JPS59199160A - Production of cylinder liner - Google Patents

Abstract

PURPOSE:To obtain easily a two-layered cylinder liner having intake holes and exhaust holes by disposing a prescribed sand core in the circumferential direction on the inside surface of a metallic mold then casting a cast iron by a centrifugal casting method. CONSTITUTION:A sand mold 2a is rammed on the inside surface of a metallic mold 1 and a sand core 3 is charged therein and finally a sand mold 2b is rammed. After the mold 1 is disposed in a centrifugal casting machine, a molten cast iron is charged into the mold 1 while said mold is rotated. The cast iron is removed from the mold 1 upon solidification and the core 3 is removed. A cylinder liner 5 opened with intake holes 6 and exhaust holes in the as-cast state is thus obtd.

Description

[Detailed description of the invention] The present invention relates to a method of manufacturing a cylinder liner.

Conventionally, cylinder liners for large diesel engines having intake holes and exhaust holes have mostly been manufactured by the sand casting method. The outline and outline of the method for manufacturing a cylinder liner using the sand mold pouring method will be explained with reference to FIG. FIG. 1 shows an example of a cylinder liner for a large diesel engine.

ol is the cylinder liner, which is made of gray cast iron, which has excellent wear resistance and has a high seizure surface pressure because the piston ring slides on the inner surface. 02 is an intake hole. The cylinder liner is made in the following manner.

It is common practice to mold the outer mold and core using a sand mold such as a Fran mold or a CO2 mold, and drop cast gray cast iron in both layers. At this time, cold metal is applied over a wide area in order to precipitate carbides on some surfaces of the core and outer mold to improve the wear resistance of the cylinder liner.

However, the above method has the following drawbacks.

This is a method of casting gray cast iron by applying a large number of chilled metals over a wide area on the surface, pounding and hardening sand on the back side to create a core, and combining this with the outer mold of a separately manufactured sand mold. ,
It requires a large amount of manufacturing man-hours and the cylinder liner is expensive.

An object of the present invention is to provide an inexpensive manufacturing method for a cylinder liner that has intake holes and exhaust holes in an as-cast state and reduces the number of manufacturing steps. After arranging a sand core that forms intake holes and exhaust holes in the direction, cast iron is cast by centrifugal casting.

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 2 and 3 show a cylinder liner having intake holes according to one embodiment of the present invention.

Figure 2 shows the situation after casting iron into a mold using the centrifugal casting method.

In the figure, 1 is a mold, which is made of cast steel (SC46). 2a and 2b are sand molds of 2 tons inserted into the inner surface of the mold 1, which are used to form a thin walled portion at the lower part of the outer periphery of the cylinder liner, and are made of a flan mold. Also, 3
is a core for forming the intake hole 6, and is molded from furan sand. 4 is a lid attached to the mold 1. 5
is gray cast iron that forms the cylinder liner. The air intake hole 6 is made by the sand core 3 in an as-cast state.

The method for manufacturing a cylinder liner according to the present invention is described below.
l'j will be explained later.

(1) First, the sand mold 2a is pounded and hardened on the inner surface of the mold 1, then the separately produced sand core 3 is inserted, and finally the sand mold 2b is pounded and hardened.

(2) Insert the lid 4 into the entrance of the mold 1 and fix the lid 4 on the outer circumferential side of the mold 1 with bolts.

(3) After placing the mold 1 assembled as described above on a centrifugal casting machine, while rotating the mold 1, the gray cast iron that will become the cylinder liner is 1. ．． 4. Cast at 00°C. The chemical composition of this gray cast iron is T, C2316%, S
]20, 92%, Mn: 0.77%, P: 0.41%,
V: 0.18%, Ti: 0.065%, remaining 5
It is Fa.

(4) After the cast iron has solidified, it is removed from the mold l and the sand core is removed.

(5) When the sand core is removed, the cylinder liner 5 with the intake holes 6 is obtained in an as-cast state. The state is shown in FIG.

The above case has the following effects.

(1) A cylinder liner having intake holes and exhaust holes is obtained in an as-cast state by centrifugal casting (IC).

(2) The cylinder liner obtained in this way is:

It is cheaper than those manufactured by the conventional sand mold pouring method.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a conventional cylinder liner. FIG. 2 is a cross-sectional view showing a state after casting of a cylinder liner according to an embodiment of the present invention, and FIG. 3 is a cross-sectional view showing a cylinder liner according to an embodiment of the present invention. ]...Mold, 3...Sand core, 5...Cylinder liner. 6...Intake hole. Su1 ku tusk 2 diagram piece 3 diagram

Claims (1)

[Claims] 1. A method for producing a cylinder liner, which comprises placing a sand core forming intake holes and exhaust holes in the circumferential direction of the inner surface of the mold, and then casting cast iron using a centrifugal casting method.