Motorised valve
By employing a combined structure of valve core, valve body unit, housing, rotor, thrust transmission component, retaining cylinder, and pressing component in the electric valve, the problem of unstable assembly of O-ring and sliding components is solved, and the stability of the seal is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- FUJIKOKI MFG CO LTD
- Filing Date
- 2025-07-29
- Publication Date
- 2026-05-29
AI Technical Summary
In existing electric valves, the assembly of O-rings and sliding parts is prone to friction, which can cause them to curl up or shift, making proper sealing impossible.
It adopts a combination structure of valve core, valve body unit, shell, rotor, thrust transmission component, retaining cylinder, annular sealing unit and pressing component. Through the design of large diameter cylindrical part and small diameter cylindrical part, a circumferential groove is formed to fix O-ring and sliding ring to ensure sealing.
This ensures stable assembly of parts, prevents O-rings from curling up or shifting, and guarantees a sealing effect.
Smart Images
Figure CN122107128A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to an electric valve. Background Technology
[0002] Electric valves have traditionally been installed in the middle of fluid piping systems for opening and closing fluid flow paths and controlling flow rate (see, for example, Patent Document 1). In such electric valves, the valve core is driven by a drive source such as a stepper motor mounted on the valve body, thereby achieving high-precision flow control.
[0003] Existing technical documents
[0004] Patent documents
[0005] Patent document 1: Japanese Patent Application Publication No. 2013-130271.
[0006] The technical problem that the invention aims to solve
[0007] In the electric valve of Patent Document 1, an annular pressing member and a valve core are arranged inside the cylindrical retaining member. A circumferential groove is formed by the small diameter portion at the upper end of the pressing member and the valve core, and an O-ring is installed in the circumferential groove to seal between the valve core and the valve core guide hole.
[0008] Here, as the valve core opens and closes, the valve core guide hole and the O-ring slide relative to each other. Therefore, to protect the O-ring, a cylindrical sliding component is sometimes fitted into its radial outer side. In this case, if an attempt is made to assemble the O-ring and the sliding component integrally onto the upper small-diameter portion of the valve core, the O-ring may roll up or shift inside the sliding component due to friction between the O-ring and the outer circumferential surface of the upper small-diameter portion. This may lead to twisting of the sliding component, resulting in an inability to achieve a proper seal. Summary of the Invention
[0009] The present invention was made in view of such a problem, and its object is to provide an electric valve in which parts can be properly assembled.
[0010] Technical means for solving problems
[0011] The electric valve of the present invention has:
[0012] Valve core;
[0013] A valve body unit, which includes a valve seat and a valve chamber;
[0014] The housing is engaged with the valve body unit;
[0015] A rotor, which is disposed inside the housing;
[0016] A thrust transmission component, which is connected to the valve core and moves axially according to the rotation of the rotor;
[0017] A retaining sleeve that houses the valve core in a slidable manner and is fixed to the valve body unit;
[0018] An annular sealing unit that seals the valve core and the retaining sleeve; and
[0019] A pressing component is used to mount the sealing unit onto the valve core.
[0020] The pressing component has a large-diameter cylindrical portion and a small-diameter cylindrical portion, the diameter of which is smaller than that of the large-diameter cylindrical portion.
[0021] The valve core has a valve core end that abuts against the small-diameter cylindrical portion.
[0022] A peripheral groove for retaining the sealing unit is formed by the first stepped portion adjacent to the small-diameter cylindrical portion of the large-diameter cylindrical portion, the first outer peripheral surface of the small-diameter cylindrical portion, the second outer peripheral surface of the valve core end, and the second stepped portion of the valve core adjacent to the second outer peripheral surface.
[0023] The sealing unit has an O-ring and a sliding ring. The O-ring contacts the bottom surface of the circumferential groove, and the sliding ring is disposed between the O-ring and the inner circumferential surface of the retaining cylinder.
[0024] The effects of the invention
[0025] According to the present invention, an electric valve capable of proper assembly of parts can be provided. Attached Figure Description
[0026] Figure 1 This is a longitudinal sectional view showing the open state of the electric valve according to the first embodiment of the present invention.
[0027] Figure 2 It is an enlarged representation Figure 1 A cross-sectional view near the upper end of the valve core.
[0028] Figure 3 This diagram illustrates the process of assembling O-rings and sliding rings into the pressing component and valve core.
[0029] Figure 4 This refers to the electric valve according to the second embodiment of the present invention. Figure 2 The same longitudinal section view.
[0030] Symbol Explanation
[0031] 1 Electric valve
[0032] 5. Valve body
[0033] 8 Valve seat components
[0034] 8a Valve Seat
[0035] 9. Valve port
[0036] 14 Retaining Cylinder
[0037] 20, 20A valve core
[0038] 20b upper small diameter section
[0039] 20Ab upper conical part
[0040] 20c stepped surface
[0041] 23 Thrust transmission components
[0042] 24, 24A Pressing Components
[0043] 24a Large-diameter cylindrical section
[0044] 24b Small-diameter cylindrical part
[0045] 24c Through Hole
[0046] 24d Lower surface of the large-diameter cylindrical part
[0047] 32c Narrow Diameter Passage Section
[0048] 40 Unique Planetary Gear Reduction Mechanism
[0049] 57 Rotor
[0050] 58. Outer shell
[0051] 61 O-ring
[0052] 62 Sliding ring
[0053] AP equalization pathway
[0054] BC back pressure chamber
[0055] CG, CGA Weekly Slots
[0056] L-axis
[0057] SC spring chamber
[0058] VC valve chamber
[0059] IT inflow management
[0060] OT outflow tube. Detailed Implementation
[0061] Hereinafter, embodiments of the electric valve according to the present invention will be described with reference to the accompanying drawings. Furthermore, in this specification, unless otherwise specified, the upper part of the drawings will be referred to as the upper direction of gravity (hereinafter simply referred to as "upper"), and the lower part of the drawings will be referred to as the lower direction of gravity (hereinafter simply referred to as "lower"). Additionally, in this specification, the flow direction is described as follows: the inflow side connected to the side of the valve chamber in the valve body is the upstream side, and the outflow pipe side connected to the lower part of the valve chamber is the downstream side. However, the electric valve of the present invention can also be used in applications with reverse flow.
[0062] [First Implementation Method]
[0063] Figure 1 This is a longitudinal sectional view showing the open state of the electric valve 1 according to the first embodiment of the present invention. Figure 2 It is an enlarged representation Figure 1 A cross-sectional view near the upper end of the valve core 20 in this embodiment. The electric valve 1 of this embodiment is used, for example, to adjust the refrigerant flow rate in a refrigeration cycle. Let the axis of the electric valve 1 be L.
[0064] The electric valve 1 mainly includes: a valve body 5 having a cylindrical body 6 made of metal such as stainless steel; a housing 58 fixedly installed on the valve body 5; a support member 19 fixedly disposed on the valve body 5 in the internal space divided by the valve body 5 and the housing 58; a valve core 20 supported by the support member 19 and disposed vertically within the internal space; and a rotor 57 mounted above the valve body 5 to enable the valve core 20 to move vertically. The rotor 57, combined with a stator (not shown) disposed on the outside of the housing 58, constitutes a stepper motor.
[0065] The cylindrical body 6 internally divides into a valve chamber VC. The cylindrical body 6 has a first transverse opening 6a on its side, opening into the valve chamber VC, and a second longitudinal opening 6b at its bottom, also opening into the valve chamber VC. A valve seat component 8 is mounted in the second opening 6b. This valve seat component 8 has a shape formed by coaxially and continuously arranging a small-diameter cylinder and a large-diameter cylinder with approximately equal wall thickness. The valve seat component 8 has a valve seat 8a at its upper end and a fitting portion 8c at its lower end, which fits into the second opening 6b. Furthermore, the valve seat component 8 has a valve port 9 opening into the valve chamber VC about its central axis L, and a connecting port 12 connected to the valve port 9, having a diameter larger than the valve port 9 and opening outwards. The valve body unit is composed of the valve seat component 8 and the valve body 5, which includes the cylindrical body 6 to which the valve seat component 8 is connected.
[0066] The end of the inflow pipe IT is inserted into the first opening 6a and brazed together, and the end of the outflow pipe OT is inserted into the connection port 12 and brazed together.
[0067] In addition, an inclined surface 8b connected to the valve seat 8a is formed at the upper end of the valve seat component 8, and the upper end of the inclined surface 8b is located below the axis O of the inflow pipe IT.
[0068] A cylindrical base 13 is installed at the upper end of the opening of the cylindrical body 6. The cylindrical base 13 has a shape in which a small-diameter cylinder and a large-diameter cylinder are coaxially and continuously arranged. At the upper end of the cylindrical base 13, the lower end of the top cylindrical outer shell 58 is joined by welding or the like.
[0069] A support member 19 is disposed inside the cylindrical base 13 and the outer casing 58. The support member 19 has a retaining cylinder 14 and a bearing member 15. The retaining cylinder 14 is continuously formed by a thin-walled cylindrical section 14e and a partition wall 14c extending radially inward from the inner circumference of the cylindrical section 14e. The hollow bearing member 15 has a shape in which an expanded diameter cylindrical section 15b and a reduced diameter cylindrical section 15a disposed below it are coaxially and continuously arranged, and an internal thread 15i is provided on the inner circumference of the reduced diameter cylindrical section 15a.
[0070] The retaining sleeve 14 is fixed to the cylindrical base 13 by pressing or other means, and the outer peripheral stepped portion of the retaining sleeve 14 abuts against the inner peripheral stepped portion of the cylindrical base 13, thereby positioning it in the axial direction. In addition, a bearing component 15 is inserted into the inner periphery of the upper end side of the retaining sleeve 14, and the retaining sleeve 14 and the bearing component 15 are connected and fixed by riveting the upper end of the retaining sleeve 14.
[0071] A spring chamber SC is defined between the partition wall 14c of the retaining cylinder 14 and the bearing component 15, and an opening spring 25 that applies force to the valve core 20 in the opening direction is housed in the spring chamber SC.
[0072] The upper part of the valve core 20 is slidably inserted into the valve core guide hole 14b formed below the partition wall 14c in the retaining sleeve 14. A coarse-diameter passage portion 32b with a tapered opening at the lower end toward the valve port 9 of the valve seat component 8 is formed in the valve core 20; and a fine-diameter passage portion (second through hole) 32c connected to the coarse-diameter passage portion 32b and open at the upper end.
[0073] The lower part 23c of the thrust transmission component 23 is fitted and fixed to the narrow-diameter passage 32c in a state that passes through the through hole (first through hole) 24c of the pressing component 24 (described later). A valve core part 20a in the shape of a generally frustum cone is formed at the lower end of the valve core 20. The valve core part 20a contacts and separates from the valve seat 8a of the valve seat component 8 to open and close the valve port 9.
[0074] Here, in the side view, the coarse diameter passage 32b is a tapered shape that linearly increases from the lower end of the fine diameter passage 32c toward the inner diameter of the valve port 9 of the valve seat component 8. However, it may also be a tapered shape that increases in a curved manner toward the valve port 9 of the valve seat component 8 (e.g., a curve formed by a parabola protruding upwards or downwards).
[0075] A unique planetary gear reduction mechanism (reduction mechanism) 40 is provided on the inner circumference of the rotor 57. This unique planetary gear reduction mechanism 40 consists of a sun gear 41 integrally formed on the rotor support member 56, a fixed gear ring 47 fixed to the upper end of a thin-walled cylindrical body 43 fixedly mounted on the upper part of the retaining sleeve 14, planetary gears 42 disposed between the sun gear 41 and the fixed gear ring 47 and meshing with them respectively, a planetary gear carrier 44 supporting the planetary gears 42 so that they can rotate freely, a bottom ring-shaped output gear 45 meshing with the planetary gears 42 from the outside, and an output shaft 46 fixedly mounted on the upper part by pressing or other means in a hole formed at the bottom of the output gear 45. Here, the number of teeth of the fixed gear ring 47 is set to be different from the number of teeth of the output gear 45. The unique planetary gear reduction mechanism 40 and a stepper motor constitute the drive mechanism.
[0076] A hole is formed at the center of the upper part of the output shaft 46, and the lower part of the support shaft 49 is inserted through this hole. The support shaft 49 is inserted through the center of the sun gear 41 (rotor support member 56) and the planetary gear carrier 44. The upper part of the support shaft 49 is inserted through the center hole of the support member 48, which is disposed above the rotor support member 56 and grounded inside the housing 58. The support member 48 has an outer diameter that is approximately the same as the inner diameter of the housing 58. The rotor 57 itself is held in a manner that prevents it from moving up and down inside the housing 58 by the support member 48, etc., so that the positional relationship between the rotor 57 itself and the stator that is externally fixed to the housing 58 remains constant.
[0077] The lower part of the output shaft 46 of the reduction mechanism 40 is rotatably inserted into the upper part of the bearing component 15, and a slit-shaped fitting portion 46a extending along the axis L is formed in the lower part of the output shaft 46. A plate-shaped blade portion 17c is provided protruding from the upper end of the rotary lifting shaft 17. The rotary lifting shaft 17 is threaded with an external thread 17a that engages with the internal thread 15i of the bearing component 15, and the blade portion 17c is slidably fitted into the fitting portion 46a. When the output shaft 46 rotates together with the rotor 57, the rotational force of the output shaft 46 is transmitted to the rotary lifting shaft 17. The threaded feed motion generated by the engagement of the internal thread 15i of the bearing component 15 and the external thread 17a of the rotary lifting shaft 17 causes the rotary lifting shaft 17 to rotate and rise simultaneously.
[0078] A stepped cylindrical thrust transmission component 23 is disposed below the rotary lifting shaft 17. This thrust transmission component 23 transmits the downward thrust of the rotary lifting shaft 17 via a ball 18 and a ball bearing 16. Furthermore, by inserting the ball 18 between the rotary lifting shaft 17 and the thrust transmission component 23, for example, even if the rotary lifting shaft 17 rotates and descends, only the downward thrust is transmitted from the rotary lifting shaft 17 to the thrust transmission component 23, and no rotational force is transmitted.
[0079] The thrust transmission component 23 is formed from top to bottom by a continuously arranged large-diameter upper part 23a, a middle body 23b, and a small-diameter lower part 23c with a diameter smaller than that of the middle body 23b. The ball bearing 16 is embedded in the inner circumference of the large-diameter upper part 23a, and the middle body 23b is slidably inserted through a hole formed in the partition wall 14c of the retaining cylinder 14. Inside the thrust transmission component 23, there is a through hole 32d with the axis L as the central axis, and a transverse hole 32e orthogonal to the through hole 32d and communicating with the back pressure chamber BC (described later). The upper opening of the through hole 32d is closed by the ball bearing 16. In addition, the through hole 32d and the transverse hole 32e constitute a through hole. Furthermore, the through hole 32d, the transverse hole 32e, and the large-diameter passage 32b and the small-diameter passage 32c of the valve core 20 constitute a pressure equalization passage AP that connects the back pressure chamber BC with the discharge path (outflow pipe OT).
[0080] As described above, the lower part 23c of the thrust transmission component 23 is fixed within the narrow-diameter passage 32c of the valve core 20 by pressing or fitting, allowing the valve core 20 and the thrust transmission component 23 to move up and down as a single unit. Furthermore, an annular pressing component 24 is inserted and fixed between the upper end face of the valve core 20 and the lower end step of the middle body 23b of the thrust transmission component 23.
[0081] exist Figure 2 In this design, the pressing member 24 is continuously and coaxially arranged with respect to the axis L, consisting of a large-diameter cylindrical portion 24a and a small-diameter cylindrical portion (also called a small-diameter cylindrical portion) 24b with a diameter smaller than that of the large-diameter cylindrical portion 24a. The pressing member 24 has a through hole 24c in the center. The valve core 20 has an upper small-diameter portion (also called a valve core end) 20b opposite to the small-diameter cylindrical portion 24b. The outer diameter of the upper small-diameter portion 20b, which is coaxial with the axis L, is approximately equal to the outer diameter of the small-diameter cylindrical portion 24b. In addition, the outer diameter of the valve core 20 inside the retaining cylinder 14, excluding the upper small-diameter portion 20b, is approximately equal to the outer diameter of the large-diameter cylindrical portion 24a. The valve core 20 has a stepped surface 20c (second stepped portion) connecting the small-diameter cylindrical portion 24b and the outer peripheral surface excluding the small-diameter cylindrical portion 24b. The stepped surface 20c is parallel to the lower surface 24d of the large-diameter cylindrical portion 24a.
[0082] By pressing the lower small-diameter portion 23c of the through hole 24c into the narrow-diameter passage portion 32c, the pressing component 24 and the valve core 20 are brought into contact and fixed together, so that the lower surface of the small-diameter cylindrical portion 24b and the upper surface of the upper small-diameter portion 20b are abutted. The lower small-diameter portion 23c may also be in an interference fit with the through hole 24c.
[0083] By connecting and fixing the pressing member 24 to the valve core 20, a peripheral groove CG is formed by the lower surface (first step portion) 24d of the large-diameter cylindrical portion 24a adjacent to the small-diameter cylindrical portion 24b, the outer peripheral surface of the small-diameter cylindrical portion 24b (also called the first outer peripheral surface), the outer peripheral surface of the upper small-diameter portion 20b (also called the second outer peripheral surface), and the step surface 20c adjacent to the upper small-diameter portion 20b. That is, the bottom surface of the peripheral groove CG is formed by the outer peripheral surface of the small-diameter cylindrical portion 24b and the outer peripheral surface of the upper small-diameter portion 20b, and the opposite side surface of the peripheral groove CG is formed by the lower surface 24d of the large-diameter cylindrical portion 24a and the step surface 20c.
[0084] An O-ring 61, which contacts the outer circumferential surface of the small-diameter cylindrical portion 24b and the outer circumferential surface of the upper small-diameter portion 20b, and a cylindrical sliding ring 62 (sealing ring or lip seal) are disposed within the peripheral groove CG. The sliding ring 62 is formed of a resin material with high sliding properties and is resistant to wear, and has approximately equal wall thickness in its circumferential cross-section. The O-ring 61 and the sliding ring 62 constitute an annular sealing unit.
[0085] The sliding ring 62 has the following on its outer periphery: an outer cylindrical surface 62a; an upper conical surface 62b extending upward from the upper end of the outer cylindrical surface 62a; and a lower conical surface 62c extending downward from the lower end of the outer cylindrical surface 62a. Additionally, the sliding ring 62 has a retaining groove 62d for retaining the O-ring 61 on its inner periphery.
[0086] With the O-ring 61 held in the retaining groove 62d, the sliding ring 62 and the O-ring 61 are assembled into the peripheral groove CG. When inserted into the valve core guide hole 14b of the retaining cylinder 14, the outer peripheral cylindrical surface 62a can slide relative to the inner peripheral surface of the valve core guide hole 14b.
[0087] Figure 3 This diagram illustrates the process of assembling the O-ring 61 and the sliding ring 62 into the pressing member 24 and the valve core 20. Here, the axial length of the small-diameter cylindrical portion 24b is defined as a, and the axial length of the upper small-diameter portion 20b is also defined as a.
[0088] like Figure 3 As shown in (a), the O-ring 61 and the sliding ring 62 are combined and placed on the upper small-diameter portion 20b of the valve core 20. In the free state (without external force applied), the inner diameter of the O-ring 61 is smaller than the outer diameter of the upper small-diameter portion 20b, so the O-ring 61 remains placed on the upper small-diameter portion 20b.
[0089] In this state, when the pressing member 24 is brought close from above, as... Figure 3 As shown in (b), the lower end of the small-diameter cylindrical portion 24b abuts against the inner diameter side of the O-ring 61. When the pressing member 24 is continued to be pressed against the valve core 20 side, the pressing member 24 and the valve core 20 are pressed evenly from both sides, thereby causing the O-ring 61 and the sliding ring 62 to elastically deform in a manner that expands their diameter. Furthermore, as... Figure 3 As shown in (c), the O-ring 61 spans the outer circumferential surface of the upper small-diameter portion 20b and the outer circumferential surface of the small-diameter cylindrical portion 24b, thereby enabling the O-ring 61 and the sliding ring 62 to be assembled into the circumferential groove CG. After assembling the O-ring 61 and the sliding ring 62 into the pressing member 24 and the valve core 20, the lower small-diameter portion 23c of the thrust transmission member 23 inserted into the retaining cylinder 14 can be pressed into the through hole 24c of the pressing member 24 and the narrow-diameter passage portion 32c of the valve core 20. Figure 2 This prevents the pressing component 24 from separating from the valve core 20. Alternatively, the O-ring 61 can be pressed into either the upper small-diameter portion 20b or the small-diameter cylindrical portion 24b first.
[0090] Next, the valve core 20, assembled with O-ring 61, sliding ring 62, and pressing member 24, is inserted into the retaining cylinder 14, and the upper surface of the large-diameter cylindrical portion 24a is pressed against the lower surface of the partition wall 14c. Then, the lower small-diameter portion 23c of the thrust transmission member 23 is inserted through the central hole of the partition wall 14c and further pressed into the through hole 24c of the pressing member 24 and the narrow-diameter passage portion 32c of the valve core 20. Alternatively, the lower small-diameter portion 23c of the thrust transmission member 23 can be pre-assembled into the retaining cylinder 14, and then the valve core 20, assembled with O-ring 61, sliding ring 62, and pressing member 24, is inserted into the retaining cylinder 14, and the lower small-diameter portion 23c protruding from the central hole of the partition wall 14c is pressed into the through hole 24c and the narrow-diameter passage portion 32c.
[0091] Assume that the pressing component 24 is completely annular (consisting only of a large-diameter cylindrical portion), and the axial length of the upper small-diameter portion 20b is (2·a) (in Figure 2 (Imaginary lines are shown in the diagram with double-dotted lines). In order to assemble the O-ring 61 and the sliding ring 62 into the circumferential groove, they must move a relatively long distance along the upper small diameter portion 20b. In this case, during the long-distance movement, the O-ring 61 may roll up (the inner circumferential side shifts outward as a whole) or shift due to friction with the outer circumferential surface of the upper small diameter portion 20b, which may cause the sliding ring 62 to twist, etc.
[0092] In contrast, according to this embodiment, when the O-ring 61 spans the outer peripheral surfaces of the upper small-diameter portion 20b and the small-diameter cylindrical portion 24b, which have the same axial length 'a', frictional forces in opposite directions are applied equally to both outer peripheral surfaces, thus suppressing undesirable conditions such as curling or shifting. Therefore, by maintaining the stable posture of the sliding ring 62 of the O-ring 61, the outer peripheral cylindrical surface 62a can be tightly fitted against the valve core guide hole 14b. Furthermore, the axial lengths of the upper small-diameter portion 20b and the small-diameter cylindrical portion 24b do not always need to be the same. For example, when the total length is (2·a), the axial length of one of the upper small-diameter portion 20b and the small-diameter cylindrical portion 24b can be arbitrarily set to be (0.7·a) or more and (1.3·a) or less.
[0093] exist Figure 1 As described above, an opening spring 25, composed of a compression coil spring, is disposed in the spring chamber SC above the partition wall 14c of the retaining cylinder 14, and the lower end of the opening spring 25 is supported by the partition wall 14c. Furthermore, a spring support body 28 is disposed around the upper end of the thrust transmission member 23, and this spring support body 28 has flange-shaped latching portions 28a and 28b at its upper and lower sides. The latching portion 28a on the upper side of the spring support body 28 rests on the upper part of the opening spring 25, and the latching portion 28b on the lower side hooks onto the lower step portion of the large-diameter upper part 23a of the thrust transmission member 23, thereby enabling the force (lifting force) of the opening spring 25 to be transmitted to the valve core 20 via the thrust transmission member 23.
[0094] Additionally, a connecting hole 14d is formed in the retaining cylinder 14, which connects the spring chamber SC with the interior of the outer casing 58 to counteract their pressure difference.
[0095] (Action of the electric valve)
[0096] When from Figure 1 The rotor 57 of the stepper motor, driven by the state shown, rotates in one direction. The rotation of rotor 57 is slowed down via the output shaft 46 of the reduction mechanism 40 and transmitted to the rotary lifting shaft 17. Through the threaded feed motion generated by the engagement of the internal thread 15i of the bearing component 15 and the external thread 17a of the rotary lifting shaft 17, the rotary lifting shaft 17 rotates and descends simultaneously. The thrust of the rotary lifting shaft 17 causes the thrust transmission component 23 and the valve core 20 to overcome the force of the valve opening spring 25 and be pressed down. Finally, the valve core portion 20a, formed by the lower end of the valve core 20, sits on the valve seat 8a, thereby closing the valve port 9. Thus, the refrigerant flowing from the inlet pipe IT into the valve chamber VC is prevented from flowing to the outlet pipe OT side.
[0097] Conversely, when the rotor 57 driving the stepper motor rotates in the opposite direction, the rotation of the rotor 57 is reduced in speed via the output shaft 46 of the reduction mechanism 40 and transmitted to the rotary lifting shaft 17. Through the threaded feed motion generated by the engagement of the internal thread 15i and the external thread 17a, the rotary lifting shaft 17 rotates and rises simultaneously. Simultaneously, the thrust transmission component 23 and the valve core 20 are lifted by the force of the valve opening spring 25, causing the valve core 20a to separate from the valve seat 8a, thereby opening the valve port 9. Thus, the refrigerant flowing from the inflow pipe IT into the valve chamber VC is allowed to flow through the valve port 9 to the outflow pipe OT side.
[0098] According to this embodiment, a back pressure chamber BC is defined above the valve core 20, between the pressing member 24 and the partition wall 14c of the retaining cylinder 14. Furthermore, the narrow-diameter passage 32c communicates with the back pressure chamber BC via the through hole 32d and the transverse hole 32e of the thrust transmission member 23. Therefore, in order to balance (counteract the pressure difference) the downward pressure (force acting in the closing direction) acting on the valve core 20 in the closed state and the upward force (force acting in the opening direction) acting on the valve core 20, the diameter of the back pressure chamber BC is set to be approximately the same as the diameter of the valve port 9. To ensure this counteracting function, it is important to seal the valve core guide hole 14b and the valve core 20 with an O-ring 61 and a sliding ring 62 to prevent refrigerant from moving from the valve chamber VC to the back pressure chamber BC. Since the sliding ring 62 has an upper conical surface 62b and a lower conical surface 62c, when the outer circumferential cylindrical surface 62a slides relative to the inner circumferential surface of the valve core guide hole 14b, it can ensure smooth sliding without jamming, regardless of whether it slides in the up or down direction.
[0099] Furthermore, since the O-ring 61 is positioned between the lower surface of the pressing member 24 and the contact surface of the upper small diameter portion 20b of the valve core 20, refrigerant cannot pass through.
[0100] [Second Implementation]
[0101] Figure 4 This refers to the electric valve of the second embodiment of the present invention. Figure 2 The same longitudinal sectional view. In this embodiment, only the pressing component 24A and the valve core 20A differ from the first embodiment; the rest of the structure is the same as the first embodiment, so repeated descriptions are omitted.
[0102] The valve core 20A differs from the first embodiment only in its upper tapered portion 20Ab; the rest of its structure is the same as the first embodiment, so repeated descriptions are omitted. The upper tapered portion 20Ab has a tapered outer peripheral surface that narrows as it faces upwards.
[0103] The pressing member 24A is coaxially and continuously formed by a large-diameter cylindrical portion 24a and a small-diameter tapered portion (also called a small-diameter cylindrical portion) 24Ab, the largest diameter of which is smaller than that of the large-diameter cylindrical portion, and has a through hole 24c in the center. The small-diameter tapered portion 24Ab has a tapered outer peripheral surface that becomes smaller as it faces downward. The cone apex angle (in the side view, the angle formed by the pair of outer peripheral surfaces that clamp the axis L) of the small-diameter tapered portion 24Ab and the upper tapered portion 20Ab are preferably the same, and their axial lengths are also preferably equal. That is, the small-diameter tapered portion 24Ab and the upper tapered portion 20Ab preferably have a common frustum-shaped cone.
[0104] According to this embodiment, by connecting and fixing the pressing member 24A to the valve core 20A, a peripheral groove CGA for retaining the O-ring 61 and the sliding ring 62 is formed by the lower surface 24d of the large-diameter cylindrical portion 24a, the conical outer peripheral surface (also called the first outer peripheral surface) of the small-diameter conical portion 24Ab, the conical outer peripheral surface (also called the second outer peripheral surface) of the upper conical portion 20Ab, and the stepped surface 20c.
[0105] Because the outer peripheral surfaces of the upper tapered portion 20Ab and the small-diameter tapered portion 24Ab have opposing tapered shapes, the O-ring 61 experiences a lower and more uniform frictional force when it straddles these two outer peripheral surfaces during assembly, thereby further suppressing the undesirable situation of the O-ring 61 curling up or shifting. Therefore, maintaining the stable posture of the sliding ring 62 of the O-ring 61 allows the outer peripheral cylindrical surface 62a to fit tightly against the valve core guide hole 14b.
[0106] Furthermore, the present invention is not limited to the embodiments described above. Any constituent elements of the above embodiments can be modified within the scope of the present invention. Additionally, any constituent elements can be added or omitted in the above embodiments. Furthermore, it can also be used in a refrigerant counter-current state, in which the refrigerant flows into the valve chamber from the outlet pipe OT and flows out from the inlet pipe IT.
[0107] This specification includes disclosures of the following inventions.
[0108] (First method)
[0109] An electric valve having:
[0110] Valve core;
[0111] A valve body unit, which includes a valve seat and a valve chamber;
[0112] The housing is engaged with the valve body unit;
[0113] A rotor, which is disposed inside the housing;
[0114] A thrust transmission component, which is connected to the valve core and moves axially according to the rotation of the rotor;
[0115] A retaining sleeve that houses the valve core in a slidable manner and is fixed to the valve body unit;
[0116] An annular sealing unit that seals the valve core and the retaining sleeve; and
[0117] A pressing component is used to mount the sealing unit onto the valve core.
[0118] The pressing component has a large-diameter cylindrical portion and a small-diameter cylindrical portion, the diameter of which is smaller than that of the large-diameter cylindrical portion.
[0119] The valve core has a valve core end that abuts against the small-diameter cylindrical portion.
[0120] A peripheral groove for retaining the sealing unit is formed by the first stepped portion adjacent to the small-diameter cylindrical portion of the large-diameter cylindrical portion, the first outer peripheral surface of the small-diameter cylindrical portion, the second outer peripheral surface of the valve core end, and the second stepped portion of the valve core adjacent to the second outer peripheral surface.
[0121] The sealing unit has an O-ring and a sliding ring. The O-ring contacts the bottom surface of the circumferential groove, and the sliding ring is disposed between the O-ring and the inner circumferential surface of the retaining cylinder.
[0122] (Second method)
[0123] In the electric valve described in the first embodiment...
[0124] The small-diameter column and the valve core end have a cylindrical shape coaxial with the axis of the electric valve and have the same outer diameter.
[0125] (Third method)
[0126] In the electric valve described in the first embodiment...
[0127] The small-diameter column portion has a tapered shape that decreases in diameter toward the valve core end portion, and the valve core end portion has a tapered shape that decreases in diameter toward the small-diameter column portion.
[0128] (Fourth method)
[0129] In the electric valve described in the third method
[0130] The small-diameter column portion and the small-diameter column portion share the same frustum-shaped cone.
[0131] (Fifth method)
[0132] In any one of the first to fourth methods of the electric valve
[0133] The axial length of the small-diameter column is approximately equal to the axial length of the valve core end.
[0134] (Sixth method)
[0135] In any one of the first to fifth methods of the electric valve
[0136] The pressing component has a first through hole, the valve core has a second through hole, and a portion of the thrust transmission component passes through the first through hole and is fitted into the second through hole by pressing.
[0137] (Seventh Method)
[0138] In any one of the first to sixth methods of the electric valve
[0139] A back pressure chamber is formed by the retaining sleeve and the valve core inserted into the retaining sleeve, and the back pressure chamber communicates with the discharge path via a through hole formed in a part of the thrust transmission component.
Claims
1. An electric valve, characterized in that, have: Valve core; A valve body unit, which includes a valve seat and a valve chamber; The housing is engaged with the valve body unit; A rotor, which is disposed inside the housing; A thrust transmission component, which is connected to the valve core and moves axially according to the rotation of the rotor; A retaining sleeve that houses the valve core in a slidable manner and is fixed to the valve body unit; An annular sealing unit that seals the valve core and the retaining cylinder; as well as A pressing component is used to mount the sealing unit onto the valve core. The pressing component has a large-diameter cylindrical portion and a small-diameter cylindrical portion, the diameter of which is smaller than that of the large-diameter cylindrical portion. The valve core has a valve core end that abuts against the small-diameter cylindrical portion. A peripheral groove for retaining the sealing unit is formed by the first stepped portion adjacent to the small-diameter cylindrical portion of the large-diameter cylindrical portion, the first outer peripheral surface of the small-diameter cylindrical portion, the second outer peripheral surface of the valve core end, and the second stepped portion of the valve core adjacent to the second outer peripheral surface. The sealing unit has an O-ring and a sliding ring. The O-ring contacts the bottom surface of the circumferential groove, and the sliding ring is disposed between the O-ring and the inner circumferential surface of the retaining cylinder.
2. The electric valve according to claim 1, characterized in that, The small-diameter column and the valve core end have a cylindrical shape coaxial with the axis of the electric valve and have the same outer diameter.
3. The electric valve according to claim 1, characterized in that, The small-diameter column portion has a tapered shape that decreases in diameter toward the valve core end portion, and the valve core end portion has a tapered shape that decreases in diameter toward the small-diameter column portion.
4. The electric valve according to claim 3, characterized in that, The small-diameter column portion and the valve core end portion share the same frustum-shaped cone.
5. The electric valve according to claim 1, characterized in that, The axial length of the small-diameter column is approximately equal to the axial length of the valve core end.
6. The electric valve according to claim 1, characterized in that, The pressing component has a first through hole, the valve core has a second through hole, and a portion of the thrust transmission component passes through the first through hole and is fitted into the second through hole by pressing.
7. The electric valve according to any one of claims 1 to 6, characterized in that, A back pressure chamber is formed by the retaining sleeve and the valve core inserted into the retaining sleeve, and the back pressure chamber communicates with the discharge path via a through hole formed in a part of the thrust transmission component.