JPH0691343A - Structure of flow strraightening part of die - Google Patents

Abstract

PURPOSE:To supply a molten metal in laminar flow to a product part and to make gas bubble exhaust to outside by alleviating the impact of pouring at a flow straightening part as to die casting. CONSTITUTION:A ceramic filter 9 is fitted in the flow straightening part 7 in the course of a runner 4b on horizontal direction, an upstream side part 10 and downstream side part 11 of the ceramic filter 9 are made to taper like gradually spreading toward the ceramic filter 9, an edge face 8a of holding groove 8 is made to taper like toward outside, further, a gas vent hole 12, one end of which is open to the holding groove 8 and the other end is open to atmosphere, is pierced in the die 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a flow straightening section of a casting die.

[0002]

2. Description of the Related Art In casting using a mold, molten metal is poured into a product part through a plan part (runner) of the mold. Slag, metal oxides, various reaction products, and the like are mixed in this molten metal, and if these slags and the like are brought into the product as they are, they cause casting defects.
Therefore, Japanese Utility Model Laid-Open No. 62-41440 or Japanese Patent Laid-Open No.
As disclosed in Japanese Patent Laid-Open No. 4-78658, it has been proposed to provide a ceramic filter in a part of the design part of the mold.

By thus providing the filter in the middle of the runner, it is possible to prevent the slag and the like from flowing into the product portion, and the filter absorbs the impact at the time of pouring to quietly and quickly melt the molten metal. Can be sent to the product section without dropping.

[0004]

However, when the filter is interposed as described above, the filter itself is a turbulent flow on the upstream side of the filter with respect to the flow of the molten metal, because the filter itself functions as a weir. Bubbles are generated by the flow. With the conventional structure of the rectifying section, it is not possible to effectively eliminate the bubbles, and the bubbles enter the product section, causing the formation of cavities.

[0005]

In order to solve the above-mentioned problems, the present invention provides a porous filter having holes on its peripheral surface in a part of the mold part of a mold, while the porous filter A gas vent hole communicating with the atmosphere was opened in the holding portion of the mold with which the peripheral surface abuts.

[0006]

The bubbles generated on the upstream side of the filter enter the gas vent hole formed in the mold from the side surface of the filter, and are discharged to the outside through the gas vent hole.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 is a diagram showing a die-matching surface of a die to which the rectifying portion structure according to the present invention is applied, FIG. 2 is a sectional view of the die, FIG. 3 is an enlarged view of a main part of FIG. 1, and FIG. 3 is a sectional view taken along the line AA of FIG. 3, and FIG. 5 is a perspective view of the filter.

The die 1 is composed of a fixed die 2 and a movable die 3 made of a copper alloy, and a plan portion 4 is formed on a mating surface of the fixed die 2 and the movable die 3. The plan portion 4 includes a vertical runner 4a and a horizontal runner 4b. The product portion 5 is continuously formed on the runner 4b, and the product portion 5 faces the core 6.

A rectifying section 7 is provided midway along the lateral runner 4b. The rectifying portion 7 has a ceramic filter 9 made of silicon carbide fitted in a holding groove 8 formed in the mold 1. The ceramic filter 9 has a rectangular shape,
As shown in FIG. 5, a large number of holes 9a are also opened on the peripheral surface. The ceramic filter 9 may have any shape such as a disk shape, but it is preferable that the ceramic filter 9 has a plate shape. If the peripheral surface is crushed and the hole 9a is not opened, a cutting process or the like is performed. The hole 9a is opened.

Also, the ceramic filter 9 of the runner 4b
The upstream side portion 10 and the downstream side portion 11 are tapered so as to gradually widen toward the ceramic filter 9. With such a shape, the flow passage area in the ceramic filter 9 portion can be sufficiently secured, so that the flowability of the molten metal is not hindered.

Further, as shown in FIG. 4, the end surface 8 of the holding groove 8 is
By making a taper so as to widen outward, matching with the shapes of the upstream side portion 10 and the downstream side portion 11 makes it extremely easy to position the filter when the filter is automatically loaded into the mold by a robot.

On the other hand, the mold 1 is provided with a gas vent hole 12 having one end open to the holding groove 8 and the other end open to the atmosphere. As shown in FIGS. 3 and 4, the gas vent hole 12 has a wide portion 12a at a portion connected to the holding groove 8 and a narrow portion 12b having a width of about 0.6 mm at other portions. With such a structure, it is possible to avoid clogging due to the molten metal and prevent dust and the like from entering from the outside.

As a casting method using the die having the above construction, for example, the fixed die 2 and the movable die 3 are closed, and the product portion 5 is provided via the vertical runner 4a, the horizontal runner 4b and the rectifying portion 7.
Pour the molten metal into. Next, when the surface layer part of the molten metal in contact with the product part 5 is rapidly cooled to form a shell-like solidified layer, it is released from the mold, and then annealed according to the cast product to improve mechanical strength and workability. To do. As the annealing treatment, for example, in a heat treatment furnace, it is held at 900 ° C. to 950 ° C. for 5 minutes to 20 minutes and then gradually cooled.

In the illustrated example, the rectifying portion is provided in the horizontal runner, but it may be provided in the vertical runner, and the die used is not limited to the one made of copper alloy, and the casting method can be applied to the inside. A general method of solidifying and then releasing can be applied.

[0015]

As described above, according to the present invention,
Since a porous filter is placed in a part of the mold part of the mold,
It is possible to prevent the slag and the like from flowing into the product portion, and it is possible to reduce the impact at the time of pouring by the filter and to send the molten metal to the product portion in a laminar flow state. Further, for the porous filter, a hole is also opened on the side surface thereof, and further, a gas release hole communicating with the atmosphere is opened in the holding portion of the mold with which the peripheral surface of the porous filter abuts. The generated air bubbles can be effectively eliminated, and a high quality product with no porosity can be obtained.

Also, by making the shape of the runners in the upstream and downstream portions of the filter gradually taper toward the filter, it is possible to secure a sufficient flow passage area and ensure the positioning when the filter is automatically set. Can be done.

[Brief description of drawings]

FIG. 1 is a view showing a mold matching surface of a mold to which a rectifying section structure according to the present invention is applied.

FIG. 2 is a sectional view of the mold.

FIG. 3 is an enlarged view of a main part of FIG.

FIG. 4 is a sectional view taken along line AA of FIG.

FIG. 5 is a perspective view of a filter.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Mold, 4 ... Design part, 4a ... Vertical runner, 4b ... Horizontal runner, 5 ... Product part, 7 ... Rectifying part, 8 ... Holding groove, 9
... Ceramic filter, 12 ... Gas vent hole.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Fumio Yamaguchi 1-10-1 Shin-Sayama, Sayama-shi, Saitama Prefecture Honda Engineering Co., Ltd. (72) Toshiaki Onuma 1-10-1 Shin-Sayama, Sayama-shi, Saitama Prefecture Within Da Engineering Co., Ltd.

Claims (1)

[Claims] 1. A structure of a rectifying part of a mold in which a porous filter is arranged in a part of a mold part of the mold, the porous filter has holes also in its peripheral surface, and the peripheral surface of the porous filter. A die rectifying portion structure, wherein a gas vent hole communicating with the atmosphere is opened in a die holding portion that abuts against.