JPH1151803A - Apparatus for detecting liquid leakage of liquid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly detect even a minute amount of liquid leakage. SOLUTION: A liquid valve 3 has a valve seat 9 surrounding a liquid path 8 formed in a housing 7 and a valve body 11 brought close to and away form the valve seat by a cylinder device (opening/closing driving means) 6 thereby opening/closing the liquid path. A bellows 40 (flexible seal member) isolates the liquid path at the side of the valve seat from a space at the side of the opening/closing driving means. The valve body 11 and flexible seal member 40 are insulated from a liquid in the liquid path. A conductive member 34 is set in the space at the side of the opening/closing driving means 6. Electricity is supplied to the conductive member 34 and liquid in the liquid path from a power source 47. A detecting means 48 detects if the flexible seal member 40 is broken to bring the liquid into touch with the conductive member 34 to conduct the electricity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid valve for opening and closing a liquid passage, and more particularly, to a liquid leak detecting device for a liquid valve capable of detecting a liquid leak from the liquid valve.

[0002]

2. Description of the Related Art Conventionally, as a liquid valve, a housing,
A liquid passage formed in the housing, a valve seat surrounding the liquid passage, a valve body which is brought into contact with and separated from the valve seat to open and close the liquid passage, and an opening and closing mechanism which is connected to the valve body to advance and retract the valve body A drive means and a flexible seal member such as a bellows, which is connected to the valve body to separate the liquid passage on the valve seat side from the space on the open / close drive means side and is operated in accordance with the advance / retreat of the valve body. And those with In the case of this type of liquid valve, if the bellows is damaged and the liquid leaks from the liquid passage to the outside, external dust or the like is mixed into the liquid and the liquid is contaminated. For this reason, conventionally, there has been proposed a liquid leak detecting device for a liquid valve capable of detecting that a bellows has been damaged and a liquid leak has occurred (for example, Japanese Patent Application Laid-Open No. Hei 6-270921, Japanese Utility Model Laid-Open No. 6-84338). No.). JP-A-6-270921 discloses a drain pan in which a drain pipe is connected to an open-to-atmosphere passage communicating the upper part of the internal space of the bellows with the outside, and a height difference is provided at a position below the drain pipe. And a sensor is provided at the lowest point of the drain pan to detect liquid leakage when the liquid comes into contact with the liquid, and the sensor detects liquid leakage. On the other hand, in the official gazette of Japanese Unexamined Utility Model Publication No. 6-84338, the upper end of a bellows-like bellows arranged in the vertical direction is connected, and at a predetermined position of an upper lid that partitions the internal space and the external space of the bellows, A pipe communicating with the internal space of the bellows is provided, and a sensor for detecting a liquid leak when the pipe is immersed in the liquid is provided to detect the liquid leak.

[0003]

However, in any case, when the amount of leakage of the liquid is relatively small, it takes a considerable time for the liquid to reach the sensor. There is a risk that time cannot be detected. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a liquid leakage detecting device for a liquid valve, which can quickly detect even a small amount of liquid leakage.

[0004]

That is, the present invention provides a housing, a liquid passage formed in the housing, a valve seat surrounding the liquid passage, and a valve body which is brought into contact with and separated from the valve seat to open and close the liquid passage. Opening / closing drive means connected to the valve body for moving the valve body forward and backward, and a liquid passage on the valve seat side connected to the valve body to be separated from a space on the opening / closing drive means side, and In a liquid valve having a flexible seal member that is operated in accordance with advance and retreat, the valve body and the flexible seal member are insulated from a liquid in a liquid passage, and the liquid and the opening / closing drive unit side are insulated. A power source that insulates the space and supplies electricity to the conductive member provided in the space and the liquid in the liquid passage;
A detection means is provided for detecting when the conductive member and the liquid in the liquid passage are energized.

[0005]

According to the above construction, when the flexible seal member is normal, the conductive member provided in the space on the opening / closing drive means side and the liquid are electrically insulated. In this state, the detecting means does not detect the energization, that is, the liquid leakage. On the other hand, when the flexible seal member is damaged and the liquid leaks into the space on the opening / closing drive means side, the liquid immediately contacts the conductive member because the conductive member is provided in the space. Liquid leakage can be immediately detected.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiment. In FIG. 1, reference numeral 1 denotes a rotary weight filling device to which the present invention is applied. A weighing table with a weighing scale (not shown) for placing containers at circumferentially equally spaced positions of the rotating body 2; and a liquid filling tank above the weighing table. A liquid valve 3 is provided. As shown in FIG.
Each of the liquid valves 3 is connected to an upper end of a lifting mechanism (not shown) via a bracket 4, and is moved up and down by the lifting mechanism via each bracket 4.

Each of the liquid valves 3 is provided with a cylinder device 6 as an opening / closing drive unit attached to the bracket 4. A liquid passage 8 is formed in a housing 7 connected to a lower end of the cylinder device 6. I have. A valve seat 9 is formed so as to surround the liquid passage 8, and a valve body 11 is attached to a lower end of a piston rod 10 of the cylinder device 6, and the valve body 11 is brought into contact with and separated from the valve seat 9. Thus, the liquid passage 8 can be opened and closed.

The cylinder device 6 includes the bracket 4
And a stepped hole 17 formed in a shaft portion of the cylinder housing 16. The stepped hole 17 has a middle diameter hole 17 b in the middle of the stepped hole 17. A disk-shaped first piston 18 is slidably fitted with airtightness, and the piston rod 10 is connected to the lower end of the first piston 18. The piston rod 10 has a small diameter hole 1 below the stepped hole 17.
The valve body 11a is slidably penetrated while maintaining airtightness, and the valve body 11 is attached to the lower end thereof. A disk-shaped second piston 19 is slidably fitted in the large-diameter hole 17c above the stepped hole 17 while maintaining airtightness.
The lifting rod 21 connected to the upper end of the piston 19 is connected to the lid member 2 for closing the upper end of the cylinder housing 16.
0 is slidably penetrated while maintaining airtightness, and is projected upward. A nut 2 is attached to the protruding end of the lifting rod 21.
2 is screwed, and the lower end position of the second piston 19 is regulated by bringing the nut 22 into contact with an adjusting member 23 provided at the upper end of the lid member 20 so as to be vertically displaceable. To be able to. A spring 24 is provided between the first piston 18 and the second piston 19.
And the spring 24 normally holds them apart, that is, the first piston 18 is held at the lower end and the second piston 19 is held at the upper end.

Further, a first pressure chamber 25 is formed below the first piston 18 and the first pressure chamber 2
5 is connected to a first passage 26 formed in the cylinder housing 16 and the bracket 4, and the first passage 26 is connected to a pressure fluid supply source via a switching valve (not shown). A second pressure chamber 27 is formed between the first piston 18 and the second piston 19, and the second pressure chamber 2
7 communicates with the pressure fluid supply source through a second passage 28 and a switching valve (not shown), and a third pressure chamber 29 formed above the second piston 19 connects the third passage 30 and a switching valve (not shown). And the above-mentioned pressure fluid supply source. Thereby, the intermediate second pressure chamber 27 is communicated with the pressure fluid source, and the first pressure chamber 25 and the third pressure chamber 2 are connected.
When the first piston 18 is held at the lower end and the second piston 19 is held at the upper end, the piston rod 10 provided on the first piston 18 is held open.
The valve body 11 at the lower end of the valve seats on the valve seat 9 to close the liquid passage 8. Further, the second pressure chamber 27 and the third
When the pressure chamber 29 is communicated with the atmosphere and the first pressure chamber 25 is communicated with the pressure fluid source, the first piston 18 is raised to a position where it contacts the second piston 19 located at the rising end. Therefore, the valve body 11 is largely separated from the valve seat 9 to open the liquid passage 8 greatly. Further, the second pressure chamber 27 is communicated with the atmosphere, and the third pressure chamber 29 is
When the third pressure chamber 29 and the third pressure chamber 29 are communicated with the pressure fluid source, the first piston 18 is raised and at the same time the second piston 19 is lowered so that they come into contact with each other.
Since the piston 19 is larger, the second piston 19 is at the lower end position, and the first piston 18 comes into contact with the second piston 19 at the lower end position, and the upper position is regulated. In this state, the rising amount of the first piston 18 is smaller than when the second piston 19 is located at the rising end, so that the valve body 11 is relatively slightly separated from the valve seat 9. As a result, the liquid passage 8 is opened at a small opening.

Next, as shown in FIG. 3, the liquid passage 8 is
A large-diameter hole 8a formed in the axial direction of the housing 7 and an upper radial hole 8b communicating therewith are provided. The upper radial hole 8b is connected to a filling tank (not shown) via a pipe 32 connected thereto. They are communicating. A lower portion of the large-diameter hole 8a is provided with a tapered hole 8c tapered downward and a lower radial hole 8d continuous with the lower end of the tapered hole 8c. Through 33, it communicates with a filling nozzle for filling the liquid into a container (not shown). The valve element 1 is provided in the large-diameter hole 8 b of the liquid passage 8.
1, the valve body 11 is a cylindrical conductive member 3
4, connected to the lower end of the piston rod 10;
Further, a bellows-like bellows 40 as a flexible sealing member is provided integrally with the valve body 11. The valve body 11 includes an annular seat portion 40 a constituting a part of the bellows 40 which is brought into contact with and separated from the valve seat 9, and a pin 41 connecting the annular seat portion 40 a to a lower end portion of the conductive member 34. Have. The bellows 40 is provided with the annular seat portion 40a.
A bellows portion 40b which is integrally connected to the annular seat portion 40a and extends upward and surrounds the conductive member 34; and a cylinder housing 16 and a liquid valve 3 which are provided continuously at the upper end of the bellows portion 40b. And a seal portion 40c sandwiched by the housing 7 and maintaining liquid tightness therebetween. At this time, the cylinder housing 16 and the housing 7 are placed in a state where the seal portion 40c is interposed therebetween and the periphery thereof is surrounded by an insulating material 42.
They are integrally connected to each other by a connection fitting 43.

The bellows 40 and the pin 41 are made of an insulating material, and the bellows 40 allows the liquid passage 8 on the valve seat 9 side to be separated from the space on the opening / closing drive means side, that is, the space in which the conductive member 34 is arranged. Electrically separated. Also, as shown in FIG.
An insulating material 44 is also interposed between the bracket 6 and the bracket 4, and the insulating material 44 electrically insulates the cylinder housing 16 from the bracket 4. As a result, the cylinder housing 16 is electrically insulated from both the housing 7 of the liquid valve 3 and the bracket 4. The bellows 40, the insulating material 42, and the insulating material 4
On the cylinder housing 16 side insulated by 4,
The conductive member 34, the piston rod 10, the cylinder housing 16, the pistons 18 and 19, the lifting rod 21, the adjusting member 22, and the like are made of a conductive metal, and the first lead wire 45 is connected to the adjusting member 23. By doing
Electricity can be supplied to the conductive member 34. On the other hand, the bellows 40, the insulating material 42, the insulating material 44
A second lead wire 46 is connected to the pipe 32 or a filling tank (not shown) on the side of the liquid passage 8 opposite to the cylinder housing 16 which is insulated by the above. To supply electricity to a liquid having Each of the lead wires 45 and 46 is connected to a power source 4.
The power supply 47 is connected to a detecting means 48 for detecting when the conductive member 34 and the liquid in the liquid passage 8 are energized, displaying the detected electric current, and displaying the detected electric current and activating an alarm.
Is provided.

In the above configuration, when the bellows 40 is not damaged and is normal, the conductive member 34 on the cylinder housing 16 side and the liquid on the liquid passage 8 side are insulated by the bellows 40, the insulating material 42 and the insulating material 44. Therefore, the leakage of the liquid is not detected by the detecting means 48. On the other hand, when the bellows 40 is broken and the liquid reaches the conductive member 34, electricity flows through the conductive member 34 and the liquid, so that the detection means 48 can promptly detect the leakage of the liquid. Become.

In the above-described embodiment, the bellows 40 is used as the flexible seal member. However, the present invention is not limited to this, and a diaphragm can be used as the flexible seal member. Further, it is not always necessary to manufacture the valve element and the flexible seal member from an insulating material, and even if these are formed from a conductive material, they can be formed into a valve element by covering them with an insulating material. What is necessary is just to insulate the flexible seal member from the liquid in the liquid passage. further,
In the above embodiment, the conductive member 34 and the piston rod 10 are formed separately, but the both can be formed integrally and the piston rod can also be used as the conductive member. Alternatively, for example, a configuration in which a thin ring-shaped conductive member is disposed on the upper surface of the annular sheet portion 40a of the bellows 40 may be employed.

[0014]

As described above, according to the present invention, there is obtained an effect that even a small amount of liquid leakage can be detected quickly as compared with the conventional apparatus.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing one embodiment of the present embodiment.

FIG. 2 is a sectional view showing the liquid valve 3.

FIG. 3 is an enlarged sectional view showing a main part of the liquid valve 3.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 3 ... Liquid valve 6 ... Cylinder device (opening / closing drive means) 7 ... Housing 8 ... Liquid passage 9 ... Valve seat 10 ... Piston rod 11 ... Valve body 16 ... Cylinder housing 18 ... 1st piston 19 ... 2nd piston 21 ... Lifting rod 23 ... adjusting member 34 ... conductive member 40 ... bellows 40a ... annular sheet portion 40b ... bellows portion 40c ... seal portion 42 ... insulating material 44 ... insulating material 45 ... first lead wire 46 ... second lead wire 47 ... power supply 48 ... Detection means

Claims (2)

[Claims] 1. A housing, a liquid passage formed in the housing, a valve seat surrounding the liquid passage, a valve element which is opened and closed by the valve seat to open and close the liquid path, and is connected to the valve element. Opening / closing drive means for moving the valve body forward and backward, and a liquid passage on the valve seat side connected to the valve body for separating from the space on the opening / closing drive means side, and being operated following the movement of the valve body. A liquid valve provided with a flexible seal member, wherein the valve body and the flexible seal member are insulated from a liquid in a liquid passage to insulate the liquid from a space on the opening / closing drive means side; A power supply for supplying electricity to the conductive member provided in the liquid passage and the liquid in the liquid passage; and a detecting means for detecting when the conductive member and the liquid in the liquid passage are supplied with electricity. A liquid leakage detecting device for a liquid valve. 2. The flexible sealing member comprises a bellows having a cylindrical bellows portion and a seat portion connected to the bellows portion, wherein the bellows portion surrounds a conductive member, and the seat portion is the housing. 2. The liquid leakage detecting device for a liquid valve according to claim 1, wherein the liquid sealing device is interposed between the housing and the housing of the opening / closing drive means to maintain liquid tightness between the housings and to electrically insulate the housings from each other.