JPH02127002A - Injection molding apparatus of ceramic - Google Patents

Abstract

PURPOSE:To prevent the occurrence of cold slug by a construction wherein a slide gate plate having a heater and an auxiliary plate having also a heater are provided on the opposite side to the surface of a fixed plate whereon a fixed die is mounted. CONSTITUTION:A fixed plate 2 and a movable half 4 are put together by lowering a movable plate 8. By pressurizing the inside of a tank 16 subsequently, a molding material 18 is injected into a fixed die 2 from a nozzle element 6a and heated by a heater 10. When prescribed injection and dwelling are completed, the heater 10 is switched off and cooling is made by passing a cooling medium through a cooling hole 12. When the molding material 18 in the mold is set, the mold is opened by making the movable plate 8 rise and a molded article is taken out. On the occasion, a heater 42 of an auxiliary plate 40 is left operating, while a nozzle part 26a on the upper side of a slide gate plate 32 is cooled down, so as to prevent the occurrence of cold slug, and thereby cleaning of the nozzle part 26a is dispensed with.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The second invention relates to a ceramic injection molding apparatus that performs low-pressure injection molding using a ceramic molding material.

[Conventional technology]

A conventional example of this type of injection molding apparatus is shown in FIG.

That is, this injection molding apparatus consists of a fixed plate 6 to which a fixed mold 2 is attached, which has a nozzle part 6a for injecting a molding material 18, which will be described later, into the fixed mold 2, and a vertically movable plate to which a movable mold 4 is attached. It is equipped with a movable plate 8. 2a is a cavity of the fixed mold 2.

It also includes a tank 16 for kneading, pressurizing, etc. the ceramic molding material 18, from which the molding material 18 is supplied to the nozzle portion 6a of the fixed plate 6 via a heat-insulated transport pipe 14. Ru. 20 is a kneading motor.

In addition, on the side of the nozzle part 6a of the fixed plate 6, there is a heater 10 that heats the molding material 18 passing therethrough during injection, and a cooling hole 12 that cools the area around the nozzle part 6a when the injection is completed.
is provided. A cooling medium such as water, oil, or air is passed through the cooling hole 12 .

To explain an example of the molding operation, first, the movable plate 8 is lowered to align the fixed mold 2 and the movable mold 4, and then the inside of the tank 16 is pressurized to move the molding material 18 from the nozzle part 6a into the inside of the fixed mold 2, etc. inject. At this time, the heater 10 is heated. When the prescribed injection and pressure holding are completed, the heater l
O is cut and a cooling medium is passed through the cooling hole 12 for cooling. When the molded material 1418 in the mold is solidified, the movable plate 8 is raised, the mold is opened, and the molded product is taken out. Thereafter, similar operations are repeated as necessary.

[Problem to be solved by the invention]

However, in the conventional injection molding equipment as mentioned above,
When one molding operation is completed and the molded product is taken out from the fixed mold 2, the molding material 18 is completely solidified in the upper part of the nozzle part 6a, but is melted in the transport pipe 14 connected to it, and any part in between The molded product is taken out by tearing at the point.

As a result, as shown in FIG. 4, for example, a protrusion 22a corresponding to the nozzle part 6a is formed on the molded product 22, and inside the nozzle part a, there is solidified or almost solidified coal remaining after being torn off. A slug 24 will remain.

And such a cold slug 24 is attached to the nosle part a.
If the next molding is performed with the remaining particles remaining in the molded product, it will enter the next molded product and cause various problems, such as forming a layer between it and the new molding material. For example, mechanical strength is reduced due to the formation of boundaries therein. Further, when the molded product is an electrical product, the electrical characteristics deteriorate due to the boundary portion.

In order to prevent such defects, each time of molding,
It is necessary to remove the fixed mold 2 and clean the nozzle part 6a to remove the cold slug 24, which is very time-consuming and has the problem of lengthening the molding cycle and reducing efficiency.

In addition, since the hardened molding material I8 cannot be mechanically cut at the nozzle portion 6a, it must be torn off.
Another problem is that it is difficult to take out (eject) the molded product from the fixed mold 2.

Therefore, the main object of the present invention is to provide a ceramic injection molding apparatus that prevents the occurrence of cold slang and facilitates the removal of molded products.

[Means to solve the problem]

In order to achieve the above object, the injection molding apparatus of the present invention includes:
A slide gate plate for opening and closing the nozzle portion on the opposite side of the fixing plate from the side on which the fixed mold is attached, which has a hole through which the molding material passes and a heater provided on the side of the hole. and a hole that communicates with the nozzle part of the fixed plate when the slide gate plate is opened so that the slide gate plate is sandwiched between the fixed plate and the molding material is supplied from the outside. The present invention is characterized in that an auxiliary plate is provided, which has a hole and a heater provided on the side of the hole.

[Effect]

According to the above configuration, at the start of injection, the slide gate plate is opened and the heaters provided on the slide gate plate and the auxiliary plate are activated so that the molding material is heated and completely melted into the mold. injected into.

Further, when the injection is completed, when the slide gate plate is closed, the molding material connected to the nozzle portion of the fixed plate is mechanically cut there. However, by keeping the heater provided on the auxiliary plate working, the molding material upstream of the slide gate plate can be kept in a molten state, so cold slug does not occur.

〔Example〕

FIG. 1 is a diagram showing a state in which molds of an injection molding apparatus according to an embodiment of the present invention are combined. Components equivalent to those in the example of FIG. 3 are given the same reference numerals, and the differences from the conventional example will be mainly explained below.

In this embodiment, a drive source 38 drives the nozzle portion 26a of the fixing plate 26 from side to side in the figure on the side opposite to the surface on which the fixing mold 2 is attached, which corresponds to the fixing plate 6 described above. A slide gate plate 32 is provided, and an auxiliary plate 40 is provided to sandwich the slide gate plate 32 between the fixed plate 26 and the fixed plate 26.

In this example, the fixing plate 26 is made of molding material 1 as described above.
8 into the fixed mold 2, a cooling hole 28 provided on the side thereof and through which a cooling medium such as water, oil, air, etc., passes; It has a heater 30.

In this example, the slide gate plate 32 includes a hole 32a through which the molding material 18 passes, and a heater 34 provided on the side thereof.
The cooling hole 36 is provided at a position facing the nozzle part 26a when the nozzle part 26a is closed, and through which the cooling medium as described above passes.

The auxiliary plate 40 has a hole 40a that communicates with the nozzle part 26a when the slide gate plate 32 is opened, and a heater 42 provided on the side of the hole 40a. Molding material 18 is supplied from.

The molding material 18 is a green material obtained by kneading, for example, a wax-based binder and ceramic powder, and after molding, it is degreased at, for example, 600'C for about 240 hours, and then heated at 1300'C for 170 hours. A ceramic product can be obtained by performing main firing at a certain level.

To explain an example of the operation of this embodiment, at the start of injection, the first
As shown in the figure, the slide gate plate 32 is opened, and the molding material 18 from the transport pipe 14 is injected into the fixed mold 2 and the like via the individual members 40a, 32a and the nozzle portion 26a. In that case, by keeping all the heaters 30, 34 and 42 working, the molding material 18 heated by them and completely melted is injected.

After injection and pressure retention are completed, for example, as shown in Figure 2,
Close the slide gate plate 32. Thereby, the molding material 18 leading from the transport pipe 14 to the nozzle section 26a is mechanically cut there.

Further, in parallel with closing the slide gate plate 32, the heaters 30 and 34 of the fixed plate 26 and the slide gate plate 32 are turned off, and a cooling medium is flowed into the cooling holes 28 and 36 of both. However, the heater 42 of the auxiliary plate 40 is left in operation.

As a result, the nozzle portion 2 above the slide gate plate 32
6a etc. are cooled, the solidification of the molding material 18 there is promoted, and the molding material 18 on the lower side (upstream side) of the slide gate plate remains heated by the heater 42, so it is kept in a molten state. , Therefore, called slug as in the conventional example does not occur.

Further, during the next molding, this molding material 18 is heated to a heater 30.
The reheating by 34 and 42 ensures that a completely molten molding material 18 is always injected.

Therefore, according to this embodiment, cold slug does not occur due to the above-mentioned action, and therefore the removal of the stationary mold 2 and the nozzle portion 26 after each molding process, which were necessary in the case of the conventional example, are not required.
There is no need to clean a. As a result, the molding operation becomes easier, and the molding cycle can be shortened to increase efficiency.

Of course, even if such cleaning is omitted, since no coal slag is generated in the first place, it will not be mixed into the molded product.

Further, since the molding material 18 is mechanically cut by the slide gate plate 32, it becomes easier to take out the molded product from the fixed mold 2, unlike the conventional case where it is torn off.

In addition, in the case of the conventional example, since the molding material 18 of the nozzle portion 6a is not mechanically cut, the molded product 22 shown in FIG.
The protrusion 22a has become quite long, and the protrusion 22a has been broken off to make a product, but in that case, the protrusion 22a
There is a risk that the area around the root part (gate part) may peel off, which puts restrictions on the design of the gate part. However, in this embodiment, the height of the protrusion part 22a is lower than that of the conventional one because it is mechanically cut by the slide gate plate 32. It is much lower than in the case of the example, and can be easily removed by cutting it, so there are no restrictions on the design of the gate section.

Note that the slide gate plate 32 has cooling holes 3 as in the above example.
Although it is preferable to provide a cooling hole 6, it is not necessary to provide the cooling hole 36, since it is possible to cool the upper side of the slide gate plate 32 and heat the lower side thereof even without it.

It is also preferable to provide the heater 30 of the fixed plate 26 as in the above example, but even if it is not provided, the heaters 34 and 4 of the slide gate plate 32 and the auxiliary plate 40
Since the molding material 18 can be sufficiently heated in this manner, the heater 30 does not necessarily need to be provided.

Further, it is preferable to provide the cooling holes 28 of the fixed plate 26 with J as in the above example, but it is also possible to cool the area around the nozzle part 26a by other means, for example from the fixed mold 22 side. In other words, it does not necessarily have to be provided.

〔Effect of the invention〕

As described above, according to the present invention, a slide gate plate having a heater and an auxiliary plate also having a heater are provided on the opposite side of the fixed plate to the side on which the fixed mold is attached, so that cold slug occurs. This makes it possible to always inject completely molten molding material.

As a result, it is no longer necessary to remove the stationary mold and clean the nozzle part after each molding, making the molding work easier, shortening the molding cycle, and increasing efficiency.

Also, since the occurrence of cold slagging is prevented,
No boundaries are formed in the molded product, and the mechanical strength or electrical properties do not deteriorate.

Moreover, since the molding material is mechanically cut by the slide gate plate, it becomes easy to take out the molded product from the fixed mold.

Furthermore, because of the same reason as above, the height of the protrusion formed on the molded product is reduced, which facilitates its removal and eliminates restrictions on the design of the gate part.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a state in which molds of an injection molding apparatus according to an embodiment of the present invention are combined. FIG. 2 is a view partially showing the device of FIG. 1 with the slide gate plate closed. FIG. 3 is a diagram showing a state in which a mold of a conventional injection molding apparatus is opened. FIG. 4 is a diagram showing a schematic example of a molded product. 2...Fixed type, 4...Movable type, 8...Movable plate, 1
8...Ceramic molding material, 26...Fixing plate, 2
6a... Nozzle part, 28... Cooling hole, 300.・Heater, 32...Slide gate plate, 32 a ---
Hole, 34... Heater, 36... Cooling hole, 40...
Auxiliary plate, 40a... hole, 42... heater.

Claims (1)

[Claims] (1) A ceramic injection molding apparatus comprising a fixed plate to which a fixed mold is attached and which has a nozzle portion for injecting ceramic molding material into the fixed die, and a movable plate to which a movable die is attached; A slide gate plate for opening and closing the nozzle portion of the plate, which has a hole through which the molding material passes and a heater provided on the side of the hole, is provided on the opposite side of the plate to the side on which the fixed mold is attached. , and so that this slide gate plate is sandwiched between the fixed plate,
An auxiliary plate is provided, which has a hole that communicates with the nozzle part of the fixed plate when the slide gate plate is opened, into which molding material is supplied from the outside, and a heater provided on the side of this hole. Ceramic injection molding equipment characterized by: