Deutsche Forschungs- Und Versuchsanstalt Fur Luft- Und Raumfahrt E.v.

Bernhard Hinz

Walter Steigleder

Richard Kochendorfer

Gerhard Gruninger

To increase the strength of a helical spring with a spring wire made of thermosetting plastic in which reinforcing fibers are embedded that run at an angle of approximately .+-.45.degree. to the longitudinal axis of the spring wire, the fibers are present as a fabric that is wound helically around the longitudinal axis of the spring wire, with the warp and woof threads being at an angle of approximately 45.degree. to the longitudinal axis. A process is also proposed for producing such helical springs.

Helical spring and process for producing it

In order to adjust the fiber orientation of a valve spring retainer made of arbon fiber reinforced synthetic material to the stresses appearing in practical operation, it is suggested that several stacked carbon fiber tissue layers be bedded into the valve spring retainer, that a conical opening run vertical to the tissue layers through these, that the weft and warp threads of the tissue layers are displaced from the cross section of the opening to the outside and each project over a part of the perimeter of the opening and that in the edge area of the opening the displaced weft and warp threads have a greater thickness than in the areas farther away from the opening. Furthermore, a process for the production of such a valve spring retainer is discussed.

Valve spring retainer and process for its production

To reduce deformation of the piston pin for the rotating connection of a ton and a connecting rod in a piston cylinder system, especially in internal combustion engines, where the piston pin is made of fiber-reinforced composite material in which fibers running in different directions are placed, it is proposed that the piston pin is secured against rotation around its longitudinal axis in the piston or in the connecting rod, and has first regions in which the fibers are arranged in planes parallel to the piston pin axis and when secured against rotation in the piston, running parallel to the piston axis, or when secured against rotation in the connecting rod, running parallel to the connecting rod axis, so that they have a component running parallel to the piston axis or to the connecting rod axis.

Piston cylinder system, especially for internal combustion engines

To avoid the necessity of piston rings in a piston-cylinder set, it is prsed that the cylinder liner be surrounded by a band consisting of a fiber composite whose thermal expansion in a radial direction is less than that of the cylinder liner, the impediment to expansion presented by the band varying over the length of the cylinder housing; that the piston be constructed with a cap consisting of a piston head facing the combustion chamber and an essentially cylindrical piston skirt adjacent to the cylinder bearing surface, and a force-transmitting core that contains the bearing for the piston pin and the spherical pressure pad; that a force-transmitting connection rotationally symmetrical to the piston's longitudinal axis be provided above the spherical pressure pad; that the cap be connected at the lower edge of the piston skirt to the force-transmitting core, but otherwise no contact be provided between cap and force-transmitting core except in the area of the force-transmitting connection; and that both cylinder liner and cap be fabricated from ceramic material.

Growing community of inventors

Frankfurt-am-Main, Germany

Bernhard Hinz