JPS6258913A - Hydraulic pressure change-over valve of hydraulic cylinder - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a hydraulic switching valve for a hydraulic cylinder, and can be used as a hydraulic device for lifting and lowering rotation of running wheels of seedling planting machines, seeding machines, etc.

Conventional technology A conventional single-bamboo transplanter uses the rotation of a valve installed in the valve chamber of the hydraulic circuit used to raise and lower the wheels on both the left and right sides of the vehicle, allowing water to flow from the hydraulic pump through the anti-return valve. An oil feeding process that sends oil into the hydraulic cylinder, an oil draining process that drains the oil in the hydraulic cylinder to the oil tank, a neutral process that returns the oil from the hydraulic pump to the oil tank, the oil feeding process, and the oil draining process. This hydraulic system has a shutoff stroke for shutting off oil supply from the hydraulic pump, and one switching passage for switching to each of these strokes.

Problems to be Solved by the Invention For example, in a seedling transplanter, during seedling cutting work, depending on the soil depth, the running wheels provided on both the left and right sides of the running body of the seedling transplanter have a float that detects this soil depth. Detect and with this detection,
By the rotational movement of the valves in the valve chambers of the left and right hydraulic circuits in contact with this detection float, the traveling wheels are individually raised or lowered, and the traveling vehicle body is maintained at a substantially constant position relative to the soil surface. In a seedling planting machine that inserts seedlings into a hydraulic cylinder, the depth of the soil becomes shallow, and as shown in Fig. 9, the rotation of the valve causes oil to be pumped into the hydraulic cylinder from the hydraulic pump. If a timing shift occurs in the rotational movement, the oil in the hydraulic cylinder may be drained into the oil tank. In such a situation, the vertical positions of the left and right running wheels will be different, causing the running The vehicle body may tilt and seedlings may not be planted at the specified W planting depth.

Means for Solving the Problems The present invention provides the following A and B by changing the position along the axial direction of a valve (3) rotatably provided in a valve chamber (2) of a hydraulic circuit (1). A hydraulic switching valve for a hydraulic cylinder.

A. Oil feeding process in which oil is sent from the hydraulic pump (4) to the hydraulic cylinder (6) via the check valve (5), and the oil in this hydraulic cylinder (6) is drained to the oil tank (7). A hydraulic switching passage (8) for switching to an oil drain stroke.

B. A neutral stroke in which the oil sent by the hydraulic pump (4) is returned to the oil tank (7), and a cutoff stroke in which the oil sent by the hydraulic pump (4) is cut off during the oil feeding stroke and the oil draining stroke. The configuration includes a neutral switching path (9) that switches between

Function of the Invention During seedling planting with a seedling transplanter, the detection floats on both the left and right sides slide on the surface of the soil, and the soil depth is detected by the vertical movement caused by sliding with the running soil surface. The valve (3) in the valve chamber (2) of each hydraulic circuit (1) connected to the valley detection float rotates, for example,
When the soil depth is deep, the valley detection float moves upward, and each valve (3) rotates, causing water to flow from each hydraulic pump (4) through the check valve (5) in the hydraulic switching passage (8). Hydraulic cylinder (
6) Oil is sent inside, the left and right running wheels of the running vehicle are lowered, and the relationship between the running vehicle and the soil surface is maintained at a substantially constant position, and seedlings are planted.

Contrary to the above, when the soil depth is shallow, the valley detection float moves down, each pulp (3) rotates, and each hydraulic cylinder (6
) The oil in each sleeve tank (
7) The oil is drained into the container, each of the traveling wheels is raised, and the relative position between the traveling vehicle body and the soil surface is maintained at a substantially constant position, and seedlings are planted. Also, when the vertical movement of the valley detection float stops, each valve (3) rotates, and the hydraulic switching passage (8) is shut off by this valve (3), and each hydraulic pump (
4) The oil is fed into the six oil tanks (7) through the neutral switching passage (9), and the lifting and lowering of each of the traveling wheels is stopped. When each valve (3) is in the neutral position, the oil sent from each hydraulic pump (4) is transferred to each neutral switching passage (9).
and refluxes into the 6 oil tank (7).

Effects of the Invention According to this invention, when each traveling wheel is raised or lowered, the oil sent from each hydraulic pump (4) is pumped through each valve (
3), oil is sent into each hydraulic cylinder (6) through each hydraulic switching passage (8), and
6) into each tank (7), and during this oil feeding stroke and oil draining stroke, a shutoff stroke to shut off oil supply from each hydraulic pump (4) and each hydraulic pump (4). At the time of the neutral stroke in which the oil is returned to the six oil tanks (7), the oil passes through each application switching passage (9) and is fed into the six oil tanks (7). Since there is no difference in timing between the rotational movements of the left and right valves (3), the traveling vehicle body does not tilt, so seedlings can always be planted at a predetermined depth.

Example In addition, in the example shown in 1, seedlings are planted 4! ! (10) is the running vehicle body (
11) A traveling transmission case (12) is provided at the front, a prime mover mounting stand (13) is provided at the front of this traveling transmission case (12), and a prime mover (14) is installed on the upper side of this prime mover mounting stand (13).
), a planting transmission case (15) is provided at the rear of the traveling vehicle body (11), and a handle (1B) is installed at the rear of the planting transmission case (15) in a state that tilts backward in the vertical direction. The base is fixed to the planting transmission case (15).

The base of a wheel case (18) having an arm (17) projecting upward is pivotally mounted on both left and right sides of the traveling transmission case (12) so as to be movable up and down. A running wheel (18) is mounted on the shaft for interlocking movement. A seedling transplanting device (20) that swings up and down via a crank mechanism is provided on both left and right sides of the lower part of the planting transmission case (15),
Above the handle (IG), there is a seedling stand (16) arranged in a backward-slanting manner along the handle (16) and supported so as to be movable from side to side.
21), and this seedling stand (21) is connected to a reciprocating mechanism provided in the planting transmission case (15) via a moving rod and an arm.

Detection floats (22), (22) are arranged on the left and right sides of the lower part of the traveling vehicle body (11), a ground leveling float (23) is arranged in the center, and a A hydraulic system is provided on both sides, and a hydraulic circuit (1) through which oil is sent from a hydraulic pump (4) of this hydraulic system consists of a hydraulic pressure switching passage (8) and a neutral switching passage (9). Valve chambers (2), (2) are provided in the hydraulic switching lane (8) and the neutral switching path (9), and a round rod-shaped valve (3) passing through the valve chambers (2), (2) is provided. ), a valve arm (27) is fixed to the shaft end of the valve (3), and a backflow prevention valve (5) is provided at the starting end of the hydraulic pressure switching passage (8). A notch (24) is provided on the outer periphery of the valve (3) in the valve chamber (2) portion of the hydraulic pressure switching passage (8), and a notch (24) is provided in the outer circumference of the valve (3) in the valve chamber (2) portion of the neutral switching passage (9). The valve (3) has a through hole (25) in its axial center and a notch (26) in its outer periphery, and the rear part of the detection float (22) has a mounting bracket attached to the rear part of the vehicle body ( 11) The front part is rotatably supported on a horizontally installed shaft, and the front part has a connecting rod between the mounting bracket (2B) provided at the front part and the valve arm (27) fixed to the valve (3). ) (29), and the ground leveling flow) (23) At the rear, a mounting bracket provided at the rear is rotatably supported on a shaft installed laterally from the handle (16), and at the front, The structure is such that it is pivotally supported by a link mechanism between a mounting bracket provided on the part and a shaft installed laterally from the traveling vehicle body (11) so as to be able to move vertically in a downwardly resilient manner.

Hydraulic cylinders (
6) and a piston (30), the piston (30
) and the arm (17) of the wheel case (18) are connected, and when the detection float (22) moves upward individually, the connecting rod (29) and the valve arm (
The valve (3) rotates via the hydraulic pump (4), and the oil sent from the hydraulic pump (4) passes through the hydraulic switching passage (8), the reverse wave prevention valve (5), and the valve chamber (27). 2) The valve in (
Oil is fed into the hydraulic cylinder (6) through the notch (24) in the piston (30), and the piston (30) protrudes.
0), the wheel case (18) individually rotates downward, and the traveling wheel (19) descends;
At this time, the valve chamber (2) of the neutral switching passage (9)
is shut off by the valve (3) so that the oil sent from the hydraulic pump (4) is not sent to the neutral switching passage (9).

Contrary to the above, when the detection flow (22) moves down individually, the valve (3) rotates via the connecting rod (29) and the valve arm (27), and the hydraulic cylinder (6) is drained into the oil tank (7) through the notch (20) of the valve (3) in the valve chamber (2) of the hydraulic pressure switching passage (8), and is drained into the oil tank (7).
0) is retracted and the wheel case (18) is retracted by the piston (3
0), the wheel cases (18) are individually rotated upwardly, and the traveling wheels (19) are raised. At this time, the oil sent from the hydraulic pump (4) is pumped from the neutral The valve (3) in the valve chamber (2) of the switching passage (9)
) The oil is fed into the oil tank (7) through the notch (26).

Each of the above detection flows) When the vertical movement of (22) stops,
(29) and the valve arm (2)
The respective valves (3) are rotated through the respective neutral switching passages (9), and the oil sent from the respective hydraulic pumps (4) is rotated through the respective neutral switching passages (9).
), the oil is sent to each oil tank (7) through the six holes (25) provided in the valve (3) of the valve chamber (2), and at this time, each oil pressure switching passage (8 ), the valve treasure (2) is blocked by each valve (3),
The oil sent from each partial pressure pump (4) is configured so that it is not sent to each hydraulic pressure switching passage (8), and when each valve (3) is neutral, the oil sent from each partial pressure pump (4) The oil to be sent from the valve chamber (
The structure is such that the water is returned to the respective tanks (7) through the chain holes (25) provided in the valves (3) of 2), and at this time, the valve chambers (2) of the respective pressure switching passages (8) ) is the valve (
3), the oil sent from the respective pressure pumps (4) is not sent to this hydraulic pressure switching passage (8).

Due to the rotation of the prime mover (14), the running wheels (18), (1
9) and the seedling planting machine (10) are driven to rotate, the traveling vehicle body (11) advances, and the detection floats (22), (22) and the soil leveling flow (23) slide on the soil surface. The seedlings loaded on the seedling platform (21), which is reciprocated from side to side by the planting transmission case (15), are transferred from the seedling take-out port to the seedling transplanting device (2).
0) and the detection floats (22), (22
) and the soil leveling float (23), the seedlings are inserted into the tube using the transplanting device (20). During this seedling planting work, the valley detection float (22) is used to Each detection float (22) slides on the soil surface while moving up and down individually depending on the depth, and detects the pressure with the soil topsoil surface, and each detection float (22) detects higher pressure as the soil depth increases. The float (22) moves upward, rotates the valve (3) via the connecting loft (29) and the valve arm (27), and the oil sent from the hydraulic pump (4) is transferred to the hydraulic switching passage (8).
) into the hydraulic cylinder (6), and the piston (
30) to protrude and rotate each wheel case (18) t-downward to lower each running wheel (18) individually.
4jA When the upward movement of each detection float (22) stops, the oil sent from the hydraulic pump (4) is transferred to the neutral switching passage (9).
The oil is sent into the oil tank (7) through the oil pressure switching passage (
8) is shut off by the valve (3), and each traveling wheel (19
) are stopped individually and the traveling vehicle body (11) is held at a substantially constant position relative to the soil surface, and seedling planting is performed.

Also, contrary to the above, when the soil depth becomes shallow, the valley detection float (22) detects a low pressure, and this detection flow)
(22) moves downward and rotates the valve (3) via the connecting rod (29) and the valve arm (27);
The oil in the hydraulic cylinder (6) passes through the hydraulic switching passage (8) and is drained into the oil tank (7), and the oil sent from the hydraulic pump (4) passes through the neutral switching passage (9). ) into the oil tank (7), the piston (3o) retracts and rotates each wheel case (1) upward, raising each traveling wheel (19) individually. When the valley detection float (22) stops moving downward, the oil sent from the hydraulic pump (4) passes through the neutral switching passage (9) and enters the oil tank (
7), and the hydraulic pressure switching passage (8) is connected to the valve (
3), each traveling wheel (19) is stopped individually, and the traveling vehicle body (11) is held at a substantially constant position with respect to the soil surface, and seedling planting is performed.

When the valve (3) is neutral, the hydraulic pump (
4) The oil sent from the tank passes through the neutral switching passage (9) and flows back into the oil tank (7).

The oil sent from the hydraulic pump (4) is supplied to the valve (
3) causes oil to be sent into the hydraulic cylinder (6) through the hydraulic switching passage (8),
6) is drained into the oil tank (7) through the hydraulic pressure switching passage (8), or is returned through the neutral passage (9) into the oil tank (7). Since there is no deviation in the cutting timing of the valve (3), the traveling vehicle body (11) does not tilt.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is an enlarged front sectional view of a part thereof, FIGS. 2 to 6 are enlarged side sectional views showing the operation of a part thereof, and FIG. 8 is a partially cutaway plan view of the seedling transplanter, and FIG. 9 is an enlarged side sectional view showing the operation of a portion of the conventional device. In the figure, (1) is the hydraulic circuit, (2) is the valve chamber, and (3) is the hydraulic circuit.
) indicates the valve, (4) indicates the hydraulic pump, (5) indicates the check valve, (6) indicates the hydraulic cylinder, (7) indicates the oil tank, (8) indicates the hydraulic switching passage, and (9) indicates the neutral switching passage. .

Claims (1)

[Scope of Claims] A hydraulic cylinder in which the following A and B are provided at different positions along the axial direction of a valve (3) rotatably provided in a valve chamber (2) of a hydraulic circuit (1). Hydraulic switching valve. A. Oil feeding process in which oil is sent from the hydraulic pump (4) to the hydraulic cylinder (6) via the check valve (5), and the oil in this hydraulic cylinder (6) is drained to the oil tank (7). A hydraulic switching passage (8) for switching to an oil drain stroke. B. A neutral stroke in which the oil sent by the hydraulic pump (4) is returned to the oil tank (7), and a cutoff stroke in which the oil sent by the hydraulic pump (4) is cut off during the oil feeding stroke and the oil draining stroke. Neutral switching path (9) for switching to and from.