1. Field of the Invention
The present invention relates to a discharge valve apparatus for a compressor. The present discharge valve apparatus is suitable for a compressor for air-conditioning a vehicle, and it is especially suitable for a reciprocative type compressor therefor.
2. Description of the Related Art
As described in Japanese Unexamined Patent Publication (Kokai) No. 131985/1987, a reed valve type valve apparatus has been used as a valve apparatus for a reciprocative type compressor conventionally. For example, there has been known a reed valve type valve apparatus as illustrated in FIG. 17. In a discharge valve of the valve apparatus, there are provided a bore 100 in which a refrigerant is compressed, a discharge chamber 103, a valve plate 105 with a port 106 formed, a plate-spring-like reed valve 107, and a retainer 109. The lead valve 107 is assembled on the valve plate 105 together with the retainer 109.
In the conventional reed valve type valve apparatus, it is usually put into a closed state. When the differential pressures between the bore 100 and the discharge chamber 103 increase to a valve opening pressure or more, the reed valve 107 is designed so that it is separated from the valve plate 105 so as to open the port 106 and thereby the valve apparatus is opened. When the valve apparatus is opened, the refrigerant which has been compressed in the bore 100 is transferred through the port 106, and it is discharged into the discharge chamber 103. Here, the opening degree of the reed valve 107 is regulated by the retainer 109.
In the above-described conventional reed valve type valve apparatus, the reed valve 107 is adhered to the retainer 109 so closely that it hardly comes off the retainer 109 because of a lubricant oil contained in the refrigerant. As a result, when the discharge operation is turned into the suction operation, a discharge gas is flowed back in the reverse direction by the retardation of the reed valve 107 in the returning, thereby deteriorating the volumetric efficiency of the compressor.