JP7114061B2 - METHOD FOR MANUFACTURING METAL POROUS MOLDED PRODUCT - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a metal porous molded article.

Conventionally, there are cases in which through-holes are provided in a metal molded product to make it porous, depending on the application. For example, in a mold that transfers the shape of the mold surface to the molded product, a permeable mold is provided with a large number of through holes that are sufficiently small to the extent that the shape of the mold surface is not affected from the mold surface to the back surface. manufacturing may take place. This air-permeable mold can adhere the molded product to the surface of the mold by applying suction from the many through-holes, and can accurately transfer the shape of the surface of the mold to the molded product.

As a method for manufacturing this permeable mold, for example, Patent Document 1 describes flocking a large number of short fibers to a conductive layer provided on the surface of a mandrel (mother mold) for forming a permeable mold. A method for manufacturing an air-permeable mold is described in which electroforming is performed on a coated conductive layer. According to this manufacturing method, during electroforming, the metal forming the mold is not electrodeposited on the implanted short fibers and extensions of the ends of the short fibers. Therefore, it is possible to manufacture an air-permeable mold in which through holes are formed at locations corresponding to the flocked locations on the surface of the conductive layer.

JP-A-2-225687

However, in the manufacturing method of Patent Document 1, it is troublesome to plant a large number of short fibers in the conductive coating. Furthermore, when the air-permeable mold is separated from the mother mold, short fibers may remain in the through-holes of the air-permeable mold. There was concern that the

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for manufacturing an air-permeable mold, which solves the above-mentioned problems, and which can manufacture the air-permeable mold more easily.

As a means for that purpose, the present invention is a method for producing a porous metal molded product, wherein fine particles are collided toward the surface of a conductive layer formed on the surface of a matrix for molding the porous metal molded product. By doing so, the conductive layer is peeled off at the location where the fine particles collided, and the conductive layer is formed with fine holes penetrating to the surface of the matrix. and a second step of electroforming the surface of the conductive layer.

According to this method, hydrogen generated on the surface of the conductive layer is less likely to separate from the conductive layer during electroforming due to the use of an electroforming liquid that does not contain a surfactant. At the same time, hydrogen generated on the surface of the conductive layer tends to collect in minute holes formed in the conductive layer and penetrating to the surface of the matrix. As a result, the metal forming the mold is not electrodeposited due to the presence of hydrogen that gathers in the areas corresponding to the minute holes. Therefore, through-holes are formed in the metal mold formed by electroforming so as to match the positions of the minute holes. Therefore, for example, a porous metal molded product can be produced more easily than a method of planting a large number of short fibers.

Furthermore, the first step is performed by using an injection device that injects a large number of microparticles from an injection opening with air pressure, moving the injection opening while separating the injection opening from the conductive layer by a predetermined distance, and moving the injection opening from the injection opening. By injecting particles and causing them to collide over the entire surface of the conductive layer, it is possible to form minute holes over the entire conductive layer. According to this, since a predetermined distance is placed from the injection port to the conductive layer, it becomes easy to control the size of the minute holes formed in the conductive layer to be constant. Therefore, it is easy to control the size of the through-holes formed in the metal porous molded article to be constant. In addition, since fine holes are provided over the entire conductive layer, through-holes are formed over the entirety of the finished porous metal molded product. For this reason, the air-permeable mold thus produced can be easily and uniformly sucked as a whole. As a result, transferability from a permeable mold, which is one of porous metal molded articles, to a resin molded article is also improved.

Further, the microparticles can be made of a material harder than the material forming the conductive layer. According to this, since the constituent material of the fine particles is harder than the constituent material of the conductive layer, peeling of the conductive layer occurs more reliably. Fine holes are more accurately formed in the conductive layer according to the size of the colliding fine particles and the location of the colliding.

Also, the material constituting the conductive layer can be silver. According to this, since silver has a high electrical conductivity and can be electroformed more accurately, the manufacturability of the metal porous molded product is improved.

Further, the microparticles may be spherical, and the outer diameter of the microparticles may be 15 to 30 times the film thickness of the conductive film. According to this, since the fine particles are spherical, the manner of collision of the fine particles becomes uniform, and the shape and size of the fine holes formed in the conductive layer tend to be uniform. If the outer diameter of the microparticles is large enough, the conductive film can be peeled off more reliably, so it is possible to further improve the accuracy of the size and location of the minute holes formed in the conductive layer. be.

In addition, the manufactured porous metal molded product can be made into an air-permeable mold. According to this, it is possible to manufacture a permeable mold having through holes.

Moreover, the manufactured metal porous molded article can be used as a metal molding jig for fiber-reinforced plastic molding. According to this, it is possible to manufacture a metal molding jig capable of molding fiber-reinforced plastic more accurately.

According to the manufacturing method of the air-permeable mold of the present invention, the air-permeable mold can be manufactured more easily.

FIG. 3 is a side view showing a prototype; FIG. 4 is a side view showing an inverse mold formed with respect to the original mold; FIG. 4 is a side view showing a matrix formed in an inverted mold; FIG. 4 is a side view showing a matrix provided with a conductive layer; FIG. 4 is a schematic diagram showing how fine particles are ejected toward the conductive layer on the surface of the matrix. It is a schematic diagram which shows a mode that microparticles were made to collide with a conductive layer. FIG. 4 is a schematic diagram showing how electroforming is performed on the conductive layer on the surface of the matrix. FIG. 4 is a schematic diagram showing how an air-permeable mold is formed on the surface of the conductive layer. 1 is a schematic diagram showing a metal molding jig for molding fiber-reinforced plastic; FIG. FIG. 4 is a schematic diagram showing the process of molding fiber-reinforced plastic with a metal molding jig.

(Embodiment 1)
EMBODIMENT OF THE INVENTION Below, Embodiment 1 which is a manufacturing method of an air-permeable metal mold|die is demonstrated with reference to drawings as an example of the manufacturing method of the metal porous molded article of this invention. First, the manufacturing procedure of the master mold 1 used for air permeable mold molding in this embodiment will be described with reference to FIGS. 1 to 3. FIG. As shown in FIG. 1, a prototype 6 having the same shape as the molded product that is finally molded by the air-permeable mold is formed. The model 6 can be made of wood, for example, so that it can be easily processed. Vinyl leather or the like having a fine uneven pattern such as a leather grain pattern is pasted on the surface 6a of the master 6 with sheet wax or the like, if necessary. The pattern of this vinyl leather or the like becomes the pattern that is finally transferred to the surface of the molded product.

As shown in FIG. 2, by molding the original mold 6, a reverse mold 7 having an uneven shape opposite to the external shape of the original mold 6 is formed. The reverse mold 7 can be obtained, for example, by casting silicone resin on the surface of the original mold 6, hardening it, and then releasing it from the original mold 6. As shown in FIG.

As shown in FIG. 3, the matrix 1 can be formed by further inverting the reversal mold 7 . The master mold 1 can be obtained, for example, by casting a resin different from the resin forming the reversal mold 7, hardening it, and then releasing it from the reversal mold 7. FIG. As a result, the outer shape of the master mold 1 to be formed becomes substantially the same as the outer shape of the original mold 6.例文帳に追加

Next, a method of manufacturing an air-permeable mold from the master mold 1 by electroforming will be described with reference to FIGS. 4 to 8. FIG. As shown in FIG. 4, a conductive layer 2 is formed on the surface of matrix 1 . Since the conductive layer 2 is formed with a substantially uniform thickness, the surface shape of the matrix 1 (including fine uneven patterns such as the above-described grained pattern in addition to the uneven shape) is applied to the surface of the conductive layer 2 as it is. appear. The conductive layer 2 can be formed by coating, spraying, wet electroless plating, dry vacuum plating, or the like. As a material for forming the conductive layer 2, a conductive material such as gold, silver, copper, nickel, or graphite can be used, but it is preferably made of silver. This is because silver has a high electrical conductivity and can be electroformed efficiently and accurately. It is preferable to wash the master mold 1 in advance before forming the conductive layer 2 . This is to prevent dirt particles and the like on the surface of the matrix 1 from affecting the shape of the surface of the conductive layer 2 .

Subsequently, as shown in FIG. 5, a large number of microparticles 3 are ejected from an ejection port 10a of an injection device 10 to collide with the surface of the conductive layer 2. Then, as shown in FIG. The injection device 10 can inject the microparticles 3 by pneumatic pressure or hydraulic pressure, for example. As shown in FIG. 6 , when the fine particles 3 collide with the conductive layer 2 , they separate the stripped pieces 2 b from the conductive layer 2 and form fine holes 2 a penetrating the conductive layer 2 to the surface of the matrix 1 . Here, it is preferable to cause the ejected microparticles 3 to collide with the entire surface of the conductive layer 2 by moving the ejection port 10a over the entire conductive layer 2 from above. Since the fine holes 2a are formed over the entire conductive layer 2, through holes are also formed over the entire air-permeable mold, the air-permeable mold is uniform as a whole. This is because the air-permeable mold can be more easily transferred to the resin molded product.

Examples of materials that constitute the microparticles 3 include stainless steel, steel, copper, ceramics, glass, and silica sand. This is because the material constituting the microparticles 3 is harder than the conductive layer 2, so that the peeling pieces 2b are reliably peeled off from the conductive layer 2 where the microparticles 3 collide.

The outer shape of the microparticles 3 may be any shape, but a spherical shape is preferable. If spherical, the fine particles 3 always collide with the surface of the conductive layer 2 in the same way, so the size and shape of the fine holes 2a formed in the conductive layer 2 tend to be uniform. The outer diameter of the microparticles 3 may be any size as long as the conductive layer 2 can be peeled off, but it is preferably 15 to 30 times the film thickness of the conductive layer 2 . If the outer diameter of the microparticles 3 is less than 15 times the film thickness, it may be difficult to reliably remove the conductive layer 2 . If the outer diameter of the microparticles 3 is larger than 30 times the film thickness, the conductive layer 2 may be peeled off more than necessary, and electroforming may not be performed sufficiently.

The position at which the microparticles 3 are injected and the speed at which the microparticles 3 are injected are determined so that the conductive layer 2 is not too peeled off to form the microscopic holes 2a of the intended size, or the microparticles 3 are Appropriate adjustment may be made so that the conductive layer 2 will not peel off even if it collides.

Subsequently, as shown in FIG. 7, the matrix 1 with the conductive layer 2 applied thereto is immersed in an electroforming solution 4 . As the electroforming liquid 4, conventionally used one can be used, and it is used properly according to the type of metal to be laminated on the surface of the conductive layer 2 by electroforming. Specifically, an electroforming liquid containing ions of the metal to be laminated is used.

Examples of materials that can be used as the electroforming liquid 4 include copper ions such as a copper cyanide electroforming liquid, a copper pyrophosphate electroforming liquid, and a copper sulfate electroforming liquid when laminating copper by electroforming. and an electroforming liquid to be used. When nickel is electroformed, an electroforming solution containing nickel ions such as a nickel sulfamate electroforming solution and a nickel sulfate electroforming solution can be used. When performing chromium electroforming, an electroforming solution containing chromium ions such as a hexavalent chromium electroforming solution can be used. When electroforming zinc, an electroforming liquid containing zinc ions such as a zinc cyanide electroforming liquid and a zinc-cyanide-free electroforming liquid can be used. When performing electroforming of tin, an electroforming solution containing tin ions such as an alkaline tin electroforming solution and an acidic tin electroforming solution can be used.

As the copper cyanide electroforming solution, for example, one containing cuprous cyanide and sodium cyanide and having a pH of 11 to 12 can be used. As the copper pyrophosphate electroforming liquid, for example, one containing copper pyrophosphate, pyrophosphoric acid, and aqueous ammonia, and having a pH of 8.2 to 8.8 can be used. As the copper sulfate electroforming solution, for example, one containing copper sulfate and sulfuric acid can be used. Examples of nickel sulfamate include those containing nickel sulfamate, nickel chloride, and boric acid, and those having a pH of 3.0 to 4.0 can be used. As the nickel sulfate electroforming liquid, for example, one containing nickel sulfate, nickel chloride, and hydrochloric acid, and having a pH of 4.0 to 5.5 can be used. As the hexavalent chromium electroforming solution, for example, one containing chromic anhydride and sulfuric acid can be used. As the zinc cyanide electroforming liquid, for example, one containing zinc cyanide, zinc chloride, and sodium cyanide can be used. As the cyanide-free zinc electroforming liquid, for example, one containing zinc chloride and sodium hydroxide and having a pH of 4.5 to 5.5 can be used. As the alkaline tin electroforming liquid, for example, one containing sodium stannate or sodium hydroxide can be used. As the acidic tin electroforming solution, for example, one containing stannous sulfate and sulfuric acid can be used.

However, the electroforming liquid 4 does not contain a surfactant such as sodium lauryl sulfate. This is because when the surfactant is contained, the hydrogen generated on the surface is separated from the surface of the conductive layer 2, and no through holes are formed in the formed mold.

As shown in FIG. 7, from the conductive layer 2 of the matrix 1 immersed in the electroforming liquid 4 and the metal (for example, copper, nickel, chromium, zinc, tin, etc.) to be laminated on the surface of the conductive layer 2, The configured electrode 12 is connected via a DC power supply 13 . As a result, from the electrode 12, which is the anode, the metal composing the electrode 12 becomes metal ions (eg, copper ions, nickel ions, chromium ions, zinc ions, tin ions, cobalt ions) and is eluted into the electroforming solution. . Some of these metal ions or some of the metal ions dissolved in the electroforming liquid 4 are electrodeposited on the surface of the conductive layer 2, which is the cathode, and laminated as a metal layer. Lamination of these metal layers forms the air-permeable mold 5 (see FIG. 8).

As shown in FIG. 8, the conductive layer 2 is formed with a plurality of fine holes 2a. During electroforming, hydrogen gas bubbles are generated on the surface of the conductive layer 2 by electrolysis. Since the electroforming liquid 4 does not contain a surfactant, the hydrogen gas bubbles do not separate from the surface of the conductive layer 2 and tend to gather in the minute holes 2a where the matrix is exposed. Therefore, electrodeposition does not occur above the minute holes 2a, and metal is not deposited above the minute holes 2a even if electroforming is continued. Therefore, when electroforming is performed on the surface of the conductive layer 2, through-holes 5a are formed at locations corresponding to the minute holes 2a in the air-permeable mold 5 to be formed.

In this embodiment, minute holes 2a are formed over the entire conductive layer 2 . Therefore, the through holes 5a formed in the air-permeable mold 5 are also formed over the entire air-permeable mold 5. As shown in FIG. According to this air-permeable mold 5, since the entire air-permeable mold 5 can be sucked, the entire molded product of the air-permeable mold 5 can be evenly sucked, and the desired surface shape or pattern can be accurately obtained on the molded product. can be transcribed.

(Embodiment 2)
The second embodiment will be described below. Although Embodiment 1 is a manufacturing method for a permeable mold, this manufacturing method can also be applied to a metal molding jig for fiber reinforced plastic (FRP) molding according to Embodiment 2. The manufacturing method of the metal molding jig for fiber-reinforced plastic molding is basically the same as the manufacturing method of the air-permeable mold of the first embodiment. The metal forming jig for fiber-reinforced plastic molding (hereinafter also simply referred to as "metal forming jig") manufactured by the method according to the second embodiment will be described below.

In conventional fiber-reinforced plastic molding, for example, first, a sheet-shaped member is prepared in a state before curing in a state in which reinforcing fibers such as carbon fibers are impregnated with a resin. Such a sheet-like member is generally called a prepreg sheet. Next, a molding jig having a shape that is a reversal of the desired shape of the fiber-reinforced plastic is prepared. The prepreg sheet described above is placed on this forming jig. The forming jig on which the prepreg sheet is placed is placed in a bag-like vacuum bag, and the pressure inside the vacuum bag is reduced. Then, the vacuum bag comes into close contact with the forming jig, and the prepreg sheet is pressed against the forming jig. After that, the molding jig wrapped in the vacuum bag is placed in an autoclave with the prepreg sheet still in close contact with it, and is pressurized and heated to harden it, thereby forming a fiber-reinforced plastic in the desired shape. can.

However, when using such a forming jig, the pressure inside the vacuum bag is reduced and the vacuum bag is brought into close contact with the forming jig to determine the shape of the prepreg sheet. That is, the prepreg sheet is brought into close contact with the forming jig by the difference between the internal pressure of the vacuum bag and the atmospheric pressure. For this reason, there is a concern that the prepreg sheet can be brought into close contact with the forming jig only at atmospheric pressure or less, and it is difficult to completely conform to the outer shape of the forming jig. Therefore, for example, when the external shape of the molding jig is complicated, or when the external shape of the molding jig is fine, it is difficult to accurately transfer the fiber-reinforced plastic to the desired shape. There were also concerns. In addition, when considering how to transfer the outer shape of the forming jig to the prepreg sheet as accurately as possible, the method of directly contacting the entire prepreg sheet in the thickness direction is more accurate. It can be expected that it will be complied with.

Here, as shown in FIG. 9, the metal molding jig 8 for molding fiber-reinforced plastic manufactured by the manufacturing method of Embodiment 2 is provided with fine through-holes 8a over its entirety ( Since FIGS. 9 and 10 are only schematic diagrams, the through hole 8a looks large, but in reality it can be formed so small that it is difficult to see at first glance). Then, as shown in FIG. 10, the metal forming jig 8 is covered with the prepreg sheet 15, and suction is applied from the through holes to bring the prepreg sheet 15 into close contact with the metal forming jig (see the arrow in FIG. 10). A).

As a result, the prepreg sheet 15 can be brought into close contact with the forming jig more strongly (at atmospheric pressure or higher) than when the forming jig with the prepreg sheet placed in the vacuum bag is placed in the vacuum bag and the pressure is reduced. Therefore, the outer shape of the metal molding jig 8 is more accurately transferred to the prepreg sheet 15, and the molding accuracy of the reinforced plastic is also improved. Further, since the metal forming jig 8 is sucked in the thickness direction of the prepreg sheet 15 by the through holes 8a, the outer shape of the metal forming jig 8 is easily transferred to the prepreg sheet 15 more accurately. Furthermore, since the through holes 8a are minute, they do not affect the external shape of the metal forming jig 8. FIG. Therefore, it does not prevent the outer shape of the metal forming jig 8 from being accurately transferred to the prepreg sheet 15 .

The metal forming jig 8 manufactured by the manufacturing method of the second embodiment is provided with minute through holes 8a over the entirety thereof. Therefore, since the entire prepreg sheet 15 can be uniformly sucked, the shape of the outer shape of the metal forming jig 8 transferred to the prepreg sheet 15 is less uneven. That is, even if different metal forming jigs 8 are used, variations in the shape transferred to the prepreg sheet 15 are less likely to occur.

Furthermore, the suction force can be adjusted by adjusting the amount and speed of the air sucked from the through holes 8a. Therefore, the prepreg sheet 15 can be molded according to the softness and strength of the prepreg sheet 15 .

The prepreg sheet 15 is cured in an autoclave that can be pressurized and heated in a state where the prepreg sheet 15 is adsorbed to the metal forming jig 8, thereby obtaining a fiber-reinforced plastic molded into a desired shape. It is possible.

(Other embodiments)
The present invention is not limited to the first and second embodiments described above with reference to the drawings, and various modifications, additions, and deletions are possible without changing the gist of the present invention. As a porous metal molded product manufactured by the manufacturing method of the present invention, for example, it can be applied to a method of manufacturing a vacuum clamp that sucks and moves a work by sucking it from a through hole.

Also, the method of producing the matrix is not limited to the one shown in the embodiment. For example, a method of machining the surface of the target base material to produce it, a photosensitive resin is applied to the surface of the polished base material, and then irradiated with light to create patterns and shapes on the base material surface. It can also be manufactured by a physical or chemical etching method such as a method of transferring to the surface.

Moreover, the shape of the matrix is not limited to the illustrated one, and various shapes may be used according to the intended shape.

Further, in the above embodiment, a large number of microparticles 3 are injected by the injection device 10 at once, but it is also possible to inject them one by one. Further, the means for ejecting the microparticles does not have to be an ejection device using air pressure, and for example, ejection by physical ejection may be used.

Reference Signs List 1 master mold 2 conductive layer 2a fine hole 3 microparticle 4 electroforming liquid 5 air-permeable mold 8 metal forming jig 10 injection device 10a injection port

Claims (6)

A method for producing a metal porous molded product, which corresponds to either a permeable mold, a metal molding jig for molding fiber-reinforced plastic, or a vacuum clamp ,
A large number of spherical microparticles injected at once by an injection device collide against the surface of a conductive layer made of silver and formed on the surface of the matrix for the metal porous molded product. a first step of exfoliating the conductive layer at locations where the fine particles collide and forming minute holes penetrating to the surface of the matrix in a plurality of locations of the conductive layer;
and a second step of immersing the master mold in an electroforming solution containing no surfactant and performing electroforming on the surface of the conductive layer. A method for producing a metal porous molded article according to claim 1,
The first step uses the injection device for injecting the large number of fine particles from the injection port, moves the injection port while separating the injection port from the conductive layer by a predetermined distance, and moves the injection port from the injection port. A method for producing a metal porous molded product, which is a step of injecting a large number of the fine particles and causing them to collide over the entire surface of the conductive layer to form the fine holes over the entire conductive layer. A method for producing a metal porous molded article according to claim 1 or 2,
A method for producing a metal porous molded article, wherein the microparticles are made of a material harder than the material forming the conductive layer. A method for producing a porous metal molded article according to any one of claims 1 to 3,
A method for producing a metal porous molded product, wherein the outer diameter of the fine particles is 15 to 30 times the film thickness of the conductive layer. A method for producing a porous metal molded article according to any one of claims 1 to 4 ,
A method for producing a porous metal molded article, wherein the porous metal molded article is an air-permeable mold. A method for producing a porous metal molded article according to any one of claims 1 to 4 ,
A method for producing a porous metal molded product, wherein the porous metal molded product is a metal molding jig for molding fiber-reinforced plastic.

Images