JPH0763771B2 - Mold for high strength cement sheet metal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a high-strength cement molding die having a compressive strength of 1,000 kgf / cm ² or more for forming a metal plate by hand and obtaining a product.

<Conventional technology and its problems> Conventionally, as a material of a molding die (hereinafter referred to as a sheet metal molding die) for molding a metal plate by hand to obtain a product, it is robust (high strength), and precise. Various products such as metal, resin, gypsum and cement have been used for the reason that various products can be obtained, they are cheap and the production period is short, but none of them are satisfactory.

For example, aluminum, zinc-based low melting point alloys, and the like have been used as materials for metal molds for sheet metal. However, although such metals are excellent in toughness,
When it is used as a sheet metal forming die, the shrinkage value at the time of curing is large, and the processing cost of precision finishing is expensive, and it takes a long time to manufacture, and it requires skill in processing. Further, the resin or gypsum sheet metal mold has a good surface transferability during the production and has a short production period, but is inferior in robustness and has a defect that it is chipped when the metal plate is knocked out. Furthermore, cement is a simple material that can be molded at room temperature, but as a mold for sheet metal, the compressive strength is usually up to about 600 kgf / cm ² , and it is inferior in toughness and further causes breathing that causes water to separate. There was a drawback that the transferability of the surface during manufacturing was poor.

The present inventors have variously studied sheet metal forming dies that are inexpensive, have excellent forming surface accuracy, and are robust,
It was found that a high-strength cement having a compressive strength of 1,000 kgf / cm ² or more has a surprising effect as a mold, and has completed the present invention.

<Means for Solving Problems> That is, the present invention is a high-strength cement sheet metal forming die made of a high-strength cement hardened material having a compressive strength of 1,000 kgf / cm ² or more.

The present invention will be described in more detail below.

The high-strength cement sheet metal forming mold in the present invention is basically a cement-based mold, which is obtained by adding a gypsum-based high-strength admixture, mortar or the like to an autoclave, or ultrafine powder and high A product obtained by combining a water-reducing agent with cement, etc., and made from a high-strength cement hardened product showing a compressive strength of 1,000 kgf / cm ² or more. Then, this sheet metal forming die can be manufactured by pouring it into the original die and inverting it.

Of these, the sheet metal mold made of cementitious substances, ultrafine powder, high-performance water-reducing agents, and high-strength cement hardeners whose main component is water is not only strength and hardness, but also surface transferability and easy molding. The sex is the best.

The cementitious substances mentioned here are alite, C ₃ S, various portland cements such as normal / early-strength / ultra-early-strength / white or sulfate resistant, cements such as alumina cement, alone or in combination, and further blast furnace slag. Commonly used is mixed cement, which is a mixture of ash and fly ash. Further, it is also possible to use blast furnace slag as a main component in combination with alkali stimulants such as hydroxides, carbonates and bicarbonates of alkali metals and / or alkaline earth metals.

It is also possible to use expansive cement as a cementitious substance to improve the shrinkage property, to use quick-hardening cement to develop the required strength in a short time, or to use a gypsum-based high-strength admixture together.

As the expansive component of the expansive cement, an ethrin guide type, such as “CSA # 2” manufactured by Denki Kagaku Kogyo Co., Ltd.
0 ", or calcined CaO is preferable, among calcined CaO 1,100-1,
It is preferable that the particles are baked at 300 ° C. and have an average crystal diameter of 10 μm or less.

Calcium aluminate type is often used as the rapid hardening component of the rapid hardening cement, for example, alumina cement or a combination of alumina cement and gypsum, and the product name "Denka ES" manufactured by Denki Kagaku Kogyo Co., Ltd. or Onoda Cement Co., Ltd. A product name such as "jet cement" is used.

In addition, the high-strength admixture is preferably a gypsum-based admixture, for example, Denka Kagaku Kogyo Co., Ltd., trade name “Denka Σ-1000”, Nippon Cement Co., Ltd., trade name “Asano Supermix”, etc. are effective. .

The ultrafine powder that can be used here is a cementitious substance (average particle size).
The average particle size is at least one order smaller (about 10 to 30 μ), and the average particle size is preferably smaller by two orders from the viewpoint of the flow characteristics of the kneaded product. Specifically, silicon, silicon-containing alloys and silica dust (silica fume) by-produced when producing zirconia and the like and siliceous dust are particularly suitable, calcium carbonate, silica gel, opalaceous silica, fly ashes, blast furnace slag, Finely pulverized products of titanium oxide, aluminum oxide or cementitious substances can also be used. In particular, use of ultrafine powder obtained by crushing opal silica, fly ash, and blast furnace slag by using a classifier and a crusher together is effective from the viewpoint of improving cure shrinkage.

The amount of ultrafine powder used is preferably 40 to 5 parts by weight with respect to 60 to 95 parts by weight of the cementitious substance, and more preferably 35 to 10 parts by weight with respect to 65 to 90 parts by weight of the cementitious substance. If the amount of the ultrafine powder used is less than 5 parts by weight, the effect of exhibiting high strength is small, and if it exceeds 40 parts by weight, the fluidity of the kneaded product is remarkably reduced, making it difficult to mold and exhibiting insufficient strength. Will be enough.

Further, the high-performance water-reducing agent referred to here is a surfactant having a large dispersing ability without causing excessive delay of setting or excessive air entrainment even when added in a large amount to cement, for example, naphthalenesulfonic acid formaldehyde condensate. Examples thereof include salts, salts of melamine sulfonic acid formaldehyde condensate, salts having a high molecular weight lignin sulfonate and polycarboxylate as main components. The amount of the high-performance water reducing agent used is conventionally 0.3 to 1% by weight as solid content with respect to the cement, but in the present invention, it is preferable to add a larger amount than that, and 1 to 5 parts by weight. Is more preferable. The high-performance water reducing agent uses a mixture of low water / (cementitious substance + ultrafine powder)
It is necessary to obtain a ratio (hereinafter referred to as water / powder ratio), and if it exceeds 10 parts by weight, it adversely affects the curing reaction. With such an amount of the high-performance water-reducing agent used, it is possible to obtain a flowable kneaded product which can be molded by an ordinary method even when the water / powder ratio is 25% or less by combining ultrafine powder.

The water used here is necessary for molding, and in order to obtain a high-strength cement hardened product, it should be as small as possible, and a mixture of cementitious material and ultrafine powder (hereinafter referred to as powder) 10
Water is preferably 10 to 30 parts by weight, more preferably 12 to 25 parts by weight, based on 0 parts by weight. When the amount of water used is more than 30 parts by weight, it is difficult to obtain a high-strength cement hardened product, and when it is less than 10 parts by weight, ordinary molding such as pouring becomes difficult. It should be noted that the compaction molding and the like are not limited to this, and molding is possible even when the amount is less than 10 parts by weight. It is also possible to use a molding method such as extrusion molding which is usually used for cement concrete.

In addition to the above materials, aggregate can be used together. Aggregate may be one generally used when mixing concrete in the field of civil engineering and construction, but a harder one, specifically,
The strength can be remarkably improved by using an aggregate selected according to any one of the criteria of Mohs hardness of 6 or more, preferably 7 or more, or Knoop indenter hardness of 700 kg / mm ² or more, preferably 800 kg / mm ² or more. Therefore, it is preferable. Examples of aggregates that meet this criterion include silica stone, emery, pyrite, magnetite, yellow jade, lawsonite, corundum, fenasite, spinel, beryl, anemite, tourmaline, granite, beryl, crossstone, zircon. , Calcined bauxite, heavy burnt shale, boron carbide, tungsten carbide, ferrosilicon nitride, silicon nitride, fused silica, fused silica, fused magnesia, silicon carbide and cubic boron nitride There are metals such as stainless steel, iron powder, and iron balls.

The amount of the aggregate used is usually selected and used within 5 times the weight of the powder. However, this is not the case in the case of a special molding method such as a prepacked construction method or a postpack construction method.

In addition to the above materials, various fibers and steels can be mixed.
As the fibers, fibers by chatter cutting method of cast iron, steel fibers, stainless fibers, various natural or synthetic mineral fibers such as asbestos and alumina fibers, carbon fibers, glass fibers, and further natural materials such as polypropylene, vinylon, acrylonitrile and cellulose. Alternatively, synthetic organic fibers and the like can be mentioned. In addition, steel rods and FR that have been conventionally used as reinforcements
It is also possible to use a P rod, which is indispensable especially in the case of a large sheet metal forming die.

It is also possible to add a so-called solid lubricant such as molybdenum disulfide or hexagonal boron nitride to impart other functions, for example, slidability, and carbon such as oil soakability may be added. It is also possible to use.

In addition, it is also possible to mix a material that imparts special properties such as thermal conductivity and electrical conductivity. The mixing and kneading methods of the above materials may be any methods as long as they can be uniformly mixed and kneaded, and the order of addition is not particularly limited.

The sheet metal molding die of the present invention is obtained by casting a kneaded product obtained in advance into a master mold having a frame or the like prepared around it, curing the kneaded product, and then removing from the master mold and curing. It can be manufactured very easily without the need for post-processing. It should be noted that the generation of bubbles on the casting surface should be taken into consideration, and it is preferable to remove the bubbles by a method of vacuum casting after vacuum kneading, or by performing deaeration before casting.
Also, when casting the sheet metal mold according to the present invention,
It is also possible to cast only the molding surface in contact with the metal plate with the kneaded product according to the present invention, and cast the remaining portion with an ordinary cement kneaded product before the kneaded product according to the present invention is cured and dried. .

Various types of curing methods are available for curing the molded objects.
Any method of normal pressure steam curing, high temperature high pressure curing and high temperature curing can be adopted, and if necessary, a combination of these can be used to obtain a high strength cement hardened product.

The metal mold for sheet metal, which is simply manufactured by the above method, is excellent in robustness because it has a transferability of the surface and a compressive strength of 1,000 kgf / cm ² or more. If the compressive strength is less than 1,000 kgf / cm ² , die breakage such as cracking, chipping and denting will occur during sheet metal forming.

Next, a sheet metal forming method by manual processing of a metal plate using the sheet metal forming die of the present invention will be described.

The metal plate to be hand-processed is a normal metal plate, is the same as the target metal plate, hot-rolled thin steel plate, cold-rolled steel plate, zinc iron plate, steel plate such as tin plate and stainless steel plate, and
Includes non-ferrous metal plates such as copper plates. If the metal plate is too thick, it will be difficult to form it by hand, and the upper limit of the plate thickness is about 2 mm.

Manual processing is carried out by bringing a metal plate into contact with the molding surface of the sheet metal mold of the present invention, and then hitting an oak tree, a bakelite spatula with a sheet metal hammer, a hammer with a wooden plate, to perform normal sheet metal work. It is a similar construction method. Therefore,
Sheet metal hammers are used in a variety of shapes such as entanglement, one-ended mouth, eboshi, pile-ups and potato shapes to perform work such as drawing and bending. Similarly, wood hammers are used in entanglement and both circle shapes. . In addition, wrought wood for bending correction, bending and time signature for smoothing, hard blade for edge folding, smoothing, leveling anvil for edge folding, wrinkling for wrinkling Various tools such as a rod are also used as needed.
Of course, it is also possible to set the metal plates formed by these processes in the sheet metal forming die of the present invention, and to join them by brazing with solder or the like, welding with gas or arc, and riveting.

<Examples> The present invention will be specifically described below with reference to Examples.

Example FIG. 1 shows a manufacturing process of a sheet metal forming die of the present invention for forming a door inner panel of an automobile by hand.

First, the wooden master 1 was manufactured (process A). Then, it was placed in a frame 2, a mold release agent “QZ-5T” manufactured by Nippon Ciba Geigy Co., Ltd. was sprayed on the surface, and a kneaded product 3 according to the present invention was cast. The kneaded material used the following materials and was vacuum kneaded with "Vacuum Omnimixer OM-30V" manufactured by Chiyoda Giken Co., Ltd., and then cast (step B). After curing in humid air at 20 ° C. or less for one day, the cured sheet metal forming die 4 was released from the mold (step C). This curing was performed under the following conditions.

80 parts by weight of white cement, 20 parts by weight of ultrafine powder, 120 parts by weight of heavy alum shale, 2 parts by weight of high-performance water reducing agent, 7 parts by weight of fiber, and 19 parts by weight of water were cast at a temperature of 50 ° C. A high-strength cement type I was prepared by performing a main curing for one day in a wet air condition.

91 parts by weight of white cement, 9 parts by weight of high-strength admixture,
A high-strength cement type II was prepared by casting a kneaded mixture of 2 parts by weight of a high-performance water-reducing agent, 100 parts by weight of silica sand, and 27 parts by weight of water, followed by main curing at 20 ° C for 28 days.

Then, a kneaded mixture of 100 parts by weight of ordinary Portland cement, 2 parts by weight of high-performance water reducing agent, 200 parts by weight of sand, and 26 parts by weight of water was cast, and the temperature was raised at a heating rate of 10 ° C / hour to 180 ° C, 10k
While maintaining gf / cm ² (gauge pressure) for 10 hours, autoclave curing was carried out to prepare high strength cement type III.

The cold-rolled steel plate 5 (SPC-2 (JIS G 3310) plate thickness 0.8 mm) is brought into contact with the sheet metal forming die 4 obtained as described above as shown in FIG. 3, and an oak wooden spatula is applied from above. Sheet metal work was performed on the inner door panel of the automobile by hitting it with a sheet metal hammer.

In addition, the compressive strength, bending strength, and hardness of the high-strength cement mold manufactured under the same conditions are measured, and the results are shown in the table together with the sheet metal working results of the high-strength cement mold.

For comparison, a kneaded mixture of 100 parts by weight of ordinary Portland cement, 250 parts by weight of sand, and 40 parts by weight of water was also added.
A mixture of 100 parts by weight of ordinary Portland cement, 100 parts by weight of sand, and 40 parts by weight of water, and a mixture of 100 parts by weight of ordinary portland cement, 100 parts by weight of sand, and 40 parts by weight of water, respectively, are used as cement types. I, II, and III were prepared and similar experiments were conducted. The results are also shown in the table.

In addition, the epoxy resin product name “EGR40” manufactured by Terada Industry Co., Ltd.
Kureha Chemical Industry Co., Ltd. 1% by volume carbon fiber resin mold, Fuji Gypsum Co., Ltd. high-strength gypsum "press gypsum" gypsum mold, and low melting point alloy The same experiment was conducted using the low melting point alloy ZAS type produced by the above. The results are also shown in the table.

<Materials used> White cement: White cement manufactured by Chichibu Cement Co., Ltd. Ordinary Portland cement: Ordinary Portland cement manufactured by Denki Kagaku Kogyo Co., Ltd. Ultrafine powder: Silica fume manufactured by Nippon Heavy Chemical Industry Co., Ltd. Heavy syllabary shale, grain size 0.3-1.2mm, 120 parts by weight Quartz sand: Kawatetsu Mining Co., Ltd. product name "Nikko silica sand", 0.15-25
mm Sand: Natural sand, Sagamigawa river sand, 5 mm or less High-performance water reducing agent: Daiichi Kogyo Seiyaku Co., Ltd. trade name “Cellflow 110P” Main component β Naphthalenesulfonic acid formalin condensate salt Water: Tap water Fiber: Kobe Steel fiber by chatter cutting manufactured by Cast Iron Co., Ltd., length 2 mm <Measurement method> Strength: Compressive strength and bending strength were measured according to JIS R 5201.

Hardness: Performed according to JIS Z 2245.

<Effects of the Invention> The high-strength cement mold of the present invention can be manufactured at low cost, has a good transfer surface, is excellent in robustness, and does not cause mold damage even when performing manual sheet metal working, A metal plate is formed by hand processing, and its effect is exhibited as a sheet metal forming die for obtaining a product.

[Brief description of drawings]

FIG. 1 is a process cross-sectional view for producing the high-strength cement mold of the present invention. That is, in step A, a wooden mold is placed, in step B, a frame is set around the wooden mold, the kneaded product is cast therein, and after curing, the mold is removed to obtain the high-strength cement mold of step C. is there. Further, FIG. 2 is a plan view of the high-strength cement type of the present invention, and FIG. 3 is a sectional view thereof. Reference numeral 1: Wooden master mold 2: Frame 3: Kneaded product 4: High strength cement mold 5: Cold rolled steel plate

Claims (1)

[Claims] 1. A high-strength cement sheet metal molding die whose molding surface is made of a high-strength cement hardened material having a compressive strength of 1,000 kgf / cm ² or more.