JPH0618045Y2 - Engine cylinder head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an engine cylinder head provided with a sound insulation cover other than a valve chamber cover.

(Prior Art) Conventionally, in a cylinder head of an engine, oil for lubrication is supplied to a valve operating mechanism arranged above the cylinder head to prevent scattering of this oil and mixing of foreign matter into the oil. A structure in which a valve operating chamber cover is provided for the purpose of providing a sound insulating cover on the outside of the valve operating chamber cover is known as disclosed in Japanese Utility Model Publication No. 59-32783.

The sound insulation cover is arranged to reduce the noise from the valve operating mechanism propagating to the outside through the valve operating chamber cover and, in the case where the fuel injection valve is installed, to cover the fuel injection valve and reduce the noise from it. There is.

(Problems to be solved by the invention) However, in the structure in which the valve chamber cover and the sound insulating cover are installed as described above, if the sealability between the cylinder head and the valve chamber cover is low, the internal There is a problem that the oil leaks. Further, generally, when the engine temperature rises, when the cylinder head is made of an aluminum alloy and the cylinder block is made of cast iron, the cylinder head bends between the head bolts due to the difference in thermal expansion when the two are fastened with head bolts. If the deformation is large as described above, there is a possibility that the gas sealing property between the both and the valve chamber cover sealing property may be impaired.

Further, regarding the installation of the structure for improving the sealing performance of the valve chamber cover and suppressing the thermal deformation of the cylinder head as described above, it is preferable that the increase in weight of the cylinder head be as small as possible.

In view of the above circumstances, the present invention has an object to provide a cylinder head for an engine that effectively suppresses an increase in weight and improves the sealing performance of the valve chamber cover and suppresses thermal deformation of the cylinder head. To do.

(Means for Solving the Problems) In order to achieve the above object, the cylinder head of the present invention has a valve chamber cover attached to the upper portion of the cylinder head, and
Regarding the sound insulating cover for covering the valve chamber cover, the sound insulating cover is provided with a pressing portion for pressing the seal portion of the valve chamber cover from above, and a head bolt fastening portion at the end of the cylinder head cylinder row. The sealing surface is formed on a part of the sealing surface, and the sealing surface is formed integrally with the reinforcing ribs between the head bolt fastening portions and the extension portions.

(Operation) In the cylinder head of the engine as described above, the sealing surface for attaching the valve operating chamber cover and the reinforcing ribs between the head bolt fastening portions and the extending portions can effectively reinforce this portion. Deformation of the head in the direction orthogonal to the cylinder row is suppressed, deformation at the time of engine temperature rise is reduced, and the sealing performance with the cylinder block is improved, and between the valve operating chamber cover and the sealing surface of the cylinder head. The sealing performance of the above is also improved by the pressing by the pressing portion of the sound insulation cover and the suppression of deformation of the cylinder head.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a plane structure of a cylinder head, FIG. 2 is a sectional structure taken in a direction orthogonal to a cylinder row, FIG. 3 is a sectional structure taken along a cylinder row of a cover portion, and FIG. The plane structure of a cylinder head is shown, respectively.

Above the cylinder head 2 of the engine 1, a rocker arm 4 of a valve mechanism that opens and closes the intake and exhaust valves 3 of each cylinder swings on a rocker shaft 5 supported by a bearing member 2a standing on the cylinder head 2. A valve operating chamber cover 6 that is movably supported and covers the valve operating mechanism is provided.

Further, on the cylinder head 2, outside the valve chamber cover 6,
A fuel injection valve 7 for injecting fuel is arranged in each cylinder, and a fuel supply pipe 8 is connected to the fuel injection valve 7. Further, an intake manifold 9 for supplying intake air to each cylinder is attached to a side surface of the cylinder head 2 on the fuel injection valve 7 side, and an exhaust manifold 10 is attached to an opposite side surface of the cylinder head 2. The intake manifold 9 includes a surge tank 9a.
A branch pipe 9b is connected to each cylinder. Further, head bolts 11 for fastening the cylinder head 2 to a cylinder block (not shown) are head bolts arranged on both sides of the center of each cylinder with respect to the cylinder row, both sides between cylinders, and both ends of the cylinder row. It is applied to the bolt fastening portion 12, and six head bolts 11 are provided on the outer circumference of each cylinder so as to be fastened at positions at substantially equal intervals. A sound insulation cover 14 is provided to cover the fuel injection valve 7 and the branch pipe 9b of the intake manifold 9 from the valve chamber cover 6.

The valve operating chamber cover 6 is attached by abutting the seal material 15 of the seal portion 6a at the lower end of the outer periphery against the seal surface 16 formed on the upper portion of the cylinder head 2 and tightening nuts 18 to the attachment bolts 17 at the three upper portions. Has been. The head bolt 11 on the exhaust side is covered with the valve operating chamber cover 6. An oil separator chamber 19 (internal structure not shown) is formed by bulging upward at the upper part of the valve operating chamber cover 6, and a blow-by gas take-out portion 20 is formed from the oil separator chamber 19 to the intake side. There is.

On the other hand, the sound insulation cover 14 is attached to the mounting bolt 17 for mounting the valve operating chamber cover 6 to the cylinder head 2 by tightening the nut 21, and the portion on the intake side is fixed to the branch pipe 9b of the intake manifold 9. It is attached at 22. In the sound insulation cover 14, the seal portion 6a of the valve chamber cover 6 that abuts on the seal surface 16 on the upper portion of the cylinder head 2 in the exhaust side portion and the cylinder row end portion side of the valve chamber cover 6 is insulated. By attaching the cover 14, a pressing portion 14a that is pressed from above is formed. The pressing portion 14a is configured such that the sealing material 23 at the lower end portion of the sound insulation cover 14 comes into contact with and presses the upper portion of the outer peripheral side of the sealing portion 6a of the valve operating chamber cover 6. The sealing material 23 on the other portion of the sound insulating cover 14 is in contact with the upper surface of the cylinder head 2 and the contact surface of the intake manifold 9.

At the end of the cylinder row of the cylinder head 2, an exhaust-side head bolt fastening portion 12a for fastening the head bolt 11 is formed on a part of the sealing surface 16 that abuts the sealing portion 6a of the valve operating chamber cover 6. The exhaust side head bolt fastening portion 12a and the intake side head bolt fastening portion 12
Reinforcing ribs 24 for connecting with b are integrally formed continuously from the sealing surface 16, and further, the reinforcing ribs 24 are extended from the intake side head bolt fastening portion 12b to the intake side surface, and are also integrated with this extended portion. Has been formed. The sealing material 23 of the sound insulating cover 14 is brought into contact with the upper surface of the reinforcing rib 24 excluding the head bolt fastening portion 12b to enhance the sound insulating effect.

An oil supply port 25 is provided on the upper surface of the valve operating chamber cover 6 so as to penetrate the sound insulation cover 14 upward. Further, a fuel supply pipe 8 connected to the fuel injection valve 7
Is a fixing member 26 fixed to the side surface of the cylinder head 2.
And is connected to a fuel injection pump (not shown) through between the branch pipes 9b of the intake manifold 9 and below the surge tank 9a.

In the structure of the above embodiment, the sealing portion 6a of the moving piece chamber cover 6 is used.
To the contact surface between the cylinder head 2 and the sealing surface 16 of the cylinder head 2.
The sound insulating cover 14 is provided so that the pressing portion 14a presses the sealing portion 6a against the sealing surface 16, and the valve operating chamber cover 6 is provided.
The oil seal between the cylinder head 2 and the cylinder head 2 is improved to prevent leakage of oil for lubricating the valve operating mechanism and to prevent foreign matter from entering from the outside, and the seal portions of both covers are overlapped to seal the cylinder head 2 side. Can be formed narrow.
Further, the sound insulation cover 14 is extended from above the valve operating chamber cover 6 to the fuel injection valve 7 and the intake manifold 9 to suppress the external propagation of noise generated from the valve operating mechanism, the fuel injection valve 7 and the like. The engine noise can be reduced.

Further, a seal surface 16 for attaching the valve operating chamber cover 6 above the cylinder head 2 at the end of the cylinder row and the reinforcing ribs 24 between the head bolt fastening portion 12 and the extension portion are integrally and continuously formed. By reinforcing the end portion of the cylinder head by means of the member, it is possible to suppress deformation of the cylinder head 2 in the direction orthogonal to the cylinder row when the engine temperature rises, and to improve the flatness between the lower surface of the cylinder head and the cylinder block. By maintaining it, the sealing performance is improved, and the upper surface of the cylinder head is less deformed, and the sealing performance with the valve operating chamber cover 6 can be improved.

(Effect of the Invention) According to the present invention as described above, the sealing surface that abuts the seal portion of the valve chamber cover at the end of the cylinder row of the cylinder head and the reinforcing ribs between the head bolt fastening portion and the extension portion are integrated. By forming this, it is possible to effectively reinforce this part with a minimum increase in weight, deformation of the cylinder head in the direction orthogonal to the cylinder row is suppressed, deformation at the time of engine temperature increase is small, and a seal with the cylinder block is formed. In addition to improving the performance, the sealing property between the valve operating chamber cover and the sealing surface of the cylinder head can be improved by the pressing by the pressing portion of the sound insulation cover and the deformation suppression of the cylinder head.

[Brief description of drawings]

FIG. 1 is a plan view showing a cylinder head of an engine according to an embodiment of the present invention, FIG. 2 is a sectional side view of the cylinder head taken along a portion of a fuel injection valve in a direction orthogonal to a cylinder row, and FIG. Is a sectional front view of the cover portion, and FIG. 4 is a plan view of the upper surface of the cylinder head. 1 ... Engine, 2 ... Cylinder head, 6 ... Valve chamber cover, 6a ... Seal part, 7 ... Fuel injection valve, 9 ...
Intake manifold, 11 ... Head bolts, 12, 12
a, 12b ... Head bolt fastening portion, 14 ... Sound insulation cover, 14a ... Pressing portion, 16 ... Sealing surface, 24 ... Reinforcing rib.

Claims (1)

[Scope of utility model registration request] 1. A valve chamber cover is attached by abutting a seal portion on a seal surface formed on an upper portion of a cylinder head, and
In a cylinder head of an engine in which a sound-insulating cover that covers the valve-chamber cover is provided, the sound-insulating cover is pressed from above by pressing the seal portion of the valve-chamber cover that is in contact with the seal surface of the upper portion of the cylinder head. And a head bolt fastening portion at the end of the cylinder head cylinder row is set at the same height as the sealing surface and is formed on a part of the sealing surface, and the sealing surface is provided between the head bolt fastening portions and the extension portion. A cylinder head for an engine, characterized by being integrally formed with the reinforcing rib of.