Processes, device for producing a high voltage and installation for electrostatic spraying of a coating product
AssigneeSames S.A.
InventorsJean-Pierre Burtin, Flavien Dobrowolski, Caryl Thome
Life of this patent
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Abstract
A method and device for monitoring operation of a high voltage generator which converts an input voltage into an output voltage which is higher than the input voltage, by measuring at least one first physical quantity which is representative of the input voltage; deriving at least one parameter from the at least one measured first physical quantity; comparing the at least one parameter with a second measured physical quantity which is representative of the magnitude of the output voltage; and producing a response when a predetermined minimum differential exists between the at least one parameter and the second measured physical quantity.
Claims17
A method for spraying a coating product, said method comprising:
- operating a high voltage generator to convert an input voltage into an output voltage which is higher than the input voltage;
- electrostatically charging the coating product with the output voltage;
- measuring at least one first physical quantity which is representative of the input voltage;
- deriving at least one parameter from the at least one measured physical quantity;
- comparing the at least one parameter with a second measured physical quantity which is representative of the magnitude of the output voltage;
- producing a response when at least a predetermined minimum differential exists between the at least one parameter and the second measured physical quantity;
- and
- spraying the coating product which has been electrostatically charged.
A method for spraying a coating product, said method comprising:
- operating a high voltage generator to convert an input voltage into an output voltage which is higher than the input voltage;
- electrostatically charging the coating product with the output voltage;
- selecting an assigned value for the output voltage;
- deriving at least one parameter from the assigned value;
- comparing the at least one parameter with at least one measured physical quantity which is representative of the magnitude of the output voltage;
- producing a response when at least a predetermined minimum differential exists between the at least one parameter and the at least one physical quantity;
- and
- spraying the coating product which has been electrostatically charged.
In an installation for spraying an electrostatically charged coating product, which installation includes a device for generating a high voltage in response to an input signal, the high voltage having a magnitude which is a given function of a parameter of the input signal, means for electrostatically charging the coating product with the high voltage, and means for spraying the electrostatically charged coating product, the improvement wherein said installation further comprises:
- means for measuring a physical quantity representative of the magnitude of the high voltage;
- and
- means for identifying correspondence between the high voltage magnitude which is the given function of the parameter of the input signal and the high voltage magnitude represented by the measured physical quantity.
A method for spraying a coating product, said method comprising:
- providing a high voltage generator which has a low voltage unit that produces a low voltage signal and a high voltage unit that produces an output voltage in response to the low voltage signal;
- measuring the magnitude of the output voltage produced by the high voltage unit;
- measuring at least one parameter defining the low voltage signal;
- deriving from the measured parameter a desired value for the magnitude of the output voltage;
- producing a response when at least a predetermined minimum differential exists between the measured magnitude and the desired value of the magnitude of the output voltage;
- and
- electrostatically charging the coating product with the output voltage and spraying the coating product when no response has been produced.
A method for generating and monitoring an electrostatic charging voltage in a coating product spraying installation, said method comprising:
- generating a low voltage signal;
- generating a high voltage in response to, and as a given function of, the low voltage signal;
- deriving a measured value representing the magnitude of the high voltage and controlling the low voltage signal in response to the measured value in a manner to cause the high voltage to have a desired magnitude;
- and
- monitoring the step of generating a high voltage by
- measuring a parameter representative of the low voltage signal and a parameter representative of the high voltage;
- calculating, on the basis of one of the measured parameters, an expected value which the other parameter would have when the measured value representing the magnitude of the high voltage is being accurately derived;
- determining whether the other measured parameter is consistent with the expected value;
- and
- using the high voltage as the electrostatic charging voltage.
In a method for generating a high voltage for electrostatically charging a coating product, which method includes converting an input voltage into an output voltage which is higher than the input voltage and constitutes the high voltage, by means of a transformer unit composed of an input transformer and a voltage multiplier connected to receive current from the input transformer, the voltage multiplier having a voltage gain, K.sub.3, and in which the high voltage has an assigned desired value, U.sub.des, the improvement comprising verifying proper generation of the high voltage by determining the relation between at least one calculated parameter, U.sub.Tcalc, and at least one measured physical quantity representative of the high voltage, wherein:
- U.sub.Tcalc =(U.sub.des +K.sub.2 .times.I.sub.HT)/(K.sub.1 .times.K.sub.3),
- where:
- K.sub.1 is a numerical coefficient dependent on the characteristics of the input transformer;
- K.sub.2 is a constant numerical coefficient characteristic of the type of voltage multiplier;
- and
- I.sub.HT is the current through the voltage multiplier.
Dependencies are inferred from the claim text.