JPH07197903A - Water storage tank - Google Patents

Abstract

PURPOSE:To provide a water storage tank for operating a hydraulic cylinder of high reliability in the simple structure, where water can be automatically changed and the hydraulic cylinder can be securely operated even in the case of a water failure. CONSTITUTION:An apparatus comprises an inflow port 31 having a constant water level valve 10 and adapted to flow fresh water, a water supply port 16 to a hydraulic cylinder 1, a water return port 17 from the hydraulic cylinder 1, and an overflow port 14 for discharging water outside. The overflow port 14 is positioned above a water stopping level 12 of the constant water level valve 10 and under a water level 21 inside a reservoir tank 7, which is elevated in the case where there is no overflow when water staying inside the hydraulic cylinder 1 returns to the reservoir tank 7. The supply port 16 is located under a water level 13 inside the reservoir tank 7, lowered in the case where water does not flow through the water inflow port 31 when the water staying inside the reservoir tank 7 is fed to the hydraulic cylinder 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water storage tank for storing water as hydraulic fluid for hydraulic cylinders.

[0002]

2. Description of the Related Art Conventionally, hydraulic cylinders have been widely used as high-load cylinders, but recently hydraulic cylinders operated by hydraulic pressure have been used for special purposes. It was

That is, from the viewpoint of prevention of oil pollution and fire prevention, hydraulic cylinders have come to be used, for example, for raising and lowering the movable floor of a movable floor pool and for raising and lowering the stage of a theater.

Generally, in a hydraulic cylinder, oil is supplied from an oil tank to the hydraulic cylinder to operate the hydraulic cylinder,
Next, oil is discharged from the hydraulic cylinder to return the hydraulic cylinder to the original state. The discharged oil is returned to the oil tank and the same oil is always used.

However, in the case of a hydraulic cylinder, if the same water is used all the time, problems such as water spoilage may occur. Therefore, it is possible to regularly replace the water in the water storage tank at relatively short intervals. is necessary.

Therefore, a method may be used in which the water discharged from the hydraulic cylinder is drained directly without returning to the water storage tank. In this case, however, the same amount of water as the water discharged from the hydraulic cylinder is used. It is necessary to supply water to the water storage tank each time.

This water supply is normally carried out automatically by using a constant water level valve such as a ball tap. However, when water cutoff occurs, the water level in the water storage tank is lowered because water is not supplied and the hydraulic cylinder is operated. It has the drawback that it cannot be activated.

The present invention has been made in view of the above points, and an object thereof is to automatically replace water for operating a hydraulic cylinder, have a simple structure, and ensure the hydraulic cylinder even if water is cut off. It is to provide a highly reliable water storage tank for operating a hydraulic cylinder.

[0009]

In order to solve the above-mentioned problems, the present invention has a new water level tank which stores water as hydraulic fluid for a hydraulic cylinder and which has a constant water level valve which opens when the water level falls below the water stop level. It is equipped with a water inlet for inflowing water, a water supply inlet for the hydraulic cylinder, a water return outlet from the hydraulic cylinder, and an overflow outlet for discharging the water to the outside. Above the water level of the valve and below the water level in the water tank, which rises when there is no overflow when the water in the hydraulic cylinder returns to the water tank, while supplying water to the water level cylinder The position of the mouth is lower than the water level (minimum water level) in the water storage tank, which is lowered when water in the water storage tank is sent to the hydraulic cylinder because the water does not flow from the water inlet. Characterized in that it is arranged.

[0010]

[Operation] When water is supplied to the hydraulic cylinder, the water level in the water storage tank will decrease from the water level before the operation to the water level reduced by the amount of water sent into the hydraulic cylinder. New water is supplied to the tank, and the water level stops at the water level of the constant water level valve.

On the other hand, when the water from the hydraulic cylinder returns, the water level in the water tank rises from the water stop position of the constant water level valve to the water level at the same level as the overflow port,
Then, the water returning from the hydraulic cylinder is drained to the outside through the overflow port.

As a result, new water is supplied to the water storage tank, and old water is automatically discharged while being diluted.

Further, even when new water is not supplied from the water inlet due to temporary water interruption, the lowest water level in the water storage tank is above the water supply opening to the hydraulic cylinder. Just by changing the water level in the water tank,
It does not hinder the operation of the hydraulic cylinder.

[0014]

FIG. 1 is a diagram showing a schematic structure of a water storage tank for operating a hydraulic cylinder according to the present invention. 7 in the figure
Is a water storage tank, and the water storage tank 7 has a water inlet 31 from the outside and a water supply port 16 to the hydraulic cylinder 1.
And a water return port 17 from the hydraulic cylinder 1 and a water overflow port 14.

A constant water level valve 10 composed of a ball tap is attached to the inflow port 31, and when the water level in the water storage tank 7 becomes lower than the stop water level 12 of the constant water level valve 10, it opens to allow tap water to flow in. There is.

The overflow port 14 is located above the water shutoff level 12 of the constant water level valve 10, and when the water in the hydraulic cylinder 1 returns to the water storage tank 7 and no overflow occurs, the water shutoff position is set. It is arranged so as to be below the water level 21 in the water storage tank 7 rising from 12.

The water supply port 16 has a water level in the water storage tank 1 (minimum water level) which is lowered from the water level 11 when tap water is not supplied when the water in the water storage tank 7 is sent to the hydraulic cylinder 1. It is arranged so as to be below 13.

On the other hand, a pump 6 driven by a motor 5 and a check valve 8 are mounted in a pipe from the supply port 16 to the hydraulic cylinder 1, and the hydraulic cylinder 1 and the return port 17 are provided.
An on-off valve 4 and a throttle valve 9 are installed in the pipe leading to. A rod 2 is attached to the hydraulic cylinder 1, and a load 3 is placed on the rod 2.

Next, the operation of the water storage tank for operating the hydraulic cylinder will be described. In FIG. 1, when the rod 2 of the hydraulic cylinder 1 is lifted to lift the load 3, the on-off valve 4
The motor 5 is operated in the closed state. As a result, the water in the water storage tank 7 is sent to the hydraulic cylinder 1 by the pump 6 and the rod 2 rises.

At this time, the water level in the water storage tank 7 tries to decrease from the water level 11 before the operation to the water level 13 reduced by the amount of water sent into the hydraulic cylinder 1. Tap water is supplied into the tank 7, and the water level stops at the water stop level 12 of the constant water level valve 10.

When lowering the rod 2 of the hydraulic cylinder 1, the open / close valve 4 is opened with the motor 5 stopped. As a result, the water in the hydraulic cylinder 1 is pushed out by the load 3, passes through the on-off valve 4 and the throttle valve 9 and returns to the water tank 7 through the return port 17, and at the same time, the rod 2 descends. At this time, the water in the hydraulic cylinder 1 does not flow back to the pump 6 side by the check valve 8 but receives a predetermined resistance by the throttle valve 9 and slowly descends the rod 2.

At this time, the water level in the water storage tank 7 rises from the water stop position 12 of the constant water level valve 10 to the water level 11 at the same level as the overflow port 14, and then the hydraulic cylinder 1
The water returning from (the water amount of the difference between the water levels 12 and 13) is drained from the overflow port 14 to the drain groove 15.

As described above, according to the present invention, every time the hydraulic cylinder 1 is operated, new water is supplied into the water storage tank 7 and old water is automatically drained while being diluted. There is no need to frequently change the water in 7.

Even when tap water is no longer supplied to the water storage tank 7 due to temporary water interruption, the lowest water level 13 in the water storage tank 7 is the water supply port 1 to the hydraulic cylinder 1.
Since it is above 6, the water level in the water storage tank 7 only fluctuates between the water levels 11 and 13, and the operation of the hydraulic cylinder 1 is not hindered.

FIG. 2 is a diagram showing an example of a concrete configuration in which the water storage tank for operating the hydraulic cylinder shown in FIG. 1 is applied to elevating a movable floor of a movable floor pool. In the figure, the same parts as those shown in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 1, the movable floor 3 is supported on the base surface 22 by a plurality of hydraulic cylinders (two hydraulic single-acting cylinders) 1a and 1b which are erected on the base surface 22 so as to be vertically movable. Has been done. These hydraulic cylinders 1a, 1
b, one ends of the pipes 23a and 23b are respectively connected, and the other ends of the pipes 23a and 23b are connected to the electromagnetic opening / closing valves 4a and 4b.
Via the hydraulic servo valve 19a, 19b port 24a,
It is connected to 24b.

One end of a pipe 26 is connected to the inlet ports 25a, 25b of the hydraulic servo valves 19a, 19b, and the other end of the pipe 26 is connected to the discharge port of the pump 6 via a check valve 8. Reference numeral 18 is a relief valve.

One end of a pipe 28 is connected to the return ports 27a and 27b of the hydraulic servo valves 19a and 19b, the other end of the pipe 28 is connected to the water storage tank 7, and the tip thereof serves as a return port 17.

One end of a pipe 29 is connected to the suction port of the pump 6, the other end of the pipe 29 is connected to the water storage tank 7 via a strainer 30, and the tip thereof is a supply port 16.

On the movable floor 3, the hydraulic cylinders 1a, 1a
b stroke detection sensors 20a and 20b are provided.

As described above, the water level 13 in the water storage tank 7 is set in the case where tap water is not supplied when the water is sent from the water storage tank 7 to the hydraulic cylinders 1a, 1b to raise the rods 2a, 2b. It is the lowest water level that drops, and a water supply port 16 to the hydraulic cylinders 1a and 1b is arranged below the water level 13.

An overflow port 14 is provided above the water storage tank 7, and a drain groove 15 is provided through a pipe 32.
Connected to.

As described above, the water level 21 in the water storage tank 7 is lowered when the ascending rods 2a, 2b descend and the water in the hydraulic cylinders 1a, 1b returns from the return port 17 to the water storage tank 7. This is the rising water level when there is no overflow. The overflow port 14 is provided below the water level 21 and above the water stop level 12 of the constant water level valve 10.

Next, the operation of the water storage tank for operating the hydraulic cylinder will be described. First, when the movable floor 3 is raised, the motor 5 is operated and the opening / closing valves 4a and 4b are opened, whereby the water in the water storage tank 7 is pumped by the pump 6 to the hydraulic cylinder 1a,
Sent to 1b. At this time, the hydraulic servo valves 19a, 19b
Receives feedback signals from the stroke detection sensors 20a and 20b of the hydraulic cylinders 1a and 1b, and
The movable floor 3 is raised while controlling the amount of each water supplied to the hydraulic cylinders 1a and 1b so that the (actually more) rods 2a and 2b of the book are raised at the same speed.

At this time, the water level in the water storage tank 7 tends to decrease from the water level 11 before the hydraulic cylinders 1a, 1b are activated to the water level 13 reduced by the amount of water sent into the hydraulic cylinders 1a, 1b. When the water level falls below the stop water level 12 of the constant water level valve 10, tap water flows in from the inflow port 31 and finally stops at the stop water level 12.

Next, when lowering the movable floor 3, the motor 5
When the on-off valves 4a and 4b are opened in a state in which the pressure is stopped, the water in the hydraulic cylinders 1a and 1b is pushed out by the weight of the movable floor 3, and the return port 1 is passed through the pipes 23a, 23b, and 28.
It returns from 7 to the water tank 7. At this time, the hydraulic servo valves 19a and 19b receive feedback signals from the stroke detection sensors 20a and 20b of the hydraulic cylinders 1a and 1b, and the two (actually, a larger number of) rods 2a and 2b move at the same speed. The movable floor 3 is lowered while controlling the amount of each water so as to lower.

The water level in the water storage tank 7 depends on the hydraulic cylinder 1.
By returning the water in a and 1b, the water level rises from the water stop level 12 of the constant water level valve 10 to the water level 11 at the same level as the overflow port 14, and the water returning thereafter flows out from the overflow port 14 and passes through the pipe 32. It is discarded in the drainage channel 15.

When the tap water is temporarily not supplied to the water storage tank 7 due to water interruption or the like, the water in the water storage tank 7 fluctuates between the water level 11 and the water level 13 as described above, and the hydraulic cylinder 1a. , 1b does not hinder the operation.

[0039]

As described in detail above, the water storage tank according to the present invention has the following excellent effects. Since the water in the water storage tank is automatically replaced, it is not necessary to frequently replace the water, and the maintenance thereof is facilitated.

Even if tap water is temporarily not supplied to the water storage tank due to water interruption or the like, the hydraulic cylinder can be reliably operated.

The structure is simple and inexpensive.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a water storage tank for operating a hydraulic cylinder according to the present invention.

FIG. 2 is a diagram showing a specific configuration example in which the water storage tank for operating the hydraulic cylinder shown in FIG. 1 is applied to elevating and lowering a movable floor of a movable floor pool.

[Explanation of symbols]

 1 Water Pressure Cylinder 7 Water Storage Tank 10 Constant Water Level Valve 12 Stop Water Level 14 Overflow Port 16 Supply Port 17 Return Port 31 Inlet Port

Claims (1)

[Claims] 1. A water storage tank for storing water as hydraulic fluid for a hydraulic cylinder, which has a constant water level valve that opens when the water level falls below a water stop level, and a water inlet for introducing new water, and water for the hydraulic cylinder. Supply port, a water return port from the hydraulic cylinder, and an overflow port for discharging water to the outside, the position of the overflow port is above the water stop level of the constant water level valve and within the hydraulic cylinder. The water is below the water level in the water tank, which rises when there is no overflow when it returns to the water tank.On the other hand, the position of the water supply port to the water level cylinder is such that the water in the water tank is sent to the hydraulic cylinder. The water storage tank is arranged so as to be below the water level in the water storage tank, which is lowered when water is not flowed in from the water inlet when the water is discharged.