Heatable liquid container for a motor vehicle

Abstract

A container (15) with a wall for accepting a liquid to be warmed in a vehicle, whereby the container (15) features a heating element (16), is characterized by the heating element (16) being fed from an electrical source of energy.

Description

[0001] The invention pertains to a container with a wall for accepting a liquid to be warmed for a vehicle, whereby the container features a heating element.

[0002] Containers of this type are known which supply a feature in a motorized vehicle (such as an automobile) with a liquid, in particular a liquid for a washing system for washing the windshield or rear window panes or the front headlights or signal lights of a motorized vehicle. Depending on the weather, the driver needing a clear view must turn on the windshield wipers.

[0003] He or she may also want to melt frozen washing fluid by suitable means, in order to melt fluids at temperatures under 0.degree. C. or even lower temperatures. (At these temperatures washing fluid may be frozen, even if it includes an additive which lowers the melting point.) However, it sometimes occurs that the car driver forgets to add a sufficient amount of antifreeze or that very low temperatures are encountered, for which the amount of antifreeze in the washing fluid does not suffice.

[0004] The following suggestion has already been made. By means of a stainless steel apparatus similar to a immersion heater, frozen washing fluid is inserted from above into a container for windshield wiper fluid, via the lid of the container. Heated radiator water passes through the frozen washing fluid. This solution of the problem proves to be awkward and expensive.

[0005] From DE 44 25 214 A1, a container is known for a windshield wiper system with a chamber for accepting a washing fluid. The known container is characterized by featuring at least one additional chamber, separate from the washing fluid chamber, through which a heating fluid (such as warmed radiator water) flows in accordance with the principle of a heat exchanger. The chamber can be shaped like a channel, or for example several channels or ducts for the heating fluid can run through the container. The heating fluid chamber is preferably connected with the engine's cooling circuit, so that the heating fluid is available when the engine is running, in order to thaw frozen washing fluid.

[0006] For example, the heating fluid chamber is formed at the bottom of the container, where it is located between the bottom wall of the container and a separating wall, which separates it from the washing fluid chamber above it. Hence, the heat exchanger is located nearby, below the pump, so this area is melted faster than the other areas.

[0007] It is the task of this invention to create an alternative solution for warming a fluid in a vehicle.

[0008] In accordance with the invention, this task is solved with a container of the type mentioned at the beginning by powering the heating element from an electrical source of energy.

[0009] The invention relates to heating any kinds of fluids, including radiator water for the engine and the fuel. If the latter is diesel fuel, at temperatures below the freezing point it tends to flocculate, especially without the addition of volatile hydrocarbons. The fluid can also be engine or hydraulic oil which loses the desired viscosity below certain temperatures and becomes syrupy.

[0010] In particular, the fluid is intended for cleaning window panes, headlights or other signal lights of the vehicle. Fluids for cleaning other objects on or in the vehicle can also be foreseen.

[0011] By warming the fluid by means of an electrical energy source, it can be heated to the desired temperature independent of how long the internal-combustion engine has been running or when it was ignited. Especially short after starting the vehicle, the driver wishes to free the window panes of precipitation, in particular frozen precipitation and dirt. With state-of-the-art windshield wiper systems, the driver is dependent on already heated radiator water.

[0012] A further disadvantage of the state of the art is that after the engine is started, the heat flowing into the washing fluid is needed while the engine is still cold. Especially with performance-optimized engines, even a slight loss of heat delays the heating of the engine, so that it does not reach its optimal operating temperature as fast as desired.

[0013] Here, the invention alleviates the situation by heating the fluid electrically. The electrical source of energy is the starter battery of a vehicle or an additional battery, such as those employed in vehicles with auxiliary heating. In particular with batteries to be used in the future which provide a voltage of 42 V, it is possible to electrically heat a fluid, in particular the windshield wiper fluid, in the vehicle.

[0014] Thus, in accordance with this invention, either a container heater can be activated in conjunction with the auxiliary heating at a point in time before the internal-combustion engine is started. Or the container heater can be switched on when starting the internal-combustion engine. In either case, a frozen fluid is thawed within a short time. In particular, the wiper water is rapidly heated to 35.degree. C., as is usual with current automobiles.

[0015] This way, the invention is suitable for replacing the known systems for heating a fluid, based on the heat exchanger principle, and for suggesting the implementation of a heatable container for vehicles; the container ensures a rapid reaction to the starting of the engine, independent of the operational status of the engine, and it does not limit other heating systems within the vehicle.

[0016] Advantageous extensions of the invention result from the subclaims and from the description in conjunction with the drawings.

[0017] It is advantageous to use the vehicle battery as the source of energy, because then no additional battery must be placed in the vehicle. Taking into consideration the additional function of heating one or several fluids, it can be arranged to install a vehicle battery with a higher capacity than that capacity which is otherwise usual for the given type of vehicle.

[0018] In a further advantageous design of the container, the heating element is permanently attached to the wall of the container. In particular, the container can consist of two parts, so that the heater can be easily attached to a lower container part. This results in design simplifications when assembling the container and mounting it in the vehicle.

[0019] If the heater occupies the entire wall of a fluid container or the bottom area and the area of the side walls or only the bottom area or part of the bottom of the container, then this ensures that the heater will quickly heat a large surface of the fluid. In particular, heating can take place near feed pumps, which can be placed in particular in the area of the bottom or side walls, in which the fluid can be simultaneously pumped. A wiper water container, for instance, is equipped with three feed pumps, one each for the front pane, the hear pane and the front lamps and signal equipment of the vehicle.

[0020] If the heating element is designed as a thick-film heater with a resistor element, then technology can be used which is proven many times in the design of water cookers or kitchen machines. Such a kitchen machine is known from, for example, DE 102 26 939 A1.

[0021] In an advantageous alternative implementation, the container is equipped with a heating element which protrudes into the container through an opening in the wall.

[0022] A special advantage of this solution is that an existing opening, usually used as a filling opening for adding consumed fluid, serves double duty. At the lid is placed a heating rod, heating plate, a heating filament, a heating coil or something similar, which is preferably dimensioned such that it does not prevent complete removal of the lid from the container when adding fluid. These implementations of the invention also ensure that the heating element has as large an area as possible. In particular, this can be achieved with a heating plate placed preferably near a pump or several pumps (assuming there are several pumps in the vehicle).

[0023] The lid can be connected with the container by means of a screw, bayonet or snap-together joint, for instance. Wires on the outside of the lid connect the heating element through the lid with the source of electrical energy.

[0024] The heating element can be designed in various ways; preferably, it is at least partially formed as a rod or plate.

[0025] In an advantageous implementation of the invention, the heating element is shaped like a filament or spiral.

[0026] It is also advantageous to use a container with which the heating element includes a rod and a plate placed at one free end of the rod.

[0027] In a further advantageous implementation of the container, it is foreseen that the heating element is at least partially placed near a feed pump for pumping the fluid out of or into the container. This eliminates the problem that feed lines connected to the pumps can become clogged by lumps or particles of the fluid which have not yet melted.

[0028] It is also advantageous when an electrical battery on board a motorized vehicle is employed as the source of energy. However, it is not ruled out that the vehicle is connected via an electrical lead with the electrical power from a garage or building, for instance when the vehicle is in the garage.

[0029] In a special implementation of the invention, the heating element placed in the container is part of an electrical circuit including the energy source, for which a first switch (which can be operated by means of ignition equipment in order to ignite an internal-combustion engine), in particular a relay, is placed between the heating element and the energy source. As current enters the circuit, this switch/relay is switched. This occurs, for instance, when the battery current begins to flow because the ignition key is inserted in the engine lock or the engine is switched on.

[0030] It is also advantageous for control equipment (in particular, a second switch) controllable by the fluid's level to be placed in a circuit including the heating element and the energy source. This way, overheating of the heating element and hence the hazard of an electrical short circuit can be prevented.

[0031] It is advantageous to have a first thermostat regulate the temperature, in order to determine the duration of heating and/or the heating energy with which the fluid in the container or in a supply line leading to the container for feeding or removing the fluid is heated.

[0032] It is advantageous to arrange for the first thermostat to open or interrupt the supply line above a specific temperature value. For example, a desirable temperature value would be 35.degree. C., as is wanted for many common automobiles today. The fluid is heated as long as the temperature is below 35.degree. C. Since the heating takes place independent of the engine, there is no hazard of an engine malfunction. When a temperature of 35.degree. C. is reached, the heating is switched off.

[0033] Additionally, in a further advantageous implementation of the container, it is foreseen that a second thermostat (serving as a safety thermostat) is inserted before the first thermostat; when a specific temperature value is exceeded, this second thermostat switches the control equipment on or off. In particular, it opens or closes the second switch. It is advantageous for 50.degree. C. to be selected for this temperature value.

[0034] This prevents the temperature of the fluid and container from increasing in an uncontrolled manner, by interrupting the supply of electrical energy when a temperature of 50.degree. C. is reached. A display unit can be foreseen, for example on the dashboard, which indicates to the driver whenever the control thermostat fails.

[0035] A level sensor can be foreseen in the container, which interrupts the heating when the fluid level is too low. This information can be forwarded to the driver and displayed to him, for instance, on the dashboard.

[0036] It is advantageous to form the container as a blast-plastic part or as plastic injection molding part.

[0037] In one implementation of the invention, it is foreseen that the container will feature a lower and upper part, and that the heating element will be placed at least in the lower part.

[0038] It is advantageous to embed at least one electrical heating filament (in particular, a spiral-shaped one) in the wall of the lower part.

[0039] A level sensor can also be placed in the container.

[0040] Additionally, in accordance with the invention it can be foreseen that lines for transporting the fluid and nozzles, to which the fluid is transported, are also heated.

[0041] The invention is explained in detail below, based on implementation examples shown in the illustrations. They show:

[0042] FIG. 1 an electrical circuit for a heating element and

[0043] FIGS. 2-4 schematic views of containers with a heating element

[0044] A container 1 (FIG. 1) for a fluid to be heated in a vehicle contains an electrical coil 2, connected via lead 3 with one of the poles 4 of a source of electrical energy 5. The other pole 6 is connected via another lead with the other terminal of the heating coil or with coil 2.

[0045] Another electrical lead connected to the source of electrical energy 5 service as a control lead. It is connected with a relay 9 having a connecting lead 7, in order to close the connecting lead when relay 9 is closed, for instance when the engine is started and the battery current flows.

[0046] A level sensor 10 is also inserted in the circuit of lead 8. Whenever the fluid in container 1 drops below a specified level, this sensor actuates a circuit breaker 11 in order to prevent the fluid in container 1 from overheating and damaging the container. A display unit 12 connected with the circuit breaker indicates to the driver that the fluid level is too low.

[0047] And, finally, in order to adhere to a minimum temperature of the fluid to be heated, another control thermometer 13 is inserted in lead 8. At a specific temperature, it actuates and closes lead 8, which supplies coil 2 with current. Hence, the temperature is maintained above a certain value, e.g., above 35.degree. C.

[0048] In case thermostat 13 malfunctions, it must be prevented that coil 2 will still be powered and continue to heat the fluid. For this reason, a safety thermostat 14 is inserted with thermostat 13. It drops out and opens the connection of the electrical lead 8 whenever a specific temperature is exceeded. This temperature is much higher than the temperature set at control thermostat 13. It can be set to, for example, 50.degree. C.

[0049] Of course, the circuit can be equipped with all kinds of display units which serve other purposes. Examples are indicating battery failure or equipment for indicating the failure of control thermostat 13.

[0050] In one implementation of the invention (FIG. 2), a heating element 16 (placed in a plastic container 15) features a cover plate 17 on the outside wall 18 of container 15. The cover plate 17 protrudes beyond an opening (not shown) in the wall 18, through which a heating rod 19 is inserted. The cover plate 17 and the heating rod 19 in the area around wall 18 consist of thermally and electrically insulating material, so that the plastic of wall 18 is not heated and cannot melt.

[0051] The inside of container 15 is filled at least partially with a fluid to be heated. The fluid can be pumped by pumps 20, 21, 22 on the bottom of the container 15. It can be transported by supply lines to the washing equipment of the front and rear windshields as well as to the front lamps and headlights of the vehicle.

[0052] Placing plate 23 near the pumps 20 through 22 ensures that these pumps and the lines connected to them for transporting the fluid will not become clogged with frozen fluid particles. In addition, however, it can be foreseen that heating elements are placed at the lines themselves and/or at the outlet-side nozzles of the lines, from which the fluid is sprayed onto the window panes or headlights.

[0053] The fluid is heated by both the heating rod 19 and a plate 23 at its lower end. A heating filament 24 runs through the heating rod 19 and the plate 23; at the plate 23 it is spirally shaped. The heating filament 24 forms an ohmic resistance heater. The heating filament 24 is embedded in an electrically insulating material 25 within the heating rod 19 and the plate 23.

[0054] In a further implementation (FIG. 3), a loop-shaped heating rod 26 is placed in the container 15, which is also inserted into the container 15 via the cover plate 17 through an opening. Instead of a single loop, of course there can be several loops, similar to a immersion heater.

[0055] In a further implementation (FIG. 4), a container 27 features a lid 28 and a lower part 29. The lid 28 has a lug 30 through which the lid 28 is joined with other design parts of the vehicle. An inlet port 31 for adding the fluid is also foreseen.

[0056] In its lower part 29, the container 27 features a wall made of electrically isolating, heat-resistant material, containing inside a heating filament 32 (shown in the exposed part of the lower part 29) in order to heat the fluid in the container 27.

[0057] The outside wall of the lower part 29 and preferably also the outside wall of the lid consists of thermally isolating material, to prevent dissipation of the heat inside the container 27 and an undesired heating of the surroundings of the container 27 in the vehicle.

[0058] The heater placed in the wall of the container 27 is designed as a thick-film heater with a resistor element, for which thin heating tracks are pressed onto an enamel stainless steel plate facing the interior of the container 27. A protective coating is applied to the heating tracks for passivating. For protection against mechanical and electrical influences from the outside of the container, the coating is covered by another layer.

Claims

1. Container (1, 15) with a wall for accepting a fluid to be heated in a vehicle, whereby the container (1, 15) features a heating element (16) characterized by the heating element (16) being fed from an electrical source of energy.

2. Container (1, 15) in accordance with claim 1, characterized by the source of energy being a vehicle battery.

3. Container (1, 15) in accordance with claim 1, characterized by a heating element (16) joined to a wall (18) of the container (1, 15).

4. Container (1, 15) in accordance with claim 3, characterized by a heating element (16) designed as a thick-film heater with a resistor element.

5. Container (1, 15) in accordance with claim 3, characterized by a heating element (16) protrudes into the container (1, 15) through an opening in the wall (18) of the container (1, 15).

6. Container (1, 15) in accordance with claim 5, characterized by an opening which is a filling opening for adding fluid to the container (1, 15).

7. Container (1, 15) in accordance with claim 1, characterized by a heating element (16) at least partially formed as a rod (19) or plate (23).

8. Container (1, 15) in accordance with claim 1, characterized by a heating element (16) shaped like a filament or spiral.

9. Container (1, 15) in accordance with claim 7, characterized by a heating element (16) including a heating rod (19) and a plate (23) placed at one free end of the heating rod (19).

10. Container (1, 15) in accordance with claim 1, characterized by a heating element (16) at least partially near a feed pump (20, 21, 22) for transporting the fluid out of the container (1, 15) or into it.

11. Container (1, 15) in accordance with claim 1, characterized by the source of energy being an electrical battery on board a motorized vehicle.

12. Container (1, 15) in accordance with claim 1, characterized by a first switch (in particular, a relay (9)) operated by means of ignition equipment for igniting an internal-combustion engine being placed in a circuit including the heating element (16) and the energy source, between the heating element (16) and the energy source.

13. Container (1, 15) in accordance with claim 1, characterized by control equipment (in particular, a second switch (10)) controllable by the fluid's level being placed in a circuit including the heating element (16) and the energy source.

14. Container (1, 15) in accordance with claim 1, characterized by a first thermostat (13) for setting the temperature being placed in the container (1, 15) or in a supply line leading to the container (1, 15) for feeding or removing the fluid.

15. Container (1, 15) in accordance with claim 14, characterized by having the first thermostat (13) open or close the supply line above a specific temperature value.

16. Container (1, 15) in accordance with claim 15, characterized by the temperature value being 35.degree. C.

17. Container (1, 15) in accordance with claim 14, characterized by a second thermostat (serving as a safety thermostat) being inserted before the first thermostat, when a specific temperature value is exceeded, this second thermostat switches the control equipment on or off. In particular, it opens or closes a second switch.

18. Container (1, 15) in accordance with claim 17, characterized by the temperature value being 50.degree. C.

19. Container (1, 15) in accordance with claim 1, characterized by it being formed as a blast-plastic part or as plastic injection molding part.

20. Container (1, 15) in accordance with claim 19, characterized by it featuring a lower (29) and upper part (28), with the heating element (16) placed at least in the lower part (29).

21. Container (1, 15) in accordance with claim 20, characterized by embedding at least one electrical heating filament (32) (in particular, a spiral-shaped one) in the wall of the lower part (29).

22. Container (1, 15) in accordance with claim 1, characterized by featuring a level sensor (10).