Electromagnetically operated valve

Abstract

Electromagnetically actuated valve, in particular pressure control valve for a slip-controllable vehicle brake system, with a seat body (16) forming a valve seat (18) which is equipped with at least one pressure medium supplying inflow channel (28) and one pressure medium discharging outflow channel (30), with a shut-off element (26, 26.1, 26.2) which interrupts a hydraulic short circuit between the inflow channel (28) and the outflow channel (30) and with a closing body (34) for controlling the valve seat (18), characterized by that the shut-off element (26.1, 26.2) is rigidly anchored in the valve (10) and comprises flow-directing means (72.1, 72.2) which cause the flow around the closing body (34) to be non-uniform in such a way that a resulting transverse force is produced which deflects the closing body (34) radially to a longitudinal axis XX of the valve (10) when the valve (10) is opened or closed.

Description

State of the art

[0001] The invention relates to an electromagnetically actuated valve, in particular a pressure control valve of a slip-controllable vehicle brake system, according to the features of the preamble of claim 1. Such valves are known, for example, from DE 10 2009 060 297 A1 with regard to their structural design. This known valve has a shut-off element that interrupts a hydraulic short circuit between the inflow channel and an outflow channel. Other such valves are known from DE 10 2010 002 469 A1 or DE 10 2011 079 339 A1.

[0002] The valve seat of these valves is controlled by a closing body. The flow against this closing body passes through the valve seat and is directed at its front end. This flow is largely centric, causing the pressure medium to flow evenly and symmetrically past the circumferential surface of the closing body. Studies have shown that this causes the closing body to vibrate radially, i.e., perpendicular to the longitudinal axis of the valve. The disadvantage of these radial vibrations is that they complicate pressure control through electronic control of such a valve in a pressure medium system. The radial vibrations therefore negatively impact the pressure control accuracy of the valve.

[0003] The invention aims to dampen these radial vibrations of the closing body by means of structurally simple and cost-effective measures that can be implemented on the valve and, indirectly, to improve the pressure control properties of a pressure medium system equipped with such a valve. Advantages of the invention

[0004] An electromagnetically actuated valve according to the features of claim 1 is equipped with a shut-off element that is rigidly anchored in the valve and comprises flow-directing means that cause the closing body to no longer be subjected to a central or symmetrical flow, but rather eccentrically or asymmetrically, so that the closing body is subjected to uneven flow. Depending on the orientation of the flow-directing means relative to the closing body, a greater or lesser volume of pressure medium flows past a segment of the entire circumference of the closing body, which consequently produces a resulting transverse force that deflects the closing body radially to its longitudinal axis when the valve is opened or closed. Because the shut-off element is rigidly anchored in the valve, the transverse force always acts on the closing body in the same radial direction, and the closing body is deflected in the same preferred direction with each movement stroke.

[0005] The flow-induced transverse force has a stabilizing effect on the stroke movement of the closing body by dampening the excitation of the closing body to radial vibrations. It can therefore be said that the stroke movement of the closing body is more controlled than in the prior art, thereby improving the control properties of the valve or a pressure medium circuit equipped with such a valve.

[0006] The subordinate claims 2 and 3 protect two embodiments of the invention. The flow-directing means on the shut-off element are technically simple and thus relatively inexpensive to implement. Simply replacing a known shut-off element with a shut-off element according to the invention is possible within the scope of ongoing series production without generating additional assembly costs.

[0007] In valves with multiple inflow channels that open into a common riser bore in the valve body, a flow-directing means according to the invention can be used to prevent partial flows from different inflow channels from directly colliding with one another and creating undesirable turbulence in the overall pressure medium flow to the closing body. By matching the cross-sections of the inflow bores to the dimensions of a gap between the outer circumference of the flow-directing means on the shut-off element and the wall of the riser bore, further homogenization or equalization of the flow is possible. This also applies to the dimensioning of a geometric distance between the end face of the flow-directing means and the valve seat orfor an angle of inclination at which an end face or a slot of the flow-directing means is inclined relative to a longitudinal axis of the valve and / or the manner in which this inclined end face is designed.

[0008] Further advantages or advantageous developments of the invention emerge from the subclaims or from the following description. drawing

[0009] Embodiments of the invention are illustrated in the drawings and explained in more detail in the following description. Regarding the overall structure of the valve and its function, reference is made to the disclosures in DE 10 2010 002 469 A1 and DE 10 2011 079 339 A1. Fig. 1 shows an electromagnetically actuated valve known from the cited prior art in longitudinal section; Fig. 2 shows a longitudinal section of a seat body of this valve, said seat body being equipped with a first embodiment of a shut-off element; Fig. 3: a seat body with inserted shut-off element according to Fig. 2 in perspective view and Fig. 4 a second embodiment of a shut-off element according to the invention, also in perspective view. Description of the embodiments

[0010] Fig. Figure 1 shows a longitudinal section of an electromagnetically actuated valve 10 known from the prior art. For the sake of clarity, a magnetic coil completing this valve 10 has been deliberately omitted. The valve 10 has a sleeve-shaped valve housing 12, in whose Fig. 1 upper, open end, a plug-shaped pole core 14 made of magnetically conductive material is inserted. This pole core 14 is firmly connected to the valve housing 12. A Fig. 1 lower open end of the valve housing 12 is closed by a seat body 16, which is also firmly connected to this valve housing 12. This seat body 16 forms a valve seat 18, which is arranged on the longitudinal axis XX of the valve 10 and is formed at the base of a first countersink 20 open towards the interior of the valve housing 12. The valve seat 18 itself is designed, for example, in the form of a conical seat. Opposite the countersink 20 open towards the interior of the valve housing 12, a second countersink 22 is formed on the seat body 16, which is open outwards towards the surroundings of the valve 10. The latter is located in a section of the seat body 16 whose outer diameter is reduced compared to the outer diameter of the seat body 16 in the region of the first countersink 20. A riser bore 24 running along the longitudinal axis XX of the valve 10 in the seat body 16 connects the two countersinks 20, 22 with one another.The riser bore 24 is closed off by a shut-off element 26 towards the second countersink 22, which is open to the outside. In this exemplary embodiment, this is a sphere which is matched to the diameter of the riser bore 24 in such a way that a press connection can be established between the shut-off element 26 and the wall of the riser bore 24. Above the shut-off element 26, a radially running inflow channel 28 opens into the riser bore 24. Several such inflow channels 28 are present in the circumferential direction of the riser bore 24, which is shown by a circular opening cross-section above the shut-off element 26 and offset to the left of the longitudinal axis XX of the valve. The valve seat 18 is located at the end of the riser bore 24 facing the first countersink 20. An outflow channel 30 can be seen radially offset from the riser bore 24 and running coaxially to the longitudinal axis XX of the valve 10.This outflow channel 30 also connects the two flat depressions 20, 22. A filter 32 is mounted on the outside of the seat body 16 at the level of the inflow channel 28. This filter consists of a frame-like filter body (not visible) with recesses covered by a filter fabric through which pressure medium flows into the inflow channel 28 of the valve 10. When the inflow channel 28 opens into the riser bore 24, this pressure medium flow is directed at a right angle, as shown in FIG. Fig. 1 is deflected upwards and directed to the valve seat 18. This valve seat 18 is according to Fig. 1 is closed by a closing body 34, so that no pressure medium can enter a pressure medium chamber 36 of the valve 10, which is located above the valve seat 18 and surrounded by the wall of the first countersink 20. With a lifting movement of the closing body 34, pressure medium flows through the valve seat 18 into this pressure medium chamber 36 and from there passes through a centrally arranged throttle opening 38 of a cap-shaped throttle element 40, which covers the open end of the first countersink 20, to a groove-shaped recess 42 in the wall of the first countersink 20. This recess 42 connects the first pressure medium chamber 36 to the outflow channel 30 of the valve 10 in a pressure-medium-conducting manner, wherein the pressure medium flow is deflected once again at a right angle after passing through the throttle opening 38 and flows opposite to the flow direction in the riser bore 24 according to Fig. 1 flows downwards out of the valve 10.

[0011] The closing body 34 for controlling the valve seat 18 is formed on a tappet 44, which is inserted with its end facing away from the valve seat 18 and thickened in the outer diameter into an associated longitudinal recess 46 of a sleeve-shaped valve armature 48 and is thus firmly connected to the valve armature 48. This valve armature 48 is guided in the valve housing 12 so as to be movable in the direction of the longitudinal axis XX of the valve 10. In the Fig. In the closed state of the valve 10 shown in Figure 1, a working air gap 54 is present between an end face 50 of the valve armature 48 facing away from the valve seat 18 and a pole core end face 52 opposite this end face 50, in which working air gap an annular disk-shaped plate spring 56 is accommodated. This plate spring is supported in the region of its outer diameter on the valve armature 48 and in the region of its inner diameter on the pole core 14. The plate spring 56 thus provides one of the force components with which the closing body 34 is pressed indirectly via the valve armature 48 against the valve seat 18. A second force component is provided by a spiral spring 58, which is accommodated inside the valve armature 48.This is supported on the one hand on the thickened end of the plunger 44 receiving the closing body 34 and on the other hand indirectly via a support bushing 60 on the pole core end face 52, wherein the support bushing 60 projects through a central opening of the annular disk-shaped plate spring 56.

[0012] A Fig. 1, a magnetic coil (not shown) is plugged onto the valve body, which can be electrically energized. A magnetic flux that occurs when this magnetic coil is energized causes magnetic attraction forces between the valve armature 48 and the pole core 14, due to which the valve armature 14 moves according to Fig. 1 moves upward toward the pole core 14, so that the originally existing working air gap 54 between these components decreases. Since the closing body 34 is firmly connected to the valve armature 48, the stroke of the valve armature 48 causes the closing body 34 to lift off the valve seat 18 and thus hydraulically connects the inflow channel 28 to the outflow channel 30 via the pressure medium chamber 36, the throttle opening 38 of the throttle element 40, and the recess 42.

[0013] The lifting movement of the valve armature 48 occurs against the restoring forces of the plate spring 56 and the spiral spring 58, which are further preloaded as a result of the lifting movement. With a withdrawal of the current supply to the solenoid coil or the removal of the magnetic forces, these spring forces cause the valve armature 48 to return to the Fig. 1, which is characterized by the fact that the closing body 34 is mechanically pressed onto the valve seat 18 and thus interrupts the pressure medium connection of the inflow channel 28 with the outflow channel 30.

[0014] Fig. Figure 2 shows the seat body 16 of the valve 10 with a shut-off element 26 designed according to the invention in longitudinal section. The geometry of the seat body 16 corresponds to that of the valve 10 according to Fig. 1, which is why functionally equivalent components have the same reference numerals as in Fig. 1.

[0015] In contrast to Fig. 1, this seat body 16 is provided with a first embodiment of a shut-off element 26.1 according to the invention. This shut-off element 26.1 is bolt-shaped and has a cylindrically shaped fastening section 70 and a likewise cylindrical flow-directing section 72.1 arranged coaxially with the fastening section 70. The fastening section 70 and the flow-directing section 72.1 are integral with one another, with the fastening section 70 having a larger outer diameter than the flow-directing section 72.1. A transition from the fastening section 70 to the flow-directing section 72.1 is formed, for example, as a rectangular shoulder 82. The shut-off element 26 is connected to the fastening section 70.1 is pressed into the riser bore 24 from the second countersink 22 of the seat body 16 and thus prevents a hydraulic short circuit between the at least one inflow channel 28 and the outflow channel 30 when the valve seat 18 is closed. The flow-directing section 72.1 adjoins the fastening section 70 towards the interior of the valve housing 12 and at least partially covers that area of ​​the seat body 26.1 at which the inflow channel or channels 28 open into the riser bore 24. Depending on the outer circumference of the flow-directing section 72.1 and the inner circumference of the wall of the riser bore 24, a more or less thick annular gap 74 is formed between the components into which the inflow channels 28 open. The annular gap 74 or an axial overlap of the mouth cross-sections of the inflow channels 28 by the flow-directing section 72.1 of the shut-off element 26.1 prevents partial pressure medium flows flowing in from different spatial directions from directly colliding and forming a highly turbulent total pressure medium flow, which ultimately flows against the closing body 34 of the valve 10. A front end 76 of the flow-directing section 72.1 of the shut-off element 26.1 is inclined to the longitudinal axis XX of the valve 10 or the seat body 16 at an angle of inclination that can be determined for the specific application. For example, the front end 76 forms an inclined, flat surface. However, it would also be conceivable for the front end 76 not to be flat, but rather to be convex or concave or crowned.

[0016] The shape and / or the inclination of the front end 76 of the flow-directing section 72.1 relative to the longitudinal axis XX of the valve 10 as well as the axial length and the diameter of the flow-directing section 72.1 of the shut-off element 26.1 can be used to determine the closing body 34 ( Fig. 1) direct the incoming flow of pressure medium in such a way that this flow is eccentric or asymmetrical and the valve armature 48 is thereby subjected to a stabilizing transverse force that dampens radial vibrations when it executes a lifting movement due to the magnetic force.

[0017] Fig. For ease of understanding, Fig. 3 shows the seat element 16 with the shut-off element 26.1 according to the invention again in a perspective view. The reference numerals from Fig. 1 and Fig. 2 were adopted for corresponding components. More clearly visible in this illustration are the valve seat 18 and the recess 42 in the wall and at the base of the first countersink 20 for the purpose of illustrating a fluid-conducting connection of this countersink 20 to the outflow channel 30 of the seat body 16 (not visible here).

[0018] In the second embodiment according to Fig. 4, the bolt-shaped shut-off element 26.2 is in contrast to the embodiment according to Fig. 2 and Fig. 3 is provided with a cylindrical flow-directing section 72.2, which has a horizontal, flat front end 76.2 and is further provided with a groove-shaped slot 78. The slot width of this slot is smaller than the outer diameter of the flow-directing section 72.2, whereby the slot 78 is bounded on both sides by remaining circumferential segments of the flow-directing section 72.2. The slot 78 extends over the entire length of the flow-directing section 72.2 and is open at the sides. With increasing distance from the fastening section 70, the slot depth of the slot 78 increases continuously, so that the slot base 80 forms a flat, inclined surface, the angle of inclination of which relative to the longitudinal axis XX of the shut-off element 26.2 can be determined for the specific application. The slot 78 acts similarly to the inclined front end 76.1 of the shut-off element 26.1 Fig. 2 or Fig. 3 flow-directing, by also ensuring that the flow to the closing body 34 ( Fig. 1) of a valve 10 equipped with such a shut-off element 26.2 is eccentric or asymmetrical. As already explained, the asymmetric flow to the closing body 34 dampens radial vibrations and the lifting movement of the valve armature 48 ( Fig. 1) stabilizing transverse force.

[0019] Of course, changes or additions to the described embodiments are possible without deviating from the basic idea of ​​the invention.

Claims

[1] Electromagnetically actuated valve, in particular pressure control valve for a slip-controllable vehicle brake system, with a seat body (16) forming a valve seat (18) which is equipped with at least one pressure medium supplying inflow channel (28) and one pressure medium discharging outflow channel (30), with a shut-off element (26, 26.1, 26.2) which interrupts a hydraulic short circuit between the inflow channel (28) and the outflow channel (30) and with a closing body (34) for controlling the valve seat (18), characterized by , that the shut-off element (26.1, 26.2) is rigidly anchored in the valve (10) and comprises flow-directing means (72.1, 72.2) which cause the flow around the closing body (34) to be non-uniform in such a way that a resulting transverse force is produced which deflects the closing body (34) radially to a longitudinal axis XX of the valve (10) when the valve (10) is opened or closed. [2] Electromagnetically actuated valve, in particular a pressure control valve for a slip-controllable vehicle brake system, with a seat body (16) forming a valve seat (18), which is equipped with at least one pressure medium supplying inflow channel (28) and one pressure medium discharging outflow channel (30) and with a shut-off element (26, 26.1, 26.2) which interrupts a hydraulic short circuit between the inflow channel (28) and the outflow channel (30), and flow-directing means (72.1, 72.2), characterized by , that the shut-off element (26.1, 26.2) is bolt-shaped and has a fastening section (70) and a flow-directing section (72.1, 72.2) which is reduced in its external dimensions compared to this fastening section (70), and wherein the flow-directing section (72.1, 72.2) of the shut-off element (26.1, 26.2) has a front end (76.1) facing the valve seat (18) which is inclined at an angle of inclination relative to a longitudinal axis XX of the valve (10). [3] Electromagnetically actuated valve, in particular a pressure control valve for a slip-controllable vehicle brake system, with a seat body (16) forming a valve seat (18), which is equipped with at least one pressure medium supplying inflow channel (28) and one pressure medium discharging outflow channel (30) and with a shut-off element (26, 26.1, 26.2) which interrupts a hydraulic short circuit between the inflow channel (28) and the outflow channel (30) and comprises flow-directing means (72.1, 72.2), characterized by , that the shut-off element (26.1, 26.2) is bolt-shaped and has a fastening section (70) and a flow-directing section (72.1, 72.2) which is reduced in its external dimensions compared to this fastening section (70), and wherein the flow-directing section (72.2) of the shut-off element (26.2) has a slot (78) extending at an angle of inclination to its longitudinal axis XX. [4] Electromagnetically actuated valve according to claim 1, 2 or 3, characterized by that the flow-directing means (72.1, 72.2) are formed in one piece with the shut-off element (26.1, 26.2). [5] Electromagnetically actuated valve according to claim 4, characterized by that on the shut-off element (26.1, 26.2) a transition from the fastening section to the flow-directing section (72.1, 72.2) is preferably designed as a right-angled shoulder (82). [6] Electromagnetically actuated valve according to claim 2 or 3, wherein the at least one inflow channel (28) extends radially to the longitudinal axis XX of the seat body (16) and opens into a riser bore (24), at one end of which the valve seat (18) is formed and wherein the riser bore (24) extends parallel to the outflow channel (30) in the direction of the longitudinal axis XX of the seat body (16), characterized by that the flow-directing section (72.1, 72.2) of the shut-off element (26.1, 26.2) at least partially covers that region of the riser bore (24) at which the inflow channel or the inflow channels (28) open into this riser bore (24). [7] Electromagnetically actuated valve according to claim 6, characterized by that the shut-off element (26.1, 26.2) is anchored, preferably pressed in, by a fastening section (70) at the end of the riser bore (24) opposite the valve seat (18) in a force-fitting, form-fitting and / or material-fitting manner. [8] Electromagnetically actuated valve according to claim 2, characterized by that the front end (76.1) of the shut-off element (26.1) reaches at least partially to the valve seat (18) of the seat body (16).

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