JP3970146B2 - lawn mower - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lawn mower having steering front wheels and left and right rear wheels.
[0002]
[Prior art]
In this type of conventional lawnmower, rear wheel differentials are provided for the left and right rear wheels, and when turning with the front wheels steered, the left and right rear wheels are differentiated to make the turn smooth. (For example, see Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-86831
[Problems to be solved by the invention]
However, when using the above-mentioned conventional technology, the left and right rear wheels are differentiated during turning, so if the grass is wet or slipping easily, when turning the front wheel more than the set angle and making a small radius turn, Due to the high running resistance, one of the rear wheels, which is in a condition that tends to slip, slips and slips at high speed, and the other rear wheel does not rotate and cannot obtain propulsive force. In addition to this, there was a risk of damaging the turf with the rear wheel that was spinning at high speed.
[0005]
An object of the present invention is to make it possible to reliably perform a small radius turn without damaging the turf.
[0006]
[Means for Solving the Problems]
The features, functions and effects of the lawn mower according to the present invention as set forth in claim 1 are as follows.
[0007]
[0008]
[0009]
[0010]
[0011]
〔Characteristic〕
A lawnmower having a front wheel for steering and left and right rear wheels, provided with a front wheel differential for the front wheel, and through a rear wheel clutch that interrupts transmission in the part of the transmission system to the rear wheel before branching. A side clutch that interrupts transmission is installed in each of the transmission system parts to each rear wheel after branching, and when the front wheel steers from a straight running position more than a set angle, the rear wheel clutch is engaged and operated And operating means for disengaging and operating the side clutch for the rear wheel inside the turn.
[0012]
[Action]
Normally, while driving with front wheel drive, when turning with the front wheel steered more than a set angle, the rear wheel clutch is engaged and operated, and the side clutch for the rear wheel inside the turn is turned off and the rear wheel outside the turn is operated. Since the side clutch is engaged and operated, the rear wheel on the outside of the turn can be driven reliably during the turn, while the rear wheel on the inside of the turn is made to follow and rotate without slipping. Prevents turf pain caused by dragging.
[0013]
〔effect〕
Therefore, it is possible to reliably perform a small radius turn by the front wheel drive and the rear wheel drive outside the turn, while reducing the turf pain associated with the turn as much as possible.
[0014]
The characteristics / actions / effects of the lawn mower according to the second aspect of the present invention are as follows.
[0015]
〔Characteristic〕
A lawnmower having a front wheel for steering and left and right rear wheels, provided with a front wheel differential for the front wheel and a rear wheel differential with a differential lock function for the left and right rear wheels, and a transmission system to the front wheel differential When a front wheel clutch that interrupts transmission is interposed, a side clutch is interposed in each transmission system portion from the rear wheel differential to each rear wheel, and when the front wheel is steered more than a set angle from a straight running posture, There is an operating means for engaging and operating the front wheel clutch, diff-locking the rear wheel differential, and disengaging the side clutch for the rear wheel inside the turn.
[0016]
[Action]
Normally, while driving with front wheel drive and rear wheel drive, when turning with the front wheels steering more than a set angle, the front wheel clutch is disengaged, while the rear differential is locked and the side with respect to the rear wheels inside the turn Since the clutch is operated so as to be turned off, the rear wheel outside the turn can be driven reliably during the above turn, while the rear wheel and the front wheel inside the turn are made to follow and rotate without slipping and the rear wheel inside the turn and the rear inside It is possible to prevent the lawn from being damaged by dragging the wheel.
[0017]
〔effect〕
Therefore, it is possible to reliably perform small-radius turning while surely and strongly performing normal straight traveling by four-wheel drive, while minimizing turf pain associated with turning.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1
As shown in FIGS. 1 and 2, the lawnmower steers the engine 4 and the front wheel 1 at the front of a body frame 3 having left and right front wheels 1 and left and right rear wheels 2 for steering. A steering handle 6 is disposed, a transmission case 5 and a driver seat 7 are disposed at the rear of the body frame 3, and a side discharge type mower 8 is disposed between the front wheel 1 and the rear wheel 2 on the body frame 3. It has a structure provided with an actuator 9 that can be moved up and down in a position and that moves the mower 8 up and down.
S is a grass collection container for storing the cut grass that is cut by the mower 8 and conveyed through the duct D.
[0019]
As shown in FIG. 3, the lawnmower has a steering sensor 10 that uses a potentiometer to detect the steering direction when the front wheel 1 is steered more than a set angle from a straight traveling posture.
[0020]
[0021]
[0022]
[0023]
As shown in FIG. 3, the traveling drive system is provided with a front wheel differential 14 for the left and right front wheels 1, and a rear wheel clutch 15 that interrupts transmission to a portion on the upper side of the transmission from the branch portion in the transmission system to the rear wheel 2. A side clutch 12 for interrupting transmission / reception is provided in each transmission system portion from the branching portion to each rear wheel 2.
[0024]
The operating means is such that the rear wheel clutch 15 and the side clutch 12 are electrically operated, and when the steering sensor 10 detects straight travel, the rear wheel clutch 15 is turned off and the both side clutches 12 are turned on, and When the steering sensor 10 detects a steering operation of a set angle or more, a microprocessor-based control device 16 is provided to operate the rear wheel clutch 15 to be engaged and to disengage the side clutch 12 inside the turn. Yes.
[0025]
According to the above configuration, when traveling straight, as shown in FIG. 3 (a), both side clutches 12 are engaged and are in an operating state, and the left and right rear wheels 2 are synchronously following and rotated. When the steering operation is performed, as shown in FIG. 3B , the turning is performed by driving and rotating the rear wheel 2 outside the turning while the rear wheel 2 inside the turning follows the rotation.
[0026]
[ Embodiment 2 ]
As shown in FIG. 4, the traveling drive system includes a rear wheel differential 11 having a differential lock function for the left and right rear wheels 2, and transmits power to each transmission system portion from the rear wheel differential 11 to the left and right rear wheels 2. An intermittent side clutch 12 is interposed. A front wheel differential 14 is provided for the left and right front wheels 1, and a front wheel clutch 17 for interrupting transmission is interposed in a transmission system portion to the front wheel differential 14.
[0027]
The operation means for operating the differential lock and the side clutch 12 is such that each of the differential lock and the side clutch 12 is electrically operated, and when the steering sensor 10 detects straight travel, the differential wheel is not locked and the rear wheel is operated. When the differential 11 is differentiated and both side clutches 12 are engaged and operated, and when the steering sensor 10 detects a steering operation at a set angle or more, the differential lock is locked to operate the rear wheel differential 11. And a control device 18 using a microprocessor for operating the side clutch 12 with respect to the rear wheel 2 on the inside of the turn.
The front wheel clutch 17 is electrically operated, and when the steering sensor 10 detects straight travel, the front wheel clutch 17 is disengaged and when the steering operation exceeding the set angle is detected, the front wheel clutch 17 is engaged and operated. It is configured as follows.
[0028]
According to the above configuration, when traveling straight, as shown in FIG. 4A, the rear wheel differential 11 is in a differential state, and both side clutches 12 are in a clutch engaged state, so that the left and right rear wheels 4 and steering beyond the set angle, as shown in FIG. 4B, the rear wheel differential 11 is in a non-differential state, and the side clutch 12 on the inside of the turn is turned off, The front wheel clutch 17 is engaged and actuated to turn the vehicle in a state where the left and right front wheels 1 and the rear outer wheel 2 are driven .
[0029]
[Another embodiment]
In the above embodiment, the differential lock, the side clutch 12, the rear wheel clutch 15, and the front wheel clutch 17 are electrically operated and linked to the steering of the front wheel 1, but these are linked mechanically to the steering of the front wheel 1. Also good.
[Brief description of the drawings]
FIG. 1 is a side view showing a first embodiment. FIG. 2 is a plan view showing the first embodiment. FIG. 3 is a schematic plan view showing the operation of the operation means in the first embodiment. Schematic plan view showing the operation 【Explanation of symbols】
1 Front wheel 2 Rear wheel 11 Rear wheel differential 12 Side clutch 14 Front wheel differential 15 Rear wheel clutch 17 Front wheel clutch

Claims (2)

  A lawnmower having a front wheel for steering and left and right rear wheels, provided with a front wheel differential for the front wheel, and through a rear wheel clutch that interrupts transmission in the part of the transmission system to the rear wheel before branching. A side clutch that interrupts transmission is installed in each of the transmission system parts to each rear wheel after branching, and when the front wheel steers from a straight running position more than a set angle, the rear wheel clutch is engaged and operated And a lawn mower provided with operating means for operating the side clutch for the rear wheel inside the turn.   A lawnmower having a front wheel for steering and left and right rear wheels, provided with a front wheel differential for the front wheel and a rear wheel differential with a differential lock function for the left and right rear wheels, for transmission to the front wheel differential When a front wheel clutch that interrupts transmission is interposed, a side clutch is interposed in each of the transmission system parts from the rear wheel differential to each rear wheel, and when the front wheel is steered more than a set angle from a straight running posture, A lawn mower provided with operating means for engaging and operating a front wheel clutch, diff-locking the rear wheel differential and disengaging the side clutch for the rear wheel inside the turn.

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