JP3132275B2 - Apparatus and method for producing fiber-reinforced metal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Fiber-reinforced metals having excellent strength and abrasion resistance are particularly suitable for metal mechanical parts such as cylinder liners and pistons of engines. This fiber-reinforced metal is provided with a preform made of fibrous silicon carbide, alumina, or the like in a metal base material similarly to FRP (fiber-reinforced plastic) or the like, and most of these 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 molten metal is poured onto the preform in the mold by a hydraulic piston or the like.
This is a method of extruding and impregnating at a high pressure equal to or higher than the atmospheric pressure. However, in this method, since the extrusion pressure of the molten metal is large, there are disadvantages such as the preform in the mold being cracked by the extrusion pressure or being greatly deformed by being compressed, and it is difficult to obtain a good fiber-reinforced metal. There are drawbacks. Therefore, as a method of compensating for this drawback, as a method of heating the mold to near the melting point of the metal base material to prevent the viscosity of the molten metal from increasing, the gas pressure is used to extrude the molten metal 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]

In the manufacturing method using such gas pressure, it is necessary to evacuate the mold in advance to a vacuum in order to facilitate the impregnation of the molten metal into the preform. For this reason, the mold is provided with an exhaust port and a vacuum valve that rubs the exhaust port. However, since this vacuum valve is a method of rubbing metals together, if dust or the like adheres to the sealing surface to create a slight gap, the injected molten metal 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, so that continuous operation is difficult and operation efficiency is low. Therefore, it is considered to improve the structure of the vacuum valve, but at present, no mechanism capable of completely sealing the sealing surface has been proposed. In addition, since the stalk for guiding the molten metal into the mold is always inserted into the molten metal, the stalk is oxidized by the air that has entered the mold and “slows” on the surface of the molten metal in the stalk. Occurs, and this is
In the next casting, it was driven into the mold, which sometimes caused a structural defect of the casting.

The present invention has been devised in order to effectively solve the above problems, and has as its object to safely and easily produce high-quality fiber-reinforced metal and to improve the production efficiency. It is an object of the present invention to provide a novel fiber reinforced metal manufacturing apparatus and a manufacturing method thereof.

[0005]

Means for Solving the Problems In order to achieve the above object, a first invention is to produce a fiber reinforced metal for forming a fiber reinforced metal by impregnating a preform disposed in a mold with a molten metal. In the apparatus, a melting furnace provided in a pressure vessel and containing a molten metal, and an upper end connected to the mold and a lower end penetrating through the pressure vessel and facing the melting furnace to form the melting furnace. A stalk for guiding the molten metal in the furnace into the mold, suction and exhaust means provided in the pressure vessel for sucking and exhausting gas inside the pressure vessel and the mold, and a pressure in the melting furnace. A melting furnace elevating means for moving up and down in the vessel to insert and remove the lower end of the stalk from the surface of the metal melt in the melting furnace, and a heating means for heating the mold and the stalk. The second invention is arranged in a mold. In a method for producing a fiber-reinforced metal by impregnating a molten metal into a formed preform to form a fiber-reinforced metal, a melting furnace in which the molten metal is stored is moved up and down in a pressure vessel to which suction and exhaust means are connected. While freely accommodating, the lower end of the stalk to which the mold is connected faces the upper surface of the melting furnace, and the pressure vessel, the heated stalk, and the interior of the mold are simultaneously evacuated and vacuumed by the suction and exhaust means. After raising the melting furnace, the lower end of the stalk is immersed in the molten metal. Thereafter, a gas is supplied into the pressure vessel by the suction / exhaust means, and the stalk is moved by the gas pressure. To impregnate the preform in the mold.

[0006]

According to the present invention, as described above, the lowering portion of the stalk is opened by lowering the melting furnace storing the molten metal accommodated in the pressure vessel by the raising and lowering means of the melting furnace to open the molten metal. By evacuating the pressure vessel, the interior of the mold connected to the stalk and the upper end of the stalk can be evacuated at the same time. Therefore, unlike the related art, there is no need to provide a vacuum valve in the mold, and the operation of cleaning the sealing surface of the vacuum valve can be omitted, and the leakage of the molten metal from the sealing surface can be prevented. Also, with the lower end of the stalk separated from the molten metal surface,
Since the "slow" generated on the surface of the molten metal can be removed, the "slow" can be prevented from being involved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 shows an embodiment of an apparatus for producing a fiber-reinforced metal according to the present invention. As shown in the drawing, in this manufacturing apparatus, a melting furnace 3 is accommodated in a pressure vessel 1 in which a working hatch 2 is formed, and a tubular stalk 4 is provided at an upper portion of the pressure vessel 1 so as to pass therethrough. ing.

At the upper end of the stalk 4, a split mold 5 is provided, and fibrous preforms 7, 7 are accommodated in cavities 6, 6 of the mold 5, respectively. ing. On the other hand, the lower end of the stalk 4 penetrates into the pressure vessel 1, extends downward and faces the upper part of the melting furnace 3.

Both ends of the stalk 4 are open, and the upper end thereof is connected to the runner 6a of each cavity 6 of the mold 5 so that the inside of the pressure vessel 1 communicates with the inside of each cavity 6 of the mold 5. It has been done. Also, this Stoke 4
A heating means 8 such as an electric heater is provided so as to surround the stalk 4 so that the stalk 4 can be heated to a desired temperature. Similarly, the mold 5 is provided with a heating means 8 such as an electric heater.
As in the case of the stalk 4, the mold 5 can be heated to a desired temperature.

The pressure vessel 1 has a gas introduction valve 9a.
And a gas supply / exhaust means 9 comprising a pump (not shown), etc., for exhausting the gas in the pressure vessel 1 as needed, and for instantly sending the gas into the pressure vessel 1. It has become.

The melting furnace 3 is provided with a melting furnace elevating means 10 for moving the melting furnace 3 housed in the pressure vessel 1 up and down arbitrarily in the pressure vessel 1. 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 lowered, the lower end of the stalk 4 is exposed above the surface of the molten metal Y. Position. In the figure, reference numeral 13 denotes a fixing member for connecting and fixing the mold 5 to the upper end of the stalk 4;
1 is a blind lid detachably provided on the work hatch 2.

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

When the temperature of the mold 5, the stalk 4, and the molten metal Y reaches a predetermined temperature in such a state, the removal rod 12 is inserted into the pressure vessel 1 from the work hatch 2 as shown in FIG. "North N" floating on the surface of molten metal Y
Then, 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 9 b of the air supply / exhaust means 9 is opened to instantaneously evacuate the pressure vessel 1. The interior of the pressure vessel 1 as well as the interior of the stalk 4 and the mold 5 communicating therewith are in a vacuum state.

Next, when the degree of vacuum in the inside reaches a predetermined value, the exhaust valve 9b is closed, and the melting furnace 3 is raised to the uppermost position in the pressure vessel 1 by the melting furnace elevating means 10, so that the stalk 4 Is immersed in the molten metal Y, the gas introduction valve 9a of the supply / exhaust means 9 is opened, and gas is instantaneously introduced from the air reservoir (not shown) into the pressure vessel 1 to a predetermined pressure. Then, the gas pressure is applied to the molten metal Y surface, which rises in the stalk 4 from the lower end of the stalk 4 and flows from the upper end through the runner 6a into the cavities 6, 6 of the mold 5, The respective preforms 7 are impregnated and cast.
At this time, since the Stoke 4 and the metal mold 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 to increase the viscosity. And the casting is performed well.

When such a casting is completed, the mold 5 is opened to take out the cast body, and new preforms 7, 7 are arranged in the cavities 6, 6 of the mold 5, and again. After the mold 5 is closed and the melting furnace 3 is lowered by the melting furnace elevating means 10 to the lowermost position in the pressure vessel 1, the same operation as described above is repeated to produce new fiber-reinforced metals one after another. Become. The control of the melting furnace elevating means 10 and the supply / exhaust means 9, the removal of the cast body, and the removal of the “slow” installation of the preform 7 can be performed not only manually but also automatically by 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 as needed during this removing operation.

The actual size of 150 × 150 × 30
After vacuuming for 5 minutes using a preform (Vt = 25%) made of aluminum borate whiskers of ^t mm, a metal melt made of an AC8A alloy at 750 ° C. is driven into this preform at 30 atm, and held for 3 minutes. As a result, as shown in FIG. 3, a good fiber reinforced metal free from "rolling in", deformation of the preform, gas defects and the like was obtained. FIG. 3 is a micrograph of the structure taken by an optical microscope. In FIG. 3, the black portions are the preforms made of aluminum borate whiskers, and the white portions are the AC8A alloy impregnated and solidified in this preform. In addition, in the conventional apparatus and method, the molten metal leak accident from the vacuum valve attached to the mold 3 times /
According to the present invention, these accidents can be prevented before they have been seen for about a year.

[0018]

In summary, according to the present invention, since the melting furnace for accommodating the molten metal can be moved up and down freely, it is possible to simultaneously perform the evacuation of the pressure vessel, the Stoke, and the mold.
The removal of the "slow" becomes easy, and the vacuum valve provided in the mold as in the conventional apparatus becomes unnecessary. Therefore,
A good quality fiber reinforced metal with no "slow" entrapment defect can be obtained, and the leakage of molten metal from the mold is prevented, improving safety and eliminating the need for cleaning work. Efficiency can be greatly improved.

[Brief description of the drawings]

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

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

FIG. 3 is a micrograph showing an example 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 Suction and exhaust means 10 Melting furnace elevating means

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-317246 (JP, A) JP-A-62-139839 (JP, A) JP-A-51-99627 (JP, A) 264157 (JP, A) JP-A-59-144567 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B22D 19/14 B22D 18/04 C22C 47/08

Claims (2)

(57) [Claims] 1. A fiber reinforced metal manufacturing apparatus for forming a fiber reinforced metal by impregnating a preform disposed in a mold with a molten metal, the melting apparatus being provided in a pressure vessel and containing the molten metal. A furnace, and a stalk for guiding the molten metal in the melting furnace into the mold while the upper end is connected to the mold and the lower end faces the melting furnace through the pressure vessel. Suction / exhaust means provided in the pressure vessel, for sucking / exhausting gas inside the pressure vessel and 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 manufacturing a fiber-reinforced metal, comprising: a melting furnace elevating means for inserting and removing a metal melt in a furnace; and a heating means for heating the mold and stalk. 2. A method for producing a fiber reinforced metal for impregnating a preform disposed in a mold with a molten metal to form a fiber reinforced metal, the method comprising: The melting furnace storing the molten metal is accommodated in a vertically movable manner, and the lower end of the stalk to which the mold is connected faces the upper surface of the melting furnace. After evacuating and evacuating the inside of the mold at the same time, raising the melting furnace, immersing the lower end of the stalk in the molten metal,
A method for producing a fiber-reinforced metal, characterized in that a gas is supplied into a pressure vessel by the suction / exhaust means, and the gas pressure causes the molten metal to pass through the stalk to impregnate the preform in the mold.