Patent Publication Number: US-2021172534-A1

Title: Valve

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This is a U.S. national stage of Application No. PCT/EP2018/085245 filed Dec. 17, 2018. Priority is claimed on German Application No. DE 10 2017 223 313.3 filed Dec. 20, 2017 the content of which is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a valve having a housing, a solenoid arranged in the housing, a pin movable by the solenoid, a pot-shaped piston connected to the pin, a seal that seals off the piston against the housing, and a seal that seals off the piston against a valve seat. 
     2. Description of Related Art 
     Valves are used, inter alia, as a diverter valve on a turbocharger in motor vehicles to open a bypass to a suction side in overrun operation, and are thus known. To prevent excessive deceleration of the turbocharger and to ensure a fast start-up, rapid opening, and closing of the valve are essential prerequisites. During the closing process, immediate closure as a result of the abutment of the piston against a valve seat is of importance. The valve seat is formed by the housing of the turbocharger, on which the valve is flange-mounted. Here, the axially displaceable piston is sealed off against the housing. The sealing is realized via a seal. Such seals often have a V-shaped cross section, with the limbs of the V being formed as sealing lips. For sealing of the piston against the valve seat, it is known to form the base of the piston with a radially encircling sealing edge. A disadvantage is that the piston and the V-shaped seal are relatively complex components, which are associated with cumbersome manufacture and accordingly entail high costs. Simpler solutions, on the other hand, have higher leakage values. 
     SUMMARY OF THE INVENTION 
     One aspect of the invention is a valve that makes possible simple sealing of the piston against the housing. The valve should furthermore be inexpensive. 
     One aspect of the invention is that the piston has, on the side facing the housing and on the side facing the valve seat, one radially encircling receiving part in which one seal is arranged. The receiving parts on the piston permit simple arrangement of the seals. Elaborate holding elements or clamps of the seals can thus be dispensed with. A further simplification is provided by the arrangement of the seals on the piston since all the seals can be fitted completely on the piston. The piston can thus be connected as a preassembled part to the valve, which facilitates the assembly. 
     A particularly simple and reliable arrangement of the seals is provided if, according to one aspect of the invention, the receiving parts are formed as beads. Beads have the advantage that they can be produced easily, and so the piston is also of simple construction. Additional securing elements for the securing of the position of the seals are not required. 
     Due to the receiving parts on the piston, a further configuration is to use the disk-shaped seals and/or O-rings as seals. The seals have a simple construction. Such a valve is particularly inexpensive. 
     In another configuration, good sealing action is achieved in that the seals consist of a plastic or an elastomer. 
     The seals can be easily fitted as separate components on the piston. An improved fit of the seals is however achieved in that the seals are injection molded as a plastic seal on the piston or are vulcanized as an elastomer seal thereon. 
     According to one aspect of the invention, the construction of the valve can be further simplified, and thus made more inexpensive, if the pot-shaped piston has a base that is inserted as a separate component into the piston. With this two-part design of the piston, the beads can be introduced into the cylindrical lateral surface of the piston in one working step. 
     For a secure and stable connection of the base to the piston, said base is welded or soldered to the cylindrical lateral surface. A further simplification with the production is provided if the base is pressed together with the piston. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described in more detail on the basis of an exemplary embodiment. In the figures: 
         FIG. 1  is a sectional illustration of a valve according to the prior art; 
         FIG. 2  is a sectional illustration of the valve according to the invention; and 
         FIG. 3  is an enlarged illustration of the piston. 
     
    
    
     DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS 
       FIG. 1  shows a valve, which comprises a housing  1 . The housing  1  has an integrally formed flange  3 , via which the housing  1  is flange-mounted on a turbocharger (not illustrated) in the region of a bypass line  4 . 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 periphery of its base  9 , has a seal  10 . Here, a spring  7   a  pushes the piston  8  in the direction of the valve seat. 
     The housing  1  has a cylindrical section  11  that extends in the direction of the piston  8 . A cylinder bushing  12  connected to the housing surrounds the cylindrical section  11 . The cylinder bushing  12  has a radially inwardly directed collar  13 , on which a V-shaped seal  14  abuts. The end of the cylindrical section  11  holds the seal  14  in position. The inner limb of the seal  14  seals off the piston  8  against the housing  1 . If the solenoid  5  is electrically energized, a magnetic force acts on the armature  2 , whereby the piston  8  is moved in the direction of the housing  1 . Here, the seal  14  seals off the piston  8  against the housing  1 . 
     The valve according to one aspect of the invention in  FIG. 2  has a pot-shaped piston  8 , which is described in more detail below. A seal  14  seals off the piston  8  against the housing  1  in that the seal  14 , in the closed state of the valve, abuts on the collar  13  of the cylinder bushing  12 . The seal  10  abuts against the valve seat  15  and closes off the bypass line  4 . 
     The piston  8  in  FIG. 3  has a cylindrical lateral surface  15 , at the ends of which in each case one bead  16  is formed. In each bead  16 , in each case one disk-shaped seal  10 ,  14  composed of polytetrafluoroethylene is injection molded. A disk-shaped base  17  is welded above the seal  10  to the cylindrical lateral surface  15 . However, it is also conceivable for the base  17  to be arranged below the seal  10 . A central bore  18  in the base serves for receiving the pin  7 , which is connected to the piston by means of a rivet connection. 
     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 design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.