JPH02204135A - Industrial vehicle - Google Patents

Abstract

PURPOSE:To efficiently prevent the slip of a nonsteered type wheel by automatically cutting off the clutch for the nonsteered type wheel when it is detected that the steered type wheel is in the steered state over a set angle. CONSTITUTION:A plurality of detecting tools 36 and 37 for detecting the steering states of the right and left wheels according to the operation positions of a steering gear 28 are supported in swingable manners onto the both side parts of the steering gear 28 through the pivotal supporting shafts 38 and 39. Further, one detecting tool 36 is connected width an operating lever 33 for clutch for front wheel through a plurality of interlocking means 40-43. Further, the other detecting tool 37 is connected with the swingable interlocking link 42 of the above-described one interlocking means through a plurality of interlocking means 45-47. When it is detected that the right and left rear wheels are in the steered state over a set angle, a clutch control mechanism 48 is constituted so that the clutch for front wheel is cut off.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a driveable steerable wheel on one of the front and rear sides of the fuselage, and a pair of left and right non-steerable wheels on the other front and rear sides of the fuselage. This invention relates to a work vehicle that is freely drivable.

[Conventional technology]

The above-mentioned work vehicle may have one steering wheel, or even if it has two wheels, its tread is extremely small compared to the tread of a non-steering wheel, or it may have two wheels and a No matter what the specifications of the non-steering wheels are, such as if the tread is the same or almost the same as the tread of the non-steering wheels, or even if the non-steering wheels cannot be driven when driving straight, By driving the left and right non-steering wheels, the vehicle can move with stable direction and propulsion.

Conventionally, in this type of work vehicle, when turning, both steered wheels and non-steered wheels are driven, and a differential mechanism is used to differentially move the left and right non-steered wheels while they are still being driven. Ta.

[Problem to be solved by the invention]

Conventionally, when turning, the non-steering wheels slip due to the drive of the non-steering wheels and the steering wheel orientation, resulting in the running surface becoming rough or the grass forming the running surface. In some cases, the turning radius of the aircraft became large compared to the wheel steering angle.

SUMMARY OF THE INVENTION An object of the present invention is to effectively avoid slippage of non-steering wheels and to enable small turns.

[Means to solve the problem]

In order to achieve the object, the present invention provides the work vehicle described at the beginning with a clutch that cuts off power transmission only to the non-steering wheels, so that the steering wheels are in a steering state exceeding a set angle. A clutch control mechanism is provided that detects a certain condition and automatically disengages the clutch only in the detected state.

Although it may be configured such that both steered wheels and non-steered wheels are driven until the clutch is disengaged, the no-spin differential mechanism for the center is used to control the output rotation speed difference when driving straight. It is advantageous to provide it in a certain state.

[For production]

The set angle is set to a wheel steering angle at which, if the non-steering type wheels remain driven, they tend to slip easily or begin to cause turning resistance. Then, when the wheel steering angle is smaller than the set angle, such as when driving straight,
If the clutch control 'a mechanism is in the non-detection state, the clutch is engaged, and the engine output is configured as a non-center differential so that it is branched and transmitted to both wheels unconditionally, the steering amount and non-steering type Both wheels are driven,
Then, a no-spin differential mechanism that branches and transmits engine output to both wheels is installed so that the output rotation speed of the steered wheel is higher than the output rotation speed of the non-steering wheel in the straight-ahead steering condition, and it is equipped with a center differential. In this case, only the non-steering wheels or both the non-steering type wheels and the steering wheels are driven, and stable running is possible in either case. When turning by steering beyond the set angle, the clutch control mechanism enters the detection state and the clutch is automatically disengaged when the clutch is operated.
In both cases with a non-center differential and with a center differential, the non-steering type wheels become idle and transfer to the ground, making it difficult for the non-steering type wheels to slip on the ground. During this turn, if the clutch is installed on the lower transmission side by a differential mechanism for non-steering wheels, the left and right non-steering wheels become idle wheels in a non-interlocked state, and the steering Due to the pushing action of the type wheels, the left and right non-steering wheels differentially roll in the same direction of rotation, or roll on the ground in the opposite direction to make a small turn. If it is installed on the upper side of the transmission than the differential mechanism for facing wheels, the left and right non-steered wheels will be in an idle state linked by the differential mechanism, and the steered wheels will be pushed. Therefore, the left and right non-steering wheels are reliably transferred to the ground in the opposite rotation direction to make a small turn.

If a no-spin differential mechanism for the center is installed so that there is a difference in output rotation speed when driving straight, the clutch can simply be installed on the non-steering wheel side, and when the steering wheel is steered beyond the set angle, the steering wheel becomes the driving wheel. In this case, the non-steering wheels become idle wheels, and when the vehicle is traveling straight, the steering wheels become idle wheels and the non-steering wheels become driving wheels.

〔Effect of the invention〕

When turning, the left and right non-steering wheels automatically become idle wheels and roll on the ground due to the clutch and clutch control mechanism, and depending on the location of the clutch, they can be reliably rolled in the opposite rotation direction. By being able to turn while avoiding roughness and damage to the running surface caused by slipping of the non-steering wheels, and by turning around with a small turn due to the reverse rotation of the left and right non-steering wheels, it is possible to improve the accuracy of the finish. It has become possible to do good work efficiently.

If the center no-spin differential mechanism is installed so that there is a difference in output rotation speed when traveling straight, only the non-steering type wheels are driven when not turning, and when turning only the steering type wheels are driven, the clutch is not activated. This can be achieved by providing only the steering wheel, and the structure can be simplified from both the transmission mechanism and control mechanism.

〔Example〕

Next, examples will be shown.

As shown in FIGS. 1 and 2, a pair of left and right non-steering type front axles (1), (1), a pair of left and right steering type non-steering wheels (2), (1) with treads smaller than the front wheel treads. 2
), a sunshade for the driving section (3), and a grass collector (5) that can swing dumping around the axis (pi) using the dump cylinder (4).
) etc. A lawn mowing device (9) is connected to the front part of the traveling machine body through a link mechanism (8) which is operated to swing up and down by a lift cylinder (7), and can be freely raised and lowered. The blade type cutting blade (11) and the rotary fan (12) are driven by the power transmitted from the rotary shaft (10) to the lawn mower (9), and the rotary fan (
The riding type lawn mower is constructed so that the cut grass is supplied to the grass collector (5) via the conveyance duct (13) by blowing air from the lawn mower (12).

As shown in Figure 2, the output pulley (1) of the engine (E)
5) and transmission bell) (16).
17) is mounted on the top of the case (18) so as to be supported by the case (18). As shown in FIGS. 3 and 4, a traveling sub-transmission (TM) interlocked with the continuously variable transmission (HST), this sub-transmission
(TM), a center no-spin differential mechanism (CD) linked to the output shaft (19) of the center differential mechanism (CD), and a multi-disc front wheel clutch ( C), the output shaft of this front wheel clutch (C) (
21), and a rear wheel power take-off shaft (22) interlocked with a bevel gear to the rear wheel output shaft (20b) of the center differential mechanism (CD). The driving transmission (17) is provided, and the front wheel differential mechanism (FD) is directly linked to the left and right front axles (LA), (LA), and the rear wheel power take-off shaft (22) is equipped with a universal joint. The transmission shaft (23), the input shaft (25) of the rear wheel transmission case (24) as shown in Fig. 5, the transmission shaft (26), and the left and right rear axles via the rear wheel no-spin differential mechanism (RD). (2a) and (2a) are linked.

In other words, as shown in Fig. 8, the rotational output of the engine (E) is transmitted to the center differential mechanism (CD) via the continuously variable transmission (HST) and the auxiliary transmission (gate). and the rear wheels, and the rotational force of the front wheels is transferred to the left and right front wheels (1), (1 ), and the rotational force on the rear wheel side is transmitted to the left and right rear wheels (2), (2) via a rear wheel differential mechanism (RD) in a state where differential operation is possible.

By forming the outer diameter of the rear wheel (2) to be smaller than the outer diameter of the front wheel (1), the reduction ratio of the transmission system from the center differential mechanism (CD) to the front wheel (1) and the center Differential mechanism (C
By changing the reduction ratio of the transmission system from D) to the rear wheels (2), the output rotation speed of the rear wheels of the center differential mechanism (CD) is higher than the output rotation speed of the front wheels when driving straight. It is configured as follows. In other words, when driving straight, the rear wheel transmission system is disconnected by the action of the center no-spin differential (CD), and the left and right rear wheels (2), (2)
It is designed so that it becomes an idle wheel.

As shown in Figures 5 and 6, the rear wheel transmission case (24
) is configured so that the input shaft side case portion (24a) and the wheel side case portion (24b) rotate relative to each other around the vertical axis (P2), and the rotation of the wheel side case portion (24b) A steering gear (28) engaged with the operating gear portion (27) is rotatably supported by a pivot shaft (29) and is rotatably operated by a steering cylinder (6). That is, the steering valve (V) is operated by rotating the steering handle (30) shown in FIG. The left and right rear wheels (2), (2) are steered by rotating the case portion (24a). In addition, the rear wheels can be steered from straight ahead to 90 degrees to the left and right.

The front wheel clutch (C) is connected to a sliding operation part (31) via a sliding shaft (32) as shown in Fig. 7, and is arranged on the outside of the transmission case (18). It is configured to be operated by a lever (33). That is, when the operating lever (33) is swung around the axis of the sliding shaft (32) to the off position (OFF), the boss portion (33a) of the operating lever (33) and the transmission case (
When the operating part (31) switches to the clutch release side to operate the sliding shaft by the cam mechanism between it and the fixed cam (34) of 18), and the swinging operation on the operating lever (33) is released. , the operating lever (33) is switched to the clutch engagement position (ON) to operate the sliding shaft by the biasing spring (35), and the operating portion (31) returns to the engagement side. As shown in FIG. 6, based on the operating position of the steering gear (2nd), the left and right rear wheels (2),
(2) A first detection odor (36) and a second detection tool (37) for detecting the steering state are distributed on both sides of the steering gear (28), and the pivot shaft (38) or (39) and the first detection tool (36).
is interlocked with the operating lever (33) via the interlocking rod (40), the swing interlocking link (42) supported by the pivot shaft (41), and the interlocking rod (43), and the second detection tool (37) The left and right rear wheels (2) are linked to the swing link (42) via the link (44), the swing link (46) supported by the pivot shaft (45), and the link rod (47). ), (2) is in a steering state exceeding a set angle, and the flanch control mechanism (48) is designed to automatically disengage the front wheel clutch (C) only in that detection state. It is completed. That is, as the left and right rear wheels (2), (2) are steered from straight forward direction to leftward and rightward, the detection device operating portion (28a) or (28b) of the steering gear (28) is activated by the first detection device (28a) or (28b).
36) roller type detection part (36a) or second detection tool (
37), and due to the rotational force of the steering gear (28), the first detection tool (36
) or the second detection tool (37) swings to swing the operating lever (33) toward cut position 1 (OFF). And center no-spin differential mechanism (CD)
Therefore, if the left and right rear wheels (2) and (2) are in the driving state, and the left and right front wheels (1) and (L) are still in the driving state, slip will begin to occur on them and the cheapest 60
When the rear wheel steering angle reaches 72°, the front wheel clutch (C) begins to switch to disengaged, and when the rear wheel steering angle reaches 72°, the front wheel clutch (C) switches to disengaged and is fully operated. This involves operating the lever (33).

In short, when driving in a straight line or nearly straight, only the left and right front wheels (1), (1) automatically become the driving wheels due to the action of the center no-spin differential (CD) and its output rotation speed difference. While preventing the wheels from slipping on the ground due to the difference in circumferential speed between the front and rear wheels when driving,
In addition, the vehicle runs while being stably oriented by driving the front wheels (1) with wider treads. And when turning, just by steering the rear wheels (2),
Due to the action of the center no-spin differential mechanism (CD) and the clutch control mechanism (48), the front wheel (1) is an idle wheel and the rear wheel (
2) is automatically switched to the drive wheel, the front wheel (1) is transferred to the ground, and the front wheel differential i (
Due to the reverse rotation caused by interlocking with FD), the front wheels are prevented from slipping while making small turns.

[Another example]

FIG. 9 shows another transmission structure in which the output of the engine (E) is transmitted to the gear branching mechanism (49) via the hydraulic continuously variable transmission (IIST) for traveling and the auxiliary transmission for traveling (TM). , the engine output is branched and transmitted unconditionally to the front wheels and the rear wheels, and both the front and rear wheels (2) become drive wheels unless the front wheel clutch (C) is disengaged. It is.

The front wheel clutch may be configured to connect and disconnect power on the lower side of the front wheel differential mechanism (FD).

The rear wheels have the same tread as the front wheels and are controlled by knuckle arms,
It may be carried out using only one rear wheel.

Alternatively, the front wheels may be used as steering wheels and the rear wheels may be used as non-steering wheels. Therefore, the front wheel (1) is replaced by a non-steering wheel (
1), in which the rear wheels (2) are used as steering wheels (2).

As the clutch control mechanism (48), an electrical configuration may be employed in addition to a mechanical configuration.

Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of the drawing]

The drawings show an embodiment of a working vehicle according to the present invention, and FIG. 1 is a partially cutaway side view of the entire riding lawn mower, and FIG. 2 is a partially cut away plan view of the entire riding lawn mower. Figure 3 is a partially expanded cross-sectional view of the driving mission, Figure 4 is a partially cutaway side view of the driving mission, Figure 5 is a cross-sectional view of the rear wheel transmission case, and Figure 6 is a plan view of the clutch control mechanism. , Figure 7 is a partially cutaway front view of the front wheel clutch operating section, Figure 8 is a transmission system diagram,
FIG. 9 is a system diagram of another implementation transmission structure. (1)...Non-steering wheels, (2)...
Steering type wheels, (48)...Clutch control mechanism,
(C)...Clutch, (CD)...
No-spin differential mechanism.

Claims (1)

[Scope of Claims] 1. A steered wheel (2) is provided on one of the front and rear sides of the fuselage in a freely drivable manner, and a pair of left and right non-steerable wheels (1), (1) is provided on the other front and rear sides of the fuselage. A working vehicle is provided so as to be freely drivable, and is provided with a clutch (C) that cuts off power transmission only to the non-steering wheel (1), and the steering wheel (2) is in a steering state at a set angle or more. The working vehicle is provided with a clutch control mechanism (48) that detects the occurrence of the occurrence of the oxidation and automatically disengages the clutch (C) only in the detected state. 2. Engine output is divided into steered wheels (2) and non-steered wheels (
1) is provided with a no-spin differential mechanism (CD) that performs branch transmission, and the output rotation speed of the steered wheel side of the no-spin differential mechanism (CD) in the straight-ahead steering state is equal to the output rotation speed of the non-steered wheel side. The work vehicle according to claim 1, wherein the work vehicle is larger than the number of vehicles.