JPH0512527Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a cylinder liner, and more specifically, to a cylinder liner having a heat insulating ring material press-fitted near the upper end of the liner in the axial direction with the same dimensions as the inner diameter of the cylinder. Regarding Raina.

(Prior Art) In FIG. 3, a cylinder liner is press-fitted into a hole formed in a cylinder block 1 on its inner peripheral surface.

By the way, as shown in FIG. 3, this cylinder liner has a wall surface corresponding to the inner circumferential surface forming the upper space of the piston P located near the axially upper end of the liner 2, in other words, immediately before the combustion stroke. An annular heat insulating material 3 (hereinafter referred to as a heat insulating ring material) is press-fitted in order to suppress heat loss due to heat transfer effects during the combustion process.

As shown in FIG. 3, this heat-insulating ring member 3 is press-fitted into a stepped portion 2a formed in the cylinder liner 2.

(Problem to be Solved by the Invention) The heat insulating ring member 3 has a lower edge in the axial direction that thermally expands due to heat received during combustion, and as shown by the two-dot chain line in FIG. There was a risk that the material would float up toward the inside of the cylinder, causing so-called curling.

Such curling impairs the smoothness of the piston sliding surface, and there is a risk that the piston or liner may be damaged by the piston sliding.

(Means for solving the problem) The present invention was made in view of the above, and
The purpose is to provide a cylinder liner that solves the above problems, and in order to achieve that purpose, the fitting part of the heat-insulating ring material in the cylinder liner is designed to prevent the heat-insulating ring material from floating toward the inside of the cylinder. A locking part is formed.

(Example) The present invention will be explained below with reference to the illustrated example.

In FIG. 1, a wet-type cylinder liner that comes into contact with the cooling water in the water jacket is shown, and in the same figure, reference numeral 10 is a cylinder block, reference numeral 11 is a cylinder liner, reference numeral 12 is a heat insulating ring member, Reference numeral 13 indicates a piston, and reference numeral 14 indicates a piston ring.

The cylinder liner 11 is connected to the cylinder block 10.
It is press-fitted into a hole formed in the water jacket 15, and a part of its outer peripheral surface comes into contact with the cooling water in the water jacket 15.

A circumferential groove 11A having a size corresponding to the axial length of the heat insulating ring 12 is formed on the inner circumferential surface of the cylinder liner 11 from near the upper edge in the axial direction, which is the press-fitting side of the heat insulating ring 12. This circumferential groove 11A
A locking portion 11a that prevents the heat insulating ring member 12 from lifting up is formed at the lower edge in the axial direction.

The locking portion 11a is formed by a sloped surface in which the inside of the cylinder of the circumferential groove is higher than the outside in FIG.

On the other hand, the heat insulating ring member 12 is formed to have the same dimensions as the inner diameter of the cylinder, and a plurality of circumferential grooves 12a for forming a heat insulating air layer are provided on the outer peripheral surface.

The lower end edge of the heat insulating ring member 12 in the axial direction is set in a shape that matches the slope of the locking portion 11a of the circumferential groove 11A of the cylinder liner 11.

The heat-insulating ring member 12 is press-fitted into the circumferential groove 11A of the cylinder liner 11, and its lower end edge in the axial direction is brought into close contact with the sloped surface of the locking portion 11a.

Note that the above-mentioned locking portion 11a is not limited to being formed on a sloped surface, and as shown in FIG.
A right-angled stepped surface may be formed on the lower edge of A in the axial direction.

(Effects of the invention) According to the invention, when the heat-insulating ring material press-fitted into the cylinder liner tries to lift up toward the inside of the cylinder, the locking part that blocks the lifting deformation prevents the ring member from lifting up. Since upward movement can be prevented, the smoothness of the piston sliding surface within the cylinder is not impaired, and the risk of the liner being damaged by the sliding piston can be avoided.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing the main part of the embodiment of the present invention, FIG. 2 is a schematic diagram showing a modification of the main part of the embodiment of the invention,
FIG. 3 is a schematic diagram showing a conventional example of a cylinder liner. 10...Cylinder block, 11...Cylinder liner, 11A...Peripheral groove, 11a...Locking portion, 1
2... Ring material for insulation.

Claims (1)

[Scope of Claim for Utility Model Registration] A cylinder having a heat insulating ring member made of a heat insulating member press-fitted with the same dimensions as the cylinder inner diameter near the axially upper end edge of a liner press-fitted into the cylinder inner circumferential surface. In the liner, a locking portion is formed at a position corresponding to the axial lower edge of the heat insulating ring to prevent the axial lower edge of the heat insulating ring from lifting up from the inner peripheral surface of the liner toward the inside of the cylinder. A cylinder liner characterized by: