Injection valve

• US 20040050971A1
• Filed: 05/13/2003
• Published: 03/18/2004
• Est. Priority Date: 03/21/2001
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Stoecklein, Wolfgang, Rueger, Johannes-Joerg, Schmieder, Dietmar
• Granted Patent: US 7,398,933 B2
• Time in Patent Office: Days
• US Class Current: 239/533.2
• CPC Class Codes: F02D 41/2096 for controlling piezoelectric injectors drive and control circuit for piezoelectric devices in general H10N30/802
• CPC Class Codes: F02M 2200/703 hydraulic
• CPC Class Codes: F02M 47/027 Electrically actuated valves draining the chamber to release the closing pressure
• CPC Class Codes: F02M 63/0026 using piezoelectric or magnetostrictive actuators
• CPC Class Codes: F02M 63/0036 with spherical or partly spherical shaped valve member ends

Abstract

An injector is proposed, in particular an injector for a combustion engine. It includes at least one nozzle module (3) which has an injection nozzle and a supply line for a fluid under a supply pressure (p_R), and a valve-control module (2), which is in operative connection with the nozzle module (3), and at least one valve-closure member (16) on which the supply pressure (p_R) acts, and includes a piezoelectric actuator (12) which is used to activate the valve-closure member (16) and which is prestressed by a spring (21) in the direction facing away from the valve-closure member (16), the piezoelectric actuator (12) being activated by a valve-control unit (30) which specifies a control gradient (dU/dt). The control gradient (dU/dt) is a variable that is dependent upon the supply pressure (p_R).

Claims

1. An injector, in particular for a combustion engine, at least comprising a nozzle module (3) which has an injection nozzle and a supply line for a fluid that is under a supply pressure (p_R), as well as a valve-control module (2), which is in operative connection with the nozzle module (3), and at least one valve-closure member (16) on which the supply pressure (p r) acts, and a piezoelectric actuator (12) which is used to activate the valve-closure member (16) and is prestressed by a spring (21) in the direction facing away from the valve-closure member (16), the activation of the piezoelectric actuator (12) being implemented by a valve-control unit (30) specifying a control gradient (dU/dt), wherein the control gradient (dU/dt) is a variable which is dependent upon the supply pressure (p_R).

2. The injector as recited in claim 1, wherein the control gradient (dU/dt) increases with the supply pressure (p_R).