Negative pressure preventive device in refrigerator

Abstract

A negative pressure preventive device in a refrigerator is provided to be mounted to a machinery room on a top side of the refrigerator, in which an opening and closing damper is provided over an evaporator for controlling external air such that warm external air is led through an evaporator to reduce a temperature difference while the warm external air passes through the evaporator for minimizing a temperature change in the refrigerator, the opening and closing damper has a control lever operative by gravity to make quick and accurate opening, closing, and air introduction to the refrigerator for compensating a pressure difference, a filter mounted to the opening and closing damper at an air introduction portion to be detachable with a packing cap for easy removal of noxious insects, microbes, and dust, and easy washing and replacement, and a packing member provided to the opening and closing damper for improving a sealing function to prevent cold air from leaking, quick compensation of the pressure difference, and eliminating difficulty in opening the door caused by the negative pressure.

1 . A negative pressure preventive device mounted to a refrigerator to guide and introduce air to an evaporator in the refrigerator, comprising:
 an air introduction pipe formed in a refrigerator wall to have fastening flanges on an insulating layer between an inner plate and an outer plate of the refrigerator wall;   an external air flow pipe fastened to the air introduction pipe having a vertical portion of a predetermined height and a diagonal portion connected to the vertical portion;   an opening and closing damper mounted to the external air flow pipe with a hinge shaft thereof passed through hinge holes in a top side of the external air flow pipe, the opening and closing damper including a packing member in close contact with a circumference of an air introduction opening for closing and opening an air flow, and a control lever secured to the hinge shaft exposed from an outer side of the air introduction pipe to have gravity; and   a filter cap placed on the external air flow pipe on an outside of the air introduction opening having a filter provided therein for preventing noxious insects and dust from entering into the refrigerator.   
     
     
         2 . The negative pressure preventive device as claimed in  claim 1 , wherein the opening and closing damper includes the control lever for opening and closing the opening and closing damper with gravity. 
     
     
         3 . The negative pressure preventive device  10  as claimed in  claim 1 , wherein the negative pressure preventive device is mounted to the refrigerator singly or in plural. 
     
     
         4 . The negative pressure preventive device as claimed in  claim 1 , wherein the negative pressure preventive device is mounted to a top of the refrigerator to introduce external air to an evaporator through the negative pressure preventive device for preventing dew from forming by a temperature difference. 
     
     
         5 . The negative pressure preventive device as claimed in  claim 1 , wherein the external air flow pipe and the air introduction pipe have square or circular cross sections, respectively.