JP3081422B2 - Lawn mower traveling operation structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lawn mower traveling apparatus capable of selectively displaying a two-wheel drive state and a four-wheel drive state.

[0002]

2. Description of the Related Art For example, as in a front mount lawn mower disclosed in Japanese Utility Model Laid-Open No. 4-71305, a four-wheel drive state in which a steered rear wheel is also driven is possible, so that the vehicle can be driven on rough roads or climbing a slope. Some have improved driving performance. However, in a general four-wheel drive structure, there is a difference in driving speed between the front and rear wheels at the time of turning, and there is a tendency that the turf is easily damaged by slipping particularly at a small turn. For this reason, most of the lawn mowers that do not damage the turf have a two-wheel drive structure that does not cause a small turning slip phenomenon even if there is some difficulty in climbing performance.

[0003]

Problems to be solved by the invention Lawn mowers are widely used in parks and golf courses, and when a large number of people drive the lawn mowers, the use of the lawn mowers is also various, and the places with many undulations are also used. The lawn mowing work is advantageous to a four-wheel drive machine that can exert a large driving force, and it has become impossible to ignore many voices that desire it.

However, if the conventional four-wheel drive structure is simply adopted, the small turning slip phenomenon again becomes a problem. Therefore, a four-wheel drive structure that can overcome the disadvantage (for example, the driving speed is adjusted in synchronization with the turning radius). A variable speed change mechanism, a center differential mechanism, etc.) must be developed and equipped, but the structure becomes complicated and expensive. SUMMARY OF THE INVENTION An object of the present invention is to provide a vehicle which can improve a small turning slip phenomenon while adopting a conventional four-wheel drive structure and having a relatively simple structure at a low cost.

[0005]

Means for Solving the Problems] characterizing feature of the present invention, prior to
Of the rear left and right wheels, one of the front and rear left and right wheels is configured as a drive wheel, and the other left and right wheel interrupts power from the drive wheel side.
That a four-wheel drive state in which the power is transmitted through the switching clutch, switching freely configured power within the Sarena physician two-wheel drive state transmission
And a foot-operated switching operation pedal for operating the switching clutch is provided , and one of the front and rear driving wheels is
A brake device that exerts a braking action on the left and right wheels, and a single foot-operated brake pedal that is disposed at a position distant from the switching operation pedal;
Operation of the switching operation pedal and the switching clutch
A linkage switching mechanism for linking with the linkage mechanism is provided.
The linkage switching mechanism, in the depression of the brake pedal, the switching clutch the <br/> brake device is in two-wheel drive state with activated is switched to four-wheel drive state, in the depression of the switching operation pedal, the brake The device is configured so that the switching clutch, which is in the two-wheel drive state without operating, is switched to the four-wheel drive state.
Is as follows .

[0006]

On a relatively good turf such as a flat ground or a gentle slope, running in a two-wheel drive state eliminates the slip phenomenon at the time of turning. When climbing a steep slope or rough terrain while driving, the four-wheel drive state will provide sufficient propulsion, and in this four-wheel drive state, the vehicle will not turn as much as possible. . In other words, by adopting a maneuvering form, the vehicle is switched to the four-wheel drive state only in a place where it is not possible to proceed unless it is absolutely necessary to use the four-wheel drive state, and returns to the two-wheel drive state without delay when the rough road portion ends. It eliminates the slip phenomenon caused by four-wheel drive. For this reason, in the present application, the two-wheel drive state and the four-wheel drive state can be selected by the switching operation pedal, so that even when approaching a rough road, the two-wheel drive state is held with both hands firmly holding the steering wheel. Can be freely switched, and this is an operation means suitable for adopting the above-described operation mode of "switching to a four-wheel drive state only at a necessary place". Further, since the switching operation pedal and the brake pedal are separately provided at distant locations, the above-described two- and four-wheel drive switching operation and brake operation can be selectively used as necessary.

However, while the driving state can be easily switched by the switching operation pedal, there is a possibility that the driving state may be inadvertently switched. For example, while climbing a steep slope with the misunderstanding that the vehicle is in a two-wheel drive state but in a four-wheel drive state, the vehicle suddenly slips, or a two-wheel drive state occurs due to an accidental pedal operation during climbing in a four-wheel drive state. The aircraft starts to slip. In such a situation, the brakes are operated to stop the aircraft first, so if the vehicle is switched to the four-wheel drive state with the brakes, the aircraft is actually started from the start of braking. Until the vehicle stops (although for a short time), it automatically switches to the four-wheel drive mode and grips the ground on each wheel.
Control force that increases the grip force and the left and right wheels
A state in which the power can be engaged and the aircraft can be stopped stably with little slippage can be obtained. Therefore, it is also possible to enable the four-wheel drive state to be restarted with a large driving force after braking. Only
Also, because the brake pedal is a single thing,
Side where a pair of left and right pedals are placed close to each other during operation
Only one side brake pedal, such as a brake pedal
Step on dull or left and right side brake pedal
Stepping on the selected driving mode, such as stepping on
It is not necessary to adopt the operation form of separating
Operate reflexively to prevent slippage at times
It is not necessary to consider stepping on
It is easy. As described above, the driving means for selecting and driving the two-wheel drive and four-wheel drive state is adopted so that the small turning slip phenomenon does not occur, and the necessary switching between the two-wheel drive and four-wheel drive is performed according to the control state. To be able to do it freely,
Further, a four-wheel drive lawn mower is realized by automatically switching to a four-wheel drive state in accordance with a brake operation.

[0008]

As a result, the structure is relatively simple because the two-wheel drive and the two-wheel drive are switched by the switching operation pedal provided separately from the main brake pedal, and the four-wheel drive state is switched by the brake operation. While using a four-wheel drive transmission with a conventional structure that is advantageous in terms of cost, large driving force can be exerted, lawn damage due to small turning slip phenomenon is reduced, and unexpected slip in two-wheel drive state etc. A four-wheel drive lawn mower that can be controlled by a brake operation can be provided.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the steering wheel 1a and the driver's seat 1
The mower 5 is moved up and down to the front of a vehicle body having a boarding operation unit 1, a driving unit 2, left and right front wheels 3 that are not steered, and left and right rear wheels 4 that are free to roll and steer. A riding lawnmower that can be suitably used in a golf course or the like by being freely connected is configured.

As shown in FIGS. 1 and 2, the engine 2a
Output from the motor through a transmission shaft 6 for a hydrostatic continuously variable transmission 7
Transmission output shaft 7a of the hydrostatic continuously variable transmission 7.
And a front wheel differential device 8 provided in the transmission case M
And gears, the power branched in the transmission case M is transmitted to the rear wheel drive unit 9, and the constant speed output shaft 7 c, which is an extension of the input shaft 7 b of the hydrostatic continuously variable transmission 7, is connected to the motor. 5 is linked with a transmission shaft 10 or the like.

The rear wheel drive unit 9 comprises a transmission shaft 9a gear-linked to a shift output shaft 7a of a hydrostatic continuously variable transmission 7, and a rear wheel differential 9b for driving left and right rear wheels 4.
Axle case A equipped with a clutch, a clutch 9c for intermittently interlocking the transmission shaft 9a and the rear wheel differential 9b, and the like. On relatively flat turf, only the front wheel 3 is driven by disconnecting the switching clutch 9c. The rear wheel 4 for steering is put into a free running state to prevent turf damage due to slippage of the rear wheel 4 at the time of steering, and on a slope or the like, the switching clutch 9c is engaged to prevent the front wheel 3 and the rear wheel 4 from being engaged. It is configured so that reliable traveling can be performed by four-wheel drive. In addition, the axle case A is supported by the front and rear bearing portions B, B so as to be able to freely roll around the front and rear horizontal axis P.

Next, an interlocking mechanism between the switching operation pedal 14 and the switching clutch 9c will be described. A fork 11 for operating the switching clutch 9c is provided so as to be swingable about a support shaft 12 and urged in a cutting direction by a return spring 13;
As shown in FIGS. 3 and 9, a first pedal (corresponding to a switching operation pedal) 14 for operating the clutch, which is disposed on the left side of the operation step 23, is swingably provided around a support shaft 15, and a rod, a wire, or the like is provided. Of the fork 11 via the interlocking member 16 of
When the first pedal 14 is depressed, the switching clutch 9c is engaged against the return spring 13 to switch to the four-wheel drive state.

A hook 19 for engaging and disengaging from a locking piece 18 attached to the mounting member 17 of the first pedal 14 is attached to a support shaft 20.
Around the torsion spring 21 and the locking piece 18
The clutch 19 is provided with a second pedal 22 for disengaging the clutch that operates the hook 19 in the disengagement direction with respect to the locking piece 18. Then, the first and second pedals 14 and 22 are arranged close to each other so that they can be simultaneously depressed with one foot, and the locking piece 18 and the hook 1
9, the hook 19 is rotated by the rotation of the locking piece 18 due to the depressing operation of the first pedal 14 and the torsion spring 2 is turned on.
1 and is engaged with the locking piece 18.

That is, when only the first pedal 14 is depressed from the state shown in FIG. 4, the switching clutch 9c is engaged, and the four-wheel drive state of the front wheel 3 and the rear wheel 4 is established. As shown in FIG. The four-wheel drive state is maintained by the action of the hook 19. When the second pedal 22 is depressed in this four-wheel drive state, the hook 19 is released from the locking piece 18 and the return spring 13
, The switching clutch 9c is disengaged to return to the two-wheel drive state in which only the front wheels 3 are driven.

As shown in FIG. 6, when the first and second pedals 14, 22 are simultaneously depressed, the four-wheel drive state is temporarily established only while the two pedals 14, 22 are being depressed. , 22 returns to the two-wheel drive state in which only the front wheels 3 are released. In short, the switching between the driving state and the idle state of the rear wheel 4 can be performed by a stepping operation, and the steering wheel 1a can be switched between the two-wheel driving state and the four-wheel driving state while reliably operating the handle 1a with both hands even in the inclined position. I have to be able to.

As shown in FIGS. 7 to 9, the support shaft 15 is a brake shaft extending to the left and right of the step 23, and rotates integrally with the main brake pedal 24 disposed on the right side of the step. The mounting member 17 is loosely supported so as to be rotatable relative to the support shaft 15. And
When the main brake pedal 24 is depressed, the brake device operates, and the switching clutch 9c in the two-wheel drive state switches to the four-wheel drive state, and when the first pedal 14 is depressed, the brake device does not operate. And so that the switching clutch 9c in the two-wheel drive state switches to the four-wheel drive state.
A link switching mechanism R for linking the main brake pedal 24 and the switching clutch 9c is provided in a state configured to span the support shaft 15 and the mounting member 17.

That is, the plate member 25 attached to the support shaft 15
A set bolt 26 with a lock nut screwed into the
The pin 27 fixed to the side surface of the mounting member 17 and the spindle 1
5 are arranged opposite to each other to form a linkage switching mechanism R. When the main brake pedal 24 is depressed, the set bolt 26 is
7, the first pedal 14 is operated to the depressed side. In other words, when the brake is operated, the switching clutch 9c is always switched to the four-wheel drive state, and when the main brake pedal 24 is depressed, the hook 19 rides on the locking piece 18 as shown in FIG. (It may be a position before that.) When the depression of the main brake pedal 24 is released, the vehicle returns to the two-wheel drive state. In short, when the brake is operated, the vehicle first enters the four-wheel drive state, then the brake is applied, and when the brake operation is released, the vehicle returns to the two-wheel drive state.

As shown in FIG. 1, a link support shaft 28 located immediately after the support shaft 15 has a first arm 30 on the input side.
a and the left and right second arms 30b, 30b on the output side are mounted so as to rotate integrally with each other. An elevating cylinder 31 is erected and connected between the first arm 30a and the transmission case M, and the second arm 30b and the mower are connected. A lift rod 33 is erected and connected to the lift arm 29 for suspension. As shown in FIGS. 10 and 11, the lifting cylinder 31 is supported by a pair of brackets 32, 32 which are fixed to the transmission case M by two bolts. The knurling process is applied to the two transmission case M connection surfaces 32a of the bracket 32, so that the transmission case M made of an aluminum alloy under a large load is applied.
Contributes to the prevention of bolt loosening due to loosening of the tightening surface.

Although not particularly shown, the brake device may be a general brake device that simultaneously brakes the four wheels or a brake device that only brakes the front and rear wheels.

[Alternative Embodiment] When the main brake pedal 24 is depressed, the first pedal 14
May be locked in the depressed position, and the four-wheel drive state may be maintained even when the depression of the main brake pedal 24 is released. In the present embodiment, the linkage switching mechanism R is configured between the support shaft 15 and the mounting member 17. For example, another operation wire is linked to the pin 27, and is directly linked to the switching clutch 9 c regardless of the mounting member 17. The structure may be sufficient.

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 an overall side view of a lawn mower.

FIG. 2 is a partially cutaway side view of a traveling transmission system.

FIG. 3 is a perspective view of a clutch operation unit.

FIG. 4 is a side view of the clutch operation unit in a two-wheel drive state.

FIG. 5 is a side view of the clutch operation unit in a four-wheel drive state.

FIG. 6 is a side view of the clutch operation unit in a temporary four-wheel drive state.

FIG. 7 is a side view showing the structure of the linkage switching mechanism.

FIG. 8 is a side view showing the state of the linkage switching mechanism during braking.

FIG. 9 is a cross-sectional view of the step portion at a spindle portion.

FIG. 10 is a side view showing a cylinder mounting bracket.

FIG. 11 is a sectional view showing a mounting state of a bracket.

[Explanation of symbols]

 3 One wheel 4 The other wheel 9c Switching clutch 14 Switching pedal 24 Brake pedal

────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yoshihiro Kawahara 64 Ishizukita-cho, Sakai-shi, Osaka Kubota Sakai Works Co., Ltd. (56) References JP-A-4-201628 (JP, A) JP-A-62 146 723 (JP, A) Jiko 60-15709 (JP, Y2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60K 17/02 A01D 69/08 F16D 67/02 F16H 48/30

Claims (1)

(57) [Claims] 1. The front, rear, left and right wheels (3) and (4)
One of the front and rear left and right wheels (3) and (3) is configured as a driving wheel, and the other left and right wheels (4) and (4) are driven from the driving wheel side.
The switching clutch (9c) is configured to be freely switchable between a four-wheel drive state in which power is transmitted via a switching clutch (9c) for intermittent power and a two-wheel drive state in which power is not transmitted.
To provide a foot-operated switching operation pedal (14)
And one of the front and rear left and right wheels that is the driving wheel
(3) A brake device for applying a braking action to (3)
And a single foot-operated brake pedal (24) disposed at a position distant from the switching operation pedal (14). The operation of the brake pedal (24) is performed by the switching operation pedal.
Interlocking mechanism between dull (14) and switching clutch (9c)
A link switching mechanism (R) for linking the
Engaging the switching mechanism (R), in depression of the brake pedal (24), wherein the switching clutch brake device is in the two-wheel drive state with activated (9c) is switched to the four-wheel drive mode, the switching operation pedal ( In step 14),
A driving operation structure for a lawnmower, wherein the switching clutch (9c) in a two-wheel drive state is switched to a four-wheel drive state without operating the brake device.