A micro differential pressure control solenoid valve

Abstract

The present invention provides a micro differential pressure control solenoid valve, comprising: a valve body, a housing, a coil assembly, a top cover, a moving iron core, a stationary iron core, a push rod, a valve core, a spring and a base. The coil assembly is installed in the housing, the moving iron core is installed in an installation cavity provided in the center of the coil assembly, the top cover is installed on the top of the housing, the valve body is fixed to the bottom of the housing, the upper half of the stationary iron core is installed in the coil assembly, the lower half of the stationary iron core is inserted into the valve body, the push rod penetrates through the stationary iron core longitudinally, the valve core is installed in a valve core installation cavity of the valve body main body, the bottom of the push rod abuts against the top of the valve core, the base is installed in a base installation cavity of the valve body main body, and the spring is installed between the valve core and the base. The micro differential pressure control solenoid valve adopts a structural design in which the push rod and the valve core are separated from each other, so that the valve core can be controlled by an electromagnetic signal to push the valve core to move by the push rod, or be pushed to move by the medium pressure alone, achieving the effect of dual control of the electromagnetic signal and the medium differential pressure.

Description

Technical Field

[0001] The present invention relates to the technical field of solenoid valves, and particularly to a solenoid valve for controlling a tiny pressure difference. Background Art

[0002] The electric drive cooling control solenoid valve is installed at the coolant control end of the cooling circulation module of the new energy vehicle electric drive system, and is used to adjust the circulation of the coolant to control the temperature of the power system to ensure its safety. The traditional coolant control valve only needs to consider the way of turning the valve on and off to control the opening and closing of the coolant passage, so only a reasonable requirement in terms of flow rate is needed. However, once there is a power failure in a new energy electric vehicle, the power signal itself may be blocked, resulting in the solenoid valve being in a temporarily powered-off state, which may affect the operation of the cooling system at this time. Therefore, in addition to the ordinary function of controlling the coolant circulation by turning the power on and off, it is necessary to consider that when the power signal is blocked, that is, in the powered-off state, the valve can be switched from the closed state to the full-flow state under the tiny pressure change (0.01 MPa) of the coolant. Due to the limitation of the diameter of the cooling system pipeline itself, the influence of the tiny pressure change of the coolant on the output force is negligible. How to amplify the change signal of the tiny flow rate through the design change of the pure mechanical structure has become a technical difficulty.

[0003] In addition, since the traditional solenoid valve switch only has a control method of controlling the opening and closing of the valve by the electromagnetic signal alone, and there is no requirement that, for the sake of safety, the valve can also be opened when the medium pressure reaches a limited value (similar to the function of a safety valve). Due to the limitation of the diameter of the solenoid valve, when the medium pressure changes slightly, the pressure change received by the spool part is extremely subtle. It is difficult to make the valve switch from the closed state to the full-flow state within the range of this pressure difference. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention provides a solenoid valve for controlling a tiny pressure difference, which adopts a structural design in which a push rod and a spool are disengaged from each other, so that the spool can be controlled by an electromagnetic signal to push the push rod to move the spool, or be pushed by the medium pressure alone to move the spool, achieving the dual control effect of electromagnetic signal and medium pressure difference. And through the structural design of the spool, when the spool is affected by the medium pressure, due to the change in the size of the area difference, the tiny pressure difference of the medium pressure is amplified to the force received by the entire spool, so that the spool can be fully opened to the maximum opening state, realizing the control of the tiny pressure difference.

[0005] To achieve the above technical solution, the present invention provides a micro differential pressure control solenoid valve, comprising: a valve body, a housing, a coil assembly, a top cover, a moving iron core, a stationary iron core, a push rod, a valve core, a spring and a base. The coil assembly is installed in the housing, the moving iron core is installed in an installation cavity provided in the center of the coil assembly, the top cover is installed on the top of the housing and encloses the coil assembly and the moving iron core in the housing, the valve body is fixed to the bottom of the housing, the upper half of the stationary iron core is installed in the coil assembly, and the lower half of the stationary iron core is inserted into the valve body. The valve body includes a valve body main body. A stationary iron core installation cavity is provided at the top of the valve body main body. A push rod moving cavity is provided below the stationary iron core installation cavity. A valve core installation cavity is provided below the push rod moving cavity. An oil inlet hole communicating with the outside is provided on the inner wall of the middle part of the push rod moving cavity. An oil passage groove is provided at the connection between the bottom inner wall of the push rod moving cavity and the valve core installation cavity. A base installation cavity is provided at the bottom of the valve core installation cavity. The lower half of the stationary iron core is inserted into the stationary iron core installation cavity of the valve body main body. The push rod runs longitudinally through the stationary iron core and the top of the push rod contacts the bottom of the moving iron core. The valve core is installed in the valve core installation cavity of the valve body main body. The bottom of the push rod abuts against the top of the valve core. The base is installed in the base installation cavity of the valve body main body. A base oil outlet hole is provided in the center of the base. The valve core is configured in a T-shaped structure. The small valve core end at the top of the valve core can be inserted into the push rod moving cavity and closes the oil passage groove provided on the push rod moving cavity. A plurality of valve core oil passing holes are provided on the side wall of the small valve core end. The large valve core end at the bottom of the valve core is installed in the valve core installation cavity. A valve core central oil outlet hole communicating with the valve core oil passing holes provided on the side wall of the small valve core end is provided in the center of the large valve core end. The spring is installed between the valve core and the base, and the top of the spring abuts against the large valve core end of the valve core, and the bottom of the spring abuts against the mounting seat.

[0006] In the above technical solution, during actual operation, the following three situations may occur with this solenoid valve: (1) When there is no electromagnetic signal and the medium pressure is less than the set value (such as less than 0.04 MPa), under the elastic force of the spring, the small end of the valve core closes the oil passage groove provided in the push rod activity cavity of the valve body body. At this time, the medium cannot pass through the valve core, and the solenoid valve is in an overall closed state. (2) When the medium pressure exceeds the set value (such as when it reaches 0.045 MPa, with a small pressure difference change), the medium enters the push rod activity cavity through the oil inlet hole provided on the outer wall of the valve body body. The small end of the valve core is slightly pushed downward by the medium, exposing the oil passage groove. At this time, the medium impacts the large end of the valve core through the oil passage groove, increasing the impact force on the valve core. Because the force-bearing area of the valve core is larger at this time, it can effectively overcome the spring force of the spring below the large end of the valve core, causing the valve core to move to the maximum opening position. The medium flows in through the valve core oil passage hole provided on the small end of the valve core, and then flows out through the valve core central oil outlet hole provided on the large end of the valve core and connected to the valve core oil passage hole, and finally is discharged from the valve body through the base oil outlet hole provided on the base, realizing the opening of the solenoid valve. Through the structural design of the valve core, the valve core is set as a T-shaped structure with a small upper end and a large lower end. When under the action of the medium pressure, due to the change in the size of the area difference, the small pressure difference of the medium pressure is amplified to the force on the entire valve core, enabling the valve core to be fully opened to the maximum opening state and realizing the control of the small pressure difference. (3) When the solenoid valve receives an electromagnetic signal and the coil assembly is energized, a mutual force is generated between the moving iron core and the static iron core, which then pushes the push rod downward. The push rod pushes the valve core, causing the valve core to move downward against the spring force. In this state, regardless of whether there is a medium with a certain pressure, the opening of the valve core can reach the open state, and the flow rate of the medium is also in the maximum state at this time.

[0007] Preferably, a filter screen installation groove is provided on the outer wall of the valve body body at the position of the oil inlet hole. The oil inlet hole is communicated with the filter screen installation groove, and a filter screen is installed in the filter screen installation groove. By setting the filter screen, the medium can be filtered to prevent impurities from blocking the oil inlet hole, the oil passage groove, or the oil outlet hole.

[0008] Preferably, a plurality of valve core oil discharge holes are provided at the bottom of the large end of the valve core, which are distributed in a circumferential array with the valve core central oil outlet hole as the center. Each valve core oil discharge hole is communicated with the valve core central oil outlet hole to enhance the pressure stability when the medium is discharged and also improve the sensitivity to oil pressure changes.

[0009] Preferably, a bracket is installed at the docking position of the housing and the valve body to facilitate the overall installation of this solenoid valve.

[0010] Preferably, a magnetic isolation sleeve is sleeved on the inner side of the coil assembly, and the moving iron core and the static iron core are both installed inside the magnetic isolation sleeve to enhance the anti-interference performance of this solenoid valve.

[0011] Preferably, a first sealing ring installation groove and a second sealing ring installation groove are respectively formed in the middle-lower part and the middle-upper part of the outer wall of the valve body main body, and the first sealing ring and the second sealing ring are respectively installed in the first sealing ring installation groove and the second sealing ring installation groove to enhance the overall sealing performance of the solenoid valve.

[0012] Preferably, a third sealing ring is installed at the contact between the static iron core and the inner wall of the static iron core installation cavity provided on the valve body main body to enhance the sealing performance at the contact between the static iron core and the inner wall of the static iron core installation cavity.

[0013] Preferably, a fourth sealing ring is installed at the contact between the static iron core and the magnetic isolation sleeve to enhance the sealing performance at the contact between the static iron core and the magnetic isolation sleeve.

[0014] The beneficial effects of the micro differential pressure control solenoid valve provided by the present invention are as follows: The micro differential pressure control solenoid valve has a simple structure and ingenious design. It adopts a structural design in which the push rod and the valve core are separated from each other, so that the valve core can be controlled by an electromagnetic signal to push the valve core to move by the push rod, or be pushed to move by the medium pressure alone, achieving the effect of dual control of electromagnetic signal and medium differential pressure. And through the structural design of the valve core, when it is affected by the medium pressure, due to the change in the size of the area difference, the micro differential pressure of the medium pressure is amplified to the force on the entire valve core, so that the valve core can be fully opened to the maximum opening state, realizing micro differential pressure control. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is an assembly cross-sectional view when the valve core of the present invention is closed.

[0016] Figure 2 It is a rear view of the present invention.

[0017] Figure 3 It is a side view of the valve body of the present invention.

[0018] Figure 4 It is a side cross-sectional view of the valve body of the present invention.

[0019] Figure 5 It is a three-dimensional structural schematic diagram of the valve core of the present invention.

[0020] Figure 6 It is a side view of the valve core of the present invention.

[0021] Figure 7 It is a side cross-sectional view of the valve core of the present invention.

[0022] Figure 8 It is an assembly cross-sectional view when the valve core of the present invention is opened by the medium pressure.

[0023] Figure 9 It is an assembly cross-sectional view when the valve core of the present invention is opened by the push rod.

[0024] In the figure: 1. Valve body; 101. Valve body main body; 102. First sealing ring installation groove; 103. Filter screen installation groove; 104. Oil inlet hole; 105. Second sealing ring installation groove; 106. Base installation cavity; 107. Spool installation cavity; 108. Oil circuit groove; 109. Push rod moving cavity; 110. Static iron core installation cavity; 2. First sealing ring; 3. Filter screen; 4. Second sealing ring; 5. Third sealing ring; 6. Bracket; 7. Fourth sealing ring; 8. Outer shell; 9. Coil assembly; 10. Top cover; 11. Moving iron core; 12. Static iron core; 13. Magnetic isolation sleeve; 14. Push rod; 15. Spool; 151. Small end of the spool; 152. Large end of the spool; 153. Oil passage hole of the spool; 154. Central oil outlet hole of the spool; 155. Oil discharge hole of the spool; 16. Spring; 17. Base; 171. Oil outlet hole of the base. Specific embodiments

[0025] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0026] Embodiment: A micro differential pressure control solenoid valve.

[0027] Referring to Figures 1 to 9 As shown, a micro differential pressure control solenoid valve includes: a valve body 1, a filter screen 3, a bracket 6, an outer shell 8, a coil assembly 9, a top cover 10, a moving iron core 11, a static iron core 12, a push rod 14, a spool 15, a spring 16 and a base 17. The coil assembly 9 is installed in the outer shell 8, the moving iron core 11 is installed in the installation cavity provided in the center of the coil assembly 9, the top cover 10 is installed on the top of the outer shell 8 and closes the coil assembly 9 and the moving iron core 11 in the outer shell 8, the valve body 1 is fixed to the bottom of the outer shell 8, the upper half of the static iron core 12 is installed in the coil assembly 9, the lower half of the static iron core 13 is inserted into the valve body 1, and a bracket 6 is installed at the docking part of the outer shell 8 and the valve body 1 to facilitate the overall external installation of this solenoid valve. A magnetic isolation sleeve 13 is sleeved on the inner side surface of the coil assembly 9, and the moving iron core 11 and the top of the static iron core 12 are both installed in the magnetic isolation sleeve 13 to enhance the anti-interference performance of this solenoid valve. A fourth sealing ring 7 is installed at the contact part between the static iron core 12 and the magnetic isolation sleeve 13 to enhance the sealing performance at the contact part between the static iron core 12 and the magnetic isolation sleeve 13;

[0028] The valve body 1 includes a valve body main body 101. A static iron core installation cavity 110 is provided at the top of the valve body main body 101. A push rod moving cavity 109 is provided below the static iron core installation cavity 110. A valve core installation cavity 107 is provided below the push rod moving cavity 109. An oil inlet hole 104 communicating with the outside is provided on the inner wall of the middle part of the push rod moving cavity 109. An oil groove 108 is provided at the connection between the bottom inner wall of the push rod moving cavity 109 and the valve core installation cavity 107. A base installation cavity 106 is provided at the bottom of the valve core installation cavity 107. The lower half of the static iron core 12 is inserted into the static iron core installation cavity 110 of the valve body main body 101. The push rod 14 penetrates the static iron core 12 longitudinally, and the top of the push rod 14 contacts the bottom of the moving iron core 11. The valve core 15 is installed in the valve core installation cavity 107 of the valve body main body 101. The bottom of the push rod 14 abuts against the top of the valve core 15. The base 17 is installed in the base installation cavity 106 of the valve body main body 101. A base oil outlet hole 171 is provided at the center of the base 17. During actual operation, when the solenoid valve receives an electromagnetic signal and the coil assembly 9 is energized, a mutual acting force is generated between the moving iron core 11 and the static iron core 12, thereby pushing the push rod 14 to move downward. The valve core 15 is pushed by the push rod 14, so that the valve core 15 moves downward against the elastic force of the spring 16, realizing the opening of the valve core 15.

[0029] The valve core 15 is arranged in a T-shaped structure with a smaller upper end and a larger lower end. The small valve core end 151 at the top of the valve core 15 can be inserted into the push rod moving cavity 109 and closes the oil groove 108 provided on the push rod moving cavity 109. A plurality of valve core oil passing holes 153 are provided on the side wall of the small valve core end 151. The large valve core end 152 at the bottom of the valve core 15 is installed in the valve core installation cavity 107. A valve core central oil outlet hole 154 communicating with the valve core oil passing holes 153 provided on the side wall of the small valve core end 151 is provided at the center of the large valve core end 107. A plurality of valve core oil discharging holes 155 are provided at the bottom of the large valve core end 152 and are arranged in a circumferential array centered on the valve core central oil outlet hole 154. Each valve core oil discharging hole 155 is communicated with the valve core central oil outlet hole 154 to enhance the pressure stability when the medium is discharged and also improve the sensitivity to oil pressure changes. The spring 16 is installed between the valve core 15 and the base 17, and the top of the spring 16 abuts against the large valve core end 152 of the valve core 15, and the bottom of the spring 16 abuts against the mounting seat 17. During actual operation, when there is no electromagnetic signal and the medium pressure is less than the set value, under the elastic force of the spring 16, the small valve core end 151 of the valve core 15 closes the oil groove 108 provided on the push rod moving cavity 109 of the valve body main body 101. At this time, the medium cannot pass through the valve core 15, and the solenoid valve is in an overall closed state.

[0030] In this embodiment, a filter screen mounting groove 103 is provided on the outer wall of the valve body main body 101 at the position of the oil inlet hole 104. The oil inlet hole 104 is communicated with the filter screen mounting groove 103, and a filter screen 3 is installed in the filter screen mounting groove 103. By providing the filter screen 3, the medium can be filtered to prevent impurities from blocking the oil inlet hole, the oil groove 108, or the oil outlet hole. A first sealing ring mounting groove 102 and a second sealing ring mounting groove 105 are respectively formed in the middle lower part and the middle upper part of the outer wall of the valve body main body 101. The first sealing ring 2 and the second sealing ring 4 are respectively installed in the first sealing ring mounting groove 102 and the second sealing ring mounting groove 105 to enhance the overall sealing performance of the solenoid valve. A third sealing ring 5 is installed at the contact position between the static iron core 12 and the inner wall of the static iron core mounting cavity 110 provided on the valve body main body 101 to enhance the sealing performance at the contact position between the static iron core 12 and the inner wall of the static iron core mounting cavity 110.

[0031] In this embodiment, during actual operation, the solenoid valve will have the following three situations:

[0032] (1) When there is no electromagnetic signal and the medium pressure is less than the set value (such as less than 0.04 MPa), under the elastic force of the spring 16, the small end 151 of the valve core 15 closes the oil groove 108 provided on the push rod activity cavity 109 of the valve body main body 101. At this time, the medium cannot pass through the valve core 15, and the solenoid valve is in an overall closed state.

[0033] (2) When the medium pressure exceeds the set value (such as when it reaches 0.045 MPa, with a small pressure difference change), the medium enters the push rod activity cavity 109 from the oil inlet hole 104 provided on the outer wall of the valve body main body 101. The small end 151 of the valve core is slightly pushed downward by the medium, exposing the oil groove 108. At this time, the medium impacts the large end 152 of the valve core through the oil groove 108, increasing the impact force on the valve core 15. Because the force-bearing area of the valve core 15 is relatively large at this time, it can effectively overcome the spring force of the spring 16 below the large end 152 of the valve core, causing the valve core 15 to move to the maximum opening position. The medium flows in through the valve core oil hole 153 provided on the small end 151 of the valve core, and then flows out through the valve core central oil outlet hole 154 and the valve core oil drain hole 155 which are communicated with the valve core oil hole 153 and provided on the large end 152 of the valve core, and finally is discharged from the valve body 1 through the base oil outlet hole 171 provided on the base 17, realizing the opening of the solenoid valve. Through the structural design of the valve core 15, the valve core 15 is set as a T-shaped structure with a small upper end and a large lower end. When under the action of the medium pressure, due to the change in the size of the area difference, the small pressure difference of the medium pressure is amplified to the force on the entire valve core 15, enabling the valve core 15 to be fully opened to the maximum opening state, thus realizing the control of the small pressure difference.

[0034] (3) When the solenoid valve receives an electromagnetic signal, the coil assembly 9 is energized, generating a mutual force between the moving iron core 11 and the static iron core 12. This further pushes the push rod 14 downward, and through the push rod 14, the valve core 15 is pushed, causing the valve core 15 to move downward against the elastic force of the spring 16. In this state, regardless of whether there is a medium with a certain pressure, the opening degree of the valve core 15 can reach the open state, and at this time, the flow rate of the medium is also in the maximum state.

[0035] The structure of this micro differential pressure control solenoid valve is simple and ingeniously designed. It adopts a structural design in which the push rod 14 and the valve core 15 are separated from each other, enabling the valve core 15 to be controlled by an electromagnetic signal to push the valve core 15 to move, or to be pushed by the medium pressure alone to move the valve core 15, achieving the effect of dual control of electromagnetic signals and medium differential pressure. And through the structural design of the valve core 15, when it is affected by the medium pressure, due to the change in the size of the area difference, the small differential pressure of the medium pressure is amplified to the force on the entire valve core 15, enabling the valve core 15 to be fully opened to the maximum opening state, realizing micro differential pressure control.

[0036] The above are the preferred embodiments of the present invention, but the present invention should not be limited to the content disclosed in this embodiment and the drawings. Therefore, all equivalent or modified implementations completed without departing from the spirit disclosed by the present invention fall within the protection scope of the present invention.

Claims

1. A micro differential pressure control solenoid valve, characterized in that Comprising: Valve body, housing, coil assembly, top cover, moving iron core, static iron core, push rod, valve core, spring and base. The coil assembly is installed inside the housing, the moving iron core is installed in the installation cavity provided in the center of the coil assembly, the top cover is installed on the top of the housing and encloses the coil assembly and the moving iron core inside the housing, the valve body is fixed to the bottom of the housing, the upper half of the static iron core is installed inside the coil assembly, and the lower half of the static iron core is inserted into the valve body. The valve body includes a valve body main body. A static iron core installation cavity is provided at the top of the valve body main body. A push rod moving cavity is provided below the static iron core installation cavity. A valve core installation cavity is provided below the push rod moving cavity. An oil inlet hole communicating with the outside is provided on the inner wall of the middle part of the push rod moving cavity. An oil passage groove is provided at the connection between the bottom inner wall of the push rod moving cavity and the valve core installation cavity. A base installation cavity is provided at the bottom of the valve core installation cavity. Among them, the lower half of the static iron core is inserted into the static iron core installation cavity of the valve body main body. The push rod runs longitudinally through the static iron core and the top of the push rod contacts the bottom of the moving iron core. The valve core is installed in the valve core installation cavity of the valve body main body. The bottom of the push rod abuts against the top of the valve core. The base is installed in the base installation cavity of the valve body main body. A base oil outlet hole is provided at the center of the base. The valve core is configured in a T-shaped structure. The small end of the valve core at the top can be inserted into the push rod moving cavity and closes the oil passage groove provided on the push rod moving cavity. A plurality of valve core oil passing holes are provided on the side wall of the small end of the valve core. The large end of the valve core at the bottom is installed in the valve core installation cavity. A valve core central oil outlet hole communicating with the valve core oil passing holes provided on the side wall of the small end of the valve core is provided at the center of the large end of the valve core. The spring is installed between the valve core and the base, and the top of the spring abuts against the large end of the valve core of the valve core, and the bottom of the spring abuts against the base; A plurality of valve core oil discharge holes are provided at the bottom of the large end of the valve core and are distributed in a circumferential array with the valve core central oil outlet hole as the center. Each valve core oil discharge hole communicates with the valve core central oil outlet hole; A bracket is installed at the docking place between the housing and the valve body.

2. The micro differential pressure control solenoid valve according to claim 1, characterized in that: A filter screen installation groove is provided on the outer wall of the valve body main body at the position of the oil inlet hole. The oil inlet hole communicates with the filter screen installation groove, and a filter screen is installed in the filter screen installation groove.

3. The micro differential pressure control solenoid valve according to claim 1, characterized in that: A magnetic isolation sleeve is sleeved on the inner side surface of the coil assembly. The moving iron core and the top of the static iron core are both installed inside the magnetic isolation sleeve.

4. The micro differential pressure control solenoid valve according to claim 1, characterized in that: A first sealing ring installation groove and a second sealing ring installation groove are respectively provided in the middle and lower part and the middle and upper part of the outer wall of the valve body main body. The first sealing ring and the second sealing ring are respectively installed in the first sealing ring installation groove and the second sealing ring installation groove.

5. The micro differential pressure control solenoid valve according to claim 1, wherein: A third sealing ring is installed at the contact place between the static iron core and the inner wall of the static iron core installation cavity provided on the valve body main body.

6. The micro differential pressure control solenoid valve according to claim 5, characterized in that: A fourth sealing ring is installed at the contact place between the static iron core and the magnetic isolation sleeve.

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