Fuel filter heater

Abstract

A fuel filter heating device comprising: an exhaust pipe (4) through which exhaust gas produced by an internal combustion engine flows, a heat transfer medium (21) which is located near a fuel filter (10), to receive radiant heat transmitted from the exhaust pipe, and to transfer the radiant heat to the fuel filter (10) upon contact, and a temperature-sensitive actuator (24) for moving the heat transfer medium (21) in a selected direction depending on the temperature of the fuel in the fuel filter (10), so that the heat transfer medium (21) contacts the fuel filter (10) to heat the fuel in the fuel filter (10), or so that the heat transfer medium (21) is separated from the fuel filter (10) to prevent heat transfer between them.

Description

Background of the invention; Field of the invention

[0001] The present disclosure relates to a fuel filter heating device. In particular, the present disclosure relates to a fuel filter heating device designed to increase the temperature of fuel (e.g., diesel) being introduced into a diesel filter when the fuel temperature is low, such as in winter. Description of the related technology

[0002] Internal combustion engines used in vehicles (e.g., motor vehicles) can generally be classified as gasoline / petrol engines and diesel engines.

[0003] The gasoline engine, which is an internal combustion engine designed to run on gasoline, generates power by introducing / injecting air and gasoline into a cylinder and by burning the compressed gasoline-air mixture, with ignition being initiated by an electric spark.

[0004] In contrast, a diesel engine, which is an internal combustion engine designed to run on diesel fuel, generates power by drawing air into a cylinder through a piston, compressing the air to high pressure, and burning fuel by injecting the fuel into the compressed air at high pressure and high temperature through auto-ignition.

[0005] The diesel engine has advantages over the gasoline engine in that fuel consumption is reduced due to better thermal efficiency, operating costs are reduced because the fuel is not expensive, and the fuel is widely available, thus providing flexibility in the use of alternative fuels.

[0006] In diesel engines, because the fuel contains a large amount of foreign matter and moisture, a filtration process is necessary to eliminate impurities such as foreign substances and moisture from the fuel before it is supplied to the engine. A fuel filter is used for this purpose.

[0007] The fuel filter is equipped with a PTC heater (e.g., a positive temperature coefficient heater) which serves to heat diesel fuel, thereby increasing the fuel temperature when the fuel temperature is low.

[0008] However, since a conventional PTC heater, which is mainly used in winter, consumes a significant amount of battery power, it negatively impacts battery life by draining the battery and reducing the vehicle's fuel efficiency. Furthermore, because a bimetallic switch, a type of temperature-sensitive on / off switch, is repeatedly switched on and off depending on the fuel temperature, this repeated activation negatively affects its lifespan.

[0009] The information disclosed in this section “Background of the Invention” is provided solely for a better understanding of the general background of the invention and should not be construed as an acknowledgment or any form of suggestion that this information constitutes the prior art already known to the person skilled in the art.

[0010] Furthermore, e.g. KR 10 2001 0 099 564 A is known a fuel filter heating device in which a part of the emitted exhaust gas is directed through a line from an exhaust pipe to the filter housing of the fuel filter heating device, thereby heating the fuel.

[0011] Furthermore, for example from WO 01 / 92 712 A1, a fuel filter heating device is known in which a fuel line through which fuel flows is wound around an exhaust pipe, thereby heating the fuel in the fuel line. Explanation of the invention

[0012] Numerous aspects of the present invention are aimed at providing a new fuel filter heating device which is able to efficiently control the temperature of fuel in a diesel fuel filter without an electric heater which consumes battery power and without associated electronic components.

[0013] In one aspect, the present invention provides a fuel filter heating device comprising: an exhaust pipe through which exhaust gas flows which is generated by an internal combustion engine, a heat transfer medium which is arranged near a fuel filter in order to receive radiant heat which is transferred from the exhaust pipe and in order to transfer the radiant heat (or the corresponding heat) to the fuel filter upon contact, and a temperature-sensitive actuator for moving the heat transfer medium in a selected direction depending on the temperature of the fuel in the fuel filter, so that the heat transfer medium contacts the fuel filter to heat the fuel in the fuel filter, or the heat transfer medium is separated from the fuel filter in order to prevent heat transfer between them (e.g. at least substantially).

[0014] In an exemplary embodiment, the exhaust pipe can be an exhaust gas recirculation pipe (EGR pipe) of an exhaust gas recirculation device (EGR device).

[0015] In another exemplary embodiment, the heat transfer medium can be configured to have a plate shape, wherein it is able to contact an outer surface of the fuel filter in a surface contact manner, and can be coupled to the temperature-sensitive actuator.

[0016] In a further exemplary embodiment, the heat transfer medium can comprise: a support plate which is arranged on an outside of the heat transfer medium in order to face the exhaust pipe and with which the temperature-sensitive actuator is coupled, and a heat transfer heat pad (e.g. a heat transfer layer) which is coupled to an inner surface of the support plate in order to allow heat transfer to the outer surface of the fuel filter.

[0017] In a further exemplary embodiment, the support plate can be a heat shield (e.g. a heat shield) made of a material that is able to block / shield at least some of the radiant heat generated by the exhaust pipe.

[0018] In a further exemplary embodiment, the temperature-sensitive actuator can be arranged on (e.g. in) a lower section of the fuel filter and the heat transfer medium can be arranged below the fuel filter.

[0019] In another exemplary embodiment, the exhaust pipe can be arranged below the fuel filter.

[0020] In another exemplary embodiment, the temperature-sensitive actuator can be a thermostat-type actuator, wherein the thermostat-type actuator comprises: a wax element which expands or contracts depending on the temperature of the fuel filter, and a pin which is coupled with a front end thereof to the heat transfer medium and which is moved forward or backward in response to the expansion or contraction of the wax element in order to move the heat transfer medium.

[0021] In a further exemplary embodiment, the section of the temperature-sensitive actuator containing the wax element can be arranged within the lower section of the fuel filter.

[0022] Other aspects and exemplary embodiments of the present invention are described below.

[0023] It should be understood that the term "vehicle" or "vehicle-..." or any other similar terms used herein includes motor vehicles in general, such as passenger cars, including so-called sport utility vehicles (SUVs), buses, trucks, numerous commercial vehicles, as well as, for example, watercraft, including a variety of boats and ships, and also, for example, aircraft and the like, and furthermore, hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles, and other vehicles powered by alternative fuels (e.g., fuels produced from resources other than petroleum). A so-called hybrid vehicle, to which reference is made herein, is a vehicle that has two or more energy sources, e.g., vehicles that are powered by both gasoline and electricity.

[0024] The above and other features of the invention are described below.

[0025] The methods and devices of the present invention have other features and advantages, which will become clear from the accompanying drawings included herein and the following detailed description, which together serve to explain certain principles of the present invention, or which are explained in more detail therein. Brief description of the drawings Fig. Figure 1 is a perspective view showing a conventional diesel fuel filter equipped with a heating device. Fig. Figure 2 is a schematic view showing a circuit connection of a conventional PTC heater. Fig. Figure 3 is a schematic cross-sectional view showing the fuel filter heating device according to the present invention. Fig. Figure 4 is a schematic cross-sectional view showing the fuel filter heating device according to the present invention, which is in a state of blocked heat transfer.

[0026] It should be clear that the attached drawings are not necessarily to scale and represent a somewhat simplified depiction of various features that illustrate the basic principles of the invention. The specific design features of the present invention, including, for example, specific dimensions, directions, positions, and shapes as disclosed herein, are partly determined by the respective intended application and environment of use.

[0027] Throughout the numerous figures in the drawing, reference symbols in the figures denote the same or essentially identical parts of the present invention. Detailed description

[0028] Various embodiments of the present invention will now be discussed in detail, examples of which are illustrated in the accompanying drawings and described below. Although the invention is described in connection with these exemplary embodiments, it is clear that the present description is not intended to limit the invention to these exemplary embodiments.

[0029] Exemplary embodiments of the present invention are described in detail below with reference to the attached drawings, so that the embodiments can be easily understood by the person skilled in the art to whom the invention relates.

[0030] Before explaining the present invention, in order to aid in understanding it, a conventional diesel fuel filter and a heating device for the diesel fuel filter should first be described with reference to the Fig. 1 and Fig. 2 described.

[0031] The Fig. Figure 1 is a perspective view showing a conventional diesel fuel filter equipped with a heating device. As shown in the drawing, a head section 11 of the diesel fuel filter 10 is provided at one position with a fuel inlet 12 through which fuel is introduced, and at another position with a fuel outlet 13 through which fuel, from which impurities such as contaminants and moisture have been removed, is discharged.

[0032] A housing of a filter part 17, which is arranged below and coupled to the head part 11, and a heating part 15 accommodate a filter element 19 for removing impurities. Fuel, which is introduced through the fuel inlet 12, is filtered by the filter element 19 and is then discharged through the fuel outlet 13.

[0033] The heating element 15 is coupled between the head section 11 and the filter section 17. If the diesel fuel is at a low temperature, the heating element 15 heats the fuel, which is introduced through the fuel inlet 12, in order to increase the fuel temperature.

[0034] The heating medium provided in the heating section 15 is usually an electric heater, for example a PTC heater, which is powered by a battery. The fuel, which is introduced through the fuel inlet 12, is heated as it passes through the PTC heater provided in the heating section 15.

[0035] The head section 11 is provided with a bimetallic switch 14 so that the PTC heater is switched on or off depending on the temperature of the fuel.

[0036] Diesel fuel is characterized by the fact that a paraffin component of it crystallizes at low temperatures. Therefore, in winter, this crystallized component of the diesel fuel clogs the pores of filter element 19 of the diesel filter 10, causing problems with fuel supply and engine starting.

[0037] In other words, since the temperature of the fuel in the diesel filter 10 is low when starting in winter, the paraffin component of the diesel can crystallize, causing a problem in the starting ability of an internal combustion engine at low temperatures.

[0038] Accordingly, to improve the flowability and starting ability of diesel at low temperatures, a PTC heater 16 (see Fig. 2) installed in the heating section 15 near the inlet of the filter to heat the fuel when the fuel is at a low temperature.

[0039] The on / off operation of the PTC heater 16 is controlled by the on / off operation of the bimetallic switch 14, which is executed / controlled depending on the temperature of the fuel. Fig. Figure 2, which represents this operation, is a schematic view showing the circuit connections in the PTC heater 16.

[0040] As it is in the Fig. As shown in Figure 2, when the ignition is switched on (ignition on or IG-on), a fuel filter heater relay 2 is activated. Subsequently, when the fuel temperature is low, the bimetallic switch 14 is activated to allow power from the battery 3 to be supplied to the PTC heater 16.

[0041] Consequently, the PTC heater generates 16 units of heat to heat the fuel.

[0042] If the fuel temperature becomes (too) high, the bimetallic switch 14 is switched off and therefore the power supply from the battery 3 is interrupted, thus switching off the PTC heater 16.

[0043] Here, the conventional PTC heater has negative effects in that it causes the battery to discharge prematurely, reduces the vehicle's fuel efficiency, and reduces the durability of the bimetallic switch due to repeated on / off operation.

[0044] To solve this problem, the fuel filter heating device according to the present invention, which is designed to heat fuel introduced into the diesel fuel filter and therefore to increase the temperature of the fuel when the fuel has a low temperature, such as in winter, is designed to heat the fuel in the fuel filter using the heat from exhaust gas of an internal combustion engine.

[0045] To implement the present invention, it is necessary to provide a high-temperature component for dissipating the heat from the exhaust gas produced by the combustion engine near the fuel filter. In a diesel fuel filter that is directly attached to the combustion engine, high-temperature components, such as an exhaust pipe through which exhaust gas from the combustion engine passes, are located in areas close to the diesel fuel filter.

[0046] To meet this need, the present invention is designed to use an exhaust pipe as a heat source, through which the exhaust gas flows, preferably an exhaust gas recirculation pipe (hereinafter referred to as EGR pipe), which forms part of an exhaust gas recirculation device (EGR device).

[0047] In a configuration where a diesel fuel filter is mounted directly on an internal combustion engine, excessive heating of the fuel filter can lead to performance problems in numerous components. Furthermore, excessively high fuel temperature within the filter can cause problems with engine control and stalling.

[0048] Accordingly, in an arrangement where a high-temperature part, such as the EGR pipe, extends into an adjacent area near the fuel filter, heat protection is applied to prevent negative effects caused by the heat generated by the EGR pipe.

[0049] Such a high-temperature component can be used as a heat source capable of heating the fuel in the diesel fuel filter when the combustion engine is started at a low temperature, such as in winter.

[0050] Accordingly, the fuel filter heating device according to the present invention is designed such that a high-temperature part of the internal combustion engine, which is arranged near the fuel filter, heats the fuel in the diesel fuel filter when starting at a low temperature. Here, the high-temperature part of the internal combustion engine can be an exhaust pipe, preferably an EGR pipe, through which exhaust gas from the internal combustion engine passes.

[0051] The Fig. Figure 3 is a schematic cross-sectional view showing the fuel filter heating device according to the present invention. In the case of the diesel fuel filter 10, which is mounted directly on the combustion engine, since the EGR pipe 4 extends under the diesel fuel filter 10, thermal energy from the EGR pipe 4 can be used to heat the fuel in the diesel fuel filter 10.

[0052] As is known in the relevant technology, the EGR device includes: an EGR cooler, which serves to lower the temperature of the recirculated exhaust gas (hereinafter referred to as EGR gas) that is emitted by the internal combustion engine and fed to an intake manifold of the internal combustion engine through the EGR pipe.

[0053] However, since the EGR gas bypasses the EGR cooler to avoid passing through it, thus preheating the combustion engine and improving fuel efficiency when the engine is started at a low temperature, the high-temperature EGR gas is fed to the intake manifold of the combustion engine at a time when the EGR pipe has the highest temperature.

[0054] Since heat is necessary to heat the fuel in the diesel fuel filter when the internal combustion engine is started at low temperatures, the present invention is designed to selectively heat the fuel in the diesel fuel filter only when the internal combustion engine is started at a low temperature.

[0055] According to one embodiment of the present invention, the fuel filter heater or fuel filter heating device comprises: an exhaust pipe 4, which serves as a heat source extending near the fuel filter and through which exhaust gas from the internal combustion engine flows; a heat transfer medium 21, which is arranged near the fuel filter 10 to receive radiant heat transmitted from the exhaust pipe 4 and which transfers the radiant heat to the fuel filter 10 upon contact; and a temperature-sensitive actuator 24 for moving the heat transfer medium 21 in a selected direction depending on the temperature of the fuel in the fuel filter 10, such that the heat transfer medium 21 comes into contact with the fuel filter 10 to heat the fuel in the fuel filter 10, or comes into distance from the fuel filter 10 to prevent heat transfer to the fuel filter 10 (e.g.,to prevent (at least in its essentials).

[0056] The exhaust pipe 4, which is used as a heat source, can be an EGR pipe through which EGR gas flows and which generates radiant heat when high-temperature EGR gas passes through the EGR pipe 4.

[0057] The heat transfer medium 21 is designed to receive radiant heat generated by the EGR pipe 4 and to transfer this radiant heat to the fuel filter 10 in order to heat the fuel in the fuel filter 10. The heat transfer medium 21 is designed in a plate-like structure, capable of contacting an outer surface of a housing 18 of the fuel filter with a large contact area, i.e., the outer surface of a base of the housing 18 of the fuel filter 10, as in this embodiment.

[0058] In an exemplary embodiment, the heat transfer medium 21 can comprise: a support plate 22, which is arranged on its outer surface to face the EGR pipe 4, and a heat transfer heat pad 23, which is arranged on the inner surface of the support plate 22 and contacts the outer surface of the housing 18 of the fuel filter 10 (e.g. selectively) to transfer heat to the fuel filter 10.

[0059] The support plate 22 can be a known heat shield capable of shielding / blocking at least some of the radiant heat generated by the EGR pipe 4. The heat shield 22 can be made of the same material as a conventional heat shield used to mount a fuel filter directly to an internal combustion engine.

[0060] The heat shield 22 blocks at least some of the radiant heat generated by the EGR pipe 4 in order to prevent heat damage to the fuel filter 10 caused by excessive radiant heat.

[0061] Since the present invention uses the EGR pipe 4 as a heat source through which high-temperature EGR gas passes, it is necessary to prevent thermal damage to the fuel filter 10 caused by excessive radiant heat generated by the EGR pipe 4. Accordingly, the plate-shaped heat shield, which is capable of blocking at least some of the radiant heat generated by the EGR pipe 4, is used as the support plate 22.

[0062] If the heat pad 23 is attached close to the lower surface of the housing 18 of the fuel filter 10 (e.g., contacting the lower surface of the housing), a portion of the radiant heat generated by the EGR pipe 4 can be partially shielded by the support plate 22, i.e., by the heat shield, and the remaining radiant heat can be transferred through the heat pad 23 to the fuel filter 10 to heat the fuel in the fuel filter.

[0063] The temperature-sensitive actuator 24 serves as a drive unit or control unit capable of controlling the heat transfer medium 21, causing it to come into contact with the fuel filter 10 to transfer heat between them, or to remain at a distance from the fuel filter 10 to shield it from heat. The temperature-sensitive actuator 24 operates depending on the temperature of the fuel in the fuel filter.

[0064] In an exemplary embodiment, the temperature-sensitive actuator 24 can be a thermostat-type actuator in which a pin 25 is displaceable in order to be moved upwards or downwards by the expansion or contraction of a wax element 26 contained therein.

[0065] The temperature-sensitive actuator 24 is fixedly positioned on the fuel filter 10, such that the section containing the wax element 26 is located within the housing 18 of the fuel filter 10. The front end of the pin 25, which moves up and down depending on the state of the wax element 26, is fixedly coupled to the heat transfer medium 21, preferably to the support plate 22 of the heat transfer medium 21.

[0066] The section of the temperature-sensitive actuator 24, which contains the wax element 26, is located within the base of the housing 18 of the fuel filter 10 to accurately reflect the temperature of the fuel in the fuel filter 10, and the front end of the pin 25 is coupled to the support plate 22, i.e., the heat shield, of the heat transfer medium 21. Consequently, when the pin 25 is moved up or down depending on the temperature of the fuel in the fuel filter 10, the entire heat transfer medium 21, including the support plate 22 (heat shield), is moved.

[0067] When using the thermostat-type actuator 24 in the fuel filter heating device according to the present invention, the front end of the pin 25 is coupled to the support plate 22 of the heat transfer medium 21, which serves as the heat shield, and the heat transfer heat pad 23 is applied between the fuel filter 10 and the support plate 22 to improve contact.

[0068] The operation of the fuel filter heating device according to the present invention is described below with reference to the Fig. 3 and Fig. 4 described.

[0069] The fuel filter heating device according to the present invention can use thermal energy from the EGR pipe 4, which is arranged below the fuel filter, to heat the fuel in the fuel filter 10, and allows the radiant heat from the EGR pipe 4 to be selectively transferred to the fuel filter 10 only at the time of operation at low temperatures (i.e., when an internal combustion engine starts at low temperatures) due to the temperature-sensitive actuator 24, which is actuated depending on the internal temperature of the fuel filter 10.

[0070] In the case where the thermostat-type actuator containing the wax element 26 is used as the temperature-sensitive actuator 24, when the temperature of the fuel in the fuel filter 10 increases, the wax element 26 expands and therefore drives the pin 25 forward. Therefore, the movement of the pin 25 causes the heat transfer medium 21 to be / reach a distance from the housing 18 of the fuel filter 10.

[0071] In the thermostat-type actuator 24, the distance over which the pin 25 moves is determined by the thermal expansion properties of the wax element 26 and the like. When the temperature of the fuel in the fuel filter 10 rises above a predetermined temperature, the support plate (i.e., the heat shield) 22 moves by the same distance as the pin 25, and therefore the heat pad 23 is separated from the housing 18 of the fuel filter 10.

[0072] At the time of operation of the diesel fuel filter 10 at a low temperature, i.e. when the combustion engine is started at a low temperature, since the temperature of the fuel in the filter is low, the wax element 26, which is contained in the actuator 24, is in a contraction state and the pin 25 of the actuator is in a retraction state.

[0073] Accordingly, the heat transfer medium 21 is in contact with the bottom of the fuel filter 10, as shown in the Fig. 3 is shown, and the heat radiation from the EGR pipe 4 to the fuel filter 10 is transferred through the heat transfer medium 21, which is formed by the heat shield 22 and the heat pad 23.

[0074] Consequently, the fuel in the fuel filter 10 is heated by the radiant heat (or the corresponding heat) which is transferred through the heat transfer medium 21, and therefore the temperature of the fuel is increased.

[0075] When the diesel fuel filter is operating at a high temperature, the wax element 26, which is contained in the actuator 24, expands, thereby driving the pin 25 forward. Accordingly, the heat transfer medium 21 is lowered and therefore released from contact with the fuel filter 10, as described in the Fig. 4 is shown.

[0076] At this point, since the heat pad 23 of the heat transfer medium 21 is separated from the fuel filter 10, the support plate 22, in particular the heat shield, performs its own function, i.e., the function of blocking radiant heat generated by the EGR pipe 4.

[0077] As is evident from the above description, when the fuel temperature in the fuel filter is low, the fuel filter heating device according to the present invention uses the pipe through which the exhaust gas emitted from the internal combustion engine passes, i.e., the EGR pipe, as the heat source to heat the fuel in the diesel fuel filter, thus increasing the fuel temperature. Therefore, it is possible to solve the problems that arise in a conventional electric heater that consumes battery power, i.e., problems of battery discharge and reduced fuel efficiency, and it is possible to solve problems related to the use of electronic components, such as a bimetallic switch, i.e., a deterioration in durability.

[0078] In other words, it is possible to efficiently control the temperature of the fuel in the fuel filter without an additional electric heater and associated components, such as an electronic sensor and a switch, and it is clear that fuel efficiency is increased and that factors which cause malfunctions of electronic components are eliminated.

[0079] To facilitate explanation and to precisely define the attached claims, the terms “upper”, “lower”, “inner” and “outer” are used to describe features of the exemplary embodiments with reference to the positions of these features shown in the drawings.

[0080] The preceding descriptions of certain exemplary embodiments of the present invention served the purpose of illustration and description. They are not intended to be exhaustive or to limit the invention to precisely the disclosed forms.

Claims

[1] A fuel filter heating device comprising: an exhaust pipe (4) through which exhaust gas produced by an internal combustion engine flows, a heat transfer medium (21) which is located near a fuel filter (10), to receive radiant heat transmitted from the exhaust pipe, and to transfer the radiant heat to the fuel filter (10) upon contact, and a temperature-sensitive actuator (24) for moving the heat transfer medium (21) in a selected direction depending on the temperature of the fuel in the fuel filter (10), so that the heat transfer medium (21) contacts the fuel filter (10) to heat the fuel in the fuel filter (10), or so that the heat transfer medium (21) is separated from the fuel filter (10) to prevent heat transfer between them. [2] The fuel filter heating device according to claim 1, wherein the exhaust pipe (4) is an exhaust gas recirculation pipe of an exhaust gas recirculation device. [3] The fuel filter heating device according to claim 1 or 2, wherein the heat transfer medium (21) has a plate shape which contacts an outer surface of the fuel filter (10) in a surface contact manner and is coupled to the temperature-sensitive actuator (24). [4] The fuel filter heating device according to any one of the preceding claims, wherein the heat transfer medium (21) comprises: a support plate (22) which is arranged on an outer side of the heat transfer medium (21) in order to face the exhaust pipe (4), and with which the temperature-sensitive actuator (24) is coupled, and a heat transfer heat pad (23) which is coupled to an inner surface of the support plate (22) to allow heat transfer to an outer surface of the fuel filter (10). [5] The fuel filter heating device according to claim 4, wherein the support plate (22) is a heat shield made of a material that is able to block at least some of the radiant heat generated by the exhaust pipe (4). [6] The fuel filter heating device according to any of the preceding claims, wherein the temperature-sensitive actuator (24) is arranged on a lower section of the fuel filter (10) and the heat transfer medium (21) is arranged below the fuel filter (10). [7] The fuel filter heating device according to claim 6, wherein the exhaust pipe (4) is arranged below the fuel filter (10). [8] The fuel filter heating device according to any of the preceding claims, wherein the temperature-sensitive actuator (24) is a thermostat-type actuator and wherein the thermostat-type actuator comprises: a wax element (26) which expands or contracts depending on the temperature of the fuel filter (10), and a pin (25) of which a front end is coupled to the heat transfer medium (21) and which is moved forward or backward in response to the expansion or contraction of the wax element (26) in order to move the heat transfer medium (21). [9] The fuel filter heating device according to claim 8, wherein a section of the temperature-sensitive actuator (24) containing the wax element (26) is arranged within a lower section of the fuel filter (10).

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