VALVE

Abstract

A valve includes a housing, a solenoid arranged in the housing, a pin that can be moved by the solenoid, a piston connected to the pin, and a spring that loads the piston against the force of the solenoid. The valve includes elements for the pressure-supported movement of the piston.

Claims

1.-13. (canceled)

14. A valve comprising: a housing; a solenoid arranged in the housing; a pin configured to be moved by the solenoid; a first piston connected to the pin; a spring configured to load the first piston against a force of the solenoid; and an element configured for pressure-supported movement of the first piston.

15. The valve as claimed in claim 14, wherein the solenoid is configured to open the valve and the element configured for pressure-supported movement of the first piston support a magnetic force of the solenoid.

16. The valve as claimed in claim 14, wherein a pressure present on one side of a valve seat is used to move the first piston.

17. The valve as claimed in claim 16, wherein the pressure used to move the first piston is a pressure present in a region of higher pressure.

18. The valve as claimed in claim 15, wherein the element configured for pressure-supported movement of the first piston comprises: a second piston arranged on the pin at a distance from the first piston; and a valve seat of the a second piston.

19. The valve as claimed in claim 18, further comprising: a pressure path for a higher pressure is formed from a region of the higher pressure through the first piston and along the pin up to the second piston.

20. The valve as claimed in claim 19, further comprising: a pressure path formed in the housing for a lower pressure that extends from a region of lower pressure along at least a part of an outside of the solenoid up to a side of the second piston facing away from the first piston.

21. The valve as claimed in claim 19, wherein the valve seat of the second piston comprises: a first partial valve seat; and a second partial valve seat, and wherein the second piston comprises a first and a second sealing face cooperating with the first partial valve seat and the second partial valve seat, wherein the first and the second sealing face have different diameters, the first and the second sealing face are axially spaced from each other such that a sealing face with a smaller diameter is arranged closer to the first piston.

22. The valve as claimed in claim 21, wherein the first partial valve seat and the second partial valve seat are formed by a pot-like cylindrical bore, wherein the first partial valve seat is arranged in a base region of the pot-like cylindrical bore, and the second partial valve seat is arranged in a cylindrical casing surface of the pot-like cylindrical bore.

23. The valve as claimed in claim 22, wherein the pot-like cylindrical bore has a widening running in a radial direction such that the second sealing face of the second piston has a distance from a casing surface in a region of the widening.

24. The valve as claimed in claim 23, wherein the widening is formed as one of a chamfer and a radius.

25. The valve as claimed in claim 23, wherein the widening is arranged at a distance from the base region of the pot-like cylindrical bore amounting to at least one of: half an opening stroke of the valve, 75 percent of the opening stroke of the valve, and 5 percent of the opening stroke of the valve.

26. The valve as claimed in claim 22, wherein the first and the second sealing face on the second piston each comprise a sealing ring.

27. The valve as claimed in claim 19, wherein the second piston is arranged on the pin at an opposite end of the pin from the first piston.

28. The valve as claimed in claim 26, wherein the sealing ring is an O-ring.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The invention will be described in more detail on the basis of an exemplary embodiment. The drawing shows:

[0020] FIG. 1 is a sectional depiction of the valve in closed state;

[0021] FIG. 2 is the valve from FIG. 1 during opening; and

[0022] FIG. 3 is the valve from FIG. 1 in open state.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

[0023] FIG. 1 shows the valve comprising a housing 1 with integrally formed socket 2 for the electrical connection of the valve. The housing 1 furthermore has an integrally molded flange 3 and three bores 3a, by which the housing 1 is flange-mounted on a turbocharger (not illustrated) in the region of the bypass line 4. A solenoid 5 with a coil 6 and a metal pin 7 is arranged in the housing 1, wherein the metal pin 7 is attached to an armature 12, which in turn is mounted inside the coil 6. At its end facing away from the solenoid 5, the metal pin 7 is connected to a pot-like piston 8. In the non-actuated state of the solenoid 5, a spring 9 preloads the piston 8 against a valve seat 10 to close off the bypass line 4, such that no medium can flow from the bypass line 4 into the line 11. Here, the spring 9 is supported on the solenoid 5 and on the piston 8. In closed state of the valve, a pressure of 3 bar is present in the bypass line 4, while the pressure in the line 11 is 1 bar.

[0024] The end of the pin 7 facing away from the piston 8 carries a second piston 13, which cooperates with a second valve seat 14. The second valve seat 14 consists of a first partial valve seat 15 and a second partial valve seat 16. The second piston 13 has two sealing faces 17, 18, each of which cooperates with a partial valve seat 15, 16. The sealing faces 17, 18 are each formed by a sealing ring configured as an O-ring. The second valve seat 14 is formed in a housing 19 formed by an upper cover plate 20 of the solenoid 5. The housing 19 has a pot-like bore 21, the base region 22 of which contains the first partial valve seat 15 on which the first sealing face of smaller diameter 17 rests. The second partial valve seat 16 is the cylindrical casing surface 23 of the bore 21. The sealing face 18 of larger diameter, which is also formed by an O-ring, bears on the cylindrical casing surface 23. In the position shown, the bypass line 4 is closed. The interior of the valve is connected to the bypass line 4 via openings 24 in the pin 7 and piston 8, so that a pressure of 3 bar is also present in this region. The pressure from the bypass line 4, which forms a region of higher pressure, is conducted via a first pressure path 25 along the metal pin 7 to the underside of the second piston 13. Because of the smaller area on which the pressure of 3 bar acts, the load on the second piston 13 is low. The spring 9 holds the valve in the closed state. The spring 9 is supported by an additional force acting in the closing direction. This force results from the pressure of 1 bar prevailing in the line 11. A second pressure path 26 is formed via a recess 27 in the housing 1, and leads from the line 11 via the recess 27 to the bore 21 and hence to the top side of the second piston 13. The recess 27 in the housing 1 surrounds the outside of the coil 6 over part of the circumference and over the entire height.

[0025] FIG. 2 shows the valve during opening. When the solenoid 5 is energized, the metal pin 7 is attracted slightly. The second sealing face 17 is thereby lifted from the first partial valve seat 15, and the pressure of 3 bar is established in the space between the two O-rings forming the sealing faces 17, 18. Because of the larger area on the underside of the second piston 13, a greater force is created, which supports the opening of the valve. During this movement, the second O-ring 18 slides over the second partial valve seat 16 but still seals against the partial valve seat 16.

[0026] FIG. 3 shows the valve in the open position in which the piston 8 clears the bypass line 4. In this movement, the second piston moves further up. The open end of the cylindrical bore 19 has a chamfer 28 acting as a widening. When, during further movement, the second sealing face of larger diameter 18 enters the region of the chamfer 28, the O-ring forming the second sealing face 18 lifts away from the second partial valve seat 16, creating a connection between the first pressure path 25 and the second pressure path 26. Via this connection, the pressure of 3 bar present in the first pressure path 25 dissipates. As a result of the pressure equalization, the pressure support for opening ends.

[0027] To close the valve, the solenoid 5 is de-energized. In the depiction shown, the metal pin 7 with the piston is pressed down by the force of the spring 9 until the piston 8 rests on the valve seat and closes the bypass line 4.

[0028] Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of de-sign choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.