JPH0327858A - Overflowing method for front end of die carving in part - Google Patents

Abstract

PURPOSE:To prevent the defect of a die engraving part by providing the boss playing an overflow-like role at the front end of a die casting so that the capacity can be changed and cutting off a projecting boss after casting. CONSTITUTION:A pin system is adopted in a die design at the front end of the engraving part so that the amt. of overflow 9 can be changed by working the pin 10. The gases in a cavity and the impurities contained in a molten metal can be eliminated by a pouring basin and air vent at the time of casting, but the fact that the run in the boss part of the product is poor is heretofore the cause for defective products. The pin 10 is worked at the front end of the engraving part to form the air vent and to cause the overflow, by which the appearance and inside of the long boss and intricase shape parts of the engraving part are formed defectless and the yield is improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a round boss that acts as an overflow in the carved part of the part away from the mold parting surface where casting defects occur, and By absorbing harmful gases into this boss, die-casting products are manufactured with no defects and sound products.

[Conventional technology]

Conventional mold structures employ mechanisms and structures that utilize overflow or vacuum methods that utilize the mold dividing surface to expel gas to the outside of the cavity.

The present invention can be applied to complex-shaped parts, carved parts, etc. using current technology.
A round boss protrusion for overflow is provided in a position where defect prevention cannot be achieved, and the gas in this area is absorbed into the boss, so that the parts that require quality are sound.

[Problem to be solved by the invention]

In the above-mentioned conventional technology, as mentioned above, overflow, vacuum method, etc. are generally employed in the vicinity of the cold mold dividing surface or in a region where the shape is easy.

However, insufficient consideration has been given to preventing casting defects in the central part of the product or in deeply carved parts.

The present invention is aimed at venting gas from positions where gas removal is difficult, and casting defects can be prevented by a simple method of providing a round boss-shaped excess wall in the product shape.

[Means to solve the problem]

In order to achieve the above purpose, the prediction of the flow of molten metal is estimated in advance when designing the mold.

In this case, in consideration of the fact that important parts are multiplied in order to satisfy product quality needs, a new pin-type boss with a round boss can be installed in the part where casting defects are expected to occur using existing technology.

Since the defective part of the existing mold is obvious, a part of the mold will be modified so that a round pin can be installed in this position.

In this case, the purpose of using the round pin method is to use it as an air vent around the pin to obtain a degassing effect, to easily change the convex volume for overflow purposes by processing the tip of the pin, and to cut the excess material if there is a problem. This is due to the fact that it is easy to remove losses, and thereby the objectives such as prevention of casting defects and improvement of yield can be achieved.

[Effect]

The structure is such that round pins are incorporated into the mold in areas where defects are expected to occur, such as in areas away from the mold engravings and dividing surfaces.

A clearance is provided around this pin for the purpose of air venting. The protrusion at the tip, which acts as an overflow, can be easily changed by processing the tip of the pin to ensure the required capacity.

In addition, if the defective part is obvious in the existing mold, a hole into which a round pin can be inserted is provided at the carved tip of the mold, and the pin is inserted into this hole. Aim to prevent overflow from occurring in cast products and improve yield.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2.

In general, the structure and part names of a mold are as shown in Figure 2. The molten metal that flows in from the sprue passes through a splitter, passes through a runner, and is filled into the cavity from the sprue. .

At this time, impurities contained in the gas in the cavity and the molten metal are removed by the tundish pool 5 and the air vent 6.

However, as shown in Fig. 1, the flow of the metal at the boss part of the product part 3 was poor, so we designed and manufactured a mold structure with pins 9 at the tip of the carved part, and by machining the pins 10, there was a protrusion of excess metal for the purpose of overflow. Capacity is determined by pin processing.

The clearance between the pin and hole is air vented, which improves the appearance of the boss and prevents internal defects, thereby producing a sound die-cast product.

〔Effect of the invention〕

According to the present invention, there are the following effects.

(1) The appearance and interior of long bosses and complex-shaped parts of die-cast products are made sound, and the yield is significantly improved.

(2) Conventionally, the interior of the boss in a blind hole was difficult to use for screw holes due to the formation of cavities, but its soundness has been improved and its uses have been expanded.

(3) Testing is easy due to the pin method, and the capacitance can be easily changed, so quality can be improved with minimal protrusions.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the overflow of the mold engraving part of the present invention,
FIG. 2 is a perspective view of a general mold.

Claims (1)

[Scope of Claims] 1. A boss having an overflow role is provided at the tip of the die-cast product formed by the mold engraving to prevent external defects and internal defects of the die-cast product; An overflow method for the tip of the die engraved part, which is characterized by creating a die with a structure that allows the capacity to be changed, and easily cutting off the convex boss to produce a defect-free die-cast product.