JPH0314971A - Double disc control valve - Google Patents

Abstract

PURPOSE:To provide a large opening area without a valve plate remaining in a fluid part upon full opening of valve by making a pair of valve plates of moving type, and moving both plates to the opening direction. CONSTITUTION:Both racks 23, 24 mutually moves in reverse directions when a pinion rotates, thereby both moving valve plates 16, 17 moves upward and downward, respectively with the same distance. The plates 16, 17 move in opposite directions to control the opening part of valve. The opening of valve is therefore formed at the center of a passage 13. Even if the opening degree is reduced to generate high speed flow, the flow generates with a distance from the inner face of the passage 13. Damage of seat ring 29 caused by the high speed flow is thus prevented and also generation of erosion on the inner face of downstream side pipe.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a double disc control valve used for general control of gases and liquids. BACKGROUND ART As such a double disc control valve, a ■-orifice gate valve shown in FIG. 5 has conventionally been used. That is, in FIG. 5, 1 is a valve casing, and inside this valve casing 1, a fixed valve plate 2 and a movable valve plate 3 are arranged in an overlapping manner. The fixed valve plate 2 is
It has a ■-shaped opening 4 and is fixed at a predetermined position in the valve casing 1. The movable valve plate 3 is a plate without an opening, and its edge 5 is formed into a circle that matches the inner shape of the valve casing 1. The movable valve plate 3 is slidable along the fixed valve plate 2, and the degree of opening of the opening 4 can be adjusted by this sliding movement. Problem to be Solved by the Invention However, in such a conventional valve, the fixed valve plate 2 exists even in the fully open layer of the valve, so the problem is that the fluid passage area of the valve gating 1 is not effectively utilized. There is a point. Further, when the opening degree is narrowed down, a small hole is formed in the valley of the ■-shaped opening 4, that is, in the vicinity of the inner circumferential surface of the valve casing 1. Because a large opening remains, the surface of the seat ring that exists on the inner peripheral surface of the valve gating 1 is easily damaged by the high-flow fluid generated by this small opening, and the sealing performance when fully closed is likely to deteriorate. There are also problems. Another problem is that the high-speed flow generated near the inner peripheral surface of the valve casing 1 tends to cause erosion on the inner surface of the valve casing 1 and the pipes connected to the valve casing 1. Therefore, the present invention solves these problems, allows a large opening area to be obtained when fully opened, prevents leakage when fully closed, and also prevents harmful erosion. With the goal. Means for Solving the Problems To achieve the above object, the present invention includes a pair of movable valve plates each having an opening; each movable valve plate is arranged such that the respective openings overlap each other, A valve opening can be formed by overlapping the openings; each movable valve plate is movable in opposite directions to each other, and the opening degree of the valve opening can be adjusted by the eight movements. It is. Each opening may have a configuration in which a half portion thereof is formed in a circular shape according to the valve diameter, and a pond portion is formed in a tapered shape. According to the present invention, the drive unit includes a drive unit for moving the movable valve plate, the drive unit rotationally drives a pinion, and a first rack that meshes with the pinion and is connected to one of the movable valve plates; It may be an elliptical valve having a second rack that engages the pinion at the opposite end of the first rack and is connected to another movable valve plate. Furthermore, according to the present invention, open! ! One portion may include a pair of actuators that respectively move each movable valve plate. According to this configuration, since both of the pair of movable valve plates are movable, by moving both movable valve plates in the opening direction, it is possible to prevent these valve plates from remaining in the fluid passage when the valve is fully opened. This results in a large opening area. In addition, by moving both valve plates together, the degree of opening of the valve opening is adjusted in the center of the fluid passage, and the narrowing of the valve opening is also performed in this center. No flow is generated, and leakage or erosion due to damage to the seat ring is prevented.

By forming half of each opening into a circular shape and forming the pond into a tapered shape, the valve opening can be smoothly adjusted from fully open to fully closed. By using an elliptical drive unit for moving the valve plates as having a pinion and a pair of racks that mesh with the pinion, both valve plates can be moved by equal amounts in opposite directions with only one drive source. Ru. When using a drive unit with a pair of actuators, both actuators are
They can be placed side by side on one side of the valve casing, or distributed on both sides of the valve casing. Embodiment In FIG. 1, a valve casing 11 constitutes a passage 13 with a circular cross section for the body 12. The valve gating 11 has a pair of valve plate housing portions 14 above and below. 15, and these valve plate housing portions 14. A movable valve plate 16, 17 located between the passages 15 and 15 ji! ! It is set up separately. Double moving valve plate 16. 17 are movable in a direction perpendicular to the passage 13 while in contact with each other so as to overlap. 29 is valve gating 11
A seat ring provided on the valve plate contacts the surface of each movable valve plate 16 and 17. Further above the valve plate accommodating part 14 in the upper part (■), there is a drive part 1.
8 are provided. This drive section 18 has a support 19, and a pinion 20 that is rotationally driven by a drive device outside of Japan is supported on this support 19. Each moving valve plate 1
Extension rods 21 and 22 are connected to the extension rods 21 and 22, respectively, and racks 23. 24 are connected. Both racks 23. 24
are arranged to sandwich the pinion 20 therebetween, and mesh with one opening and the opposite side of the pinion 20 in the radial direction. Both moving valve plates 16, 17 have openings 25. for forming the valve openings. They each have 26. Each opening 25
, 26 has a circular portion 27 corresponding to the valve diameter, that is, the diameter of the passage 13, in one half thereof, and a V-shaped tapered portion 28 in the other portion, as shown in FIG. There is. As shown in FIG. 2, the openings 25 and 26 are formed with the top and bottom opposite to each other and are arranged so as to overlap each other. In such a 4lI formation,
When the pinion 20 is rotated, both racks 23. 24 move in opposite directions. Therefore, both moving valve plates 1
6 and 17, when one moves upward, the other moves downward, and they move the same distance in opposite directions. As a result, both openings 25. The degree of opening of the valve opening formed in 26 changes as shown in fJ3 figures fa) to (C). In FIGS. 3(a) to (C), both openings 25
．． The overlapping portion of 26, that is, the valve opening, is shown by vertical and horizontal intersecting lines. Figure (a) shows a completely open layer, which is the same as in Figure 1. From this state, move the valve plate 18
, 17, both openings 25. The tapered portions 28 of 26 overlap each other, and the valve opening becomes as shown in FIG.

Figure fc) shows a state in which the tips of the tapered portions 28 overlap and the opening degree is further reduced.

From the state shown in fc), the valve plate 16, 1 is further moved.
When 7 is moved, it will finally become fully closed. Since the two moving valves 14c1G and 17 are thus moved in opposite directions to adjust the opening of the valve opening, the valve opening is formed in the center of the through FRI 13. Therefore, even if the aperture is narrowed down to a small degree as shown in FIG. 3(C) and a high-speed flow is generated, this high-speed flow will occur at a distance from the inner surface of the passage 13. Become. Therefore, the seat ring 29 is prevented from being damaged by this high-distant flow, and erosion is also prevented from occurring on the inner surface of the passage 13 or the inner surface of the pipe line connected to the downstream side.

In addition, since both valve bodies 14 and 15 are movable,
When fully open as shown in FIG. 3(a), both valve plates 16, 17 are closed at their openings 25. Parts other than 26 do not protrude into the passageway 13, and a large opening area can be obtained. Also, the opening 25. 26 is formed into a circular portion 27 corresponding to the valve diameter, this opening 25. 26 makes it possible to create a fully open state with just the right amount. In addition to the V-shaped tapered portion 28 shown in FIG.
The shape shown in FIGS. 4(a) to 4(C) and other shapes may be used. Valve plate 16. Since a pinion and rack mechanism are used to move valve plates 16 and 17, only one driving source is required to move both valve plates 16 and 17.
can be moved in opposite directions, and the amounts of movement can be made equal. A rotary air cylinder is suitable as a drive source for the pinion 20. Valve plate 16. In order to move the valve plates 16.17, each valve plate 16. A pair of actuators can be used to individually move the actuators 17, preferably air cylinders, for example. Such air cylinders may be arranged, for example, in the upper part of the valve casing 11, or alternatively, they may be arranged separately above and below the valve casing. Effects of the Invention As described above, according to the present invention, since both of the pair of valve plates are movable, by moving both movable valve plates in the opening direction, these valve plates remain in the fluid passage when the valve is fully opened. Not only can a large opening area be obtained by preventing this, but also because the valve opening is narrowed down in the center of the fluid passage, high-speed flow is not generated near the inner peripheral surface of the valve casing. This prevents leakage due to damage to the seat ring and erosion in the downstream opening. By using a pinion and rack mechanism as the drive unit for moving the valve plate, both valve bodies can be moved relative to each other with only one drive source, and the amount of movement can be made equal.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a double disc control valve according to an embodiment of the present invention, Fig. 2 is a front view of the opening in the movable valve plate of Fig. 1, and Fig. 3 is a diagram showing the operating state of the movable valve plate. , FIG. 4 is a diagram showing a modification of the opening of the movable valve plate, and FIG. 5 is a perspective view of a conventional double disc control valve.

Claims (1)

[Claims] 1. A pair of moving valve plates each having an opening; each moving valve plate is arranged so that the respective openings overlap each other, and the overlap of both openings forms a valve opening. A double disc control valve characterized in that each movable valve plate is movable in opposite directions to each other, and the opening degree of the valve opening can be adjusted by this movement. 2. The double disc control valve according to claim 1, wherein each opening has a half portion formed in a circular shape according to the valve diameter, and the other portion formed in a tapered shape. 3. A drive unit for moving the movable valve plate, and this drive unit includes a rotationally driven pinion, a first rack that meshes with the pinion and is connected to one of the movable valve plates, and a first rack. 3. The double disc control valve according to claim 1, further comprising a second rack that engages the pinion on the opposite side and is connected to the other movable valve plate. 4. The double disc control valve according to claim 1 or 2, further comprising a drive section for moving the movable valve plates, and the drive section having a pair of actuators for respectively moving each movable valve plate.