Control magnet module of miniature precise electromagnetic valve

Abstract

The control magnet module comprises a sleeve, a coil, a static iron core and a movable iron core, the coil is wound outside the sleeve, the static iron core and the movable iron core are coaxially arranged in the sleeve, the static attraction end face of the static iron core is opposite to the movable attraction end face of the movable iron core, an air gap is formed between the static iron core and the movable iron core, the static iron core is fixed, and the movable iron core is fixed. The movable iron core can axially slide along the sleeve; at least one spiral groove is formed in the peripheral surface of the movable iron core, penetrates through the two ends of the movable iron core and is designed to be gradually reduced in depth, and the depth of the spiral groove is gradually increased in the direction from the movable suction end face to the driving end face of the movable iron core; the movable iron core of the control magnet module adopts the gradually-shrunk spiral groove gradient design, the magnetic circuit efficiency is optimized, the surface magnetic leakage and the eddy current effect are reduced, the response speed and action stability of an electromagnetic valve are improved, precise control is ensured, invalid energy loss can be reduced, the energy efficiency ratio is increased, and the control valve can be matched with a control valve which is miniaturized, high in precision, fast in response and high in requirement.

Description

Technical Field

[0001] The present invention relates to the technical field of solenoid valves, and in particular to a control magnet module of a micro precision solenoid valve. Background Art

[0002] Micro-precision solenoid valve magnet systems are key components in modern microfluidics, micro-reactor systems, and biomedical engineering. These magnet systems open and close tiny fluid channels through precise electromagnetic control. They are widely used in drug delivery, microfluidic chips, biological laboratory automation, micropump systems, and precision chemical processes.

[0003] The magnet system of traditional solenoid valves mostly adopts a symmetrical cylindrical or rectangular structure. The magnetic field generated by the excitation coil is distributed axially symmetrically inside the iron core. Due to the high magnetic resistance in the edge area of the iron core, the magnetic lines of force tend to "diffuse" at the edge of the iron core, thereby forming an uneven distribution inside the iron core with high magnetic field intensity in the center area and low magnetic field intensity in the edge area. At the same time, the symmetrical iron core lacks effective magnetic shielding at the edge, and the magnetic lines of force tend to overflow from its surface and enter the surrounding air or non-magnetic materials, forming "leakage flux". Leakage flux not only causes energy loss, but also interferes with peripheral equipment. In addition, the moving iron core and the valve body are prone to wear due to long-term friction, affecting the sealing and service life, while surface treatment technology (such as plating) has limited improvement on micro-friction.

[0004] Therefore, in order to address the problems of uneven magnetic field distribution, high magnetic leakage rate, and low electromagnetic force efficiency in traditional iron core structures, it is necessary to break through the traditional symmetrical structure design and innovatively design an iron core structure that can comprehensively optimize the magnetic circuit effect and mechanical wear. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects of the prior art and provide a control magnet module for a micro precision solenoid valve to solve the problems raised in the above background technology.

[0006] In order to achieve the above object, the technical solution of the present invention is as follows:

[0007] A control magnet module for a miniature precision solenoid valve comprises a sleeve, a coil, a static iron core and a moving iron core. The coil is wound around the outside of the sleeve, and the static iron core and the moving iron core are coaxially arranged inside the sleeve. The static attraction end face of the static iron core and the dynamic attraction end face of the moving iron core are opposite to each other, with an air gap between them. The static iron core is fixed and the moving iron core can slide axially along the sleeve under the action of magnetic force to provide the valve opening and closing force. At least one spiral groove is provided on the outer peripheral surface of the moving iron core, and the spiral groove runs through both ends of the moving iron core and is designed to have a gradually decreasing groove depth, and the groove depth gradually deepens from the dynamic attraction end face to the driving end face of the moving iron core.

[0008] Furthermore, the groove depth of the spiral groove is z, 0.1mm≤z≤0.5mm, and the groove depth of the spiral groove on the driving end surface is z0, then the groove depth change rate d(z)=z0·e -kΔL , where △L is the axial distance between the spiral groove and the driving end face, and k is the decreasing index, which is 0.02-0.05.

[0009] Furthermore, an attraction structure is provided on the static attraction end face and the dynamic attraction end face, and the attraction structure includes an attraction body and an attraction hole that cooperate with each other. The attraction body is located on the dynamic attraction end face, and the attraction hole is located on the static attraction end face. An air gap is provided between the surface of the attraction body and the surface of the attraction hole. The attraction body is provided with at least one-level attraction platform, and the attraction platform is a combination of a micro-column structure and a conical structure. The micro-column structure is located at the root of the attraction platform.

[0010] Furthermore, the height of the micro-column structure is 0.4 mm ± 0.1 mm.

[0011] Furthermore, the width of the spiral groove is 0.3 mm to 1.0 mm. If a plurality of parallel spiral grooves are provided, the ratio of the groove pitch to the groove width of the spiral groove is set to 1:1 to 2:1.

[0012] Furthermore, the outer peripheral surface of the moving iron core is polished, and the inner wall surface of the sleeve is provided with a micro-woven structure.

[0013] Furthermore, the length of the micro-woven structure is smaller than the length of the moving iron core. In the initial position, the distance between the two ends of the micro-woven structure and the end surface of the moving iron core is 1 mm±0.1 mm.

[0014] Furthermore, the coil is arranged in the magnetic conductive frame, which has a U-shaped structure and a cover plate is provided on its upper port for shielding the magnetic field in combination with the magnetic conductive frame.

[0015] Furthermore, a connecting hole is provided in the middle of the cover plate, a magnetic conductive ring is clamped on the connecting hole, and the driving end of the moving iron core is located in the magnetic conductive ring and is guided to move thereby.

[0016] Furthermore, chamfers are provided on the end edges of the static attraction end face and the dynamic attraction end face.

[0017] Compared with the prior art, the control magnet module of the micro precision solenoid valve of the present invention has the following beneficial effects:

[0018] The moving iron core in this control magnet module adopts a tapered spiral groove gradient design to optimize magnetic circuit efficiency, reduce surface magnetic leakage and eddy current effects, significantly improve the response speed of the solenoid valve, and ensure its operational stability and precise control. At the same time, the tapered spiral groove structure, optimized through geometric parameter matching, can reduce ineffective energy loss, significantly lowering the overall energy consumption of the solenoid valve and improving energy efficiency.

[0019] In addition, the micro-texture on the surface of the static iron core can reduce frictional resistance, reduce wear during long-term operation, and improve the durability of the iron core. Combined with the tapered spiral grooves of the dynamic iron core, the surface polishing and surface micro-texture of the static iron core can achieve dynamic / static composite sealing, effectively suppress magnetic leakage, and improve the reliability of the solenoid valve under high-pressure and high-frequency conditions.

[0020] The improved magnet module can be adapted to fields such as medical equipment, automotive hydraulic control, and industrial automation that have strict requirements for miniaturization, high precision, and fast response, expanding its application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the assembly structure of the solenoid valve disclosed in the present invention;

[0022] Figure 2 This is an exploded view of the parts of the dynamic and static iron core assembly disclosed in the present invention;

[0023] Figure 3 A cross-sectional view of the dynamic and static core assembly disclosed in the present invention;

[0024] Figure 4 A three-dimensional diagram of the moving iron core with a first-stage attraction platform structure disclosed in the present invention;

[0025] Figure 5 A three-dimensional diagram of the moving iron core with a two-stage attraction platform structure disclosed in the present invention;

[0026] Figure 6 It is a three-dimensional diagram of the static iron core disclosed in the present invention.

[0027] In the figure: 100, moving iron core; 110, spiral groove; 120, suction body; 121, conical structure; 122, micro-column structure; 130, driving end face; 140, dynamic suction end face; 150, valve core connecting hole; 200, static iron core; 210, positioning column; 220, static suction end face; 221, chamfered structure; 230, suction hole; 300, magnetic frame; 400, sleeve; 410, micro-woven structure; 410, 500, coil; 600, valve core; 700, magnetic ring; 800, cover plate; 900, main valve body. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only the best embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0029] The present invention discloses a control magnet module for a micro precision solenoid valve. Figures 1-6 As shown, the micro precision solenoid valve includes a control magnet module and a main valve body 900. The solenoid valve main valve body 900 is connected to the control magnet module through a valve core 600. A return spring is provided on the valve core 600. When the control magnet module is energized, an electromagnetic attraction is generated to attract the moving iron core 100 to move slightly. The moving iron core 100 synchronously drives the valve core 600 to move to realize the opening and closing of the corresponding channel of the main valve body 900 under magnetic control. In order to make full use of the magnetic effect of the coil 500, the moving iron core 100 and the static iron core 200 are coaxial and inserted into the sleeve 400. The sleeve 400 also serves as a winding frame for the coil 500. The sleeve 400 is installed in the magnetic frame 300. The magnetic frame 300 is U-shaped and a cover plate 800 is provided at its upper opening to prevent the magnetic field of the coil 500 from leaking out. A positioning column 210 is provided at the fixed end of the static iron core 200. The positioning column 210 extends out of the bottom of the magnetic frame 300 and is connected to the valve body shell for fixation.

[0030] In order to increase the magnetic force of the moving iron core 100, a magnetic ring 700 is provided on the driving end of the moving iron core 100. Figure 1 The magnetic ring 700 is fixed to the connection hole in the middle of the cover plate 800. The driving end of the moving iron core 100 is located in the inner hole of the magnetic ring 700 and is guided to move by it. The valve core 600 is connected to the driving end of the moving iron core 100 and extends out of the magnetic ring 700.

[0031] The static engaging end face 220 of the static iron core 200 and the dynamic engaging end face 140 of the movable iron core 100 are opposite to each other, with an air gap provided between them. That is, under the maximum magnetic force, the static engaging end face 220 and the dynamic engaging end face 140 are parallel and have an air gap H to prevent them from colliding and being damaged by squeezing. Generally, the air gap H of the micro solenoid valve is ≤ 0.5mm. If the air gap is too large, the initial electromagnetic force will be reduced, which will weaken the response performance of the solenoid valve. The movable iron core 100 can slide axially along the sleeve 400 under the action of the magnetic force. In order to reduce movement friction, the movable iron core 100 and the sleeve 400 are clearance-fitted.

[0032] The arrangement of the spiral groove 110 structure is the core of this embodiment. In order to optimize the magnetic field distribution in the moving iron core 100 and improve the uneven magnetic field distribution and magnetic leakage phenomenon on the surface of the traditional iron core, at least one spiral groove 110 is provided on the outer circumference of the moving iron core 100. Figure 2 As shown, the spiral groove 110 runs through both ends of the moving iron core 100 and is designed to be tapered, with the groove depth gradually increasing from the dynamic attraction end face 140 toward the driving end face 130 of the moving iron core 100;

[0033] The provision of the spiral groove 110 breaks the cylindrical symmetry of the moving iron core 100 and constructs an asymmetric structure on its surface, causing the path of the magnetic lines of force thereon to be distorted and redistributed. Since the spatial distribution of the magnetic field strength and direction no longer satisfies geometric symmetry and does not follow the laws of axial symmetry or central symmetry, self-shielding can be formed on the surface of the moving iron core 100, reducing magnetic force leakage; the spiral groove 110 changes the magnetic resistance distribution inside the moving iron core 100. Since the magnetic resistance of the hollow area in the spiral groove 110 is higher than that of the solid area between the spiral grooves 110, the magnetic lines of force are forced to bypass the spiral groove 110, forming a denser intensity distribution on the ungrooved entity of the moving iron core 100, improving the magnetic field intensity distribution that gradually decays from the inside to the outside of the traditional structure, and balancing the radial magnetic field intensity distribution of the moving iron core 100;

[0034] In addition, the tapered groove depth design of the spiral groove 110 further distorts the path of the magnetic lines of force therein, and increases the magnetic flux of the dynamic attraction end surface 140 , thereby enhancing the electromagnetic effect of the attraction end and increasing the electromagnetic force on the moving iron core 100 .

[0035] As a further structural design, since the overall structural size of the micro precision solenoid valve is small, the corresponding overall length of its iron core (the sum of the lengths of the moving iron core 100 and the static iron core 200) is 10mm-100mm, and the diameter is 2mm-10mm. According to its structural size, the groove depth z of the spiral groove 110 should be set at 0.1mm-0.5mm, and the groove depth is appropriately selected according to the size of the diameter; according to the length, the number of turns of the spiral groove 110 is set to 3-8 turns, and the groove width is 0.3mm-1.0mm. If there are multiple spiral grooves 110, the spiral grooves 110 should be designed in parallel, and their helix angles are 15°-45°, preferably 30°. The groove spacing and groove width ratio of similar spiral grooves 110 is set to 1:1-2:1;

[0036] The spiral groove 110 can be an arc groove, a square groove or a V-shaped groove. The square groove or the V-shaped groove needs to be rounded at the bottom to avoid stress concentration.

[0037] The spiral groove 110 is designed to have a gradient geometric parameter matching design with exponential decrease. The groove depth of the driving end face 130 is preset to z0, and the groove depth change rate satisfies the formula: d(z) = z0·e -kΔL , where ΔL is the axial distance between the center of the spiral groove 110 and the driving end face 130, and k is a decreasing index ranging from 0.02 to 0.05.

[0038] As a further structural design, an attraction structure is provided on the static attraction end face 220 and the dynamic attraction end face 140 to increase the attraction surface area and guide the movement of the moving iron core 100. Figure 2 and Figure 3As shown, the suction structure includes a suction body 120 and a suction hole 230 that cooperate with each other. The suction body 120 is located on the dynamic suction end surface 140, and the suction hole 230 is located on the static suction end surface 220. Similarly, an air gap is provided between the surface of the suction body 120 and the surface of the suction hole 230.

[0039] The attraction body 120 protrusion is set at the center of the dynamic attraction end surface 140 and is coaxial with the moving iron core 100. The attraction body 120 can be provided with an attraction platform with one or more steps of transition. The attraction platform is a combination of a micro-column structure 122 and a conical structure 121. The micro-column structure 122 is located at the root of the attraction platform, and the conical structure 121 is connected to the end edge of the micro-column. Figure 4 The first-level suction table and Figure 5 The two-stage attraction platform shown in the figure can effectively increase the starting electromagnetic force of the solenoid valve under the same air gap. The larger the height of the micro-column structure 122, the more conducive it is to increasing the electromagnetic force under large air gaps. However, under small air gaps, due to the large contact area between the moving iron core 100 and the static iron core 200, there will be an electromagnetic field component perpendicular to the direction of movement, and even an electromagnetic field distribution in the opposite direction, which reduces the axial electromagnetic force. Therefore, the height of the micro-column structure 122 of each stage of the attraction platform is 0.4mm±0.1mm, and 0.4mm, 0.45mm, and 0.35mm can be selected. When the overall height of the attraction body 120 needs to be increased, a stepped multi-stage attraction platform structure design can be adopted. In addition, the taper of the conical structure 121 also affects the starting magnetic force of the moving valve core 600. The taper can be reduced under large air gaps, and the taper can be increased under small air gaps.

[0040] The surface micro-texture structure 410 is processed on the cylindrical surface of the inner wall of the sleeve 400 by using laser micro-machining technology, such as Figure 1 As shown, the micro-woven structure 410 guides the direction of the magnetic field lines outside the circumference of the moving iron core 100 by changing the boundary conditions of the magnetic field on the surface of the moving iron core 100, thereby achieving local enhancement of the magnetic field. At the same time, the micro-woven structure 410 can also reduce friction resistance and speed up the response time. The micro-woven structure 410 can be a concave point structure or a line structure with a depth of 2μm; and the length of the micro-woven structure is less than the length of the moving iron core. In the initial position, the two ends of the micro-woven structure are 1mm±0.1mm away from the end face of the moving iron core.

[0041] In addition, the surfaces of the static iron core 200 and the moving iron core 100 should be polished, the polishing depth is less than 2μm, and the surface roughness after polishing is less than 0.1μm. The adjacent end edges of the static iron core 200 and the moving iron core 100 are both provided with chamfered structures 221. By optimizing the magnetic field distribution at the end edge position, the electromagnetic force on the moving iron core 100 can be effectively increased within the commonly used air gap range.

[0042] The direction or orientation words mentioned in this article, such as "inside", "outside", "end", "side", and "root", are respectively Figures 1-6These terms are mainly used to better describe the present invention and its embodiments, and are not intended to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation;

[0043] Furthermore, some of the above terms may be used to express other meanings besides indicating a direction or positional relationship. For example, the terms "on" and "in" may also be used to express a dependency or connection relationship in certain circumstances. Those skilled in the art will understand the specific meanings of these terms in the present invention based on the specific circumstances.

[0044] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A control magnet module for a micro precision solenoid valve, characterized by: The valve comprises a sleeve, a coil, a static iron core, and a movable iron core. The coil is wound around the sleeve, and the static iron core and the movable iron core are coaxially arranged in the sleeve. The static engaging end face of the static iron core and the movable iron core are opposite to each other, with an air gap provided between them. The static iron core is fixed, and the movable iron core can slide along the axial direction of the sleeve under the action of magnetic force to provide the valve opening and closing force. At least one spiral groove is provided on the outer circumference of the moving iron core. The spiral groove runs through both ends of the moving iron core and is designed to have a gradually decreasing groove depth, with the groove depth gradually deepening from the moving engaging end surface toward the driving end surface of the moving iron core.

2. The control magnet module of the micro precision solenoid valve according to claim 1, characterized in that: The groove depth of the spiral groove is z, 0.1mm≤z≤0.5mm, and the groove depth of the spiral groove on the driving end surface is z0, then the groove depth change rate d(z)=z0·e -kΔL , where △L is the axial distance between the spiral groove and the driving end face, and k is a decreasing index, which is 0.02-0.

05.

3. The control magnet module of the micro precision solenoid valve according to claim 1, characterized in that: The static suction end face and the dynamic suction end face are provided with a suction structure, and the suction structure includes a suction body and a suction hole that cooperate with each other. The suction body is located on the dynamic suction end face, and the suction hole is located on the static suction end face. The air gap is provided between the surface of the suction body and the surface of the suction hole. The suction body is provided with at least one level of suction platform, and the suction platform is a combination of a micro-column structure and a conical structure. The micro-column structure is located at the root of the suction platform.

4. The control magnet module of the micro precision solenoid valve according to claim 3, characterized in that: The height of the micro-column structure is 0.4 mm ± 0.1 mm.

5. The control magnet module of the micro precision solenoid valve according to claim 1, characterized in that: The width of the spiral groove is 0.3 mm to 1.0 mm. If a plurality of parallel spiral grooves are provided, the ratio of the groove spacing to the groove width of the spiral groove is set to 1:1 to 2:

1.

6. The control magnet module of the micro precision solenoid valve according to any one of claims 1 to 5, characterized in that: The outer peripheral surface of the moving iron core is polished, and the inner wall surface of the sleeve is provided with a micro-woven structure.

7. The control magnet module of the micro precision solenoid valve according to claim 6, characterized in that: The length of the micro-woven structure is smaller than the length of the moving iron core. In the initial position, the distance between the two ends of the micro-woven structure and the end surface of the moving iron core is 1 mm±0.1 mm.

8. The control magnet module of the micro precision solenoid valve according to claim 6, characterized in that: The coil is arranged in a magnetic conductive frame, which is in a U-shaped structure. A cover plate is provided on the upper end thereof for combining with the magnetic conductive frame to shield the magnetic field.

9. The control magnet module of the micro precision solenoid valve according to claim 8, characterized in that: A connecting hole is provided in the middle of the cover plate, a magnetic conductive ring is clamped on the connecting hole, and the driving end of the moving iron core is located in the magnetic conductive ring and is guided to move by the magnetic conductive ring.

10. The control magnet module of the micro precision solenoid valve according to claim 3, characterized in that: End edges of the static suction end face and the dynamic suction end face are chamfered.

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