JPH11270427A - Cylinder fuel injection type engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To heighten the rigidity by integrating a high pressure fuel injection unit and enhance the assembling property by providing possibility of absorbing the cumulated tolerance when the unit is to be assembled to the engine. SOLUTION: An engine 2 equipped with a vertically directed crank shaft is composed of a high pressure fuel pump 32, pump drive unit 40 and high pressure regulating valve 35 which are fixed to the cylinder body 7, a fuel supplying rail 33 fixed to the cylinder head 8 and coupled with the pump 32 and valve 35, and a fuel injection valve 13 fixed to the rail. Plays are provided in the bolt 61 mounting parts of the pump 32 and drive unit 40 and a cylinder head shaft hole 81 in the fuel injection valve 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of injecting high-pressure fuel into a cylinder in an engine having a crankshaft arranged vertically.

[0002]

2. Description of the Related Art In a two-stroke engine, unburned gas such as HC is apt to be exhausted because there is a timing at which a scavenging port and an exhaust port are simultaneously communicated. Unburned gas is easily exhausted. Therefore, after the exhaust port is closed, high-pressure fuel is directly injected into the cylinder to atomize the fuel and improve combustion, and at low speed and low load, a large amount of fresh air is supplied to prevent misfiring. A method for reducing the emission of unburned gas is known. When the above-described high-pressure fuel is directly injected into the cylinder, it is necessary to provide a high-pressure fuel pump in the fuel supply system. Conventionally, in a four-cycle engine, a high-pressure fuel pump is driven using rotation of a camshaft of a valve mechanism.

In an engine that injects high-pressure fuel into a cylinder, a high-pressure fuel pump, a pump driving unit, a high-pressure pressure regulating valve, a fuel injection valve, and a high-pressure fuel pump having at least a plurality of parts connected thereto are connected. The fuel injection unit is mounted on the engine. In this case, when the fixed portion of the component extends over a plurality of members of the engine (for example, the cylinder body and the cylinder head), the integration tolerance of the high-pressure fuel injection unit to which the plurality of components are connected and the integration tolerance of the engine are absorbed. Need to be done. 2. Description of the Related Art Conventionally, in automobiles, a metal pipe pipe that withstands some deformation to absorb integrated tolerance is used as a part of a high-pressure fuel pipe.

[0004]

However, in a two-stroke engine, there is no camshaft of a valve mechanism as in a four-stroke engine, and there is a problem of how to drive a high-pressure fuel pump using existing parts. Has become. When a high-pressure fuel pump for an automobile is adopted, the high-pressure fuel pump is driven by a horizontally disposed crankshaft or camshaft. The air release, lubrication, and drive mechanisms are designed on the premise that they are installed, so when this is applied to an engine such as an outboard motor in which the crankshaft or camshaft is arranged in the vertical direction. Requires special measures and ingenuity.

Further, when the above metal pipe pipe is used, the rigidity of the entire high-pressure fuel injection unit cannot be ensured at the time of assembling. Therefore, the assemblability is poor, and excessive stress is applied to the flexible pipe and the metal pipe pipe, thereby increasing the durability. There is a problem that it decreases. In particular, in an outboard motor having large vibration, solving this problem is an important issue.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, in which a high-pressure fuel injection unit is integrated to increase its rigidity, and at the time of assembling the unit to an engine, the integration tolerance can be absorbed to improve the assemblability. It is an object of the present invention to provide an in-cylinder fuel injection engine that can be improved.

[0007]

According to the first aspect of the present invention, a pump driving unit fixed to a cylinder body, a high-pressure fuel pump, a high-pressure pressure adjusting valve, a cylinder head, and a cylinder head. 8, a fuel supply rail 33 connected to the high-pressure fuel pump and the high-pressure regulating valve, and a fuel injection valve 13 fixed to the fuel supply rail and inserted into a shaft hole 81 of a cylinder head. A play is provided between the fuel injection valve 13 and the cylinder head shaft hole 81. The invention according to claim 2 is characterized in that the high pressure fuel pump 32 according to claim 1 is provided.
4. A play is provided between a bolt 61 for mounting the pump drive unit 40 and the bolt hole.
According to the invention described in claims 1 and 2, the high-pressure fuel pump 32, the high-pressure pressure regulating valve 35 and the fuel supply rail 33 are provided.
The connectors 70 and 72 are provided at the connection portions of the O-rings 6 and O-rings 6 on the outer periphery of the connectors and the outer periphery of the fuel injection valve 13.
According to a fourth aspect of the present invention, in the engine of the fourth aspect, the crankshaft 10 is disposed in a vertical direction, and the plurality of cylinders 7a to 7f are connected to the V The fuel supply rails 33 are arranged in two rows so as to form a bank, and the fuel supply rails 33 include vertical rails 33b fixed to the cylinder heads of each row and horizontal rails 33a connected to the upper ends of the vertical rails. According to a fifth aspect of the present invention, there is provided the fuel injection valve according to any one of the first to fourth aspects.
The elastic metal sealing material 80 is disposed at the tip of the third cylinder head shaft hole 81. The invention according to claim 6, wherein the fuel supply rail 33 is fixed to the cylinder head 8 according to claims 1 to 5. The position of the bolt 66 is set close to the fuel injection valve 13.
9. The mounting stay 53 extending between the cylinder body and the V bank is fixed, and the pump drive unit 40 is fixed to the mounting stay and the cylinder body by bolts 54, 55, 56. The invention of
In Claims 1 to 7, the high-pressure fuel pump 32 includes:
A fuel supply / discharge unit 60 in which a fuel outlet pipe 60a, a fuel inlet pipe 60b, and an overflow pipe 60c are integrated is connected. The invention according to claim 9 is the invention according to claims 1 to 8, wherein A two-stroke engine, wherein the pump drive unit 40 includes a crankshaft 10
The invention according to claim 10 is characterized in that in claim 1 to 8, the engine is a four-cycle engine, and the pump drive unit 40 is driven by a crankshaft 10. I do. In addition,
The numbers added to the above configuration are compared with the drawings to facilitate understanding of the present invention, and the present invention is not limited thereto.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view of an outboard motor showing one embodiment of an in-cylinder fuel injection engine of the present invention,
Figure (A) is a plan view of the engine, and Figure (B) is B in Figure (A).
FIG. 3C is a longitudinal sectional view taken along the line B, FIG. 3C is a side view of the outboard motor, and FIG. 3D is a configuration diagram of a fuel supply system.

In FIG. 1, reference numeral 1 denotes an outboard motor, an engine 2 having a crankshaft 10 mounted vertically, a guide exhaust portion 3 connected to a lower end surface of the engine 2 and supporting the engine 2, and a guide An upper case 4, a lower case 5, and a propeller 6 connected to the lower end surface of the exhaust unit 3. The engine 2 is an in-cylinder injection V-type six-cylinder two-stroke engine, in which six cylinders 7a to 7f are horizontally arranged and vertically arranged in two rows so as to form a V bank in plan view. A cylinder head 8 is connected and fixed to the cylinder body 7.

A piston 11 is provided in each of the cylinders 7a to 7f.
Are slidably fitted, and each piston 11 is connected to the crankshaft 10. A solenoid opening / closing type fuel injection valve 13 and an ignition plug 14 which are opened and closed by magnetic force are inserted into the cylinder head 8. Cylinders 7a to 7
f is connected to the crank chamber 12 by scavenging ports (not shown), and an exhaust port 15 is connected to the cylinders 7a to 7f. In FIG. 1B, the exhaust port 15 of the left bank joins the left collective exhaust passage 16 and the exhaust port 15 of the right bank joins the right collective exhaust passage 17. An intake passage 19 branching from an intake manifold is connected to the crank chamber 12 of the engine 2.
A reed valve 20 for preventing backflow is provided at a connection portion of the reed valve 20 to the crank chamber 12.
Oil pump 21 for supplying oil to the engine
And a throttle valve 22 for adjusting the amount of intake air.

As shown in FIG. 1 (D), the fuel in a fuel tank 23 installed on the hull side is passed through a filter 26 by a manually operated first low-pressure fuel pump 25 to a second fuel tank 23 on the outboard motor side. To the low-pressure fuel pump 27. The second low-pressure fuel pump 27 is a diaphragm pump driven by a pulse pressure of the crank chamber 12 of the engine 2, and supplies fuel to a vapor separator tank 29 serving as a gas-liquid separation device.
Send to A fuel precompression pump 30 driven by an electric motor is provided in the vapor separator tank 29, and pressurizes the fuel and sends it to a high pressure fuel pump 32 via a precompression pipe 31. The discharge side of the high-pressure fuel pump 32 is connected to each cylinder 7
fuel supply rails 3 arranged longitudinally along a to 7f
3 and connected to a vapor separator tank 29 via a high-pressure regulating valve 35, a fuel cooler 36, and a return pipe 37. A preload pressure adjusting valve 3 is provided between the preload pipe 31 and the vapor separator tank 29.
9 are provided.

The high-pressure fuel pump 32 is driven by a pump drive unit 40. This pump drive unit 40
Is connected to the crankshaft 10 via a belt 41. The fuel in the vapor separator tank 29 is pre-pressed by a fuel pre-compression pump 30 to, for example, about 3 to 10 kg / cm ² , and the pressurized fuel is added by a high-pressure fuel pump 32 to about 50 to 100 kg / cm ² or more. As for the high-pressure fuel that has been pressurized and pressurized, surplus fuel exceeding a set pressure by a pressure regulating valve 35 is removed from the vapor separator tank 29.
And supplies only the necessary high-pressure fuel to the fuel supply rail 33.
And the fuel injection valve 13 attached to each of the cylinders 7a to 7f
To supply it.

An ECU (electronic control unit) 42 receives detection signals from various sensors indicating the driving state of the engine 2 and the state of the outboard motor 1 and the boat. For example, the crankshaft 10
Engine speed sensor 4 for detecting the rotation angle (rotation speed) of the engine
3. Intake air temperature sensor 4 for detecting the temperature in the intake passage 19
4. A throttle opening sensor 45 for detecting the opening of the throttle valve 22, an air-fuel ratio sensor 46 for detecting the air-fuel ratio in the uppermost cylinder 7d, a fuel pressure sensor 47 for detecting the pressure in the high-pressure fuel pipe, and an engine. A cooling water temperature sensor 48 for detecting the temperature of the cooling water is provided. The ECU 42
The detection signals of these sensors are subjected to arithmetic processing based on the control map, and the control signals are transmitted to the fuel injection valve 13, the spark plug 14, the oil pump 21, and the preload fuel pump 30.

FIG. 2 is a plan view of the engine 2 of FIG. The same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted. A drive pulley 50 is provided on the crankshaft 10, a driven pulley 52 is provided on a rotation shaft 51 of the pump drive unit 40, and a belt 41 is stretched between the drive pulley 50 and the driven pulley 52. I have. As a result, the rotation of the crankshaft 10 is
1 to drive the high-pressure fuel pump 32.

A mounting stay 53 is fixed to the cylinder body 7, and the pump driving unit 40 is connected to the mounting stay 5.
3 and three bolts 54, 55, 5 on the cylinder body 7.
6 attached. Also, the fuel supply rail 3
3 has a horizontal rail 33a and a vertical rail 33b connected to both sides of the horizontal rail 33a, and the fuel injection valve 13 is mounted on the vertical rail 33b. The high-pressure fuel pump 32 has a fuel supply / discharge unit 60 and a fuel outlet pipe 60.
a is connected to the horizontal rail 33 a of the fuel supply rail 33. In the drawing, 1a is a cowling that covers the engine 2, 57 is a starter motor, 58 is a tension pulley,
59 is a silencer.

FIG. 3 is a partial sectional view seen from the Y direction in FIG. FIG. 3 shows a state in which the pump drive unit 40 is mounted by the bolt 54 via the mounting stay 53 as described with reference to FIG. A cam 40 a is fixed to the rotating shaft 51 of the pump drive unit 40, and the cam 40 a is a plunger 32 of the high-pressure fuel pump 32.
It is configured to generate high-pressure fuel by pressing a.

The high-pressure fuel pump 32 is attached to the pump drive unit 40 by four bolts 61. This bolt connection allows the bolt hole on the side of the pump drive unit 40 to be slightly larger than the diameter of the bolt 61 to provide play, and when the high-pressure fuel pump 32 and the pump drive unit 40 are mounted, it allows some play between them. ing.

The engine 2 has a plurality of cylinders 7a to 7f arranged in two rows so as to form a V bank. A fuel supply rail 33 has a vertical rail 33b fixed to the cylinder head 8 in each row and a vertical rail 33b. A horizontal rail 33a is connected to the upper end of the rail 33b. The horizontal rail 33a and the vertical rail 33b are connected by bolts 62. The fuel passage 6 is provided inside the horizontal rail 33a and the vertical rail 33b.
3 is formed, and a connector 65 sealed with an O-ring 64 is provided at a connection portion between the two. The two vertical rails 33b are fixed to the cylinder head 8 by bolts 66, respectively, and the fuel injection valve 13 is fixed to the vertical rail 33b by bolts 67. This bolt 67
Is set to be close to the fuel injection valve 13.

The fuel supply / discharge unit 60 includes a fuel outlet pipe 60.
a, a fuel inlet pipe 60b, and an overflow pipe 60c.
Are connected to the fuel passage 63 of the horizontal rail 33a by a connector 70 sealed with an O-ring 69. The overflow pipe 60c is connected to the vapor separator tank 29. In addition, the high pressure regulating valve 35
Is connected to the pump drive unit 40 by bolts 68 (FIG. 4).
And a connector 72 sealed with an O-ring 71
Is connected to the fuel passage 63 of the horizontal rail 33a.

FIG. 4 is a partial cross-sectional view as viewed from the X direction in FIG. 3, FIG. 5A is a cross-sectional view as viewed in the direction of the arrow along the line AA in FIG. 4, and FIG. FIG. 5 is a cross-sectional view taken along the line BB in FIG. FIG. 4 shows the details of the mounting structure of the pump drive unit 40 using the mounting stay 53 and the mounting structure of the fuel supply rail 33 and the fuel injection valve 13. The mounting stay 53 is fixed to two bosses 73 formed on the cylinder body 7 by bolts 74. The pump drive unit 40 is attached to the attachment stay 53 by bolts 54 and 55, and further,
Boss 82 of cylinder body 7 with bolt 56 (FIG. 6)
, And the pump drive unit 40 and the high-pressure fuel pump 32 are fixed to the cylinder body 7 at three points. By using the mounting stay 53 in this manner, the pump drive unit 40 and the high-pressure fuel pump 32 can be mounted so as to overhang between the V banks of the cylinder body 7.

The vertical rail 33b of the fuel supply rail 33
Is fixed to a boss 75 formed on the cylinder head 8 by bolts 66, and a horseshoe-shaped spacer 76 is disposed between the flange 13a formed on the fuel injection valve 13 and the vertical rail 33b. Vertical rail 3
The fuel injection valve 13 is fixed to the vertical rail 33b by fixing 3b with a bolt 67. An O-ring 78 is provided on the fuel passage 63 side of the fuel injection valve 13, and on the combustion chamber 79 side of a shaft hole 81 of the cylinder head 8,
An elastic metal seal 80 made of a disc spring is provided. The shaft hole 81 of the cylinder head 8 is made slightly larger than the outer diameter of the fuel injection valve 13, and allows a slight play between the two when the fuel injection valve 13 is mounted.

FIG. 6 shows an exploded perspective view of FIGS. 2 to 5, wherein the pump drive unit 40, the high-pressure fuel pump 32, the high-pressure pressure regulating valve 35, the fuel supply rail 33 and the fuel injection valve 13 are provided in the present invention. The related high-pressure fuel injection unit 90 is shown. The engine 2 of the high-pressure fuel injection unit 90
The method of attaching the cable to the vehicle will be described with reference to FIGS.

First, the mounting stay 53 is fixed to the cylinder body 7 with a bolt 74. Next, the horizontal rail 33a and the vertical rail 33b of the fuel supply rail 33 are connected, the fuel injection valve 13 is mounted on the vertical rail 33b, and the pump drive unit 40, the high-pressure fuel pump 32,
4 and the high-pressure regulating valve 35 are mounted, and the fuel outlet pipe 60a of the fuel supply / discharge unit 60 and the high-pressure regulating valve 35 are connected to the horizontal rail 33a by connectors 70 and 72, respectively. After assembling the high-pressure fuel injection unit 90 in this manner, the fuel injection valve 13 is connected to the shaft hole 81 of the cylinder head 8.
After the vertical rail 33b is temporarily fixed to the cylinder head 8 by the bolt 67, the pump drive unit 40 is mounted on the cylinder body 7 and the mounting stay 53, and temporarily fixed to the cylinder body 7 by the bolts 54, 55, 56. I do.

The play between the pump drive unit 40 and the bolts 61 and the bolt holes of the high-pressure fuel pumps 32 and 34 and the play between the fuel injection valve 13 and the shaft hole 81 of the cylinder head 8 make each of the high-pressure fuel injection units The bolts 61 and 67 are fully tightened while adjusting the tolerance of the members. At this time, the elastic metal seal member 80 disposed on the outer periphery of the nozzle 13 b is pressed and contracted by the full tightening of the bolt 67, thereby causing the fuel injection valve 13 to oppose the combustion pressure and causing the combustion gas to leak from the shaft hole 81. Has been prevented.

FIG. 7 shows another embodiment of the present invention.
It is a top view of the outboard motor applied to the cycle engine. Also in the present embodiment, the pump drive unit 40 is disposed at the center of the engine 2, and the high-pressure fuel pumps 32 and 34 are disposed on both sides of the pump drive unit 40. In the figure, 7 is a cylinder body, 8 is a cylinder head, 10 is a crankshaft, 13 is a fuel injection valve, 19 is an intake pipe, 29 is a vapor separator tank, 33 is a fuel supply rail, 9
8 is an intake valve and 99 is a camshaft.

Although the embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications can be made. For example, in the above embodiment, an example in which the invention is applied to an outboard motor is described. However, the invention is also applied to a marine engine in which an engine is installed on the hull side, or a mobile engine such as a lawnmower or a stationary engine. It is possible.

[0027]

As apparent from the above description, according to the first and second aspects of the present invention, the high-pressure fuel injection unit is integrated to increase its rigidity, and the integration tolerance is increased when the unit is assembled to the engine. It is possible to improve the assemblability by making it absorbable.

According to the third aspect of the present invention, the connection between the high-pressure fuel pump and the high-pressure regulating valve and the fuel supply rail can be easily performed, and the conventional flexible piping and metal pipe piping can be solved in terms of strength. Can be
In particular, the present invention is effective for an outboard motor or the like having large vibrations. According to the fourth aspect of the present invention, it is possible to supply fuel with a simple configuration to an engine in which a plurality of cylinders are arranged in two rows so as to form a V bank. According to the fifth aspect of the present invention, the fuel injection valve can be made to oppose the combustion pressure, and the combustion gas can be prevented from leaking from the shaft hole. According to the seventh aspect of the present invention, the supply rail can be firmly fixed to the cylinder head, and the high-pressure fuel pump, the pump drive unit and the high-pressure regulating valve, which are heavy, can be compactly mounted between the engine V banks. It can be stored and the weight balance can be optimized.

According to the eighth aspect of the present invention, the piping structure can be simplified and the cost can be reduced. According to the ninth aspect of the present invention, the invention can be effectively applied to a two-cycle engine having no camshaft. be able to.

According to the tenth aspect, the present invention can be effectively applied to a four-cycle engine.

[Brief description of the drawings]

FIG. 1 is a schematic view of an outboard motor showing one embodiment of an in-cylinder fuel injection engine according to the present invention, wherein FIG. 1 (A) is a plan view of the engine, and FIG. Longitudinal sectional view along line B,
FIG. (C) is a side view of the outboard motor, and FIG. (D) is a configuration diagram of the fuel supply system.

FIG. 2 is a plan view of the engine of FIG.

FIG. 3 is a partial cross-sectional view as viewed from a Y direction in FIG. 2;

FIG. 4 is a partial cross-sectional view as viewed from an X direction in FIG. 3;

5 (A) is a sectional view taken along the line AA of FIG. 4 in the direction of the arrow, and FIG. 5 (B) is a sectional view taken along the line BB of FIG. 4 in the direction of the arrow; FIG.

FIG. 6 is an exploded perspective view of FIGS. 2 to 4;

FIG. 7 is a plan view of an outboard motor applied to a four-stroke engine according to another embodiment of the present invention.

[Explanation of symbols]

 7 ... Cylinder body 8 ... Cylinder head 10 ... Crank shaft 13 ... Fuel injection valve 32 ... High pressure fuel pump 40 ... Pump drive unit 35 ... High pressure pressure regulating valve 33 ... Fuel supply rail 54,55,56,61,66,67, 74: bolt 60: fuel supply / discharge unit 80: elastic metal sealing material 81: cylinder head shaft hole

Claims (10)

[Claims] A pump drive unit fixed to a cylinder body, a high-pressure fuel pump, and a high-pressure regulating valve; a fuel supply rail fixed to a cylinder head and connected to the high-pressure fuel pump and the high-pressure regulating valve; A fuel injection valve fixed to a fuel supply rail and inserted into a shaft hole of a cylinder head, wherein a play is provided between the fuel injection valve and the cylinder head shaft hole. . 2. The in-cylinder fuel injection engine according to claim 1, wherein play is provided between a bolt and a bolt hole for attaching the high-pressure fuel pump to a pump drive unit. 3. A connector is provided at a connecting portion between the high-pressure fuel pump or the high-pressure regulating valve and the fuel supply rail, and an O-ring is provided on an outer peripheral portion of the connector and an outer peripheral portion of the fuel injection valve. The in-cylinder fuel injection engine according to claim 1 or 2, wherein: 4. The engine has a crankshaft arranged vertically and a plurality of cylinders arranged in two rows so as to form a V bank, and the fuel supply rail is fixed to a cylinder head in each row. The in-cylinder fuel injection engine according to any one of claims 1 to 3, comprising a vertical rail provided and a horizontal rail connected to an upper end of the vertical rail. 5. The in-cylinder fuel injection engine according to claim 1, wherein an elastic metal sealing material is provided at a tip of a cylinder head shaft hole of the fuel injection valve. 6. The in-cylinder fuel injection engine according to claim 1, wherein a bolt position for fixing the fuel supply rail to the cylinder head is close to a fuel injection valve. 7. A mounting stay extending from the cylinder body to the V-bank is fixed to the cylinder body, and a pump driving unit is fixed to the mounting stay and the cylinder body by bolts. Or 6
An in-cylinder fuel injection engine according to any one of the above. 8. A fuel supply / discharge unit in which a fuel outlet pipe, a fuel inlet pipe, and an overflow pipe are integrated, is connected to the high-pressure fuel pump. In-cylinder fuel injection engine. 9. The in-cylinder fuel injection engine according to claim 1, wherein the engine is a two-stroke engine, and the pump drive unit is driven by a crankshaft. 10. The in-cylinder fuel injection engine according to claim 1, wherein the engine is a four-stroke engine, and the pump drive unit is driven by a crankshaft.