Fichtel & Sachs Ag

Mannesmann Sachs Ag

Zf Sachs Ag

Zf Friedrichshafen Ag

Manfred Grundei

Hans Reimer

Otto Samonil

Steffen Heyn

Bernd Zeissner

Gunther Braun

Norbert Deppert

Peter Wolki

Felix Woessner

Frank Gundermann

Sabine Lack

Christian Böhm

Robert Wieser

Harald Holzapfel

Vibration damper, containing a damping medium-filled cylinder, in which a piston rod with a piston is installed with freedom of axial movement, where, as a function of the stroke of the piston, a bypass connects a working space on the piston rod side to a working space on the side away from the piston rod, the two spaces being separated from each other by the piston, where the piston has at least one through-channel for at least one flow direction, the outlet side this channel being at least partially covered by at least one valve disk, so that a surface is present on the valve disk upon which pressure can act in the opening direction of the disk, where, in addition to the said pressure-actuated surface, the valve disk also has a second pressure-actuated surface, which is separated from the first when the valve disk is closed and which can be put into action by the bypass, so that the effects of the two pressure-actuated surfaces are added to each other.

Vibration damper with stroke-dependent damping force

A piston rod with a piston is installed with freedom of axial movement in a damping medium-filled cylinder, where, as a function of the stroke position of the piston, a bypass connects the two working spaces separated from each other by the piston. The piston has at least one through-channel for at least one flow direction, which channel is at least partially covered on the outlet side by at least one valve disk, so that a first pressure-actuated surface to which pressure can be applied in the opening direction is present on the valve disk. In addition to the first pressure-actuated surface, the valve disk has a second pressure-actuated surface, which is separated from the first when the valve disk is closed and which can be actuated via the bypass, in which case the effects of the two pressure-actuated surfaces are additive. The second pressure-actuated surface of the valve disk, in addition to the first pressure-actuated surface of the valve disk, is designed with its throttle point in the area of the second pressure-actuated surface at least during a certain phase of the travel of the valve disk.

A vibration damper with a hydraulic-mechanical pressure stop includes a cylinder filled with damping medium; a piston rod movable in and out of the cylinder, a first piston fixed to the piston rod with freedom of axial movement, a second piston spaced from the first piston, a transfer spring in the second working space for moving the second piston toward the third working space in response to movement of the first piston toward the second working space; and a disk valve which allows damping medium to flow from the third working space through the second piston to the second working space as the second piston moves toward the third working space. The first piston divides the cylinder into a first and a second working space where the piston rod extends through the first working space. The second piston separates the second working space from a third working space.

Vibration damper with a hydraulic pressure stop

A vibration damper includes a cylinder in which a piston rod is guided so as to be axially movable. A first piston is mounted stationary on the piston rod and a second piston is mounted so as to be displaceable axially on the rod against a spring force. The cylinder has a work space at the piston rod side, a work space remote of the piston rod, and a work space between the two pistons. Through-openings which are outfitted with valves control a connection between the work spaces. The second piston has at least one return spring on both sides, and the piston is mounted so as to be displaceable axially in two directions against the return springs.

Vibration damper

A damping device with variable damping force, including a cylinder, in which a piston rod is arranged axially movably, and an adjustable damping valve which is activated as a function of the compression travel of an axle part. The adjustable damping valve is activated by a generator device. The generator device includes an equidirectional device which causes an equidirectional regulating variable to take effect on the adjustable damping valve independently of the compression direction.

Damping force device with adjustable damping force

A vibration damper with variable damping force, including a cylinder, in which a piston with a piston rod is arranged in axially movable fashion, whereby an adjustable damping valve is activated in dependence on the deflection distance and the activation of the adjustable damping valve is carried out via a stabilizer. The vibration damper has further damping valves, whose damping effects are independent of activation by the stabilizer. The adjustable damping valve, during equilateral deflection and rebound travel of the piston rod on a vehicle axle or unilateral rebound travel, has a damping force setting that is smaller than the damping force of the further damping valves of the vibration damper.

Vibration damper with variable damping force

The invention is directed to a spring strut for motor vehicles comprising a hydropneumatic vibration damper and a supporting spring. The vibration damper has a piston rod connected with a piston and is axially guided in a piston rod guide at the end of a container. The piston rod is outwardly sealed by a piston rod seal. The piston rod guide comprises a damping valve acted upon by external forces, such as the force of the supporting spring arranged between a structural component part connected with the vehicle and a spring carrier surrounding the container of the spring strut. The spring carrier acts on the damping valve with a contact surface. The supporting spring and/or the spring carrier cooperates with at least one auxiliary device exerting a force. The auxiliary device is supported at the container by a structural component part that is fixed with respect to the container or at a vehicle part which is connected with the container.

Spring strut for vehicles

A vibration damper with variable damping force, including a cylinder, a piston and a piston rod arranged in the cylinder so as to be axially movable, an adjustable damping valve connected between the piston rod and the cylinder, and controlled as a function of a spring deflection path, a device for controlling the adjustable damping valve, and additional damping valves arranged to have a damping effect on the piston independent of the controlling device.

A piston-cylinder aggregate comprising a cylinder in which an axially movable piston rod is arranged is provided. The piston rod has two pistons, which are separated from each other and which produce a damping force of a variable magnitude depending on the piston rod's stroke position. The piston-cylinder aggregate has a bypass area defined in its inner wall along a portion of the length of the cylinder, so that the damping force is at least reduced in the stroke area of the bypass, and the two pistons have a separation equal to or less than the length of the bypass, such that depending on the position of the piston rod, a damping force of variable magnitude is produced. For example, when both pistons are disposed within a section of the cylinder defined by the bypass area, the dampening force exerted by the piston rod is minimized, while when both pistons are outside the bypass area, the dampening force in both stroke directions is maximized.

Piston-cylinder aggregate with displacement-dependent dampening force

A vibration damper, whose cylinder tube is divided into two work chambers by a piston, is attached to a piston rod. A damping valve includes a damping valve body. Embossed areas have been formed into the main body of the damping valve body. The damping valve embossed areas serve as valve support surfaces with fluid passages, which fluid passages are covered by valve disks on the valve support surfaces. The damping valve body is disk-shaped, whereby the damping valve is equipped with at least one restrictor plate, which restrictor plate partially covers the inlet side of the fluid passages for at least one direction of flow, whereby the restrictor plate has recesses for the embossed areas of the damping valve body.

Vibration damper with restrictor plate

A vibration damper has a cylinder tube which is divided into two work chambers by a piston, which is fastened to a piston rod. The piston has a piston body which has fluid passage channels which are covered by valve discs on supporting bodies with valve support surfaces, and the piston body is in a sliding or frictional connection, by way of at least one piston ring, with the cylinder tube. The piston ring covers the peripheral surface of the piston body and is axially supported respectively on the upper side and the lower side of the piston. The piston body is in a disc-shape, is in one piece and is manufactured by stamping. Starting from the piston base body, the piston body areas which are raised on one side of the piston are depressions on the axially opposite side of the piston. The piston ring is able to move axially as a function of the direction of movement, and is actuated by the friction force between the cylinder tube and the piston ring. Between the surface of the piston ring facing the piston and the surface of the piston, there is at least one advance opening cross section which is opened as a function of the axial position of the piston ring in relation to the piston body.

Piston with direction-dependent advance opening cross sections

A vibration damper includes a pressure tube in which a piston on a piston rod which can move axially is guided by means of a piston rod guide which closes the pressure tube. The piston divides the pressure tube which is filled with damping medium into two working chambers. A piston ring which covers a peripheral area of the piston has an essentially U-shaped cross section with retaining surfaces, whereby the retaining surfaces are supported on the upper and lower side of the piston. On at least one side of the piston, at least a portion of the piston on which the retaining surfaces of the piston ring are engaged has a profiled surface. The profiled surface is configured such that the distance between one side of the piston and a hypothetical reference plane which runs parallel to the piston side is alternately less than and greater than a specified size of fit.

A shock absorber with an affixed or clamped-on piston ring for a piston-cylinder unit, whereby the piston ring covers a lateral surface of the piston and creates a seal with respect to the cylinder, characterized by the fact that the piston ring has a width which is greater than the lateral surface, so that there is a projecting end of the piston ring with respect to the piston, which projecting end is shaped into a spring end which is supported on the cover side on the piston.

Shock absorbers and vibration dampers; and shock absorbers and vibration

Vibration damper, the piston valve of which is fastened to a piston rod, and which comprises a piston body with fluid passage channels which are covered by valve discs on support bodies with valve support surfaces, whereby the piston divides a cylinder tube into two work chambers by way of at least one piston ring, characterized by the fact that the piston body is realized in a disc shape, in one piece, and by way of stamping.

Shock absorber for a motor vehicle, which shock absorber has a piston

A vehicle, including a vehicle body, a chassis with wheels and tires on which the vehicle rests, a number of vehicle suspension springs and shock absorbers which are mounted between the wheels and the vehicle body and execute a change in their axial length as a function of the wheel spring travel in the form of a displacement between a piston fastened to a piston rod and a pressure tube of the shock absorber, and thereby displace a damping medium through a damping device, as well as an arrangement to fasten the piston rod and the pressure tube to the vehicle body and the wheel, characterized by the fact that the shock absorber has a damping force family of characteristics which consists of at least three individual damping force families of characteristics, the first damping force family of characteristics of which is designed so that it exerts a very low damping force, whereby this damping force family of characteristics is located in the vicinity of the normal spring deflection range of the shock absorber, and makes a transition in the decompression and compression directions respectively into damping force families of characteristics which entail a greater damping force in relation to the stroke length, compared to the first damping force family of characteristics.

Growing community of inventors

Niederwerrn, Germany

Manfred Grundei