JPH07185777A - Device for producing fiber reinforced metal and its production - Google Patents

Abstract

PURPOSE:To make a vacuum valve in a metallic mold unnecessary and to obtain a fiber reinforced metal having good quality without defect of the entrapment of slag by making a melting furnace elevatable in a pressure vessel and executing the evacuation synchronously to the pressure vessel, stoke and metallic mold. CONSTITUTION:A preform 7 is set into each cavity 6 in the metallic mold 5 and heated to a prescribed temp. with a heating means 8, and metal material is supplied into the melting furnace 3 positioned at the lowermost part in the pressure vessel 1 to produce molten metal Y. A removing rod 12 is inserted from a working hatch 2 to remove slag N on the surface of molten metal Y, and a blind cover 11 is fitted to the working hatch 2 and closed in the pressure vessel 1, and a gas exhaust valve 9b is opened to execute the evacuation. Successively, the valve 9a is closed and the melting furnace 3 is ascended to the uppermost position in the pressure vessel 1 with a melting furnace elevating means 10, and the lower end part of the stoke 4 is inserted into the molten metal Y and a valve 9a is opened to introduce gas into the pressure vessel 1. The gas pressure is applied to the surface of the molten metal Y and the molten metal Y is risen into the stoke 4, and flowed into the cavity 6 and the preform 7 is impregnated to execute the casting.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for producing fiber reinforced metal having excellent strength and wear resistance and a method for producing the same.

[0002]

2. Description of the Related Art A fiber reinforced metal having excellent strength and wear resistance is particularly suitable for metal machine parts such as engine cylinder liners and pistons. Similar to FRP (fiber reinforced plastic), this fiber reinforced metal has a metal base material provided with a preform made of fibrous silicon carbide, alumina or the like, and most of them are manufactured by a high pressure casting method. ing. In this high-pressure casting method, a preform formed in a predetermined shape in advance is placed in a mold, and then a metal melt is applied to the preform in the mold by a hydraulic piston or the like.
It is a method of extruding and impregnating at a pressure higher than atmospheric pressure. However, in this method, since the extrusion pressure of the molten metal is large, there is a disadvantage that the extrusion pressure causes the preform in the mold to crack, or the compression deforms greatly, and it is difficult to obtain a good fiber-reinforced metal. There are drawbacks such as. Therefore, as a method of compensating for this drawback, the metal mold is heated to near the melting point of the metal base material to prevent the viscosity of the metal melt from rising, and the metal pressure is used to extrude the metal melt by an extrusion pressure of 30 atm or less. A method of impregnating a preform in a mold has been proposed (JP-A-59-500135).

[0003]

By the way, in the manufacturing method using such a gas pressure, it is necessary to evacuate the inside of the mold in advance in order to facilitate the impregnation of the molten metal into the preform. Therefore, the die is equipped with an exhaust port and a vacuum valve of a type that rubs against the exhaust port. However, since this vacuum valve is a method of rubbing metal and metal together, if dust or the like adheres to the sealing surface to create a slight gap, the injected metal melt may leak from the gap and cause a serious accident. There is. In addition, since a small amount of molten metal is inserted into the sealing surface of the vacuum valve due to its structure, it has to be cleaned every casting operation, and continuous operation is difficult and work efficiency is poor. Therefore, it has been considered to improve the structure of the vacuum valve, but at present, no mechanism has been proposed that can completely seal the sealing surface. In addition, since the stalk for guiding the molten metal into the mold is always inserted into the molten metal, it is oxidized by the air that has entered the mold and "sticks" to the molten metal surface inside the stalk. Occurs, this is as it is,
It was sometimes driven into the mold during the next casting, which sometimes led to structural defects in the cast body.

Therefore, the present invention has been devised to effectively solve the above problems, and its purpose is to safely and easily produce a good quality fiber-reinforced metal and to improve its production efficiency. The present invention provides a novel fiber-reinforced metal manufacturing apparatus and a manufacturing method thereof.

[0005]

In order to achieve the above object, the first invention is to manufacture a fiber reinforced metal for forming a fiber reinforced metal by impregnating a preform placed in a mold with a molten metal. In the apparatus, a melting furnace which is provided in a pressure vessel and contains a molten metal, and an upper end portion of which is connected to the mold and a lower end portion of which penetrates the pressure vessel and faces the melting furnace side, A stalk for guiding the molten metal in the furnace into the mold, an intake / exhaust means provided in the pressure container for sucking and exhausting gas inside the pressure container and the mold, and pressure in the melting furnace. It consists of a melting furnace elevating means for moving up and down in the container to insert and remove the lower end of the stalk into and out of the surface of the molten metal in the melting furnace, and heating means for heating the die and stalk. The second invention is the In a method for producing a fiber-reinforced metal for forming a fiber-reinforced metal by impregnating a preform with a molten metal, a melting furnace in which the molten metal is stored is moved up and down in a pressure vessel to which an intake / exhaust means is connected. While freely containing, the lower end of the stalk to which the mold is connected faces above the molten metal surface of the melting furnace, and the pressure vessel and the heated stalk and the inside of the mold are simultaneously evacuated by the intake and exhaust means to form a vacuum. After that, the melting furnace is raised to immerse the lower end of the stalk into the molten metal, and then gas is supplied into the pressure vessel by the intake and exhaust means, and the molten metal is stalked by the gas pressure. Through which the preform in the mold is impregnated.

[0006]

As described above, according to the present invention, the melting furnace in which the molten metal stored in the pressure vessel is stored is lowered by the melting furnace ascending / descending means so that the lower end of the stalk opens the molten metal. By exhausting the inside of the pressure vessel, the stalk and the inside of the mold connected to the upper end of the stalk can be vacuumed at the same time. Therefore, unlike the conventional case, it is not necessary to provide a vacuum valve in the mold, the cleaning work of the sealing surface of the vacuum valve can be omitted, and the leakage of the molten metal from the sealing surface can be prevented in advance. Also, with the lower end of the stalk separated from the molten metal surface,
Since the "slag" generated on the surface of the molten metal can be removed, it is possible to prevent the "slag" from being caught.

[0007]

An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows an embodiment of an apparatus for producing fiber reinforced metal according to the present invention. As shown in the figure, this manufacturing apparatus has a melting vessel 3 housed in a pressure vessel 1 in which a working hatch 2 is formed, and a tubular stalk 4 is provided above the pressure vessel 1 so as to penetrate therethrough. ing.

A halved die 5 is provided at the upper end of the stalk 4, and fibrous preforms 7 and 7 are housed in the cavities 6 and 6 of the die 5, respectively. ing. On the other hand, the lower end of the stalk 4 penetrates into the pressure vessel 1 and extends downward, and is positioned so as to face the upper portion of the melting furnace 3.

Both ends of the stalk 4 are opened, and the upper end of the stalk 4 is connected to the runner 6a of each cavity 6 of the mold 5 so that the inside of the pressure vessel 1 and the inside of each cavity 6 of the mold 5 communicate with each other. It is in the state of being Also, this Stoke 4
A heating means 8 such as an electric heater is provided so as to surround this, and the stalk 4 can be heated to a desired temperature. Further, similarly to this, the die 5 is also provided with a heating means 8 such as an electric heater,
Like the stalk 4, the die 5 can be heated to a desired temperature.

The pressure vessel 1 has a gas introduction valve 9a.
A gas supply / exhaust means 9 including an exhaust valve 9b, a pump (not shown), etc. is provided to exhaust the gas in the pressure vessel 1 or to instantaneously send the gas into the pressure vessel 1 as necessary. It has become.

Further, the melting furnace 3 is provided with a melting furnace elevating means 10 so that the melting furnace 3 housed in the pressure vessel 1 can be arbitrarily moved up and down in the pressure vessel 1. Then, when this is raised, the lower end of the stalk 4 is immersed in the molten metal Y stored in the melting furnace 3, and when it is lowered, the lower end of the stalk 4 is exposed above the molten metal Y surface. Is located. In the figure, 13 is a fixing member for connecting and fixing the mold 5 to the upper end of the stalk 4,
Reference numeral 1 denotes a blind lid that is detachably attached to the work hatch 2.

Next, an embodiment of a method for producing a fiber reinforced metal using the device of the present invention will be described. First, as shown in FIG. 1, the preforms 7 and 7 are respectively placed in the cavities 6 and 6 of the split mold 5, and the mold 5 and the stalk 4 are heated to a predetermined temperature by the heating means 8. Along with
A material metal or a previously melted metal is supplied from the work hatch 2 to the melting furnace 3 located at the bottom of the pressure vessel 1 by the melting furnace elevating means 10 and heated to manufacture the molten metal Y.

When the die 5, the stalk 4, and the molten metal Y reach a predetermined temperature in such a state, the removal rod 12 is inserted from the work hatch 2 into the pressure vessel 1 as shown in the drawing, and the melting furnace 3 is heated. "Noro N" floating on the surface of the molten metal Y
After removing the above, a blind lid 11 is attached to the work hatch 2 to seal the inside of the pressure vessel 1, and then the exhaust valve 9b of the air supply / exhaust means 9 is opened to instantly evacuate the pressure vessel 1. The inside of the pressure vessel 1 as well as the inside of the stalk 4 and the mold 5 communicating with this are in a vacuum state.

Next, when the degree of vacuum inside these reaches a predetermined value, the exhaust valve 9b is closed, and the melting furnace elevating means 10 raises the melting furnace 3 to the uppermost position in the pressure vessel 1 to move the stalk 4 After immersing the lower end of the gas into the molten metal Y, the gas introduction valve 9a of the air supply / exhaust means 9 is opened, and gas is instantaneously introduced into the pressure vessel 1 from an air reservoir (not shown) to a predetermined pressure. Then, the gas pressure is applied to the Y surface of the molten metal, which rises in the stalk 4 from the lower end of the stalk 4, passes through the runner 6a from the upper end thereof, and flows into the cavities 6 and 6 of the die 5, Each preform 7, 7 is impregnated and cast.
At this time, since the stalk 4 and the die 5 are heated to a predetermined temperature by the heating means 8 as in the conventional method, the molten metal Y fed from the melting furnace 3 is cooled and its viscosity is increased. And the casting is well done.

When such casting is completed, the die 5 is opened to take out the cast body, and new preforms 7, 7 are placed in the cavities 6, 6 of the die 5 again. After closing the mold 5 and lowering the melting furnace 3 to the lowermost part in the pressure vessel 1 by the melting furnace elevating means 10, a new fiber-reinforced metal is produced one after another by repeating the same operation as above. Become. The control of the melting furnace elevating means 10, the air supply / exhaust means 9, the removal of the cast, the removal of the "robe" of the preform 7 and the like can be performed not only by manual work but also by automatic remote control. Also,
The sealing members such as ceramic fiber yarns used for the sealing surfaces of the divided molds 5a and 5b may be replaced if necessary during this taking out work.

Then, the dimensions are actually 150 × 150 × 30.
using ^t mm of an aluminum borate whisker consisting preform (Vt = 25%), after a 5 minutes evacuation, driving molten metal consisting of 750 ° C. of AC8A alloy 30 atmospheres preform, holding for 3 minutes As a result of manufacturing the cast body, it was possible to obtain a good fiber-reinforced metal without "rattle" entrainment, deformation of the preform, gas defects, etc. as shown in FIG. Incidentally, FIG. 3 is a structural photographic diagram by an optical microscope. In the figure, a black portion is a preform made of aluminum borate whiskers, and a white portion is an AC8A alloy impregnated and solidified in this preform. Further, in the conventional apparatus and method, the molten metal leaks from the vacuum valve attached to the mold 3 times /
Although it has been observed for about a year, these accidents can be prevented according to the present invention.

[0018]

In summary, according to the present invention, since the melting furnace for containing the molten metal can be moved up and down, the pressure vessel, the stalk, and the vacuum in the mold can be simultaneously drawn.
In addition to facilitating the removal of the "curd", the vacuum valve provided in the mold as in the conventional apparatus becomes unnecessary. Therefore,
In addition to being able to obtain good quality fiber reinforced metal that does not have a “roll” entrapment defect, the molten metal is prevented from leaking from the mold, improving safety and eliminating the need for cleaning work. The efficiency can be greatly improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing an embodiment of the present invention.

FIG. 3 is a micrograph showing an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pressure vessel 3 Melting furnace 4 Stoke 5 Mold 7 Preform 8 Heating means 9 Intake / exhaust means 10 Melting furnace ascending / descending means

Claims (2)

[Claims] 1. In a fiber-reinforced metal manufacturing apparatus for forming a fiber-reinforced metal by impregnating a preform placed in a mold with a molten metal, a melting device provided in a pressure vessel and containing the molten metal. A furnace and a stalk having an upper end connected to the mold and a lower end penetrating the pressure vessel to face the melting furnace, and for guiding the molten metal in the melting furnace into the mold. A suction / exhaust means provided in the pressure vessel for sucking / exhausting gas inside the pressure vessel and in the mold; and moving the melting furnace up and down in the pressure vessel to lower the lower end of the stalk to the melting furnace. An apparatus for producing a fiber-reinforced metal, comprising: a melting furnace ascending / descending means for inserting / removing into / from a molten metal surface inside, and a heating means for heating the die and stalk. 2. A method for producing a fiber-reinforced metal for forming a fiber-reinforced metal by impregnating a preform placed in a mold with a molten metal, wherein the pressure vessel connected to an intake / exhaust means is provided with the above-mentioned means. A melting furnace storing metal melt is housed so that it can be moved up and down, and the lower end of the stalk to which the mold is connected faces the upper surface of the melting furnace, and the pressure vessel and the heated stalk are heated and sucked by the intake and exhaust means. , The mold is evacuated at the same time to make a vacuum, then the melting furnace is raised to immerse the lower end of the stalk in the molten metal, and then
A method for producing a fiber reinforced metal, characterized in that gas is supplied into the pressure vessel by the intake and exhaust means, and the molten metal is passed through the stalk to impregnate the preform in the mold by the gas pressure.