JPH06265B2 - Cylinder block casting method - Google Patents

Description

The present invention relates to a method for casting a cylinder block having a water jacket.

(Prior Art) The cylinder block of the engine is divided into an open deck type and a closed deck type, and the open deck type cylinder block has a water jacket formed in the cylinder block and a water jacket formed in the cylinder head on the deck surface. The cylinder block of the closed deck type is connected as it is, and the water jacket formed in the cylinder head of the water jacket formed in the cylinder block is connected through the communication hole formed in the deck portion.

The cylinder block is generally made of aluminum alloy, but the water jacket is formed by the core.

By the way, in the open-deck type cylinder block, the water jacket is open on the deck surface as it is, so the core can be removed after casting. It is carried out.

On the other hand, in a closed deck type cylinder block, only the communication hole of the water jacket is opened on the deck surface, so the core cannot be pulled out after casting. Gravity casting is used because it is easily broken.

(Problems to be Solved by the Invention) As described above, in the closed-deck type cylinder block, the sand core must be used because of the shape of the water jacket, and gravity casting must be applied. Further, the sand core has a problem that it cannot be reused and is easily broken at the time of casting, and gravity casting has a disadvantage that it takes a longer casting time than the die casting method.

For this reason, if the mold is a large number of split molds, even a closed-deck type cylinder block can be cast by the die-casting method using an aluminum alloy core, but the mold itself becomes complicated, and the direction of pulling out the mold does not intersect. As a result, the entire device becomes complicated and large.

(Means for Solving Problems) In order to solve the above problems, the present invention sets an aluminum alloy core in a mold, and sets an outer surface of the aluminum alloy core and an inner surface of the mold. The aluminum alloy cylinder block body is cast by the die-casting method as a cavity for molding the cylinder block body, and then a communication hole is formed in the deck surface by machining, and then a sleeve is formed on the inner surface of the cylinder block. I tried to press fit.

(Function) Since the cavity is formed between the outer surface of the aluminum alloy core set in the mold and the inner surface of the mold, the core can be removed inside and the sleeve is attached to the inner peripheral surface of the cylinder block body. By press fitting, a water jacket is formed between the sleeve and the cylinder block.

(Examples) Examples of the present invention will be described below in the order of steps with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view of a main part of a molding apparatus in a mold matching state before pouring molten aluminum alloy. The molding die is composed of molds (1), (2) and (3). 1) has a bore (4) and a pin
(5) is integrally provided, and the aluminum alloy core (6) is set in close contact with the outside of the bore portion (4). And in this state,
A cavity (7) is formed between the molds (1), (2), (3) and the aluminum alloy core (6).

Next, after the molten aluminum alloy is poured into the cavity (7) under pressure (die casting method) and solidified, the mold (1),
(2), (3) and the aluminum alloy core (6) are removed to obtain a cylinder block body (8) as shown in FIG. The cylinder block body (8) is recessed by an aluminum alloy core (6).
Hole (1) that opens on the deck surface (10) by the pin (5).
1) Each is molded.

Thereafter, as shown in FIG. 3, the recess (9) and the hole (11) are communicated with each other by machining, and the inner peripheral surface (8a) of the cylinder block main body (8) is ground, and the recessed portion (9) and the hole (11) are ground. As shown in FIG. 5, the sleeve (12) is pressed into the inner peripheral surface (8a). And sleeve
(12) A cylinder block (14) having a water jacket (13) between the outside and the inside of the cylinder block body (8) is obtained.

(Effects of the Invention) As described above, according to the present invention, even a closed deck type cylinder block can be cast by a die casting method using an aluminum alloy core, so that the core can be recycled. It is possible to do so, the casting time is short, and there are many effects such as the number of machining points is small.

[Brief description of drawings]

FIG. 1 is a sectional view of a die before casting, FIG. 2 is a sectional view of a cylinder block body before machining, FIG. 3 is a sectional view of a cylinder block body after machining, and FIG. 4 is a cylinder block body. A sectional view and FIG. 5 are plan views of the cylinder block. In the drawings, (1), (2) and (3) are molds, (4) is a bore part, (5)
Is a pin part, (6) is an aluminum alloy core, (7) is a cavity,
(8) is a cylinder block body, (10) is a deck surface, (12) is a sleeve, (13) is a water jacket, and (14) is a cylinder block.

Claims (1)

[Claims] Claim: What is claimed is: 1. A core in the shape of a water jacket of a cylinder block is molded from an aluminum alloy, and the core is set in a mold so that the space between the outer surface of the core and the inner surface of the mold. The molten aluminum alloy is pressurized and poured into the cavity formed in the die to cast the cylinder block body by the die-casting method, then the aluminum alloy core is removed, and the hole connecting the water jacket part and the deck surface is machined. A method of casting a cylinder block, characterized in that the sleeve is press-fitted into the inner peripheral portion of the cylinder block body after drilling.