butterfly valve

Abstract

The present invention provides a butterfly valve in which the valve core is easily assembled into the valve body; the butterfly valve (1) comprises: a valve body (10) having a fluid passage (11), valve stem plates (20U, 20D) rotatably inserted into the fluid passage (11), and a valve core (30) supported by the valve stem plates (20U, 20D), which can switch the fluid passage (11) to a closed state and an open state by rotating the valve core (30). The valve core (30) comprises a first valve core (30A) and a second valve core (30B), and has an eccentrically configured valve seal (40). The valve seal (40) is held by the first valve core (30A) and the second valve core (30B). In the closed state, the valve seal (40) abuts against the inner circumferential surface of the fluid passage (11). The valve stem (20U, 20D) has a locking part (25U, 25D) on the valve core support side and a locked part (35U, 35D) is provided on one side of the valve core (30). The locking part (25U, 25D) and the locked part (35U, 35D) can be locked from the axial direction of the fluid passage (11) in the open state.

Description

Technical Field

[0001] This invention relates to butterfly valves installed in piping (fluid channels) for the flow of various fluids. Background Technology

[0002] Conventionally, butterfly valves (e.g., Patent Document 1) have been used to open and close piping (fluid passages). The butterfly valve described in Patent Document 1 includes a valve stem arranged to intersect with the fluid passage in the valve body, and a valve core mounted on the valve stem and rotating integrally with the valve stem. The valve core is a component that holds a rubber sheet that slides in contact with the inner circumferential surface of the valve body. In butterfly valves that open and close the fluid passage by rotating the valve stem and valve core integrally, at least a portion of the sliding contact portion between the rubber sheet of the valve core and the inner circumferential surface of the valve body is coated with ultra-high molecular weight polyethylene.

[0003] In addition, a butterfly valve is known in which the valve core is assembled to the piping while the valve stem is pre-assembled into the valve body (for example, Patent Document 2). The butterfly valve described in Patent Document 2 improves the assemblability of the valve core by adopting the above-described configuration.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2012-62914

[0007] Patent Document 2: Japanese Patent Publication No. 46-14302 Summary of the Invention

[0008] However, the butterfly valve described in Patent Document 1 uses a structure where the valve stem is inserted into the valve core. Therefore, after assembling the valve core into the valve body, the valve stem needs to be inserted into the valve core. Thus, the butterfly valve described in Patent Document 1 raises concerns about difficulties in aligning the valve stem and valve core, and poor assemblability.

[0009] Furthermore, the butterfly valve described in Patent Document 2 is configured such that the valve stem is divided into two parts, and the valve stem is inserted into a shaft retainer installed above and below the valve core (valve plate). In the butterfly valve described in Patent Document 2, with the valve stem pre-assembled into the valve body, the front end of the valve stem is inserted into the shaft retainer while the valve core is rotated within the piping. Therefore, the butterfly valve described in Patent Document 2 employs a structure with a gap between the valve core and the valve stem, ensuring that the valve stem and shaft retainer do not interfere with each other when the valve core rotates.

[0010] However, the butterfly valve described in Patent Document 2 has a gap designed to prevent interference between the shaft retainer and the valve stem. As a result, centering the valve stem and valve core is difficult, raising concerns about reduced assembly accuracy of the valve core.

[0011] Furthermore, when a butterfly valve is in the closed state (with the fluid passage closed by the valve core), the fluid pressure loads the forming surface (circular surface) of the valve core. Therefore, butterfly valves are typically designed to give the valve core appropriate rigidity to mitigate the maximum stress that tends to originate at the center of the valve core. On the other hand, to improve operability during assembly and reduce valve core material costs, a lightweight valve core is required, currently necessitating a certain degree of bending. However, when valve core bending is permitted, the bending caused by fluid pressure is transmitted as a significant bending stress to the valve stem (in the case of a split valve stem, to each valve stem disc). Therefore, a butterfly valve that can balance valve core lightweighting with ensuring valve core bending rigidity is sought.

[0012] Therefore, the object of the present invention is to provide a butterfly valve that allows for easy and precise assembly of the valve core into the valve body, while also reducing costs. Furthermore, the object of the present invention is to provide a butterfly valve that ensures the rigidity of the valve core and achieves lightweight design.

[0013] (1) The butterfly valve of the present invention, provided to solve the above-mentioned technical problem, is characterized by comprising: a valve body having a fluid passage extending from one end to the other end; a pair of valve stems rotatably supported on the valve body and inserted into the fluid passage from both radial sides; and a valve core disposed inside the fluid passage and supported by the pair of valve stems, which, by rotating the valve core about the axis of the valve stems, can be switched to a closed state where the fluid passage is closed by the valve core and an open state where the fluid passage is opened (the butterfly valve becomes open once it leaves the closed state, but here the open state ensuring approximately the largest fluid passage is referred to as the open state), the valve core comprising at least a first valve core and a second valve core, and A valve seal is eccentrically configured relative to the axis of a pair of valve stem pieces. The valve seal is held by a first valve core and a second valve core. When the valve cores close the fluid passage, the valve seal abuts against the radial inner circumferential surface of the fluid passage. The pair of valve stem pieces have engaging portions on the support side of the valve cores. On one side of the forming surface of the valve core, a pair of engaged portions are provided at positions corresponding to the pair of engaging portions. When engaged with the engaging portions, the pair of engaged portions are open on both sides along the forming surface of the valve core, separated by the engaging portions. The pair of engaging portions and the pair of engaged portions can engage from the axial direction of the fluid passage in the open state.

[0014] By employing the configuration described in (1) above, the butterfly valve of the present invention can convert at least a portion of the force generated by the fluid pressure acting on the valve core into shear force when the fluid passage is closed in the closed state (also known as the valve closed state). That is, the butterfly valve of the present invention can convert the bending stress applied to the valve core into shear force between the engaging portion of the valve stem and the engaged portion of the valve core. Therefore, the butterfly valve of the present invention can reduce the bending stress acting on the valve stem. Here, the engaging portion on the valve stem side can be formed into a convex shape, for example, by processing the front end of the valve stem into a flat shape, and the engaged portion on the valve core side is preferably formed into a concave shape that can be inserted along the forming surface of the valve core. Thus, the butterfly valve of the present invention can ensure a large contact area between the engaging portion and the engaged portion, and therefore can smoothly convert the bending stress between the engaging portion and the engaged portion into shear force. In addition, by constructing the engaging portion and the engaged portion by a combination of concave and convex shapes, the butterfly valve of the present invention is expected to achieve the effect of automatically aligning the valve seal relative to the valve body when the valve core is assembled to the valve stem.

[0015] Furthermore, by employing the configuration described in (1) above, the butterfly valve of the present invention allows the engaging portion of the valve core and the engaging portion of the valve stem to engage along the forming surface of the valve core when the fluid passage is open (open state). Thus, the butterfly valve of the present invention allows the valve core to be assembled to the valve stem via the fluid passage while a pair of valve stems are pre-assembled into the valve body. Therefore, the butterfly valve of the present invention improves assemblability. Additionally, since the valve stems are pre-assembled into the valve body, centering of the valve stems is easy, and assembly accuracy is improved. Furthermore, because the valve seal is held between the first and second valve cores, the butterfly valve of the present invention can suppress the valve seal from shifting or falling off as the valve core rotates.

[0016] (2) A preferred feature of the butterfly valve of the present invention is that, after the pair of engaging parts and the pair of engaged parts engage with each other, they are fastened by fastening members along the axial direction of the fluid passage in the closed state.

[0017] By employing the configuration described in (2) above, the butterfly valve of the present invention can reduce the wobbling when the engaging portion of the valve stem (valve stem) engages with the engaged portion of the valve core. Therefore, the butterfly valve of the present invention can further reduce the bending stress acting on the valve stem. Consequently, the butterfly valve of the present invention can improve the assembly accuracy of the valve core to the valve body.

[0018] (3) The preferred feature of the butterfly valve of the present invention is that the valve seal is formed of a rubber sheet.

[0019] By adopting the above-described (3) configuration, the butterfly valve of the present invention can improve the tightness between the valve core and the valve body (fluid passage), thereby improving the sealing performance.

[0020] (4) A preferred feature of the butterfly valve of the present invention is that at least a portion of the valve seal is disposed at a position abutting or close to a pair of valve stem pieces.

[0021] By employing the configuration described in (4) above, the butterfly valve of the present invention can suppress strong contact between the valve body and the valve seal when the valve core rotates. Specifically, when the valve core is in the open state and the valve seal is in sliding contact with the inner circumferential surface of the valve body, the butterfly valve of the present invention can suppress strong contact between the valve seal and the valve body caused by eccentric rotation on one side. Thus, the butterfly valve of the present invention can suppress the valve seal from shifting or being damaged.

[0022] (5) The preferred feature of the butterfly valve of the present invention is that the first valve core and the second valve core are respectively approximately circular when viewed from the axial direction of the fluid channel, and are connected to each other by a plurality of fastening components.

[0023] By employing the configuration described in (5) above, the butterfly valve of the present invention enables the first valve core and the second valve core to be fastened together along their respective circumferences. Therefore, the butterfly valve of the present invention can improve the rigidity of the valve core.

[0024] (6) A preferred feature of the butterfly valve of the present invention is that the first valve core and the second valve core are fastened by a plurality of fastening components on the inner circumferential side of the valve seal.

[0025] By employing the configuration described in (6) above, the butterfly valve of the present invention allows for the provision of a fastening point between the first valve core and the second valve core on the inner circumferential side of the valve seal (for example, near the central portion of the first valve core and the second valve core). Consequently, the butterfly valve of the present invention can further improve the rigidity of the valve core.

[0026] (7) A preferred feature of the butterfly valve of the present invention is that the first valve core and the second valve core are fastened in the circumferential direction near the inner periphery of the valve seal by a plurality of fastening components.

[0027] By employing the configuration described in (7) above, the butterfly valve of the present invention can suppress deviations (lack of strength) in the circumferential tightening strength of the valve seal. Therefore, the butterfly valve of the present invention can improve sealing performance. Furthermore, by employing the configuration described in (7) above, the butterfly valve of the present invention can improve the retention of the valve seal on the valve core. Therefore, the butterfly valve of the present invention can suppress the detachment of the valve seal.

[0028] (8) A preferred feature of the butterfly valve of the present invention is that the valve seal has at least one protrusion, and the first valve core and the second valve core have receiving portions for receiving the protrusion on their mating surfaces.

[0029] By employing the configuration described in (8) above, the butterfly valve of the present invention, due to the engagement of the protrusion (also called the ear) with the receiving portion, can reduce the influence of forces such as sliding torque generated by sliding contact with the inner circumferential surface of the valve body and flow torque generated by the fluid. Therefore, the butterfly valve of the present invention can further suppress the detachment of the valve seal.

[0030] (9) A preferred feature of the butterfly valve of the present invention is that the protrusion is formed to be deeper in the receiving direction than the receiving portion, and the volume of the protrusion is formed to be smaller than the receiving volume of the receiving portion.

[0031] By employing the configuration described above (9), the butterfly valve of the present invention allows for moderate compression of the protruding portion of the valve seal when it is housed within the housing portion of the valve core, while simultaneously releasing any remaining compression (compression amount) of the valve seal into the space of the housing portion. Consequently, the butterfly valve of the present invention can easily house the valve seal within the space of the housing portion, thus reducing the load on the fastening components or fastening portions acting on the first and second valve cores.

[0032] (10) The preferred feature of the butterfly valve of the present invention is that the first valve core and the second valve core are formed by forging.

[0033] The butterfly valve of the present invention, by adopting the above-described (10) configuration, enables the valve core to be formed with a lightweight design. Furthermore, by adopting the above-described (10) configuration, the butterfly valve of the present invention allows the formation of the radius (R) required to suppress stress concentration on the valve core without additional processing. Thus, the butterfly valve of the present invention achieves lightweight design while ensuring the strength (rigidity) of the valve core.

[0034] (11) A preferred feature of the butterfly valve of the present invention is that the valve body is formed by forging, and the draft angle required for forging is formed on the forming surface side where the engaging portion is formed, which is relatively large relative to the non-forming surface side where the engaging portion is not formed in the valve core.

[0035] By employing the above-described (11) configuration, the butterfly valve of the present invention can be formed using forging, which is easily molded into a thin-walled shape, thus enabling the valve body to be lightweight. In addition, by employing the above-described (11) configuration, the butterfly valve of the present invention can form the R (rounded corner) required to suppress stress concentration on the valve body without additional processing.

[0036] (12) The preferred feature of the butterfly valve of the present invention is that the valve body is formed by forging, and the draft angle required for forging is formed relatively large on the opposite side of the eccentric direction of the valve core.

[0037] By employing the configuration described above (12), the butterfly valve of the present invention ensures sufficient clearance for the valve seal due to eccentricity by concentrating the draft angle on the opposite side of the eccentric valve core. In other words, the butterfly valve of the present invention can utilize the draft angle required for forging the valve body to ensure sufficient clearance for the valve seal due to eccentricity, thereby improving the production efficiency of the valve body and potentially reducing manufacturing costs. Here, the draft angle is preferably formed, for example, at an inclination angle of approximately 7 degrees.

[0038] (Invention effect)

[0039] According to the present invention, a butterfly valve can be provided that allows for easy and precise assembly of the valve core into the valve body, while also reducing costs. Furthermore, according to the present invention, a butterfly valve can be provided that ensures the rigidity of the valve core and achieves lightweight design. Attached Figure Description

[0040] Figure 1 This is an overall perspective view and an enlarged exploded perspective view of the main parts of a butterfly valve according to one embodiment of the present invention.

[0041] Figure 2 From Figure 1 The front view of the fluid channel direction.

[0042] Figure 3 yes Figure 2 AA-direction sectional view.

[0043] Figure 4 This is an explanatory diagram showing the state in which the valve core is assembled onto the valve stem plate in the butterfly valve of the present invention.

[0044] Figure 5 This is an explanatory diagram showing the state of the butterfly valve of the present invention when the valve core is in the open state, as viewed from the axial direction of the fluid passage.

[0045] Figure 6 This is an explanatory diagram related to the draft angle when forging the butterfly valve of the present invention.

[0046] (Symbol Explanation)

[0047] 1: Butterfly valve

[0048] 10: Valve body

[0049] 20U: Valve stem plate (valve stem)

[0050] 20D: Valve stem plate (valve stem)

[0051] 25: Card-connecting section

[0052] 25U: Connecting part

[0053] 25D: Connecting part

[0054] 30: Valve core

[0055] 30A: First valve core

[0056] 30B: Second valve core

[0057] 31: Bolt (fastening component)

[0058] 35U: (This likely refers to a specific part of the device, possibly a card or connector)

[0059] 35D: The part that gets stuck

[0060] 40: Valve seal

[0061] 41: Protrusion (ear) Detailed Implementation

[0062] Hereinafter, a butterfly valve 1 according to one embodiment of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the figures are shown schematically for ease of understanding and may sometimes differ from the actual shape, size, and arrangement of components. Furthermore, in this embodiment, sometimes... Figure 3 The direction from right to left in the middle is called the positive pressure direction. Figure 3 The direction from left to right is referred to as the reverse pressure direction. Additionally, sometimes... Figure 3 The right side of the fluid channel 11 is called the upstream side. Figure 3 The left side of the fluid passage 11 will be described below. However, butterfly valves also have directional pressure, upstream and downstream, and... Figure 3 The opposite usage.

[0063] like Figures 1 to 3 As shown, the butterfly valve 1 of the present invention includes a valve body 10, a pair of valve stem plates 20U and 20D (also referred to as valve stems 20U and 20D), a valve core 30, and a valve seal 40 (see reference). Figure 3 )wait.

[0064] The valve body 10 is formed, for example, in a generally cylindrical shape. A fluid passage 11 extending horizontally from one end to the other is formed inside the valve body 10. In this embodiment, the valve body 10 is manufactured by forging, as will be described in detail later. Furthermore, in the vertical direction of the valve body 10, there are upper and lower valve stem support portions 12U, 12D that rotatably support a pair of valve stem plates 20U, 20D.

[0065] The fluid passage 11 is cylindrical, allowing various fluids (e.g., liquids, gases) to flow through it. In this embodiment, the valve core 30 is positioned near the center of the fluid passage 11 along its axial direction. The fluid passage 11 can be connected to appropriate piping.

[0066] The valve stem support portions 12U and 12D are formed to protrude radially up and down along the fluid passage 11. The valve stem support portions 12U and 12D are respectively formed with holes 13U and 13D radially up and down (see reference). Figure 2 and Figure 3 The valve stem plate support portions 12U and 12D can be rotatably supported by inserting the valve stem plates 20U and 20D (described later) through the holes 13U and 13D.

[0067] In this embodiment, valve stem plates 20U and 20D are arranged vertically and horizontally in the radial direction of the fluid passage 11. Valve stem plates 20U and 20D are each formed into a cylindrical shape. Valve stem plates 20U and 20D are inserted into holes 13U and 13D and are supported by valve stem plate supports 12U and 12D for free rotation. Furthermore, valve stem plates 20U and 20D penetrate holes 13U and 13D, extending radially into the fluid passage 11 from both sides. Annular seals 21 and 21 (see reference) are mounted on valve stem plates 20U and 20D. Figure 2 and Figure 3 Therefore, the gaps between the holes 13U, 13D and the valve stem plates 20U, 20D are sealed by the seals 21, 21. This prevents fluid flowing within the fluid passage 11 from leaking between the valve stem plate supports 12U, 12D and the valve stem plates 20U, 20D. In this embodiment, a key 22 is formed on the upper end side of the valve stem plate 20U. Although not shown in the figure, a suitable drive source or handle is mounted on the upper end side of the valve stem plate 20U, and the valve stem plate 20U and handle are prevented from rotating freely by engaging with the key 22. Furthermore, engaging portions 25U, 25D are formed at the front ends of the valve stem plates 20U, 20D (the ends inserted into the fluid passage 11).

[0068] In this embodiment, the engaging portions 25U and 25D are formed into a convex shape by machining the front end surfaces of the cylindrical valve stem plates 20U and 20D into a flat shape. That is, the engaging portions 25U and 25D are formed on the support side of the valve core 30 in the valve stem plates 20U and 20D. The engaging portions 25U and 25D can engage with the engaged portions 35U and 35D of the valve core 30, which will be described later. The engaging portions 25U and 25D can be rotated so that the position of the flat surface is aligned with the axial direction (fluid flow direction) of the fluid channel 11 (see reference). Figure 4 ).

[0069] like Figure 3As shown, the valve core 30 is disposed inside the fluid channel 11 and supported by a pair of valve stem plates 20U and 20D. The valve core 30 includes a first valve core 30A and a second valve core 30B, which are respectively formed to be approximately circular when viewed from the axial direction of the fluid channel 11. That is, the first valve core 30A and the second valve core 30B are respectively formed as circular plates. The valve core 30 is fastened to the first valve core 30A and the second valve core 30B by a plurality of fastening components 31 (e.g., bolts 31), thereby forming a circular shape when viewed from the front.

[0070] The first valve core 30A is disposed on the upstream side of the fluid passage 11 shown on the right side of the figure. The first valve core 30A is disposed on the upstream side of the fluid passage 11 relative to the axis of the valve stem plates 20U and 20D. That is, the first valve core 30A is disposed at a position off-center relative to the axis of the valve stem plates 20U and 20D. The first valve core 30A is formed, for example, by forging. The first valve core 30A is formed in the shape of a circular plate, and the inner peripheral side of the downstream side of the forming surface is formed to be concave. Therefore, the first valve core 30A achieves weight reduction. In addition, on the downstream side forming surface (also called the mating surface) near the outer peripheral edge of the first valve core 30A, a portion of the receiving portion 32 for receiving the valve seal 40 described later is formed. That is, the valve seal 40 is disposed at a position off-center relative to the axis of the valve stem plates 20U and 20D.

[0071] Furthermore, the first valve core 30A has a plurality of fastening portions 33 (e.g., threaded holes) formed in the circumferential direction near the inner periphery of the receiving portion 32 for fastening a plurality of bolts 31. In addition, the first valve core 30A has a plurality of fastening portions 33 formed on the inner periphery side of the valve seal 40 (receiving portion 32) for fastening a plurality of bolts 31.

[0072] The second valve core 30B is disposed downstream of the first valve core 30A in the fluid passage 11. The second valve core 30B is positioned slightly upstream of the axis of the valve stem plates 20U and 20D. That is, the second valve core 30B is positioned slightly off-center from the axis of the valve stem plates 20U and 20D. Furthermore, the second valve core 30B is forged into a generally planar circular plate shape. Additionally, a portion of a receiving portion 32 for receiving the valve seal 40 (described later) is formed near the outer periphery of the forming surface (also called the mating surface) upstream of the first valve core 30A.

[0073] Furthermore, the second valve core 30B is screwed with bolts 31 (fastening components 31) at a position corresponding to the fastening portion 33 of the first valve core 30A. The first valve core 30A and the second valve core 30B are fastened together by multiple bolts 31 in an overlapping state, thereby forming a valve core 30 integrally. This results in a valve core 30 with strength capable of withstanding a certain fluid pressure and achieving lightweight design. Additionally, by combining the first valve core 30A and the second valve core 30B, a convex receiving portion 32 for accommodating the valve seal 40 is formed. That is, the receiving portion 32 is formed on the mating surfaces of the first valve core 30A and the second valve core 30B. The valve seal 40 is held by the first valve core 30A and the second valve core 30B in a state where it partially engages with the receiving portion 32, as will be described in detail later.

[0074] Additionally, on one side of the forming surface of the second valve core 30B (the downstream forming surface in this embodiment), engaged portions 35U and 35D are formed at positions corresponding to the engaging portions 25U and 25D. For example... Figure 1 , Figure 4 , Figure 5 As shown, the engaging portions 35U and 35D can engage with the engaging portions 25U and 25D of the valve stem plates 20U and 20D in a direction along the axial direction of the fluid passage 11 from the forming surface of the valve core 30. Specifically, as... Figure 1 As shown in the enlarged exploded view of the main parts (within the double-dotted circle), the engaging portions 35U and 35D are formed in a concave shape, and they are open on both sides along the forming surface of the second valve core 30B. In other words, when engaged with the engaging portions 25U and 25D, the pair of engaging portions 35U and 35D are open on both sides along the forming surface of the valve core 30, separated by the engaging portions 25U and 25D. Therefore, by inserting the engaging portions 25U and 25D into the openings, the engaging portions 35U and 35D can be engaged with the engaging portions 25U and 25D.

[0075] Here, the engagement of the engaging parts 35U and 35D with the engaging parts 25U and 25 will be explained in detail below. Figure 4 As shown, first, rotate the valve stem plates 20U and 20D so that the flat surfaces of the engaging portions 25U and 25D are aligned along the axial direction of the fluid passage 11. Next, insert the valve core 30 into the fluid passage 11 with its forming surface aligned along the axial direction of the fluid passage 11. At this time, as... Figure 5 As shown, the engaging portions 25U and 25D are arranged opposite to the openings of the engaged portions 35U and 35D. In this embodiment, in Figure 5In this configuration, the valve core 30 is positioned slightly to the right of the fluid passage 11, so that when the valve stem plates 20U and 20D rotate, the valve core 30 (valve seal 40) rotates eccentrically and is in an open state relative to the fluid passage 11. Furthermore, the open and closed states of the butterfly valve are changed by rotating approximately 90 degrees, whether this approximately 90-degree rotation is clockwise or counterclockwise depends on the relationship with the drive source or handle.

[0076] As the valve core 30 is inserted into the fluid passage 11, the engaging portions 35U and 35D engage with the engaging portions 25U and 25D through the openings. That is, the pair of engaging portions 25U and 25D, along with the pair of engaging portions 35U and 35D, can engage along the axis of the fluid passage 11 when the fluid passage 11 is open by the valve core 30. When the engaging portions 25U and 25D engage with the engaging portions 35U and 35D, the valve stem plates 20U and 20D are rotated counterclockwise, bringing the fluid passage 11 to a closed state, where the valve core 30 closes it. Then, the engaging portions 25U and 25D, along with the engaging portions 35U and 35D, are fastened together by bolts 36 and 36 (also called fastening components 36 and 36) while in the engaged state. Thus, the valve core 30 is integrally supported by the valve stem plates 20U and 20D. That is, by rotating the valve stem plates 20U and 20D around their axis, the closed state, in which the fluid passage 11 is closed by the valve core 30, and the open state, in which the fluid passage 11 is opened, are switched. Furthermore, in this embodiment, bolts 36 are screwed from the valve stem plates 20U and 20D to the first valve core 30A.

[0077] The valve seal 40 is formed, for example, from a rubber sheet such as silicone rubber, and is capable of elastic deformation. Figure 2 As shown, the valve seal 40 is formed in an annular shape. (As indicated...) Figure 3 As shown, the valve seal 40 is formed in a convex shape in cross-section, with protrusions 41, 41 (also called ears 41, 41) formed on both sides of the base portion (inner circumferential side).

[0078] The protrusions 41, 41 are housed in a receiving portion 32 formed on the mating surfaces of the first valve core 30A and the second valve core 30B. Thus, the protrusions 41, 41 engage with the receiving portion 32, and the valve seal 40 is held by the first valve core 30A and the second valve core 30B. Here, the protrusions 41, 41 are formed such that their depth d in the receiving direction toward the receiving portion 32 is greater than the depth of the receiving portion 32 in the receiving direction. Furthermore, the volume of the protrusions 41, 41 is smaller than the receiving volume of the receiving portion 32. Figure 3 In the embodiment shown, by removing a portion of the inner circumferential side of the protrusion 41 on one side, the receptivity of the protrusion 41 to the storage portion 32 is improved.

[0079] When the fluid passage 11 is closed by the valve core 30, the valve seal 40 abuts against the radial inner circumferential surface of the fluid passage 11. Thus, when the fluid passage 11 is closed by the valve core 30, the valve core 30 and the fluid passage 11 are sealed (tightened) by the valve seal 40. Furthermore, the valve seal 40 is configured such that at least a portion (in this embodiment, the downstream side of the portion protruding radially from the valve core 30) abuts against a pair of valve stem plates 20U, 20D. Therefore, when the valve core 30 is in the open state relative to the fluid passage 11 (also referred to as the valve open state), it is possible to suppress the strong contact between the valve seal 40 and the inner circumference of the fluid passage 11 (valve body 10) caused by eccentric rotation. Specifically, the butterfly valve 1 of the present invention, when the valve core 30 is in the open state and the valve seal 40 is in sliding contact with the inner circumferential surface of the valve body 10, can suppress the strong contact between the valve seal 40 and the valve body 10 caused by eccentric rotation on one side. In other words, by positioning the valve seal 40 in contact with or near the valve stem plates 20U and 20D, the valve stem plates 20U and 20D play a role in limiting the deformation of the valve seal 40, thus suppressing a portion of the deformation of the valve seal 40 caused by eccentric rotation.

[0080] Furthermore, in this embodiment, as described above, the first valve core 30A and the second valve core 30B are fastened in the circumferential direction near the inner periphery of the valve seal 40 by a plurality of bolts 31 (fastening members 31). As a result, the valve seal 40 is reliably held by the first valve core 30A and the second valve core 30B, thus preventing the valve seal 40 from falling off.

[0081] The above describes the configuration of one embodiment of the butterfly valve 1 of the present invention. Next, referring to... Figure 6 The setting of the draft angle θ when manufacturing the valve body 10 by forging is explained in detail. In addition, in the illustration, the draft angle θ is formed as a straight line, but the part forming the draft angle θ can not only be straight, but also be formed as an arc or other shapes.

[0082] When manufacturing the valve body 10 by forging, it cannot be ejected from the mold without setting a draft angle θ (tilt angle θ) of, for example, about 7 degrees. Therefore, in this embodiment, the engaging portions 35U and 35D are not formed in the valve core 30 (see reference). Figure 3On the non-forming surface side of the valve body 10, a relatively large draft angle θ required for forging is formed on the forming surface side where the engaging portions 35U and 35D are formed. By adopting the above configuration, the butterfly valve 1 of the present invention can ensure a radius (R) on the valve body 10 that suppresses stress concentration without additional processing of the valve body 10. Furthermore, the butterfly valve 1 of the present invention can suppress interference between the valve core 30 and the valve body 10 using the aforementioned radius (R), while ensuring the contact pressure between the valve seal 40 and the valve body 10. Here, the draft angle θ is preferably formed relatively large on the side opposite to the eccentric direction of the valve core 30. This suppresses interference with the valve body 10 due to eccentric rotation of the valve core 30, thus eliminating the need for additional processing of the valve body 10, and allowing the valve body 10 to be manufactured using the draft angle θ. Therefore, cost reduction and weight reduction of the valve body 10 are expected.

[0083] The above is one embodiment of the butterfly valve 1 of the present invention. Next, the effects achieved by the butterfly valve 1 of the present invention will be described.

[0084] Effects and Functions

[0085] The butterfly valve 1 described above has the characteristic configuration shown in (A) to (L) below. Therefore, the butterfly valve 1 of the present invention can achieve the following unique effects that cannot be achieved by the prior art.

[0086] (A) The butterfly valve 1 of the present invention is characterized by comprising: a valve body 10 having a fluid passage 11 extending from one end to the other end; a pair of valve stems 20U, 20D rotatably supported on the valve body 10 and inserted into the fluid passage 11 from both radial sides; and a valve core 30 disposed inside the fluid passage 11 and supported by the pair of valve stems 20U, 20D, wherein by rotating the valve core 30 about the axis of the valve stems 20U, 20D, it is possible to switch between a closed state where the fluid passage 11 is closed by the valve core 30 and an open state where the fluid passage 11 is opened, the valve core 30 having at least a first valve core 30A and a second valve core 30B, and having a valve seal 40 eccentrically disposed relative to the axis of the pair of valve stems 20U, 20D, the valve seal 40 being supported by the first valve core 30A. A and the second valve core 30B are clamped together. When the valve core 30 closes the fluid passage 11, the valve seal 40 abuts against the radial inner circumferential surface of the fluid passage 11. A pair of valve stem plates 20U and 20D have engaging portions 25U and 25D on the support side of the valve core 30. On one side of the forming surface of the valve core 30, a pair of engaged portions 35U and 35D are provided at positions corresponding to the pair of engaging portions 25U and 25D. When engaged with the engaging portions 25U and 25D, the pair of engaged portions 35U and 35D are respectively opened on both sides along the forming surface of the valve core 30 through the engaging portions 25U and 25D. The pair of engaging portions 25U and 25D and the pair of engaged portions 35U and 35D can engage from the axial direction of the fluid passage 11 in the open state.

[0087] By employing the configuration described in (A) above, the butterfly valve 1 of the present invention can convert at least a portion of the force generated by the fluid pressure acting on the valve core 30 into shear force when the fluid passage 11 is closed by the valve core 30 in the closed state (also referred to as the valve closed state). That is, the butterfly valve 1 of the present invention can convert the bending stress applied to the valve core 30 into shear force between the engaging portions 25U, 25D of the valve stem plates 20U, 20D and the engaged portions 35U, 35D of the valve core 30. Therefore, the butterfly valve 1 of the present invention can reduce the bending stress acting on the valve stem plates 20U, 20D. Here, the engaging portions 25U, 25D on the valve stem plate 20U, 20D side can be formed into a convex shape, for example, by processing the front end of the valve stem plate 20U, 20D into a flat shape, and the engaged portions 35U, 35D on the valve core 30 side are preferably formed into a concave shape that can be inserted along the forming surface of the valve core 30. Therefore, the butterfly valve 1 of the present invention can ensure a large contact area between the engaging portions 25U, 25D and the engaged portions 35U, 35D, thus smoothly converting the bending stress between the engaging portions 25U, 25D and the engaged portions 35U, 35D into shear force. Furthermore, by constructing the engaging portions 25U, 25D and the engaged portions 35U, 35D with a concave-convex combination, the butterfly valve 1 of the present invention can be expected to achieve the effect of automatically aligning the valve seal 40 relative to the valve body 10 when the valve core 30 is assembled to the valve stem pieces 20U, 20D.

[0088] Furthermore, by adopting the configuration described in (A) above, the butterfly valve 1 of the present invention allows the engaging portions 35U and 35D of the valve core 30 and the engaging portions 25U and 25D of the valve stem plates 20U and 20D to engage along the forming surface of the valve core 30 when the valve is in the open state. Therefore, the butterfly valve 1 of the present invention allows the valve core 30 to be assembled to the valve stem plates 20U and 20D via the fluid passage 11 while the pair of valve stem plates 20U and 20D are pre-assembled into the valve body 10. Thus, the butterfly valve 1 of the present invention improves assemblability. Additionally, since the valve stem plates 20U and 20D are pre-assembled into the valve body 10, centering of the valve stem plates 20U and 20D is easy, and assembly accuracy is improved. Furthermore, since the valve seal 40 is held by the first valve core 30A and the second valve core 30B, the butterfly valve 1 of the present invention can prevent the valve seal 40 from shifting or falling off as the valve core 30 rotates.

[0089] (B) The butterfly valve 1 of the present invention is characterized in that, after a pair of engaging portions 25U, 25D and a pair of engaged portions 35U, 35D engage with each other, they are fastened by fastening member 31 along the axial direction of fluid channel 11 in the closed state.

[0090] By employing the configuration described in (B) above, the butterfly valve 1 of the present invention can reduce the wobbling that occurs when the engaging portions 25U and 25D of the valve stem plates 20U and 20D (valve stems 20U and 20D) engage with the engaged portions 35U and 35D of the valve core 30. Therefore, the butterfly valve 1 of the present invention can further reduce the bending stress acting on the valve stem plates 20U and 20D. Consequently, the butterfly valve 1 of the present invention can improve the assembly accuracy of the valve core 30 to the valve body 10.

[0091] (C) The butterfly valve 1 of the present invention is characterized in that the valve seal 40 is formed of a rubber sheet.

[0092] By adopting the above-described (C) configuration, the butterfly valve 1 of the present invention can improve the tightness between the valve core 30 and the valve body 10 (fluid passage 11), thereby improving the sealing performance.

[0093] (D) The butterfly valve 1 of the present invention is characterized in that at least a portion of the valve seal 40 is disposed at a position that abuts against or approaches a pair of valve stem plates 20U, 20D.

[0094] By employing the configuration described in (D) above, the butterfly valve 1 of the present invention can suppress strong contact between the valve body 10 and the valve seal 40 when the valve core 30 rotates. Specifically, when the valve core 30 is in the open state and the valve seal 40 is in sliding contact with the inner circumferential surface of the valve body 10, the butterfly valve 1 of the present invention can suppress strong contact between the valve seal 40 and the valve body 10 caused by eccentric rotation on one side. Thus, the butterfly valve 1 of the present invention can suppress the valve seal 40 from shifting or being damaged.

[0095] (E) The butterfly valve 1 of the present invention is characterized in that the first valve core 30A and the second valve core 30B are respectively approximately circular when viewed from the axial direction of the fluid channel 11, and are connected to each other by a plurality of fastening components 31.

[0096] By employing the configuration described in (E) above, the butterfly valve 1 of the present invention enables the first valve core 30A and the second valve core 30B to be fastened together along their respective circumferences. Therefore, the butterfly valve 1 of the present invention can improve the rigidity of the valve core 30.

[0097] (F) The butterfly valve 1 of the present invention is characterized in that the first valve core 30A and the second valve core 30B are fastened on the inner circumferential side of the valve seal 40 by a plurality of fastening components 31.

[0098] By employing the configuration described above (F), the butterfly valve 1 of the present invention allows for the provision of fastening points between the first valve core 30A and the second valve core 30B on the inner circumferential side of the valve seal 40 (for example, near the central portion of the first valve core 30A and the second valve core 30B). Consequently, the butterfly valve 1 of the present invention can further improve the rigidity of the valve core 30.

[0099] (G) The butterfly valve 1 of the present invention is characterized in that the first valve core 30A and the second valve core 30B are fastened in the circumferential direction near the inner periphery of the valve seal 40 by a plurality of fastening components 31.

[0100] By employing the configuration described in (G) above, the butterfly valve 1 of the present invention can suppress deviations (lack of strength) in the circumferential tightening strength of the valve seal 40. Therefore, the butterfly valve 1 of the present invention can improve sealing performance. Furthermore, by employing the configuration described in (G) above, the butterfly valve 1 of the present invention can improve the retention of the valve seal 40 on the valve core 30. Therefore, the butterfly valve 1 of the present invention can prevent the valve seal 40 from falling off.

[0101] (H) The butterfly valve 1 of the present invention is characterized in that the valve seal 40 has at least one protrusion 41, and the first valve core 30A and the second valve core 30B have receiving portions 32 for receiving the protrusion 41 on their mating surfaces.

[0102] By employing the configuration described above (H), the butterfly valve 1 of the present invention, through the engagement of the protrusion 41 (also referred to as the ear 41) with the receiving portion 32, can reduce the influence of forces such as sliding torque generated by sliding contact with the inner circumferential surface of the valve body 10 and flow torque generated by the fluid. Therefore, the butterfly valve 1 of the present invention can further suppress the detachment of the valve seal 40.

[0103] (I) The butterfly valve 1 of the present invention is characterized in that the protrusion 41 is formed to be deeper than the storage depth of the storage portion 32 in the storage direction, and the volume of the protrusion 41 is formed to be smaller than the storage volume of the storage portion 32.

[0104] By employing the configuration described in (I) above, the butterfly valve 1 of the present invention allows for moderate compression of the protrusion 41 of the valve seal 40 when it is housed in the housing portion 32 of the valve core 30, while simultaneously releasing any remaining compression (compression amount) of the valve seal 40 into the space of the housing portion 32. Consequently, the butterfly valve 1 of the present invention can easily house the valve seal 40 within the space of the housing portion 32, thus reducing the load on the fastening members 31 or fastening portions acting on the first valve core 30A and the second valve core 30B.

[0105] (J) The butterfly valve 1 of the present invention is characterized in that the first valve core 30A and the second valve core 30B are formed by forging.

[0106] The butterfly valve 1 of the present invention, by adopting the configuration described in (J) above, enables the valve core 30 to be formed with a lightweight design. Furthermore, by adopting the configuration described in (J) above, the butterfly valve 1 of the present invention allows the R (rounded corner) required to suppress stress concentration to be formed on the valve core 30 without additional processing. Thus, the butterfly valve 1 of the present invention achieves lightweight design while ensuring the strength (rigidity) of the valve core 30.

[0107] (K) The butterfly valve 1 of the present invention is characterized in that the valve body 10 is formed by forging, and the forging draft angle θ required by the forging is formed relatively large on the forming surface side where the engaging portions 35U and 35D are formed, relative to the non-forming surface side of the valve core 30 where the engaging portions 35U and 35D are not formed.

[0108] By employing the above-described (K) configuration, the butterfly valve 1 of the present invention allows the valve body 10 to be formed using forging, which is easily molded into a thin-walled shape, thus enabling the valve body 10 to be lightweight. Furthermore, by employing the above-described (K) configuration, the butterfly valve 1 of the present invention allows the R (rounded corner) required to suppress stress concentration to be formed on the valve body 10 without additional processing.

[0109] (L) The butterfly valve 1 of the present invention is characterized in that the valve body 10 is formed by forging, and the draft angle θ required for forging is formed relatively large on the opposite side of the eccentric direction of the valve core 30.

[0110] By employing the configuration described above (L), the butterfly valve 1 of the present invention ensures sufficient clearance for the valve seal 40 to avoid eccentricity by concentrating the draft angle θ on the opposite side of the eccentric valve core 30. That is, the butterfly valve 1 of the present invention can utilize the draft angle θ required for forging the valve body 10 to ensure sufficient clearance for the valve seal 40 to avoid eccentricity, thereby improving the production efficiency of the valve body 10 and potentially reducing manufacturing costs. Here, the draft angle θ is preferably formed, for example, an inclination angle of about 7 degrees.

[0111] Variations

[0112] The above describes the effects achieved by the butterfly valve 1 according to one embodiment of the present invention. However, the butterfly valve 1 is not limited to the above embodiment and can be modified in various ways within the scope of the present invention. For example, the butterfly valve 1 can be any butterfly valve as described in (A) above, and can be formed in various shapes and sizes. Furthermore, the butterfly valve 1 of the present invention may, for example, not have some or all of the components described in (B) to (L) above, or may have some or all of the components described in (B) to (L) above, and other components, etc. In addition, in this embodiment, the fluid from... Figure 3 The positive pressure situation where the fluid flows from the right side to the left has been described, but the butterfly valve 1 of the present invention can also be used for fluid flowing from... Figure 3The reverse pressure situation in which the flow moves from the left to the right. Even in this case, since the butterfly valve 1 of the present invention can convert the bending stress acting on the first valve core 30A and the second valve core 30B through the fluid into shear force, it can alleviate the bending stress acting on the valve stem plates 20U and 20D.

[0113] In this embodiment, the valve core 30 is configured to include a first valve core 30A and a second valve core 30B, but the valve core 30 can be formed from various valve cores, such as a single valve core or three or more valve cores. Furthermore, the valve core 30 can be formed in various shapes, sizes, and materials. Additionally, the butterfly valve 1 can be used in various orientations depending on the usage (e.g., the butterfly valve 1 can be arranged upside down or tilted left or right).

[0114] In this embodiment, the engaging portions 25U and 25D are convex, and the engaged portions 35U and 35D are concave. However, the engaging portions 25U and 25D and the engaged portions 35U and 35D can be formed in various shapes and sizes as long as they can engage with each other along the axial direction of the fluid channel 11. Furthermore, in this embodiment, the front ends of the engaging portions 25U and 25D are flat along the forming surface of the valve core 30, but the engaging surfaces of the engaging portions 25U and 25D and the engaged portions 35U and 35D can be formed in various shapes and sizes. For example, the engaging surfaces of the engaging portions 25U and 25D and the engaged portions 35U and 35D can also be formed in a concave-convex shape or a rough surface along the forming surface of the valve core 30. In this case, it is preferable to have a structure capable of converting the stress acting on the valve stem plates 20U and 20D into shear force. Alternatively, the engaging portions 25U and 25D can be interchanged with the engaged portions 35U and 35D. In this embodiment, the engaging portions 25U and 25D are formed with the same shape, but they can also be formed with different shapes. In this case, the shapes of the engaged portions 35U and 35D should preferably be modified according to the engaging portions 25U and 25D. Furthermore, in this embodiment, the engaged portions 35U and 35D have openings on both sides along the forming surface of the valve core 30, but for example, they can have openings on only one side. In this case, only the side of the engaged portions 35U and 35D that engages with the engaging portions 25U and 25D needs to be open.

[0115] In this embodiment, after the engaging parts 25U and 25D engage with the engaged parts 35U and 35D, they are fastened by the fastening member 31. However, the engaging parts 25U and 25D and the engaged parts 35U and 35D can be fastened as needed.

[0116] In this embodiment, at least a portion of the valve seal 40 is positioned to abut or approach a pair of valve stem plates 20U, 20D, but the valve seal 40 can be positioned in various locations. Furthermore, when the valve seal 40 is positioned close to the valve stem plates 20U, 20D, the distance between it and the valve stem plates 20U, 20D should be set taking into account the eccentricity of the valve during opening and closing.

[0117] Furthermore, the first valve core 30A and the second valve core 30B are not limited to the above-described embodiment and can be fastened in various positions. In this embodiment, the first valve core 30A and the second valve core 30B are fastened by bolts 31, but this is not a limitation; various fastening components can be used to fasten the first valve core 30A and the second valve core 30B. Additionally, the number and arrangement of fastening components 31 can vary depending on the size and shape of the first valve core 30A, the second valve core 30B, and the valve seal 40.

[0118] Furthermore, the shape, size, and material of the valve seal 40 are not limited to the above-described embodiment, and various shapes, sizes, and materials can be used. For example, the valve seal 40 may not have the protrusion 41. In this case, it is sufficient to provide a protrusion on the receiving portion 32 side and an engaging portion of the protrusion on the valve seal 40 side. Alternatively, if the valve seal 40 does not have the protrusion 41, it can be fixed with bolts or the like. Additionally, the receiving portion 32 can be of various shapes and sizes (volumes) depending on the shape and size of the valve seal 40.

[0119] In this embodiment, the first valve core 30A and the second valve core 30B are formed by forging, but the first valve core 30A and the second valve core 30B can be manufactured by various means. For example, in the butterfly valve 1 of the present invention, either or both of the first valve core 30A and the second valve core 30B can also be formed by means other than forging (e.g., casting). Furthermore, even when the first valve core 30A and the second valve core 30B are manufactured by forging, various forging methods can be used. Additionally, various materials can be used to form the first valve core 30A and the second valve core 30B.

[0120] Furthermore, in this embodiment, the valve body 10 is formed by forging, but the valve body 10 can be manufactured by various means. For example, the valve body 10 of the butterfly valve 1 of the present invention can also be formed by means other than forging (e.g., casting). Furthermore, even when the valve body 10 is manufactured by forging, various forging methods can be used. Additionally, the materials used to form the first valve core 30A and the second valve core 30B can be various materials. Furthermore, the butterfly valve 1 of the present invention is configured as described in (K) above, but the draft angle θ required for forging is not limited to this. The draft angle θ required for forging can be set to various tilt angles, etc., depending on the shape and size of the valve core 30 or the valve seal 40, etc. Furthermore, the butterfly valve 1 of the present invention is configured as described in (L) above, but the position where the draft angle θ is formed can be set to various positions, depending on the arrangement of the valve core 30 or the valve seal 40, etc.

[0121] The above are various embodiments and modifications of the butterfly valve involved in this invention. However, this invention is not limited to the contents illustrated in the above embodiments and modifications. Other embodiments can be obtained in accordance with the teachings and spirit of the claims without departing from the scope of the claims. This is readily understood by those skilled in the art.

[0122] (Industrial availability)

[0123] The present invention can be suitably used as a butterfly valve in piping (fluid passage) for the flow of various fluids (gas or liquid, etc.).

Claims

1. A butterfly valve, characterized in that, have: The valve body has a fluid passage extending from one end to the other end; A pair of valve stem plates, rotatably supported on the valve body, and inserted into the fluid passage from both radial sides; and The valve core is disposed inside the fluid passage and supported by a pair of valve stem plates. By rotating the valve core around the axis of the valve stem, it is possible to switch between a closed state (closing the fluid passage through the valve core) and an open state (opening the fluid passage). The valve core includes at least a first valve core and a second valve core, and has a valve seal that is axially eccentrically configured relative to the pair of valve stem plates. The valve seal is held between the first valve core and the second valve core, and when the valve cores close the fluid passage, the valve seal abuts against the radial inner circumferential surface of the fluid passage. The pair of valve stem plates have an engaging portion on the support side of the valve core. On one side of the forming surface of the valve core, a pair of engaged portions are provided at positions corresponding to the pair of engaged portions, which can engage with the pair of engaged portions. When engaged with the engaging portion, the pair of engaged portions are respectively separated from the engaging portion and open on both sides along the forming surface of the valve core. The pair of engaging portions and the pair of engaged portions can engage from the axial direction of the fluid channel in the open state.

2. The butterfly valve according to claim 1, characterized in that, After the pair of engaging parts and the pair of engaged parts are engaged with each other, they are fastened in the closed state by a fastening member along the axial direction of the fluid channel.

3. The butterfly valve according to claim 1 or 2, characterized in that, The valve seal is formed of a rubber sheet.

4. The butterfly valve according to claim 1 or 2, characterized in that, At least a portion of the valve seal is positioned to abut or approach the pair of valve stem plates.

5. The butterfly valve according to claim 1 or 2, characterized in that, The first valve core and the second valve core are approximately circular when viewed from the axial direction of the fluid channel, and are connected to each other by a plurality of fastening components.

6. The butterfly valve according to claim 1 or 2, characterized in that, The first valve core and the second valve core are fastened to the inner circumferential side of the valve seal by a plurality of fastening components.

7. The butterfly valve according to claim 1 or 2, characterized in that, The first valve core and the second valve core are fastened in the circumferential direction near the inner periphery of the valve seal by a plurality of fastening components.

8. The butterfly valve according to claim 1 or 2, characterized in that, The valve seal has at least one protrusion. The first valve core and the second valve core have receiving portions on their mating surfaces to receive the protrusions.

9. The butterfly valve according to claim 8, characterized in that, The protrusion is formed to be deeper than the storage portion in the storage direction. The volume of the protrusion is smaller than the storage volume of the receiving part.

10. The butterfly valve according to claim 1 or 2, characterized in that, The first valve core and the second valve core are formed by forging.

11. The butterfly valve according to claim 1 or 2, characterized in that, The valve body is formed by forging. The draft angle required for forging is formed on the forming surface side where the engaging portion is formed, while the non-forming surface side of the valve core where the engaging portion is formed is formed on a relatively larger scale.

12. The butterfly valve according to claim 1 or 2, characterized in that, The valve body is formed by forging. The draft angle required for forging is formed relatively large on the opposite side of the eccentric direction of the valve core.

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