JPH0141874Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a loose-fit type liner-integrated cylinder in which the liner is manually fitted into the liner fitting hole of the cylinder, thereby increasing the workability of engine assembly.

A loose-fit type liner-equipped cylinder in which the liner is loosely fitted into the liner fitting hole of the cylinder has excellent workability and facilitates replacement of the liner when the liner wears out. However, when assembling the engine, there was a problem that the liner would be lifted up by the piston ring during cranking, when the pistons were sequentially assembled to the crank, or would fall off when the engine was turned upside down.

For this reason, when assembling the engine, it was necessary to attach a liner removal prevention device to the top surface of the cylinder block before inserting the piston.

Further, the loose-fit type cylinder with a built-in liner is inconvenient because the liner rotates within the cylinder during engine inspection, etc., making the thrust direction unclear.

In view of the above points, the present invention is a loose-fit type cylinder in which a liner is loosely fitted into a liner fitting hole, and in which a liner is loosely fitted in a liner fitting hole. A protrusion for forming an interference is provided on the inner surface of the mating hole or the outer circumferential fitting surface of the liner, and the protrusion for forming an interference is placed above the position of the first piston ring at the top dead center of the piston or at the maximum position at the bottom dead center of the piston. This cylinder is located below the position of the lower piston ring, and is formed by tightly fitting a liner using this interference forming protrusion.

An embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG.

The cylinder liner 3 loosely fitted into the liner fitting hole 2 of the cylinder body 1 has a plurality of interference forming protrusions 5, 5, . is provided.

When the cylinder liner 3 is fitted into the liner fitting hole 2 of the cylinder body 1 and the engine is assembled and the piston is at the top dead center, the first piston ring fitted into the piston It is arranged slightly above the position B, and is provided at a position corresponding to the cylinder head mounting bolt holes C, H, etc.

The cylinder liner 3 thus formed is loosely fitted into the liner fitting hole 2 of the cylinder body 1,
The inner surface of the liner fitting hole 2 and the cylinder liner 3
The cylinder 6 has a desired tightening margin at the protrusions 5, 5, . . . to prevent it from slipping out of the cylinder liner 3.

Since the present invention is configured as described above, the liner is loosely fitted into the liner fitting hole 2 of the cylinder body 1, and a tightness is provided by the tightness forming protrusions 5, 5, etc., so that it is easy to tighten the liner when assembling the engine. The liner 3 is not lifted by the piston ring during ranking or the like.

In this example, a plurality of protrusions for forming an interference margin are provided at equal intervals in the circumferential direction at the lower part of the neck on the outer circumferential fitting surface of the cylinder liner, but instead of this, the protrusions for forming an interference interference may be annular throughout the circumference, or A projection for forming interference may be provided on the inner surface of the liner fitting hole of the cylinder body,
In this case, as shown in FIG. 3, the interference forming protrusion 7 is positioned slightly below the lowest piston ring position at the bottom dead center of the piston.

In addition, as shown in Fig. 4, the cylinder liner 3
A projection 8 for forming a tightness may be provided on the outer periphery of the head of the cylinder to prevent it from coming off between the inner surface of the large diameter hole of the cylinder liner fitting hole of the cylinder body, and the inner surface of the large diameter hole of the cylinder liner fitting hole. A protrusion for forming an interference margin may be provided.

Note that the reason why the interference forming protrusion is located above the position of the first piston ring at the piston top dead center and below the position of the lowest piston ring at the piston bottom dead center is that of the cylinder liner formed by the first piston ring. If it is provided within the range between the upper limit of sliding on the inner surface and the lower limit of sliding on the inner surface of the cylinder liner by the lowest piston ring, there will be problems such as a reaction force being generated on the piston via the cylinder liner due to the interference. If it is set outside, such inconvenience will not occur.

In addition, by providing the protrusion for forming a tightness margin in a position corresponding to the cylinder head mounting bolt hole,
In the conventional case, when the cylinder head mounting bolts are tightened, a considerable portion of the cylinder liner is stretched, resulting in a chrysanthemum outline shape when viewed macroscopically. This can be prevented by the tightening margin forming protrusion, and a gap is formed. It has the effect of not bothering you.

In FIG. 5, a through hole is provided in the cylinder liner, and a set screw 9 screwed into the cylinder body through the through hole prevents the cylinder liner from coming off.

The present invention has the advantage of being able to prevent a loose-fit liner, which requires manual work, from coming off without having to be lifted during cranking, and to prevent the liner from rotating.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a main part of an embodiment of the present invention, Fig. 2 is a cross-sectional view of a cylinder liner at a portion corresponding to the line shown in Fig. 1, Fig. 3 is a cross-sectional view of a main part of another embodiment, and Fig. 4 5 is a sectional view of the main part of another embodiment, and FIG. 5 is a sectional view of the main part when a set screw is used. 1... Cylinder body, 2... Liner fitting hole,
3... Cylinder liner, 4... Outer fitting surface,
5, 7, 8...Tightening margin forming protrusion, 6...Cylinder, A...Piston, B...First piston ring, C...Cylinder head mounting bolt.

Claims (1)

[Scope of utility model registration request] In a loose-fit cylinder in which a liner is loosely fitted into a liner fitting hole, an interference forming protrusion is provided on the inner surface of the liner fitting hole in the cylinder body or on the outer peripheral fitting surface of the liner. A cylinder in which a liner is tightly fitted into the liner by the interference forming protrusion, which is located above the position of the first piston ring at the top dead center of the piston or below the position of the lowest piston ring at the top dead center of the piston.