JP6243676B2 - Fuel heating system and fuel rail using the same - Google Patents

Description

  The present invention relates to a fuel heating system for heating fuel and a fuel rail using the same.

  Conventionally, a fuel supply system that injects heated fuel from a fuel injection valve and supplies the fuel to an internal combustion engine is known. For example, in the fuel rail described in Patent Document 1, the fuel ignitability is improved by supplying the fuel heated in the heating chamber to the internal combustion engine.

Japanese Patent No. 4834728

  In general, when an alcohol fuel such as ethanol or a mixed fuel of alcohol and gasoline is used for an internal combustion engine, when the alcohol concentration is high and the environmental temperature is low, the ignitability of the fuel is reduced and the internal combustion engine is started. It may be impossible. Therefore, by supplying the heated fuel to the internal combustion engine as described above, the internal combustion engine can be started regardless of the environmental temperature even with alcohol fuel or a mixed fuel with a high alcohol concentration.

  When gasoline is used for an internal combustion engine, when the environmental temperature is low, the viscosity of the fuel may increase and the particle size of the fuel spray may increase. When the particle size of the fuel spray increases, the ignitability of the fuel decreases, which may cause a decrease in the output of the internal combustion engine and a deterioration in emissions. Therefore, by supplying the fuel heated as described above to the internal combustion engine, the particle size of the fuel spray can be reduced, and even when the environmental temperature is low, it is possible to suppress the decrease in output and the deterioration of the emission of the internal combustion engine.

  By the way, Patent Document 1 discloses a fuel heating system and a fuel rail provided with a rod-shaped heat generating portion along the central axis of a cylindrical heating chamber (see FIG. 20 of Patent Document 1). Here, since the member which forms a heating chamber is cylindrical, it is hard to elastically deform. For this reason, when fuel is intermittently injected from the fuel injection valve, fuel pulsation may increase in the heating chamber. If fuel pulsation increases in the heating chamber, fuel injection from the fuel injection valve may become unstable.

  The member forming the heating chamber is formed in a long cylindrical shape by deep drawing a single plate-like material. For this reason, it is difficult to form a heating chamber having a complicated shape. When a long cylindrical member is formed by deep drawing, it is difficult to keep the plate thickness (tubular wall thickness) constant in the axial direction of the member. Therefore, when a long cylindrical member is formed while keeping the plate thickness constant by deep drawing, the processing cost may increase.

  The present invention has been made in view of the above-described problems, and an object thereof is to easily form an upper member and a lower member that form a heating chamber, and a fuel heating system that can reduce fuel pulsation in the heating chamber, And providing a fuel rail.

The present invention is a fuel heating system that is attached to an internal combustion engine or in the vicinity of the internal combustion engine together with a fuel injection valve that supplies fuel to the internal combustion engine, and that heats the fuel from the fuel supply source to lead to the fuel injection valve. And an inlet opening, an outlet opening, and a heating device.
The heating chamber forming section includes an upper member formed of a material with a predetermined plate thickness and having an upper recess, and an upper recess and a lower recess formed by joining the upper member with a lower recess formed of a material with a predetermined plate thickness. It consists of the lower member which forms a heating chamber between.

The inlet opening guides fuel from the fuel supply source into the heating chamber. The outlet opening guides the fuel in the heating chamber to the fuel injection valve.
The heating device has a heat generating portion capable of generating heat, and is provided in the heating chamber forming portion so that the heat generating portion is located in the heating chamber, and the fuel in the heating chamber can be heated by the heat generating portion.

In the present invention, the heating chamber is formed by joining an upper member and a lower member having a predetermined plate thickness. Therefore, when fuel is intermittently injected from the fuel injection valve, the pulsation of the fuel in the heating chamber can be reduced by elastically deforming the upper member or the lower member. Thereby, the fuel injection from the fuel injection valve can be stabilized.
Moreover, since the upper member and the lower member are formed of a material having a predetermined plate thickness, the mass can be reduced and the vibration resistance is excellent.

In addition, since the upper member and the lower member are made of a material having a predetermined plate thickness, the upper member and the lower member can be formed by pressing, deep drawing, etc. It can be easily formed by plastic deformation. Therefore, the manufacturing cost can be reduced as compared with the case where the upper member and the lower member forming the heating chamber are formed by, for example, cutting.
In the present invention, the outlet opening is positioned above the heat generating portion in the vertical direction in a state where the fuel heating system is attached to the internal combustion engine or the vicinity of the internal combustion engine. The heat generating part is formed in a rod shape. When the heating chamber is divided into a vertically upper area and a vertically lower area on a virtual plane including the axis of the heat generating part, both the inlet opening and the outlet opening are located in the vertically upper area. ing.

The perspective view which shows the fuel heating system and fuel rail by 1st Embodiment of this invention. FIG. 2 is a perspective view showing the fuel heating system and the fuel rail according to the first embodiment of the present invention, as viewed from a direction different from FIG. 1. Sectional drawing which shows the fuel heating system by 1st Embodiment of this invention. IV-IV sectional view taken on the line of FIG. FIG. 5 is a cross-sectional view of the fuel heating system according to the first embodiment of the present invention attached in the vicinity of the internal combustion engine, taken along line VV in FIG. 3. The perspective view which shows the upper member and lower member of the fuel heating system by 1st Embodiment of this invention. Sectional drawing which shows the lower member of the fuel heating system by 1st Embodiment of this invention. Sectional drawing which shows the fuel heating system by 2nd Embodiment of this invention. IX-IX sectional view taken on the line of FIG. It is sectional drawing of the state which attached the fuel heating system by 2nd Embodiment of this invention to the internal combustion engine vicinity, Comprising: XX sectional drawing of FIG. Sectional drawing which shows the fuel heating system by 3rd Embodiment of this invention. XII-XII sectional view taken on the line of FIG. FIG. 12 is a cross-sectional view of the fuel heating system according to the third embodiment of the present invention attached in the vicinity of the internal combustion engine, and is a cross-sectional view taken along line XIII-XIII in FIG. 11.

  Hereinafter, a fuel heating system and a fuel rail according to a plurality of embodiments of the present invention will be described with reference to the drawings. Note that, in a plurality of embodiments, substantially the same components are denoted by the same reference numerals, and description thereof is omitted. In addition, in order to avoid complicated description of the drawings, a plurality of substantially identical members or parts may be denoted by only one of the plurality.

(First embodiment)
1 to 7 show a fuel heating system according to a first embodiment of the present invention, a fuel rail using the fuel heating system, and a part thereof.

  As shown in FIG. 1, the fuel rail 1 of the first embodiment is attached in the vicinity of an internal combustion engine (hereinafter referred to as “engine”) 2. The engine 2 is a four-cylinder engine having four cylinders 3. A combustion chamber 4 is formed in each cylinder 3. The engine 2 is driven using, for example, an alcohol fuel such as ethanol or a mixed fuel of alcohol and gasoline as fuel. An intake port 5 is connected to each combustion chamber 4, and intake air is introduced into the combustion chamber 4 via the intake port 5. The intake port 5 is formed in the intake manifold 6.

A fuel injection valve 10 is provided in each intake port 5. That is, four fuel injection valves 10 are provided. The fuel injection valve 10 is provided so that the injection hole 11 is exposed in the intake port 5. The fuel injected into the intake port 5 from the injection hole 11 of the fuel injection valve 10 is atomized and introduced into the combustion chamber 4 together with the intake air, and burns in the combustion chamber 4.
In the present embodiment, the fuel rail 1 is attached to the intake manifold 6 in the vicinity of the engine 2 together with the fuel injection valve 10, and distributes fuel from the fuel tank 7 as a fuel supply source to the fuel injection valve 10.

The fuel rail 1 includes a rail portion 20, a fuel heating system 100, and the like.
As shown in FIGS. 1 and 2, the rail portion 20 includes an upper member 21 and a lower member 22.
The upper member 21 and the lower member 22 are formed, for example, by subjecting a metal plate having a predetermined plate thickness to plastic deformation such as press working. The upper member 21 and the lower member 22 are formed in a long shape. Here, the length in the longitudinal direction and the length in the short direction of the upper member 21 and the lower member 22 are substantially the same.

The upper member 21 has a recess that is recessed from one surface side to the other surface side. The lower member 22 also has a recess that is recessed from one surface side to the other surface side.
The lower member 22 is joined to the upper member 21 so that the longitudinal direction and the lateral direction correspond to the upper member 21 and the concave portion faces the concave portion of the upper member 21. Thereby, the fuel flow path 200 is formed between the recessed part of the upper member 21 and the recessed part of the lower member 22 (refer FIG. 1, 2).

  As shown in FIGS. 1 and 2, the rail portion 20 has convex portions 23 formed at substantially equal intervals in the longitudinal direction. The convex portion 23 is formed so as to protrude in a direction perpendicular to the longitudinal direction of the rail portion 20. Four convex portions 23 are formed so as to correspond to the fuel injection valve 10 to be attached.

  The upper member 21 has a fuel inlet 24 at one end in the longitudinal direction (see FIGS. 1 and 2). The fuel inlet 24 is formed to connect one surface of the upper member 21 and the other surface, that is, to penetrate the upper member 21 in the plate thickness direction.

  As shown in FIGS. 1 and 2, one end of an inlet pipe 25 is connected to the fuel inlet 24 of the rail portion 20 (upper member 21). A fuel supply path 8 extending from the fuel tank 7 is connected to the other end of the inlet pipe 25 (see FIG. 1). A fuel pump 9 is provided between the fuel tank 7 and the inlet pipe 25 in the fuel supply path 8. The fuel pump 9 sucks and discharges the fuel in the fuel tank 7. When the fuel pump 9 is activated, the fuel in the fuel tank 7 is pumped to the inlet pipe 25 via the fuel supply path 8. As a result, fuel from the fuel tank 7 flows into the fuel flow path 200.

  The fuel heating system 100 includes a heating chamber forming unit 30, an inlet opening 33, an outlet opening 34, a heating device 60, and the like. In the present embodiment, a plurality of fuel heating systems 100 are provided at substantially equal intervals along the longitudinal direction of the rail portion 20 so as to be attached to the convex portion 23 of the rail portion 20 (see FIGS. 1 and 2). Four fuel heating systems 100 are provided corresponding to the fuel injection valves 10 to be attached.

The heating chamber forming unit 30 includes an upper member 40 and a lower member 50 (see FIGS. 3 to 6).
The upper member 40 and the lower member 50 are formed, for example, by subjecting a metal plate having a predetermined plate thickness to plastic deformation processing such as pressing or deep drawing.
The upper member 40 has an upper recess 41 that is recessed from one surface side to the other surface side. The lower member 50 has a lower recess 51 that is recessed from one surface side to the other surface side.

  The heating chamber forming portion 30 is formed by joining the upper member 40 and the lower member 50 so that the upper recess 41 of the upper member 40 and the lower recess 51 of the lower member 50 face each other. As shown in FIGS. 3 and 5, the joint surface between the upper member 40 and the lower member 50 is formed in a cylindrical shape. In the present embodiment, the upper member 40 and the lower member 50 are joined by, for example, brazing. Thereby, a heating chamber 300 having a predetermined volume is formed between the upper concave portion 41 and the lower concave portion 51 of the heating chamber forming portion 30.

The heating chamber forming unit 30 includes a first wall surface 301, a second wall surface 302, a third wall surface 303, a fourth wall surface 304, and the like as planar wall surfaces that form the heating chamber 300.
The first wall surface 301, the second wall surface 302, and the third wall surface 303 are formed in the upper recessed portion 41 of the upper member 40. The fourth wall surface 304 is formed in the lower recess 51 of the lower member 50 so as to face the first wall surface 301.

As shown in FIG. 5, the second wall surface 302 is formed so as to intersect with the first wall surface 301 at a substantially right angle. As a result, a corner 310 is formed between the first wall surface 301 and the second wall surface 302. Here, the heating chamber 300 is formed to include the corner portion 310.
The third wall surface 303 is formed in the corner portion 310 so as to connect the first wall surface 301 and the second wall surface 302.

  As shown in FIG. 4, in the present embodiment, the heating chamber forming unit 30 has a fifth wall surface 305 as a curved wall surface that forms the heating chamber 300. The fifth wall surface 305 is formed along an arc centered on a specific point P in the heating chamber 300. The fifth wall surface 305 is formed so as to be substantially perpendicular to the first wall surface 301 and the fourth wall surface 304.

In this embodiment, the 1st cylinder part 31 and the 2nd cylinder part 32 are further provided.
The first cylindrical portion 31 is formed in a cylindrical shape from the same material as the upper member 40. The first cylinder portion 31 is located outside the heating chamber 300 and is formed integrally with the upper member 40 so that one end thereof is connected to the upper member 40.

The inlet opening 33 is formed at a position corresponding to one end of the first cylindrical portion 31 of the upper recess 41 of the upper member 40. The inlet opening 33 is located on the first wall surface 301 (see FIGS. 3 and 5).
The second cylindrical portion 32 is formed in a bottomed cylindrical shape from the same material as the lower member 50. The 2nd cylinder part 32 is located in the heating chamber 300, and is integrally formed with the lower member 50 so that the edge part on the opposite side to a bottom part may be connected to the lower member 50 (refer FIG. 7). In the present embodiment, the second cylinder portion 32 is formed integrally with the lower member 50 by, for example, deep drawing.

  The outlet opening 34 is formed at the bottom of the second cylinder 32 (see FIGS. 3 to 7). The end of the second cylinder portion 32 opposite to the bottom portion opens on the surface opposite to the lower recess 51 of the lower member 50 (see FIGS. 6 and 7). Here, the 2nd cylinder part 32 respond | corresponds to the "cylinder part" in a claim.

As shown in FIGS. 4, 5, and 7, the outlet opening 34 is formed so as to be positioned on the corner 310 side with respect to the axis Ax <b> 2 of the second cylindrical portion 32. That is, the outlet opening 34 is formed in the vicinity of the corner 310 and the third wall surface 303.
The inlet opening 33 and the outlet opening 34 are formed so as to be separated from each other by a predetermined distance or more.

  As shown in FIGS. 3 and 5, in the heating chamber forming portion 30, the upper member 40 is the convex portion 23 of the rail portion 20 so that the other end side of the first cylindrical portion 31 is located in the fuel flow path 200 of the rail portion 20. It is joined to (lower member 22). As a result, the fuel in the fuel flow path 200 of the rail portion 20 flows into the heating chamber 300 via the opening on the other end side of the first cylindrical portion 31, the inside, and the inlet opening 33. In the present embodiment, the heating chamber forming portion 30 (upper member 40) and the rail portion 20 (lower member 22) are joined by, for example, brazing.

  As shown in FIGS. 3 and 5, an end of the fuel injection valve 10 opposite to the injection hole 11 is connected to the inside of the second cylinder portion 32. Therefore, the fuel in the heating chamber 300 is guided to the fuel injection valve 10 via the outlet opening 34.

As shown in FIG. 3, the heating device 60 includes a main body 61, a heat generating part 62, and a holder 63.
The main body 61 is formed in a substantially cylindrical shape. The heat generating part 62 is formed in a rod shape, more specifically, a long cylindrical shape, for example, with metal. The heat generating portion 62 is provided on the main body 61 so as to be coaxial with the main body 61. The heat generating part 62 generates heat when supplied with electric power. Thereby, the heat generating part 62 can heat surrounding media (gas or liquid etc.).

  The holder 63 is formed in a substantially cylindrical shape by, for example, metal, and is provided on the upper member 40 so that one end thereof is connected to an opening formed in the upper member 40 of the heating chamber forming unit 30. The holder 63 and the upper member 40 are connected by, for example, brazing.

  The main body 61 is provided inside the holder 63 so that the heat generating part 62 is positioned in the heating chamber 300. That is, the heating device 60 is provided in the heating chamber forming unit 30 so that the heat generating unit 62 is positioned in the heating chamber 300. Thereby, the heating device 60 can heat the fuel in the heating chamber 300 by the heat generating portion 62.

  Here, the specific point P described above is located between the heat generating portion 62 and the outlet opening 34 (see FIG. 4). In addition, the heating device 60 is provided in the heating chamber forming unit 30 so that the axis of the heat generating unit 62 is inclined with respect to the first wall surface 301 and the fourth wall surface 304 (see FIG. 3). Further, the space between the main body 61 and the holder 63 is kept liquid-tight.

  In the present embodiment, each of the four heating devices 60 is provided such that the longitudinal direction is inclined with respect to the “virtual plane including the longitudinal direction of the rail portion 20 and the protruding direction of the convex portion 23” (FIG. 1). 2). That is, the heating device 60 is provided such that the axis of the main body 61 is inclined with respect to the virtual plane. Further, the four heating devices 60 are provided in the heating chamber forming section 30 so that the axes of the main bodies 61 are substantially parallel to each other (see FIGS. 1 and 2).

In the present embodiment, the fuel rail 1 further includes an attachment member 90.
The attachment member 90 has a main body 91 and an attachment portion 92.
The main body 91 is formed in a long plate shape from metal, for example. The attachment portions 92 are formed at two locations in the longitudinal direction of the main body 91 (see FIG. 2).

The attachment member 90 is provided so that the main body 91 is joined to the lower members 50 of the four heating chamber forming portions 30. The attachment member 90 and the heating chamber forming part 30 (lower member 50) are joined by, for example, brazing.
The fuel rail 1 is attached to the intake manifold 6 by passing a fastening member such as a bolt through the hole of the attachment portion 92 and fixing the attachment portion 92 to the intake manifold 6.

  As shown in FIG. 5, in the present embodiment, the fuel heating system 100 (fuel rail 1) is configured so that the corner 310, the inlet opening 33, and the outlet opening 34 are positioned above the heating chamber 300 in the vertical direction. 2 is attached to the intake manifold 6 in the vicinity. At this time, the heat generating portion 62 is located on the lower side in the vertical direction with respect to the corner portion 310, the inlet opening portion 33 and the outlet opening portion 34. That is, in the present embodiment, the corner portion 310, the inlet opening portion 33, and the outlet opening portion 34 are vertically above the heat generating portion 62 in a state where the fuel heating system 100 (fuel rail 1) is attached to the intake manifold 6. It is formed so that it may be located in.

  Here, the inlet opening 33 is formed on the upper side in the vertical direction of the heating chamber 300 in a state where the fuel heating system 100 (fuel rail 1) is attached to the intake manifold 6. More specifically, the entrance opening 33 is formed on the upper wall surface (first wall surface 301) among the wall surfaces forming the heating chamber 300.

  Further, the third wall surface 303 has a horizontal surface (vertical) so that a portion of the outer edge portion on the outlet opening 34 side is vertically upward when the fuel heating system 100 (fuel rail 1) is attached to the intake manifold 6. It is formed so as to be inclined with respect to the plane perpendicular to the direction (see FIG. 5).

  As shown in FIG. 1, this embodiment further includes an electronic control unit (hereinafter referred to as “ECU”) 12. The ECU 12 is a small computer having a CPU as a calculation unit, a ROM, a RAM as a storage unit, an input / output unit, and the like. The ECU 12 performs processing according to a program stored in the ROM based on signals from sensors attached to each part of the vehicle, and controls devices and the like of each part of the vehicle.

  In this embodiment, the ECU 12 starts the fuel injection before starting the fuel injection from the fuel injection valve 10 when the alcohol concentration of the fuel is equal to or higher than a predetermined value and the environmental temperature is equal to or lower than the predetermined value when the engine 2 is started. Preheating (preheating) is performed. At this time, it is assumed that the fuel from the fuel tank 7 flows into the heating chamber 300 via the fuel flow path 200 and the inlet opening 33 of the rail portion 20.

  The ECU 12 supplies power to the heating device 60 and causes the heat generating unit 62 to generate heat during preheating. Thereby, the fuel near the heat generating part 62 in the heating chamber 300 is heated. The fuel heated by the heat generating part 62 changes in weight, moves to the upper side in the vertical direction, that is, the corner part 310 side, and stays in the corner part 310 (near the third wall surface 303). When the fuel in the heating chamber 300 is sufficiently heated by the heat generating part 62, the preheating is completed.

  The ECU 12 instructs the fuel injection valve 10 to inject fuel after completion of preheating. As a result, the high-temperature fuel staying in the corner portion 310 of the heating chamber 300 is guided to the fuel injection valve 10 via the outlet opening 34 and injected into the intake port 5 from the injection hole 11, and the combustion of the engine 2 It is supplied to the chamber 4. Since the fuel injected at this time has a high temperature, the ignitability is improved. Therefore, the engine 2 can be started even when the alcohol concentration of the fuel is equal to or higher than the predetermined value and the environmental temperature is equal to or lower than the predetermined value.

  Even after the engine 2 is started, the ECU 12 continuously supplies power to the heating device 60 when the alcohol concentration of the fuel is equal to or higher than the predetermined value and the environmental temperature is equal to or lower than the predetermined value. Heat. Therefore, high temperature fuel heated by the heat generating portion 62 is injected from the fuel injection valve 10.

  As described above, in the present embodiment, (1) the heating chamber forming unit 30 is formed of the upper member 40 formed of a material having a predetermined plate thickness and having the upper concave portion 41, and the material having a predetermined plate thickness. The lower member 50 has a lower recess 51 and is joined to the upper member 40 to form a heating chamber 300 between the upper recess 41 and the lower recess 51.

The inlet opening 33 guides the fuel from the fuel tank 7 into the heating chamber 300. The outlet opening 34 guides the fuel in the heating chamber 300 to the fuel injection valve 10.
The heating device 60 includes a heat generating portion 62 capable of generating heat, and is provided on the upper member 40 of the heating chamber forming portion 30 so that the heat generating portion 62 is located in the heating chamber 300, and the fuel in the heating chamber 300 is supplied to the heat generating portion. 62 can be heated.

In the present embodiment, the heating chamber 300 is formed by joining the upper member 40 and the lower member 50 with a predetermined plate thickness. Therefore, when the fuel is intermittently injected from the fuel injection valve 10, the upper member 40 or the lower member 50 is elastically deformed, so that the fuel pulsation in the heating chamber 300 can be reduced. Thereby, the fuel injection from the fuel injection valve 10 can be stabilized.
Further, since the upper member 40 and the lower member 50 are formed of a material having a predetermined plate thickness, the mass can be reduced and the vibration resistance is excellent.

  Further, since the upper member 40 and the lower member 50 are made of a material having a predetermined plate thickness, even if the shape of the upper recess 41 or the lower recess 51 is complicated, the upper member 40 and the lower member 50 are pressed, for example. It can be easily formed by plastic deformation processing such as processing or deep drawing. Therefore, compared with the case where the upper member 40 and the lower member 50 which form the heating chamber 300 are formed by cutting etc., a manufacturing cost can be reduced, for example.

  In the present embodiment, (2) a second cylinder formed integrally with the lower member 50 of the heating chamber forming portion 30 so that the outlet opening 34 is formed at one end and the fuel injection valve 10 can be connected to the inside. A part 32 is further provided. Therefore, compared with the case where the member for connecting the fuel injection valve 10 to the heating chamber formation part 30 is provided separately, a number of members and manufacturing cost can be reduced.

  In the present embodiment, (3) the second cylindrical portion 32 is formed so as to be positioned in the heating chamber 300. Therefore, the outlet opening 34 can be brought close to the corner 310, and the high temperature fuel near the corner 310 or the corner 310 can be efficiently guided to the fuel injection valve 10 via the outlet opening 34. . Moreover, the physique of the fuel heating system 100 whole containing the 2nd cylinder part 32 can be made small.

  In the present embodiment, (4) the heating chamber forming unit 30 includes the first wall surface 301, the second wall surface 302 that intersects the first wall surface 301 within a predetermined angle range including a right angle, and the first wall surface 301. And a second wall 302 has a corner 310 formed to be included in the heating chamber 300. The corner portion 310, the inlet opening portion 33, and the outlet opening portion 34 are vertically above the heat generating portion 62 when the fuel heating system 100 (fuel rail 1) is attached to the intake manifold 6 (near the engine 2). It is formed so that it may be located in.

  In the present embodiment, the corner 310 is formed so as to be positioned on the upper side in the vertical direction with respect to the heat generating portion 62. Therefore, the fuel in the heating chamber 300 heated by the heat generating portion 62 changes in weight and the corner 310 side is changed. And stays at the corner 310. Since the outlet opening 34 is formed so as to be positioned on the upper side in the vertical direction with respect to the heat generating part 62, the high-temperature fuel near the corner 310 or the corner 310 is supplied to the fuel injection valve 10 via the outlet opening 34. Can be guided efficiently.

In the present embodiment, (5) the fuel rail 1 includes a rail portion 20 and four fuel heating systems 100.
The rail portion 20 is formed in an elongated shape and has a fuel flow path 200 that is connected to the inlet opening 33 and through which fuel from the fuel tank 7 flows. Four fuel heating systems 100 are provided at substantially equal intervals along the longitudinal direction of the rail portion 20. Four fuel injection valves 10 are attached to correspond to each of the four fuel heating systems 100.

  In the present embodiment, the four heating chambers 300 are provided so as to correspond to the four cylinders 3 of the engine 2, so that the difference between the cylinders related to the temperature of the fuel supplied to the combustion chamber 4 of the cylinder 3 is suppressed. The fuel from the fuel tank 7 can be efficiently heated and distributed to the fuel injection valves 10.

  In the present embodiment, the inlet opening 33 is formed on the upper side in the vertical direction of the heating chamber 300 in a state where the fuel heating system 100 (fuel rail 1) is attached to the intake manifold 6 in the vicinity of the engine 2. More specifically, the entrance opening 33 is formed on the upper wall surface (first wall surface 301) among the wall surfaces forming the heating chamber 300.

  In the present embodiment, the fuel in the heating chamber 300 heated by the heat generating unit 62 changes in weight, moves to the upper side in the vertical direction of the heating chamber 300, and stays there. Of the wall surfaces forming the heating chamber 300, the inlet opening 33 is formed on the upper wall surface (first wall surface 301) in the vertical direction, so that the heating chamber 300 is heated by the fuel flowing into the heating chamber 300 from the inlet opening 33. The high temperature fuel staying on the upper side in the vertical direction (corner portion 310) can be agitated. In addition, the low temperature fuel flowing into the heating chamber 300 from the inlet opening 33 can suppress boiling of the fuel and generation of bubbles on the upper side in the vertical direction (corner portion 310) of the heating chamber 300. Further, the low temperature fuel flowing into the heating chamber 300 from the inlet opening 33 is mixed with the high temperature fuel on the upper side in the vertical direction (corner portion 310) of the heating chamber 300, so that the fuel flowing in from the inlet opening 33 is heated early. Can be achieved. Furthermore, even if the fuel boils in the upper vertical direction of the heating chamber 300 and bubbles are generated, the bubbles can escape to the outside of the heating chamber 300 (fuel flow path 200) via the inlet opening 33. Therefore, the heating efficiency of the fuel in the heating chamber 300 can be improved.

  Further, in the present embodiment, the heating chamber forming unit 30 has a third wall surface 303 formed at the corner portion 310 so as to connect the first wall surface 301 and the second wall surface 302. As a result, the distance between the wall surface (third wall surface 303) facing the corner portion 310 and the outlet opening 34 becomes closer, and the high temperature fuel near the corner portion 310 or the corner portion 310 passes through the outlet opening portion 34. Thus, the fuel injection valve 10 can efficiently guide it.

  In the present embodiment, the third wall surface 303 of the outer edge portion on the outlet opening 34 side is on the upper side in the vertical direction when the fuel heating system 100 (fuel rail 1) is attached to the intake manifold 6. It is formed so as to be inclined with respect to the horizontal plane. As a result, the fuel heated by the heat generating portion 62 changes its weight and flows along the third wall surface 303 toward the outlet opening 34. Therefore, the high-temperature fuel heated by the heat generating part 62 can be efficiently guided to the fuel injection valve 10 via the outlet opening 34.

  Moreover, in this embodiment, the 1st cylinder part 31 is further provided. Therefore, the fuel that has flowed into the heating chamber 300 from the inlet opening 33 via the first cylindrical portion 31 flows along the axis Ax1 of the first cylindrical portion 31 and collides with the fourth wall surface 304. The fuel that has collided with the fourth wall surface 304 flows along the fourth wall surface 304 toward the heat generating portion 62. Thereby, the opportunity of contact with a fuel and the heat-emitting part 62 can be increased, and the heating efficiency of a fuel can be improved.

  In the present embodiment, the heating chamber forming unit 30 includes a fifth wall surface 305 as a curved wall surface that forms the heating chamber 300. The fifth wall surface 305 is formed along an arc centered on a specific point P in the heating chamber 300. As a result, the fuel that has flowed into the heating chamber 300 from the inlet opening 33 via the first cylindrical portion 31 flows along the axis Ax1 of the first cylindrical portion 31, collides with the fourth wall surface 304, and then has a curved surface shape. And flows along the longitudinal direction of the heat generating part 62 while being in contact with the heat generating part 62. That is, the fifth wall surface 305 guides the fuel to flow along the longitudinal direction of the heat generating portion 62. Thereby, the chance of contact between the fuel and the heat generating portion 62 can be further increased, and the heating efficiency of the fuel can be further improved.

  In the present embodiment, the fuel flow path 200 is formed by joining the upper member 21 and the lower member 22 with a predetermined plate thickness. Therefore, the pulsation of the fuel in the fuel flow path 200 can be reduced, and the processing cost of the rail portion 20 can be reduced.

  In the present embodiment, the inlet opening 33 and the outlet opening 34 are formed to be separated from each other by a predetermined distance or more. Therefore, it can be further suppressed that “the fuel flowing into the heating chamber 300 from the inlet opening 33 is guided to the outlet opening 34 without being heated by the heat generating portion 62”. Therefore, it can further suppress that the fuel with a low temperature is injected from the fuel injection valve 10.

  In the present embodiment, the four heating devices 60 are each provided such that the axis of the main body 61 is inclined with respect to a virtual plane including the longitudinal direction of the rail portion 20 and the protruding direction of the convex portion 23. The four heating devices 60 are provided in the heating chamber forming unit 30 such that the axes of the main bodies 61 are substantially parallel to each other. Therefore, when the main body 61 is fitted inside the holder 63, the main body 61 can be prevented from interfering with the adjacent heating chamber forming portion 30 and the like. Thereby, the heating apparatus 60 can be assembled | attached easily and the work efficiency regarding the assembly | attachment of the heating apparatus 60 can be improved.

(Second Embodiment)
A fuel heating system according to a second embodiment of the present invention is shown in FIGS. The second embodiment is different from the first embodiment in the internal configuration of the heating chamber.

The second embodiment further includes a guide member 70. The guide member 70 is formed, for example, by subjecting a metal plate having a predetermined plate thickness to plastic deformation such as bending.
As shown in FIGS. 8 and 9, the guide member 70 has a main body 71, a shielding part 72, and a fixing part 73.

  The main body 71 is formed in a substantially rectangular plate shape (see FIG. 9). The shielding portion 72 is formed in a substantially triangular plate shape (see FIG. 10), and is integrally formed with the main body 71 so that one side is connected to one side of the main body 71 and is orthogonal to the main body 71. The fixing portion 73 is formed in a substantially rectangular plate shape (see FIG. 9), and is formed integrally with the shielding portion 72 so that one side is connected to one side of the shielding portion 72 and is orthogonal to the shielding portion 72. Therefore, the main body 71 is formed so as to be inclined with respect to a virtual plane including the fixing portion 73.

  The guide member 70 is provided so as to be positioned in the heating chamber 300 such that the fixing portion 73 is joined and fixed in the vicinity of the inlet opening 33 of the first wall surface 301 of the upper member 40 (see FIG. 8). The fixing portion 73 and the upper member 40 (first wall surface 301) are joined by, for example, brazing. Here, the guide member 70 is provided so that the axis Ax1 of the first cylindrical portion 31 passes through the main body 71. Moreover, the main body 71 is inclined with respect to the first wall surface 301 so that a virtual plane including the main body 71 passes through a part of the heat generating portion 62 (see FIG. 10). As a result, the fuel that has flowed into the heating chamber 300 from the inlet opening 33 via the first cylindrical portion 31 flows along the axis Ax1 of the first cylindrical portion 31 and collides with the main body 71. The fuel that has collided with the main body 71 flows along the main body 71 toward the heat generating portion 62. As described above, the main body 71 can guide the fuel that has flowed into the heating chamber 300 from the inlet opening 33 toward the heat generating portion 62. Thereby, the opportunity of contact with a fuel and the heat-emitting part 62 can be increased, and the heating efficiency of a fuel can be improved.

  Further, the guide member 70 is provided such that the shielding portion 72 is located between the inlet opening 33 and the outlet opening 34. That is, the guide member 70 is provided so that at least a part thereof is positioned between the inlet opening 33 and the outlet opening 34. For this reason, the flow of the fuel flowing from the inlet opening 33 into the heating chamber 300 toward the outlet opening 34 is blocked by the shielding portion 72, and “the fuel flowing from the inlet opening 33 into the heating chamber 300 is heated by the heat generating portion 62. Without being led to the outlet opening 34 without fail. Therefore, it is possible to reliably suppress the low temperature fuel from being injected from the fuel injection valve 10.

  Further, in the present embodiment, the fuel that has flowed into the heating chamber 300 from the inlet opening 33 via the first cylindrical portion 31 flows along the axis Ax1 of the first cylindrical portion 31, and enters the main body 71 of the guide member 70. It collides and flows to the heat generating part 62 side along the main body 71. The fuel flowing along the main body 71 toward the heat generating portion 62 collides with the curved fifth wall surface 305, flows along the fifth wall surface 305, and contacts the heat generating portion 62 in the longitudinal direction. Flowing along. That is, the fifth wall surface 305 guides the fuel guided by the guide member 70 so as to flow along the longitudinal direction of the heat generating portion 62. Thereby, the chance of contact between the fuel and the heat generating portion 62 can be further increased, and the heating efficiency of the fuel can be further improved.

(Third embodiment)
A fuel heating system according to a third embodiment of the present invention is shown in FIGS. The third embodiment is different from the second embodiment in the configuration of the guide member 70.
In the third embodiment, the guide member 70 further has a hole 74. The hole 74 is formed so as to penetrate the main body 71 in the plate thickness direction.

  As shown in FIGS. 11 to 13, the hole 74 is formed in the vicinity of the axis Ax <b> 1 of the first cylindrical portion 31. Here, the axis Ax <b> 1 of the first tube portion 31 passes through a portion other than the hole portion 74 of the main body 71. As shown in FIG. 12, when the inlet opening 33 is projected onto the main body 71 in the direction of the axis Ax1 of the first tube portion 31, it overlaps with a part of the hole 74.

  With the above configuration, most of the fuel that has flowed into the heating chamber 300 from the inlet opening 33 via the first cylindrical portion 31 collides with the main body 71 and flows along the main body 71 toward the heat generating section 62. Therefore, the heating efficiency of the fuel by the heat generating part 62 can be improved. Further, a part of the fuel that has flowed into the heating chamber 300 from the inlet opening 33 via the first tube portion 31 flows to the opposite side of the main body 71 from the shielding portion 72 via the hole 74. Therefore, the high-temperature fuel staying in the opposite side of the main body 71 from the shielding portion 72, that is, the corner portion 310, can be agitated by the fuel flowing from the inlet opening 33, and the heating efficiency of the fuel in the heating chamber 300 Can be improved. Further, the low temperature fuel flowing from the inlet opening 33 is guided to the corner 310 side through the hole 74 and mixed with the high temperature fuel, thereby suppressing the boiling of fuel and the generation of bubbles in the corner 310. In addition, early heating of the fuel flowing in from the inlet opening 33 can be achieved.

(Other embodiments)
In another embodiment of the present invention, the heating device may be provided on the lower member. Further, the main body, the heat generating portion, and the holder of the heating device may be formed in any shape. The holder may be formed integrally with the upper member or the lower member. Further, the heating device may not include the main body and the holder.

Moreover, in other embodiment of this invention, the cylinder part (2nd cylinder part 32) may be formed so that it may be located outside a heating chamber, ie, the exterior of a heating chamber formation part. Moreover, the cylinder part may be formed integrally with the upper member. Moreover, the cylinder part may be formed separately from the heating chamber forming part. Moreover, it is good also as providing the member for connecting a fuel injection valve to a fuel rail separately from a cylinder part. In this case, the cylinder part (second cylinder part 32) may be omitted.
In another embodiment of the present invention, the first tube portion 31 may not be provided.

  Moreover, in the above-mentioned embodiment, the attachment member was joined to the lower member of the heating chamber forming portion, and the fuel heating system (fuel rail) was attached to the intake manifold. On the other hand, in another embodiment of the present invention, the attachment member may be joined to a portion other than the lower member such as the upper member of the heating chamber forming portion. In another embodiment of the present invention, the fuel heating system (fuel rail) may be directly attached to the internal combustion engine or the vicinity of the internal combustion engine without providing the attachment member.

In another embodiment of the present invention, the rail part may be formed by integrally forming an upper member and a lower member. Moreover, the rail part may be formed by methods other than press work, such as cutting. Further, the rail portion may be formed of any member such as a pipe-like member as long as it has a fuel flow path on the inner side and is formed in a long shape.
Moreover, in the above-mentioned embodiment, the example which joins each member by brazing was shown. On the other hand, in other embodiment of this invention, it is good also as joining each member by methods other than brazing, for example, welding.

  Moreover, in the above-mentioned embodiment, the example which attaches a fuel rail to an intake manifold so that the nozzle hole of a fuel injection valve may be exposed in an intake port was shown. On the other hand, in another embodiment of the present invention, the fuel rail may be attached to, for example, a direct injection type internal combustion engine such that the nozzle hole of the fuel injection valve is exposed to the combustion chamber of the internal combustion engine.

  Moreover, in other embodiment of this invention, the heating chamber formation part and the heating apparatus can be provided with arbitrary numbers according to the number of the fuel injection valves attached to an internal combustion engine. That is, the present invention can be applied to an internal combustion engine having an arbitrary number of cylinders. For example, the fuel heating system of the present invention can be applied to a single cylinder internal combustion engine. In this case, one heating chamber forming part and one heating device are provided, and no rail part is required.

The present invention can be applied not only to an internal combustion engine that uses alcohol fuel such as ethanol or a mixed fuel of alcohol and gasoline, but also to an internal combustion engine that uses gasoline as fuel. In this case, even when the environmental temperature is low, the fuel viscosity is lowered by heating the fuel with the heating device, and the spray particle size can be reduced. Therefore, the ignitability of the fuel in the combustion chamber can be improved.
Thus, the present invention is not limited to the above-described embodiment, and can be implemented in various forms without departing from the gist thereof.

DESCRIPTION OF SYMBOLS 100 ... Fuel heating system 30 ... Heating chamber formation part 33 ... Entrance opening 34 ... Exit opening 300 ... Heating chamber 40 ... Upper member 41 ... Upper concave portion 50 ··· Lower member 51 ··· Lower lower portion 60 ··· Heating device 62 ··· Heating portion

Claims (6)

Fuel heating that is attached to the internal combustion engine or in the vicinity of the internal combustion engine together with a fuel injection valve (10) that supplies fuel to the internal combustion engine (2), and that heats the fuel from the fuel supply source (7) and guides it to the fuel injection valve A system (100),
The upper member (40) formed of a material with a predetermined plate thickness and having an upper recess (41), and the lower member (51) formed of a material with a predetermined plate thickness and bonded to the upper member A heating chamber forming section (30) comprising a lower member (50) forming a heating chamber (300) between the upper recess and the lower recess;
An inlet opening (33) for guiding fuel from the fuel supply source into the heating chamber;
An outlet opening (34) for guiding the fuel in the heating chamber to the fuel injection valve;
A heating device (60) having a heat generating portion (62) capable of generating heat, provided in the heating chamber forming portion so that the heat generating portion is located in the heating chamber, and capable of heating fuel in the heating chamber by the heat generating portion. And comprising
The outlet opening is positioned on the upper side in the vertical direction with respect to the heat generating part in a state where the fuel heating system is attached in the vicinity of the internal combustion engine or the internal combustion engine .
The heat generating part is formed in a rod shape,
When the heating chamber is divided into a vertically upper region and a vertically lower region on a virtual plane including the axis of the heat generating portion, both the inlet opening and the outlet opening are on the upper side in the vertical direction. The fuel heating system located in the area of . 2. The fuel heating system according to claim 1, wherein the inlet opening is formed such that a shaft is twisted with respect to a shaft of the heat generating portion. One end said outlet opening is formed in, so as to be connected to the fuel injection valve on the inside, claim 1, characterized by further comprising cylindrical portion formed integrally with the heating chamber forming part (32) or 3. The fuel heating system according to 2. The fuel heating system according to claim 3 , wherein the cylindrical portion is formed so as to be positioned in the heating chamber. The heating chamber forming section includes a first wall surface (301), a second wall surface (302) intersecting within a predetermined angle range including a right angle with respect to the first wall surface, and the first wall surface and the second wall surface. Having a corner (310) formed to be included in the heating chamber in between,
The corner portion, the inlet opening portion, and the outlet opening portion are formed so as to be positioned vertically above the heat generating portion in a state where the fuel heating system is attached to the internal combustion engine or the vicinity of the internal combustion engine. The fuel heating system according to any one of claims 1 to 4 , wherein the fuel heating system is provided. A fuel heating system according to any one of claims 1 to 5 ,
A long rail portion (20) connected to the inlet opening and having a fuel flow path (200) through which fuel from the fuel supply source flows,
A plurality of the fuel heating systems are provided along the longitudinal direction of the rail portion,
A fuel rail (1), wherein a plurality of the fuel injection valves are attached to correspond to each of the plurality of fuel heating systems.

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