JPS6320255Y2 - - Google Patents

Description

[Detailed description of the invention] "Industrial application field" The invention is applicable to a passenger vehicle consisting of, for example, a planting section having a seedling stand and planting claws, and a riding section consisting of an agricultural tractor or a vehicle dedicated to rice planting. Regarding rice transplanters.

``Prior Art'' Conventionally, in a walk-behind rice transplanter equipped with a hydraulic cylinder and a valve that move the wheels that support the machine body in and out downward, there is a technology that controls the cylinder by attaching the valve to a link that supports a float on the lower side of the machine body. For example, Utility Model Application Publication No. 50-8037) was published.

``Problems to be solved by the invention'' However, the above-mentioned conventional technology adjusts the support height of the machine body by detecting the depth of the tiller on which the wheels are moved, and the planting part is placed in the riding part. In a riding rice transplanter that is supported independently, the width of the planting section is large, so the planting section must be removed and transported on general roads, and the planting section must be removed and stored at an appropriate height. When the planting part is placed on the stand, it is troublesome to remove the lifting link by reducing the hydraulic pressure supporting it to almost zero, and when moving between fields with the planting part lifted, There is a risk that the planting section will vibrate due to the tilting of the riding section, and that the hydraulic cylinder will operate due to valve malfunction, etc. Therefore, it is difficult to apply the above-mentioned conventional technology to riding rice transplanters, and it is difficult to apply the above-mentioned conventional technology to riding rice transplanters. It was difficult to achieve this goal.

"Means for Solving the Problems" The present invention solves the above-mentioned conventional drawbacks, and includes installing a planting part in the riding part so that it can be raised and lowered via an elevating link and a hydraulic cylinder, and also attaching it to the planting field. A rice transplanter in which a float is attached to the lower surface of the rice transplanter to support the planting part when grounded, and further comprising a back pressure regulating valve operated by a displacement force of the lifting link that is proportional to a change in the supporting force of the planting part. The present invention is characterized in that a bypass oil pipe is arranged in parallel with the pressure reducing valve, and a release valve is provided in the bypass oil pipe for interrupting the operation of raising and lowering the planting portion by the valve.

"Function" Therefore, since a release valve is provided for draining the hydraulic oil from the hydraulic cylinder, the planting section supported by the elevating link can be easily attached and detached, and the planting section can be removed from the riding section. In addition, when moving the planting part in a lifted state, the pressure reducing valve can be maintained in an unloaded state by operating the release valve, and the pressure reducing valve can be easily and efficiently carried out. Float grounding of a rice transplanter that can be safely handled by preventing malfunctions and improving durability, and also has a simple structure and easy-to-operate release valve by providing a bypass oil pipe in the valve. It is intended to provide a load adjustment device.

"Embodiment" An embodiment of the present invention will be described below in detail based on the drawings. Fig. 1 is a schematic side view of the riding rice transplanter, and Fig. 2 is a plan view of the same.
4 and 5 are connection frames that connect the front and rear car bodies 2 and 3 so as to be bendable only in the horizontal direction via a rotation fulcrum shaft 6; Front and rear wheels for paddy fields installed by
11 is a column whose base end is fixed to the front vehicle body 2; 12 is a preliminary seedling stand supported by the column 11; 13 is a driver's seat that is attached to the upper rear part of the front vehicle body 2 via the column 11; and 14 is the driver's seat. 13 is a hydraulic switching valve provided on the lower surface; 15 is a lift lever for operating the switching valve 14; 16 is a steering handle provided above the front of the front vehicle body 2; and 17 is an engine mounted on the rear vehicle body 3.

In addition, 18 in the figure is a planting part for six rows that is installed in the front part of the front vehicle body 2 via a three-point linkage mechanism 19 so as to be able to be raised and lowered, and 20 is a planting part that can be moved back and forth from side to side. A seedling platform 21 is a planting claw for taking out one seedling from the seedling platform 20 and planting it; 22 is a transmission case to which the seedling platform 20 and the planting claw 21 are attached;
3 is a float supporting the transmission case 22; 24;
2 is a front bumper attached to the transmission case 22;
5 is a fixed frame that supports each transmission case 22...
The seedling stand 20 and the planting claws 21 are appropriately driven via the PTO transmission shaft 26 to continuously plant seedlings.

The three-point link mechanism 19 is composed of a pair of lower links 27 and a top link 28 which is an elevating link. A back pressure regulating valve 29 is connected to the other end of the top link 28, which is connected to the upper end of the fixed frame 25 via a pin 27'', and has one end connected to the upper end of the fixed frame 25 via a pin 25'', and is provided above the front end of the front vehicle body 2. bracket 30
The valve 29 is connected and supported through a pin 31. A lateral vibration prevention spring 32 is mounted between the lower end of the fixed frame 25 and the bracket 30, and the front vehicle body 2
A lift arm 33 having one end protruding in front of the lower link 27 is connected to the middle of the lower link 27 via a connecting rod 34,
It is constructed so that the planting section 18 can be raised and lowered by swinging the lift arm 33 with appropriate hydraulic pressure.

As shown in FIG. 3, the long hole 3 at the lower end of the connecting rod 34 is inserted into the planting pin 35 on the intermediate side surface of the lower link 27.
6, and a spring 37 provided parallel to the link 34 is connected to the lower link 27 and the lift arm 3.
The float 23 sinks to a certain depth in the field under a standard load condition with a certain amount of seedlings placed on the seedling stand 20, and the ground pressure of the float 23, that is, the ground load of the float 23 and the tension of the spring 37. Formed so that the spring forces are balanced.

Furthermore, the piston rod 38'' of the hydraulic cylinder 38 attached to the front body 2 is connected to the lift arm 33. Then, a hydraulic pump 39 that is linked to the engine 17 is communicated with the cylinder 38 via the 4-port 3-position manual hydraulic switching valve 14. By this,
The lift arm 33 is rotated upward by the cylinder 38, and the pump 39 is communicated with the oil tank 40 via the switching valve 14 and the back pressure adjustment valve 29, so that the lift arm 33 is fixedly supported. The pump 39 is connected to the tank 40 via the switching valve 14 and the valve 29, and the switching valve 1
4 and the valve 29 between the variable throttle valve 41 and the switching valve 1.
By communicating with the cylinders 38 through the valves 4 and 4, the cylinders 3
The lift arm 33 is formed so as to be rotated up and down via the shaft 8.

As shown in FIG. 4, the top link 28 is
It includes a core shaft 42 and a cylindrical shaft 43 into which the core shaft 42 is slidably inserted, and a spring pressure adjustment screw 44 is screwed onto the end of the cylindrical shaft 43 from which the core shaft 42 protrudes. A spring seat 45 is fixed to the inner end of the
A float ground pressure adjustment spring 46 is stretched between the screw 44 and the spring seat 45. A coupling bolt 47 is fixed to the outer end of the core shaft 42, and the bolt 47
The core shaft 42 is connected to the fixed frame 25 via. A screw 48 connects the cylinder shaft 43 to the back pressure adjustment valve 29.
The operating shaft 49 of the valve 29 is slidably inserted into the screw 48, and one end of the shaft 49 is brought into contact with the inner end of the core shaft 42. A pressure reducing valve 51 is provided at the other end via a pressure reducing spring 50. A high pressure oil passage 52 and a low pressure oil passage 53 are formed in the valve 29, and the high pressure oil passage 52 is communicated with the switching valve 14 and the throttle valve 41, and the low pressure oil passage 53 is communicated with the tank 40. Attach the connecting bolt 5 to the end of the valve 29 near the oil pipes 52 and 53.
4 is fixed, and the end of the valve 29 is connected and supported to the bracket 30 of the front vehicle body 2 via the bolt 54. A pressure reducing valve 51 is installed in order to control communication between the high pressure oil pipe 52 and the low pressure oil pipe 53, and a back pressure hole 56 is formed in the valve 51 to short-circuit the low pressure oil pipe 53 and the back pressure chamber 55 of the pressure reducing valve 51. At the same time, the oil passages 52 and 53 are communicated with each other through a bypass oil passage 57, and the bypass oil passage 5 is connected by a float ground load adjustment release valve 58 having an adjustment release lever 59.
7 is controlled to open and close, and the planting section 18 is raised and lowered by increasing and decreasing the float grounding load due to changes in the amount of seedlings on the seedling platform 20 and the grounding pressure of the float 23.

The present embodiment is constructed as described above, and as shown in FIG. The switching valve 14 and the valve 29 are communicated with the lifting cylinder 38 via the throttle valve 41 and the switching valve 14, and the ground load of the float 23 is automatically adjusted. float 2
When the ground pressure of No. 3 is the set value, the pressure oil discharged from the hydraulic pump 39 is transferred to the tank 40 via the pressure reducing valve 51.
The throttle valve 41 is returned to the lifting cylinder 38.
A constant hydraulic pressure is applied to the planting portion 18 to maintain it at a constant height.

During the rice planting operation, if, for example, the seedling platform 20 is replenished with spare seedlings and the seedling platform 20 becomes heavy due to an increase in the number of seedlings, the spring 37 can be extended by lowering the pin 27'' as a fulcrum. The link 27 rotates, displacing the seedling stand 20 in the direction of tilting it down, retracting the core shaft 42 and the operating shaft 49, increasing the spring pressure of the pressure reducing spring 50, and increasing the throttle oil pressure of the pressure reducing valve 51. Pressure oil from the pump 39 is applied to the cylinder 38 via the throttle valve 41, and the lower link 27 is rotated upward in a direction to raise the seedling stand 20 by upwardly rotating the lift arm 33.
When the hydraulic pressures of the cylinder 38 and the pressure reducing valve 51 are balanced, that is, when the ground pressure of the float 23 is reduced and returned to the set pressure, the cylinder 38 stops and supports each link 27, 28 in a fixed state, Continuing rice planting work at a constant planting depth.

On the other hand, if the seedling platform 20 becomes lighter due to a decrease in the amount of seedlings loaded on the platform 20, the spring 3
The lower link 27 rotates with the pin 27'' as a fulcrum in the direction of contracting the seedling stand 20, and moves the core shaft 42 and the operating shaft 49 forward against the spring 46, thereby reducing the pressure reducing spring 50. The spring pressure is weakened to lower the throttle oil pressure of the pressure reducing valve 51, the pressure oil in the cylinder 38 is returned to the tank 40 via the throttle valve 41 and the pressure reducing valve 51, and the lift arm 33 is rotated downward to lower the seedling stand 20. Lower link 27 is rotated downward in the direction of collapse, and cylinder 38
When the hydraulic pressure of the pressure reducing valve 51 is balanced, that is, when the ground pressure of the float 23 is increased and returned to the set pressure, the cylinder 38 stops and the rice planting operation continues at a constant planting depth.

Furthermore, when the weight of the seedlings on the seedling platform 20 and the force of the spring 37 are balanced, for example, when the field becomes deep, the float 23 is pushed up by the muddy soil and the float 2
3 becomes high, the seedling stand 20 is displaced in the direction of falling down using the pin 27'' as a fulcrum, the core shaft 42 is retracted, and the cylinder 38 is moved in the same manner as when the weight of the seedling stand 20 increases. The lift arm 33 and lower shaft 27 are raised and rotated through the seedling stand 20.
is displaced in the direction of standing up, the hydraulic pressures of the cylinder 38 and the pressure reducing valve 51 are balanced, the ground pressure of the float 23 is returned to the set value, and rice planting work is continued at a constant planting depth.

On the other hand, when the field becomes shallow and the float 23 descends and the ground pressure of the float 23 becomes low, the seedling stand 20 is displaced in the direction of standing up using the pin 27'' as a fulcrum, and the weight of the seedling stand 20 is Similarly to the reduction, the core shaft 42 is advanced against the spring 46, the pressure oil in the cylinder 38 is returned to the tank 40, the lift arm 33 and the lower link 27 are rotated downward, and the seedling stand 20 is displaced in the direction of falling down. Then, the hydraulic pressure of the cylinder 38 and the pressure reducing valve 51 are balanced, the ground pressure of the float 23 is returned to the set value, and the rice planting operation is continued at a constant planting depth.

Next, when the operation of the hydraulic cylinder 38 by the pressure reducing valve 51 of the valve 29 is interrupted and the float grounding load adjustment operation is canceled, the release lever 59 is rotated to open the release valve 58, and the release valve 58 is opened via the bypass oil pipe 57. The oil pipes 52 and 53 are short-circuited, and the cylinder 38 and pump 39, which are communicated with the release valve 58 via the switching valve 14 and the throttle valve 41, are short-circuited to the tank 40, and the cylinder 38 is connected to the tank 40 regardless of the hydraulic pressure control of the pressure reducing valve 51. The oil pressure of the float is set to approximately zero, and the float can be driven on the road without the need for adjusting the ground contact pressure of the float.

"Effects of the Invention" As is clear from the above embodiments, the present invention is such that the planting section 18 is installed in the riding section 1 so as to be able to rise and fall freely via the elevating link 28 and the hydraulic cylinder 38, and is grounded on the planting field surface. A rice transplanter in which a float 23 supporting the planting part 18 is attached to the lower surface of the rice transplanter is provided with a back pressure regulating valve 29 operated by a displacement force of the lifting link 28 that is proportional to a change in the supporting force of the planting part 18, A bypass oil pipe 57 is provided in parallel to the pressure reducing valve 51 of the valve 29, and a release valve 58 is provided in the bypass oil pipe 57 to interrupt the lifting and lowering operation of the planting part 18 by the valve 29.
Since the release valve 58 for draining the hydraulic oil from the hydraulic cylinder 38 is provided, the planting section 18 supported by the elevating link 28 can be easily attached and detached, and the planting section 18 can be removed from the riding section 1. The work of removing, transporting and storing the plant can be performed easily and efficiently, and when moving with the planting section 18 lifted, the pressure reducing valve 51 is placed in a no-load state by operating the release valve 58. The pressure reducing valve 51
The release valve 58 can be handled safely by preventing malfunctions and improving durability, and by providing the bypass oil passage 57 in the valve 29, the release valve 58 has a simple structure and is easy to operate. This has practical effects.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, in which Fig. 1 is a schematic side view of a riding rice transplanter, Fig. 2 is a plan view of the same,
FIG. 3 is an explanatory diagram of the operation, FIG. 4 is a sectional side view of the main part, and FIG. 5 is a plan external view. 1... Riding part, 18... Planting part, 23... Float, 28... Top link (elevating link), 2
9...Back pressure adjustment valve, 38...Hydraulic cylinder,
51...Pressure reducing valve, 57...Bypass oil pipe, 58...
...Release valve.

Claims (1)

[Scope of utility model registration request] A lifting link 28 and a hydraulic cylinder 3 are provided in the riding section 1.
In a rice transplanter in which a planting part 18 is installed to be able to rise and fall freely through a rice transplanter 8, and a float 23 is attached to the lower surface of the float 23 to support the planting part 18 by being grounded on the planting field surface, the supporting force of the planting part 18 is A back pressure regulating valve 29 is provided which is operated by the displacement force of the elevating link 28 that is proportional to the change in pressure, and a bypass oil pipe 57 is provided in parallel to the pressure reducing valve 51 of the valve 29. A float ground load adjustment device for a rice transplanter, characterized in that a release valve 58 for interrupting the flow is provided in the bypass oil pipe 57.