JPS5817361Y2 - Agricultural tractor resistance control device - Google Patents

Description

[Detailed Description of the Invention] The present invention tows a working machine behind an agricultural tractor via a three-point linkage mechanism, and raises and lowers the working machine with a hydraulic lift controlled by a hydraulic switching valve.・
- This relates to a resistance control device for an agricultural tractor in which one side of a leaf spring formed in a substantially U-shape in the vertical direction is attached to the housing, and the other side of the leaf spring is connected to a top link hinge that fixes the top link.

Conventionally, the traction resistance of the rotary work machine acts as this lifting force, and changes in the lifting force of the rotary work machine are detected via the top link, and the rotary work machine is raised and lowered to increase the plowing depth. There was a technique to keep it almost constant.

However, adjusting operations to maintain a constant plowing depth in response to the soft and hard state of the cultivated soil is cumbersome, and it is difficult to distinguish between use in fields and wet fields, for example.

The present invention solves the above-mentioned conventional drawbacks, and a pair of guide rods are installed in parallel between the hydraulic lift housing and the top link hinge, which are separated from each other by a plate spring, and the length of the guide rods can be adjusted. The top link hinge is compressively held and supported by the guide rod against the pushing-opening force of Alternatively, the spring force of the leaf spring may be adjusted depending on the soft and hard state of cultivated soil in a field, etc., and the allowable maximum load to be applied to the top link hinge □ may be set by the spring force of the leaf spring, and the top link The leaf spring can be displaced by a load greater than the permissible maximum applied to the top link hinge via the guide rod, and the load required to raise the work implement via the hydraulic lifter and the permissible maximum can be separated by the guide rod. (・ can be easily matched, and can prevent the vibration of the working machine from being transmitted to the leaf spring as an impact, preventing the leaf spring from malfunctioning.) The pressing force applied to the top link hinge can be accurately detected by a leaf spring, and the mounting length of the left and right guide rods can be varied depending on the left-right inclination of the work machine or the difference in weight between the left and right sides. To provide an agricultural tractor which can be made substantially equal on both sides, and can also move the top link hinge in parallel via a guide rod when the leaf spring is compressed and pushed open, and can perform stable load detection. The present invention attempts to provide a resistance control device.

An embodiment of the present invention will be described below with reference to the drawings. Fig. 1 is a schematic side view of an agricultural tractor according to the present invention;
In the figure, 1 is the machine base on which the engine part 2 is mounted, 3 is the clutch part provided at the rear of the engine part 2, 4 is the ξ tension part installed behind the clutch part 3, and 5 is the ξ tension part 4. The PTO shaft protrudes rearward, 6 is the handle, 7 is the seat,
8 is a rear wheel, and 9 is a rear axle.

Reference numeral 10 denotes a rotary working machine, which is attached to the rear of the tractor A by a three-point link mechanism of a tomblink 11 and lower links 12, 12, and is manually operated via a bendable transmission shaft 13 connected to the PTO shaft 5. The rotary 14 is configured to be driven to rotate.

Further, the rotary work machine 10 is configured to be able to be raised and lowered via a hydraulic lift 15 fixed on the ξ-handle 3 and the lift portion 4 via lift arms 16, 16 and 17.

As clearly shown in FIGS. 2 and 3, the hydraulic lift 15 is provided with a lifting shaft 19 on the upper right side of the lift housing 18, and is connected to a lift crank 20 fitted in the center of the shaft 19 via a piston rond 21. The piston 22 is arranged so as to be axially movable, and a hydraulic switching valve 23 is provided on the left side of the housing 18.
The port 23a on one side of the switching valve 23 is communicated with the primary chamber 25 separated from the piston 22 via a high pressure oil circuit 24, and the port 23b on the other side of the switching valve 23 is separated from the piston 22 via a drain circuit 26. Secondary room (lift crank room) 27
When the spool 30 is driven via the cam 29 by operating the manual operation lever 28, the piston 22 and the piston rond 21 are axially moved, and the lifting shaft 19 is rotated via the lift crank 20. , a lift arm 16 fitted and fixed to the shift 19.
16 is configured to slide.

31 is a cylinder fixed to one side of the lift housing 18 with screws; 32 is a plastic lift fixed to the other side of the lift housing 18 with screws; The bent front side part 33a is attached to the bent side part 33b'Y) of the leaf spring 33 via the member 35 by centopol) 34.34.
The spring 37, 37 is connected so that this stress is applied to the lift link hinge 36. One end 33bY is fixed to the middle of the hinge 36.

The upper end of the top ring hinge 36 is pivoted to the protrusion 32a of the plastic lift 32 via a hinge pin 38, and the rear side of the top link hinge 36 has a plurality of mounting holes 39, 39, ... are bored in multiple stages, and the base end of the top link 11 is fixed to this knock link hinge 36.

Here, the leaf spring 33 is formed into a folded shape with an expansion curved portion 33cfx, and is installed approximately perpendicularly between the plastic lift 32 and the top link hinge 36 of the hydraulic lift 15.

Moreover, a link mechanism 41 is connected to the pin 40 provided at the lower end of the top link hinge 36.

This link mechanism 41 automatically lifts the working machine 10 when the traction resistance force of the working machine 10 on the force plate set in advance by the plate spring 33 is applied to the plate spring 33 as a compressive force. It drives the hydraulic lift 15 in order to raise the hydraulic lift 15, and is swingably fitted to the first feed bank lever 42 connected to the bin 40 and the lifting shaft 19 via a toothed ply plate 43 (see FIG. 4). The attached first and second swing brakes) 44.45, the second feed bank lever 47 attached to the upper ends of these swing brakes) 44.45 via the bin 46, and the tip of the lever 4γ It consists of a plate 48 stretched downward from the plate 48, a shaft 49 provided on the plate 48, a cam 50 fixed to the shaft 49 for moving and operating the spool 30 of the switching valve 23, and a restoring spring 51. It is something.

The first feed bank lever 42 includes a flat plate 42a pivotally supported on the bin 40, and a threaded rod 4 fixed to the flat plate 42a.
2b, a screw rod 42d connected to the screw rod 42b via an adjustment nut 42c, and a dog-shaped flat plate 42e fixed to the screw rod 42d. 7'L/-)44.45.

On the other hand, the second feed bank lever 4T includes a flat plate 47a pivotally supported on the bin 46, and a threaded rod 4 fixed to the flat plate 4γa.
7b, and an adjustment nut 47c'r on the threaded rod 47b.
: It is composed of a dogleg-shaped threaded rod 47d and a flat plate 4γe fixed to this threaded rod 47d, and is connected to the plate 48 mentioned above through a pin 53.

The spring 51 is stretched between holding plates 54 and 55, and one holding plate 54 is pivotally connected to the bottle 46, and the other holding plate 55 has a plate shape with a guide plate 56 fixed at the tip. It is installed upright on the arm 57 of.

Furthermore, a leaf spring 33 at the lower end of the bracket 32
On the left and right sides of the bracket 32)
A pair of guide rods 59 and 59v integrally formed with 58 and 58 are installed in parallel to guide the swinging of the top link hinge 36.

The rear end portions of the guide rods 59, 59 are inserted into the holes of the top link hinge 36.

Further, as shown in FIGS. 2 and 3, a pair of guide rods 59 are installed in parallel between the hydraulic lift housing 18 and the top link hinge 36 so that the length of the guide rods 59 can be adjusted. The top link hinge 36 is compressively engaged and supported by the guide rod 56 against the pushing-opening force, and the minimum pushing-opening force of the leaf spring 33 applied to the top link hinge 36 can be arbitrarily set.

Incidentally, a variable throttle valve 60 is provided in front of the connection port 24a in the high-pressure oil circuit 24 to control the flow rate.

Further, 61 is a safety valve that adjusts the pressure of oil flowing through the drain circuit 26, and 62 is a branch port that communicates with a part of the high-pressure oil circuit 24.
2 is closed with a plug.

Furthermore, 63 is an air breather, and 64 is a rotary work machine 1.
A long mechanism that restricts the descent of 0 when it is raised.
Reference numerals 65 and 65' designate lift arm bins for connecting the lift rod 1a'.

The present invention is constructed as described above, and when performing work by lowering the rotary working machine 10 shown in Fig. 1 in the direction of arrow a, When the top link 11 is caught or the depth of its action becomes deep, a force for lifting the work implement 10 is applied to the top link 11, and this lifting force is applied to the top link 11 to the lift link hinge 3.
The lifting force applied to the hinge 36 is applied to the other side 33b of the leaf spring 33 as a compressive force.

When a compressive force greater than a preset force is applied to the leaf spring 33 by the guide rod 59, the top ring hinge 36 uses the shaft 38 as a fulcrum to resist the pushing-opening force of the leaf spring 33 and move as shown in FIG. Rotate clockwise to compress the leaf spring 33.

For this reason, the bin 40 protruding from the hinge 36 moves and moves to the swing plate 44 via the first feed bank lever 42.
．． 45 rotates clockwise, and the shaft 49 and cam 50 are rotated through the second feedback lever 47 and each element 53, 48.
As a result, the hydraulic switching valve 2
The spool 30 of No. 3 moves and the port on the negative side) 23a
From high pressure oil circuit 24, variable orifice and connection port 24
Hydraulic oil is supplied to the primary chamber 25 of the hydraulic lift 15 through a, and the piston 22 and piston rond 21 move forward as shown in FIG. Operate rotation.

Therefore, together with the lifting of the lift arms 16, 16 fitted to the shaft 19, the rotary work machine 10 moves to the first position.
It is raised in the direction of the arrow in the figure.

In addition, the traction resistance of the rotary working machine 10 increases or decreases due to changes in the softness and hardness of cultivated soil in fields, fields, dry fields, and wet fields.
By increasing or decreasing the minimum push-opening force of No. 3 in accordance with the above-mentioned traction resistance, the compression sensitivity of the leaf spring 33 suitable for the cultivated soil can be obtained.

As is clear from the above embodiments, the present invention provides a working machine 10 connected to the rear of the agricultural tractor A via the three-point link mechanism LL12.
The working machine 10 is raised and lowered by the hydraulic lift 15 controlled by the hydraulic switching valve 23, and the hydraulic lift 15 has a plate spring formed in a substantially U-shape in the vertical direction on the housing 18 of the hydraulic lift 15. 33 is attached on one side, and the other side of the leaf spring 33 is connected to the top link hinge 36 that fixes the lift link 11. The hydraulic lift housing 18 and the top ring hinge 36 are separated by the leaf spring 33.
A pair of guide rods 59 are installed in parallel with each other so that the length can be adjusted, and the top link hinge 36 is compressably secured to the guide rods 59 against the pushing force of the leaf spring 33. a leaf spring 3 supported and attached to the toppling link hinge 36;
The spring force of the leaf spring 33 can be adjusted according to the soft and hard state of cultivated soil in a field or field, and is biased against the top link hinge 36. The maximum allowable load can be set by the spring force of the leaf spring 33, and the leaf spring 33 can be displaced by a load greater than the maximum allowable value applied to the top link hinge 36 via the lift link 11, and the hydraulic lift 1
Using the guide rod 59, it is possible to easily match the load required to raise the work implement 10 through the guide rod 59 with the maximum allowable value, and vibrations of the work implement 10 are transmitted as shocks to the leaf spring 33. The plate spring 33 can be prevented from malfunctioning, the load applied to the top link 11 can be accurately detected by the plate spring 33, and the load applied to the top link 11 can be accurately detected. left and right guide rods 59,5
It is possible to make the pushing force applied to the top link hinge 36 approximately equal on both the left and right sides by making the mounting lengths of the leaf springs 33 different, and the amount of compression of the leaf spring 33 on the left and right sides can be made equal. The top link hinge 36 can be moved in parallel via the left and right guide rods 59 so that it is approximately even on both sides, and load detection that is most suitable for various work conditions can be stably performed. This has a remarkable effect.

[Brief explanation of the drawing]

Figure 1 is a schematic side view of the agricultural tractor according to the present invention;
3 is a longitudinal sectional view of the hydraulic lift, FIG. 3 is a plan view of the hydraulic lift showing main parts in section, and FIG. 4 is a partial sectional view showing the relationship between the link mechanism and the lifting shaft. A...Agricultural tractor, 10...Work equipment, 11...Tomplink (three-point link mechanism),
12...Lower link (three-point link mechanism), 15
・・・・・・Hydraulic lift, 18・・・・・・Lift-・
Uzing, 23...Hydraulic switching valve, 32...
... Bracket, 33... Leaf spring, 36...
...Tomplink hinge, 59... Guide rod.

Claims (1)

[Scope of utility model registration request] The working machine 10 is towed behind the agricultural tractor A via the three-point linkage mechanism 11 and 12, and the cultivated rock 10 is raised and lowered by the hydraulic lift 15 controlled by the hydraulic switching valve 23. One side of the leaf spring 33 formed in a substantially U-shape in the vertical direction is attached to the lift housing 18, and the other side of the leaf spring 33 is connected to the top link hinge 36 that fixes the top link 11 ( ·hand,
A pair of guide rods 59 are installed in parallel between the hydraulic lift housing 18 and the top link hinge 36 with the plate spring 33 separated, and the length can be adjusted. The top link hinge 36 is held and supported by the guide rod 59 in a compressible manner, and the top link hinge 36
1. A resistance control device for an agricultural tractor, characterized in that the minimum push-opening force of a leaf spring 33 to be applied to the blade spring 33 can be arbitrarily set.