JPH0526105A - Water cooled internal combustion engine - Google Patents

Abstract

PURPOSE:To provide a water cooled internal combustion engine having excellent maintenance characteristic, which is an internal combustion engine of a structure to be assembled and fastened together, with an almost complete combustion gas seal, and with no need of a strong fastening torque for gas pressure sealing and for a cylinder fastening bolt, and which causes little deformation in the liner part by manufacturing a cylinder head, a cylinder liner, and a cylinder block individually. CONSTITUTION:A cylinder head 1, a cylinder liner 3, and a cylinder block 2 are manufactured individually, and the cylinder head 1 and the end part of the cylinder liner 3 are fastened together solidly into an integrated structure by screw connection. The cylinder liner 3 is fitted into the cylinder block 2, and is sealed by a seal ring 12 in the vicinity of the lower part so as to fasten the cylinder head 1 and the cylinder block 2 together. Spaces created between the cylinder head 1, the cylinder liner 3 and the cylinder block 2 are rendered water jackets 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention provides a cylinder head, a cylinder liner, and a cylinder block, which are separate from each other to ensure a sufficient gas seal regardless of the rigidity of the head and the block, and has a relatively simple structure. The present invention relates to a water-cooled internal combustion engine in which a casting mold can be easily manufactured.

[0002]

2. Description of the Related Art A conventional internal combustion engine in which a cylinder head and a cylinder block are separated from each other has many gas seal problems because the cylinder fastening bolts bear the combustion gas seal and the explosive force. There is a problem when using aluminum based materials. Further, an internal combustion engine in which a cylinder head and a cylinder block are separated from each other tends to have a large number of parts, and there are problems in maintenance such that tightening torque becomes excessive and deficient in assembling and a large amount of work is required. For this reason, an internal combustion engine of the type in which the cylinder head and the cylinder block are integrally formed by casting has been proposed (for example, actual Kaihei 1-17).
3436). However, the integrated structure type internal combustion engine has a problem that the combustion gas seal is perfect and the number of parts is small, but the structure is complicated and the casting mold is also complicated, resulting in poor workability and maintainability.

[0003]

In the conventional structure in which the head portion and the liner portion are integrally formed, it is not possible to replace only the liner, and it is difficult to machine the explosive surface portion of the cylinder head. It becomes difficult to process the part. Further, since the head portion and the liner portion have bottoms, there is a problem that it is difficult to perform liner processing (horning processing). The present invention has been made in view of the problems that occur in the above-described head block integrated structure, cylinder head and cylinder liner integrated structure, or parts-by-part structure. The object of the present invention is to provide a cylinder head and a cylinder liner. It is an internal combustion engine in which the cylinder block and the cylinder block are separately manufactured and assembled and fastened. The combustion gas seal is almost perfect, and no special tightening torque is required for the cylinder tightening bolt. An object of the present invention is to provide a water-cooled internal combustion engine which is hardly deformed and is excellent in maintainability.

[0004]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a water-cooled internal combustion engine in which a cylinder head, a cylinder liner, and a cylinder block are separately manufactured. The end of the liner is fastened and fixed to be integrated, and the cylinder liner is fitted into the cylinder block and sealed by a seal member near the lower portion to fasten the cylinder head and the cylinder block together. The space formed between the head, the cylinder liner and the cylinder block is watered.
Characterized by being a jacket. Further, the cylinder head and the cylinder liner are integrally structured by screwing a screw screwed at a right angle to the combustion and explosion surface of the cylinder head with a screw screwed on the upper end of the cylinder liner. And Further, in the cylinder head and the cylinder liner, a convex portion is formed on the end side of the inner wall of the cylinder portion of the cylinder head, and a concave portion is formed in the inner side thereof, and a screw is threaded on the inner wall of the convex portion. The screw is also engraved, and the distance from the liner end of the screw is at least larger than the position from the liner end of the top ring of the piston at the top dead center position to form an integral structure. Furthermore, the cylinder head and the cylinder liner have an integrated structure in which the combustion explosion surface of the cylinder head is brought into contact with the upper end surface of the cylinder liner having a flange, and the flange portion is fastened and fixed by a plurality of bolts. Characterize.

[0005]

The operation of the water-cooled internal combustion engine according to the present invention as the above means will be described with reference to the reference numerals in the accompanying drawings. The first means is similar to the case where the cylinder head and the cylinder liner 3 are integrally cast by simply fastening and connecting the cylinder head 1 and the cylinder liner 3. In addition, a gas seal is not required for this combination, and the cylinder head 1 and cylinder block 2 fastening bolts 11 need only have a force to bear the water seal and the explosive force, and the cylinder liner 3 is also excessively tightened. Since such force is not applied, the liner 3 is hardly deformed. In this means, the water jacket 10 is formed outside the abutting portion between the cylinder head 1 and the cylinder liner 3, and it is possible to cool the vicinity of the abutting portion between the cylinder head 1 and the cylinder liner 3 to be cooled most. I can. In this case, there is a certain distance from the screw connection portion to the end face seal portion (abutment portion), and the rigidity between them makes it possible to reduce the looseness of the screw and to reduce the change in the seal surface pressure due to the difference in thermal expansion. I can. With this means, the bolts 21 can be elastically tightened to improve the sealing property of the contact surface between the cylinder head 1 and the cylinder liner 3, and the surface pressure is uniform because a large number of screws 21 are tightened all around. It becomes easy to do. Further, the surface pressure can be made uniform regardless of the squareness of the threaded portion only by the flatness of the contact end surface.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical sectional view in a direction perpendicular to a crankshaft of a water-cooled internal combustion engine according to the present invention, and FIG. 2 is a vertical sectional view in a crankshaft direction. Although this embodiment shows the case of three cylinders (the number of cylinders may be single cylinder or multiple cylinders), the cylinder head 1, the cylinder liner 3, and the cylinder block 2 are separately manufactured and assembled and fastened. There is.

The cylinder head 1 has a cylinder portion 1d formed by slightly extending the periphery of the combustion explosion surface 1c in the direction of the crankshaft 6, and a female screw 1b is threaded on the inner wall of the cylinder portion 1d. . The cylinder liner 3 has a male screw 3a on its upper end and a female screw 1b of the cylinder head 1.
It is screwed to form an integrated structure. And the cylinder liner 3
The outer periphery of the lower portion is fitted into the cylinder block 2, and cooling water is sealed near the lower portion. For this reason, a plurality of grooves for the seal member 12 are provided in the lower portion of the cylinder liner. In the cylinder head 1, a lower end surface 1a of a cylinder portion 1d extending slightly downward is sealed and brought into contact with an upper end surface 2a of a cylinder block 2 and fastened with a bolt 11.
In this way, a water jacket 10 is provided between the cylinder head 1, the cylinder liner 3 and the cylinder block 2.
Is formed. An intake port 13 and an exhaust port 15 are formed in the cylinder head 1, and an intake valve 14 and an exhaust valve 16 are arranged therein. Further, a fuel injection valve 17 and the like are arranged in the head 1, and a water jacket 10 is formed around the fuel injection valve 17.

Then, the cylinder head 1 and the cylinder liner 3 are screwed together to form an integral structure, and a single unit is fitted into the cylinder block 2 for each cylinder. Therefore, no gas seal is required between the cylinder head 1 and the cylinder block 2, and the cylinder head 1 and the cylinder block 2 are not required.
The bolts 11 for fastening the bolts and the bolts need only have a force to bear the water seal and the explosive force. Since the cylinder liner 3 is not subjected to an excessive force due to the tightening, the cylinder liner 3 is hardly deformed. Reference numeral 4 denotes a camshaft arranged in a recess 2c formed on the side portion of the cylinder block 2, which pushes up a push rod 19 via a tappet 18 and a rocker arm 20 causes the intake / exhaust valve 14, 16 is opened and closed.

As is apparent from FIGS. 1 and 2, when the cylinder head 1 and the cylinder liner 3 which are integrally structured are removed from the cylinder block 2, the cylinder book 2 is opened upward (in the cylinder head direction). Become. That is, since the inner wall 2d of the cylinder block 2 does not have a convex catch, the core can be easily removed when casting, and it can be manufactured by a die such as die casting.

Next, FIG. 3 shows another embodiment of the water-cooled internal combustion engine according to the present invention. In this embodiment, a convex portion 1f is formed on the end side of the inner wall of the cylinder portion 1d of the cylinder head 1, a concave portion 1g is formed at the inner side (closer to the head), and a female screw 1b is threaded on the side surface of the convex portion 1f. Further, a male screw 3a is threaded and screwed into a predetermined position from the upper end of the cylinder liner 3. In this case, the distance H from the end of the liner 3 of the male screw 3a is at least the top ring 9 of the piston 9 at the top dead center position.
It is set larger than the position of a.

In this way, the water jacket 10 is formed outside the abutting portion between the cylinder head 1 and the cylinder liner 3, and it is possible to cool the vicinity of the abutting portion between the cylinder head 1 and the cylinder liner 3 to be cooled most. I can. In this case, there is a certain distance from the screw connection portion to the end face seal portion (abutment portion), and the rigidity between them makes it possible to reduce the looseness of the screw and to reduce the change in the seal surface pressure due to the difference in thermal expansion. I can.

FIG. 4 shows still another embodiment of the water-cooled internal combustion engine according to the present invention. In the embodiment of FIG. 4, the cylinder head 1 is not provided with a portion corresponding to the cylindrical portion 1d and has a surface having substantially the same height as the explosion surface 1c. The explosive surface 1c of the cylinder head is fastened and fixed. In this way, the upper surface 2 of the cylinder block 2 is attached to the lower surface 1a of the cylinder head 1.
Assembling is carried out by abutting a and tightening and fixing with bolts 11. The portion surrounded by the cylinder head 1, the cylinder liner 3, and the cylinder block 2 forms a water jacket 10. Thus, the bolts 11 can be elastically tightened to improve the sealing property of the contact surface between the cylinder head 1 and the cylinder liner 3, and since a large number of bolts 21 are tightened all around, the surface pressure is uniform. It becomes easy to do. Further, the surface pressure can be made uniform regardless of the squareness of the threaded portion only by the flatness of the contact end surface.

Although some embodiments of the water-cooled internal combustion engine according to the present invention are as described above, the method of fastening and fixing the cylinder head 1 and the cylinder liner 3 is not limited to the above-mentioned example,
Other fastening methods, such as a method of forming a flange at a predetermined position from the end of the cylinder liner and screwing a screw on the outer circumference of the flange to fix the flange to the cylinder head, are also conceivable.

[0014]

Since the water-cooled internal combustion engine according to the present invention is constructed as described in detail above, it has the same effect as that of the structure in which the cylinder head and the cylinder liner are integrated.
That is, when tightening the cylinder head and the cylinder block, it is sufficient to consider only the water seal and the explosive force, so the tightening torque is small and the cylinder liner is hardly deformed by tightening the head bolt, and the combustion gas seal Le will be perfect. Further, not only can the cylinder head and the cylinder block be cast using a normal mold, but also can be cast using an aluminum die cast mold or the like. Further, a water jacket having a high cooling efficiency can be formed in a necessary portion.

[0015]

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view in a direction perpendicular to a crankshaft of a water-cooled internal combustion engine according to the present invention.

FIG. 2 is a vertical cross-sectional view of the water-cooled internal combustion engine according to the present invention in the crankshaft direction.

FIG. 3 is a vertical cross-sectional view perpendicular to the crankshaft of another embodiment of the water-cooled internal combustion engine according to the present invention.

FIG. 4 is a vertical cross-sectional view of a water-cooled internal combustion engine according to another embodiment of the present invention in a direction perpendicular to a crankshaft.

[Explanation of symbols]

1 Cylinder Head 1a Cylinder Head Lower Surface 1b Female Screw 1d Cylinder Head Tube 2 Cylinder Block 2a Cylinder Block Top Surface 2d Cylinder Block Inner Wall 3 Cylinder Liner 3a Cylinder Liner Male Thread 3b Cylinder Liner Flange 6 Crankshaft 10 Water Jacket 11, 21 Tightening bolt 12 Seal ring

Claims (4)

[Claims] 1. A cylinder head, a cylinder liner, and a cylinder block are manufactured separately, and the cylinder head and the end portion of the cylinder liner are fastened and fixed to be integrated with each other, and the cylinder liner is fitted into the cylinder block. The cylinder head and the cylinder block are sealed by a seal member in the vicinity of the lower portion, and the space formed between the cylinder head, the cylinder liner, and the cylinder block is used as a water jacket. A water-cooled internal combustion engine characterized by the above. 2. A cylinder head and a cylinder liner are integrally formed by screwing a screw screwed at a right angle to a combustion explosion surface of the cylinder head with a screw screwed on an upper end of the cylinder liner. The water-cooled internal combustion engine according to claim 1, wherein 3. A cylinder head and a cylinder liner, wherein a convex portion is formed on an end side of an inner wall of a cylinder portion of the cylinder head, a concave portion is formed in the inner side thereof, and a screw is threaded on the inner wall of the convex portion. , The cylinder liner is also threaded, and the distance from the liner end of the screw is at least larger than the position from the liner end of the top ring of the piston at the top dead center position to form an integral structure. The water-cooled internal combustion engine according to claim 2. 4. The cylinder head and the cylinder liner are integrated with each other by abutting an upper end surface of a cylinder liner having a flange formed on a combustion and explosion surface of the cylinder head and fastening and fixing the cylinder liner with a plurality of bolts. The water-cooled internal combustion engine according to claim 1, wherein