JPS6023092Y2 - casting chips - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a sealing tip and an injection tip used in a casting device in which molten metal is supplied and filled into a cavity through a molten metal supply sleeve or an injection sleeve.

In a casting device, molten metal is supplied to an injection sleeve via a hot water supply sleeve, a plunger is driven at the time of injection to close the opening of the hot water supply sleeve, and the molten metal is stored on the injection plunger fitted to the injection sleeve and a waist plunger is driven. The molten metal is then filled into the product cavity, and the tip of the plunger is provided with a sealing tip or an injection tip that comes into direct contact with the molten metal.

Such a chip is in direct contact with the molten metal, and the molten metal is heated to 800°C~1
The tip is heated to 1,000° C., so the tip expands thermally and galling occurs between the tip and the inner surface of the sleeve, which impedes smooth operation and shortens the lifespan.

Therefore, as a countermeasure, it is usually 50 mm between the sleeve and the chip.
Although a clearance of about 100 μm is provided, as the number of castings increases, the space between the sleeve and the tip becomes clogged, causing galling as described above.

In order to improve the above problem, a recess 52 is provided on the inner surface of the chip 51 as shown in FIG.
It has been proposed to cool the inside of the recessed part of the chip 51 through the cooling process, thereby suppressing the thermal expansion of the chip 51. According to this method, thermal expansion can be suppressed, and the outer diameter of the chip and the inner wall of the sleeve can be cooled. On the other hand, the cooling of the chips cools the molten metal, making it difficult to maintain the best flowability, so it is preferable to keep the molten metal close to the temperature inside the furnace.

Therefore, measures such as installing a heater on the outer periphery of the sleeve to heat it are taken, and as a single chip, the part that comes into contact with the molten metal is kept at a high temperature, or at least it is not cooled, and the outer periphery of the chip is not heated. It is preferable to use cooling to eliminate this problem, but since these are contradictory factors, it is difficult to solve them.

The present invention was developed in view of the above, and its purpose is to provide a surface member made of ceramic or a member surface-treated with molybdenum or tungsten, which does not easily react with molten metal, at the tip of the chip, and To provide a casting chip in which a heat insulating space is provided between the outside surface of the chip and the conflicting demands of maintaining the chip at a high temperature as a whole and cooling it can be rationally resolved.

Next, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Fig. 1 is a vertical cross-sectional view of the main parts of the casting device, 1 is an upper mold, 2 is a gou plate that supports this, the upper mold 1 is provided with a runner 3 that communicates with a cavity (not shown), and this side A hot water supply port (not shown) is provided on one side.

An injection sleeve 4 is installed vertically so as to communicate with the runner 3, and the flange portion 4a at the upper end of the sleeve 4 is fixed and supported in a recess 2b provided at the upper periphery of the mounting hole 2a of the Goui plate 2. A heating heater 5 is installed surrounding it.

A tip 6 constituting an injection plunger is slidably fitted into the sleeve 4, and the tip 6 extends downward in the axial direction and slides within the sleeve 4 via a funnel rod 7 by a cylinder unit (not shown).

The tip 6 has a downwardly open recess 8 in the middle or lower part, and a female screw part 8a provided on the inner periphery of the lower part is connected to the rod 7.
A male threaded portion 7a provided on the tip side of the connector is screwed to close a waist recess 8.

The rod 7 is hollow, and a cooling pipe 9 is passed vertically through the rod 7. Cooling water is supplied into the recess 8 through the cooling pipe 9 to cool the chip 6, and the cooled water is passed between the pipe 9 and the rod 7.
It is discharged through a passage between the inside diameter part 7b of and the inside diameter part 7b.

A circular recess 10 that opens upward is provided in the upper part of the chip 6, and the recess 10 is recessed downward in the axial direction to an appropriate depth in the surrounding wall 10a, and between the bottom 10b and the cooling recess 8 below. A thick top portion 6b is formed.

For example, a spiral groove 11 is formed on the bottom 10b.
A portion thereof communicates with the space in the sleeve below the chip through a passage 12 that runs longitudinally around the chip.

A disc-shaped surface member 13 is fitted into the recess 10 and a waist screw 14 is inserted.
The front and back surfaces of the member 13 are flat, and a spiral space communicating with the outside air is formed between the waist back surface 13a and the bottom 10b.

The surface 13b is flush with the top of the peripheral wall 10a, and the outer diameter portion 13c of the member 13 and the peripheral wall 10a are tightly fitted to prevent molten metal from entering between the bottom surface of the recess and the back surface of the member. ing.

The above-mentioned surface member is formed from a member whose surface is treated with molybdenum, tungsten, etc., which hardly reacts with the molten metal, or ceramic.

Next, the operation and effect will be explained in detail. The molten metal supplied into the sleeve 4 is stored on the tip 6, and is filled into the cavity by the upward movement of the tip 6.

The sleeve 4 is heated by a heater 5, and the molten metal is held with good turbidity, while the chip 6 is cooled by supplying cooling water or the like into the recess 8, so that thermal deformation of the outer diameter portion is suppressed as much as possible. , prevents galling between the sleeve 4 and the sleeve 4.

The molten metal on the chip 6 contacts the surface member 13, and an insulating air layer is formed by the groove 11 between the back surface of the surface member 13 and the bottom 10b corresponding to the outer surface of the chip. Heat transfer is substantially blocked between the cooling part of the top and the molten metal contact part above, which cools the chip and prevents the molten metal from cooling, which in turn suppresses thermal expansion by cooling the chip and maintains the molten metal at a high temperature. , it is possible to rationally match the conflicting demands of preventing galling between the tip 6 and sleeve 4 and improving mixed flow performance.

The present invention has many advantages as described above.

Although the injection tip has been described in the embodiment, the same can be applied to a seal tip of a hot water supply sleeve.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of a main part of a casting apparatus including a chip according to the present invention, FIG. 2 is a plan view of the chip, and FIG. 3 is a diagram of a conventional example. In the drawing, 6 is a chip, and 13 is a surface member.

Claims (1)

[Scope of utility model registration request] A surface member made of ceramic, molybdenum, tungsten, etc. is fitted to the tip, a recess is formed that opens at the rear end, a hollow rod is installed in this recess, and a cooling water supply pipe is inserted into the hollow rod. A casting tip comprising a heat insulating groove communicating with the outside formed on a contact surface with the surface member.