JP2781314B2 - Riding lawn 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 lawn mower which steers an airframe through an Ackerman type steering link mechanism.

[0002]

2. Description of the Related Art Conventionally, a riding lawn mower is disclosed in
As shown in Japanese Patent No. 0484, it is configured such that the same angle steering operation can be performed to the left and right. That is, the steering link mechanism including the knuckle arm and the tie rod is connected to the left and right wheels arranged in a straight-ahead steering state with respect to the aircraft so that the turning angle in the lateral direction of the aircraft is the same.

[0003]

In general, a riding lawn mower discharges the cut grass cut by a mower to one side of the machine body, so that the lawn mower often turns around in a direction opposite to the release direction. In order to make a small turn, the driver completely turns the steering wheel in the turning direction. Therefore, a drag rod or a steering link that connects the steering link mechanism to the steering operation mechanism on the steering wheel that operates the steering link mechanism is used. There is a problem that an excessive force is applied to the tie rod of the mechanism and the drag rod or the tie rod bends, or an excessive force is applied to the pivot between the knuckle arm and the tie rod to cause backlash at the pivot. Was. This is because the steering angle causes a limit to the opening angle between the knuckle arm and the tie rod on the turning direction side or the bending angle between the knuckle arm and the tie rod on the side opposite to the turning direction, and such a phenomenon occurs. Therefore, as disclosed in Japanese Utility Model Laid-Open Publication No. 4-103406, it is conceivable to increase the steering operation angle via a special steering link mechanism. However, in such a case, there is a disadvantage that the structure becomes complicated. . SUMMARY OF THE INVENTION An object of the present invention is to make it possible to easily make a small turn to one side of an aircraft frequently used via an Ackerman type steering link mechanism.

[0004]

To achieve the above object, the present invention is characterized in that a knuckle arm and a tie rod of an Ackerman-type steering link mechanism are arranged in a right and left direction in which the vehicle is steered straight. The wheels are connected in an offset state so that the turning angle to one side of the fuselage is larger than the turning angle to the other side, and a steering operation mechanism on the steering wheel side that operates the steering link mechanism is provided. Another feature is that a regulation mechanism is provided for restricting the maximum steering operation amount toward the other side of the body to a state smaller than the maximum steering operation amount toward one side of the body.

[0005]

As shown in FIG. 1, the steering link mechanism S
₁Is previously biased to one side of the fuselage with respect to the left and right wheels 1b, 1b
Shown in Fig. 2
Control the aircraft in the opposite direction to the cut grass release direction.
Knuckle arm 7a and tie rod on the turning direction side
7b and the knuckle lure on the opposite side to the turning direction
There is enough room for the angle between the beam 7a and the tie rod 7b.
Yes, steering link mechanism S₁Force is applied to
You can make a small turn without any trouble. And the aircraft like this
Increasing the steering angle to one side increases the steering to the other side.
The steering angle is reduced, and the aircraft steers to the other side.
When operating the steering wheel, steer the steering wheel
The steering link mechanism S₁Unreasonable power
However, as shown in FIG.
Operating mechanism S _TwoThe maximum stearin to the other side of the aircraft
Steering operation amount to the maximum steering operation amount to one side of the aircraft.
A regulating mechanism 8 is provided to regulate the contact to a smaller state.
Dragging when turning the aircraft to the other side
Rod and steering link mechanism S₁Force is applied to
Never.

[0006]

As a result of the above construction, a simple turning of the Ackerman-type steering link mechanism in the offset state can be performed to the one side of the frequently used body without exerting excessive force on the steering link mechanism. The steering operation mechanism on the steering wheel for operating the steering link mechanism is provided with a steering operation mechanism for preventing the same amount of steering operation as the maximum steering operation amount to one side of the aircraft during the steering operation to the other side of the aircraft. Since the restricting mechanism is provided, the turning of the airframe to the other side can be performed without forcing the steering link mechanism.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 9 shows a front-mounted riding lawn mower in which a mower MA is mounted on a front portion of a traveling body A. The riding lawn mower includes a hydrostatic continuously variable transmission H from an engine E, and
The left and right front wheels 1a, 1a are driven via a transmission in a traveling transmission case M,
The left and right rear wheels 1b, 1b are steered in accordance with the operation of the steering wheel 3 disposed in front of the driver's seat 2. As shown in FIG. 1, the left and right rear wheels 1b, 1b
Is operated through an Ackerman-type steering link mechanism S _1, and includes a sector gear 4 a and a pitman arm 4 b as a steering operation mechanism S _{2 that} is engaged with a pinion gear 3 a rotated by a steering handle 3. Drag rod 6a, reversing link 6
b, the second drag rod 6c is swung driven back and forth direction, as the steering linkage knuckle arms 7a as S _1, 7a and wheel 1b the right and left rear via the tie rods 7b, 1b are steering Has become.

[0008] The steering linkage S ₁ knuckle arms 7a, and the 7a and tie rod 7b, the left and right rear disposed straight steering state against the aircraft wheels 1b, relative 1b, to the body one side towards The connection is made in an offset state so that the turning angle is larger than the turning angle to the other side, that is, the turning angle in the direction opposite to the direction in which the mower MA discharges the cut grass. Then, the steering operation mechanism S ₂ is the aircraft other side, that is, when the steering operation of the grass clippings discharge direction, it is only the steering operation the same amount as the maximum amount of steering operation in the opposite direction to the grass clippings discharge direction In other words, the pitman arm 4b comes into contact with the pitman arm 4b in order to prevent the maximum steering operation amount to the other side of the body from being smaller than the maximum steering operation amount to one side of the body. A stopper 8 is provided in the steering gear box as a regulating mechanism for regulating the amount of rotation of the handle 3. In the riding lawn mower, the maximum steering angle in the direction opposite to the lawn releasing direction is set to 60 °.

As shown in FIG. 9, a hood 9 which can swing open and close around a horizontal axis X which covers the engine E is made of a resin material provided on the inner surface below the hood 9 as shown in FIGS. The engagement member 10 and the resin engagement member 11 provided on the machine body side are configured to be engaged and lockable.

As shown in FIG. 6, the exhaust manifold 12 and the muffler 13 of the engine E are directly connected to each other, and the exhaust pipe for connecting the exhaust manifold 12 and the muffler 13 of the engine E in the conventional means is omitted. As a result, the exhaust efficiency is improved and the structure is simplified.

Further, as shown in FIGS. 7 and 8, inside the dustproof net 14 disposed on the front surface of the engine E, resistance is given to the cooling air at the center of the radiator 15 to cool the outer peripheral portion of the radiator. The ventilation slit 1 has a small opening area with respect to the center of the radiator 15 and has a larger opening area toward the outer periphery so that the wind is evenly distributed.
A resistance plate 16 provided with 6a is provided.

[Alternative Embodiment] The riding lawn mower is not limited to the front mount type, but may be a mid mount type.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is a plan view showing a steering mechanism.

FIG. 2 is a plan view showing a steering state in a direction opposite to a lawn discharging direction;

FIG. 3 is a plan view showing a state of steering in the direction of discharging grass clippings.

FIG. 4 is a longitudinal sectional view of a bonnet.

FIG. 5 is a longitudinal sectional view of a bonnet locking structure.

FIG. 6 is a rear view showing a connected state of the muffler.

FIG. 7 is a plan view showing a dustproof net.

FIG. 8 is a front view of a resistance plate.

FIG. 9 is an overall side view.

[Explanation of symbols]

1b 7a knuckle arm 7b tie rod 8 preventing mechanism S ₁ steering linkage S ₂ steering mechanism

Continuing on the front page (72) Inventor Akira Mizuno 64 Kubota Sakai Works, Sakai City, Osaka Prefecture (72) Kenji Matsuda 64 Ken Ishizu Kitamachi Town, Sakai City, Osaka Prefecture 56 Kubota Sakai Works, Ltd. References: JP-A-3-200484 (JP, A) JP-A-2-3574 (JP, A) JP-A-59-67166 (JP, A) JP-A-3-17979 (JP, U) JP-A 51-163233 (JP, U) Japanese Utility Model Showa 57-20371 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) B62D 7/08

Claims (1)

(57) [Claims] _1. A knuckle arm (7a) and a tie rod (7b) of an Ackerman type steering link mechanism (S ₁ ) are connected to right and left wheels (1b) arranged in a straight-ahead steering state with respect to the body. ) And (1b) are connected in an offset state so that the turning angle to one side of the body is larger than the turning angle to the other side, and a handle for operating the steering link mechanism (S ₁ ). A regulating mechanism (8) is provided in the side steering operation mechanism (S ₂ ) to limit the maximum steering operation amount to the other side of the fuselage to be smaller than the maximum steering operation amount to one side of the fuselage. Riding-type lawn mower.