JP2001071114A - Molten metal pouring sleeve for mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extend the service life of a molten metal pouring sleeve whose ceramic layer is difficult to crack, by arranging a second ceramic layer on the surface of a first ceramic layer arranged on the inner wall surface of a cylindrical body and by that the expansion coefficients of the first ceramic layer and the base material of the cylindrical body are more approximated than those of the second ceramic layer and the bare material of the cylindrical body. SOLUTION: The bugle-like cylindrical body 90 is formed as the base material of the molten metal pouring sleeve S for casting mold. On the inner wall surface of the cylindrical body 90, the ceramics is thermally sprayed to form the first ceramic layer 91. Further, the ceramics having different property to the first ceramic layer 91 is thermally sprayed on the surface of the first ceramic layer 91 to form the second ceramic layer 92. Then, the thermal-expansion coefficient of the first ceramic layer 91 and that of the base material of the cylindrical body 90 are mutually nearer values than in the relation of the coefficient of the second ceramic layer 92 and that of the body 90. Since the base material of the cylindrical body 90 is an iron material, the thermal-expansion coefficient of the second ceramic layer 92 becomes larger than the thermal-expansion coefficient of the first ceramic layer 91.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pouring sleeve for a mold, which is provided at a gate of the mold and is used when supplying molten metal to the mold.

[0002]

2. Description of the Related Art A conventional pouring sleeve of this kind is:
By providing a metal sprayed layer (Ni · Cr) on the inner wall surface of the iron cylinder and further providing a ceramic layer on the surface (Japanese Patent Laid-Open No. 6-218489), impact resistance and durability against molten metal are achieved. Was.

[0003]

However, in such a conventional pouring sleeve, if the ceramic layer is easily broken due to repeated thermal changes and the ceramic layer is torn, the lower metal sprayed layer (Ni.Cr) There was a disadvantage that the base material layer was eroded and, as a result, became a concave portion and the casting could not be separated.

An object of the present invention is to eliminate these disadvantages.

[0005]

In order to achieve this object, in a casting pouring sleeve according to the present invention, a first ceramic layer is provided on an inner wall surface of a cylindrical body, and a surface of the first ceramic layer is provided on a surface of the first ceramic layer. Since the second ceramic layer is provided, and the thermal expansion coefficients of these ceramic layers are different and the expansion coefficient of the first ceramic layer is closer to the expansion coefficient of the base material of the cylindrical body than the expansion coefficient of the second ceramic layer,
When the pouring sleeve is heated and thermally expanded by the molten metal, the second ceramic layer functions as a cushioning material between the first ceramic layer and the base material of the cylindrical body, so that the first ceramic layer is hardly broken. is there.

[0006]

FIG. 1 is a sectional view of a pouring sleeve for a mold according to the present invention, and FIG. 2 is a sectional view of the same pouring sleeve.

In FIG. 2, M is a molding device for a motorcycle wheel. In this apparatus M, reference numeral 10 denotes a main lower die, which casts a lower surface (in FIG. 2) of a disk portion of the wheel. Numeral 11 denotes an annular first auxiliary lower mold, which is arranged on the outer periphery of the main lower mold 10 and casts an outside of one side of a rim flange portion of the wheel. Reference numeral 12 denotes an annular second auxiliary lower die, which is arranged on the inner periphery of the main lower die 10 and casts a lower surface (in FIG. 2) of a hub portion of the wheel. Reference numeral 13 denotes an insert, which is inserted into the shaft hole 121 of the second auxiliary lower die 12 to cast the shaft hole of the wheel. Reference numeral 14 denotes a cooling hole, which is formed in the insert 13. A cooling water nozzle 15 is fitted into the cooling hole 14 to supply cooling water.

Reference numerals 20, 20 denote an annular horizontal type for casting the inside of the rim portion of the wheel.

Reference numeral 30 denotes a main upper die for casting a surface on the upper side (in FIG. 2) of the disk portion of the wheel. Reference numeral 31 denotes an annular first auxiliary upper mold, which is inserted into the inner periphery of the main upper mold 30 and casts the upper surface (in FIG. 2) of the hub portion of the wheel. A gate 311 is provided at the axis of the first auxiliary upper die 31.

The wheel-shaped casting space A is formed by the main lower die 10, the first auxiliary lower die 11, the second auxiliary lower die 12, the insert 13, the horizontal die 20, the main upper die 30, and the first auxiliary upper die 31. Is formed.

Reference numeral 50 denotes a lower plate, and reference numeral 60 denotes an upper plate.
The former 50 includes the main lower mold 10, the first auxiliary lower mold 11, or the second auxiliary lower mold
Extrusion pins 51, 51,...
, Push pins 61, 61,... Penetrating through the first auxiliary upper mold 31 are provided upright. Reference numeral 62 denotes an upper advance / retreat auxiliary plate, which advances / retreats integrally with the upper advance / retreat plate 60. Extrusion pins 61, 61 are also provided upright on the upper advance / retreat auxiliary plate 62. Also,
Numerals 70 and 70 are installed in the casting space A. The cores 70, 70 are skirting boards 7 installed on the lower advance / retreat board 50.
Supported by 1,71. Here, reference numeral 80 denotes a substrate.

Next, S denotes a pouring sleeve according to the present invention, which is fitted to the gate 311 of the first auxiliary upper die 31. The pouring sleeve S extends upward, and its upper end is fixed to the substrate 80 of the mold apparatus. This pouring sleeve S
Has a function as a riser.

The pouring sleeve S will be described in detail with reference to FIG. Reference numeral 90 denotes a substantially trumpet-shaped cylindrical body 90 which is the basis of the pouring sleeve S, and is made of an iron material in this embodiment. The pouring sleeve S is for supplying molten metal to the casting space S through the gate 311.

Reference numeral 91 denotes a first ceramic layer.
It is formed by spraying ceramic on the inner wall surface of the substrate, and has a thickness of about 150 μm. Reference numeral 92 denotes a second ceramic layer, which is formed by spraying ceramics having different properties (the first ceramic layer) on the surface of the first ceramic layer 91. It has a thickness of μm. The thermal expansion coefficient of the first ceramic layer 91 is closer to the expansion coefficient of the base material of the cylindrical body 90 than the thermal expansion coefficient of the second ceramic layer 92,
In this embodiment, since the base material of the cylindrical body 90 is an iron material, the thermal expansion coefficient of the second ceramic layer 92 is larger than that of the first ceramic layer 91.

[0015]

In order to achieve this object, in a casting pouring sleeve according to the present invention, a first ceramic layer is provided on the inner wall surface of a cylindrical body, and a second ceramic layer is provided on the surface of the first ceramic layer. Since the thermal expansion coefficients of these ceramic layers are different and the expansion coefficient of the first ceramic layer is closer to the expansion coefficient of the base material of the cylindrical body than the expansion coefficient of the second ceramic layer, When the hot water sleeve is heated and thermally expanded, the second ceramic layer functions as a cushion between the first ceramic layer and the base material of the cylindrical body, so that the first ceramic layer is not easily broken.

Therefore, if the pouring sleeve for a mold is used, the ceramic layer is less likely to be torn, so that the service life is extended.
The number of times of casting is improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a pouring sleeve for a mold according to the present invention.

FIG. 2 is a sectional view of the same use state.

[Explanation of symbols]

 M: Molding device (mold) S: Pouring sleeve for mold 311: Gate 90 ... Cylindrical body 91: First ceramic layer 92: Second ceramic layer

Claims (1)

[Claims] 1. A mold pouring sleeve, comprising a cylindrical body, installed at a gate of the mold and supplying molten metal to the mold, wherein a first ceramic layer is provided on an inner wall surface of the cylindrical body, and a surface of the first ceramic layer is provided on the surface of the first ceramic layer. A second ceramic layer is provided, and the thermal expansion coefficients of these ceramic layers are different, and the expansion coefficient of the first ceramic layer is closer to the expansion coefficient of the base material of the cylinder than the expansion coefficient of the second ceramic layer. A pouring sleeve for a mold characterized by the following.