JPH03555Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention automatically redirects the liquid transport path that was discharging the liquid when the liquid level in the liquid storage tank such as a slurry injector drops to a predetermined position during work. This invention relates to a liquid transport device for a liquid storage tank in which the circuit is switched to a circulation circuit so that the liquid circulates within the circuit.

Conventionally, with agricultural machines such as slurry injectors that have a tank, pump, etc. attached to the rear of the tractor, the operator in the driver's seat constantly checks the liquid level in the tank and performs work to prevent the tank from emptying. The pump is stopped and fluid is refilled. For this reason, people may accidentally continue working without noticing that the tank is empty, causing the pump to run dry.
The drawback was that it often caused the pump to seize up.

The present invention was devised in view of the above-mentioned actual situation and to eliminate these drawbacks. When the liquid level in the tank drops to a predetermined level, the liquid is drained and the liquid transport path is automatically switched to a circulation circuit, allowing you to work without accidentally realizing that the tank is empty. Continuing, you can reliably prevent the pump from seizing up.
The operator who is present during operation can work without constantly checking the liquid level in the tank, and an empty tank can be easily refilled with liquid using the same pump, increasing work efficiency. It is an object of the present invention to provide a liquid transport device for a liquid storage tank that can significantly improve the performance.

In order to achieve the above object, the technical means adopted by the present invention is to provide a liquid transport path at the liquid discharge port of the liquid storage tank with a pressure pump that sends the discharged liquid to the discharge port side. A circulation circuit is provided in the transportation path to circulate the flow from the discharge port side to the inlet side of the pressure pump by the operation of a switching valve provided on the outlet side of the pressure pump, and the switching valve is linked to the amount of liquid in the liquid storage tank. When the liquid level falls below a predetermined level, the liquid transport path is switched to a circulation circuit, and on the inlet side of the pressure pump, the liquid transport path communicating with the liquid discharge port is switched to a suction pipe for liquid replenishment. The present invention is characterized in that a switching valve is provided, and by switching the switching valve, liquid is replenished from the liquid transport path to the liquid storage tank via the liquid discharge port.

The structure of the present invention will be described with reference to the embodiment shown in the drawings. 1 is a tractor equipped with a driving operation section 2; 3 is a slurry injector mounted on the rear of the tractor 1; The machine travels through the field while injecting the slurry in the liquid storage tank 4 into the soil from the nozzle 5 at the rear of the machine.

Reference numeral 6 denotes a liquid discharge pipe, and a liquid discharge port 7 opens upward at the proximal end of the discharge pipe 6 that passes through the lower part of the liquid storage tank 4, and extends to the discharge port a side. The nozzle 5 mentioned above is attached to the tip. A pump 8 for pumping the liquid toward the discharge port a is interposed in the middle thereof, and a liquid transport path A is formed.

Reference numeral 9 denotes a short-circuit pipe branched from a position on the discharge port a side of the pump 8 of the discharge pipe 6 and connected to the discharge port 7 side, and a switching valve 10 provided at the branch portion on the pump 8 outlet side. By this switching operation, a circulation circuit B is formed in the liquid transport path A in which the liquid flows back from the outlet side to the inlet side of the pump 8.

Reference numeral 11 denotes a swinging arm that swings about 12 as an axis. A swinging lever 13 of the switching valve 10 is locked to one end of the swinging arm 11 via an elongated hole 14. At the other end, the discharge pipe 6
The cylinder 1 is installed upright in communication with the discharge port 7 side of the
5 piston rods 16 are locked through elongated holes 17. The switching valve 10 rotates in conjunction with the vertical movement of the piston 18, so that the liquid transport path A can be freely switched to the circulation circuit B. A spherical float 19 opens and closes the discharge port 7, and is built into a cylindrical filter 20 that covers the discharge port 7 and is inclined upwardly in the liquid storage tank 4. It floats, and when the liquid level b decreases to near the bottom of the liquid storage tank 4, it closes the discharge port 7 due to its own weight. Reference numeral 21 denotes a liquid suction pipe for liquid replenishment, and by switching the switching valve 22 provided on the inlet side of the pump 8, the liquid transport path through which the discharge port 7 communicates with the inlet side of the pump 8 can be connected to the inlet side of the pump 8. The liquid suction pipe 21 can be switched to a liquid transport path communicating with the inlet side. 23 is the switching valve 10
It is a coil bullet machine that elastically holds the switch in the switching position.

Reference numeral 24 denotes a liquid level meter, which is connected between a vertical liquid level display section 25 formed of a transparent pipe and a vertical section 27 that penetrates an upper plate 26 and inserts its lower part into the liquid storage tank 4. The lower bent part is bent into an S-shape and stores the display liquid C, and the air d is sandwiched between the liquid that has entered the vertical part 27 and the display liquid C.
An upper bend is formed for sealing. Note that the liquid amount display section 25 may be formed of a large-diameter pipe, as shown in FIG. 4.

In the above configuration, if the pump 8 is driven while the tractor 1 is traveling, the spherical float 19 floats above the filter 20, so that the liquid in the liquid storage tank 4 is discharged from the discharge port 7. The liquid is injected into the soil of the field from the nozzle 5 attached to the discharge port a side through the liquid transport path A by pressure feeding by the pump 8 (see FIG. 2). Then, as the liquid level b in the liquid storage tank 4 decreases, the float 1
9 descends and when it reaches a predetermined position, the float 19 that has descended closes the discharge port 7, so the suction of the pump 8 creates a negative pressure on the discharge port 7 side of the discharge pipe 6.
The liquid in the cylinder 15 communicating with the discharge pipe 6 decreases, and the piston 18 descends. The piston rod 16 of the lowered piston 18 swings the swinging arm 11 that is locked through the elongated hole 17, so that the switching valve 10 with the swinging lever 13 locked at one end of the swinging arm 11 rotates. switch the liquid transport path A to the circulation circuit B side. Therefore, the discharge pipe 6
The liquid inside is not sent to the discharge port a side,
Since it circulates in the circulation circuit B, the liquid storage tank 4
I didn't notice that the liquid level b inside had fallen to the specified position,
Even if the pump 8 continues to operate, the pump 8 will not seize up (see Figure 3). Moreover, since the liquid only circulates in the circulation circuit, the load applied to the pump 8 can be reduced. Then, with the switching valve 10 switched to the above-mentioned circulation circuit B, the switching valve 22 is operated to switch the liquid suction pipe 2.
1 is opened on the inlet side of the pump 8, the liquid from the liquid suction pipe 21 is pumped from the circulation circuit B to the liquid storage tank 4 side by the drive of the pump 8. Liquids can be replenished.

Also, during work, the water pressure at the bottom of the liquid storage tank 4 is transmitted to the display liquid C via the air d by the liquid that has entered the vertical part 27. The liquid in the storage tank 4 will not become opaque or the solid content mixed in will not impair the function, and the liquid level can be accurately confirmed just by visual inspection. It can be made smaller than the liquid level difference in the liquid storage tank 4, and the structure of the liquid level meter 24 is simplified. It can also be installed nearby. In addition, if the liquid display section 25 is formed of a large diameter pipe, the vertical movement stroke of the display liquid C can be further reduced, which is convenient.

In short, the present invention provides a liquid transfer path in which a pressure pump is interposed to send the discharged liquid to the discharge port side at the liquid discharge port of a liquid storage tank, and the liquid transfer path is connected to the pressure pump outlet side. A circulation circuit is provided in which the flow returns from the discharge port side to the inlet side of the pressure pump by the operation of a switching valve provided at A switching valve is provided on the inlet side of the pressure pump to switch the liquid transport path communicating with the liquid discharge port to a suction pipe for liquid replenishment. The structure is configured so that liquid is replenished from the liquid transport path to the liquid storage tank through the liquid discharge port by switching operation, so when the liquid level in the liquid storage tank drops to a predetermined position, the liquid is discharged to the discharge port side. The liquid transport path that had previously been in operation was automatically switched to a circulation circuit, and the liquid circulated within the circulation circuit with only a slight load, allowing the operator in the operation section to accidentally notice that the liquid storage tank had become empty. Even if you continue working without worrying about inadvertently burning out the pump, the operator can work without constantly checking the liquid level in the liquid storage tank. Moreover, when the liquid storage tank becomes empty,
This has extremely useful practical effects, such as being able to easily replenish liquid by simply switching the switching valve provided on the inlet side of the pressure pump, thereby significantly improving work efficiency.

[Brief explanation of the drawing]

The drawings show an embodiment of the liquid transport device for a liquid storage tank according to the present invention, in which Fig. 1 is an overall side view of the slurry injector, Fig. 2 is a longitudinal sectional view showing the liquid discharge state, and Fig. 3 The figure is a longitudinal cross-sectional view showing a liquid circulation state, and FIG. 4 is a cross-sectional view of main parts showing another embodiment. In the figure, 4...Liquid storage tank, 7...Liquid outlet, 8...Pressure pump, 10...Switching valve, A
...Liquid transport path, B...circulation circuit, a...discharge port.

Claims (1)

[Scope of utility model registration request] A liquid transport path is provided at the liquid discharge port of the liquid storage tank, and a liquid transport path is provided with a pressure pump that sends the discharged liquid to the discharge port side, and a switching valve provided at the outlet side of the pressure pump is connected to the liquid transport path. Therefore, a circulation circuit is provided for returning the flow from the discharge port side to the inlet side of the pressure pump, and the switching valve is linked to the liquid level in the liquid storage tank, so that when the liquid level falls below a predetermined level, the liquid transport path is switched off. At the same time, a switching valve is provided on the inlet side of the pressure pump to switch the liquid transport path communicating with the liquid outlet to a suction pipe for liquid replenishment, and by switching the switching valve, the liquid outlet is 1. A liquid transport device for a liquid storage tank, characterized in that the device is configured to supply liquid to the liquid storage tank from a liquid transport path through the liquid storage tank.