JPH01265805A - Hydraulic apparatus of machine for farm working - Google Patents

Abstract

PURPOSE:To stabilize the operation time of a pitching cylinder and enable to reduce the size of a hydraulic pump, by joining a returned oil from a rolling switch valve with a sent oil from the hydraulic pump to supply the joined oils into the pitching cylinder. CONSTITUTION:When there are high and low places on a field in the longitudinal direction of a frame, floats 29 are vertically moved with respect to the frame and a switch valve 41 for pitching is switched. When a pitching cylinder 34 is elongated, the left and right patty field wheels 7 are simultaneously moved only to the same distances vertically with respect to the frame and the working frame is lifted or fallen with respect to the plow sole to constantly maintain a depth for planting. The returning part T2 of a switch valve 42 for rolling is communicated with the inputting port P1 of the switch valve 41 for pitching. Thus, a sent oil separately flown from a flow priority valve 43 and a returned oil from the switch valve 42 for rolling are joined with each other and supplied into the switch valve 41 for pitching, thereby permitting to stabilize the operation time of the pitching cylinder and reduce the size of the hydraulic pump.

Description

DETAILED DESCRIPTION OF THE INVENTION A. [1] [Field of Industrial Application] The present invention relates to a hydraulic system for controlling the elevation and horizontal tilting of a working part in an agricultural machine such as a rice transplanter.

[Prior art] As a hydraulic system for controlling the work machine installed in agricultural work machines such as walk-behind rice transplanters, the work machine is raised and lowered by a pitching cylinder based on the detection results of a ground pressure sensor, and the height of the work machine relative to the field is adjusted. There is a system in which the work machine is always kept constant, and the work machine is always kept horizontal by tilting the work machine in the left and right direction using a rolling cylinder based on the detection result of a tilt sensor that detects the horizontal inclination of the work machine.

[Problems to be Solved by the Invention] By the way, since the hydraulic pump of the above-mentioned hydraulic system is driven by engine power, the double-acting rolling cylinder is prone to hunting when the engine speed fluctuates. However, there was a problem in that stable horizontal control could not be obtained.

Additionally, since hydraulic oil was sent to the rolling cylinder and pitching cylinder separately from a hydraulic pump, a pump with a large discharge volume was required, which resulted in a large load on the engine and an increase in the size of the entire device. .

Configuration of the Invention [Means for Solving the Problems] In order to solve the above problems, the present invention was constructed as follows.

That is, the hydraulic system for an agricultural working machine according to the present invention includes a pitching cylinder that controls the A lowering of the working part, and a double-acting rolling cylinder that controls the left and right tilting of the working part. The present invention is characterized in that the oil is sent at a constant pressure to the rolling switching valve that controls the rolling cylinder, and that the tank return boat of the rolling switching valve is communicated with the input port of the pitching switching valve.

[Function] Since the oil from the hydraulic pump is sent to the rolling switching valve at a constant pressure, the operating time of the rolling cylinder is always constant regardless of the engine speed, and the tilting control of the work machine is stabilized.

Additionally, by communicating the tank return port of the rolling switching valve with the input port of the pitching switching valve, the return oil from the rolling cylinder is reused as hydraulic oil for the pitching cylinder, which stabilizes the operating time of the pitching cylinder. At the same time, the hydraulic pump can be downsized.

[Example] The embodiments shown in the drawings will now be described.

A paddy field agricultural machine 1 shown in FIGS. 1 to 6 is a walking type fertilizing rice transplanter, and an engine 3 is disposed in the front part of a transmission case 2, and a rotary cover tube is mounted on both left and right sides of the mission case 2. 5, 5 are provided protrudingly, and chain cases 6, 6 are provided at the tip of the rotary cover tube so as to be rotatable downwards, and a work machine is mounted at the rear end of the chain case 6. A paddy wheel 7.7 is attached as a supporting ground wheel. moreover,
A main frame 9 is projected rearward from the rear of the mission case 2, and a planting part 10 is provided at the rear end.

The planting section 10 has a seedling tank 11. It includes a planting device 12, a handle 13, and the like. The seedling tank 11 is slidably supported by a rail 15 and a support frame 16 attached to a rear frame 14, and is laterally reciprocated by a lateral movement device 17. In addition, the planting device 12 has a planting rod 18 that moves up and down in a predetermined trajectory, and a planting rod 19 provided at the tip of the rod that picks up seedlings from the seedling mat held in the seedling tank 11. Divide it, take it out, and plant it in the field.

A fuel tank 21 and a fertilizer tank 22 are provided in the -E section of the fuselage. The fertilizer in the fertilizer tank 22 is delivered to a delivery pipe 24 by a delivery device 23, and is supplied to the field from the lower end of the delivery pipe. The upper parts of these machines are covered with a bonnet 25, and a spare seedling stand 26 is further provided above the bonnet 25. Also, on the underside of the aircraft,
A float 29 whose rear part is rotatably connected to a support shaft 27 and whose front part is supported by a variable-length link 28.
is height-adjustable. The float 29 also serves as a height sensor that detects the height of the aircraft relative to the field.

The hydraulic system for controlling the working machine of this 111 transplanter 1 has a configuration as shown in FIG. 3 or FIG.
0 will be explained.

A valve device 31 is provided at the top of the mission case 2, and a hydraulic pump 32 is provided at the side of the mission case 2. A pitching cylinder 34 for lifting and lowering the work machine is fixedly provided rearward at the lower part of the back of the valve device 31, and a link plate 35 is attached horizontally to the left and right to the rear end of the pitching cylinder. Both left and right ends of the plate are connected to the rotary cover tube 5 by connecting rods 36 and 36.
The swing arm 38 (L, R) is connected to the swing arm 38 (L, R) projecting from the top surface of the swing arm 5. Of the connecting rods 36 (L, R), the left connecting rod 36 (L) has a rolling cylinder 39 interposed in its intermediate portion for tilting the working machine from side to side.

Note that, since the hydraulic pump 32 is driven by the power of the engine 3, its discharge capacity varies depending on the engine rotation speed.

The valve device 31 includes a pitching switching valve 41, a rolling switching valve 42, a flow priority valve 43,
A check valve 44 and relief valves 45,46 are provided. In the configuration shown in FIG. 3, the secondary side of the relief valve 45 is connected to the tank, and in the configuration shown in FIG. 4, the secondary side of the relief fr 45 is connected to the return oil path of the rolling switching valve 41. Note that PI and P2 in the figure are input ports on the pump side, and T+ and T2 are return ports on the tank side. As shown in FIG. 5, the flow priority valve 43 is sandwiched between a rolling switching valve 42 on the 112th side and a pitching switching valve 41 on the lower side, and each valve has a common body. Since the help device 31 is functionally arranged and integrated with the help device 31a, the /help device 31 is compact.

Further, the spool 43a of the flow priority valve 43 is removably fitted into the body 31a with a screw plug 47.

A pendulum 50, which is a tilt sensor for detecting the left-right tilt of the aircraft body, swings in the left-right direction on a support frame 49 that projects obliquely from the top of the valve device 31 to the side (to the right in the illustrated example). It can be taken freely (=j).

A spool 42a of a rolling switching valve 42 is connected to the upper part of the pendulum rond 50a, so that the rolling switching valve 42 can be switched according to the swing of the pendulum in the left-right direction with respect to the body. Since the rolling switching valve 42 is disposed at the top of the valve device 31, the effective length L of the pendulum 50 can be increased, and a tilt sensor with high detection accuracy can be obtained. Reference numeral 54 in the figure is a rolling lock shaft, and by inserting the shaft into a hole 56 of the rod by operating a rolling lock lever 55 provided on the rear frame 14, the pendulum 50 is fixed at a neutral position, for example, for seedling loading. It is possible to prevent the horizontal control from being performed when the vehicle is running on the road or on the road.

On the other hand, a detection rod 57 attached to the float 29 is connected to a detection lever 58 attached to the spool 41a of the pitching switching valve, so that the pitching switching valve 41 can be switched in accordance with the vertical movement of the float 29. It has become.

Also, the tube 39a17 of the rolling cylinder 39)
A pilot check valve 60 and a check valve 62 adjacent to a throttle valve 61 are provided at the base. These valves may be provided across the four widths of the piping vibro, but such a configuration increases the diameter of the entire cylinder. In contrast, the configuration of the present embodiment is compact in that the diameter of the entire cylinder 39 is small.

When working in water II, if the tiller has a height in the left and right direction,
The tilt of the aircraft at that time is detected by the pendulum 50, which is a tilt sensor. When the aircraft is tilted upward to the left, the pendulum 50 swings to the right with respect to the aircraft, so the rolling switching valve 42 is switched in the direction in which the rolling cylinder 39 is extended. Then, the left chain case 6 rotates upward and the left wheel 7 (L) moves by -lr, so that the aircraft returns to a horizontal state. On the other hand, when the aircraft body is tilted to the left, the pendulum 50 swings to the left with respect to the aircraft body, so the rolling switching valve 42 is switched in the direction in which the rolling cylinder 39 is contracted.

Even if the working oil pressure sent from the hydraulic pump 32 fluctuates depending on the engine speed, the flow priority valve 43
and the relief valve 45, the rolling switching valve 4
2 is acted on by hydraulic oil at a constant pressure. Furthermore, by the action of the pilot check valve 60 and the check valve 62 with the throttle valve 61, when the work machine tilts toward the tilt adjustment wheel 7 (L) side, a runaway descent is prevented and the operation is slowed down. This prevents excessive tilting due to the weight of the working machine.

On the other hand, when there is elevation in the longitudinal direction, the float 29 moves up and down with respect to the aircraft body, and the pinching switching valve 41 is switched. When the binching cylinder 34 expands and contracts, the left and right rice field wheels 7, 7 simultaneously move up and down by the same amount with respect to the machine body.
As a result, the working machine descends A to the tiller to maintain a constant planting depth. Return report T2 of rolling switching valve 42
is the input port P of the pitching switching valve 41! Since the pitching switching valve 41 is connected to the pitching switching valve 41, the oil branched from the flow priority valve 43 and the return oil from the rolling switching valve 42 are combined and supplied.

[Effects of the Invention] Since the present invention is configured as described above, it produces the following effects.

By keeping the hydraulic pressure supplied to the rolling switching valve constant, the operation of the rolling cylinder for tilting the work machine is stabilized, preventing hunting during tilting control, and enabling stable tilting control. .

Furthermore, by supplying the return oil from the rolling switching valve to the feed oil from the hydraulic pump and supplying it to the pitching cylinder, the operating time of the pitching cylinder is stabilized, and the hydraulic pump can be downsized.

[Brief explanation of the drawing]

Fig. 1 is a side view of an agricultural machine as an example of the present invention;
The figure is a Y-plane view, Figures 3 and 4 are configuration diagrams of different hydraulic systems, Figure 5 is a front cross-sectional view of the valve device of the hydraulic system shown in Figure 3, and Figure 6 is a cross-section of the rolling cylinder. It is a diagram. ■...Walking rice transplanter (f% working machine), 7...Paddy wheel, 29...Float, 30...Hydraulic system, 31...
...Valve device, 32...Hydraulic pump, 34...Pitching cylinder, 39...Rolling cylinder, 4
1... Binching switching valve, 42... Rolling switching valve, 43... Flow priority valve. Patent applicant Iseki Agricultural Machinery Co., Ltd.

Claims (1)

[Claims] (1) In a hydraulic system for an agricultural machine that has a pitching cylinder that controls the elevation of the working part and a double-acting rolling cylinder that controls the left and right tilting of the working part, the oil sent from the hydraulic pump controls the rolling cylinder. A hydraulic system for an agricultural machine, characterized in that a constant pressure is supplied to a rolling switching valve, and a tank return port of the rolling switching valve is communicated with an input port of a pitching switching valve.