DE1813849A1 - Remote controllable, continuously electrically excitable, hydraulic damper - Google Patents

Description

Remote controllable, continuously electrically excitable hydraulic damper.

Hydraulic dampers are widely used in mechanical weighing systems, wp with their call is always separated from the locking, which in turn is the scale system should estimate against sudden loads.

In testing operations it is unavoidable, in addition to the attenuation of the scale display to dampen natural vibrations of the lever system for quick and precise reading. There are vibrations of different frequencies and amplitudes depending on the exciting forces present, whereby a fine tuning of the damper effect is desirable.

The known devices use mechanical adjustment members for this purpose such as disc pistons, with which the throttling effect for the hydraulic fluid is used so that the damping is set "harder" or "softer". One Another possibility is to make the damper fluid more viscous or thinner to choose. Both methods have one disadvantage in common: they require one Intervention in the weighing system, which in the case of a continuous test sequence (e.g. program control, Torque respectively Performance recorder) does not make sense. In addition, the effect is the change made only after the arbitrary intervention has subsided judge.

The locking of the conventional mechanical balance systems requires a limit position of the lever, so that a set balance during ongoing testing can no longer be read. However, this is desirable when a drive motor is subjected to a test run by means of a power brake and switches from power output (braking operation) to power consumption (towing operation) of the test motor. shall be. With the help of the new damping device, it is possible to start the tow motor during braking and to record the starting torque in a second, parallel, remote-controlled damper without it getting into the working force measuring system and falsifying the display of the test specimen. That was not possible with the conventional lock.

The proposed improvement aims to enable: The creation of a sensitive damping device with electrical remote control to achieve an optimal hydraulic. Damper effect in connection with a lock, which is independent of the respective lever position.

(It thus differs from the pure damping according to the German Patent No. 965 169.) For this purpose, the damper piston 1 (see illustration) is equipped with a Coil 2 provided, which is electrically excitable and thereby within the damper fluid 3 builds up a magnetic field. The oil-magnetic powder mixture 3 is in its toughness depending on the size of the magnetic induction and thus in the range of 10cSt adjustable to #. An actuator (e.g. potentiometer) not shown outside the damper enables the coil current to be changed. Because the required Electric power is low and therefore practically lossless over a distance of several stitches can be directed, the actuator becomes independent from the spatial Arrangement of the damper. The power supply can be used in the usual way, e.g. the public Can be taken from the mains, if necessary with the interconnection of ri1transformatoren, Rectifiers etc.

as well as time-dependent elements in programmed test sequences and intermittent excitation current to generate special damping effects arbitrary times.

In order to maintain the oil-magnetic powder mixture even within months of downtime To keep homogeneous, there are small permanent magnets 4, their weak magnetic field keep the powder particles in suspension against gravity.

A drain screw 6 is provided for emptying the damper housing 5.

The mechanical mixing can be achieved by the trough-shaped piston design 7 are funded. When moving up and down in the test bench operation respectively. manually During commissioning, a good mix can also be achieved in this way.

There is also the possibility of using the trough space 8 with a to fill in letterpress, uni o a combination of the "hard" oil damping with the "consecration" To create air cushioning. my particularly intensive mixing is achieved, when the trough 8 is eeist from a compressed air network via a pipe 9 and the Air throughput is reduced via an actuator (e.g. needle valve). The effect the air flushing on the mixture 3 is then comparable to that of a mammoth pump, in the case of the specifically heavier parts in the air-liquid mixture (magnetic powder particles) be promoted upwards.

Claims (2)

Claims. 1.) Remote operated, continuously electrically excitable, hydraulic Damper with a thixotropic mass, the consistency of which can be freely adjusted between the toughness axes approx. 10 c St and absolute rigidity, characterized in that for continuous reading of a measuring device the damping effect time-, force- or can be set depending on the current in such a way that foreign vibrations are superimposed and big resonances do not falsify the measurement result or even a reading at all Make Ymöglieh. 2.) Damper according to claim i), characterized in that the Lingriff be made time-, power- or current-dependent by a target / actual comparison can 3.) damper according to claim 1), characterized in that the piston head a geometric shape (e.g. trough-shaped), which results in an intensive mixing of the thixotropic mass with intense up and down movement allows 4.) damper after Claim 1), characterized in that the trough-shaped bottom with air from athrnospheric Pressure is filled 5.) Damper according to claim 1), characterized in that the Air pressure is taken from a storage or compressed air network and through the rigidity the thixotropic mass is considerably above the atmospheric pressure 6.) Damper according to claim 1), characterized in that k that the compressed air for whirling up and Mixing of the thixotropic mass is used to produce a homogeneous mixture 7.) damper according to claim 1), characterized in that ,. that permanent magnets generate a weak magnetic field, and at times the non-excitation of the coil 2 inho: .o-ene to prevent scaffolding.