Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
  • F04B49/06—Control using electricity
  • F04B49/065—Control using electricity and making use of computers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B17/00—Pumps characterised by combination with, or adaptation to, specific driving engines or motors
  • F04B17/03—Pumps characterised by combination with, or adaptation to, specific driving engines or motors driven by electric motors
  • F04B17/04—Pumps characterised by combination with, or adaptation to, specific driving engines or motors driven by electric motors using solenoids
  • F04B17/046—Pumps characterised by combination with, or adaptation to, specific driving engines or motors driven by electric motors using solenoids the fluid flowing through the moving part of the motor
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B2203/00—Motor parameters
  • F04B2203/04—Motor parameters of linear electric motors
  • F04B2203/0401—Current
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B2203/00—Motor parameters
  • F04B2203/04—Motor parameters of linear electric motors
  • F04B2203/0402—Voltage

Definitions

• the present invention relates to a method and to a device for detecting the state of charge, and in particular the no-load operation, of an electromagnetic pump with vibrating core intended for equipping a household electrical appliance.
• the invention also relates to a household electrical appliance comprising such a detection device.
• Many household appliances such as steam generator irons or automatic coffee machines, have hydraulic circuits with electromagnetic pumps with vibrating cores. These pumps are generally supplied with water from a tank with limited capacity. However, it is important for the safety of the device and the reliability of the pump to ensure that the pump is well supplied with water.
• an object of the present invention is to remedy these drawbacks by proposing a method and a device for detecting the state of charge of an electromagnetic pump with vibrating core which is simple and economical to produce.
• the subject of the invention is a method for detecting the state of charge of an electromagnetic pump with vibrating core fitted to an electrical household appliance, the pump being supplied by a rectified single-phase alternating voltage Up, characterized in that, on each power supply period of the pump, the state of charge of the pump is detected by measuring the time ⁇ T separating the instant to when the pump current lp reaches its maximum of a reference instant t ref of the cycle pump power supply.
• the method comprises the following steps:
• the method according to the invention can comprise one or more of the combinations taken in isolation or according to all the technically possible combinations:
• the instant t ref is the instant t r ⁇ f i of the supply period when the supply voltage U becomes zero;
• the instant t r ⁇ f is the instant t ref where the current of the pump l P becomes zero; - the method is used to detect the vacuum operation of the pump;
• the invention also relates to a device for detecting the state of charge of an electromagnetic pump with vibrating core supplied by a rectified alternating voltage implementing the method described above, characterized in that it comprises means for detecting the 'instant t 0 when the pump current l reaches its maximum.
• the invention also relates to a household electrical appliance provided with a electromagnetic pump with vibrating core supplied by a reservoir and comprising such a state of charge detection device.
• said state of charge detection device is used to determine the no-load operation of the pump and alert the user to the need to fill the reservoir with supplying water the pump.
• FIG. 1 is a schematic sectional view of an electromagnetic pump with vibrating core commonly used on household electrical appliances
• FIG. 2 shows the electrical supply diagram of the pump of Figure 1 equipped with a state of charge detection device according to a particular embodiment of the invention
• FIG. 3 shows two graphs arranged in parallel on the same time scale, the upper graph representing the supply voltage of the sector Us and the lower graph representing the supply voltage of the pump Up, the pump current lp to vacuum and pump current l P under load;
• FIG. 1 schematically represents an example of an electromagnetic pump 1 with a vibrating core conventionally used on an electrical household appliance of the iron type with steam generator.
• the pump is supplied with water from a reservoir not shown in the figure.
• the pump 1 comprises a coil 2 surrounding a hollow metal core 4 mounted to slide, in an axial direction, inside a tubular element 3.
• the core 4 has an end 4a forming a piston which is guided by a second tubular element 5 provided with two non-return valves 6 and 7.
• the magnetic field created by the coil 2 causes the displacement of the core 4 against a return spring 9a, the movement of the core 4 under the effect of the spring 9a being damped at the end of travel by a second spring 9b and by an elastic stop 8.
• the pump is supplied with water by the end 3a of the tubular element 3 and the water is expelled under pressure by the orifice 5a of the tubular element 5.
• the electromagnetic pump 1 is supplied by a rectified alternating voltage Up so that the core 4 moves back and forth during the periodic supply of the coil 2.
• the supply voltage Up illustrated in FIG. 3, is advantageously obtained by simple rectification, by means of a diode, of the alternating voltage Us available on the sector.
• FIG. 2 schematically illustrates the electrical supply of the pump 1 provided with a device for detecting the state of charge according to the invention.
• the pump 1 is connected to the supply voltage Up by being connected in series with a resistor.
• a microcontroller C having an input ei of analog-digital converter for measuring the pump current lp and an input e 2 for synchronizing the mains voltage is connected to the supply circuit of the pump.
• the microcontroller C measures at at each instant the pump current l P and determines, during a second step 102, the instant t 0 of the pump supply period for which the current lp is maximum.
• the microcontroller C measures the time ⁇ T elapsed between the instant t 0 previously detected and a reference instant t ref of the supply cycle of the pump.
• This reference instant t r ⁇ f is for example the instant t ref1 of the curve U P> shown in solid lines in FIG. 4, where the supply voltage Up of the pump becomes zero.
• the reference instant t re f may also correspond to the instant t r ⁇ f2 where the pump current Ip is canceled, the time separating the instant t r ⁇ f1 from the instant t rei2 being substantially constant over each feeding period and independent of the pump load 1.
• the time ⁇ T is compared with a reference time ⁇ T m e m stored in a memory.
• This reference time ⁇ Tme m is obtained by experience and corresponds to the time ⁇ T measured when the pump is running empty.
• the electrical supply to the pump is stopped and an alarm is possibly triggered to signal the need to fill the water tank.
• the steps of the method described above correspond to the steps implemented over each period of the single-phase rectified supply voltage Up, these steps being renewed cyclically.
• the method according to the invention may, in alternative embodiments, also be used to more precisely detect different states load of the pump such as low load, medium load or high load.
• the time ⁇ T measured during step 104 will be compared to a table of stored reference values ⁇ T m em obtained experimentally for different states of charge of the pump, so as to identify the value ⁇ Tmem ' a P' us close to the time ⁇ T measured and deduce the corresponding state of charge of the pump.
• the device for detecting the state of charge may include a capacitor / resistor type derivator to shape the derivative of the pump current Ip and analyze the zero crossing of the signal dlp / dt so to determine the instant t 0 when the current is maximum.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Computer Hardware Design (AREA)
• Control Of Positive-Displacement Pumps (AREA)
• Electromagnetic Pumps, Or The Like (AREA)
• Control Of Non-Positive-Displacement Pumps (AREA)
• Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)
• Reciprocating Pumps (AREA)
• Details Of Reciprocating Pumps (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=33396659

Family Applications (1)

Country Status (8)

Families Citing this family (8)

Family Cites Families (3)

• 2003
  • 2003-05-22 FR FR0306143A patent/FR2855223B1/fr not_active Expired - Fee Related
• 2004
  • 2004-04-01 WO PCT/FR2004/000823 patent/WO2004106736A1/fr not_active Ceased
  • 2004-04-01 EP EP04742421A patent/EP1520105B1/de not_active Expired - Lifetime
  • 2004-04-01 DE DE602004000339T patent/DE602004000339T2/de not_active Expired - Lifetime
  • 2004-04-01 AT AT04742421T patent/ATE316207T1/de not_active IP Right Cessation
  • 2004-04-01 CN CNB2004800007452A patent/CN100366896C/zh not_active Expired - Fee Related
  • 2004-04-01 PT PT04742421T patent/PT1520105E/pt unknown
  • 2004-04-01 ES ES04742421T patent/ES2255702T3/es not_active Expired - Lifetime

Non-Patent Citations (1)

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