Method and device for testing solenoid valves

Patent metadata

Field	Value
Publication number	US-9759760-B2
Application number	US-201213552361-A
Country	US
Kind code	B2
Filing date	Jul 18, 2012
Priority date	Jul 25, 2011
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

A device for testing a solenoid valve includes: a voltage generator for applying a short pulse of voltage, which is not long enough to open the solenoid valve, to the windings of the solenoid valve; a current meter configured for measuring the current flowing through the windings of the solenoid valve; and an analysis device which is configured for analysing the current measured by the current meter for detecting a potential fault of the solenoid valve.

First claim

What is claimed is:

1. A method for testing a solenoid valve, comprising:
applying a voltage to a winding of the solenoid valve for a period of time which is not long enough to open the solenoid valve;
obtaining a current waveform flowing through the winding that results from the applied voltage; and
analysing both of a form and an amplitude of the current waveform to identify faults of the solenoid valve.

2. The method of claim 1 , wherein the voltage is applied for less than 50 ms.

3. The method of claim 2 , wherein the voltage is applied in the form of a square pulse.

4. The method of claim 2 , wherein a disconnection is detected if the form of the current waveform indicates that no current is flowing through the winding.

5. The method of claim 2 , wherein a mechanical pin of the solenoid valve being stuck in an open position is detected if the amplitude of the current waveform is below a first threshold.

6. The method of claim 2 , wherein a mechanical pin of the solenoid valve being stuck in a closed position is detected if the amplitude of the current waveform exceeds a second threshold.

7. The method of claim 2 , wherein the step of analysing includes analysing the form of the current waveform over time.

8. The method of claim 7 , wherein a short circuit is detected if the amplitude of the current waveform is a square wave which exceeds a predetermined third threshold.

9. A device for testing a solenoid valve, comprising:
a voltage generator for applying a short pulse of voltage, which is not long enough to open the solenoid valve, to a winding of the solenoid valve;
a voltage meter configured for measuring a current waveform flowing through the winding of the solenoid valve; and
an analysis device configured for analysing both of a form and an amplitude of the current waveform to detect a fault of the solenoid valve;
wherein the current waveform is measured via components that include:
a shunt connected serially to the winding of the solenoid valve; and
the voltage meter configured to measure the current waveform via voltage caused by the current flowing through the shunt.

Assignees

• Leif Thyssen
• Mahle Int Gmbh

Inventors

• Leif Thyssen

Classifications

• G01R31/2829 Primary

  Testing of circuits in sensor or actuator systems (testing of apparatus for measuring electric or magnetic variables G01R35/00; testing of indicating or recording apparatus G01D; in airbag systems B60R21/0173; checking gas analysers G01N33/007; monitoring or fail-safe circuits for electromagnets H01F7/1844) · CPC title

• G01R31/72

  Testing of electric windings (testing of transformers G01R31/62) · CPC title

• G01R31/06 Primary

  Physics · mapped topic

• G01R31/025

  Physics · mapped topic

• G01R31/52

  Testing for short-circuits, leakage current or ground faults · CPC title