JPH088286Y2 - Engine cylinder head structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention discloses a cylinder head of an engine such as a V-type 6-cylinder DOHC engine in which a support boss of a pivot, which serves as a rocking fulcrum of a rocker arm, is integrally formed with the cylinder head. Regarding the structure.

(Prior Art) Conventionally, as a cylinder head structure of an engine of the above-mentioned example, there is a cylinder head structure of a DOHC engine described in JP-A-63-38667.

That is, an ignition plug hole is provided in a portion corresponding to the bore center of the cylinder block (bore center portion), and a total of four pivot support bores serving as rocking arm swinging fulcrums are provided to the front, rear, left and right in the crank axis direction of the ignition plug hole.
A cylinder head structure of a V-type 6-cylinder DOHC engine in which the vertical walls of the spark plug hole are connected by a reinforcing wall (upper deck) that is substantially parallel to the ceiling wall (middle deck) of the water jacket on the bore center line. However, in the 4-valve type in which the drilling points are concentrated in one place, the supporting rigidity of the HLA as a pivot is not sufficient, and it is not possible to improve the engine rotation limit by participating in the valve train. I had a problem.

(Object of the Invention) The present invention can construct a lightweight and high-rigidity cylinder head, and significantly improve the support rigidity of the pivot to improve the engine rotation limit, while at the same time, improve the castability of the core. It is an object of the present invention to provide an engine cylinder head structure capable of improving the engine.

(Constitution of device) This device has an ignition plug hole at the center of the bore.
A pivot support boss that serves as a rocking fulcrum of the rocker arm is provided at least in the front and rear of the spark plug hole in the crankshaft direction. The support boss is provided close to the spark plug hole and above the ceiling wall of the water jacket. In the cylinder head structure of the engine provided, between the ignition plug holes on the bore center line connecting the centers of the adjacent bores, an opening is made in the ceiling wall of the water jacket, and a plug member is fitted after the water jacket is formed. An opening of the core support hole to be closed is provided, the vertical wall having an inner peripheral edge that is wider than the inner peripheral edge of the opening as viewed in the axial direction of the ignition plug hole, and extending upward from the ceiling wall of the water jacket. The opening is surrounded, and only the space between the vertical wall of the core support hole and the vertical wall of the spark plug hole is Serial connecting the ceiling wall and the top wall substantially parallel of the water jacket, characterized in that the upper wall is e cylinder head structure for an engine that forms part of the pivot support boss.

(Effect of the Invention) According to this invention, the vertical walls of the core supporting hole and the ignition plug hole, which are located relatively close to each other, are connected to each other by the above-mentioned upper wall, and a hollow closed cross section is formed by them. Since this upper wall constitutes a part of the support boss of the pivot, it is possible to significantly improve the support rigidity of the pivot due to the above-described closed cross-section rigidity, and as a result, the displacement of the part that affects the valve lift performance is reduced. There is an effect that it can be suppressed and the engine rotation limit can be improved.

In addition, since the vertical wall of the core supporting hole is wider than the opening of the core supporting hole, the vertical wall is closer to the vertical wall of the ignition plug hole by that amount, and the upper wall has The rigidity around the spark plug hole when the two vertical walls are connected is sufficiently improved.

Further, by arranging the core support for supporting the core for forming the water jacket at the opening of the core support hole, the core support can prevent the core from rising due to buoyancy during casting. Since the lifting is prevented, there is an effect that the castability by the core can be improved, and a lightweight and highly rigid cylinder head as a whole can be obtained.

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

The drawings show the structure of a cylinder head of one side bank in a V-type 6-cylinder DOHC engine. In FIGS. 1 to 3, a cylinder head 2 is fixed to an upper portion of a cylinder block 1, and a valve operating valve is provided above the cylinder head 2. A cylinder head cover 14 that surrounds the chamber 3 is fixed.

The V-type engine described above has two intake valves and two exhaust valves.
A spark plug hole 6 is formed at a predetermined position of the above-mentioned cylinder head 2 corresponding to the center of the bore 5 of the cylinder block 1 (hereinafter simply referred to as the center of the bore), and the crankshaft of the spark plug hole 6 is formed. As shown in FIG. 1 of Japanese Patent Application Laid-Open No. 63-38667, the support boss 8 for the pivot, which serves as the rocking fulcrum of the rocker arm 7, is provided in the front, rear, left, and right directions.
A total of four cylinders are provided.

The pivot support boss 8 is provided near the ignition plug hole 6 and above the ceiling wall 22 of the water jacket 23 described later.

The rocker arm 7 driven by the respective cams 10 of the cam shafts 9, 9 has an intake / exhaust valve at the swing end.
The upper end of the valve stem 12 of 11 is pressed, and the valve spring 16 is stretched between the spring retainer 14 arranged on the upper end of the valve stem 12 via the split cotter 13 and the spring seat 15 of the cylinder head 2. ing.

The above-mentioned valve stem 12 is arranged in a valve guide hole 17 formed in the cylinder head 2 via a valve guide 18.

Thus, the camshafts 9 and 9 are driven to open and close the intake port 19 and the exhaust port 20 through the valve mechanism and the intake and exhaust valves 11 ...

By the way, the bottom deck 21 of the cylinder head 2 described above.
A water jacket 23 formed by a core is provided between the and the middle deck 22.

Further, an opening 25 of a core support hole is formed between the above-mentioned ignition plug holes 6 and 6 on the bore center line to form a vertical wall 24 extending above the middle deck 22 as the ceiling wall of the water jacket 23. ing.

Open the opening 25 of this core support hole with a water jacket.
After forming 23, the plug member is fitted and closed, and the opening 25 is located above the ignition plug hole 6 in the axial direction, that is, when viewed from a plane, the inner peripheral edge of the opening 25 is larger than the inner peripheral edge of the opening 25. Is surrounded by the vertical wall 24 described above.

The vertical wall 24 described above is a rectangular frame-shaped vertical wall when viewed from above, and the vertical wall 24 of the core support hole and the above-mentioned ignition plug hole 6
The upper deck 27 is connected to each other only between the vertical wall 26 and the middle deck 22 by the upper deck 27 which is substantially parallel to the middle deck 22 to form a part of the support boss 8 of the pivot.

Further, an oil return passage 28 communicating with the valve operating chamber 3 is formed in a portion surrounded by the above-mentioned middle deck 22, upper deck 27, and both vertical walls 24, 26.

Furthermore, on the upper surface of the above-mentioned middle deck 22, there is integrally formed a rib 29 that joins the outer peripheral surface 28 of the vertical wall 24 of the core supporting hole in the crankshaft direction.

In the figure, 30 is a spark plug, 31 is a head bolt hole for fixing the cylinder head 2 to the cylinder block 1,
32 is a head bolt boss.

In this way, only the vertical wall 24 of the core supporting hole and the vertical wall 26 of the ignition plug hole 6 which are relatively close to each other are connected by the upper deck 27 described above, thereby forming a hollow closed cross section. In addition, since the upper deck 27 is formed as a part of the support boss 8 of the pivot, specifically, the HLA, it is possible to significantly improve the support rigidity of the pivot due to the above-mentioned closed cross-section rigidity, and as a result, the valve lift. There is an effect that displacement of a portion that affects performance can be suppressed and the rotation limit of the engine can be improved.

In addition, since the vertical wall 24 of the core support hole is wider than the opening 25 of the core support hole, the vertical wall 24 is closer to the vertical wall of the ignition plug hole 6 by that amount.
When the upper deck 27 connects the vertical walls 24, 26, the rigidity around the ignition plug hole 6 is sufficiently improved.

On the other hand, when casting the cylinder head 2 described above,
The core support for supporting the core for forming the water jacket 23 is formed by the opening 2 of the core support hole formed between the bores.
It is arranged in 5,25, and these core supports prevent the core from floating due to the pressure of the molten metal during casting (especially when pouring) from above, and prevent the core from floating well.
The core has an effect of improving the castability, and it is possible to obtain the lightweight and highly rigid cylinder head 2 as a whole.

The casting sand (core sand) that forms the core is removed from the casting hole by using a high-pressure compressed fluid or the like after casting.

In the correspondence between the configuration of the present invention and the above-described embodiment, the engine of the present invention corresponds to the V-type 6-cylinder DOHC engine of the embodiment, and the ceiling wall of the water jacket corresponds to the middle deck 22. However, the upper wall corresponds to the upper deck 27, but the present invention is not limited to the configuration of the above-described embodiment.

[Brief description of drawings]

The drawings show one embodiment of the present invention, FIG. 1 is a sectional view showing a cylinder head structure of one side bank in a V-type 6-cylinder DOHC engine, and FIG. 2 is a sectional view taken along the line AA of FIG. FIG. 3 is a sectional view taken along the line BB of FIG. 2 ... Cylinder head, 5 ... Bore 6 ... Spark plug hole, 7 ... Rocker arm 8 ... Support boss 22 ... Middle deck (ceiling wall) 23 ... Water jacket 24 ... Vertical wall of core support hole 25 …… Opening of core support hole 26 …… Vertical wall of spark plug hole 27 …… Upper deck (upper wall)

Claims (1)

[Scope of utility model registration request] 1. A pivot support which has a spark plug hole (6) at the center of a bore (5) and which serves as a rocking fulcrum of a rocker arm (7) at least in the front and rear of the spark plug hole (6) in the crankshaft direction. A boss (8) is provided, and the support boss (8) is provided close to the ignition plug hole (6) and is provided above the ceiling wall (22) of the water jacket (23) for an engine cylinder head. In the structure, on the ceiling wall (22) of the water jacket (23), between the spark plug holes (6) and (6) on the center line of the bore (5) connecting the centers of the adjacent bores (5) and (5). Is opened,
After forming the water jacket (23), an opening portion (25) of the core support hole that is closed by fitting a plug member is provided, and inside the opening portion (25) when viewed from the axial direction of the ignition plug hole (6). The opening (25) is surrounded by a vertical wall (24) having an inner peripheral edge extending from the peripheral edge and extending upward from the ceiling wall (22) of the water jacket (23), and the vertical wall of the core supporting hole is formed. Only between the (24) and the vertical wall (26) of the spark plug hole (6) is connected an upper wall (27) substantially parallel to the ceiling wall (22) of the water jacket (23), and the upper wall (2
A cylinder head structure for an engine in which 7) is a part of the support boss (8) of the pivot.