Pressure control valve

Abstract

A pressure control valve includes a valve main body ( 10 A) having a high-pressure refrigerant inlet port ( 11 ) and a low-pressure refrigerant outlet port ( 12 ); a valve seat-attached valved passageway ( 20 ) formed in the valve main body ( 10 A) for decompressing and guiding the refrigerant from the high-pressure refrigerant inlet port ( 11 ) to the low-pressure refrigerant outlet port ( 12 ) and configured to enable a differential pressure regulating valve ( 15 ) to be fitted therein; and a throttling passageway ( 30 ) provided with an orifice ( 32 ) having a predetermined effective cross-sectional area for enabling the high-pressure refrigerant inlet port ( 11 ) to communicate, through short-cutting or detouring the valve seat ( 21 ), with a region of the valved passageway which is located downstream side of the valve seat ( 21 ), thereby enabling a magnitude of lift of the differential pressure regulating valve ( 15 ) from the valve seat ( 21 ) to be altered depending on a magnitude of difference in pressure between a high-pressure side and a low-pressure side.

1 . A pressure control valve comprising: 
 a valve main body having a high-pressure refrigerant inlet port and a low-pressure refrigerant outlet port;    a valve seat-attached valved passageway formed in the valve main body for decompressing and guiding the refrigerant from the high-pressure refrigerant inlet port to the low-pressure refrigerant outlet port and configured to enable a differential pressure regulating valve to be fitted therein; and    a throttling passageway provided with an orifice having a predetermined effective cross-sectional area for enabling the high-pressure refrigerant inlet port to communicate, through short-cutting or detouring the valve seat, with a region of the valved passageway which is located downstream side of the valve seat, to enable a magnitude of lift of the differential pressure regulating valve from the valve seat to be altered depending on a magnitude of difference in pressure between a high-pressure side and a low-pressure side.    
   
   
       2 . The pressure control valve according to  claim 1 , wherein the valve seat-attached valved passageway comprises: 
 a cylinder portion formed contiguous with the high-pressure refrigerant inlet port and provided, at a downstream end portion thereof, with the valve seat, an enlarged spring chamber formed contiguous with the downstream side of the cylinder portion and having a larger diameter than a diameter of the cylinder portion, a downstream passageway formed contiguous with the low-pressure refrigerant outlet port, and a communicating passageway for enabling the spring chamber to communicate with the downstream passageway.    
   
   
       3 . The pressure control valve according to  claim 2 , wherein the differential pressure regulating valve comprises a valve portion mounted retractively on the valve seat, a piston inserted slidably in the cylinder portion and having a diametrally enlarged portion on the distal end side thereof and a diametrally contracted portion on the valve portion side, and a spring shoe for receiving a valve-closing spring placed in the spring chamber, wherein the piston includes a longitudinal hole therein and a lateral hole for enabling a valve chamber formed between an inner circumferential wall of the cylinder portion and an outer circumferential wall of the diametrally contracted portion of the piston to be in communication with the high-pressure refrigerant inlet port.  
   
   
       4 . The pressure control valve according to  claim 3 , wherein a vibration-proof O-ring is interposed between the diametrally enlarged portion of the piston in the differential pressure regulating valve and the cylinder portion.  
   
   
       5 . The pressure control valve according to  claim 3 , wherein the valve portion of the differential pressure regulating valve includes a circular conical surface.  
   
   
       6 . The pressure control valve according to  claim 3 , wherein an adjusting screw is screw-engaged with the spring chamber so as to make it possible to adjust the set-load of the valve-closing valve.  
   
   
       7 . The pressure control valve according to  claim 3 , wherein the throttling passageway comprises a throttling hole-attached passageway formed contiguous with the low-pressure refrigerant outlet port, and a by-pass passageway formed so as to detour the valve seat portion and to enable the high-pressure refrigerant inlet port to be in communication with a region of the throttling hole-attached passageway which is located upstream in relative with the throttling hole.  
   
   
       8 . The pressure control valve according to  claim 1 , the orifice of the throttling passageway including a throttling hole having a predetermined bore size, the pressure control valve further comprising a needle valve which is designed to be inserted into the throttling hole.  
   
   
       9 . The pressure control valve according to  claim 8 , wherein the position of the needle valve is displaceable relative to the throttling hole as so to make it possible to adjust the effective cross-sectional area of the passageway of the orifice.  
   
   
       10 . The pressure control valve according to  claim 1 , wherein: 
 the valve seat-attached valved passageway comprises a cylinder portion formed contiguous with the high-pressure refrigerant inlet port and provided, at a downstream end portion thereof, with the valve seat; and an enlarged spring chamber formed contiguous with the downstream side of the cylinder portion and also with the low-pressure refrigerant outlet port and having a larger diameter than a diameter of the cylinder portion; and    the differential pressure regulating valve comprises a valve portion mounted retractively on the valve seat, a piston inserted slidably in the cylinder portion and having a diametrally enlarged portion on the distal end side thereof and a diametrally contracted portion on the valve portion side, and a spring shoe for receiving a valve-closing spring placed in the spring chamber, wherein the piston includes not only a longitudinal hole therein and a lateral hole to enable a valve chamber formed between an inner circumferential wall of the cylinder portion and an outer circumferential wall of the diametrally contracted portion of the piston to be in communication with the high-pressure refrigerant inlet port, but also with the orifice which is formed so as to enable the longitudinal hole with the spring chamber.    
   
   
       11 . The pressure control valve according to  claim 10 , wherein an adjusting screw is screw-engaged with the spring chamber so as to make it possible to adjust the set-load of the valve-closing valve, and the adjusting screw is provided with a longitudinal hole and a lateral hole for enabling the spring chamber to be communicated with the low-pressure refrigerant outlet port.  
   
   
       12 . A pressure control valve comprising: 
 a valve main body having a high-pressure refrigerant inlet port and a low-pressure refrigerant outlet port;    a valve seat-attached valved passageway formed in the valve main body for decompressing and guiding the refrigerant from the high-pressure refrigerant inlet port to the low-pressure refrigerant outlet port and configured to enable a constant pressure regulating valve to be fitted therein; and    a throttling passageway provided with an orifice having a predetermined effective cross-sectional area for enabling the high-pressure refrigerant inlet port to communicate, through short-cutting or detouring the valve seat, with a region of the valved passageway which is located downstream side of the valve seat, to enable a magnitude of lift of the constant pressure regulating valve from the valve seat to be altered depending on a magnitude of pressure on the high-pressure side.    
   
   
       13 . The pressure control valve according to  claim 12 , wherein the valve seat-attached valved passageway comprises a cylinder portion formed contiguous with the high-pressure refrigerant inlet port and provided, at a downstream end portion thereof, with the valve seat, and an enlarged spring chamber formed contiguous with the downstream side of the cylinder portion and communicating with the low-pressure refrigerant outlet port, the spring chamber having a larger diameter than that of the cylinder portion.  
   
   
       14 . The pressure control valve according to  claim 13 , wherein the constant pressure regulating valve comprises: 
 a valve portion mounted retractively on the valve seat;    a piston inserted slidably in the cylinder portion and having a diametrally enlarged portion on the distal end side thereof and a diametrally contracted portion on the valve portion side;    a spring shoe for receiving a valve-closing spring placed in the spring chamber; and    a stem portion formed contiguous with the valve portion;    wherein the piston includes a longitudinal hole therein and a lateral hole to enable a valve chamber formed between an inner circumferential wall of the cylinder portion and an outer circumferential wall of the diametrally contracted portion of the piston to be in communication with the high-pressure refrigerant inlet port; the constant pressure regulating valve being also featured in that atmospheric pressure is to be received by an end face of the stem portion which faces opposite to the piston.    
   
   
       15 . The pressure control valve according to  claim 14 , wherein the valve portion of the constant pressure regulating valve includes a circular conical surface.  
   
   
       16 . The pressure control valve according to  claim 14 , wherein an adjusting screw is screw-engaged with the spring chamber so as to make it possible to adjust the set-load of the valve-closing valve and includes a through-hole into which the stem portion is slidably inserted.  
   
   
       17 . The pressure control valve according to  claim 14 , wherein the throttling passageway includes a throttling hole-attached passageway formed contiguous with the low-pressure refrigerant outlet port, and a by-pass passageway formed in a manner to detour the valve seat portion and to enable the throttling hole-attached passageway to be in communication with the spring chamber.  
   
   
       18 . The pressure control valve according to  claim 12 , the orifice of the throttling passageway including a throttling hole having a predetermined bore size, the pressure valve further comprising a needle valve which is designed to be inserted into the throttling hole.  
   
   
       19 . The pressure control valve according to  claim 18 , wherein the position of the needle valve is displaceable relative to the throttling hole as so to make it possible to adjust the effective cross-sectional area of the passageway of the orifice.  
   
   
       20 . The pressure control valve according to  claim 12 , wherein: 
 the valve seat-attached valved passageway comprises a cylinder portion formed contiguous with the high-pressure refrigerant inlet port and provided, at a downstream end portion thereof, with the valve seat; and an enlarged spring chamber formed contiguous with the downstream side of the cylinder portion and also with the low-pressure refrigerant outlet port and having a larger diameter than a diameter of the cylinder portion; and    the constant pressure regulating valve comprises a valve portion mounted retractively on the valve seat, a piston inserted slidably in the cylinder portion and having a diametrally enlarged portion on the distal end side thereof and a diametrally contracted portion on the valve portion side, a spring shoe for receiving a valve-closing spring placed in the spring chamber, and a stem portion formed contiguous with the valve portion, wherein the piston includes not only a longitudinal hole therein and a lateral hole to enable a valve chamber formed between an inner circumferential wall of the cylinder portion and an outer circumferential wall of the diametrally contracted portion of the piston to be in communication with the high-pressure refrigerant inlet port, but also the orifice which is formed so as to enable the longitudinal hole with the spring chamber.    
   
   
       21 . The pressure control valve according to  claim 1 , wherein the valve seat is provided with a V-shaped trench functioning as the orifice.  
   
   
       22 . The pressure control valve according to  claim 12 , wherein the valve seat is provided with a V-shaped trench functioning as the orifice.