JPH1030739A - Double seal valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To immediately clean a valve stem part in contact with the atmosphere as necessary at every timing. SOLUTION: In a double seal valve, a first valve disk 7 engaged with an inner circumferential side of the valve seat 6 provided on a communication passage 3 between an upper flow passage 1 and a lower flow passage 2, is provided on a first valve stem 8, and a second valve disk 9 to be pushingly engaged with an upper part side of the valve seat 6 is provided on a second valve stem 10. Annular cleaning passages 46, 47 which are longer than the maximum stroke of the first valve stem 8 and the second valve stem 10 are formed between an outer circumferential surface of the first valve stem 8 part projected downwardly from the lower flow passage 2 and an inner circumferential surface of an annular member 17, and between an outer circumferential surface of the second valve stem 10 part projected upwardly from the lower flow passage 2 and an inner circumferential surface of an annular member 14, and cleaning solution feed ports 48, 49 and cleaning solution discharge ports 50, 51 are provided on a lower end part and an upper end part of the annular flow passages 46, 47 respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for a liquid distribution line in a machine or a plant for food production, brewing, etc., and is used to prevent the mixing of two liquids by sealing the flow path twice. More particularly, the present invention relates to a structure for cleaning a valve shaft portion that comes into contact with the atmosphere.

[0002]

2. Description of the Related Art In a double seal valve of this type, a valve seat is provided in a communication passage formed between an upper flow passage and a lower flow passage, and a first valve body engaged with an inner peripheral side of the valve seat is provided. A second valve body, which is pressed into engagement with the first valve shaft and on the upper side of the valve seat, is provided on a hollow second valve shaft slidably fitted on the first valve body, respectively. One valve shaft is interlockingly connected to the valve opening / closing drive mechanism, and the second valve body follows the upward movement of the first valve shaft by the operation of the valve opening / closing drive mechanism when the valve is opened.

In such a double seal valve, the first valve stem protruding downward from the lower flow passage and the second valve stem protruding upward from the upper flow passage are in contact with the atmosphere. The valve shaft portion that comes into contact with the atmosphere moves up and down to open and close the first valve body and the second valve body, and moves in and out of the upper flow path and the lower flow path. It is necessary to perform cleaning to prevent contamination by water. A double seal valve for cleaning such an air contact shaft portion is disclosed in, for example, Japanese Patent Application Laid-Open No. 7-25316.
No. 8 has been disclosed.

[0004]

The double seal valve described in the above publication has a structure in which the air contact valve shaft can be cleaned only when the first valve body and the second valve body are in the closed state. Therefore, there is a problem in that the cleaning operation involves time restrictions, and the cleaning cannot be performed immediately when necessary. In other words, when the valve shaft portion is contaminated, it is effective to immediately wash it, and over time, coagulation and fixation will progress,
Subsequent cleaning operations are very cumbersome and cumbersome.

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the conventional double seal valve, an object of the present invention is to make it possible to immediately clean the shaft portion of the atmospheric contact valve at any time when necessary.

[0006]

According to a first aspect of the present invention, there is provided a double seal valve comprising a valve seat in a communication passage formed between an upper flow path and a lower flow path. The first valve body 7 engaging with the inner peripheral side of the valve seat 6 is engaged with the first valve shaft 8, and the second valve body 9 engaging with the upper side of the valve seat 6 is engaged with the first valve. Each of the second valve shafts is slidably fitted to the shaft 8, and the first valve shaft 8 is operatively connected to the valve opening / closing drive mechanism 28,
In the double seal valve in which the second valve body 9 moves following the upward movement of the first valve shaft 8 due to the operation of the valve opening / closing drive mechanism 28 when the valve is opened, the first valve shaft protruding downward from the lower flow path 2. 8 between the outer peripheral surface of the portion 8 and the inner peripheral surface of the annular member 17 slidably supporting the shaft portion, and the outer peripheral surface of the second valve shaft 10 portion protruding upward from the lower flow passage 2; The first valve shaft 8 is disposed between the first valve shaft 8 and the inner peripheral surface of the annular member 14 that slidably supports the shaft portion.
And the cleaning annular passages 46 and 47 having a length longer than the respective maximum strokes of the second valve shaft 10 and
A small diameter cleaning liquid supply port 4 is provided at the lower end of each of the annular passages 46 and 47.
8 and 49, and large-diameter cleaning solution outlets 50 and 5 at the upper end.
1 is provided.

According to a second aspect of the present invention, in the double seal valve according to the first aspect, the washing annular passages 46 and 47 are provided with a plurality of helical flows of the washing liquid supplied to the annular passages 46 and 47. A spiral flow forming ring 52 having a spiral groove 52a formed on the outer peripheral surface is provided.

[0008]

FIG. 1 is a longitudinal sectional view of a lower half of the double seal valve according to the present invention, which is divided into two parts by the line aa. FIG. 2 shows an upper half. In these figures, reference numeral 1 denotes an upper flow path, 2 denotes a lower flow path, and these flow paths 1 and 2 are formed in parallel or crossing directions with each other. Are formed, and an upper opening 4 and a lower opening 5 are formed in a portion coaxially opposed to the communication passage 3 in both the flow paths 1 and 2, and a valve seat 6 is mounted in the communication passage 3. . For example, a drinking liquid or a washing liquid flows through the upper flow path 1 and the lower flow path 2, respectively.

Reference numeral 7 denotes a first valve body which engages with the inner peripheral side of the valve seat 6, and is an intermediate portion of the first valve shaft 8 inserted from the upper opening 4 through the communication passage 3 toward the lower opening 5. It is formed integrally with the lower end of the shaft 8b. A hollow lower shaft portion 8c is integrally formed coaxially below the first valve body 7, and an upper shaft portion 8a is coaxially connected to the upper portion of the intermediate shaft portion 8b, usually by screw connection. (In FIGS. 1 and 2, the intermediate shaft portion 8b and the upper shaft portion 8a are illustrated as being integrally formed.) The upper shaft portion 8a, the intermediate shaft portion 8b, and the lower shaft portion 8
c forms the first valve shaft 8.

Reference numeral 9 denotes a valve seat located above the first valve body 7.
A second valve body which is pressed into engagement with the upper side of the first valve shaft from above and is integrally formed with the lower end portion of the second valve shaft 10 which is fitted over the upper shaft portion 8a to the intermediate shaft portion 8b of the first valve shaft 8. The second valve shaft 10 is constantly urged downward by a first spring 11 formed of a coil spring as described later, thereby pressing the second valve body 9 against the upper side of the valve seat 6. The second valve shaft 10 includes an upper shaft portion 10a and a lower shaft portion 10b screwed to the upper shaft portion 10a.
A second valve body 9 is formed at the lower end of the valve body.

As is apparent from FIGS. 3 and subsequent drawings, the first valve body 7 is provided with a main annular packing 12 slidably in contact with the inner peripheral side seating surface 6 a of the valve seat 6. The sub-annular packing 13 which is fitted and attached to the fitting groove 7a for fitting, and which is closer to the upper side surface 6b of the valve seat 6 from above than the second valve body 9, is fitted to the fitting groove 9a for packing attachment. Has been installed. The upper opening 4 of the upper flow path 1 is provided with an annular member 14 that slidably supports the lower shaft portion 10b of the second valve shaft 10 that protrudes upward from the upper opening 4.
The annular member 14 includes a base 15a of a yoke 15 and a packing 16 that is in close contact with the lower shaft 10b at the lower end thereof. The lower opening 5 of the lower flow path 2 is provided with an annular member 17 slidably supporting a lower shaft portion 8c of the first valve shaft 8 protruding downward from the lower opening 5. The member 17 is the large diameter base 1 of the sleeve 18.
8a, and a packing 19 that is in close contact with the lower shaft portion 8c at the upper end thereof.

As shown in FIG. 1, a cleaning liquid supply port 20 is provided in a lower shaft portion 10 b of the second valve shaft 10, and the cleaning liquid supply port 20 is connected to the first valve shaft 8 through a communication hole 21. Internal passage 2 provided in intermediate shaft portion 8b along its central axis
2, the internal passage 22 communicates with a plurality of cleaning liquid ejection holes 23 radially provided at the lower end of the intermediate shaft portion 8b. Further, as is apparent with reference to FIG.
Outer peripheral surface of the intermediate shaft portion 8b and the lower shaft portion 10b of the second valve shaft 10.
Between the inner peripheral surface and the inner peripheral surface, the cleaning liquid supplied from the cleaning liquid supply port 20 is actively introduced at the same time as the cleaning liquid is introduced into the internal passage 22 from the communication hole 21, and from the lower end of the intermediate shaft 8 b. A cleaning annular liquid passage 44 for discharging is formed. A spiral flow forming ring 45 having a plurality of spiral grooves 45a formed on the outer peripheral surface thereof for spirally flowing the cleaning liquid introduced into the liquid passage 44 is disposed in the cleaning annular liquid passage 44. . The spiral flow forming ring 45 is formed in a ring shape from a fluororesin, and as shown in FIG. 8, a plurality of spiral grooves 45a are provided on the outer peripheral surface at regular intervals in the circumferential direction.

When the cleaning liquid is supplied from the cleaning liquid supply port 20, for example, 70% of the flow rate of the supplied cleaning liquid is introduced into the internal passage 22 of the intermediate shaft portion 8b through the communication hole, and 30% of the flow rate is increased. The cleaning liquid is simultaneously introduced into the cleaning annular liquid passage 44 through the annular portion 44a. The cleaning liquid introduced from the communication hole 21 enters the internal passage 22 of the intermediate shaft portion 8b,
Each of the cleaning liquid ejection holes 23 at the lower end squirts into an annular chamber 24 formed between the first valve body 7, the second valve body 9, and the valve seat 6. After cleaning the inner peripheral portion of the seat 6 and the inner portions of the valve bodies 7 and 9, the gas is discharged to the outside from the discharge passage 26 inside the lower shaft portion 8 c of the first valve shaft 8 through the plurality of through holes 25. On the other hand, the cleaning liquid introduced into the cleaning annular liquid passage 44 forms a spiral flow by passing through the spiral groove 45a of the spiral flow forming ring 45 and passes through the annular liquid passage 44.
While being completely washed by the spiral flow, the inside of the annular liquid passage 44 is discharged to the annular chamber 24 between the first valve body 7, the second valve body 9, and the valve seat 6. Lower shaft 8c
It is discharged to the outside from the internal discharge path 26. The cleaning liquid supply port 20 is provided with a base 27 for connecting a cleaning liquid hose.
5 through the window 15a.

As is evident with reference to FIGS. 1 and 9,
Lower shaft portion 8 of first valve shaft 8 protruding downward from lower flow passage 2
c (the first valve shaft portion) and the inner peripheral surface of the annular member 17 slidably supporting the shaft portion, and the second valve shaft 10 projecting upward from the upper flow path 1. Lower shaft 10b
The first valve shaft 8 is provided between the outer peripheral surface of the (second valve shaft portion) and the inner peripheral surface of the annular member 14 that slidably supports the shaft portion.
Washing annular passages 46 and 47 longer than the maximum strokes of the second valve shaft 10 and the second valve shaft 10, respectively, are formed at the lower ends of the washing annular passages 46 and 47, and a small-diameter washing liquid supply port 48 is provided. , 49, and large-diameter cleaning liquid outlets 50, 51 are provided at the upper end. The cleaning liquid supply ports 48 and 49 are provided with cleaning liquid supply hose connection bases 48a and 49a, and the cleaning liquid discharge ports 50 and 51 are provided with cleaning liquid discharge hose connection bases 50a and 51a. As shown in FIG. 9, the length of the lower cleaning annular passage 46 is L1, which is longer than the maximum stroke of the second valve shaft 10, and the length of the upper cleaning annular passage 47 is L2.
Therefore, it is longer than the maximum stroke of the first valve shaft 8.

FIGS. 1 and 9 show a first valve body 7 and a second valve body 9.
Shows the fully closed state of the valve, but the lower limit of the maximum stroke of the first valve shaft 8 is when the first valve body 7 is only in the partially opened state as shown in FIG. As shown in FIG. 5, the upper limit is when the valve bodies 7, 9 are open and the valves are fully opened. Further, the lower limit of the maximum stroke of the second valve shaft 10 is when the second valve body 9 is in a closed state as shown in each drawing,
The upper limit is when the valve is fully open as shown in FIG.
Therefore, the lower end and the upper end of each of the cleaning annular passages 46 and 47 are positioned lower and higher than the lower and upper limits of the maximum stroke of the first valve body 7 and the second valve body 9 as described above. In any valve state, even if the first valve shaft 8 and the second valve shaft 10 come into contact with the atmosphere, the cleaning liquid supply port 4
By supplying the cleaning liquid to the cleaning annular passages 46 and 47 from the cleaning passages 8 and 49, the air contact portions of the valve shafts 8 and 10 can be immediately cleaned, and a prompt and accurate response to contamination can be achieved.

In each of the annular cleaning passages 46 and 47,
A spiral flow forming ring 52 having a plurality of spiral grooves 52a formed on the outer peripheral surface for spirally flowing the cleaning liquid introduced into the liquid passages 46 and 47 is provided. The spiral flow forming ring 52 is formed in a ring shape with a fluororesin. As shown in FIG. 8 at the same time as the spiral flow forming ring 45, a plurality of spiral grooves 52a are provided on the outer peripheral surface at regular intervals in the circumferential direction. It is established in.

When the pressurized cleaning liquid is supplied from the cleaning liquid supply port 48 in order to clean the first valve shaft 8 portion, the cleaning liquid flows through the cleaning annular passage 46 while the lower shaft of the first valve shaft 8 is being rotated. The outer peripheral surface of the portion 8c is sufficiently cleaned, and is discharged from the cleaning liquid discharge port 50 having a diameter larger than that of the cleaning liquid supply port 48. Since the washing liquid flowing through the washing annular passage forms a spiral flow by passing through the spiral groove 52a of the spiral flow forming ring 52, the outer peripheral surface of the lower shaft portion 8c is effectively cleaned by the spiral flow. Can be. Also, the second valve shaft 1
The same applies to the cleaning of 0. When the pressurized cleaning liquid is supplied from the cleaning liquid supply port 49, the cleaning liquid sufficiently cleans the outer peripheral surface of the lower shaft portion 10b of the second valve shaft 10 while flowing through the cleaning annular passage 47. The cleaning liquid is discharged from the cleaning liquid discharge port 50 having a diameter larger than that of the cleaning liquid supply port 48, and the cleaning liquid is supplied to the spiral flow forming ring 5
A spiral flow is formed by passing through the second spiral groove 52a, and the outer peripheral surface of the lower shaft portion 10b can be effectively cleaned by the spiral flow. In this case, each cleaning liquid outlet 50, 5
1 is larger than the diameter of each of the cleaning liquid supply ports 48 and 49, the cleaning liquid discharge ports 5 and
It is possible to effectively discharge the cleaning liquid to 0,51.

Referring to FIG. 2, in FIG.
Is a first valve opening / closing drive mechanism that controls opening and closing of the first valve body 7 and the second valve body 9. The valve opening / closing drive mechanism 28 uses an upper shaft portion 8 a of the first valve shaft 8 as a piston rod, An air cylinder in which a piston 29 fixed thereto is fitted in a fixed cylinder 30 is provided, and a spring receiver 31 is disposed in an upper portion of the fixed cylinder 30. A second spring 32 composed of a coil spring having a greater spring force than the first spring 11 interposed between the piston 29 and the second valve shaft 10;
And a spring limiting stopper 33 for extending and contracting the second spring 32 to a predetermined range is interposed. The piston 29 is fixed to the fixed cylinder 30. The upper and lower chambers 30 separated
Air supply / discharge port 3 for supplying / discharging air to / from a and 30b
4, 35 are provided.

The spring support 31 comprises a ring-shaped spring support main body 31o for receiving one end of a second spring 32 and a cylindrical member 31a formed concentrically and integrally therewith. A cylindrical member 33a which is externally fitted to the piston rod (upper shaft portion 8a of the first valve shaft 8), fixed at a fixed position, and slidably fitted inside the cylindrical member 31a of the spring receiver 31; Normally, as shown in FIG. 2, the two cylindrical members 31a, 3
The engagement of the distal end engagement portions of 3a causes the spring receiver 31 and the stopper 33 to be connected in a state of maximum extension, thereby restricting the second spring 32 from further extending.

Therefore, according to the first valve opening / closing drive mechanism 28, when pressure air is not supplied to either of the upper and lower chambers 30a, 30b with the piston 29 of the fixed cylinder 30 interposed therebetween, as shown in FIG. Thus, the first interposed between the piston 29 and the upper shaft portion 10a of the second valve shaft 10
The first valve shaft 8 is urged upward and the second valve shaft 10 is urged downward by the urging force of the spring 11, and the first valve body 7 is moved through the main annular packing 12 to the inner circumferential side of the valve seat 6. The second valve body 9 closely engages with the upper side seating surface 6b of the valve seat 6 via the auxiliary annular packing 13 while being closely engaged with the seating surface 6a, and the valve is fully closed as shown in FIG. .

When pressurized air is supplied from the air supply / discharge port 35 to the lower chamber 30b of the fixed cylinder 30, the piston 29 rises against the urging force of the second spring 32, and accordingly, the stopper 33 The cylindrical member 33a contracts with respect to the cylindrical member 31a of the spring receiver 31, and the first valve shaft 8 starts to move upward, while the upper end of the first valve body 7 moves upward as shown in FIG. In contact with the lower portion on the inner peripheral side of the second valve element 9, the first valve element 7 pushes up the second valve element 9 and rises together in this abutting state, and the two valve elements 7, 9 are raised from the valve seat 6. And the stroke setting ring R fitted on the upper end side of the piston rod 8a is fixed to the upper wall 3 of the fixed cylinder 30.
By contact with 0c, the piston 29 reaches the upper limit position, and the first valve body 7 and the second valve body 9 are in the fully opened state as shown in FIG.

When the pressure air in the lower chamber 30b of the fixed cylinder 30 is discharged when the valve is fully opened, the spring receiver 31 is moved to the upper wall 30c of the fixed cylinder 30.
The piston 29 is lowered by the urging force of the second spring 32 while being pressed against the first valve shaft 8 and the second valve shaft 8.
When the valve shaft 10 moves downward, the first valve body 7 and the second valve body 9
The state returns to the fully closed state as shown in FIG. Note that the valve is fully closed (see FIG. 3).
The stroke Sa of the piston 29 in the fully opened state (see FIG. 5) and the stroke of the piston 29 in the fully opened state (see FIG. 5) are set by the stroke setting ring R which comes into contact with the upper wall portion 30c of the fixed cylinder 30.

When pressure air is supplied from the air supply / discharge port 34 to the upper chamber 30a of the fixed cylinder 30 in the fully closed state shown in FIGS. 1 and 2, the second spring 32 is actuated by the spring restricting stopper 33. Of the upper chamber 30a, the piston 29 is pushed downward, and descends together with the second spring 32 and the spring receiver 31, whereby the first valve shaft 8 is moved downward. The main annular packing 12 of the first valve body 7 slides downward on the inner peripheral side seating surface 6a of the valve seat 6 and separates as shown in FIG. Then, only the first valve element 7 is in a slightly opened valve part open state. In this way, by supplying the pressurized air to the upper chamber 30a of the fixed cylinder 30, the first valve shaft 8 can be moved down independently, and only the first valve body 7 can be partially opened. In this case, the piston 29 is
Starts descending from the position shown in FIG. 5, and stops by contacting the upper end of the second cylinder 37 described later. Accordingly, the stroke becomes Sb shown in the figure, and the first valve shaft 8 moves up and down independently of the second valve shaft 10 by this stroke Sb.

Below the first valve opening / closing drive mechanism 28, there is provided a second valve body opening / closing drive mechanism 36 also composed of an air cylinder. The second valve body opening / closing drive mechanism 36 is a fixed cylinder 30 of the first valve opening / closing drive mechanism 28.
A second cylinder 37 formed at a lower portion in communication with the second cylinder 37;
The second valve shaft 10 and the second cylinder 37
A second piston 38 which moves up and down by a predetermined stroke in a state of being externally fitted to the upper shaft portion 10a, and a third spring 39 comprising a coil spring for urging the second piston 38 to a lower limit position.
And an air supply / discharge port 40 for supplying / discharging air to / from the lower chamber 30a of the second piston 38. As can be seen from FIG. 2, the second cylinder 37 is connected to the lower end of the fixed cylinder 30 of the first valve opening / closing drive mechanism 28 by a screw connection.
The upper chamber 37b and the lower chamber 30b of the fixed cylinder 30 in the first valve opening / closing drive mechanism 28 are formed so as to communicate with each other.

In FIG. 2, reference numeral 41 denotes a stopper for regulating the lower limit position of the second piston 38.
The stopper 42 is formed on the lower wall side of the second cylinder 37 and restricts the upper limit position of the second piston 38.
Is formed on the upper wall side. Thus, the second piston 38 corresponds to the distance between the upper end 38 a on the outer peripheral side of the piston 38 and the upper limit position restricting stopper 42 between the lower limit position restricting stopper 41 and the upper limit position restricting stopper 42. The second piston 38 urged by the third spring 39 to the lower limit position.
Is shorter than the stroke S1 between the inner peripheral side upper end portion 38b and the stopper 43 projecting from the upper shaft portion 10a of the second valve shaft 10 urged to the valve closing position by the first spring 11. Since the axial play S2 is provided,
When the piston 38 moves up the stroke S1 from the lower limit position to the upper limit position, the second valve shaft 10 actually causes the difference (S1) between the stroke S1 of the second piston 38 and the axial play S2. -S2) It moves up by the amount.
As described above, the inner peripheral upper end 38 b of the second piston 38 urged to the lower limit position by the third spring 39 and the second spring 32
The stopper 4 on the side of the second valve shaft 10 urged to the valve closing position by the
3, an axial play S2 shorter than the stroke S1 of the second piston 38 is provided, so that the urging force of the second spring 32 is effectively applied to the second valve shaft 10 and
The valve body 9 can be securely pushed and engaged with the upper seat surface 6b of the valve seat 6.

In the second valve opening / closing drive mechanism 36, the state in which the second piston 38 is held at the lower limit position as shown in FIG. When the pressurized air is supplied to the lower chamber 37a, the second piston 38 starts to move upward.
The upper end 38b on the inner peripheral side of the
, The second valve shaft 10 remains held at the lowered position to close the second valve body 9. Thus, the second valve shaft 1
After the upper end 38b on the inner peripheral side of the second piston 38 hits the stopper 42, the upper end 38b is pushed up with the upward movement of the second piston 38, and the upper end 38 on the outer peripheral side of the piston 38
The valve a moves upward until it reaches the upper limit position restricting stopper 42, and as a result, as shown in FIG. 7, only the second valve body 9 is in a slightly open valve part open state. Also, the lower chamber 37a
The second piston 38 is moved to the third
While being pushed down by the spring 39, the second valve shaft 10 is moved down by the second spring 32, and the second valve body 9 is closed.

In the use of the double seal valve having the above-described structure, when no pressure air is supplied to the lower chamber 30b of the fixed cylinder 30 in the first valve opening / closing drive mechanism 28, FIGS. As shown in FIG. 3, the first valve body 7 closely engages with the inner peripheral side seating surface 6 a of the valve seat 6 via the main annular packing 12, and the second valve shaft 10 is pushed down by the first spring 11 to thereby provide the second valve shaft 10. The valve body 9 presses and engages with the upper side seating surface 6b of the valve seat 6 via the sub annular packing 13,
The first valve body 7 and the second valve body 9 are both in a fully closed state in which both valves are closed, and the communication path 3 that connects the upper flow path 1 and the lower flow path 2 is connected to the first valve on the lower flow path 2 side. Is closed in a double sealed state by the body 7 and the second valve body 9 on the upper flow path 1 side,
Mixing of the liquid flowing in the upper flow path 1 and the liquid flowing in the lower flow path 2 is prevented.

The lower chamber 3 of the fixed cylinder 30
0b is supplied with the pressure air, as shown in FIG.
As the first valve body 7 pushes up the second valve body 9 and moves up together with the upward movement of the valve shaft 8, the two valve bodies 7, 9 are sufficiently separated upward from the valve seat 6 as shown in FIG. Such a valve is fully open,
Thereby, the communication path 3 is opened, and the upper flow path 1 and the lower flow path 2 can be communicated via the communication path 3.

When using a liquid that is difficult to wash, such as a highly viscous liquid, one of the first valve element 7 and the second valve element 9 is closed, and the other is opened slightly and then opened. While washing the packing part with the cleaning liquid, the cleaning liquid is discharged. For example, high-viscosity drinking water is circulated through the upper flow path 1,
When the cleaning liquid is supplied to the lower flow path 2, when the pressurized air is supplied to the upper chamber 30 a of the fixed cylinder 30, the piston 29 descends together with the second spring 32 whose elongation is restricted by the increase in the pressure of the upper chamber 30 a. As a result, the first valve shaft 8 moves downward, and the main annular packing 12 of the first valve body 7 slides downward on the inner peripheral side seating surface 6a of the valve seat 6 to be separated, as shown in FIG. Then, only the first valve element 7 is in a slightly opened valve part open state. Thus, the cleaning liquid from the lower flow path 2 passes through the gap between the first valve element 7 and the valve seat 6 as shown by the arrow in FIG. Is introduced into an annular chamber 24 formed between the first valve body 7 and the valve seat 6, during which the main annular packing 12 of the first valve body 7 and the interior of the annular chamber 2 are washed, and then the lower portion of the first valve shaft 8 It is discharged to the outside through the discharge passage 26 inside the shaft portion 8c.

In the case where highly viscous drinking water flows through the lower flow path 2 and the washing liquid flows through the upper flow path 1,
When pressure air is supplied to the lower chamber 37a of the second cylinder 37 in the valve opening / closing drive mechanism 36, the second valve shaft 10 is pushed up by the piston 38 while the second piston 38 is moving upward, and the second piston 38 Moves upward by a predetermined stroke S1, so that the second valve shaft 10 moves in the axial play S2.
The valve is moved upward by the stroke (S1-S2) from which the minute has been subtracted, and as shown in FIG. 7, only the second valve body 9 is in a slightly open valve part open state. Thus, the cleaning liquid from the upper flow path 1 passes through the gap between the second valve body 9 and the upper seating surface 6b of the valve seat 6, as indicated by the arrow in FIG. After circulating in the annular chamber 24 formed between the second valve body 9 and the valve seat 6 to clean the sub-annular packing 13 portion of the first valve body 7 and the inside of the annular chamber 2, It is discharged to the outside through the discharge passage 26 inside the lower shaft portion 8c of the valve shaft 8.

[0031]

According to the first aspect of the present invention,
An outer peripheral surface of a first valve shaft portion projecting downward from the lower flow path;
An annular member that slidably supports the shaft portion between an inner peripheral surface of an annular member that slidably supports the shaft portion and an outer peripheral surface of a second valve shaft portion that projects upward from the upper flow path; A cleaning annular passage having a length longer than the maximum stroke of each of the first valve shaft and the second valve shaft is formed between the member and the inner peripheral surface of the member. Supply port,
In addition, by providing a large diameter cleaning liquid outlet at the upper end,
The lower end and the upper end of each cleaning annular passage are connected to the first valve body and the second valve body.
The cleaning liquid supply port can be positioned lower and higher than the lower and upper limits of the respective maximum strokes of the valve element, so that the first valve shaft and the first valve shaft contact the atmosphere in any valve state. By merely supplying the cleaning liquid to the cleaning annular passage, the air contact portion of the valve shaft can be immediately cleaned. Since the diameter of each cleaning liquid outlet is larger than the diameter of each cleaning liquid supply port, the cleaning liquid can be effectively discharged from each cleaning annular passage to the cleaning liquid discharge port.

Therefore, according to the present invention, it is possible to immediately clean the shaft portion of the atmospheric contact valve when necessary at any timing, and to take quick and accurate measures against contamination.

According to the second aspect of the present invention, the cleaning liquid supplied to the cleaning annular passage forms a spiral flow by passing through the spiral flow forming ring, and the spiral flow effectively cleans the outer peripheral surface of the valve shaft portion. Can be done.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a lower half of a double seal valve according to the present invention, and an aa line is a dividing line with an upper half.

FIG. 2 is a longitudinal sectional view showing an upper half of the double seal valve.

FIG. 3 is a longitudinal sectional view showing a central portion of a double seal valve in a fully closed state of the valve.

FIG. 4 is a vertical cross-sectional view of a central portion of the double seal valve showing a state in which the valve has transitioned from a fully closed state to an open state.

FIG. 5 is a longitudinal sectional view showing a central portion of the double seal valve in a fully opened state.

FIG. 6 is a longitudinal sectional view showing a valve part opened state in which a first valve body is slightly opened.

FIG. 7 is a longitudinal sectional view showing a valve part opened state in which a second valve body is slightly opened.

FIG. 8 is a perspective view showing a spiral flow forming ring.

FIG. 9 is an enlarged detailed sectional view showing the structure of a cleaning annular passage portion formed between the outer peripheral surface of each valve shaft and the inner peripheral surface of the annular member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper flow path 2 Lower flow path 3 Communication path 6 Valve seat 7 First valve body 8 First valve shaft 9 Second valve body 10 Second valve shaft 11 First spring 14 Ring member 17 Ring member 20 Cleaning liquid supply port 22 Inside Passage 23 Cleaning liquid ejection hole 24 Annular chamber 26 Discharge path 28 First valve opening / closing drive mechanism 32 Second spring 36 Second valve opening / closing drive mechanism 39 Third spring 46 Cleaning annular passage 47 Cleaning annular passage 48 Cleaning liquid supply port 49 Cleaning liquid supply port 50 Cleaning liquid discharge port 51 Cleaning liquid discharge port 52 Spiral flow forming ring 52a Spiral groove

Claims (2)

[Claims] A valve seat is provided in a communication passage formed between an upper flow passage and a lower flow passage, a first valve body engaging with an inner peripheral side of the valve seat is provided on a first valve shaft, and a valve seat is provided. A second valve body is provided on the second valve shaft which is slidably fitted on the first valve shaft, and the first valve shaft is interlocked with the valve opening / closing drive mechanism. An outer periphery of a first valve shaft portion protruding downward from a lower flow path in a double seal valve in which a second valve body moves following the upward movement of a first valve shaft by operation of a valve opening / closing drive mechanism when the valve is opened; Between the surface and the inner peripheral surface of the annular member slidably supporting the shaft portion, and the outer peripheral surface of the second valve shaft portion projecting upward from the upper flow path, and allowing the shaft portion to slide. A cleaning annular passage having a length longer than the maximum stroke of each of the first valve shaft and the second valve shaft is formed between the supporting member and the inner peripheral surface of the supporting member. A double seal valve comprising a cleaning liquid supply port having a small diameter at a lower end of a passage and a cleaning liquid discharge port having a large diameter at an upper end. 2. The cleaning annular passage is provided with a spiral flow forming ring in which a plurality of spiral grooves for forming a spiral flow of the cleaning liquid supplied to the annular passage are formed on an outer peripheral surface. The double seal valve according to claim 1.