Motorised valve

Abstract

The present application provides an electric valve capable of further reducing noise. The electric valve has: a valve body connectable to a pipe and provided with a valve chamber; a valve seat member installed to the valve body and provided with a valve seat; a valve core disposed in the valve chamber and seatable on the valve seat; and a valve holder disposed in the valve chamber and holding the valve core. The valve seat member has a cylindrical portion protruding into the valve chamber and formed with a rectification hole on the inside and in communication with the valve seat. The valve core has: a holding shaft portion held by the valve holder; a conical portion seatable on the valve seat; and a rectification shaft portion disposed between the holding shaft portion and the conical portion. An inner diameter of the rectification hole is smaller than an outer diameter of an end portion of the valve holder near the rectification hole. At least when the valve is closed, the rectification shaft portion is located in the rectification hole. When an end portion of the conical portion on the rectification shaft portion side is located in the rectification hole, a cross-sectional area of a gap between the rectification shaft portion and the rectification hole, as viewed from an axial direction of the electric valve, is larger than a cross-sectional area of a gap between the valve core and the valve seat.

Description

Technical Field

[0001] This invention relates to an electric valve. Background Technology

[0002] Electric valves used as flow control valves in refrigeration cycles have a threaded mechanism that engages the external thread of a valve shaft driven by an electric motor with an internal threaded hole in the valve body. This threaded mechanism converts rotational motion into axial motion, thereby displacing the valve shaft in the axial direction and controlling the flow rate. In such electric valves, it is necessary to suppress the noise of refrigerant passage.

[0003] For example, Patent Document 1 discloses an electric valve in which the passage A formed from the valve chamber to the valve port side in the first refrigerant circulation mode is set in a conical shape, and the passage B formed from the top of the passage B to the valve port side in the second refrigerant circulation mode is set in a conical shape, thereby reducing the fluid flow noise caused by eddies.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2008-128603

[0007] The technical problem that the invention aims to solve

[0008] In recent years, especially with the advancement of automobile electrification, the noise from components such as air conditioning systems in electric vehicles is easily transmitted to the occupants inside the cabin, making noise reduction requirements even more stringent. Therefore, further improvements in noise reduction are also needed in electric valves.

[0009] In a refrigeration cycle, the refrigerant typically flows from the piping into the valve body of the electric valve in a gas-liquid two-phase flow state. According to the research results of the inventors of this invention, it has been determined that when the refrigerant passing through the orifice is in a gaseous state, the change in sound through the orifice compared to when it is in a liquid state may be perceived as noise. Summary of the Invention

[0010] Therefore, the object of the present invention is to provide an electric valve that can further reduce noise.

[0011] Technical means for solving technical problems

[0012] To solve the above-mentioned technical problems, the electric valve of the present invention has the following features:

[0013] The valve body is capable of being connected to piping and has a valve chamber;

[0014] A valve seat assembly, which is mounted on the valve body and has a valve seat;

[0015] A valve core, disposed within the valve chamber and capable of sitting on the valve seat; and

[0016] A valve retainer, disposed within the valve chamber, holds the valve core.

[0017] The valve seat component has a cylindrical portion that protrudes into the valve chamber, and a flow-rectifying hole communicating with the valve seat is formed on the inner side of the cylindrical portion.

[0018] The valve core has: a retaining shaft portion held by the valve retainer, a conical portion capable of sitting on the valve seat, and a rectifying shaft portion disposed between the retaining shaft portion and the conical portion.

[0019] The inner diameter of the rectifier orifice is smaller than the outer diameter of the end of the valve holder closest to the rectifier orifice.

[0020] At least when the valve is closed, the rectifier shaft is located within the rectifier orifice.

[0021] When the end of the rectifier shaft on the conical side is located inside the rectifier hole, when viewed from the axial direction of the electric valve, the cross-sectional area of ​​the gap between the rectifier shaft and the rectifier hole is greater than the cross-sectional area of ​​the gap between the valve core and the valve seat.

[0022] The effects of the invention

[0023] According to the present invention, an electric valve that can further reduce noise can be provided. Attached Figure Description

[0024] Figure 1 This is a longitudinal sectional view showing the electric valve according to the first embodiment of the present invention.

[0025] Figure 2 This is an enlarged longitudinal sectional view showing the periphery of the valve seat component in this embodiment, indicating the valve closed state.

[0026] Figure 3 This is an enlarged longitudinal sectional view showing the periphery of the valve seat component in this embodiment, indicating the state where the needle valve is in an intermediate position between the closed and open states.

[0027] Figure 4 This is an enlarged longitudinal sectional view showing the periphery of the valve seat component in this embodiment, indicating the fully open state of the valve.

[0028] Figure 5 This is a longitudinal sectional view showing the electric valve according to the second embodiment of the present invention.

[0029] Figure 6 This is an enlarged longitudinal sectional view showing the periphery of the valve seat component in this embodiment, indicating the valve closed state.

[0030] Figure 7 This is an enlarged longitudinal sectional view showing the periphery of the valve seat component in this embodiment, indicating the state where the needle valve is in an intermediate position between the closed and open states.

[0031] Figure 8 This is an enlarged longitudinal sectional view showing the periphery of the valve seat component in this embodiment, indicating the fully open state of the valve.

[0032] Symbol Explanation

[0033] 1 Electric valve

[0034] 10 Valve body

[0035] 11, 11A Valve Seat Assembly

[0036] 11k valve seat

[0037] 15 Guide rods

[0038] 21 Valve shaft

[0039] 23 Valve retainer

[0040] 24 Coil Spring

[0041] 25 needle valve

[0042] 26 Spring bearing components

[0043] 27. Ring-shaped components

[0044] 29 Valve Chamber

[0045] 30 rotors

[0046] 35. Movable stop for valve closing direction

[0047] 36. A movable stop is used for the valve opening direction.

[0048] 55. Fixed stop for valve closing direction

[0049] 56. Fixed stop for valve opening direction Detailed Implementation

[0050] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0051] [First Implementation Method]

[0052] Figure 1This is a longitudinal sectional view of the electric valve 1 according to the first embodiment of the present invention. Here, the rotor side of the electric valve 1 is referred to as the upper side, and the needle valve side is referred to as the lower side. In addition, "throttling orifice" refers to the gap between the needle valve and the valve seat when the valve is open, and the area of ​​the annular surface formed by the outer diameter of the needle valve and the inner diameter of the valve seat at the position where the gap is the smallest is the "throttling orifice cross-sectional area".

[0053] (Structure of a flow control valve)

[0054] The electric valve 1 comprises: a bottomed cylindrical valve body 10 with an open top; a topped cylindrical outer shell 45 sealed to the upper surface of the valve body 10 by welding or the like; a guide rod 15 fixed to the inner side of the valve body 10; a valve shaft 21 disposed on the inner side of the guide rod 15; and a rotor 30 connected and fixed to the valve shaft 21 in a manner that allows it to rotate integrally with the valve shaft 21. A stator, which is externally fitted around the outer periphery of the outer shell 45, is arranged around the rotor 30 to drive its rotation, but is not shown in the figure here. The rotor 30 and the stator constitute a stepper motor. The axis of the electric valve 1 (the line aligned with the axis of rotation of the rotor) is defined as L.

[0055] The valve body 10 is formed by continuously providing a hollow cylindrical portion 10a and a bottom wall portion 10b. The valve body 10 can be formed by stamping SUS sheet metal, or it can be formed by pressing SUS material.

[0056] In the bottom wall portion 10b, a circular opening 10d is formed in the center, and a valve seat component 11 is fixed in the opening 10d by brazing or the like.

[0057] Figures 2-4 This is an enlarged longitudinal sectional view showing the periphery of the valve seat component 11.

[0058] The generally cylindrical valve seat component 11 is continuously formed by an upper cylindrical portion 11a, a middle cylindrical portion 11b with a diameter larger than that of the upper cylindrical portion 11a, and a lower cylindrical portion 11c with a diameter larger than that of the middle cylindrical portion 11b.

[0059] Furthermore, the valve seat component 11 includes an opening 11g, which is formed by coaxially arranging a cylindrical upper opening (also called a flow-rectifying orifice) 11d with a constant inner diameter, a middle opening 11e with a diameter larger than the upper opening 11d, and a lower opening 11f that tapers downward from the lower end of the middle opening 11e. Therefore, the valve seat component 11 has a cylindrical portion that protrudes into the valve chamber 29 and has a flow-rectifying orifice communicating with the valve seat 11k formed on its inner side. Furthermore, as... Figures 5-8 As indicated by the symbol 11Ad, the upper opening 11d can also be a conical shape that expands in diameter as it faces upward.

[0060] A valve seat 11k is formed on the inner circumference of the upper end of the central opening 11e that constitutes the throttling orifice. The wall thickness between the upper cylindrical portion 11a and the upper opening 11d is thicker than the wall thickness of the valve body 10, preferably more than 1.2 times. Therefore, the rigidity of the upper cylindrical portion 11a can be improved, and vibration during refrigerant passage can be suppressed, thereby reducing noise.

[0061] The middle cylindrical portion 11b is fitted into the opening 10d of the valve body 10, the upper cylindrical portion 11a protrudes into the interior of the valve body 10, and the lower cylindrical portion 11c is disposed on the exterior of the valve body 10. An annular recess 11h is formed coaxially with the axis L on the lower end face of the lower cylindrical portion 11c. The end of the first pipe T1 that enters the annular recess 11h is connected by brazing or the like.

[0062] An inlet opening 10e is formed in the hollow cylindrical portion 10a of the valve body 10. The end of the second pipe T2 is inserted into the inlet opening 10e and connected by brazing or the like. The axis of the inlet opening 10e is set to O.

[0063] exist Figure 1 In this configuration, with the lower end of the outer casing 45 abutting against the upper end of the valve body 10, a flange-shaped disc 18 is fitted into the inner circumference of the lower end of the outer casing 45 and joined together by welding. Thus, the valve body 10 and the outer casing 45 are integrated in a sealed state.

[0064] The flanged disc 18 has multiple through holes (shown in dashed lines) through which refrigerant can move between the valve body 10 side and the housing 45 side.

[0065] The resin guide rod 15, disposed inside the rotor 30, is continuously formed by a solid cylindrical body 15a and a hollow cylindrical portion 15b. The body 15a has an internally threaded hole 15c along the axis L. In addition, a movable stop member 35 for closing the valve is provided above the guide rod 15.

[0066] A flange-shaped disk 18, welded to the upper end of the valve body 10, is disposed on the outer periphery of the middle portion of the hollow cylindrical portion 15b. The guide rod 15 is fixed relative to the valve body 10 via the flange-shaped disk 18. A pressure equalization hole 15d is formed in the hollow cylindrical portion 15b.

[0067] Furthermore, to set the control origin position of the rotor 30 and valve shaft 21, a rectangular cross-section valve-closing direction fixing stop 55 is provided protruding upward on the upper surface of the main body 15a of the guide rod 15, and a rectangular cross-section valve-opening direction fixing stop 56 is provided protruding downward on the lower surface of the main body 15a of the guide rod 15. Here, the control origin position of the rotor 30 and valve shaft 21 refers to the position when the rotor 30 and valve shaft 21 reach their lowest descending position, where the movable valve-closing direction stop 35 abuts against the valve-closing direction fixing stop 55 and is locked in place.

[0068] The metal valve shaft 21 is formed by continuously and coaxially arranging the end 21a of the annular connector 32 installed on the rotor 30, the external threaded portion 21b that screws into the internal threaded hole 15c, the flange-like portion 21c formed near the lower end, and the lower end connecting portion 21d.

[0069] A movable stop 35, fixed to the valve shaft 21 in the valve closing direction, is disposed near the upper end of the external thread portion 21b and is engaged with the lower surface of the upper wall of the rotor 30. A stop portion 35a with a rectangular cross-section is formed on the lower surface of the movable stop 35 in the valve closing direction.

[0070] Furthermore, near the lower end of the external threaded portion 21b of the valve shaft 21, a movable stop member 36 for the valve opening direction is screwed in such a way that it abuts against the upper surface of the flange-shaped portion 21c. A stop member portion 36a with a rectangular cross-section is formed on the upper surface of the movable stop member 36 for the valve opening direction. Here, the movable stop member 36 for the valve opening direction is fixed to the valve shaft 21 by forming an internal thread on the inner circumference of the movable stop member 36 for the valve opening direction and screwing it into the external threaded portion 21b.

[0071] Below the valve shaft 21, the valve retainer 23 is slidably fitted into the inner side of the hollow cylindrical portion 15b. The valve retainer 23 has a topped cylindrical shape that continuously connects the hollow cylindrical portion 23a and the upper wall 23b. A stepped opening 23c is formed in the center of the upper wall 23b, and the hollow cylindrical portion 23a has a connecting hole 23d. In the closed valve state, the open lower end of the hollow cylindrical portion 23a of the valve retainer 23 is positioned below the second piping T2 and is closed by a riveted annular member 27.

[0072] With the flange-like portion 21c of the valve shaft 21 abutting against the stepped portion of the stepped opening 23c, the lower connecting portion 21d penetrates through the stepped opening 23c. By riveting the lower connecting portion 21d in an enlarged manner, the valve shaft 21 and the valve retainer 23 are fixedly connected. A valve chamber 29 is defined between the valve body 10 and the valve retainer 23.

[0073] like Figures 2-4As shown, the needle valve (also called the valve core) 25 is arranged to protrude from the lower end of the valve holder 23 through the annular member 27. The needle valve 25 is formed by continuously arranging a cylindrical shaft portion (also called the retaining shaft portion) 25a, a valve cylindrical portion (also called the rectifying shaft portion) 25b with a constant outer diameter, and a first conical portion 25c and a second conical portion 25d that taper downwards. The cone angle (the angle intersecting the axis L) of the first conical portion 25c is greater than the cone angle of the second conical portion 25d. The first conical portion 25c rests on the valve seat 11k.

[0074] Reference Figure 3 When the inner diameter of the upper opening 11d of the valve seat component 11 is set to φA, the inner diameter of the middle opening 11e is set to φa, the outer diameter of the valve cylinder portion 25b of the needle valve 25 is set to φB, and the outer diameter of the second conical portion 25d is set to φb, it is preferable that the following formula is satisfied within a range of at least from the closed valve point of the needle valve 25 to 40% of its fully open position. Here, "opening valve point" refers to the position where the needle valve 25 rises from its lower limit position where it abuts against the stop, thereby allowing a specified flow of refrigerant. "Fully open" is the upper limit stop position of the needle valve 25. Furthermore, 40% of full opening corresponds to, for example, the maximum valve opening during stable operation (adjustment phase when the room temperature approaches the set temperature) of an air conditioner in cooling or heating mode.

[0075] 1<{(φA 2 -φB 2 )·π / 4} / {(φa 2 -φb 2 )·π / 4}<100 (1)

[0076] Among them, (φA 2 -φB 2 )·π / 4 is the cross-sectional area S1 of the gap between the valve cylindrical part 25b and the upper opening part 11d, (φa 2 -φb 2 π / 4 is the cross-sectional area S2 of the throttling orifice.

[0077] Furthermore, the inner diameter of the upper opening 11d of the valve seat component 11 is preferably smaller than the outer diameter of the valve retainer 23, and more preferably smaller than the inner diameter of the hollow cylindrical portion 23a. The axial length of the upper opening 11d of the valve seat component 11 is shorter than the axial length of the valve cylindrical portion 25b.

[0078] The annular component 31 is fitted onto the outer periphery of the shaft portion 25a of the needle valve 25 by pressing or the like. The outer diameter of the annular component 31 is larger than the inner diameter of the annular component 27, thus preventing the needle valve 25 from falling off the valve holder 23. A washer 28 is provided between the annular component 31 and the annular component 27 to reduce friction when the annular component 31 and the annular component 27 rotate relative to each other.

[0079] exist Figure 1 In this device, a cylindrical spring bearing member 26 is disposed between the upper wall 23b of the valve retainer 23 and the needle valve 25. The spring bearing member 26 has a lower flange portion 26a. Furthermore, a helical spring 24 is disposed between the upper wall 23b and the lower flange portion 26a, and the helical spring 24 applies a force to the spring bearing member 26 downward relative to the valve retainer 23.

[0080] The first conical portion 25c sits on the valve seat 11k of the valve seat component 11. When subjected to an upward reaction force, the spring bearing component 26, which is exerted upward force by the needle valve 25, abuts against the lower surface (or lower end connecting portion 21d) of the upper wall 23b of the valve holder 23, thereby locking the needle valve 25 relative to the valve shaft 2 in the axial direction.

[0081] When the needle valve 25 is off the valve seat 11k (open valve state), the valve shaft 21, valve retainer 23, needle valve 25 and helical spring 24 are essentially integrated and rotate and move up and down relative to the guide rod 15.

[0082] (Action of the flow control valve)

[0083] The operation of electric valve 1 will be explained in detail.

[0084] Here, it is assumed that the refrigerant (fluid) enters the valve chamber 29 from the second pipe T2.

[0085] By supplying pulse power to the stator (not shown) from an external control device, the rotor 30 and valve shaft 21 are driven to rotate in one direction. Through a threaded feed mechanism consisting of an internal threaded hole 15c and an external threaded portion 21b, the valve shaft 21 and the valve closing direction are simultaneously rotated and lowered by a movable stop 35. Figure 2 As shown, needle valve 25 sits on valve seat 11k and closes the throttling orifice. This cuts off the flow of refrigerant from valve chamber 29 toward the first piping T1 side.

[0086] At this moment, the movable stop 35 has not yet come into contact with the fixed stop 55, and the rotation and descent of the rotor 30 and valve shaft 21 have not stopped. The pulse power supply continues until the helical spring 24 is compressed to a predetermined amount. As a result, the needle valve 25 stops rotating in the state of sitting on the valve seat 11k, while the rotor 30, valve shaft 21, valve retainer 23, etc. continue to rotate and descend.

[0087] At this time, as the valve shaft 21 and valve retainer 23 descend relative to the seated needle valve 25, the coil spring 24 is compressed, thereby absorbing the descending force of the valve shaft 21 and valve retainer 23. Then, when the compression of the coil spring 24 reaches a predetermined amount, the movable stop 35 abuts against the fixed stop 55 and locks in place, and the rotor 30 and valve shaft 21 reach their lowest descending position. Even if stator pulse power supply continues, the descent of the rotor 30 and valve shaft 21 is forcibly stopped.

[0088] In this way, even after the needle valve 25 is seated on the valve seat 11k and closes the throttling orifice, the rotor 30, valve shaft 21, and valve retainer 23 continue to rotate and descend until they reach the control origin position where the movable stop 35 abuts against the fixed stop 55 and are locked in place. As a result, the coil spring 24 is compressed. Therefore, the needle valve 25 is pressed firmly against the valve seat 11k by the force of the coil spring 24, reliably preventing refrigerant leakage, etc.

[0089] On the other hand, when the stator is powered by a pulse of opposite polarity from the control origin position, the rotor 30 and the valve shaft 21 are driven to rotate in the opposite direction to the valve closing position. Through the threaded feed mechanism consisting of the internal threaded hole 15c and the external threaded part 21b, the rotor 30, the valve shaft 21, the valve holder 23, and the movable stop 36 for the valve opening direction rotate and rise at the same time.

[0090] As a result, the pressure applied to the needle valve 25 weakens, and the coil spring 24 extends, as... Figure 3 As shown, when the needle valve 25 leaves the valve seat 11k, the throttling orifice is opened. Consequently, the refrigerant entering the valve chamber 29 from the second pipe T2 flows through the gap between the first conical portion 25c and the valve seat 11k, and through the middle opening 11e and the lower opening 11f, towards the first pipe T1.

[0091] Here, refer to Figure 2 In the state immediately after the needle valve 25 leaves the valve seat 11k, the valve cylinder portion 25b remains aligned with the upper opening 11d of the valve seat component 11 in the axial direction. Therefore, the refrigerant in the valve chamber 29 flows through the gap between the valve cylinder portion 25b and the upper opening 11d, and then through the larger space SP defined between the first conical portion 25c and the upper opening 11d, towards the throttling orifice. The cross-sectional area of ​​the space SP in the direction orthogonal to the axis is larger than the cross-sectional area of ​​the gap between the valve cylinder portion 25b and the upper opening 11d, and the space SP functions as a buffer space to improve the rectification effect of the refrigerant entering the throttling orifice. That is, when the conical end of the valve cylinder portion 25b, which serves as the rectification axis, is located within the upper opening 11d, which serves as the rectification orifice, the cross-sectional area of ​​the gap between the valve cylinder portion 25b and the upper opening 11d, viewed from the axial direction of the electric valve 1, is larger than the cross-sectional area of ​​the gap between the needle valve 25 and the valve seat 11k.

[0092] If the gap between the valve cylindrical portion 25b and the upper opening 11d is relatively large, the refrigerant may not be sufficiently rectified before entering the orifice through the upper opening 11d. Therefore, the sound produced when the refrigerant passes through the orifice in either a gaseous or liquid phase may be inconsistent and could be perceived as noise. This noise is particularly likely to occur immediately after the needle valve 25 has left the valve seat 11k.

[0093] In contrast, according to this embodiment, the refrigerant is rectified during its passage through the narrow gap between the valve cylinder portion 25b and the upper opening portion 11d, resulting in a near-uniform two-phase state throughout the entire circumference. Therefore, noise when passing through the throttling orifice can be reduced.

[0094] Furthermore, assuming that the diameter of the upper opening 11d is larger than that of the valve retainer 23, the refrigerant entering the valve chamber 29 from the second pipe T2 will, after contacting the outer peripheral surface of the valve retainer 23, move downwards along that outer peripheral surface and directly enter the gap between the valve cylinder 25b and the upper opening 11d, thereby weakening its rectification effect.

[0095] In contrast, according to this embodiment, the diameter of the upper opening 11d is smaller than the lower outer diameter of the valve retainer 23. Therefore, when the refrigerant entering the valve chamber 29 from the second pipe T2 moves downward along the outer circumferential surface of the valve retainer 23, it first contacts the upper surface of the valve seat component 11, thereby weakening its momentum. After achieving a certain degree of homogenization by circulating the refrigerant around the entire circumference, it enters the gap between the valve cylinder portion 25b and the upper opening 11d. Therefore, its rectification effect can be further improved.

[0096] Furthermore, according to this embodiment, the cross-sectional view in the closed valve state ( Figure 3 In this configuration, the extension line of the lower outer peripheral surface (the surface riveted in a conical shape) of the valve retainer 23 is blocked by the upper end surface of the valve seat component 11 before entering the upper opening 11d. Therefore, even when the refrigerant flows downward along this conical surface, its momentum is weakened by contact with the upper end surface of the valve seat component 11, further improving the aforementioned rectification effect.

[0097] In addition, according to this embodiment, the relationship of the above formula (1) is established between the valve seat component 11 and the needle valve 25. Therefore, the cross-sectional area S1 of the gap between the valve cylinder portion 25b and the upper opening portion 11d is always greater than the cross-sectional area S2 of the throttling orifice. Thus, the refrigerant flow control can be correctly realized regardless of the lifting amount of the needle valve 25.

[0098] According to this embodiment, the lifting amount of the needle valve 25 is determined based on the pulse power supply to the stator, thus enabling refrigerant flow control. Furthermore, by continuously supplying pulse power, such as... Figure 4 As shown, the valve cylindrical portion 25b disengages from the upper opening portion 11d, and the needle valve 25 is finally in a fully open state. Furthermore, under continuous pulse power supply, the movable stop 36 is locked against the valve opening direction by the fixed stop 56, thereby forcibly stopping the rotation and rising of the rotor 30, the valve shaft 21, and the valve holder 23.

[0099] [Second Implementation]

[0100] Figure 5 This is a longitudinal sectional view of the electric valve 1A according to the second embodiment. The electric valve structure, except for the valve seat component 11A, is the same as that of the first embodiment, so repeated descriptions are omitted.

[0101] Figures 6-8 This is an enlarged longitudinal sectional view showing the periphery of the valve seat component 11A. The valve seat component 11A in this embodiment differs from that in the first embodiment primarily in the shape of the upper opening 11Ad. The same symbols are used for structures common to the first embodiment, and repeated descriptions are omitted.

[0102] The inner circumferential surface of the upper opening 11Ad of the valve seat component 11A is a conical shape (conical surface) that expands in diameter as it faces upward. In this embodiment, the cross-sectional area S1 of the gap between the valve cylinder portion 25b and the upper opening 11Ad varies with the lifting amount of the needle valve 25, but regardless of the lifting amount, it satisfies the relationship of the above formula (1). Alternatively, the outer circumferential surface of the valve cylinder portion 25b can be set as a conical shape (conical surface) that narrows in diameter as it faces downward. By setting both the inner circumferential surface of the upper opening 11Ad, which serves as a flow rectifier, and the outer circumferential surface of the valve cylinder portion 25b, which serves as a flow rectifier shaft, as conical shapes, the flow path of the gap between the valve cylinder portion 25b and the upper opening 11d at low flow rates can be extended, thereby improving the noise reduction effect.

Claims

1. An electric valve, characterized in that, have: The valve body is capable of being connected to piping and has a valve chamber; A valve seat assembly, which is mounted on the valve body and has a valve seat; A valve core, disposed within the valve chamber and capable of sitting on the valve seat; and A valve retainer, disposed within the valve chamber, holds the valve core. The valve seat component has a cylindrical portion that protrudes into the valve chamber, and a flow-rectifying hole communicating with the valve seat is formed on the inner side of the cylindrical portion. The valve core has: a retaining shaft portion held by the valve retainer, a conical portion capable of sitting on the valve seat, and a rectifying shaft portion disposed between the retaining shaft portion and the conical portion. The inner diameter of the rectifier orifice is smaller than the outer diameter of the end of the valve holder closest to the rectifier orifice. At least when the valve is closed, the rectifier shaft is located within the rectifier orifice. When the conical end of the rectifier shaft is located within the rectifier hole, when viewed from the axial direction of the electric valve, the cross-sectional area of ​​the gap between the rectifier shaft and the rectifier hole is greater than the cross-sectional area of ​​the gap between the valve core and the valve seat. The conical portion is formed by a first conical portion and a second conical portion continuously arranged. The second conical portion is located on the opposite side of the rectifier shaft relative to the first conical portion. The first conical portion can sit on the valve seat. The cone angle of the first conical portion is greater than the cone angle of the second conical portion.

2. The electric valve according to claim 1, characterized in that, Within the range from the valve core's closed point to 40% of its fully open position, the cross-sectional area of ​​the gap between the rectifier shaft and the rectifier orifice is greater than 1 times and less than 100 times the cross-sectional area of ​​the gap between the valve core and the valve seat.

3. The electric valve according to claim 1 or 2, characterized in that, The wall thickness of the cylindrical portion of the valve seat component is greater than the wall thickness of the valve body.

4. The electric valve according to claim 1 or 2, characterized in that, The valve retainer is cylindrical, and the inner diameter of the rectifier hole is smaller than the inner diameter of the lower end of the valve retainer.

5. The electric valve according to claim 1 or 2, characterized in that, The rectifier shaft has a constant outer diameter.

6. The electric valve according to claim 1 or 2, characterized in that, The rectifier orifice has a constant inner diameter.

7. The electric valve according to claim 1 or 2, characterized in that, The rectifier orifice has a conical shape.

8. The electric valve according to claim 1 or 2, characterized in that, Both the rectifier orifice and the rectifier shaft have a tapered shape.

9. The electric valve according to claim 1 or 2, characterized in that, The rectifier shaft disengages from the rectifier orifice according to the valve opening amount of the valve core.

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