JP6136557B2 - Cylinder head cover for internal combustion engine - Google Patents

Description

  The present invention relates to a cylinder head cover of an internal combustion engine, and more particularly to a cylinder head cover provided in an internal combustion engine in which a cylinder axis is inclined with respect to a vertical direction.

  The cylinder head cover of an internal combustion engine in which the cylinder axis is inclined with respect to the vertical direction has a bottom portion for connecting a cam cover portion provided on the upper side in the tilt direction and the lower side in the tilt direction. Is formed. For this reason, when rain water or water repelled by the tire flows into the bottom, the water is blocked by the cam cover portion on the lower side in the inclined direction and stored at the bottom, and enters the spark plug hole. There is a risk that.

  Conventionally, as a cylinder head cover that prevents water from entering a spark plug hole, for example, there is one described in Patent Document 1. The cylinder head cover described in Patent Document 1 includes a recess in which a spark plug hole is formed, and a hook-like protrusion that is provided on the lower side in the inclination direction of the engine and forms a breather chamber. A discharge groove having a groove bottom continuous to the boundary between the bottom of the recess and the bowl-shaped protrusion is provided, and water that has flowed into the recess is discharged from the recess through the discharge groove.

  Another cylinder head cover that prevents water from entering the spark plug hole is described in Patent Document 2. The cylinder head cover described in Patent Document 2 has a drain hole that communicates the vicinity of the spark plug hole formed in the recess of the cylinder head cover and the outer periphery of the cylinder head cover above the breather chamber. The water flowing into the recess is discharged from the recess through the drain hole.

JP-A-9-88719 JP-A-11-62702

However, in the cylinder head cover described in Patent Document 1, since the opening end of the spark plug hole and the recess are provided on substantially the same plane, the water flowing into the recess temporarily moves into the bowl-shaped protrusion. This water may enter from the opening end of the spark plug hole.
Further, even in the cylinder head cover described in the cited document 2, since the opening end of the spark plug hole and the concave portion are provided on substantially the same plane, the water flowing into the concave portion has a cylinder head cover above the breather chamber. This water may intrude from the open end of the spark plug hole when it is temporarily stored on the wall surface of the spark plug.

  The present invention has been made paying attention to the above-mentioned problems, and an object of the present invention is to provide a cylinder head cover for an internal combustion engine that can prevent water from entering the spark plug hole. is there.

A first aspect of the present invention is a cylinder head cover provided in an internal combustion engine in which a cylinder shaft is inclined with respect to a vertical direction, and extends in the extending direction of the pair of cam shafts so as to cover the pair of cam shafts. A pair of cam cover portions extending along the inclination direction of the internal combustion engine and positioned on the inclination direction lower side of the internal combustion engine, and inward in the width direction in a direction orthogonal to the extending direction of the cam shaft in the pair of cam cover portions A bottom portion extending along the extending direction of the camshaft, and a boss portion provided on the bottom portion so as to be located above the cylinder of the internal combustion engine and having an ignition plug hole A breather chamber that is provided in any one of the pair of cam cover portions and separates oil from blow-by gas into gas and liquid, and the bottom portion is inward in the width direction of the cam cover portion on the lower side in the inclination direction of the internal combustion engine. The bottom of An inclination surface that inclines toward the lower side with respect to a horizontal plane as it goes toward a lower side in the width direction of the cam cover portion on the upper side in the inclination direction of the internal combustion engine, and has an inclination angle of the internal combustion engine with respect to the vertical direction. The absolute value of the inclination angle of the inclined surface with respect to the horizontal plane is formed larger than the absolute value, and the inclined surface is configured to be located below the top surface of the boss portion.

According to a second aspect of the present invention, the vertical height of the cam cover portion provided on the lower side in the inclination direction of the internal combustion engine with respect to the vertical height of the cam cover portion provided on the upper side in the inclination direction of the internal combustion engine. May be formed so that the breather chamber is formed in the cam cover portion on the lower side in the tilt direction.
As a 3rd aspect of this invention, you may make it a bottom part incline toward the other end from the end of a bottom part along the extension direction of a cam shaft.

As described above, according to the first aspect described above, the bottom portion of the cylinder head cover extends in the width direction of the cam cover portion on the upper side in the inclination direction of the internal combustion engine from the lower portion in the width direction of the cam cover portion on the lower side in the inclination direction of the internal combustion engine. It has an inclined surface that inclines downward toward the horizontal plane as it goes inward, and the absolute value of the inclination angle of the inclined surface with respect to the horizontal plane is larger than the absolute value of the inclination angle of the internal combustion engine with respect to the vertical direction. The inclined surface is positioned below the top surface of the boss portion . Thereby, the water which flowed into the bottom part can be moved below along the inclined surface. For this reason, the surface of the water moved downward can be moved away from the top surface of the boss portion, and water can be prevented from entering from the spark plug hole of the boss portion.

  According to said 2nd aspect, the vertical direction height of the cam cover part provided in the inclination direction downward side of the internal combustion engine with respect to the vertical direction height of the cam cover part provided in the inclination direction upper side of the internal combustion engine Therefore, the water entering the bottom from the outside of the cam cover portion on the lower side in the tilt direction can be blocked by the cam cover portion on the lower side in the tilt direction, and the amount of water flowing into the bottom portion can be reduced.

  In addition, since the breather chamber is formed in the cam cover portion on the lower side in the inclination direction which is raised in the vertical direction, a breather chamber having a large volume can be formed in the cam cover on the lower side in the inclination direction, and the gas-liquid separation effect of the blow-by gas can be obtained. Can be improved.

  According to said 3rd aspect, since a bottom part inclines toward the other end from the one end of a bottom part along the extension direction of a cam shaft, the water which moved below the inclination direction of the bottom part is followed along a cam shaft. It can discharge | emit to the exterior of a cylinder head cover from the other end of a bottom part.

FIG. 1 is a view showing an embodiment of a cylinder head cover of an internal combustion engine of the present invention, and is a left side view of the internal combustion engine provided with the cylinder head cover. FIG. 2 is a view showing an embodiment of the cylinder head cover of the internal combustion engine of the present invention, and is a top view of the cylinder head cover. 3 is a view showing an embodiment of the cylinder head cover of the internal combustion engine of the present invention, and is a cross-sectional view of the upper part of the cylinder head of FIG. 2 and the V1-V1 direction of the cylinder head cover. FIG. 4 is a view showing an embodiment of a cylinder head cover of the internal combustion engine of the present invention, and is a view showing a positional relationship between a boss portion and a bottom portion. FIG. 5 is a view showing an embodiment of the cylinder head cover of the internal combustion engine of the present invention, and is a cross-sectional view taken in the direction of arrows V2-V2 in FIG.

Embodiments of a cylinder head cover for an internal combustion engine according to the present invention will be described below with reference to the drawings.
1 to 5 are views showing a cylinder head cover of an internal combustion engine according to an embodiment of the present invention.
First, the configuration will be described. In FIG. 1, an engine 1 as an internal combustion engine mounted on a vehicle includes a cylinder block 2 to which a crankcase 2 </ b> A is attached and a cylinder head 3 attached to an upper portion of the cylinder block 2.

  A plurality of cylinders 2a are provided in the cylinder block 2, and a piston 2b is provided in the cylinder 2a so as to be capable of reciprocating. The piston 2b is connected to the crankshaft 5 via a connecting rod 2c, and the rotational motion of the crankshaft 5 is converted to linear motion of the piston 2b via the connecting rod 2c. Further, the engine 1 of the present embodiment is configured such that the cylinder axis O1 is inclined with respect to the vertical direction, and hereinafter, the vertical direction will be described as the vertical direction axis O. That is, the cylinder axis O1 is inclined with respect to the vertical axis O at a constant angle, for example, 15 °. The inclination angle of the engine 1 is a mounting angle in a state where the engine 1 is mounted on the vehicle.

  As shown in FIG. 3, a cam journal receiving portion 6 is provided on the upper portion of the cylinder head 3, and a cam cap 9 is fixed to the cam journal receiving portion 6 with a bolt. An intake camshaft 7 and an exhaust camshaft 8 are rotatably attached to the inner peripheral surfaces of the cam journal receiving portion 6 and the cam cap 9, and the intake camshaft 7 and the exhaust camshaft 8 are shown in FIG. It extends in the left-right direction. In addition, although the engine 1 of the present embodiment has been described by taking a so-called horizontal engine in which the crankshaft 5 extends in the left-right direction of the vehicle, it is not limited to this form.

An intake cam 7a and an exhaust cam 8a are attached to the intake cam shaft 7 and the exhaust cam shaft 8, and the intake cam 7a and the exhaust cam 8a are provided in the cylinder head 3 with the rotation thereof (not shown). An intake port and an exhaust port (not shown) formed in the cylinder head 3 are opened and closed by raising and lowering the intake valve and the exhaust valve. Here, the intake camshaft 7 and the exhaust camshaft 8 constitute a camshaft.
As shown in FIGS. 1 and 2, the cylinder head cover 4 is attached to the cylinder head 3 so as to cover the cylinder head 3.

As shown in FIGS. 1 to 3, cam cover portions 10 and 11 are provided on both sides in the width direction of the cylinder head cover 4, and the cam cover portions 10 and 11 cover the intake camshaft 7 and the exhaust camshaft 8. In this way, the intake camshaft 7 and the exhaust camshaft 8 extend along the extending direction.
Further, the cam cover portion 10 is located on the upper side in the inclination direction of the engine 1, and the cam cover portion 11 is located on the lower side in the inclination direction of the engine 1. An intake manifold (not shown) is provided on the front side of the cylinder head 3 below the cam cover portion 10, and this intake manifold introduces intake air into each cylinder 2a via an intake port.

An exhaust manifold (not shown) is provided on the rear surface side of the cylinder head 3 below the cam cover portion 11. Exhaust gas is discharged from the cylinder 2a through the exhaust port to the exhaust manifold. Therefore, in the engine 1 of the present embodiment, the cam cover portion 11 is located in the front of the vehicle, and the cam cover portion 10 is located in the rear of the vehicle.
Further, a bottom 12 is provided at the center of the cylinder head cover 4 in the width direction. As shown in FIG. 3, the bottom 12 connects the lower portions 10 a and 11 a inward in the width direction of the cam covers 10 and 11. The intake camshaft 7 and the exhaust camshaft 8 extend in the axial direction.

A boss portion 13 is provided on the bottom portion 12, and the boss portion 13 is located above each cylinder 2 a of the cylinder block 2. As shown in FIGS. 3 and 4, the boss portion 13 is formed with a spark plug hole 13a into which a spark plug (not shown) of the ignition device 14 provided for each cylinder 2a is inserted.
The ignition plug hole 13a communicates with an ignition plug hole formed in the cylinder head 3, and the ignition plug hole 13a of the cylinder head communicates with a combustion chamber of each cylinder 2a.

In FIG. 3, a part of the ignition device 14 is shown. The ignition device 14 is shown in the figure and is provided below the case 15 and is electrically connected to the ignition coil. And a tubular member 16 in which a connection member that is not to be accommodated is housed. A spark plug (not shown) is connected to the lower end of the tubular member 16 via the connection member. The spark plug is attached to the cylinder head 3 as desired in the combustion chamber of each cylinder 2a.
Here, the case 15 is placed on the top surface 13 b of the boss portion 13, and a seal member (not shown) is interposed between the lower surface of the case 15 and the top surface 13 b of the boss portion 13. For this reason, it is possible to prevent water or the like from entering the spark plug hole 13a from the opening end of the spark plug hole 13a.

The ignition device 14 energizes the ignition coil by energizing means (not shown), further generates a spark by the ignition plug by cutting off the energization, and performs combustion by igniting the spark to the air-fuel mixture. The case 15 is formed with a ventilation port 15 a, and the ventilation port 15 a communicates with the ignition plug hole 13 a through an ignition plug hole formed in the cylinder head 3.
This ventilation port 15a is an ignition formed in the cylinder head 3 for blow-by gas that leaks in a minute amount from the combustion chamber of each cylinder 2a, or ozone gas that leaks into the combustion chamber due to the high voltage at the time of ignition of the ignition plug. The plug hole and the boss 13 have a function of discharging to the outside through the spark plug hole 13a.

As shown in FIG. 3, valve chambers 17 and 18 are formed in cam cover portions 10 and 11 in which the intake camshaft 7 and the exhaust camshaft 8 are accommodated. Further, the vertical height of the cam cover portion 11 is formed higher than the vertical height of the cam cover portion 10. A breather plate 19 is provided at the center of the cam cover portion 11 in the height direction. Inside the cam cover portion 11, a breather chamber 20 is formed on the upper side by the breather plate 19, and a valve operating chamber 18 is formed on the lower side. It is formed.
The breather chamber 20 gas-liquid-separates oil from blow-by gas. This blow-by gas is an unburned gas that leaks into the crankcase 2A from the gap between the piston ring of the piston 2b that reciprocates on the inner wall of the cylinder 2a of the cylinder block 2 and the inner wall of the cylinder 2a. Contains a large amount of hydrocarbons as well as oil.
For this reason, if blow-by gas is not properly processed, engine oil may be prematurely deteriorated or the engine 1 may be rusted.
This blow-by gas is introduced into the valve operating chamber 18 through a blow-by gas recirculation passage (not shown) provided in the cylinder block 2 and the cylinder head 3 from the crankcase 2A.

  The valve operating chamber 18 and the breather chamber 20 communicate with each other through an opening formed in the breather plate 19, and the blow-by gas introduced into the valve operating chamber 18 is introduced into the breather chamber 20 through the opening, and oil is generated in the breather chamber 20. After the gas and liquid are separated, as shown in FIG. 2, the gas is discharged to the intake pipe through the breather pipe 21 provided in the cam cover portion 11. That is, the blowby gas leaked into the crankcase 2A is introduced into the blowby gas recirculation passage, the valve operating chamber 18 and the breather chamber 20 by the intake negative pressure generated in the intake pipe.

On the other hand, as shown in FIGS. 3 and 4, the bottom portion 12 includes an inclined surface 12 a inclined in a direction opposite to the inclination direction of the engine 1, and the inclined surface 12 a is inclined with respect to the vertical axis O. It has an inclination angle larger than the angle. The inclined surface 12 a is located below the top surface 13 b of the boss portion 13 and the ventilation port 15 a of the case 15. That is, the boss portion 13 of the present embodiment protrudes from the inclined surface 12 a of the bottom portion 12.
As shown in FIG. 4, the inclined surface 12 a has a steep slope 12 b inclined at a large inclination angle, for example, about 30 °, from the upper end toward the center in the width direction of the bottom portion 12 with respect to the horizontal plane, and the center in the width direction of the bottom portion 12. From the upper end to the lower end, for example, a gentle slope 12c that inclines at about 20 ° is provided, and the inclination angle is different from the upper end toward the lower end. In addition, the inclination angle of the inclined surface 12a is an illustration, Comprising: It is not limited to this.

As shown in FIGS. 1 and 2, a bulging portion 22 bulging upward from the right end of the cam cover portions 10 and 11 and in the front-rear direction of the vehicle is provided on the right side of the cylinder head cover 4. The outlet 22 is provided with an oil filler cap 23 that opens and closes an injection hole for injecting engine oil. For this reason, when replacing the engine oil, the oil filler cap 23 can be removed from the bulging portion 22 and the engine oil can be replaced through the injection hole.
As shown in FIG. 5, the bottom portion 12 extends from the right direction of the vehicle, which is one end 12d of the bottom portion 12, to the left direction of the vehicle, which is the other end 12e, along the extending direction of the intake camshaft 7 and the exhaust camshaft 8. The other end 12e of the bottom 12 is an open end.

Next, the operation will be described.
The engine 1 is configured such that the cylinder axis O1 is inclined with respect to the vertical axis O, the cam cover portion 11 is located below the inclination direction, and the cam cover portion 10 is located above the inclination direction. For this reason, when rain water, water from a car wash, or water splashed by a tire when the vehicle travels flows into the upper part of the cylinder head cover 4, the cam cover portion 11 serves as a wall and water drops on the bottom portion 12. Is done.
The bottom portion 12 of the cylinder head cover 4 of the present embodiment includes an inclined surface 12a that is inclined in a direction opposite to the inclination direction of the engine 1, and the inclined surface 12a is larger than the inclination angle of the engine 1 with respect to the vertical axis O. It has an inclination angle and is located below the top surface 13 b of the boss portion 13 and the ventilation port 15 a of the case 15.

For this reason, the water that has flowed into the bottom portion 12 can be moved rearward along the inclined surface 12a, and the water surface that has moved to the rear side of the vehicle can be moved away from the top surface 13b of the boss portion 13. It is possible to prevent water from entering from the spark plug hole 13a and the ventilation port 15a.
In particular, the inclined surface 12a of the present embodiment includes a steep slope 12b that is inclined at a large angle from the upper end toward the center in the width direction of the bottom portion 12, and a gentle slope that is gently inclined downward from the center in the width direction of the bottom portion 12. 12c, the water that has flowed into the inclined surface 12a can be quickly moved below the inclined surface 12a. Therefore, the water surface of water can be quickly moved away from the top surface 13b of the boss portion 13 and the ventilation port 15a. For this reason, it can prevent more effectively that water penetrate | invades from the spark plug hole 13a of the boss | hub part 13, and the ventilation hole 15a.

Further, the bottom 12 of the present embodiment is inclined from one end 12d of the bottom 12 toward the other end 12e along the extending direction of the intake camshaft 7 and the exhaust camshaft 8, and the other end 12e of the bottom 12 is Since it is an open end, the water that has moved below the inclined surface 12 a can be discharged from the other end 12 e of the bottom portion 12 to the outside of the cylinder head cover 4.
Moreover, since the cylinder head cover 4 of this embodiment makes the vertical height of the cam cover part 11 located below the tilt direction higher than the vertical height of the cam cover part 10 located above the tilt direction, Water entering the bottom 12 from the outside of the cam cover 11, that is, from the front of the vehicle, can be blocked by the cam cover 11, and the amount of water flowing into the bottom 12 can be reduced.

Further, in the cylinder head cover 4 of the present embodiment, the breather chamber 20 is formed in the cam cover portion 11 that is raised in the vertical direction. Therefore, the breather chamber 20 having a large volume can be formed in the cam cover portion 11, and the blow-by gas passage can be formed. It can be formed longer. For this reason, the gas-liquid separation effect of blow-by gas can be improved. Further, a larger amount of blow-by gas can be stored in the breather chamber 20, and the pressure fluctuation of the breather pipe 21 can be reduced.
In the cylinder head cover 4 of the present embodiment, the breather chamber 20 is provided in the cam cover portion 11, but the breather chamber 20 may be provided in the cam cover portion 10.

  While embodiments of the invention have been disclosed, it will be apparent to those skilled in the art that changes may be made without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims.

DESCRIPTION OF SYMBOLS 1 ... Engine (internal combustion engine), 4 ... Cylinder head cover, 7 ... Intake cam shaft (cam shaft), 8 ... Exhaust cam shaft (cam shaft), 10, 11 ... Cam cover part, 10a, 11a ... Lower part of cam cover part, 12 ... bottom, 12a ... inclined surface, 12d ... one end, 12e ... other end, 13 ... boss, 13a ... spark plug hole, 13b ... top surface, 20 ... breather chamber, O1 ... cylinder shaft

Claims (3)

A cylinder head cover provided in an internal combustion engine in which a cylinder axis is inclined with respect to a vertical direction,
A pair of cam cover portions extending along the extending direction of the pair of cam shafts so as to cover the pair of cam shafts and positioned on the upper side in the tilt direction and the lower side in the tilt direction of the internal combustion engine;
A bottom portion extending along the extending direction of the cam shaft by connecting a lower portion in the width direction in a direction orthogonal to the extending direction of the cam shaft in the pair of cam cover portions;
A boss provided at the bottom so as to be located above the cylinder of the internal combustion engine and having a spark plug hole;
A breather chamber that is provided in any one of the pair of cam cover portions and separates oil from blow-by gas.
The bottom portion is in relation to a horizontal plane as it goes from a lower portion inward in the width direction of the cam cover portion on the lower side in the inclination direction of the internal combustion engine to a lower portion in the width direction in the cam cover portion on the upper side in the inclination direction of the internal combustion engine. An inclined surface that inclines downward, and an absolute value of an inclination angle of the inclined surface with respect to the horizontal plane is larger than an absolute value of an inclination angle of the internal combustion engine with respect to the vertical direction, and the inclined surface The cylinder head cover is located below the top surface of the boss portion.   The vertical height of the cam cover portion provided on the lower side in the inclination direction of the internal combustion engine is formed higher than the vertical height of the cam cover portion provided on the upper side in the inclination direction of the internal combustion engine, The cylinder head cover for an internal combustion engine according to claim 1, wherein the breather chamber is formed in the cam cover portion on the lower side in the tilt direction.   The cylinder head cover for an internal combustion engine according to claim 1 or 2, wherein the bottom portion is inclined from one end of the bottom portion toward the other end along the extending direction of the cam shaft.

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