Proportional valve, in particular for a camshaft adjuster

Abstract

A proportional valve ( 1 ), including a piston guide sleeve ( 4 ) and a valve piston ( 3 ) that can be moved in the piston guide sleeve ( 4 ), and further including a check valve ( 13 ) arranged in a pressure medium inlet ( 10 ) to the proportional valve ( 1 ). According to the invention a proportional valve ( 1 ) is provided, in which the adaption of the check valve ( 13 ) to the proportional valve ( 1 ) is improved with respect to the prior art. This is achieved in that the check valve ( 13 ) is arranged in an annular gap ( 14 ) surrounding the piston guide sleeve ( 4 ) in a region of the pressure medium inlet ( 10 ).

1 . Proportional valve comprising: a piston guide sleeve, a valve piston that can move in the piston guide sleeve, and a check valve arranged in a pressure medium inlet to the proportional valve, the check valve is arranged in an annular gap surrounding the piston guide sleeve in an area of the pressure medium inlet. 
     
     
         2 . Proportional valve according to  claim 1 , wherein the annular gap is limited by an insert-molded part at least partially surrounding the piston guide sleeve and a receptacle sleeve comprising at least one sub-region of the insert-molded part. 
     
     
         3 . Proportional valve according to  claim 2 , wherein the receptacle sleeve has, on an axial end thereof, a receptacle gap that forms a sub-region of the annular gap and in which the check valve is inserted. 
     
     
         4 . Proportional valve according to  claim 2 , wherein the piston guide sleeve provided with the insert-molded part is connected with a material-fit connection to the receptacle sleeve. 
     
     
         5 . Proportional valve according to  claim 2 , wherein the piston guide sleeve provided with the insert-molded part is connected with a non-positive-fit connection to the receptacle sleeve. 
     
     
         6 . Proportional valve according to  claim 1 , wherein the check valve is constructed as a spring sleeve with slots in an axial direction. 
     
     
         7 . Proportional valve according to  claim 1 , wherein the check valve is produced from a metallic material. 
     
     
         8 . Proportional valve according to  claim 2 , wherein the insert-molded part includes, on a outer lateral surface thereof, a stop that is active in a radial direction in an opening direction of the check valve. 
     
     
         9 . Proportional valve according to  claim 2 , wherein the receptacle sleeve forms, on an inner lateral surface thereof, a stop that is active in the radial direction in a closing direction of the check valve. 
     
     
         10 . Installation method for a proportional valve with a piston guide sleeve, a valve piston that can move in the piston guide sleeve, and a check valve arranged in a pressure medium inlet to the proportional valve, comprising inserting the check valve into a receptacle gap of the receptacle sleeve forming a sub-region of the annular gap and then inserting the piston guide sleeve provided with the insert-molded part into the receptacle sleeve and connecting the piston guide sleeve to the receptacle sleeve. 
     
     
         11 . Proportional valve according to  claim 2 , wherein the piston guide sleeve provided with the insert-molded part is connected with a positive-fit connection to the receptacle sleeve.