KR102137404B1 - Solenoid valve with function of variable force for high pressure - Google Patents

Abstract

According to the present invention, a solenoid valve with a high-pressure proportional control function comprises: a bobbin on which a coil for generating a magnetic field when applying power is wound; a yoke coupled to one end of the bobbin to induce a magnetic field; a core coupled to the upper end of the center of the bobbin to make up a magnetic circuit; a nonmagnetic guide pin of a prescribed diameter extended and inserted downwards into the center of the core; a plunger provided with a guide hole of a prescribed diameter formed therein and inserted while the guide hole encloses the outer circumferential surface of the guide pin to guide a vertical movement by the guide pin towards the magnified core when power is applied; a main valve spring arranged around the guide pin in the core to push and elastically support the plunger in a direction of closing a flow path; a valve guide arranged on a lower portion of the core of the bobbin while enclosing the outer circumferential surface of the plunger to make up a magnetic circuit; a tube enclosing the outer circumferential surface of the upper end of the valve guide and the lower end of the core to maintain airtightness; a valve body coupled to the lower end of the valve guide to form the appearance of the lower end of the entire valve; a main valve seal installed on the lower end of the plunger in the valve body to selectively open a flow path in accordance with a vertical movement of the plunger; a valve seat arranged on a lower portion of the main valve seal in the valve body to selectively open a flow path in accordance with an ascent of the main valve seal while an orifice formed on the upper end thereof is pressed into the lower surface of the main valve seal; and a pilot valve structure arranged above the main valve seal in the plunger to selectively open a flow path prior to the main valve seal to discharge a high-pressure fluid of a flow path to relieve a high-pressure atmosphere.

Description

Solenoid valve with function of variable force for high pressure

The present invention relates to a solenoid valve, and more specifically, a high-pressure proportional control with a pilot valve (Pilot valve) built-in so that a high-pressure gas such as hydrogen can be used for both on-off control or proportional control with a small electromagnetic force. It relates to a solenoid valve having a function.

In general, a solenoid valve is installed on a power train that includes an engine of an automobile, and serves to control the flow or control the flow of fluid such as fuel and oil. For example, the fuel system controls the supply and injection of fuel, the cooling system controls the circulation of fluid for lubrication and cooling, and the power transmission system controls pressure, and so on.

Conventional proportional control solenoid valves for controlling high pressure fluids, such as hydrogen, change the nozzle inlet pressure of the jet pump on the flow path connecting the jet pump of the fuel cell system and the hydrogen tank, and at the same time control the hydrogen supply flow rate. It is mounted on the inlet side, and generally a valve body is formed with a flow path for the transfer of fluid supplied from the outside, a plunger rising or falling by a solenoid, a valve body provided at the bottom of the plunger to open or close the flow path, and a flow path It comprises a spring or the like to press the plunger in the direction of closing.

One example of such a conventional proportional control solenoid valve installed on a fluid supply flow path such as hydrogen is disclosed in detail in Korean Patent Registration No. 1930466 (hereinafter referred to as “prior literature”).

Referring to the accompanying Figure 1, the conventional proportional control solenoid valve disclosed in the prior document is a bobbin 120 coiled to generate a magnetic field when power is applied, the yoke 150 coupled to one end of the bobbin to induce a magnetic field, The core 140 coupled to the other end of the bobbin and magnetized by a magnetic field, a plunger 160 movably installed inside the yoke and moving toward the magnetized core when power is applied, in the direction of closing the flow path A spring 190 elastically supporting the plunger, a valve body 170 and 180 installed at one end of the plunger to seal the flow path, a guide fixed between the bobbin and the core and extending outward through the yoke, and It is characterized in that it is configured to include a guide cover that is coupled to one end of the guide, surrounds the periphery of the valve body, and one end is refracted inward to prevent the plunger 160 from coming off.

However, in the conventional proportional control solenoid valve having such a configuration, since the outer circumferential surface of the plunger supports the vertical reciprocating motion through the guide and the guide cover and prevents the plunger from coming off, eccentricity occurs even if the friction is continued for a certain period of time. If there is, there is a fear that the airtightness of the valve body is rapidly reduced.

In addition, since the conventional proportional control solenoid valve maintains the closed state of the valve body using only a single spring force, there is a concern that airtightness may be weak when the pressure of hydrogen pressure changes due to changes in the external environment such as temperature changes when the valve is closed. Basically, since the operating direction of the original pressure is acting in the direction in which the valve is opened, a larger spring force is required to maintain airtightness, and thus a larger solenoid is needed to overcome the greater spring force and drive the valve. There was a disadvantage that the size of the entire valve was excessively large.

Accordingly, in response to the recent development efforts of hydrogen vehicles, reliable proportional control that can operate more stably with a small electric magnetic force while having a compact configuration with a small size to apply to a circulation system of high pressure fluid such as hydrogen. The demand for the development of solenoid valves is higher than ever.

Accordingly, the present invention was invented to solve the above problems, and the present invention can be used for both on-off control or proportional control, and basically the source pressure (supply pressure) of a high pressure fluid such as hydrogen. This valve acts in the closing direction, while providing a solenoid valve with an efficient pilot valve structure that enables a more stable proportional control of high-pressure fluids such as hydrogen using a smaller size and compact structure while using a smaller electromagnetic force. It is aimed at.

The present invention for achieving the above object, the bobbin is wound coil for generating a magnetic field when power is applied; A yoke coupled to one end of the bobbin to form a magnetic circuit; A core coupled to the upper side of the central portion of the bobbin and magnetized by a magnetic field; A non-magnetic guide pin having a predetermined diameter that extends downwardly in the central portion of the core; A guide hole having a predetermined diameter is formed inside, and the guide hole is fitted while surrounding the outer circumferential surface of the guide pin, and when the power is applied, a plunger that guides movement in the vertical direction by the guide pin toward the magnetized core side; A main valve spring provided around the guide pin inside the core to elastically support the plunger in a direction to close the flow path; A valve guide disposed under the core of the bobbin while surrounding the outer circumferential surface of the plunger to constitute a magnetic circuit; A tube surrounding the lower circumference of the core and the outer circumferential surface of the valve guide to maintain airtightness; A valve body coupled to the lower end of the valve guide to form a lower end appearance of the entire valve; A main valve seal installed at a lower end of the plunger in the valve body to selectively open a flow path according to vertical movement of the plunger; A valve seat provided below the main valve seal in the valve body, the orifice formed at the upper end being press-fitted to the bottom surface of the main valve seal and selectively opening a flow path according to the rise of the main valve seal; And a pilot valve structure provided above the main valve seal inside the plunger to selectively open the flow path prior to the main valve seal to discharge high pressure fluid in the flow path to resolve the high pressure atmosphere.

In addition, the pilot valve structure includes a pilot valve seal provided below the guide pin inside the plunger and vertically moved according to the movement of the plunger; A pilot valve seal holder which is vertically moved together with the pilot valve seal while surrounding the pilot valve seal in a plunger; A pilot valve body in which a flow path is closed as the lower end of the pilot valve seal is selectively pressed into the upper orifice while being inserted into the lower end of the pilot valve seal holder inside the plunger; And a pilot valve spring provided between the pilot valve seal holder and the pilot valve body inside the plunger to elastically support the pilot valve seal holder.

In addition, the guide hole diameter (d1) of the plunger and the orifice diameter (d2) of the valve seat are configured to match.

In addition, the orifice diameter (d2) of the valve seat and the guide part outer diameter (d3) of the pilot valve body are configured to match.

In addition, the spring constant of the main valve spring is formed larger than the spring constant of the pilot valve spring.

In addition, the pilot valve seal, as a whole, has a cylindrical body, circular indentations are formed on the upper and lower surfaces of the body, and each indentation groove is provided in at least one or more fluid moving channels concaved along the outer surface of the cylindrical body. Connected by.

In addition, at the bottom of the plunger, a pilot valve stopper is installed to catch the pilot valve body when the plunger rises and ascend and the pilot valve body and the pilot valve stopper stroke the pilot valve in the power-off state (the valve is closed). It is spaced apart from each other by the gap of.

Also, as the lower end of the pilot seal holder contacts and is supported on the upper end of the pilot valve body, the pilot valve seal is protected by the pilot seal holder so as not to be damaged by excessive pressing.

In addition, the valve seat is screwed to the lower portion of the valve body, the position of the plunger and the action force of the main valve spring are adjusted as the valve seat is selectively rotated to raise and lower the valve seat. It is configured to be adjusted.

In addition, as the supply of the high pressure fluid always acts in the direction in which the pilot valve structure and the main valve seal are closed, the power is applied to the main valve seal due to the pressure difference between high pressure (supply pressure) and low pressure (control pressure) when power is not applied. Press to maintain confidentiality.

The present invention as described above can maintain high airtightness in the control of high pressure fluid such as hydrogen by adopting a pilot type solenoid valve structure in which the source pressure acts in the direction in which the valve is closed, and operate the pilot valve with only a small electromagnetic force to operate the high pressure fluid. There is an advantage that it can be used both for the purpose of proportionally controlling the flow rate or the pressure by making the force due to the pressure difference acting on the plunger and the pilot valve body balanced when on/off control or when the pilot valve is opened.

In addition, the fluid is leaked through the outer circumferential surface of the inner guide pin that guides the ascending and descending of the plunger and flows into the working portion of the pilot valve. have. Accordingly, when the valve is operated, the diameter of the orifice of the pilot valve that leaks into the pilot valve operating part and discharges high pressure can be reduced, so if the diameter of the orifice is reduced, the electromagnetic force for initial driving of the solenoid valve can also be reduced, so that the solenoid compared to the conventional solenoid valve The size of the can also be significantly reduced.

In addition, in the prior art, the outer peripheral surface of the plunger guide was super-precisionly processed to be guided to the tube and its fine clearance was used as a leakage passage. Not only does the process become very simple, it also has the effect of significantly reducing production costs.

1 is a cross-sectional view showing an embodiment of a conventional high pressure proportional control solenoid valve
Figure 2 is a three-dimensional view showing the overall appearance of the solenoid valve having a high-pressure proportional control function of the present invention
Figure 3 is a cross-sectional view showing the internal configuration of Figure 2
Figure 4 is an enlarged view of the main portion of Figure 3
5 is an enlarged perspective view showing a pilot seal according to the present invention
Figure 6 is a state diagram of the operation in the power off state of the solenoid valve of the present invention (duty rate 0%)
Figure 7 is an operating state of the solenoid valve of the present invention in the power-on state (duty rate 100%)
8 is an operating state in which only the pilot valve is opened in the solenoid valve of the present invention immediately after power-on (when on-off control) or in the low-duty region (when in proportional control).

The terms used in this specification are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, the terms “include” or “have” to “have” are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described herein, but one Or other features or numbers, steps, actions, components, parts, or combinations thereof, should not be excluded in advance.

Unless otherwise defined herein, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person skilled in the art to which the present invention pertains.

Terms such as those defined in a commonly used dictionary should be interpreted as having meanings consistent with meanings in the context of related technologies, and should not be interpreted as ideal or excessively formal meanings unless explicitly defined herein. Should not.

Hereinafter, with reference to the accompanying drawings to look at the configuration and operation of the solenoid valve having a high-pressure proportional control function of the present invention in detail as follows.

Figure 2 is a three-dimensional view showing the overall appearance of the solenoid valve having a high-pressure proportional control function of the present invention, Figure 3 is a cross-sectional view showing the internal configuration of Figure 2, Figure 4 is an enlarged view of the main part of Figure 3, Figure 5 is It is a perspective view showing an enlarged pilot seal according to the present invention.

2 to 5, the solenoid valve configuration of the present invention is a nonmagnetic material guide having a smaller cross-sectional area than the core in the hollow portion of the rod-shaped core (Core, 540) having a predetermined length and cross-sectional shape. It has a structure in which a guide pin (550) is inserted. The core 550 is a component that magnetizes when current is applied and serves to move the downward plunger 600 to be described later upward.

In addition, a valve guide (Valve guide) 560 is fitted and coupled to the lower portion of the core 540. At this time, the top of the tube 580 is wrapped with a tube 580 wrapped around the valve guide 560 again. It is welded to the core 540, and the lower end of the tube 580 is welded to the valve guide 560 to withstand high pressure of a fluid such as hydrogen, and also maintains high airtightness inside the core 540.

On the other hand, around the middle portion of the core 540, a solenoid coil (Coil, 530) is wound, and a bobbin (Bobin, 520) is fitted and coupled, the upper surface of the bobbin 520 is induced when current is applied to the coil 530 A disk-shaped yoke 510 for constructing a magnetic circuit through which magnetic flux flows is provided.

In addition, the bobbin 520, the coil 530, and the lower and circumferential portions of the yoke 510 are covered with covers of magnetic materials constituting a magnetic circuit as a whole, and the outer cover and the outer portion of the yoke are plastic injection materials. Over mold (Over mold, 410) is wrapped to protect the appearance.

In addition, at the upper end of the core 540, the hemispherical cap 400 is detachably screwed to securely fix the bundle of coil 530 overmolded with plastic to the valve guide 560 assembly.

On the other hand, the lower portion of the guide pin 550 is provided so that the plunger 600 is fitted and can be moved up and down in the vertical direction. At this time, the hollow upper portion of the core 540 is a circular shape where the guide pin 550 can be fitted. It has a small-diameter cross-sectional area, and a hollow middle end has a more-expanded cross-sectional area of a larger diameter so that the main valve spring 610 can be fitted around the guide pin 550, and the lower hollow bottom portion of the main valve spring 610 Has a larger cross-sectional area of the larger diameter so that the plunger 600 can be inserted.

The lower end of the plunger 600 is moved together when the plunger is elevated and a pilot valve body 720 is assembled with a main valve seal 620 for opening and closing the flow path of the high pressure fluid.

At this time, the plunger 600 has a structure in which a hollow guide hole 600a having a specific diameter is formed therethrough along a vertical direction, and the guide pin 550 is precisely positioned in the guide hole 600a inside the plunger 600. It has a small-diameter cross-sectional area penetrated upward so that it can be fitted and operated, and the lower end of the guide hole 600a has a medium-diameter cross-sectional area so that the pilot valve structures 700, 710, 720, 730, 740 can be inserted as a whole. .

The pilot valve structure (700, 710, 720, 730, 740) is a cylindrical pilot valve seal holder (Pilot valve seal holder, 710) is inserted into the hollow of the lower end of the plunger 600, the pilot valve seal holder A pilot valve seal 700 is interposed in the upper hollow portion of the 710, and at the lower end of the pilot valve seal holder 710, the upper end portion of a predetermined diameter of the pilot valve body 720 is precisely They are supported to each other so that they can be operated in the inserted state.

At this time, a pilot valve spring 730 is interposed between the pilot valve seal holder 710 and the pilot valve body 720, wherein the pilot valve spring includes a pilot valve seal holder 710 and a pilot valve body 720. Elastic support in the direction of pushing each other.

In addition, a pilot valve stopper 740 is installed at a lower end of the plunger 600 to entrain the pilot valve body 720 when the plunger rises, and to ascend upward, and the pilot valve body 720 and the pilot valve stopper 740 ) Maintains a state spaced apart from each other by a gap of a pilot valve stroke (see FIG. 4) in an initial state in which the power is turned off.

On the other hand, the pilot valve body 720 is formed with flow paths having a different diameter each in multiple stages along the vertical direction (a structure in which a cross-sectional area gradually increases as it goes downward), and the lower end flow path has the largest cross-sectional area and the main valve seal It is connected to the internal flow path of 620, the middle flow path has a smaller cross-sectional area than the lower flow path, the flow path of the upper end of the narrow flow path protruding upward to be opened and closed by contact with the pilot valve seal 700 It consists of a pilot valve body orifice (721).

In addition, at the lower end of the valve guide 560, the valve body 500 is screwed, and at least one supply hole 501 is formed to allow high pressure fluid such as hydrogen to flow around the middle of the valve body 500. It has a structure connected to the flow path 502 inside the valve.

In addition, a valve seat (570) is provided at a lower end of the main valve seal (620). The hollow upper end of the valve seat (570) is a valve having a small cross-sectional area to be selectively connected to a flow path of the main valve seal (620). The seat orifice 571 is formed, and a discharge passage having a larger cross-sectional area is formed at the lower end. At this time, a screw is formed on the upper outer circumferential surface of the valve seat and is screwed into the lower end of the valve body. For example, since the adjusting tool insertion groove 570a is formed on the lower surface of the valve seat, all the valve assemblies are assembled. After the test operation, when the tool is inserted into the adjusting tool insertion groove 570a to tighten or loosen the valve seat 570 in one direction, the position of the plunger is also adjusted up and down, which in turn adjusts the proportional control characteristic or airtight characteristic of the valve.

On the other hand, between the valve guide 560 and the valve body 500 excluding the flow path, between the valve seat 570 and the valve body 500, and the cap, a plurality of O-rings 501 and 561, respectively, to prevent leakage of fluid. ) Is provided.

Looking at the configuration of the pilot valve seal 700 in more detail with reference to Figure 5, the pilot valve seal 700 is provided with a cylindrical body 701, the upper and lower surfaces of the body is recessed in a certain depth in a circular shape Each indentation groove 702 is formed, and each indentation groove 702 is formed with a plurality of flow channel channels 703 to allow fluid to flow therethrough, so that the inflow grooves 702 are formed on the upper and lower surfaces of the body. Has a structure connected to each other.

At this time, the indentation grooves 702 formed on the top and bottom surfaces of the body 701 have the same structure and shape, and the indentation grooves 702 on the bottom surface are upper orifices 721 of the pilot valve body 720. By selectively contacting, it functions to open and close the flow path of the pilot valve.

Hereinafter, an operation relationship of the solenoid valve of the present invention will be described with reference to FIGS. 6 to 8.

First, the solenoid valve of the present invention is a normally closed type solenoid valve in which the pressure of a high pressure fluid such as hydrogen acts in a direction in which the valve is closed, for example, a 12V or 24V DC power supply or a square wave duty of a predetermined frequency. The solenoid valve may be driven by an on-off or proportional control function by a proportional control signal such as a control signal. At this time, as described above, the coil 530 and the core 540 on the magnetic circuit It is understandable that the electric magnetic force for moving the plunger 600 upward is derived from.

Figure 6 is a state diagram of the operation in the power off state solenoid valve of the present invention.

Referring to Figure 6 first look at the state of the present invention the solenoid valve is closed (solenoid valve is closed), the voltage applied to the coil 530 in the case of on-off control at this time, or in the case of proportional control of the proportional control signal The duty rate is 0% (Duty Rate 0%), and there is no electromagnetic force generated in the core 540 and the plunger 600.

Therefore, since the repulsive force of the main valve spring 610 provided between the core 540 and the plunger 600 is present in the power-off state as described above, the plunger guided to the guide pin 550 by the repelling force of the spring (600) is pushed forward toward the valve seat 570, and thus the bottom surface of the pilot valve seal holder 710 pressed into the bottom of the plunger 600 touches the middle surface of the pilot valve body 720 in contact with it. Will be pressed. Subsequently, the main valve seal 620 coupled to the lower end portion of the pilot valve body 720 presses and closes the upper surface of the orifice 571 of the valve seat 570, whereby the flow path of the main valve is completely blocked.

At this time, the plunger 600 has not only the repulsive force of the main valve spring 610, but also the upper high pressure part (supply pressure) and the lower low pressure part (control pressure) based on the upper orifice 571 of the valve seat 570. The force due to the pressure difference between the liver (ie, the force due to the pressure difference between the high pressure and the low pressure acting on the cross-sectional area of the upper orifice of the valve seat 570) is added to the repulsive force of the main valve spring 610 to act together downward. At the same time, the combined force of the force presses the main valve seal 620 downward, and the flow passage of the main valve is firmly closed.

At this time, since the compression force of the main valve spring 610 is greater than the compression force of the pilot valve spring 730, when the pilot valve spring 730 is compressed, the pilot valve seal 700 is also the top of the pilot valve body 720. The orifice 721 is blocked so that the pilot valve structures 700, 710, 720, 730, 740 are completely closed.

On the other hand, the lower end of the pilot valve seal holder 710 is in contact with and supported by one end of the pilot valve body 720, and is piloted by a force due to a compression force and a pressure difference (supply pressure-control pressure) of the main valve spring 610. To prevent the valve seal 700 from being excessively pressed, it acts as a stopper to support it, thereby limiting the amount of pressurization of the pilot valve seal 700, thereby preventing damage to the pilot valve seal 700 due to excessive pressure. The durability of the valve is further improved.

The operation sequence of the valve when the power is off is briefly summarized as follows.

One, the plunger 600 is pressed downward by the reaction force of the main valve spring 610

Two, the main valve seal 620 contacts the valve seat 570

Three, the pilot valve spring 730 is compressed and the pilot valve seal 700 contacts the orifice 721 of the pilot valve body 720

Four, the lower end of the pilot valve seal holder 710 contacts and supports the pilot valve body 720

Five, the pilot valve body 720 provided inside the plunger 600 is pressed by the repulsive force of the main valve spring 610 and the pressure difference between the high pressure part (supply pressure) and the low pressure part (control pressure), and the pilot valve body As the pilot valve seal 700 assembled to 720 is compressed, airtightness within the pilot valve is maintained.

7 is an operating state diagram in the power-on state (duty rate 100%) of the solenoid valve of the present invention.

When power is applied to the solenoid coil 530 through a power supply terminal (not shown) as shown in FIG. 7 (duty rate 100%), the core 540 and the plunger 600 are magnetized by the coil 530 and are strong. Since the magnetic force is generated, the plunger 600 compresses the main valve spring 610 toward the fixed core 540 and moves rapidly upward.

At this time, the electromagnetic force acting on the plunger 600 to move the plunger 600 upwards is high pressure acting on the cross-sectional area of the orifice 721 of the pilot valve body 720 and the reaction force against compression of the main valve spring 610 It must be greater than the sum of the forces pressed by (supply pressure).

Once the plunger 600 is moved upward, the pilot valve body 720 is intact and the plunger 600 is maintained at an interval of the pilot valve body 720 by an operating stroke (see Fig. 4). The pilot valve is eventually opened by lifting the pilot valve seal 700 pressurized by the plunger 600 while being moved upward by only the pilot valve stroke.

Accordingly, the fluid of high pressure (supply pressure) acting on the pilot valve operation unit (pilot valve structure) is passed through the orifice 721 and the lower flow path of the pilot valve body 720 and the flow path formed inside the main valve seal 620. By discharging downward, the atmosphere of the high pressure (supply pressure) pressing the pilot valve seal 700 is eliminated.

At this time, when the pilot valve is opened due to the rise of the pilot valve seal 700 according to the movement of the plunger 600, and the high pressure (supply pressure) atmosphere acting on the pilot valve operating portion is resolved, the plunger 600 as described above The pressure due to the pressure difference between high pressure (supply pressure) and low pressure (control pressure) acting as much as the cross-sectional area of the valve seat orifice 571 pressing down is relieved, and thus the plunger 600 is restrained by the pilot valve stopper 740. The main pilot valve body 720 and the main valve seal 620 assembled thereunder are also lifted upward by being interlocked with the plunger 600, and eventually the main valve seal 620 is opened.

On the other hand, when the pilot valve spring 730 is expanded by the operating stroke of the pilot valve structure (see FIG. 4), the plunger 600 and the pilot valve body 720 are resiliently interlocked together while keeping the pilot valve not closed again. It is supported elastically so that it can be.

On the other hand, the present invention is designed by changing the diameter of the guide pin 550 mounted on the core 540 and the guide hole 600a in the center of the plunger 600 operated by being fitted to the guide pin 550, the diameter d1. The strength of the pressing force can be adjusted by high pressure (supply pressure) acting on the upper surface of the 600. For example, when the valve is used only for on-off, the plunger 600 is formed by making the diameter d1 of the guide hole 600a of the plunger 600 larger than the diameter d2 of the orifice 571 of the valve seat 570. ) The diameter at which the force pressing downward acts (diameter of the plunger-d1) becomes small, and accordingly, the force pressing the plunger downward can be adjusted small.

That is, when the guide hole 600a of the plunger 600 has a larger diameter d1, the area in which high pressure fluid can act on the upper surface of the plunger 600 when the pilot valve is operated is orifice of the lower valve seat 570 (571) Since it is smaller than the area excluding the area, the force acting downward by the high-pressure fluid acting on the plunger () can be adjusted to be smaller than the force acting upward. On the contrary, if the diameter d1 of the guide hole 600a of the plunger 600 is decreased, the area where the high pressure fluid can act on the upper surface of the plunger 600 becomes large, and accordingly, downwards due to the pressure acting on the plunger 600 The force acting can be greatly adjusted.

Therefore, if necessary, the diameter of the guide hole 600a of the plunger 600 is larger than the diameter d2 of the valve seat 570 orifice 571 to the high pressure part (supply pressure) pressing the plunger 600 during operation of the pilot valve. By weakening the acting force, the plunger 600 can be set to be heard abruptly, and accordingly, a small electromagnetic force is applied to control on/off of a large flow rate. In addition, by adjusting the degree of force acting on the high-pressure portion (supply pressure), there is an advantage that can prevent the noise caused by the impact or damage to the spring or the core when the plunger 600 is operated. That is, changing the guide hole of the plunger described above means that not only the diameter of the guide hole of the plunger but also the outer diameter of the guide pin assembled to the guide hole to guide the plunger is equally changed to maintain the set clearance.

The operation sequence at the time of power-on is briefly summarized as follows.

One, power is supplied through the power terminal

Two, the plunger 600 is raised by the stroke of the pilot valve (see FIG. 4), and the main valve spring 610 is compressed while the pilot valve seal 700 is raised together.

Three, open pilot valve

Four, pilot valve spring 730 expansion

Five, discharge the high pressure fluid in the pilot valve and resolve the high pressure atmosphere

Six, as the plunger 600 is further raised, the pilot valve body 720 is also raised together by the pilot valve stopper 740 to open the main valve (in this case, the dimensions of the guide hole diameter of the plunger and the diameter of the guide pin) Can be set so that the main valve opens rapidly when the pilot valve is opened by changing

8 is a state diagram showing the operation of the solenoid valve according to the present invention, since only the pilot valve is opened and switched to the high pressure proportional control mode.

Referring to the case of using the solenoid valve of the present invention as a proportional control valve with reference to FIG. 8, first, the current applied to the power source is applied as a square wave or a specific waveform of a preset frequency (400Hz-1000Hz), wherein the square wave By controlling the duty ratio (Duty ratio), which is a ratio of the on-off pulse width, the electromagnetic force increases linearly in proportion to the applied duty signal.

When a driving signal (duty rate) of a certain size is applied to the solenoid valve through the power supply terminal (not shown), the plunger 600 compresses the main valve spring 610 by the electromagnetic force induced by the coil 530 and increases. In this case, the pulse width modulation for lifting the pilot valve seal 700 is set to generate an electromagnetic force capable of opening the pilot valve in this section at a duty rate of about 20% or less.

At this time, the electromagnetic force required to raise the plunger 600 is a repulsive force against compression of the main valve spring 610 when the pilot valve seal 700 is opened and a guide portion 722 of the 720 of the pilot valve body It must be greater than the combined force of the pressing force by the high pressure (supply pressure) acting on the outer diameter (d3).

In addition, when the pilot valve seal 700 is opened, as the high pressure fluid in the pilot valve structure is discharged to the low pressure part (control pressure) through the pilot valve orifice 721, the orifice 571 of the valve seat 570 eventually has a diameter d2. As the force due to the pressure acting on the area is eliminated, the force due to the pressure difference of the fluid acting in the main valve is balanced.

Therefore, at this time, since only the electromagnetic force generated in proportion to the compression force and the duty ratio of the main valve spring 610 is applied to the plunger 600 as a variable for controlling the elevation of the plunger 600, the duty ratio applied in this state is determined. The pilot valve body constrained by the plunger 600 by the pilot valve stopper 740 by proportionally raising or lowering the plunger 600 by controlling (eg, the duty rate can be controlled in the range of 20%-90%) 720) and the main valve seal 620 assembled at the bottom thereof is proportionally raised and lowered so that the valve can proportionally control the flow rate or pressure.

At this time, preferably, the diameter d1 of the guide hole of the plunger 600 is configured to be the same as the diameter d2 of the orifice 571 of the valve seat 570, and the guide pin 550 is the guide hole of the plunger 600 ( 600a) and must be configured to operate in the state of minimum leakage, and accordingly, the area where the high pressure (supply pressure) and low pressure (control pressure) interact when the pilot valve is opened according to the coincidence of the diameters d1 and d2. It becomes the same, and eventually the force by the pressure of the high pressure (supply pressure) and the low pressure (control pressure) acting on the plunger 600 can be balanced.

In addition, it is possible to prevent unintentional sudden lifting or pressing of the plunger 600, which may be caused by a difference in the working force between the high pressure (supply pressure) and the low pressure (control pressure). Other forces besides the electromagnetic force and the main spring compression force due to the duty rate should be removed)

In addition, the guide portion 722 of the pilot valve body 720, which is inserted and guided at the bottom of the pilot valve seal holder 710, also has an outer diameter (d3) of force due to a pressure difference between high pressure (supply pressure) and low pressure (control pressure). For balance, it is preferable that the diameter d1 of the guide hole 600a of the plunger 600 and the diameter d2 of the orifice 721 of the main valve body 720 are all the same.

If the force due to the pressure of the high pressure (supply pressure) and the low pressure (control pressure) is not balanced due to the mismatch of the diameters (d1, d2, d3) described above, when the pilot valve seal 700 is opened, the pilot valve body ( 720) is suddenly heard, the pilot valve seal 700 is closed again, and accordingly, the main valve seal 620, which has been opened, is also affected by the force due to the high pressure (supply pressure) due to the closing of the pilot valve seal 700. Closing may occur, which closes again.

Therefore, as described above, in a state in which the force is balanced by the pressure of the high pressure (supply pressure) and the low pressure (control pressure), the plunger 600 rises up to the operating stroke of the pilot valve, but the main valve seal 620 is still closed. On the other hand, it is preferable that the pilot valve spring 730 is expanded so that the pilot valve seal 700 is configured to remain open.

Therefore, the pilot valve spring 730 serves to maintain a gap so that the pilot valve body 720 is elastically supported by the pilot valve stopper 740 while being interlocked with the appropriate force in the proportional control mode described above.

On the other hand, at this time, the proportionally controlled flow rate (or pressure) becomes the flow rate (or pressure) discharged through the pilot valve orifice 721, in this case, the pilot valve body than the flow rate of the fluid flowing into the pilot valve operation unit (structure). The orifice diameter should be configured so that the flow rate discharged through the orifice 721 of 720 is large.

After the pilot valve is operated, if the duty ratio of the driving signal is further increased to achieve a desired flow rate or pressure, the pilot valve body (constrained by the pilot valve stopper 740 to the plunger 600 and elastically supported by the pilot valve spring 730 ( 720) increases as the duty rate increases. At this time, between the controllable section, the electromagnetic force increases linearly with the duty ratio, and accordingly, the balance with the main spring compressive force is maintained according to the rise of the plunger, thereby eventually controlling the increase or decrease of the duty ratio, thereby lowering the pilot valve body 720. By controlling the amount of opening of the main valve seal 620 assembled in, it is possible to linearly proportionally control the flow rate (or pressure) of the valve.

The operation sequence at the time of high-pressure proportional control is briefly summarized as follows.

One, application of driving signal

Two, driving signal duty rate control

Three, plunger 600 rise and main valve spring 610 compressed

(At this time, the force required to raise the plunger is the combined force with the compression repulsive force of the main valve spring and the high-pressure force acting on the orifice cross-sectional area of the pilot valve body)

Four, the pilot valve seal 700 rises (pilot valve open)

Five, as the high pressure fluid is discharged from the pilot valve, the pressure caused by the high pressure acting on the plunger 600 is relieved and the pressure applied force reaches the equilibrium state.

(At this time, only the force acting on the plunger acts as a variable due to the compression reaction force of the main valve spring and the electromagnetic force due to the duty ratio of the drive signal)

Six, as the duty ratio of the drive signal is increased by the set value of the desired flow rate, the plunger is further raised, and the main valve seal is raised by the pilot valve stopper to open the main valve.

(At this time, the pilot valve spring expands by the stroke of the pilot valve to maintain the gap between the pilot valve body and the plunger with a prescribed force, and then, when proportionally controlling the valve, the plunger and the pilot valve are integrally interlocked together)

Seven, after controlling the duty rate, by controlling the elevation of the main valve seal 620 together with the plunger 600 to control the discharge opening degree of the high pressure fluid discharged through the orifice 571 of the valve seat 570 to finalize Proportional control of flow rate or pressure

In short, in the present invention, when the valve is initially operated, the pilot valve is first opened to relieve the high pressure acting on the plunger first, and then the main valve is operated. At this time, when the main valve is operated, it leaks into the pilot valve structure inside the plunger. When the amount of fluid discharged through the pilot valve is greater than the amount of fluid, the pilot valve can be operated.

If the amount of incoming fluid is larger, the pilot valve is likely to be closed again or not controlled by the force due to the pressure difference of the fluid if the solenoid force is weak. In the conventional solenoid valve having such a structure, the fluid is leaked into the pilot valve operation part (structure) through the outer plunger outer surface. If the diameter of the plunger is large, the amount of fluid leakage increases, so for this purpose, the outer surface of the plunger and the outer surface of the plunger It is difficult to process and maintain the gaps between the plunger guides in contact with each other with great precision.

In the present invention, the fluid leaks through the outer circumferential surface of the guide pin (more precisely, the gap between the outer circumferential surface of the guide pin and the guide hole of the plunger) functioning as a guide inside the plunger, and configured to enter the pilot valve operation unit (structure). Compared to using the outer diameter of the conventional plunger as a flow path, the present invention can minimize the leakage area of the fluid by using a much smaller diameter of the guide hole inside the plunger, thereby making it possible to easily control the desired leakage amount as well as small leakage amount. According to this, the orifice diameter of the pilot valve body can also be designed to be small, thereby reducing the required valve operating force.

In addition, it is possible to reduce the size of the solenoid that generates electromagnetic force, and there is no need to ultra-precise the outer peripheral surface of the plunger as in the conventional solenoid valve, so the manufacturing process is simplified and manufacturing costs can be reduced. There is this.

In addition, the present invention is not limited only by the above-described embodiment, and it is possible to create the same effect even when changing the detailed configuration, number, and arrangement structure of the device. It is stated that various configurations can be added, deleted, and modified within the scope of the technical idea of.

400: cap 410: over mold
420: cover 500: valve body
510: York 520: Bobbin
530: coil 540: core
550: guide pin 560: valve guide
570: valve seat 580: tube
600: plunger 610: main valve spring
700: Pilot valve seal 710: Pilot valve seal holder
720: pilot valve body 730: pilot valve spring

Claims (10)

A coil wound with a coil that generates a magnetic field when power is applied;
A yoke coupled to one end of the bobbin to form a magnetic circuit;
A core coupled to the upper side of the central portion of the bobbin and magnetized by a magnetic field;
A non-magnetic guide pin having a predetermined diameter that extends downwardly in the central portion of the core;
A plunger in which a guide hole having a predetermined diameter is formed therein and the guide hole is fitted while surrounding the outer circumferential surface of the guide pin to guide movement in the vertical direction by the guide pin toward the magnetized core when power is applied;
A main valve spring provided around the guide pin inside the core to elastically support the plunger in a direction to close the flow path;
A valve guide disposed under the core of the bobbin while surrounding the outer circumferential surface of the plunger to constitute a magnetic circuit;
A tube surrounding the lower circumference of the core and the outer circumferential surface of the valve guide to maintain airtightness;
A valve body coupled to the lower end of the valve guide to form a lower end appearance of the entire valve;
A main valve seal installed at a lower end of the plunger in the valve body to selectively open a flow path according to vertical movement of the plunger;
A valve seat which is provided below the main valve seal in the valve body and selectively opens the flow path according to the rise of the main valve seal in a state in which an orifice formed at an upper end is pressed into the bottom surface of the main valve seal; And
A pilot valve structure provided above the main valve seal inside the plunger to selectively open the flow path prior to the main valve seal to discharge high pressure fluid in the flow path to resolve the high pressure atmosphere.
The pilot valve structure,
A pilot valve seal provided below the guide pin inside the plunger and vertically moved according to the movement of the plunger;
A pilot valve seal holder which is vertically moved together with the pilot valve seal while surrounding the pilot valve seal in a plunger;
A pilot valve body in which a flow path is closed as the lower end of the pilot valve seal is selectively pressed into the upper orifice while being inserted into the lower end of the pilot valve seal holder inside the plunger; And
A pilot valve spring provided between the pilot valve seal holder and the pilot valve body inside the plunger to elastically support the pilot valve seal holder,
Solenoid valve with high pressure proportional control. delete According to claim 1,
The guide hole diameter (d1) of the plunger and the orifice diameter (d2) of the valve seat coincide,
Solenoid valve with high pressure proportional control. According to claim 1,
The orifice diameter (d2) of the valve seat and the guide part outer diameter (d3) of the pilot valve body coincide,
Solenoid valve with high pressure proportional control. According to claim 1,
The spring constant of the main valve spring is greater than the spring constant of the pilot valve spring,
Solenoid valve with high pressure proportional control. According to claim 1,
The pilot valve seal,
With a cylindrical body as a whole, circular indentations are formed on the upper and lower surfaces of the body, and each indentation groove is connected by at least one fluid movement channel concavely along the outer surface of the cylindrical body.
Solenoid valve with high pressure proportional control. According to claim 1,
At the lower end of the plunger, a pilot valve stopper is installed to catch the pilot valve body when the plunger rises and ascend upward. In the power-off state, the pilot valve body and the pilot valve stopper are spaced apart from each other by a gap of the pilot valve stroke. To maintain,
Solenoid valve with high pressure proportional control. According to claim 1,
As the lower end of the pilot valve seal holder contacts and is supported on the upper end of the pilot valve body, the pilot valve seal is protected by the pilot seal holder so as not to be damaged by excessive pressing.
Solenoid valve with high pressure proportional control. According to claim 1,
The valve seat is screwed to the lower part of the valve body, and the position of the plunger and the action force of the main valve spring are adjusted as the valve seat is selectively rotated to move the valve seat up and down to increase the proportional control characteristics or airtight characteristics of the valve. To be able to adjust,
Solenoid valve with high pressure proportional control. According to claim 1,
As the supply of the high pressure fluid always acts in the direction in which the pilot valve structure and the main valve seal are closed, the power presses the main valve seal due to the pressure difference between high pressure (supply pressure) and low pressure (control pressure) when power is not applied. Confidentiality is maintained,
Solenoid valve with high pressure proportional control.

Images