JP6928819B2 - A method for manufacturing a molded product using an injection molding die device and an injection molding die device. - Google Patents

Description

The present invention relates to an injection molding die apparatus and a method for manufacturing a molded product using the injection molding die apparatus. More specifically, the present invention comprises an injection molding die apparatus provided with a hot mold raw material resin flow path connected to a mold cavity via a gate, and an injection molded article using the injection molding die apparatus. Regarding the manufacturing method of.

One of the technologies that has supported Japan's "manufacturing" industry is molding technology using molds. Examples of such molding techniques include a pressure molding method, an injection molding method, and an extrusion molding method. Among these molding methods, the injection molding method is a method of obtaining a molded product from a raw material resin by using an injection molding mold device.

Specifically, in the injection molding method, a molded product is manufactured through the following steps. (1) A step of supplying a raw material resin to a raw material resin flow path composed of (i) a sprue or (ii) a sprue and a runner and connected to a mold cavity via a gate.
(2) A step of continuously supplying the raw material resin and filling / holding the raw material resin in the mold cavity.
(3) A step of cooling the raw material resin in the mold cavity.

Here, the final molded product is usually obtained from the raw material resin located in the mold cavity. Therefore, the resin portion obtained by cooling the raw material resin located in the raw material resin flow path composed of (i) sprue or (ii) sprue and runner does not directly contribute as a component of the final molded product. Therefore, from the viewpoint of efficient use of the raw material resin, the hot mold raw material resin connected to the mold cavity via the gate in order to maintain the molten state without cooling the raw material resin located in the raw material resin flow path. A flow path may be used (see Patent Document 1). Patent Document 1 indicates that a temperature control medium path is provided along the axis of the raw material resin flow path. By providing the temperature control medium path, the raw material resin flow path can be maintained at a high temperature, whereby the raw material resin flow path can function as a hot type raw material resin flow path.

Japanese Unexamined Patent Publication No. 2002-210795

Here, the inventors of the present application have newly found that the following problems may occur when the temperature control medium path is provided along the axis of the hot-type raw material resin flow path.

Specifically, as described above, the hot-type raw material resin flow path can maintain the molten state without cooling the raw material resin located in the flow path. Further, the hot mold raw material resin flow path is connected to the mold cavity via a gate. Therefore, when the molten state of the raw material resin in the hot mold raw material resin flow path is maintained, the heat of the molten raw material resin is transferred from the hot mold raw material resin flow path side to the injection molding mold side, especially near the gate of the injection molding mold. There is a risk that it will be transmitted to the side. Therefore, when the process of cooling the raw material resin in the mold cavity is carried out, the raw material resin located in a local portion in the mold cavity near the gate due to heat transfer to the vicinity side of the gate of the injection molding mold. However, there is a risk that the temperature will be higher than that of the raw material resin located in other parts of the mold cavity. As a result, the raw material resin located in the local portion in the mold cavity near the gate is relatively difficult to cool as compared with the raw material resin located in the other portion in the mold cavity, and as a result, the raw material resin is finally located. As a whole, there is a risk that a high-precision molded product cannot be preferably obtained.

The present invention has been made in view of such circumstances. That is, an object of the present invention is to use an injection molding die apparatus and an injection molding die apparatus capable of suitably obtaining a high-precision molded product as a whole even when a hot mold raw material resin flow path is used. It is to provide a method for manufacturing a molded product.

In order to achieve the above object, in one embodiment of the present invention,
It is a mold device for injection molding.
Equipped with a hot mold resin flow path connected to the mold cavity via a gate
Provided is an injection molding die apparatus having a heat transfer control unit at least in the immediate vicinity of the gate.

In order to achieve the above object, in one embodiment of the present invention,
A method for manufacturing an injection-molded product using an injection-molding die device.
The injection molding die apparatus comprises a hot mold raw material resin flow path connected to a mold cavity via a gate, and has a heat transfer control unit at least in the immediate vicinity of the gate.
A method is provided in which a molten raw material resin is provided into the mold cavity through the hot mold raw material resin flow path.

According to one embodiment of the present invention, it is possible to preferably obtain a high-precision molded product as a whole even when a hot-type raw material resin flow path is used.

A cross-sectional view schematically showing an injection molding die apparatus according to an embodiment of the present invention. A cross-sectional view schematically showing an injection molding die apparatus according to another embodiment of the present invention. A cross-sectional view schematically showing an injection molding die apparatus according to still another embodiment of the present invention. A cross-sectional view schematically showing an injection molding die apparatus according to still another embodiment of the present invention. A cross-sectional view schematically showing an injection molding die apparatus according to still another embodiment of the present invention. A cross-sectional view schematically showing an injection molding die apparatus according to still another embodiment of the present invention. A cross-sectional view schematically showing a process mode of stereolithography composite processing in which the powder sintering lamination method is carried out (FIG. 7 (a): at the time of forming a powder layer, FIG. 7 (b): at the time of forming a solidified layer, FIG. 7 ( c): During lamination)

Hereinafter, the injection molding die apparatus according to the embodiment of the present invention will be described with reference to the drawings. The forms and dimensions of the various elements in the drawings are merely examples and do not reflect the actual forms and dimensions.

(Technical Idea of the Present Invention)
First, prior to the description of the injection molding die apparatus according to the embodiment of the present invention, the technical idea of the present invention will be described.

The inventors of the present application have diligently studied technical measures to enable a highly accurate molded product to be suitably obtained even when a hot-type raw material resin flow path is used. More specifically, the raw material resin located in the local portion in the mold cavity near the gate due to the heat transfer of the molten raw material resin from the hot mold raw material resin flow path side to the side near the gate of the injection molding mold. Measures to prevent the condition where it is relatively difficult to cool compared to the raw material resin located in other parts were enthusiastically studied.

Therefore, in order to realize such a deterrent measure, the inventors of the present application stated that "at least the heat transfer control unit capable of controlling heat transfer to the nearest region 100A of the gate G as compared with other regions 100B other than the nearest region 100A of the gate G". We have newly found the technical idea of "providing 20" (see Fig. 1).

The "closest region 100A of the gate G" referred to in the present specification is a predetermined injection molding mold closest to the gate G located at the boundary between the mold cavity 30 and the hot mold raw material resin flow path 10. Refers to an area. The “hot-type raw material resin flow path 10” as used herein refers to a heat-held raw material resin flow path in a broad sense, and refers only to a heat-held sprue or a heat-held sprue and a runner in a narrow sense. .. The “heat transfer control unit 20” as used herein refers to a region in which heat transfer can be controlled by an injection molding die.

According to this technical idea, due to the presence of the heat transfer control unit 20 in the region 100A near the gate, the injection molding mold 100 is connected to the mold cavity 30 via the gate G from the hot mold raw material resin flow path 10 side. Controls heat transfer of the molten raw material resin R in the hot-type raw material resin flow path 10 (particularly, the molten raw material resin R _{1 in the hot-type raw material resin flow path 10 located near the gate G) toward the gate G nearest region 100A.} It becomes possible to do. The heat transfer control of the heat transfer control unit 20, the heat of the gate G immediate vicinity region 100A of the injection mold 100 due to the melting heat of the molten starting resin R ₁ in the vicinity of the gate G of the hot feedstock resin passage 10 It is possible to suitably suppress and control the residual. Thus, it is possible to suppress the heat transfer from the gate G immediate vicinity region 100A of the injection mold 100 into the molten material resin R ₃ is located in the mold cavity 30 located in the vicinity the gate G.

Further, the molten raw material resin R ₃ located in the region near the gate G in the mold cavity 30 is located in another region in the mold cavity 30 due to the proximal arrangement of the hot mold raw material resin flow path 10. likely to become hotter than the molten starting resin R _4. Therefore, in the filling and holding step of the molten raw material resin in the mold cavity, the heat _{of the molten raw material resin R 3} in a higher temperature state located in the local portion 31 near the gate G in the mold cavity 30 remains. obtain. Regarding this point, when the heat transfer control unit 20 is present in the region 100A near the gate, the molten raw material resin R located in the local portion 31 near the gate G in the mold cavity 30 is controlled by the heat transfer control unit 20. It is possible to preferably suppress and control the transfer of the thermal energy in the high temperature state of No. _{3 to the region 100A in the immediate vicinity of the gate G.} Further, when the gate immediate vicinity region 100A heat transfer control unit 20 in the presence, by heat transfer control of the heat transfer unit controller 20, the molten material resin R ₃ is located in the local part 31 of the gate G near the mold cavity 30 Heat residue in high temperature conditions can be suppressed. Thus, the thermal residual high temperature of the molten material resin R ₃ is located in the local part 31 of the gate G near the mold cavity 30 it is possible to suppress to continue.

_{From the above, the molten raw material resin R 3} located in the local portion 31 near the gate G in the mold cavity 30 becomes hotter than the _{molten raw material resin R 4} located in the other portion in the mold cavity 30. It becomes possible to deter that.

As a result, in the cooling step of the molten raw material resin in the mold cavity 30, the molten raw material resin R ₃ located in the local portion 31 near the gate G in the mold cavity 30 and the other portion in the mold cavity 30 It becomes possible to carry out cooling of the molten raw material resin R _{4 located at substantially the same cooling rate.} That is, in the cooling step of the molten raw material resin R in the mold cavity 30, the molten raw material resin R ₃ located near the gate G in the mold cavity 30 is located in another portion in the mold cavity 30. it is possible to suitably suppress the than R ₄ hardly cooled. Therefore, it is finally possible to preferably obtain a high-precision molded product as a whole.

(Structure of mold device for injection molding)
Hereinafter, the configuration of the injection molding die device 200 according to the embodiment of the present invention will be described (see FIG. 1).

The injection molding die device 200 according to an embodiment of the present invention is for providing a molten raw material resin in an injection molding die 100 (consisting of a core side and a cavity side) and an injection molding die 100. It refers to a material including a hot-type sprue member 50 having a hot-type raw material resin flow path 10 (corresponding to sprue) inside. In one embodiment, the hot mold sprue member 50 is in contact with the injection molding mold 100 so that the hot mold raw material resin flow path 10 is directly connected to the gate G. The hot type sprue member 50 usually has a shape in which the diameter of the tip 50A gradually decreases. That is, the contact portion between the tip 50A of the hot die sprue member 50 and the injection molding die 100 may have an inclined surface (see FIG. 1), more specifically, a stepped surface. The configuration of the hot mold sprue member 50 is not limited to the configuration in which the hot mold raw material resin flow path 10 is in contact with the injection molding mold 100 so as to be directly connected to the gate G. For example, in one embodiment, the hot sprue member 50 may be connected to the injection molding die 100 through a runner. In this case, it should be confirmed that the hot mold raw material resin flow path 10 is composed of a sprue provided inside the hot mold sprue member 50 and a runner provided inside the injection molding die. .. The "tip 50A of the hot sprue member 50" as used herein refers to the molten raw material resin (mold cavity 30 side) from the opening provided at the bottom (or bottom or top) of the hot sprue member 50. Or it does not mean the part that flows out to the runner side). The "tip 50A of the hot type sprue member 50" as used herein refers to the outside of the hot type sprue member 50 which is in close contact with the bottom of the hot type sprue member 50 and can be in contact with the inner surface of the injection molding die 100. Refers to the side surface, that is, the "tip side outer surface". Further, the "local portion 31 in the vicinity of the gate G in the mold cavity 30" referred to in the present specification is, in a broad sense, continuous with the "inlet portion to which the molten raw material resin is supplied" and the inlet portion of the mold cavity. Refers to a portion along the forming surface of the mold cavity 30 to be formed (see FIG. 1).

Hereinafter, the case where the hot type raw material resin flow path 10 (corresponding to the sprue) in the hot type sprue member 50 is directly connected to the gate G will be described. In this case, the tip 50A of the hot die sprue member 50 comes into direct contact with the injection molding die 100 at the gate G. This means that the mold cavity 30 exists in the vicinity of the tip of the hot type sprue member 50 with the gate G in between. When the mold cavity 30 is present near the tip of the hot mold sprue member 50, the following technical problems may occur in the cooling step of the molten raw material resin filled in the mold cavity 30. Specifically, first, the heat of the molten raw material resin flowing through the hot mold raw material resin flow path 10 (corresponding to the sprue) passes through the contact portion 60 between the tip 50A of the hot mold sprue member 50 and the injection molding die 100. It can be transmitted to the region 100A closest to the gate G of the injection molding die 100. Next, the heat of the molten raw material resin flowing through the hot mold raw material resin flow path 10 (corresponding to the sprue) is located near the tip of the hot mold sprue member 50 via the local portion near the gate G of the injection molding die 100. It can be transmitted to the mold cavity 30.

Therefore, when the hot-type raw material resin flow path 10 (corresponding to the sprue) in the hot-type sprue member 50 is directly connected to the gate G, the heat transfer control unit 20 “injects the tip 50A of the hot-type sprue member 50”. It can be positioned in the region 100A closest to the gate G of the injection molding die 100, which is positioned between the "contact portion 60 with the molding die 100" and the "mold cavity 30". When the heat transfer control unit 20 is present in the nearest region 100A, the heat of the molten raw material resin flowing through the hot-type raw material resin flow path 10 (corresponding to the sprue) is transferred to the nearest region 100A of the gate G via the contact portion 60. Can be suppressed and controlled. More specifically, it is possible to heat the molten raw material resin R ₁ hot feedstock resin flow passage 10 positioned near the gate G is suppressed from being transmitted to the gate G immediate vicinity region 100A. Further, when the heat transfer control unit 20 to the gate G immediate vicinity region 100A exist, molten material resin R ₃ thermal gate G immediate vicinity region 100A located in a local portion 31 of the gate G near the mold cavity 30 (in FIG. 1 It is possible to suppress and control the transmission to the part surrounded by the dotted line. As described above, for example, when the diameter of the tip 50A of the hot sprue member 50 is gradually reduced, the contact portion 60 between the tip 50A of the hot sprue member and the injection molding die 100 has an inclined surface. Will have (see FIG. 1). In this case, the "closest region 100A of the gate G" is a region formed between the contact portion 60 having an inclined surface and the forming surface of the mold cavity 30 facing the contact portion 60 (dotted line in FIG. 1). Corresponds to the enclosed part).

The heat transfer control of the heat transfer control section 20, the vicinity of the gate G in the melting heat / mold cavity 30 of a molten raw material resin R ₁ is located in the vicinity of the gate G in the hot feedstock resin flow path 10 (corresponding to the sprue) can be favorably suppressed control the heat remaining in the gate G immediate vicinity region 100A between the contact portion 60 and the mold cavity 30 due to the melting heat of the molten material resin R ₃ is located in the local part 31 Become. Due to such heat residual suppression, the molten raw material located in the local portion 31 in the mold cavity 30 located near the tip of the hot mold sprue member 50 from the region 100A closest to the gate G between the contact portion 60 and the mold cavity 30. it is possible to suppress heat transfer to the resin R _3. As a result, in the cooling step of the molten raw material resin filled in the mold cavity 30, the hot mold sprue member 50 is placed near the tip of the hot mold sprue member 50 via the gate G immediate region 100A between the contact portion 60 and the mold cavity 30. It is possible to preferably suppress the transfer of the heat of fusion to the located mold cavity 30. As a result, in the cooling step of the molten raw material resin R in the mold cavity 30, the molten raw material resin R ₃ in the local portion 31 in the mold cavity 30 located near the tip of the hot mold sprue member 50 is in the mold cavity 30. it is possible to suitably suppress also difficult to cool than the melting material resin R ₄ other portion 32 of the.

The "heat transfer control unit 20" used in the present invention is preferably realized by the following aspects. Specifically, the "heat transfer control unit 20" includes (i) providing a cooling medium path to the area 100A in the vicinity of the gate in the injection molding die 100, and (ii) the vicinity of the gate in the injection molding die 100. This can be achieved by providing a local low density portion to the region 100A and / or providing a low heat transfer film to the surface of the injection molding die 100 in the region 100A near the (iii) gate.

(I) Heat transfer control unit 20: Cooling medium path In one aspect, the “heat transfer control unit 20” is preferably a cooling medium path 20A provided at least in the region 100A in the vicinity of the gate in the injection molding die 100. (See FIG. 2).

The "cooling medium path" referred to in the present specification is a hollow flow path for flowing a cooling medium, and the heat of fusion of the molten raw material resin flowing through the hot type raw material resin flow path 10 is the gate of the injection molding die 100. A flow path for suppressing transmission to the region closest to G and reducing the thermal energy of the raw material resin in the mold cavity near the gate G is shown. "Cooling medium" refers to a medium that flows through the cooling medium path, such as cooling liquid (water, oil), cooling gas (air, inert gas), cooling solids, cooling gas-cooling liquid mixture, or Refers to a cooled solid-cooled liquid mixture, etc.

In this case, the cooling medium path 20A as the "heat transfer control unit 20" can be positioned in the immediate vicinity of the gate G. Due to the presence of the cooling medium passage 20A, the melting heat energy of the molten raw material resin flowing through the hot type raw material resin flow path 10 is reduced by the cooling heat energy of the cooling medium flowing through the cooling medium passage 20A located in the immediate region of the gate G. .. Moreover, the presence of such a coolant passage 20A, the immediate vicinity region 100A of the molten material resin R ₃ of thermal energy injection mold gate G of the localized portion 31 of the mold cavity 30 located in the vicinity of the gate G It is reduced by the cooling heat energy of the cooling medium flowing through the located cooling medium passage 20A. The cooling medium path 20A as the "heat transfer control unit 20" may have a double structure in the immediate region of the gate G. In this case, it is possible to relatively increase the cooling heat energy of the cooling medium flowing through the cooling medium passage 20A located in the immediate region of the gate G, as compared with the case of adopting a normal single structure. Therefore, due to the fact that such a double structure is adopted, "the heat energy of melting of the molten raw material resin flowing through the hot type raw material resin flow path 10" and "locality in the mold cavity 30 located in the vicinity of the gate G". The "heat energy of the molten raw material resin of the portion" can be more preferably and effectively reduced. Further, for example, when the diameter of the tip 50A of the hot type sprue member 50 gradually decreases, the contact portion 60 between the tip 50A of the hot type sprue member and the injection molding die 100 has an inclined surface (for example, the contact portion 60 of the hot type sprue member 50 has an inclined surface. (See FIG. 2). In this case, at least a part of the cooling medium path 20A as the "heat transfer control unit 20" is formed between the contact portion 60 having an inclined surface and the forming surface of the mold cavity 30 facing the contact portion 60. It will be formed in the area. In this case, due to the presence of the cooling medium passage 20A, the molten heat energy of the molten raw material resin flowing through the hot type raw material resin flow path 10 is the forming surface of the contact portion 60 having an inclined surface and the mold cavity 30 facing the contact portion 60. It will be reduced by the cooling heat energy of the cooling medium flowing through the cooling medium passage 20A located in the region formed between the two. Moreover, the presence of the cooling medium passage 20A, facing the contact portion 60 and the contact portion 60 of the thermal energy of the molten material resin R ₃ of localized portion 31 of the mold cavity 30 located in the vicinity of the gate G has an inclined surface It is reduced by the cooling heat energy of the cooling medium flowing through the cooling medium passage 20A located in the region 100A in the immediate vicinity of the gate G formed between the forming surface of the mold cavity 30.

As described above, the thermal energy of the molten raw material in the hot mold raw material resin flow path 10 / the thermal energy of the molten raw resin located in the region near the gate G in the mold cavity 30 becomes the nearest region 100A of the gate G. It is reduced by the cooling heat energy of the cooling medium flowing through the located cooling medium passage 20A. Therefore, it is possible to suitably suppress heat remaining in the region of the injection molding die 100 in the immediate vicinity of the gate G. Such thermal residual suppression, is possible to prevent the heat transfer from the vicinity of the gate G of the injection mold 100 into the molten material resin R ₃ is located in the local part 31 of the mold cavity 30 located in the vicinity the gate G It will be possible. _{Therefore, the molten raw material resin R 3} located in the local portion 31 in the mold cavity 30 near the gate G becomes hotter than the _{molten raw material resin R 4} located in the other portion 32 in the mold cavity 30. Can be suppressed. As a result, in the cooling step of the molten raw material resin R in the mold cavity 30, the molten raw material resin located in the local portion in the mold cavity 30 near the gate G is melted in another portion in the mold cavity 30. It is possible to preferably suppress the difficulty in cooling as compared with the raw material resin.

In one aspect, when the hot-type raw material resin flow path 10 (corresponding to the sprue) is directly connected to the gate G, _{a part of the cross-sectional shape of the cooling medium path 20A 1} is injected with the tip 50A of the hot-type sprue member 50. It is preferable that the contact portion 60 with the molding die 100 follows at least one of the cross-sectional shape of the contact portion 60 and the cross-sectional shape of the forming surface of the mold cavity 30 (FIG. 3).

When a part of the cross-sectional shape of the cooling medium path 20A ₁ follows the cross-sectional shape of the contact portion 60 between the tip 50A of the hot mold sprue member 50 and the injection molding die 100, the contact is as compared with the case where the contact portion 60 is not. It is possible to make the separation distance between the portion 60 and a part of the cooling medium passage 20A _{1 relatively small.} As a result, the thermal energy of the molten raw material flowing through the hot mold raw material resin flow path 10 that can be provided to the portion between the contact portion 60 and the mold cavity 30 via the contact portion 60 is transferred to the contact portion 60. It can be effectively reduced by the cooling heat energy of the cooling medium flowing through the cooling medium passage 20A located in the portion between the mold cavity 30 and the mold cavity 30.

It is more preferable that a part of the cross-sectional shape of the cooling medium passage 20A ₁ is substantially the same as the cross-sectional shape of the contact portion 60. When such an embodiment is adopted, the separation distance can be substantially uniform at any location between the contact portion 60 and a part of the cooling medium passage 20A _1. Therefore, it is possible to uniformly apply the cooling heat energy of the cooling medium in the _{cooling medium passage 20A 1} to any part of the contact portion 60 due to the substantially uniform separation distance. This makes it possible to more effectively reduce the molten heat energy of the molten raw material resin in the hot-type raw material resin flow path 10 provided from the contact portion 60.

Further, when a part of the cross-sectional shape of the cooling medium path 20A ₁ follows the cross-sectional shape of the forming surface of the mold cavity 30 located near the tip 50A of the hot type sprue member 50, it is compared with the case where it does not follow. It is possible to make the separation distance between the forming surface of the mold cavity 30 and _{a part of the cooling medium path 20A 1 relatively small.} As a result, the cooling medium that allows the molten thermal energy of the molten raw material resin that can be supplied from the local portion 31 in the mold cavity 30 to the portion between the contact portion 60 and the mold cavity 30 to flow through the cooling medium _{passage 20A 1.} It can be effectively reduced by the cooling heat energy of.

It is more preferable that a part of the cross-sectional shape of the cooling medium passage 20A ₁ is substantially the same as the cross-sectional shape of the forming surface of the mold cavity 30. When such an embodiment is adopted, the separation distance can be substantially uniform at any position between the _{forming surface of the mold cavity 30 and a part of the cooling medium path 20A 1.} Therefore, due to the substantially uniform separation distance, _{the cooling heat energy of the cooling medium in the cooling medium passage 20A 1} is applied to any of the forming surfaces of the mold cavity 30 located in the vicinity of the tip 50A of the hot sprue member 50. It is possible to apply evenly to the location. Thereby, it is possible to more effectively reduce the melting heat energy of the molten raw material resin that can be provided from the local portion 31 in the mold cavity 30 to the portion between the contact portion 60 and the mold cavity 30. Become.

_{In particular, a part of the cross-sectional shape of the cooling medium path 20A 1} provided in the local region (that is, the region near the gate) between the contact portion 60 and the mold cavity 30 is the cross-sectional shape of the contact portion 60 and the mold. _{The cooling medium passage 20A 1} may have a flat cross-sectional shape (or an elliptical cross-sectional shape) when it follows both the cross-sectional shapes of the forming surfaces of the cavities 30. Having such a shape effectively provides the _{cooling medium passage 20A 1} over a wide area in a narrow local region (that is, a region in the immediate vicinity of the gate) between the contact portion 60 and the mold cavity 30 as compared with the perfect circular cross-sectional shape. Is possible. Therefore, it is possible to effectively apply the cooling heat energy of the cooling medium in the cooling medium passage 20A _{1 to} the forming surfaces of (1) the contact portion 60 and (2) the mold cavity 30.

In one aspect, the cooling medium path 20A as the heat transfer control unit 20 preferably has a support member 70 inside (see FIG. 4).

As described above, the cooling medium passage 20A is a hollow flow path for flowing the cooling medium. Therefore, when the cross-sectional dimension and the longitudinal dimension of the hollow flow path are relatively large, there is a possibility that the hollow flow path cannot have sufficient strength against external pressure during molding. Therefore, from the viewpoint of sufficiently ensuring the strength against the external pressure, it is preferable to provide the support member 70 for supporting the inside of the cooling medium path 20A. The support member 70 can function as a "beam member" because it is provided from the viewpoint of ensuring sufficient strength against external pressure. Although not particularly limited, the support member 70 may be made of the same material as the constituent material (for example, Fe) of the injection molding die 100 (see the lower view of FIG. 4). FIG. 4 shows a mode in which a plurality of support members 70 are provided in a cross section of the cooling medium path 20A. However, without being limited to this, it is preferable that a plurality of support members 70 are provided at predetermined intervals along the longitudinal direction of the cooling medium path 20A. As a result, the plurality of support members 70 are provided at predetermined intervals in both the longitudinal direction and the lateral direction of the cooling medium path 20A. Therefore, the cooling medium path 20A as a whole can further improve the strength against external pressure.

In one aspect, the cooling medium path 20A as the heat transfer control unit 20 is also provided to a region 100B other than the nearest region 100A of the gate G along the axial direction of the hot spiral member 50, and the cooling medium passage 20A as a whole is provided. It is preferable that the structure is spiral (see FIGS. 2 to 4).

The hot-type raw material resin flow path 10 may be provided with a plurality of heating sources 80 along the axial direction (cross-sectional view) of the hot-type raw material resin flow path 10 from the viewpoint of continuously holding the molten state as a whole. In this case, not only the hot-type raw material resin flow path 10 located near the gate G (that is, the downstream side of the hot-type raw material resin flow path 10) but also the portion extending from the upstream side to the downstream side of the hot-type raw material resin flow path 10 is hot. The heat of melting of the molten resin raw material in the hot mold raw material resin flow path 10 can be transferred to the injection molding mold 100 located around the mold raw material resin flow path 10. Specifically, there is a possibility that the heat of fusion of the molten resin raw material in the hot mold raw material resin flow path 10 is transferred from the region 100B other than the gate immediate region 100A of the injection molding die 100 to the gate immediate region 100A. .. Therefore, from the viewpoint of reducing the energy of the heat of fusion, it is preferable that the cooling medium path 20A is provided not only in the region 100A near the gate of the injection molding die 100 but also in the other region 100B. In particular, it is preferable that the cooling medium path 20A has a spiral structure as a whole. By adopting such a structure, the cooling medium passage 20A adopts a form surrounding the hot-type raw material resin flow path 10 along the axial direction of the hot-type raw material resin flow path 10. Due to the surrounding form of the cooling medium passage 20A, the portion extending from the upstream side to the downstream side of the hot mold raw material resin flow path 10 is provided to the injection molding mold 100 located around the hot mold raw material resin flow path 10. It is possible to effectively reduce the energy of the heat of fusion that can be obtained as a whole. In addition to this, due to the surrounding form of the cooling medium path 20A, a plurality of heat sources 80 provided along the axial direction (cross-sectional view) of the hot mold raw material resin flow path 10 are transferred to the injection molding die 100. It is possible to effectively reduce the heat energy of the heating source 80 that is transmitted as a whole.

In one aspect, the separation distance between the cooling medium passage 20A provided in the nearest region 100A of the gate G and the hot type sprue member 50 is such that the cooling medium passage 20A provided in the other region 100B and the hot type sprue member 50 are separated from each other. It is preferably smaller than the separation distance from and to (see FIGS. 2 to 4).

As described above, the present invention states that "a heat transfer control unit 20 (for example, a cooling medium path) capable of heat transfer control in at least the nearest region 100A of the gate G as compared with other regions 100B other than the nearest region 100A of the gate G. It has the technical idea of "providing 20A)." According to such a technical idea, it is possible to move to the gate G side from the viewpoint of reducing the transfer of heat of fusion of the raw material resin in the hot type raw material resin flow path 10 to the mold cavity 30 side located near the gate G as much as possible. It is preferable that the heat transfer control unit 20 (for example, the cooling medium path 20A) is brought as close as possible. On the other hand, the other regions 100B other than the immediate region 100A of the gate G are relatively far from the mold cavity 30 as compared with the immediate region 100A of the gate G. Therefore, it is considered that the other region 100B has a smaller transfer of heat of fusion of the raw material resin in the hot mold raw material resin flow path 10 to the mold cavity 30 side than the nearest region 100A of the gate G. Considering these points, distance _{S 1} between the cooling medium passage 20A ₁ and the hot-type sprue member 50 to be subjected to the immediate vicinity region 100A of the gate G, the cooling medium passage 20A ₂ to be subjected to other regions 100B and is preferably smaller than the distance S ₂ between the hot mold sprue member 50. Although not particularly limited, the separation distance S ₁ may be 1 mm to 10 mm, for example, 3 mm. On the other hand, the separation distance S ₂ may be 10 mm (excluding 10 mm) to 50 mm, for example, 25 mm.

As described above, since the heat transfer coefficient to the mold cavity 30 is relatively high in the immediate region 100A of the gate G located on the proximal side with respect to the mold cavity 30, the cooling medium path 20A ₁ is provided. _{The cooling medium passage 20A 1} may have a flat cross-sectional shape (or an elliptical cross-sectional shape) from the viewpoint of effective use over a wide range. On the other hand, since the heat transfer coefficient to the mold cavity 30 is relatively low in the region 100B other than the region closest to the gate G located on the distal side of the mold cavity 30, the cooling medium path 20A _The meaning of providing 2 in a wide range is not high. Therefore, the cooling medium path 20A ₂ may have a perfect circular cross-sectional shape or a substantially perfect circular cross-sectional shape.

(Ii) Heat Transfer Control Unit 20: Local Low Density Unit in Injection Molding Die 100 In one aspect, the "heat transfer control unit 20" is an injection molding die provided at least in the nearest region 100A of the gate G. It is preferably the local low density portion 20B of 100 (see FIG. 5).

The specific embodiment of the heat transfer control unit 20 is not limited to the cooling medium passage 20A described above. For example, as the heat transfer control unit 20, the local low density unit 20B of the injection molding die 100 can be used. In a broad sense, the "local low-density portion 20B" as used herein refers to a component of the injection molding die 100 having a relatively lower density than other portions. The "local low-density portion 20B" referred to in the present specification is, in a narrow sense, a component of the injection molding die 100 when the injection molding die 100 is manufactured by the powder bed melt bonding method, and is another component. It refers to a material having a relatively lower solidification density than the portion (for example, a material having a solidification density of 40 to 95% (excluding 95%)).

For example, when the hot-type raw material resin flow path 10 (corresponding to the sprue) is directly connected to the gate G, the local low-density portion 20B may be provided at least in the vicinity of the contact portion 60 located in the immediate region 100A of the gate G. .. Further, although not shown, the local low density portion 20B may be provided near the forming surface of the mold cavity 30 located in the immediate region 100A of the gate G. Without being limited to this, the local low density portion 20B may be provided in the vicinity of the interface region between the hot type raw material resin flow path 10 and the region 100B other than the immediate region 100A of the gate G. From the viewpoint of structural simplification, it is preferable that the local low density portion 20B is provided along the region of the inner surface 100C of the injection molding die 100 as shown in FIG.

In this case, the local low density portion 20B may have microscopically fine voids due to the relatively low density. Due to the presence of fine voids in the local low density portion 20B, the hot mold raw material resin flow path from the hot mold raw material resin flow path 10 side to the gate G immediate region side of the injection molding mold 100 as compared with the case where the voids do not exist. Local heat insulation of the heat of fusion of the raw material resin in No. 10 becomes possible. Further, due to the presence of fine voids in the local low density portion 20B, the inside of the mold cavity 30 into the gate G nearest region 100A of the injection molding mold 100 when the molten raw material resin is filled / held in the mold cavity. It is possible to locally insulate the heat of melting of the molten raw material resin located in the local portion 31 near the gate G of the above.

As described above, due to the presence of the local low density portion 20B of the injection molding mold 100, the heat of fusion of the molten raw material resin R in the hot mold raw material resin flow path 10 / the local portion 31 near the gate G in the mold cavity 30 local insulation to the gate G immediate vicinity region 100A of the molten raw material resin R injection mold 100 heat of fusion of ₃ to position is possible. Such localized thermal insulation, suppress heat transfer to the molten material resin R ₃ is located in the local part 31 of the mold cavity 30 located from the gate G immediate vicinity region 100A adjacent the gate G of the injection mold 100 It becomes possible to do. _{Therefore, the molten raw material resin R 3} located in the local portion 31 in the mold cavity 30 near the gate G becomes hotter than the _{molten raw material resin R 4} located in the other portion 32 in the mold cavity 30. Can be suppressed.

(Iii) Heat Transfer Control Unit 20: Low Heat Transfer Film Applied to the Surface of the Injection Molding Mold 100 In one aspect, the “heat transfer control unit 20” is a low heat applied to the surface of the injection molding mold 100. It is preferable that the low heat transfer film 20C is provided with the transfer film 20C, and the low heat transfer film 20C is provided at least in the immediate region 100A of the gate G (see FIG. 6).

The specific embodiment of the heat transfer control unit 20 is not limited to the cooling medium passage 20A and the local low density unit 20B described above. For example, as the heat transfer control unit 20, the low heat transfer film 20C provided on the surface of the injection molding die 100 can be used. The “low heat transfer film 20C” as used herein refers to a film having a relatively low heat transfer property. The low heat transfer film 20C is not particularly limited, and examples thereof include a plating film and a ceramic film having relatively low heat transfer properties. Although not particularly limited, the film thickness may be 10 μm to 300 μm, for example, 150 μm.

For example, when the hot-type raw material resin flow path 10 (corresponding to the sprue) is directly connected to the gate G, the low heat transfer film 20C may be provided at least in the vicinity of the contact portion 60 located in the immediate region 100A of the gate G. Further, although not shown, the low heat transfer film 20C may be provided near the forming surface of the mold cavity 30 located in the immediate region 100A of the gate G. Without being limited to this, the low heat transfer film 20C may be provided in the vicinity of the interface region between the hot type raw material resin flow path 10 and the region 100B other than the immediate region 100A of the gate G. From the viewpoint of structural simplification, it is preferable that the low heat transfer film 20C is provided along the region of the inner surface 100C of the injection molding die 100 as shown in FIG. Further, in addition to or instead of this, from the viewpoint of suppressing heat conduction from the inside to the outside of the hot type sprue member 50, a low heat transfer film is applied not only to the inner surface 100C but also to the outer surface 50C of the hot type sprue member 50. May be further provided.

In this case, because the low heat transfer film 20C is a film having a relatively low heat transfer property, it is used for injection molding from the hot type raw material resin flow path 10 side as compared with the case where the low heat transfer film 20C is not provided. It is possible to reduce the transferability of the heat of fusion of the raw material resin in the hot mold raw material resin flow path 10 toward the region closest to the gate G of the mold 100. Further, since the low heat transfer film 20C is a film having a relatively low heat transfer property, it is close to the gate G of the injection molding die 100 when the molten raw material resin is filled / held in the mold cavity. it is possible to reduce the transmission of heat of fusion of the molten material resin R ₃ is located in the local part 31 of the gate G near the mold cavity 30 to the area.

Thus, the presence of low heat transfer film 20C, the melting of the molten material resin R ₃ is located in the local part 31 of the gate G near the melting heat / mold cavity 30 of a molten raw material resin of the hot feedstock resin flow passage 10 It is possible to reduce the heat transfer of the heat injection molding die 100 to the region 100A in the immediate vicinity of the gate G. The reduction of such heat transfer, heat transfer to the molten material resin R ₃ is located in the local part 31 of the mold cavity 30 located from the gate G immediate vicinity region 100A adjacent the gate G of the injection mold 100 Can be suppressed. _{Therefore, the molten raw material resin R 3} located in the local portion 31 in the mold cavity 30 near the gate G becomes hotter than the _{molten raw material resin R 4} located in the other portion 32 in the mold cavity 30. Can be suppressed.

Further, the plating film, the ceramic film and the like that can be used as the low heat transfer film 20C are made of a material having high strength. Therefore, the plating film, the ceramic film, etc. not only have the property of reducing the transferability of the heat of fusion of the molten raw material resin, but also have the pressure resistance property against the external pressure generated during molding and also have the wear resistance. It is advantageous.

In one aspect, it is preferable that the inner surface 100C of the injection molding die 100 facing each other with the outer surface 50C of the hot type sprue member 50 is located outside the outer surface 50C of the hot type sprue member 50 (FIG. 2 to FIG. 6).

As described above, in the present invention, the heat transfer control unit 20 is provided at least in the nearest region 100A of the gate G. This makes it possible to prevent the heat of the molten resin raw material in the hot mold raw material resin flow path 10 from being transferred to the injection molding die 100 side. In order to suppress heat transfer of the molten resin raw material, it is preferable not only to provide the heat transfer control unit 20 but also to provide characteristics to the surface shape of the injection molding die 100. Specifically, it is preferable that the inner surface 100C of the injection molding die 100 is located outside the outer surface 50C of the hot sprue member 50. By adopting such a configuration, it is possible to provide a gap between the inner surface 100C of the injection molding die 100 and the outer surface 50C of the hot type sprue member 50. The presence of such a gap makes it possible to prevent the heat of the molten resin raw material in the hot mold raw material resin flow path 10 from being transferred to the injection molding die 100 side. Since the hot mold sprue member 50 needs to have at least its tip 50A in contact with the injection molding die 100 in order to be installed in the injection molding die 100, the contact portion (reference numeral 60 in FIGS. 2 to 6). It should be confirmed that there is no gap in (corresponding to). Further, on the premise that no gap is provided in the contact portion between the tip 50A of the hot die sprue member 50 and the injection molding die 100, in this embodiment, the hot sprue located on the upstream side of the hot sprue member 50 It is preferable that no gap is provided between the outer surface 50C of the member 50 and the inner surface 100C of the injection molding die 100 facing the outer surface 50C. As a result, when the hot type sprue member 50 is viewed as a whole, the injection molding die 100 with the outer surface 50C facing the tip side (most downstream side) of the hot type sprue member 50 and the relatively upstream side thereof. Will come into contact with the inner surface 100C of. This makes it possible to further improve the placement stability of the hot die sprue member 50 with respect to the injection molding die 100.

(Manufacturing method of mold equipment for injection molding)
Hereinafter, a method for manufacturing the injection molding die device 200 (FIG. 1) according to the embodiment of the present invention will be described. The injection molding die device 200 according to an embodiment of the present invention is for providing a molten raw material resin in an injection molding die 100 (consisting of a core side and a cavity side) and an injection molding die 100. Includes a hot-type sprue member 50 having a hot-type raw material resin flow path 10 (corresponding to sprue) inside. The injection molding die 100 can be manufactured by using the following "powder bed melt bonding method". On the other hand, as the hot type sprue member 50, a commercially available product can be used.

The "powder bed melt bonding method" used for manufacturing the injection molding die 100 is a method capable of manufacturing a three-dimensional shaped object by irradiating a powder material with a light beam. In this method, powder layer formation and solidified layer formation are alternately and repeatedly carried out based on the following steps (i) and (ii) to produce a three-dimensional shaped object.
(I) A step of irradiating a predetermined portion of the powder layer with a light beam and sintering or melt-solidifying the powder at the predetermined portion to form a solidified layer.
(Ii) A step of forming a new powder layer on the obtained solidified layer and similarly irradiating with a light beam to form a further solidified layer.

According to such a manufacturing technique, it is possible to manufacture a complicated three-dimensional shaped object in a short time. When an inorganic metal powder is used as the powder material, the obtained three-dimensional shaped product can be used as the injection molding die 100. The "metal powder" referred to here may be, for example, an iron-based metal powder having an average particle size of about 5 μm to 100 μm.

An example is a powder bed melt-bonding method in which a metal powder is used as a powder material and a three-dimensional shaped product produced by the metal powder is used as a mold 100 for injection molding. As shown in FIG. 7, first, the squeezing blade 23 is moved to form a powder layer 22 having a predetermined thickness on the modeling plate 21 (see FIG. 7A). Next, a predetermined portion of the powder layer 22 is irradiated with a light beam L to form a solidified layer 24 from the powder layer 22 (see FIG. 7B). Subsequently, a new powder layer is formed on the obtained solidified layer and irradiated with a light beam again to form a new solidified layer. When the powder layer formation and the solidification layer formation are alternately and repeatedly performed in this way, the solidification layer 24 is laminated (see FIG. 7C), and finally, the three-dimensional structure composed of the laminated solidification layer 24 is formed. A shaped object can be obtained.

By using the "powder bed melt bonding method", it is possible to provide a heat transfer control unit capable of controlling heat transfer as compared with other regions other than the region other than the region near the gate portion, at least in the region closest to the gate portion. It will be possible. When the "powder bed melt bonding method" is used, it is possible to provide the above-mentioned cooling medium passage 20A and the local low density portion 20B as the heat transfer control unit 20 by locally reducing the irradiation energy density of the light beam. .. When the low heat transfer film 20C is provided as the heat transfer control unit 20, the plating film used as the low heat transfer film 20C can be separately provided by thin film deposition sputtering. A ceramic film used as the low heat transfer film 20C can be separately provided by thermal spraying.

When the injection molding die device 200 obtained by the above method is used, the injection molding die is used from the hot mold raw material resin flow path 10 side via the gate G due to the presence of the heat transfer control unit 20 in the region 100A near the gate. It is possible to suppress heat transfer of the raw material resin in the hot-type raw material resin flow path 10 to the 100A side in the vicinity of the gate G of 100. Further, it is possible to prevent the heat of the molten raw material resin R located in the local portion 31 near the gate G in the mold cavity 30 from being transferred to the region closest to the gate G of the injection molding mold 100. As described above, due to the presence of the heat transfer control unit 20, the heat of fusion of the molten raw material resin in the hot mold raw material resin flow path 10 / the heat of fusion of the molten raw material resin located in the local portion 31 near the gate G in the mold cavity 30. Therefore, it is possible to suitably suppress heat remaining in the region 100A in the vicinity of the gate G of the injection molding mold 100. Such thermal residual deterrent, arresting the heat transfer from the gate G immediate vicinity region of the injection mold 100 into the molten material resin R ₃ is located in the local part 31 of the mold cavity 30 located in the vicinity the gate G Is possible. As a result, in the cooling step of the molten raw material resin R in the mold cavity 30, the molten raw material resin R ₃ located in the local portion 31 in the mold cavity 30 near the gate G becomes the other portion 32 in the mold cavity 30. it is possible to suitably suppress be difficult to cool than the melting material resin R ₄ located. Therefore, it is finally possible to preferably obtain a high-precision molded product as a whole.

The method for manufacturing a molded product using the injection molding die apparatus and the injection molding die apparatus according to the embodiment of the present invention has been described above, but the present invention is not limited thereto. It will be appreciated that various modifications will be made by those skilled in the art without departing from the scope of the invention as defined in the claims.

The injection molding die device according to the embodiment of the present invention can be used to obtain an injection molded product.

Cross-reference of related applications

This application is a Japanese patent application No. 2018-014898 (Filing date: January 31, 2018, title of invention: "Manufacturing a molded product using an injection molding die device and an injection molding die device". Insist on the priority under the Paris Convention based on "Methods for"). All content disclosed in this application shall be incorporated herein by this reference.

200 Injection molding mold device 100 Injection molding mold 100A Near gate area 100B Other areas other than the immediate gate area 100C Inner surface of injection molding mold 70 Support member 60 Hot mold tip of sprue member and injection molding Contact part with the mold 50 Hot type sprue member 50A Tip of hot type sprue member 50C Outer surface of hot type sprue member 30 Mold cavity 20 Heat transfer control unit 20A Cooling medium path 20A ₁ Cooling medium path 20A ₂ Cooling medium path 20B Local low density part 20C Low heat transfer film 10 Hot type raw material resin flow path G gate R Molten raw material resin S ₁ Separation distance between the cooling medium path provided in the immediate region of the gate and the hot type sprue member S ₂ Gate Separation distance between the cooling medium path and the hot sprue member provided in the area other than the nearest area.

Claims (14)

It is a mold device for injection molding.
Equipped with a hot mold resin flow path connected to the mold cavity via an injection mold and a gate.
It consists of having a heat transfer control unit at least in the immediate vicinity of the gate.
The injection molding die in which the nearest region of the gate is a predetermined region of the injection molding die closest to the gate located at the boundary portion between the mold cavity and the hot mold raw material resin flow path. Device. A hot type sprue member having the hot type raw material resin flow path inside is provided, and the hot type sprue member is the injection molding mold so that the hot type raw material resin flow path is directly connected to the gate. Is in contact with
The injection molding mold apparatus according to claim 1, wherein the heat transfer control unit is positioned between a contact portion between the tip of the hot mold sprue member and the injection molding mold and the mold cavity. .. The injection molding die device according to claim 1 or 2, wherein the heat transfer control unit is at least a cooling medium path provided in the nearest region of the gate. The tip of the hot sprue member has a shape in which the diameter of the tip gradually decreases.
In the cooling medium path as the heat transfer control unit, a part of the cross-sectional shape of the cooling medium path is the cross-sectional shape of the contact portion between the tip of the hot mold sprue member and the injection molding die and the gold. The injection molding mold apparatus according to claim 2, which is positioned between the contact portion and the mold cavity so as to follow at least one of the cross-sectional shapes of the forming surface of the mold cavity. 4. The fourth aspect of the cooling medium path as the heat transfer control unit, wherein the part of the cross-sectional shape is substantially the same as at least one of the cross-sectional shape of the contact portion and the cross-sectional shape of the forming surface of the mold cavity. The injection molding mold apparatus described in 1. The injection molding die apparatus according to any one of claims 3 to 5, wherein the cooling medium path as the heat transfer control unit has a flat cross-sectional shape. The injection molding mold device according to any one of claims 3 to 6, wherein the cooling medium path as the heat transfer control unit has a support member inside. The cooling medium path as the heat transfer control unit is also provided to a region other than the nearest region of the gate along the axial direction of the hot sprue member.
The injection molding die apparatus according to any one of claims 3 to 7, wherein the cooling medium path has a spiral structure as a whole. The separation distance between the cooling medium path provided in the nearest region of the gate and the hot sprue member is between the cooling medium path provided in the other region and the hot sprue member. The injection molding die apparatus according to claim 8, which is smaller than the separation distance. The injection molding die apparatus according to any one of claims 1 to 9, wherein the heat transfer control unit is a local low density portion of the injection molding die provided at least in the nearest region of the gate. Claims 3 to 10 according to claim 2, wherein the inner surface of the injection molding die facing the outer surface of the hot type sprue member is located outside the outer surface of the hot type sprue member. Mold device for injection molding according to any one of. Claims 1 to 11, wherein the heat transfer control unit has a low heat transfer film provided on the surface of the injection molding die, and the low heat transfer film is provided at least in the nearest region of the gate. The injection molding mold apparatus according to any one. The injection molding die apparatus according to any one of claims 1 to 12, wherein the injection molding die is provided by a powder bed melt bonding method. A method for manufacturing an injection-molded product using an injection-molding die device.
The injection molding die apparatus includes an injection molding die and a hot mold raw material resin flow path connected to a mold cavity via a gate, and has a heat transfer control unit at least in the immediate vicinity of the gate. It's made up
The nearest region of the gate is a predetermined region of the injection molding mold closest to the gate located at the boundary between the mold cavity and the hot mold raw material resin flow path.
A method of supplying a molten raw material resin into the mold cavity through the hot mold raw material resin flow path.

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