FR2694062A1 - Solenoid valve for liquid and gaseous media. - Google Patents

Abstract

A solenoid valve has a plane spool as an armature polarized by a permanent magnet. The spool (19), actuated by magnetic forces, is located in the magnetic flux created by an excitation winding (51). It is guided with lateral play between parallel bars (21, 22) made of a material which does not conduct magnetic flux and carries at least one permanent magnet (41). The arrangement is such that during the longitudinal movement of the slide (19), transverse magnetic forces cannot occur, nor the friction which could result therefrom on the guide bars (21, 22). Usable in particular as a miniature solenoid valve with continuous, quasi-continuous adjustment, of the mono-, bi- or tristable type and with a variable number of channels for multiple applications.

Description

The invention starts from a solenoid valve for

  liquid and gaseous media, including as weapons

  a flat drawer placed in the magnetic circuit

  of an electromagnet, guided by its two faces of distribution.

  bution between two planar and parallel sliding faces and movable in translation by electromagnetic forces, wherein at least one permanent magnet gives the plane drawer the quality of polarized reinforcement and wherein the drawer has at least one opening perpendicular to the faces of sliding, opening whose lateral surface delimits the wall

  a pressure chamber connected to a connection port

  cord and whose edges form distribution edges for dispensing lumens provided in the sliding faces and connected to at least one

  connection, the plan drawer being essential-

  balanced in pressure, guided in its direction of axial movement by lateral guide bars and limited in its movement by a pole piece to

least an extreme position.

  Already known such a solenoid valve with a planar drawer as a frame by the European patent o 251 075 Bl, which is designed by its construction as a fast-switching solenoid valve, low friction and compact Thanks to its flat drawer type of construction, it is possible to respect tight tolerances, so that this solenoid valve is particularly suitable for miniaturization It also has multiple applications since it can be carried out as a solenoid valve with continuous or quasi-continuous adjustment, monostable, bistable or tristable type. and that it lends itself to the control of a variable number of channels As it does not use a seal

  flexible sealing, but only labyrinth seals

  rinth, it can reach a very long life of

  service (very high number of switching cycles).

  The disadvantage of this solenoid valve is the realization of the magnetic system by which the planar drawer is operated as a polarized armature in a magnetic flux of an electromagnet. In order for the drawer to be able to perform a longitudinal movement, a small clearance is required between its lateral guide bars For the polarization of the armature, four permanent magnets arranged stationary and whose magnetic fluxes pass each time through the guide bars, which are electrically conductive, and by a magnetic conductive outer ring of the ring-shaped planar drawer, are provided. Due to this magnetic flux of the four permanent magnets, there is an attraction or hold effect on one side of the drawer between a guide bar and the plan drawer itself. On the other side of the drawer there is at the same time, a corresponding air gap is formed with respect to the other guide bar. Longitudinal movement of the spool, transverse forces which considerably increase wear and thus prevent long service life Abrasion caused by transverse magnetic forces can lead to the locking of the spool after a relatively short time already This effect is further enhanced when, for simple and inexpensive construction, the outer ring of the drawer is made of a relatively soft magnetic conductive material. The object of the invention is in particular to avoid

  the disadvantages described above.

  According to the invention, a solenoid valve as indicated at the beginning is characterized in that the permanent magnet, polarizing the armature, is arranged in the plane drawer and the lateral guide bars are

  in material that does not conduct the magnetic flux.

  A solenoid valve thus produced has the advantage, compared to the prior art, that it retains the particular properties of the solenoid valve known from this device.

  The magnetic system according to the invention makes it possible to avoid transverse magnetic forces, so that the friction due to these forces can no longer occur. The switching times of the solenoid valve are at the same time rac

  The proposed construction renders superfluous the four stationary permanent magnets and keeps the planar drawer at its extreme positions. The permanent magnets required for polarization can be incorporated in rooms that the electromagnet

  In any case, there is a valve which provides for a compact construction. Overall, a simpler and cheaper structure of the magnetic system can be obtained. Furthermore, it is possible to continue to use the components contained so far in a solenoid type. According to a particularly advantageous embodiment using a planar drawer composed of at least two concentric rings, the outer ring of the drawer is made as a permanent magnet which is magnetized radially, so that a pole is formed on its diameter the outer pole and the other pole is formed on its inner diameter This embodiment25 allows to retain the advantages of a drawer plan of

type in a circle ring.

  According to another embodiment, the planar drawer has plane and parallel lateral faces, through which it is guided between the guide bars, and it has on each of the end sides directed towards the pole pieces a permanent magnet.

  polarized in the direction of axial movement, the arrangement of the permanent magnets being such that poles of the same name are directed towards each other or are located in the end sides.

  tion allows the use of a rectangular planar drawer in horizontal projection, as

  simple and inexpensive realization of the magnetic system

tick.

  According to a particular embodiment

  advantage of the solenoid valve according to the invention, the planar drawer has in each of its lateral faces

  parallels a permanent magnet, the two permanent magnets

  are arranged in a plane perpendicular to the direction of longitudinal movement and their arrangement being such that blades of the same name are directed towards each other or are located in the lateral faces and that the perpendicular opening is situated between the permanent magnets The magnetic system of such

  solenoid valve makes it possible to produce switching

  relatively high, which provides a

  safe and fast solenoid valve.

  Other features and benefits of

  the invention will become clearer from the description of

  The following description of four nonlimiting exemplary embodiments, as well as the appended drawings, in which:

  FIG. 1 is a simplified axial section of the solenoid valve according to a first embodiment of FIG.

  invention; FIG. 2 is a diagrammatic representation

  magnetic system of the solenoid valve according to Figure 1; Figures 3 and 4 are schematic representations of magnetic systems according to a second and third embodiment respectively; and

  Figure 5 is a part of a representative

  schematic representation of the magnetic system of a fourth

exemplary embodiment.

  FIG. 1 shows, by a simplified representation, an axial section of a solenoid valve 10 whose basic structure is in itself widely known from the European patent O 251 075 BI, to which it is therefore expressly referred. The detailed construction of the solenoid valve 10 will only be described in the

  necessary measure for the understanding of the invention.

  The solenoid valve 10, having essentially the external shape of a parallelepiped and which can be made as a miniature solenoid valve, essentially consists of a valve part 11, a magnetic part 12 and a connection plate 13. valve It comprises two valve plates 14, 15 of the same construction, which define by their plane and parallel faces, directed towards one another and constituting sliding faces 16, 17, an intermediate space 18 in which is disposed a planar drawer 19 The two valve plates 14, 15 are kept at a distance from each other by two identical and parallel guide bars 21, 22, which can be seen better in FIG. 2 The planar drawer 19 is guided with a small lateral clearance between these bars 21, 22 In the zone of the end portions of the latter, there are pole pieces 23, 24 formed of several stacked sheets and serving as stops for the drawer 19 in its positio Extreme ns Admission ports 25, use lights 26, 27 and return lights 28 are arranged in a known manner in both

  sliding surfaces 16 and 17 so that, overall,

  The solenoid valve with flat drawer may have a

  Balanced construction in pressure.

  The two valve plates 14, 15, the pole pieces 23, 24 and the guide bars 21, 22 are fixed in their relative positions by stop pins 31 and 32 and are tightened by means of hollow screws 33. , 34 in the valve portion 11 The hollow screw 33, in combination with a blind hole 35 in the stopper rod 31, ensures a better flow of fluid to and from a motor connection 36 The connection for the fluid with the Another motor connection 37 is similarly possible, which is not shown, in the stop rod 34. The intake ports 25 are separated from the utilization lights 26, 27 by identical and coaxial distribution shafts. 38 The return ports 28 are connected in a manner not shown to each other and to a reservoir 29. The planar slide 19, slidably disposed in the intermediate space 18, has a ring-shaped shape and is essentially consists of two concentric rings: an inner bearing ring 39 of a relatively hard and non-magnetizable material and a magnetic outer ring 41 The drawer 19 thus forms, by its sleeve-shaped bearing ring 31 and by the magnetic ring 41, two distribution faces 42, 43 which are flat and parallel and by which the slide is applied substantially without play, metal against metal, against the sliding faces 16 or 17 of the valve plates 14, 15 The bearing ring 39 delimits this In this way, an opening perpendicular to the sliding faces 16, 17 and whose lateral surface constitutes the wall of a pressure chamber 44. This chamber also extends outside the drawer 19, through the sleeve 38 into the valve plate. 15 to a connection port 45 for the inlet To the seat ring 39, whose inside diameter corresponds exactly to the outside diameter

  sheaths 38 are made from the edges of distri-

  In addition to the outer edges 47, the magnetic ring 41 has four distribution grooves 48 of kidney-shaped shape which open into the distribution faces. 42 or 43 and can establish the connections for the fluid between the use lights 26 or 27 and the return ports 28 The valve portion 11 can thus ensure, by its plan drawer 19, a control function or four-way distribution and two positions for example, in a manner known in itself. The arresting rods 31, 32 extend into the magnetic part 12 itself, where they are interconnected at their ends by a yoke body 49 in the form of a rod of good magnetic conductor material. the zone between the two arresting rods 41, 32, the yoke body 49 carries the excitation winding 51 of the electromagnet,

  winding whose feed polarity is reversal

  in a known manner, not shown, so that the

  Magnetic flux of the electromagnet is also reversible.

sible.

  FIG. 2 diagrammatically represents the magnetic system of the solenoid valve 10 according to FIG. 1. It shows the excitation winding 51, of reversible polarity, disposed on the yoke body 49, which is connected by the two stopping rods. 31 and 32, conducting the magnetic flux, to the pole pieces 23 and 24 respectively. The latter are each covered with a plastic cap 52 and are located in the end zones of the guide bars 21, 22 parallel and delimiting , together with the valve plates 14, 15 not shown here the intermediate space 18 in which is the plane drawer 19 An essential point is that the guide bars 21, 22 are

  made of material that does not conduct the magnetic flux

  the same applies to plastic caps.

  The drawer 19, shown only in a simplified manner here, is guided with a small lateral clearance between the bars 21, 22, so that it can effect a longitudinal movement between the two pole pieces 23, 24 according to the invention. the outer magnetic ring 41 of the plane ring-shaped drawer 19 is made as a radially magnetized permanent magnet, so that the north magnetic pole is on the outside diameter of this ring and the

  south magnetic pole lies on its integer diameter

  This arrangement of the poles can also be inverted The inner bearing ring 39, made of a non-conductive magnetic hard material, carries the edges

46 and 47.

  The operation of the solenoid valve 10 will be described below, especially with regard to the action of the magnetic system according to FIG. 2, the establishment and the breaking of the connections for the pressure fluid.

  by the drawer 19 being assumed to be known.

  It is initially considered that the excitation winding 51 is not energized and that the drawer 19 occupies the extreme rightmost position shown in FIG. 2. At this extreme position, the drawer 19 is applied against the right pole piece 24 or , more exactly, against its plastic cap 52 whose outer contour is formed so that the drawer always occupies a defined position The drawer 19 is held at this extreme position by the permanent magnet formed by the magnetic ring 41 since the lines flow, passing from the north pole to the south pole, amplified through the pole piece 24, while a relatively wide air gap exists between the other pole piece 23 and the magnetic ring 41 The side of the pole piece 24 directed towards the drawer 19 is covered with the plastic cap 52 to prevent an excessive force of attraction between the drawer and this pole piece The cap creates a gap that decreases the attractiveness and the sound of

contact during switching.

  To switch the solenoid valve 10, a magnetic field is created by a voltage pulse in the excitation winding 51, so that the flux passes through the yoke body 49 and the stopping rods 31, 32 leading the flow. magnetic in the pole pieces 23, 24 It is assumed that the winding 51 is traversed by the current so that the magnetic light created in the right pole piece 24 is of the same type as that existing on the outside diameter of the drawer 19, to Namely a north pole Between the pole piece 24 and the drawer 19 is thus created a repulsive effect, while an attraction effect is created at the same time on the opposite side by the pale of opposite name, namely the north pole on the magnetic ring 41 and the south pole on the pole piece 23 The drawer 19 is thereby moved to its leftmost position and, after the fading of the voltage pulse, is magnetically held at its new extreme position As the guide bars 21, 22 are made of non-magnetic material,

  transverse magnetic forces can not be

  blir during this longitudinal movement of the drawer 19 between the latter and the bars 21, 22, so that any holding effects or friction that could result, are avoided The guide bars 21, 22 can be made of a hard material, so they also resist numbers

students of switching cycles.

  If the drawer needs to be brought from its position

  far left in its extreme right position, roll it up

  excitation member 51 is energized with a reverse polarity, so that a pale of the same name, i.e. a north pole, is created on the left pole piece 23, while the right pole piece 24 becomes the pale south The drawer 19 is thus movable from one extreme position to the other avoiding the transverse magnetic forces and the resulting friction Therefore, the clearance between the drawer 19 and the two

  21, 22 may be chosen sufficiently

  large to prevent unnecessary friction; in particular, it is advantageous for this clearance to be of a few tenths of a millimeter Even if the drawer 19 is applied by a rib against a bar 21 or 22 during its longitudinal movement between the poles 23, 24, 5 of the magnetic retaining effects or transverse magnetic forces can not occur

  switching times of the solenoid valve 10 can thus be further shortened.

  FIG. 3 is a schematic representation of the magnetic system of a second solenoid valve 60, which system differs from that of FIG.

  explained in the following description, using the same references for identical components. The second solenoid valve 60 comprises another

  planar drawer 61, having an essentially rectangular base shape. This drawer has two flat and parallel lateral faces 62, through which it is guided between the bars 21, 22. It also contains, on each of the end sides 63 directed towards the pieces. polar 23, 24, a permanent magnet 64 or 65; these magnets are polarized in the direction of axial movement of the slide 61 and are arranged in such a way that

  poles with the same name are located in the

  63 or be directed towards each other.

  The operation of the magnetic system of the second solenoid valve 60 corresponds globally to that of the magnetic system, according to FIG. 2, of the first solenoid valve 10 in that the plane slide 61, made as an armature which is polarized by the

  two permanent magnets 64, 65 are kept magnetically

  in extreme positions and is switchable by

  control pulses from one extreme position to another.

  With this embodiment of the magnetic system, there is also no transverse magnetic forces, so that the solenoid valve 60 can reach, without wear

  or drawer lock, long service life.

  FIG. 4 is a schematic representation of the magnetic system of a third solenoid valve 70,

  system which is different from that of the second

  trovanne 60 according to Figure 3 as explained in the

  following description, using the same references

  for identical components The third electro-

  valve 70 also includes a planar drawer 71 of rectangular shape in horizontal projection, on which the two permanent magnets 72, 73 are arranged in the side faces 62 and made so that they are polarized in a plane perpendicular to the direction of longitudinal movement The arrangement is such that poles of the same name of the magnets 72, 73 are in the two lateral faces 62. The flow lines 74 shown in FIG. 4 explain why the slide 71 is held magnetically on the pole piece 24. at its extreme right position The drawer 71 is switchable, as in the examples according to the

  FIGS. 2 and 3 by control pulses

  at the excitation winding 51.

  The magnetic system of the third solenoid valve 70 has the advantage that it makes it possible to create

  relatively large forces, which promotes a safe and rapid switching of the solenoid valve. FIG. 5 is a partial diagrammatic representation of the magnetic system of a fourth electrolyte.

  trovanne 80 which is understandable and relatively easily achievable from the third solenoid valve 70 according to FIG. 4 Parts identical to those of FIG. 4 bear the same references. The fourth solenoid valve 80 is of the monostable type because the drawer plane 71 is loaded unilaterally by a return spring 81 which pushes the slide towards its extreme right position. Instead of the excitation winding 51 of reversible polarity of the bistable solenoid valve 70 according to FIG. simple excitation winding whose power is

  only of the ON / OFF type The switching of the slide 71 of the solenoid valve 80 is also performed in a similar manner to that described for the elec-

  bistable trovanne 70 according to FIG. 4. Of course, modifications may be

  made to the illustrated embodiments of the elec-

  Thus, the solenoid valve can be designed as a

  on-off valve or for continuous or near-continuous adjustment; besides the bistable and mono-

  described, the solenoid valve can also be of the tristable type, that is to say in three states or stable positions, and it can be performed for a variable number of channels and functions, always with the opportunity to exploit the benefits of the system

  proposed magnet without transverse magnetic forces

  Similarly, the fluid part of the solenoid valve can be designed so that, instead of the hollow stems, solid rods of solid material can be used, which improves flow guidance.

  Accordingly, the mode of construction of the valve portion, including the planar drawer, can be smoothly modified so that the fluid streams pass more through the planar drawer.

  It is also possible to use different kinds and

  light forms and distribution edges.

Claims (4)

  1 Solenoid valve for liquid and gaseous media, comprising as armature a planar spool placed in the magnetic circuit of an electromagnet, guided by its two distribution faces between two planar and parallel slide faces and displaceable in translation by means of electromagnetic forces, in which at least one permanent magnet gives the plane drawer the quality of polarized reinforcement and in which the drawer10 has at least one opening perpendicular to the sliding faces, the opening of which the lateral surface delimits the wall of a pressure chamber connected to a connection port and whose edges form distribution edges for distribution ports arranged in the sliding faces and connected to at least one user connection, the planar drawer being substantially pressure balanced, guided in its direction of movement axially by lateral guide bars and limited in its movement by a   polar piece in at least one extreme position,   in that the permanent magnet (41; 64, 65; 72, 73) biasing the armature is arranged in the plane drawer (19; 61; 71) and the lateral guide bars (21,   22) are made of material that does not conduct the magnetic flux. tick.   2 solenoid valve according to claim 1 with a   plan drawer consisting of at least two concentric rings   characterized in that the outer ring (41) of the two rings (39, 41) of the planar spool (19) is formed as a permanent magnet (41) radially magnetized, so that a pale (N) be trained on his   outer diameter and the other pale (S) is formed on its inside diameter (Fig 2). 3 Solenoid valve according to claim 1, characterized   characterized in that the planar drawer (61) has plane and parallel side faces (62), through which it is guided between the guide bars (21, 22) and has on each of the end faces (63 ) directed to the pole pieces (23, 24) a magnet   permanent (64, 65) polarized in the direction of movement   axial arrangement, the arrangement of the permanent magnets being such that the blades of the same name are directed toward each other or are located in the end faces (63). (Fig 3).   4 Solenoid valve according to claim 1, characterized   characterized in that the plane slide (71) has in each of its parallel side faces (62) a permanent magnet (72, 73), the two permanent magnets being polarized in a plane perpendicular to the direction of longitudinal movement and their arrangement being such that poles of the same name are directed towards each other or are located in the side faces (62) and that the perpendicular opening (44) is located between the   permanent magnets (72, 73) (Fig 4).   Solenoid valve according to any one of   Claims 1 to 4, characterized in that the electro-   magnet has an excitation winding (51) of reversible polarity and the solenoid valve (10; 60; 70) is   realized to be at least bistable.   6 Solenoid valve according to any one of   Claims 1 to 4, characterized in that the electro-   magnet has an excitation winding (51) whose power supply is ON / OFF type control and the solenoid valve (80), designed for monostable operation, comprises a return spring (81) acting on the planar drawer ( 71) to bring it to an extreme position. 7 Solenoid valve according to any one of   Claims 1 to 6, characterized in that the drawer   plane (19; 61; 71) is guided between the bars of   guiding (21, 22) with a game which is in particular a few tenths of a millimeter.