Two-position four-way electromagnetic valve for reducing noise

Abstract

The invention discloses a two-position four-way electromagnetic valve for reducing noise, which comprises a valve body and a pilot device for controlling gas circuit switching of the valve body, the pilot device comprises a coil assembly, a movable iron core and a reset spring, and the two-position four-way electromagnetic valve further comprises a resistance adjusting assembly connected in series in a power supply loop of the coil assembly; the resistance adjusting assembly comprises a resistance element arranged along the moving path of the movable iron core and an adjusting contact in transmission connection with the movable iron core, and the adjusting contact is configured to perform linkage displacement in the attraction process of the movable iron core so as to increase the effective resistance connected to a power supply loop and reduce the speed of the movable iron core by reducing the electromagnetic attraction force; wherein the adjusting contact is further configured to automatically increase the initial effective resistance and reduce the initial working current of the coil assembly in response to the reset deviation of the movable iron core caused by the fatigue of the reset spring; the invention has the effects of noise reduction and fatigue compensation of the reset spring.

Description

Technical Field

[0001] This application relates to the field of solenoid valve technology, and in particular to a two-position four-way solenoid valve for noise reduction. Background Technology

[0002] The oxygen-generating solenoid valve is an indispensable part of an oxygen concentrator, and its operating capability directly determines the oxygen-generating capacity of the entire oxygen concentrator. Oxygen-generating solenoid valves generally come in two types: direct-acting shut-off and diaphragm type, with the diaphragm type being more common.

[0003] The basic principle of the diaphragm solenoid valve in an oxygen concentrator is as follows: Two solenoid valves are used as pilot valves, with symmetrically distributed valve body cavities. The upper and lower valve cores form a linkage assembly. When the first solenoid valve is energized, the air pressure pushes the linkage assembly to form an end-face seal between the upper valve core in the left cavity and the sealing surface of the valve body, controlling the intake of air through the left molecular sieve of the oxygen concentrator, while simultaneously exhausting air through the right molecular sieve. When the first circuit is cut off, when the second solenoid valve is energized, the air pressure pushes the linkage assembly in the right cavity to form an end-face seal between the upper valve core and the sealing surface of the valve body, causing the left molecular sieve of the oxygen concentrator to exhaust air, while simultaneously allowing air to enter through the right molecular sieve, thus achieving the reversal of the air path.

[0004] However, existing oxygen concentrator solenoid valves have obvious shortcomings in use: due to the lack of speed control during the engagement process, the moving iron core will strike the stationary iron core at a large instantaneous speed, resulting in a lot of noise; in addition, the internal return spring will fatigue and soften after long-term use, causing the impact force to gradually increase over time, and existing products lack effective automatic adjustment and deceleration buffering mechanisms. Summary of the Invention

[0005] To improve the current situation, this application provides a two-position four-way solenoid valve for reducing noise.

[0006] This application provides a two-position four-way solenoid valve for noise reduction, employing the following technical solution: A two-position four-way solenoid valve for noise reduction includes a valve body and a pilot device for controlling the switching of the valve body's air path. The pilot device includes a coil assembly, a moving iron core, and a return spring. It also includes a resistance adjustment assembly connected in series in the power supply circuit of the coil assembly. The resistance adjustment assembly includes a resistive element arranged along the movement path of the moving iron core and an adjustment contact drivenly connected to the moving iron core. The adjustment contact is configured to move in tandem during the engagement of the moving iron core to increase the effective resistance connected to the power supply circuit, thereby reducing the electromagnetic attraction and slowing down the moving iron core. Furthermore, the adjustment contact is configured to automatically increase the initial effective resistance and reduce the initial operating current of the coil assembly in response to the return deviation of the moving iron core caused by fatigue of the return spring.

[0007] Preferably, a free travel engagement structure is provided between the moving iron core and the adjusting contact. The free travel engagement structure is configured to provide the moving iron core with a preset free travel relative to the adjusting contact, so that the resistance adjustment component only acts on the end of the moving iron core's engagement process.

[0008] Preferably, the idle stroke fitting structure includes: a pair of limiting blocks, which are fixedly disposed at intervals on the outer peripheral wall of the moving iron core; a connecting block, which is disposed between the pair of limiting blocks and is fixedly connected to the adjusting contact; the connecting block is provided with a sliding groove that slides with the moving iron core.

[0009] Preferably, the pilot device further includes a housing, with a resistive element fixed in the inner cavity of the housing. The end of the resistive element away from the coil assembly and the adjusting contact are connected in series in the power supply circuit via wires.

[0010] Preferably, it also includes a monitoring circuit, the signal acquisition end of which is connected to the common connection point between the coil assembly and the resistance adjustment assembly; the monitoring circuit is configured to compare the sampled voltage at the common connection point with the preset voltage when the moving iron core is in the preset free travel stage, so as to determine the fatigue state of the reset spring.

[0011] Preferably, a buffer pad is provided at the end of the moving iron core facing the coil assembly.

[0012] Preferably, the valve body has an I-shaped cavity and an air inlet and an exhaust port communicating with the I-shaped cavity. The I-shaped cavity is provided with a valve core that can move back and forth. During the movement, the valve core has a first state in which the air inlet communicates with the I-shaped cavity, and a second state in which the exhaust port communicates with the I-shaped cavity. A second buffer pad is fixed on the top end face of the valve core.

[0013] Preferably, a diaphragm spring is provided inside the I-shaped cavity, and a buffer seat is provided between the diaphragm spring and the valve body. The buffer seat includes an annular base and several deformable protrusions fixed to one end face of the annular base.

[0014] In summary, this application includes at least one of the following beneficial technical effects: 1. By adjusting the resistance of the component, the resistance of the power supply circuit is automatically increased and the electromagnetic attraction is reduced at the end of the engagement process, so that the moving iron core decelerates before impact, thereby reducing the noise generated by the electromagnetic conduction component. At the same time, the initial operating current of the coil component will automatically decrease as the initial displacement of the moving iron core changes due to the fatigue of the return spring, thereby effectively suppressing the increase in the impact speed of the moving iron core caused by the fatigue of the return spring. 2. By setting up the no-stroke coordination structure, the solenoid valve maintains the maximum electromagnetic attraction force at the initial stage of startup to achieve rapid response, and deceleration is only achieved at the end of the stroke during the engagement process; 3. By setting up buffer pad No. 1, buffer pad No. 2 and buffer seat, the residual kinetic energy during the impact of the moving iron core and the valve core switching can be further absorbed, effectively improving the silent performance of the solenoid valve. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a two-position four-way solenoid valve used to reduce noise in this embodiment. Figure 2 This is a top view of a two-position four-way solenoid valve for noise reduction in this embodiment; Figure 3 for Figure 2 A cross-sectional view along the AA direction; Figure 4 for Figure 3 Enlarged structural diagram at point B; Figure 5 This is a schematic diagram of the structure of some of the pilot devices, resistance adjustment components and idle stroke cooperation structure in this embodiment; Figure 6 for Figure 2 A cross-sectional view along the CC direction; Figure 7 This is a schematic diagram of the buffer seat in this embodiment; Figure 8 for Figure 2 A cross-sectional view along the DD direction; Figure 9 This is a circuit diagram of the power supply circuit and the monitoring circuit in this embodiment; Reference numerals: 1. Valve body; 11. I-shaped cavity; 12. Air inlet; 13. Exhaust port; 14. Valve core; 15. Second buffer pad; 16. Diaphragm spring; 17. Buffer seat; 171. Annular base; 172. Protrusion; 2. Pilot device; 21. Coil assembly; 22. Moving iron core; 23. Return spring; 24. Housing; 25. First buffer pad; 3. Resistance adjustment assembly; 31. Resistance element; 32. Adjustment contact; 4. Free travel mating structure; 41. Limiting block; 42. Connecting block; 43. Slide groove. Detailed Implementation

[0016] The following is in conjunction with the appendix Figure 1-9 This application will be described in further detail.

[0017] This application discloses a two-position four-way solenoid valve for noise reduction.

[0018] Reference Figure 1 and Figure 6The valve body 1 has an I-shaped cavity 11 inside, and an air inlet 12 and an air outlet 13 that are both connected to the I-shaped cavity 11. A valve core 14 that can move back and forth is provided in the I-shaped cavity 11. A diaphragm spring 16 is also provided between the valve body 1 and the valve core 14. The valve body 1 has two states: in the first state, the lower end of the valve core 14 forms an end face seal with the sealing surface of the valve body 1, and the air inlet 12 is connected to the I-shaped cavity 11; in the second state, the upper end of the valve core 14 forms an end face seal with the sealing surface of the valve body 1, and the air outlet 13 is connected to the I-shaped cavity 11.

[0019] Reference Figure 4 , Figure 5 and Figure 8 The pilot device 2, serving as the pilot valve structure of the solenoid valve, is fixedly installed above the valve body 1 and is used to control the changes in the air path within the valve body 1. The pilot device 2 includes a housing 24, a coil assembly 21 fixed inside the housing 24, an axially movable moving iron core 22, and a return spring 23 whose two ends are respectively connected to the moving iron core 22 and the housing 24.

[0020] The moving iron core 22 is used to control the opening and closing of the pilot air path: when the coil assembly 21 is not energized, the moving iron core 22 is located away from the coil assembly 21 under the action of the reset spring 23. At this time, the pilot air path is opened, and the valve core 14 is driven to move downward by the pressure difference, so that the valve body 1 switches to the second state; when the coil assembly 21 is energized, the moving iron core 22 moves towards the coil assembly 21 under the action of electromagnetic attraction and blocks the pilot air path. At this time, the pressure cannot be applied to the valve core 14, and the valve core 14 is reset under the action of the diaphragm spring 16, so that the valve body 1 switches to the first state.

[0021] Reference Figure 4 and Figure 5 A resistor element 31 is fixed in the inner cavity of the housing 24. The resistor element 31 is arranged along the axial movement path of the moving iron core 22. The end of the resistor element 31 away from the coil assembly 21 is connected to the power supply circuit through a wire. An adjustment contact 32 is slidably installed on the resistor element 31. The adjustment contact 32 is connected to the power supply circuit through a wire, so that the resistor adjustment assembly 3, the coil assembly 21, the switch and the power supply are connected in series.

[0022] The adjusting contact 32 can slide on the resistive element 31 as the moving iron core 22 moves; when the moving iron core 22 moves, it drives the adjusting contact 32 to slide, thereby changing the effective resistance connected to the power supply circuit and adjusting the working current flowing through the coil assembly 21.

[0023] The idle stroke engagement structure 4 includes a pair of limiting blocks 41 fixedly disposed at intervals on the outer peripheral wall of the moving iron core 22, and a connecting block 42 slidably installed on the outside of the moving iron core 22 and located between the pair of limiting blocks 41. The connecting block 42 is fixedly connected to the adjusting contact 32.

[0024] Both the limiting block 41 and the connecting block 42 have a rubber layer on their outer sides to prevent noise from being generated by impact.

[0025] During the process of coil assembly 21 being energized and starting up, and moving iron core 22 moving towards coil assembly 31: First stage: The moving iron core 22 slides relative to the connecting block 42, and the adjusting contact 32 remains stationary at the initial position of the resistive element 31, thereby ensuring the response speed of the pilot valve opening.

[0026] In the second stage, the limiting block 41, which is away from the coil assembly 21, abuts against the connecting block 42, causing the moving iron core 22 to drive the connecting block 42 and the adjusting contact 32 to slide synchronously. At this time, the adjusting contact 32 moves on the resistive element 31 in the direction of increasing resistance, so that the effective resistance connected to the power supply circuit gradually increases, the operating current of the coil assembly 21 gradually decreases, and the electromagnetic attraction gradually decreases, thereby allowing the moving iron core 22 to decelerate before impact.

[0027] Reference Figure 9 The monitoring circuit includes a voltage comparator U1. The non-inverting input of the voltage comparator U1 is connected to the common connection point of the coil assembly 21 and the resistor adjustment assembly 3. The inverting input is connected to the preset voltage VCC_2. The output is connected to the receiver of the microcontroller. The output of the microcontroller is connected to a wireless communication module, which is used for remote data transmission.

[0028] The first timer periodically drives the switch Q1 to close, controlling the coil assembly 21 to perform cyclic start-stop operations; the second timer periodically drives the switch Q2 to close, so that the voltage comparator U1 is activated only at the moment the coil assembly is energized, and determines the voltage at the point of common connection.

[0029] When the voltage at the common connection point captured by the non-inverting input is lower than the preset voltage VCC_2, the voltage comparator outputs a low-level signal. After the microcontroller captures the low-level signal, it determines that the reset spring 23 is about to fail, and then generates an alarm command. It then sends a signal to the operator's mobile phone via the wireless communication module to remind him to perform timely maintenance.

[0030] Reference Figure 4 , Figure 6 and Figure 7 The moving iron core 22 is provided with a first buffer pad 25 at one end facing the coil assembly 21, and a second buffer pad 15 is fixed on the top end face of the valve core 14 to buffer the impact when the valve core reverses upward; a buffer seat 17 is also provided in the I-shaped cavity 11 between the diaphragm spring 16 and the valve body 1.

[0031] The protrusions 172 on the No. 1 buffer pad 25, the No. 2 buffer pad 15, and the buffer seat 17 are all made of rubber to further absorb mechanical impact noise.

[0032] The implementation principle of a two-position four-way solenoid valve for noise reduction disclosed in this application embodiment is as follows: when the coil assembly 21 is energized: First stage: The moving iron core 22 begins to move towards the coil assembly 21 under the action of electromagnetic force. At this time, due to the presence of the idle travel fit structure 4, the moving iron core 22 slides relative to the connecting block 42, and the adjusting contact 32 remains temporarily stationary, located at the initial position of the resistive element 31.

[0033] Second stage: After the moving iron core 22 moves a certain distance, the limiting block 41 away from the coil assembly 21 abuts against the connecting block 42. Then, the moving iron core 22 drives the adjusting contact 32 to slide synchronously on the resistive element 31. As the adjusting contact 32 moves in the direction of increasing resistance, the total resistance in the power supply circuit gradually increases, causing the current flowing through the coil assembly 21 to gradually decrease. The electromagnetic attraction force decreases accordingly, and the moving iron core moves at a lower speed and blocks the pilot air path.

[0034] When coil assembly 21 is de-energized, the electromagnetic force disappears: Reset process: The moving iron core 22 is reset downward under the action of the reset spring 23. When the limiting block 41 near the coil assembly 21 comes into contact with the connecting block 42, the moving iron core 21 drives the adjusting contact 32 to slide back to the initial position. During this process, the pilot air passage is reopened.

[0035] When the return spring 23 fatigues, the rebound stroke of the moving iron core 22 and the adjusting contact 32 during power-off reset is shortened. This means it cannot fully return to its original position, but instead generates an initial displacement towards the coil assembly 21, automatically increasing the initial effective resistance of the power supply circuit. Therefore, when power is restored, the initial operating current of the coil assembly 21 decreases, and the initial electromagnetic attraction also decreases. Since the fatigue of the return spring 23 means a reduction in resistance to the movement of the moving iron core 22, the reduced electromagnetic attraction perfectly matches the weakened spring resistance, thus avoiding the problem of excessive acceleration and violent impact of the moving iron core 22 during startup due to spring fatigue.

[0036] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A two-position four-way solenoid valve for noise reduction, comprising a valve body (1) and a pilot device (2) for controlling the air path switching of the valve body (1), the pilot device (2) comprising a coil assembly (21), a moving iron core (22), and a return spring (23), characterized in that, It also includes: a resistance adjustment component (3), which is connected in series in the power supply circuit of the coil assembly (21); the resistance adjustment component (3) includes a resistance element (31) arranged along the movement path of the moving iron core (22) and an adjustment contact (32) that is connected to the moving iron core (22) in a transmission manner; the adjustment contact (32) is configured to: move in linkage during the attraction of the moving iron core (22) to increase the effective resistance connected to the power supply circuit, and reduce the electromagnetic attraction force to decelerate the moving iron core (22); The adjusting contact (32) is further configured to automatically increase the initial effective resistance and reduce the initial operating current of the coil assembly (21) in response to the reset deviation of the moving iron core (22) caused by the fatigue of the reset spring (23).

2. A two-position four-way solenoid valve for noise reduction according to claim 1, characterized in that, A free travel engagement structure (4) is provided between the moving iron core (22) and the adjusting contact (32). The free travel engagement structure (4) is configured to provide the moving iron core (22) with a preset free travel relative to the adjusting contact (32), so that the resistance adjustment component (3) only acts on the end of the moving iron core (22) during the engagement process.

3. A two-position four-way solenoid valve for noise reduction according to claim 2, characterized in that, The idle stroke fit structure (4) includes: A pair of limiting blocks (41) are fixed at intervals on the outer peripheral wall of the moving iron core (22); A connecting block (42) is disposed between the pair of limiting blocks (41) and is fixedly connected to the adjusting contact (32); the connecting block (42) is provided with a sliding groove (43) that slides with the moving iron core (22).

4. A two-position four-way solenoid valve for noise reduction according to claim 1, characterized in that: The pilot device (2) also includes a housing (24), and the resistor element (31) is fixed in the inner cavity of the housing (24). The end of the resistor element (31) away from the coil assembly (21) and the adjusting contact (32) are connected in series in the power supply circuit through wires.

5. A two-position four-way solenoid valve for noise reduction according to claim 2, characterized in that: It also includes a monitoring circuit, the signal acquisition end of which is connected to the common connection point between the coil assembly (21) and the resistance adjustment assembly (3); the monitoring circuit is configured to compare the sampled voltage at the common connection point with the preset voltage when the moving iron core (22) is in the preset free stroke stage, so as to determine the fatigue state of the reset spring (23).

6. A two-position four-way solenoid valve for noise reduction according to claim 1, characterized in that: The moving iron core (22) has a buffer pad (25) at one end facing the coil assembly (21).

7. A two-position four-way solenoid valve for noise reduction according to claim 1, characterized in that: The valve body (1) has an I-shaped cavity (11) and an air inlet (12) and an exhaust port (13) connected to the I-shaped cavity (11). The I-shaped cavity (11) has a reciprocating valve core (14). During the movement, the valve core (14) has a first state that connects the air inlet (12) with the I-shaped cavity (11) and a second state that connects the exhaust port (13) with the I-shaped cavity (11). A second buffer pad (15) is fixed on the top end face of the valve core (14).

8. A two-position four-way solenoid valve for noise reduction according to claim 7, characterized in that: The I-shaped cavity (11) is provided with a diaphragm spring (16), and a buffer seat (17) is provided between the diaphragm spring (16) and the valve body (1). The buffer seat (17) includes an annular base (171) and a number of deformable protrusions (172) fixed on one side end face of the annular base (171).

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