JPH11218053A - Cylinder head for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve combustibility and to maintain performance of an internal combustion by a method wherein the set degree of freedom of an intake valve nipping angle and an exhaust valve nipping angle is increased, to achieve rationalization by eliminating an adverse influence on the shape and arrangement of an intake port and a fuel injection valve, and to maintain performance of the internal combustion engine. SOLUTION: With a cylinder axis nipped therebetween, an intake port 46 is formed in a combustion chamber 16 on one side in the direction of the width of a cylinder head 8 and an exhaust port 48 is formed in a combustion chamber on the other side. An intake port 52 having one end side opened to the upper surface of the cylinder head and the other end side communicated with the intake port is formed, an exhaust port 58 having one end side communicated with the exhaust port and the other end side opened to the wall part on the exhaust side of the cylinder head is formed and an intake valve 62 and an exhaust valve 64 are arranged in the intake port and the exhaust port, respectively. A valve system mechanism 90 to drive these valves is provided. A fuel injection valve 168 is arranged at the side wall part on the intake side of the cylinder head. The valve system mechanism is provided with a cam shaft disposed on extension of the valve stem of the intake valve or the exhaust valve. In this case, a ratio of the stroke length of the intake valve or the exhaust valve to the length of a cam profile is set to 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder head for an internal combustion engine, and more particularly to an overhead valve type cylinder head for an internal combustion engine having an intake valve, an exhaust valve, an intake port, a fuel injection valve, and the like. About.

[0002]

2. Description of the Related Art In an internal combustion engine mounted on a vehicle or the like, a combustion chamber is provided between a cylinder of a cylinder block, a piston slidably held by the cylinder, and a cylinder head so as to sandwich a cylinder axis of the cylinder. An intake port that opens to the combustion chamber is provided on one side in the width direction of the cylinder head, and an intake port that opens at one end to the upper surface of the cylinder head and communicates with the intake port at the other end is provided. Some have a fuel injection valve that injects fuel directly into the combustion chamber.

FIG. 17 shows a cylinder head of such an internal combustion engine. In FIG. 17, 20
2 is an internal combustion engine, 204 is a cylinder block, 206 is a cylinder, 208 is a cylinder head, 210 is a head cover, 212 is a crankshaft, 214 is an oil pan, 216
Is a connecting rod, 218 is a piston, and 220 is a combustion chamber.

The internal combustion engine 202 has a combustion chamber between a cylinder 206 of a cylinder block 204 and a top surface 222 of a piston 218 slidably held by the cylinder 206 and a cylinder head 208 mounted on the cylinder block 204. 220 are provided. This internal combustion engine 20
2 is provided with an intake port 224 that opens to the combustion chamber 220 on one side in the width direction of the cylinder head 208 with the cylinder axis L1 of the cylinder 206 interposed therebetween, and opens to the combustion chamber 220 on the other side in the width direction with the cylinder axis L1 interposed therebetween. Exhaust port 22
6 are provided.

[0005] The cylinder head 208 has an intake port 23 which is open at one end on the upper surface 228 and communicates the other end with an intake port 224 provided in the combustion chamber 220 on the lower surface 230.
An exhaust port 236 is provided on the exhaust side wall portion 234 of the cylinder head 208 so that the exhaust port 236 communicates with the exhaust port 226 at one end. Cylinder head 20
An intake manifold 238 communicating with the intake port 232 is attached to the upper surface 228 of the nozzle 8. An exhaust manifold 240 communicating with the exhaust port 236 is attached to the exhaust side wall 234 of the cylinder head 208.

The internal combustion engine 202 has an intake valve 242 and an exhaust valve 2 that open and close an intake port 224 and an exhaust port 226, respectively.
44, and a valve mechanism 246 for driving the intake valve 242 and the exhaust valve 244. Valve train 246
The intake camshaft 248 and the exhaust camshaft 25 are located on each side of the cylinder head 208 in the width direction with respect to the cylinder axis L1.
0 is pivotally provided. The intake cam shaft 248 and the exhaust cam shaft 250 are provided with an intake cam 252 and an exhaust cam 254.

The valve mechanism 246 has a swing-type intake rocker arm 256 and an exhaust rocker arm 258 which are swung by an intake cam 252 and an exhaust cam 254, respectively. The intake rocker arm 256 and the exhaust rocker arm 258 each have one end provided on the center side in the width direction of the cylinder head 208 (on the cylinder axis L1 side).
60 and the exhaust pivot portion 262, and the other surface is provided in sliding contact with the intake cam 252 and the exhaust cam 254, respectively, and the other surface of the other end is provided with the intake valve 242 and the exhaust valve 244. Is provided so as to abut.

The valve operating mechanism 246 swings the intake rocker arm 256 and the exhaust rocker arm 258 around the intake pivot 260 and the exhaust pivot 262 by the intake cam 252 and the exhaust cam 254 to drive the intake valve 242 and the exhaust valve 244. I do.

The internal combustion engine 202 has a combustion chamber 22
0 is provided with a fuel injection valve 264 for directly injecting fuel. The fuel injection valve 264 is provided on the intake side wall 266 of the cylinder head 208 so as to face the combustion chamber 220.

An example of such a cylinder head for an internal combustion engine is disclosed in Japanese Patent Application Laid-Open No. 9-236044. What is disclosed in this publication is to provide a valve operating mechanism having a swing type rocker arm, a fuel injection valve for directly injecting fuel into a combustion chamber on an intake side wall of a cylinder head, and sandwiching a cylinder axis. An intake opening that opens into a combustion chamber on one side in the width direction of the cylinder head; an intake port that communicates one end with the intake opening and opens the other end on the upper surface of the cylinder head; A combustion device (spark plug) mounting hole penetrating from the upper surface of the cylinder to the combustion chamber is provided, and the intake port is formed such that a part of the outer edge of the intake port is formed along the combustion device mounting hole on the upper surface of the cylinder head. Things.

[0011]

[0007] By the way, FIG.
The cylinder head 208 of the internal combustion engine 202 disclosed in Japanese Patent Application Laid-Open Publication No. H11-163686 has a so-called intake port 232 having one end communicating with an intake port 224 opening in the combustion chamber 220 and the other end opening in the upper surface 230 of the cylinder head 208. A tumble flow is generated in the combustion chamber 220 by the top entry port for stratification.

The cylinder head 20 of the internal combustion engine 202
8 is provided with a valve mechanism 246 having an intake rocker arm 256 and an exhaust rocker arm 258 for driving the intake valve 242 and the exhaust valve 244, and injects fuel directly into the combustion chamber 220 into the intake side wall 266 of the cylinder head 208. A fuel injection valve 264 is provided.

However, the valve operating mechanism 246 provided on the cylinder head 208 connects the intake pivot 260 and the exhaust pivot 262 which support one end of the intake rocker arm 256 and the exhaust rocker arm 258 to the center of the cylinder head 208 in the width direction. Since it is provided on the side of the cylinder axis L1, there is a problem that the intake pivot portion 260 and the exhaust pivot portion 262 interfere with the intake port 232.

For this reason, the cylinder head 208 of the internal combustion engine 202 has a disadvantage that the shape of the intake port 232 is deformed and the flow of intake air is hindered, which adversely affects the performance of the internal combustion engine 202. The cylinder head 208 of the internal combustion engine 202 includes an intake valve 242 and an exhaust valve 244.
When the included angle is reduced, the shape of the intake port 232 is affected by interference with the intake pivot portion 260 and the exhaust pivot portion 262, so that the degrees of freedom of setting the respective included angles of the intake valve 242 and the exhaust valve 244 are reduced. There is a disadvantage that it becomes smaller.

As a countermeasure against such inconvenience,
The intake pivot portion 260 and the exhaust pivot portion 262 are located on the center side in the width direction of the cylinder head 208 (the cylinder axis L1).
Side) but on each side in the width direction of the cylinder head 208.

However, when the intake pivot portion 260 and the exhaust pivot portion 262 are provided on each side in the width direction (outside in the width direction) of the cylinder head 208, the fuel injection valve provided on the intake side wall portion 264 of the cylinder head 208 is provided. 26
There is a disadvantage that the arrangement of the internal combustion engine 202 is affected, and the arrangement of the mounting angle and the like is restricted. As a result, the influence on the combustion is increased and the performance of the internal combustion engine 202 is adversely affected.

When the intake pivot 260 and the exhaust pivot 262 are provided on each side (outside in the width direction) of the cylinder head 208, respectively,
8 becomes large, there is a disadvantage that the internal combustion engine 202 becomes large, and there is a disadvantage that it is disadvantageous in mounting on a vehicle.

[0018]

SUMMARY OF THE INVENTION In order to eliminate the above-mentioned disadvantages, the present invention provides a cylinder of a cylinder block of an internal combustion engine, a top surface of a piston slidably held by the cylinder, and the cylinder block. A combustion chamber is provided between the cylinder head and the cylinder head, and an intake port is provided in the combustion chamber on one side in the width direction of the cylinder head across the cylinder axis of the cylinder, and the other side in the width direction across the cylinder axis. Providing an exhaust port opening to the combustion chamber, providing an intake port opening one end side on the upper surface of the cylinder head and communicating the other end side to the intake port, and communicating the one end side to the exhaust port. An exhaust port opening the other end side is provided on the exhaust side wall of the cylinder head, and an intake valve and an exhaust valve for opening and closing the intake port and the exhaust port, respectively, are provided. A valve mechanism for driving a gas valve and an exhaust valve; a fuel injection valve for directly injecting fuel into the combustion chamber provided on an intake side wall of the cylinder head; and the valve mechanism including the intake valve or the exhaust valve. A cam shaft is provided on the valve shaft extension of the valve, and a ratio of a stroke length of the intake valve or the exhaust valve to a cam profile length of the cam shaft is set to 1.

The valve train is provided with a cylinder head supporting an intake camshaft and an exhaust camshaft. The intake valve or the exhaust camshaft corresponds to the cam profile length of one of the intake camshaft and the exhaust camshaft. A valve mechanism for driving the intake valve and the exhaust valve by setting the ratio of the stroke length of the valve to 1 and the ratio of the stroke length to the cam profile length of the other cam shaft to be more than 1; A shaft and an exhaust camshaft are provided so as to be supported on the valve shaft extensions of the intake valve and the exhaust valve, respectively, and the intake camshaft and the exhaust camshaft directly drive the intake valve and the exhaust valve, respectively. This is a valve operating mechanism.

In the valve mechanism, tappets are provided on the intake valve and the exhaust valve, and an outer shim is provided on one of the intake tappet of the intake valve and the exhaust tappet of the exhaust valve.
A lash adjuster is provided on one of the intake tappet of the intake valve and the exhaust tappet of the exhaust valve.

The cylinder head is provided with a cover deck on the upper surface to which a head cover is attached, and a block deck on the lower surface to be attached to a cylinder block, and an intermediate member is provided between the cover deck and the block deck. A deck portion is provided, and an ignition plug guide hole portion is provided from the cover deck portion to penetrate the intermediate deck portion and reach the combustion chamber of the block deck portion, and the longitudinal direction of the cylinder head is sandwiched by the ignition plug guide hole portion. On each side, an intake port portion which penetrates from the cover deck portion through the intermediate deck portion and reaches an intake port provided in the combustion chamber of the block deck portion is provided integrally with the ignition plug guide hole portion, and the block deck portion is provided. An exhaust port is provided from the exhaust port provided in the combustion chamber of the section to the exhaust side wall of the cylinder head. Providing an intake stem guide holding portion of the air valve and an exhaust stem guide holding portion of the exhaust valve, respectively, extending the intake stem guide holding portion and the exhaust stem guide holding portion toward the block deck portion side, and An intake stem guide extension and an exhaust stem guide extension reaching the exhaust port are respectively provided, and the intake cam shaft and the exhaust cam shaft are supported on each side in the width direction of the cylinder head with the cylinder axis of the cover deck interposed therebetween. An intake tappet guide portion provided with an intake cam bearing portion and an exhaust cam bearing portion, and slidably holding the intake tappet of the intake valve on each side of the cylinder head of the intake cam bearing portion in the longitudinal direction and on the side of the intermediate deck portion. And the intake tappet guide portion is provided integrally with the intake cam bearing portion, and the cylinder head of the exhaust cam bearing portion is provided. Exhaust tappet guides for slidably holding the exhaust tappet of the exhaust valve are provided on each side in the longitudinal direction and on the side of the intermediate deck, and these exhaust tappet guides are provided integrally with the exhaust cam bearing. An injection valve mounting hole penetrating the block deck and reaching the combustion chamber is provided in the intake side wall of the cylinder head.

The cylinder head is arranged such that the ignition plug guide hole is separated from the intake cam bearing and the exhaust cam bearing, and the intake port is separated from the intake tappet guide and the exhaust tappet guide. The intake valve sandwiching angle and the exhaust valve sandwiching angle with respect to the axis are set to be large, and the intake port portions are integrally formed on each side in the longitudinal direction of the cylinder head with the ignition plug guide hole portion interposed therebetween, and are arranged in parallel in the longitudinal direction. The intake port portions facing each other of the adjacent cylinders are integrally provided, and an ignition plug guide hole portion, an intake port portion, an intake cam bearing portion, and an exhaust cam bearing portion are provided on the cover deck side. A communication deck portion is provided for connecting the ignition plug guide hole reinforcing rib extending from the communication deck toward the intermediate deck portion, and a suction port. A rib for reinforcing the intake port portion, the ignition plug guide hole portion and the intake cam bearing portion and the exhaust cam bearing portion are provided in communication with each other by the ignition plug guide hole reinforcement rib, and the intake port portion reinforcement rib is provided. A rib connects the intake port section with the intake tappet guide section and the exhaust tappet guide section.

Further, the cylinder head has a small angle between the intake valve and the exhaust valve with respect to the cylinder axis so that the ignition plug guide hole portion and the intake cam bearing portion and the exhaust cam bearing portion are continuous with each other. Intake ports are provided integrally on each side in the longitudinal direction of the cylinder head with the ignition plug guide hole interposed therebetween and arranged substantially linearly in the longitudinal direction. A communication rib is provided between the ignition plug guide hole, the intake cam bearing and the exhaust cam bearing, and the communication rib is used to connect the ignition plug guide hole, the intake cam bearing and the exhaust cam. The connecting ribs are provided in communication with each other, and reinforcing ribs are provided on both sides of the connecting rib in the longitudinal direction of the cylinder head.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A cylinder head for an internal combustion engine according to the present invention has an intake port having an opening at one end on the upper surface of the cylinder head and a communication at the other end with an intake port. A direct-acting valve train that is driven directly is provided, and a fuel injection valve that injects fuel directly into a combustion chamber is provided on an intake side wall of a cylinder head, and the valve train is provided with the intake valve or the exhaust valve. And a ratio of a stroke length of the intake valve or the exhaust valve to a cam profile length of the camshaft is set to 1. As the valve operating mechanism, an intake camshaft and an exhaust camshaft are provided on a cylinder head so as to be supported, and the intake valve or the intake valve or the exhaust camshaft with respect to the cam profile length of the camshaft of one of the camshafts. A valve mechanism for driving the intake valve and the exhaust valve by setting the ratio of the stroke length of the exhaust valve to 1 and the ratio of the stroke length to the cam profile length of the other camshaft to be greater than 1; The exhaust cam and the exhaust cam are pivotally supported on the valve shaft extensions of the intake valve and the exhaust valve, respectively, so that the intake cam shaft and the exhaust cam shaft directly drive the intake valve and the exhaust valve, respectively.

Thus, in the cylinder head of the internal combustion engine, the valve train does not include the rocker arm and the pivot portion for pivotally supporting one end of the rocker arm.
The angle between the intake valve and the angle between the exhaust valve can be freely set without considering the interference of the pivot portion with the intake port.

The valve operating mechanism can easily adjust the valve gap by replacing the shim by providing tappets on the intake valve and the exhaust valve and providing an outer shim on one of the intake tappet and the exhaust tappet. In addition, by providing a lash adjuster on one of the intake tappet and the exhaust tappet, it is not necessary to adjust the valve gap by shim replacement, thereby improving maintainability.

The cylinder head of this internal combustion engine has
A deck for the cover is provided on the upper surface, a deck for the block is provided on the lower surface, an intermediate deck is provided between the deck for the cover and the deck for the block, and the intermediate deck is penetrated from the deck for the cover. An ignition plug guide hole is provided to reach the combustion chamber of the block deck, and the block deck extends through the intermediate deck from the cover deck to the longitudinal side of the cylinder head across the ignition plug guide hole. The exhaust port reaching the intake port provided in the combustion chamber of the section is provided integrally with the ignition plug guide hole, and the exhaust port reaching the exhaust side wall of the cylinder head from the exhaust port provided in the combustion chamber of the block deck. Parts are provided, and an intake stem guide holding part and an exhaust stem guide holding part are provided on the intermediate deck part, respectively. The respectively provided an intake stem guide extension extends to the deck side for each block reaches the intake port section and an exhaust port unit and the exhaust stem guide extension,
An intake cam bearing portion and an exhaust cam bearing portion are provided on each side of the cylinder head in the width direction with the cylinder axis of the cover deck portion interposed therebetween, and on each side of the intake cam bearing portion in the longitudinal direction of the cylinder head and on the intermediate deck portion side. An intake tappet guide portion for slidably holding the intake tappet is provided, and these intake tappet guide portions are provided integrally with the intake cam bearing portion, and each side of the exhaust cam bearing portion in the longitudinal direction of the cylinder head and an intermediate deck portion. Exhaust tappet guides that slidably hold the exhaust tappet are provided on the sides, and these exhaust tappet guides are provided integrally with the exhaust cam bearing, and the block deck is penetrated through the intake side wall of the cylinder head. An injection valve mounting hole reaching the combustion chamber is provided.

As a result, the cylinder head of the internal combustion engine has an integrated spark plug guide hole and an intake port, an integrated intake cam bearing and an intake tappet guide, an exhaust cam bearing and an exhaust tappet. By integrating with the guide part, the meat of each part can be shared and the rigidity can be reduced while reducing the flesh.The intake stem guide holding part and the exhaust stem guide holding part provided on the intermediate deck part are for blocks respectively. By providing an intake stem guide extension and an exhaust stem guide extension that extend to the deck side and reach the intake port and exhaust port, respectively, the intermediate deck, the intake side wall of the cylinder head, and the deck for block The intake-side cooling water passage for cooling the combustion chamber, intake valve, and fuel injection valve is secured between the ignition plug guide hole, the intake port, and the intake stem guide extension. Exhaust valve, combustion chamber, exhaust port between the intermediate deck, the exhaust side wall of the cylinder head, the block deck, the spark plug guide hole, the exhaust port, and the exhaust stem guide extension. An exhaust-side cooling water passage for cooling the section can be secured.

In the cylinder head of this internal combustion engine, the spark plug guide hole is separated from the intake cam bearing and the exhaust cam bearing, and the intake port is separated from the intake tappet guide and the exhaust tappet guide. , The intake valve sandwiching angle and the exhaust valve sandwiching angle with respect to the cylinder axis are set to be large, and the intake port sections are respectively integrally and longitudinally parallel to each side in the longitudinal direction of the cylinder head with the spark plug guide hole interposed therebetween. The intake port portions facing each other of the adjacent cylinders are integrally provided, and the ignition plug guide hole portion, the intake port portion, the intake cam bearing portion, and the exhaust cam bearing portion are provided on the cover deck side. A communication deck section is provided for connecting the ignition plug guide hole extending from the communication deck toward the intermediate deck section and a suction port. And a spark plug guide hole reinforcing rib is provided to connect the spark plug guide hole to the intake cam bearing portion and the exhaust cam bearing portion, and an intake port portion is formed by the intake port portion reinforcing rib. And an intake tappet guide section and an exhaust tappet guide section are provided in communication with each other.

Further, the cylinder head of the internal combustion engine has a small angle between the intake valve and the exhaust valve with respect to the cylinder axis such that the spark plug guide hole is continuous with the intake cam bearing and the exhaust cam bearing. The intake ports are arranged integrally and substantially linearly in the longitudinal direction on each side in the longitudinal direction of the cylinder head with the ignition plug guide hole interposed therebetween, and each intake port facing the adjacent cylinder is provided. The connecting ribs are provided integrally between the spark plug guide hole, the intake cam bearing and the exhaust cam bearing, and the connecting rib is used to connect the spark plug guide hole, the intake cam bearing, and the exhaust cam. The connecting ribs are provided in communication with each other, and reinforcing ribs are provided on both sides of the connecting rib in the longitudinal direction of the cylinder head.

[0031]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 9 show a first embodiment of the present invention. In FIG. 1, 2 is an internal combustion engine, 4 is a cylinder block, 6 is a cylinder, 8 is a cylinder head, 10 is an intake head cover, 12 is an exhaust head cover, 14 is a piston, and 16 is a combustion chamber. The internal combustion engine 2 has a crankshaft (not shown) pivotally supported below the cylinder block 4, and a cylinder 6 is provided above the cylinder block 4. A plurality of cylinders 6 are provided so as to be oriented in the longitudinal direction of the cylinder head 8.

The internal combustion engine 2 is mounted by bringing the lower surface 20 of the cylinder head 8 into contact with the upper surface 18 of the cylinder block 4 and attaching the intake head cover 10 and the exhaust head cover 12 to the upper surface 22 of the cylinder head 8. I have. The internal combustion engine 2 includes a cylinder 6 of a cylinder block 4 and a piston 1 slidably held by the cylinder 6.
Between the top surface 24 of the cylinder head 4 and the lower surface 20 of the cylinder head 8 attached to the upper surface 18 of the cylinder block 4.
6 are provided.

The cylinder head 8 has a cover deck 26 to which the intake head cover 10 and the exhaust head cover 12 are attached on the upper surface 22 and a block deck 2 which is attached to the cylinder block 4 on the lower surface 20.
8 and an intermediate deck 30 between the cover deck 26 and the block deck 28.

As shown in FIGS. 2 and 3, the cylinder head 8 has an intake side wall portion 34 on one side surface 32 in the width direction and an exhaust side wall portion 38 on the other side surface 36 in the width direction. The width direction sides of the cover deck portion 26, the block deck portion 28, and the intermediate deck portion 30 are provided in communication with the intake side wall portion 34 and the exhaust side wall portion 38, respectively. The intermediate deck portion 30 extends from the central portion to the intake side wall portion 3.
4 and the exhaust side wall 38 are provided so as to be inclined downward.

The combustion chamber 16 is provided in the block deck portion 28 on the lower surface 20 of the cylinder head 8 by depressing the cylinder axis L1. As shown in FIG. 5, the cylinder head 8 has a cylinder axis L
An ignition plug guide hole portion 40 is provided from one portion through the intermediate deck portion 30 and reaches the combustion chamber 16 of the block deck portion 28. In the spark plug hole 42 in the spark plug guide hole 40, the spark plug 4
4 is provided by screwing.

As shown in FIG. 6, the block deck 28 of the cylinder head 8 is provided with an intake port 46 which opens into the combustion chamber 16 on one side in the width direction of the cylinder head 8 with the cylinder axis L1 interposed therebetween. An exhaust port 48 that opens to the combustion chamber 16 on the other side in the width direction with the cylinder axis L1 interposed therebetween is provided. The intake port 46 and the exhaust port 48 are connected to the combustion chamber 1 on each side in the longitudinal direction of the cylinder head 8 with respect to the cylinder axis L1.
6, two openings are provided (see FIGS. 4 and 7).

As shown in FIGS. 4 to 7, the intermediate deck 30 extends from the cover deck 26 to the cylinder head 8 on each side in the longitudinal direction of the cylinder head 8 with the spark plug guide hole 40 interposed therebetween. The two intake ports 50 reaching the two intake ports 46 provided in the combustion chamber 16 of the block deck 28 are provided integrally with the respective spark plug guide holes 40.

As shown in FIG. 4, the two intake port portions 50 are integrally arranged on the respective longitudinal sides of the cylinder head 8 with the spark plug guide hole 40 interposed therebetween and arranged in parallel in the longitudinal direction. In addition, the opposed intake port portions 50 of the adjacent cylinders 6 are integrally provided.

As a result, the cylinder head 8 is provided on the cylinder head 8 with the two intake ports 50 provided on both sides of the spark plug guide hole 40, respectively.
Two straight intake ports 52 are provided for each combustion chamber 16, one end of which is open in the vicinity and the other end of which is connected to the two intake ports 46. These intake ports 52
Is a combustion chamber 16 by a so-called top entry port.
The purpose of this is to generate a tumble flow to stratify. One end of an intake manifold 54 that communicates with an intake port 52 is attached to the upper surface 22 of the cylinder head 8.

As shown in FIGS. 4 and 7, the center of the spark plug hole 40 is defined as C1, and the centers of the two suction port portions 50 are connected to each other. Let C2 · C2 be an isosceles triangle having the center C1 of the spark plug hole 40 as the apex angle in a plan view, and gradually decrease the apex angle from the upper surface 22 to the lower surface 22 of the cylinder head 8. Arrange. The intake port portion 50 is formed such that the cross-sectional shape of the intake port 52 is changed from a perfect circle to an ellipse as it goes from the upper surface 22 to the lower surface 20 of the cylinder head 8. At this time, the deformation of the cross-sectional shape of the intake port 52 is
The deformation near the spark plug hole 40 becomes largely flat,
The spark plug hole 40 is formed such that deformation on the side away from the spark plug hole 40 is small and close to a perfect circle.

As shown in FIG. 3, the cylinder head 8 is provided with a cylinder head 8 provided in the combustion chamber 16 of the block deck 28.
From the exhaust ports 48 to the exhaust side wall portion 38 of the cylinder head 6.
The exhaust port section 56 is provided. The exhaust port portion 56 branches the combustion chamber 16 side into two exhaust ports 48 and collectively provides the exhaust side wall portion 38 side. Thus, the cylinder head 8 is provided with an exhaust port 58 communicating with one end of the exhaust port 48 and opening the other end on the side surface 36 of the exhaust side wall 38 of the cylinder head 8.
An exhaust manifold 60 communicating with the exhaust port 58 is mounted on the side surface 36 of the exhaust side wall portion 38 of the cylinder head 8.

The internal combustion engine 2 has an intake valve 62 and an exhaust valve 64 for opening and closing the intake port 46 and the exhaust port 48. The intake valve 62 and the exhaust valve 64 are provided at one end of the intake stem 66 and the exhaust stem 68 at the intake port 46 and the exhaust port 48, respectively.
An intake valve head 70 and an exhaust valve head 72 are provided respectively. The intake valve 62 and the exhaust valve 64 hold the intake stem 66 and the exhaust stem 68 in the cylinder head 8 movably in the axial direction by an intake stem guide 74 and an exhaust stem guide 76, respectively.

As shown in FIGS. 2 and 3, the cylinder head 8 is provided with an intake stem guide holding portion 78 and an exhaust stem guide holding portion 80 on the intermediate deck portion 30, respectively. The intake stem guide 74 and the exhaust stem guide 7
6 is fixed to the intake stem guide holding portion 78 and the exhaust stem guide holding portion 80. In the cylinder head 8, an intake stem guide holding portion 78 and an exhaust stem guide holding portion 80 are respectively extended toward the block deck portion 28 so as to reach the intake port portion 50 and the exhaust port portion 56. A portion 82 and an exhaust stem guide extension 84 are provided respectively.

As a result, the cylinder head 8 is
7, between the intermediate deck 30 and the block deck 28, and between the intake side wall 34, the spark plug guide hole 40, the intake port 50, and the intake stem guide extension 82. , An intake-side cooling water passage 86 is provided. The cylinder head 8 has an intermediate deck 30.
And between the block deck section 28 and the exhaust side wall section 3
An exhaust-side cooling water passage 88 is provided between the discharge port 8, the spark plug guide hole 40, the intake port 50, the exhaust port 56, and the exhaust stem guide extension 84.

The cylinder head 8 of the internal combustion engine 2 includes
Valve mechanism 90 for driving the intake valve 62 and the exhaust valve 64
Is provided. The valve operating mechanism 90 of the first embodiment is provided with the intake camshaft 9 and the intake camshaft 9 on the extension of the intake valve 62 and the exhaust valve 64 on each side in the width direction of the cylinder head 8 with the cylinder axis L1 interposed therebetween.
2 and an exhaust camshaft 94 are pivotally provided. The intake camshaft 92 and the exhaust camshaft 94
An intake cam 96 and an exhaust cam 98 that directly drive the intake valve 4 are provided, and the ratio of the stroke length of the intake valve 62 or the exhaust valve 64 to the cam profile length is set to 1. In addition,
For example, the ratio of the stroke length of the intake valve 62 to the cam profile length of the intake cam 96 of one of the intake cam shaft 92 and the exhaust cam shaft 94 is 1, and the other cam shaft. Exhaust cam 9 of exhaust cam 94
Assuming that the ratio of 8 to the cam profile length is greater than 1,
The intake valve 62 and the exhaust valve 64 can also be driven.

As shown in FIGS. 5 and 6, the cylinder head 8 has the intake camshaft 92 and the exhaust camshaft on each side in the width direction of the cylinder head 8 with the cylinder axis L1 of the cover deck 26 interposed therebetween. An intake cam bearing portion 100 and an exhaust cam bearing portion 102 that respectively support the 94 are provided. FIG. 2 shows the intake cam bearing portion 100 and the exhaust cam bearing portion 102.
-As shown in FIG. 3, the intake cam shaft 92 and the exhaust cam shaft 94
The intake cam bearing cap portion 104 and the exhaust cam bearing cap portion 106 that support the shaft are mounted and provided by an intake cam cap mounting bolt 108 and an exhaust cam cap mounting bolt 110.

An intake head cover 10 and an exhaust head cover 12 are mounted on the cylinder head 8 so as to cover the intake cam shaft 92 and the exhaust cam shaft 94, the intake cam bearing cap 104 and the exhaust cam bearing cap 106. Can be

The valve train 90 has an intake tappet 112 and an exhaust tappet 114 driven by an intake cam 96 and an exhaust cam 98. As shown in FIGS. 2 and 3, the intake tappet 112 and the exhaust tappet 114 include an intake peripheral wall portion 116, an exhaust peripheral wall portion 118, and an intake upper wall portion 1, respectively.
20 and the exhaust upper wall portion 122 are each formed in a closed bottomed bottomless cylindrical shape. Inlet tappet 112 and exhaust tappet 1
14, the inside of the upper intake wall section 120 and the upper exhaust wall section 122 is brought into contact with the other end side of the above-mentioned intake stem 66 and the exhaust stem 68, and the intake recess is formed outside the upper intake wall section 120 and the upper exhaust wall section 122. The portion 124 and the exhaust recess 126 are provided. An intake outer shim 128 and an exhaust outer shim 130, which are slidably contacted by the intake cam 96 and the exhaust cam 98, are provided in the intake recess 124 and the exhaust recess 126, respectively.

As shown in FIG. 4, the cylinder head 8 is provided with an intake tappet guide 132 on each side of the intake cam bearing 100 in the longitudinal direction of the cylinder head 8 and on the side of the intermediate deck 30. The intake tappet guide 132 is provided integrally with the intake cam bearing 100 as shown in FIGS.
Is provided slidably.

As shown in FIG. 4, the cylinder head 8 is provided with exhaust tappet guide portions 136 on each side of the exhaust cam bearing portion 102 in the longitudinal direction of the cylinder head 8 and on the intermediate deck portion 30 side. I have. As shown in FIGS. 3, 5, and 6, these exhaust tappet guides 136 are provided integrally with the exhaust cam bearing 102, and hold the exhaust tappet 114 in a slidable manner.
8 are provided.

Thus, as shown in FIG. 2, the cylinder head 8 has an intake cam chamber 140 between the intake head cover 10, the intake side wall portion 34, and the intake tappet guide portion 132, and has an intermediate position with the intake tappet guide portion 132. The intake valve operating chamber 142 is provided between the intake side wall portion 34, the spark plug guide hole 40, and the intake port portion 50 between the intake deck portion 30 and the intake side wall portion 34, and the intake baffle plate 144 is provided in the intake head cover 10. The breather chamber 146 is partitioned and provided.

As shown in FIG. 3, the cylinder head 8 has an exhaust cam chamber 148 between the exhaust head cover 12, the exhaust side wall 38, and the exhaust tappet guide 136, and has the intermediate deck 30 and the block Deck 2
8 and between the exhaust side wall portion 38, the spark plug guide hole portion 40, and the intake port portion 50.
And an exhaust breather chamber 154 is defined in the exhaust head cover 12 by an exhaust baffle plate 152.

As shown in FIGS. 2 and 3, the valve operating mechanism 90 has an intake spring 156 and an exhaust spring 158 disposed in the intake valve operating chamber 142 and the exhaust valve operating chamber 150. Intake spring 156 and exhaust spring 158
Are an intake retainer 160 and an exhaust retainer 16 fixed to the other end sides of the intake stem 66 and the exhaust stem 68, respectively.
2 and the intake spring seat 164 of the intake stem guide holding portion 78 and the exhaust spring seat 166 of the exhaust stem guide holding portion 80 provided on the intermediate deck portion 30. An urging force in a direction to close the intake port 46 and the exhaust port 48 is applied.

The internal combustion engine 2 has a fuel injection valve 1 for directly injecting fuel into a combustion chamber 16 as shown in FIG.
68 are provided. The cylinder head 8 is provided with an injection valve mounting hole 170 that penetrates through the block deck 28 in the intake side wall portion 34 and reaches the combustion chamber 16.
Injection valve mounting hole 17 for mounting fuel injection valve 168 in 70
2 are provided. Accordingly, the fuel injection valve 168 is provided on the intake side wall portion 34 of the cylinder head 8 on the side close to the intake valve 62 so as to face the combustion chamber 16, and directly injects fuel into the combustion chamber 16.

As shown in FIGS. 5 and 6, the cylinder head 8 of the internal combustion engine 2 according to the first embodiment has a spark plug guide hole 40, an intake cam bearing portion 100, and an exhaust cam bearing portion 10.
2 with respect to the cylinder axis L1 such that the intake port 50 and the intake tappet guide 132 and the exhaust tappet guide 136 are separated from each other.
Between the intake valve θ1 and the exhaust valve 64 between the exhaust valves 64
Is set to be large.

As shown in FIG. 4, the ignition plug guide hole 40, the intake port 50, the intake cam bearing 100, and the exhaust cam bearing 102 are connected to the cylinder head 8 on the cover deck 26 side. 174 for communication deck
Is provided. As shown in FIGS. 5 and 6, the cylinder head 8 is provided with the intermediate deck 3 from the connecting deck 174.
Spark plug guide hole reinforcing rib 1 extending toward zero
76 and an intake port portion reinforcing rib 178 are provided.

As shown in FIG. 4, the cylinder head 8 is provided with the spark plug guide hole 40 and the intake cam bearing 100 and the exhaust cam bearing 102 in communication with each other by a spark plug guide hole reinforcing rib 176. The intake port portion 50, the intake tappet guide portion 132, and the exhaust tappet guide portion 136 are formed by the intake port portion reinforcing ribs 178.
And contact each other.

Next, the operation of the first embodiment will be described.

In the internal combustion engine 2, the intake valve 62 and the exhaust valve 64 are directly driven by the intake camshaft 92 and the exhaust camshaft 94 of the valve mechanism 90, and the combustion chamber 1
A fuel mixture is generated by mixing the fuel introduced from the fuel injection valve 168 with the intake air introduced into the fuel injection valve 6. The mixture in the combustion chamber 16 is ignited and burned by the spark plug 44. The exhaust gas generated in the combustion chamber 16 by the combustion is exhausted from an exhaust port 58.

The cylinder head 8 of the internal combustion engine 2 according to the first embodiment is provided with an intake port 52 which is open at one end on the upper surface 22 of the cylinder head 8 and communicates with the intake port 46 of the combustion chamber 16 at the other end. And the intake valve 62 and the exhaust valve 64
And a fuel injection valve 168 for directly injecting fuel into the combustion chamber 16 is provided on the intake side wall 34 of the cylinder head 8.

The valve operating mechanism 90 is provided with an intake camshaft 9 on the extension of the intake valve 62 and the exhaust valve 64 of the cylinder head 8.
2 and the exhaust cam 94, and the intake valve 62 with respect to the profile length of the intake cam shaft 92 and the exhaust cam shaft 94.
Alternatively, the stroke length ratio of the exhaust valve 64 is set to 1, and the intake camshaft 92 and the exhaust camshaft 94 allow the intake valve 62 to operate.
And the exhaust valve 64 is a direct hit type in which each is directly driven.

Thus, the cylinder head 8 of the internal combustion engine 2 has the valve operating mechanism 90 without the conventional rocker arm or the pivot portion for pivotally supporting one end of the rocker arm. Of the intake valve 62 without considering the interference of the intake valve 62
In addition, the exhaust valve sandwiching angle θ2 of the exhaust valve 64 can be set freely.

For this reason, the cylinder head 8 of the internal combustion engine 2 can increase the degree of freedom in setting the intake valve sandwiching angle θ1 and the exhaust valve sandwiching angle θ2. θ1 and the exhaust valve sandwiching angle θ2 can be set optimally, and adverse effects on the shapes and arrangements of the intake port 52 and the fuel injection valve 168 can be eliminated.
The shape and arrangement of the internal combustion engine 68 can be optimized, the flammability can be improved, and the performance of the internal combustion engine 2 can be maintained.

In addition, the valve operating mechanism 90 controls the intake tappet 112 and the exhaust tappet 114 provided in the intake valve 62 and the exhaust valve 64, and in the first embodiment, the intake tappet 112 and the exhaust tappet 114 respectively. By providing the outer shim 128 and the exhaust outer shim 130, adjustment of the valve gap by shim replacement can be easily performed.

The cylinder head 8 of the internal combustion engine 2 includes an integral part of the spark plug guide hole 40 and the intake port part 50, an intake cam bearing part 100 and an intake tappet guide part 13.
2 and the exhaust cam bearing portion 102 and the exhaust tappet guide portion 136, a high rigidity structure can be achieved while reducing the thickness by sharing the meat of each portion.

Further, in the cylinder head 8, the intake stem guide holding portion 78 and the exhaust stem guide holding portion 80 provided on the intermediate deck portion 30 are extended toward the block deck portion 28, respectively, so that the intake port portion 50 and the exhaust Port 5
6, the intermediate stem portion 30, the intake side wall portion 34 of the cylinder head 8, the block deck portion 28, and the ignition plug guide hole portion 40 are provided with the intake stem guide extension 82 and the exhaust stem guide extension 84, respectively. An intake-side cooling water passage 86 for cooling the combustion chamber 16, the intake valve 62, and the fuel injection valve 168 can be provided between the intake port portion 50 and the intake stem guide extension 82.

The cylinder head 8 includes an intermediate deck 30, an exhaust side wall 38 of the cylinder head 8, a block deck 28, a spark plug guide hole 40, an exhaust port 56, and an exhaust stem guide extension 84. Between
An exhaust-side cooling water passage 88 for cooling the combustion chamber 16, the exhaust port 56, and the exhaust valve 64 can be secured.

For this reason, the cylinder head 8 of the internal combustion engine 2 can increase rigidity and reduce weight,
Sufficient cooling can be achieved.

In the cylinder head 8 of the internal combustion engine 2 of the first embodiment, the spark plug guide hole 40, the intake cam bearing 100 and the exhaust cam bearing 102 are separated from each other, and the intake port 50 and the intake tappet guide are separated. The intake valve sandwiching angle θ1 of the intake valve 62 and the exhaust valve sandwiching angle θ2 of the exhaust valve 64 with respect to the cylinder axis L1 are set to be large so that the 132 and the exhaust tappet guide 136 are separated from each other.

Therefore, in the cylinder head 8 of the internal combustion engine 2, the tumble flow can be strengthened by increasing the intake valve sandwiching angle θ1, and the axial center distance between the intake cam shaft 92 and the exhaust cam shaft 94 is reduced. Fig. 1
As shown in FIG. 4, a space for mounting engine components such as the intake manifold 60 and the ignition coil 180 can be easily secured between the intake camshaft 92 and the exhaust camshaft 94 of the cylinder head 8, and as shown in FIG. Auxiliary equipment such as the high-pressure pump 182 and the crank angle sensor 184 can be easily attached to the shaft ends of the camshaft 92 and the exhaust camshaft 94, which can be advantageous in the layout of the auxiliary equipment.

The cylinder head 8 of the internal combustion engine 2
As shown in FIG. 4, the communication deck 174 connects the spark plug guide hole 40, the intake port 50, the intake cam bearing 100 and the exhaust cam bearing 102, and the ignition plug guide hole 40 and the intake A spark plug guide hole reinforcing rib 176 that connects the cam bearing portion 100 and the exhaust cam bearing portion 102, and an intake port portion that connects the intake port portion 50 with the intake tappet guide portion 132 and the exhaust tappet guide 136, respectively. The provision of the ribs 178 can increase the rigidity.

In the valve operating mechanism 90 of the first embodiment, the intake tappet 112 and the exhaust tappet 114 are provided with the intake outer shim 128 and the exhaust outer shim 130, respectively, as shown in FIG. Upper wall 122
An intake recess 186 and an exhaust recess 188 are provided inside the airbag, and the intake stem 66 is provided in the intake recess 186 and the exhaust recess 188.
Intake shim 190 abutting on exhaust stem 68
And the exhaust inner shim 192 may be provided in engagement with each other.

As described above, by providing the intake inner shim 190 and the exhaust inner shim 192 on the intake tappet 112 and the exhaust tappet 114, respectively, the intake outer shim 1 is provided.
28 and the exhaust outer shim 130, the outer diameters of the intake peripheral wall portion 116 and the exhaust peripheral wall portion 118 can be made smaller, and the intake tappet 112 and the exhaust tappet 114 can be made smaller.
Can be reduced, and the intake port 52, the fuel injection valve 168,
The layout of the intake valve 62 and the exhaust valve 64 can be made advantageous, which is also advantageous for downsizing the internal combustion engine 2.

In the valve operating mechanism 90 of the first embodiment, the intake tappet 112 and the exhaust tappet 114 are provided with the intake outer shim 128 and the exhaust outer shim 130, respectively, as shown in FIG.
A hydraulic intake lash adjuster 194 and an exhaust lash adjuster 196 may be provided in the hydraulic pump 14.

As described above, the intake lash adjusters 194 are provided in the intake tappet 112 and the exhaust tappet 114, respectively.
By providing the exhaust lash adjuster 196 and adjusting the valve gap by shim replacement,
Thereby, maintainability can be improved.

FIGS. 10 to 16 show a second embodiment of the present invention. In the second embodiment, the first
The parts having the same functions as those of the embodiment are denoted by the same reference numerals, and detailed description will be omitted, and the outline will be described.

That is, in FIG. 10, reference numeral 2 denotes an internal combustion engine,
Is a cylinder block, 6 is a cylinder, 8 is a cylinder head, 10 is an intake head cover, 12 is an exhaust head cover, 14 is a piston, and 16 is a combustion chamber. Internal combustion engine 2
Is provided with a crankshaft (not shown) supported below the cylinder block 4, and a cylinder 6 is provided above the cylinder block 4. The cylinder 6 has a cylinder head 8
Are arranged in a plurality in such a manner as to be oriented in the longitudinal direction.

Further, the internal combustion engine 2 includes a
The upper deck 22 is provided with a cover deck 26 to which the intake head cover 10 and the exhaust head cover 12 are attached, and the lower deck 20 is provided with a block deck 28 to be attached to the cylinder block 4.
Further, an intermediate deck portion 30 is provided between the block deck portions 28.

Further, the cylinder head 8 is arranged as shown in FIGS.
As shown in FIG. 2, the intake side wall portion 34 is provided on the side surface 32 on one side in the width direction.
And the exhaust side wall portion 3 is provided on the side surface 36 on the other side in the width direction.
The width direction sides of the cover deck section 26, the block deck section 28, and the intermediate deck section 30 are connected to the intake side wall section 34 and the exhaust side wall section 38, respectively. The intermediate deck portion 30 is provided to be inclined so as to descend from the central portion toward the intake side wall portion 34 and the exhaust side wall portion 38, respectively.

As shown in FIG. 14, the cylinder head 8 has an ignition plug guide which passes through the intermediate deck 30 from the cylinder axis L1 of the cover deck 26 and reaches the combustion chamber 16 of the block deck 28. A hole 40 is provided. As shown in FIG. 15, the block deck portion 28 is provided with two intake ports 46 which open to the combustion chamber 16 on one side in the width direction of the cylinder head 8 with the cylinder axis L1 interposed therebetween, and also has the cylinder axis L1 interposed therebetween. , Two exhaust ports 48 opening to the combustion chamber 16 on the other side in the width direction are provided.

FIGS. 13 to 1 show the cylinder head 8.
As shown in FIG. 6, the cover deck portion 26 is provided on each side in the longitudinal direction of the cylinder head 8 with the spark plug guide hole portion 40 interposed therebetween.
Through the intermediate deck 30 to reach two intake ports 46 provided in the combustion chamber 16 of the block deck 28.
The intake port portions 50 are respectively connected to the spark plug guide hole portions 4.
0 and provided integrally.

As shown in FIG. 13, the two intake ports 50 are arranged integrally and substantially linearly in the longitudinal direction of the cylinder head 8 with the spark plug guide hole 40 interposed therebetween. In addition, the opposed intake port portions 50 of the adjacent cylinders 6 are integrally provided. Thereby, the cylinder head 8 is provided with a linear intake port 52 having one end opening near the cylinder axis L1 on the upper surface 22 and communicating the other end with the two intake ports 46 for each combustion chamber 16. Each book is provided.

As shown in FIGS. 13 and 16, the center of the ignition plug hole 40 is C1, and the centers of the two intake port portions 50 are the C1 and the two intake port portions 50, respectively. Assuming that C2 and C2 are respectively set, an isosceles triangle having the apex angle of the center C1 of the spark plug hole 40 in plan view, and the positions of the apex angles are in opposite phases on the way from the upper surface 22 to the lower surface 22 of the cylinder head 8. It is arranged so that it becomes.

In other words, as shown in FIG. 13, on the upper surface 22 of the cylinder head 8, the centers C2 and C2 of the two intake port portions 50 are larger than the center C1 of the spark plug hole 40.
14 and 15, the center C1 of the spark plug hole 40 and each of the two intake port portions 50 are provided between the upper surface 22 and the lower surface 22 of the cylinder head 8 as shown in FIGS. The centers C2 and C2 are located on a straight line extending in the longitudinal direction of the cylinder head 8, and as shown in FIG. 16, the combustion chamber 16 on the lower surface 20 side of the cylinder head 8 is located closer to the intake side wall 34. Set up.

As shown in FIG. 12, the cylinder head 8 has two exhaust ports 48 provided in the combustion chamber 16 of the block deck section 28 through the exhaust side wall section 3 of the cylinder head 6.
An exhaust port section 56 reaching 8 is provided. As a result, one end of the exhaust port 48 communicates with the cylinder head 8 and the side surface 3 of the exhaust side wall 38 of the cylinder head 8 is connected.
6 is provided with an exhaust port 58 opening at the other end.

The internal combustion engine 2 is provided with an intake valve 62 and an exhaust valve 64 for opening and closing the intake port 46 and the exhaust port 48. One end of the intake stem 66 and the exhaust stem 68 is connected to and separated from the intake port 46 and the exhaust port 48. An intake valve head 70 and an exhaust valve head 72 are provided, respectively.
Are held in the cylinder head 8 by an intake stem guide 74 and an exhaust stem guide 76 so as to be movable in the axial direction.

As shown in FIGS. 11 and 12, the cylinder head 8 has an intake stem guide holding portion 78 for fixing the intake stem guide 74 and the exhaust stem guide 76 to the intermediate deck portion 30, and an exhaust stem of an exhaust valve. Guide holder 8
0 is provided for each. The intake stem guide holding portion 78 and the exhaust stem guide holding portion 80 extend toward the block deck portion 28, respectively, to reach the intake port portion 50 and the exhaust port portion 56, respectively. Each of the units 84 is provided.

As shown in FIGS. 14 to 16, the cylinder head 8 is provided between the intermediate deck portion 30 and the block deck portion 28, and includes the intake side wall portion 34, the spark plug guide hole portion 40, and the intake port portion 50. And intake stem guide extension 8
2, an intake-side cooling water passage 86 is provided. The cylinder head 8 has an exhaust side wall portion 38, a spark plug guide hole 40, an intake port portion 50, an exhaust port portion 56, and an exhaust stem guide extension between the intermediate deck portion 30 and the block deck portion 28. An exhaust-side cooling water passage 88 is provided between the portion 84.

In the second embodiment, the direct-acting type valve operating mechanism 90 for directly driving at least one of the intake valve 62 and the exhaust valve 64 is provided on both sides in the width direction of the cylinder head 8 with respect to the cylinder axis L1. An intake cam shaft 92 and an exhaust cam shaft 94 are provided to support the intake cam shaft 92 and the exhaust cam shaft 94, respectively. The intake cam shaft 92 and the exhaust cam shaft 94 directly drive the intake valve 62 and the exhaust valve 64, respectively. Is provided.

As shown in FIGS. 14 and 15, the cylinder head 8 has an intake cam bearing 100 and an exhaust cam bearing 102 on each side in the width direction of the cylinder head 8 with the cylinder axis L1 of the cover deck 26 interposed therebetween. 11 and FIG. 1
As shown in FIG. 2, the intake cam bearing cap portion 104 and the exhaust cam bearing cap portion 106 are provided by being attached by an intake cam cap mounting bolt 108 and an exhaust cam cap mounting bolt 110, and are provided on the valve shaft extension of the intake valve 62 and the exhaust valve 64. An intake camshaft 92 and an exhaust camshaft 94 are respectively supported.

The valve operating mechanism 90 has an intake tappet 112 and an exhaust tappet 114 formed in a closed bottomed bottom cylindrical shape by an intake peripheral wall portion 116 and an exhaust peripheral wall portion 118 and an intake upper wall portion 120 and an exhaust upper wall portion 122, respectively. Are provided outside the intake upper wall portion 120 and the exhaust upper wall portion 122, and an intake outer shim 128 and an exhaust outer shim 130 are provided for sliding contact of the intake cam 96 and the exhaust cam 98, respectively.

As shown in FIG. 13, an intake tappet 11 is provided on each side of the intake cam bearing 100 in the longitudinal direction of the cylinder head 8 and on the side of the intermediate deck 30 as shown in FIG.
2 are provided so as to slidably hold the intake tappet guide portions 132, respectively.
2 is provided integrally with the intake cam bearing portion 100.

As shown in FIG. 13, an exhaust tappet 1 is provided on both sides of the exhaust cam bearing portion 102 in the longitudinal direction of the cylinder head 8 and on the side of the intermediate deck portion 30 as shown in FIG.
14 for slidably holding the exhaust tappet guide portion 138
And the exhaust tappet guide 1
38 is provided integrally with the exhaust cam bearing portion 102.

As a result, the cylinder head 8 is
As shown in FIG. 12, the intake cam chamber 140 and the intake valve train 1
42, an intake breather chamber 146, an exhaust cam chamber 148, an exhaust valve operating chamber 150, and an exhaust breather chamber 15
4 are provided.

As shown in FIGS. 11 and 12, the valve operating mechanism 90 is provided between the intake retainer 160 of the intake stem 66 and the exhaust retainer 162 of the exhaust stem 68 in the intake valve operating chamber 142 and the exhaust valve operating chamber 150. Spring 156 and exhaust spring 158 between the intake spring seat 164 and the exhaust spring seat 166 of the deck unit 30.
Are respectively provided, and the intake valve 46 and the exhaust valve 64 are connected to the intake port 46.
And an urging force in a direction to close the exhaust port 48.

As shown in FIG. 14, the cylinder head 8 is provided with an injection valve mounting hole 170 which penetrates the block deck 28 and reaches the combustion chamber 16 in the intake side wall portion 34. An injection valve mounting hole 172 for mounting the fuel injection valve 168 is provided in 170. Fuel injection valve 16
8 injects fuel directly into the combustion chamber 16.

In the cylinder head 8 of the internal combustion engine 2 of the second embodiment, as shown in FIGS. 14 and 15, the spark plug guide hole 90, the intake cam bearing 100 and the exhaust cam bearing 102 are continuous. The angle between the intake valve θ1 and the angle between the exhaust valve θ2 with respect to the cylinder axis L1 is set to be small, as shown in FIG. 13, between the spark plug guide hole 40 and the intake cam bearing 100 and the exhaust cam bearing 102. A connecting rib 198 is provided to connect the spark plug guide hole 40 with the intake cam bearing 100 and the exhaust cam bearing 100, and the connecting rib 198 extends longitudinally of the cylinder head 8. A reinforcing overlay 200 is provided on each side in the direction.

Next, the operation of the second embodiment will be described.

In the internal combustion engine 2, the intake valve 62 and the exhaust valve 64 are directly driven by the intake camshaft 92 and the exhaust camshaft 94 of the valve mechanism 90, and the combustion chamber 1
A fuel mixture is generated by mixing the fuel introduced from the fuel injection valve 168 with the intake air introduced into the fuel injection valve 6. The mixture in the combustion chamber 16 is ignited and burned by the spark plug 44. The exhaust gas generated in the combustion chamber 16 by the combustion is exhausted from an exhaust port 58.

The cylinder head 8 of the internal combustion engine 2 of the second embodiment is provided with a direct-acting valve train 90 for directly driving the intake valve 62 and the exhaust valve 64, respectively.
2 and an exhaust outer shim 128 for the exhaust tappet 114, respectively.
And an exhaust outer shim 130, and the intermediate deck 30
Between the cooling water passage 8 and the block deck 28
6 and the exhaust-side cooling water passage 88 are each secured, so that the same effects as in the first embodiment can be obtained.

The cylinder head 8 of the internal combustion engine 2 of the second embodiment has an intake valve with respect to the cylinder axis L1 such that the ignition plug guide hole 40, the intake cam bearing 100 and the exhaust cam bearing 102 are continuous. The included angle θ1 and the exhaust valve included angle θ2 are set to be small.

As a result, the cylinder head 8 can make the combustion chamber 16 compact and improve the thermal efficiency by making the intake valve sandwiching angle θ1 small, and can improve the intake stem guide holding portion 78 and the intake stem guide extension. By the rise of the cylinder head 82, the volume of the intake-side cooling water passage 86 between the cylinder head 8 and the intake side wall part 34 can be increased, the cooling performance can be improved, and the length of the cylinder head 8 in the width direction can be reduced. Thus, the internal combustion engine 2 can be downsized, which can be advantageous in mounting on a vehicle (not shown).

In the valve operating mechanism 90 of the second embodiment, the intake tappet 112 and the exhaust tappet 114 are provided with the intake outer shim 128 and the exhaust outer shim 130, respectively, as shown in FIG. Upper wall 122
Inside the intake inner shim 190 and the exhaust inner shim 19
2 are engaged with each other, so that the intake tappet 11
2 and the exhaust tappet 114 can be downsized, the layout of the intake port 52, the fuel injection valve 168, the intake valve 62 and the exhaust valve 64 can be advantageous, and the downsizing of the internal combustion engine 2 can be advantageous. As shown in FIG.
By providing the hydraulic intake lash adjuster 194 and the exhaust lash adjuster 196 in the exhaust tappet 2 and the exhaust tappet 114, adjustment of the valve gap by shim replacement can be omitted, thereby improving maintainability.

[0104]

As described above, the cylinder head of the internal combustion engine according to the present invention has a pivoting mechanism because the valve mechanism is a direct drive type and the rocker arm and the pivot portion for pivotally supporting one end of the rocker arm are not provided. The angle between the intake valve and the exhaust valve can be freely set without considering the interference with the intake port.

For this reason, the cylinder head of this internal combustion engine can increase the degree of freedom in setting the intake valve sandwiching angle and the exhaust valve sandwiching angle, and according to the type of the internal combustion engine, the intake valve sandwiching angle and the exhaust valve sandwiching angle. Can be set optimally, eliminating adverse effects on the shape and arrangement of intake ports and fuel injectors, optimizing the shape and arrangement of intake ports and fuel injectors, and improving flammability. Thus, the performance of the internal combustion engine can be maintained.

The valve operating mechanism can easily adjust the valve gap by replacing the shim by providing an outer shim on one of the intake tappet and the exhaust tappet, and the lash is applied to either the intake tappet or the exhaust tappet. By providing the adjuster, adjustment of the valve gap by shim exchange can be made unnecessary, thereby improving maintainability.

The cylinder head of this internal combustion engine is
By integrating the spark plug guide hole with the intake port, integrating the intake cam bearing with the intake tappet guide, and integrating the exhaust cam bearing with the exhaust tappet guide,
The meat of each part can be made common and a high rigidity structure can be achieved while reducing the thickness, and the deck for the middle, the intake side wall of the cylinder head, the deck for the block, the ignition plug guide hole, the intake port, and the intake stem guide An intake side cooling water passage for cooling the combustion chamber, the intake valve, and the fuel injection valve can be secured between the extension portion and the intermediate deck portion, the exhaust side wall portion of the cylinder head, the block deck portion, and the ignition plug. An exhaust-side cooling water passage for cooling the exhaust valve, the combustion chamber, and the exhaust port can be provided between the guide hole, the exhaust port, and the exhaust stem guide extension.

Therefore, the cylinder head of the internal combustion engine can increase rigidity and reduce weight, and can achieve sufficient cooling.

The cylinder head of this internal combustion engine is
The tumble flow can be strengthened by increasing the angle between the intake valves, and the distance between the axis of the intake camshaft and the exhaust camshaft can be increased. Space for mounting engine components such as ignition coils can be easily secured, and auxiliary equipment such as high-pressure pumps and crank angle sensors can be easily mounted on the shaft ends of the intake camshaft and exhaust camshaft. This can be advantageous in terms of layout.

The cylinder head of this internal combustion engine has a connecting deck for connecting the spark plug guide hole, the intake port, the intake cam bearing and the exhaust cam bearing, and a spark plug guide hole and the intake cam bearing. The rigidity is improved by providing a spark plug guide hole reinforcing rib communicating the exhaust cam bearing portion, and an intake port reinforcing rib communicating the intake port portion with the intake tappet guide portion and the exhaust tappet guide portion, respectively. Can increase.

Further, in the cylinder head of this internal combustion engine, the combustion chamber can be made compact by reducing the included angle of the intake valve, the thermal efficiency can be improved, and the intake stem guide portion and the intake stem guide extension portion rise. By increasing the volume of the intake-side cooling water passage between the cylinder and the intake side wall, the cooling performance can be improved, and the length of the cylinder head in the width direction can be reduced. This can be advantageous in mounting on a vehicle.

The cylinder head of this internal combustion engine is
Rigidity can be increased by providing a connecting rib for connecting the spark plug guide hole with the intake cam bearing and the exhaust cam bearing, and reinforcing padding on both sides of the connecting rib in the longitudinal direction of the cylinder head. .

[Brief description of the drawings]

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

FIG. 2 is an enlarged sectional view of an intake side of a cylinder head.

FIG. 3 is an enlarged sectional view of an exhaust side of a cylinder head.

FIG. 4 is a plan view of a cylinder head.

FIG. 5 is a cross-sectional view taken along line II-II of FIG.

FIG. 6 is a cross-sectional view taken along line V〓-V〓 of FIG. 4;

FIG. 7 is a cross-sectional view taken along line V〓〓-V〓〓 in FIGS. 5 and 6;

FIG. 8 is a sectional view of a cylinder head in which an inner shim is provided on a tappet.

FIG. 9 is a sectional view of a cylinder head provided with a lash adjuster on a tappet.

FIG. 10 is a sectional view of a cylinder head of an internal combustion engine showing a second embodiment of the present invention.

FIG. 11 is an enlarged sectional view of the intake side of the cylinder head.

FIG. 12 is an enlarged sectional view of an exhaust side of a cylinder head.

FIG. 13 is a plan view of a cylinder head.

FIG. 14 is a sectional view taken along the line XIII-X} in FIG. 13;

FIG. 15 is a cross-sectional view taken along the line XX in FIG.

FIG. 16 is a cross-sectional view taken along line X〓I-X〓I of FIGS. 14 and 15;

FIG. 17 is a sectional view of an internal combustion engine showing a conventional example.

[Explanation of symbols]

 2 Internal Combustion Engine 4 Cylinder Block 6 Cylinder 8 Cylinder Head 16 Combustion Chamber 26 Cover Deck 28 Block Deck 30 Intermediate Deck 34 Intake Sidewall 38 Exhaust Sidewall 40 Spark Plug Guide Hole 46 Inlet 48 Exhaust 50 Intake port part 52 Intake port 56 Exhaust port part 58 Exhaust port 62 Intake valve 64 Exhaust valve 74 Intake stem guide 76 Exhaust stem guide 78 Intake stem guide holding part 80 Exhaust stem guide holding part 82 Intake stem guide extension 84 Exhaust stem guide extension Unit 86 Intake side cooling water passage 88 Exhaust side cooling water passage 90 Valve mechanism 92 Intake camshaft 94 Exhaust camshaft 100 Intake cam bearing unit 102 Exhaust cam bearing unit 112 Intake tappet 114 Exhaust tappet 128 Intake outer shim 130 Exhaust outer shim 1 Two intake tappet guide portion 136 exhaust tappet guide portion 168 a fuel injection valve 174 contact deck portion 176 spark plug guide hole portion reinforcing rib 178 intake port portion reinforcing rib

Claims (8)

[Claims] A combustion chamber is provided between a cylinder of a cylinder block of an internal combustion engine and a top surface of a piston slidably held by the cylinder and a cylinder head mounted on the cylinder block, and a cylinder axis of the cylinder is provided. An intake port that opens to the combustion chamber on one side in the width direction of the cylinder head with an air outlet provided to the combustion chamber on the other side in the width direction across the cylinder axis; and one end on the upper surface of the cylinder head. An intake port is provided that opens to the side and communicates the other end to the intake port, and provides an exhaust port that communicates the one end to the exhaust port and opens the other end to the exhaust side wall of the cylinder head. An intake valve and an exhaust valve for opening and closing an intake port and an exhaust port, respectively, are provided, and a valve operating mechanism for driving the intake valve and the exhaust valve is provided. A fuel injection valve for directly injecting fuel into the combustion chamber is provided on a side wall portion, and the valve mechanism includes a camshaft disposed on a valve shaft extension of the intake valve or the exhaust valve. A cylinder head for an internal combustion engine, wherein a ratio of a stroke length of the intake valve or the exhaust valve to a cam profile length is one. 2. The valve operating mechanism according to claim 1, wherein the intake cam shaft and the exhaust cam shaft are supported on a cylinder head, and the intake valve corresponds to a cam profile length of one of the intake cam shaft and the exhaust cam shaft. Alternatively, the valve mechanism drives the intake valve and the exhaust valve by setting the ratio of the stroke length of the exhaust valve to 1 and setting the ratio of the stroke length to the cam profile length of the other camshaft to be greater than 1. Item 2. A cylinder head for an internal combustion engine according to item 1. 3. The valve operating mechanism according to claim 1, wherein the intake cam shaft and the exhaust cam shaft are provided on a cylinder head so as to be axially supported on the valve shaft extensions of the intake valve and the exhaust valve, respectively. The cylinder head of an internal combustion engine according to claim 1, wherein the cylinder head is a direct-acting valve train that directly drives an intake valve and an exhaust valve, respectively. 4. The valve operating mechanism according to claim 1, wherein a tappet is provided on the intake valve and the exhaust valve, and an outer shim is provided on one of the intake tappet of the intake valve and the exhaust tappet of the exhaust valve. A cylinder head for an internal combustion engine according to claim 3. 5. The valving mechanism according to claim 1, wherein a lash adjuster is provided on one of an intake tappet of the intake valve and an exhaust tappet of the exhaust valve. Cylinder head of internal combustion engine. 6. The cylinder head according to claim 1, further comprising a cover deck provided on a top surface of the cylinder head, and a block deck provided on a cylinder block provided on a lower surface of the cylinder head, between the cover deck and the block deck. An intermediate deck portion is provided, and an ignition plug guide hole is provided from the cover deck portion to penetrate the intermediate deck portion and reach the combustion chamber of the block deck portion. On each side in the longitudinal direction, an intake port portion penetrating from the cover deck portion to the intermediate deck portion and reaching the intake port provided in the combustion chamber of the block deck portion is provided integrally with the ignition plug guide hole portion, and the block is provided. An exhaust port is provided to reach the exhaust side wall of the cylinder head from the exhaust port provided in the combustion chamber of the deck for the intermediate deck. An intake stem guide holding portion of the intake valve and an exhaust stem guide holding portion of the exhaust valve are respectively provided, and the intake stem guide holding portion and the exhaust stem guide holding portion are respectively extended toward the block deck portion side to extend the intake port portion and An intake stem guide extension and an exhaust stem guide extension reaching the exhaust port are respectively provided, and the intake cam shaft and the exhaust cam shaft are supported on each side in the width direction of the cylinder head with the cylinder axis of the cover deck interposed therebetween. An intake tappet guide portion provided with an intake cam bearing portion and an exhaust cam bearing portion, and slidably holding the intake tappet of the intake valve on each side of the cylinder head of the intake cam bearing portion in the longitudinal direction and on the side of the intermediate deck portion. And each of these intake tappet guide portions is provided integrally with the intake cam bearing portion,
Exhaust tappet guides for slidably holding an exhaust tappet of the exhaust valve are provided on each side of the cylinder head of the exhaust cam bearing in the longitudinal direction of the cylinder head and on the side of the intermediate deck, and these exhaust tappet guides are connected to the exhaust cam. 4. A cylinder for an internal combustion engine according to claim 3, wherein an injection valve mounting hole is provided integrally with the bearing portion, and is provided in the intake side wall of the cylinder head so as to penetrate the block deck and reach the combustion chamber. head. 7. The cylinder head, wherein the ignition plug guide hole is separated from the intake cam bearing and the exhaust cam bearing, and the intake port is separated from the intake tappet guide and the exhaust tappet guide. The intake valve and the exhaust valve are set at a large angle with respect to the cylinder axis, and the intake ports are integrally and longitudinally provided on each side in the longitudinal direction of the cylinder head with the ignition plug guide hole interposed therebetween. The intake port portions facing each other of the adjacent cylinders are provided integrally with each other, and the spark plug guide hole portion, the intake port portion, the intake cam bearing portion, and the exhaust cam bearing are provided on the cover deck side. A communication deck portion is provided for communication with the ignition plug guide hole reinforcing rib extending from the communication deck toward the intermediate deck portion, and a suction port. A port portion reinforcing rib, the ignition plug guide hole portion, the intake cam bearing portion, and the exhaust cam bearing portion being connected to each other by the ignition plug guide hole reinforcing rib, and the intake port portion reinforcing rib. 7. The cylinder head for an internal combustion engine according to claim 6, wherein the intake port portion, the intake tappet guide portion, and the exhaust tappet guide portion are provided so as to communicate with each other. 8. The cylinder head according to claim 1, wherein the angle between the intake valve and the exhaust valve with respect to the cylinder axis is small so that the spark plug guide hole is continuous with the intake cam bearing and the exhaust cam bearing. Intake ports are provided integrally on each side in the longitudinal direction of the cylinder head with the ignition plug guide hole interposed therebetween and arranged substantially linearly in the longitudinal direction. A communication rib is provided between the ignition plug guide hole, the intake cam bearing and the exhaust cam bearing, and the communication rib is used to connect the ignition plug guide hole, the intake cam bearing and the exhaust cam. 7. The internal combustion engine according to claim 6, wherein the bearing ribs are provided in communication with each other, and reinforcing ribs are provided on both sides of the connecting rib in the longitudinal direction of the cylinder head. Cylinder head.