Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
  • F01P9/00—Cooling having pertinent characteristics not provided for in, or of interest apart from, groups F01P1/00 - F01P7/00
  • F01P9/04—Cooling having pertinent characteristics not provided for in, or of interest apart from, groups F01P1/00 - F01P7/00 by simultaneous or alternative use of direct air-cooling and liquid cooling
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
  • F01P5/00—Pumping cooling-air or liquid coolants
  • F01P5/14—Safety means against, or active at, failure of coolant-pumps drives, e.g. shutting engine down; Means for indicating functioning of coolant pumps
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
  • F01P7/00—Controlling of coolant flow
  • F01P7/02—Controlling of coolant flow the coolant being cooling-air
  • F01P7/04—Controlling of coolant flow the coolant being cooling-air by varying pump speed, e.g. by changing pump-drive gear ratio
  • F01P7/048—Controlling of coolant flow the coolant being cooling-air by varying pump speed, e.g. by changing pump-drive gear ratio using electrical drives

Definitions

• the invention relates to a method for operating an electric fan motor for an internal combustion engine of a motor vehicle. Furthermore, the invention relates to a control device for carrying out such a method.
• engine cooling fan devices are used to perform cooling functions in an internal combustion engine of a motor vehicle.
• a DC fan motor of the engine cooling fan device generally has a commutator with lamellae, via which rotor coils of the fan motor are energized by means of contacting brushes.
• a speed of the fan motor is usually controlled by an electronic control unit (ECU, Engine
• Control unit of the motor vehicle specified to ensure that an engine temperature is within an acceptable and safety-critical range.
• the engine cooling fan device may be used in such a way that by means of its air flow, a number of coolers arranged behind one another in the engine compartment of the motor vehicle are cooled.
• EP 1 871 998 discloses a method for controlling a fan motor, wherein a control unit drives a fan motor at a certain point in time for a predetermined period of time independently of the desired cooling capacity with a cleaning manipulated variable which is increased in relation to a control manipulated variable. It is the object of the present invention to provide an improved method for operating an electric fan motor for an internal combustion engine of a motor vehicle, which can prevent as far as possible pasting of the fan motor.
• the object is achieved with a method for operating an electric fan motor for an internal combustion engine of a motor vehicle, comprising:
• the method according to the invention it is advantageously possible to reproducibly implement an effective strategy for avoiding or eliminating pasting of the fan motor due to a consideration of paste critical threshold values with respect to speed and operating time of the fan motor. Due to the systematic consideration of these parameters, it is thus advantageously possible to systematically counteract pasteurization of the fan motor as early as possible, thereby advantageously prolonging the service life of the fan motor and reducing the susceptibility of the internal combustion engine of the motor vehicle.
• the commutator of the fan motor is cleaned compared to the known methods only if it is actually required due to a detected exceeding of threshold values. Preventive cleaning processes without real needs and associated wear effects and operational inconvenience are advantageously avoided in this way.
• An advantageous development of the method according to the invention provides that the critical speed with respect to pasting of the fan motor is approximately 2000 rpm (revolutions / minute). In this way, a threshold of a speed of the fan motor is advantageously predetermined and monitored, in whose long-term underrun a fattening of the fan motor is highly probable.
• a preferred embodiment of the method specifies that a relative lapse of critical service life of the fan motor is approximately one hundred hours. As a result, an operating time of the fan motor is set below the critical speed in a defined manner, when exceeded, the fan motor is highly liable to breakage.
• An advantageous development of the method provides that the defined duration of the operation of the fan motor at a speed which is greater than the critical speed with respect to paste, is approximately ten minutes. This defines a so-called washing or cleaning time for the fan motor during which the fan motor must be washed to substantially eliminate unwanted paste substances.
• a preferred embodiment of the method provides that the washing speed substantially corresponds to a maximum speed of the fan motor. Thereby, a speed is specified in a reproducible manner, in which the fan motor said washing time should be operated long to substantially eliminate unwanted pasty materials between the commutator of the fan motor.
• the method is designed as a software of a control device of the motor vehicle.
• no hardware-related modification of the fan system for the internal combustion engine of the motor vehicle is required for carrying out the method according to the invention in an advantageous manner.
• the inventive method can be implemented in a simple manner in an already existing control unit of the motor vehicle without much extra effort.
• An advantageous development of the method provides that the software is designed as part of a control software, wherein the software is processed cyclically.
• carrying out the method according to the invention at regular intervals is advantageously carried out a regular and systematic testing of the fan motor to paste. so Liquorization can be systematically prevented as far as possible during the development process.
• An advantageous development of the method according to the invention provides that the software has a high priority within the control software. This assists that the inventive method is preferably carried out, whereby a freedom from interference of the fan motor is supported and the fan motor in this way its intended cooling functionality can run as long as possible trouble-free.
• An advantageous development of the method according to the invention provides that the critical values with regard to pasteurization for the rotational speed and the operating time of the fan motor are determined from experimental and / or simulation-technical investigations of the fan motor.
• the most suitable numerical values for the rotational speed and operating time critical with respect to pasteurization can be used.
• An adaptability of the method to different types of fan motors is thereby advantageously supported.
• FIG. 1 is a schematic representation of a cooling fan device for an internal combustion engine of a motor vehicle, for which the inventive method can be used;
• Figure 2 shows part of an embodiment of the method according to the invention, wherein critical threshold values are defined, monitored and evaluated; and
• FIG. 3 shows a further part of an embodiment of the method according to the invention, wherein in particular the washing or cleaning process is shown.
• FIG. 1 shows in a highly simplified manner a cooling fan device 100, which is usually installed in an engine compartment of the motor vehicle (not shown) and used for cooling a coolant of an internal combustion engine (not shown) of the motor vehicle.
• the cooling fan device 100 generates a flow of air that passes through a radiator (not shown) and thereby cools the coolant in the radiator.
• the cooling fan device 100 is controlled by a control unit 10, which may be designed, for example, as an electronic control unit (ECU, Electronic Control Unit).
• the controller 10 is electrically connected to a fan controller 20 (Fan Control Module, FCM) which is used to drive a fan motor 20 connected to the electric fan motor 30 of the cooling fan device 100.
• FCM Fan Control Module
• the control unit 10 transmits to the fan control unit 20 a pulse-width-modulated electrical signal, which converts the fan control unit 20 into a corresponding electrical voltage, in order thereby to control the fan motor 30 in terms of speed. In this way, the controller 10 the fan motor 30 before a desired speed and controls it accordingly.
• the inventive method may preferably be implemented as a software program in the control unit 10, the control unit 10 as a central control unit (for example, as an engine control unit) of the motor vehicle or as a partial control device for controlling individual functions may be formed within the motor vehicle.
• any controller which sends speed requests to the fan control unit 20 can be implemented as a software program in the control unit 10, the control unit 10 as a central control unit (for example, as an engine control unit) of the motor vehicle or as a partial control device for controlling individual functions may be formed within the motor vehicle.
• any controller which sends speed requests to the fan control unit 20 can be implemented as a software program in the control unit 10, the control unit 10 as a central control unit (for example, as an engine control unit) of the motor vehicle or as a partial control device for controlling individual functions may be formed within the motor vehicle.
• any controller which sends speed requests to the fan control unit 20 can be implemented as a software program in the control unit 10, the control unit 10 as a central control unit (for example, as an engine control unit) of the motor
• FIG. 2 shows a part of an embodiment of the method according to the invention with a schematic flow chart for the determination and evaluation of Verpastungsschwellen.
• a step S1 it is checked whether a rotational speed of the fan motor 30 is below a rotational speed of the fan motor 30 that is critical with respect to paste.
• a threshold for this critical speed is about two thousand revolutions / minute (2000 rpm).
• a time counter which detects a time duration of operation of the fan motor 30 below the threshold speed is not operated in a step S2.
• step J of step S1 the time counter for detecting the operating time of the fan motor 30 is incremented below the threshold speed in a step S3.
• a check is made as to whether the time detected by the time counter has already reached a critical threshold with regard to pasting of the fan motor 30. A typical value for this threshold is about one hundred hours. If the critical operating time has not yet been reached (branch N of step S4), the process continues without further action.
• a bit switch is set to "true" in a step S5, whereby the method is informed that now there is an acute risk of fouling for the fan motor 30 or has already used the paste that is to say, in principle, a testing of conditions under which there is a risk of entanglement for the fan motor 30.
• the sequence of steps S1 to S5 of the method illustrated in Figure 2 is executed cyclically within the control unit 10, which supports the fan motor 30 systematically and regularly As a result, the pasting of the fan motor 30 is advantageously prevented at the beginning.
• the paste is counteracted by operating the fan motor 30 at a very high rotational speed.
• FIG. 3 shows a further part of an embodiment of the method according to the invention with a sequence of steps S6 to S12, which is carried out in time subsequent to the steps S1 to S5 (see FIG. 2).
• a step S6 it is checked whether the bit switch, which tells the procedure the risk of stickiness of the fan motor 30, is set to "true.” In case the bit switch is not set to "true" (branch N of step S6) the procedure continues without further action. Otherwise (branch J of step S6), a time counter for detecting a washing time of the fan motor 30 is incremented in a subsequent step S7.
• a subsequent step S8 it is checked whether the washing time has already reached a predefined length, at which a cleaning of the commutator of the fan motor 30 is to be expected.
• the required washing time for the fan motor 130 is about ten minutes, and the length of the washing time may depend on a washing speed of the fan motor 30. At a higher washing speed, the washing time is shortened accordingly, wherein a minimum value of the washing time is reached at the maximum speed of the fan motor 30.
• the value ten minutes of washing time is to be regarded as a typical value, which varies depending on the washing speed of the fan motor 30, wherein the embodiment of the method shown in Figure 3 starting from a maximum washing speed of the fan motor 30.
• the washing speed of the fan motor 30 is set in a step S9 by means of the manner explained with reference to FIG 1 to a value which is above the Verpastungsschwelle. Particularly advantageously, this speed substantially corresponds to a maximum speed of the fan motor 30, whereby a washing time can be minimized.
• the washing time for the fan motor 30 in this case is about ten minutes.
• step S8 In the event that the washing time for the fan motor 30 has already expired (branch N of step S8), this means that the copper commutator bars of the fan motor 30 substantially completely of pasty substances due to the centrifugal forces generated by rotating the fan motor 30 at high washing speed have been cleaned.
• step S10 the time counter for the detection of the washing time is reset to zero.
• a subsequent step S1 1 the bit switch, which informs the method of the risk of sticking and initiates the washing of the fan motor 30, is reset to "false.”
• the time counter for detecting the operating time of the fan motor 30 is also below the time of paste After completion of the execution of the steps shown in Figure 3 so the time counter for detecting the critical operating time of the fan motor 30 must be operated again about hundred hours to initiate a next cleaning or washing procedure for the fan motor 30.
• steps S6 to S12 are carried out cyclically, as a result of which a systematic cleaning of the fan motor 30 is carried out in an uninterrupted manner if necessary.
• the inventive method with the steps shown in Figure 2 and Figure 3 is performed with a high priority within a control software, which supports that the paste is already reduced or prevented in the approach. All of the steps of FIG. 2 are performed prior to the steps of FIG. 3, since the steps S1 to S5 of FIG. 2 are required in order to prevent the danger of during an operation of the fan motor 30 Define pasty defined to determine which is subsequently eliminated by means of steps S6 to S12 substantially.
• the controller 10 may be any electronic controller that sends an instruction to the fan controller 20 to rotate the fan motor 30 at a defined speed.
• the method according to the invention is preferably implemented in software of the control unit 10.
• the stated numerical values of the parameters and thresholds are only to be understood as typical values for an exemplary embodiment of the method.
• the stated numerical values can be changed, wherein the respectively most suitable values can be determined, for example, by means of experimental and / or simulation-technical methods. Due to the configuration of the method according to the invention as software of a control unit 10, the changed values can be used in a simple manner for carrying out the method.
• the inventive method for a variety of different fan motors 30 is easily adaptable.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)

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• 2011
  • 2011-06-16 DE DE102011077652A patent/DE102011077652A1/de not_active Withdrawn
• 2012
  • 2012-04-26 CN CN201280029428.8A patent/CN103717852B/zh not_active Expired - Fee Related
  • 2012-04-26 WO PCT/EP2012/057660 patent/WO2012171701A1/de active Application Filing
  • 2012-04-26 US US14/126,729 patent/US20140136077A1/en not_active Abandoned
  • 2012-04-26 EP EP12719636.8A patent/EP2721267A1/de not_active Ceased

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