JPH0668142B2 - Method for producing reinforcing cylindrical fiber molding - Google Patents

Description

Detailed Description of the Invention A. Object of the invention (1) Industrial field of application The present invention is a method for producing a reinforcing cylindrical fiber molding used for fiber-reinforced metal members, etc. A cylindrical molding die having is immersed in an aqueous solution of a molding material containing a reinforcing fiber and an inorganic binder, and a suction action is applied into the molding die to adhere the molding material to the outer peripheral surface of the molding die to form a molding material. A step of pressing the molded body material against the molding die to adjust the shape of the molded body material; a step of heating and drying the molded body material; A step of partially binding the reinforcing fibers with an inorganic binder.

(2) Conventional Technology The present applicant has proposed a method of performing a pressing step using a rubber press as a manufacturing method of this type (Japanese Patent Application No. 61-1).
1611).

(3) Problems to be Solved by the Invention In the rubber press, a molding die is installed in a pressure-resistant container, and pressurized air is supplied into the pressure-resistant container from an air pressure source to mold the molding material through the rubber. Is pressed against the outer peripheral surface of.

Dehydrated molded material by this rubber press,
Also, the thickness of the fiber molded body is determined, but as a result of various studies on the dryness of the molded body material, the variation in the wall thickness of the fiber molded body, and the surface property, the rubber press naturally has a limit. There was found.

In view of the above, the present invention improves the dryness of a molded material by using a roller press instead of a rubber press, and also reduces the variation in the wall thickness of the fiber molded product and improves the surface property. It is an object of the present invention to provide the above-mentioned manufacturing method that can be performed.

B. Configuration of the invention (1) Means for solving the problem The present invention, in the pressing step, while applying a suction action in the molding die while rotating the molding die, the outer peripheral surface of the molded body material, the ventilation This is performed by ejecting hot air from the inside of the pressing roller toward the outer periphery while rotating the pressing roller having the property of sliding.

(2) Action By the sliding rotation of the pressure roller against the molded material, the suction action into the molding die, and the blowing of hot air from the pressure roller,
It is possible to efficiently and sufficiently perform the dehydration treatment of the molded body material, improve the dryness thereof, and improve the handleability.

In addition, the wall thickness of the molded body material can be regulated by the distance between the molding die and the pressing roller, whereby the variation in the wall thickness of the fiber molded body can be reduced. At the same time, it is possible to avoid the occurrence of wrinkles on the outer peripheral surface of the molded body material and improve the surface properties of the fiber molded body and the outer peripheral surface.

(3) Example FIG. 1 shows a reinforcing cylindrical fiber molding 1 obtained by the present invention. The fiber molding 1 comprises ceramic fibers as reinforcing fibers, for example, alumina / silica fibers as an inorganic binder. Partially bonded by silica sol, alumina sol, or mixed sol thereof, and has innumerable voids into which the matrix can penetrate.

This fiber molded body 1 is made of, for example, an aluminum alloy (JIS
When casting a cylinder block using (ADC12 equivalent), it is used to obtain a fiber reinforced composite cylinder sleeve by compounding with an aluminum alloy matrix.

Next, a method for manufacturing the fiber molded body 1 will be described with reference to FIG.

As shown in Fig. 2 (a), shell sand (grain size AFS35)
Is used to form a cylindrical mold 2 having air permeability. The molding die 2 has an outer diameter of 75 mm, a wall thickness of about 5 mm, and a radial crushing strength of 65 kg / cm ² . Further, since the mold 2 is made of shell sand, it has a property of disintegrating when heated to 450 ° C.

As shown in FIG. 2 (b), holders 3 ₁ and 3 ₂ are attached to the openings of both ends of the molding die ₂ by bonding, bolting or the like to seal the openings.

As shown in FIG. 2 (c), the molding die 2 is dipped in an aqueous solution 4 of a molding material containing alumina-silica fibers having a length of 25 to 1000 μm and alumina sol having a concentration of 5%, and a pumping pump 5 is used.
By applying a suction action so that the inside of the molding die 2 becomes 200 to 600 Torr, the molding material is attached to the outer peripheral surface of the molding die 2 to a predetermined thickness, and the molding material 6 having a fiber volume ratio of 5 to 10% is molded. To do.

As shown in FIG. 2 (d), the mold 2 is erected on the rotary table 8 of the roller press. A pressing roller 9 is arranged on the side of the molding die 2 in parallel therewith. The pressure roller 9 has air permeability by providing a number of through holes 10 on its peripheral wall, and is movable back and forth with respect to the molding die 2.

While rotating the rotary table 8, and thus the mold 2, counterclockwise at a rotation speed of 200 rpm or less, a suction action is applied to the mold 2 through the rotary table 8 by the vacuum pump 11.

The pressing roller 9 is located at the position shown by the chain line in FIG. Rotate the pressure roller 9 to 20 rpm
At m or less, the hot air that has passed through the heater 13 is jetted from the compressor 12 toward the outer periphery from the inside of the pressing roller 9 while rotating clockwise in synchronization with the molding die 2.

The pressing roller 9 is moved forward toward the molding die 2 and is rubbed and rotated on the outer peripheral surface of the molding material 6. In this case, the pressing roller 9
As for the advancing speed of, the distance between the molding die 2 and the pressing roller 9 was 1 mm added to the target wall thickness tmm of the fiber molded body 1, (t
The speed is controlled until reaching +1) mm, and then controlled slowly until the distance between the two and 9 reaches the wall thickness t mm. When the pressing roller 9 is advanced at a high speed in this manner, the press work can be made efficient, and at the same time, the green body material 6 can be quickly and roughly pressed. Further, the pressing roller 9 is moved forward at a slight speed, so that the molded material 6 can be subjected to precision press working.

In the pressing step by the roller press 7, the pressing roller 9 is rotatively rubbed against the molding material 6, the suction action into the molding die 2 and the hot air is ejected from the pressing roller 9, so that the molding material 6 is dehydrated. Is performed efficiently, and moreover, it is sufficiently performed so that the surface is semi-dried, and the degree of drying can be improved to improve the handleability.

For example, when the volume of the molded body material 6 is 130 cm ³ ,
The molded body material 6 after molding contains approximately 140 g of water, but it decreases to approximately 60 g after roller pressing. It is about 80 g after rubber pressing, which shows the excellent dehydration treatment by roller pressing.

Further, the wall thickness of the molded body material 6 can be regulated by the distance between the pressing rollers 9 of the molding die 2 to reduce the variation in the wall thickness. At the same time, it is possible to avoid the occurrence of wrinkles on the outer peripheral surface of the molded material 6 and improve the surface properties of the inner peripheral surface.

As shown in FIG. 2 (e), both holders 3 ₁ ,
3 ₂ Remove the.

As shown in FIG. 2 (f), the molding die 2 is installed in the drying furnace 14, and the molding material 6 is dried at 120 ° C. for 1 hour to completely evaporate the water content.

As shown in FIG. 2 (g), the mold 2 is installed in the firing furnace 15, and the mold 2 is subjected to a disintegration treatment at 450 ° C. for 30 minutes. By this disintegration treatment, the mold 2 is completely disintegrated.

As shown in FIG. 2 (h), this time, only the molded body material 6 is installed in the firing furnace 15, and the molded body material 6 is vacuumed at 800 ° C.
At 30 minutes, a baking process is performed. As a result, the alumina-silica fibers are partially bonded by the alumina sol to obtain the fiber molding 1 shown in FIG.

FIG. 3 shows the degree of variation in the outer diameter of the fiber molded body 1 obtained by the present invention and the fiber molded body obtained by using a rubber press as a comparative example. The solid line a corresponds to the present invention, and the dotted line b corresponds to the comparative example.

As is clear from FIG. 3, in the fiber molded body 1 obtained according to the present invention, the variation in wall thickness is smaller than that of the comparative example, and wrinkles are generated on the inner and outer peripheral surfaces. It has good surface properties.

C. EFFECTS OF THE INVENTION According to the present invention, by adopting the pressing step, it is possible to efficiently and sufficiently perform the dehydration treatment of the molded body material, improve the degree of dryness thereof, and improve the handleability.

In addition, it is possible to obtain a fiber molded body having a small variation in wall thickness and an improved surface property.

[Brief description of drawings]

FIG. 1 is a perspective view of a fiber molded body, FIG. 2 is an explanatory view of a manufacturing process of the fiber molded body, and FIG. 3 is a graph showing variations in outer diameter of the fiber molded body. DESCRIPTION OF SYMBOLS 1 ... Fiber molded object, 2 ... Mold, 4 ... Aqueous solution, 5 ... Pumping pump, 6 ... Molded material, 8 ... Rotating table, 9 ... Pressing roller,
11 ... Vacuum pump, 12 ... Compressor, 13 ... Heater, 14 ... Drying furnace, 15 ... Firing furnace

Claims (1)

[Claims] 1. An air-permeable cylindrical molding die having both end openings sealed, is immersed in an aqueous solution of a molding material containing reinforcing fibers and an inorganic binder, and a suction action is applied to the inside of the molding die. A step of adhering a molding material to the outer peripheral surface of the molding die to mold a molding material; a pressing step of pressing the molding material against the molding die to adjust the shape of the molding material; the molding material In a method for manufacturing a reinforcing cylindrical fiber molded body using a step of: heating and drying the molded body material; and a step of partially bonding the reinforcing fibers with the inorganic binder. While rotating the molding die, a suction action is applied to the molding die, and a pressing roller having air permeability is rubbed and rotated on the outer peripheral surface of the molded body material while hot air is blown from the inside of the pressing roller toward the outer periphery. Gush Method for producing a reinforcing cylindrical fiber molded body which is characterized in that by causing.