Metering valve

A metering valve for viscous materials, having a housing (12), having a material channel (16) that runs in the housing (12) and ends in multiple material outlet openings (26), and having a number of valve needles (24) displaceably mounted in the housing (12), which number corresponds to the number of material outlet openings (26),

• wherein each valve needle (24) has a valve seat (22) assigned to it,
• wherein each valve needle has a first end section having a first end facing away from the valve seat assigned to it, a second end section having a second end facing the valve seat assigned to it, and a valve needle body extending between the first end section and the second end section,
• wherein each valve needle (24) is movable between a closed position in which the needle valve sits on the valve seat (22) assigned to the needle valve and closes off one of the material outlet openings (26), and an open position in which the material outlet opening (26) in question is exposed,
• wherein the valve needles (24) are produced from carbide and are passed through feed-through openings (30) in a guide block (28) arranged at a distance from the valve seats (22), in longitudinally displaceable manner,
• wherein each valve needle body passing through the feed-through opening in the guide block has a constant diameter from the feed-through opening up to the second end section,
• wherein the feed-through openings (30) have inner surfaces that lie against the valve needles (24), forming a seal,
• wherein the feed-through openings (30) have dimensions adapted to dimensions of the valve needles (24) to guide the valve needles (24) in the guide block (28) and achieve a sealing effect between the guide block (28) and the valve needles (24) to prevent exiting of the viscous materials in a direction away from the material outlet openings (26),
• wherein the guide block (28) is produced from carbide, at least on the inner surfaces of the feed-through openings (30) that face the valve needles (24), and
• wherein the carbide comprises a metal matrix composite material in which hard substances present in particle form are held together by a matrix composed of metal.