摘要:
The invention relates to a method for producing double or multilayer ferroelectret with defined cavities by: structuring at least one first surface of a first polymer film (1) forming a height profile, applying ate least one second polymer film (5, 1′) to the structured surface on the first polymer film formed in step a), joining the polymer films (1, 1′, 5) to give a polymer film composite with the formation of cavities (4, 4′) and electrically charging of the inner surfaces of the cavities (4, 4′) formed in step c) with opposing electrical charges. The invention further relates to ferroelectret multilayer composites, optionally produced by said method, comprising at least two polymer films, arranged one over the other and connected to each other, wherein cavities are formed between the polymer films. A piezoelectric element comprising a said ferroelectret multilayer composite is also disclosed.
摘要:
A method and a device for detecting faulty functioning of actuators in the air system on internal combustion engines, an actuator being operated using at least two control states, one after the other, at least one sensor, whose output signal is a function of the excursion state of the actuator, reading out the output signal of this sensor being undertaken, and an assessment of the function of the controlled actuator being undertaken from the response of this output signal to the change of the control of the actuator, during the control of the actuator, at least the control of those other actuators included in the air system being kept constant as well as additional control signals for operating the internal combustion engine, which have an influence on the output signal of the sensor.
摘要:
The present invention relates to NCO prepolymers having a low content of free monomeric diisocyanate, to a process for the production of these NCO prepolymers, to polyurethanes prepared from these NCO prepolymers and to processes for the production of these polyurethanes.
摘要:
A metal band inlay for trim strips or sealing strips of flexible material that is bent to form a section. The metal band includes a plurality of edge slots in the longitudinal direction, which are guided inwardly from an edge of the metal band transversely to the longitudinal direction. The edge slots are wedge shaped. Central slots run to a tip toward their respective two ends and are arranged between the sequential edge slots. The central slots extend transversely to the longitudinal direction, but do not extend up to the edge. To simplify the cutting, the metal band further includes throughcuts that extend transversely to the longitudinal direction of the metal band, that correspond to at least some of the central slots and that extend from at least one edge of the metal band in the direction toward the tip of the respective central slot disposed opposite to the edge.
摘要:
A control method for an actuator (1-4) of an injector of a fuel injection system in an internal combustion engine has the following steps: specification of a target value (SOISOLL) for the start of the injection; electric control of the actuator (1-4) at a specific trigger time (tTRIGGER) with a specific actuator energy (E); detection of an actual value (SOI1IST, SOI2 IST, SOI3 IST, SOI4 IST ) at the start of the injection; determination of the deviation between the target and actual values (DeltaSOI1, DeltaSOI2 , DeltaSOI3 , DeltaSOI4) at the start of the injection; and adjustment of the actuator energy (E) in accordance with the deviation between the target and actual values (DeltaSOI1 , DeltaSOI2 , DeltaSOI3 , DeltaSOI4) at the start of the injection to control the start of the injection.
摘要:
This invention relates to an apparatus and a process for rapidly and accurately dispensing fluids, in which at least one component is dispensed into the reaction vessel in two or three stages. In this process, the amount of fluid dispensed in the second and third stages is determined on the basis of the mass flow rate calculated in the preceding sub-step.
摘要:
The present invention relates to polyurethane cast elastomers which are prepared from higher molecular weight polyhydroxy compounds, durene diisocyanate and low molecular weight chain-lengthening and/or crosslinking agents. These elastomers are particularly useful for the production of moldings exposed to high mechanical stresses.
摘要:
An actuator is operatively connected to a closing member via a tappet. The closing member is introduced in a valve chamber and forms, with a conically tapering valve seat as part of a servovalve, a seal resistant to high pressure. The cross section of the closing member is configured to be mushroom-shaped, a closing head being in the form of a part-sphere and having a central flattening, with the result that the tappet has an enlarged bearing surface. A stem of the closing member is surrounded by a valve spring. The closing member is preferably shaped out of a solid sphere.
摘要:
A thermoplastic polyurethane elastomer is disclosed obtained by reactingA) diisocyanates,B) polyhydroxy compounds and/or polyamines, withC) as chain extenders mixtures ofC1) benzene substituted with at least two hydroxyalkyl, hydroxyalkoxy, aminoalkyl and/or aminoalkoxy groups andC2) an alkanediol with 4 to 44 C atoms. The reaction is further characterized in that the molar ratio C1 to C2=60 to 40 to 95 to 5 and in that the equivalent ratio of NCO groups to the sum of the NCO-reactive groups is about 0.9 to 1.20.