JP3583590B2 - Tractor hydraulic lifting device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a tractor hydraulic lifting device.
[0002]
[Prior art]
A tractor equipped with a hydraulic lifting device for a working machine having a lift arm on a rear upper surface of a tractor body is known, and is equipped with a working machine such as a rotary cultivator via a working machine coupling device such as a three-point link. Used to carry out paddy work. In this type of tractor, for example, there is a tractor equipped with a front loader.However, conventionally, a hydraulic take-out port for the front loader is provided in a transmission case of the tractor body, and hydraulic oil is supplied from the transmission case to the front loader. I was
[0003]
[Problems to be solved by the invention]
However, the tractor's hydraulic elevating device requires various hydraulic controls such as draft control and horizontal control in addition to position control. Therefore, various valve devices (valve units) are installed. By providing a hydraulic take-out port and other hydraulic ports for the loader, the hydraulic ports are concentrated here, and the hydraulic circuit is centrally arranged to enable efficient supply (including discharge) of hydraulic pressure (oil from the pump) I needed to.
[0004]
In addition, in the case where the hydraulic take-out port for the front loader is provided in the transmission case of the tractor body, it is necessary to provide a window for forming the hydraulic take-out port for the front loader in the transmission case of the tractor body. Due to the windows formed, the rigidity of the transmission case, which is most likely to be added during the loader operation, is reduced, and the transmission case may not be able to withstand the addition during the loader operation.
SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a hydraulic lift port for a tractor with a hydraulic take-out port for a front loader and other hydraulic ports. ) Can be supplied (including discharge), and a hydraulic take-out port for the front loader is not provided in the transmission case of the tractor body, eliminating the need to increase the rigidity of the transmission case that is most frequently added during loader work. It is like that.
[0005]
[Means for Solving the Problems]
A first technical means of the present invention for solving this technical problem is that a tractor 2 in which a hydraulic lifting device 10 having a lift arm 9 is mounted on a rear upper surface of a tractor vehicle body 5 includes:
A hydraulic housing 33 constituting the hydraulic lifting device 10 is provided with a hydraulic load port 48 for a front loader and a drain port 50 for a front loader.
[0006]
A second technical means of the present invention is a tractor 2 in which a hydraulic lifting device 10 having a lift arm 9 is mounted on a rear upper surface of a tractor vehicle body 5.
The point is that a hydraulic pressure take-out port 58 for an assist cylinder is provided in the hydraulic housing 33 constituting the hydraulic elevating device 10.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a tractor 2 of a two-shaft, four-wheel type equipped with a hydraulic lifting device 10 according to the present invention. Reference numeral 2 includes left and right front wheels 3 and left and right rear wheels 4. The front wheels 3 are steerable wheels and can be driven. Here, a four-wheel drive tractor is used. Two-wheel drive (rear-wheel drive) is also possible by connecting and disconnecting.
[0008]
The tractor body 5 is constructed by connecting a transmission case 7 to a rear portion of a mounted engine via a crack housing. An engine and engine accessories such as a radiator provided in front of the engine are equipped with a hood that can open and close a top plate. 8 covered.
A hydraulic lifting device 10 having left and right lift arms 9 is mounted on the rear upper surface of the tractor body 5. In FIG. 1, a rotary work machine 12 is detachably mounted so as to be liftable and controllable by a three-point link 11.
[0009]
The left and right rear wheels 4 are covered by rear wheel fenders 13 erected on the inside thereof, and a driver's seat 14 is disposed between the left and right rear wheel fenders 13. A driving control device 16 is constituted by the control handle 15 provided, and the driving control device 16 is an independently mounted (including a detachably mounted cabin on the vehicle body 5) cabin including right and left rear wheel fenders 13. It is surrounded by 17.
The cabin 17 includes a pair of left and right front struts 18, a pair of left and right rear struts 19, and an intermediate strut 20 rising from a rear wheel fender 13 between the front and rear struts 18 and 19 and approaching the rear strut 19. And a ceiling 21 having an air conditioner (cooling, heating, cooling / heating, ventilation, etc.), and a box-shaped bottom plate (floor sheet) 22 of the cabin 17. It is one step higher than the front part 22B.
[0010]
Further, the cabin 17 includes a door 23 that can be opened and closed and fixed using a pivot bracket 20A provided on the intermediate support 20 as a fulcrum. It is mounted on the tractor body 5 by vibration-proof support means such as vibration-proof rubber provided in the vehicle.
The rear support 19 of the cabin 17 is formed in an inverted shape via an intermediate bending connection 19A, and the bending connection 19A is in the vicinity of a vertical plane that crosses the rotation fulcrum (arm axis) of the lift arm 9. , The entire cabin 17 is mounted relatively frontward (about 5 cm in comparison with the related art), and the center of gravity of the entire tractor 2 is shifted forward, so that the rotary working machine 12 The weight balance between front and rear is good even if the tractor can be moved up and down freely. As a result, the entire tractor is reduced in weight and can be adapted to paddy field work.
[0011]
The front loader 101 is mounted on the tractor 2. The front loader 101 is provided with a pair of left and right booms 112 having a work implement 111 exemplified by a bucket so as to be able to move up and down on the tractor body 5 via a mast device 113, and a fluid cylinder 115 for the work implement 111 and the boom 112 , 116, and a control operation means 121 for controlling the fluid cylinders 115, 116 is provided on one (right side) of the left and right mast devices 113 so as to be operable from the driver's seat 14.
The left and right mast devices 113 are provided with a base 126 protruding outward from the tractor vehicle body 5 in a horizontally projecting shape, and on the upper surface of the base 126, a U-shaped holder receiver 127 having a front open and a plan view is provided. And a holder 128 is detachably provided on the holder receiving member 127.
[0012]
Referring to FIG. 2, left and right rear supports 19 of the cabin 17 are mounted on a tractor vehicle body 5 by a bracket 27 and vibration-proof support means 28 on a hat-shaped support base 26 bolted to a rear axle case 25. The left and right lower bodies 29 fixed to the lower ends of the rear supports 19 extend forward and are connected to the left and right front supports 18.
That is, in the related art, the rear bottom surface 29A of the left and right lower bodies 29 is mounted on the hat-shaped support 26 via the anti-vibration support means 28, whereas in the embodiment of the present invention, the lower part of the rear support 19 is It is positioned on the front side of the rear axle case 25 in the vertical direction and mounted on the tractor body 5 via a bracket 27 fixed to the column 19 and an anti-vibration support means 28, where the cabin 17 is about 5 cm ahead of the conventional one. Because the lower part of the rear strut 19 is inclined rearward upward, the living space is secured even if the cabin 17 is located at a more forward position than before, and the cabin 17 is mounted at a more forward position than before. The lifting space 30 for maintenance of the hydraulic lifting device 10 which is detachably mounted and fixed on the upper surface of the tractor body 5 is secured.
[0013]
The head portion 10A of the hydraulic lifting device 10 is covered from above by a mounting portion 22A of the floor seat 22, and a driver's seat 14 is mounted on the mounting portion 22A via a seat support 31. The seat 14 is detachably mounted on the mounting portion 22A together with the seat support 31, and the hydraulic lifting device 10 is fixed to the tractor vehicle body 5 from above through an opening window formed in the mounting portion 22A in a state where the seats 14 and 31 are removed. The up and down bolts can be tightened and loosened, and the hydraulic lifting device 10 is lifted up from the tractor body 5 in the space 30 and pulled out rearward, so that the hydraulic lifting device 10 can be maintained.
[0014]
A hydraulic pump device 32 driven by an engine is provided on the transmission case 7 in front of the hydraulic elevating device 10, and the hydraulic pump device 32 is covered by the mounting portion 22A and formed on the portion 22A. The maintenance can be performed together with the head unit 10A through the opened window.
The hydraulic pump device 32 is driven via a PTO propulsion shaft directly connected to the output shaft of the engine via a gear or the like (not shown). The hydraulic pump device 32 is usually (conventionally) provided on a side surface of the engine. Since the transmission case is provided on the upper surface of the transmission case 7, the transmission case 7 itself also serves as the hydraulic oil tank, so that the piping member can be omitted or shortened. The limitation on the steering angle has been eliminated.
[0015]
In addition, the floor seat 22 has the mounting portion 22A formed of a thin plate and the front portion 22B formed of a thick plate, which also shifts the vehicle center of gravity forward. The strength is secured by the stay for the sheet support 31 fixed to the peripheral edge of the opening window.
Referring to FIGS. 3 to 5, there is shown an embodiment in which a hydraulic lifting device 10 having left and right lift arms 9 according to the present invention is mounted, and a hydraulic housing (hydraulic cylinder body) 33 constituting the hydraulic lifting device 10 is provided. An oil passage 34 for taking out the external hydraulic pressure is formed, and a valve 35 for the external hydraulic take-out device 1 connected (communicated) to the oil passage 34 is connected between the left and right lift arms 9 above the hydraulic housing 33. It is provided in.
[0016]
More specifically, the hydraulic housing 33 is made of a casting, has a mounting portion 36A for the transmission case 7 formed in the pedestal portion 36, and lift arms on the rear left and right walls of the main body portion 37 formed in the pedestal portion 36. Left and right bosses 39 for rotatably supporting an arm shaft 38 for the cylinder 9 are provided, and a cylinder tube 40 is provided in the front inside of the main body 37 so as to be inclined upward and forward. Is slidably fitted, the opening end of the tube 40 is closed by the head lid 41, and the pedestal portion 36 with the hydraulic housing 33 covering the upper opening of the transmission case 7 is moved up and down. It is mounted detachably with bolts.
[0017]
An inlet (main) port 42 for hydraulic oil from the hydraulic pump device 32 is formed on a side wall (the right side wall in the figure) of the hydraulic housing 33, and the port 42 has a substantially threaded pipe configuration. A steel pipe can be detachably connected to the port 42 from the lateral direction in the left-right direction.
A draft control valve device 43 and a horizontal control valve device 44 are mounted on the hydraulic housing 33 so as to be divided into left and right. An oil passage 45, a priority valve 46, a relief valve 47, and the like for the valve devices 43 and 44 are provided. When the front loader 101 is mounted on the tractor 2, a hydraulic take-out port 48, a neutral port 49, a drain port 50, and the like for the loader 101 are provided.
[0018]
The draft control valve device 43 is an electromagnetic pilot valve in which an ascending and descending solenoid valve and a pilot switching valve are integrated, and transmits signals from the draft sensor 51 and the lift arm sensor 52 to the control box 53 as shown in FIG. Draft control is automatically enabled by a control signal from the control box 53.
The horizontal control valve device 44 transmits the signal of the rolling sensor 54 provided in the tractor body 5 shown in FIG. 6 to the control box 53, and transmits the signal of the lift cylinder (lift rod) 55 at the three-point link 11 from the stroke sensor 56. And so on.
[0019]
In FIG. 6, the control box 53 can be set and switched freely from a switch box 57 such as draft / horizontal control switching, draft control, and position control. Of course, the draft / position control can also be manually operated as described later. For this reason, a mounting hole for manual operation is opened on the right side of the hydraulic cylinder main body 33, and this opening is covered by a removable cover when automatic control is performed.
The lift arm 9 is provided with a mounting hole 9A for a telescopic hydraulic cylinder (assist cylinder) for lifting force (assisting hydraulic pressure enhancement), and a plurality of hydraulic take-out ports 58 for the assist cylinder are provided in the cylinder head 41. The head 41 has a drop adjusting valve 59 incorporated therein.
[0020]
The valve 35 for taking out the external hydraulic pressure is configured by including a switching spool 62 in a valve case 61, and the spool 62 can be switched by the operating force of a push-pull cable 64 via a swing arm 63. The take-out section (including the hydraulic take-out and return) 35A is constituted by a quick coupler that makes the hydraulic take-out hose detachable substantially.
The valve 35 (including the valve case and the spool, the same applies hereinafter) for taking out the external hydraulic pressure can be directly mounted on the upper surface of the hydraulic housing 33 in communication with the oil passage 34, but in the illustrated example, the oil passage 34 It is removably mounted on the upper part of the hydraulic housing 33 with a spacer 60 having a communicating oil passage 60A interposed therebetween.
[0021]
One of the valves 35 may be mounted, but in the illustrated example, a plurality of the valves 35 are vertically stacked via an intermediate spacer 65 and a head spacer 66 and are detachably mounted by bolts 67. 35A is extended rearward on the horizontal plane to facilitate the attachment and detachment of the hydraulic outlet hose.
Since the oil passage 34 for the valve 35 for taking out the hydraulic pressure is formed in the hydraulic housing 33, no exposed piping is required outside, and when the spacer 60 and the intermediate spacer (there is also an oil passage) 65 are stacked. Oil leakage can be reliably prevented by ensuring the positioning and sealing of the overlapped surface, and since it is provided between the left and right lift arms 9, the lifting and lowering operation of the lift arm 9 is not hindered together with the hydraulic extraction hose. It does not.
[0022]
The hydraulic housing 33 is equipped with a top link mount device 69 having a torsion bar (a load sensing member, which is a draft sensor) 68 on an upright surface, and a hydraulic oil supply plug A for the transmission case 7 and the like. 4 and 5, the valve 35 is mounted on one side in the left and right direction, as shown in FIG. 4, and is eccentrically mounted on the left side in the figure, whereby when the three-point link 11 is moved up and down, the valve 35 is connected to the valve 35. The interference is reduced, and as a result, the lift angle of the three-point link 11 (lift arm 9) is sufficiently ensured.
[0023]
Referring to FIGS. 7 to 13, the details of a spacer 60 having a communication passage 60A are illustrated. The spacer 60 has a plurality of bolt insertion holes 60C in a seat portion 60B for the hydraulic housing 33, and the seat portion 60B The hydraulic housing 33 is mounted on the tractor body 5 because the drain port 50 is formed on the tractor body 5 because the drain port 50 is formed on the upper surface of the hydraulic housing 33 by a vertical bolt inserted into the bolt insertion hole 60C. Thus, the valve 35 is made detachable via the spacer 60.
[0024]
Further, a mounting seat 60D for the valve 35 is formed in the spacer 60 so as to bulge, and the valve 35 can be detachably mounted on the mounting seat 60D by the bolt 67 via the intermediate spacer 65 and the head spacer 66. With the spacer 60 mounted on the hydraulic housing 33, the valve (valve unit) 35 is detachable, thereby making maintenance easier.
Referring to FIG. 14, the arm shaft 38 is inserted through a cylindrical boss that penetrates the hydraulic housing 33 as the left and right direction, and is rotatable via left and right cylindrical bushes 70 interposed between the cylindrical boss. Supported.
[0025]
The cylindrical bush 70 is liable to be lubricated without increasing the diameter of the arm 38 (without increasing the size of the hydraulic housing 33) due to severe seizure due to minute vibration. In this embodiment, the draft control valve is used. Since the device 43 and the horizontal control valve device 44 are disposed on the left and right side walls of the hydraulic housing 33 so as to be distributed left and right, the piping member 71 is loosely connected to the return oil port (tank port) of the draft control valve device 43. A part of the return oil is sent to the right bush 70 via the pipe member 71 to lubricate the bush 70 semi-forcedly, while the return oil port (tank port) of the horizontal control valve device 44 is connected to the pipe member. 72, the return oil is supplied to the left bush 70 via the pipe member 72 to partially lubricate the bush 70 to prevent seizure of the bush 70. 1 As shown in the figure, an O-ring 73 and a collar 74 are provided on the outside of the bush 70 to prevent the return oil from leaking outside, and the remaining oil forming an oil film on the left and right bushes 70 is transferred to the transmission case. It is refluxed.
[0026]
When a draft control valve that is mechanically operated (manually operated) is provided on the right side of the pipe member 71 instead of the draft control valve device (auto draft), the tank port of the draft control valve is provided. Is loosely connected.
Here, since the piping members 71 and 72 are loosely connected to the tank port, a part of the return oil returns into the transmission case through the loose insertion connection portion, and the remaining return oil passes through the piping members 71 and 72. The left and right bushings 70 are semi-forced lubricated, and as described above, a draft control valve (including an automatic or mechanical) and a horizontal control valve are separately provided on the left and right sides of the hydraulic housing, and the tank of each valve is provided. By interposing the piping members 71 and 72 in the ports, the seizure of the bush 70 is prevented. The piping members 71 and 72 may be disposed in the front-rear direction while being covered by the hydraulic housing 33. This also makes the piping easier.
[0027]
The piping members 71 and 72 may be formed in the hydraulic housing 33 in a hole shape. In the hydraulic housing 33, an oil passage 34 for taking out an external hydraulic pressure, an oil passage 45 for the valve devices 43 and 44, and the like are provided. By forming the hydraulic housing 33, the hydraulic housing 33 has a large capacity but can be reduced in weight and is significant as the hydraulic lifting device 10 in the paddy field tractor.
[0028]
【The invention's effect】
As described in detail above, according to the present invention, the hydraulic lift port of the tractor is provided with a hydraulic take-out port for the front loader and other hydraulic ports. Oil) can be supplied (including discharge). Further, it is not necessary to provide a hydraulic take-out port for the front loader in the transmission case of the tractor body, so that the rigidity of the transmission case, which is most frequently added during loader work, can be increased.
[Brief description of the drawings]
FIG. 1 is a side view of a tractor provided with a hydraulic lifting device according to the present invention.
FIG. 2 is an elevational view of the rear part of the tractor.
FIG. 3 is a side view of a hydraulic lifting device having an external hydraulic take-out device according to the present invention.
FIG. 4 is a plan view of FIG. 3;
FIG. 5 is a rear view of a main part of FIG. 3;
FIG. 6 is a configuration diagram of a hydraulic circuit.
FIG. 7 is a plan view of a spacer.
FIG. 8 is a front view of a spacer.
FIG. 9 is a side view of the spacer.
FIG. 10 is a sectional view taken along line AA of FIG. 7;
FIG. 11 is a sectional view taken along the line BB of FIG. 7;
FIG. 12 is a sectional view taken along line DD of FIG. 7;
FIG. 13 is a sectional view taken along line EE of FIG. 7;
FIG. 14 is a sectional view of a hydraulic elevating control device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 External hydraulic take-out device 2 Tractor 5 Tractor body 9 Lift arm 10 Hydraulic elevating device 33 Hydraulic housing 48 Hydraulic take-out port 50 for front loader Drain port 58 for front loader 58 Hydraulic take-out port for assist cylinder

Claims (3)

In a tractor having a hydraulic lifting device (10) having a lift arm (9) and a cabin (17) mounted on a rear upper surface of a tractor body (5),
The rear strut (19) of the cabin (17) is positioned such that its middle in the vertical direction is located above the pivot point of the shift arm (9) and its lower part is located forward of the rear axle case (25). A hydraulic take-out port (48) for a front loader and a valve (48) for taking out an external hydraulic pressure are provided on the rear upper surface side of a hydraulic housing (33) which is arranged to be inclined in the forward and downward direction and constitutes a hydraulic elevating device (10). And a main port (42) serving as an inlet for hydraulic oil is connected to a pipe from a lateral direction on a side of the hydraulic housing (33) on the side of the hydraulic pressure take-out port (48). Is provided as
A spacer (60) is mounted on the hydraulic housing (33), and a mounting seat (60D) protruding upward is provided at a rear portion of the spacer (60), and a valve (60D) for extracting an external hydraulic pressure is provided on the mounting seat (60D). 35) A hydraulic lift device for a tractor, comprising: In a tractor having a hydraulic lifting device (10) having a lift arm (9) and a cabin (17) mounted on a rear upper surface of a tractor body (5),
The rear strut (19) of the cabin (17) is positioned such that its middle in the vertical direction is located above the pivot point of the shift arm (9) and its lower part is located forward of the rear axle case (25). A hydraulic take-out port (48) for a front loader and a valve (48) for taking out an external hydraulic pressure are provided on the rear upper surface side of a hydraulic housing (33) which is arranged to be inclined in the forward and downward direction and constitutes a hydraulic elevating device (10). And a main port (42) serving as an inlet for hydraulic oil is connected to a pipe from a lateral direction on a side of the hydraulic housing (33) on the side of the hydraulic pressure take-out port (48). Is provided as
A spacer (60) is mounted on the hydraulic housing (33), and a mounting seat (60D) is provided at the rear of the spacer (60) so as to protrude to the left outside. A hydraulic lift device for a tractor, comprising a valve (35) . A draft control valve (43) and a horizontal control valve (44) are provided on both left and right sides of the hydraulic housing (33) in front of the main port (42), and operate the upper part of the hydraulic housing (33). The tractor hydraulic lifting device according to claim 1 or 2 , wherein the tractor is covered with a mounting portion (22A) of the seat (14).

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