JP2000062655A - Small-sized passenger agricultural working vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To satisfactorily keep the longitudinal weight balance of a machine body by arranging a seat, an engine and a transmission within the longitudinal width of the grounding surface of a crawler type traveling device. SOLUTION: A steering wheel 21 is stood on the front end part of a body frame 6, and a seat 22 is arranged in the rear of the steering wheel 21 with a prescribed space to constitute a driving part 3. An engine 23 is arranged in the rear of the seat 22, and a transmission 24 is arranged under the engine 23 to constitute a prime mover part 4. The seat 22 whose weight is significantly increased by sitting of a driver, and the engine 23 and transmission 24 having large weights are arranged in the inside upper part of a setting surface WB or the upper part between the forefront rolling wheel 13 and a rear idler wheel 12 of a traveling part 2, whereby the longitudinal weight balance of a small- sized passenger agricultural working vehicle A is satisfactorily kept to enhance the stability to longitudinal inclination of the body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small-sized riding agricultural work vehicle.

[0002]

2. Description of the Related Art Conventionally, there is a wheel-type small-sized passenger farm work vehicle, which is heavily used in small-scale agriculture.

[0003]

However, since the above small-sized passenger farm work vehicle is grounded only by the left, right, front and rear wheels,
In a weak field such as a wet field, running performance is not good.

Further, since the size of the machine is small, the seating area where the operator is seated and the weight is significantly increased, and the arrangement of a heavy engine and transmission becomes cramped, and the front-rear weight balance is deteriorated. There are problems such as obstacles to running and work.

[0005]

SUMMARY OF THE INVENTION In view of the above, the present invention provides a compact, self-propelled passenger vehicle in which a seat, an engine, and a transmission are arranged above a traveling section frame equipped with a pair of left and right crawler type traveling devices. It is intended to provide a small-sized agricultural working vehicle, which constitutes an agricultural working vehicle, and in which a seat, an engine, and a transmission are arranged within a front-rear width of a ground contact surface of the crawler type traveling device.

It also has the following features.

The transmission is arranged below the seat.

The left and right vertical frames respectively supporting the crawler type traveling device are connected by a front and rear gate type frame having a substantially U-shaped downward opening when viewed from the front to form a traveling part frame, and a front end portion of the crawler type traveling device. In addition, a high angle of attack and a low angle of attack were formed.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention are as follows.

The left and right vertical frames are arranged so as to extend in the front-rear direction, and the front and rear portions of the left and right vertical frames are connected by front and rear gate-shaped frames each having a substantially downward opening in a front view so that the vehicle has a large minimum ground clearance. The front and rear idler wheels that constitute the partial frame and are arranged at the front and rear ends of the left and right vertical frames, the plurality of rolling wheels that are arranged on the lower surface of the frame, and the crawlers on the outer circumference of the drive sprocket arranged above the frame, respectively. Winding to form a traveling unit including a crawler-type left / right traveling device, placing a vehicle body frame above the traveling unit, and arranging a steering wheel at a front end portion of the vehicle body frame,
A seat is placed behind the steering wheel at a predetermined interval, an engine is placed close to the back of the seat, a transmission is placed close to the bottom of the engine, and the weight is reduced by the operator sitting. The significantly increased number of seats, heavy engine and transmission are centrally arranged within the front-rear width of the ground contact surface of the crawler type traveling device to improve the front-rear weight balance of the aircraft and drive in wetlands. The performance and turning performance are improved.

Further, the front idler wheel is arranged at a position higher than the frontmost rolling wheel, and front and rear low attack angles are formed at the front ends of the crawlers, so that the front idler wheel and the running portion frame having a large minimum ground clearance are provided. In addition, we are trying to improve the running performance in wetlands and over bumps such as ridges.

[0012]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a small-sized passenger farm work vehicle A according to the present invention.
The tractor A has a vehicle body frame 5 having a driving section 3 and a prime mover section 4 mounted above a traveling section 2 equipped with crawler type left and right traveling devices 1a and 1b. A rotary cultivator 6 as an agricultural working machine is connected to the rear end of the frame 5.

As shown in FIGS. 1 to 3, the traveling unit 2 has a pair of left and right vertical frames 7a and 7b extending in the front-rear direction, and the front and rear portions of the left and right vertical frames 7a and 7b are set downward. The running frame 9 is formed by connecting the front and rear gate-shaped frames 8a and 8b whose openings are widened.
Left and right front idler wheels 11 and 12 are pivotally supported at the front ends of a and 7b via tensioners 10, and left and right rear idler wheels 12a and 12b are respectively supported at the rear ends of the left and right vertical frames 7a and 7b. A plurality of rolling wheels 13 are axially supported on the lower surfaces of the vertical frames 7a, 7b,
Further, the left and right sprockets 14a, 14b are pivotally supported above the left and right vertical frames 7a, 7b, respectively, and the front and rear idler wheels 11, 12 are
Left and right crawlers 15a and 15b are respectively wound around the outer circumferences of the plurality of rolling wheels 13 and the left and right sprockets 14a and 14b to form left and right traveling devices 1a and 1b.

In particular, in this embodiment, the left and right vertical frames 7a, 7a
The front and rear gate-shaped frames 8a and 8b are used to connect b, and the minimum ground clearance is increased to improve running performance in the field.
Further, since the working machine is connected to the rear of the small-sized passenger farm work vehicle A, the front idler wheel 11 is moved to the frontmost rolling wheel 13.
It is mounted at a higher position than that, and an attack angle α of about 21 degrees is formed at the front ends of the left and right crawlers 15a, 15b to enhance the running performance when crossing a step such as a ridge.

As shown in FIGS. 1 to 3, the vehicle body frame 5 includes left and right side members on the upper surfaces of front and rear gate frames 8a and 8b.
16a and 16b are extended in the front-rear direction, and front and rear columns 17a and 17b are erected at the front and rear ends of the left and right side members 16a and 16b, respectively. The upper frame 18 is formed in a letter shape and is inclined in the front, rear, rear, and high as a whole in a side view, and the upper frame 18 is erected on the upper ends of the front and rear columns 17a and 17b to form a frame-shaped body frame 5. ing.

A steering wheel 21 is erected on the front end of the vehicle body frame 5, and a seat 22 is arranged behind the steering wheel 21 at a predetermined interval to form a driving section 3 and The engine 23 is placed behind the engine
The transmission 24 is arranged below the 23, and the prime mover section 4 is provided.
The left and right sprockets 14a, 14b are the left and right drive shafts 25 protruding laterally from the transmission 24.
They are fitted to the outer ends of a and 25b, respectively. In the figure, 26 is a vehicle body cover, 27 is a battery, 28 is a fuel tank, and 29 is a shift lever.

In particular, the seat 22 in which the driver sits down and the weight increases significantly, the engine 23 and the transmission 24 having a large weight are provided above the inside of the ground contact surface WB, that is, the frontmost rolling wheel 13 of the traveling unit 2. It is disposed above the rear idler wheel 12 and the rear idler wheel 12 to improve the weight balance between the front and rear of the small-sized agricultural working vehicle A, and enhance the stability of the vehicle body with respect to the front and rear inclination.

Heavy objects such as the battery 27 and the fuel tank 28 are also arranged above the frontmost rolling wheel 13 and the rear idler wheel 12 to further enhance the stability of the vehicle body against the front-back inclination. There is.

The rotary cultivator 6 is connected through a three-point link mechanism 30 provided at the rear portion of the vehicle body frame 5,
The rotary cultivator 6 is moved up and down by a lifting hydraulic cylinder 32 provided between the body frame 5 and the top link 31, and the power from the engine 23 is driven by the work machine drive shaft.
To the rotary tiller 35 via 33 and the belt transmission mechanism 34,
The power from the engine 23 is transmitted.

In FIG. 4, the position where the driver 3 and the engine 23 are arranged is the same as above, but the transmission 24 is seated.
It shows another embodiment arranged below 22.
The present embodiment is different from the above embodiment in that the tensioner 10 is disposed behind the left and right vertical frames 7a and 7b to pivotally support the rear idler wheel 12 and the front idler wheel 11 via the bracket 36.

Also in this embodiment, heavy objects such as the seat 22, the engine 23, the transmission 24, the battery 27 and the fuel tank 28 are arranged above the inside of the ground contact surface WB to improve the stability.

5 to 8 show a first embodiment of the transmission 24, in which the first to ninth shafts 41 to 49 are axially supported in parallel inside the transmission case 40, and the middle of the first shaft 41 is provided. To the input side of the forward clutch 50a, and the end of the first shaft 41 via the first meshing gear 51, and the input side of the reverse clutch 50a, 50b loosely fitted in the middle of the second shaft 42, It is interlockingly connected to a lifting hydraulic pump 52, and a second meshing gear 53 is provided between a second output shaft of the forward clutch 50a and a second output clutch of the reverse clutch 50b.
The shaft 42 and the third shaft 43 are interlockingly connected to each other, and the forward / reverse clutch 50a,
The power transmission of 50b is exclusively selectable to enable forward / reverse switching of the driving direction.

The third shaft 43 is interlockingly connected to an input shaft 55 of a steering hydrostatic continuously variable transmission (hereinafter referred to as HST) 54, and a main transmission unit 57 via a third mesh gear 56. Is connected to a fourth shaft 44, which is an input shaft of the, and a slider 60 axially slid on the fourth shaft 44 in which dogs 58, 58 at both ends and a second speed driving gear 59 at the center are integrally formed. While being fitted so as to be movable and non-rotatable, the fourth shaft 44 and the fifth output shaft of the main transmission unit 57
Always meshed with the shaft 45, first and third speed meshing gears 61, 6
2 and the second shaft passive gear 63 of the sliding mesh type on the fifth shaft 45.
By fitting and sliding the slider 60, the output rotation speed of the main transmission unit 57 can be switched in three stages.

A sub-transmission unit 64 is connected in series to the main transmission unit 57, and the sub-transmission unit 64 includes the fifth shaft 45 and a sixth shaft 46, which is an output shaft of the sub-transmission unit 64. High and low speed meshing gear between
The slider 67 slidably and non-rotatably fitted to the sixth shaft 46 with 65 and 66 interposed allows the output rotation speed of the auxiliary transmission unit 64 to be in two stages, high and low, with the neutral position in between. It is possible to shift to.

In this way, the forward and backward clutches 50a and 50b,
Since the main speed change section 57 for the third speed change and the sub speed change section 64 for the second speed change are connected in series in series, finally, each of the forward and backward movements of 6
It is possible to change gears in stages.

The sixth shaft 46 is interlockingly connected to the seventh shaft 47 via a chain interlocking mechanism 68, and the left and right sun gears 69a and 69b fitted to the left and right end portions of the seventh shaft 47, respectively. 7 axis 47
And left and right cages 70a, 70b connected to the left and right drive shafts 25a, 25b arranged with the same axis, and a plurality of left and right planetary gears 71a, 71b axially attached to the left and right cages 70a, 70b, respectively.
Left and right ring gears 73a, 73 linked to the output shaft 72 of ST54
b and left and right planetary gear mechanisms 74a and 74b, and left and right sun gears 69a and 74b by the mechanical linear power transmission system M configured by the above-mentioned gear type transmission and meshing gears. The rotary power transmitted to the 69b and the left and right ring gears 73a, 73 from the HST54 of the turning power transmission system H described later.
The rotational powers transmitted to b are respectively combined, and these combined rotational powers are combined into the left and right planetary gears 71a, 71b and the left and right cages 70a, 70a,
70b and the left and right drive shafts 25a, 25b are individually transmitted to the left and right sprockets 14a, 14b.

The output shaft 72 of the HST 54 has the same output shaft 72.
The forward / reverse rotation dividing mechanism 75 that complementarily transmits the rotation speed of the right and left ring gears 73a and 73b is provided, and the forward / reverse rotating dividing mechanism 75 passes the reduction gear group 76 to the output shaft 72 of the HST 54. The eighth shaft 48 is interlockedly connected, the eighth shaft 48 is interlockedly connected to the ninth shaft 49 via the first intermediate meshing gear 77, and the left and right output gears 78a, 78b are respectively provided at the left and right ends of the ninth shaft 49. The left output gear 78a and the left ring gear 73a are interlockingly connected via two idle gears 79, 79 arranged in series,
78b and the right ring gear 73b are interlockingly connected through one idle gear 79, and the absolute values of the rotation speeds are equal, but the left ring gear 73a rotates in the same direction as the ninth shaft 49 and the right ring gear 73b. To transmit the rotation in the opposite direction to the ninth shaft 49.

Then, one end of the first shaft 41, which is the input shaft of the transmission 24, is projected from the side surface of the transmission case 40, and the projecting end and the engine output shaft 80 are interlockingly connected via the belt mechanism 34. The steering wheel 21 is interlocked with the gear shift actuating portion 104 (see FIG. 11) of the HST 54 so that the gear ratio of the HST 54 can be changed steplessly in accordance with the turning operation of the steering wheel 21. In FIG. 5, 81 is a rotary shaft, 82 is a plowing claw, and 83,84.
6 is a chain transmission mechanism. In FIG. 6, 85a and 85b are shifters of the forward and backward clutches 50a and 50b, 86 is a shifter of the main transmission unit 57, and 87 is a shifter.
Is a shifter of the sub-transmission unit 64, and 88 is a meshing bevel gear for extracting power to the outside.

With this configuration, the power from the engine 23 is transmitted to the left and right traveling devices 1a and 1b of the traveling section by shifting the power in six steps, and the output rotation speed of the HST 54 is changed according to the operation angle of the steering wheel 21. Left and right traveling device 1
By making the driving speeds of a and 1b different, the small-sized passenger agricultural work vehicle A can be turned in the direction in which the driving speed becomes slow.

Particularly, in this embodiment, since the input shaft 55 of the HST 54 is interlocked with the output side of the forward / reverse clutch 50b, the forward / reverse clutch 50a, 50b can be switched without operating the steering wheel 21. At the same time, the output rotation direction of the HST 54 is switched, and the operation direction of the steering wheel 21 and the turning direction of the small-sized passenger farm work vehicle A maintain a constant relationship,
The turning operation can be performed with a feeling substantially similar to the steering operation of the wheel type vehicle.

FIG. 9 shows a second embodiment of the transmission 24. In this embodiment, the input shaft 55 of the HST 54 is shown.
Is connected to the engine 23 without interposing the forward / reverse clutches 50a and 50b, and the input shaft 55 is always rotated in a fixed direction. Instead, the forward / reverse rotation is made between the eighth shaft 48 and the ninth shaft 49. Switching mechanism
90 forward / reverse rotation switching mechanism 90 and forward / reverse clutch 50a, 50
Left and right ring gears 73a, 73b
By changing the rotation direction of the power transmitted to the steering wheel 21, the operating direction of the steering wheel 21 and the turning direction of the small-sized passenger farm work vehicle A are maintained in a constant relationship.

That is, the first shaft 41 and the input shaft 55 of the HST 54 are interlockingly connected via the first meshing gear 91, and the eighth shaft 48
Left and right driving gears 92a, 92b are fitted on the left and right side of
The left driving gear 92a and the left passive gear 93a loosely fitted to the ninth shaft 49 are interlockingly connected via two idle gears 79, 79 arranged in series, and the right driving gear 92b and the ninth shaft 49 are connected to each other. The right passive gear 93b loosely fitted is interlockingly connected via one idle gear 79, and dogs 58, 58 are provided on the left and right ends of the ninth shaft 49, respectively.
The slider 94 having the above-mentioned structure is externally fitted so as to be slidable and non-rotatable in the axial direction, and by sliding the slider 94, the left and right sun gears 69a, 69a
The rotation direction of the power transmitted to b is switched, and the other structure is substantially the same as that of the first embodiment.

FIG. 10 shows the operating angle of the steering wheel 21, that is, the output rotation speed of the HST 54 and the left and right traveling device 1.
It shows the relationship with the drive speed of a, 1b, the vertical axis is the drive speed of the left and right traveling devices 1a, 1b, and the horizontal axis is the output rotation speed of the HST54. Each solid line shows one crawler type from the bottom. The driving speeds of the traveling device from the first speed to the sixth speed are shown, and the broken lines indicate the driving speeds of the other crawler type traveling device from the bottom to the first speed to the sixth speed, and the lower hatched portion h is , The driving speed of the slower crawler type traveling device indicates the range from zero to the direction opposite to the traveling speed of the aircraft, and the size of the arrow in the lower frame indicates the left and right traveling device 1
The drive speeds of a and 1b are shown.

In this embodiment, even if the steering wheel 21 is rotated up to the maximum operation angle θ1 by limiting the relationship between the operating angle of the steering wheel 21 and the gear ratio of the HST 54, the third speed- In the sixth speed traveling, the left traveling device 1a
The sign of the vector of the driving speed of the vehicle and the sign of the vector of the driving speed of the right traveling device 1b are the same, the pivot turn and the spin turn cannot be performed, only the normal turning is possible, and the second speed running Then, the crawler type traveling device on the slower side becomes zero, and although the pivot tan is possible, the spin turn cannot be performed.
By making the sign of the driving speed vector of 1a different from the sign of the driving speed vector of the right traveling device 1b, pivot tanning and spin turn are possible, and the steering wheel 21 can be rotated about 1 / th of the maximum operation angle θ1. When the vehicle is rotated up to an angle θ2 of 2, the left traveling device is used in the second to sixth speed traveling.
The sign of the traveling drive speed vector of 1a and the sign of the traveling drive speed vector of the right traveling device 1b are the same, and only normal turning is possible. In the first speed traveling, the slower crawler is used. The type traveling device has become zero, and the pivot tan is possible, but the spin turn is not possible.

As described above, during high speed running in the third to sixth speeds, even if the steering wheel 21 is fully operated, a sharp turn is prevented, so that safety during turning is ensured.
During low speed running at the first or second speed for work or the like, the work efficiency can be improved by performing the pivot turn and the spin turn.

FIG. 11 shows a hydraulic circuit in which the discharge side of the lifting hydraulic pump 52 is connected to the hydraulic circuit inside the HST 54 so that the lifting hydraulic pump 52 also serves as the charge pump of the HST 54. In the figure, 100 is a lifting control hydraulic valve, 101 is a relief valve, 102 and 103 are hydraulic pumps and hydraulic motors inside the HST 54, 104 is a speed change operation part, 105 is a check valve, and 106 is a throttle valve.

[0038]

According to the present invention, the following effects can be obtained.

According to the first aspect of the present invention, a small-sized riding farm work vehicle which can be self-propelled is configured by disposing a seat, an engine, and a transmission above a traveling section frame equipped with a pair of left and right crawler type traveling devices. However, by arranging the seat, the engine, and the transmission within the front-rear width of the ground contact surface of the crawler type traveling device, the front-rear weight balance of the airframe is improved, the stability of the airframe and the running performance in wetlands are improved. Can be improved.

According to the second aspect of the present invention, the transmission is arranged below the seat, so that the transmission is arranged above the ground contact surface of the crawler type traveling device to improve the front-rear weight balance of the airframe. You can

According to the third aspect of the present invention, the left and right vertical frames respectively supporting the crawler type traveling devices are connected to each other by the front and rear gate-shaped frames having a substantially downward opening in a front view to form a traveling section frame. By increasing the minimum ground clearance of the aircraft, the running performance in wetlands and rough terrain has been improved, and the front end of the crawler-type traveling device has a front-rear-low attack angle that allows it to cross over ridges and other steps. Driving performance can be improved.

[Brief description of drawings]

FIG. 1 is a side view of a small-sized riding agricultural work vehicle according to the present invention.

FIG. 2 is a plan view of a traveling unit.

FIG. 3 is a front view of a traveling unit.

FIG. 4 is a side view of another embodiment small-sized riding agricultural work vehicle.

FIG. 5 is a power transmission system diagram (first embodiment).

FIG. 6 is a sectional side view of a transmission (first embodiment).

FIG. 7 is a cross-sectional plan view of a transmission showing a straight drive train (first embodiment).

FIG. 8 is a cross-sectional plan view of the transmission showing the turning power transmission system (first embodiment).

FIG. 9 is a power transmission system diagram (second embodiment).

FIG. 10 is a graph showing the relationship between the driving speed of the left and right traveling devices and the HST output rotation speed.

FIG. 11 is a hydraulic circuit diagram.

[Explanation of symbols]

A Small passenger farm work vehicle (agricultural tractor) WB ground plane α angle of attack 1a, 1b Crawler type traveling device 7a, 7b left and right vertical frame 8a, 8b front and rear gate type frame 9 Running frame 22 seats 23 engine 24 transmission

Claims (3)

[Claims] 1. A pair of left and right crawler type traveling devices (1a) (1b)
Above the running frame (9) equipped with the seat (22),
The engine (23) and the transmission (24) are arranged to form a self-propelled small-sized riding agricultural vehicle (A), and the front and rear width of the ground contact surface (WB) of the crawler type traveling devices (1a) and (1b). A small-sized passenger farm vehicle characterized in that a seat (22), an engine (23), and a transmission (24) are arranged inside. 2. The transmission (24) is attached to a seat (2
The small-sized agricultural working vehicle according to claim 1, wherein the small-sized passenger agricultural working vehicle is arranged below (2). 3. The right and left vertical frames (7a) and (7b) respectively supporting the crawler type traveling devices (1a) and (1b) are provided with front and rear gate-shaped frames (8a) and (8b) having a substantially U-shaped downward opening in front view. The front part of the crawler type traveling device (1a) (1b) is formed with a front high rear low angle of attack (α) while the traveling frame (9) is connected by Item 1. A small-sized agricultural farming vehicle according to item 1 or 2.