, and the left rear wheel 7 (L)
When the turning angle becomes equal to or larger than the three-wheel switching angle β, the rear wheel brake device 54 is engaged, and the rotation of the left rear axle 41 (L) stops, so that the rotation speed of the right rear wheel is doubled. FIG. 8 shows a state in which the steering angle is the maximum. At this time, since the turning radius (= 2R) of the outgoing rear wheel is about twice the turning radius (= R) of the center of the fuselage, the outgoing rear wheel 7 (R The rotation speed of (2) becomes a speed suitable for turning, and the rotation can be performed smoothly with a small radius.

As described above, it is common to all countries that the turning operation is performed by turning left, and in most cases, except for special cases, only the turning operation is performed. Therefore, the clutch 46 and the brake device 54 are provided only on the left side. It should be provided. Further, the operation of the clutch 46 and the brake device 54 may not be directly linked to the deflection of the rear wheel 7 as in this embodiment, but may be linked to the operation amount of the steering handle 8.

[0023]

Embodiment 2 FIG. 9 shows the inside of a rear case of a different embodiment. The rear wheel brake device 80 of this mower is
Brake drum 8 integrated with rear axle 41 (L)
1 is pressed against the brake plate 82 to apply braking. Reference numeral 84 denotes a driving motor, which rotates an oscillating arm 86 by rotating an eccentric cam 85 by the motor. The operation of the oscillating arm is transmitted to a brake lever 88 via a spring 87, and the brake plate 82 is moved. The brake drum 81 is brought into contact with and separated therefrom. For this reason, the brake operates intermittently. A potentiometer 89 is provided at the base of the clutch lever 58. The potentiometer 89 controls the rotation speed of the motor 84 according to the steering angle detected by the potentiometer. The rotation speed of the wheel 7 is adjusted. Since appropriate braking according to the steering angle can be obtained, it is possible to perform a turn with a small turning radius without damaging the grass during circling.

[0024]

Third Embodiment FIG. 10 shows a clutch operating section according to a further different embodiment. This operating portion has an arc-shaped long hole 92 formed in the clutch lever 90 so that the end of the rod 91 can be replaced, and a stopper 93 capable of restraining the clutch lever 90 from turning to the right more than a certain amount. Is provided. Normally, as shown by the solid line, the end of the rod 91 is connected to the fixed point 94 of the clutch lever 90, and the stopper 93 is directed to the opposite side of the clutch lever 90. And the clutch 46 is turned on and off. Therefore, the state becomes the four-wheel drive state or the two-wheel drive state according to the steering angle of the rear wheel. When the end of the rod 91 is removed from the fixed point 94 and is loosely fitted in the elongated hole 92, the movement of the rod 91 is not transmitted to the clutch lever 90, so that the four-wheel drive state is always established. When the stopper 93 is directed toward the clutch lever 90 as shown by the chain line, the clutch lever 90 is restrained at the position shown by the chain line, so that the two-wheel drive state is always established.

[0025]

As described above, in the mower according to the present invention, the steering angle of the rear wheel, which is the steered wheel, becomes greater than a predetermined value.
And the rear wheel of the four-wheel vehicle rolls freely in conjunction with the turning operation
When turning, the rear wheel does not resist and does not damage the grass. Sa
In addition, when the steering angle of the rear wheel exceeds a certain value, the rotation speed of the wheel outside the turn increases in conjunction with the turning operation,
Turning only the rear wheel side without moving the front drive wheel side of a four-wheel vehicle
Since it can be driven and moved outward,
Even when mowing in the surrounding area, the front wheel side
Smoothly perform the small radius of the turn without and, also, the wheels at the time of turning
There is no gap between the grass and the rear wheel so that the grass is not damaged.

[Brief description of the drawings]

FIG. 1 is a side view of a mower according to an embodiment of the present invention.

FIG. 2 is a plan view of the mower of FIG. 1;

FIG. 3 is a sectional view showing a part of a transmission.

FIG. 4 is a cross-sectional view showing a portion of the transmission that is different from FIG. 3;

FIG. 5 is a sectional view of a rear case according to the first embodiment.

FIG. 6 is a rear view of the clutch operation unit.

FIG. 7 is a plan view of a clutch operation unit.

FIG. 8 is an explanatory diagram of a turning state.

FIG. 9 is a sectional view of a rear case according to the second embodiment.

FIG. 10 is a sectional view of a rear case according to a third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mower 2 This machine (four-wheeled vehicle) 3 Mower 6 Front wheel 7 Rear wheel 8 Steering handle 40 Rear wheel differential device 46 Claw clutch 54 Rear wheel brake device

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B62D 11/08

Claims (1)

(57) [Claims] 1. A mowing machine in which a front wheel is a non-steering drive wheel and a mower is mounted on a front portion of a four-wheeled vehicle in which a rear wheel is a steered wheel. When the steering angle of the rear wheels becomes greater than or equal to the predetermined angle α during traveling turning , the clutch of the rear inner wheel is disengaged and the left and right rear wheels roll freely.
And the steering angle of the rear wheels is increased to maintain a certain angle.
If it is more than β, the ribs protrude inward from the rear wheel differential device.
A mowing machine characterized by comprising switching means for rotating a wheel on the outer side of turning at a high speed by braking a yaxle .