JP2583845Y2 - cylinder head - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder head.

[0002]

2. Description of the Related Art FIGS. 5 to 7 show an example of a general cylinder head. The cylinder head has an intake port 1 and an exhaust port 2 and has a water jacket 3 for cooling therein. The head bolt 5 is inserted into a head bolt boss 4 provided at a required pitch in the circumferential direction at a position corresponding to the outer peripheral edge of each cylinder bore 6a of the cylinder block 6, and tightened. The upper part is fixed via a head gasket 7.

In the drawing, reference numeral 8 denotes a nozzle hole formed at the center of a cylinder bore 6a for inserting an injection nozzle, 9 denotes a cast hole for pressing a core of the water jacket 3 during casting of a cylinder head, and 10 denotes a cast hole. Intake port 1 and exhaust port 2
These are valve guide bosses for intake and exhaust valves that open and close respectively.

[0004]

However, since the cylinder head as described above is fixed on the cylinder block 6 by tightening the head bolt 5 on the head bolt boss 4, the state shown in FIG. As shown in FIG. 6B, when an upward load F is applied by an explosion in the cylinder bore 6a, a portion of the cylinder head on the cylinder bore 6a is lifted, and the bottom portion 11 of the cylinder head is distorted and the water jacket is displaced. In addition to the high tensile stress generated at the corners A, B, etc. of the third cylinder, the distortion of the bottom surface 11 of the cylinder head causes absorption and partial contact of the exhaust valve, which causes abnormal wear of the valve. I was

For this reason, it is very important to suppress the deformation of the bottom 11 of the cylinder head, and the ceiling 12
It is clear that increasing the thickness of the ceiling portion 12 or increasing the thickness of the valve guide boss 10 is an effective means, but increasing the thickness of the ceiling portion 12 over the entire surface significantly increases the weight. Also, simply increasing the thickness of the valve guide boss 10 may deteriorate the cooling state of the valve guide boss 10 and cause a failure such as seizure of the valve stem.

In view of such circumstances, the present invention can secure the rigidity and suppress the deformation without deteriorating the cooling state of the valve guide boss while minimizing the weight increase, thereby reducing the stress and operating the valve. It is an object of the present invention to provide a cylinder head capable of achieving smoothness.

[0007]

According to the present invention, in a cylinder head fixed on a cylinder block via a head gasket, a ceiling portion between a pair of head bolt bosses located diagonally across a cylinder bore center is provided. Said
The present invention relates to a cylinder head having a thick portion formed between a pair of head bolt bosses and a valve guide boss located on the cylinder bore .

On the other hand, a reinforcing rib extending in the vertical direction may be protruded at a required position on the outer periphery of the valve guide boss on the center of the cylinder bore.

[0009]

Accordingly, the ceiling portion between a pair of head bolt bosses located diagonally across the center of the cylinder bore is provided on the ceiling portion.
A pair of head bolt bosses, the case of a cylinder head forming a thick portion which connects the valve guide boss located on the cylinder bore, even acts upward load by the explosion in the cylinder bore, the ceiling thick portions As a result, the rigidity of the cylinder head is increased, so that the portion of the cylinder head above the cylinder bore becomes difficult to lift, and the bottom portion of the cylinder head hardly deforms, and high tensile stress is generated at the corner of the water jacket. In addition, abnormal wear of the intake and exhaust valves due to one-sided contact of the intake and exhaust valves does not occur.

Further, in this case, a significant increase in weight can be avoided by forming the thick portion only on a portion effective for increasing the rigidity, instead of increasing the thickness of the ceiling portion over the entire surface.

On the other hand, in the case of a cylinder head having a vertically extending reinforcing rib protruding at a required position on the outer periphery of the valve guide boss at the center of the cylinder bore, the rigidity of the cylinder head is increased by the reinforcing rib. Even when an upward load is applied, the portion above the cylinder bore of the cylinder head becomes difficult to lift, the bottom portion of the cylinder head is hardly deformed, and high tensile stress does not occur at the corner of the water jacket. At the same time, abnormal wear of the intake and exhaust valves due to one-sided contact of the valves and the like does not occur.

In this case, the valve guide boss is not simply thickened, but the reinforcing rib is protruded at a portion effective for increasing the rigidity, so that the wall thickness of the valve guide boss partially increases. Since the ribs are shaped like cooling fins, the surface area of the valve guide boss in the water jacket is increased, the cooling state is not deteriorated, and troubles such as seizure of the valve stem are avoided.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show an embodiment of the present invention. In the drawings, the portions denoted by the same reference numerals as those in FIGS. 5 to 7 represent the same components, and the basic configuration is shown in FIG. 7 is the same as the conventional one shown in FIG. 7, but the feature of this embodiment is that, as shown in FIGS. 1 and 2, a pair of head bolt bosses 4 located diagonally across the center of the cylinder bore 6a. the ceiling portion 12 between a pair of head bolt bosses 4,
Valve guide boss 1 located on the cylinder bore 6a
The point is that a thick portion 12a connecting to 0 is formed.

Since the cylinder bore 6 is constructed as described above,
Even if an upward load F is applied by an explosion in the cylinder head a, the rigidity of the cylinder head is increased by the thick portion 12a of the ceiling portion 12, so that the portion of the cylinder head above the cylinder bore 6a becomes difficult to be lifted. , The bottom portion 11 of the cylinder head hardly deforms,
A high tensile stress does not occur at the corner of the water jacket 3 and abnormal wear of the intake and exhaust valves due to a partial contact of the valves does not occur.

Further, in the case of the present embodiment, the thickness of the ceiling portion 12 is not increased over the entire surface, but the thick portion 12a is formed only at a portion effective for increasing the rigidity. Can be avoided.

The inner diameter of the cylinder bore 6a is 90 to 16
In the case of a 0 mm engine, the thickness t of the general portion of the ceiling 12
Is 5 to 10 mm, and it is effective to set the thickness T of the thick portion 12a of the ceiling portion 12 to 10 to 20 mm. In this case,
It has been confirmed that an increase in rigidity of about 20 to 30% can be expected with a weight increase of 5 to 10%.

Thus, increase in weight can be minimized, rigidity can be ensured, deformation can be suppressed, stress can be reduced, and valve operation can be facilitated. In this embodiment, it goes without saying that the cooling state of the valve guide boss 10 does not deteriorate.

FIGS. 3 and 4 show another embodiment of the present invention. In the drawings, the same reference numerals as those in FIGS. 1 and 2 denote the same parts. A reinforcing rib 10a extending in the up-down direction is provided at a required position on the center side of the cylinder bore 6a.

In the embodiment shown in FIGS. 3 and 4, since the rigidity of the cylinder head is increased by the reinforcing rib 10a protruding from the outer periphery of the valve guide boss 10, the upward load F due to the explosion in the cylinder bore 6a is increased. Even if it acts, the portion of the cylinder head above the cylinder bore 6a is difficult to lift, and the bottom 1
1 hardly deforms, no high tensile stress is generated at the corners of the water jacket 3, and
Abnormal wear and the like of the intake and exhaust valves due to one-sided contact of the valves will not occur.

In this case, the valve guide boss 10 is not simply thickened, but the reinforcing rib 10a is protruded from a portion effective for increasing the rigidity.
Although the thickness of the valve guide boss 10 is slightly increased, the reinforcing rib 10a is shaped like a cooling fin.
The surface area in the water jacket 3 is increased, the cooling state is not deteriorated, and troubles such as seizure of the valve stem are avoided.

The inner diameter of the cylinder bore 6a is 90 to 16
In the case of a 0 mm engine, the thickness B of the reinforcing rib 10a is set to 5
And the width H of the reinforcing rib 10a is 5 to 10 mm.
Has been confirmed to be effective.

Thus, in the embodiment shown in FIGS. 3 and 4, rigidity can be secured and deformation can be suppressed without deteriorating the cooling state of the valve guide boss 10, thereby reducing stress and smoothing valve operation. I can figure it out. In this embodiment, it is needless to say that an increase in weight can be minimized.

It should be noted that the cylinder head of the present invention is not limited to the above-described embodiment, but may be variously modified without departing from the gist of the present invention.

[0025]

As described above, according to the cylinder head of the present invention, the increase in weight is minimized, the rigidity is secured and the deformation is suppressed without deteriorating the cooling state of the valve guide boss. In addition, an excellent effect of reducing stress and facilitating valve operation can be achieved.

[Brief description of the drawings]

FIG. 1 is a side sectional view of one embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a side sectional view of another embodiment of the present invention.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 3;

FIG. 5 is a plan sectional view of a general cylinder head.

FIG. 6 is a sectional view taken along line VI-VI of FIG. 5;

FIG. 7 is a sectional view taken along line VII-VII of FIG. 6;

[Explanation of symbols]

 4 Head Bolt Boss 6 Cylinder Block 6a Cylinder Bore 7 Head Gasket 10 Valve Guide Boss 10a Reinforcing Rib 12 Ceiling 12a Thick

Claims (2)

(57) [Scope of request for utility model registration] 1. A cylinder head that is fixed via a head gasket on the cylinder block, a ceiling portion between the pair of head bolt bosses located diagonally across the cylinder bore center, and the pair of head bolt bosses, A cylinder head having a thick portion connected to a valve guide boss located on the cylinder bore . 2. A cylinder head fixed on a cylinder block via a head gasket, wherein a reinforcing rib extending in a vertical direction is protrudingly provided at a required position on the outer periphery of a valve guide boss on a center of a cylinder bore. .