FR2839018A1 - Heater for motor vehicles or boats, uses main fuel pump to draw engine fuel from main storage tank and delivers fuel to heater burner through a restriction valve - Google Patents

Abstract

The heater (10) has a burner fueled from the main fuel tank (18). The fuel is transported by the main fuel pump (24) to a branch in the fuel line (42), which has a restriction valve (44) to reduce pressure in the conduit supplying the burner in the heater.

Description

lO the half-hull A2 (see plate n 7/8).

DESCRIPTION

  The present invention relates to a heating device for a motor vehicle having a burner, to which a fuel or a fuel can be supplied by a fuel line from a reserve or a tank of the vehicle, from which the fuel can also be supplied to an engine internal combustion engine of a motor vehicle by means of a pressure line using a fuel pump or a fuel pump of a motor vehicle, in which the fuel line can be connected to the pressure line and is suitable for driving the fuel during auxiliary and / or complementary heating operation using the fuel pump of the motor vehicle. The invention further relates to a motor vehicle having a reserve from which a fuel can be supplied to an internal combustion engine via a pressure line using a fuel pump, and in which

  l 5 a heating device for a motor vehicle of this type is integrated.

  Motor vehicle heaters of the type described above used for air heating or water heating in motor vehicles, such as cars, trucks, buses or boats. They are generally used to heat a passenger compartment of the vehicle or to preheat the cooling water of a combustion engine in an auxiliary or complementary heating operation. The auxiliary heating operation means that, in this operating state, an internal combustion engine of the motor vehicle is not used and therefore heat cannot be extracted from it. In complementary heating operation, the heating device for a motor vehicle provides additional thermal energy during the operation of the internal combustion engine, in order to be able to heat in this way, for example, an interior space of the motor vehicle or the water of cooling the

  internal combustion engine, even for a short period.

  In today's motor vehicles, more and more efficient combustion internal combustion engines are used, which produce comparatively little waste heat. It is of increasing importance in motor vehicles of this type that additional thermal energy can be provided by a heating device for a motor vehicle as required. This heater must

  furthermore be economical in manufacture and use.

  In conventional motor vehicle heaters, fuel is drawn by a fuel metering pump to a fuel line from a tank or reserve and fed to a burner of the heater. A heating device of this type is known, for example, from the document

DE 19 545 677 A1.

  I1 is known from document WO / 06 305 an independent heating device of the engine, in which a fuel or fuel pump specific to the vehicle, for example an injection installation of an injection combustion engine, is used to produce a volumetric flow of fuel at an intake pressure (typically 0.5 mPa) to the burner of the heater. When the engine is stopped, the fuel pump is controlled by the

  heater control.

  It is known from document DE 19 619 861 A1 that, in a heating device of this type, a pressure accumulator is arranged in the fuel line before a fuel metering installation so that the pump has fuel should only be used periodically even when the engine is stopped. A non-return valve opening in the direction of the pressure accumulator is arranged in the fuel line, in the direction of circulation, before the pressure accumulator, which valve ensures that the pressure never decreases in the pressure accumulator, even when the pump

with fuel has a liver.

  The object of the present invention is to provide a motor vehicle having a heating device as described in the introduction, in which an economically achievable fuel line meets safety standards and operates reliably while

throughout its lifespan.

  This object is achieved according to the invention by a heating device for a motor vehicle as described in the introduction, in which a reduction valve is arranged in the fuel line. In addition, the object is reached by a motor vehicle which has a reserve from which fuel can be supplied to an internal combustion engine by a pressurized line using a fuel pump, and in which a heating device according to the invention of

this type is integrated.

  In a heating device according to the invention, the pressure of the fuel which must be supplied to the heating device is reduced by means of a simple reduction valve. The reduction valve thus prevents pressure dangerous to safety from appearing in the heater. Pressure at this level

  is not necessary for the operation of the heater.

  In contrast to known heating devices in which fuel is supplied to an internal combustion engine from a pressurized line, according to the invention, the pressure of the fuel arriving at the heating device is limited. The limitation can be fixed at a determined nominal pressure or be adjusted to different nominal pressures by an adjustable reduction valve. The adjustment of different nominal pressures can be carried out manually, during the manufacture of the heating device and during maintenance work, for the purpose of adapting to different types of heating devices, motor vehicles or combustion engines. internal. It can also be achieved by an external or remote control, for example by means of a magnetic reduction valve. In this context, the reduction valve can be controlled or its proper functioning can be

  controlled by a heater control device.

  The reduction valve according to the invention has the further advantage that, under certain circumstances, it can fix the nominal pressure in the heater so that a metering valve in front of only open and closed can be used in the device. In this case, the metering valve must not be synchronized as is the case with metering valves or

known dosages.

  It may also be possible that the metering valve only needs to open at the start and close at the end for the combustion operation of the heater. If necessary, this function can also be guaranteed with a valve that cannot be

  remotely controlled, for example a pressure relief valve.

  In an advantageous embodiment of the heating device for a motor vehicle according to the invention, the fuel line is provided with a metering valve, by means of which fuel can be supplied to the burner using the pressure present in driving under pressure. The metering valve can advantageously be combined with the reduction valve according to the invention, as has already been explained above. The metering valve is designed in such a way

  economical as a magnetic valve.

  The fuel line of the heating device for a motor vehicle is also advantageously provided with an accumulator and / or a moderator for the fuel. This accumulator or moderator equalizes the pressure in the fuel line and can contribute, in certain circumstances, to the fact that the different phases

  of the fuel pump operation are relatively brief.

  The reduction valve according to the invention is advantageously arranged in the direction of circulation before the metering valve and / or the moderator or the accumulator, so that these elements are protected against high pressure in the pressure line of the engine. internal combustion. This arrangement is a characteristic of

  important safety of the heating device according to the invention.

  The supply of fuel to the heating device for a motor vehicle according to the invention is advantageously controlled by a control device, in particular for controlling the metering valve, which is also suitable for controlling the pressure in the

pressure pipe.

  The control device can also be coupled in operation to the fuel pump and control it, in particular when the internal combustion engine is not used. The control can be carried out in synchronization so as to ensure consumption

  minimum electrical energy by the fuel pump.

  In order to form an adjustment circuit from the fuel pump and / or the metering valve, as well as from the reduction valve according to the invention, a pressure sensor can advantageously be arranged in the fuel line, by especially in the direction of flow before the metering valve. This is coupled to the control device, and in this, wind control times stored in a characteristic field in a functional block of the accumulator in order

  uniformly close the desired amount of fuel.

  - 5 As a variant or in addition, the signal from a volumetric flow sensor and / or from a mass flow sensor (a calorimetric sensor, for example), which is (are) agency (ies) advantageously in the conduct of fuel, can also be used as an input signal for an adjustment circuit. With a metering valve used in synchronization, it may be advantageous if a butterfly valve is arranged in the fuel line,

  especially in the direction of flow before the metering valve.

  The butterfly equalizes the pressure and brakes the volumetric Rux entrained by the

fuel pump.

  In the motor vehicle according to the invention, the coupling between the control device of the heating device and the fuel pump of the motor vehicle can advantageously be carried out by means of a data bus, in particular a bus of the type known under the 1S CAN designation. The control device controls the fuel line of the heating device with the fuel pump of the motor vehicle, in particular when the internal combustion engine is not used. Alternatively, direct control or direct connection between the heater control device and the

  motor vehicle fuel pump can also be provided.

  An exemplary embodiment of a heating device for a motor vehicle according to the invention will be described in more detail below on the basis of the accompanying schematic drawings, in which: FIG. 1 shows a block diagram of a heating device according to the current state of the art, agency in a vehicle; and Figure 2 shows a block diagram of a heating device according to the invention, as it is integrated in a motor vehicle. FIG. 1 shows a heating device for a motor vehicle 10 with its fuel supply line 12, in which a non-represented burner, arranged in the heating device 10, is

supplies fuel.

  The fuel line 12 has a suction line 14, through which a fuel pump 16 of the

  heater 10 draws fuel from a tank or reserve 18.

  The fuel pump 16 circulates the fuel simultaneously with a slight increase in pressure and a metering of quantity in a - 6 pressure line 20. The pressure line 20 leads to the burner of the heating device 10, where the fuel is discharged through a spray nozzle not shown. Such a heating device 10 according to the

  fgure 1 is known, for example, from document DE 19 545 677 A1.

  FIG. 2 shows a heating device 10 for a motor vehicle according to the invention, as it is integrated in a motor vehicle with an internal combustion engine 22 in the form of a

combustion engine.

  The internal combustion engine 22 is supplied with liquid fuel from a tank or a reserve 18 by a fuel pump 24 of the motor vehicle. Fuel pump 24 is also described as an electric fuel pump (ECP). Wile circulates the fuel through a pressure regulator 26 and a check valve 28 in a pressure line 30. This pressure line 30 leads to a fuel injection system 34 of the internal combustion engine 22, which includes the components not represented by a high pressure pump and a pressure sensor. The pressure regulator 26 regulates the pressure in the pressure line 30

  in a manner suitable to the needs of the fuel injection system 34.

  The internal combustion engine 22 is coupled in operation by a signal line 36 to an engine control device 38, which is connected to the fuel pump 24 by a line

signal 40.

  In the direction of circulation after the non-return valve 28, a line 42 for supplying fuel to the heating device 10 is connected to the pressure line 30. In the supply line 42, a reduction valve 44 is integrated in the heater 10, which reduces the pressure from the pressure line 30 to a nominal pressure for the

  operation of the heater 10.

  In the direction of circulation after the reduction valve 44, a non-return valve 46 and a pressure sensor 48 vent arranged on the supply line 42. The supply line 42 can be closed at its end by a pressure valve electrically controlled metering 50. The metering valve 50 is arranged in the immediate vicinity of a

  burner not represented by the heating device 10.

  The pressure sensor 48 and the metering valve 50 are connected by signal lines 52 and 54 with a control device 56 of the heating device. The control device 56 is in turn coupled in operation to the fuel pump 24 by a signal line 58. The control device 56 is designed so that it supplies the burner with the heating device 10, a [' using the fuel pump 24 of the motor vehicle and using the metering valve, the necessary quantity of fuel, including the nominal pressure

  maximum is limited by the reduction valve 44.

  The following numerical references are used in the figures of the accompanying drawings:: heating device 12: fuel supply line 14: suction line 16: fuel pump of the heating device 18: tank or reserve: pressure line 22: engine internal combustion 24: motor vehicle fuel pump 26: pressure regulator 28: check valve: pressure line 32: check valve 34: fuel injection system 36: signal line 38: engine control device : signal line 42: supply line 44: reduction valve 46: non-return valve 48: pressure sensor: metering valve 52: signal line 54: signal line 56: control device 58: signal line -8

Claims (11)

  1. A heating device for a motor vehicle (10) having a burner, to which a fuel can be supplied via a fuel line (42) from a reserve (18), from which the fuel can also be supplied to an engine combustion engine (22) of the motor vehicle via a pressure line (30) using a fuel pump (24) of the motor vehicle, in which the fuel line (42) can be connected to the line under pressure (30) and is adapted to conduct the fuel during auxiliary and / or complementary heating operation using the fuel pump (24) of the motor vehicle, characterized in that a valve   reduction (44) is arranged in the fuel line (42).   2. Heating device for a motor vehicle according to claim l, characterized in that the fuel line (42) is provided with a metering valve (50), by means of which fuel can be brought to the burner using pressure present   in the pressure line (30).   3. Heating device for a motor vehicle according to claim 1 or 2, characterized in that the fuel line (42)   is equipped with an accumulator and / or a fuel moderator.   4. Heating device for a motor vehicle according to the   Claims 2 and 3, characterized in that the reduction valve (44) is   arranged in the direction of circulation before the metering valve (50)   and / or the moderator or the accumulator.   5. A heating device for a motor vehicle according to claim 3, characterized; in that a control device (56) for controlling the fuel supply, and in particular for controlling the metering valve (50), is provided, which is also   suitable for controlling the pressure in the pressure line (30).   6. A heating device for a motor vehicle according to claim 5, characterized in that the control device (56) is coupled in operation to the fuel pump (24) and can in particular control it when the internal combustion engine (22 ) is not used.   7. Heating device for a motor vehicle according to one   any of claims 1 to 6, characterized in that a   pressure (48) is arranged in the fuel line (42), in particular in the direction of circulation before the metering valve (50). 8. Heating device for a motor vehicle according to one   any of claims 1 to 7, characterized in that one or more   volumetric and / or mass flow sensor (s) is (are) agency (ies) in the fuel line (42).   9. Heating device for a motor vehicle according to one   any of claims 1 to 8, characterized in that a butterfly is   agency in the fuel line (42), in particular in the direction   circulation before the metering valve (50).   10. Motor vehicle having a reserve from which fuel can be supplied to an internal combustion engine (22) by means of a fuel pump (24) via a pressure line (30), and having a device for heating (10) according to any one of claims 1 to 9.   11. Motor vehicle according to claim 10, characterized in that a data bus is provided, by means of which a control device (56) for controlling the fuel line of the heating device (10) is coupled in operation to the fuel pump (24) of the motor vehicle and can in particular control it when the