Electric valve and refrigeration cycle system equipped therewith

Abstract

To suppress sound pressure level of fluid passing sound generated in an electric valve, in the electric valve.SOLUTION: A cylindrical rectification member 36 provided separately from a valve seat 31V, has a rectification stepped hole 36H on a common axis with a center axis of a valve body 23. The rectification stepped hole 36H is composed of an enlarging portion 36A formed concentrically with the center axis of the rectification member 36, and a contacting portion 36B communicated with the enlarging portion 36A. An inner diameter D3 of the enlarging portion 36A is set to a value that is larger than an inner diameter D1 of a valve port 31Va and an inner diameter D4 of the contracting portion 36B and is an inner diameter D2 of an enlarging portion 31Vb or more.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an electric valve and a refrigeration cycle system including the same.

Background Art

[0002] In a refrigeration cycle system, an electric valve is arranged between a condenser and an evaporator as an expansion valve. In recent years, as the noise of the compressor and the fan is reduced in the refrigeration cycle system, the fluid passing sound of the refrigerant passing through the pipe and the electric valve becomes prominent, and the quietness of the electric valve with a relatively high refrigerant passing speed is desired. Such an electric valve is proposed, for example, as shown in FIG. 11 in Patent Document 1, in which a rectifying portion is provided in a second pipe joint adjacent to a valve port of a valve body in order to reduce the sound pressure level of the passing sound of the refrigerant. The valve port of such a valve body is formed by a first port, a first tapered portion, and a second port. At that time, the inner diameter of the second port is set larger than the inner diameter of the first port. Further, the inner diameter of the second port is set larger than the inner diameter of the cylindrical rectifying portion.

[0003] In such a configuration, the flow velocity of the refrigerant flowing into the first port from the first pipe joint connected to the valve body of the electric valve is decelerated because the inner diameter of the second port is set larger than the inner diameter of the first port, and the refrigerant is discharged into the second pipe joint through the rectifying portion. At that time, the sound pressure level of the passing sound of the refrigerant is reduced.

[0004] On the other hand, the refrigerant passing through the rectifying portion in the second pipe joint and flowing toward the valve port of the valve body is first rectified by the rectifying portion because the inner diameter of the rectifying portion is smaller than the inner diameter of the second pipe joint, and then the flow velocity of the refrigerant flowing into the second port of the valve body is decelerated because the inner diameter of the second port is set larger than the inner diameter of the cylindrical rectifying portion. At that time, the sound pressure level of the passing sound of the refrigerant passing through the second port is further reduced.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] International Publication No. 2018 / 230159 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, when refrigerant flows from the first pipe fitting through the first port of the valve body to the second port, the flow velocity of the refrigerant may not be sufficiently reduced between the second port and the flow straightening section. In such cases, it might be considered to set a relatively large length in the second port of the valve body along the direction of refrigerant flow. However, such a measure is not advisable because it increases the difficulty of manufacturing the second port of the valve body.

[0007] In consideration of the above problems, the present invention aims to provide an electric valve and a refrigeration cycle system equipped therewith, the electric valve capable of suppressing the sound pressure level of fluid passage noise generated within the electric valve, and the refrigeration cycle system equipped therewith. [Means for solving the problem]

[0008] To achieve the above objective, the electric valve according to the present invention comprises a valve body portion having a valve port having a first port connected to a first passage and a second port connected to a second passage, and a valve port communicating with the first and second ports, and a housing portion that movably houses a valve body unit which includes a valve body that is positioned close to or away from the valve port and controls the opening area, and a valve body unit drive mechanism that causes the valve body unit to perform an operation to control the opening area of ​​the valve port so as to adjust the flow rate of fluid passing between the tip of the valve body and the periphery of the valve port, wherein the valve seat adjacent to the second port facing the tip of the valve body has an enlarged portion that communicates with the valve port and the second port side of the valve port, and further comprises a flow straightening member separately from the valve seat, which has a stepped hole for straightening that faces the enlarged portion of the valve seat and whose inner diameter decreases as it approaches the second port.

[0009] The stepped hole for rectification of the rectifier member may have an enlarged portion with a larger inner diameter facing the enlarged portion of the valve seat, and a reduced portion with a smaller inner diameter than the enlarged portion of the stepped hole for rectification facing the second port, and the inner diameter of the enlarged portion of the stepped hole for rectification of the rectifier member may be set to a value greater than or equal to the inner diameter of the enlarged portion of the valve seat.

[0010] The stepped holes for rectification of the rectifier member may consist of two or more holes with different inner diameters, where the inner diameter decreases from the valve seat side towards the second port side, and these holes are formed on a common central axis.

[0011] When the valve body is at its lowest position, the insertion length into the valve seat from the upper surface of the valve port of the valve seat to the tip of the valve body toward the second port may be set to be less than or equal to the sum of the length along the central axis of the second port in the enlarged portion of the flow-rectifying stepped hole of the flow-rectifying member and the length from the upper surface of the valve port of the valve seat to the opening end face on the second port side of the enlarged portion of the valve seat.

[0012] The minimum inner diameter of the reduced portion of the stepped hole for rectification in the rectifying member may be set to a value greater than or equal to the inner diameter of the valve port.

[0013] Furthermore, a tapered surface may be formed at the boundary between the enlarged and reduced portions of the stepped hole for rectification in the rectifying member.

[0014] The rectifying member has a flange portion that abuts against the end face where the enlarged portion of the valve seat opens, and a cylindrical portion connected to the flange portion, and a gap may be formed between the inner circumferential surface of the conduit forming the second port and the outer circumferential surface of the cylindrical portion.

[0015] Furthermore, the refrigeration cycle system according to the present invention comprises an evaporator, a compressor, and a condenser, and the above-mentioned electric valve is provided in piping arranged between the outlet of the condenser and the inlet of the evaporator. [Effects of the Invention]

[0016] According to the electric valve and refrigeration cycle system equipped therewith, the valve seat adjacent to the second port facing the tip of the valve body has a valve port and an enlarged portion communicating with the valve port on the second port side of the valve port. Furthermore, a flow straightening member is provided separately from the valve seat on the second port side of the valve seat. This flow straightening member has an enlarged portion with a large inner diameter facing the enlarged portion of the valve seat, and a stepped hole for flow straightening in which the inner diameter decreases as it approaches the second port. By providing the enlarged portion of the flow straightening member separately from the valve seat so as to face the enlarged portion of the valve seat, the length of the enlarged portion can be increased without increasing the difficulty of processing, and this extended enlarged portion makes it possible to sufficiently reduce the fluid flow velocity. Furthermore, by having a stepped hole for flow straightening in which the inner diameter decreases as it approaches the second port, the sound pressure level of fluid passage noise generated inside the electric valve can be suppressed. [Brief explanation of the drawing]

[0017] [Figure 1] This is a partially enlarged cross-sectional view of section A in Figure 2. [Figure 2] This is a cross-sectional view showing the configuration of an example of an electric valve according to the present invention. [Figure 3] This figure schematically shows the configuration of an example of a refrigeration cycle system to which an example of an electric valve according to the present invention is applied. [Figure 4] This is a partial cross-sectional view used to explain the operation of the rectifier member shown in Figure 1. [Figure 5] (A), (B), and (C) are partial cross-sectional views showing other examples of flow rectifiers used in an example of an electric valve according to the present invention. [Figure 6] (A), (B), and (C) are partial cross-sectional views showing yet another example of a flow rectifier used in an example of an electric valve according to the present invention. [Figure 7] (A) and (B) are partial cross-sectional views showing yet another example of a flow rectifier used in an example of an electric valve according to the present invention. [Modes for carrying out the invention]

[0018] FIG. 2 shows the configuration of an example of the electric valve according to the present invention together with the piping for the pipe.

[0019] As an example of the electric valve according to the present invention, an electric valve 3 is disposed, for example, as shown in FIG. 3, between the outlet of an outdoor heat exchanger 6 and the inlet of an indoor heat exchanger 2 during a cooling operation described later in the piping of a refrigeration cycle system. During the cooling operation, the electric valve 3 is joined to a primary side pipe Du1 by a connecting pipe 32 described later, and is joined to a secondary side pipe Du2 by a connecting pipe 34. The primary side pipe Du1 connects the outlet of the outdoor heat exchanger 6 and the electric valve 3, and the secondary side pipe Du2 is supposed to connect the inlet of the indoor heat exchanger 2 and the electric valve 3. Between the outlet of the indoor heat exchanger 2 and the inlet of the outdoor heat exchanger 6, a pipe Du3 joined to the outlet of the indoor heat exchanger 2, a flow path switching valve 8, and a pipe Du6 joined to the inlet of the outdoor heat exchanger 6 are arranged. Further, a compressor 4 is joined to the flow path switching valve 8 by pipes Du4 and Du5. The other end of the pipe Du3 is joined to a port 8b of the flow path switching valve 8. The other end of the pipe Du6 is joined to a port 8d of the flow path switching valve 8. One end of the pipe Du4 is joined to a port 8c of the flow path switching valve 8, and the other end of the pipe Du4 is joined to the suction port of the compressor 4. One end of the pipe Du5 is joined to a port 8a of the flow path switching valve 8, and the other end of the pipe Du5 is joined to the discharge port of the compressor 4. During the cooling operation, the port 8a and the port 8d communicate with each other, and the port 8b and the port 8c communicate with each other. Thereby, during the cooling operation, the refrigerant in the refrigeration cycle system is circulated along the direction indicated by an arrow R shown in FIG. 3, for example, and the outdoor heat exchanger 6 functions as a condenser and the indoor heat exchanger 2 functions as an evaporator. Incidentally, during the cooling operation, the form in which the electric valve 3 is joined to the primary side pipe Du1 by the connecting pipe 32 and is joined to the secondary side pipe Du2 by the connecting pipe 34 has been described, but it is not limited to such an example. For example, during the cooling operation, the electric valve 3 may be joined to the primary side pipe Du1 by the connecting pipe 34 and may be joined to the secondary side pipe Du2 by the connecting pipe 32.

[0020] On one hand, during the heating operation, the flow path switching valve 8 is switched so that the port 8a and the port 8b communicate with each other, and the port 8c and the port 8d communicate with each other. Thereby, during the heating operation, the refrigerant in the refrigeration cycle system is circulated along the direction indicated by the arrow F shown in FIG. 3, for example, and the indoor heat exchanger 2 functions as a condenser, and the outdoor heat exchanger 6 functions as an evaporator. The compressor 4 and the electric valve 3 are driven and controlled by a control unit (not shown), and the flow path switching valve 8 is switched and controlled.

[0021] As shown in FIG. 2, the electric valve includes a valve drive unit that is arranged in a cylindrical rotor case 20 and drives a valve body unit described later, and a valve body portion 31 having a valve seat 31V that is connected to an end portion of the rotor case 20 and has a valve port where the tip of the valve body 23 approaches or separates from it, and a valve body unit including a valve body 23 that is arranged in the valve body portion 31 and approaches or separates from the valve port of the valve seat 31V.

[0022] The valve drive unit mainly includes a male screw shaft 14 that moves the valve body unit described later up and down, a female screw portion 12B formed with a female screw 12FMS that is fitted with the male screw shaft 14, a guide support portion 12 that is fixed to the valve body portion 31 and guides the valve body unit so that it can move up and down, a rotor 10 that is fixed to the guide shaft portion 14A of the male screw shaft 14, rotatably supported, and magnetized, and a stator coil 40 that is arranged on the outer peripheral portion of the rotor case 20 and rotates the rotor 10.

[0023] The guide support portion 12 has a guide surface on its inner peripheral portion that guides the cylindrical valve body case 19 that forms a part of the valve body unit so that it can move up and down.

[0024] The male threaded shaft 14 consists of a male threaded portion 14B that fits into the female thread 12FMS of the female threaded portion 12B, a connecting portion 14C formed at the lower end of the male threaded portion 14B and engaged with the periphery of the through hole 19a of the valve body case 19 via a washer (not shown), and a guide shaft portion 14A formed at the upper end of the male threaded portion 14B. The guide shaft portion 14A is rotatably supported within a cylindrical portion 20C that protrudes from the top of the rotor case 20 along the central axis toward the guide support portion 12.

[0025] A spiral guide portion 11 is formed on the outer circumference of the cylindrical portion 20C to guide the movable stopper piece 11B to move in the direction of the central axis of the cylindrical portion 20C while rotating it. One end of the movable stopper piece 11B is locked to a projection on the rotor 10. Furthermore, rotation stoppers 20US and 20LS for the movable stopper piece 11B are provided at the uppermost and lowermost ends of the cylindrical portion 20C, respectively. As a result, when the movable stopper piece 11B comes into contact with the rotation stoppers 20US and 20LS, the movable stopper piece 11B is stopped at a predetermined rotation angle corresponding to a predetermined valve closed position and a predetermined valve open (fully open) position of the valve body 23, which will be described later.

[0026] The valve drive unit described above is controlled by a drive control unit (not shown in the figure) based on a drive pulse signal supplied to the stator coil 40.

[0027] The valve body unit mainly consists of a needle-shaped valve body 23 that is positioned close to or away from the valve port 31V of the valve seat 31V (described later), a cylindrical resin spring receiving member 24 that engages the protruding portion 14F of the connecting portion 14C of the male screw shaft 14 with the inner circumference of the open end 19T of the valve body case 19 in cooperation with a washer (not shown), a coil spring 22 that is positioned between the protruding portion 24T of the spring receiving member 24 and the spring receiving flat portion at one end of the valve body 23 and biases them in a direction that separates them from each other, and a cylindrical valve body case 19 that houses the spring receiving member 24, the coil spring 22, and one end of the valve body 23.

[0028] One end of the cylindrical valve body case 19, closest to the valve seat 31V, is closed by fixing it to the outer circumference of one end of the valve body 23. The other end of the cylindrical valve body case 19 is an open end 19T having a hole 19a through which a reduced-diameter portion that positions a washer at the connecting portion 14C of the male screw shaft 14 passes. Therefore, the washer is positioned between the inner circumference of the open end 19T of the valve body case 19 and one end face of the protruding portion 14F.

[0029] The outer circumference of the cylindrical valve body case 19 is supported so as to be able to move up and down by sliding against the guide surface of the guide support portion 12 described above. As a result, when the leading edge (needle portion) of the other end of the valve body 23 is inserted into the valve port 31Va of the valve seat 31V, and the outer circumference of the needle portion of the valve body 23 comes into contact with the periphery of the opening of the valve port 31Va, the male screw shaft 14 is then lowered, and the coil spring 22 is compressed by a predetermined amount. As a result, the spring force of the coil spring 22 presses the outer circumference of the needle portion 23E of the valve body 23 against the periphery of the opening of the valve port 31Va. This closes the valve port 31Va of the valve seat 31V. Alternatively, the valve body may be prevented from coming into contact with the periphery of the opening of the valve port when the valve body is in its lowest position, thereby allowing for a small flow rate even when the valve body is in its lowest position.

[0030] The valve body 31 is made of a metal material, such as brass, stainless steel, aluminum alloy, or resin material, and has an inner valve body housing 31A that houses the lower end below the female thread portion 12B of the guide support portion 12, the other end of the valve body 23, and the cylindrical valve body case 19. The other end of the valve body 23 protrudes from the valve body housing 31A toward the valve port 31Va. The valve body housing 31A also has a first port 32P to which one end of a connecting pipe 32 serving as a first passage is connected on an axis substantially perpendicular to the central axis of the valve body 23, and a valve seat 31V adjacent to the second port 34P to which one end of a connecting pipe 34 serving as a second passage is connected on an axis common with the central axis of the valve body 23.

[0031] As partially enlarged in Figure 1, the valve seat 31V has a valve port 31Va on an axis common with the central axis of the valve body 23, and an enlarged portion 31Vb communicating with the valve port 31Va on the second port 34P side of the valve port 31Va. The inner periphery of the valve port 31Va and the inner periphery of the adjacent enlarged portion 31Vb are connected by an annular tapered surface 31Vt.

[0032] The upper end surface of a metal flow straightening member 36, which is inserted into the second port 34P of the connecting pipe 34, is in contact with the end face where the enlarged portion 31Vb of the valve seat 31V opens. The outer circumferential surface of the flow straightening member 36 is fixed to the inner circumferential surface of the connecting pipe 34.

[0033] The cylindrical flow straightening member 36 has a stepped flow straightening hole 36H on an axis common to the central axis of the valve body 23, as shown in an enlarged view in Figure 1. The stepped flow straightening hole 36H is composed of an enlarged portion 36A facing the aforementioned enlarged portion 31Vb, which is formed concentrically with the central axis of the flow straightening member 36, and a reduced portion 36B communicating with the enlarged portion 36A on the second port 34P side of the enlarged portion 36A. The inner diameter D3 of the enlarged portion 36A is set to be larger than, for example, the inner diameter D1 of the valve port 31Va and the inner diameter D4 of the reduced portion 36B, and to be greater than or equal to the inner diameter D2 of the enlarged portion 31Vb. Also, the inner diameter D4 of the reduced portion 36B is set to be greater than or equal to the inner diameter D1 of the valve port 31Va. The length L3 along the central axis of the enlarged portion 36A is set to a value greater than the length L2 from the tapered surface 31Vt along the central axis to the end face of the enlarged portion 31Vb. The length L6 along the central axis of the reduced portion 36B is set to a value greater than the orifice length L1 of the valve port 31Va. As shown in Figure 1, the distance La from the upper surface of the valve port of the valve seat 31V to the boundary between the enlarged portion 36A and the reduced portion 36B of the rectifier member 36 is set to be approximately 91% or less of the distance Lb from the upper surface of the valve port of the valve seat 31V to the end face of the rectifier member 36. This ratio is set, for example, by actually flowing refrigerant through the valve port 31Va, the enlarged portion 31Vb, and the stepped hole 36H for rectification, and detecting the sound of the refrigerant passing through, so that the sound pressure level of the sound of the refrigerant passing through is minimized.

[0034] In this configuration, the stator coil 40 of the valve drive unit is controlled by a drive pulse signal from the drive control unit, causing the valve body 23 to move up and down. As a result, the refrigerant, which is supplied as a fluid through the connecting pipe 32 or connecting pipe 34, passes through a gap passage formed between the inner circumferential surface forming the valve port 31Va of the valve seat 31V and the needle portion 23E of the valve body 23 at a predetermined flow rate, in the direction indicated by arrow F or arrow R.

[0035] In this way, the inner diameter D3 of the enlarged portion 36A in the rectifier member 36 is set to a value greater than or equal to the inner diameter D2 of the enlarged portion 31Vb, and the length L3 along the central axis of the enlarged portion 36A is set to a value greater than the length L2 from the tapered surface 31Vt along the central axis to the end face of the enlarged portion 31Vb. As a result, the deceleration region in the enlarged portion 31Vb is expanded, suppressing cavitation rupture and reducing the sound pressure level of the refrigerant passage noise. As a result, as shown in Figure 4, for example, the flow ST1 flowing in through the valve port 31Va becomes a decelerated flow ST2 due to the enlarged portion 31Vb, and furthermore, the flow ST3 that cannot be decelerated on the valve seat 31V side is decelerated by the flow path on the rectifier member 36 side (enlarged portion 36A). Although cavitation rupture occurs, the distance over which the flow velocity is reduced is long, making it difficult for its effect to reach the narrowed portion 36B of the rectifier member 36. Then, after the flow ST4 is rectified, the discharged flow ST5 is discharged into the second port 34P.

[0036] By setting the inner diameter D4 of the narrowing section 36B to be greater than or equal to the inner diameter D1 of the valve port 31Va and smaller than the inner diameter D3 of the expanding section 36A, the turbulent flow of refrigerant in the narrowing section 36B is rectified, thereby suppressing the sound pressure level of the refrigerant passage noise. Furthermore, by setting the length L6 along the central axis of the narrowing section 36B to be greater than the orifice length L1 of the valve port 31Va, the flow of refrigerant is stably rectified.

[0037] Furthermore, the sum of the length L4 from the upper surface of the valve port of the valve seat 31V to the opening end surface of the enlarged portion 31Vb and the length L3 in the enlarged portion 36A is set to be greater than or equal to the length L5 of the insertion length of the needle portion 23E into the valve seat 31A, i.e., even when controlling minute flow rates, the enlarged portion 36A of the (lower) rectifier member 36 is formed before the tip of the needle portion 23E, so the sound pressure level of the refrigerant passage noise is suppressed regardless of the position of the needle portion 23E.

[0038] Figures 5(A), (B), and (C) show other examples of rectifier members used in an example of an electric valve according to the present invention. In Figures 5(A), (B), and (C), as well as in Figures 6(A), (B), and (C), and Figures 7(A) and (B) described later, the same reference numerals are used to indicate the same components as those in the example shown in Figure 1, and their redundant explanations are omitted.

[0039] In Figure 5(A), the cylindrical metal flow straightening member 46 has a stepped hole 46H for flow straightening on an axis common to the central axis of the valve body 23. The stepped hole 46H for flow straightening consists of an enlarged portion 46A facing an enlarged portion 31Vb formed concentrically with the central axis of the flow straightening member 46, and a reduced portion 46B communicating with the enlarged portion 46A. A tapered surface 46t is formed at the boundary between the enlarged portion 46A and the reduced portion 46B. The inner diameter of the enlarged portion 46A and the inner diameter of the enlarged portion 31Vb are set to the same value. The inner diameter of the enlarged portion 46A is set to be larger than the inner diameter of the reduced portion 46B. The lengths of the enlarged portion 46A and the reduced portion 46B along the central axis are set in the same way as in the example shown in Figure 1.

[0040] In Figure 5(B), the cylindrical metal flow straightening member 48 has a stepped hole 48H for flow straightening on an axis common to the central axis of the valve body 23. The stepped hole 48H for flow straightening consists of an enlarged portion 48A facing an enlarged portion 31Vb formed concentrically with the central axis of the flow straightening member 48, and a reduced portion 48B communicating with the enlarged portion 48A. A tapered surface, as shown in Figure 5(A), is not formed at the boundary between the enlarged portion 46A and the reduced portion 46B. The inner diameter of the enlarged portion 48A and the inner diameter of the enlarged portion 31Vb are set to the same value. The inner diameter of the enlarged portion 48A is set to be larger than the inner diameter of the reduced portion 48B. The lengths of the enlarged portion 48A and the reduced portion 48B along the central axis are set in the same way as in the example shown in Figure 1.

[0041] In Figure 5(C), the cylindrical metal flow straightening member 50 has a stepped flow straightening hole 50H on an axis common to the central axis of the valve body 23. The stepped flow straightening hole 50H consists of an enlarged portion 50A1 facing the enlarged portion 31Vb formed concentrically with the central axis of the flow straightening member 50, a reduced portion 50B having an open end that opens into the second port 34P, and a tapered portion 50A2 connecting the enlarged portion 50A and the reduced portion 50B. The inner diameter of the enlarged portion 50A1 and the inner diameter of the enlarged portion 31Vb are set to the same value. The inner diameter of the enlarged portion 50A1 is set to be larger than the inner diameter of the reduced portion 50B. The lengths of the enlarged portion 50A1 and the reduced portion 50B along the central axis are set in the same way as in the example shown in Figure 1.

[0042] Figures 6(A), (B), and (C) show yet another example of a flow straightening member used in an example of an electric valve according to the present invention. The flow straightening members 52, 54, and 56 shown in Figures 6(A), (B), and (C) each have multiple stages of stepped holes for flow straightening. This is intended to increase the number of refrigerant flow separation points within the flow straightening member, thereby generating vortices and reducing the sound pressure level of the refrigerant passing through the flow straightening member.

[0043] In Figure 6(A), the cylindrical metal flow straightening member 52 has two stepped flow straightening holes 52H on an axis common to the central axis of the valve body 23. The stepped flow straightening holes 52H consist of a first enlarged portion 52A1 facing the enlarged portion 31Vb formed concentrically with the central axis of the flow straightening member 52, a second enlarged portion 52A2 communicating with the first enlarged portion 52A1, and a reduced portion 52B communicating with the enlarged portion 52A2. The inner diameter of the first enlarged portion 52A1 is set to be larger than the inner diameters of the enlarged portion 31Vb, the second enlarged portion 52A2, and the reduced portion 52B. The inner diameter of the second enlarged portion 52A2 is set to be larger than the inner diameter of the reduced portion 52B.

[0044] In Figure 6(B), the cylindrical metal flow straightening member 54 has three stepped flow straightening holes 54H on an axis common to the central axis of the valve body 23. The stepped flow straightening holes 54H consist of a first enlarged portion 54A1 facing the enlarged portion 31Vb formed concentrically with the central axis of the flow straightening member 54, a second enlarged portion 54A2 communicating with the first enlarged portion 54A1, a third enlarged portion 54A3 communicating with the enlarged portion 52A2, and a reduced portion 54B communicating with the third enlarged portion 54A3. The inner diameter of the first enlarged portion 54A1 is set to be larger than the inner diameters of the enlarged portion 31Vb, the second enlarged portion 54A2, the third enlarged portion 54A3, and the reduced portion 54B. The inner diameters of the second enlarged portion 54A2 and the third enlarged portion 54A3 are set to be larger than the inner diameter of the reduced portion 54B.

[0045] In Figure 6(C), the cylindrical metal flow straightening member 56 has a stepped hole 56H for straightening on an axis common to the central axis of the valve body 23. The stepped hole 56H for straightening consists of a first enlarged portion 56A1 facing the enlarged portion 31'Vb formed concentrically with the central axis of the flow straightening member 56, a second enlarged portion 56A2 communicating with the first enlarged portion 56A1, and a reduced portion 56B communicating with the second enlarged portion 56A2. The inner diameter of the first enlarged portion 56A1 is set to be the same as the inner diameter of the enlarged portion 31'Vb. In this case, the periphery of the opening end of the enlarged portion 31'Vb of the valve seat 31' that communicates with the valve port 31'Va is chamfered. The inner diameter of the first enlarged portion 56A1 is set to be larger than the inner diameters of the second enlarged portion 56A2 and the reduced portion 56B. The inner diameter of the second enlarged portion 52A2 is set to be larger than the inner diameter of the reduced portion 56B. An annular tapered surface is formed at the boundary between the first enlarged portion 56A1 and the second enlarged portion 56A2, and at the boundary between the second enlarged portion 56A2 and the reduced portion 56B.

[0046] Figures 7(A) and 7(B) show yet another example of a flow straightening member used in an example of an electric valve according to the present invention. The flow straightening members 58 and 60 shown in Figures 7(A) and 7(B) are to be fixed to the open end of the connecting pipe 34 by furnace brazing, respectively.

[0047] In Figure 7(A), the cylindrical metal flow straightening member 58 has a flange portion 58F that is sandwiched between the end face where the enlarged portion 31Vb of the valve seat 31V opens and the open end face of the connecting pipe 34, and a cylindrical portion 58C that is connected to the flange portion 58F. The flow straightening member 58 has a stepped hole 58H for flow straightening on its inner side, on an axis common with the central axis of the valve body 23. A predetermined gap CL is formed between the outer circumferential surface of the cylindrical portion 58C and the inner circumferential surface of the connecting pipe 34. As a result, when the flow straightening member 58 is fixed to the open end of the connecting pipe 34 by furnace brazing, there is no risk of the brazing material entering the valve port 31Va and the stepped hole 58H for flow straightening of the flow straightening member 58.

[0048] The rectifying stepped hole 58H consists of an enlarged portion 58A facing the enlarged portion 31Vb formed concentrically with the central axis of the rectifying member 58, and a reduced portion 58B communicating with the enlarged portion 58A. A tapered surface 58t is formed at the boundary between the enlarged portion 58A and the reduced portion 58B. The inner diameter of the enlarged portion 58A and the inner diameter of the enlarged portion 31Vb are set to the same value. The inner diameter of the enlarged portion 58A is set to be larger than the inner diameter of the reduced portion 58B. The lengths of the enlarged portion 58A and the reduced portion 58B along the central axis are set in the same way as in the example shown in Figure 1.

[0049] In Figure 7(B), the cylindrical metal flow straightening member 60 has a flange portion 60F that is sandwiched between the end face where the enlarged portion 31Vb of the valve seat 31V opens and the open end face of the connecting pipe 34, and a cylindrical portion 60C that is connected to the flange portion 60F. The flow straightening member 60 has a stepped hole 60H for flow straightening on its inner side, on an axis common with the central axis of the valve body 23. A predetermined gap CL is formed between the outer circumferential surface of the cylindrical portion 60C and the inner circumferential surface of the connecting pipe 34. As a result, when the flow straightening member 60 is fixed to the open end of the connecting pipe 34 by furnace brazing, there is no risk of the brazing material entering the valve port 31Va and the stepped hole 60H for flow straightening of the flow straightening member 60.

[0050] The three-stage rectifying stepped hole 60H consists of a first enlarged portion 60A1 facing the enlarged portion 31Vb formed concentrically with the central axis of the rectifying member 60, a second enlarged portion 60A2 communicating with the first enlarged portion 60A1, a third enlarged portion 60A3 communicating with the enlarged portion 60A2, and a reduced portion 60B communicating with the third enlarged portion 60A3. The inner diameter of the first enlarged portion 60A1 is set to be larger than the inner diameters of the enlarged portion 31Vb, the second enlarged portion 60A2, the third enlarged portion 60A3, and the reduced portion 60B. The inner diameters of the second enlarged portion 60A2 and the third enlarged portion 60A3 are set to be larger than the inner diameter of the reduced portion 60B. [Explanation of Symbols]

[0051] 23 Valve body 23E Needle section 31 Valve body 31A Valve body housing 31V, 31´V valve seat 31Vb Enlarged section 32 connecting pipes 32P First Port 34 connecting pipes 34P Second Port 36, 46, 48, 50, 52, 54, 56, 58, 60 Rectifying members 36A Enlarged section 36B Reduced section 36H, 46H, 48H, 50H, 52H, 54H, 56H, 58H, 60H Stepped hole for rectification

Claims

1. A valve body portion comprising a valve body unit having a first port connected to a first passage and a second port connected to a second passage, a valve port communicating with the first port and the second port, and a housing portion for movably housing a valve body unit that includes a valve body that is positioned close to or away from the valve port and controls the opening area, The valve body unit includes a valve drive unit that controls the opening area of ​​the valve port in order to adjust the flow rate of fluid passing between the tip of the valve body and the periphery of the valve port. The valve seat has an enlarged portion that communicates with the valve port, on the side of the valve port opposite to the valve drive portion in the direction of the central axis of the valve body. Furthermore, separate from the valve seat, on the side of the valve seat opposite to the valve drive portion in the direction of the central axis of the valve body, there is a flow straightening member having one or more stepped holes for straightening that face the enlarged portion of the valve seat and whose flow area decreases as it moves away from the valve seat. The stepped hole for rectification of the rectifying member comprises an enlarged portion and a reduced portion having an inner diameter smaller than the inner diameter of the enlarged portion. The inner diameter of the reduced portion is set to a value greater than or equal to the inner diameter of the valve port. The enlarged portion of the rectifier member faces the enlarged portion of the valve seat, An electric valve that includes an enlarged portion of the rectifying member, and in a cross-section perpendicular to the central axis direction of the valve body, the fluid flow path is formed only in the enlarged portion that includes the central axis of the valve body.

2. The boundary portion between the enlarged portion and the reduced portion of the rectifying member faces the enlarged portion of the valve seat. The enlarged portion of the rectifier member is formed concentrically with the central axis of the valve body, The electric valve according to claim 1, characterized in that one end of the rectifying member is located inside the valve body and the other end of the rectifying member is located outside the valve body.

Images