JP2015224709A - Butterfly valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a butterfly valve eliminating axial displacement of a valve body due to water pressure and minute water leakage due to the axial displacement of the valve body.SOLUTION: A valve body 16 arranged in a body 10 and switching a passage is press-fitted into a rubber sleeve 15, and a rotational shaft 17 is arranged while penetrating the valve body 16. With respect to the rotational shaft 17, the valve body 16 is slidably held in the axial direction of the rotational shaft, and is held in the rotational direction thereof so as to rotate together with the rotational shaft. Consequently, even when water pressure in the body 10 rises and the rotational shaft 17 displaces onto the side of a motor actuator 21, since the valve body 16 does not displace in the axial direction, water leakage due to axial displacement can be eliminated.

Description

  The present invention relates to a butterfly valve, and more particularly to a butterfly valve that is disposed in a circulation circuit or the like of a hot water heater and can perform opening / closing control, switching control, or water flow control.

  An electric valve that generally functions as an on-off valve is interposed in the circulation circuit of the water heater. As an electric valve that opens and closes such a water circuit, a butterfly valve that enables cost reduction has been proposed (see, for example, Patent Document 1).

  The butterfly valve has a passage formed by a cylindrical body, and a rubber sleeve is lined in the passage. A valve element formed by a plate is disposed in the sleeve. This valve body is fixed by spot welding to a rotating shaft that hangs down through the center of the passage. The rotating shaft is pivotally supported at one end by a bearing portion formed in the passage, and the other end is extended to the outside of the passage through a shaft seal portion by an O-ring, and is rotated by a motor actuator. Connected as possible.

  The valve body has an elliptical shape, and the major axis has a dimension such that the projected shape from the direction of the central axis is a perfect circle when it is at a predetermined angle with respect to the central axis of the passage. The minor axis is formed larger than the inner diameter of the sleeve. Thereby, when the butterfly valve is closed, both ends in the minor axis direction of the valve body are sealed by biting into the sleeve, and the other peripheral portions are sealed by being pressed against the sleeve.

Japanese Patent Laying-Open No. 2005-009670 (paragraph [0015], FIG. 4)

  In the conventional butterfly valve, the valve body and the rotating shaft are fixed by welding, and a force that constantly pushes the rotating shaft toward the motor actuator by water pressure acts on the rotating shaft. The force that pushes the rotating shaft toward the motor actuator increases as the water pressure increases, and accordingly, the valve element fixed to the rotating shaft is also pushed toward the motor actuator. When the valve body is pushed out to the motor actuator side, the peripheral part of the valve body opposite to the motor actuator side is separated from the sleeve and the sealing action is weakened. As a result, slight water leakage occurs. There was a problem of end.

  The present invention has been made in view of the above points, and an object thereof is to provide a butterfly valve that eliminates the axial displacement of the valve body due to water pressure and the slight water leakage associated with the axial displacement of the valve body. And

  In order to solve the above-described problems, the present invention provides a butterfly valve in which an elliptical valve body is provided in a cylindrical body so as to be rotatable about an axis in the short diameter direction. The butterfly valve is characterized in that the valve element is held so as to be slidable in the axial direction with respect to a rotating shaft that is driven to rotate the valve element.

  In the butterfly valve configured as described above, since the valve body is slidably held on the rotating shaft in the axial direction, even if the hydraulic pressure is increased and the rotating shaft is displaced in the direction in which the rotating shaft comes out, the valve body is moved along with the displacement of the rotating shaft. There is an advantage that there is no displacement.

  Since the valve body and the rotating shaft are not fixed to each other, a welding process is unnecessary, and a welding facility is also unnecessary, so that the manufacturing cost of the butterfly valve can be greatly reduced.

  Moreover, if the valve body and the rotating shaft are made of resin, the manufacturing cost of the butterfly valve can be further reduced.

It is a center longitudinal cross-sectional view which shows the butterfly valve which concerns on 1st Embodiment. It is AA arrow sectional drawing of FIG. It is the perspective view which shows the rotating shaft of the butterfly valve which concerns on 1st Embodiment, and explanatory drawing which shows a partial expanded section. It is a figure which shows the valve body of the butterfly valve which concerns on 1st Embodiment, Comprising: (A) is the perspective view which looked at the valve body from diagonally up, (B) The perspective view which looked at the valve body from diagonally below. . It is sectional drawing which shows the fitting state of a valve body and a rotating shaft. It is a perspective view which shows the decomposition | disassembly state and assembly state of the electric four-way control valve to which the butterfly valve which concerns on 1st Embodiment is applied. It is a perspective view which shows the example of the valve body and rotating shaft of the butterfly valve which concern on 2nd Embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, taking as an example a case where the present invention is applied to an electric four-way control valve for water circuit switching in a circulation circuit of a water heater. Each embodiment can be implemented by combining a plurality of embodiments within a consistent range.

  FIG. 1 is a central longitudinal sectional view showing a butterfly valve according to the first embodiment, and FIG. 2 is a sectional view taken along the line AA in FIG. FIG. 3 is a perspective view showing a rotating shaft of the butterfly valve according to the first embodiment and an explanatory view showing a partially enlarged cross section. 4A and 4B are views showing the valve body of the butterfly valve according to the first embodiment, in which FIG. 4A is a perspective view of the valve body viewed from diagonally above, and FIG. 4B is a perspective view of the valve body viewed from diagonally below. FIG. FIG. 5 is a cross-sectional view showing a fitting state between the valve body and the rotating shaft.

  As shown in FIGS. 1 and 2, the butterfly valve according to the first embodiment has a body 10 configured to communicate two cylindrical pipes in an orthogonal manner and communicate with each other inside. The body 10 has a first connection port 11, a second connection port 12, a third connection port 13, and a fourth connection port 14 that are open in four directions. At the center portion connecting the first connecting port 11 and the third connecting port 13, an elastic sleeve 15 made of rubber, for example, is lined. The sleeve 15 has openings 15 a and 15 b communicating with the second connection port 12 and the fourth connection port 14 on the side surface.

  A valve body 16 is disposed at the crossing center position of the body 10, and the valve body 16 is rotatably supported by a rotating shaft 17 that is suspended so as to pass through a passage in the center of the body 10. . As shown in FIG. 3, the rotating shaft 17 has a cylindrical portion 17a, a prismatic portion 17b, a seal mounting portion 17c, and a connecting portion 17d from the bottom, and is integrally molded with resin.

  The cylindrical portion 17 a of the rotating shaft 17 extends downward through the sleeve 15, and is pivotally supported by a bearing portion 18 that is recessed at the bottom of the crossing center position of the body 10. The rectangular column portion 17 b has a shape in which the corners of the quadrangular column are rounded and chamfered so that a rotational force can be transmitted to the valve body 16. In the illustrated example, the seal mounting portion 17c is provided with two grooves, and an O-ring 19 that is a ring-shaped seal member can be mounted thereon. In the example of FIG. 1, only one O-ring 19 is attached. This seal mounting portion 17c is rotatably supported by a cylindrical portion 20 formed at the upper portion of the crossing center position of the body 10, and at the same time, the O-ring 19 prevents water leakage to the outside. The connecting portion 17d has serrated serrations on the outer peripheral surface thereof, and is coupled to the output shaft 22 of the motor actuator 21 formed in a shape that fits with the serrations.

  The rotary shaft 17 is also formed so as to change smoothly by providing a gradually changing portion at the boundary between the square columnar portion 17b having a square cross section and the seal mounting portion 17c having a circular cross section. Specifically, the circular end surface of the seal mounting portion 17c of the rotating shaft 17 and the end surface of the prismatic portion 17b are coupled by a frustoconical coupling portion 17e. The connecting portion 17e has a larger circle on the side of the seal mounting portion 17c than the circumscribed circle of the prism portion 17b, and has a circle on the side of the prism portion 17b close to the circumscribed circle of the prism portion 17b. Further, the frustoconical coupling portion 17e is formed by a gradually varying coupling portion 17f having a circular arc shape (so-called R shape) in order to smooth the boundary with the circular end surface of the seal mounting portion 17c. Yes. Similarly, the boundary portion between the conical coupling portion 17e and the prism portion 17b is formed so as to be smoothly coupled by the gradually changing coupling portion 17g having an arcuate cross section.

  Similarly, the rotating shaft 17 is smoothly formed by a gradually changing coupling portion 17h having a circular arc cross section so that it does not become a right angle at a boundary portion between the rectangular column portion 17b having a quadrangular cross section and the cylindrical portion 17a having a circular cross section. .

  As described above, the boundary portion between the square columnar portion 17b having a square cross section, the seal mounting portion 17c having a circular cross section, and the cylindrical portion 17a is smoothly coupled, so that stress at the boundary portion can be dispersed. Thereby, when the rotating shaft 17 is twisted with a strong force by the motor actuator 21, it is possible to prevent the boundary portion from being broken.

  As shown in FIG. 4, the valve body 16 includes an elliptical disc portion 23 and a shaft holding portion 24 through which the prism portion 17 b of the rotary shaft 17 is inserted in the minor axis direction (vertical direction) of the disc portion 23. And have. The shaft holding portion 24 is formed such that the cross-sectional shape of the inner hole is similar to the cross-sectional shape of the prism portion 17b of the rotating shaft 17, and the minimum allowable dimension of the hole is larger than the maximum allowable size of the prism portion 17b. Thus, the valve body 16 is held by the prism portion 17b of the rotating shaft 17 so as to be slidable in the axial direction.

  Further, as shown in FIG. 5, the prism portion 17b of the rotating shaft 17 is rounded and chamfered so that the rotational force of the rotating shaft 17 is transmitted by the four curved contact portions 17i around the periphery. The stress applied to the shaft holding portion 24 of the valve body 16 is dispersed at four locations. By eliminating the stress concentration from the rotating shaft 17 to the valve body 16, the rotating shaft 17 and the valve body 16 can be prevented from being damaged. In particular, in this butterfly valve, the rotation range of the valve body 16 is defined by a mechanical lock, that is, the rotary shaft 17 is rotationally driven until the valve body 16 hits the sleeve 15 and does not physically rotate. Dispersion is very useful. On the other hand, when the rotation axis of the rotating shaft is, for example, D cut, the stress applied to the valve body from the rotating shaft is 1 of the corner portion of the D cut when the rotating shaft and the valve body are in a clearance fit. Since it concentrates on a location, it becomes easy to break.

  In the valve body 16, a plurality of ribs 25 extending in the horizontal direction across the shaft holding portion 24 are formed on both surfaces of the disc portion 23 in order to reinforce the shaft holding portion 24. In the illustrated example, four ribs 25 are formed in the longitudinal direction of the shaft holding portion 24, and two of the inner ribs are formed lower than the outer two to prevent the flow of water at the center of the passage as much as possible. I am trying not to. The valve body 16 is integrally formed of resin including the disc portion 23, the shaft holding portion 24 and the rib 25. Further, the valve body 16 is formed so that the upper part and the lower part have a line-symmetric shape so that it is not necessary to care about the vertical direction when assembling the butterfly valve.

  In the butterfly valve having the above-described configuration, the valve element 16 is slidably held in the axial direction by the rotating shaft 17, and therefore, when accommodated in the body 10, both end portions in the minor axis direction thereof. Is always held and sealed by the elasticity of the sleeve 15. For this reason, even if the water pressure in the body 10 rises and the rotary shaft 17 is displaced toward the motor actuator 21, the valve body 16 is not displaced in the axial direction, and water leakage associated with the axial displacement is eliminated. Can do. Moreover, since the valve body 16 and the rotating shaft 17 are not fixed, a welding process and welding equipment are not required, so that the manufacturing cost can be significantly reduced. Furthermore, the butterfly valve according to the first embodiment can further reduce the manufacturing cost because the valve body 16 and the rotating shaft 17 are made of resin.

  Here, when the rotary shaft 17 is rotationally driven, for example, in the counterclockwise direction by the motor actuator 21, the valve body 16 is pressed against the sleeve 15 by pressing the outer peripheral edge portion against the sleeve 15, as shown in FIG. The gap between is sealed. When the valve body 16 is in the position shown in FIG. 2, the butterfly valve is in a state where the first connection port 11 and the second connection port 12 are in communication, and at the same time, the third connection port 13 and the fourth connection port 14. And become connected. Conversely, when the valve body 16 is rotationally driven in the clockwise direction, the butterfly valve is in communication between the first connection port 11 and the fourth connection port 14, and at the same time, the second connection port 12 and the third connection port. The connection port 13 is in communication.

  That is, this butterfly valve is a four-way control that switches the first connecting port 11 to the second connecting port 12 or the fourth connecting port 14 and simultaneously switches the third connecting port 13 to the fourth connecting port 14 or the second connecting port 12. Functions as a valve.

  At this time, when the first connection port 11 and the third connection port 13 are used as inlets, water supplied to the inlet is supplied from the second connection port 12 or the fourth connection port 14 and from the fourth connection port 14 or the fourth connection port. Each of the two connecting ports 12 goes out. Moreover, when the 1st connection port 11 and the 3rd connection port 13 are made into an exit, the water supplied to the 2nd connection port 12 or the 4th connection port 14 is from the 1st connection port 11, and the 4th connection port. The water supplied to 14 or the 2nd connection port 12 comes out from the 3rd connection port 13, respectively.

Next, the assembly procedure of the above butterfly valve will be described.
FIG. 6 is a perspective view showing an exploded state and an assembled state of the electric four-way control valve to which the butterfly valve according to the first embodiment is applied.

  This electric four-way control valve has the members shown in FIG. 6 and is assembled as follows. First, the sleeve 15 is fitted into a predetermined position of the body 10. That is, the sleeve 15 is inserted from the third connection port 13 while aligning the orientations of the through holes through which the rotary shaft 17 passes and the openings 15a and 15b communicating with the second connection port 12 and the fourth connection port 14, and the tip ends thereof. It is pushed in until it fits in the receiving part formed in the 1st connection port 11 side. Next, the valve body 16 is inserted from the third connection port 13 and is press-fitted into the sleeve 15 until the shaft holding portion 24 matches the through hole of the rotating shaft 17.

  Next, the rotary shaft 17 in which the O-ring 19 is mounted in advance on the seal mounting portion 17c is inserted from the cylindrical portion 20 at the top of the body 10, and the cylindrical portion 17a at the tip is inserted into the body via the shaft holding portion 24 of the valve body 16. It is pushed in until it fits into the lower bearing portion 18 of the ten. Thereby, the assembly of the butterfly valve is completed.

  Finally, the rotary shaft 17 is inserted into the output shaft 22 of the motor actuator 21 to couple the output shaft 22 and the rotary shaft 17, and the motor actuator 21 is screwed to the body 10, whereby the electric four-way control valve. Assembly is complete.

  In the butterfly valve according to the first embodiment, the valve body 16 and the rotary shaft 17 are formed of an injection molded product made of resin, but may be formed of a metal powder injection molded product or a metal cut product. good.

FIG. 7 is a perspective view showing an example of a valve body and a rotating shaft of a butterfly valve according to the second embodiment.
The butterfly valve according to the second embodiment is formed of a press-processed product, whereas the butterfly valve according to the first embodiment is formed of an injection-molded product or a cut-processed product with a valve body and a rotary shaft. Is different.

  In the butterfly valve according to the second embodiment, the valve body 30 is configured by bonding together two elliptical plates 30a and 30b made of stainless steel, for example, in the minor axis direction of the plates 30a and 30b. V-grooves 31a and 31b are formed by pressing. When the valve body 30 is viewed from the short-diameter direction, the plates 30a and 30b are joined by appropriate joining means with the surfaces having the V grooves 31a and 31b facing outward. The space of the shaft holding part is formed. Since the plates 30a and 30b are not joined in the sleeve 15 at the time of assembly, the plates 30a and 30b can be preliminarily bonded with an adhesive, spot welding or the like.

  The rotating shaft 32 is plastically deformed so that a cross section becomes a square by pressing a part of a round bar to constitute a fitting portion 32a. The fitting portion 32a is fitted to a shaft holding portion including the V grooves 31a and 31b of the valve body 30, and the valve body 30 is slidable in the axial direction of the rotary shaft 32. This is a portion that holds the valve body 30 so as to rotate according to the rotation of the rotating shaft 32. The rotating shaft 32 is bent at its upper end, and is rotated by engaging it with the output gear of the motor actuator.

  Also in the butterfly valve according to the second embodiment, the cylindrical portion 20 through which the rotary shaft 32 is disposed is sealed by the O-ring 19. A means to regulate so that it does not escape is necessary.

  Even in this butterfly valve, even if the water pressure in the body 10 rises and the rotary shaft 32 is displaced toward the motor actuator 21, the valve body 30 is not displaced in the axial direction. Leakage can be eliminated.

  In the butterfly valve according to the second embodiment, the shaft holding portion of the valve body 30 is configured by the V grooves 31a and 31b. However, the shaft holding portion may be configured by a channel having a rectangular cross section formed by pressing. good.

  As mentioned above, although illustrated about the case where the present invention is applied to a four-way control valve, the present invention is not limited to this. For example, the present invention can be similarly applied to a three-way control valve or a two-way control valve.

DESCRIPTION OF SYMBOLS 10 Body 11 1st connection port 12 2nd connection port 13 3rd connection port 14 4th connection port 15 Sleeve 15a, 15b Opening part 16 Valve body 17 Rotating shaft 17a Cylindrical part 17b Square column part 17c Seal mounting part 17d Connection part 17e Connection Part 17f Gradual change coupling part 17g Gradual change coupling part 17h Gradual change coupling part 17i Curved surface contact part 18 Bearing part 19 O-ring 20 Cylindrical part 21 Motor actuator 22 Output shaft 23 Disc part 24 Shaft holding part 25 Rib 30 Valve body 30a , 30b Plate 31a, 31b V groove 32 Rotating shaft 32a Fitting part

Claims (6)

In the butterfly valve in which an elliptical valve body is installed in a cylindrical body so as to be rotatable around an axis in the short diameter direction,
The butterfly valve is characterized in that the valve body is held so as to be slidable in the axial direction with respect to a rotating shaft that is driven to rotate.   2. The butterfly valve according to claim 1, wherein the rotating shaft is a quadrangular prism with a rounded corner chamfered at a portion holding the valve body.   The rotation shaft is provided with a groove for mounting a ring-shaped seal member around a cylindrical portion connected to the drive source side with respect to a rectangular column portion that holds the valve body. Item 3. The butterfly valve according to Item 2.   The rotating shaft is formed by a joint portion where a boundary portion between a quadrangular column portion holding the valve body and the cylindrical portion connected in the axial direction of the quadrangular column portion gradually changes in outer shape. The butterfly valve according to claim 3.   2. The butterfly valve according to claim 1, wherein the valve body has a plurality of ribs extending in a major axis direction across a shaft holding portion through which the rotation shaft is inserted.   The valve body is characterized in that the height of the rib disposed near the center of the shaft holding portion is low and the height of the rib disposed on both axial ends of the shaft holding portion is high. The butterfly valve according to claim 5.

Images