CN111457146B - Electromagnetic valve - Google Patents

Abstract

The invention discloses an electromagnetic valve, which comprises a valve body part and a core iron part; the valve body member includes a valve housing; the core iron component comprises an end socket fixedly connected with the valve sleeve, a movable iron core component and a reset spring; the movable iron core component is at least partially arranged in the inner cavity of the valve sleeve; the movable iron core assembly comprises an outer iron core and an inner iron core which are in clearance sliding fit, and the outer iron core is in clearance sliding fit with the valve sleeve; the outer iron core comprises a first stop part, and the inner iron core comprises a second stop part which can be abutted against the first stop part; the outer iron core can drive the inner iron core to move towards the direction of the sealing head, and the axial height of the outer iron core is not lower than that of the inner iron core in a state that the second stop part is in butt joint with the first stop part; two ends of the reset spring are respectively abutted against the seal head and the inner iron core; the lower end of the inner iron core is provided with a sealing element, and the first stop part and the second stop part have a first preset distance in the axial direction when the sealing element closes the valve opening; the axial distance between the outer iron core and the end socket is greater than a first preset distance. The valve opening and closing performance of the electromagnetic valve can be improved.

Description

Electromagnetic valve

Technical Field

The invention relates to the technical field of fluid control, in particular to an electromagnetic valve.

Background

At present, a common electromagnetic valve is powered on and off through a coil and the action of a return spring, so that a movable iron core drives a sealing element to move to open or close a valve port, and the on-off of an inlet and an outlet is realized.

How to improve the structure of a solenoid valve to improve the valve opening and closing performance is one of the problems that the person skilled in the art is constantly focusing on and improving.

Disclosure of Invention

In order to solve the technical problems, the invention provides an electromagnetic valve, which comprises a valve body part and a core iron part; the valve body member includes a valve housing; the core iron component comprises an end socket, a movable iron core assembly and a return spring; the seal head is fixedly connected with the valve sleeve, and at least part of the movable iron core assembly is arranged in the inner cavity of the valve sleeve; the movable iron core assembly comprises an outer iron core and an inner iron core, the inner iron core is in clearance sliding fit with the outer iron core, and the outer iron core is in clearance sliding fit with the valve sleeve; the outer iron core comprises a first stop part, the inner iron core comprises a second stop part, and the first stop part can be abutted against the second stop part; the outer iron core can drive the inner iron core to move towards the end socket, and the axial height of the outer iron core is not lower than that of the inner iron core in a state that the first stop part is in abutting connection with the second stop part; one end of the return spring is abutted against the end socket, and the other end of the return spring is abutted against the inner iron core; the lower end of the inner iron core is provided with a sealing element, and a first preset distance is reserved between the first stop part and the second stop part in the axial direction in a state that the sealing element closes the valve opening part of the electromagnetic valve; the axial distance between the outer iron core and the end socket is greater than the first preset distance.

The invention also provides another electromagnetic valve, which comprises a coil, a valve body part and a core iron part; the valve body part comprises a valve sleeve, and the coil is sleeved outside the valve sleeve; the core iron component comprises an end socket, a movable iron core assembly and a return spring; the seal head is fixedly connected with the valve sleeve, and at least part of the movable iron core assembly is arranged in the inner cavity of the valve sleeve;

the movable iron core assembly comprises an outer iron core and an inner iron core, the inner iron core is in clearance sliding fit with the outer iron core, and the outer iron core is in clearance sliding fit with the valve sleeve; the outer iron core comprises a first stop part, the inner iron core comprises a second stop part, and the first stop part can be abutted against the second stop part; the outer iron core can drive the inner iron core to move towards the end socket, and when the coil is electrified in a state that the first stop part is in butt joint with the second stop part, the attractive force of the outer iron core and the end socket is larger than the resultant force of the inner iron core, the end socket and the reset spring; one end of the return spring is abutted against the end socket, and the other end of the return spring is abutted against the inner iron core; the lower end of the inner iron core is provided with a sealing element, and a first preset distance is reserved between the first stop part and the second stop part in the axial direction in a state that the sealing element closes the valve opening part of the electromagnetic valve; the axial distance between the outer iron core and the end socket is greater than the first preset distance.

The movable iron core assembly of the electromagnetic valve comprises an outer iron core and an inner iron core, wherein the inner iron core is in clearance sliding fit with the outer iron core, the outer iron core comprises a first stop part, the inner iron core comprises a second stop part, the first stop part can be abutted against the second stop part, the outer iron core can drive the inner iron core to move towards the direction of the sealing head, one end of a reset spring is abutted against the sealing head, the other end of the reset spring is abutted against the inner iron core, when a sealing piece at the lower end of the inner iron core is abutted against the valve opening of the electromagnetic valve, a first preset distance is formed between the first stop part and the second stop part in the axial direction, and the axial distance between the outer iron core and the sealing head is larger than the first preset distance, so that the valve opening and closing performance of the electromagnetic valve can be improved.

Drawings

FIG. 1 is a schematic diagram of a pilot solenoid valve according to an embodiment of the present invention;

FIG. 2 is an enlarged view of part of the portion A of FIG. 1;

FIG. 3 is a schematic diagram of the piston components of a pilot operated solenoid valve in an exemplary embodiment;

FIG. 4 is a schematic cross-sectional view of a pilot operated solenoid valve in an initial stage of valve opening in an exemplary embodiment;

FIG. 5 is a schematic cross-sectional view of a pilot operated solenoid valve in an open state in an embodiment;

FIG. 6 is a schematic diagram of another embodiment of a pilot operated solenoid valve according to the present invention;

fig. 7 is a schematic structural diagram of a direct-acting electromagnetic valve according to an embodiment of the present invention.

Reference numerals illustrate:

valve housing 110, valve seat 120, main valve port 121;

the end socket 210, the movable iron core assembly 220, the outer iron cores 221 and 221', a first stop portion 2211, a body portion 2212', a retainer ring 2213', an inner iron core 222, a second stop portion 2221, a positioning groove 2222 and a return spring 230;

a seal 300;

the piston member 400, the piston sleeve 410, the peripheral wall portion 411, the annular portion 412, the flow passage hole 413, the extension wall portion 414, the piston core 420, the communication hole 421, the pilot valve port portion 4211, the cavity portion 430;

an inlet nipple 500 and an outlet nipple 600;

valve housing 110a, valve seat 120a, valve port 121a;

head 210a, plunger assembly 220a, outer core 221a, inner core 222a, return spring 230a;

a seal 300a;

the first adapter 500a and the second adapter 600a.

Detailed Description

In order to better understand the aspects of the present invention, the present invention will be described in further detail with reference to the accompanying drawings and detailed description.

Referring to fig. 1 and 2, fig. 1 is a schematic structural diagram of a pilot-operated solenoid valve according to an embodiment of the present invention; fig. 2 is a partial enlarged view of the portion a in fig. 1. Fig. 1 is a schematic structural diagram of a pilot-operated solenoid valve in a closed state.

In this embodiment, the pilot operated solenoid valve includes a valve body member, a core iron member, and a piston member 400.

The valve body part has a chamber passing through axially, the valve body part further has a main valve opening 121 formed in the chamber thereof, an outlet communicating with the main valve opening 121, and an inlet communicating with the chamber, the outlet being connected with an outlet nipple 600, the inlet being connected with an inlet nipple 500, it being understood that the inlet nipple 500 may communicate with the outlet nipple 600 through the main valve opening 121.

The piston member 400 is located in the chamber, and the piston member 400 is movable in the axial direction of the chamber to open or close the main valve port portion 121, thereby achieving communication or interception of the inlet nipple 500 and the outlet nipple 600. The piston member 400 has a communication hole 421 penetrating in the axial direction, a pilot valve port portion 4211 is formed at the upper end of the communication hole 421, the communication hole 421 communicates with the main valve port portion 121, and the piston member 400 further has a flow passage hole 413, and the flow passage hole 413 communicates a chamber portion above the piston member 400 partitioned by the piston member 400 with an inlet of the valve body member.

The core iron component comprises a seal head 210, a movable iron core component 220 and a reset spring 230, wherein the seal head 210 is fixedly connected with the valve body component and seals an upper end opening of a cavity of the valve body component, the movable iron core component 220 is positioned in the cavity, and the reset spring 230 is arranged between the movable iron core component 220 and the seal head 210; the lower end of the plunger assembly 220 is connected with a seal 300. The plunger assembly 220 can move the seal 300 axially along the chamber to open or close the pilot valve port 4211 of the piston member 400. It is understood that the plunger assembly 220 has a predetermined distance from the head 210 so that the plunger assembly 220 has an axial movement space.

When the pilot solenoid valve is in a closed state, i.e., the piston member 400 closes the main valve opening 121, the sealing member 300 closes the pilot valve opening 4211, if an external solenoid (not shown) is energized, the plunger assembly 220 moves upward against the spring force of the return spring 230 under the action of electromagnetic force, driving the sealing member 300 to move upward to open the pilot valve opening 4211, and at this time, high pressure medium above the piston member 400 is discharged to the outlet nipple 600 side through the communication hole 421, and pressure balance of the upper and lower ends of the piston member 400 is broken, so that the piston member 400 moves upward to open the main valve opening 121, and the inlet nipple 500 communicates with the outlet nipple 600.

When the solenoid valve is in the open state and the external solenoid is de-energized, the plunger 220 drives the seal 300 to move downward to close the pilot valve portion 4211 under the spring force of the return spring 230, the medium in the inlet connection pipe 500 flows to the upper side of the piston member 400 through the flow passage hole 413 and accumulates to form high pressure, the pressure balance at the upper and lower ends of the piston member 400 is broken, the piston member 400 moves downward to close the main valve portion 121, and the inlet connection pipe 500 is disconnected from the outlet connection pipe 600.

In this embodiment, the movable core assembly 220 of the core iron member includes an outer core 221 and an inner core 222 inserted into the outer core 221, and the inner core 222 is in clearance sliding fit with the outer core 221, that is, the inner core 222 can slide up and down with respect to the outer core 221; the lower end of the inner core 222 protrudes out of the outer core 221, and the sealing member 300 is specifically connected to the lower end of the inner core 222.

Specifically, the outer core 221 includes a first stop portion 2211, the inner core 222 includes a second stop portion 2221, the second stop portion 2221 can abut against the first stop portion 2211, the outer core 221 can drive the inner core 222 to move towards the end socket 210, and in a state where the second stop portion 2221 abuts against the first stop portion 2211, the axial height of the outer core 221 is not lower than that of the inner core 222; that is, when the external electromagnetic coil is energized, the outer core 221 is first pressed against the end socket 210 or the outer core 221 and the inner core 222 are pressed against the end socket 210 together under the electromagnetic force.

In the actual setting, the design can also be as follows: when the external electromagnetic coil is energized in a state where the first stopper 221 of the external iron core 221 is in contact with the second stopper 2221 of the internal iron core 222, the attractive force between the external iron core 221 and the head 210 is greater than the resultant force of the internal iron core 222, the head 210 and the return spring 230.

In a specific scheme, the lower end of the outer core 221 extends radially inwards to form a first stop portion 2211, the inner core 222 comprises a large-diameter section and a small-diameter section, a second stop portion 2221 is formed at the joint of the two sections, and the outer peripheral wall of the large-diameter section of the inner core 222 is in clearance sliding fit with the inner peripheral wall of the outer core 221; that is, the inner peripheral wall of the outer core 221 has a guide section for guiding the inner core 222, and guides the axial movement of the inner core 222, avoiding deflection between the outer core 221 and the inner core 222, thereby affecting the opening or closing of the seal 300 to the pilot valve port portion 4211.

Specifically, one end of the return spring 230 abuts against the head 210, and the other end of the return spring 230 abuts against the inner core 222.

In a specific embodiment, a positioning groove is formed at the upper end of the inner core 222, and the lower end of the return spring 230 is inserted into the positioning groove to position the return spring 230.

Each relevant component is specifically configured to: in a state where the seal 300 closes the pilot valve portion 4211 of the piston member 400, the outer core 221 abuts against the piston member 400, and a first predetermined distance h (indicated in fig. 2) is provided in the axial direction between the first stopper portion 2211 of the outer core 221 and the second stopper portion 2221 of the inner core 222; the axial distance between outer core 221 and head 210 is greater than a first predetermined distance h.

That is, in the valve-closed state of the pilot type solenoid valve, the outer core 221 is supported by the piston member 400, the sealing member 300 seals the pilot valve portion 4211, and the outer core 221 has a space to move upward with respect to the inner core 222, i.e., a first preset distance h. When the outer core 221 moves upward until the first stop portion 2211 abuts against the second stop portion 2221 of the inner core 222, an axial distance is still provided between the outer core 221 and the head 210.

In a specific scheme, the value range of the first preset distance h is more than or equal to 0.2mm and less than or equal to 0.5mm.

When the pilot solenoid valve is operated from the valve-closed state to the valve-open state after the above arrangement, the outer solenoid coil is energized, and the outer core 221 and the inner core 222 are simultaneously moved upward by the electromagnetic force, but since the first preset distance h exists between the outer core 221 and the inner core 222 in the axial direction, the influence of the return spring 230 is avoided during the initial operation, and the electromagnetic attraction to the outer core 221 is large, the outer core 221 is moved upward relative to the inner core 222 in the initial stage, and after the first preset distance h between the outer core 221 and the inner core 222 is eliminated, the first stop portion 2211 of the outer core 221 abuts against the second stop portion 2221 of the inner core 222, and the outer core 221 moves upward together with the inner core 222 under the electromagnetic force until the outer core 221 and the inner core 222 abut against the head 210.

As can be understood with specific reference to fig. 4 and 5, fig. 4 shows a schematic structural diagram when the outer core 221 abuts against the inner core 222 in an initial stage of valve opening; fig. 5 shows a schematic structural view of the solenoid valve in the open state.

It can be understood that after the first stop portion 2211 of the outer core 221 abuts against the second stop portion 2221 of the inner core 222, the axial height of the outer core 221 is not lower than that of the inner core 222, when the axial height of the outer core 221 is higher than that of the inner core 222, the outer core 221 will abut against the seal head 210 first, and then the inner core 222 moves up to abut against the seal head 210 relative to the outer core 221 under the electromagnetic force, and when the axial height of the outer core 221 is equal to that of the inner core 222, the two together abut against the seal head 210.

It can be further understood that, after the first stop portion 2211 of the outer core 221 abuts against the second stop portion 2221 of the inner core 222, when the axial height of the outer core 221 is designed to be higher than that of the inner core 222, after the outer core 221 abuts against the end socket 210 and the inner core 222, there is an axial distance between the first stop portion 2211 of the outer core 221 and the second stop portion 2221 of the inner core 222, and the axial distance is the distance that the outer core 221 axially rises above the inner core 222 when the second stop portion 2221 abuts against the first stop portion 2211.

As can be seen from the upper valve opening process, due to the structural design of the movable iron core assembly 220, the movable iron core 220 moves up in a split and sectional manner, so that the valve opening performance of the electromagnetic valve is improved.

When the pilot solenoid valve is operated from the valve-opening state to the valve-closing state, since the return spring 230 is engaged with only the inner core 222, the inner core 222 moves downward under the action of the return spring 230 until the second stop portion 2221 of the inner core 222 abuts against the first stop portion 2211 of the outer core 221, and then the inner core 222 moves downward together with the outer core 221, or the inner core 222 moves downward together with the outer core 221 under the action of the return spring 230, and after the inner core 222 drives the seal 300 to close the valve opening 4211, the inner core 222 stops moving downward, and the outer core 221 continues to move downward under the action of gravity until it abuts against the piston member 400, thereby realizing valve closing, and at this time, a first preset distance h exists in the axial direction between the first stop portion 2211 of the outer core 221 and the second stop portion 2221 of the inner core 222.

As can be seen from the valve closing process, due to the structural design of the movable iron core assembly 220, the inner iron core 222 acts with the return spring 230, the outer iron core 221 does not act before the inner iron core 222 is separated from the seal head 210, and due to the small area of the inner iron core 222, the acting force of residual magnetism and an oil film is correspondingly small, the movable iron core 220 is easily separated from the seal head 210, meanwhile, negative pressure is not generated at the magnet separating ring, and the structural design enables the movable iron core 220 to be easily separated, so that the valve closing action performance of the electromagnetic valve is improved.

In a specific scheme, in a state that the sealing member 300 closes the pilot valve opening 4211, the axial distance between the outer iron core 221 and the seal head 210 is smaller than the axial distance between the inner iron core 222 and the seal head 210, so that when the valve is opened, the outer iron core 221 moves towards the seal head 210 more easily due to the closer distance between the outer iron core 221 and the seal head 210, which is beneficial to improving the action performance.

Of course, in the actual installation, the outer core 221 may be not higher than the inner core 222 in the axial direction in a state where the seal 300 closes the pilot valve portion 4211; when the first stopper 221 of the outer core 221 abuts against the second stopper 2221 of the inner core 222, the outer core 221 may be not lower than the inner core 222 in the axial direction.

In a specific scheme, the body of the outer core 221 is in a cylindrical structure, the inner core 222 is in a cylindrical structure, the maximum outer diameter of the outer core 221 is D, the maximum outer diameter of the inner core 222 is D, and on the basis that the inner core 222 comprises a large-diameter section and a small-diameter section, it can be understood that the outer diameter of the large-diameter section of the inner core 222 is the maximum outer diameter D of the inner core 222; in actual setting, D and D satisfy the following relationship: the above arrangement of the outer core 221 and the inner core 222 can improve the valve opening and closing performance of the electromagnetic valve, as proved by researches, wherein D is more than 1.5D and less than 2D.

In a further aspect, the connection between the inner core 222 and the seal 300 is specifically designed as follows: the inner core 222 is capable of hanging and supporting the sealing member 300, and the inner core 222 is capable of moving a second preset distance in an axial direction with respect to the sealing member 300; the inner core 222 is pressed against the seal 300 in a state where the seal 300 closes the pilot valve port portion 4211.

By "suspended support" is meant that the inner core 222 is capable of supporting the seal 300, but not fixed therebetween, and that the inner core 222 is capable of moving the seal 300 together in some conditions and is capable of relative displacement in other conditions.

After the above arrangement, in the initial stage of valve opening, except that the outer core 221 can move relative to the inner core 222, the inner core 222 can move up a second preset distance relative to the sealing member 300, and then the sealing member 300 is driven to move up together, so that the action performance of the movable core assembly 220 can be further optimized. Through experimental study, the electromagnetic valve adopting the split movable iron core 220 can reach 3.1MPa under 80% rated direct current voltage, and if the integrated movable iron core is adopted, the action performance of the electromagnetic valve is only 0.9MPa.

As described above, in this embodiment, in the valve-closed state, the outer core 221 of the inner core 220 is supported by the piston member 400, and after the valve is opened, the outer core 221 is separated from the piston member 400 after the inner core 220 moves up against the head 210, and the piston member 400 also moves up under the pressure difference between the upper and lower ends to open the main valve opening 121, at this time, the position where the piston member 400 moves up axially is defined by the outer core 221, that is, in this embodiment, the outer core 221 serves as a stopper for limiting the axial movement distance of the piston member 400.

In this way, the piston component 400 and the outer core 221 are limited by each other, so that the additional separate setting of corresponding limiting components can be avoided, the structure is simplified, the axial dimension of the pilot-operated solenoid valve can be shortened, and the miniaturization design of the pilot-operated solenoid valve is facilitated.

In a specific embodiment, the upper end of the piston member 400 has a concave cavity 430, the lower end of the piston member 400 has a communication hole 421 penetrating the concave cavity 430, the communication hole 421 communicates with the main valve opening 121, the upper end of the communication hole 421 forms the pilot valve opening 4211, and the flow passage hole 413 is formed in a sidewall of the upper end of the piston member 400, specifically communicating the concave cavity 430 with the inlet.

More specifically, referring to fig. 3 together, fig. 3 is a schematic structural diagram of a piston member of a pilot electromagnetic valve in the embodiment, where the piston member 400 includes a piston sleeve 410 and a piston core 420, and the piston sleeve 410 includes a peripheral wall portion 411, a lower end of the peripheral wall portion 411 extends radially inward to form an annular portion 412, the piston core 420 is fixedly inserted into the annular portion 412, a communication hole 421 is specifically formed in the piston core 420, and it is understood that the communication hole 421 penetrates the piston core 420, and an upper port thereof is a pilot valve portion 4211 and communicates with a cavity portion 430; the lower end surface of the piston core 420 is a sealing surface matched with the main valve opening 121; the peripheral wall 411, the annular portion 412, and the tip end of the piston core 420 enclose a cavity 430; referring to fig. 3 and 4, a flow passage hole 413 is formed in a peripheral wall 411 of the piston sleeve 410.

Further, the lower end of the peripheral wall portion 411 is further provided with an extension wall portion 414 extending downward in the axial direction, and the lower end of the extension wall portion is swaged to the piston core 420, so that the piston core 420 and the piston sleeve 410 can be fixed better.

Referring to fig. 1, after the piston member 400 is disposed as above, the lower end of the inner core 222 and the sealing member 300 are located at the cavity 430, and the lower end of the outer core 221 is matched with the top end of the piston sleeve 410, specifically, in the valve-closed state, the top end surface of the piston sleeve 410 is a supporting surface for supporting the outer core 221, and in the valve-open state, the lower end surface of the outer core 221 is a limiting surface for axially moving up the piston sleeve 410.

It can be seen that the above-described structural design of the piston member 400 and the plunger assembly 220 effectively shortens the axial dimension of the solenoid valve.

In this embodiment, the valve seat member includes a valve housing 110 and a valve seat 120, the valve seat 120 being fixedly connected to the lower end of the valve housing 110, the interior cavity of the valve housing 110 and the interior cavity of the valve seat 120 penetrating to form a chamber of the valve seat member.

Wherein, the main valve opening 121 and the outlet are formed on the valve seat 120, and the inlet is formed on the sidewall of the valve housing 110; specifically, the upper end of the valve seat 120 has a main valve port portion 121 communicating with its inner cavity, and the lower end has an outlet communicating with its inner cavity; it is apparent that the piston member 400 is located between the core member 220 and the valve seat 120.

In the illustrated embodiment, the valve seat 120 is located entirely within the valve housing 110, and it is understood that the valve seat 120 may be configured to be only partially inserted into the valve housing 110.

The inner wall portion of the valve housing 110 has a guide section that cooperates with the piston housing 410 to provide a guide for the axial movement of the piston member 400 to ensure the closing or opening of the piston member 400 to the main valve port 121, that is, the peripheral wall portion 411 of the piston member 400 is in clearance sliding engagement with the valve housing 110; the inner wall portion of the valve housing 110 also has a guide end that mates with the outer core 221 to provide guidance for axial movement of the outer core 221.

For ease of processing, in this embodiment, the valve housing 110 is of a straight cylindrical configuration of equal diameter. It can be understood that, in actual setting, only the guiding section formed by the outer core 221 and the piston sleeve 410 may be designed as a straight section structure, and the rest of the structures may be set according to actual requirements.

Referring to fig. 6, fig. 6 is a schematic structural diagram of another embodiment of a pilot-operated solenoid valve according to the present invention.

In this embodiment, the respective structures of the pilot type solenoid valve are basically identical to those of the above embodiments, and it can be understood with reference to the above embodiments, and are not explained, except that: in this embodiment, the outer core 221' is a split structure, and in the above embodiment, the outer core 221 is a single-piece structure.

In this embodiment, the outer core 221' includes a cylindrical body portion 2212' and a retainer ring 2213' fixedly connected to the body portion 2212', and the retainer ring 2213' forms a first stop portion that cooperates with the second stop portion 2221 of the inner core 222.

Referring to fig. 7, fig. 7 is a schematic structural diagram of a direct-acting electromagnetic valve according to an embodiment of the present invention.

In the foregoing embodiments shown in fig. 1 and 6, the solenoid valve is specifically a pilot-operated solenoid valve, and the solenoid valve provided in the embodiment shown in fig. 7 is a direct-acting solenoid valve.

In this embodiment, the direct-acting solenoid valve includes a valve body member and a core iron member.

The valve body part comprises a valve sleeve 110a and a valve seat 120a fixedly connected with the valve sleeve 110a, wherein in the scheme, the lower end of the valve sleeve 110a is inserted and fixed in the valve seat 120a, and the inner cavities of the valve sleeve 110a and the valve seat 120a are communicated. In practice, the valve housing 110a and the valve seat 120a may be fixedly connected in other manners.

The valve seat 120a has a valve port portion 121a communicating with an inner cavity thereof, a first interface connected with the first adapter 500a, and a second interface connected with the second adapter 600a, wherein the first interface communicates with the inner cavity of the valve seat 120a, the second interface communicates with the valve port portion 121a, and the first adapter 500a communicates with the second adapter 600a through the valve port portion 121 a.

Wherein, the core iron component comprises a seal head 210a, a movable iron core component 220a and a return spring 230a; the end socket 210a is fixedly connected with the valve sleeve 110a, at least part of the movable iron core assembly 220a is arranged in the inner cavity of the valve sleeve 110a, the lower end of the movable iron core assembly 220a is connected with the sealing element 300, and the movable iron core assembly 220a can drive the sealing element 300 to move along the axial direction of the valve sleeve 110a so as to open or close the valve port part 121a, so that the first connecting pipe 500a and the second connecting pipe 600a are in a communicating or cutting-off state.

In this embodiment, the plunger assembly 220a also includes an outer core 221a, an inner core 222a, and a return spring 230a, and the specific structural arrangement is identical to that of the plunger assembly 220 in the pilot operated solenoid valve described above, and will not be described in detail herein.

The electromagnetic valve provided by the invention is described in detail above. The principles and embodiments of the present invention have been described herein with reference to specific examples, the description of which is intended only to facilitate an understanding of the method of the present invention and its core ideas. It should be noted that it will be apparent to those skilled in the art that various modifications and adaptations of the invention can be made without departing from the principles of the invention and these modifications and adaptations are intended to be within the scope of the invention as defined in the following claims.

Claims (12)

1. The electromagnetic valve comprises a valve body part and a core iron part; the valve body member includes a valve housing; the core iron component comprises an end socket, a movable iron core assembly and a return spring; the seal head is fixedly connected with the valve sleeve, and at least part of the movable iron core assembly is arranged in the inner cavity of the valve sleeve;

the movable iron core assembly is characterized by comprising an outer iron core and an inner iron core, wherein the inner iron core is in clearance sliding fit with the outer iron core, and the outer iron core is in clearance sliding fit with the valve sleeve; the outer iron core comprises a first stop part, the inner iron core comprises a second stop part, and the first stop part can be abutted against the second stop part; the outer iron core can drive the inner iron core to move towards the end socket, and the axial height of the outer iron core is not lower than that of the inner iron core in a state that the first stop part is in abutting connection with the second stop part; one end of the return spring is abutted against the end socket, and the other end of the return spring is abutted against the inner iron core; the lower end of the inner iron core is provided with a sealing element, a first preset distance is formed between the first stop part and the second stop part in the axial direction in a state that the sealing element closes the valve opening part of the electromagnetic valve, and the axial distance between the outer iron core and the sealing head is larger than the first preset distance;

when the valve is opened, the electromagnetic coil of the electromagnetic valve is electrified, the outer iron core moves towards the direction of the sealing head relative to the inner iron core, after the first stop part is abutted to the second stop part, the outer iron core drives the inner iron core to move towards the direction of the sealing head together, and after the outer iron core and the inner iron core are abutted to the sealing head.

2. The solenoid valve of claim 1 wherein the lower end of the outer core extends radially inward to form the first stop and the inner core includes a large diameter section and a small diameter section, the junction of the two forming the second stop; the outer peripheral wall of the large-diameter section is in clearance sliding fit with the inner peripheral wall of the outer iron core.

3. The solenoid valve of claim 1 wherein said outer core includes a cylindrical body portion and a retainer fixedly connected to said body portion, said retainer forming said first stop portion; the inner iron core comprises a large-diameter section and a small-diameter section, and the second stop part is formed at the joint of the large-diameter section and the small-diameter section; the outer peripheral wall of the large-diameter section is in clearance sliding fit with the inner peripheral wall of the outer iron core.

4. A solenoid valve according to any one of claims 1 to 3 wherein said seal closes said valve portion with an axial distance between said outer core and said head being less than an axial distance between said inner core and said head.

5. The electromagnetic valve according to claim 4, wherein the body of the outer core is of a cylindrical structure, the inner core is of a columnar structure, and the relationship between the maximum outer diameter D of the outer core and the maximum outer diameter D of the inner core is as follows: 1.5D < D < 2D.

6. A solenoid valve according to any one of claims 1-3 further comprising a piston member disposed within said valve housing interior chamber, said piston member in clearance sliding engagement with said valve housing; the valve body part further comprises a valve seat, and the valve seat is fixedly connected with the valve sleeve; the valve port part comprises a main valve port part and a pilot valve port part, the main valve port part is arranged on the valve seat, and the pilot valve port part is arranged on the piston part;

the sealing piece is used for opening or closing the pilot valve opening part, and the outer iron core is abutted with the piston component in the state that the sealing piece closes the pilot valve opening part.

7. The electromagnetic valve according to claim 6, wherein an upper end of the piston member has a recessed cavity portion, a lower end of the piston member has a communication hole penetrating the recessed cavity portion, the communication hole is also in communication with the main valve port portion, and an upper end of the communication hole forms the pilot valve port portion; the piston part is also provided with a runner hole which is communicated with the concave cavity part and the inlet of the electromagnetic valve;

the lower end of the inner iron core and the sealing piece are positioned at the concave cavity part; the outer iron core is a limiting piece for limiting the axial movement distance of the piston component.

8. The electromagnetic valve according to claim 7, wherein the piston member includes a piston sleeve and a piston core, the piston sleeve including a peripheral wall portion, an outer peripheral wall of the peripheral wall portion being in clearance sliding engagement with an inner peripheral wall of the valve sleeve; the lower end of the peripheral wall part extends inwards along the radial direction to form an annular part, the piston core is fixedly inserted into the annular part, and the communication hole is formed in the piston core; the bottom end surface of the piston core is a sealing surface matched with the main valve opening; the peripheral wall part, the annular part and the top end of the piston core are enclosed to form the concave cavity part; the flow passage hole is formed in the piston sleeve.

9. The electromagnetic valve according to claim 8, wherein a lower end of the peripheral wall portion further has an extension wall portion extending downward in the axial direction, the lower end of the extension wall portion being swaged to the piston core.

10. A solenoid valve according to any one of claims 1 to 3 wherein said inner core is capable of hanging to support said seal and is capable of moving axially a second predetermined distance relative to said seal; the inner core is pressed against the seal member in a state where the seal member closes the valve opening portion.

11. The electromagnetic valve comprises a coil, a valve body part and a core iron part; the valve body part comprises a valve sleeve, and the coil is sleeved outside the valve sleeve; the core iron component comprises an end socket, a movable iron core assembly and a return spring; the seal head is fixedly connected with the valve sleeve, and at least part of the movable iron core assembly is arranged in the inner cavity of the valve sleeve;

the movable iron core assembly is characterized by comprising an outer iron core and an inner iron core, wherein the inner iron core is in clearance sliding fit with the outer iron core, and the outer iron core is in clearance sliding fit with the valve sleeve; the outer iron core comprises a first stop part, the inner iron core comprises a second stop part, and the first stop part can be abutted against the second stop part; the outer iron core can drive the inner iron core to move towards the end socket, and when the coil is electrified in a state that the first stop part is in butt joint with the second stop part, the attractive force of the outer iron core and the end socket is larger than the resultant force of the inner iron core, the end socket and the reset spring; one end of the return spring is abutted against the end socket, and the other end of the return spring is abutted against the inner iron core; the lower extreme of interior iron core is equipped with the sealing member, under the sealing member closed the state of solenoid valve's valve mouth, first backstop portion with second backstop portion has the first distance of predetermineeing in the axial, outer iron core with axial distance between the head is greater than first distance of predetermineeing.

12. The solenoid valve according to claim 1 or 11, characterized in that h fulfils a value of 0.2mm +.h +.0.5 mm, defining said first preset distance h.