Valve assembly with preloaded control oil return

US12044323B2 · kind B2 · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Markus Grammer · Ludwigsburg, DE
• Steffen Knapper · Kleinglattbach, DE

Key dates

• Filing date: Nov 29, 2022
• Grant date: Jul 23, 2024
• Expiry date: Jan 31, 2043

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F15B2211/67
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

A valve assembly includes a linearly moving main slider, a pilot valve, a control oil inlet, and a control oil return. The pilot valve is designed as a 4/3 proportional directional valve, via which a first end face and an opposite second end face of the main slider can be fluidly connected selectively to the control oil inlet or the control oil return so that the main slider (20) is hydraulically movable by adjusting the pilot valve. The pilot valve is electrically adjustable depending on a target current. A position sensor is provided, with which an actual position of the main slider can be measured. A positioner is provided, with which the actual position can be regulated by adjusting the target current to a predefinable target position. The pilot valve is connected to the control oil return via a check valve. The check valve only permits fluid flow from the pilot valve toward the control oil return. The check valve is preloaded to a closed position by means of a first spring so that it opens at a predetermined opening pressure. The leakages at the pilot valve from the control oil inlet toward the check valve are designed to be so large that if the pressure at the control oil inl…