Solenoid valve, especially for hydraulic brake systems with slip control

US5647644A · kind A · utility

Assignee

• ITT Automotive Europe GmbH · DE

Inventors

• Peter Volz · Darmstadt, DE
• Dalibor Zaviska · Frankfurt am Main, DE

Key dates

• Filing date: Dec 14, 1995
• Grant date: Jul 15, 1997
• Expiry date: Dec 14, 2015

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S188/01
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

A solenoid valve for use with a slip-controlled brake system has an annular piston with a switchable diaphragm in order to lower the valve noises. The annular piston moves, in response to differential pressure, between a first position at which a pressurized medium flow path parallel to the diaphragm exists and a second position at which pressurized medium flows exclusively through the diaphragm. A pressurized agent channel, arranged upstream of the valve seat, has a portion having a reduced cross section relative to the valve seat, into which a channel branch of small nominal diameter opens. With this design, the pressure energy of the pressurized medium column flowing into the solenoid valve is converted into kinetic energy, which initiates a pressure gradient in the channel branch and prevents premature switching of the annular piston into the diaphragm position during slip-free normal braking.