KR20230169794A - Butterfly valve - Google Patents

Abstract

In the present invention, when the pressure of the outflow passage is higher than the pressure of the inflow passage under low pressure conditions, the valve stem is pushed in the direction of the inflow passage due to the gap formed by the mechanical tolerance between the valve body and the valve stem, and the body installed inside the valve body This relates to a butterfly valve that can prevent backflow phenomenon caused by opening of the seat ring and the disc seat ring installed on the valve disc. In the butterfly valve including a valve body, valve stem, and valve disc, the body seat portion is the body. It includes a seat ring and a body retaining ring, and the disk seat portion includes a disk seat ring and a disk retaining ring, and the disk seat ring has an annular countercurrent hydraulic expansion groove recessed on an inner peripheral surface facing the disk retaining ring. , the disc retaining ring is characterized in that a plurality of countercurrent hydraulic inlet holes are formed through each of the surfaces facing the outflow channel to allow the hydraulic pressure of the outlet channel to flow into the countercurrent hydraulic expansion groove.

Description

Butterfly valve{BUTTERFLY VALVE}

The present invention relates to a butterfly valve that controls flow rate or hydraulic pressure by opening and closing a pipe by rotating a disc-shaped disk.

In general, a valve is a device that controls the flow rate, velocity, and pressure of fluid flowing in a pipe. Valves can be divided into several types depending on their purpose. Among them, butterfly valves are light in weight and small in size, so they can be installed in narrow spaces, so they are used in various industrial fields, especially industrial water, oil, or seawater. It is used to open or close the flow of various fluids. This butterfly valve has a simple structure and has the advantage of good space utilization.

In addition, the first eccentric, second eccentric, and third eccentric structures were developed to reduce operating torque and can be used even at ultra-low temperatures, high pressures, and high temperatures, and the seat ring made of a combination of rubber and metal of a butterfly valve can be used to It was developed so that it is not limited by the type of fluid flowing in the valve pipe by applying a combination of metal sheets.

Meanwhile, among various types of valves, valves such as butterfly valves and ball valves block water leakage by installing a seat on the inner peripheral surface of the pipe. Various technologies are being developed and applied to prevent such water leaks. However, it cannot directly block water leaks caused by mechanical tolerances caused by processing and assembly.

As shown in Figures 1 to 6, the butterfly valve according to the prior art is installed by inserting the valve stem 20 through the upper and lower parts of the valve body 10, and the valve disc 30 is installed in the valve stem 20. It is coupled to the lower part of and rotates to open and close the pipe of the valve body (10). At this time, as shown in Figures 5 and 6, depending on the pressure of the fluid flowing in the pipe due to the clearance due to the tolerance that occurs in the process of inserting and assembling the valve stem 20 through the upper and lower parts of the valve body 10. The valve stem 20 moves in the direction of the inflow passage 11 or the direction of the outflow passage 12 due to a slight displacement.

In particular, when a butterfly valve is used under low pressure conditions, and the pressure applied in the inflow passage 11 is higher than the pressure acting in the outflow passage 12, the valve stem 20 moves into the outflow passage as shown in FIG. 5. It is pushed in the direction (12), and the disc seat ring (31) fixed to the valve disc (30) comes into close contact with the body seat ring (14) installed in the internal passage (13) of the valve body (10), thereby preventing water leakage. It won't happen.

However, on the contrary, if the pressure acting in the inflow passage 11 is lower than the pressure acting in the outflow passage 12, the valve stem 20 is pushed in the direction of the inflow passage 11, as shown in FIG. 6, and the valve The disk seat ring 31 fixed to the disk 30 is separated from the body seat ring 14 installed in the internal passage 13 of the valve body 10.

At this time, there is a problem in that a backflow phenomenon occurs in which the fluid flowing from the outflow passage 12 to the inflow passage 11 leaks.

The purpose of the present invention, which was devised to solve the above problems, is that under low pressure conditions, when the pressure in the outflow passage is higher than the pressure in the inflow passage, the valve stem flows into the gap formed by the mechanical tolerance between the valve body and the valve stem. The aim is to provide a butterfly valve that can prevent backflow caused by the body seat ring installed inside the valve body and the disc seat ring installed on the valve disc being pushed in the direction of the flow path.

In order to achieve the above object, the butterfly valve according to the present invention is a valve in which the front inflow passage and the rear outflow passage are formed to communicate through a central internal passage, and the annular body seat part is installed in the internal passage. A body, a valve stem rotatably installed through the valve body, coupled to a lower part of the valve stem to open and close the internal flow path of the valve body according to the rotation of the valve stem, and an annular disk seat portion on the outer peripheral surface. In the butterfly valve including a valve disc that is installed and closes the internal flow path while being in close contact with the body seat part, the body seat part is inserted into and installed on the inner circumferential surface of the internal flow passage whose outer circumferential surface faces the outflow flow path, and the inner circumferential surface is A body seat ring whose in-body contact surface is inclined in the direction facing the inflow passage, and a body coupled to the valve body to press the rear of the body seat ring to secure the body seat ring to the inner peripheral surface of the internal passage. It includes a retaining ring, and the disk seat portion is inserted into and installed on the outer peripheral surface of the valve disk, the inner peripheral surface of which faces the outflow passage, and the disk contact surface, which is the outer peripheral surface, is formed to be inclined in the direction facing the outflow passage, thereby forming the body seat ring. A disc seat ring that is in close contact with the body contact surface and closes the internal flow passage, and a disc retainer ring coupled to the valve disc to press the rear surface of the disc seat ring and secure the disc seat ring to the outer peripheral surface of the valve disc. It includes, wherein the disk seat ring has an annular countercurrent hydraulic expansion groove recessed on the inner peripheral surface facing the disk retaining ring, and the disk retaining ring has a plurality of countercurrent hydraulic inlet holes on the surface facing the outflow passage. Each of these is formed through a penetrating channel to allow the hydraulic pressure of the outflow passage to flow into the countercurrent hydraulic expansion groove.

In addition, when the pressure of the outflow passage is higher than the pressure of the inflow passage while the valve disc closes the internal passage of the valve body, the hydraulic pressure of the outflow passage flows into each of the counterflow hydraulic inlet holes of the disc retaining ring. It is supplied to the countercurrent hydraulic expansion groove of the disc seat ring, and the hydraulic pressure supplied to the countercurrent hydraulic expansion groove of the disc seat ring increases the pressure and expands the disc seat ring in the outer diameter direction.

In addition, the body seat ring has an annular spring insertion groove recessed on the outer peripheral surface facing the body retaining ring, and the body seat portion is inserted into the spring insertion groove to move the body seat ring in the inner diameter direction by spring force. It is characterized in that it further includes a ring spring for expanding.

In addition, the ring spring is a ring-shaped leaf spring bent zigzagly along the circumference, the outer peripheral surface of which is supported in contact with the inner peripheral surface of the internal flow passage, and the inner peripheral surface presses the spring insertion groove of the body seat ring in the inner diameter direction to press the body. It is characterized by expanding the seat ring in the inner diameter direction.

In the butterfly valve according to the present invention, under low pressure conditions, when the pressure in the outflow passage is higher than the pressure in the inlet passage, the valve stem is pushed in the direction of the inlet passage, creating a gap between the body seat ring of the valve body and the disc seat ring of the valve disc. Even if this occurs, the disc seat ring is expanded in the outer diameter direction, i.e., toward the body seat ring, through the countercurrent hydraulic expansion groove of the disc seat ring and the countercurrent hydraulic inlet hole of the disc retainer ring, thereby eliminating the occurrence of clearance and preventing fluid leakage. Backflow phenomenon can be prevented.

In addition, the ring spring, which is inserted into the spring insertion groove of the body seat ring and expands by pressurizing the body seat ring in the inner diameter direction, further strengthens the adhesion between the disc seat ring and the body seat ring, more effectively preventing backflow due to fluid leakage. You can block it.

1 is a perspective view showing an embodiment of a butterfly valve according to the prior art;
Figure 2 is a front view of the embodiment of Figure 1 viewed from the front;
Figure 3 is a cross-sectional view taken along line A-A' of the embodiment of Figure 2;
Figure 4 is a side cross-sectional view showing the flow of fluid according to the opening of the valve disc in the embodiment of Figure 3;
Figure 5 is a side cross-sectional view showing the main part of the embodiment of Figure 4 with the valve disk closed and the disk seat ring and body seat ring in close contact when the pressure of the inflow passage is high;
Figure 6 is a side cross-sectional view showing the main part of the embodiment of Figure 5 showing a state in which the disc seat ring is slightly spaced from the body seat ring and flows back when the pressure in the outflow passage increases;
Figure 7 is a perspective view showing an embodiment of a butterfly valve according to the present invention;
Figure 8 is a front view of the embodiment of Figure 7 as seen from the front;
Figure 9 is a cross-sectional view taken along line B-B' of the embodiment of Figure 7;
Figure 10 is an enlarged side cross-sectional view of the main part of the valve body and body seat part of the embodiment of Figure 9;
FIG. 11 is an exploded side cross-sectional view showing the body seat portion and the disk seat portion expanded from the valve body and valve disk of the embodiment of FIG. 9, respectively;
FIG. 12 is a side cross-sectional view showing the main part of the embodiment of FIG. 9 showing a state in which the valve disc is closed and the disc seat ring and the body seat ring are in close contact when the pressure of the inflow passage is high;
Figure 13 is a main sectional side view showing the process in which the disk seat ring expands toward the body seat ring and comes into close contact with the body seat ring by the operation of the countercurrent hydraulic inlet hole and the countercurrent hydraulic expansion groove even if the pressure of the outflow passage increases from the embodiment of Figure 12;
Figure 14 is a side cross-sectional view showing another embodiment of the butterfly valve according to the present invention;
FIG. 15 is an exploded side cross-sectional view showing the body seat portion and the disk seat portion expanded from the valve body and valve disk of the embodiment of FIG. 14, respectively;
Figure 16 is an enlarged perspective view of the body seat part of the embodiment of Figure 15 partially cut away;
Figure 17 is a side cross-sectional view showing the main part of the embodiment of Figure 14 with the valve disk closed and the disk seat ring and body seat ring in close contact when the pressure of the inflow passage is high;
18 shows that even if the pressure of the outflow passage increases from the embodiment of FIG. 17, the disc seat ring expands toward the body seat ring due to the operation of the countercurrent hydraulic inlet hole and the countercurrent hydraulic expansion groove, and the body seat ring expands due to the spring force of the ring spring. This is a side cross-sectional view of the main part showing the process of expanding toward the disc seat ring and bringing the disc seat ring and body seat ring into close contact.

Hereinafter, an embodiment of the butterfly valve according to the present invention will be described in detail with reference to the attached drawings.

First, the butterfly valve according to the present invention is formed so that the front inflow passage 110 and the rear outflow passage 120 communicate through the central internal passage 130, as shown in FIGS. 7 to 10, A valve body 100 in which an annular body seat portion 140 is installed in the internal flow passage 130, a valve stem 200 rotatably installed through the valve body 100, and the valve stem 200 ) is coupled to the lower part of the valve stem 200 to open and close the internal passage 130 of the valve body 100 according to the rotation of the valve stem 200, and an annular disk seat portion 310 is installed on the outer peripheral surface of the body seat portion ( It includes a valve disk 300 that closes the internal passage 130 while being in close contact with 140).

At this time, as shown in FIGS. 9 to 11, the body seat portion 140 has an outer circumferential surface inserted into the inner circumferential surface of the inner flow passage 130 facing the outflow passage 120, and a body contact surface 141a which is the inner circumferential surface. ) fixes the body seat ring 141 to the inner peripheral surface of the internal flow passage 130 by pressing the rear surface of the body seat ring 141 and the body seat ring 141 formed inclined in the direction facing the inflow passage. It includes a body retaining ring 142 coupled to the valve body 100.

In addition, as shown in FIGS. 9 to 11, the disk seat portion 310 is inserted and installed on the outer peripheral surface of the valve disk 300, the inner peripheral surface of which faces the outflow passage 120, and the outer peripheral surface is a disk contact surface 311a. ) is formed inclined in the direction facing the outflow passage 120 and is in close contact with the body contact surface 141a of the body seat ring 141 to close the internal passage 130; It includes a disc retainer ring 312 coupled to the valve disc 300 to secure the disc seat ring 311 to the outer peripheral surface of the valve disc 300 by pressing the rear surface of the disc seat ring 311. .

In the case of a butterfly valve including the valve body 100 provided with the body seat portion 140, the valve stem 200, and the valve disk 300 provided with the disk seat portion 310 as described above, the operating unit described later The operation of 400 rotates the valve stem 200 so that the valve disc 300 opens and closes the internal passage 130 of the valve body 100. Referring to FIG. 4, it can be divided into a case where the valve disc 300 opens the internal passage 130, and a case where the valve disc 300 closes the internal passage 130 as shown in FIGS. 12 and 13. .

First, when the valve disc 300 opens the internal passage 130, there is no problem because the fluid can flow from the inflow passage 110 to the outflow passage 120, but the valve disc 300 opens the internal passage 130. ) can be divided into a case where the pressure of the inflow passage 110 is high as shown in FIG. 12 and a case where the pressure of the outflow passage 120 is high as shown in FIG. 13.

In particular, when the butterfly valve is used in low pressure conditions, as shown in FIG. 12, when the pressure of the inflow passage 110 is higher than the pressure of the outflow passage 120, the valve stem 200 exerts pressure in the direction of the outflow passage 120. is pushed by, and the valve disc 300 coupled to the valve stem 200 is also pushed in the direction of the outflow passage 120. However, as shown in FIG. 12, the disc contact surface 311a of the disk seat ring 311 is in close contact with the body contact surface 141a of the body seat ring 141 and is watertight, so a backflow phenomenon does not occur.

Conversely, when the pressure of the outflow passage 120 is higher than the pressure of the inflow passage 110, for example, referring to FIG. 6, a phenomenon occurs in which the valve stem 20 is pushed in the direction of the inflow passage 11, and the valve stem 20 ) is also slightly pushed in the direction of the inflow passage (11). When the valve disc 30 is pushed in the direction of the inflow passage 11, a gap occurs between the disk seat ring 31 and the body seat ring 14, and the fluid in the outflow passage 12 as shown in FIG. 6 It passes through the gap and goes to the inflow passage (11). This phenomenon is called a backflow phenomenon that occurs under low pressure conditions.

Therefore, the butterfly valve according to the present invention has a gap between the disk seat ring 311 and the body seat ring 141 even if the valve stem 200 is slightly pushed in the direction of the inflow passage 110, as shown in FIG. 13. It is intended to block backflow by maintaining a close contact state without this occurring, and for this purpose, as shown in FIGS. 9 and 13, the backflow hydraulic expansion groove 311b and the backflow hydraulic inlet hole 312a are connected to the disk seat ring 311. and the disk retaining ring 312, respectively.

That is, the disk seat ring 311 has an annular countercurrent hydraulic expansion groove 311b recessed on the inner peripheral surface facing the disk retaining ring 312, and the disk retaining ring 312 has an outflow passage 120. A plurality of countercurrent hydraulic inlet holes (312a) are formed through each penetrating surface on the facing surface to allow the hydraulic pressure of the outflow passage 120 to flow into the countercurrent hydraulic expansion groove (311b).

Through this, as shown in FIG. 13, in a state where the valve disc 300 closes the internal passage 130 of the valve body 100, the pressure of the outflow passage 120 increases with the pressure of the inflow passage 110. When the pressure is higher than the pressure, the hydraulic pressure of the outflow passage 120 flows into each of the countercurrent hydraulic inlet holes 312a of the disk retaining ring 312 and is supplied to the countercurrent hydraulic expansion groove 311b of the disk seat ring 311. , the disc seat ring 311 is expanded in the outer diameter direction as the pressure rises due to the hydraulic pressure supplied to the countercurrent hydraulic expansion groove (311b) of the disc seat ring 311.

Therefore, as shown in FIG. 13, even if the valve stem 200 is pushed in the direction of the inflow passage 110 and a gap occurs between the body seat ring 141 and the disk seat ring 311, the disk seat ring 311 Through the countercurrent hydraulic expansion groove 311b and the countercurrent hydraulic inlet hole 312a of the disk retaining ring 312, the disk seat ring 311 is moved in the outer diameter direction, that is, against the body contact surface 141a of the body seat ring 141. By expanding and sealing the product, the occurrence of clearance can be eliminated and backflow due to fluid leakage can be prevented.

Meanwhile, as shown in FIGS. 14 to 18, the body seat ring 141 has an annular spring insertion groove 141b recessed on the outer peripheral surface facing the body retaining ring 142, and the body seat portion 140 ) may further include a ring spring 143 that is inserted into the spring insertion groove 141b and expands the body seat ring 141 in the inner diameter direction with spring force.

That is, the ring spring 143 is a ring-shaped leaf spring bent in a zigzag pattern along the circumference, as shown in FIGS. 15 and 16. The outer peripheral surface is supported in contact with the inner peripheral surface of the internal passage 130, and the inner peripheral surface is supported by the body. The spring insertion groove 141b of the seat ring 141 is pressed in the inner diameter direction to expand the body seat ring 141 in the inner diameter direction.

Through this, as shown in FIG. 18, in a state where the valve disk 300 closes the internal passage 130 of the valve body 100, the pressure of the outflow passage 120 increases with the pressure of the inflow passage 110. When the pressure is higher, the spring force of the ring spring 143 expands the body seat ring 141 in the inner diameter direction, that is, toward the disk seat ring 311, thereby further increasing the adhesion force.

Therefore, as shown in FIG. 18, even if the valve stem 200 is pushed in the direction of the inflow passage 110 and a gap occurs between the body seat ring 141 and the disk seat ring 311, the first countercurrent hydraulic expansion groove The disk seat ring 311 is expanded toward the body contact surface 141a of the body seat ring 141 through (311b) and the countercurrent hydraulic inlet hole 312a, and is brought into close contact with the body seat ring 141 using the spring force of the second ring spring 143. By pressing and expanding the body seat ring 141 toward the disk contact surface 311a of the disk seat ring 311 and making it adhere closely, the occurrence of clearance can be eliminated and backflow due to fluid leakage can be more reliably prevented.

Meanwhile, the operating unit 400 is installed on the upper part of the valve stem 200 and rotates the valve stem 200, as shown in FIGS. 7 to 9 and 14. At this time, the valve disc 300 coupled with the valve stem 200 rotates together to open and close the internal passage 130 of the valve body 100. In addition, the control unit 400 has a manual method and an automatic method and can be installed selectively. In the case of the manual method, the user directly rotates the lever and moves the valve stem (200) to open and close the valve disc (300). In the automatic method, an actuator is installed and the user operates it as needed to automatically open and close the valve stem (200). ) is a method of opening and closing the valve disc 300 by rotating it.

The upper bush 500 is installed on the upper part of the valve body 100 as shown in FIGS. 9 to 11, 14, and 15 to rotate and support the outer peripheral surface of the valve stem 200. At this time, the upper bush 500 fixes the outer peripheral surface of the valve stem 200 to the valve body 100 and rotates when the valve stem 200 is rotated by the operating unit 400 to open and close the valve disc 300. Reduces the friction that occurs when

The lower bush 600 is installed at the lower part of the valve body 100 as shown in FIGS. 9 to 11, 14, and 15 to rotate and support the outer peripheral surface of the valve stem 200. At this time, like the upper bush 500, when the valve stem 200 is rotated by the operating unit 400 to open and close the valve disc 300, the lower bush 600 is formed on the outer peripheral surface of the valve stem 200 as the valve body 100. ) and reduces friction that occurs during rotation.

As described above, in the butterfly valve according to the present invention, when the pressure of the outflow passage 120 is higher than the pressure of the inflow passage 110 under low pressure conditions, the valve stem 200 is pushed in the direction of the inflow passage 110. Even if a gap occurs between the body seat ring 141 of the valve body 100 and the disc seat ring 311 of the valve disc 300, the counterflow hydraulic expansion groove 311b of the disc seat ring 311 and the disc retainer ring ( By expanding the disc seat ring 311 in the outer diameter direction, that is, toward the body seat ring 141, through the counterflow hydraulic inlet hole 312a of 312), the occurrence of clearance is eliminated and the backflow phenomenon due to fluid leakage is prevented. can do.

In addition, the disk seat ring 311 and the body seat ring ( 141), the adhesion can be further strengthened to more effectively block the backflow phenomenon due to fluid leakage.

The embodiments of the present invention described above and shown in the drawings should not be construed as limiting the technical idea of the present invention. The scope of protection of the present invention is limited only by the matters stated in the claims, and those skilled in the art can improve and change the technical idea of the present invention into various forms. Therefore, such improvements and changes will fall within the scope of protection of the present invention as long as they are obvious to those skilled in the art.

100: Valve body 110: Inflow passage
120: Outflow flow path 130: Internal flow path
140: body seat part 141: body seat ring
141a: Body contact surface 141b: Spring insertion groove
142: body retaining ring 143: ring spring
200: valve stem
300: valve disc 310: disc seat part
311: Disc seat ring
311a: Disc contact surface 311b: Countercurrent hydraulic expansion groove
312: Disk retaining ring 312a: Backflow hydraulic inlet hole
400: Control panel
500: Upper bush
600: Lower bush

Claims (5)

A valve body in which the front inflow passage and the rear outflow passage are formed to communicate through a central internal passage, and the annular body seat part is installed in the internal passage, and the valve stem is rotatably installed through the valve body, and A valve disc that is coupled to the lower part of the valve stem and opens and closes the internal flow path of the valve body according to the rotation of the valve stem, and has an annular disk seat part installed on the outer peripheral surface to close the internal flow path while being in close contact with the body seat part. In the butterfly valve including,
The body seat part,
A body seat ring whose outer peripheral surface is inserted and installed on the inner peripheral surface of the internal flow passage facing the outflow passage, and whose body contact surface, which is the inner peripheral surface, is inclined in the direction facing the inflow passage, and
It includes a body retaining ring coupled to the valve body to press the rear of the body seat ring and secure the body seat ring to the inner peripheral surface of the internal flow path,
The disk seat part,
The inner peripheral surface is inserted into and installed on the outer peripheral surface of the valve disk facing the outflow passage, and the disk contact surface, which is the outer peripheral surface, is formed to be inclined in the direction facing the outflow passage and is in close contact with the body contact surface of the body seat ring to form the internal passage. A disc seat ring that closes,
It includes a disc retainer ring coupled to the valve disc to press the rear surface of the disc seat ring and secure the disc seat ring to the outer peripheral surface of the valve disc,
The disc seat ring,
An annular countercurrent hydraulic expansion groove is formed recessed on the inner peripheral surface facing the disc retaining ring,
The disc retaining ring,
A butterfly valve, characterized in that a plurality of countercurrent hydraulic inlet holes are respectively formed through a surface facing the outlet flow path to allow the hydraulic pressure of the outflow channel to flow into the countercurrent hydraulic expansion groove.

According to paragraph 1,
When the valve disc closes the internal passage of the valve body and the pressure of the outflow passage is higher than the pressure of the inflow passage, the hydraulic pressure of the outflow passage flows into each of the counterflow hydraulic inlet holes of the disc retaining ring, thereby causing the disc A butterfly valve that is supplied to the countercurrent hydraulic expansion groove of the seat ring and expands the disk seat ring in the outer diameter direction as the pressure rises due to the hydraulic pressure supplied to the countercurrent hydraulic expansion groove of the disk seat ring.
According to paragraph 1,
The body seating,
An annular spring insertion groove is formed recessed on the outer peripheral surface facing the body retaining ring,
The body seat part,
A butterfly valve further comprising a ring spring that is inserted into the spring insertion groove and expands the body seat ring in the inner diameter direction with spring force.
According to paragraph 3,
The ring spring is,
A ring-shaped leaf spring bent zigzagly along the circumference of which the outer peripheral surface is supported in contact with the inner peripheral surface of the internal flow passage, and the inner peripheral surface presses the spring insertion groove of the body seat ring in the inner diameter direction to expand the body seat ring in the inner diameter direction. A butterfly valve characterized in that
According to paragraph 1,
An operating unit installed on the upper part of the valve stem to rotate the valve stem,
An upper bush installed on the upper part of the valve body to rotate and support the outer peripheral surface of the valve stem,
A butterfly valve, characterized in that it further includes a lower bush installed at the lower part of the valve body to rotate and support the outer peripheral surface of the valve stem.

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