JPH0323050A - injection device - Google Patents

Abstract

PURPOSE:To surely prevent unexpected solidification caused by temp. drop of molten metal by interposing heat insulating means between a fixed plate and a sleeve having molten metal basin part titled thereto and setting heating heater to the fitted part of the sleeve. CONSTITUTION:The sleeve 1 is fitted to the fixed plate 6 and the molten metal 3 charged into the molten metal basin part 5 arranged in this sleeve 1 is pushed out with a pressurized plunger 2 to pour the molten metal into cavity in a die (not shown in figure). In the above injecting device, the heat insulating means composed of heat insulating material 20 and air gap 22, is interposed between the above fixed plate 6 and sleeve 1. Further, the heating heater 21 is set in a part fitted at least to the fixed plate 6 in the above sleeve 1. By these heat insulating means and heating means, the temp. drop of molten metal 3 caused by heat transfer, etc., to the fixed plate 6 is prevented, and the temp. is held almost constant. By this method, the good quality molten metal with solidification prevented is poured to obtain the injecting product having good quality.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an injection device for insulating and heating a sleeve of an injection section in a molten metal forging machine.

[Conventional technology]

FIG. 2 is a cross-sectional view showing a conventional injection device. In the figure, 1 is a sleeve, 2 is a pressurized plunger that can be slid inside the sleeve 1, 3 is a molten metal such as a conductive material, and 4 is for molding. a mold having a cavity, 5 a sump part in the sleeve l;
6 is a fixed plate of the main body of the device. Next, the operation will be explained. First, a melt field 3 of a conductive material melted by a melting furnace (not shown) is supplied to the sump 5 in the sleeve 1. Next, the pressurizing plunger 2 is raised into the sleeve 1 as shown in the figure, and the cavities in the molds 4 are filled with the molten metal 3, thereby shaping the product. In addition, the sleeve l is fixed in contact with a fixed platen 6 of the machine body, and the heat of the molten metal 3 is taken away by the fixed platen 6 through the sleeve 1, the temperature of the molten metal 3 in the sump 5 decreases, and the sleeve l It solidifies from the parts that are in contact with it. As a result, in reality, the molten metal 3 whose temperature has been lowered is poured, which makes it difficult to spread the melt into the cavity, making it more likely that defects such as blowholes will occur in the product. Also,
As the molten metal 3 in contact with the sleeve solidifies, the pressurizing force of the pressurizing plunger 2 is subject to resistance from these solidified parts, and the necessary pressurizing force may not be sufficiently transmitted to the molten metal. This also has a negative effect on the quality of the injection-produced product. In response to this, an injection device as shown in FIG. 3 has been proposed in Japanese Patent Publication No. 54-42817. According to this, although the sleeve I is heated by the heater 10, such a heater 10 is not provided at the contact portion with the fixed platen 6 having a large mass. Therefore, heat is taken away by the fixed platen 6, and a large-capacity heater 10 is required to heat the sleeve. Furthermore, as shown in Fig. 4, Japanese Patent Publication No. 53-41098 discloses a device in which a heat insulating material 20 is inserted between the plunger 2 of the injection part and the molten metal 3 such as a conductive material to keep the molten metal warm. However, since this does not insulate or heat the sleeve l or fixed platen 6, solidification of the molten metal 3 during pressurization is unavoidable.

[Problem to be solved by the invention]

Since the conventional injection device is structured as described above, since the sleeve 1 and the fixed platen 6 are in direct contact with each other,
The heat of the molten metal 3 is taken away by the fixed platen 6, which has a large mass, and the temperature of the molten metal 3 decreases greatly. The entire part of the molten metal 3 is not heated evenly, and the temperature of the molten metal 3 drops significantly in one part, resulting in unevenness of the molten metal, which has a negative effect on the quality of the product. The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an injection device that can prevent the temperature of the molten metal from decreasing and reliably prevent the molten metal from solidifying inadvertently.

[Means to solve the problem]

In the injection device according to the present invention, the sleeve and the stationary plate are insulated by a heat insulating means consisting of a heat insulating material and a workpiece gap, and the sleeve is heated by a heater provided at least in a portion of the sleeve that contacts the stationary plate. This prevents the temperature of the molten metal from decreasing.

[For use]

The heat insulating means in this invention prevents the heat of the molten metal from escaping to the fixed plate by minimizing direct contact between the sleeve and the fixed plate, and the heater directly connects the sleeve to compensate for the heat escaping from the fixed plate. It heats up and acts to obtain a molten metal with a stable molten state.

【Example】

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, 1 is a sleeve, 2 is a pressure plunger, 3
5 is a molten metal such as a conductive material, 5 is a sump portion, and 6 is a stationary plate, which has almost the same structure as shown in FIGS. 2 to 4. Further, 20 is a heat insulating material interposed between the sleeve mounting portion of the fixed platen 6 and the mounting surface of the sleeve l, and 22 is an air gap provided between the fixed platen 6 and the sleeve l. The heat insulating material 20 constitutes the heat insulating means of the present invention. Reference numeral 21 denotes a heater, which connects at least the fixed plate 6 of the sleeve 1.
It is attached by a method such as embedding to the part where it is attached. Next, the operation will be explained. First, when injecting a molten metal 3 such as a conductive material from the sleeve 1, the molten metal 3 melted in a melting furnace is supplied to a sump 5 in the sleeve 1. Next, the mold is inserted, and the molten metal 3 is injected by the pressurized plunger 2 to fill the cavity of the mold. In this case, the molten metal 3 is placed in the molten metal sump 5 of the sleeve 1.
The temperature drop of this molten metal 3 from pouring to injection is:
A heat insulating material 20 interposed in the contact area between the sleeve 1 and the fixed platen 6
This is prevented by Here, the heat insulating material 20 is not placed in the entire contact area, but only in the necessary part where the sleeve 1 is attached with a predetermined holding strength, and the other part is made into an air gap 22 having a large heat insulating effect. Also, sleeve 1
Since the heater 2l is embedded inside, the sleeve 1 is efficiently heated. As a result, the temperature of the molten metal 3 poured into the sump 5 does not drop rapidly until injection, and the molten metal hardly solidifies in the portion in contact with the sleeve 1. Therefore, the resistance of the pressurizing plunger 2 during injection can be kept low, and the pressurizing force can sufficiently act on the molten metal until it solidifies after injection, producing high-quality molten metal and molded products that do not produce blowholes. Obtainable.

【Effect of the invention】

As described above, according to the present invention, a heat insulating means including a heat insulating material and an air gap is provided between the sleeve and the fixed plate,
In addition, we took care to attach a heater such as a built-in heater to the sleeve, so that the temperature of the molten metal poured into the molten metal reservoir inside the sleeve can be roughly controlled throughout the sleeve due to its insulation effect and the heating operation of the sleeve. can be held constant,
Therefore, high-quality molten metal can be injected into the mold cavity, and a high-quality product without blowholes or melting zones can be obtained.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway plan view of an injection device according to an embodiment of the present invention, Fig. 2 is a sectional view showing a conventional injection device, and Figs. 3 and 4 are improved versions of Fig. 2. FIG. 2 is a sectional view showing a conventional injection device. 1 is a sleeve, 2 is a pressurizing plunger, 3 is a molten metal, 5 is a sump, 6 is a fixed plate, 20 is a heat insulating means (insulating material), 21
2 is a heater, and 22 is a heat insulating means (air gap). In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] In an injection device equipped with a sleeve attached to a fixed platen and a pressurized plunger for pouring molten metal contained in a reservoir in the sleeve into a cavity of a mold, there is a space between the fixed platen and the sleeve. An injection device comprising an interposed heat insulating means and a heater installed in at least a portion of the sleeve that is attached to the stationary platen.