JP6692017B2 - Manufacturing method of mold for mass production of resin molded products - Google Patents

Description

  The present invention relates to a method for manufacturing a metal mold for mass production of resin molded products.

  Conventionally, when developing a new product, the prototypes of the components that make up the product are tested for physical properties and durability so that the desired performance and safety aspects of the product can be cleared, as well as a collision test, etc. Have to go through. For example, when molding interior parts and exterior parts of automobiles with resin, they are usually formed by injection molding because they have curved surfaces and inclined surfaces and are formed in an uneven shape, and the strength of the parts is also required. There are many. In this case, in order to perform a physical property test, a durability test, a collision test, or the like, a prototype must be formed by injection molding with the same material as a regular part. For that purpose, a mold for injection molding is required. It was necessary to make a new prototype to make a prototype. For example, automobile interior parts are formed in a concave and convex shape and have a complicated shape, so that a mold for injection molding for molding the parts is also complicatedly formed.

  However, since the prototype can be produced as a mass-produced product after passing various tests, for example, if one prototype is manufactured by molding a new mold as described above, It cannot be worth the cost of mold making. In addition, it takes a long time for delivery, and it was practically impractical to manufacture a mold for injection molding to manufacture a prototype.

  Conventionally, as a method for producing such a prototype, an optical molding method using a liquid resin that is cured by irradiating a laser beam, or a resin block is purchased and a cutting machine such as a machining center or an NC milling machine is used. It was performed by performing a cutting process (see Patent Document 1).

JP, 2001-260204, A

  In the above-described optical molding method, a molding base is set in a liquid photocurable resin, and the photocurable resin on the molding base is irradiated with a laser beam to mold one layer. This process is repeated and laminated to form one product. Since the portion of the photocurable resin irradiated with the laser light is cured, the cured portion is molded as one product. Therefore, the product can be completed early even with a complicated shape.

  However, in this optical molding method, the material that can be molded is limited, and it is not possible to manufacture it with the same material as the legitimate part. , Durability test or collision test is not possible.

  In addition, when a prototype is formed by cutting with a commercially available resin block, the cutting is also performed. Therefore, although it is possible to easily form one prototype in a short period of time, a general resin block is formed of a predetermined material. Therefore, even if the assembly test can be performed, the physical property test and the durability test or the collision test cannot be performed because the material does not match the material required by the manufacturer. As a result, the performance required by the regular parts formed by producing a mold for injection molding may not be achieved.

  Therefore, the present invention provides a mold manufacturing method, a molding method, a resin mold and a manufacturing method thereof for mass-producing a resin molded product, which is capable of exhibiting the required performance of a regular part manufactured by molding the mold. Is provided.

In order to achieve the above object, a method for manufacturing a metal mold for mass production of a resin molded product according to the present invention is based on a step of creating three-dimensional CAD data of a resin mold (P1) and based on the created three-dimensional CAD data of the resin mold. , A step of molding the photo-curable resin into the shape of a resin mold by using a three-dimensional printing machine (P2), a step of mounting the molded resin mold on an injection molding machine (P3), and an injection molding machine A step of performing injection molding (P4), a step of investigating a molded product obtained after performing the injection molding (P5), and a step (A) of judging whether the results of the investigation are satisfactory or not. If you are not satisfied, return to the process of (P1) and repeat until you are satisfied with (A) to redesign the resin mold to reflect the results of the survey so that you can obtain a satisfactory result. Repeatedly according to, and can be satisfied with (A) Once it becomes a cormorant, a step (P6) to produce a mold for the mass production on the basis of the three-dimensional CAD data created in the last of the (P1).
In addition, prior to the production of molds for mass production of resin molded products, using a three-dimensional printing device based on the three-dimensional CAD data of the resin mold, a photocurable resin whose deflection temperature under load after photocuring is 45 ° C. or higher. Is printed to obtain a resin mold, the resin mold is used to mold the resin raw material for mass production of resin molded products, and the molded product is investigated. It is characterized by being reflected at the time of manufacturing.

  Here, the resin mold has a light-transmitting property such that the resin raw material for mass production can be visually observed from the outside during molding, and the investigation shows that the resin raw material for mass production flows inside the resin mold. It may be possible to have a state survey.

  In order to achieve the above object, the molding method of the present invention uses a three-dimensional printing machine based on three-dimensional CAD data to form a photocurable resin having a deflection temperature under load after photocuring of 45 ° C. or higher into a resin mold shape. To obtain a resin mold, and the resin mold is used to mold a mass-produced resin raw material for molding with a mold to be manufactured later into a predetermined shape.

  In order to achieve the above object, a method of manufacturing a resin mold used for molding a mass-produced resin raw material for molding with a mold to be manufactured later according to the present invention is a three-dimensional printing machine based on three-dimensional CAD data. Using, the photocurable resin having a deflection temperature under load after photocuring of 45 ° C. or higher is printed in the shape of a resin mold.

  In order to achieve the above object, a resin mold used for molding a mass-produced resin raw material for molding with a mold to be manufactured later according to the present invention uses a three-dimensional printing machine based on three-dimensional CAD data. It can be obtained by printing a photocurable resin whose deflection temperature under load after photocuring is 45 ° C. or higher.

  Here, it is preferable that the resin mold has a light-transmitting property such that a resin raw material for mass production can be visually observed from the outside during molding.

  In the present invention, a mold manufacturing method, a molding method, a resin mold manufacturing method, and a resin mold for mass-producing a resin molded product capable of exhibiting the performance required for a regular part manufactured by molding the mold. Can be provided.

It is a flowchart which shows the manufacturing method of the resin mold which concerns on embodiment of this invention, and the manufacturing method of the metal mold | die for mass production of a resin molded product.

  Hereinafter, a molding method according to an embodiment of the present invention, a method for manufacturing a resin mold, a method for manufacturing a resin mold and a mold for mass-producing resin molded products will be described with reference to the drawings. FIG. 1 is a flow chart showing a method of manufacturing a resin mold and a method of manufacturing a metal mold for mass-producing a resin molded product according to an embodiment of the present invention.

  First, resin type three-dimensional CAD (Computer Aided Design) data is created (P1). This resin mold is designed on the assumption of a regular part shape that is molded by a mass-production mold described later.

  Next, based on the resin-type three-dimensional CAD data created in P1, a three-dimensional printing device (what is called a three-dimensional printer, a 3D printer, a three-dimensional modeling machine, or the like) is used, and a photocurable resin ( Product name: Objet Polymerized ABS-like RGD5160-DM) is molded into a resin mold shape (P2). This photocurable resin is one that is cured by irradiation with ultraviolet rays, and the deflection temperature under load after photocuring (based on the method of JIS K 7191-2: 2007B, the bending stress applied to the test piece is 0.45 MPa). It is 82-95 degreeC. Since this resin mold is an openable-closed resin mold, it is composed of an upper mold and a lower mold. The above is the method for manufacturing the resin mold according to the embodiment of the present invention. The resin mold obtained through P1 and P2 is the resin mold according to the embodiment of the present invention.

  Next, the molded resin mold is attached to the injection molding machine (P3). This injection molding machine is originally one to which a cassette-type mold is attached. The support part that supports the cassette part involved in the molding of the mold is made of metal. The resin mold according to the embodiment of the present invention is attached instead of the cassette portion and is supported by the metal supporting portion.

  Next, using the injection molding machine, injection molding is performed using a resin raw material for mass production (P4). The resin raw material for mass production is a thermoplastic resin, for example, ABS resin. This mass-produced resin raw material is heated to 190 ° C. to 220 ° C. and melted and then injected into the resin mold. This injection method is the same as the injection method used when molding a regular part with a mold for mass production. The molten resin raw material is cooled and solidified in the resin mold for 5 minutes with the upper mold and the lower mold forming the resin mold closed to form a molded product. Then the upper and lower molds are opened. Then, the molded product is separated from the resin mold by the operation of the so-called ejector pin (ejector pin) provided in the above-mentioned support portion. In the case of continuous molding, the upper mold and the lower mold are opened after molding once and the state of being cooled by air is maintained for 60 seconds, and then the next molding is carried out. The above is the molding method according to the embodiment of the present invention.

  Next, the molded product is investigated (P5). This survey is to carry out all tests such as assembly test, physical property test, durability test, collision test, etc. to evaluate whether or not a regular part can exhibit required performance.

  Next, it is judged whether or not the result of this investigation is OK, that is, satisfactory (A). If the condition is not satisfied (NO), the survey result is reflected and the resin mold is redesigned so that a satisfactory result is obtained, and the process returns to P1. Then, the process from P1 to P5 and the judgment A are repeated as necessary until the judgment A is satisfied (YES).

If the judgment A is satisfied (YES), a mold for mass production is produced based on the latest three-dimensional CAD data created in P1 (P6). The above is the manufacturing method of the metal mold for mass production of the resin molded product according to the embodiment of the present invention. After that, regular parts are mass-produced using this mold (P7).
(Main effects obtained by the embodiment of the present invention)

  As described above, the mold manufacturing method, the molding method, the resin mold manufacturing method, and the resin mold for mass-producing the resin molded product according to the embodiment of the present invention are injection-molded using the resin raw material for mass production ( It is possible to investigate the molded product through the process of P4). Therefore, a metal mold for mass production can be manufactured in which the result of the investigation is reflected, and the performance required for a regular part can be exhibited.

  This resin mold can be manufactured in about 1 hour using a three-dimensional printing machine. Further, the manufacturing cost thereof is extremely low as compared with the metal mold for mass production. Therefore, the period from the initial stage to the final stage of the design of the mold for mass production can be shortened and the cost can be reduced.

  Further, by using the resin mold according to the embodiment of the present invention, it is possible to manufacture approximately 100 molded products having the same resin composition and shape as the regular parts injection-molded using the mass-production mold. Therefore, it is possible to obtain a sufficient number of molded products for grasping the variation in the survey results during mass production.

  Further, the deflection temperature under load of the photocurable resin after curing is 82 to 95 ° C., whereas the resin raw material for mass production is heated to 190 ° C. to 220 ° C. and injected into the resin mold in a molten state. .. Therefore, there may be a concern that the resin mold cannot withstand such a temperature environment. However, in the molten resin raw material, the temperature immediately decreases in the portion in contact with the atmosphere or the resin mold, and only the inside becomes the high temperature portion. Therefore, the resin mold is not easily deformed and deteriorated by heat, and can be molded many times.

Further, a photocurable resin that is cured by irradiation of ultraviolet rays is used for the resin mold, and an ABS resin that is a thermoplastic resin is used for the resin raw material for mass production. Since these resins differ in composition, characteristics, molecular structure, etc., they hardly stick to each other during molding and are excellent in mold releasability.
(Other forms)

  The above-described manufacturing method, molding method, resin mold manufacturing method, and resin mold for mass-production of resin-molded products according to the embodiments of the present invention are examples of preferred embodiments of the present invention, but are not limited thereto. However, various modifications can be made without departing from the scope of the invention.

  For example, in the molding method, the resin mold and the manufacturing method thereof according to the embodiment of the present invention, a mold is manufactured later as a premise, but only a relatively small number of regular parts to be mass-produced are planned. If there are circumstances such as not doing so, it is possible to produce regular parts using only resin molds.

  Further, the photo-curable resin used is one that is cured by irradiation with ultraviolet rays, but a resin that is cured by other light such as laser light or visible light can be used. As the photocurable resin, a photocurable resin having a deflection temperature under load of 82 to 95 ° C. after curing is used. However, if the deflection temperature under load is 45 ° C. or higher, the suitable resin mold according to the embodiment of the present invention can be manufactured. In addition, if the deflection temperature under load is 65 ° C. or higher, a more suitable resin mold according to the embodiment of the present invention can be manufactured. The deflection temperature under load is preferably 45 to 90 ° C. from the viewpoint of availability of the photocurable resin or cost. From the viewpoint of the heat resistance of the resin mold, the deflection temperature under load is preferably 80 ° C or higher, more preferably 90 ° C or higher, and even more preferably 100 ° C or higher.

  The printing method of the photocurable resin can be selected from various methods such as a projection method, an inkjet method, and an inkjet powder laminating method. The projection method is advantageous in reducing printing costs. The inkjet method and the inkjet powder lamination method have a high printing speed. Further, the inkjet method is suitable for high-precision printing, and is particularly advantageous for printing a complicated shape such as a resin mold.

  Further, the resin mold may have a light-transmitting property such that a resin raw material for mass production can be visually observed from the outside during molding. An acrylic resin or the like is suitable as such a translucent resin. By using such a translucent resin mold, it is possible to observe with a naked eye how a mass-produced resin raw material melts and flows inside the resin mold. Then, for example, the position of the weld line formed at the time of resin molding and the generation process can be easily specified. When conducting the investigation (P5) of the molded product shown in FIG. 1, whether the position of the weld line and the generation process are appropriate is also added as an investigation item, and if the judgment A cannot be satisfied (NO), the satisfaction is obtained. It is possible to redesign the resin mold by reflecting the survey result so as to obtain the result, and to reflect the survey result when manufacturing the mold for mass production of the resin molded product. The formation position and the generation process of the weld line have been conventionally analyzed using advanced techniques such as various simulations, but the resin mold according to the present invention has a point of realizing a technique of confirmation with the naked eye. It can be said that this is an extremely innovative invention.

  In addition, when a resin raw material for mass production is melted and flows inside the resin mold using such a translucent resin mold, it is possible to observe with the naked eye that the molten resin cools. It is possible to easily specify the position of shrinkage (sink), the generation process, and the like when the process is performed. Then, when conducting the survey (P5) of the molded article shown in FIG. 1, whether or not the position and degree (amount) of the sink mark is appropriate is also added as a survey item, and if the judgment A cannot be satisfied (NO), It is possible to redesign the resin mold by reflecting the survey result so as to obtain a satisfactory result, and further reflect the survey result when manufacturing the mold for mass-producing the resin molded product.

  In addition, when a resin raw material for mass production is melted and flows inside the resin mold using such a translucent resin mold, the molten resin is It is possible to easily specify the presence or absence of a defect (filling defect) that does not extend to the entire inside of the mold, the generation process of the defect, and the like. Then, when the investigation (P5) of the molded product shown in FIG. 1 is performed, the presence or absence of the filling failure is added as a check item, and if the result of the determination A is not satisfied (NO), the result is satisfied (almost no filling failure). Therefore, the resin mold design can be redone by reflecting the results of the investigation so as to obtain the above. Further, it is possible to reflect the investigation result when manufacturing a mold for mass-production of resin-molded products and to refer to a process of generating a defective filling.

  In addition, it is possible to observe with a human eye how the resin raw material for mass production melts and flows inside the resin mold using such a translucent resin mold. It is possible to easily specify the presence or absence of discoloration (burn) and the generation process. When conducting the investigation (P5) of the molded article shown in FIG. 1, the presence or absence of burntness is also added as a surveyed item, and if the result of judgment A is not satisfied (NO), a satisfactory result (almost no burntness) is obtained. It is possible to redo the design of the resin mold, for example, by reflecting the survey results as obtained and making the outgassing good by referring to the burning generation process. Furthermore, when manufacturing a metal mold for mass production of resin molded products, it is possible to reflect the survey result and to refer to the burning generation process.

  In addition, when such a translucent resin mold is used, it is possible to observe with a naked eye how a resin raw material for mass production melts and flows inside the resin mold. Very useful for education of resin molding in the workplace. That is, it is possible to facilitate understanding of the resin molding technique by visualizing the flow condition of the molten resin.

  The resin raw material for mass production was a thermoplastic resin, and ABS resin was used. However, as the resin raw material for mass production, a thermoplastic resin such as polyethylene resin or polystyrene resin, or a thermosetting resin such as epoxy resin may be used.

  Further, the resin raw material for mass production is heated to 190 ° C. to 220 ° C. and melted and poured into the resin mold. However, this injection temperature can be set to a value suitable for molding a resin raw material for mass production. For example, when the resin raw material for mass production is ABS resin, it can be poured into the resin mold according to the embodiment of the present invention in a molten state by being heated to 180 ° C to 260 ° C. When the resin raw material for mass production is nylon or the like, it can be poured into the resin mold according to the embodiment of the present invention in a molten state by being heated to 85 ° C to 350 ° C.

  In addition, the resin raw material injected into the resin mold is cooled and solidified in the resin mold for 5 minutes with the upper mold and the lower mold closed. The cooling / solidifying time in the resin mold can be changed appropriately. However, in order to prevent the resin mold from being exposed to high temperature for an excessively long time and thus to prolong the life of the resin mold, the cooling / solidifying time in the resin mold is preferably 10 minutes or less. In consideration of molding stability, it is preferable that the cooling / solidifying time in the resin mold is 30 seconds or more. The cooling / solidifying time in the resin mold varies depending on the shape of the molded product.

  In the case of continuous molding using a resin material for mass production in a resin mold, after molding once, open the upper mold and the lower mold and maintain the state of cooling with air for 60 seconds and then perform the next molding. To do. This time can be changed appropriately. However, in order to appropriately cool the resin mold and prolong the life of the resin mold, the cooling / solidifying time in the resin mold is preferably 40 seconds or more. This time setting is about 20 to 30 seconds in the case of a mold.

  Further, in the embodiment of the present invention, the upper mold and the lower mold are opened and cooled by air, but cooling by air is not always necessary. For cooling, a so-called water pipe may be formed in one or both of the upper mold and the lower mold, and a liquid such as water may be circulated in the water pipe. In the case of a mold, it was difficult to arrange the water pipe along the molding part having a complicated shape. However, in a three-dimensional printing machine, it is very easy to form the water pipe so as to follow the shape of such a complicated molding portion, which is advantageous. For example, a resin mold printed by a three-dimensional printing machine can be designed such that 50% or more of the area of the resin mold in contact with the resin raw material is located within a distance of 1 cm from the water pipe.

  Further, when the judgment A in FIG. 1 is satisfied (YES), a mass production mold is produced based on the latest three-dimensional CAD data (P6). The meaning of "based on" the latest three-dimensional CAD data includes both using the same one as the latest three-dimensional CAD data and making corrections to the latest three-dimensional CAD data. For example, the arrangement data of the water pipe in the resin mold described above may be deleted from the arrangement data of the water pipe in the mold, and the arrangement data of another water pipe may be used.

  Further, the resin mold according to the embodiment of the present invention is made of only a photocurable resin. However, for the reason that the characteristics such as the thermal characteristics of the mold are approximated, a metal material such as a metal plate, a metal piece, and a metal powder, and / or a ceramic material such as a ceramic plate, a ceramic piece, and a ceramic powder is appropriately used as a resin. A resin type added may be used. By using a three-dimensional printing machine, it is easy to form a composite material type (resin type) containing such a resin by printing. For example, if the photocurable resin is printed on the surface of the metal plate so as to have a shape required for molding a thin resin raw material for mass production, the photocurable resin can be saved and the printing time can be shortened. By using a resin mold made of such a composite material of metal or ceramic and resin, the heat dissipation characteristics of the resin mold can be made closer to those of the mold, and therefore, the resin mold can be made to last longer, which is advantageous.

  Further, the resin mold according to the embodiment of the present invention is assumed to be for injection molding. However, the resin mold according to the embodiment of the present invention can be used for other molding such as blow molding, extrusion molding, cast molding, vacuum molding, powder molding and foam molding.

P1 Process for creating 3D CAD data of resin mold P2 Process for printing resin mold with 3D printing machine P3 Process for mounting resin mold on injection molding machine P4 Process for injection molding with resin raw material for mass production P5 Process for investigating molded product P6 Process of mold making with 3D CAD data of P1 A Judgment

Claims (1)

A method of manufacturing a metal mold for mass production of resin molded products,
A step of creating resin type three-dimensional CAD data (P1),
A step of molding the photocurable resin into the shape of the resin mold using a three-dimensional printing machine based on the created three-dimensional CAD data of the resin mold (P2),
Attaching the molded resin mold to an injection molding machine (P3),
A step of performing injection molding using the injection molding machine (P4),
A step of investigating a molded product obtained after performing the injection molding (P5),
A step of making a judgment (A) as to whether or not the result of the above-mentioned investigation is satisfactory,
If the above cannot be satisfied, the design of the resin mold is redone by reflecting the result of the above survey so that a satisfactory result can be obtained. Therefore, return to the step (P1) until the above (A) is satisfied. Repeat as needed,
When the condition (A) is satisfied, a process (P6) of manufacturing the mass-production mold is performed based on the latest three-dimensional CAD data created in the process (P1).
Manufacturing method of mold for mass production of resin molded products.