JPH08132177A - Core for water jacket - Google Patents

Abstract

PURPOSE: To provide a core, by which a water jacket in a closed deck Siamese type cylinder block can be cast without any trouble of without depending on the pressure of molten metal and molten meal pouring speed. CONSTITUTION: In the core for water jacket formed into a shape corresponding to the water jacket in the closed deck Siamese type cylinder block and having a water hole forming part 2 corresponding to a water hole for supplying cooling water to a cylinder head on the deck surface of the water jacket and arranging a core print to the end surface of the water hole forming part, the core print 4 is formed so as to connect with the water hole forming part 2 in annular state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a core for forming a water jacket used for casting a closed deck type / siamese type cylinder block.

[0002]

2. Description of the Related Art When a closed deck type / siamese type cylinder block is cast from, for example, an aluminum alloy, a core shown in FIGS. 7 to 9 is conventionally used as a core for forming a water jacket. ing. This core has a water jacket forming portion 1 corresponding to the shape of the water jacket of the product, and since the water jacket of the product is a Siamese type in which a constricted part such as a gourd does not communicate, The water jacket forming part 1 of
Naturally, it is formed in a Siamese type. In addition, the water jacket of the product is a closed deck type,
Therefore, since the deck head has the water hole for supplying the cylinder head cooling water, the core also has the water hole forming portion 2 corresponding to the shape of the water hole. The space between the adjacent water hole forming portions 2 is a deck bridge forming portion 2a, that is, a portion forming a bridge on the deck surface so that the product is a closed deck type water jacket.

Further, this core has a skirting board for fixing inside the casting mold, that is, a side skirting board 3 provided on a side surface of the water jacket forming section 1 and an end surface of the water hole forming section 2. It has an end face skirting board 9 provided. However, a conventional core end face skirting board 9 is disclosed, for example, in JP-A-59-1.
As disclosed in Japanese Patent No. 89057, the water hole forming portion 2 is simply formed in a rod-like shape and the end face skirting board 9 is held by a mold.

[0004]

A molten metal such as an aluminum alloy is poured on the inner and outer surfaces of the core for a water jacket, and the water jacket is formed by solidifying the metal. As apparent from FIG. 7 or FIG. 9, the conventional core is formed in a siamese type in which no constricted facing part is communicated with any part, and therefore, the external force in the constricted direction, that is, the arrangement direction of the cylinder Weak against external force in the orthogonal direction. On the other hand, since there is an unavoidable difference in the molten metal flow in the molten metal that flows in and out of the core, a pressure difference is inevitably generated when pouring the metal inside and outside the core. , Deck bridge formation part 2a
The molten metal flowing into the inside flows in from either the inside or outside, thus damaging the water hole forming portion 2 of the core and the end face skirting 9
Could lead to damage.

[0007] Such a weak point of the conventional core may not cause a particular problem when the pressure of the molten metal is low and the pouring speed of the molten metal is slow as in low pressure casting or gravity casting. However, when the pressure of the molten metal is high and the pouring speed of the molten metal is high, such as medium pressure casting and die casting, the core cannot be cast due to insufficient strength, and casting in a short cycle is hindered. Therefore, an object of the present invention is to provide a core capable of casting a water jacket of a closed-deck type / siamese type cylinder block regardless of the pressure and the pouring speed of the molten metal.

[0006]

The present invention has been made to achieve the above object, that is, it is formed in a shape corresponding to the water jacket of a closed deck type / siamese type cylinder block. In a water jacket core having a water hole forming portion corresponding to the water hole on the deck surface of the water hole, and a skirting board provided on an end surface of the water hole forming portion, the water hole forming portion is connected in an annular shape. A core for a water jacket, which is characterized by forming a skirting board.

[0007]

Embodiments of the present invention will be described with reference to the drawings. 1 to 5 show an embodiment of a water jacket core according to the present invention, which is a sand core and is used in casting a cylinder block, and is used in a closed deck type / siamese type cylinder block water. A core for forming a jacket. This core has a water jacket forming portion 1 corresponding to the shape of the water jacket of the product. Since the water jacket of the product is of the Siamese type, the water jacket forming portion 1 of the core also has a constricted portion communicating with it. Not formed in the Siamese type. Further, a water hole forming portion 2 is provided at the upper end of the water jacket forming portion 1 corresponding to the fact that the water jacket of the product is a closed deck type. A space portion between the adjacent water hole forming portions 2 is a deck bridge forming portion 2a which serves as a bridge on the deck surface in the product. Further, this core has a skirting board for fixing inside the casting mold, that is, a side skirting board 3 provided on a side surface of the water jacket forming section 1 and a connecting ring provided on an end surface of the water hole forming section 2. With baseboard 4. Link ring baseboard 4
Is formed so as to connect the water hole forming portions 2 in a continuous ring shape, and therefore only this part of the skirting board 4,
It is shaped like a full-jacket water jacket.

The core of this embodiment is formed as described above, and this core is set in the cavity of the casting mold as shown in FIG. That is, it is inserted into the bore pin 5a of the movable die 5 to fix the connecting ring skirting board 4, and further the side skirting board 3 is fixed by the slide core 6. When the cylinder sleeve 7 is further inserted and fixed to the bore pin 5a, and then the molten metal is injected into the cavity and the core is broken after the molten metal is solidified, a water jacket is formed at the portion where the core was. However, the cores of the lever are integrally connected by the connecting ring skirting board 4, and the connecting ring skirting board 4 reinforces the strength of the water jacket portion 1 formed in the siamese type in the constricted opposite direction. Part 1
It is also connected like a bridge in the neck direction. Therefore, as indicated by the arrow in FIG. 6, a pressure difference is generated inside and outside the core due to the difference in the flow of the molten metal flowing in and out of the core, and as a result, a force acts in the constricted direction of the water jacket portion 1. However, even if the molten metal flowing into the deck bridge forming portion 2a does not flow evenly from the inside and outside, there is no possibility of causing damage to the water hole forming portion 2 of the core and the connecting ring baseboard 4. Therefore, by using this core, it is possible to perform not only low-pressure casting and gravity casting but also medium-pressure casting or die-cast casting, and therefore productivity of a cylinder block having a closed deck type / siamese type water jacket is improved. Can be improved.

[0009]

According to the present invention, in a core for forming a water jacket of a closed deck type / siamese type cylinder block, a connecting ring baseboard is provided so as to reinforce the portion for forming the siamese type water jacket. Therefore, the core is capable of casting a closed-deck type / siamese type cylinder block without any problem regardless of the molten metal pressure and the pouring speed.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is also a front view

[Figure 3] Similarly, bottom view

FIG. 4 is a sectional view taken along the line AA in FIG.

FIG. 5 is a sectional view taken along line BB of FIG.

FIG. 6 is a sectional view showing a usage state.

FIG. 7 is a plan view showing a conventional example.

FIG. 8 is a front view of the same.

FIG. 9 is a bottom view of the same.

[Explanation of symbols]

1 ... Water jacket forming part 2 ... Water hole forming part 2a ... Deck bridge forming part 3 ... Side baseboard 4 ... Linking baseboard 5 ... Movable type 5a ... Bore pin 6 ... Slide core 7 ... Cylinder sleeve

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication location F02F 1/10 D (72) Inventor Ebisawa Kasujuo 15 Whale Ishinta, Kawagoe City, Saitama Prefecture・ Atre Kawagoe 306

Claims (1)

[Claims] 1. A water hole forming portion which is formed in a shape corresponding to a water jacket of a closed deck type / siamese type cylinder block, and which corresponds to a water hole for supplying cooling water to a cylinder head on the deck surface of the water jacket. A water jacket core having a skirting board provided on an end surface of the water hole forming section, wherein the skirting board is formed so as to connect the water hole forming section in a continuous ring shape. Core.