| 摘要 |
The instant invention relates to an apparatus for metering at least two flowable reaction components, such as polyurethane-forming components, in a predetermined ratio into a mixing chamber. The apparatus broadly comprises a metering unit for each component, which is made up of a piston and cylinder, a feed pipe leading from a storage container into the cylinder, a delivery pipe leading from the cylinder to the mixing chamber and optionally a return pipe, and a drive unit. Each drive unit is in the form of an electro-hydraulic linear amplifier which comprises a stepping motor for a control mechanism which is coupled to a hydraulic piston and cylinder, wherein the drive unit is capable of driving the metering piston. Control electronics are provided for controlling the metering units. The controls comprise at least one adjustable control frequency generator for generating signals to be fed to the electro-hydraulic linear amplifiers to control the movements of the metering pistons. A first signal path is provided for conducting signals to at least one of the electro-hydraulic linear amplifiers from a control frequency generator and a second signal path is provided for conducting the control frequency generator signals to all other electro-hydraulic linear amplifiers via an adjustable frequency reducer. |
