Low-friction self-sealing pressure balanced electromagnetic on-off valve and control method thereof

Abstract

The application discloses a low-friction self-sealing pressure balance type electromagnetic switch valve and a control method thereof, and belongs to the technical field of electromagnetic control valves. The valve comprises a static iron core, a framework, a coil, a shell, a seat body, an armature, a sealing element, a valve core and a spring. A first guide part in linear contact sliding fit is arranged between the first end of the armature and the static iron core to reduce friction. A strip-shaped groove is formed in the outer circumferential surface of the armature as a main flow channel. A pressure conduction channel is arranged in the armature, and when the valve is closed, the medium pressure is guided to the back of the sealing element to realize self-sealing in cooperation with the spring force. A pressure balance channel is further arranged in the armature, and the pressure difference between the two side cavities is balanced during dynamic balance movement. Through the synergistic effect of the linear contact guide, the medium pressure cooperative self-sealing and the dynamic pressure difference balance mechanism, the problems of large friction, easy leakage, slow response and short service life of the existing electromagnetic valve are solved, low power consumption, zero leakage, fast response and long service life are realized, and the valve is suitable for high-pressure gas medium on-off control.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic control valve technology, and in particular to a low-friction, self-sealing, pressure-balanced electromagnetic switching valve and its control method. Background Technology

[0002] Electromagnetic switching valves, as core actuators in fluid control systems, are widely used in pneumatic control, precision pneumatic circuits, aerospace piping, and other fields. Their basic function is to control the opening and closing of the valve port by driving an armature with electromagnetic force, thereby achieving on / off control of the media flow. Existing electromagnetic switching valves, such as the one disclosed in patent application CN116221480A, aim to reduce closing time delay. This involves a complex permanent magnet, stator winding, and wedge structure, attempting to increase the magnetic reluctance of the magnetic circuit to shorten the closing time when power is off. However, such existing technologies still suffer from the following insurmountable technical problems: Firstly, in terms of the mechanical motion structure, the armature and guide components of existing solenoid valves mostly adopt a surface contact sliding fit. This large-area contact structure leads to high frictional resistance between the moving parts. During long-term high-frequency operation, the parts wear out severely, which not only causes phenomena such as jamming and sluggish operation, greatly shortening the service life of the valve, but also increases the driving burden on the electromagnet.

[0003] Secondly, regarding the valve sealing mechanism, existing technologies generally rely on a single spring force to press the armature or valve core against the valve seat to achieve a seal. This sealing method can work in low-pressure environments, but under high-pressure gas medium conditions, the sealing specific pressure provided by the spring force is insufficient to resist the pushing force of the high-pressure medium, which easily leads to internal leakage of the medium, resulting in the serious problem of "incomplete valve closure" and failing to meet the stringent requirements of high pressure and zero leakage.

[0004] Secondly, in terms of fluid dynamics, existing electromagnetic switching valves do not adequately consider the pressure changes in the chambers during the armature's movement. A significant pressure difference is generated between the chambers on either side of the armature during rapid movement. This pressure difference creates an axial resistance against both electromagnetic and spring forces, known as "hydraulic resistance." This resistance not only increases the power consumption required for electromagnetic actuation but also severely reduces the valve's switching response speed and consistency, especially under high-frequency or wide-pressure-difference operating conditions, where performance degradation is particularly pronounced.

[0005] Finally, regarding environmental adaptability, existing technologies lack effective filtration of media impurities and isolation measures against thermal effects. Solid particulate impurities in the media can intrude into the gaps between moving parts, exacerbating wear and even causing jamming; while the heat from high-temperature media can be conducted to the coil through metal components, leading to increased coil resistance, decreased electromagnetic performance, and even burnout. These problems limit the reliability of electromagnetic switching valves in wide temperature, wide pressure, and harsh media conditions.

[0006] In summary, developing a novel electromagnetic switching valve that can fundamentally solve the aforementioned problems of friction and wear, high-pressure sealing, dynamic differential pressure interference, and poor adaptability to operating conditions is a technical challenge that urgently needs to be addressed by those skilled in the art. Summary of the Invention

[0007] The main objective of this invention is to propose a low-friction, self-sealing, pressure-balanced electromagnetic switch valve and its control method, aiming to solve the technical problems of existing electromagnetic switch valves, such as high motion friction, poor high-pressure sealing performance, significant differential pressure interference, slow response, short service life, and weak adaptability to operating conditions.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a low-friction, self-sealing, pressure-balanced electromagnetic switching valve, comprising: The stationary iron core has an internal flow channel; A skeleton is fitted onto the outside of the stationary iron core, and a flow inlet gap is formed between the skeleton and the stationary iron core; The coil is mounted on the frame; The outer casing is fitted over the coil and the frame and connected to the stationary iron core. The base is fixedly connected to the right end of the outer shell and has an outlet channel inside; An armature is axially reciprocatingly disposed between the stationary iron core and the base, and has a first end and a second end opposite to each other; a plurality of strip-shaped grooves are formed along the axial direction on the outer peripheral surface of the armature; A sealing element is disposed at the second end of the armature; The valve core is fixedly disposed inside the seat and has a valve port that can form a sealing fit with the sealing element; A spring, disposed between the stationary iron core and the armature, is used to apply a closing force toward the valve core to the armature.

[0009] The core of this invention lies in the integrated design of three functional mechanisms: First, the low-friction line contact guiding mechanism: A first guide portion is provided between the first end of the armature and the stationary iron core, enabling them to form a line contact sliding fit. Compared with traditional surface contact, line contact greatly reduces the contact area, thereby significantly reducing sliding friction, reducing wear on parts, extending the service life of the valve, and improving the sensitivity and reliability of its operation.

[0010] Second, the medium pressure-coordinated self-sealing mechanism: The armature has an internal pressure transmission channel. When the seal and valve port are in a sealed fit, the pressure transmission channel guides the pressurized medium from the inlet side to the side of the seal facing away from the valve port, causing the medium pressure and the closing force of the spring to be superimposed in the same direction. This mechanism achieves a positive feedback effect of "the higher the pressure, the tighter the seal," completely solving the internal leakage problem under high-pressure conditions.

[0011] Third, the dynamic differential pressure adaptive balancing mechanism: A pressure balancing channel is also provided inside the armature, connecting the cavities at the first and second ends of the armature. This channel dynamically balances the medium pressure in the cavities on both sides when the armature moves. This channel eliminates the additional differential pressure resistance generated by the armature's movement, thereby significantly improving the opening and closing response speed, reducing drive power consumption, and ensuring consistent operation across the entire voltage drop range.

[0012] In addition, the strip-shaped groove on the outer circumference of the armature forms the main channel for the medium to flow from the inlet gap to the second end cavity of the armature, while providing an outlet position for the pressure transmission channel and the pressure balance channel. It is an important structure in the overall fluid design.

[0013] Based on the aforementioned core structure, this invention also provides several preferred implementation methods.

[0014] As a specific implementation of the first guide portion, preferably, the first guide portion includes a ball disposed at the first end of the armature and a first wear-resistant ring installed in the stationary iron core, wherein the ball and the center hole of the first wear-resistant ring form a line contact sliding fit. This ball-head and wear-resistant ring fit is simple in structure, easy to process and assemble, and the wear-resistant ring can be made of wear-resistant material, further improving service life.

[0015] As a specific implementation of the pressure transmission channel, preferably, the pressure transmission channel includes a vent hole formed on the armature; a third countersunk hole for installing the seal is provided at the second end of the armature; the inner end of the vent hole communicates with the third countersunk hole, and the outer end communicates with the bottom wall of one of the strip-shaped grooves. When the valve is closed, the high-pressure medium on the medium inlet side acts on the seal through the vent hole, generating an auxiliary sealing force. Simultaneously, the vent hole also serves to release air during seal assembly, facilitating installation.

[0016] As a specific implementation of the pressure balancing channel, preferably, the pressure balancing channel includes at least one guide hole formed on the armature, one end of the guide hole being located on the first end face of the armature, and the other end communicating with the bottom wall of one of the strip-shaped grooves. The number and diameter of the guide holes can be optimized according to the valve's diameter and working pressure, and their communication with the strip-shaped grooves makes pressure balancing more efficient.

[0017] Regarding the magnetic circuit structure, to improve electromagnetic efficiency, preferably, the stationary iron core, outer shell, base, and armature together form a closed magnetic circuit; a reverse magnetic ring is installed inside the base, which is sleeved on the outside of the armature and spaced apart from it, for concentrating the magnetic field. The reverse magnetic ring can optimize the distribution of magnetic lines of force, allowing more magnetic flux to pass through the armature and enhancing the electromagnetic driving force.

[0018] In terms of filtration and protection, to prevent impurities in the medium from wearing down the moving parts, preferably, a first filter element is provided at the outlet of the inlet channel of the stationary iron core, and a second filter element is provided at the inlet of the outlet channel of the seat. This dual-filtration structure effectively prevents impurities in the medium from entering the moving parts and sealing surfaces, avoiding wear and scratches, and improving the durability and reliability of the valve.

[0019] In terms of thermal management, to prevent the influence of dielectric heat on the coil, preferably, the base is provided with an annular groove, and epoxy colloid is filled between the outer shell and the coil, with the epoxy colloid filling the annular groove to form a thermal insulation structure. This thermal insulation structure blocks the thermal conduction of dielectric heat to the coil through the metal components, ensuring that the coil can maintain a low temperature rise and stable electromagnetic performance even in high-temperature dielectric environments.

[0020] Regarding guiding stability, to balance low friction and linear motion, preferably, a second guide portion is provided between the second end of the armature and the base. This second guide portion includes a second wear-resistant ring installed within the base, which forms a surface contact sliding fit with the outer circumferential surface of the second end of the armature. That is, the first end of the armature uses line contact guidance, while the second end uses traditional surface contact guidance; the combination of these two methods ensures both low friction and the linearity and stability of the armature's movement.

[0021] Furthermore, in order to achieve a compact structural design and a smooth flow channel, preferably, the stationary iron core includes a base, a cylinder integrally formed at the right end of the base, and an externally threaded post integrally formed at the left end of the base; the outer surface of the cylinder is symmetrically provided with two tangent planes; the skeleton is sleeved on the cylinder, and the inner hole surface of the skeleton and the tangent planes together form the flow inlet gap.

[0022] Preferably, the armature has a stepped columnar structure, comprising a first cylinder, a second cylinder, and a third cylinder with decreasing diameters from the second end to the first end. The strip-shaped groove is disposed on the outer circumferential surface of the first cylinder, the sealing element is installed inside the first cylinder, and the spring is sleeved on the second cylinder. This stepped design facilitates spring positioning and medium flow.

[0023] Secondly, the present invention also provides an opening and closing control method based on the above-mentioned low-friction self-sealing pressure-balanced electromagnetic switching valve, comprising three control logics: Power-off valve closure control: When the coil is de-energized, the armature moves towards the valve core under the closing force of the spring, causing the sealing element to form a sealing fit with the valve port. Simultaneously, the pressure medium on the medium inlet side acts on the side of the sealing element opposite to the valve port through the pressure transmission channel, generating medium pressure in the same direction as the spring closing force, achieving pressure-assisted self-sealing. At this time, the higher the medium pressure, the greater the sealing force between the sealing element and the valve port, and the stronger the sealing effect.

[0024] Valve opening control via energization: When the coil is energized, it generates an electromagnetic field, which in turn generates an electromagnetic attraction force on the armature that overcomes the spring closing force and the resistance of the medium pressure difference. This force drives the armature away from the valve core, causing the seal to separate from the valve port and opening the valve. During the valve opening process, the pressure difference across the armature is quickly balanced due to the presence of the pressure balance channel, resulting in a rapid response.

[0025] Differential pressure adaptive regulation: During the movement of the armature, the pressure balance channel connects the two chambers on both sides of the armature to dynamically balance the pressure difference of the medium on both sides. Whether the valve is opening or closing, this channel can instantly conduct the pressure on both sides, eliminating additional hydraulic resistance.

[0026] Compared with the prior art, the low-friction self-sealing pressure-balanced electromagnetic switching valve and its control method provided by the present invention have the following beneficial effects: (1) The present invention adopts a line contact sliding fit between the first end of the armature and the stationary iron core, which greatly reduces the contact area and sliding friction, fundamentally reduces mechanical wear, avoids the risk of jamming, and significantly improves the service life and operation reliability of the valve.

[0027] (2) Spring-medium pressure synergistic self-sealing mechanism: This invention breaks through the limitations of traditional single spring seals. When the valve is closed, the medium pressure acts on the back of the seal through the pressure transmission channel, causing the sealing force between the seal and the valve core to increase synchronously with the increase of the medium pressure, thus realizing a positive feedback self-sealing effect of "the higher the pressure, the tighter the seal". This mechanism completely solves the industry problem of internal leakage of solenoid valves under high pressure conditions.

[0028] (3) The present invention provides a pressure balance channel on the armature, which can instantly connect the cavities on both sides of the armature and quickly balance the pressure difference caused by the movement. This eliminates the additional resistance of the medium pressure difference to the movement of the armature, thereby greatly improving the opening and closing response speed of the valve. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0030] Figure 1 This is a cross-sectional view of the overall structure of the low-friction self-sealing pressure-balanced electromagnetic switching valve provided in an embodiment of the present invention.

[0031] Figure 2 This is a three-dimensional structural diagram of the stationary iron core in this invention.

[0032] Figure 3 This is a cross-sectional view of the stationary iron core in this invention.

[0033] Figure 4 This is a three-dimensional structural diagram of the armature in this invention.

[0034] Figure 5 This is a cross-sectional view of the armature in this invention.

[0035] Figure 6 This is a cross-sectional view of the base in this invention.

[0036] Reference numerals: 1. Static iron core; 1a. Matrix; 1b. Cylinder; 1c. Externally threaded post; 1d. Tangent plane; 1e. Radial hole; 1f. Inlet hole; 1g. First countersunk hole; 1h. Second countersunk hole; 2. First filter element; 3. Epoxy colloid; 4. Coil; 5. Housing; 6. Valve core; 7. Second filter element; 8. Seat; 8a. Disc; 8b. Connecting post; 8c. First hole section; 8d. Second hole section; 8e. Third hole section; 8f. Outlet hole; 8g, annular groove; 9, external lead wire; 10, skeleton; 11, first wear-resistant ring; 12, spring; 13, armature; 13a, first cylinder; 13b, second cylinder; 13c, third cylinder; 13d, sphere; 13e, third countersunk hole; 13f, strip groove; 13g, vent hole; 13h, guide hole; 14, inverted magnetic ring; 15, seal; 16, second wear-resistant ring; 17, retaining ring; 18, liquid inlet gap. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0038] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention 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 indication will also change accordingly.

[0039] Furthermore, the use of terms such as "first" and "second" in this invention 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 with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0040] Please see Figure 1 middle Figure 6 This embodiment provides a low-friction, self-sealing, pressure-balanced electromagnetic switching valve, specifically designed for frequent, rapid, and reliable on / off control of gaseous media. The electromagnetic switching valve mainly includes: a stationary iron core 1, a first filter element 2, an epoxy colloid 3, a coil 4, a housing 5, a valve core 6, a second filter element 7, a seat 8, an external lead wire 9, a frame 10, a first wear-resistant ring 11, a spring 12, an armature 13, a reverse magnetic ring 14, a seal 15, a second wear-resistant ring 16, and a retaining ring 17.

[0041] I. Detailed structure of stationary iron core 1: like Figure 2 and Figure 3 As shown, the stationary iron core 1 is an integral magnetic conductor structure. It includes a columnar base 1a, a cylinder 1b integrally formed at the center of the right end face of the base 1a extending to the right, and an externally threaded column 1c integrally formed at the center of the left end face of the base 1a extending to the left. The externally threaded column 1c is used to connect the entire valve to an external pipeline.

[0042] To facilitate positioning and fluid channel formation, two parallel tangent planes 1d are symmetrically machined on the outer surface of the cylinder 1b. At the left end of the cylinder 1b, adjacent to the base 1a, a radial hole 1e is formed. This radial hole 1e is a stepped hole, with a smaller diameter in the middle and larger diameters at both ends to form a countersunk hole. The two outlets of the radial hole 1e are located on the two tangent planes 1d, respectively.

[0043] At the center of the stationary iron core 1, an inlet hole 1f is formed along its axial direction. This inlet hole 1f passes sequentially through the externally threaded post 1c and the base 1a, and its right end is perpendicularly connected to the middle of the radial hole 1e, thus forming a preliminary channel for the medium to enter the valve. Furthermore, on the right end face of the cylinder 1b, stepped countersunk holes are machined to the left, specifically including a larger diameter first countersunk hole 1g and a smaller diameter second countersunk hole 1h located to its left. These two countersunk holes are used to accommodate the spring 12 and the first wear-resistant ring 11.

[0044] II. Quantity and installation location of the first filter element 2: There are two first filter elements 2, which are respectively embedded in the countersunk holes at both ends of the radial hole 1e. They are used to perform initial filtration of the medium entering the valve to prevent impurities from entering the valve cavity.

[0045] III. Mounting structure of frame 10 and coil 4: The frame 10 is made of insulating material (such as engineering plastic) and has a central through hole. The frame 10 is fitted onto the cylinder 1b of the stationary iron core 1, with its left end face abutting against the right end face of the base 1a. An annular groove is formed on the outer circumference of the frame 10. The coil 4 is wound and housed in this annular groove. The coil 4 is electrically connected to an external control circuit through an external lead 9. A groove is formed on the outer circumference of the base 1a to accommodate the external lead 9.

[0046] After the skeleton 10 is installed, two axially continuous gaps will naturally form between the inner hole surface of the skeleton 10 and the tangent plane 1d on the cylinder 1b. These gaps are used as inlet gaps 18.

[0047] IV. Casing 5 and Packaging Structure: The outer casing 5 is a metal cylinder open at both ends, used to provide a magnetic circuit channel and protect the internal components. During assembly, the disc body 8a of the base 8 is inserted into the inner hole of the outer casing 5 from the right end and fixed thereto (laser welding is preferred in this embodiment). The left half of the outer casing 5 completely houses the coil 4 and the frame 10, and the left end of the outer casing 5 extends further to the left, tightly fitting onto the outer circle of the base 1a of the stationary iron core 1, forming part of the magnetic circuit.

[0048] To secure the coil 4 and provide insulation and heat protection, epoxy colloid 3 is filled inside the outer casing 5. The epoxy colloid 3 fills all gaps between the outer peripheral surface of the coil 4 and the inner surface of the outer casing 5, thus firmly encapsulating the coil 4.

[0049] V. Detailed structure of base 8: like Figure 6 As shown, the base 8 is also an integral magnetic conductor structure. It includes a disk 8a and a connecting post 8b integrally formed at the center of the right end face of the disk 8a. The connecting post 8b is provided with external threads for connecting to downstream pipelines.

[0050] The center of the seat 8 is machined with stepped through holes along its axial direction, which, from left to right (i.e. from upstream to downstream), include: the first hole section 8c with the largest diameter, the second hole section 8d with the next largest diameter, the third hole section 8e with the smallest diameter, and the outlet hole 8f on the far right.

[0051] Specifically, an annular groove 8g is formed on the outer cylindrical surface of the left end of the disk 8a. Furthermore, the outer diameter of the portion of the disk 8a located to the right of the annular groove 8g is... D2, the outer diameter of the portion located to the left of the annular groove 8g is... D1, and D1 is strictly less than D2. The purpose of this large and small diameter design is that when the disc body 8a is pressed into the inner hole at the right end of the outer casing 5... The outer circle of D2 and the inner hole of the outer shell 5 form an interference fit to ensure sealing and fixation, while An annular gap is formed between the outer circle of D1 and the inner hole of the outer shell 5. During subsequent injection of epoxy colloid 3, the liquid epoxy colloid 3 can flow smoothly through this annular gap and fill the annular groove 8g. After curing, the epoxy colloid in the annular groove 8g acts like an "anchor," firmly locking the base 8 and the outer shell 5 together to prevent loosening. Simultaneously, the cured epoxy colloid 3 effectively blocks the conduction of heat from the base 8 to the coil 4, forming a heat insulation structure.

[0052] VI. Detailed structure of armature 13: like Figure 4 and Figure 5 As shown, the armature 13 is the core component for the valve to achieve movement and sealing, and is a stepped cylinder. From right to left (i.e., from the sealing end to the driving end), it includes: a first cylinder 13a with the largest diameter, a second cylinder 13b with the next largest diameter, and a third cylinder 13c with the smallest diameter. At the left end of the third cylinder 13c, a sphere 13d is integrally formed. The diameter of the sphere 13d is larger than the outer diameter of the third cylinder 13c, forming a "ball head" structure. The sphere 13d forms a line contact sliding fit with the inner hole of the first wear-resistant ring 11, constituting the first guide part.

[0053] A third countersunk hole 13e is machined on the right end face of the first cylinder 13a for mounting the seal 15. To prevent the seal 15 from falling out, a retaining ring 17 is fitted around the outer periphery of the seal 15. During assembly, the seal 15 is first inserted into the retaining ring 17 to form an assembly, and then this assembly is pressed into the third countersunk hole 13e. The retaining ring 17 and the inner wall of the third countersunk hole 13e form an interference fit, thereby firmly fixing the seal 15 in the third countersunk hole 13e of the armature 13.

[0054] Four parallel grooves 13f are uniformly machined on the outer circumferential surface of the first cylinder 13a. These grooves 13f axially penetrate the entire first cylinder 13a, connecting its left and right end faces simultaneously, serving as the main medium flow channels. The cross-sectional shape of the grooves 13f can be semi-circular, rectangular, or trapezoidal; in this embodiment, a rectangle is preferred.

[0055] In addition, two key functional holes are provided on armature 13: vent hole 13g and guide hole 13h.

[0056] The axis of the vent 13g is perpendicular to the axis of the armature 13. Its inner end intersects the left side wall of the third countersunk hole 13e, thus connecting the internal space of the third countersunk hole 13e; its outer end opens onto the bottom wall of one of the strip-shaped grooves 13f. The vent 13g has two functions: first, to expel air from the third countersunk hole 13e during the press-fitting of the seal 15, facilitating installation; second, to allow a portion of the high-pressure medium to enter the third countersunk hole 13e after the valve is closed, acting on the left end face of the seal 15 to provide self-sealing pressure. This vent 13g constitutes a specific implementation of a pressure transmission channel.

[0057] The guide hole 13h consists of an axial hole at one end and a radial hole at the other end. One end opens onto the left end face of the first cylinder 13a, and the other end opens onto the bottom wall of one of the strip-shaped grooves 13f. The guide hole 13h is the core channel for balancing the pressure in the cavities on both sides of the armature 13, that is, a specific way of forming a pressure balance channel. When the armature 13 moves to the left, the volume of the left cavity decreases and the pressure increases, while the volume of the right cavity increases and the pressure decreases. At this time, the medium can enter the strip-shaped groove 13f through the guide hole 13h to balance the pressure. Conversely, when the armature 13 moves to the right, the medium flows from the right side through the guide hole 13h to the cavity on the left side of the first cylinder 13a, which also plays a balancing role.

[0058] VII. Guiding and Supporting Structures: To achieve extremely low sliding friction, this embodiment employs a composite guiding scheme.

[0059] The first wear-resistant ring 11 is press-fitted into the second countersunk hole 1h of the stationary iron core 1. The ball 13d at the left end of the armature 13 is disposed in the central hole of the first wear-resistant ring 11, and the outer surface of the ball 13d forms a line contact sliding fit with the inner hole of the first wear-resistant ring 11. This line contact greatly reduces the contact area and sliding friction, forming the first guide part.

[0060] Both the second wear-resistant ring 16 and the reverse magnetic ring 14 are installed within the first hole section 8c, with the reverse magnetic ring 14 located to the left of the second wear-resistant ring 16. The second wear-resistant ring 16 is fitted onto the right end of the first cylinder 13a of the armature 13, and its inner hole forms a conventional surface contact sliding fit with the outer circle of the first cylinder 13a, providing radial support and guidance, thus constituting the second guide portion. The reverse magnetic ring 14 is also fitted onto the first cylinder 13a, but a gap is left between its inner hole and the outer circle of the first cylinder 13a, preventing contact. The reverse magnetic ring 14 is made of a high-permeability magnetic material, and its main function is to concentrate and guide magnetic lines of force, optimize the magnetic flux distribution of the closed magnetic circuit, and improve electromagnetic drive efficiency.

[0061] 8. Spring 12 and valve core 6: Spring 12 is sleeved on the second cylinder 13b of armature 13, with its left end abutting against the left stepped surface of the first countersunk hole 1g of stationary iron core 1, and its right end abutting against the left end face of the first cylinder 13a of armature 13. Spring 12 is pre-compressed after assembly, so it is always in a compressed state, continuously applying a rightward thrust to armature 13, which is the initial force for closing the valve.

[0062] The valve core 6 has a central through-hole, and its right half is pressed into and welded to the second hole section 8d of the seat body 8. The left end of the valve core 6 extends out of the second hole section 8d and is configured as a boss shape. The left end face of the boss is a smooth, flat sealing surface for fitting with the seal 15. The right half of the central through-hole of the valve core 6 is designed in a flared shape to reduce flow resistance.

[0063] The second filter element 7 is installed in the third hole section 8e of the seat 8, with its left end face abutting against the right end face of the valve core 6 and completely covering the flared mouth of the valve core 6, thereby performing final filtration of the medium flowing to the outlet hole 8f.

[0064] 9. Magnetic circuit and fixed connection: The stationary iron core 1, outer shell 5, inverted magnetic ring 14, base 8, and armature 13 together constitute a highly efficient closed magnetic circuit. When coil 4 is energized, magnetic lines of force originate from the stationary iron core 1, pass through outer shell 5, base 8, and inverted magnetic ring 14, enter the armature 13, and finally return to the stationary iron core 1, forming a complete loop. The addition of inverted magnetic ring 14 allows the magnetic lines of force to pass through the armature 13 more concentratedly, increasing the electromagnetic force.

[0065] To ensure reliable connections and simplify the structure, in this embodiment, the connection between the outer shell 5 and the seat 8, as well as the connection between the valve core 6 and the seat 8, are fixed using laser welding. Laser welding has the advantages of a small heat-affected zone, high weld strength, and good sealing performance.

[0066] IX. Working Principle The working principle of the electromagnetic switching valve in this embodiment is as follows, and its opening and closing control method specifically includes: 1. Power-off valve control (stationary state / closed state): When coil 4 is not energized, no electromagnetic field is generated. At this time, the pre-compression force of spring 12 dominates, pushing the armature 13 to move to the right. The ball 13d of armature 13 slides to the right within the first wear ring 11, and the first cylinder 13a slides to the right within the second wear ring 16. The rightward movement of armature 13 causes the retaining ring 17 and the seal 15 fixed at its right end to move to the right together, until the right end face of the seal 15 tightly abuts against the boss end face at the left end of valve core 6, forming a sealing fit, thereby cutting off the flow path of the medium.

[0067] In this state, the high-pressure medium from upstream passes through the inlet hole 1f and radial hole 1e of the stationary iron core 1, and a portion of the medium enters the internal space of the third countersunk hole 13e through the vent hole 13g on the armature 13. This portion of the high-pressure medium directly acts on the left end face of the seal 15, generating a medium pressure to the right. This medium pressure is completely aligned with the rightward thrust of the spring 12, and the two are superimposed. Therefore, the higher the medium pressure at the valve inlet, the greater the resultant force acting on the seal 15, and the greater the clamping force between the seal 15 and the valve core 6, achieving "medium self-pressurization sealing." This positive feedback mechanism ensures that the valve has no leakage under high pressure.

[0068] 2. Valve opening control (opening process and opening state): When the valve needs to be opened, energize the coil 4 through the external lead 9. The coil 4 generates a magnetic field, producing a strong electromagnetic attraction in the closed magnetic circuit formed by the stationary iron core 1, armature 13, inverted magnetic ring 14, base 8, and outer shell 5. This electromagnetic attraction acts on the armature 13 in the left direction.

[0069] As the electromagnetic attraction gradually increases and becomes sufficient to overcome the rightward thrust of spring 12 and any pressure differential resistance that may exist on both sides of armature 13, armature 13 begins to accelerate to the left. The leftward movement of armature 13 causes seal 15 to move away from the boss end face of valve core 6, opening the valve port of valve core 6.

[0070] The specific flow path of the medium at the moment of valve opening and during the subsequent maintenance process is as follows: The high-pressure medium enters the inlet hole 1f of the stationary iron core 1 from the upstream pipeline, and then flows into the radial hole 1e. After initial filtration by the first filter element 2 at both ends of the radial hole 1e, the medium enters the two inlet gaps 18 formed by the inner surface of the skeleton 10 and the tangent plane 1d on the cylinder 1b of the stationary iron core 1, and then flows to the right along the inlet gaps 18. Next, the medium flows into the strip groove 13f on the first cylinder 13a of the armature 13, and flows rapidly to the right along the strip groove 13f, finally converging into the cavity between the right end face of the armature 13 and the seat 8. Afterwards, the medium smoothly passes through the central through hole of the opened valve core 6, undergoes secondary filtration by the second filter element 7, and finally exits from the outlet hole 8f of the seat 8, entering the downstream pipeline.

[0071] 3. Differential pressure adaptive regulation (dynamic equilibrium process): When the armature 13 moves rapidly to the left or right, the volume of the cavities on both sides of the first cylinder 13a changes drastically. If the pressure is not balanced, huge hydraulic resistance will be generated.

[0072] One of the core features of this invention is that a guide hole 13h is provided on the armature 13.

[0073] When the valve moves to the left: the volume of the left cavity of the armature 13 (i.e., the left cavity of the first cylinder 13a) is compressed, and the pressure increases instantaneously; while the volume of the right cavity (i.e., the space between the right end face of the first cylinder 13a and the seat 8) is expanded, and the pressure decreases instantaneously. At this time, the high-pressure medium on the left will immediately flow through the guide hole 13h, quickly flow to the strip groove 13f and enter the low-pressure cavity on the right, thereby quickly balancing the pressure on the left and right sides.

[0074] When the valve moves to the right: the right chamber of armature 13 is compressed, increasing the pressure; the left chamber is expanded, decreasing the pressure. At this time, the high-pressure medium on the right will flow in the opposite direction to the left through the guide hole 13h, which also serves to balance the pressure.

[0075] The dynamic pressure balancing effect of the guide hole for 13 hours significantly improves the valve's opening and closing response speed, reduces coil power consumption, and ensures consistency and stability of operation under different pressure conditions.

[0076] Beneficial effects verification As can be seen from the above description of the structure and working principle, the electromagnetic switching valve provided in this embodiment is: By utilizing the line contact between the ball 13d and the first wear-resistant ring 11, the motion friction is minimized, greatly extending the service life of the valve.

[0077] By utilizing the medium pressure acting on the back of the seal 15 through the vent 13g, a pressure-coordinated self-sealing is achieved. The greater the medium pressure, the more reliable the seal.

[0078] By utilizing the dynamic balancing effect of the 13h guide hole, the pressure difference resistance during the movement process is eliminated, achieving fast response and low power consumption drive.

[0079] The optimized closed magnetic circuit and inverted magnetic ring 14 improve electromagnetic efficiency; the epoxy colloid 3 in the annular groove 8g achieves effective heat insulation; and the first filter element 2 and the second filter element 7 achieve bidirectional filtration, comprehensively improving the valve's overall performance and adaptability to operating conditions.

[0080] Therefore, the present invention effectively solves the technical problems existing in the current electromagnetic switching valve and achieves the intended purpose of the invention.

[0081] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A low-friction, self-sealing, pressure-balanced electromagnetic switching valve, characterized in that, include: The stationary iron core (1) has an internal flow channel; A skeleton (10) is fitted outside the stationary iron core (1), and a flow inlet gap (18) is formed between the skeleton (10) and the stationary iron core (1). The coil (4) is mounted on the frame (10); The outer shell (5) is fitted over the coil (4) and the frame (10) and connected to the stationary iron core (1); The base (8) is fixedly connected to the right end of the outer shell (5) and has an outflow channel inside; The armature (13) is axially reciprocatingly disposed between the stationary iron core (1) and the base (8), and has a first end and a second end opposite to each other; a plurality of strip-shaped grooves (13f) are provided on the outer peripheral surface of the armature (13) along the axial direction. A sealing element (15) is disposed at the second end of the armature (13); The valve core (6) is fixedly disposed inside the seat (8) and has a valve port that can form a sealing fit with the sealing element (15); A spring (12) is disposed between the stationary iron core (1) and the armature (13) for applying a closing force toward the valve core (6) to the armature (13); A first guide portion is provided between the first end of the armature (13) and the stationary iron core (1) to enable the two to form a line contact sliding fit; The armature (13) is provided with a pressure transmission channel. When the seal (15) and the valve port are in a sealed fit, the pressure transmission channel guides the pressure medium on the medium inlet side to the side of the seal (15) facing away from the valve port, so that the medium pressure and the closing force of the spring (12) are superimposed in the same direction. The armature (13) is also provided with a pressure balance channel inside. The pressure balance channel connects the cavities on the first end side and the second end side of the armature (13) and is used to dynamically balance the medium pressure of the cavities on both sides when the armature (13) moves.

2. The low-friction self-sealing pressure-balanced electromagnetic switching valve according to claim 1, characterized in that, The first guide portion includes a ball (13d) disposed at the first end of the armature (13) and a first wear-resistant ring (11) installed in the stationary iron core (1). The ball (13d) and the center hole of the first wear-resistant ring (11) form a line contact sliding fit.

3. The low-friction self-sealing pressure-balanced electromagnetic switching valve according to claim 1, characterized in that, The pressure transmission channel includes an exhaust port (13g) opened on the armature (13); A third countersunk hole (13e) for installing the seal (15) is provided at the second end of the armature (13). The inner end of the vent (13g) is connected to the third countersunk hole (13e), and the outer end is connected to the bottom wall of one of the strip grooves (13f).

4. The low-friction self-sealing pressure-balanced electromagnetic switching valve according to claim 1, characterized in that, The pressure balance channel includes at least one guide hole (13h) opened on the armature (13), one end of the guide hole (13h) is located on the first end face of the armature (13), and the other end is connected to the bottom wall of one of the strip grooves (13f).

5. A low-friction, self-sealing, pressure-balanced electromagnetic switching valve according to claim 1, characterized in that, The stationary iron core (1), the outer shell (5), the base (8) and the armature (13) together form a closed magnetic circuit; a reverse magnetic ring (14) is installed inside the base (8), and the reverse magnetic ring (14) is sleeved on the outside of the armature (13) and spaced apart from the armature (13) to concentrate the magnetic field.

6. The low-friction self-sealing pressure-balanced electromagnetic switching valve according to claim 1, characterized in that, The static iron core (1) is provided with a first filter element (2) at the outlet of the inlet channel, and the seat (8) is provided with a second filter element (7) at the inlet of the outlet channel.

7. A low-friction, self-sealing, pressure-balanced electromagnetic switching valve according to claim 1, characterized in that, The base (8) is provided with an annular groove (8g), and epoxy colloid (3) is filled between the outer shell (5) and the coil (4). The epoxy colloid (3) is filled into the annular groove (8g) to form a heat insulation structure.

8. A low-friction, self-sealing, pressure-balanced electromagnetic switching valve according to claim 1, characterized in that, A second guide portion is provided between the second end of the armature (13) and the base (8). The second guide portion includes a second wear-resistant ring (16) installed in the base (8). The second wear-resistant ring (16) and the outer peripheral surface of the second end of the armature (13) form a surface contact sliding fit.

9. A low-friction, self-sealing, pressure-balanced electromagnetic switching valve according to claim 1, characterized in that, The stationary iron core (1) includes a base (1a), a cylinder (1b) integrally formed at the right end of the base (1a), and an externally threaded post (1c) integrally formed at the left end of the base (1a); the outer surface of the cylinder (1b) is symmetrically provided with two tangent planes (1d); the skeleton (10) is sleeved on the cylinder (1b), and the inner hole surface of the skeleton (10) and the tangent plane (1d) together form the inlet gap (18). The armature (13) is a stepped columnar structure, consisting of a first cylinder (13a), a second cylinder (13b), and a third cylinder (13c) with decreasing diameters from the second end to the first end. The strip groove (13f) is provided on the outer circumferential surface of the first cylinder (13a). The sealing element (15) is installed inside the first cylinder (13a). The spring (12) is sleeved on the second cylinder (13b).

10. A method for controlling the opening and closing of a low-friction, self-sealing, pressure-balanced electromagnetic switching valve based on any one of claims 1 to 9, characterized in that, include: Power-off valve control: When the coil (4) is de-energized, the armature (13) moves toward the valve core (6) under the closing force of the spring (12), causing the sealing element (15) to form a sealing fit with the valve port; at the same time, the pressure medium on the medium inlet side acts on the side of the sealing element (15) opposite to the valve port through the pressure transmission channel, generating medium pressure in the same direction as the closing force of the spring (12), thus achieving pressure-assisted self-sealing; Valve opening control by energization: When the coil (4) is energized, it generates an electromagnetic field, which generates an electromagnetic attraction force on the armature (13) that overcomes the closing force of the spring (12) and the resistance of the medium pressure difference, driving the armature (13) to move away from the valve core (6), so that the seal (15) is separated from the valve port and the valve port is opened; Pressure differential adaptive adjustment: During the movement of the armature (13), the two cavities on both sides of the armature (13) are connected through the pressure balance channel to dynamically balance the pressure difference of the medium on both sides.

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