Apparatus and method for driving a solenoid valve

Patent metadata

Field	Value
Publication number	US-10288186-B2
Application number	US-201715841411-A
Country	US
Kind code	B2
Filing date	Dec 14, 2017
Priority date	Dec 16, 2016
Publication date	May 14, 2019
Grant date	May 14, 2019

Abstract

The disclosure relates to an apparatus and a method for driving a solenoid valve. The apparatus comprises a PWM apparatus, an evaluation and control unit, and a current measuring apparatus The evaluation and control unit is configured to: in a test operation, generate and emit test PWM signals having test duty ratios, the test PWM signals inducing test currents through a magnet assembly of the solenoid valve that are below a response threshold that triggers a switching process of the solenoid valve; derive presently prevailing ambient conditions of the test operation from the test PWM signals and the induced test currents; and in a normal operation generate and emit a PWM signal based on the presently prevailing ambient conditions of the test operation, the PWM signal inducing a current that is above the response threshold and switches the solenoid valve.

First claim

What is claimed is:

1. A method for driving a solenoid valve ( 3 ), having the following steps:
in normal operation, generating PWM signals (PWM) and emitting said PWM signals to a magnet assembly ( 3 . 1 ) of the solenoid valve ( 3 ),
detecting resulting currents (I) through the magnet assembly ( 3 . 1 ), said currents being based on duty ratios (TV) of the PWM signals (PWM), and reporting said currents back,
wherein a current (I) that is above a response threshold of the magnet assembly ( 3 . 1 ) triggers a switching process of the solenoid valve ( 3 ),
wherein, in test operation, at least one test PWM signal (TPWM 1 , TPWM 2 ) is generated and emitted, said test PWM signal inducing a test current (IT 1 , IT 2 ) that is below the response threshold through the magnet assembly ( 3 . 1 ), distinguished by the following steps:
in test operation, generating and emitting at least two different test PWM signals (TPWM 1 , TPWM 2 ),
detecting the resulting test currents (IT 1 , IT 2 ),
deriving presently prevailing ambient conditions from the predefined test PWM signals (TPWM 1 , TPWM 2 ) and the resulting test currents (IT 1 , IT 2 ),
in normal operation, generating and emitting a subsequent PWM signal (PWM), which is based on the presently prevailing ambient conditions and induces a current (I) that is above the response threshold, for the purpose of switching the solenoid valve ( 3 ).

2. The method as claimed in claim 1 , wherein a first test PWM signal (TPWM 1 ) having a first duty ratio (TV 1 ), said first test PWM signal inducing a first test current (IT 1 ), and a second test PWM signal (TPWM 2 ) having a second duty ratio (TV 2 ), said second test PWM signal inducing a second test current (IT 2 ), are generated and emitted to the magnet assembly ( 3 . 1 ) of the solenoid valve ( 3 ) and resulting test currents (IT 1 , IT 2 ) are detected, wherein the different test PWM signals (TPWM 1 , TPWM 2 ) are generated and emitted within a predefinable time window or in an event-oriented manner or at predefined times.

3. The method as claimed in claim 2 , wherein, for the presently prevailing ambient conditions, a present functional relationship between the duty ratios (TV 1 , TV 2 ) and the resulting test currents (IT 1 , IT 2 ) from the predefined duty ratios (TV 1 , TV 2 ) of the test PWM signals (TPWM 1 , TPWM 2 ) and the resulting detected test currents (IT 1 , IT 2 ) is determined and, in normal operation, a corresponding duty ratio (TV) of the subsequent PWM signal (PWM), which is to be applied, is extrapolated by means of the functional relationship and a corresponding subsequent PWM signal (PWM) is generated and emitted.

4. The method as claimed in one of claims 1 to 3 , wherein, in normal operation, presently prevailing ambient conditions are derived from the PWM signals (PWM) and the resulting currents (I) and, for a subsequent switching process, a subsequent PWM signal (PWM) having a duty ratio (TV) is generated and emitted based on the presently prevailing ambient conditions, said subsequent PWM signal inducing a current (I) that is above the response threshold, for the purpose of switching the solenoid valve ( 3 ).

5. An apparatus ( 1 ) for driving a solenoid valve ( 3 ), having an evaluation and control unit ( 10 ), a PWM apparatus ( 20 ) and a current measuring apparatus (AM), wherein, in normal operation, the evaluation and control unit ( 10 ) generates a PWM signal (PWM) having a duty ratio (TV) and emits said PWM signal to a magnet assembly ( 3 . 1 ) of the solenoid valve ( 3 ) by means of the PWM apparatus ( 20 ), wherein the current measuring apparatus (AM) detects a current (I) through the magnet assembly ( 3 . 1 ) resulting from the PWM signal (PWM) and reports said current back to the evaluation and control circuit ( 10 ), wherein a current (I) that is above a response threshold of the magnet assembly ( 3 . 1 ) triggers a switching process of the solenoid valve ( 3 ), and wherein, in test operation, the evaluation and control circuit ( 10 ) generates and emits at least one test PWM signal (TPWM 1 , TPWM 2 ) having a duty ratio (TV 1 , TV 2 ) by means of the PWM apparatus ( 20 ), said at least one test PWM signal inducing a test current (IT 1 , IT 2 ) that is below the response threshold through the magnet assembly ( 3 . 1 ), wherein, in test operation, the evaluation and control unit ( 10 ) generates and emits at least two different test PWM signals (TPWM 1 , TPWM 2 ) and detects the resulting test currents (IT 1 , IT 2 ), wherein the evaluation and control unit ( 10 ) derives presently prevailing ambient conditions from the predefined test PWM signals (TPWM 1 , TPWM 2 ) and the resulting test currents (IT 1 , IT 2 ) and, in normal operation, generates and emits a subsequent PWM signal (PWM) based on the presently prevailing ambient conditions, said subsequent PWM signal inducing a current (I) that is above the response threshold, for the purpose of switching the solenoid valve ( 3 ).

6. The apparatus ( 1 ) as claimed in claim 5 , wherein the evaluation and control unit ( 10 ) generates a first test PWM signal (TPWM 1 ) having a first duty ratio (TV 1 ), said first test PWM signal inducing a first test current (IT 1 ), and a second test PWM signal (TPWM 2 ) having a second duty ratio (TV 2 ), said second test PWM signal inducing a second test current (IT 2 ), and emits said test PWM signals to the magnet assembly ( 3 . 1 ) of the solenoid valve ( 3 ) by means of the PWM apparatus ( 20 ), wherein the current measuring apparatus (AM) reports the resulting test currents (IT 1 , IT 2 ) back to the evaluation and control unit ( 10 ).

7. The apparatus ( 1 ) as claimed in claim 6 , wherein, for the presently prevailing ambient conditions, the evaluation and control unit ( 10 ) determines a present functional relationship between the duty ratios (TV 1 , TV 2 ) and the resulting test currents (IT 1 , IT 2 ) from the predefined duty ratios (TV 1 , TV 2 ) of the test PWM signals (TPWM 1 , TPWM 2 ) and the resulting measured test currents (IT 1 , IT 2 ) and extrapolates, in normal operation, a corresponding duty ratio (TV) of the PWM signal (PWM), which is to be applied, by means of the functional relationship and generates and emits a corresponding PWM signal (PWM) by means of the PWM apparatus ( 20 ).

8. The apparatus ( 1 ) as claimed in one of claims 5 to 7 , wherein the evaluation and control unit ( 10 ) generates and emits the different test PWM signals (TPWM 1 , TPWM 2 ) within a predefinable time window or in an event-oriented manner or at predefined times by means of the PWM apparatus ( 20 ).

9. The apparatus ( 1 ) as claimed in one of claims 5 to 8 , wherein, in normal operation, the evaluation and control unit ( 10 ) derives presently prevailing ambient conditions from the PWM signals (PWM) and the resulting currents (I) and, for a subsequent switching process, generates and emits a subsequent PWM signal (PWM) having a duty ratio (TV) based on the presently prevailing ambient conditions, said subsequent PWM signal inducing a current (I) that is above the response threshold, for the purpose of switching the solenoid valve ( 3 ).

10. A hydraulic assembly ( 5 ) having at least one solenoid valve ( 3 ) and at least one apparatus ( 1 ) for driving a solenoid valve ( 3 ), wherein the apparatus ( 1 ) for driving a solenoid valve ( 3 ) is embodied as claimed in one of claims 5 to 9 .

Assignees

• Bosch Gmbh Robert

Inventors

• Gardt Andrej
• Eisele Christoph
• Schubitschew Valentin
• Edelmann Volker

Classifications

• B60T2270/406

  Test-mode; Self-diagnosis · CPC title

• B60T8/171 Primary

  Detecting parameters used in the regulation; Measuring values used in the regulation · CPC title

• H01F7/18

  Circuit arrangements for obtaining desired operating characteristics, e.g. for slow operation, for sequential energisation of windings, for high-speed energisation of windings · CPC title

• F16K31/06 Primary

  using a magnet {, e.g. diaphragm valves, cutting off by means of a liquid} · CPC title

• B60T8/885

  using electrical circuitry · CPC title