JPH0614072Y2 - Fuel piping structure in V-type multi-cylinder engine - Google Patents

Description

Detailed Description of the Invention A. Purpose of the Invention (1) Field of Industrial Use The present invention relates to a piping structure for supplying fuel to a fuel injection nozzle of an internal combustion engine, and more particularly to a V-type multi-cylinder engine horizontally mounted in an engine room of an automobile. The present invention relates to a fuel piping structure for the rear cylinder row.

(2) Prior Art As a fuel piping structure for a fuel injection nozzle of a V-type multi-cylinder engine having a front side cylinder row and a rear side cylinder row, a structure described in Japanese Utility Model Laid-Open No. 62-69074 is known. .

The fuel pipe structure described in the above publication includes two fuel pipes arranged along the inside of each cylinder row, and the fuel supplied from the fuel pump to the fuel pipes of the front cylinder row is connected through the connecting pipe. It is sent to the fuel pipe of the rear cylinder row through, and then discharged to the return pipe through the fuel pressure regulating valve. Then, the fuel is distributed to each fuel injection nozzle in the process of passing through both fuel pipes, where it is mixed with the intake air supplied from the intake manifold and sent to the combustion chamber of the cylinder.

(3) Problems to be solved by the invention By the way, recent automobiles are equipped with a large number of accessories such as oil pumps for power steering and compressors for air conditioning. Since many of them are formed to be low, the distribution of cooling air inside the engine room tends to deteriorate. In the case where the V-type multi-cylinder engine is mounted horizontally as in the above-mentioned conventional example, the cooling air is blocked by the front cylinder row, and the inside of both cylinder rows is apt to become hot. There is a possibility that vapor will be generated in the fuel pipe and a vapor lock phenomenon will occur in the fuel injection nozzle.

The present invention has been made in view of the above circumstances, and vapor lock can be applied not only to each fuel injection nozzle in the front cylinder row but also to each fuel injection nozzle in the rear cylinder row of a horizontal V-type multi-cylinder engine. It is an object of the present invention to provide a fuel piping structure having a simple structure that can effectively prevent the occurrence of the fuel.

B. Configuration of the Invention (1) Means for Solving the Problems According to the present invention in order to achieve the above object, according to the present invention, a front cylinder row and a rear cylinder row of a V-type multi-cylinder engine horizontally mounted in an engine room of an automobile. In a fuel piping structure in which two fuel pipes are arranged in front and rear along a row, and the fuel is supplied from each of the fuel tubes to a plurality of injection nozzles of the corresponding cylinder row, the front fuel tube is A front lower stage passage obtained by branching a plurality of connecting portions respectively communicating with the plurality of fuel injection nozzles of the front cylinder row, a front upper stage passage arranged above the front lower stage passage, and a rear fuel pipe are A rear lower passage that branches a plurality of connecting portions that respectively communicate with the plurality of fuel injection nozzles of the rear cylinder row,
A rear upper stage passage arranged on the upper side of the rear lower stage passage is provided, and a fuel supply pipe is connected to one end of the front lower stage passage and one end of the front upper stage passage is connected to the other end. A fuel return pipe is connected to one end of the lower stage passage through a fuel pressure regulating valve, and one end of a rear upper stage passage is connected to the other end thereof, and the other ends of the front and rear upper stage passages are connected to each other. Connected via a pipe.

(2) Function The fuel supplied from the fuel supply pipe is first supplied to the front lower stage passage from one end side thereof, and is supplied to each fuel injection nozzle of the front cylinder row through a plurality of connecting portions branched from the front lower stage passage. To be distributed. The remaining fuel flows from the other end of the front lower stage passage into one end of the front upper stage passage, further from the other end of the front upper stage passage through the connecting pipe to the rear upper stage passage from the other end side. To do. The fuel in this rear upper passage is
After being supplied from the one end of the passage to the other end of the rear lower passage, the fuel is distributed to each fuel injection nozzle of the rear cylinder row through a plurality of connecting portions branched from the rear lower passage. The remaining fuel is discharged to the fuel return pipe from one end of the lower rear passage through the fuel pressure regulating valve.

In the above fuel supply process, the fuel supplied from the fuel supply pipe to the front lower passage of the front fuel pipe is not heated to a particularly high temperature by the relatively low temperature front fuel pipe, so that the fuel flowing in the front lower passage is The amount of vapor generated is relatively small, and the generated vapor also concentrates on the front upper passage side due to the difference in specific gravity from the fuel, so vapor is mixed into the fuel distributed from the front lower passage to each fuel injection nozzle. It is possible to avoid doing as much as possible. Next, the fuel supplied from the connecting pipe to the relatively high-temperature rear fuel pipe is heated in the rear upper passage before reaching the rear lower passage even if it is slightly heated as it passes through the front fuel pipe. Is efficiently separated, and the vapor generated from the fuel flowing through the rear lower passage is also concentrated on the rear upper passage side due to the difference in specific gravity with the fuel, so that the vapor from the rear lower passage to each fuel injection nozzle It is possible to prevent vapor from being mixed into the distributed fuel as much as possible.

(3) Embodiment An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, FIG. 2 and FIG. 7, the engine E mounted horizontally in the engine room R of the automobile Am is a V type 6 engine.
In the cylinder engine, three cylinders 2 are arranged inside each cylinder block 1 of the front and rear cylinder rows C ₁ and C ₂ arranged in a V shape. A combustion chamber 5 is formed on the bottom surface of a cylinder head 4 facing a piston 3 slidably fitted to each cylinder 2, and an intake port 6 and an exhaust port 7 opening to the combustion chamber 5 are an intake valve 8 and an exhaust valve, respectively. It is opened and closed by 9. The intake valve 8 is connected to the camshaft 10 located above the cylinder head 4.
Of the exhaust cam 1 of the cam shaft 10 is engaged with the intake cam 10a of the cam shaft 10 via a cam follower 11.
0b through a cam fore 12, a push rod 13, and a rocker arm 14.

This engine E is equipped with a turbocharger TC, and high-speed exhaust gas discharged from each of the exhaust ports 7 is introduced into the turbocharger TC to drive the turbine wheel T to rotate at a high speed, and then to a muffler M. It is discharged toward. On the other hand, the air sucked in through the air cleaner A is compressed by the compressor wheel C that rotates together with the turbine wheel T and is sent to the air duct 15.
And as is clear from FIG. 2, this air duct 1
5 extends from the turbocharger TC to the opposite end of the engine E through the upper part of the rear cylinder row C ₂ .

As shown in FIGS. 1 and 3, both cylinder rows C ₁ , C
_A water-cooled intercooler IC is arranged in the V-bank consisting of _two . The intercooler IC has a box-shaped casing 16 and is screwed from below with a bolt 18 to the lower surface of an intake manifold, which will be described later, via four brackets 17 protruding from both sides thereof. The inlet hole 16a formed in the upper rear portion of the casing 16 is connected to the air duct 15, and the outlet hole 16b formed in the front portion of the casing 16 is connected to the throttle body 20 having the throttle valve 20a therein via the elbow 19. It is connected. As is clear from FIG. 3, a heat exchanger 21 having a water supply pipe 21a and a drain pipe 21b is obliquely arranged inside the casing 16 of the intercooler IC, and the pump 2
2 and the radiator 23 are the water supply pipe 21a and the drain pipe 21b.
Is connected to form a circulation path for cooling water.

An intake manifold 24 having a saddle shape as a whole is provided above the inside of the V bank to distribute the supply air from the throttle body 20 to the intake ports 6. This intake manifold 24 has a throttle body 20 at one end.
Has an intake chamfer 24a that extends along the upper part of the V bank, and this intake chamber 24a has three intake passages 24b connected to the intake ports 6 of each cylinder row C ₁ , C ₂ on both sides. And six cooling fins 24c for heat dissipation are provided on the upper surface thereof.
As is apparent from FIG. 4, the six intake passages 24b are opened in the joint surface formed on the lower surface of the intake manifold 24 with respect to the cylinder head 4, and each intake passage 2 is formed.
A fuel injection nozzle N is arranged near the opening of 4b. The intercooler IC described above is fastened to the lower surface of the intake manifold 24 in a suspended state by four bolts 18, and the intake manifold 2
4 is fastened to the cylinder head 4 from above by nine bolts 25 via a gasket G.

FIGS. 5 and 6 show a gasket G used in the front cylinder row C _1, and the gasket G has three intake through holes 26 each having a bulge portion 26 a corresponding to the fuel injection nozzle N. And a plurality of bolt insertion holes 27 for attaching the intake manifold 24 to the cylinder head 4 are formed. Reference numeral 28 is an EGR through hole formed only in the front gasket G. The gasket G has a structure in which three stainless steel plates 29a and 29b are laminated, and the outer two stainless steel plates 29b have N layers.
It is coated with BR-based heat-resistant rubber. And by using this gasket G,
While absorbing the height difference between the front and rear cylinder rows C ₁ and C ₂ , the cylinder head 4 to the intake manifold 24
It is possible to reduce the heat conduction to the. The structure of the rear gasket G is the same as that of the front gasket G described above, but only the shape is different, and thus the duplicated description will be omitted.

As shown in FIG. 7, a cooling fan 32 forcibly driven by a motor 31 is mounted on the back surface of the air intake hole 30a formed in the bonnet 30 facing the upper part of the engine E. The motor 31 that drives the cooling fan 32 is controlled by the operating conditions of the engine E, and the air taken in from the outside via the air intake hole 30a is introduced to the upper surface of the engine E. The cooling fins 24c formed on the intake manifold 24 located there are sprayed to cool.

Further, in the engine room R, a radiator 46 and a radiator fan 47 for water cooling of the engine body are arranged in front of the engine E.

Next, the engine E will be described with reference to FIGS. 1, 2 and 8.
The fuel piping is explained.

As shown in FIGS. 1 and 2, the fuel to the fuel injection nozzle N of the cylinder banks C _1, C ₂ corresponding along the inside of each cylinder bank C _1, C ₂ are in a V-bank of the engine E A front fuel pipe F ₁ and a rear fuel pipe F _{2 to} be supplied are arranged, and a connector 33 provided at an end of the front fuel pipe F ₁ is provided.
Is connected to a fuel pump (not shown) via a fuel supply pipe 34. The connector 35 provided in the middle of the front fuel tube F ₁ via the connecting pipe 36 is connected to a connector 37 provided in the fuel pipe F ₂ of the rear, the fuel tube F ₂ of the rear more fuel It is connected to a fuel return pipe 39 via a pressure regulating valve 38.

The fuel pipe described above will be described in more detail with reference to FIG. 8. The front fuel pipe F ₁ includes a front lower passage 40 having a connector 33 at one end for connecting to the fuel supply pipe 34.
The front lower stage passage 40 is provided with a relatively short front upper stage passage 42 arranged on the upper side of the front lower stage passage 40, and the other end of the front lower stage passage 40 communicates with one end of the front upper stage passage 42 at the folded portion 41. ing. Then, from the front lower stage passage 40, three connecting portions 40 a respectively connected to the three fuel injection nozzles N of the front cylinder row C ₁ branch, and a connector provided at the other end of the front upper stage passage 42. A connection pipe 36 extending to the fuel pipe F ₂ on the rear side is connected to 35.

On the other hand, the rear side fuel pipe F ₂ has three connecting portions 4 that communicate with the three fuel injection nozzles N of the rear side cylinder row C ₂ , respectively.
5 a is provided with a rear lower stage passage 45 and a rear upper stage passage 44 formed to have the same length as the rear lower stage passage 45 and arranged on the upper side thereof. One end of the rear lower stage passage 45 has a fuel pressure regulating valve 38. It is connected to the fuel return pipe 39 via the other end, and the other end of the rear lower stage passage 45 communicates with one end of the rear upper stage passage 44 at the folded portion 43. Further, the other end of the rear upper passage 44 is connected to the connecting pipe 36.

Next, the operation of this embodiment will be described.

The intake air purified by passing through the air cleaner A is compressed to a high temperature / high pressure state by the compressor wheel C of the turbocharger TC and sent to the air duct 15. The intake air flowing from the air duct 15 into the casing 16 of the intercooler IC arranged in the V bank of the engine E is
After passing through the heat exchanger 21 to be cooled and increased in density, it reaches the intake chamber 24a of the intake manifold 24 via the throttle valve 20a. At this time,
Cooling fins 24 formed on the upper surface of the intake chamber 24a
Cooling fan 3 provided on the back of bonnet 30 with respect to c
Cooling air is supplied from 2, and this cooling air, together with the traveling air and the cooling air from the radiator fan 46, cools the intake manifold 24, and further lowers the temperature of the intake air flowing therein. The intake air cooled as described above is branched from the intake chamber 24a into the six intake passages 24b, and is further supplied into the intake port 6 connected to the intake passages 24b.

On the other hand, the fuel delivered from the fuel pump (not shown) passes through the fuel supply pipe 34 and the connector 33, and the fuel pipe F on the front side.
₁ is supplied to the front lower passage 40, and the front lower passage 4
It is distributed to each fuel injection nozzle N of the front side cylinder row C ₁ via three connecting portions 40 a branched from 0. The remaining fuel flows from the folded-back portion 41 at the end of the front lower stage passage 40 into the front upper stage passage 42, and further, the connector 35, the connecting pipe 36,
It passes through the connector 37 and reaches the rear upper passage 44 of the fuel pipe F _{2 on} the rear side. The fuel in the rear upper stage passage 44 flows into the rear lower stage passage 45 from the folded-back portion 43, and is distributed to each fuel injection nozzle N of the rear cylinder row C ₃ from here through the three connecting portions 45a. In this way, the front and rear 6
The fuel is supplied to each of the fuel injection nozzles N, and the surplus fuel is discharged from the rear lower passage 45 of the rear fuel pipe F ₂ through the fuel pressure regulating valve 38 to the fuel return pipe 39.

Since the fuel supply process described above, the fuel from the fuel supply pipe 34 is supplied to the front lower passage 40 of the front fuel tube F ₁ is not heated to a special high temperature by the relatively low temperature of the front fuel tube F _1, the front portion The amount of vapor generated in the fuel flowing through the lower passage 40 is relatively small, and the generated vapor also concentrates on the front upper passage 42 side due to the difference in specific gravity from the fuel. Therefore, each fuel is injected from the front lower passage 40. Nozzle N
Mixing of vapor into the fuel distributed to is minimized. Then, from the connecting pipe 36, the relatively high temperature rear fuel pipe F
_The fuel supplied to _{No. 2} is efficiently separated from the vapor in the fuel in the rear upper stage passage 44 before reaching the rear lower stage passage 45 even if the fuel is heated to some extent when passing through the front fuel pipe F _1. In addition, the vapor generated from the fuel flowing in the rear lower stage passage 45 also concentrates on the rear upper stage passage 44 side due to the difference in specific gravity from the fuel, so that the fuel distributed from the rear lower stage passage 45 to each fuel injection nozzle N It is also possible to prevent the vapor from being mixed in. The vapor concentrated in the passages 42 and 44 naturally disappears when the temperature of the fuel pipes F ₁ and F ₂ decreases after the engine E is stopped.

The fuel supplied to each of the fuel injection nozzles N as described above is injected from the fuel injection nozzle N to the intake port at a predetermined timing, and is mixed there with the intake air and sent to the combustion chamber 5 of each cylinder 2. . Then, the exhaust gas discharged from the combustion chamber 5 is supplied to the turbocharger TC via the exhaust port 7 and rotationally drives the turbine wheel T thereof.

Although the embodiment of the fuel piping structure in the V-type multi-cylinder engine according to the present invention has been described in detail above, the present invention is not limited to the above-described embodiment, and the present invention described in the scope of utility model registration is claimed. Various small design changes can be made without departing.

C. As described above, according to the present invention, the fuel supplied from the fuel supply pipe to the front lower passage of the front fuel pipe is not heated to a special high temperature by the front fuel pipe having a relatively low temperature. The amount of vapor generated in the fuel flowing through the lower passage is relatively small, and the generated vapor can be concentrated on the front upper passage side due to the difference in specific gravity from the fuel.
It is possible to avoid vapor as much as possible from mixing in the fuel distributed from the front lower passage to each fuel injection nozzle. Then, the fuel supplied from the front side fuel pipe to the rear side relatively high temperature fuel pipe through the connecting pipe is heated to some extent while passing through the front side fuel pipe, but the fuel is supplied to the rear portion before reaching the rear lower passage. The vapor in the fuel can be efficiently separated in the upper passage, and the vapor generated from the fuel flowing in the rear lower passage can also be concentrated on the rear upper passage side due to the difference in specific gravity from the fuel. It is possible to avoid vapor as much as possible from being mixed into the fuel distributed from the lower rear passage to each fuel injection nozzle. As a result, the vapor lock phenomenon occurs inside the fuel injection nozzle in both the front and rear cylinder rows. Since it can be effectively prevented from occurring, it can greatly contribute to the stabilization of the operating state of the engine.

In each fuel pipe, the front and rear upper passages for concentrating the vapor in the fuel upwardly apart from the fuel injection nozzles are provided above the front and rear lower passages each having a connection to each fuel injection nozzle. Because they are installed side by side,
While making the fuel piping structure compact as a whole, a relatively large capacity vapor collection space can be secured between the passages of the front and rear lower passages, and moreover, in the front and rear upper passages, Since it is not necessary to specially branch the connection portion to each fuel injection nozzle, the passage structure can be simplified and the cost can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a V-type multi-cylinder engine according to an embodiment of the present invention, FIG. 2 is a plan view taken along the line II of FIG. 1, and FIG. 3 is of FIG. III-III line sectional view, FIG. 4 is a IV-IV line sectional view of FIG. 1, FIG. 5 is a plan view of the gasket, and FIG. 6 is VI of FIG.
-VI sectional view, FIG. 7 is a vertical sectional view of the engine room, and FIG. 8 is a perspective view of the fuel pipe. C _{1, C 2} ...... cylinder bank, E ...... engine (V-type multi-cylinder _engine), F 1, _{F 2} ...... fuel pipe, N ...... fuel injection nozzle 2 ...... cylinders, 34 ...... fuel supply pipe, 38 ... Fuel pressure regulating valve, 39 ... Fuel return pipe, 40 ... Front lower passage, 42 ... Front upper passage, 44 ... Rear upper passage,
45 ... Rear lower passage

Claims (1)

[Scope of utility model registration request] 1. A front cylinder row (C) of a V-type multi-cylinder engine (E) horizontally mounted in an engine room (R) of an automobile.
₁ ) and two fuel pipes (F ₁ , F ₂ ) in the front and rear are respectively arranged along the rear cylinder line (C ₂ ), and the corresponding cylinder line (F ₁ , F ₂ ) C ₁ , C ₂ )
In the fuel piping structure in which fuel is supplied to each of the plurality of injection nozzles (N), the front fuel pipe (F ₁ )
Is a front lower stage passage (40) obtained by branching a plurality of connecting portions (40a) communicating with the plurality of fuel injection nozzles (N) of the front cylinder row (C ₁ ), and the front lower stage passage (40). The front upper passages (42) lined up on the upper side, and the rear fuel pipe (F ₂ ) communicates with the plurality of fuel injection nozzles (N) of the rear cylinder row (C ₂ ). A rear lower passage (45) obtained by branching the portion (45a),
A rear upper passage (44) arranged on the upper side of the rear lower passage (45) is provided, and the front lower passage (40) has a fuel supply pipe (34) at one end thereof and a front end at the other end thereof. One ends of the upper part passages (40) are connected to each other, and a fuel return pipe (39) is connected to one end of the rear lower part passages (45) via a fuel pressure regulating valve (38), and another rear upper part is connected to the other end. One end of the passage (44) is connected to each other, and the other ends of the front and rear upper passages (42, 44) are connected to each other via a connecting pipe (36). Fuel piping structure in a multi-cylinder engine.