Pressure-limiting valve

Abstract

A pressure-limiting valve includes a housing and a pressure adjustment device provided therein. The pressure-limiting valve further includes a valve seat arranged in the housing and configured to be closed by a spring-loaded closing element of the pressure adjustment device. The housing is composed of cast iron having spherical graphite. The housing is surface-hardened at least in a region of the valve seat.

The invention claimed is: 
     
       1. A pressure-limiting valve, comprising:
 a housing defining a first piston chamber, a second piston chamber, a first receptacle, and a second receptacle; 
 a first spring-loaded closing element at least partially located in the first receptacle; 
 a second spring-loaded closing element at least partially located in the second receptacle; 
 a first valve seat formed in the housing and configured to be closed by the first spring-loaded closing element; 
 a second valve seat formed in the housing and configured to be closed by the second spring-loaded closing element; 
 a first guide piston extending directly from the first spring-loaded closing element and located in the first piston chamber, the first guide piston including a first terminal end surface of the first spring-loaded closing element located in the first piston chamber; 
 a second guide piston extending directly from the second spring-loaded closing element, the second guide piston including a second terminal end surface of the second spring-loaded closing element located in the second piston chamber, 
 wherein (i) the first receptacle, the first spring-loaded closing element, the first piston chamber, and the first guide piston; and (ii) the second receptacle, the second spring-loaded closing element, the second piston chamber, and the second guide piston are configured substantially mirror-symmetrically with respect to one another in the housing, 
 wherein the first piston chamber is a blind hole, 
 wherein the second piston chamber is another blind hole, 
 wherein a line of symmetry extends directly between the first piston chamber and the second piston chamber, 
 wherein the housing, the first valve seat, and the second valve seat are composed of cast iron with spheroidal graphite, and 
 wherein at least the first valve seat and the second valve seat are surface-hardened. 
 
     
     
       2. The pressure-limiting valve as claimed in  claim 1 , further comprising:
 a pressure adjustment device at least partially arranged in the first receptacle, 
 wherein the first receptacle includes the first valve seat. 
 
     
     
       3. The pressure-limiting valve as claimed in  claim 2 , wherein the first valve seat is arranged away from the pressure adjustment device in a closing direction of the first spring-loaded closing element. 
     
     
       4. The pressure-limiting valve as claimed in  claim 3 , wherein:
 the first spring-loaded closing element has a closing cone, and 
 the first guide piston is arranged on the first spring-loaded closing element in the closing direction proceeding from the closing cone. 
 
     
     
       5. The pressure-limiting valve as claimed in  claim 4 , further comprising:
 a spring plate of the pressure adjustment device arranged on the first spring-loaded closing element counter to the closing direction proceeding from the closing cone. 
 
     
     
       6. The pressure-limiting valve as claimed in  claim 5 , wherein the first spring-loaded closing element and the spring plate are in single-part or multi-part form. 
     
     
       7. The pressure-limiting valve as claimed in  claim 5 , wherein a transition of the first receptacle between the spring plate and the first valve seat is at least partially of conical form. 
     
     
       8. The pressure-limiting valve as claimed in  claim 2 , wherein the first valve seat is accessible from only a single side through the first receptacle for the surface-hardening and/or for finish machining by a tool. 
     
     
       9. The pressure-limiting valve as claimed in  claim 1 , wherein the first guide piston is movably located within the first piston chamber. 
     
     
       10. The pressure-limiting valve as claimed in  claim 1 , further comprising:
 a ring-shaped chamber located between the first piston chamber and the first valve seat, the ring-shaped chamber defined by the housing. 
 
     
     
       11. The pressure-limiting valve as claimed in  claim 10 , wherein the first guide piston is spaced apart from the ring-shaped chamber.