Expansion valve for rear seat air conditioner

Abstract

The present invention relates to an expansion valve for a rear seat air conditioner of an automotive vehicle, which can circulate a flow of refrigerant stagnated between a compressor and the rear seat air conditioner through a bleeding channel of the expansion valve when only a front seat air conditioner is operated stopping the operation of the rear seat air conditioner, thereby supplying oil contained in refrigerant between the compressor and the rear seat air conditioner to the compressor.

1 . An expansion valve for a rear seat air conditioner of an automotive vehicle, which comprises: a low-pressure refrigerant channel for connecting an outlet of a rear evaporator with a compressor; a high-pressure refrigerant channel having an entrance portion for introducing refrigerant into the high-pressure refrigerant channel, a discharge portion connected to an inlet of the rear evaporator, and an orifice for connecting the entrance portion and the discharge portion with each other; a pressure delivery bar liftably mounted across the low-pressure refrigerant channel and the orifice of the high-pressure refrigerant channel; a temperature sensing bulb connected with the pressure delivery bar; and a ball valve mounted on a communication path fluidically communicating with the orifice and the entrance portion for adjusting an opening degree of the orifice in link with the pressure delivery bar, 
 wherein the orifice includes a slant enlarged portion formed on the communication path side so that a ball of the ball valve is seated on the slant enlarged portion, and    wherein the orifice has a bleeding channel formed on an inner circumferential surface thereof so as to fluidically communicate the communication path and the discharge portion with each other even when the ball of the ball valve is seated on the slant enlarged portion.    
   
   
       2 . The expansion valve according to  claim 1 , wherein the bleeding channel includes a groove formed on the slant enlarged portion.  
   
   
       3 . The expansion valve according to  claim 1 , wherein the bleeding channel includes a groove formed on the ball side, which is in contact with the slant enlarged portion.  
   
   
       4 . The expansion valve according to  claim 1 , wherein the orifice includes a straight portion formed on the discharge portion side, a diameter of the straight portion is within the range of 2.6 mm to 3.1 mm, and a diameter of the ball of the ball valve is within the range of 3.1 mm to 3.5 mm.  
   
   
       5 . The expansion valve according to  claim 2 , wherein the bleeding channel has three to twelve grooves.  
   
   
       6 . The expansion valve according to  claim 2 , wherein a sectional area of the entire passageway of the grooves is corresponded to a sectional area of a circle, which has a diameter ranging 0.3 mm to 0.8 mm.