Electromagnetically operated valve with pole plate and use of the valve as a regeneration valve

Abstract

Electromagnetically actuated valve (1), comprising a pole plate (12) which comprises a base body with a receptacle (17) for a sliding bushing (11), wherein the pole plate (12) receives a sliding bushing (11) therein and wherein an armature (4) is guided in the sliding bushing (11), which armature removes a seal from a sealing seat (6) or supplies it thereto, characterized in that the base body comprises a sintered material or is made of a sintered material, wherein the receptacle (17) is designed in the manner of a sleeve with a cylindrical passage (20) and wherein jaws (18) protrude from both sides of the receptacle (17).

Description

[0001] The invention relates to a valve according to the preamble of claim 1.

[0002] DE 690 11 728 T2 discloses such a valve, in which a magnetically conductive part is arranged between two flanges of a plastic coil body, with an armature arranged with a sliding fit in a bore of the coil body. DE 33 35 169 A1 shows a valve in which an armature and a pole piece are made of sintered iron.

[0003] An electromagnetically actuated valve is opened or closed by an electromagnetic device actively moving a sealing elastomer or a sealing body. In such a valve, currents are passed through a coil to generate a magnetic field, whose magnetic force actively moves an armature. The movement of the armature is used to actively move the sealing body to open or close a sealing seat, thus allowing or preventing fluid flow.

[0004] A valve of this type is known, for example, from DE 10 2012 013 820 B3. Valves of this type are used to meter fuel vapor from a motor vehicle's activated carbon filter and are typically made of robust, easy-to-manufacture, and cost-effective components.

[0005] A particularly important component of such a valve is the so-called pole plate, which performs both mechanical and magnetic functions. The pole plate typically accommodates a sliding bushing and positions and centers the sliding bushing relative to a pole core. The pole plate conducts a magnetic flux between a magnetic return bar and the sliding bushing, enabling a mechanical connection to the magnetic return bar.

[0006] Currently, pole plates are manufactured from deep-drawn sheet metal. However, this comes with several disadvantages. Precise manufacturing at acceptable costs is only possible to a limited extent. The mechanical strength, especially dimensional stability, of an overmolding process cannot always be optimal due to the strong forces exerted while the plastic flows around a valve coil.

[0007] The invention is therefore based on the object of providing a dimensionally stable pole plate for use in an electromagnetically actuated valve, which can be connected to another material largely without problems.

[0008] The present invention solves the above-mentioned problem by the features of patent claim 1.

[0009] According to the invention, it was initially recognized that a metal sintering process represents a particularly cost-effective manufacturing method for producing a pole plate. Such a pole plate, which comprises sintered material or is made entirely of such a material, is mechanically stable and exhibits high dimensional stability, particularly when overmolded with a plastic, especially a hot and / or viscous plastic. Such a pole plate can also be made of a material with particularly good magnetic conductivity or comprise such a material.

[0010] Advantageously, such a pole plate can be stably positioned and centered relative to a pole core. The pole plate exhibits high dimensional accuracy, is very easy to reproduce, and ensures a high degree of process reliability. The diameter of the support for the sliding bushing can be specified very precisely and manufactured with very tight tolerances. Such a pole plate also offers design freedom with regard to wall thicknesses or the type of connection to a valve's return bar. The invention ensures optimal raw material utilization during pole plate production.

[0011] The base body could be made of or comprise a material containing 50 to 100 weight percent, preferably 99.39 to 100 weight percent, iron with admixtures of less than or up to 0.01 weight percent carbon, less than or up to 0.1 weight percent oxygen, and 0 to 0.5 weight percent phosphorus. The lower limits for carbon and oxygen are 0 weight percent. Such a material is particularly suitable for sintering or for use as a sintered metal. These compositions represent a successful approach among the many known compositions of sintered metals.

[0012] The base body could be made of a material or have a material that has a density in the range of 7.0 g / cm 3 up to 7.5 g / cm 3 Such a material is particularly suitable for use in motor vehicles because it allows for weight savings.

[0013] The base body could comprise the above-mentioned materials with the above-mentioned compositions, including iron, carbon, oxygen, and phosphorus, be made of them, or comprise or be made of a material that exhibits a magnetic flux density of 1.5 T to 1.8 T at 20,000 A / m. Such a material allows the armature of a sealing device to respond particularly well to a magnetic field generated by a coil, so that it can be moved easily and without problems by the magnetic field.

[0014] The pole plate could have a corrosion-inhibiting, preferably electroplated, surface coating containing zinc with a layer thickness in the range of 8-15 µm. Such a coating is sufficiently thin and light, yet effective against corrosion. The surface coating is preferably a galvanic zinc coating, a galvanic zinc-iron alloy coating, or a galvanic zinc-nickel alloy coating.

[0015] The mount is sleeve-like with a cylindrical passage, with jaws protruding from both sides. A cylindrical sliding bushing can be easily pressed into the passage, and the jaws can form a positive and / or material fit with the plastic.

[0016] An electromagnetically actuated valve comprises the pole plate of the type described here, wherein the pole plate accommodates a sliding bushing, and wherein an armature is guided in the sliding bushing, which removes a seal from or supplies it to a sealing seat. Said pole plate can be manufactured with high precision and exhibits excellent mechanical and magnetic properties.

[0017] The pole plate could be firmly bonded to a plastic sheath. This allows the pole plate to be molded tightly with a plastic. The valve can be largely enclosed by the plastic sheath.

[0018] A coil could enclose a pole core, with a stop pin engaging the pole core on the side facing the armature, against which the armature rests under spring load and / or against which the armature can be abutted. A stop pin can be made of a different material than the pole core. This allows for optimized magnetic flux conditions.

[0019] A valve of the type described here could be used as a regeneration valve for degassing or venting a motor vehicle's activated carbon canister. Valves of this type are used to meter fuel vapor from a motor vehicle's activated carbon canister.

[0020] In the drawing show Fig. 1 in the left view a section through an electromagnetically actuated valve, which has a connection piece to an engine of a motor vehicle and a connection piece to an activated carbon container of the motor vehicle, and in the right view a sectional detail of the sealing area together with the electromagnetic device for actuating a movable armature according to the prior art, Fig. 2 a side sectional view of a valve with a pole plate made of a sintered metal, Fig. 3 a sectional detailed view of the sealing area of ​​the valve according to Fig. 2 together with the electromagnetic device for actuating a movable armature, Fig. 4 a top view of the sintered metal pole plate and Fig. 5 a perspective view of the pole plate according to Fig. 4.

[0021] Fig. 1 shows in Fig. 1a shows a section through an electromagnetically actuated valve 1' of the prior art, which has a connection piece 2 to an engine of a motor vehicle (not shown) and a connection piece 3 to an activated carbon container of the motor vehicle.

[0022] Fig. 1 shows in Fig. 1b a sectional detailed view of the sealing area together with the electromagnetic device for actuating a movable armature 4 of the valve 1' according to Fig. 1a.

[0023] The armature 4 is firmly and positively connected to a sealing elastomer 5, so that by moving the armature 4, the sealing elastomer 5 can be lifted from a sealing seat 6. This creates a fluid-conducting connection between the two connecting pieces 2, 3, which are Fig. 1a are shown.

[0024] When an electric current is passed through the coil 7, the armature 4 is pulled upwards in the plane of the drawing toward a pole core 8. The density elastomer 5 or the armature 4 are lifted against the contact force of a spring 9, in this case a spiral spring. As soon as the magnetic field of the coil 7 exerts a force on the armature 4 that exceeds the contact force of the spring 9, the density elastomer 5 lifts off the sealing seat 6 and establishes the aforementioned fluid connection. An adjustment screw 10 is also provided, with which the contact force of the spring 9 can be adjusted. The armature 4 is guided in a sliding bushing 11, and the sliding bushing 11 is enclosed by a pole plate 12' of the prior art.

[0025] Fig. 2 shows a valve 1 with a pole plate 12 made of a sintered metal. Fig. Figure 2 shows a section through the electromagnetically actuated valve 1, which has a connection piece 2 to an engine of a motor vehicle (not shown) and a connection piece 3 to an activated carbon canister of the motor vehicle. The valve 1 further has an electrical connection 13, which protrudes from the valve 1 in the same direction as the connection piece 3 to the activated carbon canister.

[0026] Fig. Figure 3 shows, in a partial sectional view, that the valve 1 has a pole plate 12 made of sintered metal, which accommodates the sliding bushing 11, so that the sliding bushing 11 protrudes neither upwards nor downwards beyond the pole plate 12. The armature 4 is guided in the sliding bushing 11. The coil 7 surrounds the pole core 8, which in turn accommodates a stop pin 14, against which the armature 4 is resiliently supported.

[0027] The armature 4 is firmly and positively connected to a sealing elastomer 5, so that by moving the armature 4, the sealing elastomer 5 can be lifted from a sealing seat 6. This creates a fluid-conducting connection between the two connecting pieces 2, 3, which are Fig. 2 are shown.

[0028] When an electric current is passed through the coil 7, the armature 4 is pulled upwards in the plane of the drawing toward the pole core 8. The density elastomer 5 and the armature 4 are lifted against the contact force of the spring 9, in this case a spiral spring. As soon as the magnetic field of the coil 7 exerts a force on the armature 4 that exceeds the contact force of the spring 9, the density elastomer 5 lifts from the sealing seat 6 and establishes the aforementioned fluid connection. The armature 4 is guided in the sliding bushing 11, and the sliding bushing 11 is enclosed by the pole plate 12.

[0029] The coil 7 is surrounded by a return bar 15. A plastic overmolding or plastic sheath 16 is provided, which at least partially surrounds the coil 7, the return bar 15, and the pole plate 12 and connects them to one another in a form-fitting and / or material-fitting manner.

[0030] Fig. 4 and Fig. 5 show the pole plate 12. A sleeve-like receptacle 17 with a cylindrical passage 20 can accommodate the cylindrical sliding bush 11 according to Fig. 3 concentrically. Two jaws 18 protrude from the receptacle 17 in diametrically opposite directions, the surfaces 19 of which are projected beyond the receptacle 17 on one side, namely the side facing the sealing seat 6. This is shown in Fig. 3 particularly clearly visible.

[0031] This pole plate is for an electromagnetically actuated valve 1 according to Fig. 2 and Fig. 3 and comprises a base body with a receptacle 17 for its sliding bushing 11. The base body is made of a sintered material. The base body is made of a material that contains iron with admixtures of less than or up to 0.01 weight percent carbon, less than or up to 0.1 weight percent oxygen, and 0 to 0.5 weight percent phosphorus. The material has a density in the range of 7.0 g / cm 3 up to 7.5 g / cm 3 The base body is made of a material that allows a magnetic flux density of 1.5T to 1.8T at 20,000 A / m.

[0032] The pole plate 12 has a corrosion-inhibiting galvanic surface coating with a layer thickness in the range of 8-15 µm, which contains zinc.

[0033] The receptacle 17 is sleeve-like with a cylindrical passage 20, with the above-mentioned jaws 18 projecting from the receptacle 17 on both sides.

[0034] Fig. 2 and Fig. 3 show an electromagnetically actuated valve 1, comprising the pole plate 12, wherein the pole plate 12 receives the sliding bushing 11 and wherein the armature 4 is concentrically guided in the sliding bushing 11, which removes a seal, here a sealing elastomer 5, from a sealing seat 6 or supplies it to it.

[0035] The pole plate 12 is integrally bonded to a plastic casing 16. The plastic casing 16 also encloses the return loop 15 and the coil 7.

[0036] The coil 7, in turn, surrounds the pole core 8, with a stop pin 14 engaging in the pole core 8 on the side facing the armature 4, against which the armature 4 is spring-loaded and against which the armature 4 can be abutted. The stop pin 14 is arranged concentrically to the pole core 8, the armature 4, the sliding bushing 11, and the receptacle 17 of the pole plate 12.

[0037] Valve 1 is used as a regeneration valve for degassing or venting an activated carbon canister of a motor vehicle. Reference symbol 1, 1' valve 2 connection ports to the engine 3 connection pieces to the activated carbon container 4 anchors 5 Density elastomer 6 Sealing seat 7 coil 8 Poker 9 spring 10 Adjustment screw 11 sliding bushing 12, 12' pole plate 13 electrical connection 14 Stop pin 15 return bracket 16 Plastic covering 17 recording 18 cheeks 19 Surface 20 passage of 17

Claims

[1] Electromagnetically actuated valve (1), comprising a pole plate (12) which comprises a base body with a receptacle (17) for a sliding bushing (11), wherein the pole plate (12) accommodates a sliding bushing (11) and wherein an armature (4) is guided in the sliding bushing (11), which removes a seal from a sealing seat (6) or supplies it to it, characterized by that the base body comprises a sintered material or is made of a sintered material, wherein the receptacle (17) is sleeve-like with a cylindrical passage (20) and wherein jaws (18) protrude from both sides of the receptacle (17). [2] Electromagnetically actuated valve (1) according to claim 1, characterized bythat the base body is made of or comprises a material which contains iron with admixtures of less than or up to 0.01% by weight of carbon, less than or up to 0.1% by weight of oxygen and 0 to 0.5% by weight of phosphorus. [3] Electromagnetically actuated valve (1) according to claim 1 or 2, characterized by that the base body is made of a material or has a material which has a density in the range of 7.0 g / cm 3 up to 7.5 g / cm 3 has. [4] Electromagnetically actuated valve (1) according to one of the preceding claims, characterized by that the base body is made of a material or has a material which allows a magnetic flux density of 1.5 T to 1.8 T at 20000 A / m. [5] Electromagnetically actuated valve (1) according to one of the preceding claims, characterized bya corrosion-inhibiting surface coating of the pole plate (12) with a layer thickness in the range 8-15 µm, which contains zinc. [6] Electromagnetically actuated valve (1) according to one of the preceding claims, characterized by that the pole plate (12) is integrally connected to a plastic sheath (16). [7] Electromagnetically actuated valve (1) according to one of the preceding claims, characterized by that a coil (7) surrounds a pole core (8), wherein a stop pin (14) engages in the pole core (8) on the side facing the armature (4), against which the armature (4) is supported in a spring-loaded manner and / or against which the armature (4) can be struck. [8] Use of an electromagnetically actuated valve (1) according to one of claims 1 to 7 as a regeneration valve for degassing or venting an activated carbon container of a motor vehicle.

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