JPS6140617A - Liquid supply device - Google Patents

Abstract

PURPOSE:To confirm accurately the corrent operation of a pressure detecting means by providing an operation confirming means consisting of a manual switching valve, which cuts off a signal air line, and a pump which transmits an operation confirming pressure to the signal air line. CONSTITUTION:When the operation of an interface valve V is confirmed, an operation rod 54 of an operation confirming means 40 is pressed in. A port 50 is closed in an opening process S1 of a manual switching valve 41 by a piston 46 to cut off lines L2 and L3. Next, air in the first chamber 47 is compressed in an operating process S2 of a pump 42, and the operation confirming pressure equivalent to the signal voltage of a level sensor 25 is applied to the first flexible film chamber 5 of the interface valve V through a port 52 and the line L3. Then, a flexible film 3a is raised, and the interface valve V is operated similarly to the case where the signal pressure is applied. Thus, the correct operation of the interface valve V is confirmed with the easy operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a liquid supply device for actually supplying oil to, for example, a zero tank or tank, and in particular to a level sensor that detects the level of the liquid to be supplied, and a device for supplying oil from the level sensor. This invention relates to a liquid supply device which is provided with a means for constantly checking the operation of the pressure detecting means, which is interposed in an air line connecting the pressure detecting means for controlling an on-off valve for overflow prevention based on the drop signal pressure.

[Conventional example] It is extremely difficult to see the liquid level inside a tank such as a low-rise tank or an underground tank. As a result, when working with liquid, it may not be possible to judge how high the liquid level has reached, and the liquid may leak out. For this purpose, a control circuit equipped with a leakage prevention level sensor and a pressure detection means for controlling an on-off valve for overflow prevention based on the minute pressure from the level sensor h) is known (for example, the present applicant (Japanese Unexamined Patent Publication No. 187675/1987). This known technique will be explained with reference to FIG.

In FIG. 4, the oil in the oil storage tank 21 is supplied to a tank 24 by a pump 22 through an overflow prevention valve, that is, an on-off valve 23 provided at the pump 1. Inside the tank 24, there is provided a level sensor 25 in the shape of an inverted top, called a sensor whose pressure increases as the liquid level rises. Now, by the operation of the pump 22, it is stretched and supplied into the tank 24,
What if the tank 24 becomes almost full and the lower opening of the level sensor 25 is blocked and the liquid level rises further? The air within the level sensor 25 is compressed by the rising liquid level and its pressure increases.

The signal pressure of this level sensor 25 is transmitted to the first flexible membrane chamber 5 of the interface valve V, which is a pressure detection means, through the inlet L2, the manual switching valve 26 for operation confirmation, and the line L3. Further, the internal pressure of the tank 24 is transmitted to the second flexible membrane chamber 6 via the line L4. [5 is a paper recovery line for returning oil vapor in the tank 24 to the oil storage tank 21. Compressed air from a suitable pressurized air source 27 is passed through a switching valve 28 to the interface valve V from line L6. Further, the branch line L1 is connected to the flow rate control circuit 29.
It is connected to the operation confirmation switching valve 26 via. The interface valve V is connected to a clutch cylinder 30 for releasing the valve opening lock 31 of the on-off valve 23 via a line L8. The switching valve 28 is intended to prevent air from being wasted when the valve 23 is closed, and is in the position shown when the valve 23 is open, and moves to the shutoff position where the valve 23 is closed. There is. clutch cylinder 30
receives air pressure from the line [8 to project the piston, release the inter-valve lock 31 of the valve 23, and close the valve 23. Further, when the operation confirmation manual switching valve 26 is switched from the illustrated position, the fluid in the line L7 flows to the line L3 to confirm whether the interface valve V operates properly.

In operation, the valve opening lock 30 is engaged to open the valve 23, and the oil level rises to the position of the level sensor 25 while the low tank 24 is being refueled. Then, the air within the level sensor 25 is compressed by the rising oil level, its pressure increases, and this pressure is applied to the first flexible membrane chamber 5 via the inlets L2 and L3.

On the other hand, the internal pressure of the tank 24 is applied to the second flexible membrane chamber 6 via the line L4, but since the internal pressure of the first flexible membrane chamber 5 increases, the flexible membrane 3a moves upward, and the interface valve ■
is switched. For this purpose, compressed air flows from line L6 to line L8, actuating the clutch cylinder 30, releasing the valve opening lock 31, and closing the valve 23 to prevent overflow.

By the way, since the signal pressure of the level sensor 25 is weak,
The interface valve V may not operate due to jamming, etc. Therefore, as mentioned above, the manual switching valve 26 for operation confirmation is
By switching from the position shown in the figure, the operating pressure of line L7 is guided to line 13, and it is confirmed whether or not interface valve (2) operates properly. However, even though this operating pressure is supplied via the flow rate control device 29, it is much stronger than the signal pressure, and the difference in meat pressure is too large to confirm the proper operation of the interface valve ■. There is.

EObject of the Invention 1 The present invention has been made in view of the above-mentioned problems, and its purpose is to provide a liquid supply device equipped with an operation confirmation means that can confirm the proper operation of the pressure detection means. .

[Configuration 1 of the Invention The operation confirmation means according to the present invention includes a manual switching valve that shuts off one signal air line and a pump that sends operation confirmation air to the signal air line.

[Operations and Effects of the Invention] Since the present invention is configured as described above, it is possible to confirm the proper operation of the pressure detection means by closing the manual switching valve and sending air for operation confirmation using the pump. Furthermore, the structure of the liquid supply device can be simplified by eliminating the conventional operating air line for confirming operation and the flow rate control device installed in the line.

[Preferred Embodiment] When implementing the present invention, it is preferable to set the operation confirmation pressure equal to the signal pressure. In this way, proper operation of the pressure sensing means can be accurately confirmed. Further, when carrying out the present invention, it is preferable that the pump and the manual switching valve are linked. In this way, the operation confirmation operation can be simplified. Furthermore, when carrying out the present invention, it is preferable that the manual switching valve and the pump are integrally formed. In this way, the structure of the operation confirmation means can be simplified.

[Example 1] The present invention will be described in detail below with reference to FIGS. 1 and 2. In these drawings, parts corresponding to those in FIG. 3 are designated by the same reference numerals and redundant explanation will be omitted.

In FIG. 1, a signal air line, ie, a line L2, which connects the level sensor 25 and the interface valve V, which is a pressure detection means, is provided with an operation confirmation means 40, which is indicated as a whole by 40. are the manual switching valve 41 and the interface valve V on the level sensor 25 side.
It consists of a pump 42 on the side. The manual switching valve 41 and the pump 42 are integrally formed as shown in FIG. The main body 43 of the integrally formed operation confirmation means 40 has a hollow pipe 44 for guiding the piston in the center.
A cylinder 45 is formed. A hollow pipe 44 and a piston 46 in contact with the cylinder 45 are fitted into the cylinder 45, and the piston 46 defines the chamber 45 into a first chamber 47 and a second chamber 48. A spring 49 is interposed between the piston 46 and the main body 43.

The first chamber 47 is communicated with the level sensor 25 side of the line L2 via a boat 5o provided in contact with the piston 46 of the hollow pipe 44 and a boat 51 provided in the main body 43, and is also provided in the main body 43. It is connected to the interface valve V side of the line [3] via a boat 52.

The second chamber 48 is open to the atmosphere via a boat 53 provided in the main body 43 so as not to hinder the movement of the piston 46. The tip of the operating rod 54 of the piston 46 protrudes outside the main body 43, and when the operating rod 54 is pushed against the spring 49, the piston 46 closes the boat 50 (this is caused by manual switching of the operation confirmation means 40). (corresponds to the valve closing stroke [S1] as the valve 41), then the piston 46
compresses the fluid in the first chamber 47 until it comes into contact with the inner wall 43a of the main body 43 (this is done by the pump 4 of the operation confirmation means 40).
2). Then, as shown in FIG. 3, the level sensor 25
The liquid level that enters the inner chamber 25a when the liquid level is such that a pressure signal that activates the interface valve V of the h1 inner chamber 25 is determined.
If the cross-sectional area of a is a, and the cross-sectional area of the first chamber 47 is A, then AXS2 +axh, that is, the pressure for differential confirmation of the pump 42 is the level sensor 2.
The signal pressure is set to be approximately equal to the signal pressure of 5.

With this structure, when confirming the operation of the interface valve V, it is sufficient to push in the operating rod 54 of the operation confirmation means 4°. Then, the boat 50 is closed by the piston 46 in the valve closing stroke S1 of the manual switching valve 41, and the lines L2 and L3 are cut off. Next, during the operation stroke s2 of the pump 42, the air in the first chamber 47 is compressed, and an operation confirmation pressure equal to the signal pressure of the level sensor 25 is applied to the boat 5.
2. The voltage is applied to the first flexible membrane chamber 5 of the interface valve (2) through the line L3. Then, the flexible membrane 3a is lifted and the interface valve V operates in the same way as when signal pressure is applied. In this way, the proper operation of the interface valve V, which is the pressure detection means, can be accurately confirmed by a simple operation of pushing in the operating rod 54 of the operation confirmation means 40.

[Summary] As explained above, according to the present invention, the operation confirmation means is constituted by a manual switching valve that shuts off the signal air line and a pump that sends pressure for operation confirmation to the Shinmi airline. The proper operation of the system can be accurately confirmed.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a control circuit of a liquid supply device using the operation confirmation means according to the present invention, Fig. 2 is a sectional view showing a preferred embodiment of the operation confirmation means according to the present invention, and Fig. 3 is a level view. An explanatory diagram of the operation of the sensor, and FIG. 4 is an explanatory diagram of a control circuit of a conventional liquid supply device. L9...Signal pressure line V...In-Taface valve 23...Opening/closing valve 25...Level sensor 40...Operation confirmation means 41...Manual switching valve
42... Pump 2nd JP-A-6L-40617 (4) 3rd 4th! Yo tower □゛

Claims (1)

[Claims] A liquid supply device controlled by the output of a level sensor, characterized in that the liquid supply device is provided with operation confirmation means for outputting a pseudo level signal separately from the level sensor.