JPH08130910A - Hydraulic apparatus of farm tractor - Google Patents

Abstract

PURPOSE: To provide a hydraulic apparatus of a farm tractor, facilitating the connection work, attaching work and maintenance work and having improved operability by slidably passing a position rod through a rear partition wall of a machine body, protruding the rod to the outside of the machine body and connecting the rod in interlocked state to a position valve for the lifting of the working machine. CONSTITUTION: This hydraulic apparatus for a farm tractor is provided with a hydraulic case 68 connected to a hydraulic pump and placed under a seat, a position valve 65 for lifting a working machine and attached to the hydraulic case 68 and a position rod 65a slidably passed through the rear partition wall W of the machine body, protruded to the outside of the machine body and connected to the position valve 65 in interlocked state. The hydraulic case 68 connected to the hydraulic pump is preferably placed under the seat and a hydraulic valve 65, etc., for controlling the vertical motion and swinging motion of the working machine are collectively attached to the hydraulic case 68.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an agricultural tractor hydraulic system.

[0002]

2. Description of the Related Art Conventionally, a working machine connected to the rear of an agricultural tractor has been replaced according to agricultural work.

Further, a plurality of hydraulic cylinders are used for raising and lowering or swinging the working machine,
These hydraulic cylinders are controlled by hydraulic valves that are interlocked with an operating device such as an operating lever provided in the operating unit.

[0004]

However, when connecting the working machine to the agricultural tractor, it is necessary to operate the elevating mechanism on the tractor side to adjust the height of the connecting mechanism to the height of the working machine. For this height adjustment, it is necessary to delicately operate the position lever arranged in the driving part, and it is difficult to visually recognize the connecting part from the driving part, so it is difficult to adjust the height,
Therefore, when performing the connecting work by one person, it was necessary to reciprocate between the driving section and the rear of the tractor. In particular, in the case of a tractor with a cabin, the position lever cannot be operated unless the tractor comes into the cabin, which makes the connection work even more complicated.

Further, since the hydraulic valves for controlling the hydraulic cylinders for raising and lowering or swinging the working machine are arranged in a disjointed manner, the interlocking mechanism between the operating lever of the operating section and the hydraulic valves becomes complicated, Further, the hydraulic piping is complicated and it is inconvenient to install and maintain the hydraulic piping.

[0006]

According to the present invention, a hydraulic case communicating with a hydraulic pump is arranged below a seat, and a position valve for raising and lowering a working machine is attached to the hydraulic case. The invention provides a hydraulic device for an agricultural tractor, characterized in that a position rod projecting to the outside of the machine body is interlockingly connected to the rear partition wall so as to be freely inserted and removed.

Further, the present invention is also characterized in that a hydraulic case communicating with a hydraulic pump is arranged below the seat, and hydraulic valves for controlling the raising and lowering and swinging of the working machine are centrally attached to the hydraulic case. .

[0008]

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

1 to 3 show an agricultural tractor A according to the present invention. The tractor A has a machine frame 2 mounted on an upper surface of a crawler type traveling device 1 and is mounted on the machine frame 2. The engine part 3 is mounted on the front part of the plane, and the aircraft frame 2
A cabin 7 enclosing a driving section 6 including a steering handle 4 and a seat 5 is mounted on the rear portion of the upper surface of the vehicle body frame 2
A rotary cultivator as a working machine B is movably connected to the rear end portion of the machine through a three-point link mechanism 8 and a lifting mechanism 9.

As shown in FIG. 1, the crawler type traveling device 1 has a horizontal frame-shaped traveling frame 10 having left and right front sprockets 11 pivotally supported on the left and right front ends thereof. The left and right driven sprockets 12 are rotatably supported at the rear end, the upper roller 13 is rotatably supported on the upper surface of the traveling frame 10, and the two lower rollers 14 are respectively rotatably supported below the traveling frame 10. A pair of equalizers 15 is attached.

The left and right drive sprockets 11, the left and right driven sprockets 12, the left and right upper rolling wheels 13, and the lower rolling wheels 14
Left and right crawlers 16 are respectively wound around the outer periphery of ..., and left and right drive sprockets 11 are linked to left and right hydraulic motors 17 that form part of a hydrostatic transmission described later, and are mounted on the prime mover section 3. The power from the engine 18 is changed by the hydrostatic transmission to be transmitted to the left and right crawlers 16 to drive the tractor A.

In FIG. 3, reference numeral 19 denotes a tow hitch, which is provided at the lower center of the rear surface of a rear partition wall W, which will be described later.

In the agricultural tractor A, the working machine B is vertically movable via a three-point link mechanism 8 attached to and an elevating mechanism 9.

As shown in FIGS. 1 and 4 to 6, the three-point link mechanism 8 has a rear partition wall W provided upright on the rear portion of the traveling frame 10, and left and right lower link supports on the left and right sides of the rear partition wall W. The bodies 23 and 24 are formed, and the front ends of the left and right lower links 25 and 26 of the three-point link mechanism 8 are rotatably pivotally attached to the rear partition wall W.
The front end of the top link 29 is rotatably pivoted to the upper center of the rear surface via a buffer mechanism 28, and the rear ends of the left and right lower links 25, 26 and the top link 29 are rotatably pivoted to the work machine frame 30, respectively. By wearing the work machine B, the work machine B is vertically movable.

As shown in FIGS. 5 and 6, the cushioning mechanism 28 has a cushioning mechanism support 28a projecting from the center of the upper portion of the rear partition wall W, and the lower rear end of the cushioning mechanism support 28a is inserted therethrough. A rocking plate 92 is rotatably pivoted via a pivot 91, and a spring 93 is interposed between the upper part of the buffer mechanism support 28a and the upper part of the rocking plate 92. By elastically supporting the forward load from the top link 29 pivotally attached to the middle portion of 92, the upward impact that the working machine B receives from the ground is alleviated, and the top link 29 is bent at three points. The link mechanism 8 is prevented from being damaged.

As shown in FIGS. 1, 4 and 5, the elevating mechanism 9 has left and right cylinder support members 35 and 36 formed slightly above and above the left and right lower link support members 23 and 24 to form left and right cylinder support members. Left and right lifting hydraulic cylinders 3 on bodies 35 and 36 respectively
The bottoms 39 and 40 of the 7,38 are rotatably pivotally mounted, and left and right lift arm supports 52 and 53 are formed on the upper left and right sides of the rear partition W, respectively.
Left and right lift arms 58,5 that are bent in a substantially V shape at 52,53
The front end of 9 is rotatably pivoted, and the left and right lifting hydraulic cylinders 37, 3 are attached to the middle parts of the left and right lift arms 58, 59.
The piston rods 60 and 61 of 8 are pivotally attached to each other, and the rear end of the left lift arm 58 is rocked.
Interlockingly connected to the middle part of the left lower link 25, and connecting the rear end of the right lift arm 59 to the middle part of the right lower link 26 via an ascending / descending connecting rod to connect the left and right lifting hydraulic cylinders 37, 38. By the expansion and contraction operation, the working machine B connected via the three-point link mechanism 8 is moved up and down, and the rocking hydraulic cylinder is moved.
The work machine B is swung left and right by the expansion and contraction operation of 62.

As described above, since the lifting operation of the working machine B is performed by the left and right lifting hydraulic cylinders 37, 38, the working machine having a wider width and the heavier work than those performed by one hydraulic cylinder. The lifting and lowering operation of the machine becomes easy, and the left and right balance is improved.

In particular, as shown in FIGS. 3 to 6, 8 and 9, the left and right lower link supports 23 and 24 are provided on the rear surface of the rear partition W, respectively, and each of a pair of inner and outer three vertically elongated strips. It consists of the point support plates 23a, 23b, 24a, 24b, and the buffer mechanism support 28
Since a is composed of a pair of left and right cushioning mechanism support plates 28b, 28c projectingly provided on the rear surface of the rear partition wall W, the above six support plates are provided.
23a, 23b, 24a, 24b, 28b, 28c not only support the three-point link mechanism 8, the lifting mechanism 9 and the buffer mechanism 28, but also function as reinforcing ribs for increasing the strength and rigidity of the rear partition wall W. are doing.

FIG. 7 shows a hydraulic circuit. In the hydrostatic transmission, the left and right hydraulic motors 17, 1 are respectively connected to the variable displacement left and right hydraulic pumps 20, 20 which are linked to the engine 18.
7 are connected in series so that the left and right hydraulic pumps 20, 20 can be changed in a stepless manner by changing the discharge amount. The left and right hydraulic motors 17, 17 are also variable displacement type, and can be changed to high and low two stages respectively. It is configured to be possible.

In the figure, 50 is a hydraulic pump, 42 is a swash plate control section for controlling the discharge amounts of the left and right hydraulic pumps 20, 20,
43 is a hydraulic valve for shifting which is connected to the left and right sub-transmission mechanisms 22 and 22, 51 is a hydraulic valve for braking which controls the hydraulic pressure to the hydraulic servo type brake 21, 54 is a brake pedal, and 55 is a brake pedal.
Is a hydraulic oil tank, 56 is an oil cooler, and 57 is an oil filter.

Further, the left and right lifting hydraulic cylinders 37, 38
Is connected to the hydraulic case 68 connected to the hydraulic pump 50 through the position valve 65, the safety valve 66 and the check valve 67 on the bottom 39, 40 side, and the rod side 69, 7
0 is connected to the hydraulic case 68 via the oil passage switching valve 82 connected to the operation switch 81 arranged in the operation unit 6, so that the operation switch 81 is pressed and the rod side 69, 70
Also, the hydraulic pressure from the hydraulic pump 50 is applied to the hydraulic cylinders 37, 38 for left and right lifting, so that the operating directions of the hydraulic cylinders 37, 38 for left and right lifting can be changed. .

The swing hydraulic cylinder 62 is connected to the hydraulic case 68 via a float control valve 83.

With this configuration, the position valve 65
Operate the bottoms 39,4 of the hydraulic cylinders 37,38 for left and right lifting.
Apply hydraulic pressure to the 0 side to move the left and right lifting hydraulic cylinders 37, 38
The work machine B is raised by extending the work machine B, the position valve 65 is switched, the hydraulic pressure on the bottom 39, 40 side of the left and right lifting hydraulic cylinders 37, 38 is drained, and the work machine B's own weight is used to lift the left and right lifting hydraulic cylinders 37, 38. The work implement B can be lowered by retracting 38.

In particular, when the working machine B is rapidly lowered, the operation switch 81 of the operating section 6 is pressed to cause the hydraulic pressure from the hydraulic pump 50 to the rod sides 69, 70 of the left and right lifting hydraulic cylinders 37, 38. The hydraulic cylinders 37, 38 for raising and lowering the left and right can be rapidly retracted by the action of, and the working machine B can be rapidly lowered.

8 and 9 show a hydraulic case 68. The hydraulic case 68 is attached to the upper surface of the body frame 2 in front of the rear partition W and is located below the seat 5. A plurality of oil passages are formed inside the wall of 68, and a plurality of hydraulic valves 65, 66, 67, 8 for raising and lowering and swinging the working machine B are provided on the front surface and the left and right side surfaces of the hydraulic case 68.
3, the hydraulic valves 65, 66, 67 and 83 are connected to the hydraulic pump 50 by the oil passages.

In this way, the plurality of hydraulic valves 65, 66, 67, 8
By arranging 3 centrally, hydraulic piping can be shortened and simplified.

As shown in FIGS. 5 and 10, a position rod insertion hole W1 is formed in the upper right portion of the rear partition W, and the position rod 65a is inserted into and removed from the rod insertion hole W1. The front end of the position rod 65a is interlockingly connected to the positioning lever 79, the rear end of the position rod 65a is projected rearward of the rear partition wall W, and the rear end of the position rod 65a can be gripped to connect the work machine outside the machine body. From the position, the positioning lever 79 can be operated to move the rear ends of the left and right lower links 25, 26 of the three-point link mechanism 8 up and down to match the height of the connecting position of the working machine B.

Further, as shown in FIGS. 4 and 10, a feedback rod insertion hole W2 is formed on the right side of the central portion of the rear partition wall W, and the feedback rod 65b is inserted into and removed from the feedback rod insertion hole W2. , The front end of the feedback rod 65b is interlockingly connected to the valve shaft 65d of the position valve 65 via the upper arm 65c, and the rear end of the feedback rod 65b is interlockingly connected to the right lift arm 59, so that the working machine B moves up and down. When the upper and lower limits are reached, the position valve 65 is returned to the neutral position to stop the lifting operation.

A buffer rod insertion hole W3 is formed on the right side of the rear partition W, and the buffer rod 28d is inserted into and removed from the buffer rod insertion hole W3 so that the buffer rod 28d can be inserted and removed.
Of the position valve 65 via the lower arm 65e, and the rear end of the buffer rod 28d is connected to the rocking plate 92 of the buffer mechanism 28 so that the working machine B is not obstructed on the ground. When the rocking plate 92 is moved forward and the swing plate 92 is displaced forward, the position valve 65 is switched in the direction of raising the working machine B to raise the working machine B, so that a large impact can be dealt with.

As shown in FIGS. 5, 6 and 10, the buffer rod insertion hole W3 has a buffer mechanism support 28a.
A rear cover interlocking rod 132 that is interlockingly connected to the rear cover 131 shown in FIG. 1 via a relay shaft 130 that is rotatably inserted through
The rear cover interlocking rod 132 has its front end linked to the position valve 65 so that the raising / lowering operation of the rear end of the rear cover 131 can be transmitted to the position valve 65.

Further, as shown in FIGS. 9 and 10, the rear partition wall W has hydraulic hoses to the left and right lifting hydraulic cylinders 37 and 38 and the swing hydraulic cylinder 62 on the inner surface of the rear partition wall W.
An inner connector 102 provided in the middle of 100 and the external hydraulic pressure take-out hose 101 is inserted and fixed, and the outer connector 103 of each of the hoses 100 and 101 can be attached to the outer surface of the rear partition wall W.

Further, as shown in FIG. 10, the rear wall 7a of the cabin 7 is extended obliquely rearward and upward from the upper edge of the rear partition wall W to separate the operating unit 6 and the working machine B from each other.

FIGS. 10 and 11 show the construction of the operating unit 6, where 41 is a vehicle speed control lever, 63 is an accelerator lever, 71 is an instrument panel, 72 is a one-touch lifting lever, 73 is a power takeoff lever, and 74 is Parking lock lever, 75 and 76 are power take-out gear shift levers, 77 is a small storage case, 78 is a mechanical auto draft lever, 79 is a positioning lever, 80 is a lifting height control dial for the working section, and 81 is for rapidly lowering the working section. Operation switch.

As described above, since the hydraulic case 68 to which a plurality of hydraulic valves are attached is arranged below the seat 5, the operating lever and the like are close to the hydraulic valve. Therefore, the operating lever and the like are provided. It is possible to simplify the interlocking mechanism between the hydraulic valve and the plurality of hydraulic valves.

A hydraulic oil tank 55 is arranged on the left side of the cabin 7, and a fuel tank 10 is arranged on the right side of the cabin 7.
5 are arranged.

As shown in FIGS. 12 and 13, the fuel tank is a box-like shape having a trapezoidal shape when viewed from the side, and the outer surface of the upper surface 106 is inclined downwardly toward the outside, and the fuel filling port is provided near the front end of the outer surface of the upper surface 106. A grab rail 10 that forms a bar 107 and extends in the front-rear direction at the same height as the inner surface 108 of the upper surface of the fuel tank 105.
The grab rail 109 is fixed to the outer edge of the upper outer surface 106 of the fuel tank 105 through the downward bending portions formed at the front and rear ends of the grab rail 109.
However, it functions as a handle when the fuel tank rotates, which will be described later, and when the fuel is refueled, the container 110 such as a petroleum can is stably held in a state of straddling the upper inner portion 108 of the fuel tank 105 and the grab rail 109. I am able to place it.

Further, a step plate storage space 111 is provided under the fuel tank 105, and a step plate 112 which can be freely taken in and out is stored in the step plate storage space 111. When the fuel is refueled, the step plate 112 is pulled out and the step plate 112 is pulled out. 112 The worker is able to go up and perform refueling work.

The left and right side ends of the rear wall 7a of the cabin 7 and the vertical pivots 114 and 115 projecting from the left and right sides of the upper rear surface of the body frame 2 are respectively provided at the upper and lower positions of the inner side rear portion of the fuel tank 105. The upper and lower pivot parts 116 and 117 are pivotally attached to each other, and the fuel tank is centered on the upper and lower pivot shafts 114 and 115.
105 The rear part can be rotated outward.

Further, as shown in FIG. 3, the fuel tank 105
On the back surface of the hydraulic oil tank 55, a tail lamp unit 120 including a reflecting mirror 118 and a direction indicator lamp 119 is arranged with the reflecting mirror 118 inside.

14 to 16 show the crawler 16 and have left and right protrusions 121 and 122 on the upper surfaces on the left and right sides of the central portion, respectively.
An endless crawler 16 is formed by enclosing the outer circumference of a core metal 123 that has been formed with a rubber 124 that extends in the front-rear direction.
125 and 126 are formed, and in particular, the left and right lugs 125 and 126 are raised to enhance the slip prevention effect, and as shown in FIGS. 4 and 5, the front and rear positions of the left lug 125 and the right lug 126 are offset from each other. I feel comfortable.

In FIGS. 15 and 16, reference numeral 127 denotes a tooth fitting hole of the drive sprocket 11.

[0042]

According to the present invention, a hydraulic case communicating with a hydraulic pump is arranged below a seat, and a position valve for raising and lowering a working machine is attached to the hydraulic case. By interlockingly connecting the position rod protruding through the partition wall to the outside of the fuselage, the position valve was operated from the outside rear position of the fuselage via the position rod, and the three-point link mechanism was moved up and down. Since the height of the three-point link mechanism can be made to match the height, even when one person performs the connecting work, it is not necessary to go to the driving section for the lifting operation, and the connecting work can be facilitated. .

Further, a hydraulic case communicating with a hydraulic pump is arranged below the seat, and hydraulic valves for raising and lowering and swinging control of the working machine are centrally attached to the hydraulic case, whereby Since the operation lever and the hydraulic valve are close to each other, the interlocking mechanism between the operation lever and the hydraulic valve can be simplified, and the hydraulic piping can be made short and simple, and the installation work and the maintenance work can be facilitated.

[Brief description of drawings]

FIG. 1 is a side view of an agricultural tractor equipped with a hydraulic device according to the present invention.

FIG. 2 is a plan view of the same.

FIG. 3 is a rear view of the same.

FIG. 4 is a side view of a three-point link mechanism and a lifting mechanism.

FIG. 5 is a side view of the buffer mechanism.

FIG. 6 is a plan view of a buffer mechanism.

FIG. 7 is a hydraulic circuit diagram.

FIG. 8 is a plan view of a hydraulic case.

FIG. 9 is a rear view of the same.

FIG. 10 is a side view of a driving unit.

FIG. 11 is a plan view of a driving unit.

FIG. 12 is a side view of the fuel tank.

FIG. 13 is a front view of the same.

FIG. 14 is a partially cutaway side view of the crawler.

FIG. 15 is a bottom view of the same.

FIG. 16 is a front view of the same section.

[Explanation of symbols]

 A Agricultural tractor B Work machine W Rear bulkhead 5 Seat 50 Hydraulic pump 68 Hydraulic case 65 Position valve 65a Position rod 66 Safety valve 67 Check valve 83 Float control valve

Claims (2)

[Claims] 1. A hydraulic case (68) communicating with a hydraulic pump (50) is arranged below the seat (5), and a position valve (65) for raising and lowering the working machine (B) is arranged in the hydraulic case (68). ) Is attached to the position valve (65), and the position rod (65a) protruding through the rear bulkhead (W) of the machine body is inserted and inserted so that it can be inserted and removed. apparatus. 2. A hydraulic case (68) which communicates with a hydraulic pump (50) is arranged below the seat (5), and the hydraulic case (68) is used for controlling the lifting and swinging of the working machine (B). Hydraulic valves (65)
(66) (67) (83) is a centralized installation of a hydraulic system for agricultural tractors.