The valves are electrically operated and the refrigeration cycle system is in place.

Abstract

An electrically operated valve that reduces noise during fluid flow even when the fluid is not moving. The direction consists of pipe joint 1(12) which is installed on the side face of the valve body(30) and The valve seat (33) which contains the valve port (70) is constructed by being installed as part of the valve body (30). This is a separate part from the valve body (30) and the pipe joint 2 (15) which is connected through to the joint. Connect the pipe 1(12) mentioned above through the valve port(70) mentioned above, which the valve port(70) consists of: Port 1(70a) which is located at the end of the valve side (17) and the tapered section 1(70b) which is extended. The inner diameter of the port 1(70a) is directed to the pipe joint 2(15) and Port 2 (70c) which is constructed on the side of the pipe joint 2 (15) of the tapered section 1 (70b) Inside the pipe joint 2(15) mentioned above or between the valve port(70) mentioned above and the pipe joint 2 mentioned above. (15) There is a cylindrical flow adjuster (80) which adjusts the flow of fluid, placed or mounted. build The image chosen is image number 2.

Description

Electric valve and refrigeration cycle system

[0001] The present invention relates to a motor-operated valve and a refrigeration cycle system using the motor-operated valve.

[0002] Conventionally, in refrigeration cycles, noise generated by motor-operated valves that control the flow rate of a fluid can be a problem when the fluid passes through them. As a motor-operated valve that suppresses such noise, a motor-operated valve 100 is known that has a structure in which a valve port 120 is provided with a long second port 120c as a flow straightening portion below a first port 120a that is an orifice, as shown in Figures 15 and 16 (see, for example, Patent Document 1).

[0003] 16, in this motor-operated valve 100, the fluid that is throttled in the gap between the valve element 114 and the first port 120a flows along the tapered portion 120b to the second port 120c, where it is rectified. Furthermore, by providing the long second port 120c, the pressure of the fluid does not suddenly recover, suppressing the bursting of cavitation, thereby reducing the noise of the fluid passing through.

[0004] JP 2013-234726 A

[0005] However, in the above-mentioned electric valve 100, the passing noise of the fluid is improved when the fluid flows from the first pipe joint 111 to the second pipe joint 112 (hereinafter referred to as the forward direction), but there are cases where this effect is not achieved when the fluid flows from the second pipe joint 112 to the first pipe joint 111 (hereinafter referred to as the reverse direction).

[0006] 16, when the fluid flows in the reverse direction, the fluid reaches the first port 120a without slowing down, so the fluid flow velocity at the first port 120a is greater than the fluid flow velocity when the fluid flows in the forward direction.The pressure of the fluid then recovers rapidly after being throttled at the first port 120a, so the cavitation bursts become more pronounced and the sound of the fluid passing through becomes louder.

[0007] For this reason, in the past, measures were taken such as limiting the flow direction of the fluid to the forward direction in order to suppress the noise of the fluid passing through. However, in recent years, as the ways in which electric valves are used have become more diverse, it is expected that they will be able to be used without any problems even if the fluid is flowed in the reverse direction.

[0008] An object of the present invention is to provide an electrically operated valve capable of reducing the passing noise of a fluid regardless of the direction of the fluid flow, and a refrigeration cycle system using the electrically operated valve.

[0009] The motor-operated valve of the present invention converts the rotational motion of a rotor housed in the inner periphery of a case into linear motion by threaded engagement between a male screw member and a female screw member, and moves a valve element housed in a valve body in the axial direction based on this linear motion, and is characterized in that it comprises: a first pipe fitting attached to the side of the valve body; a valve seat member provided as part of the valve body or as a separate component from the valve body, and having a valve port formed therein; and a second pipe fitting communicating with the first pipe fitting via the valve port, wherein the valve port includes a first port located closest to the valve element side, a first tapered section whose inner diameter widens from the first port towards the second pipe fitting, and a second port formed on the second pipe fitting side of the first tapered section, and a cylindrical rectifying section for rectifying the flow of fluid is disposed or formed inside the second pipe fitting or between the valve port and the second pipe fitting.

[0010] In this way, by providing the first tapered section and the second port within the valve port, when the fluid flows in the forward direction, the flow that was throttled at the first port is rectified, preventing a sudden recovery of pressure and suppressing the bursting of cavitation. Also, by arranging a substantially cylindrical rectifying section inside the second pipe fitting, when the fluid flows in the reverse direction, the fluid does not directly hit the first port, thereby suppressing the generation of noise such as valve vibration and the bursting of cavitation.

[0011] Therefore, the passing noise of the fluid can be reduced whether the fluid flows in the forward direction or the reverse direction.

[0012] In the motor-operated valve of the present invention, an end of the rectifying portion on the valve body side is in contact with the valve seat member.

[0013] This eliminates the gap between the rectifying section and the valve port, and the fluid flowing from the rectifying section to the valve port, or from the valve port to the rectifying section, does not come into direct contact with the inside of the second pipe fitting, thereby more reliably suppressing the noise of the fluid passing through.

[0014] In addition, the motor-operated valve of the present invention is characterized in that the inner circumferential diameter of the flow rectifying portion is larger than the inner circumferential diameter of the first port.

[0015] This makes it possible to suppress pressure loss caused by the flow straightening section when the fluid is made to flow in the forward direction.

[0016] In the motor-operated valve of the present invention, the axial length of the flow straightening portion is longer than the axial length of the first port.

[0017] In this way, by having the flow rectifying portion have a certain length or more, the flow of the fluid can be rectified accurately.

[0018] The motor-operated valve of the present invention is characterized in that the flow rectifying portion is further disposed inside the first pipe joint or between the valve body and the first pipe joint.

[0019] This prevents the fluid discharged from the first pipe fitting into the valve chamber from suddenly expanding and becoming turbulent when the fluid is flowing in the forward direction, thereby more effectively suppressing the noise of the fluid passing through.

[0020] The electric valve of the present invention is also characterized in that the rectifying portion is extended at the end of the second pipe fitting that is connected to the valve port by reducing the inner and outer diameters, and is provided with an extension portion that is inserted into the valve port.

[0021] This shortens the distance from the first port to the upper end of the rectifying section (the upper end of the extension section), thereby preventing the fluid rectified by the rectifying section from being dispersed again in the third port and becoming a turbulent flow, and preventing the rectifying effect achieved by the rectifying section from being impaired.

[0022] The motor-operated valve of the present invention is also characterized in that the valve port further includes a second tapered portion whose inner diameter widens from the second port toward the second pipe fitting, and a third port formed on the second tapered portion on the second pipe fitting side.

[0023] In this way, by providing the valve port with an additional taper and port, it is possible to more accurately suppress the passing noise of the fluid. Furthermore, even when the fluid flows in the reverse direction, the fluid that has passed through the flow straightening section is once decelerated in the port, so the passing noise of the fluid can be reduced accurately.

[0024] The motor-operated valve of the present invention is characterized in that the valve port has an inner diameter that increases continuously from the third port toward the second pipe fitting as the tapered portions and ports increase, and includes an nth tapered portion and an (n+1)th port formed on the second pipe fitting side of the nth tapered portion, wherein the value of n is 10 or less.

[0025] The refrigeration cycle system of the present invention is a refrigeration cycle system including a compressor, a condenser, an expansion valve, an evaporator, and the like, characterized in that the above-mentioned motor-operated valve is used as the expansion valve.

[0026] According to the present invention, it is possible to provide an electrically operated valve that can reduce the passing noise of a fluid regardless of the direction in which the fluid flows, and a refrigeration cycle system that uses the electrically operated valve.

[0027] 1 is a schematic cross-sectional view of a motor-operated valve according to an embodiment; FIG. 2 is an enlarged view of a main portion of the motor-operated valve according to an embodiment; FIG. 3 is a view showing a case where a flow rectifying portion is further provided in a first pipe fitting in the motor-operated valve according to an embodiment; FIG. 4 is a view showing a case where the inner circumferential diameter of the flow rectifying portion is wider than the inner circumferential diameter of the second port in the motor-operated valve according to an embodiment; FIG. 5 is a view showing a case where a constricted portion for crimping the flow rectifying portion is formed in the second pipe fitting in the motor-operated valve according to an embodiment; FIG. 6 is a view showing a case where a plurality of recesses for crimping the flow rectifying portion are formed in the second pipe fitting in the motor-operated valve according to an embodiment; FIG. 7 is a view showing a case where a flow rectifying portion is brazed and fixed in the second pipe fitting in the motor-operated valve according to an embodiment; FIG. 8 is a view showing a case where the valve body and the inside of the second pipe fitting are connected by a flow rectifying member in the motor-operated valve according to an embodiment; FIG. 9 is a view showing a case where the flow rectifying portion is molded integrally with the pipe fitting in the motor-operated valve according to an embodiment; Fig. 1 is an enlarged view of a main part of the motor-operated valve according to the embodiment when a second pipe fitting having a different upper end diameter is used. Fig. 2 is an enlarged view of a main part of the motor-operated valve according to the embodiment when a second pipe fitting having a different upper end diameter is bent. Fig. 3 is an enlarged view of a main part of the motor-operated valve according to the embodiment when a second pipe fitting having a different upper end diameter is connected to a valve seat member that is a separate member from the valve body. Fig. 4 is a schematic cross-sectional view of a conventional motor-operated valve. Fig. 5 is an enlarged view of a main part of the conventional motor-operated valve.

[0028] Hereinafter, a motor-operated valve according to an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a schematic cross-sectional view of a motor-operated valve 2 according to an embodiment. In this specification, "upper" and "lower" are defined as being in the state shown in Fig. 1. In other words, the rotor 4 is located above the valve body 17.

[0029] In this motor-operated valve 2, the valve body 30 is integrally connected by welding or the like to the lower open side of a case 60 made of metal and shaped like a cylindrical cup.

[0030] The valve body 30 is made of a metal such as stainless steel and has a valve chamber 11 therein. A first pipe fitting 12 that directly communicates with the valve chamber 11 is fixedly attached to the side of the valve body 30, and a second pipe fitting 15 that communicates with the first pipe fitting 12 via the valve chamber 11 is fixedly attached to the bottom of the valve body 30. The first pipe fitting 12 and the second pipe fitting 15 are made of a metal such as stainless steel or copper.

[0031] A valve port 70 is formed in the lower portion of the valve body 30, and this portion functions as a valve seat member. The valve port 70 will be described in detail later.

[0032] A rotatable rotor 4 is housed inside the case 60, and a valve shaft 41 is disposed around the axial core of the rotor 4 via a bushing member (not shown). The rotor 4 is made of a magnetic material or contains a magnetic material. The bushing member and the valve shaft 41 are both made of a metal such as stainless steel, and the valve shaft 41 and rotor 4 connected by the bushing member move together vertically while rotating. A male thread 41a is formed on the outer circumferential surface near the middle of the valve shaft 41. In this embodiment, the valve shaft 41 functions as a male thread member.

[0033] A stator including a yoke, a bobbin, a coil, and the like (not shown) is disposed on the outer periphery of the case 60, and the rotor 4 and the stator constitute a stepping motor.

[0034] Below the valve shaft 41, a valve shaft holder 6 is fixed so as not to be rotatable relative to the valve body 30. The valve shaft holder 6 forms a screw feed mechanism A between the valve shaft 41 and the valve shaft 41 as described below and has the function of suppressing tilt of the valve shaft 41.

[0035] The stem holder 6 comprises a cylindrical portion 6a having a female thread 6d (described later) formed on the inner periphery of its upper side, a fitting portion 6c that is housed inside the valve body 30, and a substantially ring-shaped flange portion 6f. The flange portion 6f of the stem holder 6 is fixed to the upper end of the valve body 30 by welding or the like. A housing chamber 6h that houses a valve guide 18 (described later) is formed inside the stem holder 6. The stem holder 6 is made of resin material except for the metal flange portion 6f.

[0036] Furthermore, a female screw 6d is formed downward to a predetermined depth from an upper opening 6g of the cylindrical portion 6a of the stem holder 6. Therefore, in this embodiment, the stem holder 6 functions as a female screw member. The male screw 41a formed on the outer periphery of the valve stem 41 and the female screw 6d formed on the inner periphery of the cylindrical portion 6a of the stem holder 6 constitute a screw feed mechanism A.

[0037] Furthermore, a pressure equalizing hole 51 is drilled in the side surface of the cylindrical portion 6a of the stem holder 6, and this pressure equalizing hole 51 connects the stem holder chamber 83 in the stem holder 6 to the rotor accommodating chamber 67 (second back pressure chamber). By providing this pressure equalizing hole 51, the space that accommodates the rotor 4 in the case 60 communicates with the space inside the stem holder 6, allowing the valve element 17 to move smoothly.

[0038] A cylindrical valve guide 18 is disposed below the valve stem 41 so as to be slidable relative to the accommodation chamber 6h of the valve stem holder 6. The ceiling portion 21 side of the valve guide 18 is bent at a substantially right angle by press molding. A through hole 18a is formed in the ceiling portion 21. A flange portion 41b is also formed below the valve stem 41.

[0039] Here, the valve shaft 41 is loosely inserted into the through-hole 18a of the valve guide 18 so as to be rotatable and radially displaceable relative to the valve guide 18, and the flange 41b is disposed within the valve guide 18 so as to be rotatable and radially displaceable relative to the valve guide 18. The valve shaft 41 passes through the through-hole 18a and is disposed so that the upper surface of the flange 41b faces the ceiling 21 of the valve guide 18. The flange 41b has a larger diameter than the through-hole 18a of the valve guide 18, thereby preventing the valve shaft 41 from coming off.

[0040] Since the valve shaft 41 and the valve guide 18 are movable radially relative to each other, concentricity with the valve guide 18 and the valve body 17 can be achieved without requiring a particularly high degree of concentric mounting precision in terms of the positioning of the valve shaft holder 6 and the valve shaft 41.

[0041] Next, the main components of the motor-operated valve 2 according to the embodiment will be described. FIG. 2 is an enlarged view of the main components of the motor-operated valve 2 according to the embodiment. As shown in FIG. 2, the valve port 70 formed in the lower portion of the valve body 30 has a shape in which the inner diameter gradually increases downward. That is, the valve port 70 has a first port 70a, a first tapered portion 70b, a second port 70c, a second tapered portion 70d, and a third port 70e. In addition, a groove 30a for mounting the second pipe fitting 15 is formed in the lower portion of the valve body 30, and a rectifying portion 80, which is a member for rectifying the flow of a fluid, is disposed inside the second pipe fitting 15.

[0042] The first port 70a is a cylindrical space located at the top (closer to the valve body 17), and has the smallest inner diameter D1 of the valve ports 70. The axial length L1 of the first port 70a is the shortest among the lengths of the ports and tapers included in the valve port 70, and is formed to be an infinitesimal length.

[0043] The first tapered portion 70b is a space that continues downward from the first port 70a, and has a shape in which the inner diameter widens downward.

[0044] Similarly, the second port 70c is a cylindrical space that continues downward from the first tapered section 70b. The second tapered section 70d is a space that continues downward from the second port 70c and has an inner diameter that widens downward. The third port 70e is a cylindrical space that continues downward from the second tapered section 70d and has the widest inner diameter of all the ports and tapers included in the valve port 70.

[0045] The flow rectifying portion 80 is a cylindrical component made of a metal such as stainless steel, and its upper end portion 80a is disposed in contact with the lower end portion 70k of the valve body 30. The inner circumferential diameter D2 of the flow rectifying portion 80 is wider than the inner circumferential diameter D1 of the first port 70a (D1<D2) and narrower than the inner circumferential diameter D3 of the second port 70c (D2<D3). The inner circumferential diameter D4 of the third port 70e is wider than the inner circumferential diameter D2 of the flow rectifying portion 80 and the inner circumferential diameter D3 of the second port 70c (D2<D4, D3<D4). The axial length L2 of the flow rectifying portion 80 is longer than at least the axial length L1 of the first port 70a (L1<L2).

[0046] Next, a description will be given of a case where a fluid flows through the motor-operated valve 2 according to the embodiment. First, when a fluid flows in the forward direction from the first pipe fitting 12 to the second pipe fitting 15, the fluid discharged from the first pipe fitting 12 is decelerated in the valve chamber 11 and then flows into the gap between the valve element 17 and the first port 70a. The fluid is throttled in the gap between the valve element 17 and the first port 70a, then follows the first tapered portion 70b and flows along the second port 70c, where it is rectified by the inner wall surface of the second port 70c. Furthermore, because the inner diameter D3 of the second port 70c is wider than the inner diameter D1 of the first port 70a (D1 < D3), the fluid that flows into the second port 70c is decelerated. However, because the fluid does not flow directly from the first port 70a, which has the narrowest diameter, to the third port 70e, which has the widest inner diameter, the pressure of the fluid does not suddenly recover at the second port 70c. This reduces the noise caused by the pressure of the fluid passing through.

[0047] The fluid is then gradually decelerated in the second tapered section 70d, which forms a gradually expanding flow path, and flows along the third port 70e, where it is again straightened. This further slows the flow velocity in the third port 70e, reducing the noise of the fluid passing through. The fluid that has passed through the third port 70e is discharged to the second pipe fitting 15 via the straightening section 80.

[0048] On the other hand, when a fluid flows in the opposite direction, from the second pipe fitting 15 to the first pipe fitting 12, the fluid in the second pipe fitting 15 is first guided to the flow rectifying section 80, as shown in Fig. 2. Because the inner peripheral diameter D2 of the flow rectifying section 80 is narrower than the inner peripheral diameter of the second pipe fitting 15, turbulence in the fluid is rectified by passing through the flow rectifying section 80. This suppresses the collapse of cavitation and reduces the passing noise of the fluid.

[0049] The fluid passes through the flow straightening section 80 and is then discharged to the third port 70e. Here, because the inner circumferential diameter of the third port 70e is wider than the inner circumferential diameter D2 of the flow straightening section 80, the fluid expands radially in the third port 70e and is decelerated, further reducing the noise of the fluid passing through.

[0050] Next, the fluid is gradually rectified as it passes through the second tapered portion 70d, the second port 70c, and the first tapered portion 70b, and then passes through the first port 70a. In this way, the fluid that has passed through the rectifying portion 80 is gradually rectified without directly hitting the first port 70a, further suppressing vibration of the valve element 17 and cavitation rupture. The fluid that has passed through the first port 70a passes through the valve chamber 11 and is discharged to the first pipe fitting 12.

[0051] According to the electric valve 2 of this embodiment, multiple tapered sections and ports are provided within the valve port 70 to suppress the bursting of cavitation when fluid is flowed in the forward direction, and a cylindrical flow straightening section 80 is placed inside the second pipe fitting 15 to suppress valve vibration and the bursting of cavitation when fluid is flowed in the reverse direction, thereby reducing the sound of fluid passing through whether the fluid is flowing in the forward or reverse direction.

[0052] The valve port 70 also has a second tapered section 70d and a third port 70e below the first tapered section 70b and the second port 70c, and has a shape that widens discontinuously downward. This allows for accurate suppression of fluid passing noise when the fluid flows in the forward direction. Furthermore, when the fluid flows in the reverse direction, the fluid that passes through the flow rectifying section 80 is temporarily decelerated at the third port 70e, allowing for accurate reduction of fluid passing noise.

[0053] Furthermore, by bringing the upper end 80a of the rectifying section 80 into contact with the lower end 70k of the valve body 30, the gap between the rectifying section 80 and the valve port 70 can be eliminated, and the fluid flowing from the rectifying section 80 to the valve port 70, or from the valve port 70 to the rectifying section 80, will not come into direct contact with the inside of the second pipe fitting, thereby more reliably suppressing the noise of the fluid passing through.

[0054] Furthermore, by forming the inner circumferential diameter D2 of the flow rectifying section 80 to be wider than the inner circumferential diameter D1 of the first port 70a (D1<D2), it is possible to suppress pressure loss caused by the flow rectifying section 80 when the fluid is flowing in the forward direction. Furthermore, by forming the inner circumferential diameter D2 of the flow rectifying section 80 to be narrower than the inner circumferential diameter D3 of the second port 70c (D2<D3), it is possible to reduce the amount of fluid that directly hits the valve disc 17 when the fluid is flowing in the reverse direction. Therefore, vibration of the valve disc 17 caused by the fluid directly hitting the disc 17 is suppressed, and noise caused by the vibration of the valve disc 17 can be suppressed.

[0055] Furthermore, since the flow rectifying section 80 has a certain length or more, the flow of the fluid can be rectified accurately.

[0056] 3, a flow rectifying section 82 may be further disposed within the first pipe fitting 12. In this case, when the fluid flows in the forward direction, the fluid discharged from the first pipe fitting 12 into the valve chamber 11 is prevented from suddenly expanding and becoming turbulent, thereby making it possible to more effectively suppress the passing noise of the fluid.

[0057] In this case, it is preferable that the end face 82a of the flow rectifying portion 82 on the valve chamber 11 side be aligned flush with the end face 12a of the first pipe fitting 12 on the valve chamber 11 side. Alternatively, an annular flange (not shown) protruding toward the inner diameter of the first pipe fitting 12 may be provided on the end face 12a of the first pipe fitting 12, and the flow rectifying portion 82 may be positioned so that the end face 82a comes into contact with the flange.

[0058] In the above-described embodiment, as shown in Fig. 2, the inner circumferential diameter D2 of the flow rectifying portion 80 is narrower than the inner circumferential diameter D3 of the second port 70c (D2<D3). However, as shown in Fig. 4, the inner circumferential diameter D2 of the flow rectifying portion 80 may be wider than the inner circumferential diameter D3 of the second port 70c (D2>D3). In this case, even if a high pressure difference occurs between the valve chamber 11 and the valve port 70 when the fluid is flowing in the forward direction, the fluid is not suddenly depressurized. This allows the fluid to be decelerated in stages, thereby effectively suppressing the sound of the fluid passing through.

[0059] In the above-described embodiment, a constricted portion 91 that is constricted in an annular shape may be formed in the second pipe fitting 15, as shown in Fig. 5 . This allows the flow rectifying portion 80 to be crimped by the constricted portion 91 when attached to the second pipe fitting 15, thereby enabling the flow rectifying portion 80 to be accurately fixed so as not to shift position. Furthermore, as shown in Fig. 6 , a plurality of recesses 93 may be formed in the second pipe fitting 15, and the flow rectifying portion 80 may be crimped therein. This technique may also be used when the flow rectifying portion 80 is disposed inside the first pipe fitting 12.

[0060] In the above-described embodiment, the flow rectifying portion 80 may be fixed to the second pipe joint 15 and the valve body 30 by brazing 84, as shown in FIG.

[0061] Furthermore, in the above-described embodiment, instead of arranging the flow rectifying portion 80 inside the second pipe fitting 15, a flow rectifying portion may be arranged between the valve body 30 and the second pipe fitting 15. For example, as shown in Figure 8, a flow rectifying member 85 is used which has upper and lower cylindrical side walls 85a, 85b and has a flow rectifying portion 85f formed between the side walls 85a and 85b with a narrowed inner diameter. In this case, the side wall 85a is inserted into the groove 30a of the valve body 30 to connect the flow rectifying member 85 to the valve body 30, and the second pipe fitting 15 is connected to the flow rectifying member 85 by inserting the side wall 85a into a groove 85c formed inside the side wall 85b of the flow rectifying member 85.

[0062] In this case, it is preferable to form the inner diameter of the side wall 85b to be the same as or slightly smaller than the outer diameter of the second pipe fitting 15 so that the straightening member 85 and the second pipe fitting 15 can be connected accurately.

[0063] This technique may also be applied to the first pipe joint 12. In this case, the flow rectifying member 85 is connected to the side wall of the valve body 30, and the first pipe joint 12 is further connected to the flow rectifying member 85.

[0064] Furthermore, in the above-described embodiment, an example has been described in which the flow rectifying portion 80 is disposed as an independent component within the second pipe fitting 15, but the flow rectifying portion may be molded integrally with the second pipe fitting 15. For example, as shown in Fig. 9, a flow rectifying portion 86 may be molded at the upper end of the second pipe fitting 15 so as to narrow the inner circumferential diameter of the second pipe fitting 15. Similarly, a flow rectifying portion 88 may be molded at the end of the first pipe fitting 12 on the valve chamber 11 side so as to narrow the inner circumferential diameter of the first pipe fitting 12.

[0065] Furthermore, in the above-described embodiment, the valve seat member is integrally incorporated into the valve body 30. However, as shown in FIG. 9 , the valve seat member 33 having the valve port 70 may be disposed within the valve body 30 as an independent component.

[0066] In the above-described embodiment, as shown in Figures 10 and 11, the valve port 70 may not be provided with the second tapered portion 70d and the third port 70e, but may be provided with only the first port 70a, the first tapered portion 70b, and the second port 70c.

[0067] In this case, when fluid passes in the forward direction from the first pipe fitting 12 to the second pipe fitting 15, the fluid is throttled in the gap between the valve element 17 and the first port 70a, follows the first tapered portion 70b, and flows along the second port 70c, where it is rectified by the inner wall surface of the second port 70c. Furthermore, because the inner diameter D3 of the second port 70c is wider than the inner diameter D1 of the first port 70a (D1 < D3), the fluid flowing into the second port 70c is decelerated. This suppresses the collapse of cavitation and reduces the noise of the fluid passing through. The fluid passing through the second port 70c is discharged to the second pipe fitting 15 via the rectifying portion 80.

[0068] On the other hand, when a fluid flows in the opposite direction, from the second pipe fitting 15 to the first pipe fitting 12, the fluid that flows into the second pipe fitting 15 is first guided to the flow rectifying section 80, as shown in Fig. 11. Because the inner diameter of the flow rectifying section 80 is narrower than the inner diameter of the second pipe fitting 15, turbulence in the fluid is rectified by passing through the flow rectifying section 80. This suppresses the collapse of cavitation and reduces the noise of the fluid passing through.

[0069] After passing through the flow rectifying section 80, the fluid is discharged to the second port 70c. Here, because the inner circumferential diameter D3 of the second port 70c is wider than the inner circumferential diameter D2 of the flow rectifying section 80 (D3 > D2), the fluid expands radially and is decelerated in the third port 70e, further reducing the noise of the fluid passing through. The fluid discharged to the second port 70c is further rectified as it passes through the first tapered section 70b, and then passes through the first port 70a. The fluid that has passed through the first port 70a passes through the valve chamber 11 and is discharged to the first pipe fitting 12.

[0070] Furthermore, in the above-described embodiment, a type of second pipe fitting 16 having a different diameter at the upper end may be used. For example, as shown in Fig. 12, the second pipe fitting 16 may be provided with a thick-walled portion 16a at the end connected to the valve port 70, which is formed by narrowing only the inner diameter while maintaining the outer diameter and increasing the wall thickness of the side wall, and an extended portion 16b that extends upward while maintaining the inner diameter of the thick-walled portion 16a constant. In other words, the extended portion 16b is provided in a cylindrical shape by reducing both the inner and outer diameters of the second pipe fitting 16 on the side connected to the valve port 70.

[0071] In this case, the valve port 70 also has a shape that allows connection of the second pipe fitting 16. Specifically, the valve port 70 has an annular flat portion 71a located on the outer circumferential side of the lower edge of the third port 70e, and a connection portion 71b formed below the annular flat portion 71a while maintaining the outer circumferential diameter of the annular flat portion 71a.

[0072] When the second pipe fitting 16 is connected to the valve body 30, the extension 16b is inserted into the valve port 70, and the thick-walled portion 16a is inserted into the connecting portion 71b. That is, the outer peripheral surface of the extension 16b abuts against the inner peripheral surface of the third port 70e, and the outer peripheral surface of the thick-walled portion 16a abuts against the inner peripheral surface of the connecting portion 71b. In addition, the upper end 16f of the thick-walled portion 16a, which is formed on the outer peripheral side of the extension 16b, abuts against the annular flat portion 71a.

[0073] In this state, the extension portion 16b and the thick portion 16a form the flow regulating portion described in the above embodiment.

[0074] When using such a second pipe fitting 16 of a type having a different diameter at the upper end, at least a portion of the flow straightening portion is disposed within the valve port 70. Therefore, even if the length of the valve port 70 is extended in the axial direction, the distance from the first port 70a to the upper end of the flow straightening portion (the upper end of the extension portion 16b) can be shortened. This prevents the fluid that has been straightened in the flow straightening portion from being dispersed again within the third port 70e and becoming a turbulent flow, and prevents the straightening effect achieved by the flow straightening portion from being impaired.

[0075] 13, the second pipe fitting 16 may be bent. In such a case, if the flow straightening portion (thick portion 16a, extended portion 16b) is located inside the valve port 70, there is no need to lower the portion to be bent by the length of the flow straightening portion, and therefore the inter-fitting pitch h between the first pipe fitting 12 and the second pipe fitting 16 does not increase. Therefore, the overall height of the motor-operated valve 2 does not increase, and the motor-operated valve 2 can be made compact even when the second pipe fitting 16 is bent.

[0076] Furthermore, as described above, when assembling the second pipe fitting 16 to the valve body 30, the extension portion 16b is inserted into the valve port 70, and the thick-walled portion 16a is inserted into the connecting portion 71b. This allows the second pipe fitting 16 to be positioned while ensuring concentricity with the valve seat, and also allows for stable brazing.

[0077] Even when a second pipe fitting 16 having a different upper end diameter is used, the inner circumferential diameter D2 of the flow straightening portion (thick-walled portion 16a, extended portion 16b) is wider than the inner circumferential diameter D1 of the first port 70a (D1<D2). The inner circumferential diameter D4 of the third port 70e is wider than the inner circumferential diameter D2 of the flow straightening portion and the inner circumferential diameter D3 of the second port 70c (D2<D4, D3<D4). Furthermore, the axial length L2 of the flow straightening portion 80 is longer than at least the axial length L1 of the first port 70a (L1<L2).

[0078] 14 , the valve seat member 33 having the valve port 70 may be disposed as an independent component within the valve body 30. Furthermore, regardless of whether the valve seat member 33 is an independent component, the flow rectifying portion 88 may be formed within the first pipe fitting 12.

[0079] In addition, the technology described using Figures 3 to 9 and 12 to 14 in the above-mentioned embodiments can also be applied to a motor-operated valve in a configuration in which the valve port 70 is provided with only the first port 70a, the first tapered portion 70b, and the second port 70c, as shown in Figures 10 and 11.

[0080] Furthermore, in the above-described embodiment, the valve port 70 may further increase its inner diameter while successively increasing the tapered portions and ports from the third port 70e toward the second pipe fitting. In this case, a third tapered portion, a fourth port, ..., an nth tapered portion, and an (n+1)th port are formed continuously below the third port 70e. For example, when the value of n is 10, a tenth tapered portion and an eleventh port are formed within the valve port 70. The technology described using Figures 3 to 9 and 12 to 14 may be applied to a motor-operated valve having a valve port having an nth tapered portion and an (n+1)th port formed in this manner.

[0081] The motor-operated valve 2 of the above-described embodiment is used, for example, as an expansion valve provided between a condenser and an evaporator in a refrigeration cycle system including a compressor, a condenser, an expansion valve, an evaporator, and the like.

[0082] DESCRIPTION OF SYMBOLS 2 Motor-operated valve 4 Rotor 6 Valve stem holder 6a Cylindrical portion 6c Fitting portion 6d Female thread 6f Flange portion 6g Upper opening 6h Accommodation chamber 11 Valve chamber 12 First pipe joint 12a End face of first pipe joint on the valve chamber 11 side 15 Second pipe joint 16 Second pipe joint 16a Thick-walled portion 16b Extended portion 16f Upper end portion 17 Valve element 18 Valve guide 18a Through hole 21 Ceiling portion 30 Valve body 30a Groove 33 Valve seat member 41 Valve stem 41a Male thread 41b Flange portion 51 Pressure equalizing hole 60 Case 67 Rotor accommodation chamber 70 Valve port 70a First port 70b First tapered portion 70c Second port 70d Second tapered portion 70e Third port 70k Lower end portion of valve body 30 71a Annular flat portion 71b Connection portion 80 Flow rectifying portion 80a Upper end portion of flow rectifying portion 80 82 Flow rectifying portion 82a End surface of flow rectifying portion 82 on the valve chamber 11 side 83 Valve stem holder chamber 84 Brazed and fixed 85 Flow rectifying member 85a Side wall 85b Side wall 85c Groove 85f Flow rectifying portion 86 Flow rectifying portion 88 Flow rectifying portion 91 Neck portion 93 Recess 100 Motor-operated valve 111 First pipe joint 112 Second pipe joint 114 Valve body 120 Valve port 120a First port 120b First tapered portion 120c Second port D1 Inner peripheral diameter of first port 70a D2 Inner peripheral diameter of flow rectifying portion 80 D3 Inner diameter of second port 70c D4 Inner diameter of third port 70e h Pitch between pipe fittings