A closure arrangement for closing off an insertion opening in a front wall of a housing for a connector which is insertable through the insertion opening, on a displacement travel extending at right angles to the front wall, into the interior of the housing and which can be contacted there with a contact piece, the closure arrangement having: the front wall, two closure parts (5, 5') which are arranged on the inner side of the front wall and which, counter to spring forces, can be acted on by the connector inserted into the insertion opening such that they are movable away from one another from a closed position, in which they each close off half of the insertion opening and in which the closure parts (5, 5') bear against one another, by way of their end sides (7, 7') facing toward one another, in the center of the insertion opening, into an open position, in which the connector can pass through, the closure parts (5, 5') are, with their mutually opposite regions directed toward the front wall, displaceably in contact with slide curves (3, 3') of the front wall, which extend from the outer region to the inner region of the insertion opening such that they diverge from one another, wherein those regions of the closure parts (5, 5') which bear against the slide curves (3, 3') have contours (6, 6') corresponding to the slide curves (3, 3'), and the closure parts (5, 5') are acted on displaceably toward one another along the slide curves (3, 3') by first spring forces, characterised in that the slide curves (3, 3') diverge from one another in convex fashion, and in that the closure parts (5, 5') are, after an initial travel out of the closed position in the direction of the open position, pivotable counter to second spring forces about axes of rotation extending transversely with respect to the displacement travel, wherein the closure arrangement further comprises a single-piece spring element fastenable to the housing, the single-piece spring element generating the first spring forces and the second spring forces, and in that the spring element is a closed, stadium-shaped spring plate element, the plate plane of which extends in the displacement travel direction, wherein spring arms (10, 10') which generate the first spring forces are arranged at the central regions (14, 14') of the longitudinal extent of the stadium-shaped spring plate element, by means of which spring arms the closure parts (5, 5') are acted on toward one another with a preload. the front wall, two closure parts (5, 5') which are arranged on the inner side of the front wall and which, counter to spring forces, can be acted on by the connector inserted into the insertion opening such that they are movable away from one another from a closed position, in which they each close off half of the insertion opening and in which the closure parts (5, 5') bear against one another, by way of their end sides (7, 7') facing toward one another, in the center of the insertion opening, into an open position, in which the connector can pass through, the closure parts (5, 5') are, with their mutually opposite regions directed toward the front wall, displaceably in contact with slide curves (3, 3') of the front wall, which extend from the outer region to the inner region of the insertion opening such that they diverge from one another, wherein those regions of the closure parts (5, 5') which bear against the slide curves (3, 3') have contours (6, 6') corresponding to the slide curves (3, 3'), and the closure parts (5, 5') are acted on displaceably toward one another along the slide curves (3, 3') by first spring forces, characterised in that the slide curves (3, 3') diverge from one another in convex fashion, and in that the closure parts (5, 5') are, after an initial travel out of the closed position in the direction of the open position, pivotable counter to second spring forces about axes of rotation extending transversely with respect to the displacement travel, wherein the closure arrangement further comprises a single-piece spring element fastenable to the housing, the single-piece spring element generating the first spring forces and the second spring forces, and in that the spring element is a closed, stadium-shaped spring plate element, the plate plane of which extends in the displacement travel direction, wherein spring arms (10, 10') which generate the first spring forces are arranged at the central regions (14, 14') of the longitudinal extent of the stadium-shaped spring plate element, by means of which spring arms the closure parts (5, 5') are acted on toward one another with a preload.