JPH0957721A - Manufacture of cement molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To mold a molding raw material without cutting caused by its extension during pressing and to make a molding dense by transferring a preliminary molding preliminary molded into a bottom mold while the shape of the preliminary molding is held and performing press molding of it. SOLUTION: An indentation roller 23 is driven to indent a sheetlike raw material to a stopper 24 side and to deform it to the roller group 22 side without a press sheet 21 and it is deformed along the roller group 22 to form a preliminary molding 6a. The press sheet 21 is removed and the preliminary molding 6a is sucked on the suction face of a transfer machine and it is transferred to the position above a bottom mold 41 of a press molding machine. Suction of the transfer machine 3a is released and the preliminary molding 6a is transferred on the bottom mold 41 and the top mold 41 and the bottom mold 42 of the press molding machine are closed together to mold a molding. Therefore, as the preliminary molding 6a with an approximately the shape of the molding is press-molded by means of the press molding machine, no large plastic deformation of the raw material occurs during press molding and as the result, a corrugated molding can be obtd. without generating cuttings and cracks.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a cement molded product.

[0002]

2. Description of the Related Art Conventionally, as a method for producing a cement molded product such as a straight roof tile by press molding, Japanese Patent Publication No.
Japanese Patent Application No. 4-144266, Japanese Patent Application No. 3-1266 filed by the applicant of the present invention.
The method disclosed in 79290 has already been proposed.

That is, in the former method, the upper die is provided at the lower end of the high-pressure press piston which moves up and down, and the upper die is provided with a vacuum suction hole for water squeezing and carrying, and the lower surface thereof has a wire mesh and a dehydrating cloth. Automatic cement roof tile manufacturing equipment with a vertically movable mold frame around the fixed lower mold,
In addition, cement, aggregate such as silica sand, and if necessary, reinforcing fibers are mixed with a large amount of water in a stoichiometric amount or more necessary for hardening of cement to form a slurry state or a soft block state with excellent fluidity. Cement-based composition is now used as a molding raw material, dropping the molding raw material onto the lower mold, closing the upper mold and the lower mold and filling the molding raw material in the mold by pressing, Excess water is removed through a dehydration step of suction dehydration from a suction hole (not shown) provided in the upper mold to obtain a dense and complex molded body.

On the other hand, the latter method is, for example, cement,
Using a cement composition having poor fluidity, which is a mixture of aggregate, reinforcing fiber, and water-soluble polymer with water in an amount close to the stoichiometric amount required for hardening cement, as a forming raw material, as shown in FIG. This molding raw material 101 is supplied onto the lower mold 102 and press-molded between the upper mold 103 and the lower mold 102 while applying vibration to obtain a dense cement compact.

[0005]

[Problems to be Solved by the Invention] However, the above 2
The kinds of methods have the following problems. That is, in the former method of passing through the dehydration step, since the molding raw material has fluidity, it is easy to supply the raw material to the lower mold, and the molding raw material easily spreads to the details even in a complicated mold shape. Although it has an advantage, it remains as a void in the molded body where the water escape path at the time of dehydration was obtained, or because it could not be dehydrated to the stoichiometric amount, excess water remained in the molded body,
There are limits to the densification of organizations.

On the other hand, in the latter method which does not pass through the dehydration step, since the forming raw material 101 contains only a small amount of water close to the stoichiometric amount necessary for the hardening of cement, almost no water passage or surplus water is contained. Although it does not exist, a very dense molded body can be obtained, but since the flowability of the molding raw material 101 is inferior, when a complex shape such as a deep wave shape is attempted to be molded,
There was a problem that the molding raw material 101 was stretched out at the time of pressing and small cracks were formed.

Therefore, as a result of further diligent studies, the applicant of the present invention, as shown in FIG. 8, made a plate of a cement-based composition containing water in an amount close to the stoichiometric amount required for hardening the cement. Conveyor 201 on which the raw material 200 is placed
Facing the upper side of the lower mold 202, and the belt conveyor 20
1, the plate-shaped raw material 200 is transferred to the belt conveyor 20.
This belt conveyor 20 is being fed from the tip of 1.
1 is moved at a speed substantially the same as the transport speed of the plate-shaped raw material 200 in the direction opposite to the delivery direction of the plate-shaped raw material 200 to move the plate-shaped raw material 200 to a desired position of the lower mold 202, and then press-molding. I proposed the method first (Japanese Patent Application No. 6-2734).
87).

According to this method, when the above problems are solved and a hydraulic inorganic composition mixed with a stoichiometric amount of water is used as a forming raw material to form a corrugated complex molded product, Even if there is, it is possible to perform molding without causing the molding raw material to be stretched out at the time of pressing, so that the compacted body can be densified. However, according to this method, the plate-shaped raw material 200 is moved by its own weight along the inner surface shape of the lower mold 202.
Since 0 is transferred to the lower mold 202, it takes time to transfer, and the press molding operation is stopped during that time, which causes a problem in productivity.

The method for producing a cement molded product according to the present invention is applicable to a case where a corrugated complex molded product is molded by using a hydraulic inorganic composition mixed with a stoichiometric amount of water as a molding raw material. For the purpose of providing a method for producing a cement molded product having excellent productivity as well as being capable of molding without causing elongation of the molding raw material at the time of pressing and densifying the molded product. There is.

[0010]

In order to achieve such an object, a method for manufacturing a cement molded product according to the invention of claim 1 (hereinafter referred to as "manufacturing method of claim 1") is In a method for producing a cemented compact, in which a raw material made of a cementitious composition containing water in an amount close to the stoichiometric amount necessary for curing is press-molded between upper and lower molds, a large number of rollers are along the outline of the surface of the compact. A plate-shaped raw material of a desired length is placed on the upper end surface of the roller group arranged so as to form a locus, and one end surface of this plate-shaped raw material is received by a stopper and pressed onto the upper surface of the plate-shaped raw material. With the plates in contact,
A step of driving the pushing roller provided on the other end side of the roller group to push the plate-shaped raw material toward the stopper to preform the plate-shaped raw material into a shape along the upper surface of each roller of the roller group; The preforming body is transferred to the lower mold while maintaining the shape of the preforming body and press-molded.

A method for manufacturing a cement molded product according to the invention of claim 2 (hereinafter referred to as "manufacturing method of claim 2") is
In a method for producing a cement molded product in which a raw material composed of a cement-based composition containing water having a stoichiometric amount close to that required for the hardening of cement is press-molded between upper and lower molds, a raw material in a plate shape having a desired length, At least one of a step of placing a large number of rollers on a roller group in a state where they are horizontally arranged at the same height position, a step of fixing one end of the plate-shaped raw material, and a roller forming the roller group. The height position of the roller of the part is gradually changed from the fixed end side of the plate-shaped raw material to a predetermined position, and the plate-shaped raw material is deformed so as to substantially follow the locus of each roller top of the roller group, and the shape of the molded body is formed. And a step of transferring the preformed preform to the lower mold while maintaining the shape of the preform and press forming.

In the above-mentioned constitution of the present invention, as the cementitious composition, in addition to cement and water, for example, a water-soluble polymer substance, an inorganic filler, a reinforcing fiber and the like can be appropriately added. The cement used in the present invention is not particularly limited, but for example, plain portland cement, special portland cement, alumina cement, plain cement such as roman cement, acid resistant cement, fire resistant cement, special cement such as water glass cement, gypsum, lime. , And magnesia cement, etc., and portland cement and alumina cement are preferably used in terms of strength and water resistance. These may be used alone or in combination of two or more.

The water-soluble polymer substance is not particularly limited, but examples thereof include cellulose ethers such as methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose and hydroxypropyl methyl cellulose, polyvinyl alcohol, polyacrylic acid, lignin sulfonate and the like. Can be mentioned.

The inorganic filler is not particularly limited, but examples thereof include aggregates for cement mortar such as silica sand and river sand, admixtures for mixed cement such as fly ash, silica flower, silica fume, bentonite and blast furnace slag, sepiolite, Examples include wollastonite, natural minerals such as mica, calcium carbonate, and diatomaceous earth.
Further, inorganic foams such as silica balloons, pearlite, fly ash balloons, shirasu balloons, glass balloons, and foamed and baked clay may be used for the purpose of weight reduction. These may be used alone or 2
More than one species may be used in combination.

The reinforcing fiber is not particularly limited,
For example, synthetic fibers such as vinylon, polyamide, polyester, polypropylene and aramid, inorganic fibers such as glass, potassium titanate and steel, and natural fibers such as pulp and hemp can be used. In addition, since the size of the plate-like raw material hardly requires the flow at the time of pressurization, it is desirable that the size is substantially along the entire mold surface of the lower die. However, from the discharge width of the raw material feeder, the forming die, and the product shape, It can be determined appropriately.

Further, the preformed body does not have to be completely in conformity with the formed body, as long as it has a substantially shaped body. The cement molded product obtained by the molding method of the present invention is not particularly limited, but after curing and curing for a certain period of time under predetermined conditions, a desired coating or the like may be applied to the surface portion as necessary. I don't mind.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. First, in the manufacturing method of the first aspect, a cement molded product can be obtained by using the molding device 1a as shown in FIGS. That is, the molding apparatus 1 includes a preforming apparatus 2, a transfer machine 3 and a press molding machine 4.

The preforming apparatus 2 comprises a pressing plate 21, a roller group 22, a pushing roller 23 and a stopper 24. The roller group 22 is composed of a large number of freely rotating rollers 22a.
And the pushing roller 23 provided on the inlet side is arranged so as to form a shape along the outer surface shape of the molded body.

The push-in roller 23 is rotationally driven by a motor (not shown), and the plate-shaped raw material 5a will be described later.
Is pushed toward the stopper 24. The pressing plate 21 is provided between the upper end of the roller group 22 and the plate-shaped raw material 5a.
Is arranged so as to form a gap having a width substantially the same as the thickness of the preform 6a, and the preform 6a is moved to a position where the preform 6a is not disturbed when the preform 6a is transferred by the later-described transfer machine 3. ing.

The press die 4a is composed of a lower die 41 and an upper die 42. The transfer machine 3a is provided with a suction surface 31 which is suctioned on the upper surface of the preformed body 6a preformed by the preforming device 2, and a large number of small holes (not shown) formed in the suction surface 31. ), The preform 6a is adsorbed, picked up from the preforming device 2, and transferred to the lower mold 41 of the press molding machine 4a.

The manufacturing method using the molding apparatus 1a will be described in detail in the order of steps. As shown in FIG. 1, a plate-shaped raw material 5a extruded from an extrusion die (not shown) with a predetermined thickness and cut into a predetermined length.
Is received by the upper end of the roller group 22, and one end thereof is brought into contact with the stopper 24, and then the pressing plate 21 is brought into contact with the upper surface of the plate-shaped raw material 5a.

The pushing roller 23 is driven to push the plate-shaped raw material 5 a toward the stopper 24. One end of the plate-shaped raw material 5a is suppressed by the stopper 24, and the upper surface is pressed by the pressing plate 21, so that the plate-shaped raw material 5a does not have the pressing plate 21 as shown in FIG. It deforms to the side and deforms along the roller group 22 to form the preform 6a.

The pressing plate 21 is removed, the preform 6a is adsorbed to the adsorption surface 31 of the transfer machine 3, and is moved onto the lower die 41 of the press molding machine 4a as shown in FIG. The suction of the transfer machine 3a is released, and the preform 6a is transferred to the lower mold 41 as shown in FIG. The upper and lower dies 41 and 42 of the press molding machine 4a are closed to mold a molded body (not shown).

As described above, according to the above-mentioned manufacturing method, the plate-shaped raw material 5a is preliminarily preformed into the shape of the hollow body and the preformed body 6a is press-molded by the press molding machine 4a. Does not cause plastic deformation. Therefore, a corrugated plate-shaped molded product can be obtained without causing breaks or cracks. Moreover, since the press molding can be performed by the press molding machine 4a and the preforming can be performed at the same time, the productivity is good.

On the other hand, in the manufacturing method of the second aspect, the molded body is molded by using the molding apparatus 1b as shown in FIG. That is, the molding apparatus 1b is configured such that the extrusion die 7
A roller group 8, a transfer machine 3b, and a press molding machine 4b.

The extrusion die 7 is adapted to extrude the forming raw material sent from the extruder into a plate shape. The roller group 8 is provided in front of the extrusion die 7, and has a fixed roller 81 fixed at a predetermined position and a fixed roller 81.
First movable roller 8 capable of vertically moving upward from the horizontal position of
2 and a second movable roller 83 that is vertically movable downward from the horizontal position of the fixed roller 81.
And the second movable rollers 83 are alternately arranged with the fixed roller 81 interposed therebetween.

The roller group 8 has a chuck-shaped fixing member 9 at its rear end, that is, at the end opposite to the extrusion die 7.
It has. The press molding machine 4b includes an upper mold 43 and a lower mold 4.
And 4. Although not shown, the transfer machine 3b is provided with a large number of small holes on the suction surface 34, and by sucking from the small holes, the preform 6b is sucked and the roller group 8 is sucked, as described later. It can be transferred from the upper part to the lower mold 44.

The molding apparatus 1b is configured as described above, and a molded body can be manufactured as follows. As shown in FIG. 5, the plate-shaped raw material 5b continuously extruded from the extrusion die 7 of the extruder and cut by the cutter 71 into a predetermined length is fed to the first movable roller 82 and The state in which the second movable roller 83 is fixed at the height position of the fixed roller 81, that is, all the rollers 81, 82, 8
3 is placed on the roller group 8 in a state where they are horizontally arranged.

After fixing the end portion of the plate-shaped raw material 5b with the fixture 9, as shown in FIG.
The first movable roller 82 closest to the fixed end of b is gradually lifted vertically. Since one end of the plate-shaped raw material 5b is fixed by the fixture 9, the portion of the first movable roller 82 that is raised while the other end is pulled toward the one end side as the first movable roller 82 is raised is convex upward. Transforms into.

As shown in FIG. 6B, the second movable roller 83, which is adjacent to the first movable roller 82 that has risen and the fixed roller 81, is gradually lowered vertically. Since one end of the plate-shaped raw material 5b is fixed by the fixture 9, the part of the second movable roller 83 that is lowered while the other end is further pulled toward the one end side as the second movable roller 83 is raised is projected downward. Transforms into a shape.

As shown in FIGS. 6C and 6D, the first movable roller 82 and the second movable roller 8 are sprinkled one after another.
By moving up and down in the order of 3, a preform 6b is obtained as shown in FIG. As shown in FIG. 6E, the suction surface 33 of the transfer machine 3b
After the preform 6b is adsorbed on, the preform 6b is picked up from the roller group 8 and transferred to the lower mold 44 of the press molding machine 4b (not shown) as shown in FIG. 6 (f). .

The upper and lower dies 43 and 44 are closed to press-form the preform 6b. As described above, according to the above-mentioned manufacturing method, the plate-shaped raw material 5b is preliminarily preliminarily formed into the shape of a hollow compact and the preliminarily molded body 6b is press-molded by the press molding machine 4b. Do not wake up. Therefore, a corrugated plate-shaped molded product can be obtained without causing breaks or cracks.

Moreover, since preforming can be performed simultaneously with press forming by the press forming machine 4b,
Good productivity. Further, since the plate-shaped raw material 5b is gradually deformed from one end side to be preformed, the plate-shaped raw material 5b does not have any breaks or cracks during the preforming.

[0034]

EXAMPLE Next, a more specific example of claim 2 will be described together with a comparative example. (Example 1) Normal Portland cement 100 parts by weight Silica powder (Blaine value 6000, average particle size 40 μm) 40 parts by weight Vinylon fiber (2 denier, length 4 mm) 2 parts by weight Water 30 parts by weight Methylcellulose ( 2% aqueous solution at 20 ° C has a viscosity of 30,000 cps) 2 parts by weight

A composition obtained by mixing the above-mentioned proportions of the mixture in an Erich mixer for 10 minutes was used to obtain a screw diameter of 100.
A plate-shaped raw material 5b having a width of 300 mm and a thickness of 20 mm was obtained by extruding into a plate shape through an extrusion die 7 by an extrusion molding machine of mm and cutting. This plate-shaped raw material 5b is shown in FIGS.
After the step (f), press molding was performed by the press molding machine 4b to obtain a corrugated plate-shaped molded body.

As a result of observing the obtained molded body, no cracks or breaks were found in the molded body.

Comparative Example 1 A molded body was obtained in the same manner as in Example 1 except that the plate-shaped raw material 5b obtained in Example 1 was directly molded by the press molding machine 5b without preforming. As a result of observing the obtained molded body, fine cracks were formed on the surface of the molded body, and cracks of the material were observed in the recesses.

The present invention is not limited to the above embodiment. For example, in the embodiment of claim 2 described above, the roller group 8 is composed of three types of rollers, that is, the fixed roller 81, the first movable roller 82, and the second movable roller 83, but all the rollers can be freely moved up and down. It does not matter if it can be moved to.

[0039]

As described above, according to the manufacturing method of the above-mentioned claim 1 and claim 2, since the preformed body preformed in the corrugated shape is press-formed by the press machine,
Even if a molding raw material containing only a small amount of water close to the stoichiometric amount required for cement hardening is used, a compact and excellent appearance can be formed without causing stretch.

Further, since the preforming step of mechanical preforming and the press forming step of press forming the preform can be carried out at the same time, the time for transferring the molding material to the press machine can be shortened and the productivity can be improved. Can also be improved.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the steps of the method for manufacturing a cemented compact according to the present invention, which is an explanatory diagram for explaining the state before preforming.

FIG. 2 is a diagram for explaining the steps of the manufacturing method according to claim 1, which is an explanatory diagram for explaining the preforming state thereof.

FIG. 3 is a diagram illustrating a step of the manufacturing method according to claim 1, and an explanatory diagram illustrating a state of a transfer stage of the preform.

FIG. 4 is a diagram for explaining the steps of the manufacturing method according to claim 1, and is an explanatory diagram for explaining a state in which the preform is transferred to a pressing machine.

FIG. 5 is a front view showing an example of a molding apparatus used in the manufacturing method of claim 2.

6A and 6B are explanatory views for explaining a manufacturing method using the molding apparatus of FIG. 5 in order of steps.

FIG. 7 is a diagram illustrating a conventional manufacturing method.

FIG. 8 is a diagram illustrating the previously proposed manufacturing method.

[Explanation of symbols]

 4a Press molding machine 4b Press molding machine 41 Lower mold 42 Upper mold 43 Upper mold 44 Lower mold 5a Plate raw material 5b Plate raw material 6a Preformed body 6b Preformed body 8 Roller group 81 Fixed roller 82 First movable roller 83 Second Movable roller 21 Holding plate 22 Roller group 22a Roller 23 Push-in roller 24 Stopper

Claims (2)

[Claims] 1. A method for producing a cemented compact, in which a raw material made of a cementitious composition containing water in a stoichiometric amount necessary for hardening cement is press-molded between upper and lower molds, and a large number of rollers are molded. On the upper end surface of the roller group arranged so as to form a trajectory along the outline of the surface of, the plate-shaped raw material of a desired length is placed, and one end surface of this plate-shaped raw material is received by the stopper, With the pressing plate in contact with the upper surface of the plate-shaped raw material, the pushing roller provided on the other end side of the roller group is driven to push the plate-shaped raw material toward the stopper, and the plate-shaped raw material is applied to each roller of the roller group. A step of preforming into a shape along the upper surface of the preform, and a step of transferring the preformed preform to a lower mold while maintaining the shape of the preform and press-forming. A method for producing a cement molded product. 2. A method for producing a cement molded product, which comprises press-molding a raw material made of a cement-based composition containing water in a stoichiometric amount required for hardening cement between upper and lower molds to obtain a plate-shaped product having a desired length. Placing the raw material on the roller group in a state where a large number of rollers are arranged at the same height position in the horizontal direction, fixing one end of the plate-shaped raw material, and rollers forming the roller group. Among them, the height position of at least some of the rollers is gradually changed from the fixed end side of the plate-shaped raw material to a predetermined position, and the plate-shaped raw material is deformed so as to substantially follow the locus of each roller top of the roller group. And a step of preforming into a compact shape, and a step of transferring the preformed preform to a lower mold while maintaining the shape of the preform and press-molding. A method for producing a cement molded product.