Filter element especially for filtering liquids or gases

Abstract

A filter element for filtering liquids or gases, having a concentrically arranged filter medium with zigzag pleats. The filter medium is provided with end disks on its axial end faces, each end disk having an inside that is connected to the filter medium and an outside that faces away from the filter medium. At least a first end disk carries a valve element which is situated concentrically inside the filter medium. This valve element includes a valve seat which bulges outward above the plane of the outer side of the end disk. The valve element includes a valve body which cooperates with the valve seat and which is arranged on the first end disk so that it is axially movable and is inside of and surrounded by the filter medium.

1 . A filter element for filtering a liquid or a gas, the filter element comprising:
 a concentrically arranged filter medium having an open interior, the filter medium folded in zigzag pleats and being provided with end disks at axial end faces of the filter medium,   each end disk having an inner side that is secured to the filter medium and an outer side that faces away from the filter element;   wherein a first end disk of said end disks includes:
 a valve opening extending axially through the first disk into said open interior; 
 an annular cambered convex curved arch region formed onto said outer side of said first end disk, said annular cambered region arching outwardly to bulge outwardly above said a plane of said outer side of said first end disk surrounding said annular cambered convex curved arch region; 
 a valve seat formed on an inwardly facing side of said annular chambered region proximate to said valve opening; 
 wherein said valve seat is arranged outwardly above said plane; 
   a valve body arranged concentrically inside said filter medium, said valve body mounted on the first end disk extending into said open interior, said valve body mounted in an axially movable manner, said valve body including
 a valve body sealing member having a sealing surface which sealably closes against the valve seat; 
 said valve body having a first end secured to an inner side of said valve body sealing member and extending axially inwardly away from said valve body sealing member into said open interior of said filter element; 
 wherein said filter element includes guide webs guiding axial movement of said valve body relative to said valve seat. 
   
     
     
         2 . The filter element according to  claim 1 , wherein at least three guide webs are provided. 
     
     
         3 . The filter element according to  claim 1 , further comprising:
 contact pins provided on an inside surface of the first end disk extending toward the other end disk, said contact pins for holding a pre-defined axial position of said end disk relative to a central support tube.   
     
     
         4 . The filter element according to  claim 2 , wherein said valve body surface is a cylindrical or conical surface and is guided so it slides axially along the guide webs. 
     
     
         5 . The filter element according to  claim 1 , wherein said first end disk is provided with snap-in elements protrusions extending axially outwardly from said outside surface of said first disk, said protrusions having snap end elements formed on an outwardly arranged end of said protrusions. 
     
     
         6 . The filter element according to  claim 1 , wherein the valve body is provided with axially extending notches on the side of the valve body facing away from the valve seat. 
     
     
         7 . The filter element according to  claim 2 , wherein said guide webs form a stop for limiting axial movement of the valve body. 
     
     
         8 . A filter element according to  claim 1 , wherein the valve body and the end disks are made of an elastomer. 
     
     
         9 . A filter device comprising
 a housing with an inlet opening for fluid to be filtered and a discharge opening for filtered fluid,   a central support tube mounted in said housing for receiving a filter element, and   a filter element according to  claim 1  mounted on said central tube in said housing.   
     
     
         10 . A filter device according to  claim 9 , wherein
 said valve body of said filter element engages against an axially moveable intermediate member arranged in a filter support tube of said housing, said intermediate member acted upon by a spring urging said intermediate member to press said valve body against said valve seat.   
     
     
         11 . A method of maintaining a filter device according to  claim 9 , said method comprising:
 removing a cover of the housing to access said filter element inside said housing;   separating the filter element from the central tube with the valve body remaining on the filter element in contact with the valve seat;   pushing a new filter element onto the support tube such that the side of the valve body facing away from the valve seat engages a spring biased member on the support tube which pushes the valve body toward the valve seat, and contact pins on the filter element engage contact surfaces on the support tube; and   replacing the housing cover.