JPH0560014A - Cylinder head cover structure of internal combustion engine - Google Patents

Abstract

PURPOSE:To reduce noise of a cylinder head cover caused by resonance with engine vibration. CONSTITUTION:A pair of ribs 6 are provided on either one of an inner face or an outer face of a cylinder head cover 1 against a plug tower 2b, and a pair of projected parts 5 forming bent edges 5a are provided on both right and left on the other side. Either one of the ribs 6 and the bent edges 5a are extended in the radiated state from the plug tower 2b toward the outer edge of the cylinder head cover 1, and the other is arranged crossing with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder head cover structure for an internal combustion engine in which vibration noise is reduced.

[0002]

2. Description of the Related Art A cylinder tower cover of an internal combustion engine is provided with a plug tower that forms a plug hole.
In this plug tower, a plug cap for supplying electricity to the spark plug from the outside or an ignition coil directly connected to the spark plug is fixed or supported. However, in such a cylinder head cover structure, engine vibration is transmitted to the plug cap and the ignition coil through the ignition plug, and further transmitted to the cylinder head cover through the plug tower that fixes or supports the plug cap and the ignition coil. As a result, the cylinder head cover resonates and causes noise.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a cylinder head cover structure which reduces noise due to resonance with engine vibration.

[0004]

SUMMARY OF THE INVENTION According to the present invention to achieve the above object, a cylinder head cover mounted on an upper portion of a cylinder head is provided with a plug tower for forming a plug hole, and a plug cap or an ignition coil is fixed or supported on the plug tower. In the internal combustion engine described above, a rib that forms a pair with the periphery of the plug tower is provided on one of the outer surface and the inner surface of the cylinder head cover, and a convex portion that forms a pair of bent edges on the left and right sides on the other side. Is provided, and any one of the rib and the bent edge portion is radially extended from the plug tower toward the outer edge of the cylinder head cover, and the other is arranged in a relationship intersecting with each other. .

As described above, one of the outer surface and the inner surface of the cylinder head cover is provided with a pair of ribs for the periphery of the plug tower, and the other is provided with a convex portion having bent edge portions on both left and right sides. In addition, since the ribs and the bent edges intersect each other between the outer surface and the inner surface and one of them is extended radially from the plug tower to the outer edge of the cylinder head cover, the rigidity around the plug hole is increased. Is improved, and as a result, resonance due to engine vibration of the cylinder head cover is suppressed.

In the present invention, the effect of improving the rigidity can be achieved by providing one of the rib and the convex portion on the outer surface of the cylinder head cover and the other on the inner surface, but it is preferable that the rib and the convex portion be provided. Is preferably provided on the inner surface side and the convex portion is provided on the outer surface side. By providing the rib on the inner surface side in this way,
The rib can also be used as a partition wall forming a breather chamber for separating the lubricating oil, which can be advantageous for downsizing the structure.

[0007]

1 to 4 are four-cylinder internal combustion engines (three intake valves and two exhaust valves per cylinder) according to an embodiment of the present invention.
The main parts of Fig. 5 and Fig. 5 and 6 show the inside of the chain case. This internal combustion engine is configured by mounting a cylinder head on the upper part of a cylinder block and mounting a cylinder head cover on the upper part of the cylinder head, as is well known.

1 and 2 show a cylinder head cover which constitutes such an internal combustion engine. FIG. 1 shows the outer surface side and FIG. 2 shows the inner surface side. In the central portion of the cylinder head cover 1, plug towers 2b that form four plug holes 2a corresponding to four cylinders are provided in rows, and the ignition coils 3 are respectively supported by the plug towers 2b ( However, only one place is shown in FIG. 1). A groove-shaped recess 4a is formed along the plug towers 2b arranged in a row, and a groove-shaped recess 4b extending from the end of the groove 4a to the outer edge of the cylinder head cover. The recesses 4a and 4b are formed. The wire harness in which the lead wires and the like for guiding electricity to the ignition coil are converged is stored.

On the outer surface side of the cylinder head cover 1,
The convex portions 5 are formed so as to be arranged at regular intervals at positions facing each other with the plug holes 2a arranged in a line therebetween. The convex portion 5 has bent edge portions 5a, 5a formed on both left and right sides thereof, and the bent edge portion 5a extends from the central region of the cylinder head cover 1 toward the outer edge. On the other hand, on the inner surface side of the cylinder head cover 1, as shown in FIG. 2, a pair of ribs 6 radially extending from the periphery of each plug tower 2b toward the outer edge are formed, and each plug tower 2b is further formed.
Ribs 6 are also provided for connecting the columns in the column direction. Among these ribs, a pair of radially extending ribs 6 are arranged so that the bent edge portion 5a of the convex portion 5 provided on the outer surface side intersects. Since the rib 6 and the bent edge portion 5a are provided so as to intersect with each other around the plug tower 2b in this manner, the rigidity around the plug hole is significantly improved, resonance of engine vibration is suppressed, and noise is reduced. be able to.

Further, the rib 6 on the inner surface side is covered with a plate so that a portion hatched by a chain line forms a gap between the rib 6 and the tip of the rib, and one rib is formed as a partition wall 6a at this portion. Two breather chambers 7 and 8 are formed. These breather chambers 7 and 8 are communicated with a lower cam chamber (not shown) through openings 9 and 10, and blow-by gas is introduced to repeat compression and expansion to separate mist-like lubricating oil. I am trying. Of the two breather chambers, one breather chamber 7 is connected to an external breather device (not shown) via a connecting pipe 11, and the other breather chamber 8 is connected.
Is connected to an intake system (not shown) via a connecting pipe 12.

3 and 4, FIG. 3 shows the upper surface of the cylinder head, and FIG. 4 shows the lower surface of the cylinder head. The cylinder head 20 has four plug holes 2a at the center thereof corresponding to the four cylinders.
The plug towers 2b forming the above are provided in a row, and each plug hole 2a communicates with the lower combustion chamber 21 (FIG. 4). Three lifter guides 22 are provided on the intake port side of each plug hole 2a corresponding to three intake valves per cylinder, and two exhaust valves are provided on the exhaust port side per cylinder. Two lifter guides 23 are provided corresponding to the above.

Further, on the outer wall surface of each plug tower 2b,
Horizontally extending ribs 24 are integrally formed on both sides thereof, and the ribs 24 are formed so as to be widened toward the intake side lifter guide 22. By installing such ribs 24, the rigidity of the plug hole 2a and the lifter guides 22 and 23 is improved. A cam shaft 25 that drives an intake valve is provided above one lifter guide 22, and a cam shaft 26 that drives an exhaust valve is provided above the other lifter guide 23. The variable valve timing device 2 is provided at the end of the camshaft 25 on the intake side.
A sprocket 28 is formed on the outer periphery of the sprocket 28. A drive sprocket 29 is fixed to one end of the camshaft 26 on the exhaust side, and two camshaft angle sensors 31 are provided opposite to the other end.

The cam chain case 32 for accommodating the sprockets 28, 29 is provided with an opening corresponding to bolts 33, 34 for fixing the sprockets 28, 29 to the ends of the cam shafts 25, 26, respectively. Bolts 33,3
There are provided lids 35 and 36 which are recessed so as to avoid 4. Further, as shown in FIG. 4, in the cylinder head 20, a gas passage 37 for blow-by gas is provided below the intake port.
And an oil return passage 38 for returning the lubricating oil that has lubricated the cam and the cam bearing, etc., are provided integrally and in parallel. 39 is an ascending passage for blow-by gas rising from the crank chamber, 40
Is a passage for returning the separated lubricating oil to the crank chamber.

5 and 6 show the inside of the cam chain case. 25 and 26 are the above-mentioned cam shafts, 41 is a crank shaft, 42 is a cooling water pump, and 43 is an oil pump.
The cooling water pump 42 and the oil pump 43 are mounted on the surface of a cam chain case 44 mounted on the side surface of the cylinder block 50. The housings of the cooling water pump 42 and the oil pump 43 are provided in the cam chain case 44.
Are integrally formed with each other (see FIG. 6).

[0015]

As described above, the cylinder head cover of the present invention is provided with a pair of ribs on one of the outer surface and the inner surface, and on the other is provided with a convex portion having bent edges on both left and right sides,
These ribs and bent edges intersect each other between the outer surface and the inner surface, and one of them has a structure that extends radially from the periphery of the plug tower toward the outer edge of the cylinder head cover. The action of the bent edge improves the rigidity around the plug hole. Therefore, the cylinder head cover is suppressed from resonating with engine vibration, and noise can be reduced.

[Brief description of drawings]

FIG. 1 is a top view of a cylinder head cover of an internal combustion engine according to an embodiment of the present invention.

2 is a bottom view of the cylinder head cover of FIG. 1. FIG.

FIG. 3 is a top view of a cylinder head of the internal combustion engine.

FIG. 4 is a bottom view of the cylinder head.

FIG. 5 is a side view showing the inside of the cam chain case of the internal combustion engine without the cover.

6 is a sectional view taken along the line AA of FIG.

[Explanation of symbols]

1 Cylinder head cover 2a Plug hole
2b Plug tower 3 Ignition coil 5 Convex part
5a Bend edge 6 Rib 20 Cylinder head 5
0 cylinder block

Claims (1)

[Claims] 1. An internal combustion engine in which a cylinder head cover mounted on an upper part of a cylinder head is provided with a plug tower for forming a plug hole, and a plug cap or an ignition coil is fixed to or supported by the plug tower, the inner surface and the inner surface of the cylinder head cover. One of the surfaces is provided with a pair of ribs for the plug tower, and the other is provided with a convex portion forming a pair of bent edges on the left and right sides, and one of the rib and the bent edge is provided. A cylinder head cover structure for an internal combustion engine, which extends radially from the plug tower toward the outer edge of the cylinder head cover, and the other of them is arranged in a crossing relationship with each other.