JP5545643B2 - Injection molding apparatus and insert molding apparatus - Google Patents

Description

  The present invention relates to an injection molding apparatus for injecting and molding a molten synthetic resin into a cavity through a gate in a state where the fixed mold and the movable mold are closed, and the fixed mold and the movable mold are opened. After setting the insert made of thermoplastic synthetic resin in the cavity, the fixed mold and the movable mold are closed, and the molten synthetic resin is injected into the cavity through the gate and integrated. The present invention relates to an insert molding device.

  This type of injection molding apparatus, for example, as disclosed in Patent Document 1 or the like, heats a surface-side cavity forming surface that molds the surface side of a molded product before injecting a molten synthetic resin, thereby transferring transferability. Techniques for improvement have been proposed. Further, for example, Patent Document 2 discloses a technique for raising the gate cut shutter to separate the synthetic resin in the gate and the synthetic resin in the cavity.

JP-A-6-254924 JP-A-11-330112

  However, according to the former technique, when the heat of the synthetic resin is transmitted to the movable mold and the gate cut member is raised to separate the synthetic resin in the gate and the synthetic resin in the cavity, Since the temperature of the synthetic resin is lowered, there is a problem that the separation surface of the synthetic resin is not glossy and becomes rough. Further, according to the latter technique, since the synthetic resin is separated by pressing so that the upper surface of the gate cut member is brought into contact with the fixed mold forming the gate, burrs are formed in the molded product when the press is not partitioned. There is a risk of causing a situation that remains.

  Therefore, in view of the above points, the present invention prevents burrs from remaining on the molded product, has good transferability, and the separation surface of the synthetic resin is glossy and has no rough skin, and this separation surface and other non-separable surfaces. The purpose is to mold so that the boundary between and is not understood as much as possible.

Therefore, the first invention is an injection molding apparatus for injecting and molding a molten synthetic resin into a cavity through a gate in a state in which a fixed mold and a movable mold are closed.
The opening end of the guide passage for moving the gate cut member that separates the synthetic resin in the cavity and the synthetic resin outside the cavity is disposed so as to face the bottom surface or the top surface of the cavity, and
The opening end of the gate is communicated with the guide passage through a communication port, and the tip of the gate cut member before the moving operation is disposed so as to face the communication port .

According to a second aspect of the present invention, an insert made of a thermoplastic synthetic resin is set in a cavity in a state where the fixed mold and the movable mold are opened, and then the fixed mold and the movable mold are closed. In an insert molding device for injecting a molten synthetic resin into the cavity through a gate and making it an integral product,
The opening end portion of the guide passage for moving the gate cut member that separates the synthetic resin in the cavity and the synthetic resin outside the cavity is disposed so as to face an intermediate position of the bottom surface or the upper surface of the cavity, and
An opening end portion of the gate is communicated with the guide passage through a communication port, and a distal end portion of the gate cut member before the moving operation is disposed so as to face the communication port,
The molten synthetic resin that has passed through the guide passage located near the cavity from the gate and the gate cut member is injected into the cavity through the opening of the insert.
It is characterized by that .

  According to the present invention, no burrs are left in the molded product, the transferability is good, the separation surface of the synthetic resin is glossy and has no rough skin, and the boundary between this separation surface and other non-separable surfaces is as much as possible. It can be molded so that it is not known.

It is a vertical front view of the injection molding apparatus of 1st Embodiment. It is the elements on larger scale of FIG. 1 of the state before the injection of a synthetic resin and before a gate cut member raises. FIG. 2 is a partially enlarged view of FIG. 1 in a state after injection of synthetic resin and before the gate cut member is raised. FIG. 2 is a partially enlarged view of FIG. 1 after a synthetic resin is injected and in a state in which the gate cut member is raised. It is the elements on larger scale of the injection molding apparatus of 2nd Embodiment, Comprising: It is the elements on larger scale of the state before the injection of a synthetic resin and before a gate cut member raises. It is the elements on larger scale of the injection molding apparatus of 2nd Embodiment, Comprising: It is the elements on larger scale of the state after the injection of a synthetic resin and before a gate cut member raises. It is the elements on larger scale of the injection molding apparatus of 2nd Embodiment, Comprising: It is the elements on larger scale of the state where the gate cut member rose after injection of the synthetic resin. It is the elements on larger scale of the injection molding apparatus of 3rd Embodiment, Comprising: It is the elements on larger scale of the state before the injection of a synthetic resin and before a gate cut member raises. It is the elements on larger scale of the injection molding apparatus of 3rd Embodiment, Comprising: It is the elements on larger scale of the state after the injection of a synthetic resin and before a gate cut member raises. It is the elements on larger scale of the injection molding apparatus of 3rd Embodiment, Comprising: It is the elements on larger scale of the state after injection | emission of a synthetic resin and the gate cut member rose. It is the elements on larger scale of the injection molding apparatus of 4th Embodiment, Comprising: It is the elements on larger scale of the state before the injection of a synthetic resin and before a gate cut member raises. It is the elements on larger scale of the injection molding apparatus of 4th Embodiment, Comprising: It is the elements on larger scale of the state after the injection of a synthetic resin and before a gate cut member raises. It is the elements on larger scale of the injection molding apparatus of 4th Embodiment, Comprising: It is the elements on larger scale of the state where the gate cut member rose after injection of the synthetic resin. It is the elements on larger scale of the injection molding apparatus of 5th Embodiment, Comprising: It is the elements on larger scale of the state before the injection of a synthetic resin and before a gate cut member raises. It is the elements on larger scale of the injection molding apparatus of 5th Embodiment, Comprising: It is the elements on larger scale of the state after the injection of a synthetic resin and before a gate cut member raises. It is the elements on larger scale of the injection molding apparatus of 5th Embodiment, Comprising: It is the elements on larger scale of the state after injection | emission of a synthetic resin and the gate cut member rose. It is a perspective view of an insert thing. It is the elements on larger scale of the injection molding apparatus of 6th Embodiment, Comprising: It is the elements on larger scale of the state before the injection of a synthetic resin and before a gate cut member raises. It is the elements on larger scale of the injection molding apparatus of 6th Embodiment, Comprising: It is the elements on larger scale of the state after the injection of a synthetic resin and before a gate cut member raises. It is the elements on larger scale of the injection molding apparatus of 6th Embodiment, Comprising: It is the elements on larger scale of the state after injection | emission of the synthetic resin and the gate cut member rose. It is the elements on larger scale of the injection molding apparatus of 7th Embodiment, Comprising: It is the elements on larger scale of the state before the injection of a synthetic resin and before a gate cut member raises. It is the elements on larger scale of the injection molding apparatus of 7th Embodiment, Comprising: It is the elements on larger scale of the state after the injection of a synthetic resin and before a gate cut member raises. It is the elements on larger scale of the injection molding apparatus of 7th Embodiment, Comprising: It is the elements on larger scale of the state after injection | pouring of a synthetic resin, and the gate cut member raised. It is the elements on larger scale of the injection molding apparatus of 8th Embodiment, Comprising: It is the elements on larger scale of the state before the injection of a synthetic resin and before a gate cut member raises. It is the elements on larger scale of the injection molding apparatus of 8th Embodiment, Comprising: It is the elements on larger scale of the state after the injection of a synthetic resin and before a gate cut member raises. It is the elements on larger scale of the injection molding apparatus of 8th Embodiment, Comprising: It is the elements on larger scale of the state after injection | emission of the synthetic resin and the gate cut member rose. It is a vertical front view of the injection molding apparatus of 9th Embodiment. It is the elements on larger scale of FIG. 28 of the state before injection | pouring of a synthetic resin and before a gate cut member descend | falls. FIG. 29 is a partially enlarged view of FIG. 28 in a state after the injection of the synthetic resin and before the gate cut member is lowered. FIG. 29 is a partially enlarged view of FIG. 28 in a state where the gate cut member is lowered after the injection of the synthetic resin. It is the elements on larger scale of the injection molding apparatus of 10th Embodiment, Comprising: It is the elements on larger scale of the state before injection | pouring of a synthetic resin and before a gate cut member descend | falls. It is the elements on larger scale of the injection molding apparatus of 10th Embodiment, Comprising: It is the elements on larger scale of the state after the injection | pouring of a synthetic resin and before a gate cut member descend | falls. It is the elements on larger scale of the injection molding apparatus of 10th Embodiment, Comprising: It is the elements on larger scale of the state after injection | pouring of a synthetic resin, and the gate cut member descend | falls. It is the elements on larger scale of the injection molding apparatus of 11th Embodiment, Comprising: It is the elements on larger scale of the state before the injection of a synthetic resin and before a gate cut member descend | falls. It is the elements on larger scale of the injection molding apparatus of 12th Embodiment, Comprising: It is the elements on larger scale of the state before the injection of a synthetic resin and before a gate cut member raises. It is the elements on larger scale of the conventional injection molding apparatus, Comprising: It is the elements on larger scale of the state after the injection of a synthetic resin and before a gate cut member raises. It is the elements on larger scale of the conventional injection molding apparatus, Comprising: It is the elements on larger scale of the state which extracted the synthetic resin in a gate after the injection of a synthetic resin and before a gate cut member raises. It is the elements on larger scale of the conventional injection molding apparatus, Comprising: It is the elements on larger scale of the state after injection | pouring of a synthetic resin, and after the synthetic resin in a gate was pulled out.

  A first embodiment of an injection molding apparatus according to the present invention will be described below with reference to FIGS. First, the overall configuration of the injection molding apparatus will be described with reference to FIG. Reference numeral 1 denotes a fixed-side assembly attached to a fixed platen (not shown) with bolts. The fixed-side assembly 1 includes a fixed-side first base plate 2 and a fixed-side first base plate 2 fixed to the fixed-side first base plate 2 with bolts. 2 base plate 3, fixed side third base plate 4 fixed to the fixed side second base plate 3 by bolts, and the fixed side third base plate 4 disposed in a recess formed in the lower surface of the fixed side third base plate 4. 3 a fixed mold 6 fixed to the base plate 4 by bolts, a locate ring 7 provided near the fixed platen of the fixed first base plate 2 and positioning the fixed first base plate 2 with respect to the fixed platen, It consists of a sprue bush 8 or the like disposed adjacent to the locating ring 7.

  A first sprue 9 is formed at the center of the sprue bushing 8 for passing molten synthetic resin injected from the injection nozzle, and a first runner 10 is formed at the lower end thereof. A second sprue 11 serving as an outlet of the second runner 12 is formed, and a second runner 12 is formed at a lower end portion of the second sprue 11, and a gate 13 </ b> A serving as an outlet of the second runner 12 is formed.

  A gate cut member 17 separates the synthetic resin in the cavity S and the synthetic resin outside the cavity S. The gate cut member 17 is a guide passage 27 provided in the movable-side fourth base plate 24 and the movable mold 26 described later. And 28 can be moved up and down in the vertical direction.

  A cavity S for making a flat molded product is formed by the fixed mold 6 and the movable mold 26, and the upper opening of the guide passage 27 is located at the middle position of the bottom surface of the cavity S from below. Communicating with That is, the upper opening end portion (which becomes a synthetic resin injection port) of the guide passage 27 is disposed so as to face the bottom surface intermediate position of the cavity S.

  The gate 13A is composed of a linear gate portion 13A1 extending in the horizontal direction and a curved gate portion 13A2 that rises after being lowered, and the end portion of the gate portion 13A2 is connected to the guide passage via the communication port 14A. The upper end portion of the gate cut member 17 is located slightly below the communication port 14A. That is, the open end of the gate portion 13A is communicated with the guide passage 27 located near the cavity S from the gate cut member 17 before the movement operation through the communication port 14A.

  Therefore, as a result, the guide passage 27 located above the gate cut member 17 communicates with the gate 13A through the communication port 14A, and thus forms a part of the gate through which the synthetic resin flows. Become. For this reason, the gate communicates with the cavity S from below at the middle position of the bottom surface of the cavity S, and the synthetic resin is placed in the cavity S through the upper opening of the guide passage 27 at the middle position of the bottom surface of the cavity S. It will be injected. For this reason, the upper opening of the guide passage 27 serves as a synthetic resin injection port.

  On the other hand, 20 is a movable side assembly attached to a movable platen (not shown) with a bolt. The movable side assembly 20 is a movable side first base plate 21 and a movable side fixed to the movable side first base plate 21 with bolts. A side second base plate 22 (ejector plate), a movable side third base plate 23 fixed to the movable side first base plate 21 by bolts so as to surround the movable side second base plate 22, and the movable side third base plate 23 The movable-side fourth base plate 24 fixed by bolts, and a movable mold 26 and the like that are fitted into a recess formed on the upper surface of the movable-side fourth base plate 24 and fixed to the fourth plate 24. .

  Then, a guide bar (not shown) standing on the movable third base plate 23 is inserted into a guide hole provided in the fixed third base plate 4, and the guide bar is guided into the guide hole. Thus, the movable side assembly 20 can be moved up and down.

  A cavity S is formed by the upper surface of the movable mold 26 and the concave portion formed on the lower surface of the fixed mold 6, and a molten synthetic resin is injected into the cavity S through the upper opening of the guide passage 27. Thus, a molded product is produced.

  30 is a heat medium passage formed in the fixed third base plate 4 near the fixed mold 6, 31 is a heat medium passage formed in the movable fourth base plate 24 near the movable mold 26, and 32 is the above Heat medium passages formed in the intermediate portion of the movable mold 26. These heat medium passages 30, 31, and 32 are arranged in the fixed mold 6 and the movable side according to the temperature suitable for the synthetic resin injected into the cavity S. The heat medium is constantly supplied so that the fourth base plate 24 and the movable mold 26 are maintained at a predetermined temperature.

  Reference numeral 35 denotes a heat medium passage formed along the cavity S in a portion close to the cavity S of the fixed die 6, and 36 a guide passage for guiding the raising and lowering of the gate cut member 17 of the movable die 26. 27, specifically, a heat medium passage formed near the position where the guide passage 27 communicates with the gate portion 13A2, and the number is not limited to one, and a plurality may be provided as necessary.

  A heating medium such as hot steam or a cooling medium such as cooling water is allowed to flow into the heat medium passages 35 and 36 so that the cavity forming surface side of the fixed mold 6 and the movable mold 26 The periphery of the gate cut member 17 (and thus the gate cut member 17) is heated or cooled. Accordingly, the heat medium passages 35 and 36 and the heating medium constitute a heating means, and the heat medium passages 35 and 36 and the cooling medium serve as a cooling means.

  With the above configuration, the operation of the injection molding of the first embodiment will be described below. First, a heat medium is always supplied to the medium passages 30, 31, 32, and the fixed mold 6, the movable-side fourth base plate 24. The movable mold 26 is maintained at a predetermined temperature. In this state, hot steam as a heat medium is supplied into the heat medium passage 35 of the fixed mold 6 and the heat medium passage 36 of the movable mold 26 to move the movable mold and the cavity forming surface side of the fixed mold 6. The temperature rise is started so that the periphery of the gate cut member 17 of the mold 26 reaches a predetermined temperature according to the type of the synthetic resin injected into the cavity S, and the fixed side assembly 1 and the movable side assembly 20 are moved. The mold is closed (see FIGS. 1 and 2).

  Thus, the mold closing is not limited to when the temperature rise is started, and the mold may be closed simultaneously with the start of the temperature rise, or the temperature rise may be started after the mold is closed. In the case where there is not, it should be interpreted as such even if it is expressed that “the mold is closed after the temperature rise is started”.

  In this case, the temperature around the cavity forming surface of the fixed mold 6 and the temperature around the gate cut member 17 is set to the ambient temperature of the softening point temperature of the injected synthetic resin (within the temperature range before and after the softening point temperature). Let it heat. That is, in the case of a synthetic resin having a low softening point temperature, the cavity forming surface side of the fixed mold 6 is softened so that the softening point temperature is exceeded and the periphery of the gate cut member 17 is lower than the softening point temperature. In the case of a synthetic resin having a high point temperature, the cavity forming surface side of the fixed mold 6 and the gate cut member of the fixed mold 6 so that the cavity forming surface side of the fixed mold 6 and the periphery of the gate cut member 17 exceed the softening point temperature. Heat around 17.

  Specifically, in the case of a synthetic resin having a low softening point temperature, if the softening point temperature is 70 ° C., for example, the cavity forming surface side of the fixed mold 6 is about 120 ° C. above the softening point temperature. And it heats so that the circumference | surroundings of the gate cut member 17 may be about 50 degreeC below the said softening point temperature.

  As described above, in the case of a synthetic resin having a low softening point temperature, if the periphery of the gate cut member 17 is heated to be equal to or higher than the softening point temperature, the synthetic resin in the cavity S and the synthetic resin outside the cavity S This is because cutting and separation are poor and thin burrs are easily formed. In the case of a synthetic resin having a high softening point temperature, if the softening point temperature is 90 ° C., for example, the cavity forming surface side of the fixed mold 6 and the periphery of the gate cut member 17 are 120 ° C. above the softening point temperature. The cavity forming surface side of the fixed mold 6 and the periphery of the gate cut member 17 are heated so that the degree becomes approximately. As described above, in the case of a synthetic resin having a high softening point temperature, if the periphery of the gate cut member 17 is heated to be lower than the softening point temperature, a crack is generated on the cut separation surface during the above-described cutting and separation. It is because it becomes easy to do.

  When the cavity forming surface side of the fixed mold 6, the gate cut member 17 of the movable mold 26, and the periphery of the gate cut member 17 reach the softening point temperature, the supply of steam is stopped and the temperature rise is stopped. To do. Then, the injection nozzle is passed through the sprue bush 8, and the molten synthetic resin J is guided through the first sprue 9, the first runner 10, the second sprue 11, the second runner 12, the gate 13 </ b> A and the gate cut member 17. Through the cavity S formed by the movable mold 26 and the fixed mold 6 (see FIG. 3).

  As described above, in the process in which the molten synthetic resin J flows and is injected into the cavity S, the upper end portion (tip portion) of the gate cut member 17 positioned slightly below the communication port 14A is the molten synthetic resin. It will be heated by J. In other words, the molten synthetic resin J is injected into the cavity S through the upper opening of the guide passage 27 while heating the upper end portion of the gate cut member 17.

  And after inject | pouring this molten synthetic resin J, in order to raise the compression density of this synthetic resin J, while starting compression, it maintains pressure | pressure while maintaining injection pressure. Then, immediately before the flow of the synthetic resin J before the injection of the injected synthetic resin J stops, that is, immediately before the injection pressure or the holding pressure reaches the peak, the gate cut member 17 is raised, and the synthesis in the cavity S is performed. The resin J and the synthetic resin outside the cavity S are separated (see FIG. 4).

  In this case, when the gate cut member 17 rises in the guide passages 27 and 28, while pushing the synthetic resin in the guide passage 27 located above the gate cut member 17 into the cavity S and the gate 13A, The synthetic resin in the cavity S and the synthetic resin outside the cavity S are separated. That is, the gate cut member 17 rises to a position where the upper surface forms the bottom surface of the cavity S, in other words, rises to the same level as the lower surface of the cavity S, and the synthetic resin in the cavity S and the composite outside the cavity S are combined. Separate the resin.

  According to the first embodiment, as described above, by supplying hot steam into the heat medium passage 36 of the movable mold 26, the molten synthetic resin J further flowing in the gate 13A and the guide passage 27 is supplied. Is injected into the cavity S while heating the upper end of the gate cut member 17. Therefore, the cut and separation surface portion of the synthetic resin is maintained in a state where it is not hardened. Therefore, the synthetic resin pushed into the cavity S and the gate 13A and the synthesis before the inside was pushed into the cavity S and the gate 13A. Since the resin and the resin are fused beautifully, the separation surface of the synthetic resin is clean with no rough skin. Further, as in the prior art disclosed in JP-A-11-330112, the synthetic resin is not separated by pressing the upper surface of the gate cut member 17 so as to contact the fixed mold 6 forming the gate. The situation where burrs remain on the molded product (product) when the press is not partitioned can be avoided as much as possible.

  As described above, in this embodiment, the gate cut member 17 is raised immediately before the flow of the synthetic resin J stops, that is, immediately before the injection pressure or the holding pressure reaches the peak. It may be increased immediately after the flow of gas stops, that is, immediately after the injection pressure or the holding pressure reaches a peak. Other embodiments described below should be interpreted in this way unless there is a specific description.

  In any of these cases, when the gate cut member 17 rises to separate the synthetic resin in the cavity S and the synthetic resin outside the cavity S, the flow of the synthetic resin J stops, and this time the synthetic resin J is reversed. Since the force to come out of the cavity S is applied to the upper surface of the gate cut member 17 (the separation surface of the gate cut member 17), the upper surface of the gate cut member 17 is particularly heated, so that the synthetic resin J is solidified. In combination with the fact that the separation surface portion of the synthetic resin J is not solidified due to a delay, the transferability is good, the separation surface of the synthetic resin J is also glossy, and there is no rough skin. And the other non-separated surface can be molded so that the boundary between them is as little as possible.

  Then, when the synthetic resin in the cavity S and the synthetic resin outside the cavity S are separated by the rising of the gate cut member 17, it is placed in the heat medium passage 35 of the fixed mold 6 and the heat medium passage 36 of the movable mold 26. Instead of the heating medium, supply of cooling water as a cooling medium is started. Therefore, the cavity forming surface side of the fixed mold 6 of the synthetic resin J is solidified, and the synthetic resin in the gate 13 near the periphery of the gate cut member 17 of the movable mold 26 is cooled and solidified.

  Then, when the synthetic resin J in the cavity S is solidified, cooling is continued until it can be taken out from both molds 6 and 26 as a molded product, and the synthetic resin J is solidified enough to be taken out from the cavity S, the heating medium The supply of the cooling water into the passages 35 and 36 is stopped, then the mold is opened, and the molded product by the ejector pin is released to prepare for the production of the next molded product.

  Next, the second embodiment will be described with reference to FIGS. 5 to 7. However, the same reference numerals and symbols as those of the first embodiment described above have the same functions, and the description is omitted. Only the different parts will be described.

  That is, in the first embodiment, the lower end of the gate cut member 17 is disposed so as to be positioned slightly below the communication port 14A, but in the second embodiment, The upper end portion of the gate cut member 17 in the lowered state before the moving operation faces the communication port 14A (that is, faces), that is, the upper end portion of the gate cut member 17 is positioned at an intermediate position in the vertical direction of the communication port 14A. (See FIG. 5).

  In the first embodiment, before the molten synthetic resin is injected into the cavity S, hot steam is injected into the heat medium passage 35 of the fixed mold 6 and the heat medium passage 36 of the movable mold 26. By supplying, the temperature around the cavity forming surface side of the fixed mold 6 and the ambient temperature around the gate cut member 17 was raised to the ambient temperature of the softening point temperature of the synthetic resin to be injected. In the embodiment, hot steam is not supplied into the heat medium passage 36.

  When the cavity forming surface side of the fixed mold 6 reaches the above ambient temperature of the softening point temperature of the synthetic resin, the supply of steam is stopped and the temperature rise is stopped, and the injection nozzle is passed through the sprue bush 8 for melting. The movable mold 26 and the stationary mold 6 are passed through the first synthetic sprue 9, the first runner 10, the second sprue 11, the second runner 12, the gate 13 </ b> A and the guide passage 27 above the gate cut member 17. And injected into the cavity S formed by (see FIG. 6).

  In the process where the molten synthetic resin J flows and is injected into the cavity S, the upper end portion of the gate cut member 17 facing the communication port 14A is heated by the molten synthetic resin J. In other words, the molten synthetic resin J flows while directly heating the upper end portion of the gate cut member 17 and is injected into the cavity S.

  And after inject | pouring this molten synthetic resin J, in order to raise the compression density of this synthetic resin J, while starting compression, it maintains pressure | pressure while maintaining injection pressure. Then, immediately before the flow of the synthetic resin J before the injection of the injected synthetic resin J stops, that is, immediately before the injection pressure or the holding pressure reaches the peak, the gate cut member 17 is raised, and the synthesis in the cavity S is performed. The resin J and the synthetic resin outside the cavity S are separated (see FIG. 7).

  In this case, when the gate cut member 17 rises in the guide passages 27 and 28, while pushing the synthetic resin in the guide passage 27 located above the gate cut member 17 into the cavity S and the gate 13A, The synthetic resin in the cavity S and the synthetic resin outside the cavity S are separated. That is, the gate cut member 17 rises to a position where the upper surface forms the bottom surface of the cavity S and is separated.

  According to the second embodiment, as described above, hot steam is not supplied into the heat medium passage 36 of the movable mold 26, but the molten synthetic resin J heats the upper end portion of the gate cut member 17. While being injected into the cavity S, the tip of the gate cut member 17 is sufficiently heated. Therefore, the cut and separation surface portion of the synthetic resin is maintained in a state where it is not hardened. Therefore, the synthetic resin pushed into the cavity S and the gate 13A and the synthesis before the inside was pushed into the cavity S and the gate 13A. Since the resin and the resin are fused beautifully, the cut and separated surface of the synthetic resin has no rough skin and is beautiful.

  Then, when the synthetic resin in the cavity S and the synthetic resin outside the cavity S are separated by the rising of the gate cut member 17, it is placed in the heat medium passage 35 of the fixed mold 6 and the heat medium passage 36 of the movable mold 26. Supply of cooling water as a cooling medium is started. Therefore, the cavity forming surface side of the fixed mold 6 of the synthetic resin J is solidified, and the synthetic resin in the gate 13 near the periphery of the gate cut member 17 of the movable mold 26 is cooled and solidified.

  When the synthetic resin J has solidified enough to be taken out from the cavity S as a molded product, the supply of cooling water into the heat medium passage 35 of the fixed mold 6 and the heat medium passage 36 of the movable mold 26 is stopped. Then, the mold is opened and the molded product by the ejector pin is released to prepare for the production of the next molded product.

  Next, the third embodiment will be described with reference to FIGS. 8 to 10. However, the same reference numerals and symbols as those of the first embodiment described above have the same functions, and the description thereof is omitted. Only the different parts will be described.

  That is, in the first embodiment, the gate 13A serving as the outlet of the second runner 12 is composed of a straight gate portion 13A1 extending in the horizontal direction and a curved gate portion 13A2 rising after being lowered. The end portion of the gate portion 13A2 communicates with the upper portion of the guide passage 27 through the communication port 14A, and the upper end portion (tip portion) of the gate cut member 17 is positioned below the communicating portion. It is arranged.

  However, in the third embodiment, the gate 13B serving as the outlet of the second runner 12 includes a linear gate portion 13B1 extending in the vertical direction and a linear gate portion 13B2 extending obliquely upward. The end portion of the gate portion 13B2 communicates with the upper portion of the guide passage 27 through the communication port 14B, and the upper end portion of the gate cut member 17 is disposed slightly below the communicating portion. (See FIG. 8). That is, the opening end of the gate portion 13B2 is communicated with the guide passage 27 located near the cavity S through the communication port 14B from the gate cut member 17 before the movement operation.

  The operation of the injection molding of the third embodiment is the same as that of the first embodiment, and hot steam is supplied into the heat medium passage 35 of the fixed mold 6 and the heat medium passage 36 of the movable mold 26. Thus, the molten synthetic resin J is heated up until the cavity forming surface side of the fixed mold 6, the gate cut member 17 of the movable mold 26, and the periphery of the gate cut member 17 reach the above ambient temperature of the softening point temperature. The gas is injected into the cavity S through the gate 13B and the guide passage 27 above the gate cut member 17 (see FIG. 9), and the inside of the cavity S is raised by the gate cut member 17 whose upper surface rises to a position where the bottom surface of the cavity S is formed. The synthetic resin and the synthetic resin outside the cavity S are separated (see FIG. 10), but the description is omitted here. The third embodiment can provide the same effects as those of the first embodiment, but the description thereof is omitted.

  Next, the fourth embodiment will be described with reference to FIGS. 11 to 13. The same reference numerals and symbols as those in the first or third embodiment described above have the same functions. Omitted and only different parts will be described.

  That is, as in the third embodiment, the gate 13B serving as the outlet of the second runner 12 includes a linear gate portion 13B1 extending in the vertical direction and a linear gate portion 13B2 extending obliquely upward. .

  However, in the third embodiment, the end portion of the gate portion 13B2 communicates with the upper portion of the guide passage 27 via the communication port 14B, and the upper end portion of the gate cut member 17 is slightly smaller than the communicating portion. In the fourth embodiment, the upper end portion (tip portion) of the lowered gate cut member 17 faces the communication port 14B, that is, the gate cut. It arrange | positions so that the upper end part of the member 17 may be located in the intermediate position of the up-down direction of the communicating port 14B (refer FIG. 11).

  In the first and third embodiments, before the molten synthetic resin is injected into the cavity S, the heat medium passage 35 of the fixed mold 6 and the heat medium passage 36 of the movable mold 26 are inserted. By supplying hot steam, the temperature at the cavity forming surface side of the fixed mold 6 and the surrounding temperature of the gate cut member 17 was raised to the above-mentioned ambient temperature of the softening point temperature of the synthetic resin. In the fourth embodiment, hot steam is not supplied into the heat medium passage 36.

  The operation of the injection molding of the fourth embodiment is the same as that of the second embodiment. By supplying hot steam into the heat medium passage 35 of the stationary mold 6, the cavity forming surface of the stationary mold 6 is obtained. The temperature is raised until the side reaches the ambient temperature of the softening point temperature, and the molten synthetic resin J flows while directly heating the upper end portion of the gate cut member 17 facing the communication port 14B, and the gate 13B and the gate cut member 17 is injected into the cavity S through the upper guide passage 27 (see FIG. 12), and the synthetic resin in the cavity S and the cavity S are raised by the gate cut member 17 whose upper surface rises to a position where the bottom surface of the cavity S is formed. The outer synthetic resin is separated (see FIG. 13), but the description is omitted here. The fourth embodiment can provide the same effects as those of the second embodiment, but the description thereof is omitted.

  Next, the fifth embodiment will be described with reference to FIGS. 14 to 16. However, the same reference numerals and symbols as those of the first embodiment described above have the same functions, and the description thereof will be omitted. Only the different parts will be described.

  The overall configuration of the injection molding apparatus of the fifth embodiment is the same as the overall configuration of the injection molding apparatus of the first embodiment, and the gate 13A serving as the outlet of the second runner 12 is a straight line extending in the horizontal direction. The gate portion 13A1 and a curved gate portion 13A2 that rises after being lowered, and the end portion of the gate portion 13A2 communicates with the upper portion of the guide passage 27 via the communication port 14A. The upper end portion of the cutting member 17 is disposed so as to be slightly below the communicating portion.

  However, the feature of the fifth embodiment is that in the insert molding in which an insert which is a primary molded product is inserted and molded by injection molding into an integrated product, the composite in the cavity S is formed by the raised gate cut member 17. The purpose is to separate the resin and the synthetic resin outside the cavity S.

  The operation of the insert molding of the fifth embodiment will be described below. First, an insert 40, which is a primary molded product made of thermoplastic synthetic resin, is set in the cavity S in a state where the mold is opened, and then the mold is closed. To do. As shown in FIG. 17, the insert 40 has a rectangular outer shape, for example, and has a length substantially the same as the length of the cavity S in the front-rear and left-right directions. Is formed. Accordingly, the upper opening of the guide passage 27 faces the opening 41 of the insert 40.

  First, in a state where the fixed mold 6, the movable side fourth base plate 24 and the movable mold 26 are maintained at a predetermined temperature, the heat medium passage 35 of the fixed mold 6 and the heat medium passage 36 of the movable mold 26. Hot steam, which is a heat medium, is supplied into the cavity, and the cavity forming surface side of the fixed mold 6 and the periphery of the gate cut member 17 of the movable mold 26 are heated and injected into the cavity S. The temperature rise is started toward a predetermined temperature according to the type of the synthetic resin for molding, and the fixed side assembly 1 and the movable side assembly 20 are closed (see FIG. 14).

  In this case, the temperature around the cavity forming surface of the fixed mold 6 and the temperature around the gate cut member 17 is the ambient temperature of the softening point temperature of the synthetic resin (within the temperature range before and after the softening point temperature). Let it heat. That is, in the case of a synthetic resin having a low softening point temperature, the cavity forming surface side of the fixed mold 6 is softened so that the softening point temperature is exceeded and the periphery of the gate cut member 17 is lower than the softening point temperature. In the case of a synthetic resin having a high point temperature, the cavity forming surface side of the fixed mold 6 and the gate cut member of the fixed mold 6 so that the cavity forming surface side of the fixed mold 6 and the periphery of the gate cut member 17 exceed the softening point temperature. Heat around 17.

  Then, when the temperature at the cavity forming surface side of the fixed mold 6, the gate cut member 17 of the movable mold 26, and the periphery of the gate cut member 17 reaches the ambient temperature, the supply of steam is stopped and the temperature rise is stopped. Then, the injection nozzle is passed through the sprue bush 8, and the molten synthetic resin J is guided through the first sprue 9, the first runner 10, the second sprue 11, the second runner 12, the gate 13 </ b> A and the gate cut member 17. Through the cavity S formed by the movable mold 26 and the fixed mold 6 (see FIG. 15).

  As described above, in the process in which the molten synthetic resin J flows and is injected into the cavity S, the upper end portion (tip portion) of the gate cut member 17 positioned below the communication port 14A is the molten synthetic resin J. It will be heated by. In other words, the molten synthetic resin J is injected into the cavity S while heating the tip of the gate cut member 17.

  Since the upper opening of the guide passage 27 faces the opening 41 of the insert 40, the molten synthetic resin J is injected into the cavity S through the opening 41 of the insert 40. As a result, it gradually flows outward with the upper opening of the guide passage 47 as the center, and proceeds from the opening 41 of the insert 40 to the surface of the insert 40 and the surface of the stationary mold 6 where the cavity S is formed. It will be filled inside. In order to increase the compression density of the injected synthetic resin J, compression is started and the injection pressure is maintained and maintained. Thereby, the synthetic resin for secondary injection molding is joined (fused) with the insert 40 and integrated. And just before the flow of the synthetic resin J before the injection of the injected synthetic resin J stops, that is, immediately before the injection pressure or the holding pressure reaches the peak, the upper surface of the gate cut member 17 is the bottom surface of the cavity S. It raises to the position to form, and the synthetic resin J in the cavity S and the synthetic resin outside the cavity S are separated (see FIG. 16).

  In this case, when the gate cut member 17 rises in the guide passages 27 and 28, while pushing the synthetic resin in the guide passage 27 located above the gate cut member 17 into the cavity S and the gate 13A, The synthetic resin in the cavity S and the synthetic resin outside the cavity S are separated.

  According to the fifth embodiment, as described above, by supplying hot steam into the heat medium passage 36 of the movable mold 26, the molten synthetic resin J further moves the upper end of the gate cut member 17. It is injected into the cavity S while heating. Therefore, the cut and separation surface portion of the synthetic resin is maintained in a state where it is not hardened. Therefore, the synthetic resin pushed into the cavity S and the gate 13A and the synthesis before the inside was pushed into the cavity S and the gate 13A. Since the resin and the resin are fused beautifully, the separation surface of the synthetic resin is clean with no rough skin. Further, as in the prior art disclosed in JP-A-11-330112, the synthetic resin is not separated by pressing the upper surface of the gate cut member 17 so as to contact the fixed mold 6 forming the gate. The situation where burrs remain on the molded product (product) when the press is not partitioned can be avoided as much as possible.

  When the gate cut member 17 is raised to separate the synthetic resin in the cavity S from the synthetic resin outside the cavity S, the flow of the synthetic resin J stops, and this time, the synthetic resin J will come out of the cavity S. Is applied to the upper surface of the gate cut member 17 (the separation surface of the gate cut member 17). In particular, since the upper surface of the gate cut member 17 is heated, solidification of the synthetic resin J is delayed and the synthetic resin is delayed. Combined with the fact that the separation surface portion of J is not solidified, the transferability is good, the separation surface of the synthetic resin J is glossy and has no rough skin, and this separation surface is not separated from the others. It can be molded so that the boundary with the surface is not known as much as possible.

  Then, when the synthetic resin in the cavity S and the synthetic resin outside the cavity S are separated by the rising of the gate cut member 17, it is placed in the heat medium passage 35 of the fixed mold 6 and the heat medium passage 36 of the movable mold 26. Supply of cooling water as a cooling medium is started. Therefore, the cavity forming surface side of the fixed mold 6 of the synthetic resin J is solidified, and the synthetic resin in the gate 13 near the periphery of the gate cut member 17 of the movable mold 26 is cooled and solidified.

  Then, when the synthetic resin J in the cavity S is solidified, cooling is continued until it can be taken out from both molds 6 and 26 as a molded product, and the synthetic resin J is solidified enough to be taken out from the cavity S, the fixed metal The supply of the cooling water into the heat medium passage 35 of the mold 6 and the heat medium passage 36 of the movable mold 26 is stopped, and then the mold is opened to release the molded product by the ejector pin, and the next molded product Prepare for production.

  Next, the sixth embodiment will be described with reference to FIGS. 18 to 20. The same reference numerals and symbols as those of the first and second embodiments described above are assumed to have the same functions. Omitted and only different parts will be described.

  The overall configuration of the injection molding apparatus according to the sixth embodiment is the same as the overall configuration of the injection molding apparatus according to the second embodiment, and the gate 13A serving as the outlet of the second runner 12 is a straight line extending in the horizontal direction. The gate portion 13A1 and a curved gate portion 13A2 that rises after being lowered, and the end portion of the gate portion 13A2 communicates with the upper portion of the guide passage 27 through the communication port 14A. Then, the gate cut member 17 in the lowered state is arranged so that the upper end portion (tip portion) faces the communication port 14A, that is, the tip portion of the gate cut member 17 is positioned at an intermediate position in the vertical direction of the communication port 14A. (See FIG. 18).

  However, the feature of the sixth embodiment is that, as in the fifth embodiment, in insert molding in which an insert is inserted and molded by injection molding to form an integral part, the raised gate cut member 17 causes a cavity. The purpose is to separate the synthetic resin in S from the synthetic resin outside the cavity S.

  Further, in the fifth embodiment, before the molten synthetic resin is injected into the cavity S, hot steam is injected into the heat medium passage 35 of the fixed mold 6 and the heat medium passage 36 of the movable mold 26. By supplying, the ambient temperature of the softening point temperature of the synthetic resin that injects the temperature around the cavity forming surface side of the fixed mold 6 and the gate cut member 17 (within the temperature range before and after the softening point temperature) is obtained. However, in the sixth embodiment, hot steam is not supplied into the heat medium passage 36.

  The operation of the insert molding of the sixth embodiment will be described below. First, an insert 40, which is a primary molded product made of a thermoplastic synthetic resin, is set in the cavity S in a state where the mold is opened, and then the mold is closed. To do.

  When the cavity forming surface side of the fixed mold 6 reaches the ambient temperature around the softening point temperature of the synthetic resin described above, the supply of steam is stopped and the temperature rise is stopped, the injection nozzle is passed through the sprue bushing 8, and the secondary The molten synthetic resin J for injection molding is injected into the cavity S through the first sprue 9, the first runner 10, the second sprue 11, the second runner 12, the gate 13 </ b> A and the guide passage 27 above the gate cut member 17. (See FIG. 19).

  In the process in which the molten synthetic resin J flows and is injected into the cavity S, the upper end (tip) of the gate cut member 17 facing the communication port 14A is heated by the molten synthetic resin J. It becomes. In other words, the molten synthetic resin J flows while directly heating the tip of the gate cut member 17 and is injected into the cavity S.

  Since the upper opening of the guide passage 27 faces the opening 41 of the insert 40, the molten synthetic resin J is injected into the cavity S through the opening 41 of the insert 40. As a result, it gradually flows outward with the upper opening of the guide passage 47 as the center, and proceeds from the opening 41 of the insert 40 to the surface of the insert 40 and the surface of the stationary mold 6 where the cavity S is formed. It will be filled inside. In order to increase the compression density of the injected synthetic resin J, compression is started and the injection pressure is maintained and maintained. Thereby, the synthetic resin for secondary injection molding is joined (fused) with the insert 40 and integrated. And just before the flow of the synthetic resin J before the injection of the injected synthetic resin J stops, that is, immediately before the injection pressure or the holding pressure reaches the peak, the upper surface of the gate cut member 17 is the bottom surface of the cavity S. It raises to the position to form, and the synthetic resin J in the cavity S and the synthetic resin outside the cavity S are separated (see FIG. 20).

  In this case, when the gate cut member 17 rises in the guide passages 27 and 28, while pushing the synthetic resin in the guide passage 27 located above the gate cut member 17 into the cavity S and the gate 13A, The synthetic resin in the cavity S and the synthetic resin outside the cavity S are separated.

  According to the sixth embodiment, as described above, hot steam is not supplied into the heat medium passage 36 of the movable mold 26, but the molten synthetic resin J heats the tip of the gate cut member 17. However, since it is injected into the cavity S, the tip of the gate cut member 17 is sufficiently heated. Therefore, the cut and separation surface portion of the synthetic resin is maintained in a state where it is not hardened. Therefore, the synthetic resin pushed into the cavity S and the gate 13A and the synthesis before the inside was pushed into the cavity S and the gate 13A. Since the resin and the resin are fused beautifully, the separation surface of the synthetic resin is clean with no rough skin.

  Then, when the synthetic resin in the cavity S and the synthetic resin outside the cavity S are separated by the rising of the gate cut member 17, it is placed in the heat medium passage 35 of the fixed mold 6 and the heat medium passage 36 of the movable mold 26. Supply of cooling water as a cooling medium is started. Therefore, the cavity forming surface side of the fixed mold 6 of the synthetic resin J is solidified, and the synthetic resin in the gate 13 near the periphery of the gate cut member 17 of the movable mold 26 is cooled and solidified.

  When the synthetic resin J has solidified enough to be taken out from the cavity S as a molded product, the supply of cooling water into the heat medium passage 35 of the fixed mold 6 and the heat medium passage 36 of the movable mold 26 is stopped. Then, the mold is opened and the molded product by the ejector pin is released to prepare for the production of the next molded product.

  Next, the seventh embodiment will be described with reference to FIGS. 21 to 23. The same reference numerals and symbols as those of the third embodiment described above have the same functions, and the description thereof will be omitted. Only the different parts will be described.

  The overall configuration of the injection molding apparatus according to the seventh embodiment is the same as the overall configuration of the injection molding apparatus according to the third embodiment, and is omitted here. However, as in the fifth and sixth embodiments, the seventh embodiment is characterized in that the gate cut member is raised in insert molding in which an insert is inserted and molded by injection molding to be an integral part. 17 is to separate the synthetic resin in the cavity S from the synthetic resin outside the cavity S.

  The operation of the injection molding of the seventh embodiment is the same as that of the fifth embodiment. First, after setting the insert 40 made of thermoplastic synthetic resin in the cavity S under the mold open state. The mold is closed, and hot steam is supplied into the heat medium passage 35 of the fixed mold 6 and the heat medium passage 36 of the movable mold 26, so that the cavity forming surface side of the fixed mold 6, The temperature of the gate cut member 17 and the periphery of the gate cut member 17 is increased to the above-mentioned ambient temperature of the softening point temperature, and the melted synthetic resin J is cavity C through the guide passage 27 above the gate 13B and the gate cut member 17. (See FIG. 22).

  In this case, the molten synthetic resin J is injected into the cavity S through the opening 41 of the insert 40, and gradually flows outward centering on the upper opening of the guide passage 47. From the opening 41 of the object 40, the surface of the insert object 40 and the surface of the stationary mold 6 where the cavity S is formed are filled, and the cavity S is filled. In order to increase the compression density of the injected synthetic resin J, compression is started and the injection pressure is maintained and maintained. Thereby, the synthetic resin for secondary injection molding is joined (fused) with the insert 40 and integrated. And just before the flow of the synthetic resin J before the injection of the injected synthetic resin J stops, that is, immediately before the injection pressure or the holding pressure reaches the peak, the upper surface of the gate cut member 17 is the bottom surface of the cavity S. It raises to the position to form, and the synthetic resin J in the cavity S and the synthetic resin outside the cavity S are separated (see FIG. 23). The seventh embodiment can provide the same effects as those of the first and fifth embodiments, but the description thereof is omitted.

  Next, the eighth embodiment will be described with reference to FIGS. 24 to 26. The same reference numerals and symbols as those of the fourth embodiment described above have the same functions, and the description thereof will be omitted. Only the different parts will be described.

  The overall configuration of the injection molding apparatus according to the eighth embodiment is the same as the overall configuration of the injection molding apparatus according to the fourth embodiment, and is omitted here. However, the feature of the eighth embodiment is that, as in the fifth to seventh embodiments, the gate cut member is raised in insert molding in which an insert is inserted and molded by injection molding to be an integral part. 17 is to separate the synthetic resin in the cavity S from the synthetic resin outside the cavity S.

  The operation of the injection molding of the eighth embodiment is the same as that of the sixth embodiment. A molten synthetic resin J is injected into the cavity S (see FIG. 25), and its upper surface forms the bottom surface of the cavity S. The synthetic resin in the cavity S and the synthetic resin outside the cavity S are separated by the gate cut member 17 raised to the position (see FIG. 26), but the description is omitted here.

  Next, the ninth embodiment will be described with reference to FIGS. 27 to 30. The same reference numerals and symbols as those of the first to eighth embodiments have the same functions, and the description thereof is omitted. Only the different parts will be described.

  A first runner 10A is formed at the lower end of the first sprue 9, a second sprue 11A is formed as an outlet of the first runner 10A, and the lower end of the second sprue 11A is the upper surface of the cavity S (molding). It is arranged so as to face an intermediate position on the design surface side of the product. Therefore, the second sprue 11A is also a gate.

  The gate cut member 17A that separates the synthetic resin in the cavity S and the synthetic resin outside the cavity S is formed in a diagonally upward and downward direction through guide passages 28A and 27A provided in the fixed third base plate 4 and the fixed mold 6. Although it is possible to move up and down, the lower surface of the gate cut member 17A is a horizontal plane parallel to the upper surface of the cavity S.

  The lower opening end of the guide passage 27A is disposed so as to face the middle position of the bottom surface of the cavity S, and is also disposed so as to communicate with the communication port with the cavity S of the second sprue 11A. Accordingly, the lower opening end of the guide passage 27A and the lower opening (synthetic resin injection port) of the second sprue 11A are both disposed so as to face an intermediate position on the upper surface of the cavity S, and the guide passage 27A, The second sprue 11A and the cavity S communicate with each other at an intermediate position on the upper surface of the cavity S. That is, the communication port with the cavity S is not only the lower opening of the second sprue 11A but also the lower opening of the guide passage 27A.

  As shown in FIG. 28, when the gate cut member 17A is in the raised position in the state before the lowering operation, it is the same height as the lower ends of the walls forming the guide passage 27A and the second sprue 11A. Is a level.

  Then, when the gate cut member 17A descends to separate the synthetic resin in the cavity S and the synthetic resin outside the cavity S, an inner end portion that forms the lower opening of the guide passage 27A of the fixed mold 6 A protrusion 6A is formed so that the peripheral side portion of the gate cut member 17A contacts. That is, the protrusion 6A is formed so that the inner surface of the protrusion 6A and the longitudinal direction (axial direction) of the gate cut member 17A are parallel, and when the gate cut member 17A is lowered, The communication port between the cavity S and the lower opening of the guide passage 27A and the lower opening of the second sprue 11A is blocked.

  The operation of the injection molding of the ninth embodiment is the same as that of the first embodiment and the like, and hot steam is supplied into the heat medium passage 35 of the fixed mold 6 and the heat medium passage 36A of the fixed mold 6. Thus, the temperature is increased until the cavity forming surface side of the fixed mold 6, the gate cut member 17 </ b> A of the fixed mold 6, and the periphery of the gate cut member 17 </ b> A reach the above-mentioned ambient temperature of the softening point temperature. Is injected into the cavity S through the second sprue 11A (see FIG. 29).

  In the process where the molten synthetic resin J flows and is injected into the cavity S, the lower end portion of the gate cut member 17A is heated by the molten synthetic resin J. Then, the synthetic resin in the cavity S and the synthetic resin outside the cavity S are separated by the gate cut member 17A lowered to a position where the lower surface forms the upper surface of the cavity S (see FIG. 30).

  At the time of separation, the peripheral side portion of the gate cut member 17A is lowered so as to contact the projection 6A, and the lower surface of the gate cut member 17A is the upper surface of the cavity S (design surface of the molded product). It becomes the same surface and forms a part of the cavity S, and the communication port between the cavity S and the lower opening of the guide passage 27A and the lower opening of the second sprue 11A is blocked.

  As described above, when the synthetic resin in the cavity S and the synthetic resin outside the cavity S are separated, the flow of the synthetic resin J stops, and this time the force that the synthetic resin J tries to exit the cavity S is reversed. Is added to the lower surface of the gate cut member 17A (the separation surface of the gate cut member 17A). In particular, since the lower surface of the gate cut member 17A is heated, the solidification of the synthetic resin J is delayed and the synthetic resin J is separated. Combined with the fact that the surface portion is not solidified, the transferability is good, the separation surface of the synthetic resin J is glossy and has no rough skin, and this separation surface and other non-separable surfaces It can be molded so that the border is not as much as possible.

  In the ninth embodiment shown in FIGS. 27 to 30, the molten synthetic resin J is placed in the second sprue 11A with the state before the separation operation being slightly lowered from the position shown in FIG. It may flow through the second sprue 11A while being directly heated at the upper end portion of the gate cut member 17A into which a part has entered, and may be injected into the cavity S.

  Further, the ninth embodiment may be applied to the insert molding as described above. In this case, the molten synthetic resin that has passed through the second sprue 11A is disposed in the cavity S so that the lower opening of the second sprue 11A faces the opening 41 of the insert 40. Injecting J into the cavity S through the opening 41 of the insert 40 is the same as in the other embodiments of insert molding described above.

  Next, the tenth embodiment will be described with reference to FIGS. 31 to 33. The same reference numerals and symbols as those of the first to ninth embodiments have the same functions, and the description thereof is omitted. Only the different parts will be described.

  The gate cut member 17B that separates the synthetic resin in the cavity S and the synthetic resin outside the cavity S is arranged in the vertical direction via the guide passage of the fixed third base plate 4 and the guide passage 27B provided in the fixed mold 6. Although it is possible to move up and down, the lower surface of the gate cut member 17B is a horizontal plane parallel to the upper surface of the cavity S. The guide passage 27B communicates with an intermediate position on the upper surface of the cavity S.

  A first runner 10A is formed at the lower end of the first sprue 9, a second sprue 11B (also a gate) is formed as an outlet of the first runner 10A, and a lower portion of the second sprue 11B is It is curved and communicates with the guide passage 27B through the communication port 14C. That is, the opening end of the second sprue 11B is communicated with the guide passage 27B located near the cavity S from the gate cut member 17B before the movement operation through the communication port 14C.

  Further, the lower end portion (tip portion) of the gate cut member 17B in the raised state faces the communication port 14C, that is, the lower end portion of the gate cut member 17B is positioned at an intermediate position in the vertical direction of the communication port 14C. It arrange | positions (refer FIG. 31). The guide passage 27B located below the gate cut member 17B constitutes a part of the gate. In the tenth embodiment, hot steam as a heat medium is not supplied into the heat medium passage 36B of the movable mold 26 before and after closing the mold.

  The operation of the injection molding of the tenth embodiment is the same as that of the first embodiment and the like. By supplying hot steam into the heat medium passage 35 of the stationary mold 6, the cavity of the stationary mold 6 is formed. The temperature is raised until the surface side reaches the ambient temperature of the softening point temperature, and the molten synthetic resin J is injected into the cavity S through the second sprue 11B (see FIG. 32).

  In the process in which the molten synthetic resin J flows and is injected into the cavity S, the molten synthetic resin J is injected while being in contact with the lower end portion of the gate cut member 17B. Therefore, the lower end portion of the gate cut member 17B is It will be heated. Then, the synthetic resin in the cavity S and the synthetic resin outside the cavity S are separated by the gate cut member 17B lowered to a position where the lower surface forms the upper surface of the cavity S (see FIG. 32). The lower surface of the gate cut member 17B lowered during the separation is flush with the upper surface of the cavity S (design surface of the molded product), and forms a part of the cavity S.

  As described above, when the synthetic resin in the cavity S and the synthetic resin outside the cavity S are separated, the flow of the synthetic resin J stops, and this time the force that the synthetic resin J tries to exit the cavity S is reversed. Is added to the lower surface of the gate cut member 17B (separation surface of the gate cut member 17B), and particularly the molten synthetic resin J is injected while being in contact with the lower end portion of the gate cut member 17B. Since the lower end portion is heated directly, the solidification of the synthetic resin J is delayed, and the separation surface portion of the synthetic resin J is maintained in a state where it is not solidified. The separation surface is glossy and has no rough skin, and can be molded so that the boundary between this separation surface and other non-separated surfaces is not known as much as possible.

  The state before the separation operation in the tenth embodiment shown in FIGS. 31 to 33 is the same as that in the eleventh embodiment shown in FIG. 34. The lower end of the gate cut member 17B is connected to the communication port 14C. It is good also as a position slightly raised. In the eleventh embodiment, hot steam as a heat medium is supplied into the heat medium passage 36 of the movable mold 26 before and after closing the mold.

The eleventh embodiment will be described. When the molten synthetic resin J that has entered the guide passage 27B comes into contact with the lower end of the gate cut member 17B before being injected into the cavity S, the gate cut is performed. The lower end portion of the member 17B is heated and eventually injected into the cavity S. The molding operation and effects after this injection are the same as those in the tenth embodiment, and are omitted here.

  Further, the tenth and eleventh embodiments may be applied to the insert molding as described above. In this case, the molten synthetic resin that has passed through the second sprue 11B is disposed in the cavity S so that the lower opening of the second sprue 11B faces the opening 41 of the insert 40. Injecting J into the cavity S through the opening 41 of the insert 40 is the same as in the other embodiments of insert molding described above.

  In the first to eleventh embodiments described above, the opening end of the guide passage 27 that guides the gate cut member 17 is arranged so as to face the middle position of the bottom surface of the cavity S, or the gate cut members 17A and 17B. The opening ends of the guide passages 27A and 27B for guiding the surface of the cavity S are arranged so as to face the intermediate position of the upper surface (surface) of the cavity S, but not limited to this, the peripheral edge of the bottom surface of the cavity S or the peripheral edge of the upper surface It may be provided as follows.

  That is, based on FIG. 35, a twelfth embodiment in which the opening end portion of the guide passage 27 for guiding the gate cut member 17 is disposed so as to face the peripheral portion of the bottom surface of the cavity S will be described.

  Further, the gate cut member 17 in the lowered state is arranged so that the upper end portion (tip portion) thereof faces the communication port 14B, that is, the upper end portion of the gate cut member 17 is positioned at an intermediate position in the vertical direction of the communication port 14B. Set up. In the twelfth embodiment, hot steam as a heat medium is not supplied into the heat medium passage 36 of the movable mold 26 before and after closing the mold.

  The operation of the injection molding of the twelfth embodiment will be described. By supplying hot steam into the heat medium passage 35 of the fixed mold 6, the ambient temperature at which the cavity forming surface side of the fixed mold 6 is at the softening point temperature is described. The melted synthetic resin J flows while heating the upper end of the gate cut member 17 facing the communication port 14B directly through the guide passage 27 above the gate 13B and the gate cut member 17. The synthetic resin in the cavity S and the synthetic resin outside the cavity S are separated by the gate cut member 17 which is injected into the cavity S and raised to a position where the upper surface thereof forms the bottom surface of the cavity S.

  When the synthetic resin in the cavity S and the synthetic resin outside the cavity S are separated, the flow of the synthetic resin J stops, and the force that the synthetic resin J tries to exit from the cavity S is reversed. Since the upper surface of the gate cut member 17 is heated in particular, the solidification of the synthetic resin J is delayed and the separation surface portion of the synthetic resin J does not solidify. Combined with the state being maintained, the transferability is good, the separation surface of the synthetic resin J is also glossy and there is no rough skin, and the boundary between this separation surface and other non-separated surfaces is not understood as much as possible. Can be molded.

  In the first to twelfth embodiments, the second sprues 11A and 11B, the gates 13A and 13B, and the guide passages 27, 27A, and 27A may be formed in a round tube shape or a rectangular tube shape.

  In the first to twelfth embodiments, the gate cut member is raised to a position where the upper surface forms the bottom surface of the cavity S, or the lower surface is raised to a position where the upper surface of the cavity S is formed. Although the synthetic resin in the cavity S and the synthetic resin outside the cavity S are separated, it does not necessarily have to be raised or lowered to the same level as the bottom or top surface of the cavity S. That is, the communication ports 14A, 14B, and 14C between the gate and the gate cut member may be raised or lowered to a position where they are closed, and not necessarily raised or lowered to the same level as the bottom surface or the top surface of the cavity S.

  Furthermore, in the above first to twelfth embodiments, the guide passage 27 located above the gate cut member 17, the guide passage 27A located below the gate cut member 17A, and the gate cut member. The guide passage 27B located below 17b communicates with the gates 13A, 13B and the second sprues (also gates) 11A, 11B through the communication ports 14A, 14B, 14C, so that the gate through which the synthetic resin flows It will constitute a part of.

In the above first, third, fifth, seventh, ninth and eleventh embodiments, the movable mold 26 is moved back and forth before the mold is closed by the fixed mold 6 and the movable mold 26. Hot steam, which is a heat medium, is supplied into the heat medium passages 36, 36A, 36B to heat the surroundings of the gate cut members 17, 17A, 17B of the movable mold 26, and the molten synthetic resin J is a cavity. Before being injected into S, it comes into contact with the tip of the gate cut members 17, 17A, 17B, and is then injected into the cavity S.

  However, for example, when the volume of the molded product is small, that is, when the volume of the cavity S is small, it is not always necessary to supply steam as a heating medium into the heat medium passages 36, 36A, 36B. When the volume of the cavity S is small, the tip portions of the gate cut members 17, 17A and 17B are sufficiently heated by the molten synthetic resin in the process of injecting the molten synthetic resin J into the cavity S. Because it will be.

  Furthermore, in the second, fourth, sixth, eighth, tenth and twelfth embodiments described above, the movable mold 26 is moved back and forth before the stationary mold 6 and the movable mold 26 are closed. The molten synthetic resin J flows in contact with the front end portions of the gate cut members 17 and 17B without supplying hot steam as the heat medium into the heat medium passages 36 and 36B of the gate cut members 17 and 17B. It is injected into the cavity S while heating the front end portion.

  However, when the volume of the molded product is large, that is, when the volume of the cavity S is large, a heating medium may be supplied into the heat medium passages 36 and 36B. When the volume of the cavity S is large, the tip portions of the gate cut members 17 and 17B may not be sufficiently heated by the molten synthetic resin in the process in which the molten synthetic resin J is injected into the cavity S. Because.

  Therefore, in any of the embodiments of the present invention, hot steam as a heat medium is or is not supplied into the heat medium passages 36, 36A, and 36B of the movable mold 26 as necessary before and after mold closing. You just have to choose.

  In the first to twelfth embodiments described above, the gates 23A and 23B are separated after the synthetic resin in the cavity S and the synthetic resin outside the cavity S are separated by the gate cut members 17, 17A and 17B. The synthetic resin in the second sprue (which is also a gate) 11A and 11B is pulled out of the injection molding apparatus.

  However, conventionally, after the molten synthetic resin J is injected into the cavity S (see FIG. 36), the synthetic resin J in the gate 13B is pulled out of the injection molding apparatus (FIG. 37), and thereafter the gate cut member 17 , The synthetic resin inside the cavity S and the synthetic resin outside the cavity S were separated (see FIG. 38).

  In such a prior art, since the synthetic resin J in the gate 13B was pulled out of the injection molding device before raising the gate cut member 17, the synthetic resin facing the communication port 14B when being pulled out. J may have a bulging portion JB. For this reason, when the separation is performed by raising the gate cut member 17, the bulging portion JB is cut into a small piece JP and left in the gate 13B.

  Therefore, in the next molding operation, the solidified piece JP enters the cavity S together with the molten synthetic resin J, and this small piece JP sometimes exists on the design surface (front side) of the molded product. If it was to be done, the workmanship of this molded product was poor, which was not preferable.

  Therefore, in the above first to twelfth embodiments of the present invention, after the synthetic resin in the cavity S and the synthetic resin outside the cavity S are separated by the gate cut members 17, 17A, 17B, the gate is cut. Since the synthetic resin in 23A, 23B and the second sprues 11A, 11B is pulled out of the injection molding apparatus, it is possible to prevent such an undesirable situation from occurring.

  As described above, the embodiments of the present invention have been described. However, various alternatives, modifications, and variations can be made by those skilled in the art based on the above description. Including alternatives, modifications or variations.

6 Fixed mold 11, 11A, 11B Second sprue 13A, 13B Gate 14A, 14B Communication port 17, 17A Gate cut member 26 Movable mold 27, 27A, 27A Guide path 28 Guide path 35 Heat medium path 36, 36A, 36B Heat medium passage 40 Insert 41 Opening S Cavity

Claims (2)

In an injection molding apparatus for injecting and molding molten synthetic resin into a cavity through a gate in a state where a fixed mold and a movable mold are closed,
The opening end of the guide passage for moving the gate cut member that separates the synthetic resin in the cavity and the synthetic resin outside the cavity is disposed so as to face the bottom surface or the top surface of the cavity, and
An injection molding apparatus characterized in that an opening end portion of the gate is communicated with the guide passage through a communication port, and a front end portion of the gate cut member before the moving operation is disposed so as to face the communication port. . After setting the insert made of thermoplastic synthetic resin in the cavity in a state where the fixed mold and the movable mold are opened, the fixed mold and the movable mold are closed, and the insert is made through the gate. In an insert molding device that injects molten synthetic resin into a cavity to make it an integral product,
  The opening end portion of the guide passage for moving the gate cut member that separates the synthetic resin in the cavity and the synthetic resin outside the cavity is disposed so as to face an intermediate position of the bottom surface or the upper surface of the cavity, and
  An opening end portion of the gate is communicated with the guide passage through a communication port, and a distal end portion of the gate cut member before the moving operation is disposed so as to face the communication port,
  The molten synthetic resin that has passed through the guide passage located near the cavity from the gate and the gate cut member is injected into the cavity through the opening of the insert.
An insert molding device characterized by that.

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