JP2005320884A - Fuel supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent loss of pressure control by pressure rise downstream of a regulator due to flow passage resistance when a flow rate of fuel passing through the regulator increases in a fuel supply device. <P>SOLUTION: In the fuel supply device 1 having a fuel pump 6, the regulator 7, a fuel filter 5 and the like provided in a fuel tank 2 as one piece, a relief valve 11 for suppressing pressure rise is provided in the downstream of the regulator 7. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel supply apparatus that is integrally provided with a fuel pump, a regulator, and the like in a fuel tank and supplies fuel in the fuel tank to an internal combustion engine.

  Conventionally, various fuel supply devices have been proposed. Patent Document 1 discloses a fuel supply apparatus as an example.

  The fuel supply device of the above publication is integrally provided with a fuel pump, a fuel filter, and a regulator, and cleans the fuel in the fuel tank and sends it to the internal combustion engine.

  The fuel discharged from the fuel pump is distributed to the fuel supplied to the internal combustion engine and the fuel returned to the fuel tank after passing through the fuel filter.

  The regulator opens the valve body with a predetermined set pressure in order to adjust the line pressure of the supply passage to the internal combustion engine, that is, the injection pressure of the fuel injection valve of the internal combustion engine. The fuel that has flowed out by opening the valve element returns to the fuel tank.

The fuel flowing out of the regulator passes through the nozzle before returning to the fuel tank. Fuel is introduced into the sub-tank in the fuel tank using the negative pressure generated by the nozzle jet.
JP-A-9-268957

  In the above fuel supply device, when the amount of fuel supplied to the internal combustion engine is small, that is, when the flow rate of the fuel returned to the fuel tank via the regulator is large, the flow resistance by the nozzle downstream of the regulator causes the upstream side of the nozzle. The pressure, that is, the pressure on the downstream side of the valve body of the regulator increases. Here, the valve body of this type of regulator, because of its structure, reaches the maximum valve opening amount when the pressure on the downstream side becomes too high, and the valve body does not move even if the pressure further increases. There has been a problem that it becomes impossible to control the line pressure of the supply passage to the internal combustion engine, that is, the injection pressure of the fuel injection valve.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent the pressure on the downstream side of the regulator from becoming high in the fuel supply device and the regulator from being unable to control the line pressure in the supply passage. It is in.

  In order to achieve the above object, the invention of claim 1 is characterized in that, in a fuel supply apparatus integrally provided with a fuel pump and a regulator, a relief valve for suppressing a pressure rise is provided downstream of the regulator.

  According to a second aspect of the present invention, in the first aspect of the present invention, a case surrounding the fuel pump is provided, a fuel reservoir is formed downstream of the regulator in the case, and the relief valve is connected to the fuel in the fuel reservoir. It is set as the structure provided to discharge.

  According to the first aspect of the present invention, since the pressure increase on the downstream side of the regulator can be prevented by the relief valve, even when the flow rate of fuel returning to the fuel tank through the regulator is large, the regulator is operated as usual. Can function.

  According to the invention of claim 2, since the relief valve is provided so as to discharge the fuel in the fuel pool formed in the case, it can be efficiently laid out in the case, and the space in the fuel tank is effectively used can do. In addition, since the case is integrated in the case, there is an advantage that it is possible to save the manufacturing cost and to save the labor of assembling as compared with the case where the case is provided separately.

  (First Embodiment) A first embodiment of the present invention will be described below with reference to the drawings. In the present embodiment, a system for supplying fuel to an automobile engine as an internal combustion engine is illustrated.

  FIG. 1 is a diagram showing a schematic configuration of a fuel supply system. As shown in the figure, the fuel supply device 1 is attached to a fuel tank 2 mounted on a vehicle.

  The fuel tank 2 is configured as a vertical tank having a main tank 2m and a sub tank 2s, and the fuel supply device 1 is fixed to the upper surface side of the main tank 2m and is suspended in the main tank 2m. The case 3, the chamber 4, the fuel filter 5, the fuel pump 6 and the like are integrally provided.

  Further, in the present embodiment, a regulator 7 (FIG. 3), which will be described later, is provided integrally in the fuel supply apparatus 1, and in this embodiment, only the fuel pipe 8 that supplies fuel exists in the present embodiment, and the engine A so-called non-return type fuel supply system without a return pipe from 60 is constructed.

  FIG. 2 is a longitudinal sectional view of the fuel supply device. As shown in the figure, the case 3 has a mounting bracket 3a, a spacer 3b, and a main case 3c from the upper side. For example, after molding each of them with a resin material, they are welded and bonded together. Formed with.

  The attachment bracket 3a is attached so as to close an opening provided on the upper surface side of the fuel tank 2, and a pipe 9 for connecting the fuel pipe 8 to the engine 60 is attached to the upper surface (outer surface). In addition, a connector 10 is provided for energizing electrical components in the fuel tank 2 such as the fuel pump 6.

  The spacer 3b is joined to the lower surface of the mounting bracket 3a, and functions as a spacer for accommodating a relief valve 11 (FIG. 3) described later. In addition, a plurality of recesses are formed on the lower surface of the spacer 3b, and the upper and lower surfaces of these recesses are the upper surfaces of the fuel passage 14 and the fuel reservoir 20.

  The main case 3c joined to the lower surface of the spacer 3b is mounted with various parts integrated with the fuel supply device 1, such as the fuel pump 6 and the fuel filter 5 for purifying the fuel. A fuel passage is formed therebetween. A plurality of recesses are also formed on the upper surface of the main case 3 c, and the lower bottom surfaces of these recesses are the bottom surfaces of the fuel passage 14 and the fuel reservoir 20. The fuel pump 6 sucks the fuel in the chamber 4 through the suction filter 12.

  FIG. 3 is a longitudinal sectional view of the fuel supply device for explaining the connection relationship of the fuel passages in the case. This figure shows a longitudinal section of main fuel passages formed in the case, expanded in a horizontal row. FIG. 4 is a plan view of the main case as viewed from above.

  In the main case 3c, a plurality of fuel passages 16, 17, 19, 21, and 22 extending in the vertical direction are formed. As shown in FIG. 4, these fuel passages 16, 17, 19, 21, and 22 are appropriately laid out collectively on one side (the right side) of the region where the fuel tank and the fuel filter 5 are formed (the left side in FIG. 4). Thus, the main case 3c and thus the fuel supply device 1 is prevented from becoming larger in the radial direction.

  Furthermore, a bottomed circular hole 13 is formed in the main case 3c adjacent to the fuel pump 6 so as to extend downward with the upper surface as an opening. The fuel filter 5 is fitted into the bottomed circular hole 13. . The inlet of the fuel filter 5 communicates with the discharge port 6a of the fuel pump 6 through a fuel passage 14 extending in the lateral direction.

  The bottom region of the bottomed circular hole 13 serving as the outlet of the fuel filter 5 communicates with the main fuel passage 16 via a fuel passage 15 extending in the lateral direction. The main fuel passage 16 is provided so as to penetrate the spacer 3b and the mounting bracket 3a, and communicates with the inside of the pipe 9 of the mounting bracket 3a at the upper end thereof.

  The main fuel passage 16 communicates with a fuel passage 17 on the lower side, and the fuel passage 17 is connected to an upper bottom portion of a hole 18 formed in a lower end of the main case 3c. The regulator 7 is fitted into the hole 18 from below and fixed.

  The upper bottom portion of the hole 18 further communicates with a return passage 19, and the upper end of the return passage 19 communicates with a fuel reservoir 20 formed at the joint surface between the spacer 3 b and the main case 3 c.

  Two fuel passages 21 and 22 communicate with the fuel reservoir 20. Among them, the fuel passage 21 communicates with a fuel passage 23 formed in the chamber 4. Specifically, pipes 24 projecting downward on the back surface side of the fuel reservoir 20 of the main case 3 c are fitted and inserted into pipes 25 projecting upward from the bottom surface of the chamber 4. , 25 are fuel passages 21,23. Here, a through hole 26 is formed at the lower end of the pipe 25, and a jet pump nozzle 27 is fitted into the through hole 26 from below. A coil spring 28 as an urging means is wound around the outer periphery of the pipe 24 of the main case 3c between the root of the pipe 24 and the tip of the pipe 25. 4 is pressed against the bottom surface of the fuel tank 2.

  Further, a pipe 29 extending downward is provided on the back side of the fuel reservoir 20, and a jet pump nozzle 30 is fitted into the opening. A fuel passage 22 is downstream of the jet pump nozzle 30. Here, the jet outlet 30 a of the jet pump nozzle 30 communicates with the introduction pipe 33 to which the fuel tube 32 from the sub tank 2 s is connected via the fuel passage 31. The lower end of the fuel passage 22 is opened inside the chamber 4.

  With the configuration described above, the fuel discharged from the fuel pump 6 is introduced into the fuel filter 5 from the discharge port 6a through the fuel passage 14, and after passing through the fuel filter 5 from the top to the bottom, the fuel is purified. The main fuel passage 16 is reached via the fuel passage 15.

  In the main fuel passage 16, fuel is supplied to the engine 60 via the pipe 9 and the fuel pipe 8 (FIG. 1), and returns to the fuel tank 2 (inside the chamber 4) via the return passage 19. Distributed to things. In the present embodiment, since it is a non-return system, all of the fuel discharged from the fuel pump 6 that is not supplied to the engine 60 side flows into the regulator 7. The fuel discharged from the regulator 7 is introduced into the fuel reservoir 20 through the return passage 19 and is distributed to the fuel passages 21 and 22 here.

  The fuel that has flowed into the fuel passage 21 is ejected from the jet pump nozzle 27. Due to the jet flow of the jet pump nozzle 27, a pressure drop occurs on the downstream side of the jet outlet 27 a, and a fuel flow is generated from the opening 4 a on the bottom surface of the chamber 4 toward the inside of the chamber 4. Thereby, fuel is introduced into the chamber 4 from the main tank 2m.

  Further, the jet flow of the jet pump nozzle 30 causes a pressure drop on the downstream side of the jet outlet 30a, and a fuel flow from the introduction pipe 33 to the fuel passage 22 through the fuel passage 31 is generated. As a result, the fuel in the sub tank 2 s upstream of the introduction pipe 33 is introduced into the chamber 4 through the fuel tube 32 and the fuel passages 31 and 22.

  As described above, in the present embodiment, the fuel discharged from the regulator 7 is ejected from the two jet pump nozzles 27 and 30, and the pressure drop due to the jets is utilized to make the inside of the chamber 4 from the main tank 2m and the sub tank 2s. I am trying to introduce fuel.

  Now, the fuel supply apparatus 1 according to the present embodiment includes a relief valve 11 that suppresses the pressure increase on the downstream side of the regulator 7. In the example of FIG. 3, the relief valve 11 is provided in the spacer 3 b and discharges the fuel introduced from the introduction port 34 provided on the upper surface of the fuel reservoir 20 into the spacer 3 b from the upper discharge port 35. The fuel that has flowed into the spacer 3b returns to the fuel tank 2 from a through hole 41 provided on the side surface of the spacer 3b.

  FIG. 5 is a cross-sectional view of the relief valve. As shown in the figure, the relief valve 11 accommodates a valve body 37, a spring 38 as an urging means, and a lid body 39 in a substantially cylindrical casing portion 36, and the valve body is urged by the urging force of the spring 38. 37 is pressed against the valve seat 40. The lid 39 is fixed by crimping the mouth of the casing portion 36. With such a configuration, when the pressure on the inlet 34 side, that is, the fuel reservoir 20 side rises, the valve body 37 opens, and the fuel in the fuel reservoir 20 flows into the spacer 3 b through the casing portion 36 and the discharge port 35.

  By providing such a relief valve 11, according to the present embodiment, it is possible to suppress the pressure increase on the downstream side of the regulator 7, so that the problem that the regulator 7 does not function normally is eliminated, and the internal combustion engine is prevented. The line pressure of the main fuel passage 16 as the supply passage, that is, the injection pressure of the fuel injection valve can be controlled as usual.

  Further, since the relief valve 11 is provided in the case 3, the fuel supply device 1 can be configured more compactly than in the case where it is provided separately outside the case 3, and the space in the fuel tank 2 is reduced. It can be used effectively. Moreover, compared with the case where it provides separately, there also exists an advantage that the effort of an assembly | attachment can be reduced and manufacturing cost can be reduced.

  The relief valve 11 is particularly effective when the jet pump nozzles 27 and 30 for sucking fuel are set downstream of the regulator 7 as in the present embodiment. That is, the set pressure of the relief valve 11 can suppress the pressure on the downstream side of the regulator 7 from rising more than necessary, and thereby the flow rate of the jet flow from the jet pump nozzles 27 and 30 can be more stable. It is because it will be able to be secured. That is, according to this embodiment, even when the flow rate of the fuel passing through the regulator 7 is small, the function of the jet pump nozzles 27 and 30 is ensured, and the flow rate of the fuel introduced by the jet pumps 27 and 30 is Decrease can be suppressed.

  (Second Embodiment) A second embodiment of the present invention will be described below with reference to the drawings.

  FIG. 6 is a longitudinal sectional view of the fuel supply device for explaining the connection relationship of the fuel passages in the case. This figure shows a longitudinal section of main fuel passages formed in the case, expanded in a horizontal row. FIG. 7 is a plan view of the main case as viewed from above. The fuel supply device 1A according to the present embodiment has the same configuration as the fuel supply device 1 according to the first embodiment. In the following, the same components are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 6, in this embodiment, the relief valve 11 is provided on the back surface side of the bottom surface of the main tank 53c, specifically, the fuel reservoir 20A. By doing so, the spacer provided to accommodate the relief valve 11 in the first embodiment can be eliminated, and the case 53 can be constituted by only the mounting flange 53a and the main tank 53c, and accordingly, the first embodiment. Further, the height of the fuel supply device 1A can be reduced.

  In each of the above embodiments, an example is shown in which the present invention is applied to a vertical tank, but the fuel supply device of the present invention can also be applied to a fuel tank having a shape other than a vertical tank. Also in this embodiment, the same operation and effect as the above embodiment can be obtained.

  Further, technical ideas other than the claims that can be grasped from the above embodiment will be described together with the effects thereof.

  (A) In the fuel supply device described in claims 1 and 2, it is preferable that the fuel reservoir is formed on the upper side of the fuel pump, and the relief valve is provided on the back side of the fuel reservoir.

  In this case, the height of the fuel supply device can be reduced as compared with the case where the relief valve is provided on the upper surface side of the fuel reservoir.

  (B) In the fuel supply device described in claims 1 and 2 and (a), it is preferable to provide a jet pump nozzle downstream of the regulator.

  In this way, the pressure increase beyond the regulator downstream can be suppressed by the set pressure of the relief valve, the jet flow of the jet pump nozzle can be further stabilized, and consequently the fuel introduced by the jet pump nozzle. It is possible to suppress a decrease in the flow rate.

1 is a schematic configuration diagram of an entire fuel supply system including a fuel supply apparatus according to an embodiment of the present invention. 1 is a longitudinal sectional view of a fuel supply device according to a first embodiment of the present invention. The longitudinal cross-sectional view which expanded and showed the main fuel channel | paths formed in the case of the fuel supply apparatus concerning 1st Embodiment of this invention. The top view which looked at the main case of the fuel supply apparatus concerning 1st Embodiment of this invention from the upper side. The longitudinal cross-sectional view of the relief valve of the fuel supply apparatus concerning embodiment of this invention. The longitudinal cross-sectional view which expanded and showed the main fuel passage formed in the case of the fuel supply apparatus concerning 2nd Embodiment of this invention. The top view which looked at the main case of the fuel supply apparatus concerning 2nd Embodiment of this invention from the upper side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel supply apparatus 2 Fuel tank 3 Case 6 Fuel pump 7 Regulator 11 Relief valve 20 Fuel reservoir

Claims (2)

In a fuel supply apparatus that integrally includes a fuel pump that discharges fuel in a fuel tank, and a regulator that is provided on the discharge side of the fuel pump and adjusts pressure,
A fuel supply device comprising a relief valve for suppressing pressure rise downstream of a regulator. A case surrounding the fuel pump;
Forming a fuel sump downstream of the regulator in the case;
The fuel supply apparatus according to claim 1, wherein the relief valve is provided so as to discharge the fuel in the fuel pool.

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