Pressure detection unit has a housing section of injection molded plastics with glass fibers fitted to a second housing section to form a pressure detection chamber with a sensor and a sealed fit for the O-ring seal

To produce a pressure detection unit, such as at an O-ring seal, an initial housing (3) is formed by injection molding of a plastics into a mold with the required inner contour shape. The housing (3) is fitted to a second housing (7) to give a pressure detection chamber (10) to contain a sensor (1). An O-ring (12) is between the housing sections (3,7) as a hermetic seal, which is compressed between the housing sealing surfaces of the seal groove (13) and a press unit (9). The mold has an upper surface which matches the seal, to shape the sealing surface of the first housing section (3), and an inlet opening is at a suitable point for the injected plastics to flow into the hollow zone of the mold on a path which is generally parallel to the surface matching the seal. The first housing section (3) has a cylindrical shape, fitted to the second housing section (7) with a joint at its axial end side. The sealing surface of the first housing section (3) is arranged at the axial end side of the first housing, and is parallel to its end side. The mold injection inlet is open towards a surface towards the hollow zone of the mold, at right angles to the surface matching the seal. The plastics material contains glass fibers. The O-ring (12) is fitted at the periphery of the pressure detection chamber. Eine Druckerfassungsvorrichtung besteht aus einem ersten Gehäuse (3) und eingespritzten Verbindungsstiften (4) und einem zweiten Gehäuse (7) aus Metall. Das erste und das zweite Gehäuse sind zusammengefügt, um eine Druckerfassungskammer (10) zu bilden, die hermetisch mit einem O-Ring (12) abgedichtet ist, der zwischen Dichtoberflächen (9a, 13a) der beiden Gehäuse zusammengepreßt ist. Das erste Gehäuse wird mittels einer Form (200) hergestellt, die einen Einlaß (GT) zum Einspritzen von Plastik näherungsweise parallel mit einer mit der Dichtung korrespondierenden Oberfläche (205) aufweist, um die Dichtfläche des ersten Gehäuses zu bilden.