JP2009019542A - Fuel distribution structure of direct injection type engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the size, while restraining pulsation of fuel pressure from having influence on fuel injection by a fuel injection valve, in a fuel distribution structure of a direct injection type engine. <P>SOLUTION: A plurality of cylinders are respectively divided into first and second cylinder groups composed of cylinders unadjacent in ignition order. The fuel distribution structure is provided with a fuel introducing part for introducing high pressure fuel, a body part 12 extending to one side in the cylinder bank direction from this fuel introducing part and juxtaposing and forming first and second fuel main chambers 12a and 12b respectively communicating with the fuel introducing part on the inside so as to extend in the cylinder bank direction, and a plurality of cup parts 13 arranged in series to the cylinder bank direction so as to correspond to the respective cylinders in this body part 12 and storing the fuel injection valve. The first fuel main chamber 12a communicates via a communicating hole 15 with the respective cup parts 13 corresponding to the first cylinder group, and the second fuel main camber 12b communicates via the communicating hole 15 with the respective cup parts 13 corresponding to the second cylinder group. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fuel distribution structure for a direct injection engine in which a plurality of cylinders are arranged in series.

In a so-called direct injection multi-cylinder engine, generally, high-pressure fuel from a high-pressure fuel pump is supplied to a fuel injection valve for each cylinder through a fuel distribution pipe, and the high-pressure fuel supplied by the fuel injection valve is supplied to each cylinder. It directly injects into a combustion chamber (for example, refer patent document 1).
JP 2001-90630 A

  The fuel pressure in the fuel distribution pipe pulsates as each fuel injection valve is opened. In order to suppress the pulsation caused by each fuel injection valve from affecting the fuel injection by other fuel injection valves, the fuel distribution pipe Therefore, there is a problem that the size of the fuel distribution pipe is increased.

  The fuel distribution pipe is usually made of stainless steel or cast iron, but it is conceivable to make it made of aluminum cast for the purpose of weight reduction. In this case, considering the nest often generated in an aluminum casting product, it is necessary to increase the thickness of the fuel distribution pipe, and thus the size of the fuel distribution pipe is further increased.

  The present invention has been made in view of such a point, and an object of the present invention is a direct injection type for directly injecting high-pressure fuel into a combustion chamber of each cylinder of an engine in which a plurality of cylinders are arranged in series. In the fuel distribution structure of the engine, the object is to make the system compact while suppressing the pulsation of the fuel pressure from affecting the fuel injection by the fuel injection valve.

  A first invention is a fuel distribution structure of a direct injection engine for directly injecting high-pressure fuel into a combustion chamber of each cylinder of an engine in which a plurality of cylinders are arranged in series, wherein the plurality of cylinders are respectively The ignition sequence is divided into first and second cylinder groups composed of cylinders that are not adjacent to each other. The fuel introduction portion into which the high-pressure fuel is introduced, and extends from the fuel introduction portion to one side in the cylinder row direction. A main body portion formed side by side so that the first and second fuel main chambers respectively communicating with the fuel introduction portion extend in the cylinder row direction, and the main body portion in series in the cylinder row direction so as to correspond to each cylinder The first fuel main chamber communicates with each cup portion corresponding to the first cylinder group through a communication hole. The second fuel main chamber corresponds to the second cylinder group. Through the cup portion and the communicating hole is characterized in that in communication.

  Thus, the first fuel main chamber and the cup portions corresponding to the first cylinder group composed of cylinders whose ignition order is not adjacent to each other are communicated, and the second fuel main chamber and the cylinder whose ignition order is not adjacent to each other. Since the cup portions corresponding to the second cylinder group consisting of are communicated with each other, the fuel pressure pulsation is compared with the case where the fuel main chamber communicates with the cup portions corresponding to the cylinders whose ignition order is adjacent. Can suppress the fuel injection by the fuel injection valve. Since the influence of pulsation on fuel injection can be suppressed in this way, the volume of each fuel main chamber can be set smaller, and the main body can be made compact. From the above, not only when this structure is made of stainless steel or cast iron, but also of aluminum casting, while suppressing the pulsation of fuel pressure from affecting the fuel injection by the fuel injection valve, , And can be made compact.

  According to a second invention, in the first invention, one side portion of the main body portion in a predetermined direction orthogonal to the cylinder row direction and the axial direction of each cup portion corresponds to each cup portion. A plurality of fastening boss portions are arranged in series in the cylinder row direction, and the first fuel main chamber is disposed on the back side of each cup portion so as to be orthogonal to the axis of each cup portion. In the second fuel main chamber, the distance between the second fuel main chamber and each cup portion corresponding to the second cylinder group in a cross-sectional view of the main body portion is the first fuel main chamber and the first cylinder. On the back side of each cup part, on the opposite side to the fastening boss part with respect to the first fuel main chamber in the predetermined direction so as to be shorter than the distance to each cup part corresponding to the group. It is characterized by that.

  As a result, the first fuel main chamber is disposed on the back side of each cup portion so as to be orthogonal to the axis of each cup portion, and the second fuel main chamber is the second fuel section in a cross-sectional view of the main body portion. The back side of each cup portion so that the distance between the fuel main chamber and each cup portion corresponding to the second cylinder group is shorter than the distance between the first fuel main chamber and each cup portion corresponding to the first cylinder group. Since the first fuel main chamber is disposed on the opposite side of each fastening boss portion in a predetermined direction orthogonal to the cylinder row direction and the axial direction of each cup portion, the main body portion is made compact with respect to the predetermined direction. obtain. For this reason, the structure can be further downsized.

  According to a third invention, in the first or second invention, the axis of each communication hole passes through an opening of each cup portion communicating with each communication hole.

  Thereby, since the axis of each communication hole is set so as to pass through the opening of each cup portion communicating with each communication hole, each communication hole is formed from the opening of each cup portion during the manufacture of this structure. Can do.

  According to a fourth invention, in any one of the first to third inventions, a portion of the main body portion corresponding to the cup portion furthest away from the fuel introduction portion is formed inside the first and second fuel mains. Only the fuel main chamber communicating with the cup portion farthest from the fuel introduction portion is formed in the chamber, and is narrower than the portion corresponding to the remaining cup portion.

  As a result, the part of the main body part corresponding to the cup part farthest from the fuel introduction part is made thinner than the part corresponding to the remaining cup part, so compared with the case where the main body part has a constant thickness. The main body can be made compact. For this reason, the structure can be further downsized.

  According to the present invention, the first fuel main chamber and the cup portions corresponding to the first cylinder group composed of cylinders whose ignition order is not adjacent to each other are communicated, and the ignition sequence is adjacent to the second fuel main chamber. Since each cup portion corresponding to the second cylinder group consisting of the cylinders that do not match is communicated, it is possible to suppress the pulsation of the fuel pressure from affecting the fuel injection by the fuel injection valve. Therefore, the volume of each fuel main chamber can be set small, and the main body can be made compact. From the above, the pulsation of the fuel pressure causes the fuel injection by the fuel injection valve. This structure can be made compact while suppressing the influence.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  A direct injection engine 1 according to an embodiment of the present invention is a direct injection in-line four-cylinder engine in which four cylinders 2 (only one is shown in FIG. 1) are arranged in series as shown in FIGS. . In the present embodiment, these cylinders 2 are called the first to fourth cylinders in order from the fuel introduction part 11 side of the fuel distribution structure 10, and the first cylinder, the third cylinder, the fourth cylinder, and the second cylinder. It is supposed to be ignited in the order. The cylinder 2 is divided into a first cylinder group composed of first and fourth cylinders whose ignition order is not adjacent to each other, and a second cylinder group composed of second and third cylinders whose ignition order is not adjacent to each other. . In FIGS. 2 to 4, # 1 to # 4 are respectively indicated as symbols, and these mean positions and portions corresponding to the first to fourth cylinders, respectively. It does not show the fourth cylinder itself.

  The engine 1 includes a cylinder block 1a serving as a main body of the engine 1 having a cylinder 2, a cylinder head 1b placed on the cylinder block 1a so as to cover the cylinder 2, and a lid on the upper portion of the cylinder head 1b. And a head cover 1c. A mounting hole 4 that opens toward the combustion chamber 3 for each cylinder 2 is formed in the intake side portion of the cylinder head 1b. In this mounting hole 4, the nozzle portion 16 a of the fuel injection valve 16 is inserted and fixed so as to face the combustion chamber 3. A fuel distribution structure 10 made of metal (for example, made of stainless steel, cast iron, or aluminum casting) is fixed to the side surface of the intake side of the cylinder head 1b so as to extend in the cylinder row direction. Further, the downstream end of each branch pipe of an intake manifold 5 (not shown in FIG. 2) that is distributed and connected from the carburetor to the intake port of each cylinder 2 is connected to the upper part.

  2 to 9, the fuel distribution structure 10 extends from the fuel introduction portion 11 to one side in the cylinder row direction (right side in FIG. 2, left side in FIGS. 3 and 4). A main body 12, four cup parts 13,... Integrally arranged in series in the cylinder row direction so as to correspond to each cylinder 2 on the outer peripheral surface of the main body 12, and a cylinder row on the outer peripheral surface of the main body 12 And five fastening boss portions 14, which are integrally arranged in series in the direction. The main body portion 12 extends slightly from the fuel introduction portion 11 to the other side in the cylinder row direction. That is, it can be said that the fuel introduction part 11 is provided at one end of the main body part 12 in the cylinder row direction.

  As shown in FIGS. 2 to 4, 8, and 9, the fuel introduction portion 11 is formed on the outer periphery of the bottomed substantially cylindrical main body portion 11 a and the open end portion of the main body portion 11 a. A flange portion 11b for coupling with a pipe (not shown) so that high-pressure fuel from a high-pressure fuel pump (not shown) is introduced through the opening of the fuel pipe and the main body portion 11a. It has become.

  As shown in FIGS. 5 to 7, the main body portion 12 communicates with the inside of the fuel introduction portion 11 and is supplied with pressurized fuel from the fuel introduction portion 11. , 12b are formed side by side so as to extend in the cylinder row direction. The first fuel main chamber 12a communicates with the inside of each cup portion 13 (cup portions 13 and 13 for the first and fourth cylinders) corresponding to the first cylinder group via the communication hole 15, respectively. The two fuel main chambers 12b communicate with the insides of the cup portions 13 (cup portions 13 and 13 for the second and third cylinders) corresponding to the second cylinder group via the communication holes 15, respectively. Each communication hole 15 has a circular shape in which an axis line (a chain line shown in FIGS. 5 and 7) extends in a direction perpendicular to the cylinder row direction (hereinafter referred to as a cylinder row orthogonal direction). It is formed across the portion 13.

  As shown in FIGS. 5 and 7, each cup portion 13 is formed with a circular accommodation hole 13 a in which an axis line (a chain line shown in FIGS. 5 and 7) extends in the cylinder row orthogonal direction. The receiving hole 13a has a truncated cone-shaped opening side hole 13b that gradually decreases in diameter from the opening side toward the tip side, and an intermediate part having a constant diameter continuously to the opening side hole 13b. It consists of a hole 13c and a tapered tip side hole 13d having a diameter that gradually decreases from the opening side toward the tip side continuously with the intermediate hole 13c. And in each accommodation hole 13a, the base end part 16b (refer FIG. 1) of the fuel injection valve 16 is accommodated and fixed to the opening side hole part 13b and the intermediate | middle hole part 13c part. The fuel injection valve 16 is supplied with high-pressure fuel from the fuel main chamber 12a (or 12b) through the communication hole 15 and the front end side hole 13d of the cup part 13, and the supplied pressurized fuel is supplied to each cylinder 2. Are directly injected into the combustion chamber 3.

  Among the five fastening boss portions 14,..., The four fastening boss portions 14,... Are arranged so as to correspond to the cup portions 13 and to be continuous with the cup portions 13, as shown in FIGS. Has been. Specifically, the fastening boss portions 14, 14 for the first and second cylinders are positioned on the fuel introduction portion 11 side of the cup portions 13, 13 for the first and second cylinders, respectively. The cylinder fastening boss portions 14 and 14 are located on the opposite side of the fuel introduction portion 11 of the cup portions 13 and 13 for the third and fourth cylinders, respectively. On the other hand, the remaining one fastening boss portion 14 is disposed between the cup portion 13 for the second cylinder and the cup portion 13 for the third cylinder. By disposing the fastening boss portions 14 as described above, the fastening boss portions 14 and 14 are disposed on both sides of each cup portion 13 in the cylinder row direction.

  As shown in FIGS. 2, 4, and 6, each fastening boss portion 14 has a substantially cylindrical shape in which a circular insertion hole 14 a is formed. Then, bolts (not shown) are inserted into the insertion holes 14a, and the fuel distribution structure 10 is bolted to the cylinder head 1b with the inserted bolts.

  Hereinafter, the configuration of the fuel distribution structure 10 will be described in detail.

  As shown in FIGS. 5 to 7, each fastening boss portion 14 has a predetermined direction (vertical direction in FIGS. 5 to 7) perpendicular to the cylinder row direction of the main body portion 12 and the axial direction of each cup portion 13. Is disposed on one side portion (upper portion in FIGS. 5 to 7).

  The first fuel main chamber 12a is disposed on the back side (right side in FIGS. 5 to 7) of each cup portion 13 so as to be orthogonal to the axis of each cup portion 13. In the second fuel main chamber 12b, the distance between the second fuel main chamber 12b and each cup portion 13 corresponding to the second cylinder group in the cross-sectional view of the main body portion 12 is the same as the first fuel main chamber 12a and the first cylinder. Arranged on the back side of each cup portion 13 on the side opposite to each fastening boss portion 14 with respect to the first fuel main chamber 12a in the predetermined direction so as to be shorter than the distance to each cup portion 13 corresponding to the group. Has been. In other words, the lengths of the communication holes 15 for connecting the inside of the second fuel main chamber 12b and the inside of the cup portion 13 for the second and third cylinders are the same as those in the first fuel main chamber 12a and the first and fourth, respectively. It is shorter than the communication holes 15 and 15 which connect the inside of the cylinder cup parts 13 and 13.

  As shown in FIG. 5, the axis of the communication hole 15 that communicates the inside of the first fuel main chamber 12a and the inside of each cup portion 13 corresponding to the first cylinder group has each cup portion 13 corresponding to the first cylinder group. Are substantially coincident with each other and pass through the opening of each cup portion 13. As described above, the axes of the communication holes 15 and 15 for communicating the inside of the first fuel main chamber 12a with the inside of the cup parts 13 and 13 for the first and fourth cylinders pass through the openings of the respective cup parts 13 respectively. Therefore, the communication holes 15 can be formed from the openings of the cup portions 13 when the fuel distribution structure 10 is manufactured.

  On the other hand, as shown in FIG. 7, the axis of the communication hole 15 that communicates the inside of the second fuel main chamber 12b and the inside of each cup portion 13 corresponding to the second cylinder group has each cup corresponding to the second cylinder group. It intersects the axis of the portion 13 and passes through the opening of each cup portion 13. In this way, the axes of the communication holes 15 and 15 for communicating the inside of the second fuel main chamber 12b with the inside of the cup parts 13 and 13 for the second and third cylinders pass through the openings of the respective cup parts 13 respectively. Therefore, when the fuel distribution structure 10 is manufactured, the communication holes 15 can be formed through the openings of the cup portions 13.

  A portion 17 of the main body portion 12 corresponding to the cup portion 13 (the fourth cylinder cup portion 13) farthest from the fuel introduction portion 11 has a first and a second inside as shown in FIGS. Of the two fuel main chambers 12a and 12b, only the first fuel main chamber 12a communicating with the inside of the cup portion 13 for the fourth cylinder is formed, and is thinner than the portion 18 corresponding to the remaining cup portion 13. Specifically, the end 17 of the main body 12 on the side opposite to the fuel introduction part 11 has a substantially cross-sectional view in which a part on the second fuel main chamber 12b side is removed and only a part on the first fuel main chamber 12a side is left. The remaining portion 18 has a substantially racetrack shape in cross section.

  Hereinafter, the operation of the fuel distribution structure 10 will be described.

  When the direct injection engine 1 is operated, the first cylinder, the third cylinder, the fourth cylinder, and the second cylinder are ignited in this order. The fuel pressure in the fuel main chambers 12a and 12b pulsates each time the fuel injection valve 16 is opened. In the present structure 10, the first and second fuel main chambers 12a and 12b are communicated with the cup portions 13 corresponding to the first and second cylinder groups each including the cylinders 2 that are not adjacent to each other in the ignition order. Therefore, it is possible to suppress the pulsation of the fuel pressure from affecting the fuel injection by the fuel injection valve 16 as compared with the case where the fuel main chamber communicates with each cup portion corresponding to the cylinder whose ignition order is adjacent.

-Effect-
As described above, according to the present embodiment, the first fuel main chamber 12a and the cup portions 13 corresponding to the first cylinder group including the first and fourth cylinders whose ignition order is not adjacent to each other are communicated. Since the second fuel main chamber 12b communicates with each cup portion 13 corresponding to the second cylinder group consisting of the second and third cylinders whose ignition order is not adjacent, the fuel main chamber and the ignition order are adjacent to each other. Compared with the case where each cup part corresponding to a cylinder is connected, it is possible to suppress the pulsation of the fuel pressure from affecting the fuel injection by the fuel injection valve 16. Since the influence of pulsation on fuel injection can be suppressed in this way, the volume of each fuel main chamber 12a, 12b can be set small, and the main body 12 can be made compact. From the above, it is possible to suppress the pulsation of the fuel pressure from affecting the fuel injection by the fuel injection valve 16 even if the structure 10 is made of stainless steel or cast iron, even if it is made of aluminum. However, it can be made compact.

  The first fuel main chamber 12 a is arranged on the back side of each cup portion 13 so as to be orthogonal to the axis of each cup portion 13, and the second fuel main chamber 12 b is shown in a cross-sectional view of the main body portion 12. The distance between the second fuel main chamber 12b and each cup portion 13 corresponding to the second cylinder group is shorter than the distance between the first fuel main chamber 12a and each cup portion 13 corresponding to the first cylinder group. Since the first fuel main chamber 12a is disposed on the back side of each cup portion 13 on the opposite side to each fastening boss portion 14 in a predetermined direction perpendicular to the cylinder row direction and the axial direction of each cup portion 13. The main body 12 can be made compact with respect to the predetermined direction. For this reason, the structure 10 can be further downsized.

  Since the axis of each communication hole 15 is set so as to pass through the opening of each cup portion 13 communicating with each communication hole 15, each communication hole 15 is opened from the opening of each cup portion 13 when the structure 10 is manufactured. Can be formed.

  Since the part corresponding to the cup part 13 farthest from the fuel introduction part 11 of the main body part 12 is made thinner than the part corresponding to the remaining cup parts 13, it is compared with the case where the main body part 12 is of a constant thickness. Thus, the main body 12 can be made compact. For this reason, the structure 10 can be further downsized.

(Other embodiments)
In the above embodiment, the engine 1 is constituted by an in-line four-cylinder engine, but the number of cylinders is not limited to this as long as it is an in-line multi-cylinder engine. However, considering that the cylinder 2 is divided into first and second cylinder groups each having an ignition order that is not adjacent to each other, the number of cylinders is substantially an even number.

  In the above embodiment, the fuel introduction portion 11 is formed at the end portion of the main body portion 12 on the first cylinder side, but the fuel introduction portion 11 may constitute the end portion of the main body portion 12 on the fourth cylinder side. .

  In the said embodiment, although the 1st and 2nd fuel main chambers 12a and 12b are arrange | positioned as mentioned above, it is not restricted to this. For example, in the second fuel main chamber 12b, the distance between the second fuel main chamber 12b and each cup portion 13 corresponding to the second cylinder group in the cross-sectional view of the main body portion 12 is the same as the first fuel main chamber 12a and the first fuel main chamber 12b. Arranged on the same side as each fastening boss portion 14 with respect to the first fuel main chamber 12a in the predetermined direction on the back side of each cup portion 13 so as to be shorter than the distance to each cup portion 13 corresponding to the cylinder group. May be.

  In the above-described embodiment, the portion 17 of the main body portion 12 corresponding to the cup portion 13 for the fourth cylinder is formed with only the first fuel main chamber 12a inside, and from the portion 18 corresponding to the remaining cup portion 13. However, the present invention is not limited to this, and for example, both the fuel main chambers 12a and 12b may be formed in the inside so as to have the same thickness as the portion 18 corresponding to the remaining cup portion 13. However, the former is desirable from the viewpoint of compacting the structure 10.

  The present invention is not limited to the embodiments, and can be implemented in various other forms without departing from the spirit or main features thereof.

  As described above, the above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. The scope of the present invention is defined by the claims, and is not limited by the specification. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  As described above, the fuel distribution structure of a direct injection engine according to the present invention can be applied to a purpose of downsizing while suppressing the pulsation of the fuel pressure from affecting the fuel injection by the fuel injection valve.

It is the front view which fractured | ruptured the direct injection type engine which concerns on embodiment of this invention partially. It is the side view which looked at the direct injection type engine from the intake side. It is a front view of a fuel distribution structure. It is the bottom view which looked at the fuel distribution structure from the cylinder head attachment side. FIG. 5 is a cross-sectional view taken along line VV in FIG. 4. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 4. FIG. 7 is a sectional view taken along line VII-VII in FIG. 4. It is the side view which looked at the fuel distribution structure from the fuel introduction part side. It is the side view which looked at the fuel distribution structure from the opposite side to the fuel introduction part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Direct injection type engine 2 Cylinder 3 Combustion chamber 10 Fuel distribution structure 11 Fuel introduction part 12 Main-body part 12a 1st fuel main chamber 12b 2nd fuel main chamber 13 Cup part 14 Fastening boss part 15 Communication hole 16 Fuel injection valve 17 Main body part , Part corresponding to the cup part for the fourth cylinder 18 part corresponding to the remaining cup part of the main body part

Claims (4)

A fuel distribution structure of a direct injection engine for directly injecting high-pressure fuel into a combustion chamber of each cylinder of an engine in which a plurality of cylinders are arranged in series,
The plurality of cylinders are divided into first and second cylinder groups each consisting of cylinders whose ignition orders are not adjacent to each other.
A fuel introduction part into which the high-pressure fuel is introduced;
A main body portion that is formed side by side so as to extend from the fuel introduction portion to one side in the cylinder row direction and in which first and second fuel main chambers communicating with the fuel introduction portion respectively extend in the cylinder row direction;
The main body includes a plurality of cups that are arranged in series in the cylinder row direction so as to correspond to the cylinders and that accommodate fuel injection valves.
The first fuel main chamber communicates with each cup portion corresponding to the first cylinder group through a communication hole.
The fuel distribution structure of a direct injection type engine, wherein the second fuel main chamber communicates with each cup portion corresponding to the second cylinder group through a communication hole. The fuel distribution structure for a direct injection engine according to claim 1,
A plurality of fastening boss portions are arranged in series in the cylinder row direction so as to correspond to the cup portions on one side portion of the main body portion in a predetermined direction orthogonal to the cylinder row direction and the axial direction of the cup portions, respectively. Arranged,
The first fuel main chamber is disposed on the back side of each cup part so as to be orthogonal to the axis of each cup part,
In the second fuel main chamber, the distance between the second fuel main chamber and each cup portion corresponding to the second cylinder group in a cross-sectional view of the main body portion is the first fuel main chamber and the first cylinder group. Is arranged on the back side of each cup portion on the opposite side of the first fuel main chamber with respect to the fastening boss portion in the predetermined direction so as to be shorter than the distance to each cup portion corresponding to A fuel distribution structure for a direct-injection engine. The fuel distribution structure for a direct injection engine according to claim 1 or 2,
A fuel distribution structure for a direct injection engine, wherein the axis of each communication hole passes through the opening of each cup portion communicating with each communication hole. The fuel distribution structure for a direct injection engine according to any one of claims 1 to 3,
The portion of the main body portion corresponding to the cup portion furthest away from the fuel introduction portion has a fuel main chamber communicating with the cup portion farthest from the fuel introduction portion among the first and second fuel main chambers. The fuel distribution structure for a direct injection engine is characterized in that it is only formed and is thinner than the portion corresponding to the remaining cup portion.

Images