A valve seat assembly for injection molding fixed electromagnetic valve

Abstract

The utility model discloses a kind of injection molding solidification type solenoid valve valve seat assemblies, it is related to solenoid valve core component technical field.The valve seat assembly includes sleeve of metal material and valve seat of plastic material, both are consolidated by injection molding integration;Sleeve is hollow thin-walled rotary member, from top to bottom is equipped with outer flange face, middle straight cylinder guide section and lower end inside turning portion in sequence, straight cylinder section wall is circumferentially provided with side flow channel hole, and inside turning portion inside lower end forms inlaid locking end face;Valve seat upper end center is projected and forms valve core cooperation sealing valve port, and upper portion is provided with sleeve inlaid covering locking groove, and plastic melt is wrapped inlaid locking end face when injection molding, and form the mechanical clamping structure of axial and circumferential double locking.This utility model replaces traditional welding process, there is no thermal deformation defect, and high bonding strength, reliable sealing, simple structure, low manufacturing cost, suitable for mass production application.

Description

Technical Field

[0001] This utility model relates to the field of solenoid valve technology, specifically to a valve seat assembly for an injection-molded solidified solenoid valve. Background Technology

[0002] The solenoid valve seat assembly is the main functional component of the fluid control solenoid valve. It is usually composed of two parts: a sleeve and a valve seat. The internal structure forms a fluid flow channel, and the valve seat, as a sealing base, cooperates with the valve core to achieve fluid on / off control.

[0003] Existing valve seat assemblies mainly adopt the following two types of fixing schemes: The first type is the metal welding solution, where both the sleeve and the valve seat are made of metal and are fixed together using processes such as laser welding or argon arc welding. This type of solution has obvious drawbacks: the welding process is cumbersome and the investment in specialized equipment is high; the local high temperature generated during the welding process can easily cause thermal deformation of the parts, resulting in the flatness of the sealing surface and the coaxiality of the parts exceeding the standard, directly causing sealing failure; the weld area is a weak point of stress concentration, and after long-term exposure to high pressure fluid differential and high-frequency opening and closing impact of the valve core, it is prone to problems such as weld fatigue cracking and media leakage, resulting in a significant upper limit to its service life; in addition, the overall processing cost of bimetallic parts is high and the mass production efficiency is low.

[0004] The second category includes simple press-fit, bonding, or ordinary injection molding embedding schemes. Ordinary injection molding embedding schemes typically involve creating simple straight grooves or through holes on the outer wall of the sleeve, with plastic filling the groove during injection molding to achieve basic positioning. This type of scheme has a simple locking structure, only achieving basic axial positioning, and has weak circumferential torsional resistance. Under the reciprocating impact of the valve core and the action of fluid swirling, the sleeve is prone to circumferential movement, leading to flow channel displacement and sealing coaxiality failure. Simultaneously, the sealing path at the mating surface is short and the fit is insufficient, making it easy for the medium to leak along the mating surface between the sleeve and the plastic under high-pressure conditions, failing to meet the requirements for high-pressure, high-frequency opening and closing.

[0005] In summary, existing solenoid valve seat assemblies generally suffer from technical defects such as high processing costs, insufficient structural strength, poor sealing reliability, and short fatigue life. There is an urgent need for a valve seat assembly structure that combines low cost, high strength, and high sealing performance. Utility Model Content

[0006] This invention provides a valve seat assembly for injection-molded solidified solenoid valves, which can solve the technical defects of existing solenoid valve seat assemblies, such as high processing cost, insufficient structural strength, poor sealing reliability, and short fatigue life.

[0007] To achieve the above objectives, this utility model provides the following technical solution: a valve seat assembly for an injection-molded solenoid valve, comprising a metal sleeve and a plastic valve seat, wherein the sleeve and the valve seat are integrally fixed by injection molding. The sleeve is a hollow thin-walled rotating part, which, from top to bottom, consists of an outwardly flared flange face, a middle straight cylindrical guide section, and a lower inwardly flared portion. The inner side of the lower inwardly flared portion forms a ring of embedded locking end face. The middle straight cylindrical guide section has a side flow channel hole circumferentially opened on its cylindrical wall. The valve seat is an integrally injection-molded rotating body, with a ring-shaped valve core forming a central protrusion at its upper end. The valve seat has a sleeve-embedded locking groove on its upper part. The lower end of the sleeve is embedded in this locking groove. During injection molding, the molten plastic wraps around the embedded locking end face and covers the outer wall of the lower end of the sleeve, forming a mechanical snap-fit ​​structure with dual axial and circumferential locking. In the axial direction, the plastic snap-fit ​​is engaged above the embedded locking end face, preventing the sleeve from being pulled out axially. In the circumferential direction, the inward-turning structure and the mating surface of the plastic restrict relative rotation between them. This dual locking significantly improves the bonding strength, allowing it to withstand high-pressure fluid differential pressure and high-frequency impact kinetic energy of the valve core for extended periods without the risk of loosening or failure.

[0008] Preferably, the flange face and the lower middle straight cylinder guide section are smoothly transitioned by a flange straight cylinder transition fillet. The fillet transition makes the overall sleeve more uniformly stressed, which can effectively delay the generation of fatigue cracks under long-term alternating loads of valve core reciprocating impact and fluid pressure pulsation.

[0009] Preferably, the closed shape formed by the embedded locking end face is polygonal, and the edge-fitting structure completely restricts the circumferential relative rotation between the sleeve and the valve seat, significantly improving the circumferential torsional resistance.

[0010] Preferably, the outer wall of the lower inward-turned portion is an arc surface, and the central angle of the arc surface is not less than 80°. The valve seat includes a valve seat injection molding base, and the sleeve is embedded in the upper end face of the valve seat injection molding base. The outer diameter of the valve seat injection molding base is the same as the outer diameter of the lower inward-turned portion. The larger contact area increases the bonding force between the plastic and the sleeve, and the axial pull-out strength is greatly improved. The arc surface extends the path of medium leakage along the joint surface, significantly improving the sealing reliability under high pressure conditions and further reducing the risk of leakage at the joint surface. At the same time, the arc surface also guides the injection molding plastic to cover the outer wall of the sleeve during injection molding.

[0011] Preferably, the side flow channel holes are located near the valve seat and are evenly distributed around the circumference. The evenly distributed flow channels ensure that the valve core is subjected to balanced circumferential force, thus preventing the valve core from experiencing unilateral wear due to uneven load.

[0012] Preferably, the sleeve is made of stainless steel, which improves the media adaptability and environmental weather resistance of the valve seat assembly and makes it applicable to a wider range of working conditions.

[0013] Compared with the prior art, the beneficial effects of this utility model are: The metal sleeve and plastic valve seat are injection molded into a single integrated structure, replacing the traditional metal welding process. There is no high-temperature heat input throughout the process, which completely avoids sealing failure and dimensional inaccuracy caused by welding heat deformation. The single injection molding process completes the fixing of parts and sealing of the mating surfaces simultaneously, eliminating the need for secondary assembly processes and significantly reducing equipment investment and production costs.

[0014] The lower end of the sleeve is turned inward to form an embedded locking end face. After injection molding, the plastic completely wraps around the sleeve to form a double mechanical snap-fit ​​structure in both the axial and circumferential directions. The joint strength is high and it can withstand the pressure difference of high-pressure fluid and the high-frequency impact of the valve core for a long time without the risk of loosening or failure. The fully fitted and seamless joint surface effectively blocks the path of media leakage along the joint surface, greatly improving the sealing reliability. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a front sectional view of the present invention; Figure 3 This is a three-dimensional structural diagram of the sleeve of this utility model; Figure 4 This is a three-dimensional structural diagram of the valve seat of this utility model.

[0016] Figure label: 1. Sleeve; 2. Valve seat; 11. Middle straight guide section; 12. Flange face; 13. Lower inward turnout; 14. Side flow channel hole; 15. Embedded locking end face; 16. Flange straight transition fillet; 21. Valve core mating to seal the valve port; 22. Sleeve embedded locking groove; 23. Valve seat injection molded base; 24. Annular sealing groove. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0018] like Figure 1-4As shown, this utility model provides a solution to address the common technical defects of existing solenoid valve seat assemblies, such as high processing costs, insufficient structural strength, poor sealing reliability, and short fatigue life. The present utility model provides the following technical solution: a valve seat assembly for an injection-molded solenoid valve, comprising a metal sleeve 1 and a plastic valve seat 2, wherein the sleeve 1 and the valve seat 2 are integrally fixed by injection molding. The sleeve 1 is a hollow thin-walled rotating part, consisting of, from top to bottom, an outwardly turned flange face 12, a middle straight cylindrical guide section 11, and a lower inwardly turned portion 13. The inner side of the lower inwardly turned portion 13 forms an embedded locking end face 15. The middle straight cylindrical guide section 11 has a circumferentially circumferentially opened side flow channel hole 14. The valve seat 2... The device is a rotary body integrally injection molded. Its upper center protrusion forms an annular valve core that seals the valve port 21. The upper part of the valve seat 2 has an embedded locking groove 22. The lower end of the sleeve 1 is embedded in this embedded locking groove 22. During injection molding, the molten plastic wraps around the embedded locking end face 15 and covers the lower outer wall of the sleeve 1, forming a mechanical snap-fit ​​structure with dual axial and circumferential locking. During injection molding, the molten plastic wraps around the embedded locking end face and fills the embedded locking groove 22. After cooling, the mechanical snap-fit ​​structure is formed: in the axial direction, the plastic snap-fit ​​is locked above the embedded locking end face, preventing the sleeve from being pulled out axially; in the circumferential direction, the inward-turning structure and the mating surface of the plastic restrict relative rotation between them. This dual locking significantly improves the bonding strength, allowing it to withstand high-pressure fluid differential pressure and high-frequency impact kinetic energy of the valve core for extended periods without the risk of loosening or failure. The sleeve 1 is made of stainless steel, which improves the media adaptability and environmental weather resistance of the valve seat assembly and makes it applicable to a wider range of working conditions.

[0019] In this embodiment, the flange face 12 and the lower middle straight cylindrical guide section 11 are smoothly transitioned by the flange straight cylindrical transition fillet 16. The fillet transition makes the overall sleeve more uniformly stressed, which can effectively delay the generation of fatigue cracks under long-term alternating loads of valve core reciprocating impact and fluid pressure pulsation.

[0020] In this embodiment, the closed shape formed by the embedded locking end face 15 is polygonal, and the edge-fitting structure completely restricts the circumferential relative rotation between the sleeve and the valve seat, significantly improving the circumferential torsional resistance.

[0021] In this embodiment, the outer wall of the lower inwardly turned portion 13 is an arc surface, and the central angle of the arc surface is not less than 80°. The valve seat 2 includes a valve seat injection molding base 23, and the sleeve is embedded in the upper end surface of the valve seat injection molding base 23. The outer diameter of the valve seat injection molding base 23 is the same as the outer diameter of the lower inwardly turned portion 13. The larger contact area increases the bonding force between the plastic and the sleeve, and the axial pull-out strength is greatly improved. The arc surface extends the path of medium leakage along the joint surface, significantly improving the sealing reliability under high pressure conditions and further reducing the risk of leakage at the joint surface. At the same time, the arc surface also guides the injection molding plastic to cover the outer wall of the sleeve 1 during injection molding.

[0022] In this embodiment, the side flow channel hole 14 is located near the valve seat 2 and is evenly distributed around the circumference. The evenly distributed flow channel makes the valve core circumferentially stressed evenly, avoiding unilateral wear of the valve core due to uneven load.

[0023] The following is in conjunction with the appendix Figure 1-4 The specific embodiments of this utility model are described in detail. These embodiments are implemented based on the technical solution of this utility model and provide detailed implementation methods and specific operation processes. However, the protection scope of this utility model is not limited to the following embodiments.

[0024] like Figure 1 As shown in the figure, the valve seat assembly for an injection-molded solenoid valve disclosed in this embodiment mainly consists of a metal sleeve 1 and a plastic valve seat 2, which are integrally fixed into a whole structure through an insert injection molding process. This valve seat assembly is assembled inside the solenoid valve and serves as both a medium fluid delivery channel and a sealing switch base for controlling the flow of fluid.

[0025] Among them, sleeve 1 is a hollow thin-walled rotating part formed in one piece by continuous stamping process of stainless steel plate, without cutting process, with high overall coaxiality and good dimensional consistency. Sleeve 1 consists of flange face 12, middle straight cylindrical guide section 11 and lower inward turn section 13 from top to bottom.

[0026] The flange face 12 is an annular outward-facing structure with a flat, fitted upper surface that can be riveted to the solenoid valve's stationary iron component to achieve axial and radial centering and fixation of the entire sleeve 1. The flange face 12 and the lower central straight guide section 11 are smoothly transitioned through the flange straight transition fillet 16 to eliminate stress concentration at the junction.

[0027] The central straight cylindrical guide section 11 is a thin-walled cylindrical base with a high-precision smooth cylindrical surface on its inner wall. This surface serves as a guide for the reciprocating motion of the solenoid valve's moving iron valve core, ensuring coaxiality throughout the valve core's movement and reducing uneven wear. Near the lower end of the central straight cylindrical guide section 11, multiple side flow channel holes 14 are evenly distributed along the circumference, connecting the inner cavity of the sleeve with the outer cavity and serving as a flow channel for fluid inflow and outflow.

[0028] The lower inward folding part 13 is formed by folding the lower end of the middle straight cylindrical guide section 11 inward. Its outer side wall is a continuous arc surface with a central angle of not less than 80°. The inner side of the lower inward folding part 13 forms a horizontal embedded locking end face 15. The closed contour formed by the embedded locking end face 15 can be set as a polygonal structure such as a regular hexagon or a regular octagon to improve the circumferential locking capability.

[0029] The valve seat 2 is integrally molded from high-strength engineering plastic using insert injection molding, forming a rotating structure with the main body being the valve seat injection molding base 23. An annular sleeve-embedded locking groove 22 is formed on the upper surface of the valve seat injection molding base 23, and the lower end of the sleeve 1 is embedded within this sleeve-embedded locking groove 22. During injection molding, the molten plastic fills the groove and completely encloses the outer wall of the lower inward-turned portion 13 and the embedded locking end face 15, forming a mechanical snap-fit ​​structure after cooling. The outer diameter of the valve seat injection molding base 23 is consistent with the outer diameter of the lower inward-turned portion 13, ensuring a smooth transition of the component's outer wall.

[0030] The valve seat 2 has a raised center at the top to form an annular valve core that seals the valve port 21. Its upper surface is a precision-machined flat surface that can precisely fit with the lower end face of the solenoid valve's moving iron valve core. The sealing control of fluid flow is achieved by relying on the end face contact.

[0031] The valve seat injection molding base 23 is hollow inside, forming a medium downward channel. This channel is interconnected with the inner cavity of the sleeve 1 and the side flow channel hole 14, forming a complete medium flow cavity. An annular sealing groove 24 can be opened on the lower outer circle of the valve seat injection molding base 23 for assembling an O-ring seal to achieve an external static seal between the valve seat assembly and the solenoid valve housing.

[0032] In this embodiment, the molding of the valve seat assembly is divided into two main processes, as detailed below: The first step is sleeve stamping. Select a stainless steel sheet of a preset thickness, and complete blanking, cylindrical stretching, punching of side flow channel holes 14, upper end flanging forming of flange face 12 and flange straight cylinder transition radius 16, lower end inward forming of lower inward part 13 and embedded locking end face 15 through continuous stamping die, and finally obtain a complete sleeve 1 finished product. The whole process has no cutting processing, with high production efficiency and low cost.

[0033] The second step is insert injection molding and solidification. The stamped sleeve 1 is used as an insert and is precisely positioned in the cavity of the injection mold to ensure the coaxiality of the sleeve and the mold cavity. After the mold is closed, molten engineering plastic is injected into the cavity. The molten plastic fills the cavity space around the lower end of the sleeve, completely covering the outer wall of the lower inward turnout 13 and the inner locking end face 15, and simultaneously forming all structures such as the valve core, the sealing valve port 21, and the valve seat injection base 23. After the plastic cools and solidifies, the mold is opened. The sleeve 1 and the valve seat 2 have been permanently solidified into one piece through the mechanical interlocking structure, without the need for subsequent welding, bonding or other secondary assembly processes.

[0034] When this valve seat assembly is installed inside the solenoid valve, the flange face 12 is riveted and fixed to the solenoid valve's stationary iron. The lower end of the valve seat is inserted into the solenoid valve housing and static sealing is achieved through an external sealing ring. When the solenoid valve is energized, the moving iron valve core moves upward along the central straight guide section 11 under electromagnetic force, and the lower end face leaves the valve core mating and sealing valve port 21. Fluid enters the inner cavity of the sleeve from the side flow channel hole 14 and then flows out through the downward channel in the center of the valve seat, and the solenoid valve is in the conducting state. When the solenoid valve is de-energized, the moving iron valve core moves downward under the action of the return spring, and the lower end face is tightly pressed against the valve core mating and sealing valve port 21, blocking the fluid passage, and the solenoid valve is in the closed state. During operation, the fluid pressure difference and the valve core impact force are evenly transmitted to the plastic valve seat through the embedded locking end face 15, and there is no relative displacement at the mating surface. The double locking structure ensures no loosening under long-term high-frequency opening and closing, the fully fitted encapsulated structure prevents media leakage along the mating surface, and the rounded transition structure disperses impact stress, effectively improving the overall service life of the assembly.

[0035] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0036] Furthermore, in this utility model, the use of terms such as "first," "second," etc., is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly and specifically defined.

[0037] In this utility model, unless otherwise explicitly specified and limited, the terms "connection," "fixing," etc., should be interpreted broadly. For example, "fixing" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0038] Furthermore, the technical solutions of the various embodiments of this utility model can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

Claims

1. A valve seat assembly for an injection-molded solenoid valve, comprising a metal sleeve (1) and a plastic valve seat (2), wherein the sleeve (1) and the valve seat (2) are integrally fixed by injection molding, characterized in that: The sleeve (1) is a hollow thin-walled rotating part, which consists of an outwardly turned flange face (12), a middle straight cylindrical guide section (11) and a lower inwardly turned part (13) from top to bottom. The inner side of the lower inwardly turned part (13) forms an embedded locking end face (15). The middle straight cylindrical guide section (11) has a side flow channel hole (14) circumferentially opened on the cylinder wall. The valve seat (2) is a rotating body integrally injection molded. The upper center of the valve seat has a ring-shaped valve core that fits to seal the valve port (21). The upper part of the valve seat (2) has a sleeve embedded covering locking groove (22). The lower end of the sleeve (1) is embedded in the sleeve embedded covering locking groove (22). During injection molding, the plastic melt wraps the embedded locking end face (15) and covers the lower outer wall of the sleeve (1), forming a mechanical buckle structure with axial and circumferential double locking.

2. The valve seat assembly for an injection-molded fixed solenoid valve according to claim 1, characterized in that: The flange face (12) and the lower middle straight tube guide section (11) are smoothly transitioned by the flange straight tube transition fillet (16).

3. The valve seat assembly for an injection-molded fixed solenoid valve according to claim 1, characterized in that: The closed shape formed by the embedded locking end face (15) is polygonal.

4. The valve seat assembly for an injection-molded fixed solenoid valve according to claim 1, characterized in that: The outer wall of the lower inwardly turned part (13) is an arc surface, and the central angle of the arc surface is not less than 80°.

5. The valve seat assembly for an injection-molded fixed solenoid valve according to claim 4, characterized in that: The valve seat (2) includes a valve seat injection molding base (23), and the sleeve embedded locking groove (22) is provided on the upper end face of the valve seat injection molding base (23). The outer diameter of the valve seat injection molding base (23) is consistent with the outer diameter of the lower end inward turning part (13).

6. The valve seat assembly for an injection-molded fixed solenoid valve according to claim 1, characterized in that: The side flow channel hole (14) is located near the valve seat (2) and is evenly distributed around the circumference.

7. The valve seat assembly for an injection-molded fixed solenoid valve according to claim 1, characterized in that: The sleeve (1) is made of stainless steel.

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