JP2012223987A - Mold apparatus, and molding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold apparatus that can form a resin molded product that can prevent a flow mark from occurring even when a concave part is formed on a surface and to provide a molding method.SOLUTION: The mold apparatus 10 includes: a gas pressure introduction pipe line 27, one end side of which is connected to a gas vent 26 and to which the gas exhausted from the cavity 23 is introduced; a cylinder hole 28 to which the other end side of a gas pressure introduction pipe line 27 is connected and an opening 28a communicates with the cavity 23; an extrusion piece 30 that can move the cylinder hole 28 according to the pressure of the gas; and a first positioning member 33 that limits the draw-in position in the cylinder hole 28 of the extrusion piece 30. The end face 30a of the opening 28a side of the extrusion piece 30 is positioned at the part to become flush with the inner wall surface 23a in a state being positioned by the first positioning member 33. After the gas pressure introduced into the cylinder hole 28 has increased, the extrusion piece 30 is extruded to the inner part of the cavity 23 rather than the flush position of the end face 30a.

Description

  The present invention relates to a mold apparatus and a molding method.

  Resin molded products formed by injection molding are used in various products, but as such plastic molded products, they are also commonly used in exterior parts that can be seen at a glance. Here, in the exterior component, various marks are also formed by forming irregularities on the surface thereof. When such marks are formed inside the mold, productivity can be improved.

  Here, as a technique for forming a convex portion in a resin molded product inside the mold, there is one disclosed in Patent Document 1. According to the technical content disclosed in Patent Document 1, the piece is provided in the recess so as to be movable. When the uncured resin is filled, the piece is positioned at a flat position with respect to the inner surface of the cavity, and then the piece is retracted to the inside of the recess. Thus, the technical content of filling the concave portion with an uncured resin is disclosed.

Japanese Patent Laid-Open No. 2004-343483

  By the way, when a mark consisting of a recess is formed on the surface of the exterior component, it is confirmed that a flow mark is formed on the surface of the exterior component on the downstream side of the flow of the uncured resin from the recess, resulting in poor appearance. ing. On the other hand, when a mark consisting of convex parts is formed on the surface of the exterior part, the flow mark is formed on the downstream side of the flow of uncured resin from the convex part, but the flow mark is mainly formed on the back surface of the exterior part. It has been confirmed that That is, the problem that the appearance defect due to the formation of the flow mark does not occur on the surface of the exterior part does not occur in Patent Document 1, and is a problem peculiar to the case where a mark made of a recess is formed on the surface of the exterior part. It can be said.

  Here, as described above, in the case where a mark made of a recess is formed on the surface of an exterior component, at present, it is formed by providing a protruding portion inside the cavity. For this reason, a flow mark is formed on the surface of the exterior component on the downstream side of the flow of the uncured resin with respect to the protruding portion. In particular, when the uncured resin contains a glittering material, the orientation of the added glittering material is changed, so that a flow mark is formed, resulting in a remarkable appearance defect.

  The present invention has been made to solve at least one of the above-described problems, and can form a resin molded product capable of preventing the occurrence of a flow mark even when a concave portion is formed on the surface. A mold apparatus and a molding method are provided.

  In order to solve the above problems, a mold apparatus according to the present invention is a mold apparatus in which an uncured resin is introduced into a cavity formed by joining a first mold and a second mold, and communicates with the cavity. One end side of the gas vent is connected to the gas vent, and a gas pressure introduction line into which the gas discharged from the cavity is introduced, and the other end side of the gas pressure introduction line are connected to the first or second mold. A cylinder hole whose opening is in communication with the cavity, an extrusion piece that moves the cylinder hole in response to the pressure of the gas in the cylinder hole, and a cylinder hole in the extrusion piece that is provided in the cylinder hole. A first positioning member that restricts the pull-in position of the extrusion piece, and the end face on the opening side of the extrusion piece is positioned by the first positioning member. In a state where the pressure of the gas introduced into the cylinder hole through the gas pressure introduction pipe is increased, the gas is introduced into the cylinder wall through the gas pressure introduction line. The pushing piece is pushed out into the cavity from the position where the end faces are flush with each other.

  When configured in this way, in a state before the uncured resin is caused to flow into the cavity, the extrusion piece is located at a portion where the end surface is flush with the inner wall surface of the first mold or the second mold. positioned. In this state, when the uncured resin is caused to flow into the cavity, the uncured resin flows in the same manner as the surrounding inner wall surface in the vicinity of the extrusion piece. That is, in the conventional configuration, turbulent flow is generated in the flow of the uncured resin due to the presence of the protruding portion, and furthermore, the temperature in the cavity is also uneven due to the presence of the protruding portion. And it is thought that it will be in the state where a flow mark is formed by these non-uniformity of turbulence and temperature.

  However, in the above-described configuration, it flows in the same manner as the inner wall surface around the pushing piece. Then, after the inside of the cavity is filled with uncured resin, the extrusion piece is pushed out from the opening, and the uncured resin before curing is pushed in. Thereby, the uncured resin is pushed out in a static state, and the depression is formed in the resin molded product. As a result, when filling the uncured resin into the cavity, it is possible to prevent a flow mark from being formed on the downstream side of the flow of the uncured resin, as in the case of providing a protrusion inside the cavity as in the past. It becomes.

  According to another aspect of the present invention, in the above invention, the cylinder hole is provided with a piston that is moved along the cylinder hole by gas pressure while sealing the cylinder hole. It is preferable that a biasing means for applying a biasing force in a direction of pulling the piston from the opening is connected to a non-opposing end surface of the piston that does not face the pushing piece.

  In such a configuration, a piston is disposed in the cylinder hole, and a gas pressure acts on the piston. Thereby, it becomes possible to extrude an extrusion piece favorably from the opening part of a cylinder hole. Further, since the urging means is connected to the piston, the urging means and the first urging means are in the state before the gas flows in through the gas pressure introduction conduit and the pressure acting on the piston increases. With the positioning member, the push-out piece can be automatically kept in the retracted position.

  Furthermore, in another aspect of the present invention, in the above-described invention, it is preferable that the cylinder hole is provided with a second positioning member that limits a protruding length by which the pushing piece protrudes from the cylinder hole.

  In such a configuration, the protruding length of the pushing piece is limited by the second positioning member. As a result, it becomes possible to satisfactorily form a recess having a specified length.

  The molding method according to another aspect of the present invention is a mold apparatus in which an uncured resin is introduced into a cavity formed by joining a first mold and a second mold. One end side is connected to the gas vent communicating with the cavity, a gas pressure introduction pipe into which the gas discharged from the cavity is introduced, and the other end side of the gas pressure introduction pipe are connected to the first mold or A cylinder hole whose opening communicates with the cavity, and an extrusion piece that can move the cylinder hole in response to the pressure of the gas in the cylinder hole. A resin inflow process in which uncured resin is allowed to flow into the cavity in a state where the end surface on the opening side is located at a position flush with the inner wall surface of the first mold or the second mold, Gas that is discharged from the cavity when uncured resin flows into the cylinder acts on the cylinder hole via the gas pressure introduction pipe, and is introduced into the cylinder hole via the gas pressure introduction pipe It is preferable to comprise an extruding step of extruding the extruding piece into the cavity from a position where the end faces are flush with each other after the pressure of the pressure increases.

  When configured in this way, in a state before the uncured resin is caused to flow into the cavity, the extrusion piece is located at a portion where the end surface is flush with the inner wall surface of the first mold or the second mold. positioned. In this state, when the uncured resin is caused to flow into the cavity in the resin inflow process, the uncured resin flows in the vicinity of the extrusion piece in the same manner as the surrounding inner wall surface. That is, in the conventional configuration, turbulent flow is generated in the flow of the uncured resin due to the presence of the protruding portion, and furthermore, the temperature in the cavity is also uneven due to the presence of the protruding portion. And it is thought that it will be in the state where a flow mark is formed by these non-uniformity of turbulence and temperature.

  However, in the above-described configuration, it flows in the same manner as the inner wall surface around the pushing piece. Then, after the inside of the cavity is filled with the uncured resin, the extrusion piece is pushed out from the opening in the extrusion process, and the uncured resin before curing is pushed in. Thereby, the uncured resin is pushed out in a static state, and the depression is formed in the resin molded product. Therefore, when filling the uncured resin into the cavity, the flow mark is formed on the downstream side of the flow of the uncured resin as in the case of providing a protrusion inside the cavity as in the prior art. It becomes possible to prevent.

It is a sectional side view which shows the structure of the metal mold | die apparatus which concerns on one embodiment of this invention. It is a top view which shows the cavity side of the 2nd type | mold among the metal mold apparatuses of FIG. It is a partial sectional side view which expands and shows the part enclosed by the line P of FIG. It is a perspective view which shows the shape of a resin molded product. It is a sectional side view which shows the state before and behind an extrusion piece being extruded from an opening part. It is a sectional side view which shows the conventional structure of the metal mold | die with which a protrusion part protrudes in a cavity. It is a sectional side view which shows the shape and operation | movement of the extrusion piece which concerns on the modification of this invention.

  Hereinafter, a mold apparatus 10 and a molding method according to an embodiment of the present invention will be described with reference to the drawings.

<1. About Configuration of Mold Device 10>
FIG. 1 is a side sectional view showing the configuration of the mold apparatus 10. FIG. 2 is a plan view showing a state of the mold apparatus 10 when the second mold 22 is viewed from the cavity 23 side, and shows a portion other than the cavity 23 with hatching. The mold apparatus 10 includes a first mold 21 that is a male mold and a second mold 22 that is a female mold, and is uncured in a space portion (cavity 23) formed by meshing them. Resin is allowed to flow.

  In addition, although the uncured resin in the present embodiment contains a glitter material, aluminum flakes, silica flakes, pearl pigments, mica pigments, and the like can be used as the glitter material. The uncured resin is preferably a thermoplastic resin such as an acrylic resin, a polycarbonate resin, a polyethylene resin, a polyvinyl chloride resin, or an ABS (acrylonitrile butadiene styrene) resin. However, the uncured resin may be a thermosetting resin such as a phenol resin, an epoxy resin, or a polyurethane resin.

  Further, the first mold 21 may be a female mold instead of a male mold, and similarly, the second mold 22 may be a male mold instead of a female mold.

  The mold apparatus 10 includes a sprue 24 that is an introduction port for uncured resin, and a gate 25 that guides introduction of the uncured resin into the cavity 23 and guides uniform diffusion of the uncured resin. Is provided. The mold apparatus 10 is provided with a gas vent 26. The gas vent 26 is a portion for letting air existing inside the cavity 23 or gas generated from uncured resin (hereinafter collectively referred to as a mixed gas) to escape from the inside of the cavity 23.

  The mold apparatus 10 is provided with a gas pressure introduction conduit 27. One end of the gas pressure introduction pipe line 27 is connected to the gas vent 26, and gas can enter the gas pressure introduction pipe line 27 from the gas vent 26. Here, as shown in FIG. 2, the gas vents 26 are provided on both ends of the cavity 23 in the width direction (Y direction in FIG. 2).

  FIG. 3 is an enlarged partial side sectional view showing a portion surrounded by a line P in FIG. As shown in FIG. 3, the other end side of the gas pressure introduction conduit 27 is connected to the cylinder hole 28. The cylinder hole 28 communicates with the cavity 23 at the opening 28a.

  A piston 29 is disposed inside the cylinder hole 28, and the mixed gas flowing in from the gas pressure introduction conduit 27 can apply pressure to the piston 29. That is, the cylinder hole 28 is formed with the line L in FIG. 3 as the center line, and is formed so that the piston 29 can be moved along the direction along the line L (X direction). Therefore, the portion of the cylinder hole 28 where the piston 29 slides has the same cross section in any part when cut by a plane perpendicular to the line L (plane perpendicular to the X direction), and the center of the cross section. Is provided so that line L passes through.

  In the present embodiment, the gas pressure introduction pipe line 27 has branch pipe parts 27 a respectively connected to the gas vents 26 located on both ends in the width direction (Y direction) of the cavity 23. And the branch pipe part 27a merges and becomes the main pipe part 27b of the gas pressure introduction pipe line 27.

  The piston 29 is provided so that the cylinder hole 28 can be moved in accordance with the pressure of the mixed gas while sealing the cylinder hole 28 without rattling. An extrusion piece 30 is connected to the piston 29 via a connecting member 31. As will be described later, the extrusion piece 30 pushes in a resin before curing (resin molded product 40 (see FIG. 4); hereinafter referred to as a resin molded product 40 (exterior part) regardless of before and after curing). This is a portion for forming the recess 41 in the molded product 40. Further, the end face (inner end face 30 a) on the cavity 23 side of the extrusion piece 30 is formed so as to be flush with the inner wall surface 23 a of the cavity 23.

  In the configuration shown in FIG. 2, the pushing piece 30 is configured to integrally extrude a mark composed of a plurality of concave portions 41. Therefore, the cylinder hole 28 is also provided in a rectangular shape.

  Here, one end side of the spring 32 is connected to the end surface 29 b of the piston 29 on the side not facing the push piece 30. The other end of the spring 32 is connected to the inner wall of the gas pressure introduction conduit 27. The balance load of the spring 32 is set in advance so as to balance with the pressure before the pressure of the compressed mixed gas becomes maximum. Thereby, after filling the uncured resin, the extrusion piece 30 can be pushed out to the uncured resin (resin molded product 40) at an appropriate timing when the pressure of the mixed gas exceeds the balance load of the spring 32. .

  As shown in FIG. 3, the cylinder hole 28 is provided with a first stopper 33 and a second stopper 34. The first stopper 33 can be brought into contact with the end face 29b described above. The first stopper 33 is a position in the cylinder hole 28 where the inner end surface 30a of the pushing piece 30 is flush with the inner wall surface 23a of the cavity 23 when the first stopper 33 is in contact with the end surface 29b. Is provided. That is, the first stopper 33 is a positioning member that regulates the position where the piston 29 is returned (pushed) into the cylinder hole 28.

  The spring 32 corresponds to an example of an urging means in the claims. The first stopper 33 corresponds to an example of a first positioning member in the claims, and the second stopper 34 corresponds to an example of a second positioning member in the claims.

  Further, the second stopper 34 can be brought into contact with the end face 29 a on the side of the piston 29 facing the push piece 30. The second stopper 34 is set at a position where the pushing piece 30 protrudes most into the cavity 23 when the second stopper 34 is in contact with the end surface 29 a in the cylinder hole 28. That is, the second stopper 34 is a positioning member that restricts the piston 29 from protruding into the cylinder hole 28.

  In addition, the mold apparatus 10 is provided with driving means (not shown) for sliding the first mold 21 or the second mold 22. The mold apparatus 10 is provided with a supply means (not shown) for supplying uncured resin to the sprue 24.

<2. Operation of mold apparatus 10>
Subsequently, the operation of the mold apparatus 10 of the present embodiment will be described. When uncured resin is supplied from a supply means (not shown) to the sprue 24 at a predetermined pressure, the uncured resin flows into the cavity 23 via the gate 25. Then, the mixed gas existing inside the cavity 23 is discharged from the cavity 23 through the gas vent 26 as the uncured resin is filled. At this time, the discharged mixed gas flows into the cylinder hole 28 from the gas vent 26 through the gas pressure introduction pipe line 27. Due to the inflow of the mixed gas, a pressure directed toward the opening 28 a of the cylinder hole 28 acts on the end surface of the piston 29. On the other hand, since the pulling force of the spring 32 acts on the piston 29, the mixed gas is compressed inside the cylinder hole 28 and the gas pressure introduction conduit 27.

  As shown in FIG. 5A, in a state before the piston 29 is moved by the compression force of the mixed gas, the end surface 29b of the piston 29 abuts on the first stopper 33, and the inner end surface 30a is a cavity. 23 is flush with the inner wall surface 23a.

  When the uncured resin spreads inside the cavity 23 and the uncured resin does not flow so much in the vicinity of the opening 28 a of the cylinder hole 28, the piston 29 opens against the pulling force of the spring 32. It is moved toward the portion 28a. The timing at which the push-out piece 30 is pushed out is a little earlier than when the compressed mixed gas becomes maximum, and the volume of the cylinder hole 28 on the gas pressure introduction conduit 27 side increases due to the movement of the piston 29. Even so, the pushing piece 30 is set to be sufficiently pushed out.

  5B, the extrusion piece 30 is pushed out from the opening 28a, and the uncured resin (resin molded product 40) is pushed in, so that a recess 41 is formed in the resin molded product 40. Here, after the uncured resin has already flowed into the cavity 23 and the uncured resin does not flow so much, the extrusion piece 30 protrudes from the opening 28a. Further, in a state before the uncured resin is caused to flow into the cavity 23, as shown in FIG. 5A, the extrusion piece 30 has an inner end face 30 a of the first mold 21 or the second mold 22. It is located at the same level as the inner wall. When the uncured resin is caused to flow into the cavity 23 in this state, the uncured resin flows in the vicinity of the extrusion piece 30 in the same manner as the surrounding inner wall surface 23a.

  That is, in the conventional configuration as shown in FIG. 6, turbulent flow is generated in the flow of the uncured resin due to the presence of the protruding portion 50 protruding inside the cavity 23 (see arrow B in FIG. 6; The arrow A indicates the direction of the flow of the uncured resin), and the presence of the protrusion 50 also causes temperature non-uniformity inside the cavity 23. And it is thought that it will be in the state where a flow mark is formed by these non-uniformity of turbulence and temperature.

  However, when the uncured resin is filled into the cavity 23, it flows in the vicinity of the extrusion piece 30 in the same manner as the surrounding inner wall surface 23 a. Therefore, the uncured resin is filled in a state that prevents the occurrence of turbulent flow that has occurred when the protruding portion 50 protrudes into the cavity 23 as in the prior art. In the present embodiment, since the uncured resin is filled in the cavity 23 in the state where the protrusions 50 are not present, the interior of the cavity 23 is as in the case where the conventional protrusions 50 are present. There is no temperature non-uniformity.

  Then, after the inside of the cavity 23 is filled with uncured resin, the extrusion piece 30 is pushed out from the opening 28a, and the uncured resin before curing is pushed in. As a result, the extrusion piece 30 is pushed out in a static state of the uncured resin, and the recess 41 is formed in the resin molded product 40. And the resin (resin molded product 40) before hardening in which the recessed part 41 was formed hardens | cures after predetermined time passes. For this reason, a situation in which a flow mark is formed on the resin molded product 40 on the downstream side of the flow when the uncured resin flows in does not occur. That is, when a mark composed of the recess 41 is formed on the surface of the exterior part that is the resin molded product 40, for example, a streak-like flow mark is not formed around the mark.

  In addition, even if the orientation of the glittering material is changed by pushing the extrusion piece 30, it is considered that the change in the orientation due to the pushing hardly causes poor appearance. The reason is considered that the orientation changes around the portion where the pushing piece 30 is pushed in. For this reason, it is considered that there is almost no problem such as a change in orientation, especially in the downstream of the flow of the uncured resin.

<3. Effects in the present embodiment>
According to the mold apparatus 10 and the molding method having the above-described configuration, after the uncured resin is filled in the cavity 23 and the uncured resin is in a static state, the extrusion piece 30 is pushed out to form the resin. A recess 41 is formed in the product 40. Accordingly, when filling the uncured resin into the cavity 23, a flow mark is formed on the downstream side of the uncured resin flow as in the case of providing the protrusion 50 inside the cavity 23 as in the conventional example of FIG. It is possible to prevent the formation.

  In the present embodiment, a piston 29 is disposed in the cylinder hole 28, and a gas pressure acts on the piston 29. As a result, the extrusion piece 30 can be favorably extruded from the opening 28 a of the cylinder hole 28. In addition, since the spring 32 is connected to the piston 29, the first gas 32 and the first spring 32 are in a state before the pressure of the gas flowing into the piston 29 through the gas pressure introduction pipe 27 and acting on the piston 29 increases. With the stopper 33, the pushing piece 30 can be automatically put on standby at the retracted position.

  Further, in the present embodiment, the protruding length of the pushing piece 30 is limited by the second stopper 34. Thereby, it is possible to satisfactorily form the recess 41 having a specified length.

<4. Modification>
Although one embodiment of the present invention has been described above, the present invention can be variously modified. This will be described below.

(4-1) Modification 1
In the above-described embodiment, the shape of the inner end face 30a of the pushing piece 30 is not particularly described. However, the shape of the inner end face 30a of the extrusion piece 30 can be set to a desired shape according to the mark formed on the resin molded product 40 (exterior part). FIG. 7 shows this image.

  FIG. 7 shows an example of the pushing piece 30 having the inner end face 30a corresponding to the mark. In this example, the pushing piece 30 is formed with a protruding end surface portion 30b that protrudes most into the cavity 23, and a hollow portion 30c that is recessed toward the drawing side of the cylinder hole 28 from the protruding end surface portion 30b. Then, as shown in FIG. 7A, the protruding end surface portion 30 b is located at a portion that is flush with the inner wall surface 23 a of the cavity 23 before the push-out piece 30 is pushed out. On the other hand, as shown in FIG. 7B, when the pushing piece 30 is pushed out, the bottom surface of the recess 30 c is located at a portion that is flush with the inner wall surface 23 a of the cavity 23. However, when the pushing piece 30 is pushed out, the bottom surface of the recessed portion 30 c does not have to be located at a position where it is flush with the inner wall surface 23 a of the cavity 23.

  Here, as shown in FIG. 7A, when the uncured resin flows into the cavity 23, the cavity 23 has a recessed portion due to the presence of the recessed portion 30c. However, as described above, when a mark made of a convex portion is formed on the surface of the resin molded product 40 (exterior component), the flow mark is mainly formed on the back surface of the resin molded product 40 (exterior component). Has been confirmed. Therefore, since the flow mark due to the influence of the hollow portion is generated on the back side of the resin molded product 40 (exterior part), the cylinder hole 28 exists in the cavity 23 when the uncured resin flows in as shown in FIG. There is almost no influence of the flow mark on the side (surface side of the resin molded product 40). Therefore, even when the extrusion piece 30 as shown in FIG. 7 is used, it is possible to prevent the flow mark from being formed on the downstream side of the flow of the uncured resin.

(4-2) Modification 2
In the above-described embodiment, the timing of pushing out the pushing piece 30 may be as follows. That is, when the uncured resin is cured, a so-called sink is generated in the resin molded product 40 due to curing shrinkage. Therefore, in a state where curing has started, the extrusion piece 30 may be gradually pushed out as the curing proceeds. In this way, if the depression 41 is formed by pushing out the extrusion piece 30 so as to keep pace with the sink, the influence of sink marks can be reduced in the resin molded product 40, and the dimensional accuracy of the resin molded product 40 can be increased. It becomes possible to improve. Here, when the pushing piece 30 is pushed so as to keep pace with the sink, the inner end surface 30a of the pushing piece 30 may be slightly heated to slightly remelt the molded product of the resin molded product 40.

(4-3) Modification 3
In the above-described modified example 2 or separately from the above-described modified example 2, the pushing piece 30 may be configured to be pushed out by driving an actuator or the like whose driving is controlled by a control unit, for example. In this case, the piston 29 is connected to the driving force transmission mechanism of the actuator. In this case, the gas pressure introduction pipe line 27 may be configured to apply the gas pressure of the mixed gas to the piston 29, but the gas pressure introduction pipe line 27 is configured to apply the gas pressure of the mixed gas to the piston 29. Without being connected (that is, the gas pressure introduction pipe line 27 is not connected to the cylinder hole 28), a gas pressure detection sensor for detecting the gas pressure in the chamber may be provided connected to a separate chamber. .

  When the gas pressure introduction pipe line 27 is connected to the above-described chamber and a gas pressure detection sensor is further provided, the control unit operates the actuator when the gas pressure reaches a preset gas pressure threshold value. Then, the pushing piece 30 is pushed out. If it does in this way, it will become possible to set it as the structure which extrudes the extrusion piece 30 by using a gas pressure as a trigger.

  As described above, when the push-out piece 30 is pushed out by using the gas pressure as a trigger, the push-out piece 30 is pushed out by operating the actuator immediately after the gas pressure reaches the gas pressure threshold. However, after a predetermined time has elapsed since the gas pressure reached the gas pressure threshold value, the actuator may be operated to push out the pushing piece 30. When the pushing piece 30 is pushed out after a predetermined time has elapsed after the gas pressure reaches the gas pressure threshold, the pushing timing can be optimized in view of the progress of curing of the resin molded product 40. Thereby, it becomes possible to improve quality in the resin molded product 40 (exterior part) which has the mark which consists of the recessed part 41. FIG.

(4-4) Modification 4
In the third modification described above, a case is described in which the pushing piece 30 is pushed out after a predetermined time has elapsed after the gas pressure reaches the gas pressure threshold. However, the predetermined time may be determined in consideration of the glass transition temperature of the uncured resin. For example, when the temperature of the mold apparatus 10 is constant by the operation of the cooling mechanism of the mold apparatus 10, the filling of the uncured resin into the cavity 23 and the timing at which the uncured resin is cooled to the glass transition temperature. Is in a state of correlation. Therefore, the predetermined time may be determined in correspondence with the time for cooling to the glass transition temperature.

(4-5) Modification 5
In the above-described embodiment, the diameter of the cylinder hole 28 may be changed between a portion where the pushing piece 30 slides and a portion where the piston 29 slides. In other words, the portion of the cylinder hole 28 where the piston 29 slides may be optimized by using the Pascal principle to optimize the force for pushing out the pushing piece 30 by the action of gas pressure. Further, the diameter of the portion of the cylinder hole 28 where the push piece 30 slides may be optimized in accordance with the size of the recess 41 formed in the resin molded product 40.

(4-6) Modification 6
In the above-described embodiment, various shapes can be adopted as the cross-sectional shape of the cylinder hole 28. As the cross-sectional shape of the cylinder hole 28, various shapes such as a polygonal shape such as a circular shape, a triangular shape, and a rectangular shape, and a shape corresponding to a mark formed on the resin molded product 40 (exterior part) as the concave portion 41 are adopted. Is possible.

DESCRIPTION OF SYMBOLS 10 ... Mold, 21 ... 1st type | mold, 22 ... 2nd type | mold, 23 ... Cavity, 23a ... Inner wall surface, 24 ... Sprue, 25 ... Gate, 26 ... Gas vent, 27 ... Gas pressure introduction pipe line, 27a ... Branch pipe part, 27b ... main pipe part, 28 ... cylinder hole, 28a ... opening, 29 ... piston, 29a, 29b ... end face, 30 ... extruding piece, 30a ... internal end face, 31 ... connecting member, 40 ... resin molded product , 41... Recessed portion, 32... Spring (corresponding to an example of biasing means), 33... First stopper (corresponding to an example of first positioning member), 34... Second stopper (an example of second positioning member) 40 ... resin molded product, 41 ... recess, 50 ... projection

Claims (4)

A mold apparatus in which an uncured resin is introduced into a cavity formed by joining a first mold and a second mold,
A gas pressure introduction line connected to one end side of the gas vent communicating with the cavity, and into which gas discharged from the cavity is introduced;
A cylinder hole connected to the other end of the gas pressure introduction pipe and provided in at least one of the first mold or the second mold, the opening of which communicates with the cavity;
An extrusion piece that is moved in accordance with the pressure of the gas in the cylinder hole;
A first positioning member that is provided in the cylinder hole and restricts a pull-in position in the cylinder hole of the push piece;
Comprising
The end face on the opening side of the pushing piece is in a portion that is flush with the inner wall surface of the first die or the second die when the pushing piece is positioned by the first positioning member. Is located
After the pressure of the gas introduced into the cylinder hole through the gas pressure introduction pipe increases, the push piece is pushed into the cavity from the position where the end faces are flush with each other,
A mold apparatus characterized by that. The mold apparatus according to claim 1, wherein
The cylinder hole is provided with a piston that is moved along the cylinder hole by the pressure of the gas while sealing the cylinder hole, and the piston is connected to the extrusion piece,
The non-opposing end surface of the piston that is not opposed to the pushing piece is connected to a biasing unit that applies a biasing force in a direction in which the piston is pulled from the opening.
A mold apparatus characterized by that. The mold apparatus according to claim 1 or 2,
The cylinder hole is provided with a second positioning member that limits a protruding length by which the pushing piece protrudes from the cylinder hole.
A mold apparatus characterized by that. A mold apparatus in which an uncured resin is introduced into a cavity formed by joining a first mold and a second mold, and the mold apparatus is connected at one end to a gas vent communicating with the cavity, The gas pressure introduction pipe into which the gas discharged from the cavity is introduced and the other end of the gas pressure introduction pipe are connected, and are provided in at least one of the first mold or the second mold. A cylinder hole whose opening communicates with the cavity, and an extrusion piece that can move the cylinder hole in response to the pressure of the gas in the cylinder hole,
Resin inflow for allowing the uncured resin to flow into the cavity in a state where the end face on the opening side of the extrusion piece is located at a position flush with the inner wall surface of the first mold or the second mold Process,
When the uncured resin flows into the cavity by the resin inflow step, the pressure of the gas discharged from the cavity is applied to the cylinder hole through the gas pressure introduction pipe, and the gas pressure is introduced. An extruding step of extruding the extruding piece into the cavity from a position where the end faces are flush with each other after the pressure of the gas introduced into the cylinder hole through a pipe line increases;
The molding method characterized by comprising.

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