JP6107521B2 - Fuel rail - Google Patents

Description

  The present invention relates to a fuel rail, and more particularly to a fuel rail having a function of heating fuel.

  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 ignitability of fuel in the combustion chamber is improved by supplying heated fuel to the combustion chamber of 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 combustion chamber as described above, the internal combustion engine can be started regardless of the environmental temperature even if the fuel is alcohol fuel or mixed fuel having 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. Thus, by supplying the heated fuel to the combustion chamber as described above, it is possible to suppress a decrease in output and an emission deterioration of the internal combustion engine even when the environmental temperature is low.

Incidentally, Patent Document 1 describes a fuel rail in which a plurality of heating units are provided in a rail body so as to correspond to a plurality of fuel injection valves (see FIGS. 1 and 3 of Patent Document 1). Here, only one fuel chamber communicating with the plurality of fuel injection valves is formed in the rail body. Therefore, for example, when the fuel rail is mounted in the vicinity of the internal combustion engine so that the axis of the rail main body forms a predetermined angle with respect to the horizontal direction, the heated fuel rises to one end side of the rail main body, and one place in the rail main body There is a risk of accumulating. This may cause a difference between cylinders in the temperature of the fuel supplied to the combustion chamber of the internal combustion engine. Therefore, there is a possibility that a difference between cylinders occurs in the ignitability of the fuel, and the startability and output of the internal combustion engine may be reduced.
Patent Document 1 describes a fuel rail in which a plurality of fuel chambers are formed outside the rail body so as to correspond to a plurality of fuel injection valves, and a heating unit is provided in each of the fuel chambers (Patent Document 1). 1 (see FIG. 7). In this configuration, although the difference between the cylinders in the temperature of the fuel supplied to the combustion chamber of the internal combustion engine can be reduced regardless of the mounting position of the rail body, the fuel chambers protrude to the outside of the rail body. The whole physique may be increased.
Patent Document 1 discloses a fuel rail provided with a rod-shaped heating portion so as to follow the central axis of a cylindrical fuel chamber (see FIG. 20 of Patent Document 1). Here, in a state where the fuel rail is attached in the vicinity of the internal combustion engine, the fuel inlet for guiding the fuel from the fuel supply source to the fuel chamber is formed vertically below the central portion of the heating portion, The fuel outlet that guides the fuel to the fuel injection valve is formed on the upper side in the vertical direction with respect to the central portion of the heating portion. In this configuration, since all the fuel that has flowed into the fuel chamber is heated, there is a concern that the fuel that is not required for injection may be heated. Therefore, the heating efficiency of the fuel by the heating unit may be reduced.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a small fuel rail capable of reducing a difference in temperature of fuel supplied to a combustion chamber of an internal combustion engine between cylinders.

The present invention is a fuel rail that is attached in the vicinity of an internal combustion engine together with a plurality of fuel injection valves that supply fuel to the internal combustion engine, and distributes fuel from a fuel supply source to the fuel injection valves. And a cylindrical member.
The rail body is formed in a cylindrical shape. A plurality of fuel chambers are formed inside the rail body so as to correspond to a plurality of fuel injection valves. Each of the fuel chambers has a fuel inlet through which fuel from a fuel supply source flows and a fuel outlet through which fuel flows out to the fuel injection valve. The heating unit is provided in each of the plurality of fuel chambers and can heat the fuel in the fuel chamber. The cylindrical member is provided in the fuel chamber so that a fuel outlet is formed at one end and the other end side is connected to the fuel injection valve. One end of the cylindrical member is located on the upper side in the vertical direction of the fuel chamber in a state where the fuel rail is attached in the vicinity of the internal combustion engine. The heating part is formed in a rod shape, the axis is parallel to the axis of the cylinder member, or the angle formed by the axis and the axis of the cylinder member is a right angle, and the axis does not intersect the axis of the cylinder member, The outer peripheral wall is provided outside the cylindrical member so as to face the outer peripheral wall of the cylindrical member .

  In the present invention, since the heating section is provided in each of the plurality of fuel chambers, the difference in the heating temperature of the fuel in each fuel chamber can be reduced. Therefore, the difference in the temperature of the fuel supplied from the fuel injection valve to the combustion chamber of the internal combustion engine can be reduced. Therefore, the ignitability of the fuel can be improved in any of the plurality of cylinders.

In the present invention, since the fuel chamber is provided so as to correspond to the plurality of fuel injection valves, for example, even when the fuel rail is mounted in the vicinity of the internal combustion engine so that the axis of the rail body forms a predetermined angle with respect to the horizontal direction. , "The heated fuel rises to one end side of the rail body and collects at one place in the rail body" can be prevented. Therefore, it is possible to reduce the inter-cylinder difference in the temperature of the fuel supplied to the combustion chamber of the internal combustion engine regardless of the mounting posture of the fuel rail.
In the present invention, since the plurality of fuel chambers are formed in the rail body, for example, the physique of the entire fuel rail is made smaller than a conventional fuel rail in which the plurality of fuel chambers are provided outside the rail body. Can do.

The typical sectional view showing the fuel rail by a 1st embodiment of the present invention. The figure which looked at FIG. 1 from the arrow II direction. The perspective view which shows the fuel rail by 1st Embodiment of this invention. The schematic diagram which shows the fuel rail by 2nd Embodiment of this invention. The perspective view which shows the fuel rail by 2nd Embodiment of this invention. (A) is the fragmentary sectional view which shows the fuel rail by 3rd Embodiment of this invention, (B) is the figure which looked at (A) from the arrow B direction. (A) is typical sectional drawing which shows the fuel rail by 4th Embodiment of this invention, (B) is the figure which looked at (A) from the arrow B direction. The perspective view which shows the fuel rail by 4th Embodiment of this invention. The schematic diagram which shows the fuel rail by 5th Embodiment of this invention. The perspective view which shows the fuel rail by 5th Embodiment of this invention. The schematic diagram which shows the fuel rail by 6th Embodiment of this invention. The typical sectional view showing the fuel rail by a 7th embodiment of the present invention. The fragmentary sectional view which shows the fuel rail by 8th Embodiment of this invention. The perspective view which shows the fuel rail by 8th Embodiment of this invention. The fragmentary sectional view which shows the fuel rail by 9th Embodiment of this invention. The schematic diagram which shows the fuel rail by 10th Embodiment of this invention. The fragmentary sectional view which shows the fuel rail by 11th Embodiment of this invention. (A) is typical sectional drawing which shows the fuel rail by 12th Embodiment of this invention, (B) is the figure which looked at (A) from the arrow B direction. (A) is typical sectional drawing which shows the fuel rail by 13th Embodiment of this invention, (B) is the figure which looked at (A) from the arrow B direction.

Hereinafter, fuel rails 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. The third embodiment is a reference form.
(First embodiment)
A fuel rail according to a first embodiment of the present invention is shown in FIGS.

  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.

  Each of the intake ports 5 is provided with a fuel injection valve 10. 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 in the vicinity of the engine 2 together with the fuel injection valve 10, and distributes fuel from the fuel tank 6 as a fuel supply source to the fuel injection valve 10.
The fuel rail 1 includes a rail body 20, a fuel chamber 40, a heating device 50, and the like.

  The rail body 20 is formed in a cylindrical shape from, for example, metal. The rail body 20 has a cylindrical wall 21, a side wall 22, a partition wall 23, and the like. As shown in FIG. 1, in the present embodiment, the fuel rail 1 is disposed in the vicinity of the engine 2 so that the axis of the rail body 20 is substantially horizontal, that is, the axis of the rail body 20 is substantially orthogonal to the vertical direction. It is attached.

  In this embodiment, the cylinder wall 21 is formed in the square cylinder shape. The side wall 22 is provided so as to close both ends of the cylindrical wall 21. Three partition walls 23 are provided so as to partition the inside of the cylindrical wall 21 into four. Thus, four fuel chambers 40 surrounded by the cylinder wall 21, the side wall 22, and the partition wall 23 are formed inside the rail body 20.

  The cylindrical wall 21 is formed with holes 211 and 212 that communicate the inside and the outside. Four holes 211 and 212 are formed so as to correspond to the four fuel chambers 40, respectively. In this embodiment, the hole 211 is formed in a wall parallel to the vertical direction in the state where the fuel rail 1 is mounted in the vicinity of the engine 2 among the four planar walls of the cylindrical wall 21. Yes. On the other hand, the hole portion 212 is formed in a wall portion located on the lower side in the vertical direction in the state where the fuel rail 1 is mounted in the vicinity of the engine 2 among the four planar wall portions of the cylindrical wall 21.

  In the present embodiment, one end of the inlet pipe 8 is connected to the rail body 20. The other end of the inlet pipe 8 is connected to a discharge port of a fuel pump 7 that sucks and discharges fuel from the fuel tank 6. A flow port 9 is formed at one end of the inlet pipe 8 at a position corresponding to the hole 211 of the cylindrical wall 21. The inlet pipe 8 is attached to the rail body 20 so that the circulation port 9 and the hole 211 communicate with each other. In this embodiment, the inlet pipe 8 is joined to the rail body 20 by brazing, for example, in the vicinity of each flow port 9. As a result, the fuel discharged from the fuel pump 7 flows into the fuel chamber 40 via the flow port 9 of the inlet pipe 8 and the hole 211 of the cylindrical wall 21. That is, the fuel chamber 40 has a fuel inlet 41 into which fuel from the fuel tank 6 flows at the position of the hole 211.

  In the present embodiment, a connection cup 31 and a cylindrical member 32 are provided on the rail body 20. Four connection cups 31 and four cylindrical members 32 are provided so as to correspond to the four fuel injection valves 10. The connection cup 31 is formed in a cup shape, and a bottom portion opposite to the opening is provided at a position corresponding to the hole portion 212 of the outer wall of the cylindrical wall 21. The cylindrical member 32 is provided in the fuel chamber 40 so that one end passes through the hole 212 and is connected to the hole formed in the bottom of the connection cup 31. Thereby, the inside of the fuel chamber 40 and the inside of the cylindrical member 32 and the inside of the connection cup 31 are communicated.

  The fuel rail 1 is attached in the vicinity of the engine 2 in a state where the end of the fuel injection valve 10 opposite to the injection hole 11 is connected to the inside of the connection cup 31. Thereby, the fuel in the fuel chamber 40 is guided to the fuel injection valve 10 from the other end opening of the cylinder member 32 through the inside of the cylinder member 32 and the connection cup 31. That is, the fuel chamber 40 has a fuel outlet 42 through which fuel to the fuel injection valve 10 flows out at the position of the other end opening of the cylindrical member 32. FIG. 3 shows a state in which the fuel injection valve 10 is connected to the connection cup 31 of the fuel rail 1.

  Four heating devices 50 are provided so as to correspond to the four fuel chambers 40. The heating device 50 includes a main body 51 and a heating unit 52. In the present embodiment, the main body 51 is formed in a substantially cylindrical shape. The heating unit 52 is formed in a rod shape from, for example, metal. The temperature of the heating unit 52 increases as the power supplied to the heating device 50 increases.

  The heating device 50 is attached to the rail body 20 such that the main body 51 is exposed to the outside of the rail body 20 and the heating unit 52 is exposed to the fuel chamber 40. In the present embodiment, the heating device 50 is attached so that the axis of the heating unit 52 and the axis of the cylindrical member 32 are substantially parallel, and the heating unit 52 is positioned in the vicinity of the cylindrical member 32. In the present embodiment, the heating device 50 protrudes upward in the vertical direction from the outer wall of the cylindrical wall 21 so that the axis of the main body 51 is in the vertical direction when the fuel rail 1 is mounted in the vicinity of the engine 2. (See FIGS. 1 and 2). When electric power is supplied to the heating device 50 and the temperature of the heating unit 52 rises, the fuel in the fuel chamber 40, particularly in the vicinity of the heating unit 52, is heated.

  In the present embodiment, the rail body 20 further includes a partition wall 24 that partitions each fuel chamber 40 into two regions. The partition wall 24 partitions the fuel chamber 40 into a heating region 43 that includes the heating unit 52 and where the fuel is heated, and a non-heating region 44 that does not include the heating unit 52. In the present embodiment, the cylindrical member 32 is provided in the heating region 43. In the present embodiment, the heating region 43 partitioned by the partition wall 24 is set to a predetermined volume.

The partition wall 24 has a communication port 45 that allows the heating region 43 and the non-heating region 44 to communicate with each other. The communication port 45 is formed on the lower side in the vertical direction of the fuel chamber 40 in a state where the fuel rail 1 is attached in the vicinity of the engine 2 (see FIGS. 1 and 2). Here, the communication port 45 is formed in a long rectangular shape so as to connect the opposed inner walls of the cylindrical wall 21 (see FIG. 2).
In the present embodiment, the partition wall 24 is joined to the inner wall of the cylindrical wall 21 by, for example, brazing.

Further, the other end opening of the cylindrical member 32, that is, the fuel outlet 42 is located on the upper side in the vertical direction of the fuel chamber 40 in a state where the fuel rail 1 is attached in the vicinity of the engine 2. Further, the heating unit 52 is provided so that at least a part thereof is positioned below the fuel outlet 42 in the vertical direction when the fuel rail 1 is attached in the vicinity of the engine 2 (see FIGS. 1 and 2).
Further, in the present embodiment, since the cylindrical wall 21 is formed in a square cylindrical shape, the fuel chamber 40 is formed with four corners 46. The fuel outlet 42 is located at one of the two corners 46 on the upper side in the vertical direction when the fuel rail 1 is attached in the vicinity of the engine 2 (see FIG. 2).
Moreover, in this embodiment, the heating part 52 is provided in each fuel chamber 40 so that it may be located on the virtual straight line which connects the communicating port 45 and the fuel outflow port 42 (refer FIG. 1).

  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 the present embodiment, the ECU 12 increases the electric power supplied to the heating device 50 when the engine 2 is started 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. Thus, the fuel heated by the heating unit 52 of the heating device 50 is injected into the intake port 5 from the fuel injection valve 10 and supplied to the combustion chamber 4 of the engine 2. 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.

  As described above, in this embodiment, since the heating unit 52 is provided in each of the plurality of fuel chambers 40, the difference in the heating temperature of the fuel in each fuel chamber 40 can be reduced. Therefore, the difference between the cylinders in the temperature of the fuel supplied from the fuel injection valve 10 to the combustion chamber 4 of the engine 2 can be reduced. Therefore, the ignitability of the fuel can be improved in any of the plurality of cylinders 3.

In this embodiment, since the fuel chamber 40 is provided so as to correspond to the plurality of fuel injection valves 10, the fuel rail 1 is connected to the engine 2 so that the axis of the rail body 20 forms a predetermined angle with respect to the horizontal direction, for example. Even if it is attached in the vicinity, it is possible to prevent such a situation that “the heated fuel rises to one end side of the rail body 20 and accumulates at one place in the rail body 20”. Therefore, regardless of the mounting posture of the fuel rail 1, the difference between the cylinders of the temperature of the fuel supplied to the combustion chamber 4 of the engine 2 can be reduced.
In the present embodiment, since the plurality of fuel chambers 40 are formed in the rail body 20, for example, the physique of the entire fuel rail is made larger than a conventional fuel rail in which the plurality of fuel chambers are provided outside the rail body. Can be small.

  In the present embodiment, the fuel chamber 40 is divided into a heating region 43 that includes the heating unit 52 and the fuel is heated and a non-heating region 44 that does not include the heating unit 52, and the heating region 43 and the non-heating region 44 are divided. A partition wall 24 having a communication port 45 communicating therewith is further provided. Thereby, since the volume of the fuel to be heated can be set to a predetermined amount, the fuel can be efficiently heated by the heating unit 52.

  Further, in the present embodiment, the other end opening of the cylindrical member 32, that is, the fuel outlet 42 is located on the upper side in the vertical direction of the fuel chamber 40 in a state where the fuel rail 1 is attached in the vicinity of the engine 2. Further, the heating unit 52 is provided so that at least a part thereof is positioned below the fuel outlet 42 in the vertical direction when the fuel rail 1 is attached in the vicinity of the engine 2 (see FIGS. 1 and 2). As a result, the fuel heated by the heating unit 52 moves upward in the vertical direction within the heating region 43 and accumulates at a predetermined location above the heating region 43. In the present embodiment, since the fuel outlet 42 is located at a location where the heated fuel accumulates, the fuel heated by the heating unit 52 can be efficiently sent to the fuel injection valve 10.

  Moreover, in this embodiment, the cylinder wall 21 of the rail main body 20 is formed in the square cylinder shape. The fuel outlet 42 is located near the corner 46 of the fuel chamber 40. Therefore, when the fuel rail 1 is mounted in the vicinity of the engine 2 so that the corner portion 46 where the fuel outlet 42 is located is on the upper side in the vertical direction, the fuel heated by the heating portion 52 accumulates in the corner portion 46. The spent fuel can be efficiently sent to the fuel injection valve 10.

Moreover, in this embodiment, the heating part 52 is provided in each fuel chamber 40 so that it may be located on the virtual straight line which connects the communicating port 45 and the fuel outflow port 42 (refer FIG. 1). As a result, the fuel that has flowed into the heating region 43 from the non-heating region 44 via the communication port 45 is guided to the fuel outlet 42 through the vicinity of the heating unit 52 and sent to the fuel injection valve 10. Therefore, the fuel in the fuel chamber 40 can be efficiently heated by the heating unit 52.
In the present embodiment, the fuel inflow port 41 and the fuel outflow port 42 are formed so as to be positioned on the upper side in the vertical direction with respect to the central portion of the heating unit 52 in a state where the fuel rail 1 is attached in the vicinity of the engine 2. (See FIG. 2).

(Second Embodiment)
A fuel rail according to a second embodiment of the present invention is shown in FIGS. 2nd Embodiment differs from 1st Embodiment in the attachment position to the rail main body of a heating apparatus.

  In the second embodiment, the heating device 50 projects the axis of the heating unit 52 and the axis of the cylindrical member 32 when the axis of the heating unit 52 and the axis of the cylindrical member 32 are projected onto a virtual plane perpendicular to the axis of the rail body 20. Are attached to the rail body 20 in such a state that they are substantially orthogonal to each other (see FIG. 4). Further, in the present embodiment, the heating device 50 is arranged so that the axis of the main body 51 is substantially perpendicular to the vertical direction in the state where the fuel rail is attached in the vicinity of the engine 2 and from the outer wall of the cylindrical wall 21 in the horizontal direction. It is attached so as to protrude (see FIGS. 4 and 5). Thereby, even when the space above the engine 2 is narrow, the fuel rail can be easily attached.

Moreover, in this embodiment, the heating part 52 is provided so that an axis | shaft may become substantially parallel to the longitudinal direction of the communicating port 45 (refer FIG. 4). Further, the heating unit 52 is provided so that all of the heating unit 52 is positioned below the fuel outlet 42 in the vertical direction in a state where the fuel rail is attached in the vicinity of the engine 2 (see FIG. 4). Moreover, the heating part 52 is provided in each fuel chamber 40 so that it may be located on the virtual straight line which connects the communicating port 45 and the fuel outflow port 42 (refer FIG. 4). Therefore, the fuel flowing into the heating region 43 via the communication port 45 can be efficiently heated by the heating unit 52.
In the present embodiment, the fuel inlet 41 and the fuel outlet 42 are formed so as to be positioned above the center of the heating unit 52 in the vertical direction in a state where the fuel rail is attached in the vicinity of the engine 2. (See FIG. 4). Furthermore, in this embodiment, the fuel inlet 41 and the fuel outlet 42 are formed so as to be positioned on the upper side in the vertical direction with respect to the entire heating unit 52 in a state where the fuel rail is attached in the vicinity of the engine 2. (See FIG. 4).

(Third embodiment)
A fuel rail according to a third embodiment of the present invention is shown in FIG. The third embodiment differs from the first embodiment in the arrangement of the heating unit of the heating device.

In the third embodiment, the heating device 50 is attached to the rail body 20 so that the end of the heating unit 52 opposite to the body 51 is located inside the cylindrical member 32.
Moreover, the heating area | region 43 divided by the division wall 24 is formed so that a volume may become small compared with 1st Embodiment.
With this configuration, in the present embodiment, the fuel can be heated more efficiently by the heating unit 52.
In the present embodiment, the fuel inlet 41 and the fuel outlet 42 are formed so as to be positioned above the center of the heating unit 52 in the vertical direction in a state where the fuel rail is attached in the vicinity of the engine 2. (See FIG. 6).

(Fourth embodiment)
A fuel rail according to a fourth embodiment of the present invention is shown in FIGS. The fourth embodiment differs from the second embodiment in the arrangement of inlet pipes and the like.
In the fourth embodiment, the inlet pipe 8 is provided so as to cross each fuel chamber 40 so that the end opposite to the fuel pump 7 is located in the rail body 20.

  In the present embodiment, the four holes 211 are not formed in the cylindrical wall 21 as in the first and second embodiments. On the other hand, a hole 213 is formed in one of the two side walls 22, and the end of the inlet pipe 8 is inserted into the hole 213 and brazed. A distribution port 9 of the inlet pipe 8 is open to each fuel chamber 40. Thereby, the fuel discharged from the fuel pump 7 flows into the fuel chamber 40 via the flow port 9 of the inlet pipe 8. That is, in the present embodiment, the fuel chamber 40 has a fuel inlet 41 into which the fuel from the fuel tank 6 flows at the position of the circulation port 9.

In the present embodiment, since the end of the inlet pipe 8 is located in the rail body 20, the physique of the fuel rail including the inlet pipe 8 can be reduced. Further, since the number of holes formed in the rail body 20 and the brazed portions between the inlet pipe 8 and the rail body 20 are less than those in the first and second embodiments, the manufacturing process can be reduced, and the inlet pipe 8 And the rail body 20 can be prevented from leaking fuel.
In the present embodiment, the fuel inlet 41 and the fuel outlet 42 are formed so as to be positioned above the center of the heating unit 52 in the vertical direction in a state where the fuel rail is attached in the vicinity of the engine 2. (See FIG. 7). Furthermore, in this embodiment, the fuel inlet 41 and the fuel outlet 42 are formed so as to be positioned on the upper side in the vertical direction with respect to the entire heating unit 52 in a state where the fuel rail is attached in the vicinity of the engine 2. (See FIG. 7).

(Fifth embodiment)
A fuel rail according to a fifth embodiment of the present invention is shown in FIGS. The fifth embodiment differs from the second embodiment in the shape of the rail body.

  In the second embodiment, the cylindrical wall 21 of the rail body 20 is formed such that a portion corresponding to the cylindrical member 32 is smaller in the axial direction of the heating unit 52 than in the second embodiment. Further, the cylindrical wall 21 is formed such that the portion other than the portion corresponding to the cylindrical member 32 is smaller in the axial direction of the cylindrical member 32 than in the second embodiment (see FIGS. 9 and 10). That is, the cylindrical wall 21 is formed flat compared to the second embodiment except for a portion corresponding to the cylindrical member 32. Therefore, the volume of the rail body 20 is smaller than that of the second embodiment.

  With the above configuration, in this embodiment, the overall size of the fuel rail can be reduced as compared with the second embodiment. Moreover, since the volume of the heating area | region 43 is small compared with 2nd Embodiment, a fuel can be heated more efficiently by the heating part 52. FIG.

(Sixth embodiment)
A fuel rail according to a sixth embodiment of the present invention is shown in FIG. The sixth embodiment differs from the second embodiment in the shape of the rail body.

  In the sixth embodiment, as shown in FIG. 11, one of the four planar wall portions (wall portion 214) of the cylindrical wall 21 corresponds to either the axis of the cylindrical member 32 or the axis of the heating unit 52. However, it is formed so as to be inclined at about 45 degrees. A hole 211 is formed in the wall 214 and the inlet pipe 8 is connected thereto.

In the present embodiment, the corner portion 47 is formed between the wall portion 214 and the wall portion that forms an acute angle with respect to the wall portion 214. Further, a corner portion 48 is formed between the wall portion 214 and the wall portion that forms an obtuse angle with respect to the wall portion 214. The other corners 46 are formed between the walls that intersect at substantially right angles. In the present embodiment, the fuel outlet 42 is located in the vicinity of the corner 47. Further, the tip of the heating unit 52 is located in the vicinity of the corner 48.
Further, in the present embodiment, as shown in FIG. 11, the fuel rail is attached in the vicinity of the engine 2 so that the axis of the rail body 20 is substantially horizontal and the axis of the cylindrical member 32 is vertical. In this case, the corner 47 is located on the upper side in the vertical direction.

With the above configuration, in this embodiment, the overall size of the fuel rail can be reduced as compared with the second embodiment. When the fuel rail is attached in the vicinity of the engine 2 so that the axis of the rail body 20 is substantially horizontal and the axis of the cylindrical member 32 is vertical, the corner 47 of the fuel chamber 40 is vertical. Located on the upper side. Therefore, the fuel heated by the heating unit 52 rises along the inclined wall portion 214 and accumulates in the corner portion 47. Thereby, the heated fuel can be efficiently sent to the fuel injection valve 10.
In the present embodiment, the fuel inlet 41 and the fuel outlet 42 are formed so as to be positioned above the center of the heating unit 52 in the vertical direction in a state where the fuel rail is attached in the vicinity of the engine 2. (See FIG. 11). Furthermore, in this embodiment, the fuel inlet 41 and the fuel outlet 42 are formed so as to be positioned on the upper side in the vertical direction with respect to the entire heating unit 52 in a state where the fuel rail is attached in the vicinity of the engine 2. (See FIG. 11).

(Seventh embodiment)
A fuel rail according to a seventh embodiment of the present invention is shown in FIG. The seventh embodiment is different from the first embodiment in the shape of the rail body.

  In 7th Embodiment, as shown in FIG. 12, a part of wall part to which the heating apparatus 50 was attached among the four planar wall parts of the cylinder wall 21 (between the partition wall 24 and the hole part 211). However, it is formed so that it may approach the wall part in which the connection cup 31 was provided to the communication port 45 side edge part position of the division wall 24. FIG. As a result, a substantially rectangular column-shaped space 25 is formed in the rail body 20 between the partition wall 24 and the hole 211.

  In the present embodiment, the partition wall 24 is formed integrally with the cylindrical wall 21 so as to constitute a part of the wall portion of the cylindrical wall 21. The cylindrical wall 21 having such a shape can be formed by, for example, pressing a rectangular cylindrical cylindrical member. Therefore, unlike the first embodiment, it is not necessary to join the partition wall 24 separate from the cylindrical wall 21 to the inner wall of the cylindrical wall 21 by brazing. Therefore, the number of members can be reduced.

In the present embodiment, a space 25 is formed in the rail body 20. Therefore, for example, if the fuel rail is attached so that some of the other devices near the engine 2 are located in the space 25, the space near the engine 2 can be used effectively.
In the present embodiment, the fuel inlet 41 and the fuel outlet 42 are formed so as to be positioned above the center of the heating unit 52 in the vertical direction in a state where the fuel rail is attached in the vicinity of the engine 2. (See FIG. 12).

(Eighth embodiment)
A fuel rail according to an eighth embodiment of the present invention is shown in FIGS. The eighth embodiment differs from the seventh embodiment in the attachment position of the heating device and the like.

In the eighth embodiment, the heating device 50 is attached to the partition wall 24 so that the main body 51 is positioned in the space 25. Here, the heating device 50 is provided such that the axes of the main body 51 and the heating unit 52 are substantially parallel to the axis of the cylindrical wall 21. Thereby, in the state where the fuel rail is attached in the vicinity of the engine 2, the height of the fuel rail in the vertical direction can be reduced by the length in the axial direction of the main body 51 of the heating device 50 compared to the seventh embodiment. it can. Therefore, the physique of the whole fuel rail can be made small.
In the present embodiment, the fuel inlet 41 and the fuel outlet 42 are formed so as to be positioned above the center of the heating unit 52 in the vertical direction in a state where the fuel rail is attached in the vicinity of the engine 2. (See FIG. 13). Furthermore, in this embodiment, the fuel inlet 41 and the fuel outlet 42 are formed so as to be positioned on the upper side in the vertical direction with respect to the entire heating unit 52 in a state where the fuel rail is attached in the vicinity of the engine 2. (See FIG. 13).

(Ninth embodiment)
A part of the fuel rail according to the ninth embodiment of the present invention is shown in FIG. The ninth embodiment differs from the first embodiment in the configuration near the heating unit in the rail body.

  In the ninth embodiment, the rail body 20 includes the plate member 26 between the tip end portion of the heating unit 52 of the heating device 50 and the cylindrical member 32. Here, the plate member 26 is formed in a long rectangular shape so as to extend in the axial direction of the cylindrical member 32 from the wall portion where the connection cup 31 of the cylindrical wall 21 is provided and to connect the opposing inner walls of the cylindrical wall 21. ing.

With the above configuration, the fuel that has flowed into the heating region 43 from the non-heating region 44 via the communication port 45 collides with the plate member 26 and flows toward the heating unit 52 (see FIG. 15). Thereby, the fuel that has flowed into the heating region 43 from the non-heating region 44 can be efficiently heated by the heating unit 52.
In the present embodiment, the fuel inlet 41 and the fuel outlet 42 are formed so as to be positioned above the center of the heating unit 52 in the vertical direction in a state where the fuel rail is attached in the vicinity of the engine 2. (See FIG. 15).

(10th Embodiment)
A fuel rail according to a tenth embodiment of the present invention is shown in FIG. The tenth embodiment differs from the second embodiment in the configuration of the partition walls.

In the tenth embodiment, unlike the second embodiment, the communication port 45 is formed so as to be cut out only on the side of the partition wall 24 to which the inlet pipe 8 is attached.
As shown in FIG. 16, in this embodiment, the fuel that has flowed into the heating region 43 via the communication port 45 flows near the tip of the heating unit 52 and is guided to the fuel outlet 42.
In the present embodiment, the fuel inlet 41 and the fuel outlet 42 are formed so as to be positioned above the center of the heating unit 52 in the vertical direction in a state where the fuel rail is attached in the vicinity of the engine 2. (See FIG. 16). Furthermore, in this embodiment, the fuel inlet 41 and the fuel outlet 42 are formed so as to be positioned on the upper side in the vertical direction with respect to the entire heating unit 52 in a state where the fuel rail is attached in the vicinity of the engine 2. (See FIG. 16).

(Eleventh embodiment)
FIG. 17 shows a part of a fuel rail according to an eleventh embodiment of the present invention. The eleventh embodiment differs from the second embodiment in the configuration of the partition walls.

In the eleventh embodiment, the partition wall 24 is provided such that the plate surface is inclined with respect to the axis of the cylindrical member 32. Therefore, the end of the partition wall 24 opposite to the communication port 45 is located near the end of the tubular member 32 opposite to the connection cup 31 as compared to the second embodiment. Therefore, the fuel heated by the heating unit 52 rises along the inclined partition wall 24 and accumulates in the vicinity of the end of the cylindrical member 32 opposite to the connection cup 31. Thereby, the heated fuel can be efficiently sent to the fuel injection valve 10.
In the present embodiment, the fuel inlet 41 and the fuel outlet 42 are formed so as to be positioned above the center of the heating unit 52 in the vertical direction in a state where the fuel rail is attached in the vicinity of the engine 2. (See FIG. 17). Furthermore, in this embodiment, the fuel inlet 41 and the fuel outlet 42 are formed so as to be positioned on the upper side in the vertical direction with respect to the entire heating unit 52 in a state where the fuel rail is attached in the vicinity of the engine 2. (See FIG. 17).

(Twelfth embodiment)
A fuel rail according to a twelfth embodiment of the present invention is shown in FIG. The twelfth embodiment differs from the first embodiment in the configuration of the fuel chamber.
As shown in FIG. 18, in the twelfth embodiment, the fuel rail does not include the partition wall 24. Therefore, the heating area | region 43, the non-heating area | region 44, and the communicating port 45 which were shown in 1st Embodiment are not formed.

  In the present embodiment, the fuel inflow port 41 and the fuel outflow port 42 are formed so as to be positioned on the upper side in the vertical direction with respect to the central portion of the heating unit 52 in a state where the fuel rail is attached in the vicinity of the engine 2 ( (See FIG. 18). Therefore, the fuel that has flowed into the fuel chamber 40 from the fuel inlet 41 can be efficiently heated by the heating unit 52 and guided to the fuel injection valve 10 via the fuel outlet 42. Thereby, it can suppress that the fuel which is not required for injection is heated, and the heating efficiency of the fuel by the heating part 52 can be improved.

(13th Embodiment)
A fuel rail according to a thirteenth embodiment of the present invention is shown in FIG. The thirteenth embodiment differs from the fourth embodiment in the configuration of the fuel chamber.
As shown in FIG. 19, in the thirteenth embodiment, the fuel rail does not include the partition wall 24. Therefore, the heating area | region 43, the non-heating area | region 44, and the communicating port 45 which were shown in 4th Embodiment are not formed.
In the present embodiment, the fuel inflow port 41 and the fuel outflow port 42 are formed so as to be positioned on the upper side in the vertical direction with respect to the central portion of the heating unit 52 in a state where the fuel rail is attached in the vicinity of the engine 2 ( (See FIG. 19). Furthermore, in this embodiment, the fuel inlet 41 and the fuel outlet 42 are formed so as to be positioned on the upper side in the vertical direction with respect to the entire heating unit 52 in a state where the fuel rail is attached in the vicinity of the engine 2. (See FIG. 19). Therefore, the fuel that has flowed into the fuel chamber 40 from the fuel inlet 41 can be efficiently heated by the heating unit 52 and guided to the fuel injection valve 10 via the fuel outlet 42. Thereby, it can suppress that the fuel which is not required for injection is heated, and the heating efficiency of the fuel by the heating part 52 can be improved.

(Other embodiments)
In other embodiment of this invention, the main body and heating part of a heating apparatus may be formed in what kind of shape. Further, the heating device may not include the main body.

Further, in another embodiment of the present invention, the fuel outlet does not have to be positioned on the upper side in the vertical direction of the fuel chamber in a state where the fuel rail is attached in the vicinity of the internal combustion engine. That is, the fuel rail may be attached in any posture.
Further, in another embodiment of the present invention, the cylinder member connected to the connection cup may not be provided, the fuel outlet may be formed in the connection cup, and the fuel in the fuel chamber may be directly guided to the connection cup.

Moreover, in the above-mentioned embodiment, the rail main body was formed in the square cylinder shape, and the example which a fuel outflow port is located in the corner | angular part vicinity of a fuel chamber was shown. On the other hand, in other embodiments of the present invention, the fuel outlet may be formed at a location other than the vicinity of the corner of the fuel chamber. In another embodiment of the present invention, the cylindrical wall may be formed in a polygonal cylindrical shape such as a triangular cylindrical shape or a pentagonal cylindrical shape, or a cylindrical shape.
Moreover, in other embodiment of this invention, a heating part, a communicating port, and a fuel outflow port may each be provided so that it may become what kind of positional relationship mutually.

  Moreover, in the above-mentioned embodiment, the example which attaches a fuel rail so that the nozzle hole of a fuel injection valve is exposed in an intake port was shown. On the other hand, in other embodiment of this invention, it is good also as attaching a fuel rail so that the nozzle hole of a fuel injection valve may be exposed in an intake manifold, for example. Further, 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.

In another embodiment of the present invention, any number of fuel chambers and heating units can be provided depending on the number of fuel injection valves attached to the internal combustion engine. That is, the present invention can be applied to an internal combustion engine having an arbitrary number of cylinders.
In another embodiment of the present invention, the inlet pipe may not be provided, and the fuel may be directly introduced into the fuel inlet of the fuel chamber through a plurality of pipes.

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.

1 ... Fuel rail 2 ... Engine (internal combustion engine)
6 ··· Fuel tank (fuel supply source)
DESCRIPTION OF SYMBOLS 10 ... Fuel injection valve 20 ... Rail main body 40 ... Fuel chamber 41 ... Fuel inlet 42 ... Fuel outlet 52 ... Heating part

Claims (7)

A fuel rail (1) attached in the vicinity of the internal combustion engine together with a plurality of fuel injection valves (10) for supplying fuel to the internal combustion engine (2) and distributing fuel from a fuel supply source (6) to the fuel injection valves. There,
A tubular rail body (20);
A plurality of fuel inlets (41) formed inside the rail body to correspond to the plurality of fuel injection valves, respectively, into which fuel from the fuel supply source flows, and fuel to the fuel injection valves flow out. A fuel chamber (40) having a fuel outlet (42);
A heating section (52) provided in each of the plurality of fuel chambers and capable of heating the fuel in the fuel chamber;
A cylinder member (32) provided in the fuel chamber so that the fuel outlet is formed at one end and the other end side is connected to the fuel injection valve;
One end of the cylindrical member is located on the upper side in the vertical direction of the fuel chamber in a state where the fuel rail is attached in the vicinity of the internal combustion engine,
The heating unit is formed in a rod shape, the axis is parallel to the axis of the cylindrical member, or the angle formed by the axis and the axis of the cylindrical member is perpendicular, and the axis is the axis of the cylindrical member A fuel rail provided outside the cylindrical member such that the outer peripheral wall faces the outer peripheral wall of the cylindrical member without intersecting .   The fuel chamber is divided into a heating region (43) that includes the heating unit and the fuel is heated and a non-heating region (44) that does not include the heating unit, and communication between the heating region and the non-heating region is established. Further comprising a partition wall (24) having a mouth (45);
  The communication port is located on the lower side in the vertical direction of the fuel chamber in a state where the fuel rail is attached in the vicinity of the internal combustion engine,
  The fuel rail according to claim 1, wherein the heating unit is provided between the communication port and one end of the cylindrical member.   The fuel rail according to claim 2, wherein the heating unit is provided on an imaginary straight line connecting the communication port and the fuel outlet. The fuel inflow port and the fuel outflow port are formed so as to be positioned vertically above the central portion of the heating unit in a state where the fuel rail is attached in the vicinity of the internal combustion engine. The fuel rail according to any one of claims 1 to 3 . The fuel inflow port and the fuel outflow port are formed so as to be positioned vertically above the entire heating unit in a state where the fuel rail is attached in the vicinity of the internal combustion engine. The fuel rail as described in any one of 1-4 . The heating unit is provided so that at least a part thereof is positioned on a lower side in a vertical direction than the fuel outlet in a state where the fuel rail is attached in the vicinity of the internal combustion engine. fuel rail according to any one of 5. The rail body is formed in a polygonal cylindrical shape,
The fuel rail according to any one of claims 1 to 6 , wherein the fuel outlet is located in the vicinity of a corner (46, 47) of the fuel chamber.

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