JP2000234560A - Intake system structure for cylinder injection type engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To standingly arrange and injector with an appropriate angle in cylinder injection type engine in which a pair of intake ports are opened at one side surface of a cylinder head in each cylinder, and an injector is arranged on its lower side. SOLUTION: A main pipe 33 of a fuel distributor pipe 30 is arranged parallelly to a side surface of a cylinder head 2, that is, in an axial direction of an output shaft. The main pipe 33 is offset in an axis (y) of an injector 22 in a longitudinal view of an engine, in the opposite direction to intake ports 7, 8. The second intake port 8 for generating tumble is formed on the upper side of the first intake port 7 for generating swirl. A fastening bolt is arranged on a lower side of the second intake port 8, so as to overlap with the injector 22 in a longitudinal view of the engine. An injector holder 34 is thus fastened to the cylinder head 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake system for an in-cylinder injection type engine in which an injector is disposed so as to face a combustion chamber of the engine and a pair of intake ports are disposed above the injector for each cylinder. Regarding the structure.

[0002]

2. Description of the Related Art Conventionally, in an in-cylinder injection engine in which fuel is directly injected into an in-cylinder combustion chamber of an engine by an injector, the pressure of fuel supplied to the injector becomes extremely high. Various devices have been devised for the arrangement structure of the fuel distribution and supply pipe. For example,
In the engine disclosed in Japanese Patent Application Laid-Open No. H8-246992, a delivery pipe (fuel distribution supply pipe) for distributing and supplying fuel to the injector is positioned on the axis of the injector attached to the cylinder head, and a bolt is attached to the cylinder head. At the same time, the injector is pressed and fixed by the delivery pipe itself, with an O-ring interposed on the base end side of the injector and fitted inside the fuel supply hole of the delivery pipe. That is, using the delivery pipe as a strength member, the injector is positioned with respect to the cylinder head, and the fuel introduction port of the injector and the fuel supply hole of the delivery pipe are communicated in an airtightly sealed state.

[0003]

Incidentally, in a so-called four-valve engine in which two intake valves and two exhaust valves are provided for each cylinder of a gasoline engine, those four valves are arranged so as to surround the cylinder center line. Generally, a structure in which a spark plug is provided at the center thereof is employed. In this structure, the injector is usually arranged on the periphery of the combustion chamber so as not to interfere with the four valves and the spark plug, and the intake port side is preferable because the influence of the exhaust heat is reduced.
The injector is disposed below the two intake ports so as to be sandwiched between the two intake ports so as to inject fuel from the side into the combustion chamber.

When the fuel is supplied to the combustion chamber from the side, the inclination angle of the injector with respect to the cylinder center line is reduced by reducing the inclination angle of the injector with respect to the cylinder center line in order to reduce the problem caused by the wall surface of the injected fuel. It is necessary to spray from above toward the top surface. That is, the injector must be placed upright and as close as possible to the upper intake port.

However, in the case where the delivery pipe is arranged on the axis of the injector as in the above-mentioned conventional fuel injection device, when the injector is arranged close to the intake port, the delivery pipe interferes with the cylinder head and the intake manifold. Therefore, there is a problem that the injector cannot be arranged at an appropriate angle. And
As a result, if the adhesion of the fuel to the wall surface cannot be sufficiently reduced, the fuel efficiency will be degraded and harmful exhaust components will increase.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to provide a pair of intake ports for each cylinder, which are opened side by side on one side of the engine. An in-cylinder injection engine in which an injector is arranged in the middle and below the cylinder, the injector is arranged at an appropriate angle by devising the arrangement of the intake port and the fuel distribution supply pipe. .

[0007]

In order to achieve the above object, according to the present invention, a main supply pipe portion of a fuel distribution supply pipe for distributing fuel to an injector is viewed from a direction of an output shaft of an engine. To the injector axis with respect to the axis of the injector, and open one of the intake ports on one side of the engine above the other intake port, and fasten the fuel distribution supply pipe to the space below it. The fastening member was disposed so as to overlap with the injector when viewed from the output shaft direction.

More specifically, according to the first aspect of the present invention, an injector facing the combustion chamber in the cylinder of the engine is disposed on one of the left and right sides sandwiching the output shaft of the engine, and the injector is provided with fuel from outside the engine. A first and a second intake port connected to the distribution supply pipe and communicating with the combustion chamber,
It is premised on an intake system structure of a direct injection type engine formed above the injector so as to sandwich the injector. The fuel distribution pipe has a main supply pipe section extending in the output axis direction on the side opposite to the intake port with respect to the axis of the injector when viewed from the output axis direction of the engine, and a branch from the main supply pipe section. A distribution pipe connected to an injector, wherein the second intake port is formed such that an upstream end thereof is opened above a first intake port on one side of the engine, and the fuel distribution / supply pipe Is fastened to a side surface of the engine by a fastening member, and the fastening member is provided on the side of the second intake port with respect to the injector when viewed from a direction orthogonal to the output shaft of the engine, when viewed from the output shaft direction. And is arranged so as to overlap the injector.

According to the above configuration, the main supply pipe portion of the fuel distribution supply pipe is offset on the side opposite to the intake port with respect to the injector axis when viewed from the engine output shaft direction. Therefore, even if the main supply pipe is disposed close to the upper intake port, the main supply pipe does not interfere with the cylinder head or the like. For this reason, the injector can be set up at an appropriate angle with respect to the conventional example, so that the adhesion of fuel to the wall can be reduced, and problems such as deterioration of fuel efficiency and increase of harmful exhaust components can be solved.

The fuel in the main supply pipe is supplied to the injector through the distribution pipe, and is directly injected into the combustion chamber of the engine from the injection hole at the tip end of the injector. At this time, the fuel pressure is extremely high. Therefore, usually, a strong reaction force acts on the distribution pipe portion. For this reason, if the main supply pipe is offset with respect to the injector axis as described above,
There is a possibility that the distribution pipe may rise from the injector and cause fuel leakage, and further, a strong torsional moment may act on the main supply pipe to reduce reliability.

On the other hand, in the present invention, the upstream end of the second intake port is opened above the first intake port on one side of the engine, and the fuel distribution pipe is provided below the second intake port. A fastening member to be fastened to one side of the engine,
It is arranged so as to overlap with the injector when viewed from the output shaft direction. Thereby, the distribution pipe portion is pressed sufficiently strongly toward the injector side, and fuel leakage therebetween can be reliably prevented. Further, if the distribution pipe portion is directly fixed to one side of the engine by the fastening member, it is possible to prevent the torsion moment from acting on the main supply pipe portion.

According to the second aspect of the invention, the first and second intake ports communicate with the first and second upstream intake passages, respectively, and the second intake passage is provided with an intake flow control valve. Shall be established. With this, if the intake flow control valve is closed, the flow of intake air from the first intake port is enhanced, so that the intake swirl in the combustion chamber can be strengthened.
If the intake flow control valve is opened, the intake flow rates of both intake ports become substantially the same, and the intake tumble in the combustion chamber can be strengthened.

According to a third aspect of the present invention, the intake flow control valve according to the second aspect comprises a butterfly valve, the valve shaft of which passes through the peripheral wall of the second intake passage and is located above the first intake passage. Was arranged to extend in the direction of the output shaft of the engine. As a result, the valve shaft of the intake air flow control valve disposed in the second intake passage does not pass through the adjacent first intake passage, so that the flow of intake air in the first intake passage depends on the valve shaft. It is possible to avoid being disturbed and increasing the intake resistance.

According to the fourth aspect of the present invention, the cross sections of the first and second intake ports are each formed in a different shape so as to avoid interference with the injector when viewed from the axial direction of the injector. Thus, the injector can be arranged closer to the first and second intake ports, so that the injector can be set up correspondingly and arranged at an appropriate angle.

According to a fifth aspect of the present invention, the injector is fixed to one side of the engine by a fixing member, and the fixing member is disposed at substantially the same position as the injector when viewed from a direction orthogonal to the output shaft of the engine. I do. Thus, the injector can be securely fixed to one side of the engine, and a fixing member therefor can be arranged so as not to interfere with the fastening member.

According to a sixth aspect of the present invention, the fixing member of the fifth aspect is fixed to one side of the engine by a bolt extending parallel to the axis of the injector, and the main supply pipe of the fuel distribution pipe is connected to the injector. When viewed from the axial direction of the bolt, it is positioned on the head of the bolt. Thus, the main supply pipe portion of the fuel distribution supply pipe can be compactly arranged as close as possible to the injector as viewed from the output shaft direction.

According to a seventh aspect of the invention, the injector according to the fifth aspect of the invention is provided with a connecting coupler on a side opposite to the fastening member when viewed from a direction orthogonal to the output shaft. As a result, the fastening member is arranged on the side of the output shaft direction with the second intake port with respect to the injector, and the connecting coupler is arranged on the opposite side, so that compact arrangement is possible by effective use of space. become.

According to an eighth aspect of the present invention, in the invention of the seventh aspect, the opening surface at the upstream end of the intake port protrudes from one side of the engine, and the coupler and the fixing member of the injector are connected to the axis of the injector. When viewed from a direction perpendicular to the opening, the opening is located closer to the tip of the injector. Thus, the connecting coupler and the fixing member of the injector can be more compactly disposed inside the engine than the opening of the intake port.

According to a ninth aspect of the present invention, a fuel pressure sensor is provided at an end of the main supply pipe portion of the fuel distribution supply pipe according to the seventh aspect of the present invention on the side where the fastening member is located with respect to the injector. Shall be. This reduces the distance between the fuel pressure sensor and the fastening member, so that a heavy fuel pressure sensor can be stably supported via the fuel distribution / supply pipe.

According to a tenth aspect of the present invention, the engine is an in-line multi-cylinder engine in which a plurality of cylinders are arranged in a line, and two exhaust ports communicating with the combustion chamber are provided for each cylinder, and the intake and exhaust ports are provided. It is assumed that intake and exhaust valves for opening and closing are arranged so as to surround the center line of the cylinder, and a spark plug is arranged so as to be surrounded by the intake and exhaust valves.

That is, in the engine having such a configuration, the location of the injector is substantially limited below the intake port, so that the main supply pipe portion of the fuel distribution supply pipe interferes with the engine side. It is particularly effective that the injector can be set up at an appropriate angle while standing as much as possible while avoiding the need to operate the injector.

[0022]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic configuration of a direct injection type engine 1 according to an embodiment of the present invention, mainly around a combustion chamber. Reference numeral 2 denotes a cylinder head disposed on a cylinder block 3; Reference numeral denotes a cylinder formed in the cylinder block 3 and reference numeral 5 denotes a piston slidably fitted in the cylinder 4. A cylinder 4 is provided on the lower surface of the cylinder head 2.
The combustion chamber 6 is defined by the concave portion, the top surface of the piston 5 and the side wall of the cylinder 4.

The concave portion of the cylinder head 2 corresponding to the upper surface of the combustion chamber 6 extends from a substantially central portion toward the left and right sides in the drawing to the vicinity of the lower end surface of the cylinder head 2 (the mating surface with the cylinder block 3). Two inclined surfaces are formed. A pair of first and second intake ports 7 and 8 are opened on the right inclined surface, and a pair of exhaust ports 9 and 9 are opened on the left inclined surface. , Are provided with an intake valve and an exhaust valve 10, respectively. The intake valve and the exhaust valve 10 are arranged so that a total of four of them, two for each cylinder, surround the cylinder center line x in plan view.
The ignition plug 11 is disposed along the cylinder center line x and is surrounded by 0, 10,... And faces the combustion chamber 6 from above.

The first and second intake ports 7, 8 both extend obliquely upward and rightward in the figure from the combustion chamber 6, and are located on the right side of the cylinder head 2 (right side in the figure). An opening is formed at a joint surface (opening surface) 2a with the intake manifold formed so as to project obliquely. Further, the exhaust port 9 extends substantially horizontally to the left from the combustion chamber 6,
It is open on the left side of the engine 1.

The first and second intake ports 7, 8 are vertically displaced from each other, and the second intake port (one intake port) 8 is connected to the first intake port (the other intake port) at the joint surface 2a of the cylinder head 2. Port 7 is formed above the first intake port 7 and communicates with the combustion chamber 6 at a large incident angle from above the first intake port 7.
As a result, the intake air flow from the first intake port 7 flows into the combustion chamber 6 at a relatively small angle with respect to the horizontal direction in the drawing, while the intake air flow from the second intake port 8 becomes a relatively large angle. So that both intake ports 7, 8
Are suitable for swirl and tumble generation, respectively.

A two-part intake manifold is mounted on the right side of the engine 1, and the downstream member 12 has a downstream flange surface joined to the joint surface 2 a of the cylinder head 2. , Bolts 13, 13, ... are fastened to the screw holes 15, 15, ... opened in the joint surface 2a, thereby being fixed to the cylinder head 2 and extending substantially horizontally toward the outside of the engine. The upstream member 14 connected to the upstream end of the downstream member 12 is
It is largely curved downward and extends below the cylinder head 2 so as to surround a fuel dispipe 30 described later.

In the downstream member 12 of the intake manifold, there are first and second two independent passages 12a, 12 communicating with the first and second intake ports 7, 8 for each cylinder.
In the second passage 12b, there is provided an intake flow control valve 16 composed of a butterfly valve for adjusting the intake flow state of the combustion chamber 6 by opening and closing this passage. The intake flow control valves 16 are provided for the respective cylinders 4 and are connected to each other by a common valve shaft 16a. The valve shaft 16a penetrates the peripheral wall of the second passage 12b, and the first passage 12a Extends in the front-rear direction of the engine, and is turned around an axis by an actuator (not shown). Since the valve shaft 16a is disposed so as not to pass through the first passage 12a in this manner,
The flow of intake air in the first passage 12a is not disturbed, and the intake resistance does not increase.

The bolts 13, 13,... For fixing the downstream member 12 are boss portions 12 provided in the cylinder row direction.
, 12c,..., and the valve shaft 16a
The bosses 12c are arranged so as not to interfere with the bosses 12c.

When the intake flow control valve 16 is closed, most of the intake air flows from the first passage 12a and the first intake port 7, and a strong intake swirl is generated in the combustion chamber 6. As the intake flow control valve 16 opens, the intake air flows in from both passages 12a and 12b in the same manner, so that the tumble component of the intake air becomes stronger and the swirl component becomes weaker. The control of the intake flow control valve 16 is performed by a control device (not shown) according to the operating state of the engine 1. For example, on the low load side of an operation region where a stratified combustion state is described later, in order to avoid overspreading and bending of the spray, the intake flow control valve 16 is opened to some extent to reduce the swirl, while increasing the load as the load increases. The intake flow control valve 16 is closed to strengthen the swirl.
Further, on the engine high-speed rotation side in an operation region where a uniform combustion state is described later, the opening degree of the intake flow control valve 16 is increased to secure the intake charge amount.

As shown in FIG. 2, for example, the engine 1 has four cylinders 4, 4, 4, and 4 in which the crankshaft extends.
An in-line four-cylinder engine arranged in a row. The joint surface 2a with the intake manifold 12 is formed from the front end to the rear end of the cylinder head 2, and FIG.
As shown in FIG. 2, a total of eight intake ports 7, 8,..., Two for each cylinder 4, are opened in a staggered manner.

Further, on the upper part of the cylinder head 2,
Two camshafts 17 and 18 on the intake side and the exhaust side are provided rotatably. These two camshafts 17, 1
Reference numeral 8 denotes the engine 1 by a timing belt (not shown) or the like.
When the intake camshaft 17 is rotated in synchronization with the rotation of the crankshaft, the cam formed on the camshaft 17 causes the valve lifter 19 to rotate.
Each intake valve 10 is reciprocated in the valve axis direction via (see FIGS. 1 and 2), and the intake ports 7, 8,... Are opened and closed at a predetermined timing for each cylinder. Similarly, when the exhaust-side camshaft 18 is rotated, the exhaust valve 10 reciprocates and the exhaust ports 9, 9,... Are opened and closed.

As shown in FIGS. 1 and 3, a hole 21 communicating with the combustion chamber 6 is opened for each cylinder 4 on the right side surface of the cylinder head 2, and the injector 2 is provided therein.
2 are accommodated. The injection hole at the tip end of the injector 22 approaches the periphery of the combustion chamber 6 near the head of the intake valve 10 and injects fuel into the combustion chamber 6 from the side. When the fuel is injected from the side as described above, it is preferable that the injector 22 be disposed upright as much as possible so that the injected fuel does not adhere to the cylinder wall surface as much as possible. 2 intake ports 7, 8
Has a sectional shape along the outer periphery of the injector 22, and the injector 22 is particularly connected to the first intake port 7.
8 are arranged so as to be close to each other (FIG. 8).
reference). As a result, the inclination angle of the injector axis y with respect to the cylinder center line x is about 45 °, and the adhesion of the fuel to the wall surface is sufficiently reduced. Note that the inclination angle may be set to 50 ° or less.

When the engine 1 is in a predetermined region of low load and low speed, fuel is injected by the injector 22 in the latter half of the compression stroke of each cylinder 4 and the ignition plug 11
Is in a stratified combustion state in which the air-fuel mixture is unevenly distributed in the vicinity of. On the other hand, if the engine 1 is in the high load or high speed region, the fuel injection is performed in the first half of the intake stroke of each cylinder 4 to bring about a uniform combustion state. Such fuel injection control is performed by a controller (not shown), and a signal cable (not shown) between the controller and the controller is connected to the injector 2.
2 are connected via a connection coupler 23 provided on the outer peripheral portion.

As the injector 22, for example, a high-pressure swirl injector is preferably used.
This high-pressure swirl injector generates swirl in the fuel spray to promote atomization, and in the latter stage of the compression stroke in which the pressure in the combustion chamber 6 is high, the spray angle becomes a narrow angle of 30 ° or less. In the injection in the intake stroke in which the pressure in the chamber 6 is low, the spray angle is wider than that.

On the right side surface of the cylinder head 2 shown in FIG. 3, a pedestal 25 is formed protruding below the hole 21 for accommodating the injector 22 for each cylinder 4.
5, a nozzle holder (fixing member) 26 for fixing the injector 22 is fastened by a bolt 27, as shown in FIG. As shown in detail in FIG. 5, this nozzle holder 26 has a bolt hole 26a formed through the center of a rectangular main body, and two arms 26b, 26b extending forward and obliquely downward from the main body. In a state where the main body is fastened to the pedestal 25 by bolts 27, the lower ends of the two arms 26b, 26b abut against the flanges of the injectors 22, respectively, and the injectors 22 are moved along their axis y. It is pressed downward in the direction, and can be securely fixed to the cylinder head 2 against the high pressure of the combustion chamber 6. The bolt 27 extends parallel to the injector axis y.

On the front side (right side in FIG. 3) of the engine of each of the holes 21, another pedestal 28 which is one step higher than the pedestal 25 is formed. 29, the bolt hole 29
Then, a fastening bolt 31 of a fuel dispipe (fuel distribution / supply pipe) 30 is screwed and fastened. That is, as shown in FIG.
A fuel dispipe 30 for distributing and supplying fuel (gasoline) to each injector 22 is provided, and the fuel dispipe 30 extends in the front-rear direction of the engine.
At a position adjacent to the front side of the injector 22 (right side in FIG. 6) of the injector 22 for each cylinder 4, a fastening bolt (fastening member) 3
Are fixed to the cylinder head 2 by 1, 31,.

As shown in FIG. 7 in detail, the fuel dispipe 30 has a main pipe (main supply pipe) 33 extending parallel to the right side of the cylinder head 2 and protrudes vertically from the main pipe 33, respectively. And four injector holders (distribution pipe sections) 34, 34, 34, 34, 34, which are formed integrally with each other and extend toward the injector 22 of each cylinder 4.
34, 34. At the rear end side of the main pipe 33 (left end side in FIGS. 6 and 7), a mounting seat 33a to which an upstream fuel supply pipe 35 is airtightly mounted is provided. The fuel is supplied from a high-pressure supply pump (not shown).

On the other hand, a flange 33b is provided at the front end (the right end in FIGS. 6 and 7) of the main pipe 33, and a fuel pressure sensor 36 is attached thereto. That is, the fuel pressure sensor 36 is disposed at the front end of the engine where the fastening bolts 31 are provided for the injectors 22 of the respective cylinders 4 at the front and rear ends of the fuel dispipe 30. As a result, the distance between the fastening bolt 31 arranged in the first cylinder 4 on the front end side of the engine and the fuel pressure sensor 36 becomes extremely short, so that the heavy fuel pressure sensor 36 can be stably supported by the fuel dispipe 30. it can.

At the distal end of each of the injector holders 34, there is provided a receiving hole 37 for receiving the base end of the injector 22. As shown in FIG.
Is fitted airtightly into the accommodation hole 37 via an O-ring fitted on the fitting shaft. The accommodation hole 37 has a main pipe 33.
The front end of the distribution passage 38 branched from the fuel passage 33c is opened, and the fuel pressure-fed from the high-pressure supply pump to the main pipe 33 by the fuel supply pipe 35 as described above is supplied from the fuel passage 33a to each cylinder 4 Is distributed through the distribution passage 38 to reach the accommodation hole 37.
Is supplied to the fuel inlet of the injector 22 facing the fuel cell. Further, a through hole 39 is formed in each of the injector holders 34 at a position corresponding to the pedestal 28 of the cylinder head 2, and the fastening bolt 31 is inserted into the through hole 39.

A first characteristic of the present invention is that the main pipe 33 of the fuel dispensing pipe 30 is arranged such that the main pipe 33 of the fuel dispensing pipe 30 as shown in FIGS.
2 is located on the side opposite to the intake ports 7, 8 with respect to the axis y of the second. That is, the main pipe 33
Is offset to the side away from the cylinder head 2 with respect to the injector axis y, and the accommodation hole 37 and the distribution passage 38 in each injector holder 34 form an L-shape. For this reason, even if the injector 22 is placed upright as close as possible to the intake ports 7 and 8 above it, the main pipe 33 does not interfere with the cylinder head 2 and the intake manifold 12. In other words, in this embodiment, the injectors 22 for each cylinder 4 can be arranged upright as compared with the conventional example.

A second feature of the present invention is that, as shown in FIG. 8, the first and second intake ports 7, 8 for each cylinder 4,
Injector 22, nozzle holder 26, fastening bolt 31
And so on. That is, first, the fastening bolt 31
Utilizing the fact that the second intake port 8 is shifted upward from the first intake port 7 and opened at the joint surface 2a of the cylinder head 2, the second intake port 8 is brought closer to the lower side of the second intake port 8. , Are arranged adjacent to the front side of the engine of the injector 22 (the right side in FIG. 8). Therefore, when viewed from the front and rear direction of the engine as shown in FIGS. 1 and 4, the fastening bolt 31 is disposed so as to overlap the injector 22, whereby the reaction force of the fuel injection with respect to the injector holder 34 is reduced. Even if it acts strongly, the injector holder 34 can be fixed to the cylinder head 2 sufficiently strong so as not to lose the reaction force.

When viewed along the injector axis y as shown in FIG. 8, the connecting coupler 23 of the injector 22 is located at the rear side of the engine of the injector 22 (left side in FIG. 8), and the nozzle holder 26 is an injector 22
Below, that is, the injector 2
2 are arranged at substantially the same position. When viewed from this direction, the main pipe 33 of the fuel dispipe 30 is located above the head of the bolt 27 that fixes the nozzle holder 26. That is, the connection coupler 23, the nozzle holder 26 and the fastening bolt 31 are connected to the injector 22.
Are effectively arranged to avoid interference with each other, and the main pipe 33 is also compactly arranged as close to them as possible.

Further, as shown in FIG. 1, the connection coupler 23 and the nozzle holder 26 are connected to the injector axis y.
In the direction, the fuel injection device can be compactly arranged with respect to the engine 1 because the fuel injection device is arranged on the tip side of the injector 22 with respect to the joint surface 2a of the cylinder head 2, that is, inside the engine with respect to the joint surface 2a.

Therefore, according to this embodiment, by offsetting the main pipe 33 of the fuel dispipe 30 away from the intake ports 7 and 8, it is possible to avoid interference between the fuel dispipe 30 and the cylinder head 2 and the like. , The injector 22 can be raised and positioned at an appropriate angle, which allows the injector 2
The adhesion of the fuel injected from 2 to the combustion chamber 6 to the cylinder wall surface is sufficiently reduced, and problems such as deterioration of fuel efficiency and increase of harmful exhaust components can be solved.

The first and second intake ports 7, 8 are
The bolts 31, 31,... Of the fuel dispipe 30 are displaced upward for each cylinder 4 by utilizing the fact that they are formed vertically displaced so as to be suitable for swirl and tumble generation. The injector holder 34 is disposed below the intake port 8 so as to overlap with the injector 22 when viewed from the engine front-rear direction, so that even if a reaction force of the fuel injection acts on the injector holder 34 strongly, the injector holder does not lose the reaction force. 34 sufficiently strong cylinder head 2
Can be fixed. This allows the injector 2
Fuel leakage between the fuel injector 2 and the injector holder 34 can be reliably prevented. Moreover, the fastening bolt 31
Can directly connect each injector holder 34 to the cylinder head 2.
Therefore, no torsional moment acts on the main pipe 33 from the injector holder 34, so that the reliability of the fuel dispipe 30 is improved.

Further, the engine 1 of this embodiment is of a four-valve type in which the ignition plug 11 is disposed along the cylinder center line x, and the location of the injector 22 is substantially limited below the intake port 7. In such a case,
It is extremely effective that the injector 22 can be arranged upright as much as possible while avoiding interference with the cylinder block 2 of the fuel dispipe 30 as described above.

[0048]

As described above, according to the intake system structure of the direct injection engine according to the first aspect of the present invention,
By offsetting the main supply pipe section of the fuel distribution supply pipe to the side opposite to the intake port with respect to the injector axis when viewed from the engine output axis direction, the injector is prevented from interfering with the main supply pipe section and the cylinder head. Can be positioned upright and at the right angle,
By reducing the adhesion of fuel to the wall, it is possible to solve problems such as deterioration of fuel efficiency and increase of harmful exhaust components. Further, one of the intake ports is formed so as to be shifted above the other intake port, and a fastening member for fastening the fuel distribution supply pipe to the engine is formed below the one intake port with the injector as viewed from the output shaft direction. By arranging them so as to overlap, it is possible to reliably prevent fuel leakage between the distribution pipe section and the injector.

According to the second aspect of the present invention, the intake swirl and tumble in the combustion chamber can be strengthened by the intake flow control valve.

According to the third aspect of the present invention, the valve shaft of the intake flow control valve provided in one intake passage does not increase the intake resistance of the adjacent intake passage.

According to the fourth aspect of the invention, the injector for each cylinder can be arranged closer to the intake port and arranged at a more appropriate angle.

According to the fifth aspect of the present invention, the injector can be securely fixed to one side of the engine by the fixing member, and the fixing member can be arranged so as not to interfere with the fastening member.

According to the invention of claim 6, the main supply pipe portion of the fuel distribution / supply pipe can be compactly arranged as close to the injector as possible.

According to the seventh aspect of the present invention, the space around the injector can be effectively used, and the fastening member and the connecting coupler can be compactly arranged.

According to the invention of claim 8, the coupler and the fixing member of the injector can be compactly arranged around the engine.

According to the ninth aspect, the fuel pressure sensor can be stably supported via the fuel distribution / supply pipe.

In the engine according to the tenth aspect of the present invention, the location of the injector is limited below the intake port, so that the effect of the first aspect of the invention is particularly effective.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view illustrating a schematic configuration of a direct injection engine according to an embodiment of the present invention.

FIG. 2 is a top view of the cylinder head.

FIG. 3 is a right side view of the cylinder head.

FIG. 4 is an enlarged sectional view showing an arrangement structure of an injector.

5A is a top view showing the configuration of the nozzle holder, and FIG. 5B is a cross-sectional view taken along line zz.

FIG. 6 is a view showing a structure of disposing a fuel dispipe with respect to a cylinder head, as viewed along the injector axis from the upper right side of the engine as indicated by an arrow in FIG. 1;

FIG. 7 is a front view (a), a right side view (b), and a top view (c) of the fuel dispipe.

FIG. 8 is an enlarged view of FIG. 6 showing a positional relationship of an intake port, an injector, a nozzle holder, a fastening bolt and the like for each cylinder.

[Description of Signs] 1 Engine 2 Cylinder head 2a Joining surface (opening surface) 4 Cylinder x Cylinder center line 6 Combustion chamber 7 First intake port 8 Second intake port 9 Exhaust port 10 Intake valve, exhaust valve 11 Spark plug 12, Reference Signs List 14 intake manifold 12a, 12b intake passage 16 intake flow control valve 16a valve shaft 21 hole 22 injector y injector shaft center 23 connecting coupler 26 nozzle holder (fixing member) 30 fuel dispipe (fuel distribution supply pipe) 31 fastening bolt ( Fastening member) 33 Main pipe (Main supply pipe) 34 Injector holder (Distribution pipe) 36 Fuel pressure sensor

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02F 1/42 F02F 1/42 K F02M 37/00 321 F02M 37/00 321B 51/06 51/06 M 55 / 02 350 55/02 350E 350H 61/14 310 61/14 310A 320 320A 61/16 61/16 J 69/04 69/04 Z (72) Inventor Tadashi Hashiguchi Tadashi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Co., Ltd. (72) Inventor Keiji Araki 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture F-term (reference) 3G023 AA02 AA03 AB01 AC02 AD03 AD05 AD07 AD12 AF01 3G024 AA04 AA09 BA27 DA01 DA06 DA10 DA18 FA08 GA00 3G065 AA04 AA06 AA07 CA12 EA07 HA03 HA21 3G066 AA02 AA03 AA05 AB02 AD05 AD12 BA12 BA17 BA23 BA35 BA65 BA67 CB01 CB05 CB12 CC01 CC05U CC48 CD04 CD28 CE21 CE30 DB08 DB09 DB12 DB13 DC18

Claims (10)

[Claims] An injector facing a combustion chamber in a cylinder of an engine is disposed on one of right and left sides of an output shaft of the engine, and a fuel distribution supply pipe is connected to the injector from outside the engine. 1st communicating with the combustion chamber
And a second intake port formed above the injector so as to sandwich the injector, wherein the fuel distribution / supply pipe is provided at an axial center of the injector when viewed from an output shaft direction of the engine. A main supply pipe section extending in the output axis direction on the side opposite to the intake port; and a distribution pipe section branched from the main supply pipe section and connected to an injector, wherein the second intake port has an upstream end. The fuel distribution supply pipe is fastened to one side of the engine by a fastening member, and the fastening member is connected to an output of the engine. The injector is disposed on the side where the second intake port is located with respect to the injector when viewed from a direction perpendicular to the axis so as to overlap the injector when viewed from the output axis direction. Structure of the direct injection engine. 2. The first intake port according to claim 1, wherein first and second intake ports are respectively connected to first and second upstream intake passages, and an intake flow control valve is disposed in the second intake passage. An intake system structure for a direct injection engine, which is provided. 3. The intake flow control valve according to claim 2, wherein the intake flow control valve comprises a butterfly valve, and a valve shaft thereof penetrates a peripheral wall of the second intake passage and extends above the first intake passage in a direction of an output shaft of the engine. An intake system structure for a direct injection engine, which is arranged to extend. 4. The fuel injection system according to claim 1, wherein the cross sections of the first and second intake ports are each formed in a different shape so as to avoid interference with the injector when viewed from the axial direction of the injector. The intake system structure of the direct injection engine. 5. The injector according to claim 1, wherein the injector is fixed to one side surface of the engine by a fixing member, and the fixing member is provided at substantially the same position with respect to the injector as viewed from a direction orthogonal to an output shaft of the engine. The intake system structure of a direct injection type engine which is characterized in that: 6. The injector according to claim 5, wherein the fixing member is fixed to one side surface of the engine by a bolt extending parallel to the axis of the injector, and the main supply pipe of the fuel distribution pipe is connected to the axis of the injector. An intake system structure for a direct injection type engine, which is located on a head of the bolt when viewed from a direction. 7. The direct injection engine according to claim 5, wherein the injector is provided with a connection coupler on a side opposite to the fastening member when viewed from a direction orthogonal to an output shaft of the engine. Intake system structure. 8. The injector according to claim 7, wherein the opening surfaces of the upstream ends of the first and second intake ports protrude from one side of the engine, and the coupler and the fixing member of the injector are orthogonal to the axis of the injector. The intake system structure of a direct injection type engine, which is disposed closer to the tip end of the injector than the opening surface when viewed from the direction of movement. 9. The fuel pressure sensor according to claim 7, wherein a fuel pressure sensor is provided at an end of the main supply pipe of the fuel distribution supply pipe on a side where the fastening member is located with respect to the injector. The intake system structure of the in-cylinder injection engine. 10. The engine according to claim 1, wherein the engine is an in-line multi-cylinder engine in which a plurality of cylinders are arranged in a line, and two exhaust ports communicating with the combustion chamber are provided for each cylinder. An in-cylinder injection engine, wherein intake and exhaust valves for opening and closing the cylinder are arranged so as to surround a center line of the cylinder, and a spark plug is arranged so as to be surrounded by the intake and exhaust valves. The intake system structure.