EP1875479B1 - Solenoid unit and method for producing said solenoid unit and a magnet housing for such a solenoid unit - Google Patents

Description

The present invention relates to a solenoid unit for a solenoid valve, comprising a solenoid and a ferromagnetic circuit surrounding the solenoid, comprising a stationary magnet housing and a movable magnet armature. Furthermore, the invention relates to a method for producing such a solenoid unit and to a method for producing a magnet housing for such a solenoid unit.

Electromagnetically driven valves have a solenoid, a magnet armature for opening and closing the valve and a magnet housing. In simple designs, the magnet housing consists of a U-shaped bent solid sheet metal part. These designs are preferably suitable for a DC drive. In an AC drive, these designs generate large eddy current losses. Taking into account the permissible heating, this means that less effective power and thus less magnetic force is available. Furthermore, for example, from the generic DE 198 60 631 A1 known to produce the magnet housing in one piece from a metal strip, which is first punched out and then rolled or bent. The possibilities of shaping are limited here.

Other AC operated solenoid valves are equipped with magnet housings made of sintered ferrite material to avoid eddy currents. Although these are also suitable for operation with DC voltage, however, two valve designs are made for cost reasons. In contrast to an AC-operated valve, the magnet housing of a DC-operated valve does not use expensive special material such as sintered ferrite, but inexpensive sheet steel.

From the GB 2 040 585 A In addition, a solenoid unit is known which, in addition to a magnetic coil, has a ferromagnetic circuit surrounding it, which comprises a stationary magnet housing and a movable magnet armature. A cover, shell and bottom of the magnet housing shown are composed of multilayer transformer sheets. GB 2 040 585 A discloses the preamble of claims 1 and 12.

The object of the present invention is to specify an electromagnet unit and a method for producing a magnet housing of a solenoid unit whose cover part is designed such that the electromagnet unit can be used flexibly for different types of solenoid valves.

The invention provides a solenoid unit for a solenoid valve having the features of claim 1, wherein the magnet housing is composed of a cover, a shell and a bottom in the form of multilayer transformer sheet metal parts. An advantage is the favorable shape of the magnet housing, since it encloses the magnetic coil. In addition, thin sheet metal layers can be accurately formed with little effort, and the electrical resistance at the layer boundaries is already sufficient to reduce eddy current effects to an acceptable level. Thus, for cost reasons, a production of two valve versions for DC and AC is no longer necessary.

Transformer sheets are particularly suitable because they have a small thickness of a few tenths of a millimeter in addition to the appropriate magnetic properties. Furthermore, transformer sheets are an industrial mass product and correspondingly inexpensive to use. They are also available with an electrically insulating coating, which is an advantage for even better eddy current reduction.

In one embodiment, the transformer sheet metal parts are stamped and bent as needed. Since the sheet metal parts used have a small thickness, these processing steps are simple and inexpensive to carry out.

The transformer sheet metal parts have multiple layers, it being possible that these layers are interconnected. This increases the stability of the transformer sheet metal parts and reduces the gap width between the individual Layers. Suitable connection methods are, for example, packaging, gluing or riveting.

The bottom and / or the lid may have a central opening. As a result, a simple assembly of the solenoid unit is possible, for example, by simply inserting the armature, the armature counter-pole and / or a core guide tube axially.

In this embodiment, a radial slot extending from the central opening to the outer circumference is preferably provided in the lid and / or in the bottom. This slot reduces occurrence of eddy currents in the circumferential direction of the lid or the floor.

The bottom and / or the lid may be caulked in the assembled state with the jacket. This is a particularly inexpensive and reliable method of attachment. Before the connection of the sheet metal parts, the solenoid can be easily inserted into the shell, so that very easily a pre-assembled assembly of the bottom, the cover, the shell and the solenoid is created by caulking.

In one embodiment, the shell of the magnet housing has at least one opening, and the magnet coil is potted, pressed or overmolded. About this breakthrough, a liquid plastic material is introduced into the magnet housing, so that the solenoid receives a plastic embedding. After curing of the plastic mass possible gaps or cavities are closed and the sheet metal parts of the magnet housing and the solenoid are fixed so that the occurrence of rattling noises in valve operation is no longer possible.

The jacket may have a smaller thickness than the bottom, wherein the bottom may also have a greater thickness than the lid. Thus, increased magnetoresistance, which occur mainly on the ground by the non-magnetic core guide tube and the air gap to the movable armature, compensated by larger Blechteildicken. Due to the multi-layer structure of the sheet metal parts, the sheet metal thickness can be varied very easily over the number of layers. The layered sheet metal parts of the cover, shell and bottom may vary in thickness and property of the individual sheets, e.g. isolated or not isolated, differ.

In one embodiment, the cover comprises an inner cover part and an outer cover part, wherein the outer contour of the inner cover part is complementary to the inner contour of the outer cover part, so that the cover parts can be assembled in a form-fitting manner. As a cover part is not a single Designated transformer plate of the lid, but a built-up of several transformer laminations laminated core. This construction of two cover parts has the advantage that the produced with relatively high effort, inner cover part can be used identically even with different cover sizes and the necessary adjustment is made by the producible with less effort, outer cover part. Due to the positive connection of the lid composed of inner and outer lid part acts substantially as a one-piece (but constructed of several metal layers) lid, so that the magnetic flux is not affected in the lid plane.

Preferably, the outer cover part is U-shaped. Thus, the protective conductor terminal of the inner lid part, which is responsible for the increased production cost of the inner lid part, in all the execution sizes of the lid is easily accessible.

Furthermore, the lid may have a cover part which covers the assembled lid parts. With this cover, the sheet metal thickness of the laminated core is increased for larger covers on the one hand, on the other hand, the base of the lid is not separated over its entire thickness by a joint between the inner and the outer cover part. Both contribute to a reduction of the magnetoresistance.

1. A) Stanzen von Blechen aus ferromagnetischem Material;
2. B) Schichten der Bleche zu Blechpaketen, die als Mantel, Boden oder Deckel bzw. Deckelteil eines Magnetgehäuses der Elektromagneteinheit verwendet werden;
3. C) Zusammensetzen des Magnetgehäuses durch Herstellen einer formschlüssigen Verbindung zwischen dem Deckel und dem Mantel sowie dem Boden und dem Mantel.

Furthermore, the invention comprises a method for producing a magnet housing of a solenoid unit for a solenoid valve with the features of claim 12, comprising the following steps:

1. A) punching sheets of ferromagnetic material;
2. B) layers of the sheets into laminated cores, which are used as a jacket, bottom or cover or cover part of a magnet housing of the solenoid unit;
3. C) assembling the magnet housing by establishing a positive connection between the cover and the shell and the bottom and the shell.

By this method, a magnet housing for a solenoid unit, which is suitable for both a DC drive and an AC drive, easily and inexpensively manufactured.

In the embodiments, prior to assembly of the magnet housing, the cover is composed of an inner cover part and an outer cover part, wherein the outer contour of the inner cover part is complementary to the inner contour of the outer cover part. Preferably, the cover parts are then connected positively and / or non-positively. The positive connection, but also a possible frictional connection perpendicular to the lid plane provide for an unimpeded magnetic flux in the lid plane and are easy to manufacture. The cover parts with the complementary contours are preferably punched, the frictional connection can e.g. be achieved via a press fit between the lid parts. The legs of the U-shaped cover part can be pressed apart and deformed during positive connection with the inner cover part slightly so that they clamp after the connection, the inner cover part and prevent relative movement between the cover parts perpendicular to the cover plane.

After assembling the inner and outer cover part, a cover part can additionally be attached to the inner and / or outer cover part. By such a cover member, which is constructed as well as the inner and outer cover part of transformer plates, the cover thickness can be adapted very easily with increasing cover surface, i. be enlarged. The cover is caulked for example with the inner and / or outer cover part.

1. A) Stanzen von Blechen aus ferromagnetischem Material;
2. B) Schichten der Bleche zu Blechpaketen, die als Mantel, Boden oder Deckel bzw. Deckelteil eines Magnetgehäuses der Elektromagneteinheit verwendet werden;
3. C) Formen des Mantels, so daß er eine Magnetspule wenigstens teilweise umgeben kann;
4. D) Einsetzen der Magnetspule in den Mantel;
5. E) Zusammensetzen des Magnetgehäuses durch Herstellen einer formschlüssigen Verbindung zwischen dem Deckel und dem Mantel sowie dem Boden und dem Mantel.

Furthermore, the invention comprises a method for producing a solenoid unit for a solenoid valve, which comprises the following steps:

1. A) punching sheets of ferromagnetic material;
2. B) layers of the sheets into laminated cores, which are used as a jacket, bottom or cover or cover part of a magnet housing of the solenoid unit;
3. C) forming the shell so that it can at least partially surround a magnetic coil;
4. D) inserting the magnetic coil in the jacket;
5. E) Assembling the magnet housing by establishing a positive connection between the lid and the jacket and the bottom and the jacket.

In a variant of the method, the assembly of the magnet housing begins even before the insertion of the magnet coil into the shell, by already producing a positive connection between the bottom and the shell or the cover and the shell. Accordingly, this substep is omitted in step E.

By this method, the magnet housing and the magnet coil are produced in the same way as a preassembled unit, wherein the magnet coil is protected inside the preassembled unit. After attaching a fixed armature counter pole and a core guide tube with a movable armature, the solenoid unit is completed.

Preferably, after assembly of the magnet housing, a liquid plastic mass is introduced into the assembled magnet housing through an opening provided in the magnet housing to embed the magnet coil. The breakthrough is made before or after the layers of the sheets, for example by punching. After initiation and hardening of the plastic compound, the sheet metal parts of the magnet housing and the magnetic coil are fixed so that no rattling noises can occur.

• Figur 1 einen schematischen Schnitt durch eine Elektromagneteinheit; und
• Figur 2 eine perspektivische Ansicht eines Deckels, eines Bodens und eines Mantels einer erfindungsgemäßen Elektromagneteinheit;
• Figur 3 eine perspektivische Ansicht eines inneren Deckelteils und eines äußeren Deckelteils;
• Figur 4 eine perspektivische Ansicht eines Deckels für eine erfindungsgemäße Elektromagneteinheit, der aus dem inneren und dem äußeren Deckelteil nach Figur 3 zusammengesetzt ist;
• Figur 5 eine perspektivische Explosionsansicht eines Magnetgehäuses für eine erfindungsgemäße Elektromagneteinheit, mit einem mehrteiligen Deckel.

Further features and advantages of the invention will become apparent from the following description of a preferred embodiment with reference to the drawings. In these show:

• FIG. 1 a schematic section through a solenoid unit; and
• FIG. 2 a perspective view of a lid, a bottom and a shell of a solenoid unit according to the invention;
• FIG. 3 a perspective view of an inner lid part and an outer lid part;
• FIG. 4 a perspective view of a lid for a solenoid unit according to the invention, from the inner and the outer lid part after FIG. 3 is composed;
• FIG. 5 an exploded perspective view of a magnet housing for a solenoid unit according to the invention, with a multi-part lid.

The FIG. 1 shows a solenoid unit for actuating a solenoid valve, with a magnetic coil 10 which defines a coil axis A and the winding of which is received by a bobbin 12. Furthermore, a ferromagnetic circuit is shown in FIG. 1 a fixed magnet housing, a movable armature 14 and a fixed armature counterpart pole 16 comprises. The magnet housing has in the present case a cover 18, a bottom 20 and a jacket 22. In addition, a non-magnetic core guide tube 24 is provided, which extends in the interior of the magnetic coil 10 between the bobbin 12 and the armature 14 and the armature counter-pole 16. The power supply of the magnetic coil 10 via axially led out terminals 26, which are also shown schematically.

When energized solenoid 10, the armature 14 is generally acted upon by a spring (not shown) so that the solenoid valve is in a desired position (open or closed). When the magnet coil 10 is energized, the magnet coil is formed inside the magnet coil axially aligned magnetic field. The armature 14, the armature counter-pole 16 and the magnet housing (in detail the cover 18, the bottom 20 and the shell 22) form a ferromagnetic circle, which is decisive for the force on the armature 14. Between the armature 14 and the armature counter-pole 16 there is an axial air gap 28, so that the armature 14 is attracted to the armature counter-pole 16. The axial extent of the air gap 28 is equivalent to a drive stroke of the solenoid valve.

The FIG. 2 shows a particularly advantageous embodiment of the magnet housing, consisting of the lid 18, the bottom 20 and the shell 22. It can be seen that the sheet metal parts of the magnet housing are constructed of multilayer transformer sheet. The cover 18 and the bottom 20 have in the axial direction, the jacket 22 in the radial direction a plurality of layers. The orientation of the laminated cores, ie, the axial layering for the cover 18 and the bottom 20 and the radial layering of the jacket 22 is selected according to the course of the magnetic field lines, wherein the perpendicular to the magnetic field lines eddy current paths are interrupted at the layer boundaries ,

In the present embodiment, the individual layers of transformer sheet, which has a thickness of about 1mm and can be coated with an electrically insulating coating. In general, however, a mere stratification of non-insulated transformer plates is sufficient to largely eliminate the eddy currents due to the increased electrical resistance at the layer boundaries. In the FIG. 2 By way of example, some layers for the individual housing components are shown, but which are merely intended to symbolize a multi-layer structure. For layer thicknesses of 1-1.2 mm, the individual components preferably comprise 2 to 9 layers. To increase the stability and reduce the gap, the layers of the components can be connected, for example by packaging, gluing or riveting.

The sheet metal parts of the magnet housing can be varied very easily in their thickness by a sizing of the number of layers. In general, points For example, the bottom 20 more layers than the lid 18 or the jacket 22 to compensate in the region of the bottom 20, the increased magnetoresistance by the non-magnetic core guide tube 24 and the air gap between the core guide tube 24 and the movable armature 14 at least partially.

On the lid 18 and the bottom 20 recesses 30 are provided, can be inserted into the tabs 32 of the shell 22. A connection of the lid 18 with the jacket 22 and the bottom 20 with the jacket 22 is made by assembling the parts and caulking the tabs 32. The solenoid 10 can be easily used axially before assembling the magnet housing and is after caulking the tabs 32 enclosed inside the magnet housing. According to another embodiment, the cover 18 or the bottom 20 is welded or screwed to the jacket 22.

The FIG. 2 shows in the casing 22 a plurality of openings 36, is introduced through the after insertion of the magnetic coil 10 and the assembly of the magnet housing, a liquid plastic mass to embed the magnetic coil 10 and to fix. Injection, Umpressen or encapsulation are common methods for embedding the magnetic coil 10. The openings 36 are preferably provided where the effect of the ferromagnetic circuit is least affected. Of course, the lid 18 or the bottom 20 have openings for this purpose.

The cover 18 and the bottom 20 each have a central opening into which the Kernfuhrungsrohr 24 can be inserted with the armature 14 and the armature counterpart 16. Furthermore, the cover 18 and the bottom 20 each have a radial slot 34 extending from the central opening to the outer circumference, which reduces the formation of eddy currents in the circumferential direction of the cover 18 or of the base 20.

Depending on the respective series of the solenoid valve, the individual sheet metal parts of the magnet housing may have special features. So is in FIG. 2 the substantially circular lid 18 cut along a chord to facilitate the axial lead-out of the terminals 26 of the solenoid 10. The extent of the shell 22 in the circumferential direction depends essentially on the valve series and only has to ensure a sufficient magnetic flux. Preferably, however, the multilayer jacket 22 surrounds at least half of the magnet coil 10 and, in the extreme case, encloses it completely, wherein at least one axially extending slot should be provided in order to reduce the occurrence of eddy currents in the circumferential direction.

The FIGS. 3 and 4 show an inner cover member 38 and an outer, U-shaped cover member 40, or a cover made of these cover parts 38, 40 cover 18. For simplicity, in the following only from a lid 18 or cover parts 38, 40 the speech, of course Also, the bottom 20 of several parts, from corresponding parts of the floor, may be composed.

The method for producing the multi-part lid 18 will now be described with reference to FIGS. 3 and 4 explained. First, the inner and outer cover parts 38, 40 are made analogous to the base 20 and shell 22 by stamping, laminating and bonding ferromagnetic transformer sheets, the outer contour of the inner cover part 38 being complementary to the inner contour of the outer cover part 40. To form a protective conductor connection 42 on one side of the inner cover part 38, individual transformer plates are recessed over the height of the cover 18 and others are provided with projections, so that a complex contour results, the production of which is associated with increased tooling costs. Due to this greater manufacturing effort, the inner cover member 38 is used with the protective conductor terminal 42 of identical design. In the case of small magnet housings, the inner cover part 38 forms the entire cover 18, whereas in the case of larger magnet housings the easy-to-manufacture, U-shaped, outer cover part 40 is positively and / or non-positively connected to the inner cover part 38. The recesses 30 of the inner lid portion 38 are then not the connection with the jacket 22 (see. FIG. 2 ), but the positive connection with corresponding projections 44 of the outer cover part 40. For better positive and / or non-positive connection of the cover parts 38, 40 may be provided additional cooperating grooves and projections, in FIG. 4 are shown in dashed lines.

In FIG. 5 is an exploded view of a magnet housing with a multi-part lid 18 can be seen. In order to adjust for larger cover 18, the sheet metal thickness of the lid 18, a cover 46 is provided, said cover 46 covers the cover parts 38, 40, ie the base of the cover 46 corresponds to the base of composite inner and outer cover member 38, 40th With the compared to FIG. 2 slightly longer tabs 32 of the shell 22 in this case, the jacket 22, the outer cover member 40 and the cover 46 are caulked together. In addition, the cover 46 may be fixedly connected to the inner lid portion 38. To reduce eddy currents in the circumferential direction of the lid 18, a radial slot 34 is also provided in the cover 46.

Claims (14)

1. A solenoid unit for a solenoid valve, comprising a magnet coil (10) and a ferromagnetic circuit which surrounds the magnet coil (10) and includes a stationary magnet housing and a movable magnet armature (14), the magnet housing being assembled of a cover (18), a shell (22) and a bottom (20) in the form of multilayer transformer sheet metal parts, characterized in that the cover (18) comprises an inner cover part (38) and an outer cover part (40), the outer contour of the inner cover part (38) being complementary to the inner contour of the outer cover part (40), so that the cover parts (38, 40) can be assembled with an interlocking fit.
2. The solenoid unit according to claim 1, characterized in that the transformer sheet metal parts are punched and, if required, bent.
3. The solenoid unit according to either of the preceding claims, characterized in that the transformer sheet metal parts have a plurality of layers, these layers being connected to each other.
4. The solenoid unit according to any of the preceding claims, characterized in that the cover (18) and/or the bottom (20) have/has a central opening.
5. The solenoid unit according to claim 4, characterized in that the cover (18) and/or the bottom (20) have/has a radial slot (34) that is continuous from the central opening up to the outer periphery.
6. The solenoid unit according to any of the preceding claims, characterized in that in the assembled condition, the cover (18) and/or the bottom (20) are/is caulked to the shell (22).
7. The solenoid unit according to any of the preceding claims, characterized in that the shell (22) has at least one aperture (36) and the magnet coil is potted or is coated or encased by injection molding.
8. The solenoid unit according to any of the preceding claims, characterized in that the shell (22) has a thickness that is lower than that of the bottom (20).
9. The solenoid unit according to claim 8, characterized in that the bottom (20) has a thickness that is greater than that of the cover (18).
10. The solenoid unit according to claim 1, characterized in that the outer cover part (40) is formed in the shape of a U.
11. The solenoid unit according to any of the preceding claims, characterized in that the cover (18) has a covering part (46) which covers the cover parts (38, 40) in the assembled condition.
12. A method of manufacturing a magnet housing of a solenoid unit for a solenoid valve, comprising the following steps:

    A) punching of metal sheets of a ferromagnetic material;

    B) stacking the metal sheets to form laminated sheet packages which are used for the shell (22), the bottom (20) or the cover (18) or a cover part of a magnet housing of the solenoid unit;

    C) assembling the magnet housing by producing an interlocking connection between the cover (18) and the shell (22) and between the bottom (20) and the shell (22),

    characterized in that prior to step C), the cover (18) is assembled from an inner cover part (38) and an outer cover part (40), the outer contour of the inner cover part (38) being complementary to the inner contour of the outer cover part (40).
13. The method according to claim 12, characterized in that the cover parts (38, 40) are connected with an interlocking fit and/or with a frictional fit.
14. The method according to claim 12 or 13, characterized in that subsequent to assembling the inner and outer cover parts (38, 40), a covering part (46) is mounted to the inner and/or to the outer cover part (38, 40).

Images