JPH0421882B2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a liquid supply device for supplying oil to a lorry tank, for example, and in particular to a level sensor that detects the level of the supplied liquid and a signal pressure from the level sensor. The present invention relates to a liquid supply device provided with a means for confirming the operation of a pressure detecting means interposed in an air line connecting the pressure detecting means for controlling an on-off valve for preventing overflow based on the pressure detecting means.

[Conventional example] For example, in tanks such as lorry tanks and underground tanks, it is extremely difficult to see the internal liquid level. For this reason, it may not be possible to judge how high the liquid level has reached during liquid supply work, and the liquid may overflow. To prevent overflow, a control circuit is known that includes a level sensor and pressure detection means that controls an overflow prevention on-off valve based on the minute pressure from the level sensor (for example, Publication No. 58-187675). Such a known technique will be explained with reference to FIG. In FIG. 4, the oil in the oil storage tank 21 is supplied to the tank 24 of the lorry by a pump 22 via an overflow prevention valve, that is, an on-off valve 23 provided in the liquid supply pipe L1. Inside the tank 24 is a level sensor 2 with an inverted top shape called a probe, which increases the pressure as the liquid level rises.
5 is provided. Now, oil is supplied into the tank 24 by the operation of the pump 22, and the tank 24 becomes almost full, blocking the lower opening of the level sensor 25, and when the liquid level rises further, the air inside the level sensor 25 The rising liquid level causes it to be compressed and its pressure to rise. The signal pressure from the 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 line 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.
L5 transfers the oil vapor in the tank 24 to the oil storage tank 21.
It is a vapor recovery line to return to.
Compressed air from an appropriate pressure air source 27 is supplied to the switching valve 2.
8 and is sent from line L6 to interface valve V. Further, the branch line L7 is connected to the flow control circuit 2.
9 to the operation confirmation switching valve 26. The interface valve V is connected via a line L8 to a clutch cylinder 30 for releasing the valve lock lock 31 of the on-off valve 23. Switching valve 28
This is 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 is moved to the shutoff position where the valve 23 is closed. clutch cylinder 30
receives air pressure from line L8 to project the piston, removes the valve opening lock 31 of the valve 23,
The valve 23 is closed. In addition, when the manual switching valve 26 for operation confirmation is switched from the position shown in the figure,
This is to check whether the fluid in line L7 flows to line L3 and the interface valve V operates properly.

When operating, the valve opening lock 30 is engaged and the valve 23 is closed.
is opened, and the oil level rises to the position of the level sensor 25 while refueling the tank 24 of the lorry. 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 lines 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 V is switched. For this purpose, compressed air flows from line L6 to line L8, actuating the clutch cylinder 30, and locking the valve open lock 3.
1 is removed, the valve 23 is closed and overflow is prevented.

By the way, since the signal pressure of the level sensor 25 is weak, it may not operate due to jamming of the interface valve V or the like. For this reason, as described above, the manual switching valve 26 for operation confirmation is switched from the position shown in the figure to guide the operating pressure of line L7 to line L3 to confirm whether or not the interface valve V operates properly. . However, even though this operating pressure is passed through the flow control device 29, it is much stronger than the signal pressure, and the difference between the two pressures is too large to confirm the proper operation of the interface valve V. There's a problem.

[Problems to be Solved] Therefore, an object of the present invention is to provide a fluid supply device that closes an on-off valve when the interface valve detects pressure from a level sensor, and in which the operation of the interface valve can be confirmed. It is in.

[Means for Solving the Problems] According to the present invention, a liquid supply pipe having an on-off valve, a level sensor for detecting a rise in the liquid level in a supplied liquid tank, and a liquid supply pipe connected to the level sensor via an air line are provided. Confirming the operation of the switching valve that shuts off the air line and the interface valve in a liquid supply device that has an interface valve and is configured to close when the interface valve detects pressure from a level sensor. An operation confirmation device consisting of a pump that sends out air is provided.

[Explanation of function and effect] Therefore, the switching valve is closed to cut off the air line, and the pump sends out air for checking the operation of the pressure detection means, so that the switching valve operates and the air flows from the sensor through the air line. The air is inactive, and the same effect occurs when the level sensor detects a rise in the liquid level due to the pressure from the pump. Therefore, the operation of the interface valve can be confirmed, and it can be confirmed whether the liquid supply device operates properly when the tank is full.

Furthermore, since the operation is simple, confirmation work can be easily performed.

[Example] Hereinafter, an example of the present invention will be described 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 operation confirmation means, generally indicated by 40. 40 is a manual switching valve 41 on the level sensor 25 side and a pump 4 on the interface valve V side.
It consists of 2. And these manual switching valves 4
The pump 1 and the pump 42 are integrally formed as shown in FIG. The main body 43 of the integrally formed operation confirmation means 40 is formed with a cylinder 45 having a hollow pipe 44 for guiding the piston in the center. A piston 46 is inserted into the cylinder 45 and is in sliding contact with the hollow pipe 44 and the cylinder 45.
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 port 50 provided in contact with the piston 46 of the hollow pipe 44 and a port 51 provided in the main body 43, and is also provided in the main body 43. The line L3 is connected to the interface valve V side of the line L3 through a port 52. The second chamber 48 is open to the atmosphere through a port 53 provided in the main body 43 so as not to interfere with 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 port 50 (this causes the operation confirmation means 4
0), the fluid in the first chamber 47 is compressed until the piston 46 comes into contact with the inner wall 43a of the main body 43 (this corresponds to the valve closing stroke [S1] as the manual switching valve 41 of 0). pump 42
(corresponds to the operating stroke [S2]). As shown in FIG. 3, let h be the liquid level that enters the inner chamber 25a when the liquid level is such that it generates a pressure signal that activates the interface valve V of the level sensor 25, and let a be the cross-sectional area of the inner chamber 25a. , and when the cross-sectional area of the first chamber 47 is A, A×S2≈a×h That is, the differential confirmation pressure of the pump 42 is set to be approximately equal to the signal pressure of the level sensor 25.

With this configuration, when confirming the operation of the interface valve V, the operation confirmation means 40
All you have to do is push in the operating rod 54. Then, the port 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. Then, in the operation stroke S2 of the pump 42, the first
The air in the chamber 47 is compressed and the level sensor 25
The operation confirmation pressure equal to the signal pressure of port 5
2. Applied to the first flexible membrane chamber 5 of the interface valve V via line L3. Then, the flexible membrane 3a
is lifted and the interface valve V operates as if signal pressure were 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 the operation rod 54 of the operation confirmation means 40.

As described above, the present invention provides the following excellent effects.

(1) Since the switching valve is closed and the pump outputs the same air signal as when the level sensor is activated, it is possible to reliably confirm whether the interface valve is activated or not.

(2) Therefore, it is possible to prevent the inconvenience that the liquid supply device is inoperative when the tank is full and the liquid overflows.

(3) Verification work can be performed simply and easily.

[Brief explanation of drawings]

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...Interface valve, 23...Opening/closing valve, 25...Level sensor, 40...Operation confirmation means, 41...Manual switching valve, 42...Pump.

Claims (1)

[Claims] 1 A liquid supply pipe having an on-off valve, a level sensor that detects a rise in the liquid level in a liquid tank to be supplied, and an interface valve connected to the level sensor via an air line, and the interface valve In a liquid supply system in which the on-off valve is closed when the valve detects pressure from a level sensor, an operation confirmation device consisting of a switching valve that shuts off the air line and a pump that sends out air to confirm the operation of the interface valve. A liquid supply device characterized by being provided with.