Abstract: Diameters and the number of respective wires are inputted, and a diameter of a virtual wire formed by converting a wire bundle to a model through a predetermined arithmetic expression derived from rule of thumb, and based upon this, a flexure life estimating process of the virtual wire is carried out. It is possible to easily estimate the flexure life and also to estimate the flexure life and obtain the results immediately after an application subject and a wire harness to be placed have been designed; thus, it becomes possible to shorten the developing period.

Abstract: Diameters and the number of respective wires are inputted, and a diameter of a virtual wire formed by converting a wire bundle to a model through a predetermined arithmetic expression derived from rule of thumb, and based upon this, a flexure life estimating process of the virtual wire is carried out. It is possible to easily estimate the flexure life and also to estimate the flexure life and obtain the results immediately after an application subject and a wire harness to be placed have been designed; thus, it becomes possible to shorten the developing period.

Abstract: The bend test device includes a fixed stand for fixing a first fixing point of an electrical cable or wire harness, and a mobile stand for fixing a second fixing point of the electrical cable or wire harness, the mobile stand being placed at a given distance from the fixed stand. The bend test device further includes a reciprocation device configured to move the mobile stand back and forth relative to the fixed stand along the reciprocation axis. The reciprocation device includes a shift regulator for defining the reciprocation distance of the mobile stand relative to the fixed stand. The first and second fixing points of the respective fixed and mobile stands are placed on the same elevation level, so that the electrical cable or wire harness is repeatedly bent at its middle point between the first and second fixing points.

Abstract: A rubber plug includes a seal portion and an extension portion. Inner and outer peripheral lips form respective water-tight seals between the rubber plug and a cavity, and the rubber plug and a wire. The extension portion extends from the seal portion toward an open end of the cavity. When a bending force acts on the wire, the extension portion slightly deforms elastically, Put the seal portion will not be deformed. Therefore, the water-tight condition between the cavity and the wire is maintained. Therefore, even when a bending force acts on the wire, water is prevented from intruding into the cavity.