JPH1182159A - Engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attach/detach an injector unit and a cylinder head cover without a hindrance to each other so as to make independent maintenance possible. SOLUTION: In a center injection type direct injection engine E, two camshafts are arranged between a cylinder head and a cylinder head cover 30, and an injector 38 is arranged between the camshafts and above the center of a combustion chamber. A fuel passage member 80 for supplying fuel to the injector 38 is piped between a plurality of protruding parts 102, 104 extended along each camshaft provided at the cylinder head cover 30. A plurality of protruding parts 102, 104 and an injector unit INJ composed of at least the injector 38, the fuel passage member 80 and first and second connection parts 92, 94 are so arranged as not to overlap in plane projection.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a plurality of camshafts arranged between a cylinder head and a cylinder head cover.
A so-called gasoline direct injection engine in which an injector is arranged above the center of the combustion chamber between these camshafts,
In particular, the present invention relates to an engine characterized by the arrangement and shape of a pipe for supplying fuel to an injector and a cylinder head cover.

[0002]

2. Description of the Related Art In general, there are two types of engines: a system in which fuel (fuel atomized by a carburetor) is induced by negative pressure due to a downward movement of a piston, and a fuel injection system in which fuel is injected by an injector. The injection method includes a method of injecting fuel into an intake port and a method of directly injecting fuel into a combustion chamber.

The fuel injection system has attracted attention in terms of accurate distribution of fuel to multiple cylinders and improvement of intake resistance, and has been developed and put into practical use.

[0004] A fuel injection system for a gasoline engine, in particular, an injector is mainly disposed below an intake port, which is easy to design and install, but the injector is disposed above the center of the combustion chamber. This is described, for example, in JP-A-9-137759.

By arranging the injector above the center of the combustion chamber, the fuel spray from each injection hole of the injector nozzle can be made uniform, and the mixing ratio of air and fuel can be made uniform.

[0006]

However, when the injector is arranged upright in the center of the combustion chamber, the piping for supplying fuel to the injector has the following three problems.

(1) When the pipe is arranged on the cylinder head cover, when the cylinder head cover is attached and detached for frequently adjusting valves and tappets and performing maintenance, etc.
The fuel supply system must be turned off.

(2) If the piping is arranged below the cylinder head cover, it becomes necessary to remove the cylinder head cover during maintenance of the fuel supply system, and it is necessary to take measures against oil (such as a seal structure) for the injector / pipe / electrical wiring. .

(3) At the time of fastening work for fixing the injector to the cylinder head, if the pipe is above, the work cannot be performed, so that the connection with the pipe must be made after the injector is fixed. As a result, the distance between the fixed point of the injector and the pipe connection point becomes long, it is difficult to ensure the reliability of the fuel seal at the pipe connection part, and a flexible structure must be added to the pipe.

The present invention has been made in consideration of such problems, and has as its object to provide an engine capable of solving all of the above-mentioned problems when an injector is arranged upright in the center of a combustion chamber.

[0011]

According to the present invention, there is provided an engine having a plurality of camshafts arranged between a cylinder head and a cylinder head cover, and an injector arranged above the center of a combustion chamber between the camshafts. A fuel passage member for supplying fuel to the injector is disposed between a plurality of protrusions extending along each cam shaft provided on the cylinder head cover, and at least the injector and the fuel passage member In addition, an injector portion, which is a connecting portion between the injector and the fuel passage member, and the plurality of protruding portions are arranged so as not to overlap on a plane projection.

Thus, the injector section and the cylinder head cover do not hinder each other in attachment and detachment, and maintenance of the injector section and the valve / tappet can be performed independently of each other. All of the above-mentioned problems in the case of disposing vertically can be solved.

[0013] In the above structure, at least one of the plurality of protruding portions is provided with an attachment portion of the fuel passage member connected to the injector to the engine near the one protruding portion, and the other protruding portion is provided. A space is formed nearer to allow the injector to be attached and detached.

In this case, a large space is created on one side of the fuel passage member (closer to the other protruding portion), so that a tool for fixing (tightening) the injector can be easily inserted and removed, and the injector can be easily attached and detached using the tool. become.

As a result, when the injector is fixed / removed from / to the cylinder head cover or the cylinder head, the operation can be performed while the fuel passage member is connected to the injector, and the work efficiency can be improved.

Further, in the above configuration, the injector may be offsetly arranged near the one protruding portion. As a result, a larger space is formed on one side of the fuel passage member (closer to the other protruding portion), so that the injector can be easily fixed / removed.

Further, in the above configuration, the head cover may be integrated by connecting the plurality of protrusions at one end in the cam shaft direction. In this case, the number of parts is reduced, and the efficiency of engine assembly work can be increased.

In the above structure, the head cover is integrated by connecting the plurality of protrusions at one end in the cam shaft direction, and further driven by the cam shaft at the other end side in the cam shaft direction. May be arranged.

In this case, the number of parts can be reduced.
The efficiency of the engine assembly operation can be improved, and the fuel passage from the fuel pump to the fuel passage member can be shortened.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which an engine according to the present invention is applied to, for example, an engine of a hybrid vehicle (hereinafter simply referred to as an engine according to the embodiment) will be described below with reference to FIGS. Prior to that, a hybrid vehicle V to which the engine according to the present embodiment is applied will be described.
Will be briefly described with reference to FIG.

As shown in FIG. 1, the hybrid vehicle V generates the driving force by burning gasoline, and the engine E (three cylinders) according to the present embodiment generates the driving force by electric power. It includes a motor generator M capable of regenerating electric power, a flywheel F for smooth rotation, and a transmission T for switching the driving force and transmitting the driving force to the drive shaft 10.

The motor generator M is driven and controlled by a motor drive circuit 12. The motor drive circuit 12 supplies / charges high-voltage power, for example, a first capacitor 13 comprising a capacitor, A second power storage device 15 that stores power via a downverter 14 is connected.

The hybrid vehicle V has a management control circuit 16. The management control circuit 16 includes a motor control circuit 17 for controlling the motor generator M via the motor drive circuit 12, and an internal combustion engine E. Is connected to an engine control circuit 18 for controlling

The engine according to the embodiment is
As shown in FIG. 2, the oil pan 22, the cylinder block 24, the cylinder head 26, and the cylinder head cover 3
5, more specifically, as shown in FIG. 5, a plurality of (for example, two) camshafts 32 and 34 (an intake valve driving camshaft 32 and an exhaust valve) are provided between the cylinder head 26 and the cylinder head cover 30. A driving camshaft 34: shown by a two-dot chain line in FIG. 5) is arranged, and an injector 38 is arranged above the center of the combustion chamber 36 between these camshafts 32 and 34, that is, a so-called center injection type direct injection. It has an engine configuration.

Here, the main part of the engine E according to the present embodiment will be described with reference to FIGS. 3 to 5. The engine E is a DOHC engine having four valves per cylinder, and its cylinder head 26 is A space (accommodating space) 40 for accommodating each of the camshafts 32 and 34 is formed in an upper portion, and a concave portion for defining a pent roof type combustion chamber (hereinafter, referred to as a combustion chamber for convenience) is formed on a lower surface. 36 are formed corresponding to the respective cylinders.

The cylinder head 26 is formed with an intake hole 42 and an exhaust hole 44 reaching the combustion chambers 36 from the side surfaces thereof.
, An injector holder 48 for holding the pipe 46 in which the injector 38 is accommodated in a substantially vertical direction is formed integrally with the cylinder head 26, and further corresponds to each side of the cylinder head 26 from the side of each exhaust hole 44. An ignition plug holder 52 that houses and holds an ignition plug (not shown) is formed integrally with the cylinder head 26 over the combustion chamber 36. A threaded hole is formed in the lower inner wall of the pipe 46 so that the tip end of the threaded injector 38 is screwed.

The injector holder 48 has a cylindrical shape whose inside diameter is slightly smaller than the outside diameter of the pipe 46, and has a hole 58 penetrating to the combustion chamber 36 at the bottom thereof. The hole 58 is provided at the bottom of the holder 48.
A gasket for hermetic sealing is attached. When the injector 38 is mounted on the cylinder head 26, first, the pipe 46 is press-fitted into the injector holder 48 and fixed, and then the injector 38 is inserted into the pipe 46, and further, the tip of the injector 38 (shown in FIG. ) Is screwed into a screw hole (not shown) provided in the lower inner wall of the pipe 46. When detaching, the reverse operation is performed.

The attachment / detachment work of the injector 38 can be performed, for example, by screwing a portion 62 (see FIG. 4) of, for example, a hexagon bolt formed on the upper portion of the injector 38 using a special tool 64.

The injector 38 supplies a current to the solenoid coil through the electric terminal 70 to generate a magnetic force through the solenoid coil, and pulls the plunger rearward of the injector 38 by the magnetic force. It is designed to eject fuel.

As shown in FIGS. 3 and 4, a fuel passage member 80 for supplying fuel to each injector 38 is provided above the injector 38 attached to each combustion chamber 36. I have. This fuel passage member 80
Is constituted by a substantially straight pipe, and at one end thereof, a supply hole 84 through which high-pressure fuel (hereinafter, simply referred to as high-pressure fuel) supplied from a high-pressure pump 82 is supplied, and a fuel passage member 80. Exhaust hole 8 from which excess fuel (low pressure) is led out
6 are provided. The high-pressure pump 82 has a drive unit attached to one end of the exhaust valve drive cam shaft 34 on the rear side,
The high pressure pump 82 is driven by the rotation of the cam shaft 34 for driving the exhaust valve by the timing belt, and the high pressure fuel is delivered from the fuel outlet 88.

As described above, since the high-pressure pump 82 is attached to the rear camshaft (exhaust valve driving camshaft) 34, it is advantageous to lower the bonnet line. Although not shown, the high-pressure pump 82 is fixed to the cylinder head 26 at two points provided below and is fixed to the cam holder 100 at two points provided above, so that the supporting rigidity is high. ing.

The fuel passage member 80 has three communication passages (not shown) formed at its lower portion for supplying high-pressure fuel to the injectors 38, respectively. As shown in FIG. A mounting portion 90 for mounting 80 to the engine E (more precisely, a cam holder 100 described later)
Are arranged at equal intervals.

Therefore, at the top of each injector 38,
A bolt fastening portion 92 for fastening the mounting portion 90 and the cam holder with bolts is provided. Further, a cable (not shown) extending from a drive circuit (not shown) for supplying a current to the injector 38 and each electric A connector 94 for connecting to the terminal 70 is provided.

As shown in FIG. 5, a cam holder 100 for rotatably holding the cam shafts 32 and 34 is mounted on the cylinder head 26 by, for example, bolting. , The cylinder head cover 30 is attached by, for example, bolting. An oil seal is applied to a contact between the cam holder 100 and the pipe 46 and a contact between the cylinder head 26 and the cylinder head cover 30.

In particular, the cylinder head cover 30 of the engine E according to the present embodiment, as shown in FIGS.
Two protruding portions (a front protruding portion 102 and a rear protruding portion 104) extending in parallel along the two camshafts 32 and 34, respectively, and partially connect the two protruding portions 102 and 104. The connecting portion 106 is integrally formed of one member, and has a substantially U-shaped planar shape. The front-side protruding portion 102 and the rear-side protruding portion 104 are set so that the front-side protruding portion 102 is lowered. This is, for example, such that the hood line can be lowered, and the injector 38 described later is used. The operation by the special tool 64 for attaching and detaching the can be easily performed.

On the surfaces of the projections 102 and 104 facing each other, recesses 108 and 110 are formed at locations corresponding to the three combustion chambers 36, respectively, and are formed between the projections 102 and 104. The space of the portion corresponding to each combustion chamber 36 in the space 112 thus expanded is enlarged.

The size of the space 112 (including the portion enlarged by the concave portions 108 and 110) 112 formed between the projecting portions 102 and 104 is determined by the fuel passage member 80 (including the mounting portion 90) and The fuel passage member 80 is connected to the cam holder 1
00, and a connector 94 for electrically connecting a drive circuit (not shown) to the injector 38.

That is, three injectors 38, a fuel passage member 80 (including a mounting portion), three bolt fastening portions 92,
An injector unit INJ including three connector portions 94 is included in the space 112, and the two protrusions 1
02 and 104 and the injector unit INJ do not overlap each other on a plane projection.

The first and second in each injector 38
The coupling portions 92 and 94 are provided near the rear-side protruding portion 104, and the concave portions 110 provided in the rear-side protruding portion 104.
The first and second coupling portions 92 and 94 are accommodated in a space 112a formed by.

Accordingly, the space 112b near the front-side protruding portion 102 of the fuel passage member 80 is widely opened, and the dedicated tool 64 for detachably operating the injector 38 with respect to the injector holder 48 can be easily inserted. ,
The screwing operation using the special tool 64 can be easily performed. In addition, since the concave portion 108 for inserting the special tool 64 is arranged at least in front of the vehicle V, the workability in attaching and detaching the injector 38 is improved.

Further, as shown in FIG.
The mounting position of 8 is set slightly closer to the rearward projecting portion 104 than the center of the combustion chamber 36. The space 112b near the front protrusion 102 of the fuel passage member 80 is correspondingly added.
The screwing operation by the dedicated tool 64 can be easily performed.

The outer peripheral portion of the cylinder head cover 30 (the outer peripheral portion of each of the protrusions 102 and 104) has six first head cover fastening portions 11 for fastening the cylinder head cover 30 to the cylinder head 26 with bolts.
4 are provided on the inner peripheral portion of the cylinder head cover 30 (the inner peripheral portions of the respective protruding portions 102 and 104). Seven points of second head cover fastening portions for fastening the cylinder head cover 30 to the cam holder 100 with bolts are provided. 116 are provided.

Next, a procedure for mounting the injector 38 in the engine E according to the embodiment will be described.

First, the housing space 40 of the cylinder head 26
, Two pipes 46 are press-fitted into the injector holder 48, and then the cam holder 1 is closed so as to close the upper opening of the cylinder head 26.
After being covered with 00, it is fixed to the cylinder head 26 by bolting.

Thereafter, the cylinder head cover 30 is placed on the cylinder head 26 so as to cover the cam holder 100.
After mounting the cylinder head cover 30, the first
Is fixed to the cylinder head 26 by bolting at the head cover fastening portion 114, and is fixed to the cam holder 100 by bolting at the second head cover fastening portion 116.

Next, after the three injectors 38 are inserted into the respective pipes 46, the hexagonal bolt portions 62 of the injectors 38 are screwed using a special tool 64, and the tip portions of the injectors 38 (shown in FIG. ) Is screwed into a screw hole (not shown) provided in the lower inner wall of the pipe 46. At this time, it is screwed gently to leave a temporary fixing state.

Next, the position of each injector 38 is adjusted while the fuel passage member 80 is attached over the upper part of each injector 38, and the branch passage 90 of the fuel passage member 80 and the injector 38 are connected to the first connecting portion 92. Connect through. Then, at the stage where the mounting positions of the injectors 38 are aligned, the injectors 38 are screwed using the special tool 64 so that the distal end (not shown) of the injector 38 is screwed on the lower inner wall of the pipe 46. Screw it completely into the hole (not shown). That is, the main fixing is performed.

Thereafter, a cable (not shown) extending from a drive circuit (not shown) and the electric terminal 7 of the injector 38 are provided.
0 is connected via the second coupling portion 94, the mounting operation of the injector 38 is completed. When the injector 38 is to be removed, the operation opposite to the above is performed.

As described above, in the engine E according to the present embodiment, the cylinder head cover 30
Between the two protrusions 102 and 104
And the injector unit INJ and the aforementioned 2
Since the two projections 102 and 104 are arranged so as not to overlap on a plane projection, the fuel passage member 80 and the cylinder head cover 30 do not hinder each other from being attached or detached, and maintenance can be performed independently of each other. Becomes

In particular, in the present embodiment, the first and second coupling portions 92 and 94 are located closer to the rear projection 104.
Is arranged, a large space 112b is created near the front-side protruding portion 102, so that the insertion / removal of the special tool 64 and the attachment / detachment work of the injector 38 using the special tool 64 become easy. Thereby, when fixing / removing the injector 38 with respect to the cylinder head cover 30,
This can be performed while the fuel passage member 80 is connected to the injector 38, and the efficiency of the attachment / detachment work of the injector 38 can be improved.

Further, in the present embodiment, the injector 38 is arranged to be offset toward the rear-side protruding portion 104, so that a larger space 112b is formed near the front-side protruding portion 102. Is very easy to fix / remove.

Further, in the present embodiment, the front-side protruding portion 102 and the rear-side protruding portion 104, and these protruding portions 1
The cylinder head cover 30 is integrally formed with one member by integrally forming the connecting portion 106 that partially connects the 02 and 104 with one member, so that the number of parts can be reduced. Thus, the efficiency of the assembly work of the engine E can be improved.

The engine E according to the above embodiment, in particular,
Although the cylinder head cover 30 has a configuration in which the two projections 102 and 104 are integrated into a substantially U-shaped plane, the two projections 102 and 104 may be completely separated.

In the above embodiment, the hybrid vehicle V
Although the example applied to the engine E is shown, it can be easily applied to a normal four-cylinder engine and a six-cylinder engine.

It should be noted that the engine according to the present invention is not limited to the above-described embodiment, but can adopt various configurations without departing from the gist of the present invention.

[0056]

As described above, according to the engine of the present invention, a plurality of camshafts are arranged between the cylinder head and the cylinder head cover.
In an engine in which an injector is disposed above the center of a combustion chamber, a passage for supplying fuel to the injector is provided between a plurality of protrusions extending along each cam shaft provided on the cylinder head cover. Is arranged.

For this reason, the pipe and the cylinder head cover do not hinder each other from being attached to or detached from each other, so that maintenance can be performed independently of each other, and all problems in the case where the injector is arranged upright at the center of the combustion chamber are eliminated. be able to.

[Brief description of the drawings]

FIG. 1 is a configuration diagram schematically showing a hybrid vehicle to which an engine according to an embodiment is applied.

FIG. 2 is a side view showing the engine according to the embodiment.

FIG. 3 is a perspective view showing a main part of the engine according to the embodiment.

FIG. 4 is a plan view showing a main part of the engine according to the embodiment.

FIG. 5 is a sectional view taken along line IV-IV in FIG. 3;

[Explanation of symbols]

V ... Hybrid vehicle E ... Engine 26 ... Cylinder head 30 ... Cylinder head cover 32,34 ... Cam shaft 36 ... Combustion chamber 38 ... Injector 42 ... Intake hole 44 ... Exhaust hole 46 ... Pipe 48 ... Injector holder 64 ... Dedicated tool 80 ... Fuel Passage member 82 High-pressure pump 84 Supply hole 86 Discharge hole 88 Fuel outlet section 90 Branch path 92 First connecting section 94 Second connecting section 100 Cam holder 102 Front protruding section 104 Rear side Projecting part 106 ... Connecting part 108, 110 ... Recess 112,11
2a, 112b ... space INJ ... injector unit

Claims (5)

[Claims] 1. An engine in which a plurality of camshafts are disposed between a cylinder head and a cylinder head cover, and an injector is disposed above the center of a combustion chamber between the camshafts. And a fuel passage member for supplying fuel to the injector is disposed between the plurality of protrusions. At least the injector, the fuel passage member, and An engine, wherein an injector portion, which is a connecting portion between the injector and the fuel passage member, and the plurality of protrusions are arranged so as not to overlap in plan projection. 2. The engine according to claim 1, wherein an attachment portion of the fuel passage member connected to the at least the injector to the engine is disposed near one of the plurality of projections. An engine, characterized in that a space for attaching and detaching the injector is formed near the other protrusion. 3. The engine according to claim 2, wherein said injector is offsetly arranged near said one protrusion. 4. The engine according to claim 1, wherein the head cover has a plurality of protrusions connected at one end in a cam shaft direction to be integrated. engine. 5. The engine according to claim 1, wherein the head cover has a plurality of protrusions connected at one end in a cam shaft direction to be integrated, and the head cover has an integral shape. An engine, wherein a fuel pump driven by the camshaft is disposed at the other end in the direction.