US-12617248-B2 - Inductive shock absorber

Abstract

An inductive shock absorber for a motor vehicle is provided having a cylindrical damper tube and a damper rod. A related method for operating a shock absorber is also provided.

Inventors

• Ronny Demmler
• Jürgen Pöppel

Assignees

• AUDI AG

Dates

Publication Date

20260505

Application Date

20230202

Priority Date

20220203

Claims (13)

1. 1 . A shock absorber for a motor vehicle, comprising: a cylindrical damper tube; and a damper rod, which can move in a linear manner inside the damper tube, and in which at least one permanent magnet is situated, wherein at least two coils are arranged in the damper tube, wherein a first coil and a second coil of the at least two coils are configured to be energized, during operation, by electric currents of different current strength simultaneously to regulate dampening characteristics of the shock absorber.
2. 2 . The shock absorber according to claim 1 , wherein the at least two coils are arranged one on top of the other inside the damper tube.
3. 3 . The shock absorber according to claim 1 , wherein the at least two coils comprise cylindrical coils having an inner diameter which is larger than the outer diameter of the damper rod.
4. 4 . The shock absorber according to claim 1 , wherein the at least two coils comprise toroidal coils having an inner diameter which is larger than the outer diameter of the damper rod.
5. 5 . The shock absorber according to claim 1 , comprising exactly two coils.
6. 6 . The shock absorber according to claim 1 , comprising more than two coils.
7. 7 . The shock absorber according to claim 1 , wherein the electrical terminals of the at least two coils are led out from the damper tube.
8. 8 . The shock absorber according to claim 1 wherein the first coil of the at least two coils is configured to set dampening of a traction stage of the shock absorber.
9. 9 . The shock absorber according to claim 1 wherein the second coil of the at least two coils is configured to set dampening of a compression stage of the shock absorber.
10. 10 . The shock absorber according to claim 1 , further comprising a third coil, wherein the third coil is configured to remain non-energized and to be used for energy recovery.
11. 11 . The shock absorber according to claim 1 , further comprising a third coil, wherein the third coil is configured for fine tuning the dampening behavior of the shock absorber.
12. 12 . A method for operating a shock absorber of a motor vehicle, the shock absorber including a cylindrical damper tube and a damper rod that can move linearly inside the damper tube, wherein the damper tube includes at least two coils and the damper rod includes at least one permanent magnet, the method comprising: regulating a dampening characteristic of the shock absorber by conducting electric currents of different current strength simultaneously through individual coils of the at least two coils; and using kinetic energy of the damper rod to generate electrical energy; and taking the energy out from the at least two coils.
13. 13 . The method according to claim 12 wherein a first individual coil of the at least two coils is configured to set dampening of a traction stage of the shock absorber and a second individual coil of the at least two coils is configured to set dampening of a compression stage of the shock absorber.

Description

BACKGROUND Technical Field An embodiment of the invention includes an inductive shock absorber, such as a chassis damper for a motor vehicle, and a method of operating the shock absorber. Description of the Related Art The shock absorber is a safety-relevant component of the chassis. Shock absorbers have the task of dampening vibrations of the vehicle body on the suspension springs and vibrations of the wheels on the tire springs. Without a dampening, the body vibrations in the range of eigenfrequencies would become too large, so that both the ride comfort and the driving safety would be adversely affected. Too much dampening worsens the ride comfort, but improves the road contact. Therefore, the fine tuning between ride comfort and driving safety is always a compromise. By designing the damper in the traction and compression direction for both small and large damper speeds, one can make sure that the demands for driving dynamics and ride comfort are satisfied as much as possible. The traction stage is usually designed to be harsher than the compression stage, to improve the “springing” when hitting ramp-shaped individual obstacles and to achieve a harmonious build-up of the roll angle during quick evasive maneuvers. In EP 1 510 721 A1 there appears a shock absorber, which performs a telescopic movement as a reaction to a force acting from the outside. The shock absorber has a ball screw mechanism, which converts the telescopic movement into a rotary movement, and which consists of a ball nut and a threaded shaft. A motor is arranged coaxial to the shock absorber. The motor generates an electromagnetic resistance acting against the rotary movement of a shaft of the motor. A cylindrical element is provided, enclosing the shock absorber and the motor on the outside, and its piece covering the motor also serves as the motor frame. A dampening force is generated by the electromagnetic force of the motor, acting against the telescopic movement of the shock absorber. CN 208134000 U relates to an electromagnetic shock absorber and a control circuit, making possible a recovery of energy. A coil winding regulating circuit is used to realize the multistage regulation of the dampening of the shock absorber. An acceleration sensor measures the irregularities of the road surface and provides feedback to the regulating circuit. CN 209948927 U discloses a current generating device for an automotive shock absorber, comprising a shock absorbing rod, a cylindrical body, a sliding cavity, an upper shell, an upper connecting piece and a lower shell, a spring, a magnet, a coil, a wire, a support plate, a lower connecting piece, a traction spring, a rotatable connecting piece, and a compression rod. The shock absorbing rod presses the magnet back and forth through the coil by utilizing the downward pressure on the shock absorbing rod generated by the vehicle in the up and down impact process, and current is generated by electromagnetic induction, which can be used by any electrical component in the vehicle. BRIEF SUMMARY Some embodiments provide a shock absorber with electrically adjustable dampening characteristic, and which can furthermore be used for generating a current. Some embodiments include a shock absorber, for example a chassis damper for a motor vehicle having a cylindrical damper tube and a damper rod, which can move in a linear manner inside the damper tube. In the damper rod there is at least one permanent magnet (magnetic core), and in the damper tube there are arranged at least two coils. In one embodiment, the at least two coils are arranged one on top of the other inside the damper tube, i.e., along the longitudinal axis of the cylindrical damper tube. The shock absorber described herein can be used for example as a chassis damper for a motor vehicle. Other examples of possible uses include a chassis damper in trailers of motor vehicles and utility vehicles, a chassis damper in railway vehicles, seat suspensions, e.g., in trucks or farming vehicles, vibration dampening in ships, in aerospace vehicles, dampers in machine building, in the aerospace industry, dampers in heat pumps or wind turbines, vibration dampers in washing machines, vibration dampers in buildings, and vibration dampers in test stands. The damper rod can move in linear manner inside the cylindrical damper tube. In addition, springs or a hydraulic medium can be provided in the damper for dampening the movement, depending on the need. In one embodiment, no additional dampening medium is present. The dampening then occurs solely through the inductance. In the damper rod there is at least one permanent magnet (magnetic core). In one embodiment, a magnetic core is situated near the lower end of the damper rod. In another embodiment, a magnetic core is situated in the middle of the damper rod. In another embodiment, multiple magnetic cores are present in the damper rod, such as two, three or four magnetic cores, which are spaced apart from each othe