JP2015143543A - control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to suppress release of a fluid that causes noise or erosion that occurs in a clearance channel formed in an inner circumferential surface of a valve seat of a needle valve in an expansion valve of a refrigerating cycle apparatus.SOLUTION: In a control valve, a recessed portion 26R1 having a circular arc cross-section is formed annularly in a portion in which a conical surface 26E3 and a conical surface 26E4 on the other end 26EB of a valve element 26 cross each other and a recessed portion 26E1 having a generally V-cross-section is formed annularly in a portion in which a conical surface 26E2 crosses an outer circumferential surface of the other end 26EB, and a recessed portion 30E1 having a generally V-cross-section is formed annularly around a central axis of a curved surface 30E2 in a portion in which a flat surface of a valve seat 30V facing a tip end portion of the other end 26EB of the valve element 26 crosses one end portion of the curved surface 30E2 and a recessed portion 30R1 having a circular arc cross-section is formed annularly around a central axis of a channel 30Va in a portion in which the other end portion of the curved surface 30E2 crosses an inner circumferential surface 30E4.

Description

  The present invention relates to a control valve.

  In the refrigeration cycle apparatus, a needle valve is arranged as an expansion valve between the condenser and the evaporator. In the expansion valve, for example, as shown in paragraph [0022] of Patent Document 1 and FIG. 5, the flow separation occurs at the orifice inlet of the gap flow path formed by the inner peripheral edge of the valve seat and the needle. Occur. The fluctuation between the development and disappearance of the separation flow, or the separation flow itself causes noise in the expansion valve. In addition, when a vortex is generated at the inlet of the orifice, the foaming point fluctuates due to the behavior of a series of vortices, so that pressure fluctuations that cause noise occur. In such a case, in order to reduce the noise level, it has been proposed that the angle formed between the needle tip and the orifice inlet is set to 60 ° or less. Furthermore, as shown in Patent Document 2, for example, when a bubble disappears, the needle valve has an angle α formed by the outer peripheral surfaces of the valve body so as to reliably suppress noise generated by an impact force. It is proposed that the angle between the inner surfaces of the port portions of the valve port is not less than β and the difference between these angles (α−β) is not more than 10 °.

JP 2007-32979 A JP 2008-291928 A

  However, when a corner is formed on the wall surface of the valve seat or the outer peripheral surface of the needle valve forming the gap channel as described above, fluid separation occurs at the corner, thereby Since peeling and reattachment occur, there is a risk of causing noise and erosion.

In recent years, as a countermeasure against global warming, a refrigerant having a low global warming coefficient such as CO ₂ refrigerant or R410a has been used. Since these are higher in pressure than existing refrigerants, the flow velocity at the orifice is high, and noise due to the flow of fluid has become more obvious.

  In view of the above problems, the present invention is a control valve that can suppress separation of fluid that causes noise and erosion generated in a gap flow path formed on the inner peripheral surface of the valve seat. The purpose is to provide.

  In order to achieve the above-mentioned object, a control valve according to the present invention has a first port connected to a first passage and a second port connected to a second passage, A valve body having an accommodating portion that movably accommodates a valve body unit that includes a valve body that controls opening and closing of the second port, and is connected to the valve body unit. A valve body unit drive mechanism for performing an operation for controlling opening and closing of the second port so as to adjust the flow rate of the fluid passing between the front end of the second port and the peripheral edge of the second port. At a portion where at least two curved surfaces intersect each other among a plurality of curved surfaces in the cross section of the flow path of the valve seat forming the second port facing the tip portion or the peripheral edge of the second port, A concave portion in which a fluid vortex is generated is formed.

  In addition, a recess in which at least two conical surfaces of the plurality of conical surfaces forming the tip of the valve body intersect each other may be formed with a fluid vortex inside, and the recess has an arc-shaped cross section. It may have, and may have a substantially V-shaped cross section. Recesses may be formed at both ends of at least one enlarged surface in the cross section of the flow path of the valve seat that forms the periphery of the second port, and the valve seat that forms the periphery of the second port A recess may be formed at a portion where a plurality of enlarged surfaces intersect in the cross section of the flow path.

  According to the control valve of the present invention, a plurality of curved surfaces in the cross section of the wall surface forming the second port facing the tip of the valve body or the flow path of the valve seat forming the peripheral edge of the second port A recess in which a fluid vortex is formed inside is formed at a portion where at least two curved surfaces intersect each other, which causes noise and erosion generated in the gap flow path formed on the inner peripheral surface of the valve seat Fluid separation can be suppressed.

It is a fragmentary sectional view which expands and shows the principal part of 1st Example of the control valve which concerns on this invention partially. It is a fragmentary sectional view showing roughly the composition of the 1st example of the control valve concerning the present invention. It is a fragmentary sectional view which expands and shows a part in the example shown by FIG. It is a fragmentary sectional view which expands and shows the principal part of 2nd Example of the control valve which concerns on this invention partially.

  FIG. 2 shows a first embodiment of the control valve according to the present invention together with a pipe for piping.

  In FIG. 2, for example, the control valve is arranged as an expansion valve between a condenser and an evaporator in the air conditioner. The control valve is provided in a cylindrical rotor case 20 and includes a valve drive unit that drives a valve body unit, which will be described later, and a valve seat 30V that is connected to the end of the rotor case 20 and is opened and closed at the front end of the valve body 26. And a valve body unit including a valve body 26 that is disposed in the valve body 30 and opens and closes the valve seat 30V.

  The valve drive unit includes a male screw shaft 14 that moves the valve body unit up and down, a guide support unit 12 that has a female screw part fitted to the male screw shaft 14 and guides the valve body unit so that the valve body unit can move up and down, and a male screw shaft 14. And a rotor coil (not shown) that is rotatably supported and magnetized, and a stator coil (not shown) that is arranged on the outer periphery of the rotor case 20 and rotates the rotor. Yes. The guide support part 12 has a guide surface for guiding the case 18 of the valve body unit on the inner peripheral part. The valve drive unit is controlled based on a drive pulse signal supplied by a drive control unit (not shown).

  In the valve body unit described above, a needle-like valve body 26 that opens and closes a flow path 30Va of a valve seat 30V, which will be described later, and a flanged connection end 14a of the male threaded shaft 14 cooperate with the washer 16 at one end of the case 18. The retainer member 24 to be held, the coil spring 22 disposed between one end of the retainer member 24 and the annular flat portion of the one end 26EA of the valve body 26, and energizing both of them in a direction away from each other, the retainer member 24, the coil The main body includes a spring 22 and a cylindrical case 18 that houses one end 26EA of the valve body 26.

  One end of the cylindrical case 18 is closed by being fitted to the outer peripheral portion of one end 26EA of the valve body 26. The other end of the cylindrical case 18 has an open end into which the flanged connecting end 14a is inserted.

  A washer 16 is disposed between the inner peripheral edge of the opening end of the case 18 and the flange of the flanged connecting end 14a. The end surface of the retainer member 24 is in contact with the end surface of the flanged connecting end 14a.

  The outer peripheral part of the cylindrical case 18 is slidably contacted with the guide surface of the above-mentioned guide support part 12 and supported so as to be movable up and down. As a result, the leading edge of the other end 26EB of the valve body 26 is inserted into the flow path 30Va of the valve seat 30V, and after a conical surface 26E2 of the valve body 26 described later contacts the pointed head 30EP, the male screw continues. When the shaft 14 is lowered, the coil spring 22 is compressed. Thereby, the conical surface 26E2 of the valve body 26 is pressed against the pointed head 30EP by the spring force. Thereby, the flow path 30Va of the valve seat 30 is closed.

  The tip of the other end 26EB of the valve body 26 has a tapered portion that is inserted into the flow path 30Va of the valve seat 30V, as shown partially enlarged in FIG. The tapered portion is formed by conical surfaces 26E2, 26E3, and 26E4. The first reduced diameter portion 26EP1 formed at a portion where the conical surface 26E2 and the conical surface 26E3 intersect is connected to the outer peripheral surface of the other end 26EB via the conical surface 26E2 having a predetermined apex angle α. The conical surface 26E2 forms part of the generatrix of the cone. The diameter VD of the first reduced diameter portion 26EP1 is set to be substantially the same as the inner diameter PD of the flow path 30Va. Further, the conical surface 26E3 that is continuous with the first reduced diameter portion 26EP1 and extends toward the foremost end has a predetermined apex angle β that is smaller than the apex angle α. The conical surface 26E4 that intersects the conical surface 26E3 has an apex angle γ that is greater than the apex angle α. A concave portion 26R1 having an arc-shaped cross section is formed in an annular shape at a portion where the conical surface 26E3 and the conical surface 26E4 intersect. Furthermore, a concave portion 26E1 having a substantially V-shaped cross section is formed in an annular shape at a portion where the conical surface 26E2 and the outer peripheral surface of the other end 26EB intersect.

  The valve main body 30 is made of a metal material, for example, brass, stainless steel, aluminum alloy, resin material, etc., and accommodates the lower end of the guide support 12, the other end 26 </ b> EB of the valve body 26, and the cylindrical case 18. It has a body accommodating portion 30A inside. The other end 26EB of the valve body 26 protrudes from the valve body housing portion 30A. Further, the valve body accommodating portion 30A has a port 32P as a first port to which one end of a connection pipe 32 as a first passage is connected on an axis substantially orthogonal to the central axis of the valve body 26; A valve seat 30V adjacent to the port 34P as a second port is formed on one axis common to the central axis of the valve body 26 and connected to one end of the connection pipe 34 as the second passage. . The diameter of the port 34P is set to be substantially the same as the diameter of the port 32P.

  The cross section which is a surface forming the flow path at the periphery of the opening end of the flow path 30Va formed in the valve seat 30V facing the tip of the other end 26EB of the valve body 26 described above is partially enlarged in FIG. As shown, it is formed of curved surfaces 30E2 and 30E3 that are connected to the flat surface of the valve seat 30V in a funnel shape, and an inner peripheral surface 30E4 that forms the inner peripheral portion of the flow path 30Va. The diameter of the flow path 30Va is set smaller than the diameter of the port 34P. The flat surface of the valve seat 30 </ b> V is formed so as to be orthogonal to the central axis of the other end 26 </ b> EB of the valve body 26. The inner peripheral surface 30E4 extends in parallel with the central axis of the other end 26EB of the valve body 26. The curved surfaces 30E2 and 30E3 connect the flat surface of the valve seat 30V and the inner peripheral surface 30E4. In a portion where one end of the curved surface 30E2 and the flat surface of the valve seat 30V intersect, a concave portion 30E1 having a substantially V-shaped cross section is formed in an annular shape around the central axis of the flow path 30Va. A concave portion 30R1 having an arc-shaped cross section is formed in an annular shape around the central axis of the flow path 30Va at a portion where the other end of the curved surface 30E2 and the inner peripheral surface 30E4 intersect. In the intermediate portion of the boundary portion between the curved surface 30E2 and the curved surface 30E3, when the valve body 26 is closed with respect to the flow path 30Va, as shown by a two-dot chain line in FIG. A pointed head 30EP with which the surface 26E2 abuts is formed on the circumference around the central axis of the flow path 30Va.

  In such a configuration, the stator coil of the valve drive unit is controlled by the drive pulse signal from the drive control unit, and the valve body 26 is moved up and down, so that fluid supplied through the connection pipe 32 or the connection pipe 34 is obtained. Is formed between the wall surface from the curved surface 30E2 of the valve seat 30V to the inner peripheral surface 30E4 along the direction indicated by the arrow F or the arrow R and the tapered portion of the other end 26EB of the valve body 26. It will pass through the flow path at a predetermined flow rate.

  At that time, for example, when the fluid flows in the direction indicated by the arrow F as shown in a partially enlarged view in FIG. 3A, a vortex that rotates in the direction indicated by the arrow Fa is formed in the recess 30R1. The flow of a part of the fluid becomes a turbulent flow having a high apparent viscosity due to the vortex. Thereby, the fluid along the curved surface 30E3 flows along the turbulent boundary layer of the vortex surface in the vicinity of the concave portion 30R1, and flows along the inner peripheral surface 30E4 without being separated from the curved surface 30E3. Even in the vicinity of the recess 30E1 and the recess 26E1 and the recess 26R1 in the other end 26EB of the valve body 26, the fluid behaves in the same manner, so that the fluid flows without being separated from the wall surface. Therefore, noise is reduced by suppressing reattachment due to separation of the fluid from the wall surface.

  On the other hand, for example, as shown partially enlarged in FIG. 3B, when the fluid flows in the direction indicated by the arrow R, a vortex that rotates in the direction indicated by the arrow Fb is formed in the recess 30R1. The flow of a part of the fluid becomes a turbulent flow having a high apparent viscosity due to the vortex. Thereby, the fluid along the inner peripheral surface 30E4 flows along the turbulent boundary layer of the vortex surface in the vicinity of the recess 30R1, and flows along the curved surface 30E3 without being separated from the inner peripheral surface 30E4. Therefore, even when the fluid flows in the direction indicated by the arrow R, the fluid flows without being separated from the wall surface, and noise is reduced by suppressing reattachment of the fluid due to the separation of the fluid from the wall surface. .

  FIG. 4 shows an enlarged view of the main part of the valve body used in the second embodiment of the control valve according to the present invention.

  In the first embodiment shown in FIG. 1, the other end 26EB of the valve body 26 has recesses 26E1, 26R1 at two locations, and the valve seat 30V has recesses 30E1, 30R1 at two locations. Instead, however, in the second embodiment shown in FIG. 4, the other end 36EB of the valve body 36 has recesses 36R1, 36R2, and 36R3 at three locations, and the valve seat 40V at four locations. The recesses 40E1, 40R1, 40R2, and 40R3 are provided.

  Also in the example shown in FIG. 4, the control valve is arranged as an expansion valve between a condenser and an evaporator in the air conditioner, for example. The control valve is arranged in the above-described cylindrical rotor case 20 and drives a valve body unit, which will be described later, and a valve seat connected to the end of the rotor case 20 and opened and closed at the front end of the valve body 36. The valve body 40 includes 40V, and a valve body unit including a valve body 36 that is disposed in the valve body 40 and opens and closes the valve seat 40V. The rotor case 20 and the valve drive unit have the same configuration as the example shown in FIG.

  The tip of the other end 36EB of the valve body 36 has a tapered portion that is inserted into the flow path 44P, as shown in a partially enlarged view in FIG. The tapered portion is formed by conical surfaces 36E1, 36E2, 36E3, and 36E4. A first reduced diameter portion 36EP1 formed at a portion where the conical surface 36E1 and the conical surface 36E2 intersect is connected to the outer peripheral surface of the other end 36EB via a conical surface 36E1 having a predetermined apex angle αA and a recess 36R1. . The conical surface 36E1 forms part of the generatrix of the cone. A diameter VD of the first reduced diameter portion 36EP1 is set to be substantially the same as a minimum inner diameter PD of a flow path 44P described later. Further, the conical surface 36E2 that is continuous with the first reduced diameter portion 36EP1 and extends toward the forefront has a predetermined apex angle βA that is smaller than the apex angle αA. The conical surface 36E3 that intersects the conical surface 36E2 has an apex angle γA that is greater than the apex angle βA. The conical surface 36E4 intersecting with the conical surface 36E3 has an apex angle δA larger than the apex angle γA, and a concave portion 36R3 having an arc-shaped cross section is formed in an annular shape at a portion intersecting with the conical surface 36E3. . Thus, since the conical surface 36E4 is formed in a constricted shape, the fluid is rectified at the lowermost end of the conical surface 36E4, and the flow of the flow path 44P from the conical surface 36E4 becomes smooth.

  A concave portion 36R2 having an arc-shaped cross section is formed in an annular shape at a portion where the conical surface 36E2 and the conical surface 36E3 intersect. Further, a concave portion 36R1 having an arcuate cross section is formed in an annular shape at a portion where the conical surface 36E1 and the outer peripheral surface of the other end 36EB intersect.

  The valve main body 40 is made of a metal material, for example, brass, stainless steel, aluminum alloy, a resin material, and the like, and has a valve body housing portion 40A that houses the other end 36EB of the valve body 36 inside. One port to which one end of a connection pipe 32 serving as a first passage is connected to an axis substantially orthogonal to the central axis of the valve body 36 is connected to the valve body accommodating portion 40A, and the central axis of the valve body 36 The other port to which one end of the connection pipe 34 as a second passage is connected is formed on the common axis.

  As shown in FIG. 4, the transverse cross section of the opening edge of the flow path 44P formed in the valve seat 40V adjacent to the other port facing the tip of the other end 36EB of the valve body 36 is a funnel shape. The curved surfaces 40E2 and 40E3 that are continuous with the flat surface of the valve seat 40V, the smallest diameter-reduced surface portion 40E4, and the cross-sectional shape of the divergent nozzle, gradually expand gradually toward the inner peripheral surface 40E8 having the maximum inner diameter described later. It is formed from enlarged surfaces 40E5, 40E6, 40E7 and an inner peripheral surface 40E8 that forms the inner peripheral portion of the flow path 44P. Thus, since the enlarged surface 40E5 and the enlarged surface 40E6 do not expand rapidly, the contracted flow is suppressed. The central axis of the inner peripheral surface 40E8 extends along a straight line common to the central axis of the other end 36EB of the valve body 36. The flat surface of the valve seat 40V described above is formed to be orthogonal to the central axis of the other end 36EB of the valve body 36.

  The curved surfaces 40E2 and 40E3 connect the flat surface of the valve seat 40V and the minimum diameter-reduced surface portion 40E4. At a portion where one end of the curved surface 40E1 and the flat surface of the valve seat 40V intersect, a recess 40E1 having a substantially V-shaped cross section is formed in an annular shape around the central axis of the flow path 44P.

  A concave portion 40R1 having an arc-shaped cross section is formed in an annular shape around the central axis of the flow path 44P at a portion where the other end of the curved surface 40E3 and the upper end of the minimum diameter reducing surface portion 40E4 intersect. When the valve body 36 is in a closed state at the boundary portion between the curved surface 40E2 and the curved surface 40E3, as shown by a two-dot chain line in FIG. 4, the pointed portion on which the conical surface 36E1 of the valve body 36 abuts. 40EP is formed on the circumference around the central axis of the flow path 44P.

  A concave portion 40R2 having an arc-shaped cross section is formed in an annular shape around the central axis of the flow path 44P at a portion where the lower end of the minimum diameter reducing surface portion 40E4 and one end of the enlarged surface 40E5 intersect. The curvature radius of the cross section of the recess 40R2 is set larger than the curvature radius of the cross section of the recess 40R1. Furthermore, a concave portion 40R3 having an arc-shaped cross section is formed in an annular shape around the central axis of the flow path 44P at a portion where the other end of the enlarged surface 40E5 and one end of the enlarged surface 40E6 intersect. The curvature radius of the cross section of the recess 40R3 is preferably set to be substantially the same as the curvature radius of the cross section of the recess 40R2. The radius of curvature of the cross section of the recess 40R3 may be a value different from the radius of curvature of the cross section of the recess 40R2.

  In such a configuration, when the stator coil of the valve drive unit is controlled by the drive pulse signal from the drive control unit and the valve body 36 is moved up and down, the fluid supplied through the connection pipes 32 and 34 is changed to the arrow F. Or, along the direction indicated by the arrow R, the valve body 36 passes through the gap flow path formed between the tapered portion of the other end 36EB of the valve body 36 and the minimum diameter-reduced surface portion 40E4 of the valve seat 40V at a predetermined flow rate. .

  At that time, for example, in FIG. 4, when the fluid flows in the direction indicated by the arrow F, a vortex rotating in a predetermined direction is formed in the recesses 40E1, 40R1, 40R2, and 40R3, and a part of the fluid The flow becomes a turbulent flow with a high apparent viscosity due to this vortex. Thereby, the fluid in the vicinity of the curved surfaces 40E2 and 40E3 flows along the turbulent boundary layer of the vortex surface in the vicinity of the concave portions 40E1 and 40R1, and flows along the minimum diameter reducing surface portion 40E4 without being separated from the curved surfaces 40E2 and 40E3. . In the vicinity of the recesses 40R2, 40R3, and the other end 36EB of the valve body 36, the fluid behaves in the same manner in the vicinity of the recesses 36R1, 36R2, and 36R3, so that the fluid flows without peeling from the wall surface. Therefore, noise is reduced by suppressing reattachment due to separation of the fluid from the wall surface.

  On the other hand, for example, when the fluid flows in the direction indicated by the arrow R, in the recesses 40R3, 40R2, 40R1, and 40E1, a vortex that rotates in the direction opposite to the above-described direction is formed, and a part of the fluid flows This vortex creates a turbulent flow with a high apparent viscosity. As a result, the fluid along the curved surfaces 40E3 and 40E2 flows along the turbulent boundary layer of the vortex surface in the vicinity of the recesses 40R1 and 40E1, and does not peel off the curved surfaces 40E3 and 40E2 but on the flat surface of the upper surface of the valve seat. Flowing along. The fluid behaves similarly in the vicinity of the recesses 40R3 and 40R2 and the recess 36R3, the recess 36R2, and the recess 36R1 in the other end 36EB of the valve body 36. Therefore, even when the fluid flows in the direction indicated by the arrow R, the fluid flows without peeling from the wall surface. Therefore, noise is reduced by suppressing reattachment due to separation of the fluid from the wall surface.

  In the first and second embodiments of the control valve according to the present invention described above, the concave portion having a substantially V-shaped and arc-shaped cross section is formed on the entire circumference. However, the present invention is limited to this example. Instead, the recesses may be formed in a dimple shape so as to be dispersed and separated from each other at a portion where adjacent wall surfaces forming the above-described gap flow path intersect.

  Further, in the first embodiment and the second embodiment of the control valve according to the present invention described above, the control valve is applied to a control valve provided with an electric valve drive unit, but is not limited to such an example. For example, the present invention may be applied to a manual control valve that manually operates a screw feed mechanism or an electromagnetic control valve that drives a valve body by a solenoid. Furthermore, in the above-described first and second embodiments of the control valve according to the present invention, the valve seat 30V having the flow path 30Va inside is separately provided at a position inside the valve main body 30 adjacent to the port 34P. However, the present invention is not limited to such an example, and the valve seat including the flow path in which the above-described recess and enlarged surface are formed may be formed integrally with the valve main body 30. .

26, 36 Valve body 30, 40 Valve body 30V, 40V Valve seat 34P, 44P Flow path 26E1, 26R1, 36R1, 36R2, 36R3 Recess 30E1, 30R1, 40E1, 40R1, 40R2, 40R3 Recess

Claims (6)

A first port connected to the first passage and a second port connected to the second passage, and communicates with the first port and the second port; A valve main body including a housing portion that movably houses a valve body unit including a valve body that controls opening and closing of the port; and
A valve body that causes the valve body unit to perform an operation of controlling the opening and closing of the second port so as to adjust the flow rate of the fluid that passes between the tip of the valve body and the peripheral edge of the second port. A unit drive mechanism,
A wall surface forming the second port facing the tip of the valve body, or at least two curved surfaces of a plurality of curved surfaces in a cross section of a flow path of a valve seat forming a peripheral edge of the second port The control valve is characterized in that a concave portion in which the vortex of the fluid is generated is formed at a portion where the two intersect each other.   2. The control according to claim 1, wherein a concave portion in which the vortex of the fluid is generated is formed in a portion where at least two conical surfaces of the plurality of conical surfaces forming the tip of the valve body intersect with each other. valve.   The control valve according to claim 1, wherein the recess has an arc-shaped cross section.   The control valve according to claim 1, wherein the recess has a substantially V-shaped cross section.   The said recessed part is each formed in the both ends of the at least 1 enlarged surface in the cross section of the flow path of the valve seat which forms the periphery of the said 2nd port, The Claim 1 or Claim 2 characterized by the above-mentioned. Control valve.   3. The control valve according to claim 2, wherein the recess is formed at a portion where a plurality of enlarged surfaces intersect in a cross section of a flow path of the valve seat that forms a peripheral edge of the second port.

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