JP2017019141A - Method for molding thick resin molded article, and thick resin molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for molding a thick resin molded article capable of shortening cooling time with a simple structure, and to provide a thick resin molded article.SOLUTION: A method for molding a thick resin molded article includes: projecting a plate-like member 13i (i=1,2, ..., n) from an inner surface 12a of a second mold piece 12 into a cavity W formed of first and second mold pieces 11 and 12, forming a first space portion W1 in the cavity W, injecting a molten resin 91 into the first space portion W1 in the state where the first space portion W1 is formed and then cooling the first space portion W1, retreating the plate-like member 13i (i=1,2, ..., n), forming a second space portion W2 in the cavity W, and injecting the molten resin 91 into the second space portion W2 in the state where the second space portion W2 is formed and then cooling the second space portion W2.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for molding a thick resin molded article such as a plastic lens and a thick resin molded article.

  In general, in the molding of a thick resin molded product, a long cooling time is required until the internal resin temperature reaches the mold temperature during injection molding. Therefore, for example, as in Patent Document 1, the thickness is sequentially increased from one surface side in the thick direction of the thick resin lens toward the other surface side, and finally reaches a specified thickness. There has been considered a method for molding a thick-walled resin lens in which the cooling time is shortened by using the movable mold and the fixed mold.

Japanese Patent Laying-Open No. 2006-62359 (FIG. 1)

  However, the molding method as described above requires a mold having a plurality of cavities with different lengths in the thickness direction of the molded product in order to shorten the cooling time, and thus the configuration is complicated. was there.

  The present invention has been made to solve the above-described problems, and provides a method for molding a thick resin molded product and a thick resin molded product that can reduce the cooling time with a simple configuration.

  In the molding method for a thick resin molded article according to the present invention, the first space is formed in the cavity by projecting the movable member from the inner surface of the mold in the cavity formed by the pair of molds. Then, the molten resin is injected into the first space portion and then cooled, and then the movable member is retracted to form the second space portion in the cavity, and then the molten resin is injected into the second space portion. After cooling.

  According to the present invention, the resin inside, which is difficult to dissipate heat, can be cooled by projecting the movable member into the cavity. For this reason, the cooling time can be shortened with a simple configuration.

It is side surface sectional drawing of the metal mold | die for shaping | molding of the thick-walled resin molded product in Embodiment 1 of this invention. It is a figure which shows the structure of the die piece used for shaping | molding of the thick resin molded product in Embodiment 1 of this invention. It is side surface sectional drawing explaining the shaping | molding method of the thick resin molded product in Embodiment 1 of this invention. It is a graph which shows the relationship between the thickness of a resin molded product, and mold slow cooling time. It is a figure which shows the model of the numerical simulation which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the die piece used for shaping | molding of the thick resin molded product in Embodiment 2 of this invention. It is side surface sectional drawing explaining the shaping | molding method of the thick resin molded product in Embodiment 2 of this invention. It is a figure which shows the structure of the die piece used for shaping | molding of the thick resin molded product in Embodiment 3 of this invention. It is a figure which shows the structure of the die piece used for shaping | molding of the thick resin molded product in Embodiment 4 of this invention. It is side surface sectional drawing explaining the shaping | molding method of the thick resin molded product in Embodiment 4 of this invention. It is a graph which shows the relationship between the thickness of a resin molded product, and mold slow cooling time when the temperature of one mold piece is made lower than the mold temperature. It is side surface sectional drawing of the metal mold | die for shaping | molding of the thick resin molded product in Embodiment 5 of this invention. It is a figure which shows the structure of the die piece used for shaping | molding of the thick resin molded product in Embodiment 5 of this invention. It is side surface sectional drawing explaining the shaping | molding method of the thick resin molded product in Embodiment 5 of this invention. It is side surface sectional drawing of the metal mold | die for shaping | molding of the thick resin molded product in Embodiment 6 of this invention. It is a figure which shows the structure of the die piece used for shaping | molding of the thick resin molded product in Embodiment 6 of this invention. It is side surface sectional drawing explaining the shaping | molding method of the thick resin molded product in Embodiment 6 of this invention.

Embodiment 1 FIG.
The first embodiment of the present invention will be described below with reference to FIGS. The molding die 10 used in the present embodiment is used for molding a thick resin molded product such as a thick or uneven plastic lens having an optical mirror surface on at least one surface. As shown in FIG. The first mold base 81 and the second mold base 82 are combined. A first mold piece 11 and a second mold piece 12, that is, a pair of molds, are assembled on the combination surfaces of the respective mold bases, and the first and second mold pieces 11, 12 are assembled. A cavity W having a thick portion with a thickness H is formed in the space surrounded by. The first mold piece 11 has a concave inner surface 11a and forms an optical mirror surface such as a plastic lens. The second mold piece 12 has a planar inner surface 12a and forms side surfaces and a bottom surface of a plastic lens or the like. Further, a protruding piece 13 is attached to the second mold piece 12 so as to be slidable in and out of the cavity. The first mold base 81 is provided with an injection port (not shown), and the molten resin injected from the injection port is injected into the cavity W through the sprue runner 14 and the gate 15 which are injection paths. Is done. The first and second mold bases 81 and 82 are provided with a temperature control device 161 and a thermocouple 171 for temperature measurement, respectively, and the temperature control is performed by the thermocouple 171 while external temperature control is performed. The temperature of the molding die 10 as a whole is controlled by controlling and heating / cooling the temperature adjusting device 161 with an apparatus (not shown). The first and second mold pieces 11 and 12 are also provided with a temperature control device 16 and a thermocouple 17, respectively. The first and second mold pieces 11 are the same as in the case of the entire mold described above. , 12 are controlled. The temperature control devices 16 and 161 are not particularly limited, and water temperature control, oil temperature control, a cartridge heater, or the like can be used.

  2A is a side cross-sectional view of the first and second mold pieces 11 and 12 in a state where the protruding piece 13 is retracted, and FIG. 2B is a cross-sectional view taken along line AA in FIG. It is sectional drawing. As shown in the figure, the protruding piece 13 is an n-plate member 13i (i = 1, 2,..., N) having a thickness s, that is, an assembly of movable members. They are arranged in a comb shape with an interval xi (i = 1, 2,..., N−1). When the protruding piece 13 is retracted, the surface 13a of each plate-like member is flush with the inner surface 12a of the second mold piece 12, and forms a part of the inner surface of the cavity W. Yes. Each of the plate-like members 13i (i = 1, 2,..., N) can slide in the cavity W, and the slidable range is set for each plate-like member. ing. Further, as the plate-like member 13i (i = 1, 2,..., N), for example, a member having good thermal conductivity such as copper can be used, but is not limited thereto.

  FIG. 2C is a side sectional view of the first and second mold pieces 11 and 12 in a state in which the protruding piece 13 is protruded from the inner surface 12 a of the second mold piece 12. The plate-like member 13i (i = 1, 2,..., N) has an interval yi (i = 1, 2,...) Between the surface 13a and the inner surface 11a of the first mold piece 11. n). In the first space W1 surrounded by the inner surface 11a of the first mold piece 11, the inner surface 12a of the second mold piece 12, and the protruding piece 13, the portion corresponding to the thick part of the cavity W is A thickness yi (i = 1, 2,..., N) surrounded by the inner surface 11a of the first mold piece 11 and the surface 13a of the plate-like member 13i (i = 1, 2,..., N). Formed between the thin-walled portion and the respective plate-like members 13i (i = 1, 2,..., N), and the respective thicknesses are spaced xi (i = 1, 2,..., N−1). It is divided into thin parts. For example, a toggle mechanism, a spring, or a cylinder of a molding machine can be used to project, hold, and retract the projecting piece 13. Further, here, the protruding piece 13 is structured to protrude from the same plane of the inner surface 12a of the second mold piece 12. However, the invention is not limited to this, and the protruding piece 13 is protruded into the cavity W. If there is, it may protrude from any direction.

  In the present embodiment, for each parameter, the thickness H of the thick portion of the thick resin molded product 100 is 20 mm, and the number of plate-like members 13 i (i = 1, 2,..., N) is n = 5. , The thickness s = 5 mm of each plate-like member 13i (i = 1, 2,..., N), and the distance xi between each plate-like member 13i (i = 1, 2,..., N) (I = 1, 2,..., N−1) = 5 mm (equal interval), the surface 13a of each plate member 13i (i = 1, 2,..., N) and the first mold piece 11 The distance yi (i = 1, 2,..., N) = 5 mm between the inner surface 11a and the inner surface 11a is not limited to this, and may be appropriately changed according to molding conditions.

Next, a method for molding a thick resin molded product in the present embodiment will be described.
First, as shown in FIG. 3A, the surface 13a of each plate member 13i (i = 1, 2,..., N) is flush with the inner surface 12a of the second mold piece 12. From the state, as shown in FIG. 3B, the distance between the surface 13a of the plate member 13i (i = 1, 2,..., N) and the inner surface 11a of the first mold piece 11 is yi (i = 1, 2,..., N), the respective plate-like members are protruded to form the first space portion W1.

  Next, for example, polycarbonate, polycycloolefin, etc. melted by an injection molding machine (not shown) while maintaining the state in which the respective plate-like members 13i (i = 1, 2,..., N) are projected. A molten resin 91 made of a thermoplastic resin such as polymethyl methacrylate is injected from an injection port (not shown) provided in the first mold base 81, and as shown in FIG. 3C, the sprue runner 14 and the gate. Through 15, the first space W <b> 1 is injected and filled.

  After filling the molten resin 91 into the first space W1, the temperature of the first and second mold pieces 11, 12 and the molding die 10 as a whole is kept constant by the temperature control devices 16, 161. The temperature of the molten resin 91 filled in the first space W1 is set and cooled from the melting temperature to the mold temperature. The molten resin 91 filled in the first space W1 is cooled from the outside by the first and second mold pieces 11 and 12, and the plate-like member 13i (i = 1, 2,..., N ) Is also cooled from the inside. As described above, in the first space portion W1, the thick portion has a thickness of yi (i = 1, 2,..., N) or xi (i = 1, 2,..., N 1), the molten resin 91 is also cooled in the state of the thin portion.

  After the molten resin 91 filled in the first space W1 is uniformly cooled to the mold temperature, as shown in FIG. 3 (d), each plate member 13i (i = 1, 2,..., N ), The plate-like members 13i (i = 1, 2,..., N) are gradually retracted until the surface 13a is flush with the inner surface 12a of the second mold piece 12. The second space W2 is formed between the molten resin 91 and the cooled molten resin 91. The second space portion W2 is composed of n plate-like thin portions having a thickness s.

  Next, with the second space W2 formed, molten resin 91 is injected from an injection port (not shown) provided in the first mold base 81 while applying pressure by an injection molding machine (not shown). Then, after the molten resin 91 is injected and filled into the second space W2 through the sprue runner 14 and the gate 15 as shown in FIG. 3E, the molten resin 91 filled in the second space W2 is filled. Cool from melting temperature to mold temperature. As described above, since the second space W2 is composed of n plate-shaped thin portions having a thickness s, the molten resin 91 is cooled in a thin portion having a thickness s. .

After the molten resin 91 filled in the second space W2 is uniformly cooled to the mold temperature, the molding die 10 is opened, and the thickness of the thick part is as shown in FIG. The thick resin molded product 100 which is H is taken out.
As described above, in the present embodiment, the cooling of the molten resin 91 in the thick part of the cavity W is performed using the thick part xi (i = 1, 2,..., N−1), yi. (I = 1, 2,..., N), s (each of which is 5 mm as described above in paragraph 0012). For this reason, the cooling time of the molten resin 91 is equivalent to the case of cooling the thin portion having a thickness of 5 mm twice.

  FIG. 4 shows a mold slow cooling time (time required for cooling the resin from the melting temperature to the mold time) required for molding a rectangular-shaped resin molded product 1001 having a thickness h as shown in FIG. It is a graph which shows the result of having calculated | required by numerical simulation. In this numerical simulation, a rectangular parallelepiped cavity having a thickness h formed by a pair of molds 811 and 821 is filled with molten resin, and the molten resin is cooled from the outside by both molds 811 and 821. In this numerical simulation, the melting temperature is set to 250 ° C., and the mold temperatures of the mold 811 and the mold 821 are set to 105 ° C. In addition, heat transfer works only in the y direction, and heat transfer in the x direction is ignored. As shown in FIG. 4, when h = 20 mm, the mold slow cooling time is 1300 s, whereas when the h = 5 mm cooling is performed twice, the mold slow cooling time is 170 s (= 85 s × 2). Thus, it can be seen that the molding method of the thick-walled resin molded product in the present embodiment shortens the cooling time of the molten resin.

  According to the present embodiment, in the state in which the plate-like member of the protruding piece protrudes into the cavity to form the first space portion, the molten resin is injected into the first space portion and then cooled, so that heat dissipation is performed. Difficult resin interior can be cooled. For this reason, the cooling time can be shortened with a simple configuration.

  In addition, by arranging a plurality of plate-like members at intervals, the contact area with the molten resin is increased and the cooling efficiency is increased, so that the cooling time can be further shortened.

  Moreover, by making the protruding piece into a plate shape, the contact area with the molten resin is increased, and the cooling efficiency can be further increased.

  Moreover, since the molten resin is uniformly and gradually cooled to the mold temperature, a thick resin molded product with less distortion and excellent surface accuracy can be obtained.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described with reference to FIGS. Note that the same or corresponding parts as in FIGS. 1 to 3 are denoted by the same reference numerals, and description thereof is omitted.
This embodiment is different from the first embodiment in that the second mold piece 12 includes a communication path forming piece 18, that is, a protruding member, as shown in FIG. 6A is a side cross-sectional view of the first and second mold pieces 11 and 12 in a state where the protruding piece 13 and the communication path forming piece 18 are retracted, and FIG. It is BB sectional drawing of (a). The communication path forming piece 18 is slidable inward and outward of the cavity W, and its width extends from the gate 15 to a plate-like member 131 which is a plate-like member farthest from the gate 15. Further, when the protruding piece 13 is retracted, the communication path forming piece 18 is also retracted, and its surface 18a is on the same plane as the inner surface 12a of the second mold piece 12, and the cavity W A part of the inner surface is formed.

  6C is a side sectional view of the first and second mold pieces 11 and 12 in a state where the protruding piece 13 and the communication path forming piece 18 are protruded from the inner surface 12a of the second mold piece 12. FIG. It is. Each plate-like member 13i (i = 1, 2,..., N) has a distance yi (i = 1, 2,...) Between the surface 13a and the inner surface 11a of the first mold piece 11.・, N) is held in a state. Further, the communication path forming piece 18 is held in a state where the distance between the surface 18 a and the inner surface 12 a of the second mold piece 12 is z and blocks a part of the gate 15. In the first space W1 surrounded by the inner surface 11a of the first mold piece 11, the inner surface 12a of the second mold piece 12, the protruding piece 13 and the communication path forming piece 18, the thick portion of the cavity W Is a thickness yi (i = 1, 2, 1) surrounded by the inner surface 11a of the first mold piece 11 and the surface 13a of the plate-like member 13i (i = 1, 2,..., N). , N) are formed between the thin-walled portion and the respective plate-like members 13i (i = 1, 2,..., N), and the respective thicknesses are separated by an interval xi (i = 1, 2,. -It divides | segments into the thin part equal to n-1). The distance z between the surface 18a of the communication path forming piece 18 and the inner surface 12a of the second mold piece 12 can be set to z = 5 mm, for example. In addition, as with the protruding piece 13, a toggle mechanism, a spring, and a cylinder of the molding machine can be used for protruding, holding, and retracting the communication path forming piece 18.

Next, a method for molding a thick resin molded product in the present embodiment will be described.
First, as shown in FIG. 7A, the surface 13a of each plate-like member 13i (i = 1, 2,..., N) and the surface 18a of the communication path forming piece 18 are formed on the second mold piece 12. From the state of being on the same plane as the inner surface 12a, the surface 13a of the plate-like member 13i (i = 1, 2,..., N) and the first mold piece 11 as shown in FIG. Each plate-like member is projected until the distance from the inner surface 11a becomes yi (i = 1, 2,..., N), and the surface 18a of the communication path forming piece 18 and the second mold piece 12 The communication path forming piece 18 is protruded until the distance from the inner surface 12a becomes z, thereby forming the first space portion W1. At this time, the communication path forming piece 18 blocks a part of the gate 15.

  Next, each of the plate-like members 13i (i = 1, 2,..., N) and the communication path forming piece 18 are maintained in a protruding state, while being melted by an injection molding machine (not shown). A molten resin 91 made of a plastic resin is injected from an injection port (not shown) provided in the first mold base 81 and passes through the sprue runner 14 and the gate 15 as shown in FIG. Fill and fill the part W1.

  After filling the molten resin 91 into the first space W1, the temperature of the first and second mold pieces 11, 12 and the molding die 10 as a whole is kept constant by the temperature control devices 16, 161. The temperature of the molten resin 91 filled in the first space W1 is set and cooled from the melting temperature to the mold temperature. The molten resin 91 filled in the first space portion W1 is cooled from both the outside and the inside as in the first embodiment.

  After the molten resin 91 filled in the first space W1 is uniformly cooled to the mold temperature, as shown in FIG. 7D, each plate-like member 13i (i = 1, 2,..., N ) And the surface 18a of the communication path forming piece 18 are on the same plane as the inner surface 12a of the second mold piece 12, and the respective plate-like members 13i (i = 1, 2,..., N) The communication path forming piece 18 is gradually retracted to form a second space W2 between the surface 13a of the plate-like member 13i (i = 1, 2,..., N) and the cooled molten resin 91. In addition, a communication path W3 is formed between the surface 18a of the communication path forming piece 18 and the cooled molten resin 91. The second space portion W2 is composed of n plate-like thin portions having a thickness s. The communication path W3 has a height of z and communicates the gate 15 and the second space W2.

  Next, in a state where the second space portion W2 and the communication passage W3 are formed, melting is performed from an injection port (not shown) provided in the first mold base 81 while applying pressure by an injection molding machine (not shown). After injecting resin 91 and injecting and filling molten resin 91 into second space W2 and communication path W3 as shown in FIG. 7 (e) through sprue runner 14 and gate 15, second space W2 And the molten resin 91 with which the communicating path W3 was filled is cooled. Since the subsequent steps are the same as those in the first embodiment, the description thereof is omitted.

  According to the present embodiment, the same effect as in the first embodiment can be obtained.

  In addition, when the molten resin is filled into the second space portion, a communication path that connects the molten resin injection path and the second space portion is formed, so that the molten resin can be easily injected into the second space portion. become.

Embodiment 3 FIG.
Next, Embodiment 3 of the present invention will be described with reference to FIG. 2 that are the same as or equivalent to those in FIG.
What is this embodiment? The protruding piece is different from the first and second embodiments. FIG. 8A is a side sectional view of the first and second mold pieces 11 and 12 in a state in which the protruding piece 23 is retracted, and FIG. 8B is a cross-sectional view taken along line C- in FIG. It is C sectional drawing. As shown in the figure, the protruding piece 23 has m × n cylindrical protruding pins 23ij (i = 1, 2,... N, j = 1, 2,. ), That is, an assembly of movable members, and each protruding pin has a distance xi (i = 1, 2,... N-1) and wj (j = 1, 2,. And arranged in a grid. The intervals xi (i = 1, 2,... N-1) and wj (j = 1, 2,... M-1) can be set to 5 mm, for example. When the protruding piece 23 is retracted, the surface 23a of each protruding pin is flush with the inner surface 12a of the second mold piece 12 and forms part of the inner surface of the cavity W. . The protruding pins 23ij (i = 1, 2,... N, j = 1, 2, .. m) can be slid in and out of the cavity W, and the slidable ranges are respectively It is set for each protruding pin. For the protruding pins 23ij (i = 1, 2,... N, j = 1, 2, .. m), for example, a member having good thermal conductivity such as copper can be used. It is not a thing. Further, here, cylindrical pins are used as the protruding pins 23ij (i = 1, 2,... N, j = 1, 2, .. m). Can be used.

  Since the other configuration and the molding method of the thick resin molded product are the same as those in the first embodiment, the description thereof is omitted.

  According to the present embodiment, the same effect as in the first embodiment can be obtained.

  Further, by forming the protruding piece as an assembly of a plurality of protruding pins, the contact area between the molten resin and the protruding piece is increased and the cooling efficiency is increased, so that the cooling time can be further shortened.

Embodiment 4 FIG.
Next, a fourth embodiment of the present invention will be described with reference to FIGS. Note that the same or corresponding parts as those in FIG. 1 to FIG.
This embodiment is different from the first embodiment in the plate member of the protruding piece. FIG. 9A is a side cross-sectional view of the first and second mold pieces 11 and 12 in a state in which the protruding piece 33 is retracted, and FIG. 9B is a portion D of FIG. 9A. FIG. As shown in the figure, the protruding piece 33 is an n-plate member 33i (i = 1, 2,..., N) having a thickness s, that is, an assembly of movable members. They are arranged in a comb shape with an interval xi (i = 1, 2,..., N−1). Each of the plate-like members 33i (i = 1, 2,..., N) includes a cooling pipe 33b inside, and by flowing water or the like through the cooling pipe 33b, It is possible to set the temperature to a constant temperature. In addition, temperature control of each plate-shaped member is performed by an external temperature control device (not shown). When the protruding piece 33 is retracted, the surface 33a of each plate-like member is flush with the inner surface 12a of the second mold piece 12, and forms part of the inner surface of the cavity W. Yes. Each of the plate-like members 33i (i = 1, 2,..., N) is slidable in and out of the cavity W, and the slidable range is set for each plate-like member. ing. Further, for the plate-like member 33i (i = 1, 2,..., N), for example, a member having good thermal conductivity such as copper can be used, but is not limited thereto.

Next, a method for molding a thick resin molded product in the present embodiment will be described.
First, as shown in FIG. 10A, the surface 33a of each plate-like member 33i (i = 1, 2,..., N) is on the same plane as the inner surface 12a of the second mold piece 12. From the state, as shown in FIG. 10B, the distance between the surface 33a of the plate-like member 33i (i = 1, 2,..., N) and the inner surface 11a of the first mold piece 11 is yi (i = 1, 2,..., N), the respective plate-like members are protruded to form the first space portion W1.

  Next, a molten resin made of a thermoplastic resin melted by an injection molding machine (not shown) while maintaining the state in which the respective plate-like members 33i (i = 1, 2,..., N) are projected. 91 is injected from an injection port (not shown) provided in the first mold base 81, and is injected and filled into the first space W1 through the sprue runner 14 and the gate 15 as shown in FIG. 10C. To do.

  After filling the molten resin 91 into the first space W1, the temperature of the first and second mold pieces 11, 12 and the molding die 10 as a whole is kept constant by the temperature control devices 16, 161. In addition to setting, the temperature of the plate member 33i (i = 1, 2,..., N) is set to a temperature lower than the mold temperature, and the temperature of the molten resin 91 filled in the first space W1. Is cooled from the melting temperature to the mold temperature. The molten resin 91 filled in the first space portion W1 is cooled from both the outside and the inside as in the first embodiment.

  After the molten resin 91 filled in the first space portion W1 is uniformly cooled to the mold temperature, as shown in FIG. 10D, each plate-like member 33i (i = 1, 2,..., N ) Until the surface 33a is flush with the inner surface 12a of the second mold piece 12, the respective plate-like members 33i (i = 1, 2,..., N) are gradually retracted, and the surface 33a The second space W2 is formed between the molten resin 91 and the cooled molten resin 91. The second space portion W2 is composed of n plate-like thin portions having a thickness s.

  Next, in a state where the second space W2 is formed, the molten resin 91 is poured from an injection port (not shown) provided in the first mold base 81 while applying pressure by an injection molding machine (not shown). After injecting, through the sprue runner 14 and the gate 15, the molten resin 91 is injected and filled into the second space W2 as shown in FIG. 10E, and then the molten resin 91 filled in the second space W2. Is cooled from the melting temperature to the mold temperature. Since the subsequent steps are the same as those of the first embodiment, the description thereof is omitted.

  FIG. 11 shows the result of numerical simulation corresponding to this embodiment added to the graph of FIG. In the figure, the dotted line graph is the same as the graph of FIG. 4 described in paragraph 0019, and corresponds to the first embodiment. The solid line graph corresponds to the present embodiment. Of the molds 811 and 821 for cooling the molten resin, the temperature of the mold 821 is set to a temperature (80 ° C.) lower than the mold temperature (105 ° C.). Yes. Other conditions are the same as in FIG. As shown in FIG. 11, the solid line graph shows that the mold slow cooling time is 63 s when h = 5 mm, and therefore the mold slow cooling time in the case of this embodiment is 126 s (= 63 s × It is understood that the cooling time is further shortened compared to the case of the first embodiment (170 s).

  According to the present embodiment, the same effect as in the first embodiment can be obtained.

  Further, the cooling pipe is provided inside the plate member of the protruding piece, and the temperature of the plate member is set lower than the mold temperature, so that the cooling time can be further shortened.

Embodiment 5. FIG.
Next, a fifth embodiment of the present invention will be described with reference to FIGS. Note that the same or corresponding parts as in FIGS. 1 to 3 are denoted by the same reference numerals, and description thereof is omitted.
The mold base 81 of the molding die 50 includes a temperature control device 261 and a thermocouple 271 around the sprue runner 14 as shown in FIG. Moreover, the 1st metal mold | die piece 11 is equipped with the temperature control apparatus 26 and the thermocouple 27 around the sprue runner and the gate 15, as shown in FIG. The temperature control devices 26 and 261 are for heating the sprue runner 14 and the gate 15 which are injection paths of the molten resin, and measure the temperature by thermocouples 27 and 271 respectively, while external temperature control devices (illustrated). None). The temperature control devices 26 and 261 are not particularly limited, and water temperature control, oil temperature control, a cartridge heater, or the like can be used.
Since other configurations are the same as those of the first embodiment, description thereof is omitted.

Next, a method for molding a thick resin molded product in the present embodiment will be described.
First, as shown in FIG. 14A, the surface 13a of each plate member 13i (i = 1, 2,..., N) is flush with the inner surface 12a of the second mold piece 12. From the state, as shown in FIG. 14B, the distance between the surface 13a of the plate-like member 13i (i = 1, 2,..., N) and the inner surface 11a of the first mold piece 11 is yi (i = 1, 2,..., N), the respective plate-like members are protruded to form the first space portion W1.

  Next, a molten resin made of a thermoplastic resin melted by an injection molding machine (not shown) while maintaining the state in which the respective plate-like members 13i (i = 1, 2,..., N) are projected. 91 is injected from an injection port (not shown) provided in the first mold base 81, and is injected and filled into the first space W1 through the sprue runner 14 and the gate 15 as shown in FIG. 14 (c). To do.

  After the molten resin 91 is filled in the first space W1, the temperature of the first and second mold pieces 11, 12 and the molding die 50 as a whole is kept constant by the temperature control devices 16, 161. The temperature of the molten resin 91 filled in the first space W1 is set and cooled from the melting temperature to the mold temperature. The molten resin 91 filled in the first space W1 is composed of an outer surface in contact with the first and second mold pieces 11, 12 and the respective plate-like members 13i (i = 1, 2,..., N). It is cooled from the inside that touches. The molten resin 91 filled in the first space portion W1 is cooled from both the outside and the inside as in the first embodiment.

  At the same time as the molten resin 91 filled in the first space portion W1 is uniformly cooled to the mold temperature, the resin filled in the sprue runner and the gate 15 is heated and remelted by the temperature control devices 26 and 261. 14D, until the surface 13a of each plate member 13i (i = 1, 2,..., N) is flush with the inner surface 12a of the second mold piece 12. Each plate-like member 13i (i = 1, 2,..., N) is gradually retracted to form a second space W2 between the surface 13a and the cooled molten resin 91. The second space portion W2 is composed of n plate-like thin portions having a thickness s.

  In the state where the second space W2 is formed, molten resin 91 is injected from an injection port (not shown) provided in the first mold base 81 while applying pressure by an injection molding machine (not shown). After the molten resin 91 is injected and filled into the second space W2 through the runner 14 and the gate 15 as shown in FIG. 14E, the molten resin 91 filled in the second space W2 is removed from the melting temperature. Cool to mold temperature. Since the subsequent steps are the same as those of the first embodiment, the description thereof is omitted.

  According to the present embodiment, the same effect as in the first embodiment can be obtained.

  In addition, when the molten resin is filled in the second space portion, the pressure required to fill the molten resin into the second space portion is reduced by remelting the resin in the injection path in advance. The radiant power of the injection molding machine can be suppressed.

Embodiment 6 FIG.
Next, a sixth embodiment of the present invention will be described with reference to FIG. 15 and FIG. Note that the same or corresponding parts as in FIGS. 1 to 3 are denoted by the same reference numerals, and description thereof is omitted. As shown in FIG. 15, the molding die 60 includes a hot runner 19 between the first die base 81 and the first die piece 11, and the first die piece 11 includes two sprue pieces. Runners 14 and 24 and gates 15 and 25, that is, two molten resin injection paths are provided. Further, the second mold piece 12 includes a communication path forming piece 28, that is, a protruding member. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

FIG. 16A is a side cross-sectional view of the first and second mold pieces 11 and 12 and the hot runner 19 in a state where the protruding piece 13 and the communication path forming piece 28 are retracted, and FIG. ) Is an EE cross-sectional view of FIG. One end of the hot runner 19 is connected to an inlet (not shown) provided in the first mold base 81, and the other end of the primary sprue 19a is provided on the other end of the primary sprue 19a. A runner 19b extending to both sides and two secondary sprues 19c1 and 19c2 respectively extending from both ends of the runner 19b are provided. The two secondary sprues 19c1 and 19c2 are connected to the sprue runners 14 and 24 via open / close gates 19d1 and 19d2 having an open / close function, respectively. The two sprue runners 14 and 24 are connected to the gates 15 and 25, respectively. Connected to the cavity W. Around the primary sprue 19a, the runner 19b and the two secondary sprues 19c1, 19c2, a temperature control device 36 for heating them and a thermocouple 37 for temperature measurement are provided to melt the resin in the hot runner 19 It is possible to keep it in a state. The hot runner 19 can control the injection of the molten resin by the open / close gates 19d1 and 19d2.
The communication path forming piece 18 can slide in and out of the cavity W, and its width extends from the plate member 131 to the plate member 13n. Further, when the protruding piece 13 is retracted, the communication path forming piece 28 is also retracted, and its surface 28 a is on the same plane as the inner surface 12 a of the second mold piece 12, and the cavity W A part of the inner surface is formed.

  FIG. 16C is a side sectional view of the first and second mold pieces 11 and 12 in a state in which the protruding piece 13 and the communication path forming piece 28 are protruded from the inner surface 12a of the second mold piece 12. It is. Each plate-like member 13i (i = 1, 2,..., N) has a distance yi (i = 1, 2,...) Between the surface 13a and the inner surface 11a of the first mold piece 11.・, N) is held in a state. Further, the communication path forming piece 28 is held in a state where the distance between the surface 28 a and the inner surface 12 a of the second mold piece 12 is z, and closes the gate 25. In the first space W1 formed in the space surrounded by the inner surface 11a of the first mold piece 11, the inner surface 12a of the second mold piece 12, the protruding piece 13 and the communication path forming piece 28, the cavity The portion corresponding to the thick portion of W is the thickness yi (i) surrounded by the inner surface 11a of the first mold piece 11 and the surface 13a of the plate-like member 13i (i = 1, 2,..., N). = 1, 2,..., N) and the respective plate-like members 13i (i = 1, 2,..., N), each having a thickness xi (i = It is divided into thin portions equal to 1, 2,..., N-1).

Next, a method for molding a thick resin molded product in the present embodiment will be described.
First, as shown in FIG. 17A, the surface 13a of each plate-like member 13i (i = 1, 2,..., N) and the surface 28a of the communication path forming piece 28 are formed on the second mold piece 12. From the state of being on the same plane as the inner surface 12a, as shown in FIG. 17B, the surface 13a of the plate-like member 13i (i = 1, 2,..., N) and the first mold piece 11 Each plate-like member is projected until the distance from the inner surface 11a becomes yi (i = 1, 2,..., N), and the surface 28a of the communication path forming piece 28 and the second mold piece 12 are The communication path forming piece 28 is projected until the distance from the inner surface 12a becomes z, thereby forming the first space portion W1. At this time, the communication path forming piece 28 closes the gate 25. The open / close gate 19d1 of the hot runner 19 is opened and the open / close gate 19d2 is closed.

  Next, each of the plate-like members 13i (i = 1, 2,..., N) and the communication path forming piece 28 are maintained in a protruding state, while being melted by an injection molding machine (not shown). A molten resin 91 made of a plastic resin is injected into the molding die 60 from an injection port (not shown) provided in the first mold base 81. The injected molten resin 91 is injected and filled into the primary sprue 19a, the runner 19b, and the secondary sprues 19c1 and 19c2, and as shown in FIG. The first space W1 is injected and filled through the gate 15. At this time, since the open / close gate 19d2 is in a closed state, the molten resin 91 does not flow into the sprue runner 24 and the gate 25 from the secondary sprue 19c2. In addition, since the gate 25 is blocked by the communication path forming piece 28, the molten resin 91 that has flowed from the gate 15 into the first space W1 does not enter the gate 25.

  After filling the molten resin 91 into the first space W1, the temperature of the first and second mold pieces 11, 12 and the molding die 60 as a whole is kept constant by the temperature control devices 16, 161. The temperature of the molten resin 91 filled in the first space W1 is set and cooled from the melting temperature to the mold temperature. The molten resin 91 filled in the first space portion W1 is cooled from both the outside and the inside as in the first embodiment. The molten resin 91 filled in the hot runner 19 is kept in a molten state while the molten resin 91 filled in the first space W1 is cooled by the temperature control device 36.

  After the molten resin 91 filled in the first space portion W1 is uniformly cooled to the mold temperature, as shown in FIG. 17 (d), each plate-like member 13i (i = 1, 2,..., N ) And the surface 28a of the communication path forming piece 28 are in the same plane as the inner surface 12a of the second mold piece 12, and the respective plate-like members 13i (i = 1, 2,..., N) The communication path forming piece 28 is gradually retracted to form a second space W2 between the surface 13a of the plate-like member 13i (i = 1, 2,..., N) and the cooled molten resin 91. At the same time, a communication path W3 is formed between the surface 28a of the communication path forming piece 28 and the cooled molten resin 91. At the same time when the second space W2 and the communication path W3 are formed, the open / close gate 19d1 is closed and the open / close gate 19d2 is opened. The second space portion W2 is composed of n plate-like thin portions having a thickness s. The communication path W3 has a height z and communicates the gate 25 and the second space W2.

  By injecting the molten resin 91 from an injection port (not shown) provided in the first mold base 81 by an injection molding machine (not shown) with the second space W2 and the communication path W3 formed. The molten resin 91 is injected from the secondary sprue 19c2 through the open / close gate 19d2 and through the sprue runner 24 and the gate 25 into the second space W2 and the communication passage W3 as shown in FIG. 17 (e). After filling, the molten resin 91 filled in the second space W2 and the communication path W3 is cooled. Since the subsequent steps are the same as those in the first embodiment, the description thereof is omitted.

  According to the present embodiment, the same effect as in the first embodiment can be obtained.

  Further, the molding die has two injection paths for the molten resin into the cavity, and the second space is obtained by using different injection paths for filling the first and second space portions with the molten resin. It is easy to fill the part with the molten resin, and the cooling time can be further shortened.

  Similarly to the second embodiment, when the molten resin is filled in the second space, a communication path that connects the molten resin injection path and the second space is formed. It becomes easier to inject the molten resin into the resin.

100, thick resin molded product 10, 50, 60 Mold for molding, 11 First mold piece, 11a inner surface, 12 Second mold piece, 12a Inner surface, 13, 23, 33 Projecting piece, 131 -135, 331-335 Plate member, 2311-2355 Columnar member, 33b Cooling pipe, 14, 24 Sprue runner, 15, 25 Gate, 18, 28 Communication path forming piece, 91 Molten resin, W cavity, W1 No. 1 space part, W2 2nd space part, W3 communicating path.

Claims (10)

  In a state where a movable member protrudes from the inner surface of the mold in the cavity formed by a pair of molds and the first space portion is formed in the cavity, molten resin is added to the first space portion. Cooling after injecting, and then cooling after injecting molten resin into the second space in a state where the movable member is retracted to form the second space in the cavity. Molding method for thick resin molded products.   The method for molding a thick resin molded product according to claim 1, wherein a plurality of the movable members are arranged at intervals.   The method for molding a thick-walled resin molded product according to claim 1, wherein the movable member has a plate shape.   The method for molding a thick-walled resin molded product according to claim 1, wherein the movable member has a columnar shape. The method for molding a thick-walled resin molded product according to any one of claims 1 to 4, wherein the movable member has a cooling pipe therein.   The method for molding a thick-walled resin molded article according to any one of claims 1 to 5, wherein the molten resin is injected into the first and second space portions using the same injection path.   The method for molding a thick-walled resin molded article according to claim 6, wherein when the molten resin is injected into the second space, the resin filled in the injection path is heated.   The mold includes a plurality of injection paths leading to the cavity, and injection of molten resin into the first and second space portions is performed using different injection paths. 5. A method for molding a thick resin molded article according to any one of 5 above.   When the molten resin is filled in the first space portion, a protruding member is protruded from the inner surface of the mold to close a part of the injection path to the second space portion, and the first space portion After the molten resin filled in is cooled, the projecting member is retracted together with the movable member to form a communication path that connects the injection path to the second space and the second space. The method for molding a thick resin molded article according to any one of claims 1 to 8.   A thick resin molded article molded by the method for molding a thick resin molded article according to any one of claims 1 to 9.

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