JPH06170515A - Manufacture of composite material - Google Patents

Abstract

PURPOSE:To obtain a satisfactory composite material by keeping the temp. of molten metal in a cavity of a mold so as to sufficiently impregnate into a preform body. CONSTITUTION:At the time of inserting the preform body 13 inserted in a core 12 into a mold hole 15, the ratio of the width size of the cavity A formed with the inner peripheral surface of the mold hole 15 and the outer peripheral surface of the preform body 13 and the thickness size of the preform body 13 is made to be the larger going to the deeper inner part from a molten metal pouring hole 16, thereby keeping the temp. of the molten metal in the cavity a so as to sufficiently impregnate into the preform body 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a tubular member whose inner thick portion is made of metal or ceramics and whose outer thick portion is made of a composite material such as aluminum alloy.

[0002]

2. Description of the Related Art A method of manufacturing a cylindrical member made of a composite member will be described with reference to FIG. As shown in FIG. 2, after arranging the preform (3) inside the movable mold (1) and the fixed mold (4) of the mold via the core (2), the movable mold (1) and Casting method of a composite material in which a molten metal of a matrix metal (7) is poured into a cavity (a) formed with a fixed die (4) and the molten metal is solidified by a movable die (1) and a fixed die (4). It has been known. That is, in such a conventional casting method, first, a preform (3) made of metal, ceramics or the like and having an inner peripheral surface previously formed in a tapered shape is attached to a core (2) mounted on a movable die (1). Mating. Then, the movable mold (1) is moved toward the fixed mold (4), and the preform (3) fitted into the core (2) is inserted into the mold hole (5) of the fixed mold (4). It is housed, a predetermined cavity (a) is formed between the preform (3) and the mold hole (5), and the cavity (a) is sealed by the movable mold (1) and the fixed mold (4). . When the hermetically sealed state is completed, a matrix metal (7) such as an aluminum alloy is poured from the pouring port (6) and solidified. In this case, the draft of the outer peripheral surface (2 ') of the core (2) of the movable mold (1) and the inner peripheral surface (5') of the mold hole (5) of the fixed mold (4) are both 0.5. Is about 1.0 °. In the above-mentioned conventional example, as shown in FIG. 2, the outer peripheral surface (2 ′) of the core (2), the inner peripheral surface (3 ′) and the outer peripheral surface (3 ″) of the preform (3), and The gradients of the inner peripheral surface (5 ') of the mold hole (5) are all parallel, and after casting, in the cutting process, as shown by the dotted line in FIG. The inner and outer peripheral surfaces of the metal (7) are scraped off to form a complete cylindrical member.

[0003]

When a cylindrical member made of a composite material is manufactured by the above conventional casting method, the outer periphery of the preformed body (3) made of metal, ceramics or the like for reinforcing the matrix metal (7). The width dimension of the cavity (a) formed between the surface (3 ") and the inner peripheral surface (5 ') of the mold hole (5) of the fixed mold (4) is constant from the entrance to the back. The molten metal in the cavity (a) quickly solidified from the inner part, cracked and deformed unimpregnated parts and cavities, and the preform, and a good composite material could not be obtained.
In addition, the positioning of the preform (3) depends on the core (2) of the movable die (1) and is held by frictional force, which increases the machining allowance when processing the product, resulting in waste. . Furthermore, the holding of the preform (3) was also uncertain.

According to the present invention, the molten metal in the mold cavity is
The purpose is to obtain a good composite material by devising so that a temperature sufficient for impregnating the preformed body can be maintained.

[0005]

In order to achieve the above object, the present invention provides a fixed mold having a taper-shaped mold hole that widens toward an opening, and a mold hole having a pouring port. A movable die provided with a tapered core having a small diameter toward the tip inserted into the mold hole, and a tapered surface having an inner diameter surface fitted into the inner core and an outer diameter surface of the inner core. The outer diameter surface is a straight preform, and when the preform fitted into the core is inserted into the mold hole, the cavity formed by the mold hole inner peripheral surface and the preform outer peripheral surface The ratio of the width dimension to the wall thickness dimension of the preform becomes larger from the pouring port to the inner part so that the molten metal in the cavity maintains a sufficient temperature to impregnate the preform. It was done by.

According to the present invention, positioning claws for the preform are provided at at least three equidistant positions around the pouring port on the bottom surface of the mold hole.

Further, according to the present invention, the tapered core is made longer than the preform.

[0008]

[Function] When the preform inserted into the core is inserted into the mold hole, the ratio of the width dimension of the cavity formed by the inner peripheral surface of the mold hole and the outer peripheral surface of the preform to the wall thickness dimension of the preform. However, since it becomes larger from the pouring port to the back, when pouring molten metal of matrix metal from the pouring port,
Solidification starts from the inner part of the cavity, but since the inner part of the cavity is wider, the time to complete solidification is longer in the inner part. The temperature can be maintained sufficient to impregnate the. As a result, there is no cracking or deformation of the preform, and the matrix metal is uniformly impregnated into the preform to obtain a good composite material.
And at the bottom of the mold hole, at least 3 around the pouring spout
By disposing the positioning claws of the preform at equal positions of the locations, displacement of the preform in the mold is prevented at the time of mold matching and pouring. Further, since the tapered core is made longer than the preform, it is possible to prevent the matrix metal from entering the inner peripheral surface side of the preform during pouring, and the post-processing of the product By cutting the uncomposited part at one place, a tubular product can be obtained, which is easy.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view of the method of the present invention.
1) is a movable mold, (12) is a core, (13) is a preform, (14) is a fixed mold, (15) is a mold hole, (16) is a pouring port, and (17) is a matrix metal. ing.

The movable mold (11) has a tapered core (12) integrally fixed and suspended at the center of the lower surface which is a flat surface. The core (12) has a taper shape that narrows toward the lower tip side, and the gradient of the outer peripheral surface is 0.5 to 5 °. An annular feeder (11 ') is formed around the base of the core (12) on the lower surface of the movable die (11). From the feeder (11') to the upper side of the movable die (11). One to a plurality of gas vent holes (not shown) are formed. The core (12) is longer than the preform (13) (for example,
About 10 mm). The movable type (11) is a fixed type (1
It is configured to be able to move up and down while maintaining a concentric state with respect to 4).

The preform (13) is the core (12).
An inner diameter surface to be inserted into is formed into a taper surface that is substantially the same as the outer diameter surface of the core (12), and the outer diameter surface is formed into a straight surface in advance. The material of the preformed body (13) is a matrix metal (1
It is selected and used from the materials for reinforcing 7).

The fixed mold (14) has a flat upper surface,
The structure is such that a tapered mold hole (15) that widens toward the upper opening is provided at the center thereof, and a pouring port (16) is provided below the mold hole (15). The mold hole (15)
Of the matrix metal (1) between the inner peripheral surface and the outer peripheral surface of the preform (13).
A cavity (A) for casting 7) with a predetermined wall thickness can be formed. The movable die (11) descends while maintaining the concentric state with respect to the fixed die (14),
The lower surface of the movable mold (11) and the upper surface of the fixed mold (14) are in close contact with each other to seal the cavity (A). The positioning claws (18) of the preform (13) are installed at at least three equidistant positions around the pouring port (16) on the bottom surface of the mold hole (15).
The positioning claw (18) is fixed to the fixed mold (14).

As described above, the outer peripheral surface of the preform (13) is a straight surface, and the fixed mold (14).
Since the inner peripheral surface of the mold hole (15) of (1) is a tapered surface that widens toward the upper opening, the movable mold (1
1) When the preform (13) fitted into the core (12) is inserted into the mold hole (15), the inner peripheral surface of the mold hole (15) and the outer peripheral surface of the preform (13). The ratio between the width of the cavity (A) formed by and the thickness of the preform (13) increases from the pouring port (16) toward the inner part.

According to the method for producing a composite material of the present invention, the preform (1) is attached to the core (12) of the movable mold (11) having the above-mentioned structure.
3) is inserted and the movable mold (11) is lowered, or the preform (13) is placed in the mold hole (15) of the fixed mold (14) and the bottom surface of the mold hole (15). Positioning is set using the positioning claw (18), and in this state,
By lowering the movable die (11) and bringing it into close contact with the fixed die (14), the cavity (A) is closed and the matrix metal (17) can be poured. In this state, the molten metal of the matrix metal (17) is poured under pressure from the bottom pouring port (16) of the fixed mold (14). As a result, the molten metal of the matrix metal (17) fills from the pouring port (16) to the inner part of the cavity (A). When the positioning claws (18) are provided, the molten metal flows in between the positioning claws (18). In this way, the matrix metal (1
In 7), solidification starts from the inner part of the cavity (A) far from the pouring port (16). However, since the width of the cavity (A) is larger in the inner part, the time required until the solidification is completed becomes longer in the inner part, and in the end, the total is
Solidification of the matrix metal (17) is caused by the cavity (A)
It becomes possible to maintain the temperature sufficient for the matrix metal (17) to be impregnated in the preform (13) over the entire length (entire region) of the preform (13) without any cracking or deformation. Impregnate. In this way, when the solidification of the matrix metal (17) is completed, the movable type (1
1) is lifted to bring the product into the core (12) and the mold hole (1
Extract from 5) by utilizing the fact that each is tapered.
Then, the inner and outer peripheral surfaces of this product are cut into a cylindrical member so as to be a straight surface parallel to the axis as shown by the dotted line in FIG. The matrix metal (17) is, for example, an aluminum alloy or the like.

Although the above embodiment illustrates the case of the pressure casting method, the present invention can be applied to other casting methods.

[0016]

According to the present invention, the solidification of the molten metal in the cavity is maintained over the entire area of the cavity at a temperature sufficient to impregnate the preform.
A good composite material can be obtained by uniformly impregnating the preform with the matrix metal without cracking or deformation of the preform. Further, by disposing the positioning claws at the equidistant positions on the bottom surface of the mold hole, it is possible to center the preform and prevent misalignment. Furthermore, by making the tapered core longer than the preform, post-processing of the product can be facilitated.

[Brief description of drawings]

FIG. 1 is a process explanatory view showing an embodiment of a manufacturing method of the present invention.

FIG. 2 is a process explanatory view of a conventional manufacturing method.

[Explanation of symbols]

 11 Movable type 12 Core 13 Preformed body 14 Fixed type 15 Mold hole 16 Pouring port 17 Matrix metal 18 Positioning claw A Cavity

Claims (3)

[Claims] 1. A fixed mold having a taper-shaped mold hole that expands toward an opening and a pouring port provided in the mold hole, and a diameter that decreases toward a tip portion inserted into the mold hole. It consists of a movable mold with a tapered core, and a preform with a tapered surface whose inner diameter surface fitted into the core is substantially the same as the outer diameter surface of the core, and whose outer diameter surface is a straight surface. , When the preform inserted in the core is inserted into the mold hole,
The molten metal in the cavity is made so that the ratio of the width dimension of the cavity formed by the inner peripheral surface of the mold hole and the outer peripheral surface of the preform to the wall thickness dimension of the preform increases from the pouring port to the inner part. The method for producing a composite material is characterized in that the temperature is maintained sufficient to impregnate the preform. 2. The method for producing a composite material according to claim 1, wherein positioning jigs for locating the preform are provided at at least three equidistant positions around the pouring port on the bottom surface of the mold hole. 3. The method for producing a composite material according to claim 1, wherein the tapered core is longer than the preform.