Patent ID: 9157461
Filing Date: 2015-10-13
Classification: F15B,Y10T

Abstract:
1. A digital hydraulic valve, comprising: a plurality of digitally switchable individual valves that are connected in parallel with respect to a consumer, each of the digitally switchable valves having a through-flow cross section of a first size or greater and being configured to be selectively opened and closed in accordance with digital control signals; at least one compensating valve connected in parallel to the plurality of digitally switchable individual valves and having a through-flow cross section of at least the first size, the at least one compensating valve being configured to be opened and closed in accordance with a PWM signal to produce through-flow rates that are equivalent to through-flow rates produced by valves having through-flow cross sections less than the first size; and a controller configured to generate the digital control signals and the PWM signal, the controller being configured to generate the PWM signal such that the PWM signal has a duty cycle within a range from a first duty cycle to a second duty cycle, the second duty cycle being larger than the first duty cycle, wherein the compensating valve is configured to operate in the first duty cycle in such a manner that the compensating valve alternates in short intervals between a fully closed position and a first position between the fully closed position and a fully open position without arriving at the fully open position, wherein the duty cycle includes an intermediate duty cycle between the first and second duty cycles at which the compensating valve is configured to operate in such a manner that the compensating valve alternates at a predetermined frequency between the fully closed position and the fully open position, and wherein the compensating valve is a two-way two-position switching valve having a predetermined maximum switching frequency.