JPH11201280A - Hydraulic system of rice-planting machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce cost by interposing a static hydraulic continuously variable transmission in a traveling transmission system, connecting a planting part with a machine body via a hydraulic elevating/lowering device and introducing return oil of the elevating/lowering device into a hydraulic fluid supply port of the continuously variable transmission. SOLUTION: A hydraulic pump 46 is driven by an engine 9 via an input shaft 26 and sucks hydraulic fluid which is also lubricating oil by a piping 55 via an oil filter F within a transmission case 11. A discharge port of the pump 46 is connected with an elevating/lowering switching valve 47, a load check valve 50 and a relief valve 48, an A port on the secondary side of the valve 47 is communicated with a hydraulic cylinder 19 for elevating and lowering a planting part via a variable restriction 49 and a piping 57, and the secondary side of the valve 50 detours around the variable restriction 49 and is communicated with the hydraulic cylinder 19. A B port on the secondary side of the valve 47 is communicated with the secondary side of the relief valve 48 together with a tank port T on a primary side and is communicated with a hydraulic fluid supply port C of a static hydraulic continuously variable transmission via a piping 56 and a line filter 51. Therefore, the number of pump can be reduced and cost is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic configuration of a rice transplanter in which a walking type or a riding type rice transplanter is shifted by a hydrostatic stepless transmission, and furthermore, a planting portion can be moved up and down by hydraulic pressure. About.

[0002]

2. Description of the Related Art In recent years, a main transmission of a rice transplanter often employs a hydrostatic continuously variable transmission in order to perform an accurate planting operation and a delicate traveling speed, and to adjust to a desired traveling speed. It is becoming possible. Such a hydrostatic continuously variable transmission includes a variable displacement hydraulic pump and a fixed displacement hydraulic motor, and the hydraulic pump and the hydraulic motor are fluidly connected to form a closed circuit. The supply of the working oil to the closed circuit has been supplied from a charge pump different from the hydraulic pump of the hydraulic lifting device for raising and lowering the planting section.

[0003]

As described above, the configuration is such that the hydraulic oil is supplied to the hydrostatic stepless transmission and the hydraulic lifting device by separate hydraulic pumps, resulting in high cost. . Further, if the hydraulic pump is arranged near the engine, the piping for the hydrostatic continuously variable transmission and the hydraulic lifting device becomes longer, and the efficiency is reduced.

[0004]

The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described. That is, according to claim 1, in a rice transplanter in which a hydrostatic stepless transmission is interposed in a traveling transmission system that transmits engine power to an axle, and a planting portion is connected to a machine body through a hydraulic lifting device, The return oil of the hydraulic lifting device is introduced into a hydraulic oil supply port of the hydrostatic continuously variable transmission.

According to a second aspect of the present invention, a hydraulic pump provided in the hydraulic lifting device is mounted on a housing of the hydrostatic stepless transmission and driven by an input shaft thereof.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment in which the present invention is applied to a small riding rice transplanter will be described. FIG. 1 is an overall side view of a riding rice transplanter equipped with the hydraulic device of the present invention, FIG. 2 is a plan view of a transmission, FIG. 3 is a side view of one half of a case removed, and FIG. 5 and FIG. 5 are plan exploded cross-sectional views of the front part of the transmission case, FIG. 6 is a cross-sectional plan view of the first transmission, FIG. 7 is a rear cross-sectional view of one front axle case, and FIG. FIG. 9 is a side sectional view of the front part of the transmission case, and FIG. 10 is a hydraulic circuit diagram of the present invention.

First, the overall structure of a riding rice transplanter will be described with reference to FIG. The rice transplanter comprises a front running section 1 and a planting section 2 arranged at the rear. The running section 1 has an engine 9 mounted on a front portion of a body frame 10, and the engine 9 is covered by a bonnet 3. A steering handle 4 is arranged above a handle post 5 arranged on the rear upper surface of the hood 3.
The body frame 1 is covered with a body cover 6, and a seat 7 is
The steps 8 on both sides of the vehicle body cover 6 and the hood 3 and the front part of the seat 7 are integrally formed of synthetic resin.

The transmission case 11 of the present invention is constructed such that the lower part of the body frame
It extends to the lower rear, and is arranged at the front high and rear low in a side view, and is formed long in the front-rear direction. A front axle case 12 is provided on the front left and right sides of the transmission case 11.
The front wheel 13 is supported via the transmission case 1
The rear axle 99 protrudes from the rear part of the rear wheel
I support.

The planting section 2 is mounted on the rear of the traveling section 1 via a hydraulic lifting device 17 so as to be able to ascend and descend to the ground. A supporting frame connected between the rear of the body frame 10 and the rear of the transmission case 11 is provided. 16 is a hydraulic lifting device 17
Is supported, and a hydraulic cylinder 19 is interposed between the front part of the hydraulic lifting device 17 and the body frame 10, and the planting section 2 can be raised and lowered by expanding and contracting the hydraulic cylinder 19.

The planting section 2 attached to the rear of the hydraulic lifting device 17 is mounted on a planting case 20 as usual.
1 is arranged so as to be able to reciprocate left and right, a float 22 is suspended below, a transmission case 23 projects from the rear, and a planting claw 24 is attached to the transmission case 23 via a crank mechanism.

Power is transmitted to the planting case 20 via a universal joint, a transmission shaft, or the like to a PTO shaft 25 projecting rearward from above the front of the transmission case 11, so that the seedling mounting table 21 and the planting claws are transmitted. The seedlings 24 are taken out from the seedling mounting table 21 by the planting claws 24 while driving and driving the seedling 24, and the seedlings are continuously planted during the running.

Next, the structure of the transmission of the present invention will be described with reference to FIGS. The transmission case 11 for accommodating the transmission includes left and right halved case halves 11L and 11R that can be separated from each other.
A driving shaft 34, a transmission input shaft 35, and a final shaft 60 are horizontally laid on a front portion in the transmission case 11 in parallel.
The driving shaft 34 penetrates from the left side surface of the transmission case 11 and protrudes outward, and an input pulley 30 is fixed on an end thereof. Power is input from the engine 9 to the input pulley 30 via a belt 33. A first transmission 31 serving as a main transmission is attached to a front portion of a right side surface of the transmission case 11. The first transmission 31 is provided on an end surface of the driving shaft 34 exposed on a left side surface of the transmission case 11 with an input shaft. 26, and the transmission input shaft 3 similarly exposed on the left side surface of the transmission case 11.
Output shafts 27 are connected to end surfaces of the transmission gears 5, and are horizontally laid in the transmission case 36 in parallel with each other along the machine body left-right direction.

As shown in FIGS. 5 and 6, the first transmission 31 is a hydrostatic continuously variable transmission comprising a variable displacement hydraulic pump 40 and a fixed displacement hydraulic motor 41.
It is housed in a space defined by the transmission case 36 and the center section 37, and a pump mounting surface and a motor mounting surface are formed on the inner side surface of the center section 37. The center section 37 opposite to the pump mounting surface and the motor mounting surface is a right case half 1 of the transmission case 11.
It is fixed to the front outer surface of 1R.

The center section 37 and the transmission case 3
The rotation axis of the cylinder block 42 is locked on the input shaft 26 rotatably supported by the rotation shaft 6 so as to be relatively non-rotatable, and is rotatably slidable on the pump mounting surface. The pistons 43 are reciprocally fitted into the plurality of cylinder holes of the cylinder block 42 via biasing springs.
The input shaft 26 penetrates through the central opening of the movable swash plate 44 while being in contact with the thrust bearing 44a. Thus, the axial piston type hydraulic pump 40 is configured.

The amount and direction of oil discharged from the hydraulic pump 40 can be changed by tilting the piston contact surface of the movable swash plate 44 with respect to the rotation axis of the cylinder block 42. The swash plate 44 is connected to the right and left trunnion shafts 39 as usual, and the movable swash plate 44 can be tilted by rotating a shift arm (not shown) fixed to one of the trunnion shafts 39 extending outside the case. I have to.

The rotation axis of the cylinder block 52 is locked on the output shaft 27, which is rotatably mounted between the center section 37 and the transmission case 36, so as to be relatively non-rotatable. Are arranged so as to be rotatable and slidable. Are reciprocally fitted into the plurality of cylinder holes of the cylinder block 52 via urging springs, and the heads of the pistons 53 are fixed swash plates 54. , And the output shaft 27 passes through the central opening of the fixed swash plate 54. Thus, the axial piston type hydraulic motor 41 is configured.

The suction section and the discharge section of the hydraulic pump 40 and the hydraulic motor 41 are fluidly connected to each other by an oil passage provided in a center section 37 (not shown) to form a closed circuit. Input shaft 26
Is rotated to drive the hydraulic pump 40. At this time, the movable swash plate 44 is tilted to send pressure oil to the hydraulic motor 41, thereby driving the output shaft 27 and the transmission input shaft 35 to rotate steplessly. The rotation direction and the number of rotations are
Can be changed by the tilting operation of. Thus, the hydrostatic continuously variable transmission is configured.

Further, as shown in FIG.
Extends through the right side surface of the transmission case 36 and extends into the valve case 45 to drive a hydraulic pump 46 disposed in the valve case 45. The valve case 45 further includes an elevating switching valve 47, Relief valve 48, variable throttle 4
9, a check valve 50 and the like are provided. However, the transmission case 36 and the valve case 45 can be formed of a single housing, and the hydraulic pump 46 can be provided inside the transmission case 36.

Next, with reference to FIGS. 4, 5 and 7, a power transmission configuration of the front wheels in the traveling power transmission system in the transmission case 11 will be described. Left case half 1 opposite to right case half 11R in which first transmission 31 is installed.
A bulging portion 11a bulging leftward (in the axial direction of the transmission shaft 34 and the transmission input shaft 35) is formed at the front of the 1L.
The second transmission 32 is accommodated in the bulging portion 11a. That is, the large-diameter gear 6 is mounted on the transmission input shaft 35.
7 and a wide small-diameter gear 68 are fixedly mounted, and a final shaft 60 is provided below and parallel to the transmission input shaft 35.
Is mounted horizontally in the transmission case 11, and on the final shaft 60, two transmission gears 63 meshable with the gears 67 and 68 are spline-fitted slidably in the axial direction. An output gear 66 is fixed.

The transmission gear 63 slides in the axial direction on the final shaft 60 by operating a sub-transmission lever provided on the side of the seat 7, and meshes with one of the large-diameter gear 67 and the small-diameter gear 68. As a result, the final shaft 60 can be provided with two stages of high-low gear rotation. And the output gear 66
Is a differential gear device 6 disposed in front of the final shaft 60.
The front differential gear device 69 differentially connects the left and right front wheel drive shafts 71L and 71R. 72 is a differential lock device.

As shown in FIG. 7, a front axle case 12 is mounted on the outer surface of the left and right case halves 11L and 11R to accommodate the front wheel drive shafts 71L and 71R.
A bevel gear 73 is supported in the L.12R, and is connected to the end of the front wheel drive shafts 71L, 71R. Further, a kingpin shaft 75 is supported and protrudes downward in the front axle cases 12L and 12R so as to extend substantially vertically, and a lower portion of the kingpin shaft 75 extends into a rotating case 76 and is rotatable. A bevel gear 74 is fixed to the upper end of the king pin shaft 75,
A bevel gear 77 is fixedly provided at the lower end of the king pin shaft 75, and is meshed with a bevel gear 78 fixedly attached to the front axles 79L and 79R horizontally laid below the rotating case 76. The front wheel 13 is attached to the outer end of the front axle 79L / 79R.
13 is fixed.

FIG. 2 shows the upper surface of the rotating case 76.
As shown in FIG. 7, a knuckle arm 59 is fixedly connected to the steering handle 4 via a tie rod (not shown), and the front wheels 13 are moved right and left by the rotation of the steering handle 4. Steering is enabled.

Next, the power transmission configuration of the work transmission system will be described. Between the transmission gear 63 and the sprocket 65 on the final shaft 60, there are provided two PTO transmission gears 64a and 64
4b is loosely fitted so as not to move in the axial direction. As shown in FIGS. 5 and 9, a first counter shaft 61 and a second counter 62 are rotatably supported on the left inner surface of the left case half 11L on the rear portion of the bulging portion 11a. A gear 81 is externally fitted on the first counter shaft 61 via a one-way clutch 80, and the gear 81
The gear is always meshed with the PTO transmission gear 64a fixed on the upper side. The PTO transmission gear 64b is connected to the transmission input shaft 3
5 always meshes with the small diameter gear 68. The one-way clutch 80 causes the gear 81 to rotate the first counter shaft 6 only when the transmission input shaft 35 rotates in the machine forward direction.
1 to transmit the power of the transmission input shaft 35 to the first counter shaft 61, that is, to the planting portion 2 side. The first counter shaft 61 projects outward from the left side surface of the left case half 11L, and
2 is removably fixed, and the gear 82 meshes with a gear 83 removably fixed on a second counter shaft 62 protruding outward from the left side surface of the left case half 11L. 83 is covered by a cover detachably attached to the left side surface of the left case half 11L. The bevel gear 8 is provided in the transmission case 11 of the second counter shaft 62.
4 is fixedly engaged with a bevel gear 85 fixed on the PTO clutch shaft 86.

The PTO clutch shaft 86 is laid in the front-rear direction at the mating surface of the left and right case halves 11L and 11R, and is coaxially arranged at the rear end of the PTO clutch shaft 86 on the same axis.
The O-axis 25 is rotatably arranged. A PTO clutch 90 and a torque limiter 91 are arranged between the PTO clutch shaft 86 and the PTO shaft 25. The PTO clutch 90 has a clutch claw 92 fixed to a front portion on a PTO clutch shaft 86, and a hollow shaft 93 is rotatably fitted to a rear portion thereof,
A sliding claw 94 is spline-fitted on the hollow shaft 93 so as to be slidable in the axial direction, and is disposed so as to be disengageable from the clutch claw 92. The sliding claw 94 is slid by rotating a PTO operation shaft 95 pivotally supported on the right side surface of the right case half 11R. The PTO operation shaft 95 is connected to the side of the seat 7 via a link or a wire. Of the clutch claw 9 by connecting the planting operation lever to the "in" position.
2 and the sliding claws 94 can be engaged to drive the planting portion 2.

The rear portion of the hollow shaft 93 and the PTO shaft 25
A claw clutch type torque limiter 91 is disposed between the torque limiter 91 and the power is transmitted to the PTO shaft 25 via the torque limiter 91. When an overload is applied to the planting portion 2 side, the PTO shaft 25 is driven by the torque limiter 91. It is configured to run idle to prevent damage to the transmission components of the work transmission system. 91
a is a spring that defines a set torque. The PT
The O-shaft 25 protrudes rearward from the bulging portion 11a at the front upper portion of the transmission case 11, and is configured to transmit power to the planting portion 2 via a universal joint or a transmission shaft.

Next, the power transmission configuration of the rear wheels will be described. As shown in FIG. 8, the rear portion of the transmission case 11 has a side clutch shaft 97, a reduction shaft 98, and a rear axle 99L.
99R is rotatably supported in parallel, and a sprocket 100 is fixedly mounted at the left and right center of the side clutch shaft 97, and the sprocket 100 and the final shaft 60 are fixed.
Chain 1 between output sprocket 65 fixed above
01 is wound, and the power of the final shaft 60 is
To be communicated to Reference numerals 100b and 100b denote chain tensions provided at an upper portion and a lower portion of the chain 101.

Side gears 102L and 102R are fitted on both sides of the sprocket 100 on the side clutch shaft 97 so as to be rotatable and slidable in the axial direction.
Side clutches 111L and 111R are configured to be disengageable from the internal teeth 100a and 100a provided on both sides of 00. Further, friction plates are respectively locked and superimposed on the side gears 102L and 102R and the left and right case halves 11L and 11R, and a flange-shaped pressing body is formed on an outer peripheral portion of the side gears 102L and 102R. Brake 10
3L and 103R are configured. The side gears 102L and 102R are connected to a side clutch arm 104.
The side clutch arm 104L / 104R is slid by rotating the L / 104R, and the side clutch arm 104L / 104R is provided on a step of an operating unit via a link or the like to an arm 106L / 106R (FIG. 2) provided outside the transmission case 11. Each of the left and right side brake pedals is interlocked and linked, and by depressing one of the side brake pedals, the side gear 102
, The side clutch 111L or 111R is disengaged to cut off the driving force of the rear inner wheel so that the vehicle can make a gentle turn, and the side brakes 103L and 103R can be braked to make a sharp turn.

The side gears 102L and 102R
Are two reduction gears 105 installed on a reduction shaft 98.
L · 105R and the reduction gear 105
The small-diameter gear L / 105R meshes with gears 107L / 107R fixed on the inner ends of the rear axles 99L / 99R, and the rear wheels 15/15 are mounted on the outer ends of the rear axles 99L / 99R. . Since the rear wheels 15 are mounted on the rear axles 99L and 99R protruding from both sides of the rear portion of the transmission case 11, a rear axle case for accommodating the reduction gear is not required, and a compact configuration can be achieved.
Thus, the first transmission 31 and the second transmission 3
After the gears are shifted by the second gear, the output sprocket 65, the chain 101, the sprocket 100, the side clutch devices 111L and 111R, and the side brakes 103L and 10L
The differential rotation is transmitted to the rear axle 99 via 3R, and the rear wheel 15 is driven.

Next, the hydraulic circuit configuration of the present invention will be described with reference to FIG. As described above, the hydraulic pump 46
The power from the engine 9 is the belt 33 and the input pulley 3
0, driven by being transmitted to the input shaft 26 via the transmission shaft 34. A pipe 5 is connected to the suction port of the hydraulic pump 46.
5 is connected so that lubricating oil and hydraulic oil can be sucked in through an oil filter F arranged at the front bottom in the transmission case 11. A lift port 47, a load check valve 50, and a relief valve 48 are connected in parallel to the discharge port of the hydraulic pump 46.
A hydraulic port 19 for raising and lowering the planting section 2 is communicated to the secondary port A through a variable throttle 49 and a pipe 57, and the secondary side of the check valve 50 bypasses the variable throttle 49. And is connected to the hydraulic cylinder 19 via a pipe 57.

The B port on the secondary side of the lift switching valve 47 is communicated with the secondary side of the relief valve 48 together with the tank port T on the primary side. It is in communication with the hydraulic oil supply port C of the closed circuit of the hydraulic continuously variable transmission. 28 ・ 28
Is a check valve that allows only oil to pass from the hydraulic oil supply port C in the direction of the closed circuit. The oil pressure in this closed circuit is set to a constant pressure by a relief valve 58.

The up / down switching valve 47 is a 5-position switching valve, which can be switched by operating an up / down lever arranged on the side of the seat 7. In the position (a), the tank port and the B port are connected to the piping 56. Hydraulic pump 4
6 is drained from the tank port T to the pipe 56, and the return oil from the hydraulic cylinder 19 is a variable throttle 49,
Port A, up / down switching valve 47, port B to piping 56
The drain oil that merges with the drain oil is introduced into the hydraulic oil supply port C of the closed circuit. At this time, the hydraulic cylinder 19 contracts, and the planting section 2 descends rapidly.

The position (b) is a transient position for restricting the drain oil amount of the hydraulic cylinder 19 and lowering the planting section 2 slowly, and the position (c) blocks the A port and the B port. This is a neutral position where the load check valve 50 is closed to stop the planting section 2 at an arbitrary height, and the discharge oil of the hydraulic pump 46 is unloaded through the tank port T. The position (d) is a transient position where the amount of drain oil of the hydraulic pump 46 is limited and the planting section 2 is slowly lifted, and the position (e) is a position where the drain of the hydraulic pump 46 and the hydraulic cylinder 19 is blocked and loaded. Check valve 50
Is opened to feed the oil to the hydraulic cylinder 19 via the pipe 57 to raise the planting section 2. In this way, by switching the elevation switching valve 47 from the arbitrary position (a) to the position (e), the hydraulic cylinder 19 can be expanded and contracted to move the planting section 2 up and down.

[0033]

As described above, the present invention has the following advantages. That is, as set forth in claim 1, a rice planting plant in which a hydrostatic stepless transmission is interposed in a traveling transmission system for transmitting engine power to an axle, and a planting portion is connected to the body via a hydraulic lifting device. On the machine,
Since the return oil of the hydraulic lifting device is introduced into the hydraulic oil supply port of the hydrostatic continuously variable transmission, the return oil of the hydraulic lifting device can be used as the hydraulic oil of the hydrostatic continuously variable transmission. This makes it possible to reduce the number of pumps and reduce costs as compared with a configuration in which a dedicated hydraulic oil replenishing hydraulic pump is provided and driven in a conventional hydrostatic continuously variable transmission and driven.

Further, the hydraulic pump provided in the hydraulic lifting device is mounted on the housing of the hydrostatic stepless transmission and driven by the input shaft thereof, so that the hydraulic pump is driven by the engine. Rather than being located near, both are located closer and the hydraulic piping can be shortened,
The number of parts is also reduced, and the cost can be reduced.
In addition, since the hydraulic pump is driven by the shift input shaft of the hydrostatic continuously variable transmission, the drive system can be simplified and power loss can be reduced. Then, the hydraulic system can be centrally arranged, the piping path is shortened, and maintenance is facilitated.

[Brief description of the drawings]

FIG. 1 is an overall side view of a riding rice transplanter equipped with a hydraulic device of the present invention.

FIG. 2 is a plan view of a transmission.

FIG. 3 is a side view in which a case half on one side is removed.

FIG. 4 is a sectional plan view of the transmission case.

FIG. 5 is a sectional plan view of a front portion of a transmission case.

FIG. 6 is a plan sectional view of the first transmission.

FIG. 7 is a rear cross-sectional view of one front axle case.

FIG. 8 is a developed cross-sectional view of the rear part of the transmission case.

FIG. 9 is a side sectional view of a front portion of a transmission case.

FIG. 10 is a hydraulic circuit diagram of the present invention.

[Description of Signs] 2 Planting Unit 9 Engine 11 Transmission Case 19 Hydraulic Cylinder 31 Hydrostatic Continuously Variable Transmission 26 Input Shaft 46 Hydraulic Pump

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shinya Sakakura 2-181-1, Inadera, Amagasaki-shi, Hyogo

Claims (2)

[Claims] 1. A rice transplanter in which a hydrostatic stepless transmission is interposed in a traveling transmission system that transmits engine power to an axle, and a planting portion is connected to an airframe through a hydraulic lifting device. A hydraulic device for a rice transplanter, wherein return oil from an elevating device is introduced into a hydraulic oil supply port of the hydrostatic continuously variable transmission. 2. The hydraulic pressure of a rice transplanter according to claim 1, wherein the hydraulic pump provided in the hydraulic lifting device according to claim 1 is mounted on a housing of the hydrostatic stepless transmission and driven by an input shaft thereof. apparatus.