Dosing valve for additives at risk of freezing, method for producing a dosing valve and motor vehicle

A method for producing a dosing valve, the method comprising the following steps:

• a) providing a valve housing having a duct formed therein defining an inner duct wall and a longitudinal axis, the valve housing having an inlet and an outlet defining a flow path therebetween for a liquid additive at risk of freezing;
• b1) inserting a hollow valve body into the duct of the valve housing for conducting the flow path through the hollow valve body partly along the longitudinal axis;
• b2) inserting a spring into the duct of the valve housing, the spring configured to conduct the liquid additive at risk of freezing through the spring along part of the flow path;
• b3) inserting a calibration body into the duct of the valve housing, the calibration body bearing against the inner duct wall;
• c) tensioning the spring and causing the spring to exert a predefined force on the valve body;
• configuring the dosing valve for dosing the liquid additive at risk of freezing by:
• d1) producing a press-fit connection between the calibration body and the valve housing, the press-fit connection being configured for fastening the calibration body in the valve housing to support and hold the spring in a predefined position by direct contact between the spring and the calibration body, before
• d2) producing at least one brazed connection or welded connection between the calibration body and the valve housing, the brazed connection or welded connection being configured for fastening the calibration body in the valve housing to prevent the calibration body from changing its position even under an action of ice pressure in the event of freezing of the liquid additive at risk of freezing in the dosing valve;
• and
• producing the press-fit connection and the brazed connection or welded connection by using a different tool.

A dosing valve for dosing a liquid additive at risk of freezing, the dosing valve comprising:

• a valve housing having a duct formed therein defining an inner duct wall and a longitudinal axis, said valve housing having an inlet and an outlet defining a flow path therebetween for the liquid additive at risk of freezing;
• a hollow valve body through which said flow path passes partly along said longitudinal axis, said valve body disposed in said duct and movable to open and close the dosing valve, said flow path issuing from said hollow valve body into said duct in a flow direction of the dosing valve from said inlet to said outlet;
• a spring disposed in said duct upstream of said hollow valve body in the flow direction and exerting a spring force on said valve body to hold said valve body in a rest position, said spring configured to conduct the liquid additive at risk of freezing through said spring along part of said flow path;
• and
• at least one calibration body disposed in said duct upstream of said spring in the flow direction, bearing against said inner duct wall and directly contacting and supporting said spring, said at least one calibration body being fastened in said valve housing by a press-fit connection and additionally by a brazed connection or a welded connection differing from said press-fit connection.