Electromagnet, specially for actuating valves

Information

  • Patent Grant
  • 6344783
  • Patent Number
    6,344,783
  • Date Filed
    Friday, November 12, 1999
    25 years ago
  • Date Issued
    Tuesday, February 5, 2002
    22 years ago
Abstract
An electromagnet for actuating valves includes a sheath-like magnet housing encompassing a pole core forming a one-sided closure of the housing. The housing is connected to the pole core by an annular groove in its periphery, by an O-ring accommodated in the groove as a sealing element and by an annular groove in the magnet housing. The magnet housing forms bearing surfaces joined in positive fit to the inner walls of the annular groove and a sealing surface located on the O-ring.
Description




FIELD OF THE INVENTION




The present invention relates to an electromagnet, particularly for actuating valves, with a sheath-like magnet housing. The housing encompasses a pole core on the actuation side of the electromagnet. An actuation member is accessible on the electromagnet and is movable by means of the armature of the magnet. The magnet housing is connected with the pole core in an area adjacent to the actuating side by means of a connection which is tightly fitting at least in that area.




BACKGROUND OF THE INVENTION




An electromagnet for actuating valves is disclosed in DE 195 04 185 A1. For this electromagnet to satisfy requirements for higher structural resistance and problem-free sealing of the magnet housing from the exterior environment, which sealing is particularly important during its use for the actuation of hydraulic valves, a costly structure with considerable manufacturing outlay generally results for conventional valves.




SUMMARY OF THE INVENTION




Objects of the present invention are to provide an electromagnet for actuating valves which is relatively simple and inexpensive to manufacture, particularly in view of its especially beneficial sealing and resistance properties.




The objects of the present invention are attained by an electromagnet having a connection between its magnet housing and pole core incorporating an annular groove formed between magnet housing and pole core in the periphery of the pole core. A removable sealing element is fitted in that groove. Another annular groove in the magnet housing also engages the sealing element. The connection forms contacts surfaces by engaging tightly and fitting on the interior walls of the pole core annular groove, as well as a contacting sealing surface encompassing the sealing element.




By virtue of this construction, with tightly fitting application of the frictional connection between the magnet housing and pole core, a problem-free sealing by contact of the annular groove of the magnet housing on the sealing element located in the adjacent annular groove is obtained simultaneously. As opposed to conventional electromagnets, wherein grooves forming inwardly aligned openings are uniformly distributed around the periphery of the magnet housing to form the connection, the connection obtained according to the present invention is without penetrating openings passing all the way through for a pressure-sealed sealing off of the housing.




The sealing element can be an O-ring, a gap seal or a suitable coating of the interior of the annular groove and/or of the pole housing in the area of the annular groove.




The manufacture is especially simple and low-cost when the magnet housing is a one-piece extrusion-molded part. That part includes an inwardly aligned open pole tube on its bottom, opposite the actuating end, open to the exterior of the magnet housing. The magnet housing is also the reverse side of the pole body.




Other objects, advantages and salient features of the present invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawing, discloses a preferred embodiment of the present invention.











BRIEF DESCRIPTION OF THE DRAWING




Referring to the drawing which forms a part of this disclosure:





FIG. 1

is a side elevational view in section of an electromagnet connected with a multi-way valve according to an embodiment of the present invention.











DETAILED DESCRIPTION OF THE INVENTION





FIG. 1

illustrates an electromagnet


1


and a multi-way valve


2


to be actuated by the electromagnet. Electromagnet


1


has a magnet housing


3


constructed by extrusion molding and forming one integral part. The magnet housing has the shape of a circular cylindrical beaker, from the bottom part


5


of which a central tubular pipe or pole tube


7


extends inward. The central tubular pipe is formed during the extrusion-molding procedure. Within magnet housing


3


, it forms a rear pole tube


7


of one integral piece with the housing.




Within magnet housing


3


, a spool or bobbin


9


, hereinafter spool


9


, incorporates a magnetizing coil


11


. The coil electrical connecting lugs


13


are guided outward through bottom openings


15


stamped out of bottom part


5


of magnet housing


3


. On the interior of pole tube


7


and on the interior of spool


9


, a thin walled tube


17


of nonmagnetic metal is engaged. The back or bottom of the tube


17


forms a guide for the armature piston


19


. From its front, outwardly tapered part, the thin tube


17


extends along the interior of spool


9


as far as its front end facing connecting lugs


13


.




Spool body


9


with magnetizing coil


11


and connecting lugs


13


, inserted into magnet housing


3


, is sprayed with insulating plastic. By means of built-in tube


17


, the sprayed plastic material surrounds the exterior of the magnetizing coil


11


and fills the space between the coil and the interior of magnet housing


3


. In this manner, an extruded connecting part


21


extends through bottom openings


15


as one integral spray-molded part formed on bottom part


5


. The connecting part closes bottom openings


15


as well as the exterior opening of tube


17


. This connecting part


21


also forms an integral plus part


23


for forming a contact with connecting lugs


13


of magnetizing coil


11


. Also, connecting part


21


is of such configuration that a surrounding annular groove


25


is formed in it to receive an O-ring


27


.




On the actuation end, an actuating pin


29


, connected with armature piston


19


, is accessible from the outside; and pole core


31


forms the actuation-side sealing of electromagnet


1


. Pole core


31


includes a widened-out flange part


33


, on the interior shoulder of which spool body


9


is supported. An encircling annular groove


35


extends into the exterior peripheral surface of flange part


33


, and accommodates a sealing element in the form of an O-ring


37


. Another annular groove


39


in magnet housing


3


is aligned with annular groove


35


such that magnet housing


3


contacts the interior walls of annular groove


35


, forming a tightly fitting connection between magnet housing


3


and pole core


31


. Since the groove


39


does not totally penetrate through the wall of magnet housing


3


, an encircling sealing surface is also obtained. The contact of the magnet housing


3


on the O-ring


37


in annular groove


35


forms a connection providing a pressure-tight sealing of magnet housing


3


.




Instead of the preferred O-ring


37


, a sealing arrangement of a different type could also be provided as the sealing element. For example, a gap seal arrangement or a coating with a sealing material could be provided.




A part of pole core


31


extends along the interior of spool body


9


in axial alignment with pole tube


7


, and has an annular groove accommodating an O-ring


41


for sealing off the tube


17


engaged on spool body


9


. This projecting part of pole body


31


terminates in a conical or tapered socket surface


43


facing pole tube


7


. Socket surface


43


is separated by an air gap


45


from the adjacent end of pole tube


7


.




For pressure compensation, an interior axial bore


47


penetrates or extends through magnet or armature piston


19


. Between armature piston


18


and the adjacent end of pole core


31


, an adhesive-resistant plate


49


of the conventional type is located. Actuation pin


29


engages with its contact surface on valve piston


51


of multi-way valve


2


which is to be actuated. Valve piston


51


is pre-biased by a compression spring


53


into contact with actuation pin


29


.




On the side of valve housing


54


predetermined for the application or connection of electromagnet


1


, multi-way valve


2


has a widened-out collar


55


. Magnet housing


3


is extended outward forming a free extension area


57


beyond groove


39


. Extension area


57


is beaded to accommodate the fastening of valve housing


54


to the exterior end surface


59


of pole core


31


with collar


55


of valve housing


54


.




Integration into one unit is obtained as a result of the overall spraying of spool body


9


by means of the incorporated tube


17


, to form the assembly comprising magnet housing


3


, spool


9


and tube


17


. Simultaneously, thin walled tube


17


is thus being guided and controlled. Tube


17


seals off the magnet from the exterior on the oil side, and in turn simultaneously offers armature piston


19


its guiding, and causes the magnetic disconnection.




With the sealed-off construction of electromagnet


1


provided by the annular groove


25


with O-ring


27


on connecting part


21


, oil-tight construction of electromagnet


1


in an oil chamber within a walled-off compartment or covering


61


is obtained. Since connecting part


21


projecting out of covering


61


is a plastic member and the other part of electromagnet


1


within covering


61


in the oil chamber is protected from exterior corroding influences, further exterior protection of electromagnet


1


against corrosion can be abandoned. Since tube


17


is supported on the exterior by the plastic material which has been sprayed on and on the interior of magnet housing


3


by spray-covered spool body


9


, electromagnet


1


can withstand increased interior pressure loads.




While a particular embodiment has been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.



Claims
  • 1. An electromagnet for actuation of valves, comprising:a sheath-like magnet housing being an extrusion-molded part forming one integrated piece and having a bottom part; a pole core encompassed by said housing on an actuation side of the electromagnet, said bottom part of said housing being opposite the actuation side; a magnet armature movably mounted in said housing; an actuation member connected to and moved by said magnet armature; a sealed connection between said magnet housing and said pole core on the actuation side including a first annular groove extending into a periphery of said pole core, a sealing element fitted in said first annular groove and a second annular groove in said magnet housing, said second annular groove forming contact surfaces on said magnet housing tightly engaging on interior walls of said first annular groove and forming an encompassing sealing surface engaging said sealing element; and a pole tube on said bottom part aligned with and extending inwardly toward a reverse side of said pole core.
  • 2. An electromagnet according to claim 1 whereinsaid sealing element is an O-ring.
  • 3. An electromagnet according to claim 1 whereinsaid magnet housing, on the actuation side of the electromagnet, extends and forms an extension area projecting over an exterior end surface of said pole core, said extension area being connected with a structural part actuated by the electromagnet.
  • 4. An electromagnet according to claim 3 whereinsaid structural part comprises a valve housing connected with said magnet housing, and comprises a collar engaging and adjacent said end surface of said pole core, said collar being connected with said extension area of said magnet housing by beading.
  • 5. An electromagnet according to claim 1 whereinsaid bottom part forms a connection side of the electromagnet, and has an opening formed by said pole tube and a plurality of bottom openings; and a spool body carries a magnetizing coil in an interior of said magnet housing, and is sprayed to form an integral connecting part sprayed therein that extends outwardly from said magnetizing coil through said bottom openings of said magnet housing to provide an electrical connection and to close said openings formed by said pole tube and said plurality of bottom openings.
  • 6. An electromagnet according to claim 5 whereinsaid connecting part comprises an exterior part extending out of said bottom openings of said magnet housing, said exterior part having a peripheral annular groove receiving an O-ring.
  • 7. An electromagnet according to claim 6 whereinsaid connecting part comprises a plug part, formed as one integral piece therewith, for electrical connections to said magnetizing coil.
  • 8. An electromagnet according to claim 5 whereina thin walled tube of nonmagnetic material extends about and guides movement of said magnet armature, and is sprayed together with said spool body and said connecting part.
  • 9. An electromagnet according to claim 8 whereinsaid pole core extends from an end surface thereof incorporating said first annular groove along said thin walled tube; said thin walled tube extends on an interior of said spool body; and said pole core comprises an annular groove receiving an O-ring forming a seal with said thin walled tube.
  • 10. An electromagnet according to claim 9 whereina part of said pole core extends along the thin walled tube for aligning a magnetic field, and terminates in a tapered socket facing an adjacent end of a pole tube on said magnet housing and spaced therefrom by an air gap.
  • 11. An electromagnet for actuation of valves, comprising:a sheath-like magnet housing, said magnet housing on an actuation side of the electromagnet extending and forming an extension area, said extension area being connected with a structural part actuated by the electromagnet; a pole core encompassed by said housing on an actuation side of the electromagnet, said extension area projecting over an exterior end surface of said pole core; a magnet armature movably mounted in said housing; an actuation member connected to and moved by said magnet armature; and a sealed connection between said magnet housing and said pole core on the actuation side including a first annular groove extending into a periphery of said pole core, a sealing element fitted in said first annular groove and a second annular groove in said magnet housing, said second annular groove forming contact surfaces on said magnet housing tightly engaging on interior walls of said first annular groove and forming an encompassing sealing surface engaging said sealing element.
  • 12. An electromagnet according to claim 11 whereinsaid structural part comprises a valve housing connected with said magnet housing, and comprises a collar engaging and adjacent said end surface of said pole core, said collar being connected with said extension area of said magnet housing by beading.
  • 13. An electromagnet according to claim 11 whereinsaid magnet housing comprises a bottom part forming a connection side of the electromagnet and having an opening formed by a pole tube and a plurality of bottom openings; and a spool body carries a magnetizing coil in an interior of said magnet housing, and is sprayed to form an integral connecting part sprayed therein that extends outwardly from said magnetizing coil through said bottom openings of said magnet housing to provide an electrical connection and to close said openings formed by said pole tube and said plurality of bottom openings.
  • 14. An electromagnet according to claim 13 whereinsaid connecting part comprises an exterior part extending out of said bottom openings of said magnet housing, said exterior part having a peripheral annular groove receiving an O-ring.
  • 15. An electromagnet according to claim 14 whereinsaid connecting part comprises a plug part, formed as one integral piece therewith, for electrical connections to said magnetizing coil.
  • 16. An electromagnet according to claim 13 whereina thin walled tube of nonmagnetic material extends about and guides movement of said magnet armature, and is sprayed together with said spool body and said connecting part.
  • 17. An electromagnet according to claim 16 whereinsaid pole core extends from an end surface thereof incorporating said first annular groove along said thin walled tube; said thin walled tube extends on an interior of said spool body; and said pole core comprises an annular groove receiving an O-ring forming a seal with said thin walled tube.
  • 18. An electromagnet according to claim 17 whereina part of said pole core extends along the thin walled tube for aligning a magnetic field, and terminates in a tapered socket facing an adjacent end of said pole tube on said magnet housing and spaced therefrom by an air gap.
  • 19. An electromagnet for actuation of valves, comprising:a sheath-like magnet housing, said magnet housing having a bottom part forming a connection side of the electromagnet, said bottom part having an opening formed by a pole tube and a plurality of bottom openings; a pole core encompassed by said housing on an actuation side of the electromagnet; a magnet armature movably mounted in said housing; an actuation member connected to and moved by said magnet armature; a sealed connection between said magnet housing and said pole core on the actuation side including a first annular groove extending into a periphery of said pole core, a sealing element fitted in said first annular groove and a second annular groove in said magnet housing, said second annular groove forming contact surfaces on said magnet housing tightly engaging on interior walls of said first annular groove and forming an encompassing sealing surface engaging said sealing element; and a spool body carrying a magnetizing coil in an interior of said magnet housing, said spool body being sprayed to form an integral connecting part sprayed therein that extends outwardly from said magnetizing coil through said bottom openings of said magnet housing to provide an electrical connection and to close said openings formed by said pole tube and said plurality of bottom openings.
  • 20. An electromagnet according to claim 19 whereinsaid connecting part comprises an exterior part extending out of said bottom openings of said magnet housing, said exterior part having a peripheral annular groove receiving an O-ring.
  • 21. An electromagnet according to claim 19 whereinsaid connecting part comprises a plug part, formed as one integral piece therewith, for electrical connections to said magnetizing coil.
  • 22. An electromagnet according to claim 19 whereina thin walled tube of nonmagnetic material extends about and guides movement of said magnet armature, and is sprayed together with said spool body and said connecting part.
  • 23. An electromagnet according to claim 22 whereinsaid pole core extends from an end surface thereof incorporating said first annular groove along said thin walled tube; said thin walled tube extends on an interior of said spool body; and said pole core comprises an annular groove receiving an O-ring forming a seal with said thin walled tube.
  • 24. An electromagnet according to claim 23 whereina part of said pole core extends along the thin walled tube for aligning a magnetic field, and terminates in a tapered socket facing an adjacent end of said pole tube on said magnet housing and spaced therefrom by an air gap.
Priority Claims (1)
Number Date Country Kind
197 17 445 Apr 1997 DE
PCT Information
Filing Document Filing Date Country Kind
PCT/EP98/00893 WO 00
Publishing Document Publishing Date Country Kind
WO98/49696 11/5/1998 WO A
US Referenced Citations (1)
Number Name Date Kind
3303445 Flentge Feb 1967 A
Foreign Referenced Citations (5)
Number Date Country
19525058 Mar 1996 DE
4439422 Jun 1996 DE
19504185 Aug 1996 DE
2385199 Oct 1978 FR
2 686 387 Jul 1996 FR