Bypass valve piston seal arrangement

Abstract

A valve includes a housing, a solenoid arranged in the housing, a pin movable by the solenoid, a piston connected to the pin, and a seal arranged between the housing and the piston. The seal is an axially acting seal which, in the closed state of the valve, interacts with a sealing surface of the piston.

Claims

1. A valve comprising: a housing (1); a solenoid (5) arranged in the housing (1); a pin (7) movable by the solenoid (5); a piston (8) connected to the pin (7) and having a sealing surface (24) having a first diameter; and a seal (16) arranged between the housing and piston, wherein the seal (16) is an axially acting seal which, in a closed state of the valve, interacts with the sealing surface (24) of the piston (8), wherein the seal (16) has a housing-side sealing surface (18) and a piston-side sealing surface (20) that are connected to one another by an angular elastically deformable region (21), and wherein the angular elastically deformable region (21) is defined by parallel diagonal surfaces, the angular elastically deformable region (21) being configured to space the housing-side sealing surface (18) and the piston-side sealing surface (20) apart from one another in both the radial and the axial directions.

2. The valve as claimed in claim 1, wherein piston (8) comprises a lateral surface (14), the lateral surface (14) of the piston (8) having a second diameter that is smaller than the first diameter of the sealing surface (24) of the piston (8).

3. The valve as claimed in claim 2, wherein the sealing surface (24) of the piston (8) is part of a radially outwardly projecting edge (23) at an upper portion of the lateral surface (14).

4. The valve as claimed in claim 1, wherein the piston (8) is made of one selected from the group of metal and plastic.

5. The valve as claimed in claim 3, wherein the piston (8) is made of metal, and the radially outwardly projecting edge (23) of the piston (8) is produced by deep drawing of the piston (8) or by flanging of the side of the piston (8) that faces toward the solenoid (5).

6. The valve as claimed in claim 1, wherein the seal (16) is made of Polytetrafluoroethylene (PTFE).

7. The valve as claimed in claim 1, wherein an inner diameter of the seal (16) is greater than an outer diameter of a region of the lateral surface (14) of the piston (8) that is moved past the seal (16) during the movement of the piston (8).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be described in more detail on the basis of an exemplary embodiment. In the figures:

(2) FIG. 1 is a sectional illustration of a valve according to the prior art; and

(3) FIG. 2 is an enlarged illustration of the piston of a valve according to an embodiment of the invention in the sealing region.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

(4) FIG. 1 shows a valve comprising a housing 1 with integrally molded socket 2 for the electrical connection of the valve. The housing 1 furthermore has an integrally formed 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. In the installed position shown, the flange 3 is adjoined by a housing bushing 13. In the housing 1, there is arranged a solenoid 5 with a coil 6 and a metal pin 7. The metal pin 7 is connected to a pot-shaped piston 8, which, at the circumference of its base 9, has an axially projecting annular sealing surface 10. In the closed position shown, the sealing surface 10 bears against the valve seat 11 in order to close off the bypass line 4, so that no medium can flow from the line 4 into the line 12. Here, a spring 7a pushes the piston 8 in the direction of the valve seat 11. The force generated by the spring 7a is counteracted by the force that acts on the base 9 owing to the pressure in the line 12.

(5) FIG. 2 shows that region of the piston 8 which faces toward the housing 1, with its cylindrical lateral surface 14, in a closed position. The housing bushing 13 has a radially inwardly pointing collar 15. A seal 16 lies on the collar 15. The seal 16 has a region 17 with a housing-side sealing surface 18 and a region 19 with a piston-side sealing surface 20. The regions 17, 19 and thus the sealing surfaces 18, 20 are connected by an elastically deformable region 21. The housing-side region 17 is clamped between the collar 15 and a cylinder 22 arranged in the housing bushing 13, such that the seal 16 is arranged fixedly in the housing bushing 13. The piston 8, which is made of metal, has, at its open end, a radially outwardly projecting edge 23 which is produced by flanging and which has a sealing surface 24. During the closing of the piston 8, the sealing surface 24 moves downward.

(6) Immediately before the closed position is reached, the sealing surface 24 of the piston 8 comes into contact with the sealing surface 20 of the seal 16. During the further movement of the piston 8 into the closed position, the sealing surface 24 presses against the sealing surface 20, which leads to a deformation of the elastic region 21. As a result of this deformation, a preload of the two sealing surfaces 24, 20 is realized. Thus, while there have been 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 design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.