JP3852042B2 - Resin mold - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resin molding die that is used in a synthetic mold of mortar and metal, and in particular, uses mortar for reinforcing a molding die.
[0002]
[Prior art]
A resin mold using concrete is used as a backup material for electroforming.
FIG. 6 is a step diagram showing a manufacturing procedure of a fixed mold using conventional concrete. FIG. 7 is a partial sectional view of a conventional fixed type and movable type.
Referring to FIG. 6, the manufacturing procedure of the conventional fixed mold using concrete will be described. First, the fixed mold using concrete is manufactured after the electroformed shell 2 having the design surface 1 is formed (FIG. 6A). The mold body 4 is attached to the mounting plate 5 on which the injection ports 7 and 7 are formed and sealed with the electroformed shell 2 (FIG. 5B).
Next, after the concrete 6 is poured from the injection ports 7 and 7 and hardened, the fixed mold 3 is completed (FIG. (C)).
As shown in FIG. 7, the movable mold 9 has a metal mold such as a casting provided on the mounting plate 5, and the resin injected between the fixed mold 3 and the movable mold 9 is the shape of the design surface of the electroformed shell. To be molded.
In the example shown in Japanese Patent Laid-Open No. Sho 62-170302, a high-strength cement molding die containing a cementitious substance as a main component, and a molding made of a material that is easy to cut at a position where the molding die is attached to a molding machine. A machine mounting member is provided.
[0003]
[Problems to be solved by the invention]
However, when the concrete is poured from the injection port 7 when manufacturing the mold using the above-described conventional concrete, if the viscosity of the concrete is high, the fluidity is poor and it is difficult to flow into a narrow space. As shown in FIG. The cavities 8 due to defects may remain, and the cavities 8 may be depressed due to resin pressure during resin molding.
Furthermore, after completion of a mold using concrete, triaxial tensile and compressive stresses are generated in the mold during resin molding, so the concrete part that is particularly sensitive to tensile stress may break or crack. .
[0004]
Accordingly, an object of the present invention is to provide a resin molding die which is a synthetic die of mortar and metal having a great improvement in tensile strength and high rigidity.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, a resin molding die of the present invention is cast and solidified in a die body, an electroformed shell having a design surface covering the bottom of the die body, and the die body . Mortar , metal fiber is embedded on the electroformed shell side of the mortar , and the mortar contains 500 to 560 parts by weight of Portland cement, 400 to 470 parts by weight of slag powder, and water as main components. the contains 700 to 1000 parts by weight of 280 to 350 parts by weight of sand, the mortar until the narrow space in the mold is characterized in that it is filled.
Further, the resin molding mold includes a mold body, an electroformed shell having a design surface covering the bottom of the mold body, and a mortar poured into the mold of the mold body and solidified, and the above mortar Metal fiber is embedded in the electroformed shell side, and the mortar is 500 to 560 parts by weight of Portland cement, 400 to 470 parts by weight of slag powder, 280 to 350 parts by weight of water and 700 to 1000 parts by weight of sand. other parts, contains gypsum, to a narrow space in the mold and the mortar is filled, that the expansion of the mortar is suppressed to the metal fibers, it reinforces the design surface of the conductive Ikara Features.
[0006]
In the resin molding mold having such a configuration, since a high fluidity mortar is used, it is possible to fill a narrow space in every corner of the mold body, and prevent formation of a gap due to self-shrinkage of the filling material. Can do.
In addition, the combination of high-fluidity mortar and fiber greatly improves the tensile strength of high-fluidity mortar, making it possible to produce a synthetic mold of mortar and metal with high rigidity.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, based on FIGS. 1 to 5, a preferred embodiment of a resin molding die according to the present invention will be described using substantially the same members as those in the past using the same reference numerals.
In this embodiment, a special mortar is used instead of the conventional concrete, and a fiber such as metallic iron is embedded and reinforced in a place where the tensile stress is high.
FIG. 1 shows an embodiment of a fixed mold in a resin mold of the present invention.
The procedure for producing the fixed mold of this embodiment is substantially the same as that of the prior art. However, as shown in FIG. 1, the fixed mold 10 of the resin mold uses a high-fluidity mortar 12 instead of concrete, and the mounting plate 5 The electroformed shell 2 shaped like a design surface is fixed to the bottom of the mold body 4 provided on the mold body 4, and the high fluidity mortar 12 is poured into the mold 13 from the inlet 7 of the mounting plate 5 and hardened.
[0008]
At this time, the fibers 14 are embedded at an appropriate density in the vicinity of the electroformed shell 2 side, but the fibers are mixed in advance with the high fluidity mortar 12 and then poured into the mold.
The fiber is, for example, an iron fiber having a diameter of 0.1 to 1.0 and a length of 10 to 50 mm. The volume mixing ratio and mixing position of this fiber are determined by estimating the stress distribution in the mortar part of the resin mold to be manufactured by CAE (Computer Aided Engineering) and passing the strength test, but usually 10 to 20%. Is in range.
In addition, the strength test is performed, for example, by applying a compression load by a compression test apparatus to a thick cylindrical test body, and simultaneously applying hydraulic pressure to the cylinder of the test body by a hydraulic unit, so that the durability test under triaxial stress is possible. Make an evaluation.
[0009]
As described above, in the fixed mold according to the present embodiment, since the high fluidity mortar is used, the high fluidity mortar surely flows into the narrow space, and the design surface is depressed due to the poor inflow of the concrete as in the past. There is no.
[0010]
FIG. 2 is a schematic diagram of stress received by the fiber embedded in the high fluidity mortar according to the present embodiment.
As shown in FIG. 2, the high-fluidity mortar 12 expands when solidified (described later with reference to FIG. 4) and pulls the fiber 14, but the fiber 14 does not expand, so that the reaction force makes contact with the fiber 14. The portion of the high-fluidity mortar 12 is prevented from expanding by the fiber 14 and is in a tension state. In FIG. 2, 22 indicates before expansion, 24 indicates expansion, 26 indicates expansion force and reaction force, and 28 indicates expansion force.
Thus, the high fluidity mortar of this embodiment becomes strong against the tensile stress of external force.
[0011]
Next, the composition and characteristics of the high fluidity mortar according to this embodiment will be described.
FIG. 3 is a composition diagram of the high fluidity mortar according to the present embodiment.
The high fluidity mortar according to the present embodiment is mainly composed of Portland cement, slag powder, water and sand, preferably 500 to 560 parts by weight of Portland cement, 400 to 470 parts by weight of slag powder, and 280 to 350 parts of water. It is better to use parts by weight. In this case, the amount of sand is selected from the viewpoint of compensating for the shrinkage caused by the hydration reaction of Portland cement or slag powder, and it may be blended in, for example, 700 to 1000 parts by weight.
In addition to these main components, gypsum such as anhydrous gypsum and dihydrate gypsum, a water reducing agent, an antifoaming agent and the like may be further blended in order to adjust properties such as shrinkage and strength.
[0012]
Further suitable high fluidity mortar composition, Portland cement 500~560kg / m ³ as shown in the composition diagram of Figure 3, the slag powder 400~470kg / m ^3, sand 850~950kg / m ^3, water 280 to 350 kg / m ³ , anhydrous gypsum (ad. A in FIG. 3) is 90 to 120 kg / m ³ , water reducing agent (ad. B in FIG. 2) is 2 to 5 kg / m ³ , defoaming agent (fig. 3) is 1 to 4 kg / m ³ . Here, the slag powder is produced by 6000 cm ² / g blast furnace granulation, and the sand is limestone crushed sand of 1.2 mm or less.
The mortar having such a composition has a fluidity of 280 ± 40 mm and high fluidity. In addition, the mixture of Portland cement and slag powder is what is called slag cement.
[0013]
FIG. 4 is a diagram comparing the length change of the high fluidity mortar according to the present embodiment and the normal Portland cement depending on the material age (days).
As apparent from FIG. 4, the length change A (black circle) of the high fluidity mortar according to the present embodiment is expanded as a whole, whereas the length change B (white circle) of ordinary Portland cement is contracted. It is.
[0014]
In such a high fluidity mortar, as shown in FIG. 4, unlike ordinary Portland cement, when it is poured into a mold, the generation of a gap due to self-shrinkage accompanying the hydration reaction of the cement is prevented.
Furthermore, as shown in FIG. 2, since the fiber is embedded, the combination of the high fluidity mortar that expands simultaneously with the development of strength by the hydration reaction of cement and the fiber that does not expand, The compressive force (this compressive force is called pre-stress) is introduced into the high-fluidity mortar by the reaction force of the fiber pulled by expansion, and the resistance to the external tensile force is increased by that amount (this resistance Is called the chemical pre-stress effect).
[0015]
FIG. 5 is a characteristic diagram of a high fluidity mortar with and without fibers. In addition, the compressive strength and bending strength in FIG. 5 are the characteristics of the high fluidity mortar hardened under the conditions of sealing curing at 20 ° C.
As shown in FIG. 5, when a steel fiber of φ0.5 × 20 mm is put in a high fluidity mortar at a volume mixing rate of 14.3%, for example, the compressive strength and bending strength are higher than when no steel fiber is put. Greatly improved.
For example, when viewed on the 7th, the compressive strength is 90 N / mm ² or more, especially 100 N / mm ² or more, and the bending strength is 20 N / mm ² or more, especially 40 N / mm ² or more. .
[0016]
As described above, the resin-molding mold of this embodiment uses a highly fluid mortar having expandability and is reinforced with fibers, so that a narrow space at every corner of the mold can be filled with mortar, and the tensile strength is remarkably high. large.
Furthermore, the formation of gaps due to the self-shrinkage of the filling material can be prevented, and the tensile strength can be significantly improved by the chemical press effect due to the outer frame reaction force and the chemical prestress effect due to the fiber reaction force. A mold that can withstand repeated use is obtained.
[0017]
【The invention's effect】
As can be understood from the above description, in the resin molding die of the present invention, since a high fluidity mortar is used, it is possible to fill a narrow space in every corner of the die body, and the self-shrinkage of the filling material It has the outstanding effect that formation of the clearance gap by can be prevented.
Moreover, the combination of the high fluidity mortar and the fiber has the effect that the tensile strength of the high fluidity mortar is greatly improved, and a synthetic mold of mortar and metal rich in rigidity can be formed.
[Brief description of the drawings]
FIG. 1 is an embodiment of a fixed mold in a resin mold according to the present invention.
FIG. 2 is a schematic diagram of stress received by a fiber embedded in a high fluidity mortar according to this embodiment.
FIG. 3 is a composition diagram of a high fluidity mortar according to the present embodiment.
FIG. 4 is a diagram comparing length changes of a high fluidity mortar according to the present embodiment and normal Portland cement according to material age (days).
FIG. 5 is a characteristic diagram of a high fluidity mortar with and without fibers.
FIG. 6 is a step diagram showing a manufacturing procedure of a fixed mold using conventional concrete.
FIG. 7 is a partial cross-sectional view of a conventional fixed mold and movable mold.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Design surface 2 Electroformed shells 3, 10 Fixed mold 4 Mold body 5 Mounting plate 6 Concrete 7 Inlet 8 Cavity 9 Movable mold 12 High fluidity mortar 14 Fiber

Claims (2)

A mold body, an electroformed shell having a design surface covering the bottom of the mold body, and a mortar poured into the mold of the mold body and solidified;
Metal fibers are embedded on the electroformed shell side of the mortar,
The mortar contains 500 to 560 parts by weight of Portland cement, 400 to 470 parts by weight of slag powder, 280 to 350 parts by weight of water, and 700 to 1000 parts by weight of sand as the main components , and a narrow space in the mold A resin mold characterized by being filled with the mortar . A mold body, an electroformed shell having a design surface covering the bottom of the mold body, and a mortar poured into the mold of the mold body and solidified;
Metal fibers are embedded on the electroformed shell side of the mortar,
The mortar contains 500 to 560 parts by weight of Portland cement, 400 to 470 parts by weight of slag powder, 280 to 350 parts by weight of water, 700 to 1000 parts by weight of sand, and gypsum. The mortar is filled up to the space,
Expansion of the mortar is suppressed to the metal fiber, a resin mold, characterized in that to reinforce the design surface of the conductive Ikara.

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