Electromagnetic valve for automobile braking system and control method of electromagnetic valve

Abstract

The invention relates to an electromagnetic valve for an automobile braking system and a control method of the electromagnetic valve, and belongs to the technical field of automobile braking systems.The electromagnetic valve for the automobile braking system comprises a valve element assembly and a coil assembly installed outside the valve element assembly, the valve element assembly comprises a static iron core, a movable iron core and a switch element, and the static iron core is connected with a valve seat through a main valve sleeve to form a containing cavity structure; the movable iron core and the switch element move in the containing cavity structure in the axial direction, the valve seat is arranged to be an integrated valve seat, a main valve is formed between one end of the switch element and the valve seat, and an auxiliary valve is formed between the other end of the switch element and the movable iron core. The electromagnetic valve is simple in structure and easy to manufacture, the risk that the sealing base falls off is avoided, and braking response is rapid.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile braking systems, and in particular to a solenoid valve for an automobile braking system and a control method thereof. Background Art

[0002] In order to control the brake pressure, the automobile brake system has multiple solenoid valves for opening and closing the channels of the brake oil pressure line. By controlling the relevant solenoid valves, the brake hydraulic pressure of the wheel cylinders of different wheels can be adjusted to ensure the braking safety and comfort of the automobile. These solenoid valves include normally open solenoid valves that are usually maintained in an open state and normally closed solenoid valves that are usually maintained in a closed state.

[0003] For example, the patent with publication number CN103398205A discloses a solenoid valve for automobile braking system, in which the gland is fixedly connected to the main valve seat by four evenly distributed screws, a sealing gasket is arranged between the gland and the main valve seat, the gland, magnetic shell, coil bracket, shoulder and main valve seat are axially pressed in sequence, an inward flange is arranged at the center hole of the magnetic shell, the upper inner ring of the magnetic shell and the upper outer ring of the solenoid valve body have a radial clearance match, the lower inner ring of the magnetic shell and the outer ring of the magnetic gasket have a radial clearance match, the inner ring of the magnetic gasket and the outer ring of the shoulder have a clearance match, and a large annular groove and a small annular groove are arranged on the solenoid valve body.

[0004] The above-mentioned solenoid valve has the following problems: First, the sealing base and the valve body are in interference fit, and there is a risk of falling off. In the structure of the prior art, the connection strength between the sealing base and the valve body can only be improved by increasing the diameter size. After the solenoid valve is pressed into the valve body block, the lower part of the valve body is squeezed by the interference fit of the valve body block, and the lower part of the valve body is deformed, which puts the sealing base at risk of falling off. In addition, when there is a high back pressure differential force between the lower part of the valve body and the side port, the position of the sealing base will change according to the high pressure differential force acting axially, and may even fall off. Second, the solenoid valve has only one hydraulic oil flow path, and the brake pressure cannot be adjusted, resulting in a slow brake response. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a solenoid valve for an automobile braking system and a control method thereof, which has a simple structure and is easy to manufacture, avoids the risk of the sealing base falling off, and enables a rapid braking response.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present invention to solve its technical problem is: the solenoid valve for the automobile braking system includes a valve core assembly and a coil assembly installed outside the valve core assembly, the valve core assembly includes a static iron core, a moving iron core and a switching element, the static iron core is connected to the valve seat through a main valve sleeve to form a cavity structure, the moving iron core and the switching element move axially in the cavity structure, the valve seat is configured as an integrated valve seat, a main valve is formed between one end of the switching element and the valve seat, and an auxiliary valve is formed between the other end of the switching element and the moving iron core.

[0007] A positioning boss is arranged on the inner wall of one end of the valve seat away from the moving iron core so that an oil passage I is formed at the bottom of the valve seat, an oil hole I is arranged on the side of the valve seat, and one end of the oil passage I cooperates with the switch element to form the main valve.

[0008] The oil hole I, the inner cavity of the valve seat and the oil passage I form a flow passage I for opening the main valve.

[0009] The switch element is configured as a columnar component, an oil passage II is axially arranged at the center of the switch element, a closing element for blocking the oil passage II is installed at one end of the moving iron core, and the closing element and the oil passage II form the auxiliary valve.

[0010] A necking section with a reduced aperture is provided at one end of the oil passage II close to the moving iron core, and the aperture of the necking section is smaller than the aperture of the oil passage I in the valve seat.

[0011] An auxiliary valve sleeve is fixed to one end of the moving iron core close to the switch element, and the auxiliary valve sleeve is axially sleeved and connected to the switch element.

[0012] The auxiliary valve sleeve is arranged in the valve seat, and the auxiliary valve sleeve and the valve seat are gap-matched to form an external oil passage. The auxiliary valve sleeve is provided with a plurality of through holes at intervals along the circumferential direction. The oil hole I, the external oil passage and the through holes form a flow passage II for opening the auxiliary valve.

[0013] A flange for preventing the auxiliary valve sleeve from being separated from the switch element is arranged at one end of the switch element close to the moving iron core.

[0014] The switch element sleeve is connected with a compression spring I, which is located below the auxiliary valve sleeve. One end of the compression spring I is in contact with one end of the switch element, and the other end of the compression spring I is fixedly connected to the valve seat.

[0015] The valve seat is provided with a sink for positioning and fixing the compression spring I.

[0016] The switch element is outer-connected with a compression spring I, which is located in the auxiliary valve sleeve, and one end of the compression spring I is in contact with one end of the switch element, and the other end of the compression spring I is in contact with one end of the auxiliary valve sleeve.

[0017] A blind hole is provided at one end of the moving iron core close to the static iron core, a compression spring II is installed in the blind hole, and one end of the compression spring II extends out of the blind hole and is connected to one end of the static iron core.

[0018] The initial pressure difference between the oil passage I and the oil hole I is greater than the magnetic field force generated by the coil assembly, the magnetic field force generated by the coil assembly is greater than the elastic force of the compression spring I, and the elastic force of the compression spring I is less than the elastic force of the compression spring II.

[0019] The outside of the valve seat is fixedly connected to a filter screen, and the filter screen is blocked outside the oil hole I.

[0020] A control method for a solenoid valve for a vehicle braking system includes a control process of quickly pressing a brake pedal and quickly releasing the brake pedal.

[0021] The control process of the quick brake pedal step includes opening the auxiliary valve, opening the main valve, closing the auxiliary valve and fully opening the main valve in sequence, so that the hydraulic oil in the brake master cylinder enters the pedal simulator.

[0022] The control process of the quick-release brake pedal includes closing the auxiliary valve and fully opening the main valve, and the hydraulic oil in the pedal simulator flows back into the brake master cylinder.

[0023] The beneficial effects of the present invention are:

[0024] 1. The present invention provides a solenoid valve, which integrates the sealing base and the valve body in the prior art into one body to form an integrated valve seat, thereby avoiding the risk of the sealing base falling off due to the pressure difference at the inlet and outlet of the hydraulic oil, and at the same time avoiding the loosening problem caused by the sealing base being pressed into the lower part of the valve body in the prior art due to overpressure, simplifying the assembly process of the entire solenoid valve, and avoiding the problem of difficult control of the sealing base press-fitting in the prior art.

[0025] 2. The present invention connects a switch element axially in the valve seat, and a main valve is formed between one end of the switch element and the valve seat, and an auxiliary valve is formed between the other end of the switch element and the moving iron core. When the brake pedal is pressed quickly, the auxiliary valve is opened first under the action of the magnetic field force; as the pressure difference at the inlet and outlet of the hydraulic oil decreases, until the magnetic field force exceeds the hydraulic oil pressure difference borne by the main valve, the moving iron core lifts the switch element under the action of the auxiliary valve sleeve to open the main valve; the pressure difference at the inlet and outlet of the hydraulic oil further decreases until the pressure difference is less than the elastic force of the compression spring I installed outside the switch element, and the compression spring I pushes the switch element upward until the auxiliary valve is closed, and at the same time the main valve is fully opened, so that the main valve is gradually opened, avoiding vibration shock caused by the sudden opening of the main valve, and ensuring the reliability of the opening of the main valve; the above process realizes the adjustment of the hydraulic oil flow from small to large, ensuring that the hydraulic oil in the brake master cylinder can quickly enter the pedal simulator, making the braking response faster. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The following is a brief description of the contents expressed in the drawings of the present invention and the symbols in the drawings:

[0027] Figure 1 1 is a schematic structural diagram of a solenoid valve for a vehicle braking system in a closed state according to an embodiment of the present invention;

[0028] Figure 2 This is a structural schematic diagram of the hydraulic oil flow path when the brake pedal is pressed quickly and the auxiliary valve is open in the first embodiment of the present invention;

[0029] Figure 3 This is a structural schematic diagram of the hydraulic oil flow path when the brake pedal is pressed quickly and the auxiliary valve and the main valve are both in the open state in the first embodiment of the present invention;

[0030] Figure 4 It is a structural schematic diagram of the hydraulic oil flow path in a quick-release brake pedal in an embodiment of the present invention, with the auxiliary valve closed and the main valve fully opened;

[0031] Figure 5 is a structural schematic diagram of a solenoid valve for a vehicle braking system in a closed state according to a second embodiment of the present invention;

[0032] The marks in the above figures are: 1. Coil assembly, 2. Static iron core, 3. Moving iron core, 31. Blind hole, 32. Closing element, 4. Switching element, 41. Oil channel II, 42. Neck section, 43. Flange, 44. Step stop, 5. Main valve sleeve, 6. Valve seat, 61. Positioning boss, 62. Oil channel I, 63. Oil hole I, 64. Sink, 7. Main valve, 8. Auxiliary valve, 9. Auxiliary valve sleeve, 91. Through hole, 10. External oil channel, 11. Compression spring I, 12. Compression spring II, 13. Filter. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0034] In the description of the present invention, it should be noted that the directions or positional relationships indicated by terms such as “upper”, “lower”, “front”, “back”, “left”, “right”, “vertical”, “inside” and “outside” are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0035] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] The present invention provides a solenoid valve for an automobile braking system and a control method thereof, which will be specifically described in the following embodiments.

[0037] Embodiment 1

[0038] like Figure 1 to Figure 4 As shown, the present invention provides a solenoid valve for an automobile brake system, including a valve core assembly and a coil assembly 1 installed outside thereof, the valve core assembly including a static iron core 2, a moving iron core 3 and a switch element 4, the static iron core 2 is connected to a valve seat 6 through a main valve sleeve 5 to form a cavity structure, the moving iron core 3 and the switch element 4 move axially in the cavity structure, wherein the valve seat 6 is configured as an integrated valve seat, that is, the sealing base and the valve body in the prior art are integrated into one body, thereby avoiding the risk of the pressure difference at the inlet and outlet of the hydraulic oil acting on the sealing base and causing it to fall off, and at the same time avoiding the problem of loosening caused by the sealing base being pressed into the lower part of the valve body due to overpressure in the prior art, simplifying the assembly process of the entire solenoid valve, and avoiding the problem of difficult control of pressing the sealing base in the prior art.

[0039] A main valve 7 is formed between one end of the switch element 4 and the valve seat 6, and an auxiliary valve 8 is formed between the other end of the switch element 4 and the moving iron core 3, so that the entire solenoid valve forms a two-stage valve structure, which can adjust the flow of oil entering the pedal valve simulator (PFS) to make the braking response faster.

[0040] Specifically, a positioning boss 61 is provided on the inner wall of one end of the valve seat 6 away from the moving iron core 3 so that an oil passage Ⅰ62 is formed at the bottom of the valve seat 6, and an oil hole Ⅰ63 is provided on the side of the valve seat 6. One end of the oil passage Ⅰ62 cooperates with the switch element 4 to form the main valve 7. The positioning boss 61 cooperates with one end of the switch element 4, and one end of the switch element 4 can be set as a spherical surface, and one end of the positioning boss 61 can be set as a conical surface, so that the oil passage Ⅰ62 can be reliably blocked to achieve reliable closure of the main valve 7. The oil hole Ⅰ63, the inner cavity of the valve seat 6 and the oil passage Ⅰ62 form a circulation channel Ⅰ for opening the main valve 7. When one end of the switch element 4 is blocked and matched with the positioning boss 61, the circulation channel Ⅰ can be cut off to achieve closure of the main valve 7.

[0041] Specifically, the switch element 4 is configured as a columnar component, and an oil passage II 41 is axially arranged at the center of the switch element 4. A closing element 32 for closing the oil passage II 41 is installed at one end of the moving iron core 3, and the closing element 32 and the oil passage II 41 form an auxiliary valve 8. The closing element 32 can be configured as a spherical structure, and a necking section 42 with a reduced aperture is provided at one end of the oil passage II 41 close to the moving iron core 3. A conical surface matching the closing element 32 is provided on the outer end surface of the necking section 42, which can ensure the reliable closure of the auxiliary valve 8. Moreover, the aperture of the necking section 42 is smaller than the aperture of the oil passage I 62 in the valve seat 6, and the pressure difference force it bears is small. When the coil assembly 1 is energized, the magnetic field force generated by it acts on the moving iron core 3, causing the moving iron core 3 to move upward and first open the auxiliary valve 8.

[0042] An auxiliary valve sleeve 9 is fixed to one end of the moving iron core 3 close to the switch element 4, and the auxiliary valve sleeve 9 is axially sleeved and connected with the switch element 4. The auxiliary valve sleeve 9 is arranged in the valve seat 6, and the auxiliary valve sleeve 9 and the valve seat 6 are gap-matched to form an external oil passage 10. The auxiliary valve 8 is provided with a plurality of through holes 91 at intervals along the circumferential direction. The oil hole Ⅰ63, the external oil passage 10 and the through hole 91 form a flow passage Ⅱ for opening the auxiliary valve 8. After the hydraulic oil enters the oil hole Ⅰ63 from the brake master cylinder through the oil pipe, it enters the auxiliary valve 8 through the multiple through holes 91 on the auxiliary valve sleeve 9 through the external oil passage 10, so that a pressure difference is generated between the oil passage Ⅰ62 and the oil hole Ⅰ63. Since the initial pressure difference between the oil passage Ⅰ62 and the oil hole Ⅰ63 is greater than the magnetic field force generated by the coil assembly 1, the pressure difference at this time is greater than the magnetic field force generated by the coil assembly 1, so that the switch element 4 can move downward relative to the moving iron core 3, so that the auxiliary valve 8 is opened.

[0043] The end of the switch element 4 close to the moving iron core 3 is provided with a flange 43 to prevent the auxiliary valve sleeve 9 from being separated from the switch element 4. As the auxiliary valve 8 is opened, the pressure difference between the oil passage Ⅰ62 and the oil hole Ⅰ63 is gradually reduced until the magnetic field force exceeds the pressure difference borne by the main valve 7, the moving iron core 3 moves upward, and the flange 43 at one end of the moving iron core 3 drives the auxiliary valve sleeve 9 to lift the switch element 4, so that the main valve 7 is also gradually opened.

[0044] The switch element 4 is outer-connected with a compression spring Ⅰ11, which is located below the auxiliary valve sleeve 9. The switch element 4 is provided with a step stop 44, and the step stop 44 is spaced a distance from the flange 43, which is the sliding distance of the switch element 4 relative to the auxiliary valve sleeve 9. One end of the compression spring Ⅰ11 is connected to the step stop 44 on the switch element 4, and the other end of the compression spring Ⅰ11 is connected to the valve seat 6 for positioning and fixing. That is, the valve seat 6 is provided with a sink 64 for positioning and fixing the compression spring Ⅰ11. When the auxiliary valve 8 and the main valve 7 are both open, the pressure difference between the oil channel Ⅰ62 and the oil hole Ⅰ63 is further reduced. Since the initial pressure difference between the oil channel Ⅰ62 and the oil hole Ⅰ63 is greater than the magnetic field force generated by the coil assembly 1, and the magnetic field force generated by the coil assembly 1 is greater than the elastic force of the compression spring Ⅰ11, the initial pressure difference between the oil channel Ⅰ62 and the oil hole Ⅰ63 is greater than the elastic force of the compression spring Ⅰ11. When the pressure difference between the oil channel Ⅰ62 and the oil hole Ⅰ63 is reduced to less than the elastic force of the compression spring Ⅰ11, the compression spring Ⅰ11 pushes the switch element 4 to move toward the static iron core 2, thereby closing the auxiliary valve 8 and fully opening the main valve 7, increasing the circulation of the hydraulic oil and ensuring that the hydraulic oil in the brake master cylinder can quickly enter the pedal simulator (PFS), making the braking response faster.

[0045] A blind hole 31 is provided at one end of the moving iron core 3 close to the static iron core 2, and a compression spring II12 is installed in the blind hole 31. One end of the compression spring II12 extends out of the blind hole 31 and is connected to one end of the static iron core 2. The elastic force of the compression spring I11 is smaller than the elastic force of the compression spring II12, which can ensure that the coil assembly 1 can maintain a closed state when it is not powered on.

[0046] In addition, the valve seat 6 is fixedly connected to the filter screen 13 by interference fit, and the filter screen 13 is blocked outside the oil hole Ⅰ63, which plays a role in filtering the hydraulic oil, preventing impurities from entering the solenoid valve and affecting the normal operation of the solenoid valve. The static iron core 2 and the main valve sleeve 5 are connected by laser welding, so that a sealed cavity is formed between the static iron core 2, the main valve sleeve 5, the valve seat 6 and the switch element 4. The main valve sleeve 5 and the valve seat 6 are connected by interference fit or riveting, which can achieve sealing without relative movement under high hydraulic pressure.

[0047] like Figure 1 As shown, when the coil assembly 1 in the solenoid valve is not energized, under the action of the compression spring II 12, the closing element 32 at the end of the moving iron core 3 abuts against the port of the necking section 42 of the switch element 4, so that the auxiliary valve 8 is closed. At the same time, because the elastic force of the compression spring II 12 is greater than the elastic force of the compression spring I 11, the moving iron core 3 presses the switch element 4 under the action of the compression spring II 12, so that the lower end of the switch element 4 blocks the port of the oil passage I 62 of the valve seat 6, so that the main valve 7 is closed.

[0048] The control method of the electromagnetic valve for the automobile braking system includes the control process of quickly pressing the brake pedal and quickly releasing the brake pedal.

[0049] The control process of fast braking pedal includes opening the auxiliary valve 8, opening the main valve 7, closing the auxiliary valve 8 and fully opening the main valve 7 in sequence, so that the hydraulic oil in the brake master cylinder enters the pedal simulator. The specific control process is as follows:

[0050] 1) If Figure 2 As shown, the brake pedal is pressed quickly, and the hydraulic oil in the brake master cylinder enters the interior of the solenoid valve from the oil hole Ⅰ63, so that there is a pressure difference between the oil passage Ⅰ62 and the oil hole Ⅰ63; because the aperture of the oil passage Ⅱ41 of the switch element 4 is larger than the aperture of the necking section 42, the pressure difference force it bears is smaller. When the coil assembly 1 is energized, a magnetic field force is generated between the static iron core 2 and the moving iron core 3, so that the moving iron core 3 first overcomes the elastic force of the compression spring Ⅱ12 and moves toward the static iron core 2 under the action of the magnetic field force. Therefore, the closing element 32 is away from the port of the necking section 42 of the switch element 4, so that the auxiliary valve 8 is opened, and the hydraulic oil in the brake master cylinder enters the pedal simulator;

[0051] 2) If Figure 3 As shown, as the auxiliary valve 8 is opened, the pressure difference between the oil passage Ⅰ62 and the oil hole Ⅰ63 is gradually reduced until the magnetic field force exceeds the pressure difference borne by the main valve 7, so that the moving iron core 3 moves upward, and the moving iron core 3 drives the auxiliary valve sleeve 9 to lift the switch element 4, so that the main valve 7 is also gradually opened;

[0052] 3) When both the auxiliary valve 8 and the main valve 7 are open, the pressure difference between the oil channel Ⅰ62 and the oil hole Ⅰ63 is further reduced. When the pressure difference between the oil channel Ⅰ62 and the oil hole Ⅰ63 is reduced to less than the elastic force of the compression spring Ⅰ11, the compression spring Ⅰ11 pushes the switch element 4 to move in the direction of the static iron core 2, thereby closing the auxiliary valve 8 and fully opening the main valve 7 to achieve brake clamping, increasing the circulation of the hydraulic oil, and ensuring that the hydraulic oil in the brake master cylinder can quickly enter the pedal simulator, making the braking response faster.

[0053] The control process of the quick brake pedal includes closing the auxiliary valve 8 and fully opening the main valve 7, and the hydraulic oil in the pedal simulator flows back to the brake master cylinder. The specific control process is:

[0054] like Figure 4As shown, the brake pedal is quickly pressed until the hydraulic pressure between oil channel Ⅰ62 and oil hole Ⅰ63 is stable. At this time, the auxiliary valve 8 is closed and the main valve 7 is fully opened. The brake pedal is quickly withdrawn. The pressure of the hydraulic oil at oil channel Ⅰ62 is greater than the pressure of the hydraulic oil at oil hole Ⅰ63, so that a pressure difference is formed between oil channel Ⅰ62 and oil hole Ⅰ63, so that the hydraulic oil enters oil channel Ⅰ62 through the oil pipe from the pedal simulator, enters the solenoid valve, and then flows back to the brake master cylinder through the oil hole Ⅰ63 to achieve brake release.

[0055] Embodiment 2

[0056] The difference from the first embodiment is that, Figure 5 As shown, the installation structure of the compression spring Ⅰ11 is different. That is, the switch element 4 is connected with the compression spring Ⅰ11, and the compression spring Ⅰ11 is located in the auxiliary valve sleeve 9. The switch element 4 is provided with a step stop 44, and the step stop 44 is separated from the flange 43 at one end of the switch element 4 by a distance, which is the installation area of ​​the compression spring Ⅰ11. The lower end of the auxiliary valve sleeve 9 is stopped by the step stop 44, so that the moving iron core 3 can drive the auxiliary valve sleeve 9 to lift the switch element 4 and open the main valve 7. One end of the compression spring Ⅰ11 is connected to the flange 43 at one end of the switch element 4, and the other end of the compression spring Ⅰ11 is connected to one end of the auxiliary valve sleeve 9.

[0057] When the auxiliary valve 8 and the main valve 7 are both open, the pressure difference between the oil channel Ⅰ62 and the oil hole Ⅰ63 is further reduced. When the pressure difference between the oil channel Ⅰ62 and the oil hole Ⅰ63 is reduced to less than the elastic force of the compression spring Ⅰ11, the end of the compression spring Ⅰ11 close to the auxiliary valve sleeve 9 remains stationary, and the compression spring Ⅰ11 pushes the switching element 4 to move in the direction of the static iron core 2, thereby closing the auxiliary valve 8 and fully opening the main valve 7, ensuring that the hydraulic oil in the brake master cylinder can quickly enter the pedal simulator, making the braking response faster.

[0058] The control method of the solenoid valve is the same as that in the first embodiment and will not be described again here.

[0059] In summary, the present invention has the following advantages over the prior art:

[0060] 1) By integrating the sealing base and the valve body in the prior art into one body to form an integrated valve seat 6, the risk of the sealing base falling off due to the pressure difference at the inlet and outlet of the hydraulic oil is avoided. At the same time, the loosening problem caused by the sealing base being pressed into the lower part of the valve body due to overpressure in the prior art is avoided, the assembly process of the entire solenoid valve is simplified, and the problem of difficult control of the sealing base press-fitting in the prior art is avoided.

[0061] 2) When the brake pedal is pressed quickly, the auxiliary valve 8 is opened first under the action of the magnetic field force; as the pressure difference at the hydraulic oil inlet and outlet decreases, until the magnetic field force exceeds the hydraulic oil pressure difference that the main valve 7 can withstand, the moving iron core 3 lifts the switch element 4 under the action of the auxiliary valve sleeve 9, so that the main valve 7 opens; the pressure difference at the hydraulic oil inlet and outlet is further reduced, until the pressure difference is less than the elastic force of the compression spring Ⅰ11 installed outside the switch element 4, the compression spring Ⅰ11 pushes the switch element 4 upward until the auxiliary valve 8 is closed, and at the same time the main valve 7 is fully opened, so that the main valve 7 is gradually opened, avoiding vibration shock caused by the sudden opening of the main valve 7, and ensuring the reliability of the opening of the main valve 7; the above process realizes the adjustment of the hydraulic oil flow from small to large, ensuring that the hydraulic oil in the brake master cylinder can quickly enter the pedal simulator, making the braking response faster.

[0062] In summary, the solenoid valve designed in the present invention has a simple structure and is easy to manufacture, thereby avoiding the risk of the sealing base falling off and enabling rapid braking response.

[0063] The above description is only used to illustrate some principles of the present invention. This specification is not intended to limit the present invention to the specific structure and application scope shown and described. Therefore, all corresponding modifications and equivalents that may be used belong to the patent scope applied for by the present invention.

Claims

1. A solenoid valve for an automobile brake system, comprising a valve core assembly and a coil assembly mounted outside thereof, wherein the valve core assembly comprises a stationary iron core, a moving iron core and a switch element, wherein the stationary iron core is connected to a valve seat through a main valve sleeve to form a cavity structure, wherein the moving iron core and the switch element move axially in the cavity structure, and wherein: The valve seat is configured as an integrated valve seat, a main valve is formed between one end of the switch element and the valve seat, and an auxiliary valve is formed between the other end of the switch element and the moving iron core.

2. The solenoid valve for automobile braking system according to claim 1, characterized in that: A positioning boss is arranged on the inner wall of one end of the valve seat away from the moving iron core so that an oil passage I is formed at the bottom of the valve seat, an oil hole I is arranged on the side of the valve seat, and one end of the oil passage I cooperates with the switch element to form the main valve.

3. The solenoid valve for automobile brake system according to claim 1, characterized in that: The oil hole I, the inner cavity of the valve seat and the oil passage I form a flow passage I for opening the main valve.

4. The solenoid valve for automobile brake system according to claim 1, characterized in that: The switch element is configured as a columnar component, an oil passage II is axially arranged at the center of the switch element, a closing element for blocking the oil passage II is installed at one end of the moving iron core, and the closing element and the oil passage II form the auxiliary valve.

5. The solenoid valve for automobile brake system according to claim 4, characterized in that: A necking section with a reduced aperture is provided at one end of the oil passage II close to the moving iron core, and the aperture of the necking section is smaller than the aperture of the oil passage I in the valve seat.

6. The solenoid valve for automobile brake system according to any one of claims 2 to 5, characterized in that: An auxiliary valve sleeve is fixed to one end of the moving iron core close to the switch element, and the auxiliary valve sleeve is axially sleeved and connected to the switch element.

7. The solenoid valve for automobile brake system according to claim 6, characterized in that: The auxiliary valve sleeve is arranged in the valve seat, and the auxiliary valve sleeve and the valve seat are gap-matched to form an external oil passage. The auxiliary valve sleeve is provided with a plurality of through holes at intervals along the circumferential direction. The oil hole I, the external oil passage and the through holes form a flow passage II for opening the auxiliary valve.

8. The solenoid valve for automobile brake system according to claim 6, characterized in that: A flange for preventing the auxiliary valve sleeve from being separated from the switch element is arranged at one end of the switch element close to the moving iron core.

9. The solenoid valve for automobile brake system according to claim 6, characterized in that: The switch element sleeve is connected with a compression spring I, which is located below the auxiliary valve sleeve. One end of the compression spring I is in contact with one end of the switch element, and the other end of the compression spring I is fixedly connected to the valve seat.

10. The solenoid valve for automobile brake system according to claim 9, characterized in that: The valve seat is provided with a sink for positioning and fixing the compression spring I.

11. The solenoid valve for automobile brake system according to claim 6, characterized in that: The switch element is outer-connected with a compression spring I, which is located in the auxiliary valve sleeve, and one end of the compression spring I is in contact with one end of the switch element, and the other end of the compression spring I is in contact with one end of the auxiliary valve sleeve.

12. The solenoid valve for automobile brake system according to claim 9, characterized in that: A blind hole is provided at one end of the moving iron core close to the static iron core, a compression spring II is installed in the blind hole, and one end of the compression spring II extends out of the blind hole and is connected to one end of the static iron core.

13. The solenoid valve for automobile brake system according to claim 9, characterized in that: The initial pressure difference between the oil passage I and the oil hole I is greater than the magnetic field force generated by the coil assembly, the magnetic field force generated by the coil assembly is greater than the elastic force of the compression spring I, and the elastic force of the compression spring I is less than the elastic force of the compression spring II.

14. The solenoid valve for automobile brake system according to claim 6, characterized in that: The outside of the valve seat is fixedly connected to a filter screen, and the filter screen is blocked outside the oil hole I.

15. A control method for a solenoid valve for a vehicle brake system according to any one of claims 1 to 14, characterized in that: Including the control process of quickly pressing the brake pedal and quickly releasing the brake pedal, The control process of fast braking pedal comprises opening the auxiliary valve, opening the main valve, closing the auxiliary valve and fully opening the main valve in sequence, so that the hydraulic oil in the brake master cylinder enters the pedal simulator. The control process of the quick-release brake pedal includes closing the auxiliary valve and fully opening the main valve, and the hydraulic oil in the pedal simulator flows back into the brake master cylinder.

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