JPS5825860B2 - cylinder head of internal combustion engine - Google Patents

Description

Detailed Description of the Invention When the cylinder head of an internal combustion engine is fixed to the crankcase by using four or more cylinder head tightening bolts for each cylinder, for example, six, as shown in Figs. 1 and 2, , the case where the bolts 2 are arranged and tightened symmetrically on the crankshaft center line on the cylinder head 1 and at approximately equal intervals;
As shown in the figure, six bolts 2 may be arranged at irregular intervals.

In the figure, 3 and 4 are an intake passage and an exhaust passage. In the former case, since the bolts of adjacent cylinders are close to each other as shown by 1, the cylinder spacing becomes large, and this tendency is particularly noticeable in in-line engines.

In the latter case, the bolts 2 will be arranged at uneven intervals, so
The tightening force of the cylinder head 1 becomes uneven, which tends to cause gas leakage, and the bolts of adjacent cylinders are also close together as shown by 2", which is disadvantageous for the strength of the crankcase. The passages 3 and 4 are arranged in areas with wide bolt spacing, and cannot be arranged in the same direction with respect to the crankshaft center line, and intake and exhaust bundle pipes that continue to the intake and exhaust passages 3 and 4 are installed on both left and right sides of the engine. As a result, the width of the engine becomes larger.

The present invention has been proposed in order to eliminate such drawbacks, and the present invention has been proposed in order to fix the independent cylinder head of each cylinder to the crankcase. In a cylinder head arranged at approximately equal intervals on a concentric circle centered on a core line, the bolts are arranged symmetrically with respect to a plane that includes a cylinder axis center line and is inclined at a constant angle with respect to a crank axis center line, Two bolts of the same bolt are positioned on the plane, and the 2,000 planes of the adjacent cylinders are made substantially parallel to each other, and the concentric circles of the adjacent cylinders are made to partially intersect with each other. A cylinder head of an internal combustion engine characterized in that cylinder heads are located close to each other.

This is related to. The present invention will now be described with reference to the illustrated embodiment shown in FIG.

Six bolts 12 for fixing the cylinder head 11 to the crankcase are arranged at approximately equal intervals on the circumference of a concentric circle 23 centered on the cylinder axis 20 at an angle of 55° to 65°, Also, the pitch angle α of the bolt 12 with respect to the crankshaft centerline 21 includes the cylinder axis centerline.
A certain angle within 172, preferably θ-10~20°
arranged symmetrically with respect to a plane 22 inclined at an inclination angle of
An intake passage 13 and an exhaust passage 14 are arranged in parallel in the same direction with respect to the crankshaft center line.

Further, the planes 22, 22 of adjacent cylinders are parallel to each other.

Furthermore, the adjacent cylinders have their concentric circles 23.23
are placed close to each other so that some of them intersect with each other.

In addition, a fuel injection pipe, a starting valve, a safety valve, etc. are provided on the opposite side of each of the passages 13 and 14, perpendicular to the crankshaft center line.

Therefore, in the illustrated embodiment, six cylinder head tightening bolts 12 are arranged at equal intervals for each cylinder, so that the tightening force of the cylinder head can be made uniform, and the crankshaft centerline The intake passage 13 and the exhaust passage 14 can be arranged on the same side.

As a result, the intake pipe and the exhaust pipe do not protrude on both sides with respect to the crankshaft as in the conventional engine, and the intake pipe and the exhaust pipe protrude in one direction, making it possible to narrow the width of the engine.

Further, since the arrangement of the bolts 12 is asymmetrical with respect to the crankshaft center line, the distance between the bolts 12' located between the adjacent cylinder heads 11, 11 with a gap between them increases. , both cylinder heads 11,1
1, the cylinder spacing can be shortened while the intake passage 13 and exhaust passage 14 are installed on the same side with respect to the crankshaft center line, which is useful for downsizing the engine. .

As described above, according to the present invention, it is possible to maintain a wide minimum interval between bolts located between adjacent cylinders and to make the interval between cylinders smaller than that of the conventional system.

Therefore, the engine can be made smaller and more compact, gas leakage from the cylinder head mounting surface can be prevented, and the strength of the crankcase near the bolt tightening surface can also be improved.

Furthermore, as mentioned above, the bolts are arranged at equal intervals, and the intake and exhaust passages are arranged on the same side with respect to the crankshaft center line, which together make the engine more compact, which is advantageous for maintenance. Additionally, bolts can be installed on the cylinder spacer wall, improving the rigidity of the cylinder head.

As described above, according to the present invention, four or more cylinder head tightening bolts for fixing the cylinder head to the crankcase are arranged at approximately equal intervals on a concentric circle centered on the cylinder axis. In the installed cylinder head, by arranging the bolts symmetrically with respect to a plane that includes the cylinder axis and is inclined at a certain angle with respect to the crankshaft, the intake and exhaust passages are installed on the same side with respect to the crankshaft. Close the cylinder head spacing while keeping the
This allows the engine to be made smaller and more compact.

Although the present invention has been described above with reference to embodiments, the present invention is, of course, not limited to such embodiments, and can be modified in various designs without departing from the spirit of the present invention. .

[Brief explanation of the drawing]

1 to 3 are plan views of a cylinder head of a conventional internal combustion engine, and FIG. 4 is a plan view showing an embodiment of a cylinder head according to the present invention. 11... Cylinder head, 12... Bolt, 13... Intake passage, 14... Exhaust passage.

Claims (1)

[Claims] 1 Tighten the cylinder head tightening bolts to secure the independent cylinder head to the crankcase for each cylinder.
In a cylinder head in which four or more bolts per cylinder are arranged at approximately equal intervals on a concentric circumference centered on the cylinder axis, the bolts are attached to a plane that includes the cylinder axis and is inclined at a certain angle with respect to the crankshaft. two bolts of the same bolt are positioned on the plane, the two planes of the adjacent cylinders are made substantially parallel to each other, and the adjacent cylinders are arranged symmetrically with respect to the concentric circle. A cylinder head for an internal combustion engine, characterized in that parts of the cylinder head intersect and are close to each other.