Patent Grant
7458365
The following is based on and claims priority to Japanese Patent Application No. 2006-116279, filed Apr. 20, 2006, which is hereby incorporated by reference in its entirety.
This invention relates to a fuel supply system and, more particularly, to a fuel supply system with a cooling plate.
Various fuel supply systems are proposed in the prior art. For instance, JP-A-H07-293397, JP-A-S62-35088, JP-A-2001-99029, JP-A-2004-137986, and others disclose a fuel supply system that supplies the fuel in the fuel tank to an internal combustion engine via an electric fuel pump. In JP-A-H07-293397, for instance, a controller electrically controls operation of the fuel pump. It is necessary to cool the controller because electronic parts mounted on the controller, such as a power transistor, generate heat.
Conventionally, the controller is equipped with a cooling fin for air cooling. More specifically, the cooling fin is provided on an external surface of a lid member of the fuel tank. Also, the cooling fin is provided between the fuel tank and a car body member. However, if the clearance between the fuel tank and the car body member is small, the cooling fin may be smaller, which disadvantageously reduces the cooling capability of the controller.
In partial response to this problem, systems have been proposed that include a cooling structure for cooling the controller with the fuel instead of via air cooling. For instance, JP-A-S62-35088 and JP-A-2001-99029 disclose this type of system.
More specifically, JP-A-S62-35088 discloses a structure in which the controller contacts the external surface of a metallic lid member, and a cooling fin is included that is capable of exchanging heat with the fuel. The cooling fin is provided on the inside of the lid member, and the cooling fin is cooled by the fuel. As such, the lid member is interposed between the controller and the cooling fin, and accordingly cooling capability may be insufficient. More specifically, if the lid member is made of a resin, the cooling capability decreases considerably because the resin has low thermal conductivity.
Furthermore, JP-A-2001-99029 discloses a structure in which a metallic cooling plate contacting the controller is provided, and the cooling plate is insert-molded with resin so as to be formed coupled to and around a resin-made fuel pipe through which the fuel circulates. Thus, the cooling plate is cooled by the circuiting fuel. As such, the resin-made fuel pipe is interposed between the circulating fuel and the cooling plate, and accordingly the cooling capability may be decreased.
A fuel supply system is disclosed for supplying fuel in a fuel tank to an internal combustion engine. The fuel supply system includes an electric fuel pump for increasing a pressure of the fuel and moving the fuel. The system also includes a controller for controlling operations of the fuel pump and a cooling plate that is disposed in the fuel tank and cools the controller by contacting the controller. Moreover, the system includes a fuel outlet device that allows for a flow of the fuel onto the cooling plate for heat exchange between the fuel and the cooling plate.
A fuel supply system is also disclosed for supplying fuel in a fuel tank to an internal combustion engine. The fuel supply system includes a sub tank disposed in the fuel tank and a fuel pump that is disposed in the sub tank, increases a pressure of the fuel, and moves the fuel. Furthermore, the system includes a controller for controlling operations of the fuel pump. Also, the system includes a cooling plate that is disposed in the sub tank and cools the controller by contacting the controller.
Hereafter, a plurality of embodiments of this invention will be described based on the drawings.
The pump module 10 is coupled to a fuel tank 2. The pump module 10 increases a pressure of the fuel in the fuel tank 2, and moves the fuel to supply the fuel to a delivery pipe 4. A pressure sensor 60 (i.e., a fuel pressure detecting device) is operatively coupled to the delivery pipe 4 and detects the pressure of the fuel in the delivery pipe 4. The pressure sensor 60 outputs a detection signal of the fuel pressure to an ECU 90. Fuel injection valves 8 are operatively coupled to the delivery pipe for supplying fuel to respective cylinders of an internal combustion engine 6.
The FPC 70 is supplied electric power from a battery 80 and controls driving signals of a fuel pump 40 (see
Next, the fuel supply system will be explained in detail.
As shown in
The pump module 10 includes a flange 12 serving as a lid member, the fuel pump 40, a fuel filter 42, a suction filter 48, etc. The pump module 10 is of an in-tank type wherein components other than the flange 12 are housed in a fuel tank 2.
The flange 12 is made of a resin. The flange 12 is a disc that covers a circular opening 201 formed in the upper wall of the fuel tank 2. A fuel discharge pipe 14, a fuel vapor outlet pipe 15, a fuel vapor control valve 17, an electric connector 16, the FPC 70, etc. are coupled to the flange 12. Among these members, the fuel discharge pipe 14, the fuel vapor outlet pipe 15, and the electric connector 16 are coupled to an upper and outer side of the flange 12. The fuel vapor control valve 17 and the FPC 70 are coupled to the lower and inner side of the flange and are provided inside the fuel tank 2.
The fuel discharge pipe 14 is connected with the fuel pump 40 via a pipe. As such, supply fuel is increased in pressure by the fuel pump 40 and foreign substances are removed by the fuel filter 42 and then are discharged outside of the fuel tank 2 by the fuel discharge pipe 14. A pressure regulator 44 is also operatively provided in the fuel tank 2 and between the discharge port of the fuel pump 40 and the fuel discharge pipe 14. The pressure regulator 44 discharges a portion of the fuel that the fuel pump 40 discharges from a drainage port 441 when the discharge pressure of the fuel pump 40 exceeds a predetermined pressure. As such, the discharge pressure of the fuel pump 40 is adjusted.
The electric connector 16 is electrically connected with the fuel pump 40 and a fuel gauge 50 by lead wire 24.
The fuel vapor outlet pipe 15 couples the inside of the fuel tank 2 and a canister (not shown) outside the fuel tank 2. The fuel vapor control valve 17 is operatively coupled to an end the fuel vapor outlet pipe 15. When the pressure inside the fuel tank 2 becomes larger than the predetermined value, the fuel vapor control valve 17 opens. This allows the fuel vapor produced inside the fuel tank 2 to be discharged into the canister, and accordingly the pressure inside the fuel tank 2 decreases. The vapor of the fuel passed through the fuel vapor control valve 17 flows out of the fuel tank 2 into the canister. For example, when fuel is fed into the fuel tank 2, the fuel vapor control valve 17 opens, and fuel vapor that would be otherwise pushed outside of the fuel tank 2 by refueling is adsorbed by the canister.
Incidentally, instead of the fuel vapor control valve 17, a float valve may be provided that blocks a passage when the fuel fed into the fuel tank. When fueling, the float valve blocks the passage, which forbids air from being discharged from the fuel tank 2 to the outside, and fueling is halted.
The fuel gauge 50 is mounted on the peripheral wall of the fuel pump 40. The fuel gauge 50 has a sender gage 51, an arm 52, and a float 54. The float 54 is linked to the arm 52. The float 54 moves up and down in response to a remaining quantity of the fuel, thereby rotating the arm 52, and the sender gage 51 detects the remaining amount of the fuel tank 2 based on the turning position of the arm 52. A corresponding detection signal is outputted to the FPC 70 through the lead wire 24.
The FPC 70 is attached on the inside of the fuel tank 2 of the flange 12, and is electrically connected with the electric connector 16. A CPU, ROM, etc. are mounted on the FPC 70. The CPU of the FPC 70 controls the driving signal of the fuel pump 40 by executing a control program stored in the ROM. The FPC 70 controls the discharge pressure of the fuel pump 40 by adjusting a duty ratio of a driving voltage impressed to the fuel pump 40. When the duty ratio of the driving voltage impressed to the fuel pump 40 increases, the discharge pressure of the fuel pump 40 will increase. When the duty ratio of the driving voltage impressed to the fuel pump 40 decreases, the discharge pressure of the fuel pump 40 will decrease.
The discharge pressure control of the fuel pump 40 by the FPC 70 will be explained more concretely. First, the ECU 90 outputs an optimal target pressure to the FPC 70 depending on an operating state of the internal combustion engine and the detection signal from the pressure sensor 60. Next, the FPC 70 sets a target combustion pressure to the pressure output by the ECU 90, and alters the duty ratio of the driving voltage output to the fuel pump 40 so that the combustion pressure inside the delivery pipe 4 detected by the pressure sensor 60 may approach the target pressure. Through such a duty control, the discharge pressure of the fuel pump 40 is controlled by the FPC 70.
Next, a cooling structure of the FPC 70 will be explained using
The FPC 70 has a circuit board 72 with electronic parts (not shown) mounted thereon, such as a power transistor. The FPC 70 also includes a resin-made case 71 for housing the circuit board 72, and a metallic cooling plate 73 contacting the circuit board 72. In one embodiment, the cooling plate 73 is made of a material having corrosion-resistance to the fuel and having heat radiation capability. For example, in one embodiment, the cooling plate 73 is made of aluminum. The cooling plate 73 has a contact part 731 that is provided inside the case 71 and contacts the circuit board 72 and a heat radiation part 732 provided outside the case 71.
The heat radiation part 732 is provided adjacent to and opposes the drainage port 441 of the pressure regulator 44. Therefore, the fuel that flows out of the drainage port 441 flows onto and over the heat radiation part 732. As such, the cooling plate 73 is cooled by heat exchange with the fuel to thereby cool the circuit board 72. Incidentally, the fuel poured on the heat radiation part 732 flows downward and is retained in the fuel tank 2, and the fuel is discharged toward the delivery pipe 4 by the fuel pump 40. The pressure regulator 44 corresponds to a “fuel outlet device.”
Moreover, a sealant 74 (shown with cross hatching in
As shown in
The FPC 70 also extends toward the fuel pump 40 from the flange 12, and is orientated such that the circuit board 72 is substantially perpendicular to the opening 201. As such, the FPC 70 is in a so-called longitudinal arrangement.
As shown in
Moreover, the broken circular line 421 shown in
The opening 201 of the fuel tank 2 is also shown in
Thus, according to this first embodiment, since the cooling plate 73 is disposed in the fuel tank 2 and the cooling plate 73 exchanges heat with the fuel, cooling of the circuit board 72 of the FPC 70 is improved compared with the conventional structure of fin-based air cooling as described above. Also, the first embodiment is relatively compact for use even in a vehicle with relatively small clearance between the fuel tank 2 and the car body. In addition, according to this first embodiment, since the cooling plate 73 contacts the circuit board 72 of the FPC 70 and the fuel can be poured directly over the cooling plate 73, the cooling capability is improved compared with cooling structures described in JP-A-S62-35088 and JP-A-2001-99029.
Furthermore, according to this first embodiment, the cooling plate 73 directly contacts the circuit board 72 that is a source of heat generation. Therefore, the cooling capability can be improved compared with a structure in which the cooling plate 73 is made to contact only the case 71.
Here, the flange 12 supports the fuel discharge pipe 14, the fuel vapor outlet pipe 15, the fuel vapor control valve 17, and the electric connector 16, relatively little space is necessary for mounting the FPC 70 on the flange 12. Also, since in this first embodiment, the cooling plate 73 and the FPC 70 are in the longitudinal arrangement as described above, the flange 12 can also support the FPC 70 so that the fuel discharge pipe 14, the fuel vapor outlet pipe 15, the fuel vapor control valve 17, and the electric connector 16 do not interfere with the FPC 70.
In one embodiment, the metallic cooling plate 73 is insert molded with resin so as to be coupled with the resin-made case 71. When the case 71 swells due to the fuel, the cooling plate 73 is unlikely to swell. Therefore, a gap might be produced between the case 71 and the cooling plate 73, thereby allowing fuel to flow into the case 71. To address this problem, according to this first embodiment, the sealant 74 is provided between the cooling plate 73 and the case 71, and the sealant 74 swells to a much greater degree than the case 71.
Therefore, even if the case 71 deforms due to swelling in a direction moving away from the cooling plate 73, the gap between the case 71 and the cooling plate 73 is filled with the sealant 74 because the sealant 74 swells to a larger degree than the case 71. Moreover, the case 71 swells elastically as described above such that the sealant 74 restores its original state. Accordingly, the gap between the case 71 and the cooling plate 73 remains sealed by the sealant 74.
Referring now to
The pump module 10 in the second embodiment is equipped with a sub tank 30 placed inside the fuel tank 2. The fuel pump 40, the fuel filter 42, the suction filter 48, and the pressure regulator 44 are arranged in the sub tank 30. A point 733 of the cooling plate 73 is provided inside the sub tank 30.
The sub tank 30 is linked with the flange 12 by stays 31. The linkage will be explained concretely. The flange 12 is provided with a press-fit part 32 in which one end of each of the two stays 31 is press-fit on the sub-tank 30 side thereof. The other ends of the stays 31 are loosely inserted in support parts (not illustrated) formed on a peripheral side wall of the sub tank 30. Therefore, the sub tank 30 is slidable in the up/down direction relative to the flange 12.
The spring 33 is fit in a periphery of the stay 31 and provides a spring force in a direction in which the flange 12 and the sub tank 30 separate from each other. Therefore, in a state where the pump module 10 is coupled to the fuel tank 2, the sub tank 30 is pressed to a bottom inner wall 202 of the fuel tank 2 due to the spring force of the spring 33.
A jet pump (not shown) pumps fuel in the fuel tank 2 into the sub tank 30. Thus, even when fuel level is relatively low in the fuel tank 2, if there is as much fuel in the fuel tank 2 as fills the sub tank 30, fuel is pumped to the sub tank 30, and accordingly fuel in the sub tank 30 contacts the cooling plate 73.
Although in the first embodiment described above, the FPC 70 is disposed under the flange 12, in this second embodiment the FPC 70 is disposed above the flange 12 (on the other side of the flange 12 to the sub tank 30), and the FPC 70 is provided outside the fuel tank 2. The FPC 70 according to this second embodiment is disposed to be in an orientation in which the circuit board 72 thereof is substantially parallel to the flange 12. As such, the FPC 70 is disposed in a so-called transverse arrangement.
As shown in
Thus, in this embodiment, the cooling plate 73 contacts the circuit board 72 of the FPC 70 and is disposed in the sub tank 30. Thus, the cooling plate 73 continually exchanges heat with the fuel in the sub tank 30. Therefore, regardless of the clearance between the fuel tank 2 and the car body, the circuit board 72 of the FPC 70 can be sufficiently cooled compared with the conventional structure of air cooling type equipped with a cooling fin. Furthermore, since the cooling plate 73 contacts the circuit board 72 of the FPC 70 and the cooling plate 73 directly contacts the fuel, the cooling capability is improved compared with the cooling structure described in JP-A-S62-35088 and JP-A-2001-99029.
Referring now to
In this third embodiment, the position of the cooling plate 73 is altered from the second embodiment described above. Three patterns of
The cooling plate 73 shown in
Incidentally, a broken line 424 shown in
According to this third embodiment, when viewing a longitudinal projection of the cooling plate 73, the filter case 422, the stay 31, and the fuel pump 40 through the opening 201, the cooling plate 73 is spaced from the filter case 422, the stay 31, and the fuel pump 40. Therefore, regardless of the length of the cooling plate 73, the cooling plate 73 is spaced from the filter case 422, the stay 31, and the fuel pump 40. However, the system is relatively compact and can be mounted in a relatively small space in the vehicle.
In the first embodiment described above, the pressure regulator 44 is described as a “fuel outlet device”. However, the fuel outlet device is not limited to the pressure regulator 44. For example, in a fuel supply system equipped with return pipe arrangement that returns surplus fuel in the delivery pipe 4 to the fuel tank 2, the return pipe arrangement may function as a fuel outlet device by pouring the fuel returned to the fuel tank 2 through the return pipe arrangement over the cooling plate 73.
As another example of a “fuel outlet device,” there can be further enumerated means for discharging, toward the cooling plate 73, a portion of the fuel being discharged toward the delivery pipe 4 from the fuel pump 40. However, in this case, power consumption of the fuel pump 40 may be increased by an amount of electricity required to discharge the fuel toward the cooling plate 73. On the contrary, when the pressure regulator 44 according to the first embodiment or the above-mentioned return pipe arrangement is the fuel outlet device, the problem of increase in power consumption described above can be avoided.
In the pump module 10 according to the first embodiment described above, the FPC 70 disposed in the longitudinal arrangement may be disposed in the transverse arrangement. In the pump module 10 by the second embodiment described above, the FPC 70 disposed in the transverse arrangement may be in the longitudinal arrangement. Moreover, although the FPC 70 according to the first embodiment is disposed so that the circuit board 72 is substantially perpendicular to the opening 201, it is suitable that the FPC 70 is disposed to be in an orientation in which the circuit board 72 crosses the opening 201. Also, an orientation of the FPC 70 shown in
The resin-made case 71 of the FPC 70 may have a structure to be attached on the flange 12 by fixing means, such as snap fit, or may be integral with the flange 12 using a resin.
Although in each embodiment described above, the FPC 70 is coupled to the flange 12 to form a constitutional component of the pump module 10, the FPC 70 may be installed on a location other than the flange 12, and the FPC 70 may be made as a separate member from the pump module 10. Also, although the flange 12 by the first embodiment described above is made of the resin, it may be made of a metal.
In each embodiment described above, the cooling plate 73 is disposed to be in the orientation in which the plate face of the cooling plate 73 is substantially perpendicular to the opening 201. However, it is suitable that the cooling plate 73 is disposed to be in an orientation in which the plate face thereof crosses the aperture of the opening 201. For example, the orientation of the cooling plate 73 shown in
As in the foregoing, this invention is not limited to the above-mentioned embodiments, and can be applied to various fuel supply systems and the like, as possible embodiments, without departing from the spirit and scope thereof.
While only the selected preferred embodiments have been chosen to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims. Furthermore, the foregoing description of the preferred embodiments according to the present invention is provided for illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
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