Hydraulic control device

US6250202A · kind A · utility

Assignee

• Mannesmann Rexroth AG · DE

Inventors

• Peter Buttner · Stockelsdorf, DE
• Armin Stellwagen · Lohr am Main, DE

Key dates

• Filing date: Oct 1, 1999
• Grant date: Jun 26, 2001
• Expiry date: Oct 1, 2019

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F15B20/002
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

A hydraulic control arrangement which has a directional control valve, a hydraulic pump and a two-way cartridge valve constructed as a seat valve. The directional control valve is connected to an inlet line and to a discharge line leading to a tank. Leading off from it is a load line leading to a hydraulic load. The hydraulic pump draws pressure medium from a tank and discharges it into the inlet line. The two-way cartridge valve is arranged in the inlet line and, in a closed position, isolates a second inlet line section leading off from the latter to the directional control valve from a first inlet line section running between the two-way valve and the hydraulic pump. A control piston of the two-way cartridge valve has an annular opening surface exposed to the pressure in the first inlet line section, a central circular opening surface exposed to the pressure in the second inlet line section, and a closing surface, which can be subjected to the pressure in the first inlet line section via a pilot valve in a first position of the latter and can be relieved from the pressure to the tank via the pilot valve in a second position of the latter. The two-way cartridge valve closes when …