Fuel flow path module in inline pump type fuel injection apparatus

To make a length in a horizontal direction of a vapor return joint small, thereby improving an assembling property of a fuel flow path module to a fuel tank, a vapor inflow hole, a fuel outflow hole and a regulator fuel inflow hole are provided in a fuel tube portion of a fuel flow path module, a vapor return joint is provided uprightly in an upper side of the vapor inflow hole, the vapor return joint comprises by a first straight pipe portion, and a second straight pipe portion connected to an upper end of the first straight pipe portion at a narrow angle A downward, an intersection between the first straight pipe portion and the second straight pipe portion is arranged above an upper opening end of the second straight pipe portion.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a fuel injection apparatus which boosts fuel stored within a fuel tank by a fuel pump, adjusts a pressure of the boosted fuel to a predetermined pressure by a pressure regulator, and supplies the fuel to an engine via a fuel injection valve, and more particularly to a fuel flow path module used in an inline pump type fuel injection apparatus in which the fuel pump is arranged in an outer side of the fuel tank, and is arranged within a fuel inflow pipe extending toward an outer side from the fuel tank.

2. Description of the Conventional Art

A description will be given of a fuel flow path module in a conventional inline pump type fuel injection apparatus with reference toFIG. 2.

A fuel flow path module M in which a plurality of fuel flow paths are respectively formed independently is formed in the following manner.

Reference numeral1denotes a fuel tube portion formed in a tubular shape in a vertical direction. An attaching collar portion1aformed in a flat shape toward a side portion from an outer periphery of the fuel tube portion1is formed in the fuel tube portion1, and a screw insertion hole1bis provided through in the attaching collar portion1a.

Further, a vapor inflow hole2, a fuel outflow hole3and a regulator fuel inflow hole4which are independent from each other are provided from a lower end1cof the fuel tube portion1toward an upper end1d.

In other words, the holes2,3and4are open to the lower end1cand the upper end1d.

Further, a vapor return joint5is pressure inserted to and provided uprightly in an opening portion to the upper end1dof the vapor inflow hole2.

The vapor return joint5mentioned above is formed by a metal pipe member, and is formed by a straight pipe portion5adirected toward an upper side, and a U-shaped pipe portion5bbent in an inverse-U shape from an upper end of the straight pipe portion5a, and a lower opening portion5baof the U-shaped pipe portion5bis open toward a lower side.

Further, a pressure regulator R is inserted to the opening portion to the upper end1dof the regulator fuel inflow hole4so as to be arranged to be connected.

Reference symbol K denotes a sealed-state pump receiving case arranged at a lower position of the fuel tank T, a fuel inflow hole6is open to a lower side of the pump receiving case, and a vapor discharge hole7is open to an upper side thereof.

The fuel pump P is provided with a motor Pm and an impeller Pa driven by the motor Pm, and a pressure difference is generated between front and rear sides of a blade groove in an outer periphery of an impeller Pa on the basis of a rotation of the impeller Pa, whereby the fuel is sucked into a pump chamber from a pump suction path Pb, and the boosted fuel is discharged from a pump discharge path Pc. Further, a strainer S is arranged in the pump suction path Pb.

Further, the fuel pump P provided with the strainer S is arranged within the pump receiving case K. At this time, a fuel chamber Ka which can store the fuel is formed between an inner periphery of the pump receiving case K and an outer periphery of the fuel pump P.

Reference symbol D denotes a fuel distribution pipe in which a fuel distribution path8is provided. A fuel injection valve J is inserted and supported to the fuel distribution pipe D, and the fuel supplied into the fuel distribution path8is supplied toward the fuel injection valve J.

The fuel flow path module M is fixedly arranged in the fuel tank T in the following manner.

A module insertion hole Tb to which the fuel tube portion1of the fuel flow path module M can be inserted is provided in a bottom portion Ta of the fuel tank T.

Further, an upper side portion of the fuel tube portion1including the vapor return joint5of the fuel flow path module M and the pressure regulator R is inserted and arranged within the fuel tank T via the module insertion hole Tb, and an upper surface of the attaching collar portion1ais arranged so as to be brought into contact with the bottom portion Ta of the fuel tank T via a packing9. In the state mentioned above, a screw10is inserted into the screw insertion hole1bof the attaching collar portion1a, and the attaching collar portion1ais fixed by screw toward the bottom portion Ta of the fuel tank T.

In accordance with the structure mentioned above, the fuel flow path module M is fixedly arranged in the bottom portion Ta of the fuel tank T, the module insertion hole Tb of the fuel tank T is closed by the attaching collar portion1a, the pressure regulator R including the vapor return joint5and the return fuel hole Ra is received and arranged within the fuel tank T, and lower sides of the vapor inflow hole2, the fuel outflow hole3and the regulator fuel inflow hole4are open to the lower end1cof the fuel tube portion1.

Further, the fuel flow path module M, the pump receiving case K and the fuel distribution pipe D are connected by flow paths in the following manner.

The fuel out flow hole3of the fuel flow path module M and the fuel inflow hole6of the pump receiving case K are connected by a fuel inflow pipe11.

The discharge path Pc of the fuel pump P and the fuel distribution path8of the fuel distribution pipe D are connected by a fuel outflow pipe12.

Further, a regulator fuel pipe13branched from the fuel outflow pipe12is connected to the regulator fuel inflow hole4of the fuel flow path module M.

Further, the vapor discharge hole7of the pump receiving case K and the vapor inflow hole2of the fuel flow path module M are connected by a vapor relief pipe14.

In accordance with the inline pump type fuel injection apparatus formed in the manner mentioned above, the fuel stored within the fuel tank T is supplied into the fuel chamber Ka of the pump receiving case K via the fuel outflow hole3, the fuel inflow pipe11and the fuel inflow hole6, the fuel pump P sucks the fuel supplied into the fuel chamber Ka into the fuel pump P via the strainer S and the pump suction path Pb, and the fuel boosted by the fuel pump P is discharged into the fuel outflow pipe12via the pump discharge path Pc.

Further, a part of the fuel within the fuel outflow pipe12is supplied to the pressure regulator R via the regulator fuel pipe13and the regulator fuel inflow hole4, and is adjusted to a predetermined pressure by the pressure regulator R.

An excess fuel at a time of being adjusted by the pressure regulator R is returned into the fuel tank T via the return fuel hole Ra.

In accordance with the structure mentioned above, the fuel having the pressure adjusted to the predetermined fuel pressure is supplied toward the fuel distribution path8of the fuel distribution pipe D from the fuel outflow pipe12, and the fuel within the fuel distribution path8is injected and supplied toward the engine (not shown) via the fuel injection valve J.

On the other hand, if the fuel inflow pipe11is warmed up by a heat radiation from the engine or an outside air temperature, a vapor is generated in the fuel flowing within the fuel inflow pipe11, and the vapor flows into the fuel chamber Ka within the receiving case K from the fuel inflow hole6.

Further, if the fuel pump P is driven, the motor Pm generates heat, the fuel within the fuel chamber Ka is warmed up on the basis of the heat generation of the motor Pm and the vapor is generated.

Further, if the fuel pump P is driven and the impeller Pa rotates within the pump chamber, the vapor is generated within the pump chamber, and the vapor is discharged into the fuel chamber Ka via a vapor bleeding hole Pd of the fuel pump P.

Further, the vapor generated in the manner as mentioned above is discharged into the fuel tank T via the vapor discharge hole7, the vapor relief pipe14, the vapor inflow hole2and the vapor return joint5through an upper space of the fuel chamber Ka.

Further, in the vapor return joint5, an upper end of the straight pipe portion5ais bent in the inverse-U shape toward the lower side by the U-shaped pipe portion5b. Accordingly, even if the vapor return joint5is in a state of being arranged so as to be immersed into the fuel within the fuel tank T, the fuel within the fuel tank T is prevented from flowing toward the inner side of the vapor relief pipe14.

This is because a peak5bbof the U-shaped pipe portion5bis arranged in an upper side of the lower opening portion5ba.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

In accordance with the vapor return joint5of the conventional fuel flow path module M mentioned above, it is impossible to make a length W in a horizontal direction inFIG. 2of the vapor return joint5small.

This is because a bending radius r of the U-shaped pipe portion5bdepends on a pipe diameter d of the vapor return joint5, and it is necessary to set the bending radius r to be twice as large as the pipe diameter d or more.

If the bending radius r is less than double of the pipe diameter d, the U-shaped pipe portion5bis collapsed, a cross sectional area of the pipe diameter is largely reduced, and it is impossible to execute a good vapor bleeding.

As mentioned above, in accordance with the structure in which the length W in the horizontal direction of the vapor return joint5is large, the vapor return joint5is inserted while being inclined and screw rotated at a time of inserting the vapor return joint5of the fuel flow path module M into the fuel tank T via the module insertion hole Tb of the fuel tank T. Accordingly, an assembling property of the fuel flow path module is deteriorated, and there is a risk that the pressure regulator R is brought into contact with the module insertion hole Tb so as to be damaged.

Further, it is possible to move the vapor return joint5in a linear direction so as to insert into the fuel tank T, by enlarging the hole diameter of the module insertion hole Tb, however, in the case that the module insertion hole Tb is enlarged in diameter, it is necessary to increase a pressing force to the packing9in comparison with the conventional structure, and it is necessary to enlarge a diameter of the screw10and increase a number of the screw10.

The present invention is made by taking the problem mentioned above into consideration, and an object of the present invention is to provide a fuel flow path module in which a length in a horizontal direction of a vapor return joint is made smaller in comparison with the conventional structure, and the vapor return joint5can be moved in a linear direction so as to be arranged to be inserted into a fuel tank even in the case of using the conventional module insertion hole Tb, thereby improving an assembling property of the fuel flow path module including the vapor return joint to the fuel tank.

In order to achieve the object mentioned above, in accordance with the present invention, there is provided a fuel flow path module in an inline pump type fuel supply apparatus comprising:

a fuel tube portion formed in a vertical direction;

an attaching collar portion formed toward a side portion from an outer periphery of the fuel tube portion;

a vapor inflow hole, a fuel outflow hole and a regulator fuel inflow hole provided toward an upper end from a lower end of the fuel tube portion;

a vapor return joint provided uprightly in an upper side of the vapor inflow hole; and

a pressure regulator arranged so as to be connected to the regulator fuel inflow hole,

wherein the vapor return joint comprises:

a fuel flow path module which is formed by a first straight pipe portion extending toward an upper side, and a second straight pipe portion arranged so as to be connected at a narrow angle from an upper end of the first straight pipe portion toward a downward direction, and in which an intersection of connection between the first straight pipe portion and the second straight pipe portion is arranged at an upper position from an upper opening end of a lower opening portion of the second straight pipe portion;

a pump receiving case which receives a fuel pump, and in which a fuel inflow hole is open to a lower side and a vapor discharge hole is open to an upper side; and

a fuel distribution pipe in which a fuel injection valve is arranged so as to be inserted toward a fuel distribution path,

wherein the fuel tube portion provided with the vapor return joint and the pressure regulator of the fuel flow path module is inserted into a fuel tank via a module insertion hole open to a bottom portion of the fuel tank, and the fuel flow path module is fixedly arranged in the fuel tank via an attaching collar portion, and

wherein the fuel outflow hole and the fuel inflow hole are connected by a fuel inflow pipe, the vapor discharge hole and the vapor inflow hole are connected by a vapor relief pipe, the pump discharge path and the fuel distribution path are connected by a fuel outflow pipe, and a regulator fuel pipe branched from the fuel outflow pipe is connected to the regulator fuel inflow hole.

In accordance with the fuel flow path module on the basis of the present invention, since the vapor return joint is formed by the first straight pipe portion and the second straight pipe portion arranged so as to be connected at the narrow angle from the upper end of the first straight pipe portion toward the downward direction, and the intersection of connection between the first straight pipe portion and the second straight pipe portion is arranged at the upper position from the upper opening end of the lower opening portion of the second straight pipe portion, it is possible to make the length in the horizontal direction of the vapor return joint smaller in comparison with the conventional length in the horizontal direction.

In accordance with the structure mentioned above, since the fuel tube portion including the vapor return joint can be moved in a linear direction with respect to the module insertion hole of the conventional fuel tank, so as to insert and arrange in the fuel tank it is possible to largely improve an assembling property of the fuel flow path module to the fuel tank.

Further, in accordance with the structure mentioned above, it is possible to prevent the pressure regulator from being brought into contact with the module insertion hole so as to be damaged.

Further, since it is not necessary to expand the hole diameter of the conventional module insertion hole, it is possible to securely close and hold the module insertion hole by the attaching collar portion while using the conventional screw and packing as they are. Further, since the intersection of connection between the first straight pipe portion and the second straight pipe portion is arranged at the upper position from the upper opening end of the lower opening portion of the second straight pipe portion, the fuel within the fuel tank is prevented from flowing into the vapor relief pipe via the vapor return joint even if the vapor return joint is in a state of being arranged so as to be immersed into the fuel within the fuel tank.

A description will be given below of an embodiment of a fuel flow path module in an inline pump type fuel supply apparatus in accordance with the present invention with reference toFIG. 1.

In this case,FIG. 1is different fromFIG. 2only in a vapor return joint. Accordingly, a description will be given only of the vapor return joint, and the description inFIG. 2is applied to the other structures.

A vapor return joint20is formed by a first straight pipe portion20aformed by a pipe member and extending toward an upper side, and a second straight pipe portion20cconstituted by a pipe member connected toward an obliquely downward right side from an upper end20bof the first straight pipe portion20a.

At this time, a longitudinal axial line X-X of the second straight pipe portion20cis connected so as to be intersected at a narrow angle (an angle A) smaller than 90 degree with respect to a longitudinal axial line Y-Y of the first straight pipe portion20a.

In the present embodiment, the second straight pipe portion20cis arranged so as to be inclined at 60 degree with respect to the first straight pipe portion20a.

In accordance with the structure mentioned above, a lower opening portion20dof the second straight pipe portion20cis open toward an obliquely downward right side. At this time, an intersection B of connection between inner passages of the first straight pipe portion20aand the second straight pipe portion20cis positioned at a distance h above an upper opening end20daof the lower opening portion20dof the second straight pipe portion20c.

Further, a lower side of the first straight pipe portion20aof the vapor return joint20is connected so as to be inserted to an upper opening portion of the vapor inflow hole2of the fuel flow path module M.

As mentioned above, in accordance with the fuel flow path module M on the basis of the present invention, since the vapor return joint20is formed by the first straight pipe portion20aand the second straight pipe portion20cand the second straight pipe portion20cis arranged so as to be connected to the upper end20bof the first straight pipe portion20aat the narrow angle (the angle A), it is possible to make the length W in the horizontal direction of the vapor return joint20shorter than the conventional structure. Accordingly, the fuel tube portion1provided with the vapor return joint20and the pressure regulator R can be arranged so as to be inserted to the module insertion hole Tb of the conventional fuel tank T in the linear direction, and it is possible to largely improve an attaching property of the fuel flow path module M to the fuel tank T.

Further, in accordance with the structure mentioned above, since the pressure regulator R and the vapor return joint20are not brought into contact with the module insertion hole Tb, it is possible to prevent them from being damaged.

In this case, the narrow angle (the angle A) is appropriately determined taking the layout of the pressure regulator R or the like into consideration.

Further, since the intersection B of connection between the first straight pipe portion20aand the second straight pipe portion20cis arranged at the upper position of the upper opening end20daof the lower opening portion20dof the second straight pipe portion20c, it is possible to form an air reservoir in the upper portions of the first and second straight pipe portions20aand20ceven if the vapor return joint20is immersed into the fuel within the fuel tank T. Accordingly, the fuel within the fuel tank T does not flow into the vapor relief pipe14via the second straight pipe portion20cand the first straight pipe portion20a.