JPH0536153Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) This invention relates to a double seal valve used in liquid distribution lines in food manufacturing, brewing, etc. machines and plants. The present invention relates to a valve structure that prevents mixing of two liquids by doing so.

(Prior Art) As shown in FIG. 4, a conventional double seal valve of this type forms a communication passage 4 between an upper passage 2 and a lower passage 3 provided in a housing 1. , upper and lower openings 5a and 5b are formed in the coaxially opposing portions of the communication path 4 in both flow paths 2 and 3, and the communication path 4
A first valve shaft 8 is provided, which has a first valve body 7 that presses into engagement with a valve seat 6 attached to the valve seat 6 from above, and is in close contact with the lower opening 5b so as to be able to slide in the axial direction.
The valve stem 8 has a valve seat 6 located above the first valve body 7.
A second valve shaft 10 having a second valve body 9 that presses into engagement with the upper opening 5a from above and comes into close contact with the upper opening 5a so as to be able to slide in the axial direction is made relatively movable in the axial direction and is attached to the spring. Therefore, the mantle is fitted so as to be constantly biased downward, and as the first valve shaft 8 moves upward when the valve is opened, the second valve body 9 moves to follow the upward movement of the first valve body 7, Further, when the valve is closed, as the first valve shaft 8 moves downward, the second valve shaft 10 also moves downward, so that both the valve bodies 7 and 9 engage with the valve seat 6.

(Problem to be solved by the invention) In the conventional double seal valve as described above,
Shaft portion 8a where first valve shaft 8 is in close contact with lower opening 5b
However, since the diameter of the first valve body 7 is much smaller than that of the first valve body 7, water hammer, etc. may occur in the closed state where the valve bodies 7 and 9 are seated on the valve seat 6. When excessive pressure is generated in the flow path 3, the pressure instantly pushes up the first valve body 7 and further pushes up the second valve body 9. As a result, the valve becomes open and the liquid on the flow path 3 side flows into the flow path. There was a problem that the liquids in both flow paths 2 and 3 were mixed together.

The present invention solves such problems.

(Means for Solving the Problems) The double seal valve of the present invention includes an engaging portion provided on the first valve shaft and a stopper disposed so as to be movable forward and backward in a direction orthogonal to the first valve shaft. member, and an advance/retreat drive means having a fluid pressure cylinder that drives the advance/retreat of the stopper member, the stopper member is moved backward and disengaged from the engagement portion when the valve is opened, and the stopper member is moved back and forth when the valve is closed. The first valve shaft is configured to be moved inward and engaged with the engaging portion, thereby fixing the first valve shaft at the valve closing position.

(Example) In FIG. 1 showing the entire double seal valve according to the present invention, 11 is a housing, inside of which are an upper passage 12 through which, for example, a beverage liquid flows, and a lower passage 13 through which, for example, a cleaning liquid flows. Two channels are formed in parallel or intersecting directions, and
A communication path 14 is formed between the upper flow path 12 and the lower flow path 13, and an upper opening 15a and a lower opening 15b are formed in the portions of both flow paths 12 and 13 coaxially facing the communication path 14. A valve seat 16 is attached to the communication passage 14.

Reference numeral 17 denotes a first valve body that is pressed into engagement with the lower side of the valve seat 16 from above, and is connected to the communication path 1 from the upper opening 15a.
4 and inserted into the lower opening 15b side.
It is formed integrally with an intermediate shaft portion 18b of the valve shaft 18, and a hollow lower shaft portion 18c is connected to this intermediate shaft portion 18b by a screw connection. In addition, the intermediate shaft portion 1
An upper shaft portion 18a is screwed to the upper end portion of 8b, and these upper, middle and lower shaft portions 18a,
A first valve shaft 18 is formed by 18b and 18c.

19 is located above the first valve body 17 and is connected to the valve seat 16.
The second valve body presses into engagement with the upper side of the first valve shaft 18 from the upper shaft portion 18a to the intermediate shaft portion 18b of the first valve shaft 18.
The second valve shaft 20 is integrally formed with the lower end of a hollow second valve shaft 20 which is fitted so as to be slidable in the axial direction, and the second valve shaft 20 is rotated downward by a coil spring as will be described later. energized.

A cleaning liquid injection pipe 21 is connected to the lower end of the intermediate shaft part 18b of the first valve shaft 18 concentrically with the inside of the lower shaft part 18a by a screw connection, and an internal passage 21a of this cleaning liquid injection pipe 21 is connected to the lower end of the intermediate shaft part 18b. is the intermediate shaft part 1
8b communicates with the hollow chamber 22 at the lower end, and this hollow chamber 22
communicates with an annular chamber 24 formed between the first valve body 17 and the second valve body 19 through a plurality of cleaning liquid pouring holes 23 provided through the lower end of the intermediate shaft portion 18b; Furthermore, this annular chamber 24 communicates with a passage 26 formed between the lower shaft portion 18c and the cleaning liquid injection pipe 21 via a plurality of through holes 25 provided through the first valve body 17. Further, as is clear from FIG. 2, the first valve body 17 is equipped with a seat ring 17a that comes in close contact with the valve seat 16, and the second valve body 19 is equipped with a seat ring 19a that comes in close contact with the valve seat 16, and a seat ring 17a that comes in close contact with the valve seat 16. A seat ring 19b that is in close contact with the valve body 17 is attached. The upper opening 15a is provided with an opening frame 27, on which is attached a packing 28 that is in close contact with the second valve shaft 20, and the lower opening 15b is provided with a flange 29, on which the first A packing 30 is attached to the lower shaft portion 18c of the valve shaft 18 in close contact with the valve shaft 18.

Further, in FIG. 1, 31 is the first valve body 17.
and a valve opening/closing drive mechanism that controls opening and closing of the second valve body 19. This valve opening/closing drive mechanism 31 is composed of an air cylinder in which the upper shaft portion 18a of the first valve shaft 18 is a piston rod, and the cylinder body 32 is connected to a housing. 11 through a yoke 33,
A piston 34 fixed to the piston rod, which is the upper shaft portion 18a, is provided in the cylinder body 32 so as to be able to slide vertically, and a compression coil spring 35 is interposed between the piston 24 and the upper cylinder cover 32a, so that the piston 34 and the lower cylinder The lower cylinder chamber 36 formed between the covers 32b is used as a pressure air chamber, and between the upper end of the second valve shaft 20, which is thrust into the pressure air chamber 36 from the lower cylinder cover 32b, and the piston 34, A compression coil spring 37 having a smaller spring force than the spring 35 is interposed, and an air supply/discharge port 39a for supplying and discharging air to and from the lower cylinder chamber 36 is provided.
An air discharge port 39b is provided on the 8 side, and the air supply/discharge port 3
An air pipe _P1 from a pressure air source is connected to 9a.

Therefore, according to this valve opening/closing drive mechanism 31, when pressure air is not supplied to the lower cylinder chamber 36 in the cylinder body 32 as shown in FIG. is pushed down by the urging force of the coil springs 35 and 37, thereby causing the first valve body 17 to press against the ring seat 17.
a, and the second valve body 19 closely engages with the upper side of the valve seat 16 through the ring seat 19a, resulting in a completely closed state ( (See Figure 1). At this time, the first valve body 17
A gap S is formed between the second valve body 19 and the second valve body 19 .
Furthermore, when pressurized air is supplied to the lower cylinder chamber 36, the piston 34 rises against the biasing force of the coil spring 35, and accordingly, the first valve shaft 18 begins to move upward, and the first valve body 17 is separated from the valve seat 16 and enters the valve open state, and as the piston 34 rises, the first valve element 17, which had been maintaining a distance S between it and the second valve element 19, is moved through the ring seat 19b. The second valve body 19 is brought into close contact with the second valve body 19, and in this state of close contact, the second valve body 19 is pushed up and moved upward while opening the upper side of the valve seat 16. When the piston 34 rises to a predetermined upper limit position, the first As shown in FIG. 2, the valve body 17 and the second valve body 18 rise together to above the valve seat 16, and the valve becomes fully open. Further, when the pressure air in the lower cylinder chamber 36 of the cylinder body 32 is discharged from such a fully open valve state, the piston 3
4 is lowered by the biasing force of the coil spring 35, the first valve shaft 18 and the second valve shaft 20 are moved downward, and the first valve body 17 and the second valve body 19 are moved down as shown in FIG. The valve will return to the closed position as shown.

At the top of the above-mentioned valve opening/closing drive mechanism 31, a first
A valve stem locking mechanism 40 is provided for locking the valve stem 18 in a closed position (lower limit position). As shown in FIG. 1 and further in FIG.
A cylinder case 41 is coaxially fixed to the upper part, and the upper shaft part 18a of the first valve shaft 18 extending upward from the cylinder body 32 is passed through the cylinder case 41 in a vertically slidable manner and in a close state. A piston 42 is disposed on the upper side of the cylinder case 41 and is slidable in the axial direction with respect to the inner circumferential surface of the cylinder case 41 and the outer circumferential surface of the piston 42 with respect to the inner circumferential surface of the cylinder case 41. A ring-shaped support frame 44 having an annular groove 43 that opens toward the upper shaft portion 18a is provided on the lower side of the cylinder case 41 and is fixed to the inner peripheral surface of the cylinder case 41. 44 annular grooves 43
In this case, a plurality of stopper members 45, which are formed by dividing a cylindrical body whose inner circumferential surface is tapered into a plurality of parts in the circumferential direction, are placed in the annular groove 43 so that the radius of the stopper member 45 is These stopper members 45 are fitted and disposed so as to be movable in the direction, and endless elastic bands 46 made of coil springs or the like that can be expanded and contracted in the circumferential direction are arranged on the outer peripheral surface of the stopper members 45 at two locations above and below.
These stopper members are mounted so as to be held and tied together (see FIG. 3), and a cylindrical protruding wall 47 is provided to protrude downward from the lower end of the inner peripheral side of the piston 42, and each stopper member 45 is attached to the lower end of the cylindrical protruding wall 47. A tapered portion 49 corresponding to the tapered surface 48 is formed, and the first valve shaft 18
An engaging portion 50 is annularly protruded from the upper shaft portion 18a and engages with the lower end of each stopper member 45 when the valve is in the valve closing position (lower limit position). Further, a chamber 51 on the upper side of the piston 42 in the cylinder case 41 is used as a pressure air chamber, and this piston 42
A coil spring 52 for return is interposed between the upper side chamber 51 and the support frame 44, and an air pipe _P2 is connected to the air supply/discharge port 41a of the upper side chamber 51. This air pipe _P2 is connected to the air pipe ₁ on the valve opening/closing mechanism 31 side so as to receive pressurized air from a common air supply source. Further, although not shown, the lower side chamber of the piston 42 in the cylinder case 41 can be ventilated with the outside of the cylinder case 41.

According to the valve shaft locking mechanism 40 as described above, as shown in FIG. In this case, the valve opening/closing drive mechanism 3
Pressure air is not supplied to the pressure air chamber 36 on the first side and the pressure air chamber 51 on the valve stem locking mechanism 40 side, and the piston 42 in this valve stem locking mechanism 40 is moved by the biasing force of the coil spring. Each stopper member 45 is held at the upper limit position, and is engaged with an engaging portion 50 on the upper shaft portion 18a in close proximity to the outer circumferential surface of the upper shaft portion 18a by an elastic band 46. The valve stem 18 is held and fixed at the lower limit position. When the valve is opened, pressure air is supplied to the pressure air chamber 36 on the valve opening/closing drive mechanism 31 side, and at the same time, pressure air is also supplied to the pressure air chamber 51 on the valve shaft locking mechanism 40 side. 42 is pushed down against the biasing force of the coil spring 52, and as a result, the tapered portion 49 at the lower end of the cylindrical protruding wall 47 touches the tapered surface 48 of each stopper piece 45.
While slidingly contacting each stopper piece 45 with the upper shaft portion 18
a (in the outward radial direction) to disengage each stopper piece 45 from the engaging part 50 of the upper shaft part 18a with which it is engaged, and as a result, the first valve shaft 18 is released from the lock. is pushed up by the piston 34 of the valve opening/closing drive mechanism 31, and the second
The valve will be in the open state as shown in the figure.

Furthermore, when the pressurized air in the upper side chamber 51 of the cylinder case 41 and the lower side chamber 36 of the cylinder body 32 in the valve opening/closing drive mechanism 31 is discharged from such a valve open state, the first valve shaft 18 moves into the valve opening/closing drive mechanism 31. The piston 42 is moved downward to the lower limit position by the biasing force of the coil spring 35, and as the piston 42 is pushed up by the biasing force of the coil spring 52 in the valve shaft locking mechanism 40, each stopper member 45 is moved by the elastic band 46 to the upper shaft portion. 18a, whereby each stopper member 45 engages with the engaging portion 50,
The first valve stem 18 is locked in the closed position.

As mentioned above, the first valve stem 18 in the valve closed position
is locked by the stopper member 45 of the valve stem locking mechanism 40 to prevent upward movement, so even if excessive pressure is generated in the lower flow passage 13 due to water hammer phenomenon etc., the first Valve body 17
is not pushed up, and therefore there is no possibility that the cleaning liquid flowing through the lower flow path 13 will mix with the beverage liquid flowing through the upper flow path 12. In particular, since the stopper member is moved forward and backward by the air pressure supplied into the cylinder case 41 as a fluid pressure cylinder and the biasing force of the coil spring 52, the first valve shaft 18 can be moved to the closed position. It has the advantage that it can be fixed automatically and in a timely manner without relying on human power, and that a reliable fixed state can be obtained.

In addition, as described above, if the ring seat of the first valve body 17 or the second valve body 19 causes a seal failure, the liquid in the upper flow path 12 or the lower flow path 13 leaks to the inside of both the valve bodies 17 and 19. Both valve bodies 17, 1 are not only used when the valve is opened or closed, but also during normal valve opening/closing operation.
9 and especially the inner ring seat 19b of the second valve element 19, the liquid that passes through when the valve is opened tends to adhere and remain. There is a possibility that the remaining liquid adhering inside may mix into the upper flow path 12 or the liquid in the upper flow path and 13. Therefore, in such a case, the required cleaning liquid is injected from the cleaning liquid injection pipe 21 at an appropriate pressure, and the cleaning liquid is poured into both valve bodies 1 through the spout hole 23.
Spray inside between 7 and 19 to clean the inside.

In this embodiment, the stopper member is a stopper member 45 divided into a plurality of parts in the circumferential direction, and the means for driving the stopper member forward and backward with respect to the first valve shaft in a direction orthogonal to the first valve shaft is provided in the cylinder case 41.
A piston 42 moves up and down in response to air pressure supplied to an upper side chamber and the urging force of a coil spring 52 provided in a lower side chamber, and an elastic band 4 that holds and binds a plurality of stopper members 45 from the outer circumferential side.
6, a tapered portion 49 formed on the lower end side of the piston 42, and a tapered surface 48 formed on each stopper member 45 and in sliding contact with the tapered portion 49, but the stopper member and forward/backward driving means of the present invention is not limited to this example. For example, a single stopper member formed in an appropriate shape is attached to the piston rod of a fluid pressure cylinder serving as a forward/backward driving means, and the cylinder reciprocates the piston rod in a direction orthogonal to the first valve shaft. The stopper member at the tip may be engaged with and disengaged from the engaging portion on the first valve shaft.

(Operations and effects of the invention) According to the double seal valve of the invention, when the valve is closed, the first
When the valve stem is at the lower limit position, the first valve body is pressed into engagement with the lower side of the valve seat, and the second valve body is pressed into engagement with the upper side of the valve seat. The communication path between the upper flow path and the lower flow path is double sealed. In this valve closed state, the first valve shaft is prevented from moving upward by engaging the stopper member with the engaging portion on the first valve shaft. Therefore, even if excessive pressure is generated in the lower flow path due to water hammer phenomenon or the like, the first valve body will not be pushed up, and therefore a pushing force will also act on the second valve body. Therefore, both valve bodies can maintain close contact with the valve seat, and mixing of the two liquids can be reliably prevented. Furthermore, since the advancing body of the stopper member is driven and operated by a forward/backward driving means having a fluid pressure cylinder, the first valve shaft can be automatically fixed at the valve closing position in a timely manner, and the fixed state of the first valve shaft can be ensured. There is an effect that can be expected.

[Brief explanation of the drawing]

Fig. 1 is a half-longitudinal sectional view showing an embodiment of the double seal valve according to the present invention, showing the valve in the closed state, and Fig. 2 is an enlarged view of the main parts of the double seal valve shown in Fig. 1. , which shows the valve in an open state, FIG. 3 is a cross-sectional view taken along the line -- in FIG. 1, and FIG. 4 is a cross-sectional view showing a conventional double seal valve. 11...Housing, 12...Upper channel, 13
... Lower flow path, 14 ... Communication path, 15a ... Upper opening, 15b ... Lower opening, 16 ... Valve seat,
17...first valve body, 18...first valve shaft, 18a...
... lower shaft part, 18b ... middle shaft part, 19 ... second
Valve body, 20... Second valve stem, 31... Valve opening/closing drive mechanism, 40... Valve stem locking mechanism, 41... Cylinder case, 42... Piston, 43... Annular groove, 4
4... Support frame, 45... Stopper member, 46...
Endless elastic band, 47... Cylindrical protruding wall, 48
...Tapered surface, 49...Tapered portion, 50...Engaging portion, 52...Coil spring.

Claims (1)

[Scope of utility model registration request] A communication path is formed between the upper flow path and the lower flow path,
A first valve body that presses and engages from above on the lower side of the valve seat provided in the communication passage is a first valve shaft, and a second valve body that presses and engages from above on the upper side of the valve seat. , provided on a second valve shaft that is slidably mounted on the first valve shaft and fitted so as to be constantly biased downward by a spring, and interlockingly connects the first valve shaft to a valve opening/closing drive mechanism; In a double seal valve in which a second valve body moves up to the first valve stem to follow the first valve body when the valve is opened, an engaging portion provided on the first valve stem and the first valve stem are connected to each other. A stopper member disposed to be movable forward and backward in orthogonal directions, and a forward/backward driving means having a fluid pressure cylinder for driving and operating the forward and backward movement of the stopper member, the stopper member is moved backward when the valve is opened, and the The first valve shaft is disengaged from the engaging portion, and when the valve is closed, the stopper member is moved in and engaged with the engaging portion, thereby fixing the first valve shaft at the valve closing position. Heavy seal valve.