A miniature self-locking solenoid valve

Abstract

This invention provides a miniature self-locking solenoid valve, comprising a housing and pole shoes, an armature, a first magnetic isolation ring, a coil assembly, a permanent magnet ring, and a valve seat installed in the inner hole of the housing. The armature is disposed between the pole shoes and the valve seat. The valve seat has a protruding valve port on its end face facing the armature. The coil assembly is fitted around the armature. When the coil assembly is energized, it controls the armature to move away from or against the valve port to open or close the valve. The first magnetic isolation ring is disposed between the armature and the coil assembly. A convex ring is provided at one end of the armature, which is slidably connected to the first magnetic isolation ring. A butterfly spring is fitted around the other end of the armature to keep the armature in a centered position relative to the first magnetic isolation ring. By reducing the friction surface when the armature slides, the valve's volume, weight, and energy consumption are reduced. At the same time, the flexible butterfly spring supports the cantilever end of the armature, keeping the armature centered and avoiding the risk of unilateral friction between the armature and the inner wall of the first magnetic isolation ring due to radial force, which could generate metal particles.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic valve technology, specifically relating to a miniature self-locking electromagnetic valve for a fluid management system suitable for micro-propulsion systems. Background Technology

[0002] With the increasing need for IoT space base station construction, the demand for low-altitude satellites is growing. Due to the small mass and high specific impulse of electric propulsion systems, they are particularly suitable for attitude and orbit control of small satellites. Self-locking solenoid valves, due to their low power consumption, are widely used in electric propulsion gas supply management modules for controlling the on / off flow of gas media. For example, Chinese patent CN101709806A provides a miniature self-locking solenoid valve. The solenoid valve also includes a permanent magnet disposed between the valve seat and the side of the valve core, with the permanent magnet near the end face of the valve seat. The solenoid coil is a single-coil solenoid coil that can be energized in both directions. A flange magnetic sleeve is provided between the permanent magnet, the valve seat, and the valve core, and a cylindrical first magnetic isolation ring is provided between the solenoid coil and the valve core. The valve is opened and closed by controlling the valve core to slide in the first magnetic isolation ring through the energization of the solenoid coil. Since the fit between the valve core and the first magnetic isolation ring is not perfect, when subjected to radial force, the first magnetic isolation ring and the valve core will inevitably form one-sided contact. Long-term use leads to one-sided wear, generating debris that causes pollution, seriously affecting the reliability of the self-locking solenoid valve and the entire electric propulsion power system. In addition, the asymmetrical flow channel setting exacerbates the one-sided wear. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a miniature self-locking solenoid valve. By reducing the friction surface when the armature slides, the magnetic force required for startup is reduced, and the volume and weight of the coil assembly are decreased, thereby reducing the valve's volume, weight, and energy consumption. Simultaneously, the armature cantilever end is supported by a flexible butterfly spring to keep the armature centered, avoiding the risk of generating metal particles due to unilateral friction between the armature and the inner wall of the first magnetic isolation ring caused by radial force.

[0004] This invention is achieved through the following technical solution:

[0005] A miniature self-locking solenoid valve includes a housing and pole shoes, an armature, a first magnetic isolation ring, a coil assembly, a permanent magnet ring, and a valve seat installed in the inner hole of the housing. The armature is disposed between the pole shoes and the valve seat. The valve seat has a protruding valve port on the end face facing the armature. The coil assembly is fitted around the armature. When the coil assembly is energized, it controls the armature to move away from or against the valve port to open or close the valve. A first magnetic isolation ring is disposed between the armature and the coil assembly. A convex ring is disposed at one end of the armature and is slidably connected to the first magnetic isolation ring. A butterfly spring is fitted around the other end of the armature to keep the armature in a centered position relative to the first magnetic isolation ring. This significantly reduces the friction surface when the armature slides, greatly reduces the magnetic force required for start-up, reduces the volume and weight of the coil assembly, and reduces the volume, weight, and energy consumption of the valve. At the same time, the cantilever end is supported by a flexible butterfly spring to keep the armature centered and avoids the risk of generating metal particles due to unilateral friction between the armature and the inner wall of the armature tube caused by radial force.

[0006] It also includes a second magnetic isolation ring. The pole shoe is provided with a first shoulder and a second shoulder. The first shoulder abuts against the coil group, the permanent magnet ring, the second magnetic isolation ring and the valve seat in sequence. The pole shoe and the valve seat are fixedly connected to both ends of the inner hole of the cover. An armature tube is provided between the armature and the coil group, the permanent magnet ring and the second magnetic isolation ring. One end of the armature tube is fixedly connected to the second magnetic isolation ring, and the other end of the armature tube abuts against the first magnetic isolation ring and the second shoulder in sequence. The outer ring of the disc spring is fixed in the inner hole of the second magnetic isolation ring. The magnetic circuit is constructed through the pole shoe, the armature tube, the permanent magnet ring, the cover, the valve seat and the armature circuit.

[0007] The armature center is provided with a floating sealing component. When the armature is in contact with the valve seat, the floating sealing component is in contact with the valve port at the same time. This ensures that the magnetic gap between the armature and the valve seat is zero when the valve body is sealed, thereby reducing magnetic resistance, increasing magnetic force in the holding state, and improving the reliability of the valve.

[0008] The floating sealing assembly includes a baffle and a baffle spring. A countersunk hole is provided at the center of the end face where the armature fits with the valve seat. The baffle is slidably installed in the countersunk hole. A baffle spring is provided between the bottom of the countersunk hole and the baffle. A retaining ring is fixed at the opening of the countersunk hole to prevent the baffle from falling out of the countersunk hole. This allows the process of the baffle and the valve port fitting together to be carried out independently from the process of the armature and the valve seat fitting together. This reduces the parallelism requirement between the sealing surface of the baffle and the fitting surface of the armature, making the seal more reliable. At the same time, the armature is more likely to maintain a centered position relative to the first magnetic isolation ring.

[0009] It also includes a flow channel that runs through the pole shoe, armature, disc spring and valve seat in sequence. The flow channel is symmetrically distributed on the armature, so that the pressure generated by the fluid when passing through the armature is balanced in the radial direction, making it easier to maintain the center position.

[0010] It also includes an inlet pipe fitting, which is installed at the center of the pole shoe. The inlet pipe fitting has a flow channel that connects with the flow channel of the pole shoe to form a flow channel inlet. A filter screen is installed at the connection between the inlet pipe fitting and the pole shoe to reduce the entry of impurities from the fluid medium or pipeline into the valve body and block the valve orifice, thereby improving the reliability of the valve.

[0011] The permanent magnet ring is formed by joining two semi-circular rings together, which facilitates installation. The polarity of the permanent magnet ring is set radially, which facilitates the arrangement of the magnetic circuit.

[0012] The coil assembly includes an open coil and a closed coil with opposite magnetic directions when energized, and the open coil and the closed coil are nested together radially.

[0013] When the self-locking solenoid valve is in the closed state, the gap between the armature and the pole shoe is 0.2mm to 0.25mm.

[0014] When the self-locking solenoid valve is in the closed state, the gap between the baffle and the retaining ring is 0.1mm to 0.12mm.

[0015] The beneficial effects of this invention are as follows:

[0016] Compared to existing technologies, by adding a convex ring for sliding connection at one end of the armature, the friction surface during armature sliding is significantly reduced, the magnetic force required for start-up is greatly reduced, the volume and weight of the coil assembly are reduced, and the volume, weight, and energy consumption of the valve are reduced. Simultaneously, the flexible disc spring support at the cantilever end of the armature keeps the armature centered, avoiding the risk of metal particles generated by unilateral friction between the armature and the inner wall of the armature tube due to radial force. A floating sealing component at the center of the armature ensures that the magnetic gap between the armature and the valve seat is minimized while the valve body is sealing, reducing magnetic resistance, increasing magnetic force in the holding state, and improving valve reliability. Furthermore, the flow channel sealing process and the magnetic circuit sealing process are performed independently, reducing the parallelism requirement between the baffle sealing surface and the armature contact surface, reducing the impact of the valve seat on the sealing surface when the valve is closed, resulting in a more reliable seal. The armature is also easier to keep centered relative to the armature tube. By installing a filter screen at the connection between the inlet pipe joint and the pole shoe, the entry of impurities from the fluid medium or pipeline into the valve body and clogging of the outlet is reduced, further improving valve reliability. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention;

[0018] Figure 2 yes Figure 1 Enlarged view of the structure at point A in the middle;

[0019] Figure 3 This is a schematic diagram of the coil frame assembly in this invention;

[0020] Figure 4This is a schematic diagram of the armature assembly in this invention;

[0021] Figure 5 yes Figure 4 Structural view in direction B;

[0022] Figure 6 This is a schematic diagram of the magnetic circuit of the self-locking solenoid valve of the present invention in the closed state;

[0023] Figure 7 yes Figure 6 Magnetic circuit simulation analysis under the condition;

[0024] Figure 8 This is a schematic diagram of the magnetic circuit during the opening process of the self-locking solenoid valve of the present invention;

[0025] Figure 9 yes Figure 8 Magnetic circuit simulation analysis under the condition;

[0026] Figure 10 This is a schematic diagram of the magnetic circuit of the self-locking solenoid valve of the present invention in the open state;

[0027] Figure 11 yes Figure 10 Enlarged view of the structure at point C;

[0028] Figure 12 yes Figure 10 Magnetic circuit simulation analysis under the condition;

[0029] Figure 13 This is a schematic diagram of the magnetic circuit during the closing process of the self-locking solenoid valve of the present invention;

[0030] Figure 14 yes Figure 13 Magnetic circuit simulation analysis under the condition.

[0031] In the diagram: 1-Inlet pipe connector, 2-Pole shoe, 3-Filter screen, 4-Open coil, 5-Close coil, 6-First magnetic isolation ring, 7-Armature tube, 8-Permanent magnet ring, 9-Second magnetic isolation ring, 10-Butterfly spring, 11-Pressure ring, 12-Cover, 13-Valve seat, 14-Retaining ring, 15-Baffle, 16-Retaining ring, 17-Baffle spring, 18-Armature, 201-First shoulder, 202-Second shoulder, 1301-Valve port, 1801-Protruding ring. Detailed Implementation

[0032] The technical solution of the present invention is further described below, but the scope of protection is not limited to what is described.

[0033] like Figures 1 to 4As shown, a miniature self-locking solenoid valve includes a housing 12 and a pole shoe 2, an armature 18, a first magnetic isolation ring 6, a coil assembly, a permanent magnet ring 8, and a valve seat 13 installed in the inner hole of the housing 12. The armature 18 is disposed between the pole shoe 2 and the valve seat 13. The valve seat 13 has a protruding valve port 1301 on one end face facing the armature 18. The coil assembly is fitted around the armature 18. When the coil assembly is energized, it controls the armature 18 to move away from or abut against the valve port 1301 to open or close the valve. The first magnetic isolation ring 6 is disposed between the armature 18 and the coil assembly. One end of the armature 18 is provided with... A convex ring 1801 is provided, which is slidably connected to the first magnetic isolation ring 6. A butterfly spring 10 is fitted on the outer ring of the other end of the armature 18 to keep the armature 18 in a centered position relative to the first magnetic isolation ring 6. This greatly reduces the friction surface when the armature slides, greatly reduces the magnetic force required for starting, reduces the volume and weight of the coil assembly, and reduces the volume, weight and energy consumption of the valve. At the same time, the cantilever end is supported by a flexible butterfly spring to keep the armature in the center and avoid the risk of generating metal particles due to unilateral friction between the armature and the inner wall of the first magnetic isolation ring caused by radial force.

[0034] like Figure 1 , Figure 3 As shown, it also includes a second magnetic shielding ring 9. The pole shoe 2 is provided with a first shoulder 201 and a second shoulder 202. The first shoulder 201 abuts against the coil group, the permanent magnet ring 8, the second magnetic shielding ring 9, and the valve seat 13 in sequence. The pole shoe 2 and the valve seat 13 are fixedly connected to both ends of the inner hole of the cover 12, respectively. An armature tube 7 is provided between the armature 18 and the coil group, the permanent magnet ring 8, and the second magnetic shielding ring 9. One end of the armature tube 7 is fixedly connected to the second magnetic shielding ring 9, and the other end of the armature tube 7 abuts against the first magnetic shielding ring 6 and the second shoulder 202 in sequence. In this embodiment, the inner ring of the butterfly spring 10 is fixed to the outer ring of the armature 18 by cooperating with the shoulder of the end of the armature 18 through the retaining ring 16. The outer ring of the butterfly spring 10 is fixed in the second magnetic shielding ring 9 by cooperating with the shoulder of the second magnetic shielding ring 9 through the pressure ring 11. The inlet pipe joint 1, the pole shoe 2, the filter screen 3, the first magnetic shielding ring 6, the armature tube 7, and the second magnetic shielding ring 9 constitute the coil frame assembly. In this embodiment, the pole shoe 2, cover 12, valve seat 13, and armature 18 are made of soft magnetic alloy; the armature tube 7 is made of magnetically conductive stainless steel; the permanent magnet ring 8 is made of neodymium iron boron or samarium cobalt; the first magnetic isolation ring 6 and the second magnetic isolation ring 9 are made of non-magnetically conductive materials, preferably 1Cr18Ni9Ti; a valve-opening holding magnetic circuit is constructed through the pole shoe 2, armature 18, armature tube 7, permanent magnet ring 8, cover 12, and valve seat 13. A closed holding magnetic circuit is constructed through the permanent magnet ring 8, armature tube 7, armature 18, valve seat 13, and cover 12.

[0035] like Figure 1 , Figure 2 , Figure 4As shown, a floating sealing assembly is provided at the center of the armature 18. When the armature 18 is in contact with the valve seat 13, the floating sealing assembly is in contact with the valve port 1301 at the same time. This ensures that the magnetic gap between the armature and the valve seat is minimized when the valve body is sealed, thereby reducing magnetic resistance, increasing magnetic force in the holding state, and improving the reliability of the valve.

[0036] like Figure 1 , Figure 2 , Figure 4 , Figure 5 As shown, the floating sealing assembly includes a baffle 15 and a baffle spring 17. A countersunk hole is provided at the center of the end face of the armature 18 that contacts the valve seat 13. The baffle 15 is slidably installed in the countersunk hole. A baffle spring 17 is provided between the bottom of the countersunk hole and the baffle 15. A retaining ring 14 is fixed to the opening of the countersunk hole to prevent the baffle 15 from falling out of the countersunk hole. This allows the process of the baffle and valve port contacting each other to be independent of the process of the armature and valve seat contacting each other, reducing the parallelism requirement between the sealing surface of the baffle and the contact surface of the armature, resulting in a more reliable seal. Simultaneously, the armature is more easily kept in a centered position relative to the first magnetic isolation ring. The retaining ring 14, baffle 15, baffle spring 17, and armature 18 constitute the armature assembly.

[0037] like Figure 1 , Figure 4 , Figure 5 As shown, it also includes a flow channel that passes through the pole shoe 2, armature 18, butterfly spring 10 and valve seat 13 in sequence. The flow channel is symmetrically distributed on the armature 18 so that the pressure generated by the fluid when passing through the armature is balanced in the radial direction, making it easier to maintain the centered position.

[0038] like Figure 1 , Figure 3 As shown, it also includes an inlet pipe connector 1, which is installed in the center of the pole shoe 2. The inlet pipe connector 1 has a flow channel that connects with the flow channel of the pole shoe 2 to form a flow channel inlet. A filter screen 3 is provided at the connection between the inlet pipe connector 1 and the pole shoe 2 to reduce the entry of impurities from the fluid medium or pipeline into the valve body and block the outlet, thereby improving the reliability of the valve.

[0039] like Figure 1 As shown, the permanent magnet ring 8 is formed by connecting two semi-circular rings, which facilitates installation. The polarity of the permanent magnet ring 8 is set radially, which facilitates the arrangement of the magnetic circuit.

[0040] like Figure 1 As shown, the coil assembly includes an open coil 4 and a closed coil 5 with opposite magnetic directions when energized, and the open coil 4 and closed coil 5 are fitted together radially. In this embodiment, the closed coil 5 is fitted outside the open coil 4, or the open coil 4 can be fitted outside the closed coil 5.

[0041] like Figure 1 , Figure 2As shown, when the self-locking solenoid valve is in the closed state, the gap H between the armature 18 and the pole shoe 2 is 0.2mm to 0.25mm, and the gap L between the baffle 15 and the retaining ring 14 is 0.1mm to 0.12mm; Figure 10 , Figure 11 As shown, when the self-locking solenoid valve is in the open state, there is a gap δ between the baffle 15 and the valve port 1301, where δ = HL, so that the sliding stroke of the armature 18 is greater than the gap between the baffle 15 and the valve port 1301, ensuring that when the armature 18 is in contact with the valve seat 13, the floating sealing assembly is in contact with the valve port 1301 at the same time.

[0042] The working principle of this application is as follows:

[0043] like Figure 6 As shown, when the self-locking solenoid valve is in the closed state, the permanent magnet ring 8 generates two closed permanent magnet circuits, MPL and MPR. Due to the presence of the magnetic gap H in the left magnetic circuit, the magnetic flux of MPR is greater than that of MPL. Therefore, the armature assembly is subjected to a rightward permanent magnet resultant force. This permanent magnet resultant force minus the spring force constitutes the holding force of the armature assembly in the closed position, and at the same time, it is the sealing force that ensures a reliable seal at the valve port 1301. The results of the magnetic circuit simulation analysis using Ansoft Maxwell software in this state are as follows: Figure 7 As shown.

[0044] like Figure 8 As shown, when the opening coil 4 is energized, it will generate an electromagnetic circuit ME. ME and MPL are superimposed, while ME and MPR cancel each other out, ultimately generating a leftward opening force on the armature assembly. This causes the armature assembly to slide to the left until it is in the open state (as shown). Figure 10 As shown in the figure, the magnetic circuit simulation analysis results performed using Ansoft Maxwell software in this state are as follows: Figure 9 As shown.

[0045] like Figure 10 As shown, when the self-locking solenoid valve is in the open state, due to the presence of the magnetic gap H in the right magnetic circuit, the magnetic flux of MPR is much smaller than that of MPL. The armature assembly is subjected to a leftward permanent magnet resultant force, which overcomes the force of the disc spring 10 and keeps the self-locking solenoid valve in the open state. The magnetic circuit simulation analysis results performed using Ansoft Maxwell software in this state are as follows: Figure 12 As shown.

[0046] like Figure 13 As shown, when the closing coil 5 is energized, the closing coil 4 will generate an electromagnetic circuit ME'. ME' cancels out MPL, while ME' and MPR superimpose, ultimately generating a rightward closing force (including the force of the disc spring 10) on the armature assembly, causing the miniature self-locking valve to close until it reaches the position shown. Figure 6The image shows the off state. The magnetic circuit simulation analysis results performed using Ansoft Maxwell software in this state are as follows: Figure 14 As shown.

[0047] This invention provides a miniature self-locking solenoid valve. By setting a convex ring at one end of the armature for sliding connection, the friction surface during armature sliding is significantly reduced, the magnetic force required for start-up is greatly reduced, and the volume and weight of the coil assembly are reduced, thus reducing the valve's volume, weight, and energy consumption. Simultaneously, a flexible disc spring supports the cantilever end of the armature, keeping the armature centered and avoiding the risk of metal particles generated by unilateral friction between the armature and the inner wall of the armature tube due to radial force. A floating sealing assembly at the center of the armature ensures zero magnetic gap between the armature and the valve seat during valve body sealing, reducing magnetic resistance, increasing magnetic force in the holding state, and improving valve reliability. Furthermore, the flow channel sealing process and the magnetic circuit sealing process are performed independently, reducing the parallelism requirement between the baffle sealing surface and the armature contact surface. The floating baffle structure reduces impact and makes the seal more reliable. The armature is also more easily centered relative to the first magnetic isolation ring. By setting a filter screen at the connection between the inlet pipe joint and the pole shoe, the entry of impurities from the fluid medium or pipeline into the valve body and clogging the outlet is reduced, further improving valve reliability.

Claims

1. A miniature self-locking solenoid valve, characterized in that: The system includes a housing (12) and pole shoes (2), an armature (18), a first magnetic isolation ring (6), a coil assembly, a permanent magnet ring (8), and a valve seat (13) installed in the inner hole of the housing (12). The armature (18) is located between the pole shoes (2) and the valve seat (13). The valve seat (13) has a convex valve port (1301) on one end face facing the armature (18). The coil assembly is fitted around the armature (18). When the coil assembly is energized, it controls the armature (18) to move away from or abut against the valve port (1301) to open or close the valve. The first magnetic isolation ring (6) is provided between the armature (18) and the coil assembly. One end of the armature (18) is provided with a convex ring (1801), which is slidably connected to the first magnetic isolation ring (6). The other end of the armature (18) is fitted with a butterfly spring (10) to keep the armature (18) in a centered position relative to the first magnetic isolation ring (6). A floating sealing assembly is provided at the center of the armature (18). The floating sealing assembly is such that when the armature (18) is in contact with the valve seat (13), the floating sealing assembly is also in contact with the valve port (1301). When the self-locking solenoid valve is in the closed state, the gap between the armature (18) and the pole shoe (2) is 0.2mm to 0.25mm.

2. The miniature self-locking solenoid valve as described in claim 1, characterized in that: It also includes a second magnetic isolation ring (9). The pole shoe (2) is provided with a first shoulder (201) and a second shoulder (202). The first shoulder (201) abuts against the coil group, the permanent magnet ring (8), the second magnetic isolation ring (9) and the valve seat (13) in sequence. The pole shoe (2) and the valve seat (13) are fixedly connected to the two ends of the inner hole of the cover (12) respectively. An armature tube (7) is provided between the armature (18) and the coil group, the permanent magnet ring (8) and the second magnetic isolation ring (9). One end of the armature tube (7) is fixedly connected to the second magnetic isolation ring (9), and the other end of the armature tube (7) abuts against the first magnetic isolation ring (6) and the second shoulder (202) in sequence. The outer ring of the butterfly spring (10) is fixed in the inner hole of the second magnetic isolation ring (9).

3. The miniature self-locking solenoid valve as described in claim 1, characterized in that: The floating sealing assembly includes a baffle (15) and a baffle spring (17). A countersunk hole is provided at the center of the end face of the armature (18) that is in contact with the valve seat (13). The baffle (15) is slidably installed in the countersunk hole. A baffle spring (17) is provided between the bottom of the countersunk hole and the baffle (15). A retaining ring (14) is fixed at the opening of the countersunk hole to prevent the baffle (15) from falling out of the countersunk hole.

4. A miniature self-locking solenoid valve as described in claim 1 or 2, characterized in that: It also includes flow channels that pass through pole shoe (2), armature (18), butterfly spring (10) and valve seat (13) in sequence, and the flow channels are symmetrically distributed on armature (18).

5. A miniature self-locking solenoid valve as described in claim 1 or 2, characterized in that: It also includes an inlet pipe connector (1), which is installed in the center of the pole shoe (2) and has a flow channel that connects with the flow channel of the pole shoe (2) to form a flow channel inlet. A filter screen (3) is provided at the connection between the inlet pipe connector (1) and the pole shoe (2).

6. A miniature self-locking solenoid valve as described in claim 1 or 2, characterized in that: The permanent magnet ring (8) is formed by connecting two semi-circular rings, and the polarity of the permanent magnet ring (8) is set radially.

7. A miniature self-locking solenoid valve as described in claim 1 or 2, characterized in that: The coil assembly includes an open coil (4) and a closed coil (5) with opposite magnetic directions after being energized, and the open coil (4) and the closed coil (5) are fitted together radially.

8. A miniature self-locking solenoid valve as described in claim 3, characterized in that: When the self-locking solenoid valve is in the closed state, the gap between the baffle (15) and the retaining ring (14) is 0.1mm to 0.12mm.

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