WO2017186449A1

WO2017186449A1 - Electromagnetic valve and operating method

Info

Publication number: WO2017186449A1
Application number: PCT/EP2017/057595
Authority: WO
Inventors: Jörg BÜRSSNER; Peter Vincon; Sven Roos
Original assignee: Eto Magnetic Gmbh
Priority date: 2016-04-27
Filing date: 2017-03-30
Publication date: 2017-11-02
Also published as: DE102016107766A1

Abstract

The invention relates to an electromagnetic valve (1), in particular a 2/3-way valve, comprising a coil element (2) and an armature (4), which can be moved between different switching positions relative to a core (3) against the spring action of a first restoring spring (16) and a second restoring spring (17) by energization of the coil element (2) and which is operatively connected to a pilot closing body (11) for interacting with a pilot valve seat (15) and to a valve closing body (12) for interacting with a valve seat (14), in such a way that, in an open switching position, the pilot closing body (11) is spaced apart from the pilot valve seat (15) thereof and the valve closing body (11) is spaced apart from the valve seat (14) thereof and, in a closed switching position, the pilot closing body (11) lies against the pilot valve seat (15) thereof and the valve closing body (12) lies against the valve seat (14) thereof and that, in a pilot switching position arranged axially between the open switching position and the closed switching position, the valve closing body (12) is spaced apart from the valve seat (14) and the pilot closing body (11) lies against the pilot valve seat (15) while leaving a pilot opening (23) open, through which a pilot volumetric flow can flow, wherein the first restoring spring (16) and the second restoring spring (17) are designed and arranged, in particular preloaded, in such a way that a first spring force of the first restoring spring (16) is less than a second spring force of the second restoring spring (17) in the open switching position and/or the intermediate switching position.

Description

Electricity valve and operating procedure

The invention relates to a solenoid valve, more precisely a pilot switching valve, according to the preamble of claim 1, in particular in the form of a 2/3-way valve, preferably for use in a coolant circuit of a motor vehicle. Furthermore, the invention relates to a method for operating such a solenoid valve. Are known η / 3-solenoid valves in the center-centric slider design. In this case, two springs center the slide in a central position, wherein the slider is deflectable by two reluctance in both directions. In addition, lever-operated slide valves are known which are pressed by a spring to a locking mechanism - by adjusting the catch, the various positions or switching positions are approached. Switching valves with cascaded springs are likewise known from the prior art, for example from DE 42 364 82 A1, DE 199 08 102 C1, DE 1 0 2007 009 167 A1, DE 10 2013 217 580 A1, EP 0 595 014 A1 or DE 37 00 356 C2.

The disadvantage of a slide valve design is the function-related leakage in the closed position and also the sensitivity to contamination. In addition, the required high-precision and therefore cost-intensive production of the sliding pair is disadvantageous. The disadvantage of the switching valves with cascaded springs, as described for example in DE 10 2013 216 568 A1, is that the return springs act on each switching position to each other and thus add up the tolerances. Based on the aforementioned prior art, the present invention seeks to provide an improved switching valve, which is less critical to tolerance. In addition, the pilot switching position (throttle position) and the closing switching position (closed valve position) should be able to be defined very precisely and with as little tolerance as possible. Furthermore, the object is to provide a method for operating such an improved switching valve.

This object is achieved with respect to the switching valve with a solenoid valve with the features of claim 1, i. in a generic electromagnetic valve, characterized in that the second return spring is the spring-loading the valve body axially in the direction of the valve seat, and that the armature from the opening switching position until reaching the intermediate switching position exclusively against the spring force of the first return spring is adjustable.

With regard to the method of operation, the object is achieved with the features of claim 12, i. in a generic operating method in that the adjustment of the armature from the open position into the intermediate switching position takes place exclusively against the spring force of the first return spring and / or that an adjusting movement of the armature against the spring force of both the first and the second return spring exclusively on the way of the Intermediate switching position takes place in the closed position, ie the second return spring is moved from the opening shaft position into the intermediate shaft division only along the adjustment direction, without a force being applied to the second return spring.

Advantageous developments of the invention are specified in the subclaims. All combinations of at least two features disclosed in the description, the claims and / or the figures fall within the scope of the invention. In order to avoid repetitions, features disclosed in accordance with the device should be deemed to be disclosed according to the method and to be able to be claimed. Likewise, according to the method disclosed features should also be considered as disclosed device and claimable.

The solenoid valve according to the invention is a pilot switching valve, wherein the armature by energizing the coil means with different high (effective) coil currents between an open switch position, a closed switch position and an intermediate switch position (throttle switch position or pilot switch position) is adjustable, the armature both with a pilot-closing body as well as with a valve-closing body is operatively connected to these between a cooperating with the respective seat (valve seat or pilot valve seat) position in which the respective closing body rests against the associated seat and a position spaced from the respective seat position. In the opening switching position, both the pilot-closing body and the valve-closing body are spaced apart from its valve seat, while in the closed switch position the pilot-closing body rests against its pilot valve seat and the valve-closing body against its valve seat in order to completely prevent a medium flow which can be controlled by the solenoid valve, while in the intermediate switching position located axially between the opening switching position and the closing switch position, the valve closing body is lifted off its valve seat and only the pilot closing body bears against its pilot valve seat and thereby keeps a throttle opening open, in order to flow through a reduced or throttled medium volume flow in relation to the opening switch position to let. In order to move the armature from the opening switching position to the intermediate switching position, the coil means must be energized via a suitable control unit with a first coil current, which is dimensioned such that the spring force of the first return spring is overcome, so that the pilot closing body is in contact with its Pilot valve seat can come, wherein the first coil current is further dimensioned so that the generated electromagnetic force is not sufficient still plant of the pilot-closing body on the pilot valve seat to overcome the spring force of the second return spring. To achieve this and also to bring the valve closing body to bear against its valve seat, the coil means must be energized via the control unit with a larger second coil current, which is so dimensioned to overcome the spring force of the second return spring in addition to the spring force of the first return spring. In this case, the first spring force of the first return spring and the second spring force of the second return spring in the opening switch position and / or the intermediate switch position of the armature are matched to one another such that the first spring force is smaller than the second spring force. The specification or setting of the first and second spring force in the opening switching position can be selected by selecting appropriate spring constants, wherein preferably the spring constant of the second return spring is larger, in particular significantly greater than the spring constant of the first return spring - additionally or alternatively, the different spring force be adjusted by appropriate choice of the spring preloads (springs with the same or different spring constant).

In contrast to solenoid valves of the prior art erfindungemäß is now provided according to the invention that the second return spring, the valve closing body axially in the direction of adjustment of the armature when energized the coil means is spring-loaded in the direction of its valve seat and is further arranged so that the spring force of the second return spring does not counteract an adjusting movement of the armature from the opening switching position to the intermediate switching position, so that the armature from the opening switching position until reaching the intermediate switching position exclusively against the spring force of Return spring (ie not additionally against the spring force of the second return spring) is adjustable. In other words, the second return spring is arranged such that it is compressible only after installation of the pilot-closing body on the pilot valve seat and a corresponding application of force by the armature or an energization of the coil means with the second coil current. In contrast to the prior art, the power is transmitted from the armature to the pilot-closing body on the way from the opening switching position to the intermediate switching position not via the second return spring, but exclusively via the first return spring. The second return spring is thus displaced axially in the compression of the first return spring only between the open switch position and the intermediate switch position without resulting force application, ie the axially spaced abutment or support elements (for example, a bump-side abutment and the pilot closing body), in which the second Restored spring, are not subjected to force on this adjustment against each other. This overcomes the disadvantage of the prior art that the springs do not interact with each other permanently, but only from the intermediate switching position into the closed switching position, so that tolerances do not add up to reaching the intermediate switching position in contrast to the prior art. As a result, a lower tolerance dependence in the intermediate switching position (throttle position) is achieved than in the prior art. In addition, a separate adjustment of the spring engagement points is possible, both geometrically and by the choice of a corresponding Vorstellkraft. The throttle rate or throttle position (intermediate switching position) is defined as a whole comparatively tolerance-free.

Preferably, in the closed switching position between armature and core still a residual axial gap is present and the closed switching position is defined by interaction between the valve closing body and the associated valve closing body and the associated valve seat (stop).

Constructively advantageous is a variant in which the first and the second return spring are axially spaced and are most preferably located on two spaced apart sides of the core, which in turn is preferably penetrated by a later to be explained plunger. Preferably, the first return spring is supported with an axial end directly or indirectly on the armature and with the opposite or remote from the further axial end directly or indirectly on the core, is thus sandwiched between armature and core, so that the first return spring in an adjustment the armature between opening switch position and intermediate switch position and between the intermediate switch position and the closed switch position is compressed.

From a constructive point of view, it has proven to be advantageous if both the valve closing body and the pilot closing body, in particular at the end, are arranged on an elongate plunger extending along the adjustment axis of the armature. In particular, for assembly reasons, it is advantageous if the ram and the armature are separate from one another but fixed to one another, for example, by screwing, welding or pressing. In principle, an embodiment variant is conceivable in which the disturbance ßel at least in sections of the anchor itself, that is monolithically formed with this. In principle, it is preferred if the plunger is arranged such that it axially passes through the first return spring and / or the second return spring and / or the core preferably arranged between the return springs.

It is particularly preferred if the second return spring together with the plunger is axially adjustable, in particular such that these only after reaching the intermediate switching position (starting from the opening switching position) by pressing the pilot-closing body against the pilot valve seat due to the corresponding energization of the coil means with the second (higher) coil current is compressible. To achieve this, it has proven to be advantageous if an abutment is formed or fixed on the plunger on which the second return spring is axially supported with an end remote from the pilot closing body. Preferably, the second return spring is supported with the axial end oriented in the direction of the pilot closing body indirectly or directly on the pilot closing body, in particular in such a way that the second return spring is compressed after contact of the pilot lock body with the pilot valve seat and an axial further movement of the armature and the plunger, since Distance between the valve closing body and the relative to the plunger fixed position abutment is reduced or seen relative to the plunger, the pilot-closing body is displaced away from the armature facing away from the axial end towards the anchor.

Preferably, the abutment is arranged in all switching positions of the armature equidistant from the valve closing body, which is preferably arranged immovable or stationary in all switching positions relative to the plunger. Particularly preferred is an embodiment in which the valve closing body forms an indirect or immediate axial stop for the pilot valve body in the opening switching position until reaching the intermediate switching position and axially from the valve closing body Komprimi- tion of the second return spring when energized with the second coil current, ie on the way of the armature of the intermediate switching position in the closed switching position lifts.

Particularly advantageous is an embodiment of the solenoid valve according to the invention has been found in which the valve seat and the pilot valve seat are arranged radially side by side, in particular in a common axial plane or axial position. In other words, preferably the valve seat and the pilot valve seat are not or alternatively only slightly offset axially. To be particularly advantageous, it has been found that the valve seat and the pilot valve seat, but not mandatory in a radial juxtaposition, are arranged on a common valve seat component, which in the opening switching position both from the valve closing body and the pilot closing body and in the intermediate switching position exclusively from the valve closing body axially is spaced.

Especially useful is a radial interleaving or nesting of the valve closing body and the pilot closing body, of which preferably at least one, preferably both cup-shaped, in particular to cooperate with a pot bottom axially spaced pot opening peripheral edge with the respectively associated seat. It is particularly expedient to arrange the valve closing body radially inside the pilot closing body. It has been found to be particularly expedient here, the valve closing body axially in the opening switching position and the intermediate switching position relative to the front acting end of the pilot closing body in Return to the direction of armature, this return offset is overcome by compressing the second return spring after passing through the Zwischschaltstellung. Particularly expedient is an embodiment in which the pilot-closing body and the valve-closing body are arranged axially outside a housing of the solenoid valve receiving the armature, the core and the coil means, preferably magnetically conducting, which is preferably axially penetrated by the aforementioned plunger. The invention also leads to a method for operating a solenoid valve according to the invention. According to the invention, the adjustment of the armature from the open position to the intermediate position is exclusively counter to the spring force of the first return spring, which does not additionally counter to the spring force of the second return spring and / or that an adjusting movement of the armature against the spring force both the first return spring and the second return spring takes place exclusively on the way from the intermediate switch position to the closed switch position. In the context of the method, the energization of the coil unit with different effective coil currents preferably takes place via a control unit assigned to the solenoid valve in the context of a valve system. The system preferably comprises a coolant circuit of an internal combustion engine, in particular of a motor vehicle, within the scope of which the method according to the invention is used or the solenoid valve according to the invention fulfills its function.

Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments and from the drawings. These show in:

1 shows a solenoid valve according to the invention in a Offnungs- switching position,

FIG. 2 shows the electromagnetic valve according to FIG. 1 in its intermediate switching position, and FIG

Fig. 3: the aforementioned solenoid valve (almost) in its Schließschaltstellung.

In the figures, like elements and elements having the same function are denoted by the same reference numerals. In the figures, designed as a 3/2-way valve electromagnetic pilot switching valve (solenoid valve) 1 is shown. This comprises an axially along an adjustment axis V by energizing coil means 2 relative to a stationary core 3 adjustable armature 4. The coil means 2 comprise a Bestrombare winding 5, which is arranged on a here formed as a plastic injection molded coil support 6, which radially outside the armature surrounds. The armature 4 is assigned in the specific embodiment, an armature guide tube 7, within which the armature 4 is guided in its axial adjustment movement. Within the armature 4 is a through hole 8, to provide for axial pressure balance on both opposite axial sides of the armature 4 in an adjustment concern.

At the armature 4, an elongated plunger 9 is set, which passes axially through the core 3 and protrudes axially from a housing 10 which receives the coil means, the armature 4 and the core 3 and also has flow-conducting properties to close the magnetic circuit. In a side facing away from the armature 4 end of the plunger 9 are a cup-shaped pilot closing body 1 1 and a radially encapsulated therein, also cup-shaped valve closing body 12, these are adjustable by adjusting the armature 4 relative to a common valve seat member 13 which is fixedly arranged and a Valve seat 14 for sealing cooperation with the valve closing body 12 and a radially adjacent thereto, located in the same axial plane pilot valve seat 15 is formed for axial abutment of the pilot closing body 1 first From Fig. 1 it can be further seen that sandwiched between the armature 4 and the core 3, a first return spring 16 is arranged, which has a smaller spring constant in the concrete embodiment than a second return spring 17, which is axially received between one on the plunger. 9 trained and permanently stationary to this arranged abutment 18 and the pilot closing body 1 1. In addition or as an alternative to different spring constants, different spring forces can be achieved in the illustrated open switch position and the intermediate switch position (compare FIG. 2) by selecting corresponding spring voltages. In any case, the first spring force of the first return spring 16, which momentarily acts on the respectively supporting components, is less than the second spring force of the second return spring 17.

As can be seen from Fig. 1, the second return spring 17 is supported directly on the plunger-fixed abutment 18 and opposite to the relative to the plunger 9 displaceable pilot-closing body 1 1. This in turn is supported axially directly on the ram-proof or permanently fixed to the plunger 9 arranged valve closing body 12, which is clamped between a ram ring shoulder 19 and an end-side axial lock nut 20. In the illustrated opening switching position of the armature 4, the one in the Drawing plane upper or facing away from the core 3 end position, a maximum Medium volume flow through an area axially between the seats 14,

15 and the closing bodies 1 1, 12 flow in the direction of arrow 21 or in the opposite directions, depending on the connection or arrangement of the solenoid valve 1 in a fluid circuit, in particular in a cooling circuit of an internal combustion engine, preferably a motor vehicle.

It can be seen that, in the opening switch position shown, the armature 4 is supported on the bottom of the sleeve-shaped armature guide tube 7 via an elastomeric ring seal 22, which is accommodated in a retaining groove on the end face.

In the following, FIGS. 2 and 3 are explained, with only differences in the switching positions being discussed in order to avoid repetitions - with regard to similarities and in particular the design of the electromagnetic valve 1, reference is made to FIG. 1 with associated description of the figures.

If the coil means 2, more precisely their winding 5, flows through from the opening switching position with a first coil current, the armature 4 moves into the intermediate switching position (throttle position) shown in FIG. 2, which is defined by abutment or abutment of the pilot closing body 1 1 on the pilot valve seat 15, with the exception of a pilot opening 23 (throttle opening) to ensure a pilot volume flow in the direction of arrows 24 or the opposite directions. It can be seen that the first return spring 16 has been (further) compressed by this adjusting movement in comparison to the opening switching position, but the second return spring 17 is not. The power transmission from the armature 4 to the pilot valve seat during this adjusting movement until reaching the intermediate switching position was effected exclusively via the first return spring 16 or by compression of the first return spring

16 - while the second return spring 17 is not in the power transmission is involved. Until reaching the intermediate switching position and in the intermediate switching position takes place, as explained, no compression or Komprimierkraftbeaufschlagung the second return spring 17, so that the relative position between the pilot closing body 1 1 and valve closing body 12 remains unchanged. In other words, the adjustment movement was carried out in the intermediate switching position shown in Fig. 2 exclusively under application of force to the first return spring 16. The first coil current is such that it does not compress the second return spring 17 after reaching the intermediate representation. If the coil means 2 are then energized with a second coil current which is greater than the first coil current, the armature 4 is moved further in the direction of the core 3, specifically until the valve-closing body 12 abuts against its valve seat member 14 in a sealing manner As shown in FIG. 3, this end position is not quite reached.

In other words, a sealing contact of the valve closing body 12 is given to the valve seat 14 in the closed switching position, so that no medium volume flow can flow more. In the closed position, a Restaxialspalt 25 between anchor 4 and core 3 is given. The Verstellbe- movement of the intermediate switching position in the closed position takes place or takes place with simultaneous compression of the second return spring 17 and increasing the Axialabstandes between the pilot closing body 1 1 and the valve closing body 1 2, wherein during this movement step anchor 4 and pilot closing body 1 1 under compression approximate the second return spring 17 along the adjustment axis V. LIST OF REFERENCE NUMBERS

1 solenoid valve

2 coil means

3 core

4 anchors

5 winding

6 bobbins

7 anchor guide

8 through hole

9 pestles

10 housing

1 1 pilot closing body

12 valve closing body

13 valve seat element

14 valve seat

15 pilot valve seat

16 first return spring

17 second return spring

18 abutments

19 ring shoulder

20 locknut

21 arrow directions

22 ring seal

23 pilot opening (s)

24 arrow directions

25 residual axial gap

V adjustment axis

Claims

claims

1 . Solenoid valve (1), in particular 2/3-way valve comprising coil means (2) and one by energizing the coil means (2) against the spring action of a first return spring (16) and a second return spring (17) between different switching positions relative to a Core (3) adjustable armature (4), which is operatively connected to a pilot closing body (1 1) for cooperation with a pilot valve seat (15) and with a valve closing body (12) for cooperation with a valve seat (14), such that in an opening switching position the pilot closing body (1 1) of its pilot valve seat (15) and the valve closing body (1 1) from its valve seat (14) is spaced and in a Schließschaltstellung the pilot closing body (1 1) at its pilot valve seat (15) and the valve closing body (12) his valve seat (14) is applied and that arranged in an axially between the open switching position and the Schließschaltstellung Pilotschaltstel The valve closing body (12) is spaced apart from the valve seat (14) and the pilot closing body (1 1) rests against the pilot valve seat (15) with the opening of a pilot opening (23) through which a pilot volume flow can flow, the first return spring (16 ) and the second return spring (17) designed and arranged, in particular biased, are that in the opening switching position and / or the intermediate switching position, a first spring force of the first return spring (16) is less than a second spring force of the second return spring (17) characterized in that the second return spring (17) is arranged to urge the valve closing body (12) axially in the direction of the valve seat (14), and that the armature (4) moves from the opening switch position to the first Reaching the intermediate switching position exclusively against the spring force of the first return spring (16) is adjustable.

Electromagnetic valve according to claim 1,

characterized,

that the first (16) and the second return spring (17) are axially spaced.

Electromagnetic valve according to one of the preceding claims,

characterized,

the first return spring (16) is supported at one end on the core (3) and at the other end against the armature (4).

Electromagnetic valve according to one of the preceding claims, characterized

in that the valve closing body (12) and the pilot closing body (1 1), preferably on the end, on a, preferably the first return spring (16) and / or the second return spring (17) and / or the core (3) aaxially penetrating, ram (9) are arranged, which is fixed to the armature (4) or monolithically formed therewith.

Electromagnetic valve according to claim 4,

characterized,

the second return spring (17) is arranged at one end on an axially between the valve closing body (12) and the armature (4) and / or the first return spring (16), preferably in all switching positions of the armature (4) equidistant from the valve closing body (12). arranged, abutment (18) of the plunger (9) and the other end on the pilot closing body (1 1) is supported. Electromagnetic valve according to one of the preceding claims, characterized

in that the pilot-closing body (11) is adjustable relative to the valve-closing body (12) only when adjusting the armature (4) between the intermediate switching position and the closed-switch position, compressing the second return spring (17).

Electromagnetic valve according to one of the preceding claims, characterized

in that the valve closing body (12) is spring-loaded by the second return spring (17) against the pilot closing body (11) and / or is axially supported on the pilot valve body (15) in the opening switch position and / or the intermediate switch position.

Electromagnetic valve according to one of the preceding claims, characterized

in that the valve seat (14) and the pilot valve seat (15) are arranged radially next to one another, in particular at the same axial position, and / or on a common valve seat element (13), preferably axially spaced from the first (16) and second return springs (17) ,

Electromagnetic valve according to one of the preceding claims, characterized

in that the preferably cup-shaped valve closing body (12) and the preferably pot-shaped, pilot-closing body (1 1) are arranged radially one inside the other, in particular such that the valve closing body (12) is received radially in the pilot closing body (11) and / or the valve closing body (12) is axially offset relative to a support end of the pilot-closing body (1 1) for supporting the pilot valve seat (15) until it reaches the closing switch position.

10. Electromagnetic valve according to one of the preceding claims, characterized

in that the pilot closing body (11) and the valve closing body (12) are arranged outside a housing (10) of the electromagnetic valve (1) receiving the armature (4), the core (3) and the coil means (2).

1 1. Electromagnetic valve according to one of the preceding claims, characterized

that the armature (4) by energizing the coil means (2) with a first coil current axially from the open position against the spring force of the first return spring (16) to, preferably exclusively, in the intermediate switching position is adjustable and by energizing a second coil current, the larger is adjustable as the first coil current from the opening switching position and / or intermediate switching position against the spring forces of the first (16) and the second return spring (17) in the closed position. 12. A method for operating a solenoid valve (1) according to one of the preceding claims, wherein the armature (4) from the open position by energizing the coil means (2) is adjusted with a first coil current in the closed position and thereby in the opening switching position by the pilot valve seat (15) and the valve seat (14) flowing medium volume flow is reduced to a smaller medium pilot volume flow and that the armature (4) for closing the solenoid valve (1) from the open position or the intermediate switching position in the closed position by energizing the coil means (2) is adjusted with a second coil current that is greater than the first volume flow, characterized in that the adjustment of the armature (4) from the open position to the intermediate switching position exclusively against the spring force of the first return spring (16) and / or that an adjusting movement of the armature (4) against the spring force of both the first (16) and the second return spring (17) takes place exclusively on the way from the intermediate switching position into the closed switching position. 13. The method according to claim 12,

characterized,

the valve closing body (12) and the pilot valve body (11) are arranged radially next to one another in the closed position and / or interact with the same valve seat element (13).