SOLENOID VALVE

Description

[0001] The invention relates to an electromagnetic valve comprising an electromagnet containing at least one magnetic coil, a magnet armature, a pole core, a magnetic yoke and a housing closing the magnetic circuit, and a valve assembly containing at least one valve sleeve, a valve spool and a return spring, wherein the valve assembly is completely enclosed by the housing.

[0002] Prior art publications such as DE 10 2012 010 986 A1 and DE 10 2014 015 559 A1 describe solenoid valves whose valve assemblies are enclosed within the solenoid housing. Manufacturing these solenoid valves is complex, and the frictional friction that occurs during operation of the solenoids reduces the accuracy of the functional chain generated by the solenoid valves.

[0003] It is an object of the present invention to simplify the manufacture of the solenoid valve and to make it more cost-effective and, in a further development of the invention, to reduce the solid friction between the moving components.

[0004] These problems are solved by the features of the first patent claim, and the subclaims develop this solution.

[0005] The invention includes the technical teaching that the pole core consists of an outer magnetic pole and a valve sleeve encompassed by the magnetic pole, wherein between the valve sleeve and the magnetic pole, at least two fluid channels run in the axial direction of said components in fluid-tightly delimited zones on the circumference of the valve sleeve.

[0006] The valve sleeve has at least two cavities, preferably transverse bores, running at right angles to the central axis of the valve sleeve, which are fluidically connected to the above-mentioned fluid channels and, in cooperation with the control edges of the valve spool, determine the function of the valve assembly depending on the axial position of the valve spool.

[0007] The fluid channels arranged between the valve sleeve and the magnetic pole provide a very cost-effective fluidic connection between the transverse bores in the valve sleeve and the fluidic connections, and the transverse bores cost-effectively generate control edges which interact with the control edges of the valve spool to open or close the valve.In this way, pressure control functions, throttle functions or switching functions can be represented as valve functions in a known manner, whereby throttle functions and switching functions act in a known manner via the stroke of the valve spool generated by the electromagnet against the force of the return spring, while pressure control functions are achieved in a known manner by mechanically comparing a pressure force acting on the valve spool with the force of the electromagnet also acting on the valve spool, and the valve spool stroke resulting from the force difference releases fluid flows from the P port to the A port or from the A port to the T port.

[0008] The dependent claims contain advantageous developments of the invention.

[0009] Advantageously, in a first embodiment, the at least two fluid channels for the connections P and T run in cavities of the magnetic pole, wherein the axial lengths of the cavities are dimensioned such that, on the one hand, there is a fluid connection to a sealed flange zone of a flange surface and, on the other hand, there is a fluid connection to the transverse bores in the valve sleeve and, furthermore, a fluid connection of the connection P to an armature chamber of the electromagnet is blocked.

[0010] The ports P and T are connected to the flange zones of the flange surface, and the armature chamber of the electromagnet is preferably connected to the port T, via the fluid channel emanating from the port T or via another fluidic connection.

[0011] A particularly cost-effective way to create the fluid channels in the cavities of the magnetic pole is to produce the magnetic pole through a sintering process, with the fluid channels being created by the pressing tool. In this design, the third fluid channel for port A is represented by a central bore in the valve sleeve, which also accommodates the valve spool. In this design, the third fluid channel does not require any additional cavity.

[0012] In a second advantageous embodiment, the fluid channels for the connections P and T run in flats and / or in grooves of the valve sleeve, wherein the axial lengths of the flats are also dimensioned such that, on the one hand, there is a fluid connection to a sealed flange zone of a flange surface and, on the other hand, there is a fluid connection to the transverse bores in the valve sleeve and, furthermore, a fluidic connection of the connection P to the armature space is blocked.

[0013] In this second design, no axial or inclined holes are required for the fluid channels P and T.

[0014] The axially extending fluid channels mentioned are preferably designed as flats, but if larger cross sections are required or flats are to be excluded for manufacturing reasons, they are designed as grooves or both flats and grooves are provided.

[0015] In a variant of the first embodiment, not just two, but three fluid channels for the connections P, T and A run in cavities of the magnetic pole, wherein the lengths of the cavities are dimensioned such that, on the one hand, there is a fluid connection to a sealed flange zone of a flange surface and, on the other hand, there is a fluid connection to the first and second transverse bores and to a third transverse bore in the valve sleeve and, furthermore, a fluid connection of the connections P and A to the armature space of the electromagnet is blocked.

[0016] In this variant of the first design, all three flange zones on the flange surface are arranged at the same distance from the center of the flange surface, thus providing more space for port A. Here, the designer has the freedom to apply the pressure of port A to one end face of the valve spool or not, depending on the design of the valve spool and the function of the valve.

[0017] In a variant of the second embodiment, three fluid channels for the connections P, T and A run in flattened portions of the valve sleeve, wherein the lengths of the flattened portions are again dimensioned such that, on the one hand, there is a fluid connection to a sealed flange zone of a flange surface and, on the other hand, there is a fluid connection to the first and second transverse bores and a third transverse bore in the valve sleeve and, furthermore, a fluid connection of the connections P and A to the armature space is blocked.

[0018] In an advantageous embodiment, the magnet armature is radially supported on one side by a bearing and on the other side by a slide head of the valve slide. The magnet armature contacts the slide head with a conical surface, and radial forces can be transferred from the magnet armature to the slide head. This design allows for a high degree of accuracy in the relative radial position of the magnet armature to the magnetic pole, cost-effectively, without requiring additional support for the magnet armature in the magnetic pole. The solid-state friction at the magnet armature is particularly low in this design.

[0019] In another advantageous embodiment, the effective length of the bearing for supporting the magnet armature corresponds to at least one third of the length of the magnet armature, preferably half the length and more preferably 70% of the length, wherein the magnet armature touches the slide head of the valve slide with a flat surface, and wherein the valve slide has a flattened slide head which only allows a transmission of an axial compressive force from the magnet armature to the slide head.

[0020] This design is a proven belly mounting of the magnet armature, the flattened slide head prevents the transmission of radial forces to the valve slide, which, due to its small diameter play relative to the valve sleeve, can only absorb small radial forces if its solid body friction is to remain small.

[0021] In the first embodiment of the solenoid valve, the flange surface has three flange zones, wherein the third flange zone is fluidically connected to a central bore in the valve sleeve which accommodates the valve spool, and wherein the three flange zones are sealed from each other and from the environment by a molded seal.

[0022] The use of the molded seal simplifies the assembly of the solenoid valve with another device that supports the solenoid valve and contains the aforementioned fluid lines.

[0023] In the second version of the solenoid valve, the three flange zones are also sealed against each other and the environment by a molded seal, but there is no central flange zone for port A. The flange zone for port A can be larger in this second version than in the first version.

[0024] Advantageously, the molded seal contains three filter mats arranged in the flange zones and bonded to the material of the molded seal either force-fitting, form-fitting, or material-fitting. Arranging the filters as filter mats in the molded seal simplifies assembly and thus reduces manufacturing costs.

[0025] The electromagnetic valve according to the invention can be used, for example, as a pressure control valve in the design of a three-way pressure control valve, wherein a first volume with a fluid pressure to be controlled is connected to the connection A, a second volume with a supply pressure is connected to the connection P and a line leading to a storage tank is connected to the connection T.

[0026] In the solenoid valve on the valve spool, a force comparison is made between the force of the electromagnet and the pressure force of the fluid at port A, wherein, in the event that the force of the electromagnet predominates, a fluidic connection is made between port P and port A in the valve assembly, and wherein, in the event that the said pressure force predominates, a fluidic connection is made between port A and port T.

[0027] The solenoid valve according to the invention can also be used in a known manner as a fluidic switching valve (also called directional control valve) with a suitable design of the components of the valve assembly, in that when the electromagnet in the valve assembly is not energized, there is a fluidic connection between the port A and the port T and / or when the electromagnet in the valve assembly is sufficiently energized, there is a fluidic connection between the port P and the port A.

[0028] It is also possible to use the invention in a way that, when the electromagnet in the valve assembly is not energized, it provides a fluidic connection between the port P and the port A and / or when the electromagnet in the valve assembly is sufficiently energized, it provides a fluidic connection between the port A and the port T.

[0029] The electromagnet is sufficiently energized if the magnetic force resulting from the energization is sufficient under all intended operating conditions to move the valve spool from a rest position to a working position against the force of the return spring, against the acting pressure forces of the connected fluid volumes and against the frictional forces on the valve spool, whereby in the working position the fluidic connection exists between the port P and the port A.

[0030] With a suitable design, the directional control valve can also be operated proportionally in a conventional manner. In this case, the electric current through the solenoid coil corresponds to a proportional stroke of the valve spool, which in turn determines the fluid connections through the valve assembly. The valve spool is designed in such a way that it has no effective area for the connected pressures at ports A and P.

[0031] Further details, features and advantages of the invention will become apparent from the following description with reference to the drawing.

[0032] It shows: Figure 1 a sectional view of the first embodiment of the solenoid valve, Figure 2 a sectional view of the second embodiment of the solenoid valve Figure 3 a sectional view of the third embodiment of the solenoid valve Figure 4 a view of the molded seal of the first embodiment with the filter mat Figure 5 a view of the molded seal of the second embodiment Figure 6 a sectional view of the fourth embodiment of the solenoid valve

[0033] Figure 1shows an inventive solenoid valve 1, which has an electromagnet 2 containing a solenoid coil 3, a magnet armature 4, a pole core 5, a magnet yoke 6, and a housing 7 closing the magnetic circuit. The solenoid valve 1 further comprises a valve assembly 10 containing a valve sleeve 11, a valve spool 12, and a return spring 13, wherein the valve assembly 10 is completely enclosed by the housing 7.

[0034] The pole core 5 consists of an outer magnetic pole 8 and a valve sleeve 11 enclosed by the magnetic pole 8, wherein at least two fluid channels 14, 15 extend in the axial direction between the valve sleeve 11 and the magnetic pole 8 in fluid-tightly delimited zones on the circumference of the valve sleeve 11.

[0035] The valve sleeve 11 has at least two transverse bores 17, 18 which are fluidically connected to the fluid channels 14, 15 and, in cooperation with control edges of the valve spool 12, perform the valve function depending on an axial position of the valve spool 12.

[0036] In the design of the solenoid valve 1 according to Figure 1 the at least two fluid channels 14, 15 for the connections P and T run in cavities 28, 29 of the magnetic pole 8, wherein the axial lengths of the cavities 28, 29 are dimensioned such that, on the one hand, there is a fluid connection to a sealed flange zone 21, 22 of a flange surface 20 and, on the other hand, there is a fluid connection to the transverse bores 17, 18 in the valve sleeve 11 and, furthermore, a fluid connection of the connection P to the armature chamber 24 is blocked.

[0037] In the design of the solenoid valve 1 according to Figure 2the fluid channels 14, 15 for the connections P and T run in flattened portions 25, 26 of the valve sleeve 11, wherein the axial lengths of the flattened portions 25, 26 are dimensioned such that, on the one hand, there is a fluid connection to a sealed flange zone 21, 22 of a flange surface 20 and, on the other hand, there is a fluid connection to the transverse bores 17, 18 in the valve sleeve 11 and, furthermore, a fluidic connection of the connection P to the armature chamber 24 is blocked.

[0038] In the design of the solenoid valve 1 according to Figure 3Three fluid channels 14, 15, 16 for the connections P, T and A run in cavities 28, 29, 30 of the magnetic pole 8, wherein the axial lengths of the cavities 28, 29, 30 are dimensioned such that, on the one hand, there is a fluid connection to a sealed flange zone 21, 22, 23 of a flange surface 20 and, on the other hand, there is a fluid connection to the first and second transverse bores 17, 18 and to a third transverse bore 19 in the valve sleeve 11 and, furthermore, a fluid connection of the connections P and A to the armature chamber 24 is blocked.

[0039] In a further embodiment not shown, three fluid channels 14, 15, 16 for the connections P, T and A run in flattened portions 25, 26, 27 of the valve sleeve 11, wherein the lengths of the flattened portions 25, 26, 27 are dimensioned such that, on the one hand, there is a fluid connection to a respective sealed flange zone 21, 22, 23 of a flange surface 20 and, on the other hand, there is a respective fluid connection to the first and second transverse bores 17, 18 and a third transverse bore 19 in the valve sleeve 11 and, furthermore, a respective fluid connection of the connections P and A to the armature chamber 24 is blocked.

[0040] In the versions of the solenoid valve 1 according to Figure 1 the magnet armature 4 is radially mounted on the one hand in a bearing 32 and on the other hand in a slide head 9 of the valve slide 12, wherein the magnet armature 4 touches the slide head 9 with a conical surface, and wherein radial forces can be transferred from the magnet armature 4 to the slide head 9.

[0041] In the design of the solenoid valve 1 according to Figure 6 the effective length of the bearing 32 for supporting the magnet armature 4 corresponds to at least one third of the length of the magnet armature 4, preferably half the length and more preferably 70% of the length, wherein the magnet armature 4 touches the slide head 9 of the valve slide 12 with a flat surface and wherein the valve slide 12 has a flattened slide head 9 which only allows a transmission of an axial compressive force from the magnet armature 4 to the slide head 9.

[0042] In the design of the solenoid valve 1 according to Figure 1 and Figure 2 the flange surface 20 has three flange zones 21, 22, 23, wherein the third flange zone 23 is fluidically connected to a central bore 31 in the valve sleeve 11, which receives the valve slide 12, and wherein the three flange zones 21, 22, 23 are separated from each other and from the environment by a Figure 4shown shaped seal 35 are sealed.

[0043] The Figure 5 shows the molded seal for a solenoid valve in the design according to Figure 3 , whereby here too the three flange zones 21, 22, 23 are sealed against each other and against the environment by a shaped seal 35.

[0044] In the versions of the molded seal 35 according to the Figures 4 and 5 The shaped seal 35 contains three filter mats 36, 37, 38, which are arranged in the flange zones 21, 22, 23 and are connected to the material of the shaped seal in a force-fitting, form-fitting or material-fitting manner.

[0045] The foregoing description of the present invention is for illustrative purposes only and not for the purpose of limiting the invention. Various changes and modifications are possible within the scope of the invention without departing from the spirit and scope of the invention as defined by the subject matter of the appended claims. List of reference symbols

[0046] 1 Solenoid valve 2 Electromagnet 3 Solenoid coil 4 Armature 5 Pole core 6 Magnetic yoke 7 Housing 8 Magnetic pole 9 Spool head 10 Valve assembly 11 Valve sleeve 12 Valve spool 13 Return spring 14 First fluid channel 15 Second fluid channel 16 Third fluid channel 17 First cross bore 18 Second cross bore 19 Third cross bore 20 Flange face 21 First flange zone 22 Second flange zone 23 Third flange zone 24 Armature chamber 25 First flat 26 Second flat 27 Third flat 28 First cavity 29 Second cavity 30 Third cavity 31 Bore 32 Bearing 35 Molded seal 36 Filter mat 37 Filter mat 38 Filter mat

Claims

1. Solenoid valve (1) having an electromagnet (2) which contains at least one magnet coil (3), a magnet armature (4), a pole core (5), a magnet yoke (6) and a housing (7) closing the magnetic circuit, and a valve assembly (10) which contains at least one valve sleeve (11), a valve slide (12) and a restoring spring (13), wherein the valve assembly (10) is surrounded in its axial extent by the housing (7), characterized in that the pole core (5) consists of an outer magnetic pole (8) and a valve sleeve (11) surrounded by the magnetic pole (8), wherein at least two fluid channels (14, 15) run in the axial direction between the valve sleeve (11) and the magnetic pole (8) in fluid-tightly delimited zones on the periphery of the valve sleeve (11) and / or within the magnetic pole (8), and wherein the valve sleeve (11) has at least two transverse bores (17, 18) or other cavities which run perpendicularly with respect to the centre axis of the valve sleeve (11), are fluidically connected to the fluid channels (14, 15) and interact with control edges of the valve slide (12) in a manner dependent on an axial position of the valve slide (12).

2. Solenoid valve (1) according to Claim 1, characterized in that the at least two fluid channels (14, 15) for the connectors P and T run in cavities (28, 29) of the magnetic pole (8), wherein the axial lengths of the cavities (28, 29) are dimensioned in such a way that firstly there is a fluid connection to in each case one sealed flange zone (21, 22) of a flange surface (20), and secondly there is in each case a fluid connection to the transverse bores (17, 18) in the valve sleeve (11), and, furthermore, a fluid connection of the connector P to an armature space (24) is blocked.

3. Solenoid valve (1) according to Claim 1, characterized in that the fluid channels (14, 15) for the connectors P and T run in flattened portions (25, 26) and / or grooves of the valve sleeve (11), wherein the axial lengths of the flattened portions (25, 26) and / or grooves are dimensioned in such a way that firstly there is a fluid connection to in each case one sealed flange zone (21, 22) of a flange surface (20), and secondly there is in each case a fluid connection to the transverse bores (17, 18) in the valve sleeve (11) and, furthermore, a fluid connection of the connector P to the armature space (24) is blocked.

4. Solenoid valve (1) according to Claim 1, characterized in that three fluid channels (14, 15, 16) for the connectors P, T and A run in cavities (28, 29, 30) of the magnetic pole (8), wherein the lengths of the cavities (28, 29, 30) are dimensioned in such a way that firstly there is a fluid connection to in each case one sealed flange zone (21, 22, 23) of a flange surface (20), and secondly there is in each case a fluid connection to the first and the second transverse bore (17, 18) and to a third transverse bore (19) in the valve sleeve (11), and, furthermore, in each case a fluid connection of the connectors P and A to the armature space (24) is blocked.

5. Solenoid valve (1) according to Claim 1, characterized in that three fluid channels (14, 15, 16) for the connectors P, T and A run in flattened portions (25, 26, 27) and / or grooves of the valve sleeve (11), wherein the lengths of the flattened portions (25, 26, 27) and / or grooves are dimensioned in such a way that firstly there is a fluid connection to in each case one sealed flange zone (21, 22, 23) of a flange surface (20), and secondly there is in each case a fluid connection to the first and the second transverse bore (17, 18) and a third transverse bore (19) in the valve sleeve (11), and, furthermore, in each case a fluid connection of the connectors P and A to the armature space (24) is blocked.

6. Solenoid valve (1) according to one of the preceding claims, characterized in that the magnet armature (4) is radially mounted firstly in a bearing (32) and secondly by a slide head (9) of the valve slide (12), wherein radial forces can be transmitted from the magnet armature (4) to the slide head (9).

7. Solenoid valve (1) according to one of Claim 6, characterized in that the effective length of the bearing (32) for mounting the magnet armature (4) corresponds to at least one third of the length of the magnet armature (4), preferably half the length and more preferably 70% of the length, wherein the valve slide (12) has a flattened slide head (9) which permits only a transmission of an axial pressure force from the magnet armature (4) to the slide head (9).

8. Solenoid valve (1) according to Claim 6, characterized in that the magnet armature (4) touches the slide head (9) by way of a conical surface.

9. Solenoid valve (1) according to Claim 7, characterized in that the magnet armature (4) touches the slide head (9) of the valve slide (12) by way of a planar surface.

10. Solenoid valve (1) according to either of Claims 2 or 3, characterized in that the flange surface (20) has three flange zones (21, 22, 23), wherein the third flange zone (23) is fluidically connected to a central bore (31) in the valve sleeve (11), which receives the valve slide (12), and wherein the three flange zones (21, 22, 23) are sealed off from one another and from the surroundings by a shaped seal (35).

11. Solenoid valve (1) according to either of Claims 4 or 5, characterized in that the three flange zones (21, 22, 23) are sealed off from one another and from the surroundings by a shaped seal (35).

12. Solenoid valve (1) according to either of Claims 10 or 11, characterized in that the shaped seal (35) contains three filter mats (36, 37, 38) which are arranged in the flange zones (21, 22, 23) and are connected to the material of the shaped seal (35) in a force-fitting, form-fitting or integrally joined manner.

13. Pressure regulating valve, having a solenoid valve (1) according to one of the preceding claims, characterized in that a first pressurized volume at a fluidic pressure to be regulated can be connected to the connector A, a second volume at a supply pressure can be connected to the connector P, and a line leading to a storage tank can be connected to the connector T, wherein a force comparison between the force of the electromagnet (2) and the pressure force of the fluid at the connector A takes place in the solenoid valve (1) at the valve slide (12), and wherein, in the event that the force of the electromagnet predominates, a fluidic connection takes place in the valve assembly (10) between the connector P and the connector A, and wherein, in the event that the pressure force predominates, a fluidic connection takes place between the connector A and the connector T.

14. Fluidic switching valve, having a solenoid valve (1) according to one of Claims 1 to 12, characterized in that, when the electromagnet (2) is not energized, there is a fluidic connection in the valve assembly (10) between the connector A and the connector T, and in that, when the electromagnet (1) is energized sufficiently, there is a fluidic connection in the valve assembly (10) between the connector P and the connector A.

15. Fluidic switching valve, having a solenoid valve (1) according to one of Claims 1 to 12, characterized in that, when the electromagnet (2) is not energized, there is a fluidic connection in the valve assembly (10) between the connector P and the connector A, and in that, when the electromagnet (1) is energized sufficiently, there is a fluidic connection in the valve assembly (10) between the connector A and the connector T.