JP2004058538A - Molding mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a molding mold in which distances between a temperature control medium channel in an insert and respective regions of a cavity are almost equal to one another throughout the cavity. <P>SOLUTION: This molding mold comprises a first block 21 which has a molding surface 210 constituting a part of the inner surface of the cavity 3 and which is formed in such a manner that a thickness between the molding surface 210 and a surface 211 on the other side of the molding surface 210 is almost uniform in the respective regions, and a second block 22 which has a following surface 221 formed in a shape capable of being brought into close contact with the surface 211 of the first block 21. A groove 23 for the temperature control medium channel is formed in at least one of the surface 211 and the following surface 221 of the second block 22, and both the surfaces 211 and 221 are brought into close contact with each other and bonded together. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
According to the present invention, a molded product is obtained by putting a molten polymer into a cavity (molding space) formed by closing (mold closing) two or more mold bodies (eg, nests) and solidifying the cavity. For molds.
[0002]
[Prior art]
In the technique of obtaining a resin molded product by injection molding, in order to obtain a molded product having a good appearance in a short cycle time, repetitive control is performed in which a molding surface of a mold is heated and then cooled. That is, by heating the molding surface prior to the injection of the molten resin, good transferability is obtained, and by cooling immediately after the transfer, solidification is promoted, and the time until removal is shortened.
[0003]
[Problems to be solved by the invention]
In order to obtain a molded product without appearance defects (sink, warp, weld, etc.), when heating / cooling the mold molding surface to the target temperature, uniform heating / cooling so as not to generate a local temperature distribution It is necessary to.
In addition, in order to obtain a molded product in a short cycle time, it is necessary to heat / cool the mold molding surface sufficiently quickly.
[0004]
However, in the conventional mold, it has been difficult to perform heating / cooling of the mold forming surface sufficiently quickly so as not to generate a local temperature distribution.
The reason will be described with reference to FIG.
[0005]
FIG. 6A shows a longitudinal section of a main part of a conventional injection mold.
In the illustrated mold, after the molten resin is injected into the cavity 30 formed by the nests 10 and 20, cooling water is flowed through the temperature control medium channel 203 to cool the mold, and the molded product is taken out. As shown, the distance between the temperature control medium channel 203 and each part of the cavity 30 is T2 at the shortest part and T1 at the longest part. Because of such a large difference, the rate of temperature decrease during cooling varies from part to part, and as a result, it is difficult to cool the molding surface to a uniform temperature.
[0006]
Although cooling has been described above, substantially the same problem occurs during heating. For example, if heating is performed by flowing a heating medium through the temperature control medium channel 203, the same problem as described above occurs. In addition, if heating is performed by a heater or the like provided outside the nest (a template or the like) and the degree of heating is adjusted in relation to cooling, the problem described above regarding cooling is indirect. Will have an effect.
[0007]
In order to solve the above-mentioned problem, the temperature control medium flow path 203 is provided along the cavity 30, and the distance between the temperature control medium flow path 203 and each part of the cavity 30 is substantially equal in the entire area of the cavity 30. What is necessary is just to make it uniform.
However, in the conventional mold, the temperature control medium channel 203 cannot be provided along the cavity 30. The reason is that the temperature control medium channel 203 is formed by drilling the insert 20 with a drill. That is, since it is impossible to drill a hole in a non-linear shape with a drill, the hole cannot be drilled along a cavity having a complicated shape. Therefore, the temperature control medium flow path 203 is provided along the cavity 30. You cannot do it.
[0008]
The present invention provides a molding die in which the distance between the temperature control medium flow path and each part of the cavity is substantially the same over the entire area of the cavity by providing the temperature control medium flow path along the cavity. Aim.
Another object of the present invention is to provide a molding die in which the thermal distance (defined below) between the temperature control medium flow path and each part of the cavity is substantially the same over the entire area of the cavity.
[0009]
[Means for Solving the Problems]
The configuration of the present invention is described in the following [1] to [4].
[0010]
[1] First configuration:
The first configuration is described using the reference numerals in FIG. 1 for easy understanding, but this does not mean that the first configuration is limited to the configuration in FIG.
A molding die for obtaining a molded product by putting a molten polymer into a cavity (3) constituted by closing two or more mold bodies (1/2) and solidifying the cavity, and
At least one of the mold bodies (1/2) is
The cavity (3) has a molding surface (110/210) which forms a part of the inner surface, and the thickness (t) between the molding surface (110/210) and the opposite surface (111/211) is determined by each part. A first block (11/21) formed to be substantially uniform with
A second surface having a follow surface (121/221) formed in a shape following the opposite surface (111/211) so as to be able to adhere to the opposite surface (111/211) of the first block (11/21); Block (12/22),
And at least one of the opposite surface (111/211) of the first block (11/21) and the following surface (121/221) of the second block (12/22) has a temperature control medium flow path. After forming the groove (13/23), the both surfaces (the opposite surface (111/211) and the follow-up surface (121/221)) are closely adhered to each other.
A mold for molding, characterized in that:
[0011]
The number of molds constituting the cavity is usually two (eg, upper mold and lower mold, movable mold and fixed mold), but may be three or more depending on the desired molded product shape. The mold body is generally nested, but is not limited to nesting. When the molding surface is formed directly on the movable platen or the fixed platen-side template, the template corresponds to a mold body.
[0012]
Examples of the polymer include a thermoplastic resin, a thermosetting resin, a thermoplastic elastomer, a natural rubber, a synthetic rubber, and the like. In other words, any material that can be uniformly and quickly heated / cooled to obtain a good molded product can be mentioned as a target of molding using the mold of the present invention.
Examples of the thermoplastic resin include styrene resins (for example, polystyrene, butadiene / styrene copolymer, acrylonitrile / styrene copolymer, acrylonitrile / butadiene / styrene copolymer, etc.), ABS resin, AES resin, AAS resin , Polyethylene, polypropylene, ethylene-propylene resin, ethylene-ethyl acrylate resin, polyvinyl chloride, polyvinylidene chloride, polybutene, polycarbonate, polyacetal, polyphenylene oxide, polymethyl methacrylate, saturated polyester resin (for example, hydroxycarboxylic acid such as polylactic acid) Condensate, condensate of diol and dicarboxylic acid such as polybutylene succinate), polyamide resin, fluororesin, polysulfone, polyethersulfone, polyaryle DOO, polyetheretherketone, can be exemplified one or two or more thereof such as a liquid crystal polymer.
[0013]
The method of putting the molten polymer in the cavity is arbitrary. In other words, the molding method using the mold of the present invention is not particularly limited. The mold of the present invention can be used in various molding methods. For example, it can be used for injection molding, blow molding, compression molding, extrusion molding, vacuum molding, and the like.
[0014]
Examples of the temperature control medium include, for example, cooling water, but are not limited to cooling water. Cooling air, cooling gas, cooling oil or the like may be used. Further, the temperature control medium may be a heating medium such as heated air, heated steam, superheated steam, or hot water.
[0015]
[2] Second configuration:
The second configuration is described using reference numerals in FIGS. 1 and 2 for easy understanding, but this does not mean that the second configuration is limited to the configuration in FIG. 1 and the like.
In the above [1],
A groove (24) for a sealant is formed along the groove (23) for the temperature control medium flow path, and the first block (21) is formed after filling the groove (24) for the sealant with a liquid adhesive. ) Is adhered by closely contacting the opposite surface (211) of the second block (22) with the following surface (221) of the second block (22).
A mold for molding, characterized in that:
[0016]
Examples of the liquid adhesive include a liquid gasket, a two-component solventless synthetic rubber-based elastic adhesive, a cyanoacrylate instant adhesive, a one-component epoxy adhesive, a two-component epoxy adhesive, and a hot melt type. EAV saponified special resin adhesive, polyester hot melt adhesive, two-part modified silicone instant elastic adhesive, two-part modified acrylic adhesive, one-part heat-curable zirconia / silica inorganic adhesive, One-part heat-curable alumina-based inorganic adhesive, one-part heat-curable silica-based inorganic adhesive, solvent-free heat-curable epoxy-based adhesive, solvent-based epoxy-based adhesive, two-part curable urethane-based adhesive, One-part curable urethane adhesive, solvent-type urethane adhesive, heat-cured modified nylon-based adhesive, solvent-free one-part moisture-curable silyl group-containing special polymer adhesive, ultraviolet curable adhesive Adhesive, UV-curable heat-curable acrylic adhesive, UV-curable moisture-curable acrylic adhesive, UV-curable anaerobic curable acrylic adhesive, UV-curable primer-curable acrylic adhesive, silicone Damper agent (one-part curing silicone gel, two-part heat curing silicone gel, ultraviolet curing silicone gel), one-part solventless anaerobic sealing agent, one-part non-solvent UV curing anaerobic sealing agent, One-component synthetic rubber adhesives and the like can be mentioned.
The liquid gasket has a specific gravity of 1.00 to 2.50, for example, a one-component solvent type in which a main component is a modified alkyd resin, a cellulose ester resin, a synthetic rubber, or a metal colloid, and a main component is a fatty acid-modified phenol resin. , A one-part solventless type which is a modified ester resin, a one-part aqueous type where the main component is an aqueous acrylic resin, a one-part anaerobic type where the main component is an acrylic resin, and a silicone type Acetone), modified silicone-based (deacetone), silicone-based (deoxime) one-component solventless type, and the like.
[0017]
[3] Third configuration:
The third configuration is described using reference numerals in FIG. 5 for easy understanding, but this does not mean that the third configuration is limited to the configuration in FIG.
A resin molding die for obtaining a molded product by putting a molten resin into a cavity (7) formed by closing two or more mold bodies (5/6) and solidifying the cavity, and
At least one (6) of the mold bodies (5/6)
The cavity (7) has a molding surface (610) that forms a part of the inner surface, and the thermal thickness (t0, t1) between the molding surface (610) and the opposite surface (611) is substantially equal at each portion. A first block (61 (= 6101/6102)) formed so as to be uniform and the opposite surface (611) forms a flat surface;
A flat surface (621) is formed to follow the opposite surface (611) of the first block (61) so as to be in close contact with the opposite surface (611), and the following surface (621) is formed. A second block (62) in which a temperature control medium channel (630) is formed at a position at a certain depth from
And an opposite surface (611) of the first block (61) and a follow-up surface (621) of the second block (62) are closely bonded to each other.
A mold for molding, characterized in that:
[0018]
The expression that the thermal thickness is substantially uniform in each part means that the thermal conductivity in the thickness direction is substantially uniform in each part in the molding surface (in the opposite surface). For example, even if the distance between one surface and the other surface is different for each part, the amount of heat conducted per unit cross-sectional area and per unit time from one surface to the other surface is substantially equal in each part. In this case, it is defined that the thermal thickness of each part is substantially equal.
[0019]
[4] Fourth configuration:
The fourth configuration is described using reference numerals in FIGS. 1 and 5 for easy understanding, but this does not mean that the fourth configuration is limited to the configuration in FIG. 1 and the like.
In any one of the above [1] to [3],
The mold body (1/2/5/6) is nested;
A mold for molding, characterized in that:
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, with reference to the drawings, respective embodiments (first embodiment, modifications of the first embodiment, and second embodiments) in which the present invention is embodied as a mold for injection molding will be described. Will be described in order.
[0021]
(1) First embodiment (FIGS. 1 to 3):
The first embodiment corresponds to the configuration of [1].
FIG. 1 is a longitudinal sectional view schematically showing a main part (near the cavity 3) of the injection mold according to the first embodiment. FIG. 2 is a top view showing a second block 22 of the movable nest 2 in FIG. FIG. 3 is a cross-sectional view schematically showing the vicinity of an adhesive portion between the first block 21 and the second block 22 of the movable nest 2 (the groove 23 for the temperature control medium flow path and the groove 24 for the sealant). It is. In FIG. 1, runners, gates, and the like are not shown because they do not directly affect the gist of the present invention.
[0022]
As shown in the drawing, the mold of the first embodiment has a fixed nest 1 supported by a fixed-board-side template 100 and a movable nest 2 supported by a movable-board-side template 200. In addition, P is a mold dividing surface.
An electric heater (seed heater) 1001 is provided on the fixed platen side template 100 so as to surround the outer surface of the fixed nest 1. Similarly, an electric heater (seed heater) 2001 is provided on the movable platen-side template 200 so as to surround the outer surface of the movable nest 2.
[0023]
The movable nest 2 includes a first block 21 that forms a part of the molding surface of the cavity 3 and a second block 22 that is remote from the cavity 3.
[0024]
The first block 21 has a molding surface 210 that forms a part of the inner surface (molding surface) of the cavity 3. The first block 21 is formed such that the thickness t between the molding surface 210 and the opposite surface 211 opposite to the molding surface 210 is substantially uniform at each portion on the molding surface 210. This thickness t is, for example, about 1 to 30 mm.
[0025]
The rear of the second block 22 (the lower side in FIG. 1) is supported by the movable platen-side template 200. The front side (upper side in FIG. 1) of the second block 22 is the “following surface 221” described in the configuration of [1]. That is, it is a surface formed in a shape that follows the opposite surface 211 so that it can be in close contact with the opposite surface 211 of the first block 21. The shape of the following surface 221 is realized by aligning the following surface 221 with the opposite surface 211 of the first block 21 and performing electric discharge machining.
[0026]
At least one of the opposite surface 211 of the first block 21 and the follow-up surface 221 of the second block 22 has a groove for a temperature control medium flow channel and a groove for a liquid adhesive before the two surfaces are adhered to each other. (A groove for a sealant) is formed by cutting. In FIG. 2, a groove 23 for the temperature control medium flow path formed by cutting on the following surface 221 of the second block 22, and a liquid adhesive formed along both sides of the groove 23 for the temperature control medium flow path (Groove for sealant) 24 of FIG. As shown, the grooves 23 and 24 are cut and formed with a complicated curve so as to avoid the extrusion pin hole 25. Since the groove is cut on the exposed surface, such a complicated curve can be easily formed. Further, since the cutting process can be performed so as to avoid the extrusion pin hole 25, the extrusion pin hole 25 can be arranged at an optimum position. As shown in FIG. 3, these grooves 23 and 24 are configured as conduits by closely adhering the opposite surface 211 of the first block 21 and the following surface 221 of the second block 22. However, it is impossible to machine such a complicated curved pipe line by drilling. FIG. 6B shows an example in which the temperature control medium channel 203 cannot be processed linearly when the extrusion pin hole 205 is to be arranged at an optimum position.
[0027]
In the illustrated example, the opposite surface 211 of the first block 21 and the following surface 221 of the second block 22 are bonded by a liquid gasket applied and filled in a groove 24 having a sealing agent outflow preventing function. Alternatively, another adhesive may be used instead of the liquid gasket. After the bonding, the united member including the first block 21 and the second block 22 is horned as a single member, and further, processing for forming the insert 2 is performed. Thus, the nest 2 in which the temperature control medium flow path 23 is formed along the cavity 3 is obtained. That is, the nest 2 in which the distance between the temperature control medium flow path 23 and each part of the cavity 3 is substantially the same in the entire area of the cavity 3 is obtained.
Although the above description has been made with reference to the movable nest 2, the temperature control medium flow path 13 can be formed in the same manner for the fixed nest 1.
[0028]
(2) Modification of the first embodiment (FIG. 4):
FIG. 4 is a longitudinal sectional view schematically showing a main part (near the cavity 3) of an injection molding die modified from the first embodiment. In FIG. 4, "a" is added to the reference numeral of the corresponding member in FIG. 1 to indicate the correspondence relationship with each member of the mold in FIG.
[0029]
The mold of FIG. 4 is substantially the same as the mold of FIG. The difference between the mold of FIG. 4 and the mold of FIG. 1 is that the periphery of the first block 21a of the movable nest 2 is extended so as to project more than the mold of FIG. The point is that it is in contact with the plate 200 over a large area. When the second block 22a is made of iron (pre-hardened steel) and the first block 21a is made of beryllium copper, which is a material having a higher thermal conductivity than iron, the heat of the electric heater 2001 is quickly transferred to the molding surface 210a of the cavity 3. Therefore, good temperature control (rapid heating without local slowdown) can be performed not only at the time of cooling but also at the time of heating.
[0030]
(3) Second embodiment (FIG. 5):
The second embodiment corresponds to the configuration of the above [3].
FIG. 5 is a longitudinal sectional view schematically showing a main part (near the cavity 7) of the injection mold according to the second embodiment. In FIG. 5, the fixed nest is indicated by reference numeral “5”, and the movable nest is indicated by reference numeral “6”.
[0031]
In the mold of FIG. 5, the movable insert 6 is configured by joining a first block 61 and a second block 62. The first block 61 includes a plate material 6101 made of pre-hardened steel obtained by processing a forming surface 610 on the surface (the upper surface in FIG. 6), and an internal member 6102 made of beryllium copper sintered inside the plate material 6101. . The second block 62 is a member made of beryllium copper formed by drilling a pipe 630 for cooling water, and is embedded in the internal member 6102. The bent portion (right-angled portion) of the cooling water pipe 630 is formed by piercing two linear pipes so as to intersect with each other, and then closing an unnecessary portion.
[0032]
In the mold of FIG. 5, the distance between the cooling water pipe 630 and the molding surface 610 of the cavity 7 is t0 at the shortest part and t1 at the longest part, and the difference between the two is large. However, most of the long distance portion is made of beryllium copper having a high thermal conductivity, so that there is no significant difference in heat conduction from the short distance portion. In other words, the thermal thickness is substantially equal between the portion where the distance between the cooling water pipe 630 and the molding surface 610 of the cavity 7 is short and the portion where the distance is long. For this reason, the cooling effect of the cooling water can be made substantially equal at each part on the molding surface 610 of the cavity 7, and good cooling (quick cooling without a local slowdown) can be performed. Also, with respect to heating by the heater 2001, the peripheral portion of the first block 61 is extended so as to protrude greatly, and is in contact with the fixed platen-side template 200 over a large area. The heat can be quickly transmitted to the molding surface 610 of the cavity 7, and good heating (rapid heating without a local slowdown) can be performed.
[0033]
【The invention's effect】
In the configuration of the above [1], at least one of the mold bodies (eg, nests) has a molding surface that forms a part of the inner surface of the cavity, and the thickness between the molding surface and the opposite surface is substantially equal at each portion. A first block formed so as to be uniform, and a second block having a following surface formed in a shape following the opposite surface so as to be able to be in close contact with the opposite surface of the first block; Since the molding die is formed by forming a groove for the temperature control medium flow path on at least one of the opposite surface of the one block and the follow-up surface of the second block, and then adhering the two surfaces in close contact with each other, the temperature control medium flow path Can be provided along the cavity, and it is possible to provide a molding die in which the distance between the temperature control medium flow path and each part of the cavity is substantially the same throughout the cavity.
[0034]
In the configuration of [3], at least one of the mold bodies (for example, nests) has a molding surface forming a part of the inner surface of the cavity, and a thermal thickness between the molding surface and the opposite surface is different from each other. A first block formed so as to be substantially uniform and the opposite surface forming a flat surface, and a flat surface shape following the opposite surface so as to be able to be in close contact with the opposite surface of the first block. A second block in which a temperature control medium flow path is formed at a position at a certain depth from the following surface, and a surface opposite to the first block and a following surface of the second block are formed. Since the molding die is formed by closely contacting and joining, it is possible to provide a molding die in which the thermal distance between the temperature control medium flow path and each part of the cavity is substantially the same over the entire area of the cavity. it can.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view schematically showing a main part of an injection mold according to a first embodiment corresponding to the configuration [1]. The position of the cut surface is indicated by the line AA in FIG.
FIG. 2 is an explanatory view showing the second block 22 and the movable platen-side mold plate 200 of the movable nest 2 of the mold shown in FIG.
FIG. 3 is a cross-sectional view schematically showing a bonded portion between a first block 21 and a second block 22 of the movable nest 2; (A) is an example in which the groove 23 for the temperature control medium flow path and the groove 24 for the sealant are formed in both the first block 21 and the second block 22, and (b) is an example in which the groove 23 is formed only in the second block 22. Is shown.
FIG. 4 is a longitudinal sectional view schematically showing a main part of an injection molding die according to a modification of the first embodiment corresponding to the configuration [1].
FIG. 5 is a longitudinal sectional view schematically showing a main part of an injection molding die according to a second embodiment corresponding to the configuration [3].
FIG. 6 is an explanatory view showing problems of a conventional injection mold. (A) shows a problem caused by the positional relationship between the temperature control medium channel 203 and the cavity 30, and (b) shows a problem caused by the positional relationship between the temperature control medium channel 203 and the extrusion pin hole.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 fixed nest 2 movable nest 3 cavity 11 first block 12 of fixed nest 1 second block 13 of fixed nest 1 temperature control medium flow path 21 of fixed nest 1 first block 22 of movable nest 2 second block of movable nest 2 23 Temperature control medium flow path of movable nest 2 24 Sealing agent groove 25 formed in movable nest 2 Extrusion pin hole 100 provided in movable nest 2 Fixed platen side template 110 Molding surface 200 of fixed nest 1 Movable plate Side template 210 Molding surface 1001 of movable nest 2 Electric heater 2001 provided on fixed platen template 100 Electric heater provided on movable platen template 200

Claims (4)

A molding die for obtaining a molded product by putting a molten polymer in a cavity configured by closing two or more mold bodies and solidifying the molten polymer,
At least one of the mold bodies,
A first block having a molding surface that forms a part of the cavity inner surface, and formed so that the thickness between the molding surface and the opposite surface is substantially uniform at each portion;
A second block having a following surface formed in a shape following the opposite surface so as to be able to be in close contact with the opposite surface of the first block;
Having a groove for a temperature control medium flow path formed on at least one of an opposite surface of the first block and a follow-up surface of the second block, and both surfaces are adhered to each other,
A mold for molding, characterized in that: In claim 1,
A groove for a sealant is formed along the groove for the temperature control medium flow path, and after filling the groove for the sealant with a liquid adhesive, the opposite surface of the first block and the follow-up surface of the second block. The above-mentioned adhesion is performed by contacting
A mold for molding, characterized in that: A molding die for obtaining a molded product by putting a molten polymer in a cavity configured by closing two or more mold bodies and solidifying the molten polymer,
At least one of the mold bodies,
A molding surface forming a part of the cavity inner surface, such that the thermal thickness between the molding surface and the opposite surface is substantially uniform at each portion and the opposite surface forms a flat surface. A first block formed;
A flat surface that follows the opposite surface of the first block so as to be in close contact with the opposite surface of the first block, and a temperature control medium channel is formed at a position at a certain depth from the following surface. A second block;
Having an opposite surface of the first block and a following surface of the second block in close contact with each other,
A mold for molding, characterized in that: In any one of claims 1 to 3,
The mold body is nested;
A mold for molding, characterized in that:

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