Solenoid valve with improved magnetic flux conduction, and method for producing same

Abstract

The invention relates to a solenoid valve comprising a first connection (1), a second connection (2), a third connection (3), and a core (4), in which the first connection (1) is formed as a through-opening and which has an inner cone (4e). The solenoid valve comprises at least one closure part (7; 7a, 7b) for opening and closing the first connection (1) and the second connection (2); an armature (5) for moving the at least one closure part (7; 7a, 7b); and a coil (6) for moving the armature (5). The armature (5) extends in a cylindrical manner about the at least one closure part (7; 7a, 7b) and comprises a section (5a) which protrudes axially beyond the at least one closure part (7; 7a, 7b) and comprises an end face (5e) that tapers in a conical manner and can be inserted into the inner cone (4e) of the core (4) in order to conduct a magnetic flux current.

Description

[0001] DESCRIPTION

[0002] Solenoid valve with improved magnetic flux guidance and method for its manufacture

[0003] The present invention relates to a solenoid valve with improved magnetic flux guidance and a method for its manufacture and in particular to a 2 / 3-way valve with magnetic flux guidance via conical end faces.

[0004] Solenoid valves are used, for example, as 2 / 3-way valves for pressure control of anti-lock braking systems (ABS) or traction control systems (ASR) in commercial vehicles or buses. These solenoid valves are subject to intensive use during operation and must function reliably over many actuations.

[0005] However, due to the high stress they are subjected to, conventional solenoid valves show significant wear over time, meaning that reliable switching (opening and / or closing) is no longer possible or only inadequately possible. In particular, the sudden switching processes and the resulting high forces, which are caused, among other things, by pressure differences, often lead to mechanical wear on the valve seats and / or the closing components. This wear can be further exacerbated by the air routing, i.e., the redirection of the air flows within the valve. With conventional valves, it has been shown that the components used are often unable to withstand the strong air flows over the long term.

[0006] Therefore, there is a need for alternative designs for solenoid valves that, on the one hand, enable simple manufacturing and, on the other hand, can ensure reliable operation throughout their entire service life.

[0007] At least some of the above-mentioned problems are solved by a solenoid valve according to claim 1 and a manufacturing method according to claim 11. The dependent claims define further advantageous embodiments of the subject matter of the independent claims.

[0008] The present invention relates to a solenoid valve with a first port, a second port, a third port, and a core. The core comprises the first port as a through-opening (e.g., as a valve seat) and is a conical recess (inner cone). The solenoid valve comprises at least one closure part for opening and closing the first port and the second port, an armature for moving the at least one closure part, and a coil for moving the armature. The armature extends cylindrically around the at least one closure part and comprises a section projecting axially beyond the at least one closure part with a conically tapered end face. The conical end face can be inserted into the inner cone of the core (when the armature is moved) in order to conduct a magnetic flux current.

[0009] The armature has a section that protrudes axially beyond the at least one closure part and has an optional through-opening or slot. The armature can also have an axially extending side channel (e.g., a groove) to direct air flow from the first port to the third port. This transforms the solenoid valve into a 3 / 2-way solenoid valve.

[0010] A through-hole can be defined as a passage for air flow that has a closed edge in a cross-section perpendicular to the air flow. It is therefore not a notch or cut, but rather a hole or punched hole, for example. The closure part can be a single-piece or multi-piece design and serves as a sealing plug(s), reliably sealing the corresponding valve seat. They can be flat or tapered to achieve a good seal. The direction of movement of the armature defines an axial direction.

[0011] The armature can then have a (partially) closed end face to the core. Optionally, the end face of the armature can form a cone. The core can optionally form an inner cone on the side facing the armature. This increases the magnetic surface area. The inner cone of the core and / or the cone of the armature can each be formed by two angled sections.

[0012] The following technical effects can be achieved with this design. Firstly, the guidance of the magnetic field lines changes. The double cone geometry of the core and armature means that the magnetic force tends to decrease for small distances between armature and core, but increases for larger distances between core and armature. This has a positive effect on the switching behavior of the valve, as the valve can be reliably closed without excessive forces acting on the core when the closure part hits the valve seat. Compared to conventional armatures, which have a slotted armature geometry (i.e. have no through holes), the magnetic force increases at larger distances, also due to the continuous end face of the armature towards the core. The closed pole face on the armature generally increases the magnetic force, which also contributes to the reliable movement of the armature through the coil.Overall, by influencing the characteristic curve, a higher magnetic force can be achieved at larger distances between the core and armature. This ensures that the armature moves through the coil even at larger distances between the core and armature. This ensures that the magnetic force is greater than the spring force of the compression spring between the armature and core, even at large distances.

[0013] Optionally, the at least one closure part comprises a first closure part and a second closure part. The first closure part couples to the armature and opens or closes the first port in response to movement of the armature. The second closure part couples to the armature and closes or opens the second port in response to movement of the armature. The solenoid valve can then further comprise at least one damping spring arranged between the first closure part and the second closure part and configured to cushion the closing of the first port and / or the second port.

[0014] The through-opening may be a first through-opening and the armature may optionally have a second through-opening in a region formed axially between the first closure part and the second closure part to provide pressure equalization between an inner region of the cylindrical armature and the third port.

[0015] Optionally, the first through-hole and the second through-hole are identically constructed. "Identical" means that they can be produced with the same tool (e.g., drill) and therefore do not differ—apart from their position. Optionally, multiple first through-holes and / or multiple second through-holes can be provided to better distribute the airflow.

[0016] Optionally, the first and second closure parts each comprise a head-shoulder region for closing the associated first or second connection. The armature can have a projection projecting radially into the interior and, at an opposite end, an annular recess with a stop element. The projection can be configured to form a stop for the head-shoulder region of the first closure part. The recess can be configured to fix the second closure part in the axial direction by the stop element after insertion of the first closure part, the damping spring, and the second closure part.

[0017] Optionally, the stop element is a disc that is secured within the recess by an edge compression of the anchor. However, it does not have to be a continuous disc. It is sufficient to form an axial stop for the second locking part. However, it should not be completely fixed.

[0018] The first closure part can also be structurally identical to the second closure part. This offers the advantage that only one type of closure part needs to be produced. After insertion, the two closure parts are only rotated by 180° relative to each other. This enables simple and cost-effective production. Only one damping spring needs to be arranged between the first closure part and the second closure part, which damping spring presses the first closure part and the second closure part away from each other. The solenoid valve can have a chamber into which the armature can be moved linearly together with the at least one closure part and the first, second and third connections provide a connection to the chamber (e.g. via external connection parts).When the coil is energized, the at least one closure part can close the first port and establish a fluid connection via the chamber between the second port and the third port. When the coil is deenergized, the at least one closure part can close the second port and establish a fluid connection via the chamber between the first port and the third port.

[0019] Embodiments also relate to a method for manufacturing a previously defined solenoid valve having a first port, a second port, a third port, an armature with a cylindrical interior, and a coil for moving the armature. According to embodiments, the method may further comprise the following steps:

[0020] - Providing the anchor with a side channel;

[0021] - forming a through hole through the anchor; and

[0022] - Inserting at least one closure part into the armature, wherein after the insertion step the armature has a portion projecting axially beyond the at least one closure part and the through-bore is formed in the projecting portion in order to guide an air flow from the first port to the third port.

[0023] Optionally, the through-bore is a first through-bore and the at least one closure part comprises a first closure part and a second closure part.

[0024] The method may then further comprise forming a second through-bore in a region of the armature that lies axially between the first closure part and the second closure part. The same tool may be used for this purpose.

[0025] It is understood that all of the previously described features of the solenoid valve can be implemented through additional optional process steps. Furthermore, it is understood that the order in which the steps are listed does not necessarily reflect the order in which the process steps are executed. The steps can also be performed in a different order, or only some of the process steps are performed.

[0026] Embodiments of the present invention overcome the problems mentioned above by using bores that can be formed in (only) one work step and do not compromise the stability of the anchor. Slots and notches could instead lead to burrs forming, which would require laborious removal.

[0027] When multiple closure parts are used, the (single) spring offers the advantage of dampening the impact of both closure parts on the valve seats. This is possible, for example, by closing both ports on opposite sides, which can be dampened using a simple compression spring.

[0028] Some designs offer the further advantage that the double damping significantly increases the service life of the solenoid valve. Less damage occurs, and opening and closing occurs with high precision. Therefore, the solenoid valves are suitable for applications that require a high number of switching operations, such as ABS solenoid valves.

[0029] A further advantage of these embodiments is that both closure parts can have the same design and can thus be manufactured interchangeably. This significantly simplifies and reduces the cost of production. Cost savings are also achieved by requiring fewer parts due to the dual damping.

[0030] The same applies to the formation of the through-holes, which can be formed by similar bores, since both the through-hole in the central area between the two closure parts and in the upper end area can be produced in a single work step using the same tool. According to exemplary embodiments, the outer groove along the anchor can already be present in the precursor material (rod material), which also shortens the manufacturing process and production time.

[0031] The embodiments of the present invention will be better understood from the following detailed description and the accompanying drawings of the various embodiments, which, however, should not be construed to limit the disclosure to the specific embodiments, but are for explanation and understanding only.

[0032] Fig. 1 shows a solenoid valve according to an embodiment of the present invention.

[0033] Fig. 2 shows a schematic flow diagram for a manufacturing method for a solenoid valve from Fig. 1 .

[0034] Fig. 1 shows a solenoid valve with improved damping according to an embodiment of the present invention. The valve shown is a 3 / 2-way valve which can selectively connect three ports to one another by means of two switching positions. For this purpose, the solenoid valve comprises a first port 1, a second port 2, a third port 3, an armature 5, a coil 6, a first and a second closure part 7a, 7b, and a damping spring 8. The coil 6 serves to move the armature 5 (by magnetic forces). The first closure part 7a couples to the armature 5 and opens or closes the first port 1 when the armature 5 is moved by the coil 6. The second closure part 7b also couples to the armature 5 and opens or closes the second port 2 when the coil 6 moves the armature 5. The damping spring 8 is arranged between the first closure part 7a and the second closure part 7b.When the first port 1 and / or the second port 2 is closed, the damping spring 8 absorbs the impact (or impact) on the corresponding valve seat. It thus improves the damping and protects the closure parts 7a, 7b and the valve seats on the ports 1, 2. The coil 6 can, for example, be accommodated in a valve body housing 10 and extend cylindrically around a core 4 and the armature 5. The core 4 can, for example, be fixedly arranged within the coil 6 and provide the first port 1 as a through opening. The armature 5 is displaceable in the axial direction (vertical in Fig. 1), with a compression spring 11 being present between the core 4 and the armature 5, which generates a preload.The armature 5 can, for example, have a protruding section 5a that projects axially beyond the first closure part 7a and defines a cylindrical inner region in which the compression spring 11 is guided and which accommodates a valve seat 12 of the first connection 1. A further advantage of the protruding section 5a of the armature 5 is that it provides the installation space for the compression spring 11 between the armature 5 and the core 4. This makes the assembly more compact. In conventional solenoid valves, the compression spring is located on the outside of the armature and thus requires additional installation space. A long groove in the core 4 between the valve seat and the pole face would also be much more complex to manufacture than the protruding section 5a of the armature 5, as designed in exemplary embodiments.

[0035] The first and second closure parts 7a, 7b can move relative to the armature 5 by compressing the damping spring 8. However, this movement is limited axially in both directions by a stop. For this purpose, the first and second closure parts 7a, 7b each comprise a narrowed region 17a, 17b forming a shoulder-head region, with the head portion serving to close the associated first or second opening 1, 2, and the shoulder serving as a stop.

[0036] In addition, the armature 5 comprises a projection 5c projecting radially into the interior, which forms the stop for the shoulder portion 17a of the first closure part 7a. The compression spring 11 can also engage this inner projection 5c and press the armature 5 away from the core 4. At an opposite end, an annular recess 5d is formed in the armature 5. The annular recess 5d, together with the head-shoulder region 17b of the second closure part 7b, is formed in such a way that a disc 9, for example, can be inserted there, which is easily fixed, for example, by compressing the armature 5. Then, both closure parts 7a, 7b are fixed in the armature 5 by an axial stop. When the coil 6 is de-energized, the compression spring 11 presses the armature 5 away from the core 4. As a result, the first closure part 7a opens the first connection 1, since the first closure part 7a is moved by the stop 5c.At the same time, the pre-adjusting force of the compression spring 11 is sufficient to move the armature 5 until the armature 5 closes the opposite second connection 2 through the second closure part 7b. The contact of the second closure part 7b with the second connection 2 is dampened by the damping spring 8.

[0037] When the coil 6 is energized, thus generating a magnetic field, the armature 5 is magnetically drawn toward the core 4 against the spring tension of the compression spring 11, until the first closure part 7a closes the first connection 1. In this case, the stop, via the disc 9, transfers the force from the armature 5 to the second closure part 7b, which then transfers the force to the first closure part 7a via the damping spring 8. The pressure force when closing the first connection 1 is thus limited to the spring force of the damping spring 8, thus protecting the solenoid valve.

[0038] As a result of this movement, either the second port 2 or the first port 1 is opened or closed. When the second port 2 is open (energized state), a fluid connection exists between the third port 3 and the second port 2. The third port 3 can be formed in a base section next to the second port 2 in the valve body 10. In this case, no further provisions for air flow between the second and third ports 2, 3 are required.

[0039] Fig. 1 shows only the switching position with the first connection 1 open. To guide the air flow from the first connection 1 into the interior of the valve housing 10, the armature 5 has at least two through-openings 13 and at least one side channel 14 (e.g. formed as a groove). The at least two through-openings 13 connect an interior region of the armature 5 and the side channel 14 and provide a fluid connection between the first connection 1 and the third connection 3. For example, at least one first through-opening 13a is formed in the protruding section 5a and at least one second through-opening 13b is formed in a region 5b of the armature 5 that is located axially between the first closure part 7a and the second closure part 7b. The at least one second through-opening 13b provides pressure equalization between the interior region of the armature 5 and the third connection 3.The second through-opening(s) 13b are located axially at the height of the damping spring 8 and reduce the wear on the first closure part 7a and the second closure part 7b due to the pressure equalization.

[0040] According to exemplary embodiments, the armature 5 comprises a (partially) closed end face 5e, which faces the core 4. The end face 5e of the armature 5 forms, for example, a cone. Analogously, the core 4 can form an inner cone 4e on the side facing the armature 5. This enlarges the magnetic surface. In particular, the inner cone 4e of the core 4 and the cone 5e of the armature 5 can each form two angled regions. In this way, the end face of the armature 5 forms a completely or partially closed armature surface relative to the pole face of the core 4. Compared to conventional armatures with slotted pole faces, the magnetic force is increased by the larger pole face according to exemplary embodiments.

[0041] The two pole faces can be designed, in particular, as a double cone or with angled sections (see Fig. 1) to generate the additional magnetic surfaces. The two pole faces thus formed further increase the area of ​​the armature 5 relative to the core 4, and thus the magnetic force with a larger air gap, since this geometry positively influences the armature characteristic.

[0042] It is understood that multiple through-openings 13 and / or multiple side channels may be provided to distribute the air flows as evenly as possible throughout the interior due to the considerable pressure conditions. The second port 2 and the third port 3 can be formed as through-openings in the valve body housing 10. The core 4 can optionally also be axially movable in the valve body 10, with its axial movement being effected via a separate control system. In the illustrated embodiment, the second port 2 is thus closed in the idle state (de-energized coil).

[0043] Fig. 2 shows a schematic flow diagram for a method for manufacturing one of the previously described solenoid valves. The method comprises:

[0044] - Providing S110 the armature 5 with a side channel 14;

[0045] - Forming S120 a through hole 13 through the anchor 5; and

[0046] - Inserting S130 at least one closure part 7; 7a, 7b into the anchor.

[0047] The steps are carried out such that, after the insertion step S130, the armature 5 has a portion 5a projecting axially beyond the at least one closure part 7; 7a, 7b, and the through-bore 13 is formed in the projecting portion 5a in order to guide an air flow from the first port 1 to the third port 3.

[0048] The through-bore 13 can be a first through-bore 13a, and the at least one closure part 7a, 7b can comprise a first closure part 7a and a second closure part 7b. Optionally, the method can then further comprise forming S135 a second through-bore 13b in a region 5b of the armature 5 that lies axially between the first closure part 7a and the second closure part 7b.

[0049] Optionally, the method comprises, as a further method step, forming S135 a stop for the second closure part 7b in order to ensure that the first closure part 7a, the second closure part 7b, and the damping springs 8 arranged therebetween are fixed within the cylindrical cavity of the armature 5. Forming the stop can, for example, comprise inserting the disk 9 and compressing the edge of the armature 5. After that, the disk 9 can no longer be removed from the recess without being destroyed. It is understood that all of the other features of the solenoid valve described above can be implemented as further optional method steps during production. Furthermore, it is understood that the order in which they are mentioned does not necessarily represent the order in which the method steps are carried out. The steps can also be carried out in a different order, or only some of the method steps are carried out.

[0050] The assembly and media routing can be summarized as follows:

[0051] The assembly sequence can therefore be as follows: first, the cylindrical armature 5 is prepared, into which the first closure part 7a is inserted. The first closure part 7a comprises a head region and a shoulder region, wherein the radially inwardly projecting projections 5c of the armature 5 engage in the shoulder region and provide a stop, so that the first closure part 7a can only be moved up to the radial projections. The damping spring 8 can then be inserted into the cylindrical armature 5. Finally, the second closure part 7b is placed onto the damping spring 8. Finally, the disk 9 is inserted. Since the second closure part 7b also has a shoulder section and a head section, the disk abuts the shoulder region and thus provides a stop for the second closure part 7b. For this purpose, the armature 5 comprises the circumferential recess 5d, into which the disk 9 can be inserted.After the compression of the armature 5 at one axial end, removal of the disc 9 and thus the second closure part 7b from the interior of the armature 5 is no longer possible, since deformation of the axial end of the armature 5 prevents removal of the disc 9. Subsequently, the armature can be inserted together with the core 4 into the interior of the valve housing 10, and after fixing the core 9, the solenoid valve is ready for use.

[0052] The air movement in the individual switching positions occurs along the through-openings 13 and the outer grooves 14. For this purpose, one or more grooves 14 are provided along the outer cylindrical surface of the armature 5, which allow an axial air flow into or from the third port 3. The media guide (air) therefore goes from the first port 1 to the third port 3 through the core valve seat 12 and is guided through the transverse bore 13 in the armature 5. From the transverse bore 13 in the armature 5, the air guide continues via the aforementioned outer grooves to the third port 3. An advantage of this air guide is that the outer grooves 14 of the armature 5 can already be present in the raw material and do not have to be manufactured separately. For example, they can be formed using a turning process before the armature 5 is manufactured. This saves process time and therefore costs.The transverse bore 13 in the armature 5 allows air to flow both from the inside to the outside and from the outside to the inside. Furthermore, the transverse bores 13, which serve to guide air between the first connection 1 and the third connection 3, can be identical in design to the transverse bore 13b, which provides pressure equalization between the first closure part 7a and the second closure part 7b.

[0053] The features of the invention disclosed in the description, the claims and the figures may be essential for the realization of the invention both individually and in any combination.

[0054] LIST OF REFERENCE SYMBOLS

[0055] 1, 2, 3 connections

[0056] 4 core 4e (inner) cone section

[0057] 5 anchors

[0058] 5a,5b,5c,5d,5e sections of the anchor

[0059] 6 coil

[0060] 7, 7a, 7b, closure part(s)

[0061] 8 Damping spring

[0062] 9 disc

[0063] 10 housing body

[0064] 11 compression spring

[0065] 12 Valve seat (Kem) 13, 13a, 13b Through holes

[0066] 14 Side channel, groove

[0067] 15 chamber (interior)

[0068] 17a, 17b narrowed area (shoulder-head area / section)

Claims

PATENT CLAIMS 1. Solenoid valve with a first port (1), a second port (2), a third port (3) and a core (4) in which the first port (1) is designed as a through-hole and which has an internal cone (4e), the solenoid valve is characterized by - at least one locking part (7; 7a, 7b) for opening and closing the first port (1 ) and the second port (2); - an anchor (5) for moving the at least one locking part (7; 7a, 7b), wherein the anchor (5) extends cylindrically around the at least one locking part (7; 7a, 7b); and - a coil (6) for moving the armature (5), wherein the armature (5) has a section (5a) projecting axially beyond the at least one closure part (7; 7a, 7b) with a conically tapered end face (5e) which can be inserted into the inner cone (4e) of the core (4) to conduct a magnetic flux current.

2. Solenoid valve according to claim 1, characterized in that the end face (5e) forms an annularly closed cone.

3. Solenoid valve according to claim 2, characterized in that the inner cone (4e) of the core (4) and the cone (5e) of the armature (5) are each formed by two angled areas.

4. Solenoid valve according to one of the preceding claims, characterized in that the at least one closure part (7a, 7b) has a first closure part (7a) and a second closure part (7b), wherein the first closure part (7a) couples to the armature (5) and opens the first port (1) upon movement of the armature (5). or closes and couples the second closure part (7b) to the armature (5) and closes or opens the second port (2) upon movement of the armature (5); and that the solenoid valve further comprises at least one damping spring (8) arranged and designed between the first closure part (7a) and the second closure part (7b) to cushion the closing of the first port (1) and / or the second port (2).

5. Solenoid valve according to claim 4, characterized in that the armature (5) has a first through-opening (13a) in a section (5a), an axially extending side channel (14) and a second through-opening (13b) in a region (5b), wherein the section (5a) projects axially beyond the first closure part (7a) and the region (5b) is formed axially between the first closure part (7a) and the second closure part (7b) to provide pressure equalization between an inner region of the cylindrical armature (5) and the third port (3).

6. Solenoid valve according to claim 5, characterized in that the first through-hole (13a) and the second through-hole (13b) are identical bores.

7. Solenoid valve according to one of claims 4 to 6, characterized in that - the first and second closure part (7a, 7b) each have a head-shoulder area (17a, 17b) for closing the associated first or second connection (1, 2), - the anchor (5) has a radially projecting projection (5c) into the interior and at an opposite end an annular recess (5d) with a stop element (9), wherein the projection (5c) is designed to form a stop for the head-shoulder region (17a) of the first locking part (7a) and the recess (5d) is designed to allow, after insertion of the first locking part (7a), the damping spring (8) and the second The locking part (7b) is used to fix the second locking part (7b) in the axial direction via the stop element (9).

8. Solenoid valve according to claim 7, characterized in that the stop element (9) is a disc (9) which is fixed within the recess (5d) by an edge compression of the armature (5).

9. Solenoid valve according to one of claims 4 to 8, characterized in that the first closure part (7a) is identical in construction to the second closure part (7b) and only a damping spring (8) is arranged between the first closure part (7a) and the second closure part (7b), which pushes the first closure part (7a) and the second closure part (7b) away from each other.

10. Solenoid valve according to one of the preceding claims, wherein the solenoid valve has a chamber (15) into which the armature (5) together with the at least one closure part (7; 7a, 7b) are linearly movable and the first, second and third connection (1, 2, 3) provide a connection to the chamber (15), characterized in that - in a current-energized state of the coil (6) that at least one sealing element (7; 7a, 7b) closes the first terminal (1 ) and establishes a fluid connection via the chamber (15) between the second terminal (2) and the third terminal (3) and - in a state of the coil (6) that at least one closure part (7; 7a, 7b) closes the second terminal (2) and establishes a fluid connection via the chamber (15) between the first terminal (1 ) and the third terminal (3).

11. Method for manufacturing a solenoid valve according to any one of claims 1 to 10.

12. Method according to claim 11, characterized in that: - a first through-hole (13a) in a section (5a) and a second through-hole (13b) in a region (5b) of the anchor (5) is produced using the same tool, wherein the section (5a) projects axially beyond the first closure part (7a) and the region (5b) is formed axially between the first closure part (7a) and the second closure part (7b) to provide pressure equalization between an inner region of the cylindrical anchor (5) and the third connection (3).

13. Method according to claim 10 or claim 11, characterized in that the first and second closure part (7a, 7b) are identical in construction.

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