JP3626332B2 - engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a so-called gasoline direct injection engine in which a plurality of camshafts are disposed between a cylinder head and a cylinder head cover, and an injector is disposed between the camshafts above the center of a combustion chamber. The present invention relates to an engine characterized by the arrangement and shape of piping for supplying fuel and a cylinder head cover.
[0002]
[Prior art]
In general, there are two types of engines: a system that draws fuel (fuel atomized by the carburetor) by negative pressure due to the lowering of the piston, and a fuel injection system that injects fuel using an injector. The latter fuel injection system is There are a method of injecting fuel into the intake port and a method of injecting fuel directly into the combustion chamber.
[0003]
This fuel injection system has attracted attention in terms of accurate fuel distribution to multiple cylinders and improved intake resistance, and is being developed and put to practical use.
[0004]
And the fuel injection system for gasoline engines, especially as the placement of the injector, the lower side of the intake port, which is easy to design and install, is mainstream, but the injector is placed at the upper center of the combustion chamber, For example, it is described in JP-A-9-137759.
[0005]
By disposing the injector above the center of the combustion chamber, fuel spray from the nozzle nozzle holes of the injector can be made uniform, and the mixing ratio of air and fuel can be made uniform.
[0006]
[Problems to be solved by the invention]
However, when the injector is arranged upright in the center of the combustion chamber, piping for supplying fuel to the injector becomes a problem in the following three points.
[0007]
(1) When the piping is arranged on the cylinder head cover, the fuel supply system must be cut off when the cylinder head cover is attached or detached for frequent adjustment or maintenance of valves and tappets.
[0008]
(2) When the piping is arranged under the cylinder head cover, it is necessary to remove the cylinder head cover during maintenance of the fuel supply system, and it is necessary to take oil measures (seal structure, etc.) for the injector / piping / electrical wiring.
[0009]
(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. Therefore, after the injector is fixed, it must be connected to the pipe. As a result, the distance between the fixed point of the injector and the pipe joint becomes long, it is difficult to ensure the reliability of the pipe joint at the fuel seal, and a flexible structure must be added to the pipe.
[0010]
The present invention has been made in view of such problems, and an object of the present invention is to provide an engine that can solve all the problems in the case where an injector is arranged upright in the center of a combustion chamber.
[0011]
[Means for Solving the Problems]
In the engine in which a plurality of camshafts are disposed between a cylinder head and a cylinder head cover, and an injector is disposed between the camshafts above the center of the combustion chamber, each cam provided on the cylinder head cover is provided. between the plurality of projecting portions extending along the axis, arranged fuel passage member for supplying fuel to the injector, at least the injector, the fuel passage member, the及beauty before Symbol fuel passage member A space of a portion corresponding to the combustion chamber in a space formed between the plurality of projecting portions, wherein the mounting portion for mounting to the engine and the plurality of projecting portions are arranged so as not to overlap each other on a planar projection. the facing surfaces of said plurality of projections so as to enlarge the can that is concave respectively formed at positions corresponding to the combustion chamber.
[0012]
As a result, the injector unit and the cylinder head cover do not interfere with each other, and maintenance of the injector unit, valves, tappets, etc. can be performed independently, and the injector stands upright in the center of the combustion chamber. All of the above-mentioned problems in the case of arranging them can be solved.
[0013]
And in the said structure, the attachment part to the engine of the said fuel path member connected to the said injector is arrange | positioned at least near one protrusion part among these several protrusion parts, and the said protrusion part near the said other protrusion part A space for attaching and detaching the injector is formed.
[0014]
In this case, a large space is created on one side (near the other protruding portion) of the fuel passage member, and it becomes easy to insert and remove a tool for fixing (tightening) the injector and to attach and detach the injector using the tool.
[0015]
As a result, when the injector is fixed / removed from the cylinder head cover or the cylinder head, the injector can be performed while the fuel passage member is connected to the injector, and the efficiency of the work can be realized.
[0016]
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 (near the other protrusion) of the fuel passage member, so that the injector can be easily fixed / removed.
[0017]
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 can be reduced, and the efficiency of engine assembly can be improved.
[0018]
In the above configuration, the head cover is integrated by connecting the plurality of projecting portions at one end portion in the cam shaft direction, and further the fuel driven from the cam shaft to the other end side in the cam shaft direction. A pump may be arranged.
[0019]
In this case, the number of parts can be reduced, the efficiency of the assembly work of the engine can be improved, and the fuel passage from the fuel pump to the fuel passage member can be shortened. Further, in the configuration described above, a fuel pump that is driven by a cam shaft on one of the plurality of projecting portions among the plurality of cam shafts is attached to one end of the cam shaft via the driving portion, and It is preferable that one protrusion is set to be lower than the other protrusion. A bolt fastening portion for attaching the fuel passage member to the engine together with the attachment portion is provided near the one protrusion portion, and a space formed by a recess portion provided in the one protrusion portion among the recess portions. You may make it the said bolt fastening part fit in.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment in which the engine according to the present invention is applied to an engine of a hybrid vehicle, for example (hereinafter simply referred to as an engine according to the embodiment) will be described with reference to FIGS. A hybrid vehicle V to which the engine according to the present embodiment is applied will be briefly described with reference to FIG.
[0021]
As shown in FIG. 1, this hybrid vehicle V generates an engine E (three cylinders) according to the present embodiment that generates a driving force by burning gasoline, and generates a driving force by electric power, while regenerating electric power. A motor generator M capable of rotating, a flywheel F for smooth rotation, and a transmission T for switching the driving force and transmitting it to the drive shaft 10.
[0022]
The motor generator M is driven and controlled by the motor drive circuit 12. The motor drive circuit 12 supplies / charges high-voltage power, for example, a first capacitor 13 made of a capacitor, and a downverter 14. Is connected to the second battery 15 for storing power.
[0023]
The hybrid vehicle V has a management control circuit 16, which controls a motor control circuit 17 that controls the motor generator M and the internal combustion engine E via the motor drive circuit 12. An engine control circuit 18 is connected.
[0024]
The engine according to the present embodiment has an oil pan 22, a cylinder block 24, a cylinder head 26, and a cylinder head cover 30 as shown in FIG. 2, and more specifically, as shown in FIG. A plurality of (for example, two) cam shafts 32 and 34 (intake valve driving cam shaft 32 and exhaust valve driving cam shaft 34: indicated by a two-dot chain line in FIG. 5) are disposed between the head 26 and the cylinder head cover 30. A so-called center injection type direct injection engine in which an injector 38 is disposed between the cam shafts 32 and 34 above the center of the combustion chamber 36 is provided.
[0025]
Here, the main part of the engine E according to the present embodiment will be described with reference to FIGS. 3 to 5. This engine E is a DOHC engine having 4 valves per cylinder, and its cylinder head 26 is located at the upper part. A space (accommodating space) 40 for accommodating each of the cam shafts 32 and 34 is formed, and a concave portion (hereinafter referred to as a combustion chamber for convenience) 36 for partitioning a pent roof type combustion chamber, for example, is formed on the lower surface. Three are formed corresponding to the cylinders.
[0026]
Further, the cylinder head 26 is formed with intake holes 42 and exhaust holes 44 that reach the respective combustion chambers 36 from the side surfaces thereof, and pipes 46 that respectively accommodate the injectors 38 from the respective combustion chambers 36 to the accommodation spaces 40. An injector holder 48 for holding in a substantially vertical direction is formed integrally with the cylinder head 26, and further, an ignition plug (not shown) extends from the side surface on the exhaust hole 44 side of the cylinder head 26 to the corresponding combustion chamber 36. Is formed integrally with the cylinder head 26. A threaded hole is formed in the lower inner wall of the pipe 46 so that the tip of the threaded injector 38 is screwed.
[0027]
The injector holder 48 has a cylindrical shape whose inner diameter is slightly smaller than the outer diameter of the pipe 46, and a hole 58 penetrating to the combustion chamber 36 is formed at the bottom thereof. A gasket for hermetically sealing the hole 58 is attached to the bottom of the holder 48. When the injector 38 is attached to the cylinder head 26, first, the pipe 46 is press-fitted and fixed in the injector holder 48, and then the injector 38 is inserted into the pipe 46. Further, the tip of the injector 38 (not shown) Is screwed into a screw hole (not shown) provided in the lower inner wall of the pipe 46. When removing, the reverse operation is performed.
[0028]
The attachment / detachment work of the injector 38 can be performed, for example, by screwing, for example, a hexagon bolt portion 62 (see FIG. 4) formed on the upper portion of the injector 38 using a dedicated tool 64.
[0029]
The injector 38 generates a magnetic force through the solenoid coil by supplying a current to the solenoid coil through the electrical terminal 70, and the plunger is pulled toward the rear of the injector 38 by the magnetic force, thereby ejecting fuel from the injection nozzle 76. It is a mechanism to let you.
[0030]
As shown in FIGS. 3 and 4, a fuel passage member 80 for supplying fuel to each injector 38 is piped on the upper portion of the injector 38 attached to each combustion chamber 36. The fuel passage member 80 is constituted by a substantially straight pipe, and at one end thereof, a supply hole 84 to which high-pressure fuel (hereinafter simply referred to as high-pressure fuel) delivered from the high-pressure pump 82 is supplied, and a fuel passage. A discharge hole 86 through which excess fuel (low pressure) that has passed through the member 80 is led out is provided. The driving portion of the high pressure pump 82 is attached to one end of the exhaust valve driving camshaft 34 on the rear side, and the exhaust valve driving camshaft 34 is rotated by a timing belt, whereby the high pressure pump 82 is driven and its fuel is supplied. High pressure fuel is sent out from the lead-out part 88.
[0031]
Thus, the high-pressure pump 82 is attached to the rear camshaft (exhaust valve drive camshaft) 34, which is advantageous for lowering 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 support rigidity is increased. ing.
[0032]
The fuel passage member 80 is formed with three communication passages (not shown) for supplying high pressure fuel to the injector 38 at the lower portion thereof, and the fuel passage member 80 is connected to the engine as shown in FIG. Attachment portions 90 for attachment to E (exactly, a cam holder 100 described later) are arranged at equal intervals.
[0033]
Accordingly, a bolt fastening portion 92 for fastening the mounting portion 90 and the cam holder with bolts is provided on the top of each injector 38, and further from a drive circuit (not shown) for supplying current to the injector 38. An extending cable (not shown) and a connector portion 94 for connecting to each electrical terminal 70 are provided.
[0034]
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, and further covers the cam holder 100. The cylinder head cover 30 is attached by, for example, bolt tightening. Oil seals are applied to the contact points between the cam holder 100 and the pipe 46 and the contact points between the cylinder head 26 and the cylinder head cover 30.
[0035]
In particular, the cylinder head cover 30 of the engine E according to the present embodiment includes two protrusions (front portions) extending in parallel along the two cam shafts 32 and 34, as shown in FIGS. The side protrusions 102 and the rear side protrusions 104) and the connecting portions 106 that partially connect the two protrusions 102 and 104 are integrally formed with a single member, and have a substantially U-shaped planar shape. The front projecting portion 102 and the rear projecting portion 104 are set so that the front projecting portion 102 is lowered. This is, for example, a bonnet line that can be lowered, and an injector 38 described later. This makes it possible to easily perform the work with the dedicated tool 64 for performing the attaching / detaching operation.
[0036]
Also, recesses 108 and 110 are formed at locations corresponding to the three combustion chambers 36 on the surfaces of the protrusions 102 and 104 facing each other, and a space formed between the protrusions 102 and 104. Of 112, the space of the part corresponding to each combustion chamber 36 is enlarged.
[0037]
The size of the space 112 (including the portion enlarged by the recesses 108 and 110) 112 formed between the protrusions 102 and 104 is determined by the fuel passage member 80 (including the mounting portion 90) and the fuel passage. The size includes a bolt fastening portion 92 for fastening the member 80 to the cam holder 100, and a connector portion 94 for electrically connecting a drive circuit (not shown) and the injector 38.
[0038]
That is, an injector unit INJ including three injectors 38, a fuel passage member 80 (including a mounting portion), three bolt fastening portions 92, and three connector portions 94 is included in the space 112, and the two protruding portions 102 are included. And 104 and the injector unit INJ are in a relationship such that they do not overlap each other on a planar projection.
[0039]
Bolt fastening portion 92 and the connector portion 94 of each injector 38 is provided on the rear side projection 104 toward the bolt fastening portion 92 in a space 112a formed in the recess 110 provided on the rear side in the projecting portion 104 And the connector part 94 is accommodated.
[0040]
Therefore, the space 112b near the front side protruding portion 102 of the fuel passage member 80 is in a wide open state, and the dedicated tool 64 for attaching and detaching the injector 38 to and from the injector holder 48 can be easily inserted. The screwing operation by 64 can be easily performed. Moreover, since the recess 108 for inserting the dedicated tool 64 is disposed at least in front of the vehicle V, the workability for attaching and detaching the injector 38 is improved.
[0041]
As shown in FIG. 5, the mounting position of the injector 38 is set slightly closer to the rear side protruding portion 104 than the center of the combustion chamber 36. Accordingly, a space 112b near the front protrusion 102 of the fuel passage member 80 is widened so that the screwing operation by the dedicated tool 64 can be easily performed.
[0042]
A six-point first head cover fastening portion 114 for fastening the cylinder head cover 30 to the cylinder head 26 with bolts is provided on the outer peripheral portion of the cylinder head cover 30 (the outer peripheral portion of each protrusion 102 and 104). The cylinder head cover 30 is provided with seven second head cover fastening portions 116 for fastening the cylinder head cover 30 to the cam holder 100 with bolts on the inner peripheral portion of the cylinder head cover 30 (inner peripheral portions of the protrusions 102 and 104). ing.
[0043]
Next, in the engine E according to the above embodiment, a procedure for attaching the injector 38 will be described.
[0044]
First, the two cam shafts 32 and 34 are assembled in the accommodation space 40 of the cylinder head 26, the pipe 46 is press-fitted into the injector holder 48, and then the cam holder 100 is put over the upper surface opening of the cylinder head 26. After that, it is fixed to the cylinder head 26 by bolting.
[0045]
Thereafter, after the cylinder head cover 30 is placed on the cylinder head 26 so as to cover the cam holder 100, the cylinder head cover 30 is fixed to the cylinder head 26 by bolting at the first head cover fastening portion 114, and The second head cover fastening portion 116 is fixed to the cam holder 100 by bolting.
[0046]
Next, after the three injectors 38 are inserted into the pipes 46, the hexagon bolt portion 62 of the injector 38 is screwed using a dedicated tool 64, and the tip end portion (not shown) of the injector 38 is removed. Screw into a screw hole (not shown) provided in the lower inner wall of the pipe 46. At this time, it is lightly screwed in and temporarily set.
[0047]
Next, the position of each injector 38 is aligned while attaching the fuel passage member 80 over the top of each injector 38, and the fuel passage member 80 is connected to the cam holder 100 via the bolt fastening portion 92 with a bolt . Then, at the stage where the mounting positions of the injectors 38 are aligned, the tips (not shown) of the injectors 38 are screwed on the lower inner wall of the pipe 46 by screwing the injectors 38 using the dedicated tool 64. Screw completely into the hole (not shown). That is, the main fixing is performed.
[0048]
Thereafter, a cable (not shown) extending from a drive circuit (not shown) and the electrical terminal 70 of the injector 38 are connected via the connector portion 94, whereby the mounting operation of the injector 38 is completed. In addition, when removing the injector 38, the operation | work contrary to the above-mentioned is performed.
[0049]
Thus, in the engine E according to the present embodiment, the fuel passage member 80 is piped between the two protrusions 102 and 104 constituting the cylinder head cover 30, and the injector unit INJ and the two protrusions are further connected. Since the portions 102 and 104 are arranged so as not to overlap with each other in the planar projection, the fuel passage member 80 and the cylinder head cover 30 do not interfere with each other and can be independently maintained. .
[0050]
In particular, in the present embodiment, since the bolt fastening portion 92 and the connector portion 94 are arranged near the rear side protruding portion 104, a large space 112b is created near the front side protruding portion 102, and the dedicated tool 64 The insertion / removal operation of the injector 38 using the dedicated tool 64 is facilitated. Thereby, when fixing / removing the injector 38 with respect to the cylinder head cover 30, it can carry out with the fuel path member 80 connected to the injector 38, and the efficiency of the attachment / detachment work of the injector 38 can be realized. .
[0051]
In the present embodiment, since the injector 38 is arranged offset toward the rear side protruding portion 104, a larger space 112b is formed near the front side protruding portion 102, thereby fixing / injecting the injector 38. Removal is very easy.
[0052]
Further, in the present embodiment, the front-side protruding portion 102 and the rear-side protruding portion 104 and the connecting portion 106 that partially connects the protruding portions 102 and 104 are integrally formed with a single member, thereby forming a cylinder. Since the head cover 30 is integrated with a single member, the number of parts can be reduced, and the efficiency of the assembly work of the engine E can be realized.
[0053]
The engine E according to the above-described embodiment, in particular, the cylinder head cover 30 has a substantially U-shaped plane, and the two protrusions 102 and 104 are integrated. The shape may be completely separated.
[0054]
Although the example applied to the engine E of the hybrid vehicle V has been described in the above embodiment, it can be easily applied to a normal 4-cylinder engine or a 6-cylinder engine.
[0055]
Of course, the engine according to the present invention is not limited to the above-described embodiment, and various configurations can be adopted without departing from the gist of the present invention.
[0056]
【The invention's effect】
As described above, according to the engine according to the present invention, a plurality of cam shafts are disposed between the cylinder head and the cylinder head cover, and an injector is disposed between the cam shafts and above the center of the combustion chamber. And a passage for supplying fuel to the injector is arranged between a plurality of protrusions extending along the cam shafts provided in the cylinder head cover.
[0057]
For this reason, the piping and the cylinder head cover do not interfere with each other, and maintenance can be performed independently of each other, and all problems in the case where the injector is arranged upright in the center of the combustion chamber can be solved. .
[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 an engine according to the present embodiment.
FIG. 3 is a perspective view showing a main part of the engine according to the present embodiment.
FIG. 4 is a plan view showing a main part of the engine according to the present embodiment.
FIG. 5 is a cross-sectional view showing a main part of the engine according to the present embodiment .
[Explanation of symbols]
V ... Hybrid vehicle E ... Engine 26 ... Cylinder head 30 ... Cylinder head covers 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 part 90 ... Mounting part 92 ... Bolt fastening part 94 ... Connector part 100 ... Cam holder 102 ... Front side protrusion part 104 ... Back side protrusion part 106 ... Connection Portions 108, 110 ... recesses 112, 112a, 112b ... space INJ ... injector unit

Claims (7)

In an engine in which a plurality of camshafts are disposed between a cylinder head and a cylinder head cover, and an injector is disposed between the camshafts above the center of the combustion chamber.
The cylinder head cover has a plurality of protrusions extending along each cam shaft,
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, a mounting portion for mounting the及beauty before Symbol fuel passage member to the engine and said plurality of protrusions are arranged so as not to overlap on a plane projection,
Of the spaces formed between the plurality of protrusions, the surfaces of the plurality of protrusions facing each other so as to expand the space of the portion corresponding to the combustion chamber are respectively located at locations corresponding to the combustion chamber. An engine having a recess . The engine according to claim 1.
Wherein among the plurality of protrusions, the one protruding portion near the attachment to the engine of the fuel passage member that is connected to at least said injector is arranged,
Engine and a space for attaching and detaching operation of the injector to the protrusion side of the other side is formed. The engine according to claim 2, wherein
The engine is characterized in that the injector is offset from the one projecting portion. The engine according to any one of claims 1 to 3,
The engine according to claim 1, wherein the head cover is integrated by connecting a plurality of protrusions at one end in the cam shaft direction. The engine according to any one of claims 1 to 3,
The head cover is integrated by connecting a plurality of protrusions at one end in the camshaft direction,
An engine characterized in that a fuel pump driven by the cam shaft is disposed on the other end side in the cam shaft direction. The engine according to claim 1.
Of the plurality of cam shafts, a fuel pump driven by a cam shaft on one projecting portion side of the plurality of projecting portions is attached to one end of the cam shaft via a driving portion,
An engine characterized in that the one protrusion is set to be lower than the other protrusion. The engine according to claim 6.
A bolt fastening portion for attaching the fuel passage member to the engine together with the attachment portion is provided near the one projecting portion,
The engine according to claim 1, wherein the bolt fastening portion is housed in a space formed by a recess provided in the one protruding portion among the recesses.

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