Solenoid valve, battery of solenoid valves, method of manufacturing a solenoid valve, and mold

Abstract

In a solenoid valve having a magnetic drive including a housing which is at least partly formed from an injection molding compound, the magnetic drive includes a magnet coil having a winding, a magnet yoke, and a movably mounted magnet armature which is arranged outside the magnet coil. The housing has a first section which encloses the magnet coil having the winding and the magnet yoke, and the housing has a second section which encloses at least most of the movably mounted magnet armature. Further proposed are a battery having a plurality of solenoid valves, a method of manufacturing a solenoid valve, and a mold.

Claims

1. A solenoid valve comprising a magnetic drive having a housing which is at least partly formed from an injection molding compound, the magnetic drive including a magnet coil having a winding, a magnet yoke such that injection molding compound covers the magnet coil and the magnet yoke all around except for pole faces of the yoke, and a movably mounted magnet armature which is arranged outside the magnet coil, the housing having a first section which encloses the magnet coil having the winding and the magnet yoke, and the housing having a second section which encloses at least most of the movably mounted magnet armature, wherein the second section includes a cavity for receiving the movably mounted magnet armature and the cavity has an opening on one side for inserting the magnet armature after injection molding of the housing has been completed, wherein the magnet armature includes two pole pieces and the housing includes an injection molded section in the first section, the injection molded section being bordered by the pole pieces and the winding of the magnet coil and filling the area bordered by the pole pieces and the winding, wherein a wall of the cavity has an inwardly facing raised portion extending from the injection molded section along an inner surface of the cavity, wherein the raised portion, serving as a flow aid, allows the injection molded section to be produced between the winding of the magnet coil and the pole pieces relatively centrally within the housing.

2. The solenoid valve according to claim 1, characterized in that the second section is more particularly of a cup-shaped or trough-shaped configuration.

3. The solenoid valve according to claim 1, characterized in that an end of the raised portion serving as a flow aid rests against a wall of the cavity.

4. The solenoid valve according to claim 3, characterized in that the injection molded section has the height of the housing.

5. The solenoid valve according to claim 4, characterized in that the raised portion serving as a flow aid has a cross-sectional area (flow cross-section) which is selected such that the injection molded section is fully formed during the injection molding process.

6. The solenoid valve according to claim 1, characterized in that a cover is provided for closing an opening of the cavity of the second section.

7. The solenoid valve according to claim 6, characterized in that the cover is connected with the housing, in particular adhesively bonded or ultrasonically welded.

8. The solenoid valve according to claim 1, characterized in that it further includes an actuating member having a sealing element for opening a valve seat, the magnet armature cooperating with the actuating member.

9. The solenoid valve according to claim 1, characterized in that the injection molding compound is a thermoplastic material.

10. The solenoid valve according to claim 1, characterized in that the injection molding compound is a material having a high flowability.

11. The solenoid valve according to claim 1, characterized in that the injection molding compound is a liquid crystal polymer (LCP).

12. The solenoid valve according to claim 1, characterized in that the injection molding compound partly penetrates into the winding of the magnet coil.

13. A battery comprising a plurality of solenoid valves according to claim 1.

14. A battery of solenoid valves according to claim 13, wherein an opening of a cavity of at least one solenoid valve is closed by a side wall of an adjacent solenoid valve.

Description

DESCRIPTION OF THE DRAWING FIGURES

(1) The features and aspects of the invention will now be described in more detail below by means of an exemplary embodiment and with reference to the drawing figures, in which:

(2) FIG. 1 shows a cross-sectional view of the housing of a magnetic drive for a solenoid valve according to an exemplary embodiment of the invention, after the first manufacturing step;

(3) FIG. 2 shows a longitudinal section taken along line II of FIG. 1, with a cover;

(4) FIG. 3 shows a cross-sectional view of a solenoid valve with a magnetic drive according to an exemplary embodiment of the invention, in the assembled condition;

(5) FIG. 4 shows a perspective view of a cover for closing the housing; and

(6) FIG. 5 shows a perspective view of a battery of solenoid valves according to aspects of the invention.

DETAILED DESCRIPTION

(7) FIG. 1 shows a cross-section of the solenoid valve according to the invention with a magnetic drive 10 after a first manufacturing step. The magnetic drive 10 is shown after the first method step, in which the housing 12 was manufactured in an injection molding method step with a first section A1 having the magnet coil 14 and the magnet yoke 16 and a second section A2 for the magnet armature (not shown). Accordingly, all of the components of the housing that are shown are produced from an injection molding compound, except for the magnet coil 14 and the magnet yoke 16. In particular, these components are produced from an injection molding compound in one step of an injection molding method.

(8) Accordingly, the housing 12 essentially comprises the first section A1 and the second section A2. The second section A2 has a bottom surface 18 (which, by the way, also extends over the entire first region A1), from which the side walls of the housing 12 extend substantially perpendicularly (that is, toward the observer). The second section A2 has a cavity 100 which is open toward the observer. The cavity 100 is surrounded by a first side wall 20 which is arranged at the upper end of the housing 12. Viewed clockwise, a second side wall 22 extends perpendicularly to the first side wall 20. Provided opposite the first side wall 20 of the housing 12 is a third side wall 24 which extends as far as into the second section A2 and cooperates with a fluid housing (not illustrated here). The fourth side wall 4 of the cavity 100 is provided by the first section A1, in which the magnet coil 14, which is fully encased in injection molding material, and the magnet yoke 16 are located. A further outer wall 26 is provided by the second section.

(9) The first section A1 of the housing 12 is thus completely encased in injection molding material and contains the magnet coil 14 and the magnet yoke 16, which are almost completely surrounded by the injection molding compound. Only the pole faces 44 and 46 of the magnet yoke 16 are not covered by injection molding compound.

(10) The housing 12 further includes a second section A2 which, in the embodiment shown, is situated between an outer surface of the second side wall 22 and the first section A1. This second section A2 serves to receive a magnet armature, which has not yet been inserted here.

(11) As is clearly apparent from FIG. 1, the injection molded housing 12 has a complex structure since the walls 20 to 26 are provided with various recesses and indentations, so that a plastic material that flows well can be used as the injection molding compound for the manufacture of the housing 12.

(12) For example, a first indentation 30 and a plug receiving portion 32 are formed in the outer wall 26 of the housing 12. The plug receiving portion 32 is located between the side wall 26 and the side wall 24, with an actuating channel 24 being also formed along the side wall 24, the actuating channel 24 serving to receive an actuating member which is not yet inserted. The second side wall 22 further includes a second indentation 36 on the outside and a spring seat 38 in the area of the cavity 100.

(13) The second side wall 22 further has an inwardly directed raised portion 40 provided thereon which functions as a flow aid. The raised portion 40 extends along the bottom surface 18 of the second section A2. The raised portion 40 extends over the entire width B40 of the cavity 100.

(14) The raised portion, or flow aid, 40 serves to appropriately distribute the injection molding compound when the housing 12 is injection molded, so that a uniform injection molding around the magnet coil 14 is obtained. The raised portion or flow aid 40 allows a complete injection molded section 42 to be produced between the winding of the magnet coil 14 and the pole pieces (also magnet yoke legs) 28 and 52 of the magnet yoke 16 relatively centrally within the housing 12.

(15) The injection molded section 42 directly engages the magnet coil 14 (there is also a complete flow around magnet coil 14 here), fills the space between the pole pieces (also magnet yoke legs) 28 and 52, and terminates flush with the pole faces 44, 46 of the magnet yoke 16.

(16) The pole faces 44, 46 are facing the cavity 100 of the second section A2. Together with the winding section 42 encased in injection molding material, the two pole faces 44, 46 form a flush edge which faces the second section A2 and forms the fourth side wall for the cavity 100 of the second section A2.

(17) The flow cross-section QF of the flow aid or the cross-section of the raised portion 40 is selected such that the magnet coil 14 is fully surrounded by the injection molding compound, in particular also in the area of the injection molded section 42.

(18) In addition, the injection molded section 42 has the same height as the side walls 20 to 26 of the housing 12.

(19) The height H of the housing 12 as well as further features regarding the second section A2 are apparent from FIG. 2, which is a longitudinal section taken along line II shown in FIG. 1.

(20) FIG. 2 shows the housing 12 in a longitudinal section, with a cover 48 being now shown which closes the cup-shaped section A2. The cover 48 may be glued to the housing 12 or may be attached thereto by means of ultrasonic welding.

(21) FIG. 2 further clearly shows the two pole faces 44, 46 of the magnet yoke 16, which border the injection molded section 42.

(22) Further apparent from FIG. 2 are the raised portion 40 and its height. In this exemplary embodiment, the raised portion 40 rises from the bottom wall 18 only to a minimum extent, the height of the raised portion 40 in this exemplary embodiment corresponding to roughly half the thickness of the bottom wall 18 of the housing 12.

(23) The flow cross-section QF is also emphasized (dashed line). The flow cross-section QF is a function of the required distribution of the injection molding compound. The larger the surface area of the cross-section QF of the raised portion or flow aid 40, the larger the amount of injection molding compound that passes through the flow aid 40 during the injection molding process.

(24) FIG. 3 shows the magnetic drive 10 in a cross-sectional view analogous to the cross-sectional view of FIG. 1, with FIG. 3 showing the magnetic drive 10 in an installed condition, i.e. the entire solenoid valve 200 can be seen. The solenoid valve 200 thus comprises the magnetic drive 10 (with the housing 12) and a fluid housing 66.

(25) In the completed condition, the magnetic drive 10 includes a magnet armature 50 which contacts the first pole face 44. On the opposite side, the magnet armature 50 is mounted by means of a spring 54 such that the magnet armature 50 is movably arranged inside the cavity 100 of the housing 12. The spring 54 is furthermore supported against the second side wall 22 and is inserted in the spring seat 38.

(26) The magnet armature 50 extends through the cavity 100 of the second section A2, the magnet armature 50 having an L-shaped configuration. Thus, the magnet armature 50 includes a long leg 56 and a short leg 58; in the position shown, it rests against the first pole face 44 by its long leg 56.

(27) The short leg 58 of the magnet armature 50 cooperates with an actuating member 60. The actuating member 60 is in the form of a lever and partly extends into the actuating channel 34.

(28) On the side facing away from the magnet armature 50, the actuating member 60 is acted upon by a spring 62 such that the actuating member 60 pushes the magnet armature 50 to the initial position shown. The spring 62 is supported against a plug 64 here, which is inserted in the plug receiving portion 32.

(29) Moreover, a fluid housing 66 is fastened to the housing 12. The fluid housing 66 is fastened to the housing 12 by means of a pair of brackets 68, the brackets 68 engaging into the first and second indentations 30, 36 of the housing 12.

(30) The fluid housing 66 includes a first valve seat 70 and a second valve seat 72, with the first valve seat 70 being closed by a sealing element 74 in the embodiment shown.

(31) The sealing element 74 is arranged on the actuating member 60 such that the sealing element 74 closes one of the two valve seats 70, 72. In the initial position shown here, the first valve seat 70 is closed by the sealing element 74.

(32) The operating principle of the magnetic drive 10 here is as follows:

(33) A current is conducted through the magnet coil 14, so that a magnetic field builds up, which attracts the magnet armature 50 in particular at the second pole face 46. In this process the force is so high that it overcomes the spring force of the spring 62, so that the short leg 58 of the magnet armature 50 shifts the actuating member 60.

(34) As a result, the sealing element 74 arranged on the actuating member 60 clears the first valve seat 70 and closes the second valve seat 72.

(35) The advantage of the magnetic drive 10 according to the invention resides in the space-saving housing 12, which is formed in one method step of an injection molding method such that the magnet coil 14 is encased in injection molding material and, at the same time, the second section A2 is formed, so that both can be arranged in a housing consisting of the housing 12 and the cover 48.

(36) To this end, at first the magnet coil 14 and the magnet yoke 16 are placed in an injection mold or mold.

(37) Following this, the injection molding compound is introduced into the mold, so that the magnet coil 14 is enclosed by the injection molding compound and, at the same time, the housing 12 is formed, complete with side walls 20 to 26.

(38) The raised portion 40 here allows the injection molded section 42 to be formed such that a sufficient wall thickness of the housing 12 is ensured all over.

(39) After the injection molding compound has cooled down, the further components such as, for example, the magnetic armature 50, can be inserted into the cavity 100 of the housing 12.

(40) Finally, the housing 12 is closed with the cover 48, so that a housing is formed in which the magnet coil 14 is also surrounded by only one wall, as a result of which a correspondingly miniaturized embodiment of a magnetic drive 10 is provided.

(41) A perspective view of the cover 48 is shown in FIG. 4, from which it is apparent that the cover is merely large enough to close the cavity 100 of the second section A2 of the housing 12. More particularly, the cover does not extend into the first section A1, as a result of which the desired reduction in the height H, i.e. the dimension determining the structural size, is achieved.

(42) According to an exemplary embodiment of the invention, the method of manufacturing a magnetic drive may comprise the following steps.

(43) First, the magnet coil 14 along with the magnet yoke 16 is placed in an injection mold (mold). The coil 14 and the yoke 16 may be placed on pedestals which may be used here to provide a distance from the mold, so that a wall made from injection molding compound can be formed also below the coil 14 and the yoke 16. The injection mold or mold has a suitable profile for the manufacture of the housing. In particular, the mold is configured such that the sections A1 and A2 of the housing 12 are formed in one injection molding process.

(44) The mold (injection mold) more particularly has a shape configured to produce the cavity 100 in the second section A2 of the housing 12. In addition, the mold provides a groove or a channel in the form of the flow aid (later the raised portion 40 within the housing). By means of this flow aid, an even and sufficient distribution of the injection molding compound during the injection process is achieved.

(45) In a next step, the injection molding compound is injected into the injection mold (mold), so that, for one thing, the first section for the magnet yoke 16 and the magnet coil 14 is formed from the injection molding compound. At the same time, the second section having the cavity for the magnet armature 50 is formed from the injection molding compound. In particular, by means of the flow aid 40, the injection molded section 42 is sufficiently supplied with injection molding compound; in this way, the coil 14 is uniformly covered from all sides.

(46) In this process, the pedestals on which the coil 14 and the yoke 16 were placed are also encased in injection molding material.

(47) When the injection molding and curing of the housing 12 are completed, the magnet armature 50 and the further components such as, e.g., springs, are installed in the cavity of the second section A2.

(48) Then the second section can be closed with a cover 48.

(49) FIG. 5 shows a perspective view of a battery of solenoid valves 200 according to aspects of the invention. Each solenoid valve 200 has a housing 12 according to the preceding aspects of the invention. In the direction D, all of the solenoid valves 200 have the dimension H (the dimension determining the structural size) corresponding to the height H shown in FIG. 2. This dimension H is thus decisive for how tightly the solenoid valves 200 can be packed next to one another. Such batteries may comprise 8, 10 (as in the example illustrated), 16, 32 or more solenoid valves. The grid dimension for the solenoid valves may be in the range between 2.5 mm and 5 mm, preferably 4.5 mm. The maximum height H which a valve may have in the direction D also results from this. Thus, H then also amounts to between 2.5 mm and 5 mm and preferably 4.5 mm. To achieve such tight packings, the housing 12 of each solenoid valve can preferably be configured in accordance with the aspects and exemplary embodiments of the invention, since a double side wall can thereby be dispensed with.