Metering valve for automatic fluid metering devices, particularly for industrial ink and paint

摘要

A metering valve wherein an outer casing (48) defines a first (100a) and second (100b) chamber communicating with each other via a hole (105) and respectively communicating externally of the casing via a fluid inlet conduit (107) and a fluid recirculating conduit (108). The first chamber also communicates externally via a supply conduit (98), and houses a shutter (111) movable axially inside the chamber between a first position wherein a first portion (130) of the shutter closes the aforementioned hole (105), and a second position wherein a second portion (135) of the shutter closes the supply conduit (98). For any intermediate position between the first and second positions, the total area of the gaps between the supply conduit (98) and the second portion (135) and between the hole (105) and the first portion (130) is notably constant, so that, for any position of the shutter, the total section of the fluid passage of the metering valve is constant.