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US5161779A Expired / Lapsed US ⏱️ 0.0 years remaining

Magnet system

Assignee: Robert Bosch GmbH
•
Filing: 1991-05-20
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Granted: 1992-11-10
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Expires: 2011-05-20
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Abstract

Abstract A magnet system for magnet valves for controlling liquids including an electromagnet and a permanent magnet that produces magnetic fluxes, the magnetic fluxes of which are oriented opposite one another in a working air gap formed between a free-floating armature and a magnet pole. To attain a course of the force of attraction acting upon the armature that becomes negative beyond a certain excitation of the electromagnet, and to reduce the trigger power for the electromagnet, a magnetic opposite pole is disposed on the side of the armature remote from the working air gap, forming a second working air gap, which is coupled to the magnet housing, optionally via a stray air gap, via a flow guide element annularly engaging the permanent magnet.

Inventors

  • 👤 Juergen Graner
  • 👤 Guenther Bantleon
  • 👤 Hans Kubach
  • 👤 Marcel Kirchner

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 19:03
CPC Classifications
H; H01; H01F; H01F7/00; H01F7/06; H01F7/08; H01F7/16; H01F7/1638; H01F7/1646; H01F2007/1676; H01F7/121; H01F7/122

Claims Analysis

Total Claims: 31
Claim 1
Independent Claim 228 words
A magnet system for magnet valves for controlling liquids, in particular for fuel injection valves, having an electromagnet, which has a magnet core forming a magnet pole, an exciter coil surrounding the magnet core and a magnet housing coaxial with and surrounding the exciter coil, said housing forms a magnetic short circuit and is connected via a short-circuit yoke to a face end of the magnet core remote from a pole face, an annular permanent magnet with an axial direction of magnetization, the permanent magnet being disposed coaxially with the magnet core near its pole face, and having an approximately disk-shaped armature, which is located free-floatingly opposite the magnet pole, forming a working air gap with the pole face thereof, wherein a circulation of the exciter coil and the disposition of the permanent magnet are selected such that the magnetic fluxes of the electromagnet and permanent magnet are in opposite directions to one another in the working air gap, a magnetic opposite pole (29) disposed on a side of the armature (28) remote from the working air gap (31), said magnetic opposite pole (29) forms a second working air gap (32) between its pole face (30) and the armature (28), said magnetic opposite pole is coupled to the magnet housing (25) via a magnetic flux guiding pole plate (35) which is spaced circumferentially from the permanent magnet (21).
Claim 2
Dependent Claim 228 words
A magnet system for magnet valves for controlling liquids, in particular for fuel injection valves, having an electromagnet, which has a magnet core forming a magnet pole, an exciter coil surrounding the magnet core and a magnet housing coaxial with and surrounding the exciter coil, said housing forms a magnetic short circuit and is connected via a short-circuit yoke to a face end of the magnet core remote from a pole face, an annular permanent magnet with an axial direction of magnetization, the permanent magnet being disposed coaxially with the magnet core near its pole face, and having an approximately disk-shaped armature, which is located free-floatingly opposite the magnet pole, forming a working air gap with the pole face thereof, wherein a circulation of the exciter coil and the disposition of the permanent magnet are selected such that the magnetic fluxes of the electromagnet and permanent magnet are in opposite directions to one another in the working air gap, a magnetic opposite pole (29) disposed on a side of the armature (28) remote from the working air gap (31), said magnetic opposite pole (29) forms a second working air gap (32) between its pole face (30) and the armature (28), said magnetic opposite pole is coupled to the magnet housing (25) via a magnetic flux guiding pole plate (35) which is spaced circumferentially from the permanent magnet (21).
Claim 3
Dependent Claim 36 words
A magnet system as defined by claim 1, in which the coupling of the magnetic opposite pole (29) to the magnet housing (25) by the pole plate (35) is performed via a stray air gap (34).
Claim 4
Dependent Claim 70 words
A magnet system as defined by claim 1, in which the end face of the magnet housing (25) remote from the short-circuit yoke (26) is connected to the magnet core (24), near its pole face (23), via a preferably integral annular land (27); that the permanent magnet (21) rests on the annular land (27); and that the annular land (27) has a magnetic constriction (40) acting in the radial direction.
Claim 5
Dependent Claim 70 words
A magnet system as defined by claim 2, in which the end face of the magnet housing (25) remote from the short-circuit yoke (26) is connected to the magnet core (24), near its pole face (23), via a preferably integral annular land (27); that the permanent magnet (21) rests on the annular land (27); and that the annular land (27) has a magnetic constriction (40) acting in the radial direction.
Claim 6
Dependent Claim 41 words
A magnet system as defined by claim 3, in which the magnetic constriction (40) is embodied such that it is magnetically saturated, or attains this saturation state very quickly upon application of an electric exciter current to the exciter coil (38).
Claim 7
Dependent Claim 41 words
A magnet system as defined by claim 4, in which the magnetic constriction (40) is embodied such that it is magnetically saturated, or attains this saturation state very quickly upon application of an electric exciter current to the exciter coil (38).
Claim 8
Dependent Claim 29 words
A magnet system as defined by claim 3, in which the magnet constriction (40) is achieved by means of an annular groove (39) provided in the annular land (27).
Claim 9
Dependent Claim 29 words
A magnet system as defined by claim 4, in which the magnet constriction (40) is achieved by means of an annular groove (39) provided in the annular land (27).
Claim 10
Dependent Claim 29 words
A magnet system as defined by claim 5, in which the magnet constriction (40) is achieved by means of an annular groove (39) provided in the annular land (27).
Claim 11
Dependent Claim 29 words
A magnet system as defined by claim 6, in which the magnet constriction (40) is achieved by means of an annular groove (39) provided in the annular land (27).
Claim 12
Dependent Claim 50 words
A magnet system as defined by claim 3, in which the magnetic opposite pole (29) with the pole plate is embodied as an integral pole plate (35), which annularly surrounds the permanent magnet (21) with radial spacing and is magnetically coupled to the annular land (27) and/or magnet housing (25).
Claim 13
Dependent Claim 50 words
A magnet system as defined by claim 5, in which the magnetic opposite pole (29) with the pole plate is embodied as an integral pole plate (35), which annularly surrounds the permanent magnet (21) with radial spacing and is magnetically coupled to the annular land (27) and/or magnet housing (25).
Claim 14
Dependent Claim 50 words
A magnet system as defined by claim 7, in which the magnetic opposite pole (29) with the pole plate is embodied as an integral pole plate (35), which annularly surrounds the permanent magnet (21) with radial spacing and is magnetically coupled to the annular land (27) and/or magnet housing (25).
Claim 15
Dependent Claim 58 words
A magnet system as defined by claim 11, in which between the pole plate (35) and the annular land (27) or magnet housing (25), a stray air gap (34) is formed, which is magnetically biased by means of a magnetic flux which is tapped at the permanent magnet (21), in its region (67) protruding beyond the armature (28).
Claim 16
Dependent Claim 58 words
A magnet system as defined by claim 12, in which between the pole plate (35) and the annular land (27) or magnet housing (25), a stray air gap (34) is formed, which is magnetically biased by means of a magnetic flux which is tapped at the permanent magnet (21), in its region (67) protruding beyond the armature (28).
Claim 17
Dependent Claim 58 words
A magnet system as defined by claim 13, in which between the pole plate (35) and the annular land (27) or magnet housing (25), a stray air gap (34) is formed, which is magnetically biased by means of a magnetic flux which is tapped at the permanent magnet (21), in its region (67) protruding beyond the armature (28).
Claim 18
Dependent Claim 38 words
A magnet system as defined by claim 11, in which the pole plate (35) has a concentric through opening (47) for a valve member (48) for the magnet valve, which member is firmly joined to the armature (28).
Claim 19
Dependent Claim 38 words
A magnet system as defined by claim 14, in which the pole plate (35) has a concentric through opening (47) for a valve member (48) for the magnet valve, which member is firmly joined to the armature (28).
Claim 20
Dependent Claim 49 words
A magnet system as defined by claim 11, in which the pole plate (35) is secured to the magnet housing (25) via a holder (37), and that the holder (37) is of nonmagnetic material or of soft magnetic material having a Curie temperature of 80° C., such as iron-nickel.
Claim 21
Dependent Claim 49 words
A magnet system as defined by claim 14, in which the pole plate (35) is secured to the magnet housing (25) via a holder (37), and that the holder (37) is of nonmagnetic material or of soft magnetic material having a Curie temperature of 80° C., such as iron-nickel.
Claim 22
Dependent Claim 49 words
A magnet system as defined by claim 17, in which the pole plate (35) is secured to the magnet housing (25) via a holder (37), and that the holder (37) is of nonmagnetic material or of soft magnetic material having a Curie temperature of 80° C., such as iron-nickel.
Claim 23
Dependent Claim 58 words
A magnet system as defined by claim 1, in which the annular cross-sectional area of the permanent magnet located parallel to the pole face (23) of the magnet pole (22) facing the armature (28) is approximately 1.5 times larger than the sum of the pole faces (23, 30) of the magnet pole (22) and the opposite pole (29).
Claim 24
Dependent Claim 58 words
A magnet system as defined by claim 2, in which the annular cross-sectional area of the permanent magnet located parallel to the pole face (23) of the magnet pole (22) facing the armature (28) is approximately 1.5 times larger than the sum of the pole faces (23, 30) of the magnet pole (22) and the opposite pole (29).
Claim 25
Dependent Claim 58 words
A magnet system as defined by claim 3, in which the annular cross-sectional area of the permanent magnet located parallel to the pole face (23) of the magnet pole (22) facing the armature (28) is approximately 1.5 times larger than the sum of the pole faces (23, 30) of the magnet pole (22) and the opposite pole (29).
Claim 26
Dependent Claim 18 words
A magnet system as defined by claim 1, in which the permanent magnet (21) is made from iron-neodymium.
Claim 27
Dependent Claim 18 words
A magnet system as defined by claim 2, in which the permanent magnet (21) is made from iron-neodymium.
Claim 28
Dependent Claim 18 words
A magnet system as defined by claim 3, in which the permanent magnet (21) is made from iron-neodymium.
Claim 29
Dependent Claim 94 words
A magnet system as defined by claim 1, in which the armature (28) at least partially overlaps the permanent magnet (21), forming an annular gap (33), and the permanent magnet (21) is set back far enough with respect to the pole face (23) of the magnet pole (22) that with a minimum working air gap (31) between the armature (28) and the pole face (23) of the magnet pole (22), the annular air gap (33) between the armature (28) and the permanent magnet (21) is equivalent to the maximum stroke of the armature (28).
Claim 30
Dependent Claim 95 words
A magnet system as defined by claim 2, in which the armature (28) at least partially fits over the permanent magnet (21), forming an annular gap (33), and the permanent magnet (21) is set back far enough with respect to the pole face (23) of the magnet pole (22) that with a minimum working air gap (31) between the armature (28) and the pole face (23) of the magnet pole (22), the annular air gap (33) between the armature (28) and the permanent magnet (21) is equivalent to the maximum stroke of the armature (28).
Claim 31
Dependent Claim 94 words
A magnet system as defined by claim 3, in which the armature (28) at least partially overlaps the permanent magnet (21), forming an annular gap (33), and the permanent magnet (21) is set back far enough with respect to the pole face (23) of the magnet pole (22) that with a minimum working air gap (31) between the armature (28) and the pole face (23) of the magnet pole (22), the annular air gap (33) between the armature (28) and the permanent magnet (21) is equivalent to the maximum stroke of the armature (28).

References Cited (Backward Citations)

US4403765A Cited
US4890815A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1995-11-10 1996-05-11 1996-11-10 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1999-11-10 2000-05-11 2000-11-10 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2003-11-10 2004-05-11 2004-11-10 $7700.00 Window Closed / Lapsed

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