JPS62192545A - Production of cylindrical fiber molding for reinforcement - Google Patents

Abstract

PURPOSE:To efficiently produce a molding for reinforcement having good dimensional accuracy by immersing an air permeable molding tool into an aq. soln. of a molding material contg. reinforcing fibers, sticking the molding material thereto by suction and crushing the molding tool then calcining the sticking molding stock. CONSTITUTION:Cap-shaped holders 31, 32 are fitted to the outside peripheral faces at both ends of the air permeable cylindrical molding tool 2 formed by using shell sand to close apertures; at the same time, the outside peripheral faces at both ends are subjected to masking. Such molding tool 2 is immersed into the aq. soln. 4 of the molding material contg. reinforcing fibers and inorg. binder and the molding material is stuck to the molding tool 2 by the suction effect to form the molding stock 6. The molding tool 2 is installed in a pressure resistant vessel 7 and compressed air is pressed to the outside peripheral face of the molding tool 2 to trim the shape of the molding stock 6. After such molding tool 2 is dried, the molding tool is installed in a crushing machine 1, by which pressing force is exerted to the molding tool 2 to crush the entire part of the molding tool. The molding stock 6 is installed in a calcination furnace 19 and is calcined, by which the cylindrical molding partially bound with the mixed fibers is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Δ1 Object of the Invention (1) Industrial Application Field The present invention relates to a method for manufacturing a reinforcing cylindrical fiber molded body used for fiber reinforcing metal members and the like.

(2) Conventional technology Conventionally, this type of fiber molded article is produced by sealing the openings at both ends of a cylindrical mold with air permeability, and immersing the mold in an aqueous solution of a molding material containing reinforcing fibers and an inorganic binder. , a step of applying a suction action within the mold to adhere the molding material to the outer peripheral surface of the mold to form a molded body material; a step of pressing the molded body material against the mold to adjust the shape of the molded body material; A process of opening both end openings of the mold and pulling the mold out of the molded body material, a process of heating and drying the molded body material, and a process of firing the molded body material and partially bonding the reinforcing fibers with an inorganic binder. Manufactured through.

(3) Problems to be solved by the invention However, as mentioned above, when the mold is pulled out from the molded material before the molded material is heated and dried, the molded material contains a large amount of water and retains its shape. Because of the poor properties, there is a problem that the molded body material is deformed and the dimensional accuracy of the fiber molded body is deteriorated.

An object of the present invention is to provide the manufacturing method capable of solving the above problems.

B8 Structure of the Invention (1) Means for Solving Problems The present invention seals both end openings of a breathable cylindrical mold that collapses as a whole due to a pressing force applied to the outer peripheral surface of at least one end, and seals the openings at both ends of the mold. Masking is applied to the outer peripheral surface of the
Next, the mold is immersed in an aqueous solution of a molding material containing reinforcing fibers and an inorganic binder, and then a suction action is applied within the mold to cause the molding material to adhere to the outer peripheral surface of the mold, excluding the masking. a step of pressing the molded body material against the mold to adjust the shape of the molded body material; a step of heating and drying the molded body material; and a step of drying the molded body material by the masking. applying a pressing force to the outer circumferential surface of the one end of the mold where adhesion has been avoided to completely collapse the entire mold;
The method is characterized by using a step of firing the molded body material and partially bonding the reinforcing fibers with the inorganic binder.

(2) Function As mentioned above, since the molded body material is heated and dried while it is attached to the mold, the mold is pulled out from the undried molded body material (possibly causing deformation of the molded body material). Problems can be avoided.

In addition, after heating and drying the molded body material, a pressing force is applied to the outer circumferential surface of the mold (at least one end) to completely collapse the mold, so that the mold can be easily removed without deforming the molded body material. It can be done simply and reliably.

(3) Example Figure 1 shows a reinforcing cylindrical fiber molded article 1 obtained according to the present invention.
The fiber molded body l is made by partially bonding mixed short fibers of carbon fiber and alumina fiber as reinforcing fibers with silica sol, alumina sol, or a mixed sol thereof as an inorganic binder, and the matrix is infiltrated. It has countless voids that can be removed.

This fiber molded body 1 is used, for example, in order to obtain a fiber-reinforced composite cylinder sleeve by combining with an aluminum alloy matrix when casting an aluminum alloy cylinder bronc.

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

As shown in FIGS. 2(al) and (az), a cylindrical mold 2 having air permeability is formed using shell sand (grain size AFS35). This mold 2 has an outer diameter of 75 mm and a thickness of 5 mm. On the inner circumferential surface of the mold 2, a plurality of notch grooves (four in the illustrated example) having a V-shaped cross section extending over the entire length in the generatrix direction are formed at equal intervals on the circumference. The radial crushing strength of No. 2 is set to 45 to 50 ktr/a+I. Therefore, if a pressing force exceeding the above-mentioned radial crushing strength is applied to the outer circumferential surface of at least one end of the mold 2, the bottom of each notch groove g will break and the entire mold 2 will collapse completely.

As shown in FIG. 2 [b], the outer peripheral surface 2 of both ends of the mold 2
Fit the cap-shaped holders 31.3□ to each of the mold 2 by gluing and bolting each holder 31, 3□.
and seal the openings at both ends. As a result, mold 2
The outer circumferential surface 2a of both ends of is the circumferential wall portion 3a of both holders 31.3□
Since the outer circumferential surfaces 2a of both ends are covered with masking, masking is applied to each of the outer circumferential surfaces 2a of both ends.

As shown in FIG. 2(C), an aqueous solution 4 of a molding material containing mixed fibers of carbon fibers and alumina fibers and alumina sol
The mold 2 is immersed in the mold 2, and the vacuum pump 5 is used to remove the mold 2.
The molding material is adhered to the outer peripheral surface of the mold 2 to a predetermined thickness by applying suction inside the mold 2, and the molded body material 6 is molded. The molding operation using the vacuum pump 5 takes approximately 2 minutes. Since the outer peripheral surfaces 2a of both ends of the mold 2 are masked by both the holders 31, 3□, adhesion of the molding material to them is avoided.

As shown in FIG. 2 (dl), the mold 2 is placed in a pressure container 7 of a rubber press, and pressurized air is supplied from an air pressure source 8 into the pressure container 7 to pass the molded body material 6 through the rubber 9. is pressed onto the outer peripheral surface of the mold 2 with a pressure of 8 to 1Q kg/cd,
This adjusts the shape of the molded body material 6 and determines its density at the same time.

As shown in FIG. 2(e), both holders 33 are removed from the mold 2.
, Remove 3□.

As shown in FIG. Since it is made of shell sand, it will not collapse at this drying temperature, and since its coefficient of thermal expansion is small, it will not cause any dimensional change to the molded body material 6.

FIG. 2 (g+) and (gz) show the disintegrator 1) of the mold 2. The disintegrating machine 1) consists of a machine base 12, a pair of supports 13 erected opposite to the machine base 12, a support shaft 14 installed between both supports 13, and a pair of supports 14 on the support shaft 14. A press lever 16 is rotatably attached to each end of the press part 15 of the machine base 12; A pair of press lever stoppers 18 are provided facing each other on the top.

When collapsing the mold 2, place the mold 2 on the disintegrating machine 1) with the outer circumferential surfaces 2a of both ends thereof placed i5i on both support stands 17, and press levers 16 to press the outer circumferential surfaces 2a of both ends of the mold 2 into A pressing force exceeding the above-mentioned radial crushing strength is applied. Since the bottom of each notch g is broken by this pressing force, the entire mold 2 completely collapses. In this case, since the mold 2 collapses into approximately four parts, it is easy to remove it, and since the mold material 6 is dry, it is difficult to install the mold 2 into the disintegrator 1). It does not deform during demolition work, etc., and is easy to handle.

As shown in FIG.
The molded body material 6 is subjected to a firing treatment at 800° C. for 1 hour. As a result, the mixed fibers are partially bonded by the alumina sol, and a fiber molded body 1 shown in FIG. 1 is obtained.

Note that it is also possible to collapse the mold 2 by applying a pressing force only to the outer circumferential surface 2a of one end thereof.

It is also possible to thermally collapse the mold 2 by heating it to a high temperature, but if such a method is adopted, cracks may occur in the molded body material 6 due to thermal expansion of the mold 2. The mechanical collapse means of the invention can completely avoid the problems associated with thermal collapse means.

C3 Effects of the Invention According to the present invention, since the molded body material is heated and dried while it is attached to the mold, there is no deformation of the molded body material by pulling out the mold from the undried molded body material. Such problems can be avoided.

In addition, after the molded material is heated and dried, a pressing force is applied to the outer peripheral surface of at least one end of the mold to completely collapse the entire mold, making it easy to remove the mold without deforming the molded material. It can be done reliably. Therefore, according to the present invention, fiber molded articles with good dimensional accuracy can be efficiently produced.

[Brief explanation of drawings]

Fig. 1 is a perspective view of the fiber molded body, and Fig. 2 is an explanatory diagram of the manufacturing process of the fiber molded body.
2 (gt) is a sectional view taken along the line A-A of
,) is a view taken in the direction of arrow B.

Claims (2)

[Claims] (1) The openings at both ends of a breathable cylindrical mold that collapses as a whole due to the pressing force applied to the outer circumferential surface of at least one end are sealed, and the outer circumferential surface of the one end is masked, and then the mold is filled with reinforcing fibers and A process of forming a molded body material by immersing it in an aqueous solution of a molding material containing an inorganic binder and then applying suction into the mold to adhere the molding material to the outer peripheral surface of the mold excluding the masking. ; a step of pressing the molded body material against the mold to adjust the shape of the molded body material; a step of heating and drying the molded body material; and a step of avoiding adhesion of the molding material to the mold by the masking. completely collapsing the entire mold by applying a pressing force to the outer circumferential surface of the one end; and firing the molded body material to partially bond the reinforcing fibers with the inorganic binder. A method for producing a reinforcing cylindrical fiber molded article, characterized in that: (2) The reinforcing cylindrical fiber molded article according to claim (1), wherein a plurality of notch grooves extending over the entire length in the generatrix direction are formed on the inner peripheral surface of the mold. manufacturing method.