JP2003251661A - Apparatus for manufacturing porous body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately manufacture a porous body with a plurality of fine holes. <P>SOLUTION: In an apparatus for manufacturing the porous body provided with a movable mold 3 forming a cavity C between it and a fixed mold 2, a group 10 of molding pins which freely slidably passes through the movable mold 3 and the apex parts of which forwards into the cavity C and a hydraulic cylinder 6, a gate 13 for injecting a molding material R into the cavity C is provided at a position facing the periphery of the group 10 of the molding pins. The hydraulic cylinder 6 controls movement of the movable mold 3 in such a way that the molding material is filled into the cavity C under a condition where the apex parts of the group 10 of the molding pins are retreated from the cavity C and thereafter, the apex parts of the group 10 of the molding pins are pushed into the molding material R under a plasticized condition in the cavity C and the movable mold 3 moving in the direction separated from the fixed mold 2 in accordance with pushing of the group 10 of the molding pins is moved while a pressure is applied on the molding material in the cavity C. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a porous body manufacturing apparatus, and more particularly to a manufacturing apparatus suitable for manufacturing a porous body in which a plurality of pores are arranged at high density. . Conventionally, a molded product (hereinafter referred to as "porous body") in which a plurality of pores are formed has been widely used for collimators, filters and the like. When molding these porous bodies by injection molding, if the molding pin for forming the pores has a minute diameter of about 0.5 to 1 mm, the filling pressure of the molding material and the shrinkage when the molding material solidifies The forming pin sometimes falls or deforms due to the force. This means
This is because the pressure distribution of the molding material in the cavity is not uniform. Also, when molding a porous body in which a large number of pores are arranged at high density at narrow intervals,
A large number of molding pins must be arranged at a narrow interval in the cavity. However, if the space between the molding pins is narrow, the molding material is difficult to enter between the molding pins, so that the molding material is insufficiently filled between the molding pins. When the molding pin falls or deforms, or when the molding material becomes insufficiently filled between the molding pins,
Naturally, there arises a problem that the pores of the porous body cannot be formed with high accuracy. In order to solve the above-mentioned problems, Japanese Patent Laid-Open No. Hei 4
-261802 discloses a core pin for molding pores in a molded body molding space (cavity) in a state where both ends thereof are fixedly supported by a fixed mold and a movable mold, and
A slide insert that concentrically holds the core pin is arranged so as to be movable, and when the molding material is injected into the cavity, the slide insert is held by the filling pressure of the molding material while holding the core pin with the slide insert. A method of retreating to form a molded body having pores is disclosed. In this prior art, when a molding material is injected into a cavity, the core pin is held by a slide insert so as to prevent the core pin from being deformed by a filling pressure of the molding material. In this prior art, the slide material is retracted by the filling pressure of the molding material so that the molding material can be filled into the cavity with a uniform density. Japanese Patent Laid-Open No. 7-241881 discloses that a porous body is formed by inserting a molding pin group consisting of a plurality of pins into a molding material while the molding material injected into the cavity is in a plastic state. A method of forming is disclosed. Also, when inserting the molding pin group into the molding material,
A method is disclosed in which the movable mold wall is moved to expand the molding space (cavity) by an amount corresponding to the volume of the molding pin group inserted in the molding material. This prior art is intended to solve the lack of flow of molding material in the vicinity of each molding pin by inserting a group of molding pins into a molding material in a plastic state. In addition, when inserting the molding pin group into the molding material, it is possible to prevent damage to the pin due to the pressure rise in the cavity by enlarging the cavity by an amount corresponding to the volume of the molding pin group inserted into the molding material. Yes. Japanese Patent Application Laid-Open No. 11-216885 discloses an introduction guide provided so as to seal all the outlets of one of the through holes (pores of the molded body), and a molding pin for molding the through holes. A method is disclosed in which a molding material is used, a molding material is injected into the die in a direction parallel to the axis of the molding pin, and an introduction guide portion of the resulting molded body is removed after molding. In this prior art, a molding material introduction guide portion is provided in a molding die, and a molding material gate is provided in the introduction guide portion, so that the flow of the molding material in a direction perpendicular to the axis of the molding pin is parallel. In other words, the molding material can be filled uniformly and sufficiently in a state of good fluidity in the gap between adjacent molding pins. However, in the method disclosed in the above-mentioned Japanese Patent Laid-Open No. 4-261802, the core pin is fixedly supported in the cavity between the fixed mold and the movable mold. Therefore, there is a problem that the structure of the molding die becomes complicated. In this method, when the thickness of the molded product is small, it is difficult to arrange the gate for injecting the molding material in the axial direction of the molding pin because of the structure of the molding die. It will be filled from directions other than an axial direction. Therefore, there is a problem that the molding pin falls or deforms due to the filling pressure of the molding material. Furthermore, in this prior art, only the case of molding a molded body having one pore is mentioned, but when this method is applied to a molded body having a large number of pores, the molding material is used for each molding pin. Therefore, if the space between the molding pins is narrow, the molding material is difficult to enter, and the molding material is insufficiently filled between the molding pins. Further, according to the method disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 7-241881, it is said that the shortage of flow of the molding material in the vicinity of each molding pin can be solved, but if the space between the molding pins is narrow The problem that the molding material is difficult to enter and the molding material is insufficiently filled between the molding pins has not been solved. In addition, when inserting the molding pin group into the molding material, it is possible to prevent the breakage of the pin due to the pressure increase in the cavity by enlarging the cavity by an amount corresponding to the volume of the molding pin group inserted into the molding material. However, since the cavity is enlarged by the volume corresponding to the volume of the molding pin group to be inserted into the molding material, when the tip of the molding pin group is inserted into the molding material in the plastic state, the molding in the plastic state is accordingly performed. There is a tendency for the material to flow around the molding pin group without entering between the molding pins.
As a result, a filling failure of the molding material may occur between the molding pins, or the molding pins may fall down or bend due to the flow pressure of the molding material. Further, the above-mentioned Japanese Patent Laid-Open No. 11-216885.
In the method disclosed in Japanese Patent Publication No.
It can be changed to flow in a direction parallel to the molding pin, and it is said that the molding material can be filled uniformly and sufficiently in a state of good fluidity in the gap between adjacent molding pins. If the width is narrow, the molding material is difficult to enter, and the problem of insufficient filling of the molding material between the molding pins has not been solved. In addition, since the molding material easily enters the portion without the molding pin between the molding pins, the molding material is filled in the cavity first from the portion without the molding pin. Therefore, the pressure distribution of the molding material filled in the cavity is not uniform, and there is a problem that the molding pin falls down or deforms due to the difference in the pressure distribution. In the method disclosed in Japanese Patent Laid-Open No. 7-241881, the gate 20 is disposed at a position facing the tip of the molding pin group 21 as shown in FIG. Since the molding material R is injected in the vicinity of the gate 20, the temperature is higher than that of the other parts in the cavity C. Therefore, after the filling of the molding material R into the cavity C is completed, as shown in FIG. 9B, the molding material R in the vicinity of the gate flows or shrinks toward the gate 20, and the molding pin 21 in the vicinity of the gate. There was a problem of falling or deforming. In view of the above, the present invention eliminates the problem of the molding pins falling or deforming due to the pressure difference or temperature difference of the molding material in the cavity without complicating the structure of the molding die, and the molding material between the molding pins. It is an object of the present invention to provide a porous body manufacturing method capable of preventing insufficient filling and forming pores of the porous body with high accuracy, and a mold apparatus used in the manufacturing method. In order to solve the above-mentioned problems, the present invention provides a porous body manufacturing apparatus for manufacturing a porous body having a plurality of pores formed in parallel to each other by injection molding. And a movable mold that forms a cavity between the fixed mold and the fixed mold, and the distal end portion of the movable mold or the fixed mold is slidably penetrated to enter the cavity. A group of molding pins that advance parallel to each other, an injection device that fills the cavity with the molding material in a state in which a tip portion of the molding pin group is retracted from the cavity, and after injection of the molding material by the injection device, A molding pin driving device that pushes the tip of the molding pin group into the molding material in the plastic state in the cavity, and a moving mold that moves in a direction away from the fixed mold in response to the pressing of the molding pin group, Previous A brake mechanism for controlling movement of the movable mold so as to move while applying pressure to the molding material in the cavity, and a gate for injecting the molding material into the cavity faces around the molding pin group It is characterized by being provided at a location. With this configuration, first, the molding material is filled into the cavity by the injection device with the tip of the molding pin group retracted from the cavity, so that each molding pin is injected with the molding material. It does not fall down or deform due to the flow. Then, a molding pin group is formed by applying a pressure necessary to cause the molding pin to flow in the molding pin axial direction with respect to the molding material by the movable mold after the molding material is filled in the cavity by the molding pin driving device. Since the tip portion of the resin is pushed into the molding material in the plastic state, the molding material flows along the axial direction of the molding pin. Therefore, the molding material does not fall or deform, and the molding material can be filled between the molding pins while keeping the molding pins parallel to each other. Further, when the molding pin group is pushed in, the pressure of the molding material rises by the amount of the molding pin group entering, and the moving mold is pushed by the molding material and moves (retreats) away from the fixed mold. However, in the apparatus of the present invention, the moving mold is controlled to move backward while applying pressure to the molding material in the cavity by the moving mold by the brake mechanism, so that the molding material can be sufficiently filled between the molding pins. it can. Further, by providing a gate for injecting the molding material into the cavity at a location facing the periphery of the molding pin group, the molding material filled in the cavity is solidified as compared with other parts in the cavity. Even if it flows or shrinks toward the vicinity of the gate having a high temperature, since there is no molding pin in the vicinity of the gate, it is possible to prevent the molding pin from falling or deforming due to the flow or shrinkage of the molding material. Note that the fact that the tip of the molding pin group is retracted from the cavity does not mean that the tip of the molding pin group should not enter the cavity, depending on the thickness of the molding pin. It may be slightly inside the cavity. That is, as long as each molding pin does not fall down due to the flow of the molding material to be injected, the tip portion of the molding pin group may enter the cavity. DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of a mold apparatus used in the porous body manufacturing apparatus of the present invention. FIG. 2 is an enlarged view of the periphery of the fixed mold and the movable mold in FIG. FIG. 3 is an enlarged view around the cavity in FIGS. In FIG. 3, the guide pins shown in FIGS. 1 and 2 are not shown, and the molding material is solidified in the cavity. As shown in FIG. 1, the mold apparatus 1 includes a fixed mold 2 and a movable mold 3.
Is further provided with a core 4 that forms a cavity C (see FIGS. 2 and 3) corresponding to the porous body M (see FIG. 8) with the fixed mold 2. The fixed mold 2 is attached to the fixed-side mounting plate 5, and in order to inject molten resin as a molding material into the cavity C, as shown in an enlarged view in FIG. Runners 12 and gates 13 are formed. Of the cavity surface of the fixed mold 2, the molding pin group 10 is formed so that the gate 13 does not face the tip of the molding pin group 10.
It is provided in the place which faces the circumference (right side in the figure). The fixed mold 2 is configured so that the upper part 2a and the lower part 2b can be separated. As shown in FIG. 1, the moving mold 3 includes a receiving plate 7.
The pressure distribution of the molding material R in the cavity C is made uniform by the driving force provided from the hydraulic cylinder 6. A pressure can be applied to the molding material R filled in the cavity C. Also,
The moving mold 3 moves backward in the direction away from the fixed mold 2 in accordance with the filling pressure of the molding material R filled in the cavity C shown in FIG. 3 by controlling the hydraulic pressure of the hydraulic cylinders 6 and 6. It is also possible to do. The hydraulic cylinder 6
Corresponds to a “brake mechanism”. In addition, the brake mechanism is formed by a hydraulic cylinder 6 to form a molding material R in the cavity C.
It is not limited to those that generate a drag force, but may be a brake that uses friction or a spring that generates a drag force. A pin holder 9 slidable with respect to the moving mold 3 is attached to the moving side mounting plate 8 as shown in an enlarged view in FIG. And the front-end | tip part 9a of the pin holder 9
3, a plurality of parallel forming pins (forming pin group 10) for forming a plurality of pores H (see FIG. 8) of the porous body M are fixed as shown in FIG. Yes.
Each molding pin of the molding pin group 10 is slidably penetrated through the core 4 which is a part of the movable mold 3, and a tip portion 10 a thereof is provided facing the cavity C. Further, the tip 9 a of the pin holder 9 moves to the cavity C when the moving mold 3 moves in a direction approaching or separating from the fixed mold 2 and when the forming pin group 10 slides with respect to the core 4.
A guide pin 11 is provided so as to guide the movement of the core 4 and the forming pin group 10 when moving inward. The guide pin 11 penetrates the core 4 in a slidable manner. The pin holder 9 is supported on the moving side mounting plate 8 via a hydraulic cylinder 15 which is a forming pin driving device. That is, by driving the hydraulic cylinder 15, the pin holder 9 approaches and separates from the stationary mold 2, so that the molding pin group 10 fixed to the tip end portion 9 a of the pin holder 9 can advance and retreat into the cavity C. It is possible. The mold apparatus 1 is used by being attached to an injection molding machine (injection apparatus) (not shown), and the operation of injection and the operation of the hydraulic cylinders 6, 6 and 15 are controlled by a control apparatus (not shown). A porous body manufacturing apparatus is configured. Next, the mold apparatus 1 constructed as described above.
The operation of the (porous body manufacturing apparatus) will be described with reference to FIGS. First, as shown in FIG.
The core 4 is moved closer to the fixed mold 2 by driving, and a space (cavity C) having the same capacity as the amount of the molding material used for the porous body after molding is formed between the fixed mold 2 and the movable mold 3. The forming pin group 10 is retracted from the cavity C by driving the hydraulic cylinder 15 so that the tip 10b (see FIG. 3) of each forming pin is flush with the cavity surface of the core 4. To do. Next, as shown in FIG. 5, the molding material R is injected from the gate 13 by the injection device, and the cavity C is filled with the molding material R. After the cavity C is filled with the molding material R, the tip portion 10a of the molding pin group 10 is plasticized by the hydraulic cylinder 15 while applying pressure to the molding material R with the moving mold 3, as shown in FIG. It pushes into the molding material R of a state. At this time, the movement of the pin holder 9 is guided by the guide pin 11 provided at the tip end portion 9a of the pin holder 9 being slidably penetrating the core 4, so that the forming pin group 10
Can be reliably slid with respect to the core 4. Since the molding material R enters between the molding pins from the tip portion 10a of the molding pin group 10 along the axial direction of the molding pin group 10, the molding material R is formed around the tip portion 10a of the molding pin.
The pressure is uniform and each molding pin does not fall down or deform. At this time, since the volume of the cavity C is increased by the volume of the molding pin group 10 entering the molding material R, the pressure of the molding material R rises and the core 4 and the movable mold 3 are increased. Moves in a direction away from the fixed mold 2. The hydraulic cylinder 6 generates a resistance against the movement of the core 4 and the moving mold 3, so that pressure is applied to the molding material R through the cavity surface of the core 4. Due to this pressure, the molding material R enters the narrow gaps between the molding pins, so that the molding material R is sufficiently filled. Further, since the molding material R is sequentially filled between the molding pins with this pressure, the molding pin group 10 is kept in a state where the pressure between the space between the molding pins and the outside of the molding pin group 10 is always kept uniform. Since it is pushed into the molding material R, each molding pin does not fall down or deform. As a result, the pores of the porous body can be formed in parallel with each other. When the tip 10b of the molding pin reaches the cavity surface of the fixed mold 2, the pressurized state is maintained while applying pressure to the molding material R by the moving mold 3 (core 4).
The molding material R is cooled and solidified with the pressure of the molding material R in the cavity C made as uniform as possible. The cooling at this time can be performed by passing a cooling medium through the mold apparatus 1. At this time, as shown in FIG. 3, the gate 13 is formed around the molding pin group 10 on the cavity surface of the fixed mold 2 so as not to face the tip portion 10 a of the molding pin group 10. Even if the molding material R filled in the cavity C flows or contracts toward the vicinity of the gate 13 having a higher temperature than the other parts in the cavity C, the vicinity of the gate 13 is provided. Since there is no molding pin group 10 in the part, the molding pin can be prevented from falling or deforming due to the flow of the molding material R. When the molding material R is solidified, as shown in FIG. 7, after the upper part 2a of the fixed mold 2 is separated from the lower part 2b, the movable mold 3 is fixed by the driving force of the hydraulic cylinders 6 and 6. The molded product M is moved forward in a direction approaching the lower part 2a of the mold 2 so that the molded product M protrudes from the cavity C and is released from the mold. Then, the molded product manufactured by the mold apparatus 1 is cut from the gate, and the surface formed by the fixed mold 2 is machined to open each pore H. As shown in FIG. 9, a porous body M in which a plurality of pores H are formed in parallel to each other can be obtained. As described above, according to the porous body manufacturing apparatus of the present embodiment, it is possible to manufacture a porous body in which pores are arranged at high density and have pores that are deeper than the diameter. . For example, such a porous body has a thickness of about 5 mm and a diameter of 0.5 m.
About 1,000 pores H of about m are arranged in high density in a staggered pattern and penetrated in the thickness direction, and the interval between the pores H is an extremely narrow interval of about 0.2 mm. Yes. This porous body M is excellent in the straightness and parallelism of each pore H. For example, when the light parallel to each pore H is irradiated from one side of the porous body M and received on the other side, the incident light quantity The ratio R (= O / I) of the emitted light quantity O to I is 0.8 or more. Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and can be implemented with appropriate modifications. For example, the gate for injecting the molding material R is not limited to the illustrated part, but the moving mold 3,
You may provide in the lower part 2b of the fixed metal mold | die 2. FIG. Further, in the embodiment, the molding pin group 10 is provided slidably with the movable mold 3. However, the molding pin group 10 is slidably provided with respect to the fixed mold 2, and the molding pin group is pushed from the cavity surface of the fixed mold 2. , Molding material R
It is also possible to form pores. Further, in the embodiment, the case where the tip 10b of the molding pin group 10 is brought into contact with the cavity surface of the fixed mold 2 is exemplified, but the tip 10b of the molding pin group 10 is not brought into contact with the cavity surface,
It is also possible to stop at the position inside the molding material R and form a large number of pores having a bottom in the molded body. Furthermore, by changing the cross-sectional shape and arrangement of the forming pins, the pores of the porous body are not limited to a circular cross section, but may be a polygon such as a quadrangle or a hexagon, and the arrangement thereof is also arbitrary. Can be manufactured. As described in detail above, according to the present invention, the molding pin collapses due to the pressure difference or temperature difference of the molding material in the cavity without complicating the structure of the molding die. Alternatively, deformation and insufficient filling of the molding material between the molding pins can be prevented, and as a result, the pores of the porous body can be accurately formed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a mold apparatus used in a porous body production apparatus of the present invention. FIG. 2 is an enlarged view of the periphery of a fixed mold and a moving mold in FIG. 3 is an enlarged view around the cavity in FIGS. 1 and 2. FIG. FIG. 4 is a cross-sectional view of a mold apparatus, showing a state before a molding material is filled into a cavity. FIG. 5 is a cross-sectional view of a mold apparatus showing a state in which a molding material is filled in a cavity. FIG. 6 is a cross-sectional view of a mold apparatus, showing a state in which a tip portion of a molding pin group is pushed into a molding material. FIG. 7 is a cross-sectional view of a mold apparatus, showing a state in which a movable mold is moved in a direction approaching a fixed mold and a molded product is protruded from a cavity and released. FIG. 8 is a perspective view showing a porous body manufactured by a mold apparatus. FIG. 9 is a view for explaining the flow of a molding material when a conventional gate is disposed above a molding pin group;
Indicates the state in which the molding material is filled in the cavity,
(B) shows a state in which the molding material flows toward the molding pin. [Description of Symbols] 1 Mold device 2 Fixed mold 3 Moving mold 4 Core 5 Fixed side mounting plate 6 Hydraulic cylinder 7 Receiving plate 8 Moving side mounting plate 9 Pin holder 10 Forming pin group 10a Tip portion 11 Guide pin 12 Runner 13 Gate 15 Hydraulic cylinder C Cavity R Molding material M Porous body

Continued front page    (72) Inventor Masanori Ishiguro             2-1-12 Ogimachi, Odawara-shi, Kanagawa Prefecture             Shishi Photo Film Co., Ltd. F-term (reference) 4F202 AG18 AG20 AH03 CA11 CB01                       CK18 CK52

Claims (1)

What is claimed is: 1. A porous body manufacturing apparatus for manufacturing a porous body having a plurality of pores formed in parallel to each other by injection molding, comprising: a fixed mold; and A movable mold that forms a cavity between them, a group of molding pins that are parallel to each other so that the tip portion advances into the cavity by slidably penetrating the movable mold or the fixed mold, and the molding An injection device that fills the cavity with a molding material in a state in which a tip portion of the pin group is retracted from the cavity, and the molding of the molding material in the plastic state in the cavity after the injection of the molding material by the injection device A molding pin driving device that pushes the tip of the pin group, and a moving mold that moves away from the fixed mold in response to the pressing of the molding pin group, move while applying pressure to the molding material in the cavity. And a brake mechanism for controlling the movement of the movable mold, and a gate for injecting the molding material into the cavity is provided at a location facing the periphery of the molding pin group. .