JPH0913975A - Internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the noises generated in an engine from being leaked to the outside by connecting one end of a suction auxiliary port to the other end of a suction port in a cam cap, and connecting an intake manifold to the other end of the suction auxiliary port. SOLUTION: Cam shafts 12, 13 are provided along the train direction of cylinders 6 on a cylinder head 3, and multiple bearings rotatably supporting the cam shafts 12, 13 are integrally formed. A cam cap 4 having a ladder frame shape and rotatably supporting the cam shafts 12, 13 is fixed, a suction auxiliary port 20 is formed in the cam cap 4, one end 20b of the suction auxiliary port 20 is connected to the other end 8a of a suction port 8, and an intake manifold 35 is connected to the other end 20a. The noises generated in an engine can be prevented from being leaked to the outside, the number of assembling man- hours is reduced, and the assembling accuracy can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine that ignites an air-fuel mixture in a combustion chamber and burns the air-fuel mixture, and more particularly to an intake device that generates a stratified swirl flow in the combustion chamber.

[0002]

2. Description of the Related Art A gasoline engine (hereinafter, simply referred to as an engine) is generally known as an internal combustion engine for performing an ignition process on an air-fuel mixture in a combustion chamber. In this engine, a piston is inserted into a cylinder, the intake valve is opened when the piston slides from the top dead center to the bottom dead center, air is introduced into the combustion chamber through an intake port, and a vertical vortex ( Tumble)
Generate a flow, drive the injector at a predetermined timing of the intake and compression processes to inject fuel into the combustion chamber, drive the spark plug at the end of the compression process to perform the combustion process, and then
In the exhaust process, exhaust gas is configured to be exhausted through an exhaust port by opening an exhaust valve when the piston moves up.

In order to improve the output of the above-mentioned engine, it is desirable to increase the volumetric efficiency at the time of intake and to exhaust as much exhaust gas as possible in the combustion chamber especially at the time of exhaust. For this reason, it is necessary to reduce the flow resistance of intake and exhaust and to generate a scavenging airflow having an excellent scavenging effect. Further, in order to realize the stratified lean burn in the aforementioned engine, it is necessary to collect the fuel spray as compactly as possible and collect the rich air-fuel mixture in the vicinity of the spark plug to ensure combustion stability.

Therefore, as disclosed in Japanese Unexamined Patent Publication No. 5-240044, there is an intake opening end that opens to the combustion chamber on one side with respect to the plane including the cylinder axis, and the intake opening end is located above. An extending intake port, an exhaust port having an exhaust opening end that opens to the combustion chamber on the other side with respect to the plane including the cylinder axis, and an injector arranged so that the injection port faces the combustion chamber in the vicinity of the intake port. , And guides air from the intake port into the combustion chamber during intake,
A reverse tumble flow engine has been proposed which produces a reverse tumble flow in a combustion chamber.

[0005]

In the above-described reverse tumble flow engine, the intake port is provided substantially along the cylinder axis, and the upstream end of the intake port is provided at the approximate center of the upper surface of the cylinder head along the cylinder row. It is open.
An intake manifold is connected to this opening, and the intake manifold is arranged above the cylinder head. The intake port and the intake manifold must be integrally connected, and the intake manifold is integrally fixed to the cylinder head cover, and the cylinder head cover is integrally fixed to the cylinder head.

However, since the cylinder head cover is fixed to the cylinder head by metal touch in the reverse tumble flow engine, noise such as driving noise and combustion noise of the intake / exhaust valve is generated outside the cylinder head cover. There is. Therefore, when the noise from the engine is large, the cylinder head cover must be elastically supported by the cylinder head to reduce the noise. When the cylinder head cover is elastically supported by the cylinder head, the intake manifold is fixed to the cylinder head cover elastically supported by the cylinder head, and the vibration of the intake manifold impairs the sealing performance of the elastically supported portion. Dots occur. Further, in order to reduce the vibration, it may be considered that the intake manifold, the cylinder block, the cylinder head and the like are fixed to each other by a reinforcing member, but there is a problem that the reinforcing member becomes large. Further, in a reverse tumble flow engine, when assembling the camshaft to the cylinder head with a plurality of camshaft bearings, it is difficult to make the clearances of the camshaft bearings uniform due to mounting errors and machining errors of the camshaft bearings. It was

Also, a DOHC (double overhead camshaft) type upright intake port engine, that is, extending in the cylinder row direction, the intake port opens on the upper surface of the cylinder head near the reference plane including the cylinder axis, and the intake port is sandwiched. In an engine with multiple camshafts, if the camshafts are fixed using independent cam caps, the cylinder head cover and the intake manifold must be installed separately on the top surface of the cylinder head. Since it is necessary to secure the sealing surface of the manifold on the upper surface of the cylinder head, there is a problem that the engine becomes large. In order to solve this problem, it is conceivable to increase the wall thickness of the cylinder head around the intake port opening where it is most difficult to secure the sealing surface. In this case, the thick portion of the cylinder head may interfere with the processing jig such as the valve spring mounting surface or the valve operating system, so it is necessary to increase the valve holding angle, which also causes an increase in engine size. Dots occur.

Therefore, the object of the present invention is to solve the above-mentioned problems, prevent the noise generated in the engine from leaking to the outside, reduce the assembly man-hours and improve the assembling accuracy. An object is to provide an internal combustion engine that can be downsized.

[0009]

According to a first aspect of the present invention, in an internal combustion engine having a cylinder row, a camshaft provided on an upper surface of a cylinder head along a cylinder row direction and each cylinder inside the cylinder head. An intake port, which is formed substantially along the axis, has one end open to one side of the combustion chamber with respect to the reference plane including each axis and the other end opens to the upper surface of the cylinder head, and rotatably supports the camshaft. A plurality of bearings that are integrally formed and that are respectively formed inside the cam cap and the cam cap that is placed on the upper surface of the cylinder head.One end is connected to the other end of the intake port, and the other end has an intake manifold. It is a configuration having an intake auxiliary port to be connected.

According to a second aspect of the invention, in the internal combustion engine according to the first aspect, there is provided a structure having a positioning means for positioning the cam cap with respect to the cylinder head.

According to a third aspect of the present invention, in the internal combustion engine according to the second aspect, the positioning means includes a plurality of engaging portions provided on either one of the cylinder head and the cam cap and the cylinder head or the cam cap. It is provided on either of the other ones, and is configured to include a plurality of engaged parts with which the engaging parts engage.

According to a fourth aspect of the present invention, in the internal combustion engine according to the first aspect, the second aspect or the third aspect, one cam shaft is arranged on each side of the reference plane, and each intake auxiliary port is provided for each cam. A hole is provided in each part of the cam cap that corresponds to the cam shaft except each bearing, and a rocker cover that covers each hole along each cam shaft is provided on the upper surface of the cam cap. It is a configuration provided.

According to a fifth aspect of the present invention, in the internal combustion engine according to the fourth aspect, the rocker cover is attached via an elastic supporting member.

The invention of claim 6 relates to claim 1, claim 2, and
The internal combustion engine according to claim 3, 4, or 5, wherein the intake manifold is provided on one side or the other side of the reference surface and extends along the surface of the rocker cover in a direction away from the reference surface. Is.

According to a seventh aspect of the present invention, in the internal combustion engine according to the fourth, fifth or sixth aspect, the mounting surface on which the rocker cover is mounted and the mounting surface on which the intake manifold is mounted are the upper surfaces of the cam caps. It is a structure formed in the same plane.

[0016] The invention of claim 8 is, claim 1, claim 2,
In the internal combustion engine according to claim 3, claim 4, claim 5, claim 6, or claim 7, a fuel injection valve that faces the interior of the combustion chamber and injects fuel directly into the interior, and the inner surface of the cylinder head. And a spark plug arranged in the.

[0017]

FIG. 1 shows an embodiment of the present invention. In FIG. 1, reference numeral 1 indicates an in-line 4-cylinder engine as an internal combustion engine. The engine 1 is of a double overhead cam type with four valves per cylinder, and is mainly configured by stacking a cylinder block 2, a cylinder head 3, and a cam cap 4 in this order on a crankcase (not shown) and integrating them. . Since the cylinders of the engine 1 have the same configuration, only the first cylinder will be described here.

Inside the crankcase are housed crankshafts and connecting rods (not shown) for converting the reciprocating motion of each piston 5 into a rotary motion. Inside the cylinder block 2, a cylinder 6 into which each piston 5 is inserted is formed. Inside the cylinder head 3, a pair of intake / exhaust ports 8 and 9 respectively communicating with the combustion chamber 7 formed on the lower surface thereof are formed, and a pair of poppet valves for opening / closing these intake / exhaust ports 8 and 9 are formed. The intake and exhaust valves 10 and 11 are respectively housed therein.

Cylinder block 2 of cylinder head 3
On the lower surface adjacent to the combustion chamber 7 adjacent to
A long wedge-shaped recess 12 is formed in a direction substantially parallel to a plane AA including all the cylinder axis lines A passing through the center of. The wedge-shaped concave portion 12 forms a part of the combustion chamber, and the tip of the wedge-shaped concave portion 12 is located substantially in the center of the combustion chamber 7. This wedge-shaped recess 1
2, an intake port 8 is provided on one side of the plane AA, and an exhaust port 9 is provided on the other side of the plane AA. Further, an ignition plug 15 is attached at a substantially central position of the wedge-shaped recess 12.

The intake port 8 is formed inside the cylinder head 3 so as to be bifurcated at an intermediate portion from the upstream side to the downstream side, and the upstream opening end 8a thereof is formed.
The downstream open ends 8b communicate with the combustion chamber 7 via the intake valves 10, respectively. The intake port 8 is formed in the cylinder head 3 so as to extend straight along the cylinder axis A in the vertical direction. On the other hand, the exhaust port 9 is formed in the inside of the cylinder head 3 so as to meet at an intermediate portion from the upstream side to the downstream side, and each upstream opening end 9 a thereof communicates with the combustion chamber 7 via the exhaust valve 11. , The downstream opening end 9b,
The side wall surface of the cylinder head 3 is opened. Further, the exhaust port 9 is formed by curving approximately 90 degrees in a direction away from the plane AA from each upstream opening end 9a and extending straight as it is.

An injector 16 for injecting a predetermined amount of fuel into the combustion chamber 7 at a predetermined time is provided at a portion outside the intake port 8 on one side of the plane AA of the cylinder head 3 near each downstream opening end 8b. Is provided. A high-pressure pump and a control device (not shown) are connected to the injector 16. In addition, a recess 5a is formed in the upper part of the piston 5 to promote formation of a reverse tumble flow during intake.

On the upper surface of the cylinder head 3, a camshaft 12 for driving a pair of intake / exhaust valves 10 and 11,
13 is provided, and the camshafts 12, 1 are further provided.
A cam cap 4 having a ladder frame shape that rotatably supports 3 is fixed by a bolt (not shown). As shown in FIG. 2, the cam cap 4 has a plurality of cams that support the intake auxiliary port 20 communicating with each upstream opening end 8a, the ignition plug attachment hole 21 for attaching the ignition plug 15, and the cam shafts 12 and 13. The shaft bearing portion 22 is formed.

The intake auxiliary ports 20 are provided at the positions corresponding to the upstream opening end 8a along the cylinder row on the partition wall formed in the substantially central portion of the cam cap 4.
Both side portions of the partition wall are integrally connected to an outer wall of the cam cap 4 in the lateral direction. In addition, the intake auxiliary port 2
0 is formed such that its downstream opening end 20b is connected to the upstream opening end 8a and extends straight upward from the downstream opening end 20b substantially along the cylinder axis A, and the upstream opening end 20a is formed on the upper surface of the cam cap 4. Is forming. The spark plug mounting holes 21 for mounting the spark plugs 15 are respectively provided in the partition of the intake auxiliary port 20 in the vicinity of each port 20.

On the upper surface side of the cylinder head 3, there is provided a semicircular camshaft bearing portion 3a. This bearing portion 3
a is the camshaft 1 along the camshafts 12 and 13.
They are arranged at positions corresponding to the lower half portions of the shaft portions 2 and 13, respectively. A semicircular camshaft bearing portion 22 is provided on the lower surface side of the cam cap 4 so as to connect the outer wall in the longitudinal direction of the cam cap 4 and the partition wall of the intake auxiliary port 20. The camshaft bearing portions 22 are arranged along the camshafts 12 and 13 at positions corresponding to the upper half portions of the shaft portions of the camshafts 12 and 13, respectively. Furthermore, the cam shafts 12, 1 of the cam cap 4
A hole 23 as a clearance hole for the cam is provided at a position corresponding to the upper portion of the cam of No. 3.

Further, as shown in FIG. 3, on the upper surface of the cylinder head 3, knock pins 25 as engaging portions for positioning the cam caps 4 are fixedly provided near both ends of the cylinder head 3 in the cylinder row direction. Has been done. An engaging hole 26 as an engaged portion with which the knock pin 25 is engaged is provided in a portion of the cam cap 4 corresponding to the knock pin 25. The knock pin 25 and the engagement hole 26 constitute a positioning means. Further, the cam cap 4 is formed by mold molding, and the intake auxiliary port 20, the spark plug mounting hole 21, the cam shaft bearing portion 22, the hole 23, etc. are formed during molding.

Next, the assembly process will be described. First,
The cam cap 4 is placed on the cylinder head 3, and the cam shaft bearing portion 22 is formed on the cylinder head 3 and the cam cap 4 by a processing device. After that, the cam cap 4 is once removed from the cylinder head 3, and the cam shafts 12 and 13 are attached to the cam shaft bearing portion 3a of the cylinder head 3.
Is placed. After confirming the placement of the cam shafts 12 and 13, the cam cap 4 is attached to the cylinder head 3 again.

In such a mounting method, a hole for mounting the cam shafts 12, 13 called a cam-in head is opened in the cylinder head 3, and the cam shafts 12, 13 are mounted in the mounting holes from the lateral direction of the cylinder head 3. The diameters of the shaft portions of the camshafts 12 and 13 can be reduced as compared with the assembling method in which they are respectively inserted and attached to the cylinder head 3, and the weight of the camshafts 12 and 13 can be reduced. In addition, the intake manifold 35 and the rocker cover 3
Since it is not necessary to secure the sealing surfaces of 0 and 31 on the upper surface of the cylinder head, it is not necessary to increase the wall thickness of the cylinder head around the opening portion of the intake port. Therefore, there is no risk that the machining jig such as the valve spring mounting surface or the valve operating system will interfere with the cylinder head, the valve holding angle can be reduced, and the engine can be downsized. Further, in this embodiment, the cam cap 4 is positioned with respect to the cylinder head 3 by engaging the knock pin 25 with the engagement hole 26, so that the cam shafts 12 and 13 and the cam shaft bearing portion 22.
The clearance between and can be made uniform. further,
Since the camshaft bearing portion 22 has a ladder frame shape, the camshaft bearing portions 22 can be firmly connected to each other, and the camshaft bearing portion 22 and the intake auxiliary port 20 are connected to each other with a partition wall, so that the cam is more firmly connected. The shaft bearing portion 22 can be connected.

In FIG. 1, the upper surface of the cam cap 4 is
The rocker covers 30 and 31 covering the holes 23 and the intake manifold 35 are fixed to the flat surface. That is, the rocker covers 30, 31 and the intake manifold 35 are mounted on the same plane.

The rocker covers 30 and 31 are arranged along the camshafts 12 and 13, respectively. Between the rocker covers 30 and 31 and the cam cap 4, a resin rubber 3 as an elastic support member for sealing the gap is provided.
2, the rocker covers 30 and 31 are floatingly supported by the cam cap 4 by the rubber 32, respectively. A height of the rocker cover 31 is limited by an intake manifold 35, and a PCV (positive crankcase ventilation) valve (not shown) for controlling a flow rate of blow-by gas entering the intake manifold 35, which will be described later, is provided in the PCV. Forming a chamber. The rocker cover 30 forms a breather chamber.

The intake manifold 35 is fixed to the cam cap 4 by a bolt (not shown) corresponding to the upstream opening end 20a of the intake auxiliary port 20. A gasket (not shown) is interposed between the intake manifold 35 and the cam cap 4. An engagement hole (not shown) with which the knock pin 25 engages is provided in the vicinity of the connection end of the intake manifold 35 with the cam cap 4 to facilitate the connection between the intake manifold 35 and the cam cap 4. . The intake manifold 35 extends straight from the vicinity of the connection with the intake auxiliary port 20 in a direction away from the plane AA along the upper surface of the rocker cover 31 and straightly extends to the end edge of the rocker cover 31. The rocker cover 31 is formed so as to incline below the rocker cover 31 after passing over. Also,
The intake manifold 35 is fixed to the cylinder block 2 via a stay 50.

Since the rocker covers 30 and 31 and the intake manifold 35 are mounted on the same plane of the upper surface of the cam cap 4, surface processing when machining these mounting surfaces becomes easy, and Rocker covers 30, 3
Since there is no step on the mounting surface of the intake manifold 35 and the intake manifold 35, a uniform sealing surface pressure can be secured, the sealing area and the gasket area are increased, and the sealing reliability and the gasket reliability are improved.

The intake air flowing from the intake manifold 35 into the combustion chamber 7 through the intake port 8 at the time of intake air is directed to the upper surface of the piston 5 along the cylinder axis A and makes a U-turn along the surface of the recess 5a. An inverse tumble flow (indicated by arrow B in FIG. 1) is generated. Further, when the compression of the piston 5 is completed, the fuel is sprayed into the combustion chamber 7 by the injector 16, and the sprayed fuel collides with the recess 5 a and is scattered toward the spark plug 15. At this time, ignition processing is performed by the ignition plug 15 and combustion is performed in the combustion chamber 7.

FIG. 4 shows the results of measurement of the idle noise at a position 0.3 m directly above the engine when the engine of the present invention and the conventional engine described above are used alone. In FIG. 4, the horizontal axis represents the center frequency (Hz) of the idle sound, and the vertical axis represents the sound pressure level (dB).
A) is shown respectively. Further, the characteristic of the engine of the present invention is shown by the C line (solid line), and the characteristic of the conventional engine is shown by the D line (dotted line).

As can be seen from the test results, in the present invention, the clearance of the camshaft bearing 22 is made uniform, the noise from the camshafts 12 and 13 is reduced, and the rocker covers 30 and 31 interpose the rubber 32. Since it is attached to the cam cap 4 as compared with the conventional engine, noise such as driving noise of the intake and exhaust valves and combustion noise is prevented from leaking to the outside as compared with the conventional engine. In particular, the noise insulation effect is remarkable when the center frequency exceeds 630 Hz. Further, since the intake manifold 35 is firmly attached to the cam cap 4 via the gasket, the intake manifold 35
It is also possible to reduce the vibration. Further, since the intake manifold 35 is firmly attached to the cylinder block 2 via the stay 50, vibration of the intake manifold 35 can be reduced. Further, since the intake manifold 35 is firmly attached to the cam cap 4, the stay 50 can be made smaller and lighter than a conventional stay.

Further, FIG. 5 shows the results of measurement of the idle noise when the engine of the present invention and the conventional engine described above are mounted on the vehicle body and the idle noise near the engine grill, respectively. In FIG. 5, the horizontal axis represents the idle sound volume range (kHz), and the vertical axis represents the sound quality range (kH).
z) are shown respectively. Further, the characteristic of the engine of the present invention is indicated by E (circle mark), and the characteristic of the conventional engine is indicated by F (triangle mark).

As can be seen from the test results, even when the engine is mounted on the vehicle body, the engine noise is prevented from leaking to the outside. The noise insulation effect can be confirmed even near the engine grill.

Next, a modification of the above-mentioned embodiment is shown in FIG. In the figure, the same members as those shown in FIG. 1 are denoted by the same reference numerals as those used in FIG. 1, and the description thereof will be omitted, and different points will be described. The main difference from the first embodiment is that the arrangement position of the intake manifold is different.

As shown in FIG. 6, the intake manifold 40 and the rocker covers 41, 42 are provided on the upper surface of the cam cap 4.
Are arranged respectively. The intake manifold 40 is
It is fixed by a bolt (not shown). The rocker covers 41 and 42 are attached via the rubber 32, respectively, and one rocker cover 41 forms a PCV chamber,
The other rocker cover 42 forms a breather chamber.

The end of the intake manifold 40 connected to the cam cap 4 is the upstream opening end 20 of the intake auxiliary port 20.
It is joined to a. The intake manifold 40 has a plane AA.
Regarding the side opposite to the exhaust port 9, the rocker cover 41
Along the upper surface of the rocker cover 41, it is curved approximately 90 degrees in a direction away from the plane AA, and extends straight as it is.

By disposing the intake manifold in this way, positional interference with the exhaust manifold connected to the exhaust port is prevented, and it becomes easy to secure a space for disposing the intake manifold and the exhaust manifold. In addition, the degree of freedom in setting the shapes and sizes of the intake manifold and the exhaust manifold is increased.

In the embodiment described above, the intake manifold 3
Although the stay 50 for fixing 5 is attached to the cylinder block 2, it may be attached to a member such as the cylinder head 3. The stay 50 may be used as needed and may not be provided depending on the shape and material of the intake manifold 35. Further, in the above-described embodiment, the series type engine in which a plurality of cylinders are arranged in series has been described, but the present invention is not limited to the series type engine and a V type in which a plurality of cylinders are arranged in a V type. It can also be applied to the engine. In this case, if the intake manifold is arranged between the banks formed by both cylinder rows and the surge tank portion of the intake manifold extending from both cylinder rows is integrated, the cams in which the intake manifolds are mounted on both cylinder rows are integrated. Since it is fixed to the cap, the vibration of the intake manifold can be further reduced. Since the vibration is reduced, the stay used for the intake manifold can be a smaller and lighter stay.

[0042]

As described above, according to the invention of claim 1, since the reverse tumble flow is generated in the combustion chamber by the intake air flowing from the intake port at the time of intake, the flow resistance to the intake air becomes low, It is possible to improve the intake efficiency into the combustion chamber and also improve the exhaust efficiency within the combustion chamber. The reverse tumble flow can also accelerate the burning speed of the fuel in the combustion chamber. Further, the work of mounting the bearing of the camshaft is improved, and the internal combustion engine (engine) can be downsized.

According to the invention of claim 2 or 3,
When the cam cap is positioned with respect to the cylinder head by the positioning means, all the bearings are positioned with respect to the cam shaft at once, so the knock pin provided for each bearing of the conventional cam shaft becomes unnecessary, The number of knock pins of the bearing is reduced to reduce the cost, and the work of mounting the bearing is improved.

According to the fourth aspect of the present invention, the camshaft bearings can be firmly connected and the camshaft bearings can be prevented from falling.

According to the fifth aspect of the present invention, since the engine noise is reduced by the elastic support member, it is possible to prevent the engine noise from being emitted into the vehicle interior or the outside. Also, even if the rocker cover vibrates due to engine noise, this vibration is absorbed by the elastic support member,
The durability of the seal between the cylinder head and the cam cap is improved.

According to the invention of claim 6, the internal combustion engine can be downsized, and in particular in the axial direction of the cylinder. Therefore, when the internal combustion engine is vertically arranged in the engine room, the intake manifold is installed. It can be stored easily without interfering with the hood.

According to the invention of claim 7, since the mounting surface of the rocker cover and the mounting surface of the intake manifold are formed in the same plane of the cam cap, the mounting surfaces of the rocker cover and the intake manifold can be easily processed. It can be carried out.

According to the invention of claim 8, the fuel injection valve for directly injecting the fuel into the combustion chamber faces the inside of the combustion chamber, and the spark plug is arranged on the inner surface of the cylinder head. The fuel can be injected only within a predetermined range of the tumble flow, and the fuel spray can be guided to the vicinity of the spark plug even if the entire mixture becomes lean.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a first cylinder of an internal combustion engine showing an embodiment of the present invention.

FIG. 2 is a plan view of a cam cap.

FIG. 3 is an exploded view of a cylinder head and a cam cap.

FIG. 4 is a characteristic diagram comparing the idle sounds of the internal combustion engine of the present invention and the conventional internal combustion engine when the engine is a single unit.

FIG. 5 is a diagram comparing idle sounds when the internal combustion engine of the present invention and a conventional internal combustion engine are mounted on a vehicle body.

FIG. 6 is a side sectional view of a first cylinder showing a modified example in which an intake manifold is disposed at a different position.

[Explanation of symbols]

 1 Engine as Internal Combustion Engine 2 Cylinder Block 3 Cylinder Head 4 Cam Cap 5 Piston 6 Cylinder 7 Combustion Chamber 8 Intake Port 9 Exhaust Port 12, 13 Camshaft 15 Spark Plug 16 Injector 20 Intake Aid Port 22 Camshaft Bearing 25 Engagement Part Knock pin 26 as an engaging hole as an engaged portion 30, 31, 41, 42 rocker cover 32 rubber as an elastic support member 35, 40 intake manifold A cylinder axis AA plane including cylinder axis

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display area F02F 1/24 F02F 1/24 RQ 1/42 1/42 F K 3/26 3/26 C 3/28 3/28 B (72) Inventor Takeo Kume 5-3-8, Shiba, Minato-ku, Tokyo, Mitsubishi Motors Corp. (72) Inventor, Keiya Igarashi 5-33-8, Shiba, Minato-ku, Tokyo No. ・ In Mitsubishi Motors Industry Co., Ltd. (72) Inventor Hiroaki Ochiai 5-3-8, Shiba, Minato-ku, Tokyo ・ In Mitsubishi Motors Co., Ltd.

Claims (8)

[Claims] 1. In an internal combustion engine having a cylinder row, a cam shaft is provided on an upper surface of a cylinder head along the cylinder row direction, and is formed inside the cylinder head so as to be substantially along the axis of each cylinder. , An intake port having one end open to one side of the combustion chamber with respect to the reference plane including the axes and the other end open to the upper surface of the cylinder head, and a plurality of bearings rotatably supporting the camshaft. A cam cap that is integrally formed and is placed on the upper surface of the cylinder head, and is formed inside the cam cap. One end is connected to the other end of the intake port, and the intake manifold is connected to the other end. An internal combustion engine, comprising: 2. The internal combustion engine according to claim 1, further comprising positioning means for positioning the cam cap with respect to the cylinder head. 3. The positioning means is provided on a plurality of engaging portions provided on one of the cylinder head and the cam cap, and on the other of the cylinder head and the cam cap. 3. The internal combustion engine according to claim 2, further comprising a plurality of engaged parts with which the engaging parts engage. 4. The camshafts are respectively arranged on both sides of the reference surface, the intake auxiliary ports are provided between the camshafts, and the cam caps except the bearings are provided. 2. A hole is provided in a portion corresponding to the cam shaft, and a rocker cover is provided on the upper surface of the cam cap to cover the hole along the cam shaft. The internal combustion engine according to claim 2 or 3. 5. The internal combustion engine according to claim 4, wherein the rocker cover is attached via an elastic support member. 6. The intake manifold is provided on one side or the other side of the reference surface and extends along the surface of the rocker cover in a direction away from the reference surface. The internal combustion engine according to claim 2, claim 3, claim 4, or claim 5. 7. A mounting surface on which the rocker cover is mounted and a mounting surface on which the intake manifold is mounted,
The internal combustion engine according to claim 4, wherein the cam cap is formed in the same plane as the upper surface of the cam cap. 8. A fuel injection valve that faces the interior of the combustion chamber and injects fuel directly into the interior of the combustion chamber, and an ignition plug disposed on the inner surface of the cylinder head. The internal combustion engine according to claim 1, claim 2, claim 3, claim 4, claim 5, claim 6, or claim 7.