Component for a magnetic actuator as well as a method for its manufacture

Abstract

A single-piece component for a magnetic actuator, in particular for fuel injection, including an internal pole, a magnetic sleeve, and a non-magnetic separating sleeve, the internal pole, the magnetic sleeve and the separating sleeve being integrated into the single-piece component. A method for manufacturing a single-piece component for an magnetic actuator with the aid of a two-component powder injection molding method.

Claims

1. A method for manufacturing a solenoid valve structure, the method comprising: performing a two-component powder injection molding operation, which includes performing the following, either simultaneously or in any sequence, to form a single-piece component that includes an internal pole, a magnetic sleeve, and a non-magnetic separating sleeve: injection molding a non-magnetic material; and injection molding a magnetic material; and attaching a winding to the single-piece component; wherein: a plurality of axial coordinates are shared by both (a) a position of at least a portion of the internal pole and (b) a position of at least a portion of the winding; and the non-magnetic separating sleeve separates the internal pole from the magnetic sleeve and radially separates the internal pole from the winding at all of the plurality of axial coordinates shared by the positions of the at least the portion of the internal pole and the at least the portion of the winding.

2. An arrangement for a magnetic actuator, which is part of a solenoid valve, the arrangement comprising: a winding; and a single-piece component in which are integrated: an internal pole, wherein a plurality of axial coordinates are shared by both (a) a position of at least a portion of the internal pole and (b) a position of at least a portion of the winding; a magnetic sleeve; and a non-magnetic separating sleeve that separates the magnetic sleeve from the internal pole and that radially separates the internal pole from the winding at all of the plurality of axial coordinates shared by the positions of the at least the portion of the internal pole and the at least the portion of the winding.

3. The arrangement of claim 2, further comprising: a housing, which is additionally integrated into the single-piece component.

4. The arrangement of claim 3, wherein the housing has a connecting flange for a connection of the single-piece component.

5. The arrangement of claim 2, wherein the internal pole has a radial flange directed radially outwards.

6. The arrangement of claim 2, wherein the separating sleeve has a radially outwards directed first wall area on a first axial end and a radially outwards directed second wall area on a second axial end.

7. The arrangement of claim 6, further comprising: a winding, which is situated in a receiving space formed between the first and the second wall areas.

8. The arrangement of claim 2, further comprising: a metal housing that is integrated into the single-piece component and that includes a base region and a connecting flange, wherein: in a radial direction, the connecting flange is more interior than the base region; the connecting flange is directly connected to the inner pole; and at least a portion of the winding is arranged radially between the separating sleeve and the base region of the metal housing.

9. A single-piece component for a magnetic actuator, which is part of a solenoid valve, the single-piece component comprising, integrated with each other: an internal pole; a magnetic sleeve; and a non-magnetic separating sleeve that separates the magnetic sleeve from the internal pole and that includes: a circumferential wall that, in a radial direction, is positioned immediately adjacent to the internal pole; and a plurality of separating walls that each extends radially from the circumferential wall into the internal pole, the separating walls thereby dividing the internal pole into a plurality of segments with respect to a circumferential direction.

10. An arrangement for a magnetic actuator, which is part of a solenoid valve, the arrangement comprising: a winding; and a single-piece component in which are integrated: an internal pole; a magnetic sleeve; and a non-magnetic separating sleeve that: separates the internal pole from the magnetic sleeve; radially separates the internal pole from the winding; and has a profiling formed of a series of annular grooves separated axially by respective annular projections for accommodating a winding.

11. A single-piece component for a magnetic actuator, which is part of a solenoid valve, the single-piece component comprising the following integrated with each other: a magnetic sleeve; a non-magnetic separating sleeve that has a radially outwards directed first wall area on a first axial end and a radially outwards directed second wall area on a second axial end; and an internal pole that is situated between the first wall area and the second wall area and is separated from the magnetic sleeve by the non-magnetic separating sleeve.

12. The component of claim 11, wherein one of the wall areas of the separating sleeve forms a stop for a valve needle or a component connected to the valve needle.

13. A solenoid valve, comprising: a magnetic actuator, which is an injector for fuel injection, the magnetic actuator including: a winding; and a single-piece component in which are integrated: an internal pole, wherein a plurality of axial coordinates are shared by both (a) a position of at least a portion of the internal pole and (b) a position of at least a portion of the winding; a magnetic sleeve; and a non-magnetic separating sleeve that separates the internal pole from the magnetic sleeve and that radially separates the internal pole from the winding at all of the plurality of axial coordinates shared by the positions of the at least the portion of the internal pole and the at least the portion of the winding.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a schematic sectional view of a single-piece component for an injector according to a first exemplary embodiment of the present invention.

(2) FIG. 2 shows a schematic sectional view of a single-piece component for a magnetic actuator according to a second exemplary embodiment of the present invention.

(3) FIG. 3 shows a schematic sectional view of a single-piece component for an injector according to a third exemplary embodiment of the present invention.

(4) FIG. 4 shows a schematic sectional view of a single-piece component for an injector according to a fourth exemplary embodiment of the present invention.

(5) FIG. 5 shows a schematic sectional view of the single-piece component of FIG. 4 having a mounted winding.

(6) FIG. 6 shows a schematic sectional view of a single-piece component for an injector according to a fifth exemplary embodiment of the present invention.

(7) FIG. 7 shows a schematic sectional view of the single-piece component of FIG. 6 along Line V-V.

(8) FIG. 8 shows a schematic sectional view of a single-piece component for an injector according to a sixth exemplary embodiment of the present invention.

(9) FIG. 9 shows a schematic sectional view of a single-piece component for an injector according to a seventh exemplary embodiment of the present invention.

DETAILED DESCRIPTION

(10) A single-piece component provided as a single-piece valve component 1 will be described in detail below with reference to FIG. 1 according to a first exemplary embodiment of the present invention.

(11) As is apparent from FIG. 1, single-piece valve component 1 includes a valve housing 2, which is made of a metallic material, and a cylindrical internal pole 3, which is made of a magnetizable material. Furthermore, single-piece valve component 1 includes a cylindrical magnetic sleeve 4 made of a magnetically conductive material and a cylindrical separating sleeve 5 made of a non-magnetic material such as, for example, an austenitic material or a ceramic. X-X denotes an axial axis of single-piece valve component 1, in the direction of which a needle stroke of a needle, which is not shown, is carried out.

(12) Furthermore, a receiving space 6 is provided between separating sleeve 5 and valve housing 2 for accommodating a winding (not shown). Reference numeral 20 denotes a connecting flange.

(13) Thus, a non-magnetic separating sleeve 5 is integrated in the case of single-piece valve component 1 according to the present invention, an integral connection being provided in each case between the above-described subareas, including valve housing 2, internal pole 3, magnetic sleeve 4 and separating sleeve 5. The single-piece valve component is manufactured by a two-component powder injection molding method. The integration of non-magnetic separating sleeve 5 makes it possible to avoid magnetic losses in the separating sleeve. The magnetic field lines extend between the armature and the internal pole and not across the separating sleeve. This makes it possible to provide a powerful magnetic circuit for a solenoid valve, which is very cost-effective to manufacture. The integration of non-magnetic separating sleeve 5 into single-piece valve component 1 also integrates a function of a magnetic separation into single-piece valve component 1. A magnetic material of internal pole 3 may be configured to have the highest possible saturation induction, in order to optimize the magnetic efficiency. In addition, the single-piece valve component also provides a fuel-tight and high-pressure-tight connection between the individual parts without the necessity of complex connection techniques, such as, for example, welding or the like. The tight connection is achieved by the two-component powder injection molding method.

(14) FIGS. 2 through 8 show alternative embodiments of the present invention, identical or functionally identical parts being denoted by the same reference numerals as in the first exemplary embodiment in each case.

(15) FIG. 2 shows a second exemplary embodiment of a single-piece component 1, the single-piece component being provided without a housing. Thus, the single-piece component includes only one cylindrical magnetic sleeve 4 made of a magnetically conductive material, one cylindrical, non-magnetic separating sleeve 5 and one cylindrical internal pole 3. As is apparent from FIG. 2, separating sleeve 5 is situated on an end face of internal pole 3, so that single-piece component 1 has a constant external diameter.

(16) FIG. 3 shows a third exemplary embodiment in which internal pole 3 has a radial flange 30 directed outwards, which projects radially outwards from a cylindrical main body of internal pole 3. This radial flange 30 may, if necessary, also be subdivided into segments by providing electrically non-conductive subareas between the individual segments. This embodiment of single-piece component 1 results in a further improvement, i.e., a reduction of eddy currents occurring. In this exemplary embodiment, the valve housing includes two cylindrical subareas 2 and 20.

(17) FIGS. 4 and 5 show a fourth exemplary embodiment in which non-magnetic separating sleeve 5 has a cylindrical base area and a radially outwards directed first wall portion 51 on a first axial end. Further, separating sleeve 5 has a second radially outwards directed wall area 52 on a second axial end. Thus, a receiving space 6 for accommodating a winding 7 (see FIGS. 4 and 5) is produced in axial direction X-X between the two wall areas 51, 52. After winding 7 has been wound on the outer periphery of separating sleeve 5 between wall areas 51, 52, a cover sleeve 8 will be pushed on, which covers winding 7. A portion of valve housing 2 is formed in one piece with internal pole 3; another portion of the valve housing is provided by separate cover sleeve 8. The cylindrical internal pole is situated radially within separating sleeve 5.

(18) The fifth exemplary embodiment shown in FIGS. 6 and 7 is substantially similar to the fourth exemplary embodiment, a plurality of segmenting areas 53, 54, which are made of electrically non-conductive material, being additionally provided in cylindrical internal pole 3. Segmenting areas 53, 54 are provided as wall areas extending in axial direction X-X, which are formed in one piece extending radially inwards on the inner circumference of separating sleeve 5. This causes internal pole 3 to be subdivided into multiple segments 3a, 3b, 3c, which makes it possible to minimize the generation of eddy currents during operation. In this way, a more powerful magnetic circuit is obtained.

(19) FIG. 8 shows a sixth exemplary embodiment of a single-piece component 1, separating sleeve 5, which is made of a non-magnetic material, having a radially outwards directed first wall area 57 and a second wall area 58. In the sixth exemplary embodiment, however, internal pole 3 is accommodated in the space formed in the axial direction between the two wall areas 57, 58 and situated radially outside of base area 50. As is apparent from FIG. 8, internal pole 3 is thus enclosed on three sides by separating sleeve 5. Between a radial outer side of internal pole 3 and valve housing 2, receiving space 6 is in turn provided for accommodating the winding, which is not shown. Thus, in addition to the function of magnetic separation, separating sleeve 5 additionally provides protection against corrosive media, such as, for example, fuel for internal pole 3. This makes it possible for the magnetic material for internal pole 3 to be configured to have maximum saturation induction. Depending on the choice of material for separating sleeve 5, a stop surface 56 for a valve needle and a component connected to the valve needle may additionally be provided. This in particular makes it possible to dispense with a separate component for a stop for the valve needle. The use of this specific embodiment of single-piece component 1 makes it possible in particular to implement a very compact configuration for the injector.

(20) FIG. 9 shows a seventh exemplary embodiment of the present invention, which has a separating sleeve 5 made of non-magnetic material, on the outer circumference of which a profiling 55 is formed. Profiling 55 includes a plurality of annular grooves and projections for accommodating a winding (not shown). Thus, a winding carrier is additionally integrated into non-magnetic separating sleeve 5, making it possible to further reduce the number of parts for the injector by integrating the winding carrier. It should be noted that such an integrated winding carrier may also be provided in the other described exemplary embodiments, except for the sixth exemplary embodiment.

(21) For all exemplary embodiments described, it should be noted that they may be configured to have either a single-piece internal pole 3, or an internal pole subdivided into multiple segments.

(22) It should also be noted that all described exemplary embodiments may also be used as magnetic actuators in other technical fields instead of in solenoid valves.