JPH1030737A - Double seal valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily clean a sliding clearance part between a first valve stem and a second valve stem with the cleaning solution to be fed from a cleaning solution feed port of the second valve stem. SOLUTION: In a double seal valve, a valve seat 6 is provided on a communication passage 3 to communicate an upper flow passage 1 with a lower flow passage 2, a first valve disk 7 engaged with an inner circumferential side of the valve seat 6 is provided on a first valve stem 8, 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, and the cleaning solution to be fed from a cleaning solution feed port 20 of the second valve stem 110 is sprayed from a cleaning solution spray port 23 in a lower end part through an inner flow passage 22 of the first valve stem 8. An annular cleaning solution passage 44 which simultaneously and positively feeds the cleaning solution to be fed from the cleaning solution feed port 20 in parallel, and discharges the solution from the lower end side of the second valve stem 10 is formed between the outer circumferential surface of the first valve stem 8 and the inner circumferential surface of the second valve stem 10.

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. The present invention relates to a seal valve, and more particularly to a structure for cleaning the inside of a valve.

[0002]

2. Description of the Related Art A conventional double seal valve of this type is
A valve seat is provided in a communication passage formed between the upper flow passage and the lower flow passage, and a first valve body engaged with the inner peripheral side of the valve seat is pushed on the first valve shaft and on the upper side of the valve seat. A second valve body to be in contact and engagement is provided on each of the hollow second valve shafts slidably fitted to the first valve body, and the first valve shaft is interlockedly connected to a valve opening / closing drive mechanism to open and close. When the first valve shaft is moved upward by the actuation of the valve opening / closing drive mechanism at the time of valve opening, the second valve body moves in accordance with the movement of the first valve shaft. A cleaning liquid supply port is provided, an internal passage extending in the axial direction is provided inside the first valve shaft, and a plurality of cleaning liquid injection holes are radially provided at a lower end thereof.

[0003]

In the above-mentioned conventional double seal valve, the cleaning liquid supplied from the cleaning liquid supply port of the second valve shaft is introduced into the internal passage of the first valve shaft, and the cleaning liquid is injected at the lower end thereof. The inner peripheral part of the valve seat and the inner part of the valve body are cleaned well because they are ejected from the hole, but are slidably fitted on the outer peripheral surface of the first valve shaft. The sliding gap between the inner peripheral surface of the second valve shaft cannot be washed,
Therefore, to clean the sliding gap, the first valve shaft and the second
It was necessary to disassemble the valve stem, which required a lot of work.

[0004] The present invention is designed to easily clean the sliding gap between the first valve shaft and the second valve shaft with the cleaning liquid supplied from the cleaning liquid supply port provided in the second valve shaft. It is an object of the present invention to provide a double-sealed valve that has been provided.

[0005]

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. The second valve shaft 10 is provided on a hollow second valve shaft 10 slidably fitted on the shaft 8, and the first valve shaft 8 is operatively connected to a valve opening / closing drive mechanism 28 so that the valve opening / closing drive mechanism 28 operates when the valve is opened. The second valve body 9 is caused to follow the upward movement of the first valve shaft 8, and the cleaning liquid supplied from the cleaning liquid supply port 20 of the second valve shaft 10 is further passed through the internal passage 22 of the first valve shaft 8. In the double seal valve which is ejected from the washing liquid ejection hole 23 at the lower end thereof, the outer peripheral surface of the first valve shaft 8 and the second valve shaft 10
The cleaning liquid supplied from the cleaning liquid supply port 20 of the second valve shaft 10 is concurrently and positively introduced simultaneously with the inner peripheral surface of the second valve shaft 10 and discharged from the lower end side of the second valve shaft 10. It is characterized in that an annular liquid passage 44 is formed.

A second aspect of the present invention is the double seal valve according to the first aspect, wherein a cleaning annular passage formed between an outer peripheral surface of the first valve shaft 8 and an inner peripheral surface of the second valve shaft 10. In the fluid path 44,
It is characterized in that a spiral flow forming ring 45 having a plurality of spiral grooves 45a formed on the outer peripheral surface for spirally flowing the cleaning liquid introduced into the liquid passage 44 is provided.

[0007]

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. The first valve body 7 is disposed between the upper opening 4 and the lower valve opening 5 through the communication passage 3. 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 designates a valve seat 6 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 6a 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. The upper end of the cleaning annular liquid passage 44 has an annular portion 44a having a slightly larger diameter so that the cleaning liquid from the cleaning liquid supply port 20 can be effectively supplied to the communication hole 21 and the liquid passage 44. doing. In addition, a plurality of spiral flow forming rings 45 in which a plurality of spiral grooves for forming a spiral flow of the cleaning liquid introduced into the cleaning liquid passage 44 are formed on the outer peripheral surface of the annular flow passage 44 for cleaning, For example, they are provided at two locations above and below. 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% is increased in diameter. 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. in this way,
By supplying the cleaning liquid from the cleaning liquid supply port 20,
The inner peripheral portion of the valve seat 6 and the inner portions of the valve bodies 7 and 9 can be cleaned, and at the same time, the outer peripheral surface of the intermediate shaft portion 8b of the first valve shaft 8 and the second valve shaft 10
The so-called sliding gap between the lower shaft portion 10b and the inner peripheral surface of the lower shaft portion 10b can be automatically and completely cleaned. The cleaning liquid supply port 20 is provided with a base 27 for connecting a cleaning liquid hose.
5 through the window 15a.

Referring to FIG. 2, reference numeral 28 in FIG. 2 denotes a first valve opening / closing drive mechanism for opening and closing the first valve body 7 and the second valve body 9. The upper shaft portion 8a of the first valve shaft 8 is an air cylinder in which a piston rod fixed to the upper shaft portion 8a is fitted into a fixed cylinder 30. A spring receiver 31 is disposed in the upper portion of the fixed cylinder 30. The piston 29 and the second valve shaft 10 are located between the spring receiver 31 and the piston 29.
A second spring 32 composed of a coil spring having a greater spring force than the first spring 11 interposed between the second spring 32 and the second spring 32 fixed to the piston rod 8a and connected to the spring receiver 31 so as to be able to expand and contract. A spring limiting stopper 33 for limiting the extension of the two springs 32 to a certain range is interposed. The fixed cylinder 30 is provided with an air supply for supplying and discharging air to upper and lower chambers 30a and 30b via a piston 29. Discharge ports 34 and 35 are provided.

The spring support 31 comprises a ring-shaped spring support 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, 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 pressure air is supplied to the lower chamber 30b of the fixed cylinder 30 from the air supply / discharge port 35, the piston 29 rises against the urging force of the second spring 32, and 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 limiting 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 configuration, 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 should be closed, and the other should be slightly opened and 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, the second flow path is used.
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.

[0026]

In the invention according to the first aspect, the cleaning liquid supplied from the cleaning liquid supply port provided in the second valve shaft is introduced into the internal passage of the first valve shaft, 1
It is introduced in parallel into the washing annular liquid passage between the outer peripheral surface of the valve shaft and the inner peripheral surface of the second valve shaft. The cleaning liquid introduced into the internal passage of the first valve shaft is jetted from a cleaning liquid jet hole at a lower end into an annular chamber formed between the first valve element, the second valve element, and the valve seat. After cleaning the inner peripheral part and the inner part of the valve body, it is discharged to the outside. On the other hand, the cleaning liquid introduced into the cleaning annular liquid passage is discharged from the lower end side of the second valve shaft to the outside while completely cleaning the inside by passing through the annular liquid passage.

Therefore, according to the present invention, by supplying the cleaning liquid from the cleaning liquid supply port, the inner peripheral part of the valve seat and the inner part of the valve body can be cleaned, and at the same time, the outer peripheral surface of the first valve shaft and the second peripheral part can be cleaned. The sliding gap between the inner peripheral surface of the valve shaft and the inner peripheral surface can be automatically and completely cleaned.

According to the second aspect of the present invention, the cleaning liquid introduced into the cleaning annular liquid passage forms a spiral flow by passing through the spiral flow forming ring. It can be effectively cleaned.

[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 cross-sectional view showing a portion of a cleaning annular liquid passage formed between a first valve shaft and a second valve shaft.

[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 20 Cleaning liquid supply port 21 Communication hole 22 Internal passage 23 Cleaning liquid Spout 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 44 Washing annular liquid passage 45 Spiral flow forming ring 45a 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 that is pressed and engaged on the upper side of the first valve shaft is provided on each of the hollow second valve shafts that are slidably fitted on the first valve shaft, and the first valve shaft is connected to the valve opening / closing drive mechanism. When the valve opens and closes, the valve opening and closing drive mechanism activates the first
The second valve body follows the upward movement of the valve shaft,
Further, the cleaning liquid supplied from the cleaning liquid supply port of the second valve shaft is supplied to the first valve.
In the double seal valve, the cleaning liquid is ejected from a cleaning liquid ejection hole at a lower end portion through an internal passage of the valve shaft, the second seal is provided between an outer peripheral surface of the first valve shaft and an inner peripheral surface of the second valve shaft. A washing liquid supply port provided on the valve shaft, a cleaning liquid supply passage is formed, and a cleaning annular liquid passage for discharging the liquid from the lower end side of the second valve shaft by simultaneously and positively introducing the cleaning liquid at the same time is formed. Seal valve. 2. A cleaning annular liquid passage formed between an outer peripheral surface of the first valve shaft and an inner peripheral surface of the second valve shaft has a spiral flow of the cleaning liquid introduced into the liquid passage. The double seal valve according to claim 1, wherein a spiral flow forming ring having a plurality of spiral grooves formed on an outer peripheral surface thereof is disposed.