JPS5828686Y2 - Nozzle heating device in hot chamber die casting machine - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a nozzle heating device for a hot chamber die-casting machine.

In a hot chamber die-casting machine, the high-temperature molten metal in the melting pot or gooseneck is press-fitted into the mold from the nozzle tip by an injection device consisting of a sleeve and a plunger slidably fitted into the sleeve. It is common to heat the nozzle to prevent the molten metal from cooling and solidifying at the contact area between the metal and the mold.

Conventionally, a burner is used as a means of heating the nozzle, but this tends to result in uneven heating temperature (therefore, it is often overheated, which shortens the life of the nozzle. It became.

Also, according to the burner, not only the nozzle but also the mold (fixed)
This thermally expands to heat the other mold (movable).
In view of the above-mentioned defects, this idea was designed so that only the nozzle could be electrically heated to a uniform temperature using a heater. This is what I did.

An embodiment of this invention will be described below with reference to the drawings.

In the molten metal injection device A, a sleeve holder 2 is buried in the inner bottom of the melting pot 1, and a sleeve 4 into which a plunger 3 of a cylinder is slidably inserted is vertically inserted into the sleeve holder 2. It is.

The opening at the lower end of this sleeve 4 is communicated with a loop hole 5 formed on the side of the melting pot 1, and the opening at the other end of this loop hole 5 is provided with a mold clamp opposite to the injection device A. The nozzle 7 that presses the molten metal into the mold 6 of the device B is inserted.

This nozzle 7 has a cylindrical shape made of heat-resistant special steel, and has a tapered surface 7a on its outer periphery.

A nozzle heater 9 is removably fitted onto the outer periphery of the nozzle 7, and has a tapered surface 8a formed on the inner periphery of a fitting hole 8 in the center to match the tapered surface 7a of the nozzle 7. .

As shown in FIGS. 1 and 2, this nozzle heater 9 has a cylindrical shape made of cast iron, in which a coiled heating wire 9a is embedded, and a handle 10 is provided on the side. It is fixed.

In such a configuration, when the heating wire 9a is energized to cause the nozzle heater 9 to generate heat, the nozzle 7 is heated by conduction of the heat.
is heated.

By the way, since the nozzle heater 9 thermally expands at this time, the fitting hole 8 expands and a gap is created between it and the nozzle 7, and as a result, the thermal conductivity to the nozzle 7 may decrease.

However, in this case, a decrease in thermal conductivity can be prevented by sliding the nozzle heater 9 behind the nozzle 7 along the tapered surface to eliminate the gap.

As mentioned above, this idea is a cylindrical nozzle heater that removably fits around the nozzle of a molten metal injection device.
The fitting hole is characterized in that a tapered surface is formed to match the outer circumference of the nozzle.

Since this device is constructed as described above, it is easy to maintain a uniform heating temperature for the nozzle, and since only the nozzle is heated and the mold is not heated, the mold (fixed) can be easily maintained. Thermal expansion will not cause dimensional differences with the other mold (movable), and even if there is a gap between the nozzle heater and the nozzle due to thermal expansion, the nozzle heater can be placed behind the nozzle along the tapered surface. By sliding the two, it is possible to bring them into close contact and prevent a decrease in thermal conductivity.

In addition, the tip of the nozzle, which discharges high-temperature molten metal, tends to wear out in a relatively short period of time, so it must be replaced each time.In this case, with this device, you can hold the handle in your hand and use the cylindrical nozzle heater. Simply remove the nozzle heater, replace the nozzle from f, and then fit the nozzle heater back into the new nozzle.

Therefore, the nozzle heater of this device not only does not interfere with the nozzle replacement work, but also can be used over and over again, which greatly contributes to cost savings.

[Brief explanation of drawings]

The figures show an embodiment of the nozzle heating device for hot chamber die casting according to this invention, and FIG. 3 is an explanatory view of the nozzle heating device portion of the same as above, and FIG. 3 is a rear view of the nozzle heating device of the present invention. A... Molten metal injection device, 7... Nozzle, 8... Fitting hole, 7a, 8a... Taper surface, 9...・Nozzle heater.

Claims (1)

[Scope of utility model registration request] A nozzle heater that is removably fitted to the outer periphery of a nozzle of a molten metal injection device, characterized in that the fitting hole is formed with a tapered surface that is tapered to match the outer periphery of the nozzle, and a handle is fixed to the outside. Nozzle heating device in hot chamber die casting machine.