Electric valve and refrigeration cycle system

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 disposed 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 rate 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 that has passed through the rectifying portion in the second pipe joint and flows 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 rate 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 Summary of the Invention Problems to be Solved by the Invention

[0006] However, when the refrigerant flows from the first pipe joint through the first port of the valve body to the second port, the flow velocity of the refrigerant may not be sufficiently decelerated between the second port and the rectifying portion. In such a case, it may be considered to set the length along the flow direction of the refrigerant at the second port of the valve body to be relatively large. However, such a measure is not a good solution because the processing difficulty of the second port of the valve body becomes high.

[0007] In view of the above problems, the present invention provides an electric valve and a refrigeration cycle system including the same, which can suppress the sound pressure level of the fluid passing sound generated in the electric valve. Means for Solving the Problems

[0008] In order to achieve the above object, the electric valve according to the present invention has a first port connected to a first passage and a second port connected to a second passage, has a valve port communicating with the first port and the second port, and includes a valve body unit that movably accommodates a valve body that is close to or separated from the valve port and controls the opening area, and a valve body unit driving mechanism that causes the valve body unit to perform an operation of controlling the opening area of the valve port so as to adjust the flow rate of the fluid passing between the tip of the valve body and the periphery of the valve port. An enlarged portion communicating with the valve port is formed in the valve seat adjacent to the second port facing the tip of the valve body on the second port side of the valve port and the valve port, and further, separately from the valve seat, on the second port side of the valve seat, there is provided a rectifying member having a stepped hole for rectification that faces the enlarged portion of the valve seat and has an inner diameter that becomes smaller toward the second port.

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

[0010] The stepped hole for flow rectification of the flow rectifying member may have two or more holes with different inner diameters whose inner diameters decrease from the valve seat side toward the second port side 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 side may be set to a value equal to or less than the sum of the length along the central axis of the second port in the enlarged portion of the stepped hole for flow rectification of the flow rectifying member and the length from the upper surface of the valve port of the valve seat to the opening end surface 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 flow rectification of the flow rectifying member may be set to a value equal to or greater than the inner diameter of the valve port.

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

[0014] The flow rectifying member has a flange portion that abuts against the end surface 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 peripheral surface of the pipe forming the second port and the outer peripheral surface of the cylindrical portion.

[0015] And the refrigeration cycle system according to the present invention includes an evaporator, a compressor, and a condenser, and is characterized in that the above-described electric valve is provided in a pipe arranged between the outlet of the condenser and the inlet of the evaporator.

Advantages of the Invention

[0016] According to the electric valve and the refrigeration cycle system including the same according to the present invention, on the valve seat adjacent to the second port facing the tip of the valve body, a valve port and an enlarged portion communicating with the valve port are formed on the second port side of the valve port. Further, separately from the valve seat, a rectifying member is provided on the second port side of the valve seat. On this rectifying member, an enlarged portion with a large inner diameter is formed facing the enlarged portion of the valve seat, and it has a stepped hole for rectification with an inner diameter that becomes smaller toward the second port. By providing the enlarged portion of the rectifying member separately from the valve seat so as to face the enlarged portion of the valve seat in this way, the length of the enlarged portion can be increased without increasing the difficulty of processing, and the fluid flow rate can be sufficiently reduced by this lengthened enlarged portion. Further, since the rectifying member has a stepped hole for rectification with an inner diameter that becomes smaller toward the second port, the sound pressure level of the fluid passing sound generated in the electric valve can be suppressed by these.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

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

[0019] As an example of the motor-operated valve according to the present invention, a motor-operated 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 motor-operated valve 3 is joined to the primary-side pipe Du1 by a connection pipe 32 described later, and is joined to the secondary-side pipe Du2 by a connection pipe 34. The primary-side pipe Du1 connects the outlet of the outdoor heat exchanger 6 and the motor-operated valve 3, and the secondary-side pipe Du2 is supposed to connect the inlet of the indoor heat exchanger 2 and the motor-operated 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, the 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, for example, along the direction indicated by an arrow R shown in FIG. 3, and the outdoor heat exchanger 6 functions as a condenser and the indoor heat exchanger 2 functions as an evaporator. Incidentally, although the form in which the motor-operated valve 3 is joined to the primary-side pipe Du1 by the connection pipe 32 and is joined to the secondary-side pipe Du2 by the connection pipe 34 during the cooling operation has been described, it is not limited to such an example. For example, during the cooling operation, the motor-operated valve 3 may be joined to the primary-side pipe Du1 by the connection pipe 34 and may be joined to the secondary-side pipe Du2 by the connection 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. As a result, during the heating operation, the refrigerant in the refrigeration cycle system circulates 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 main body unit 31 that is connected to an end of the rotor case 20 and has a valve seat 31V having a valve port where the tip of the valve body 23 approaches or separates from. The valve main body unit 31 includes a valve body unit that is arranged in the valve main body unit 31 and includes a valve body 23 that 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 main body unit 31 and guides the valve body unit so as to be movable up and down, a rotor 10 that is fixed to a 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 a cylindrical valve body case 19 that constitutes a part of the valve body unit so as to be movable up and down.

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

[0025] On the outer peripheral portion of the cylindrical portion 20C, a spiral guide portion 11 is formed to guide the movable stopper piece 11B to move in the central axis direction of the cylindrical portion 20C while rotating. One end of the movable stopper piece 11B is locked to the protrusion of the rotor 10. Also, at the uppermost and lowermost ends of the cylindrical portion 20C, rotation stoppers 20US and 20LS for the movable stopper piece 11B are provided respectively. Thereby, when the movable stopper piece 11B abuts against the rotation stoppers 20US and 20LS, the movable stopper piece 11B is stopped at a predetermined rotation angle corresponding to a predetermined valve closing position and a predetermined valve opening (fully open) position of a valve body 23 described later.

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

[0027] The valve body unit mainly includes a needle-shaped valve body 23 that approaches or separates from a valve port 31Va of a valve seat 31V described later, a columnar resin spring receiving member 24 that engages an overhanging portion 14F of the connecting portion 14C of the male screw shaft 14 with the inner peripheral edge of the opening end portion 19T of the valve body case 19 in cooperation with a washer (not shown), a coil spring 22 that is disposed between an overhanging portion 24T of the spring receiving member 24 and a spring receiving flat portion at one end of the valve body 23 and biases both in a direction to separate from each other, and a cylindrical valve body case 19 that houses the spring receiving member 24, the coil spring 22, and one end portion of the valve body 23.

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

[0029] The outer peripheral portion of the cylindrical valve body case 19 is in sliding contact with the guide surface of the above-described guide support portion 12 and is supported so as to be movable up and down. As a result, the leading end (needle portion) of the other end of the valve body 23 is inserted into the valve port 31Va of the valve seat 31V, and after the outer peripheral surface of the needle portion of the valve body 23 abuts against the peripheral edge of the opening of the valve port 31Va, when the male screw shaft 14 is continuously lowered, the coil spring 22 is compressed by a predetermined amount. Thereby, the outer peripheral surface of the needle portion 23E of the valve body 23 is pressed against the peripheral edge of the opening of the valve port 31Va by the spring force of the coil spring 22. Thereby, the valve port 31Va of the valve seat 31V is closed. Note that, when the valve body is in the lowest state, a minute flow rate may be obtained even in the lowest state of the valve body by not bringing the valve body into contact with the peripheral edge of the opening of the valve port.

[0030] The valve main body portion 31 is made of a metal material, for example, brass, stainless steel, aluminum alloy, or a resin material, etc., and has inside a lower end below the female screw portion 12B in the guide support portion 12, the other end of the valve body 23, and a valve body accommodating portion 31A for accommodating the cylindrical valve body case 19. In the valve body accommodating portion 31A, the other end of the valve body 23 protrudes toward the valve port 31Va. Further, in the valve body accommodating portion 31A, a first port 32P to which one end of a connecting pipe 32 as a first passage is connected on an axis substantially orthogonal 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 as a second passage is connected on an axis common with the central axis of the valve body 23 are formed.

[0031] As shown in an enlarged partial view in Fig. 1, the valve seat 31V has a valve port 31Va on the same axis as 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 peripheral edge of the valve port 31Va and the inner peripheral edge of the adjacent enlarged portion 31Vb are joined by an annular tapered surface 31Vt.

[0032] On the end face where the enlarged portion 31Vb of the valve seat 31V opens, the upper end face of a metal rectifying member 36 inserted into the second port 34P of the connecting pipe 34 is abutted. The outer peripheral surface of the rectifying member 36 is fixed to the inner peripheral surface of the connecting pipe 34.

[0033] As shown enlarged in Fig. 1, the cylindrical rectifying member 36 has a stepped hole 36H for rectification on the same axis as the central axis of the valve body 23. The stepped hole 36H for rectification is composed of an enlarged portion 36A facing the above-described enlarged portion 31Vb formed concentrically with the central axis of the rectifying 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 a value larger than, for example, the inner diameter D1 of the valve port 31Va and the inner diameter D4 of the reduced portion 36B and equal to or larger than the inner diameter D2 of the enlarged portion 31Vb. Also, the inner diameter D4 of the reduced portion 36B is set to a value equal to or larger than the inner diameter D1 of the valve port 31Va. The length L3 along the central axis in the enlarged portion 36A is set to a value larger 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 larger than the orifice length L1 of the valve port 31Va. As shown in Fig. 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 rectifying member 36 is set to, for example, about 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 rectifying member 36. This ratio is set, for example, by actually flowing a refrigerant through the valve port 31Va, the enlarged portion 31Vb, and the stepped hole 36H for rectification and detecting the passing sound of the refrigerant so that the sound pressure level of the passing sound becomes the smallest.

[0034] In such a configuration, the stator coil 40 of the valve driving unit is controlled by a drive pulse signal from the drive control unit, and the valve body 23 is moved up and down, so that the refrigerant as the fluid supplied through the connection pipe 32 or the connection pipe 34 passes through the gap flow path formed between the inner peripheral 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 along the direction indicated by the arrow F or the arrow R.

[0035] In this way, the inner diameter D3 of the enlarged portion 36A of the rectifying member 36 is set to a value equal to or greater than 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 surface of the enlarged portion 31Vb. As a result, the deceleration region in the enlarged portion 31Vb is enlarged, so that the cavitation rupture is suppressed and the sound pressure level of the passing sound of the refrigerant is suppressed. As a result, as shown in FIG. 4, for example, the flow ST1 flowing in through the valve port 31Va becomes the flow ST2 decelerated by the enlarged portion 31Vb, and further, the flow ST3 that cannot be decelerated on the valve seat 31V side is decelerated by the flow path (enlarged portion 36A) on the rectifying member 36 side. Although cavitation rupture occurs, the distance at which the flow velocity decreases is long, so the influence hardly reaches the reduced portion 36B of the rectifying member 36. Then, after the flow ST4 is rectified, the discharged flow ST5 is discharged into the second port 34P.

[0036] Since the inner diameter D4 of the reduced portion 36B is set to a value equal to or greater than the inner diameter D1 of the valve port 31Va and smaller than the inner diameter D3 of the enlarged portion 36A, the turbulent refrigerant flow in the reduced portion 36B is rectified, so that the sound pressure level of the passing sound of the refrigerant is suppressed. Further, since 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, the refrigerant flow 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 equal to or greater than the length from the upper surface of the valve port of the valve seat 31V to the lower end of the needle portion 23E of the valve body 23, that is, the insertion length L5 of the needle portion 23E into the valve seat 31. Therefore, even during minute flow rate control, since the enlarged portion 36A of the rectifying member 36 is formed ahead (lower side) of the tip of the needle portion 23E, the sound pressure level of the passing sound of the refrigerant is suppressed regardless of the position of the needle portion 23E.

[0038] Figures 5(A), (B), and (C) each show another example of a rectifying member used in an example of the 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 components as those in the example shown in Figure 1 are denoted by the same reference numerals, and the overlapping description thereof is omitted.

[0039] In Figure 5(A), the cylindrical metal rectifying member 46 has a stepped hole 46H for rectification on the same axis as the central axis of the valve body 23. The stepped hole 46H for rectification is composed of an enlarged portion 46A facing the enlarged portion 31Vb formed concentrically with the central axis of the rectifying 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 is set to the same value as the inner diameter of the enlarged portion 31Vb. The inner diameter of the enlarged portion 46A is set to be larger than the inner diameter of the reduced portion 46B. The lengths along the central axes of the enlarged portion 46A and the reduced portion 46B are set in the same manner as in the example shown in Figure 1, respectively.

[0040] In Fig. 5(B), the cylindrical metal rectifying member 48 has a stepped rectifying hole 48H on the same axis as the central axis of the valve body 23. The stepped rectifying hole 48H is composed of an enlarged portion 48A facing the enlarged portion 31Vb formed concentrically with the central axis of the rectifying member 48, and a reduced portion 48B communicating with the enlarged portion 48A. At the boundary between the enlarged portion 46A and the reduced portion 46B, a tapered surface as shown in Fig. 5(A) is not formed. The inner diameter of the enlarged portion 48A is set to the same value as the inner diameter of the enlarged portion 31Vb. The inner diameter of the enlarged portion 48A is set larger than the inner diameter of the reduced portion 48B. Note that the lengths along the central axes of the enlarged portion 48A and the reduced portion 48B are set in the same manner as in the example shown in Fig. 1, respectively.

[0041] In Fig. 5(C), the cylindrical metal rectifying member 50 has a stepped rectifying hole 50H on the same axis as the central axis of the valve body 23. The stepped rectifying hole 50H is composed of an enlarged portion 50A1 facing the enlarged portion 31Vb formed concentrically with the central axis of the rectifying member 50, a reduced portion 50B having an open end opening 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 is set to the same value as the inner diameter of the enlarged portion 31Vb. The inner diameter of the enlarged portion 50A1 is set larger than the inner diameter of the reduced portion 50B. Note that the lengths along the central axes of the enlarged portion 50A1 and the reduced portion 50B are set in the same manner as in the example shown in Fig. 1, respectively.

[0042] Figs. 6(A), (B), and (C) each show still another example of a rectifying member used in an example of an electric valve according to the present invention. The rectifying members 52, 54, and 56 shown in Figs. 6(A), (B), and (C) each have a plurality of stepped rectifying holes. This is intended to increase the separation points of the refrigerant flow in the rectifying member to cause the generation of vortices, thereby reducing the sound pressure level of the passing sound of the refrigerant in the rectifying member.

[0043] In FIG. 6(A), the cylindrical metal rectifying member 52 has two-step rectifying stepped holes 52H on the same axis as the central axis of the valve body 23. The rectifying stepped holes 52H are composed of a first enlarged portion 52A1 facing the enlarged portion 31Vb formed concentrically with the central axis of the rectifying 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 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 larger than the inner diameter of the reduced portion 52B.

[0044] In FIG. 6(B), the cylindrical metal rectifying member 54 has three-step rectifying stepped holes 54H on the same axis as the central axis of the valve body 23. The rectifying stepped holes 54H are composed of a first enlarged portion 54A1 facing the enlarged portion 31Vb formed concentrically with the central axis of the rectifying 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 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 larger than the inner diameter of the reduced portion 54B.

[0045] In FIG. 6(C), the cylindrical metal rectifying member 56 has a stepped rectifying hole 56H on the axis common with the central axis of the valve body 23. The stepped rectifying hole 56H includes a first enlarged portion 56A1 facing the enlarged portion 31´Vb formed concentrically with the central axis of the rectifying 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. At this time, chamfering is applied to the peripheral edge of the opening end of the enlarged portion 31´Vb of the valve seat 31´ communicating with the valve port 31´Va. 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. Annular tapered surfaces are 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, respectively.

[0046] FIGS. 7(A) and (B) each show still another example of a rectifying member used in an example of the electric valve according to the present invention. The rectifying members 58 and 60 shown in FIGS. 7(A) and (B) are each to be fixed by in-furnace brazing to the opening end portion of the connecting pipe 34.

[0047] In FIG. 7(A), the cylindrical metal rectifying member 58 has a flange portion 58F sandwiched between the end face where the enlarged portion 31Vb of the valve seat 31V opens and the opening end face of the connecting pipe 34, and a cylindrical portion 58C continuous with the flange portion 58F. The rectifying member 58 has a stepped rectifying hole 58H inside on the axis common with the central axis of the valve body 23. A predetermined gap CL is formed between the outer peripheral surface of the cylindrical portion 58C and the inner peripheral surface of the connecting pipe 34. Thus, when the rectifying member 58 is fixed to the opening end portion of the connecting pipe 34 by in-furnace brazing, there is no risk of the brazing material entering the valve port 31Va and the stepped rectifying hole 58H of the rectifying member 58.

[0048] The stepped hole 58H for rectification is composed 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 is set to the same value as the inner diameter of the enlarged portion 31Vb. The inner diameter of the enlarged portion 58A is set larger than the inner diameter of the reduced portion 58B. Note that the lengths of the enlarged portion 58A and the reduced portion 58B along the central axis are set in the same manner as the example shown in FIG. 1.

[0049] In FIG. 7(B), the cylindrical metal rectifying member 60 has a flange portion 60F sandwiched between the end face where the enlarged portion 31Vb of the valve seat 31V opens and the opening end face of the connecting pipe 34, and a cylindrical portion 60C continuous with the flange portion 60F. The rectifying member 60 has a stepped hole 60H for rectification inside on the same axis as the central axis of the valve body 23. A predetermined gap CL is formed between the outer peripheral surface of the cylindrical portion 60C and the inner peripheral surface of the connecting pipe 34. Thereby, when the rectifying member 60 is fixed to the opening end of the connecting pipe 34 by brazing in the furnace, there is no possibility that the brazing will enter the valve port 31Va and the stepped hole 60H for rectification of the rectifying member 60.

[0050] The three-stage stepped hole 60H for rectification is composed 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 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 larger than the inner diameter of the reduced portion 60B.

Explanation of Reference Numerals

[0051] 23 Valve body 23E Needle portion 31 Valve body main portion 31A Valve body housing portion 31V and 31´V valve seats 31Vb enlarged portion 32 connecting pipe 32P first port 34 connecting pipe 34P second port 36, 46, 48, 50, 52, 54, 56, 58, 60 rectifying members 36A enlarged portion 36B reduced portion 36H, 46H, 48H, 50H, 52H, 54H, 56H, 58H, 60H stepped holes for rectification

Claims

1. A valve body unit having a first port connected to a first passage and a second port connected to a second passage, the valve body unit having a valve port communicating with the first port and the second port, and including a valve body that is close to or separated from the valve port and controls an opening area, and a housing portion that movably houses the valve body unit; A valve driving unit that causes the valve body unit to perform an operation of controlling 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; On the valve seat, an enlarged portion communicating with the valve port is formed on the side opposite to the valve driving portion in the central axis direction of the valve body of the valve port; Further, separately from the valve seat, on the side opposite to the valve driving portion in the central axis direction of the valve body of the valve seat, there is provided a rectifying member having one or more stepped holes for rectification that face the enlarged portion of the valve seat and have a flow path area that becomes smaller as they are separated from the valve seat; The stepped hole for rectification of the rectifying member includes 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 equal to or greater than the inner diameter of the valve port; An electric valve, wherein the enlarged portion of the rectifying member faces the enlarged portion of the valve seat.

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 rectifying member is formed concentric with the central axis of the valve body; The electric valve according to claim 1, wherein one end of the rectifying member is located inside the valve body portion and the other end of the rectifying member is located outside the valve body portion.

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