JP2016151310A - Motor valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor valve capable of effectively reducing noise due to cavitation in a normal direction flow state and noise due to gas-liquid two-phase flow in a reverse direction flow state.SOLUTION: A valve port orifice 22 comprises: a narrowest part 22b comprising a cylindrical surface connecting from a valve seat part 29a of a valve seat 29 toward a downstream side; a conical surface part 22c connected to a downstream side end surface 29b of the valve seat 29; and a bubble fragmentation part provided between the narrowest part 22b and the comical surface part 22c, and having an angle formed by itself and the narrowest part 22b of 90 degrees or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a motor-operated valve used as a flow control valve or the like in a refrigeration cycle such as an air conditioner or a refrigerator, and in particular, a motor-operated valve capable of reducing noise due to a gas-liquid two-phase flow. About.

  A conventional example of this type of electric valve is shown in FIG. The illustrated motor-operated valve 1 ′ includes a stepped inverted conical valve body 24 provided at a lower end portion of a valve shaft 25 including an upper small-diameter portion 25 a, an intermediate large-diameter portion 25 b, and a lower intermediate-diameter portion 25 c, and a fluid ( A refrigerant inlet / outlet fluid inlet pipe (joint) 61 and a fluid outlet pipe (joint) 62 are connected to each other, and a valve seat 29 and a valve chamber 21 in which a valve orifice 22 is opened and closed by the valve body 24. The valve main body 20 having the above structure is provided, and the flow rate of the fluid such as the refrigerant is adjusted by controlling the lift amount of the valve body 24 with respect to the valve seat 29. A lower end portion of a cylindrical can 40 having a lower opening having a ceiling portion 40a is hermetically joined to the flange-like member 23 of the valve body 20 by butt welding.

  A rotor 30 is disposed on the inner periphery of the can 40 with a predetermined gap α, and a yoke 51, a bobbin 52, a stator are disposed on the outer periphery of the cylindrical portion of the can 40 to rotate the rotor 30. A stator 50 including a coil 53 and a resin mold cover 56 is externally fitted, and the rotor 30 and the stator 50 constitute a stepping motor.

  A drive mechanism is provided between the rotor 30 and the valve shaft 25 to bring the valve body 24 into contact with or away from or close to the valve seat 29 using the rotation of the rotor 30. This drive mechanism is formed on the outer periphery of a cylindrical guide bush 26 in which the lower end portion 26a is press-fitted and fixed to the valve body 20 and the valve shaft 25 (intermediate large diameter portion 25b) is slidably inserted. The fixed screw portion (male screw portion) 28 is formed on the inner periphery of a cylindrical valve shaft holder 32 having a lower opening disposed on the outer periphery of the valve shaft 25 and the guide bush 26. The screw feed mechanism includes a moving screw portion (female screw portion) 38 screwed together.

  The valve shaft holder 32 and the rotor 30 are coupled via a support ring 36, and the upper protrusion of the valve shaft holder 32 is caulked and fixed to the support ring 36, whereby the rotor 30, the support ring 36, and the valve The shaft holder 32 is integrally connected.

  A lower stopper body (fixed stopper) 27 constituting one of the stopper mechanisms is fixed to the guide bush 26, and an upper stopper body (moving stopper) 37 constituting the other stopper mechanism is fixed to the valve shaft holder 32. ing.

  The upper small diameter portion 26b of the guide bush 26 is inserted into the upper portion of the valve shaft holder 32, and the upper small diameter portion 25a of the valve shaft 25 is inserted into the insertion hole 32b formed at the center of the ceiling portion 32a of the valve shaft holder 32. Has been inserted. A push nut 33 is fixed (press-fit) to the upper end of the upper small diameter portion 25a of the valve shaft 25 (the portion protruding from the insertion hole 32b). When the upper stopper body 37 is not in contact with the lower stopper body 27 and the valve body 24 is not in contact with the valve seat 29, the ceiling portion of the valve shaft holder 32 is caused by the elastic force of the compression coil spring 34 described later. 32 a is pressed against the bottom surface of the push nut 33.

  Further, the valve shaft 25 is extrapolated to the upper small-diameter portion 25a of the valve shaft 25, and between the ceiling portion 32a of the valve shaft holder 32 and the upper terrace surface of the intermediate large-diameter portion 25b of the valve shaft 25. It is always urged downward (in the valve closing direction) by a compression coil spring 34 for valve closing and buffering that has been mounted. In this case, the upper end portion of the compression coil spring 34 is locked to the lower surface of the ceiling portion 32a of the valve shaft holder 32 via a spring receiving member 39 such as a washer. A return spring 35 made of a coil spring is disposed on the ceiling portion 32 a of the valve shaft holder 32. The return spring 35 is moved again by the lowering of the rotor 30 after the rotor 30 is lifted by the drive mechanism and the moving screw part (female screw part) 38 and the fixed screw part (male screw part) 28 are disengaged. It is provided for screwing the screw portion 38 to the fixing screw portion 28.

  In the motor-operated valve 1 ′ configured as described above, the rotor 30 and the valve shaft holder are controlled against the guide bush 26 fixed to the valve body 20 by performing energization (pulse supply) control to the stator coil 53. 32 is rotated integrally, and the valve shaft 25 (valve body 24) is moved up and down by screw feed between the fixed screw portion 28 of the guide bush 26 and the moving screw portion 38 of the valve shaft holder 32, and the valve orifice 22 is moved. Opened and closed. Therefore, in this motor-operated valve 1 ′, the lift amount (valve opening degree) of the valve body 24, that is, the passage flow rate of the fluid can be adjusted by the rotation amount of the rotor 30. Since it is controlled by the number, the fluid passage flow rate can be adjusted with high accuracy.

  Next, the detailed configuration around the valve seat 29 of the conventional motor-operated valve 1 ′ will be described with reference to FIG. 6. The valve orifice 22 formed in the valve seat 29 has a valve chamber 21 side (upstream side). In order from the downstream side to the downstream side, it is composed of an inverted conical surface portion 22a, a cylindrical surface portion (narrowest portion) 22b, and a conical surface portion 22c, and the upstream end (valve seat portion 29a) of the cylindrical surface portion 22b in this valve orifice 22 In addition, the inverted conical valve body 24 is configured to come in contact with or away from or close to.

  In the above-described conventional motor-operated valve 1 ′, fluid (refrigerant) flows into the valve chamber 21 from the fluid introduction pipe 61 and further flows into the fluid outlet pipe 62 through the valve orifice 22 that is opened and closed by the valve body 24 ( Since the downstream portion of the valve orifice 22 is configured by the conical surface portion 22c in the forward flow state), the speed of the fluid passing through the valve orifice 22 is decreased, and the fluid pressure is increased accordingly. As a result, noise is reduced (Patent Document 1).

JP 2010-19406 A

  By the way, the motor-operated valve as described above usually has a flow state in the positive direction as described above, and fluid flows into the valve chamber from the fluid outlet pipe via the valve orifice, and is formed on the side of the valve chamber in the valve body. It is used in both directions of the reverse flow state flowing to the fluid introduction pipe through the formed inlet, but in the reverse flow state described above, particularly in the reverse flow state in the gas-liquid two-phase flow, Still, there was a problem that annoying noise was generated.

  The present invention has been made in view of the above problems, and its object is to effectively reduce noise caused by gas-liquid two-phase flow in a flow state in the opposite direction to noise caused by cavitation in the flow direction in the forward direction. An object of the present invention is to provide an electric valve that can be reduced.

  The present invention has been made on the basis of knowledge obtained by repeatedly performing numerical analysis and trial experiment with various changes to the shape of the valve orifice orifice and the like, and consideration based on the knowledge.

  That is, the electric valve according to the present invention basically includes a valve shaft having a valve body provided at a lower end portion thereof, and a valve orifice having a valve seat portion in which the valve body is brought into contact with, separated from, or close to the valve body. A valve body provided with a seat and formed with a valve chamber into which fluid is introduced and led out; a can joined to the valve body; a rotor disposed inside the can; and a rotor driven to rotate A stator disposed outside the can; and a lift drive mechanism that lifts and lowers the valve body with respect to the valve seat portion by using rotation of the rotor, and fluid flows from the valve chamber to the valve orifice. The motor-driven valve is adapted to flow in the forward direction toward the valve head and in the reverse direction toward the valve chamber from the valve port orifice, and the valve port orifice is connected downstream from the valve seat portion. The narrowest part consisting of a cylindrical surface and under the valve seat A conical surface portion connected to the side end surface, and a bubble subdivision portion provided between the narrowest portion and the conical surface portion and having an angle of 90 degrees or less with the narrowest portion. It is a feature.

  In a preferred embodiment, the bubble subdivided part has an annular flat surface part having an angle of 90 degrees with at least the narrowest part.

  In another preferred embodiment, the bubble subdivided portion is provided at least on an inverted conical surface portion having an angle of less than 90 degrees with the narrowest portion and on the outer side of the reverse conical surface portion, And an annular flat surface portion having an angle of 90 degrees.

  In another preferred embodiment, a separate annular flat surface comprising the downstream end surface of the valve seat is provided around the downstream end of the conical surface portion.

  According to the motor-operated valve of the present invention, the valve port orifice has a narrowest portion formed of a cylindrical surface connected to the downstream side from the valve seat portion, a conical surface portion connected to the downstream end surface of the valve seat, A valve seat is provided between the narrowest portion and the conical surface portion, and is configured by a bubble subdivision portion having an angle of 90 degrees or less with the narrowest portion. As with the conventional motor-operated valve, the conical surface portion connected to the downstream end surface of the cylinder makes it difficult for cavitation to occur, and as a result, noise is reduced and the fluid (refrigerant) is in a reverse flow state. Since the bubbles contained in the gas collide with the bubble subdivided portion and are destroyed or subdivided, noise due to the gas-liquid two-phase flow can be effectively reduced.

  In addition, since the bubble subdivided portion has an annular flat surface portion having an angle of 90 degrees with at least the narrowest portion, the bubbles contained in the fluid (refrigerant) are further broken down in the reverse flow state or Since it becomes easy to subdivide, the noise by a gas-liquid two-phase flow can be reduced more effectively.

  In addition, the bubble subdivided portion is provided at least on the reverse conical surface portion having an angle of less than 90 degrees with the narrowest portion and on the outer side of the reverse conical surface portion, and the angle formed with the narrowest portion is 90 °. By having an annular flat surface portion that is a degree, bubbles contained in the fluid (refrigerant) in the flow direction in the reverse direction are less likely to enter the narrowest portion by the reverse conical surface portion, and on the reverse conical surface portion and the outside thereof. Since it becomes easy to collide with the provided annular flat surface portion and is easily broken or subdivided, noise due to gas-liquid two-phase flow can be further effectively reduced.

The longitudinal cross-sectional view which shows 1st Embodiment of the motor operated valve which concerns on this invention. The principal part expanded sectional view of the valve main-body part of the motor operated valve shown by FIG. The longitudinal cross-sectional view which shows 2nd Embodiment of the motor operated valve which concerns on this invention. The principal part expanded sectional view of the valve main-body part of the motor operated valve shown by FIG. The longitudinal cross-sectional view which shows an example of the conventional motor operated valve. The principal part expanded sectional view of the motor operated valve shown by FIG.

  Hereinafter, embodiments of a motor-operated valve according to the present invention will be described with reference to the drawings. In each drawing, gaps formed between members, separation distances between members, etc. may be exaggerated for easy understanding of the invention and for convenience of drawing. is there. Further, in this specification, descriptions representing positions and directions such as up and down, left and right are based on the direction arrow indications of FIGS. 1 and 3 and do not indicate positions and directions in actual use.

  Further, for the motor-operated valves 1 and 1A of the first and second embodiments shown below, the same reference numerals are given to the portions corresponding to the respective parts of the motor-operated valve 1 ′ of the conventional example shown in FIG. 5 and FIG. The detailed description is omitted, and in the following, differences will be mainly described.

  Further, in this specification, the fluid introduction pipe side connected to the side of the valve chamber in the valve body is the upstream side, and the fluid outlet pipe side connected to the lower side of the valve chamber is the downstream side. The direction toward the fluid outlet pipe through the inlet port formed on the side of the valve chamber in the main body, the valve chamber, and the vertical valve orifice formed in the valve seat is defined as the “positive direction”, and the fluid outlet pipe The direction toward the fluid introduction pipe through the valve orifice, the valve chamber, and the inlet is defined as “reverse direction”.

[First Embodiment]
FIG. 1 is a longitudinal sectional view showing a first embodiment of a motor-operated valve according to the present invention, and FIG. 2 is an enlarged sectional view of an essential part (around a valve seat).

  In the motor-operated valve 1 according to the first embodiment, the valve orifice 22 formed in the valve seat 29 is formed in order from the valve chamber 21 side (upstream side) to the downstream side in the reverse conical surface portion 22a and the cylindrical surface portion (the outermost surface). Narrow portion) 22b, annular flat surface portion (bubble subdivision portion) 22d, and conical surface portion 22c, and a stepped inverted cone at the upstream end (valve seat portion 29a) of the narrowest portion 22b in the valve orifice 22 The valve body 24 is in contact with or away from or close to and away from. The stepped inverted conical valve body 24 provided at the lower end portion of the valve shaft 25 is composed of an upper conical surface upper valve body portion 24a, an intermediate insertion portion 24b, and a lower front end portion 24c from above. The taper angle of each part is increased in the order of the intermediate insertion part 24b, the upper valve body part 24a, and the lower tip part 24c, and the vicinity of the lower end of the upper valve body part 24a is in contact with or separated from the upstream end of the narrowest part 22b. It is designed to be closely spaced. In the present specification, the taper angle means an angle formed between the sides when each part such as the upper valve body part 24a, the intermediate insertion part 24b, and the lower tip part 24c is viewed from the lateral direction. .

  Specifically, the reverse conical surface portion 22 a constituting the valve orifice 22 has a taper angle slightly larger than the taper angle of the upper valve body portion 24 a of the valve body 24. The narrowest portion 22b is connected to the valve seat portion 29a from the valve seat portion 29a (in other words, the downstream end of the reverse conical surface portion 22a) toward the downstream side (downward) and the valve shaft 25. It consists of concentric cylindrical surfaces. Further, the annular flat surface portion 22d extends in a lateral direction (a direction perpendicular to the narrowest portion 22b) by a predetermined width from the downstream end (lower end) of the narrowest portion 22b (that is, the narrowest portion). The conical surface portion 22c extends from the outer end of the annular flat surface portion 22d to a downstream end surface 29b of the valve seat 29 so as to expand in a tapered shape. It extends.

  The diameter φc of the downstream end (lower end) opening of the conical surface portion 22c of the valve orifice 22 is set smaller than the inner diameter φb of the distal end portion of the fluid outlet pipe 62, and the downstream side of the valve seat 29 around the downstream end opening of the conical surface portion 22c. A separate annular flat surface portion 29c composed of the end surface 29b is provided.

  In this example, the lower end of the lower tip 24c is near the downstream end face 29b of the valve seat 29 when the upper valve part 24a of the valve body 24 is in contact with or closest to the upstream end of the narrowest part 22b. And the valve body 29 (the intermediate insertion portion 24b and the lower front end portion 24c thereof) and the valve seat 29 so that the lower end of the intermediate insertion portion 24b is positioned below the lower end of the narrowest portion 22b or the annular flat surface portion 22d. The height in the vertical direction of the narrowest portion 22b and the conical surface portion 22c is set.

  In addition, here, the circular inlet 63 is formed at the inner diameter of the tip of the fluid introduction pipe 61 and at the side of the valve chamber 21 in the valve body 20 and the tip face of the fluid introduction pipe 61 is brought into contact with the outer surface thereof. And the inner diameter of the valve chamber 21 are set to the same (φa) (see FIG. 1).

  As described above, in the motor-operated valve 1 of the present embodiment, the valve orifice 22 has the narrowest portion 22b formed of a cylindrical surface connected to the valve seat portion 29a from the valve seat portion 29a toward the downstream side, and the valve seat 29. A conical surface portion 22c connected to the downstream end surface 29b, and an annular flat surface portion 22d provided between the narrowest portion 22b and the conical surface portion 22c and having an angle θd of 90 degrees with the narrowest portion 22b. In the forward flow state, the conventional motor-operated valve is configured by the conical surface portion 22c connected to the downstream end surface 29b of the valve seat 29 and the annular flat surface portion 22d on the inner side. As in the case of, cavitation is less likely to occur, and as a result, noise is reduced, and in a reverse flow state, bubbles contained in the fluid (refrigerant) collide with the annular flat surface portion 22d to be destroyed. Since properly is subdivided, it is possible to effectively reduce the noise caused by the gas-liquid two-phase flow.

  Further, by providing a separate annular flat surface portion 29c composed of the downstream end surface 29b of the valve seat 29 around the downstream end of the conical surface portion 22c, the connection is fixed around the downstream end of the conical surface portion 22c by brazing or the like. It is also possible to ensure the connection strength of the fluid outlet pipe 62 (the tip portion thereof).

[Second Embodiment]
FIG. 3 is a longitudinal sectional view showing a second embodiment of the motor-operated valve according to the present invention, and FIG. 4 is an enlarged sectional view of an essential part (around the valve seat).

  In the motor-operated valve 1A of the second embodiment, the valve orifice 22A formed in the valve seat 29A has an inverted conical surface portion 22aA and a cylindrical surface portion (the outermost surface) sequentially from the valve chamber 21A side (upstream side) to the downstream side. Narrow portion) 22bA, reverse conical surface portion 22eA, annular flat surface portion 22dA, and conical surface portion 22cA, and a stepped reverse conical shape at the upstream end (valve seat portion 29aA) of the narrowest portion 22bA in the valve orifice 22A. The valve body 24A is contacted / separated or closely separated. The inverted conical surface portion 22eA and the annular flat surface portion 22dA constitute a bubble subdivided portion.

  An annular flat surface portion 22fA having a predetermined width is provided between the narrowest portion 22bA and the inverted conical surface portion 22eA in consideration of manufacturing variations.

  Further, here, the taper angle of the inverted conical surface portion 22eA formed with the narrowest portion 22bA is smaller than 90 degrees is larger than the taper angle of the reverse conical surface portion 22aA on the valve chamber 21A side (upstream side), and It is set to be equal to the taper angle of the downstream conical surface portion 22cA. Further, as compared with the motor-operated valve 1 of the first embodiment, the length (vertical height) from the upstream end to the downstream end of the narrowest portion 22bA is equal to the vertical height of the inverted conical surface portion 22eA. The width of the annular flat surface portion 22dA outside the inverted conical surface portion 22eA is set to be slightly smaller.

  In the second embodiment, as in the first embodiment, when the upper valve body portion 24aA of the valve body 24A is in contact with or closest to the upstream end of the narrowest portion 22bA, the lower tip portion 24cA While the lower end reaches the vicinity of the downstream end surface 29bA of the valve seat 29A, and the lower end of the intermediate insertion portion 24bA is positioned below the lower end of the narrowest portion 22bA, the valve element 24A (the intermediate insertion portion 24bA and the lower end portion thereof) 24cA) and the height of the valve seat 29A (the narrowest portion 22bA, the reverse conical surface portion 22eA, and the conical surface portion 22cA) are set in the vertical direction.

  Thus, in the motor operated valve 1A of the present embodiment, the valve orifice 22A is provided between the narrowest portion 22bA, the conical surface portion 22cA, the narrowest portion 22bA, and the conical surface portion 22cA, and the narrowest portion. A reverse cone surface portion 22eA having an angle θeA formed with the portion 22bA smaller than 90 degrees, and an annular flat surface portion 22dA provided outside the reverse cone surface portion 22eA and having an angle θdA formed with the narrowest portion 22bA of 90 degrees; It is comprised with the bubble subdivision part which consists of. That is, with respect to the motor-operated valve 1 of the first embodiment, an inverted conical surface portion 22eA having an angle θeA formed by the narrowest portion 22bA smaller than 90 degrees is interposed between the narrowest portion 22bA and the annular flat surface portion 22dA. It is installed. This makes it difficult for bubbles contained in the fluid (refrigerant) in the reverse flow state to enter the narrowest portion 22bA by the reverse conical surface portion 22eA, and the reverse conical surface portion 22eA and the annular flat surface portion provided outside thereof. Since it easily collides with 22 dA and is easily broken or subdivided, noise due to gas-liquid two-phase flow can be further effectively reduced.

  Needless to say, the present invention can be applied to various types of motor-operated valves. As an example, for example, when the valve body is in the lowest lowered position, a valve-type motorized valve in which the valve body contacts (seats) the valve seat portion and the flow of fluid is cut off, A motorized valve of a type that ensures a predetermined amount of passing flow rate through a communication hole provided in the valve body or a bleed groove provided in the valve seat part while contacting (sitting) the valve seat part (all When the valve disc is at the lowest position (normally fully closed), a gap of a predetermined size is provided between the valve disc and the valve seat portion. And a valve-closing type motor-operated valve (a motor-operated valve in which the valve element is moved close to and away from the valve seat).

1 Motorized valve 20 Valve body 21 Valve chamber 22 Valve orifice 22a Reverse conical surface portion 22b Narrowest portion 22c Conical surface portion 22d Annular flat surface portion (bubble subdivision portion)
23 Rod-shaped member 24 Valve body 25 Valve shaft 29 Valve seat 29a Valve seat portion 30 Rotor 40 Can 50 Stator 61 Fluid introducing pipe 62 Fluid outlet pipe 63 Inlet

Claims (4)

A valve shaft having a valve body provided at a lower end thereof, a valve seat having a valve orifice having a valve seat portion with which the valve body is brought into contact with, separated from, or close to, and a valve chamber into which fluid is introduced and led out; A formed valve body, a can joined to the valve body, a rotor disposed inside the can, a stator disposed outside the can to rotationally drive the rotor, and the rotor An elevating drive mechanism that raises and lowers the valve body with respect to the valve seat using rotation, and a forward direction of fluid from the valve chamber toward the valve orifice and from the valve orifice to the valve chamber A motorized valve that is made to flow in the opposite direction,
The valve orifice includes: a narrowest portion including a cylindrical surface connected to the downstream side from the valve seat portion; a conical surface portion connected to a downstream end surface of the valve seat; the narrowest portion and the conical surface portion; A motor-operated valve comprising: a bubble subdividing portion that is provided between the narrowest portion and has an angle of 90 degrees or less with the narrowest portion.   2. The motor-operated valve according to claim 1, wherein the bubble subdivided portion has an annular flat surface portion having an angle of 90 degrees with at least the narrowest portion.   The bubble subdivided portion is provided at least on an inverted conical surface portion having an angle of less than 90 degrees with the narrowest portion and on the outer side of the reverse conical surface portion, and an angle with the narrowest portion is 90 degrees. The motor-operated valve according to claim 1, further comprising an annular flat surface portion.   The motor-operated valve according to any one of claims 1 to 3, wherein a separate annular flat surface including a downstream end surface of the valve seat is provided around a downstream end of the conical surface portion.

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