Fuel pump module for vehicle

Abstract

 The invention provides a fuel pump module for vehicle in which the overall length can be largely reduced and the vapor generated in the inside can be discharged to the outside.
To achieve this, an electrically driven fuel pump 13 and a fuel filter 14 which are contained in a module case 12 are so disposed that their longitudinal axes are parallel to each other, and a vapor separating chamber 26 for receiving the vapor generated in the electrically driven fuel pump 13 and the fuel filter 14 and for feeding the vapor separated from the fuel to a fuel return port 22 is disposed in the module case 12 adjacently to one end in the longitudinal direction of each of the electrically driven fuel pump 13 and the fuel filter 14.

Description

Specification

[0001] The present invention relates to a fuel pump module for vehicle such as a motorcycle, and particularly to an improvement in a fuel pump module for vehicle which includes a module case provided with a fuel inlet for receiving a fuel from a fuel tank, a fuel outlet for supplying the fuel to a fuel injection valve of an engine, and a fuel return port for recirculating an excess fuel to the fuel tank, in the state of opening to the outside of the module case, an electrically driven fuel pump and a fuel filter intermediately disposed in series in the passage for connecting between the fuel inlet and the fuel outlet, and a fuel pressure regulator intermediately disposed in a pressure regulating passage connecting between the fuel outlet and the fuel return port, the electrically driven fuel pump and the fuel filter and the fuel pressure regulator being contained in the module case.

[0002] Such a fuel pump module as above has already been known, as disclosed, for example, in Japanese Patent Laid-open No. 2001-248510.

[0003] In such a fuel pump module as above according to the prior art, the electrically driven fuel pump and the fuel filter are disposed in series on the same axis. Therefore, the overall length of the fuel pump module would be very large, and it is difficult to lay out the fuel pump module in a compact form at the time of mounting it on the engine. In addition, where the fuel pump module is disposed in proximity to the engine, a vapor is generated in the fuel pump module under the effect of radiant heat of the engine, possibly causing a trouble in hot starting or high-speed operation of the engine.

[0004] The present invention has been made in consideration of the above circumstances. Accordingly, it is an object of the present invention to provide the above-mentioned fuel pump module for vehicle in which the overall length can be reduced greatly and the vapor generated therein can be discharged to the exterior.

[0005] In order to attain the above object, the present invention is firstly characterized in that, in a fuel pump module for vehicle which includes a module case provided with a fuel inlet for receiving a fuel from a fuel tank, a fuel outlet for supplying the fuel to a fuel injection valve of an engine, and a fuel return port for recirculating an excess fuel to the fuel tank, in the state of opening to the outside of the module case, an electrically driven fuel pump and a fuel filter intermediately disposed in series in a passage for connecting between the fuel inlet and the fuel outlet, and a fuel pressure regulator intermediately disposed in a pressure regulating passage connecting between the fuel outlet and the fuel return port, the electrically driven fuel pump and the fuel filter and the fuel pressure regulator being contained in the module case, the electrically driven fuel pump and the fuel filter are so disposed that their longitudinal axes are parallel to each other, and a vapor separating chamber for receiving the fuel containing a vapor generated in the electrically driven fuel pump and the fuel filter and for feeding the vapor separated from the fuel to the fuel return port is provided in the module case adjacently to one end in the longitudinal direction of each of the electrically driven fuel pump and the fuel filter.

[0006] According to the first characteristic feature, owing to the parallel arrangement of the electrically driven fuel pump and the fuel filter, it is possible to largely reduce the overall length of the module case and to contrive a compact arrangement of the fuel pump module.

[0007] In addition, since the vapor generated in the fuel filter and the electrically driven fuel pump is received into the vapor separating chamber together with the fuel, separation between the fuel and the vapor is conducted in the chamber and the vapor floats up and is fed to the fuel return port, the fuel in a good condition which does not contain the vapor can be supplied to the fuel injection valve, and a stable engine operation condition can always be secured.

[0008] In addition, since the vapor generated in the fuel filter and the electrically driven fuel pump is separated from the fuel in the vapor separating chamber and fed to the fuel return port, the fuel in a good condition not containing the vapor can be supplied to the fuel injection valve, and a stable operation condition of the engine can always be secured.

[0009] Besides, the present invention is secondly characterized in that, in addition to the first characteristic feature, a vapor discharge hole at an upper portion of the vapor separating chamber is opened into the pressure regulating passage on the downstream side of the fuel pressure regulator, and a negative pressure is applied to the vapor discharge hole by an ejector effect generated by the passage of the excess fuel through the pressure regulating passage.

[0010] According to the second characteristic feature, the application of the negative pressure to the vapor discharge hole by the ejector effect makes it possible to effectively promote the discharge of the vapor from the vapor separating chamber into the pressure regulating passage and, attendantly, to promote also the vapor separating action in the vapor separating chamber.

[0011] Therefore, not only the discharge of the vapor from the vapor separating chamber into the pressure regulating passage can be promoted effectively, but also the vapor separating action in the vapor separating chamber can be promoted.

[0012] Further, the present invention is thirdly characterized in that, in addition to the first or second characteristic feature, the fuel filter is intermediately disposed in the passage between the fuel inlet and the electrically driven fuel pump.

[0013] According to the third characteristic feature, the electrically driven fuel pump can incorporate a brushless type motor, and the fuel filter can be of the inexpensive low-pressure type.

[0014] Furthermore, the present invention is fourthly characterized in that, in addition to the first or second characteristic feature, the interior of the module case is communicated to the fuel inlet and is thereby filled with the fuel, the electrically driven fuel pump is immersed in this fuel, and the fuel filter is intermediately disposed in the passage between the electrically driven fuel pump and the fuel outlet.

[0015] According to the fourth characteristic feature, the motor incorporated in the electrically driven fuel pump can be cooled with the fuel present in the module case.

[0016] Therefore, even where the motor is an ordinary brushed motor, the brush sliding contact portion can be effectively cooled with the fuel. In addition, in this case, even if abraded powder generated at the brush sliding contact portion is mixed into the fuel in the module case and is sucked into the electrically driven fuel pump, the abraded powder can be trapped by the fuel filter and can thereby be inhibited from flowing to the side of the fuel injection valve.

[0017] Furthermore, the present invention is fifthly characterized in that, in addition to any of the first to fourth characteristic features, the module case is disposed adjacently to one side of an intake pipe of the engine so that the longitudinal axes of the module case and the intake pipe are roughly orthogonal to each other.

[0018] Incidentally, the intake pipe corresponds to a throttle body 6 in an embodiment of the present invention which will be described later.

[0019] According to the fifth characteristic feature, in combination with the shortening of the overall length of the fuel pump module, the intake system of the engine can be made compact.

[0020] A mode for carrying out the present invention will be described below based on embodiments of the present invention shown in the accompanying drawings.

Fig. 1 is a side view of a major part of a motorcycle provided with a fuel pump module according to a first embodiment of the present invention.

Fig. 2 is an enlarged vertically sectional side view of portion 2 of Fig. 1.

Fig. 3 is a sectional view taken along line 3-3 of Fig. 2.

Fig. 4 is a sectional view taken along line 4-4 of Fig. 3.

Fig. 5 is a general outline view of a fuel supply system in a motorcycle, including the fuel pump module.

Fig. 6 is an illustration of the constitution and actions of a tilt-down shut-off valve.

Fig. 7 is a general outline view of a fuel supply system in a motorcycle provided with a fuel pump module according to a second embodiment of the present invention.

[0021] Description will be started with a description of a first embodiment of the present invention shown in Figs. 1 to 7.

[0022] In Fig. 1, a body frame 1 of a motorcycle M as a vehicle is composed of a front pipe 1f extending rearwardly downwards from a head pipe which is not shown, and a rear pipe 1r erected from the rear end of the front pipe 1f and extending rearwards. A 4-cycle engine E disposed on the lower side of the front pipe 1f is suspended from the front pipe 1f, and a fuel tank T is disposed on the rear pipe 1r.

[0023] The engine E has a cylinder block 3 disposed roughly horizontally, with a cylinder head 2 directed to the front side of the vehicle body, a throttle body 6 having an intake passage 5 communicated to an intake port 4 is jointed to an upper end surface of the cylinder head 2, and an air cleaner 7 is connected to the upstream end of the throttle body 6. An exhaust pipe 9 communicated to an exhaust port 8 is jointed to a lower end surface of the cylinder head 2.

[0024] A throttle valve 10 for opening and closing the intake passage 5 is shaft-supported on the throttle body 6, and an electromagnetic type fuel injection valve I for injecting a fuel toward the intake port 4 is fitted to an injection valve fitting boss 1 formed on a side wall of the throttle body 6 on the downstream side of the throttle valve 10. A fuel pump module Mp for supplying the fuel in the fuel tank T to the fuel injection valve I is fitted to the throttle body 6.

[0025] First, the general constitution of the fuel pump module Mp will be described referring to the general outline view shown in Fig. 6.

[0026] The fuel pump module Mp includes a module case 12, and an electrically driven fuel pump 13, a low-pressure type fuel filter 14, a fuel pressure regulator 15 and a tilt-down shut-off valve 16 which are contained in the module case 12, as main components.

[0027] The module case 12 has a fuel inlet 20, a fuel outlet 21 and a fuel return port 22 opening in an outside surface thereof, a fuel supply pipe 23 extended from a bottom portion of the fuel tank T is connected to the fuel inlet 20, and the fuel in the fuel tank T flows into the fuel inlet 20 under the action of gravity.

[0028] In addition, a fuel return pipe 24 having a terminal end opening to a gas phase portion inside the fuel tank T is connected to the fuel return port 22, and the fuel outlet 21 is connected to an introduction port of the fuel injection valve I.

[0029] The module case 12 is provided therein with a main chamber 25, and a vapor separating chamber 26 adjacent to the main chamber 25 through a partition wall 27 therebetween, and the electrically driven fuel pump 13 and the fuel filter 14 are contained in the main chamber 25. In this case, the fuel filter 14 has an inlet pipe 28 at one end in the longitudinal direction thereof connected to the fuel inlet 20, and has an outlet pipe 29 at the other end in the longitudinal direction thereof opening into the vapor separating chamber 26. The electrically driven fuel pump 13 has a suction pipe 30 and a vapor discharge pipe 31 at one end in the longitudinal direction thereof opening into the vapor separating chamber 26, and has a discharge pipe 32 at the other end in the longitudinal direction thereof communicated to an inlet hole 33 of the tilt-down shut-off valve 16.

[0030] An outlet hole 34 of the tilt-down shut-off valve 16 is communicated to the fuel outlet 21 through an injected fuel passage 35, and a check valve 36 for inhibiting backflow of the fuel from the fuel outlet 21 to the side of the tilt-down shut-off valve 16 is provided at an intermediate portion of the injected fuel passage 35.

[0031] A pressure regulating passage 40 leading to the fuel return port 22 is branched from the injected fuel passage 35 on the downstream side of the check valve 36, and a fuel pressure regulator 15 is intermediately provided in the pressure regulating passage 40. The fuel pressure regulator 15 includes a valve seat 42 formed at an intermediate portion of the pressure regulating passage 40 and directed to the downstream side, a valve body 43 oppositely disposed to be seatable on the valve seat 42, and a pressure regulating spring 44 for energizing the valve body 43 to the side of the valve seat 42 with a predetermined set load. The fuel pressure regulator 15 is so constructed that when the discharge pressure of the electrically driven fuel pump 13 reaches or exceeds a prescribed value, the valve body 43 parts from the valve seat 42 to release the excess pressure to the fuel return port 22.

[0032] A vapor discharge hole 45 piercing through a ceiling wall of the vapor separating chamber 26 is opened in the inside surface of the pressure regulating passage 40 on the downstream side of the fuel pressure regulator 15 so that a negative pressure is applied to the vapor discharge hole 45 by an ejector effect generated by the passage of the excess fuel through the pressure regulating passage 40 at a high velocity.

[0033] Again in Fig. 1, an electronic control unit 47 is disposed at a front surface of the air cleaner 7. The electronic control unit 47 controls the operations of the fuel injection valve I, the electrically driven fuel pump 13, an ignition coil (not shown) and the like, based on such signals as engine revolution number Ne, engine temperature (for example, the temperature of a lubricating oil) Te, the opening Th of the throttle valve 10, crank position Cp and the like which are inputted thereto.

[0034] During operation of the engine E, the fuel in the fuel tank T flows down through the fuel supply pipe 23 to reach the fuel inlet 20 of the fuel pump module Mp, and is then filtered by the fuel filter 14, and once flows into the vapor separating chamber 26. Thus, the supply of the fuel to the fuel inlet 20 is effected by gravity, so that when the vapor is generated in the fuel supply pipe 23, the vapor naturally floats up to the side of the fuel tank T. The fuel having flowed into the vapor separating chamber 26 is sucked from the inlet pipe 28 and fed under pressure into the discharge pipe 32 by the operation of the electrically driven fuel pump 13, then flows through the tilt-down shut-off valve 16 and the check valve 36, is supplied from the fuel outlet to the fuel injection valve I, and is injected from the valve I to the intake port 4.

[0035] Meanwhile, the vapor generated in the fuel filter 14 and the electrically driven fuel pump 13 is discharged into the vapor separating chamber 26, in which separation between the fuel and the vapor is performed, so that the vapor floats up and passes through the vapor discharge hole 45 into the pressure regulating passage 40 on the downstream side of the fuel pressure regulator 15.

[0036] As mentioned above, the excess fuel having opened the valve at the fuel pressure regulator 15 passes through the pressure regulating passage 40 at high velocity, and the ejector effect of this applies a negative pressure to the vapor discharge hole 45. Therefore, the discharge of the vapor from the vapor separating chamber 26 into the pressure regulating passage 40 is promoted effectively, and, attendantly, the vapor separating action in the vapor separating chamber 26 is also promoted. When the vapor is thus discharged from the fuel filter 14 and the electrically driven fuel pump 13, the fuel in a good condition not containing the vapor can be supplied to the fuel injection valve I, whereby a stable operation condition of the engine E can always be secured.

[0037] The fuel and the vapor having passed through the pressure regulating passage 40 flow through the fuel return port 22 and the fuel return pipe 24 to be released to the gas phase portion inside the fuel tank T, so that the vapor can be separated from the fuel in the gas phase portion.

[0038] Next, the above-mentioned tilt-down shut-off valve 16 will be described referring to Fig. 6.

[0039] As shown in Fig. 6(N), the tilt-down shut-off valve 16 includes a cylindrical first valve chamber 55 assuming a leftwardly upward posture when the motorcycle M is in a normal upright condition, and a cylindrical second valve chamber 56 reversely assuming a rightwardly upward posture, and the upper end of the first valve chamber 55 is connected to an intermediate portion of the second valve chamber 56. First and second valve seats 55a, 56a are formed respectively at upper portions of the first and second valve chambers 55, 56, the above-mentioned inlet hole 33 is opened at a lower portion of the first valve seat 55a, and the above-mentioned outlet hole 34 is opened at an upper portion of the second valve seat 56a. The lower ends of the first and second valve chambers 56 are plugged up with spherical plug bodies 59, 60. Spherical valve bodies 58, 59 seatable respectively on the first and second valve seats 55a, 56a are contained in the first and second valve chambers 55, 56. The lower ends of the first and second valve chambers 55, 56 are plugged up with the plug bodies 59, 60.

[0040] When the motorcycle M is in the normal upright condition, as shown in Fig. 6(N), the first and second valve bodies 58, 59 part from the first and second valve seats 55a, 56a and stay on the plug bodies 59, 60 due to their own weights. Therefore, the inlet hole 33 and the outlet hole 34 are communicated with each other, to allow the fuel to be supplied from the electrically driven fuel pump 13 to the fuel injection valve I.

[0041] However, if the motorcycle M is tilted down to the left or right side, as shown in Fig. 6(L) or (R), the first valve chamber 55 or the second valve chamber 56 is tilted roughly horizontally, and, attendantly, the first valve body 57 or the second valve body 58 is seated on the first valve seat 55a or the second valve seat 56a by the inertial force thereof; in any case, the inlet hole 33 and the outlet hole 34 are shut off from each other. Once the first valve body 57 or the second valve body 58 is thus seated on the first valve seat 55a or the second valve seat 56a, the seated condition is maintained by the pressure of the fuel on the side of the inlet hole 33. Therefore, even when a damage is present on the side of the fuel injection valve I due to tilting-down of the motorcycle M, ejection of the fuel from the fuel outlet 21 can be prevented from occurring.

[0042] An embodiment of the fuel pump module Mp as described above is shown in Figs. 2 to 5.

[0043] In Figs. 2 and 3, the module case 12 includes a case main body 12a provided with the main chamber 25, and a case cover 12b provided with the vapor separating chamber 26 and jointed to the case main body 12a through a partition wall 27 therebetween to assume a roughly sector shape in cross section. In this case, seal members 48, 48 are intermediately disposed between joint surfaces of the case main body 12a, the partition wall 27 and the case cover 12b. The cylindrically shaped electrically driven fuel pump is disposed at a central portion of the sector, in the main chamber 25. On the other hand, the fuel filter 14 formed in a circular arc shape is disposed along a circular arc portion of the sector, in the main chamber 25. Thus, the electrically driven fuel pump 13 and the fuel filter 14 are so disposed that their longitudinal axes are parallel to each other in the main chamber 25. Therefore, the overall length of the module case 12 can be shortened greatly, and, in combination with the cross sectional shape being the roughly sector shape, it can be contrived to make the fuel pump module Mp compact.

[0044] As clearly shown in Figs. 2 and 3, the case main body 12a is provided with a pair of fitting bosses 49, 49 arranged side by side in the longitudinal direction, on the outside of the circular arc portion thereof, and the bosses 49, 49 are attached to one side wall of the throttle body 6 by bolts 50, 50. In this case, the module case 12 is so disposed that its longitudinal axis X is orthogonal to the axis Y of the intake passage 5 of the throttle body 6. With this arrangement, in cooperation with the reduction of the overall length of the fuel pump module Mp, it is possible to make the intake system of the engine E compact.

[0045] In addition, a side wall of the case main body 12a is provided with the fuel inlet 20 on the rear side and with the fuel outlet 21 on the front side. Particularly, the fuel inlet 20 is provided in a cap 51 formed integrally with a front wall of the case main body 12a and fitted to a head portion of the fuel injection valve I, and it is communicated directly to the fuel introduction port of the fuel injection valve I, so that it is unnecessary to provide a piping between the fuel outlet 21 and the fuel injection valve I, which can contribute to simplification of fuel piping.

[0046] Further, the tilt-down shut-off valve 16 is incorporated in the case main body 12a.

[0047] On the other hand, the fuel pressure regulator 15 is incorporated in the case cover 12b, and a rear wall thereof is provided with the fuel return port 22.

[0048] When the fuel inlet 20 and the fuel return port 22 are provided in the rear wall of the module case 12 as described above, the fuel supply pipe 23 and the fuel return pipe 24 connected to them can be disposed at a comparatively central portion of the motorcycle M, which is effective for obviating the interference thereof with other things.

[0049] The other constitutions are the same as those shown in the general outline view of Fig. 5; in Figs. 2 to 5, the portions corresponding to those in Fig. 5 are denoted by the same reference symbols.

[0050] Next, a second embodiment of the present invention shown in Fig. 7 will be described.

[0051] In the second embodiment, a strainer 61 is fitted to the fuel inlet 20 of the module case 12. The main chamber 25 is communicated to the fuel inlet 20, the main chamber 25 is thereby filled with the fuel from the fuel tank T, and an electrically driven fuel pump 113 and a fuel filter 114 are immersed in this fuel. The electrically driven fuel pump 113 and the fuel filter 114 are disposed in the main chamber 25 so that their longitudinal axes are parallel to each other, in the same manner as in the preceding embodiment. The electrically driven fuel pump 113 has the suction pipe 30 opened into the main chamber, the fuel in the main chamber 25 is sucked, and the fuel is fed under pressure through the discharge pipe 32 to the fuel filter 114. Therefore, the fuel filter 114 in the second embodiment must be of the high pressure type. The high-pressure fuel filtered by the fuel filter 114 is fed through an outlet pipe 29 to the tilt-down shut-off valve 16, and is then injected from the fuel injection valve I to the intake port 8 of the engine E after being fed through the same route as that in the preceding embodiment.

[0052] The electrically driven fuel pump 113 incorporates an ordinary brushed motor. Therefore, not only the brush sliding contact portion but also the entire part of the motor are cooled with the fuel in the main chamber 25. In this case, abraded powder generated at the brush sliding contact portion may come out into the main chamber 25 and may be sucked into the electrically driven fuel pump 113 together with the fuel, but the abraded powder is trapped by the fuel filter 114 disposed on the discharge side of the electrically driven fuel pump 113, so that the abraded powder is prevented from flowing to the side of the fuel injection valve I.

[0053] An upper portion of the main chamber 25 is communicated to the vapor separating chamber 26 through a belt hole 62 so that the vapor generated inside the main chamber 25 floats up and moves into the vapor separating chamber 26. In addition, the vapor discharge pipe 31 of the electrically driven fuel pump 113 is opened into the vapor separating chamber 26, in the same manner as in the preceding embodiment.

[0054] The other constitutions are the same as in the preceding embodiment; in Fig. 7, the portions corresponding to those in the preceding embodiment are denoted by the same reference symbols as before, and the description thereof is omitted.

[0055] The present invention is not limited to the above embodiments, and various design modifications are possible without parting from the scope of the gist of the invention. For example, in the case where the engine E is a multi-cylinder engine, the throttle body 6 may be coupled to the cylinders heads 2 through an intake manifold, and fuel injection valves corresponding respectively to the cylinders may be fitted to the intake manifold. In that case, besides, the fuel pump module Mp may be fitted to the intake manifold.

[0056] The invention provides a fuel pump module for vehicle in which the overall length can be largely reduced and the vapor generated in the inside can be discharged to the outside. To achieve this, an electrically driven fuel pump 13 and a fuel filter 14 which are contained in a module case 12 are so disposed that their longitudinal axes are parallel to each other, and a vapor separating chamber 26 for receiving the vapor generated in the electrically driven fuel pump 13 and the fuel filter 14 and for feeding the vapor separated from the fuel to a fuel return port 22 is disposed in the module case 12 adjacently to one end in the longitudinal direction of each of the electrically driven fuel pump 13 and the fuel filter 14.

Claims

1. A fuel pump module for vehicle comprising a module case (12) provided with a fuel inlet (20) for receiving a fuel from a fuel tank (T), a fuel outlet (21) for supplying the fuel to a fuel injection valve (I) of an engine (E), and a fuel return port (22) for recirculating an excess fuel to said fuel tank (T), in the state of opening to the outside of said module case (12), an electrically driven fuel pump (13, 113) and a fuel filter (14, 114) intermediately disposed in series in a passage for connecting between said fuel inlet (20) and said fuel outlet (21), and a fuel pressure regulator (15) intermediately disposed in a pressure regulating passage connecting between said fuel outlet (21) and said fuel return port (22), said electrically driven fuel pump (13, 113) and said fuel filter (14, 114) and said fuel pressure regulator (15) being contained in said module case (12), wherein
   said electrically driven fuel pump (13, 113) and said fuel filter (14, 114) are so disposed that their longitudinal axes are parallel to each other, and a vapor separating chamber (26) for receiving the fuel containing the vapor generated in said electrically driven fuel pump (13, 113) and said fuel filter (14, 114) and for feeding the vapor separated from the fuel to said fuel return port (22) is provided in said module case (12) adjacently to one end in the longitudinal direction of each of said electrically driven fuel pump (13, 113) and said fuel filter (14, 114).

2. A fuel pump module for vehicle as set forth in claim 1, wherein
   a vapor discharge hole (45) at an upper portion of said vapor separating chamber (26) is opened into said pressure regulating passage (40) on the downstream side of said fuel pressure regulator (15), and a negative pressure is applied to said vapor discharge hole (45) by an ejector effect generated by the passage of the excess fuel through said pressure regulating passage (40).

3. A fuel pump module for vehicle as set forth in claim 1 or 2, wherein
   said fuel filter (14) is intermediately disposed in the passage between said fuel inlet (20) and said electrically driven fuel pump (13).

4. A fuel pump module for vehicle as set forth in claim 1 or 2, wherein
   the interior of said module case (12) is communicated to said fuel inlet (20) and is thereby filled with the fuel, said electrically driven fuel pump (113) is immersed in this fuel, and said fuel filter (114) is intermediately disposed in the passage between said electrically driven fuel pump (113) and said fuel outlet (21).

5. A fuel pump module for vehicle as set forth in any of claims 1 to 4, wherein
   said module case (12) is disposed adjacent to one side of an intake pipe (6) of said engine (E) so that the longitudinal axes (X, Y) of said module case (12) and said intake pipe (6) are roughly orthogonal to each other.

Drawing