JP2022073469A - Injection molding machine - Google Patents

Abstract

To provide an injection molding machine adopting a new gate cutting method that prevents distortion, deformation, cracking, etc. from occurring at the gate connection part even when the rigidity of the molded product is low.SOLUTION: While a pressing portion 4, which forms part of the inner wall of a gate G, presses a resin molding body 100 around the opening of the gate G, an extrusion-blocking portion 5 prevents residual resin 200, which remains in a resin channel including the gate G in a manner of integrated with the resin molding body 100, from being extruded into a cavity 2 side, thereby cutting the resin molding body 100 off the residual resin 200. The residual resin 200, which is left in a form that cannot be extruded into the cavity 2 side by the extrusion-blocking portion 5, is detached from the extrusion-blocking portion 5 by rotating it around a predetermined rotational axis Z.SELECTED DRAWING: Figure 8

Description

The present invention relates to an injection molding apparatus.

Panel members for vehicles include large parts such as those long in a predetermined direction. When molding such a large part, resin injection is often performed from a multi-point gate. However, in the case of a multi-point gate, as many gate cutting operations as the number of gates are required by cutting so as to break the connection between the resin residue remaining in the gate and the molded product and separating the two. The gate cutting work is a work performed after the mold is opened, and a special jig for cutting and a time for cutting are required. Therefore, there is a problem that the more gates there are, the more time and effort it takes. On the other hand, according to the technique of Patent Document 1, since the gate is automatically cut when the molded product is extruded, the labor of the gate cutting work after molding can be reduced.

Japanese Unexamined Patent Publication No. 2019-14411

However, in the case of Patent Document 1, when the rigidity of the molded product is low, distortion, deformation, and cracking may occur at the gate connection portion. Specifically, as shown in FIG. 3 in Patent Document 1, two pressing portions 10 for pushing out a molded product have a positional relationship so as to sandwich the gate, and each of them is located at a position away from the gate. be. For this reason, in a molded product having low rigidity, there is a problem that when the molded product is extruded, bending deformation occurs in a shape that dents the vicinity of the gate, and further, whitening occurs at the bending deformation portion.

Note that FIGS. 5A to 5E of Patent Document 1 and the corresponding figures are only schematic views, and the position of the pressing portion 10 is different from the actual position as shown in FIG. 3 for ease of explanation. It is illustrated. However, even in these schematic views, the pressing portion 10 does not press the position closest to the gate. That is, even if the positional relationship is as shown in FIGS. 5A to 5E, the molded product may be bent and deformed.

An object of the present invention is to provide an injection molding apparatus incorporating a new gate cutting method so that distortion, deformation, cracking, etc. are unlikely to occur at a gate connection portion even when the rigidity of a molded product is low. ..

Means for Solving Problems and Effects of Invention

In order to solve the above problems, the injection molding apparatus of the present invention is used.
An injection molding device that molds a resin molded body by injecting molten resin into the molding space formed between the core and the cavity and cooling and solidifying it.
A part of the inner wall surface of the gate that opens from the core side to the cavity side with respect to the molding space, and a pressing portion located around the opening so as to face the resin molded body on the core side.
The first extrusion means for extruding the resin molded body toward the cavity side by pressing the pressing portion against the cavity side with the cavity and the core opened.
An extrusion blocking portion having a shape that prevents the resin residue that remains in the resin flow path including the gate leading to the molding space and is cooled and solidified by molding the resin molded body to the cavity side.
By extruding the resin molded product toward the cavity side by the first extrusion means, the resin molded body is separated from the resin residue whose extrusion to the cavity side is blocked by the extrusion blocking portion, and is released from the core. With
After the mold release, the second extrusion means for extruding the resin residue separated from the resin molded body together with the extrusion blocking portion toward the cavity side.
A rotating means for rotating the resin residue extruded to the cavity side by a predetermined distance by the second extrusion means in a predetermined rotation direction around a predetermined rotation axis extending in the mold opening direction of the cavity and the core.
The extrusion blocking portion is characterized in that it has a shape that allows it to be detached from the resin residue by the rotation.

According to the present invention, the extruded portion is positioned so as to form a part of the inner wall surface of the gate and to wrap around and face the resin molded body on the core side. Therefore, the extruded portion can push the position close to the gate of the resin molded product when extruded to the cavity side by the first extrusion means. By pushing the molded product at the position closest to the gate, it is unlikely that the conventional bending deformation will occur.

Further, according to the present invention, the resin residue including the inside of the gate is prevented from being extruded to the cavity side by the extrusion blocking portion. As a result, the gate can be automatically cut when the molded product is extruded. After that, in order to discharge the remaining resin residue, first, by the second extrusion means, the resin residue and the extrusion blocking portion are kept in the above-mentioned extrusion blocking state, for example, the resin residue is on the PL surface. Extrude a predetermined distance until it exceeds. The extrusion blocking part makes it impossible to extrude the resin residue to the cavity side, but since it has a shape that allows rotation around a predetermined rotation axis extending in the mold opening direction, the resin is next around this rotation axis. By rotating the residue, the resin residue is separated from the extrusion blocking portion. After that, the resin residue may be appropriately recovered by a robot arm or the like. In this way, the extrusion blocking portion provided for gate cutting can be separated from the resin residue by moving in a direction different from the extrusion direction of rotation, instead of extruding to the cavity side, so that the resin residue can be separated from the resin residue. Can be easily ejected from the mold.

The rotating means can rotate the rotating shaft portion, which is integrally rotatably engaged with the resin residue around the rotating axis, around the rotating axis. According to this configuration, the rotating shaft portion is used as the pressing portion that pushes the resin residue toward the cavity side. This rotation shaft portion bites into the resin residue so that it can rotate integrally around the rotation axis. Therefore, the rotating means can be realized with a simple configuration of simply rotating the rotating shaft portion.

When the second extruding means extrudes the resin residue by the predetermined distance and then further extrudes the resin residue into the rotating shaft portion and the penetrating portion of the core to which the rotating shaft portion penetrates, each other is extruded. Is provided with a rotation guide portion for relative rotation in a predetermined rotation direction around the rotation axis, and the rotation means includes the second extrusion means, and the rotation guide provided on the rotation shaft portion and the penetration portion. Can have a part and. According to this configuration, the resin residue can be automatically rotated and separated from the extrusion blocking portion only by pressing the resin residue by the second extrusion means.

When the resin molded body is extruded by the first extrusion means, the extrusion blocking portion is urged to the side opposite to the cavity so that the resin residue is not extruded to the cavity side together with the resin molded body. It can be equipped with urging means. Immediately after molding the resin molded body, the resin residue is connected to the resin residue, so when the resin molded body is extruded to the cavity side, the resin residue may also be extruded, but the urging means extrudes. Since the blocking portion is reliably stopped on the core side, it is possible to prevent the resin residue from being extruded, and it is possible to reliably generate a gate cut.

The plan view which showed the resin molded body molded by the injection molding apparatus which is an Example of this invention. FIG. 1A is a cross-sectional view taken along the line AA of FIG. The schematic diagram which showed the core just after the mold opening of the injection molding apparatus of FIG. 1 in a plan view. The schematic diagram which showed the injection molding method using the injection molding apparatus of FIG. 1 simply by using the BB cross section of FIG. The figure following FIG. The figure following FIG. The figure following FIG. The figure following FIG. The figure following FIG. The figure following FIG. The perspective view which showed the shape of the runner push part of the tip of a rotating shaft part simply. FIG. 8 is a schematic diagram showing more simply using a plan view. FIG. 9 is a schematic diagram showing a simpler view using a plan view. FIG. 12 is an enlarged view of part C of FIG. The figure which showed the resin residue remaining in the vicinity of a gate by enlarging the D1 part (a) of FIG. 14, the E1 direction view (b), and the F1-F1 cross section (c). In the modified example of this invention, the enlarged view which showed the part corresponding to the part C of FIG. The figure which showed the resin residue remaining in the vicinity of a gate by enlarging the D2 part (a) of FIG. 17, the E2 direction view (b), and the F2-F2 cross section (c).

Hereinafter, examples of the present invention will be described with reference to the drawings.

FIG. 1 is a resin molded body 100 molded by using the injection molding apparatus 1 of this embodiment. The resin molded body 100 here is an exterior part for a vehicle (for example, a molding), and is a longitudinal member (here, a panel member) that extends longitudinally in a predetermined direction (vertical direction in FIG. 1). As shown in the cross-sectional view of FIG. 2, the resin molded body 100 has a molded body main portion 101 having a main surface 101a forming a design surface, and a main portion 101 of the molded body main portion 101 from one end of the molded body main portion 101. It has a bent shape having a bent end portion 102 that extends in a bent shape toward the back surface 101b. The surface 102a of the bent end portion 102 continuous from the main surface 101a of the molded body main portion 101 also forms a design surface.

As shown in FIGS. 3 and 4, the injection molding apparatus 1 includes a mold 10 in which a molding space 9 is formed between the core 3 and the cavity 2, a first extrusion means 40, and a second extrusion means. 50 and a rotating means 70 are provided. Further, the die 10 has a pressing portion 4 (molded body pressing portion) and an extrusion blocking portion 5 on the core 3 side together with the core 3 and the cavity 2.

As shown in FIGS. 4 and 5, the mold 10 is a first position facing the main surface 101a of the resin molded body 100 molded between the core 3 and the cavity 2 (molding space 9). It includes a cavity 2 forming a mold and a core 3 forming a second mold located facing the main back surface 101b on the back side of the main surface 101a. In the molding space 9 here, a molding space 9 in which the main portion molding space 91 for molding the molded body main portion 101 and the bent end portion molding space 92 for molding the bent end portion 102 communicate with each other is formed inside. As shown in FIG. 3, the molding space 9 here is formed side by side so that two resin molded bodies 100 having the same shape can be molded at the same time so that the bent end portions 102 face each other on close sides to each other. Will be done.

Further, as shown in FIGS. 3 to 5, the mold 10 has a gate G and a runner L on the core 3 side so as to be a flow path (resin flow path) of the molten resin injected into the molding space 9. .. The mold 10 molds the resin molded body 100 by injecting the molten resin from the gate G into the molding space 9 and cooling and solidifying it, while in the gate G and the runner L, the remaining molten resin is the resin molded body 100. It is molded as a resin residue 200 by cooling and solidification accompanying molding, and remains inside.

The gate G forms a resin flow path leading to the molding space 9 and has an opening communicating with the molding space 9. As shown in FIG. 3, a plurality of gates G (here, three) are provided in the longitudinal direction (vertical direction in FIG. 3) with respect to one molding space 9. Further, as shown in FIG. 3, each gate G for the two forming spaces 9 arranged side by side in FIG. 4 is formed at the same position in the longitudinal direction (vertical direction in FIG. 3). As shown in FIGS. 4 and 5, each gate G has a cavity from the core 3 side with respect to the molding space 9 at a position facing the tip surface 102c of the bending end 102 to be molded in the bending end molding space 92. An opening is made toward the 2 side (opening toward the upward direction in FIGS. 4 and 5).

As shown in FIG. 4, the pressing portion 4 forms a gate forming portion of the core 3 forming the gate G together with the core main body 30. The pressing portion 4 forms a part of the inner wall surface of the gate G, the core main body 30 forms the inner wall surface of the other gate G, and the gate G is formed between them facing each other. Further, the pressing portion 4 is located so as to face the resin molded body 100 (tip surface 102c) on the core 3 side, and forms a part of the inner wall surface (reference numeral 4c) of the molding space 9. Specifically, the pressing portion 4 forms a part (4c) of the inner wall surface of the molding space 9 that continues from the edge of the opening of the gate G.

As shown in FIG. 6, the first extrusion means 40 moves the pressing portion 4 (which can also be said to be the pressing portion) to the cavity 2 side (FIG. 6) in a state where the cavity 2 and the core 3 are opened after molding the resin molded body 100. The resin molded body 100 is extruded toward the cavity 2 in a form of being pressed (pressed) (upward). Here, the first extrusion means 40 has an extrusion plate 41, an extrusion shaft portion 42, and a well-known drive source 43 (see FIG. 4) such as electric motor and hydraulic pressure, and the driving force from the drive source 43. The extrusion plate 41 can be moved toward the cavity 2 side based on the above. Specifically, the first extrusion means 40 moves the extrusion plate 41 to the cavity 2 side by a predetermined first distance d. As a result, the extrusion shaft portion 42 is extruded toward the cavity 2, the extrusion shaft portion 42 extrudes the pressing portion 4 toward the cavity 2, and the pressing portion 4 extrudes the resin molded body 100 toward the cavity 2. .. As a result, the pressing portion 4 pushes one end surface (tip surface 102c) of the resin molded body 100 toward the cavity 2, and the resin molded body 100 can be separated (released) from the core 3. An extrusion shaft portion insertion hole 34 is formed through the core main body 30 in the mold opening direction (vertical direction in FIG. 4), and the extrusion shaft portion 42 is inserted and arranged. The extrusion shaft portion 42 projects on one end side protruding from the extrusion shaft portion insertion hole 34 to face and abut on the extrusion plate 41, while the pressing portion 4 is integrated with a fastening member such as a bolt or nut on the other end side. It is fixed to.

The first distance d may be set as a distance at which the resin molded body 100 and the resin residue 200 are surely cut (gate cut).

The runner L communicates with the gate G on the opposite side of the molding space 9 in the mold 10, and forms a resin flow path leading to the molding space 9 together with the gate G. The runner L here is located between two molding spaces 9 arranged side by side in FIG. 3, and has an intermediate point M of gates G at the same position in the longitudinal direction (vertical direction in FIG. 3) of the molding spaces 9. It has a rotationally symmetric shape centered on it. This also applies to the gate G, and the resin flow path composed of the gate G and the runner L, and the resin residue 200 that remains inside the gate G and is cooled and solidified with the molding of the resin molded body 100 It has a rotationally symmetric shape centered on the intermediate point M (rotational axis Z described later). Here, at the midpoint M of the runner L, a sprue (not shown) is connected from the cavity 2 side.

As shown in FIG. 4, the tip of the rotating shaft portion 71 (tip portion 71A) enters the space of the runner intermediate portion LM including the intermediate point M of the runner L (see FIG. 3) from the core 3 side. There is. The rotating shaft portion 71 has a rod shape extending along a predetermined axis Z extending in the mold opening direction (vertical direction in FIG. 4) of the cavity 2 and the core 3, and the axis Z passes through the intermediate point M (FIG. 3). reference). The tip (71A) of the rotating shaft portion 71 is engaged with the resin residue 200 so that the rotating shaft portion 71 can rotate integrally with the resin residue 200 (see FIG. 5) around the rotating axis Z. The rotary shaft portion 71 here is formed in a prismatic shape (here, a square pillar shape) in which the tip (71A) is tapered as shown in FIG. 11, and is formed so that the resin residue 200 surrounds it, and the resin residue is formed. It will be in a state of biting into the body 200. The resin residue 200 and the tip (71A) biting into the resin residue 200 form an engaged state in which the resin residue 200 and the rotating shaft portion 71 can be integrally rotated around the rotation axis Z. As shown in FIG. 4, a rotating shaft portion insertion hole 37 (penetrating portion) is formed through the core main body 30 in the mold opening direction (vertical direction in FIG. 4), and the rotating shaft portion 71 is inserted and arranged. The rotary shaft portion 71 projects from the rotary shaft portion insertion hole 37 on one end side and faces the extrusion plate 41 at a predetermined first distance d, while the tip (71A) is formed on the other end side. There is.

As shown in FIGS. 4 and 6, in the resin flow path including the gate G and the runner L, an extrusion blocking portion 5 is provided so as to prevent the resin residue 200 formed in the flow path from being extruded toward the cavity 2. It is arranged in the form of approaching. The extrusion blocking portion 5 is provided on the core 3 side and has a wedge shape that wraps around the cavity 2 side with respect to a part 201 of the resin residue 200 (extrusion blocking locking portion: see FIG. 6), whereby the resin residue is formed. It prevents the 200 from moving / pushing out to the cavity 2 side. The extrusion blocking portion 5 here is provided at the tip of a rod-shaped urging shaft portion 51 extending in the mold opening direction (vertical direction of FIGS. 4 and 6) of the cavity 2 and the core 3. An urging shaft portion insertion hole 35 is formed through the core main body 30 in the mold opening direction, and the urging shaft portion 51 is inserted and arranged. The urging shaft portion 51 projects from the urging shaft portion insertion hole 35 on one end side and faces the extrusion plate 41 at a predetermined first distance d (see FIG. 4), while the extrusion prevention is performed on the other end side. The portion 5 is formed.

Further, when the other end side (cavity 2 side) of the urging shaft portion 51 including the extrusion blocking portion 5 receives a force pushed toward the cavity 2, the urging shaft portion 51 is urged so as to be pulled toward the opposite one end side. The urging means 52 (here, a spring member) is provided. As a result, even if the resin residue 200 is extruded toward the cavity 2, the urging force of the urging means 52 opposes it, and the extrusion blocking portion 5 prevents the resin residue 200 from being extruded toward the cavity 2.

As shown in FIG. 7, the second extrusion means 50 disengages the resin molded body 100 from the core 3 (after mold release), and then puts the resin residue 200 together with the extrusion blocking portion 5 (here, at the same time) into the cavity 2. Extrude to the side (upward in FIG. 7). The second extrusion means 50 here has an extrusion plate 41, an urging shaft portion 51, a rotary shaft portion 71, and a drive source 43 (see FIG. 4), and is based on the drive force of the drive source 43. The extrusion plate 41 can be moved to the cavity 2 side. Specifically, the extrusion plate 41 that has been moved to the cavity 2 side by the first distance d by the first extrusion means 40 is further moved to the cavity 2 side by a predetermined second distance e (see FIG. 8). As a result, the urging shaft portion 51 and the rotating shaft portion 71 are pushed out toward the cavity 2 by the extrusion plate 41. The extruded urging shaft portion 51 extrudes the resin residue 200 by pressing its tip (runner pressing portion) against both ends LN of the runner L of the resin residue 200 (near the gate G). On the other hand, the extruded rotary shaft portion 71 extrudes the resin residue 200 by pressing the resin residue 200 against the portion inside the runner intermediate portion LM of the resin residue 200 at its tip (runner pressing portion). As a result, as shown in FIG. 8, the resin residue 200 is detached from the core body 30.

As shown in FIG. 4, a connecting member 8 for connecting the urging shaft portion 51 and the rotating shaft portion 71 is provided on the core 3 side. The extrusion shaft portion 42 is arranged so as to penetrate the connecting member 8. The urging shaft portion 51 and the rotating shaft portion 71 integrated by the connecting member 8 are attached by being positioned at a predetermined first distance d (see FIG. 4) from the extrusion plate 41 in the mold opening direction. The force shaft portion 51 and the rotary shaft portion 71 are pushed out to the cavity 2 side later than the extrusion shaft portion 42. As a result, the resin molded body 100 is extruded to the cavity 2 side by the pressing portion 4 (FIG. 6 → 7) first, and the resin residue by the urging shaft portion 51 and the rotating shaft portion 71 is delayed by a certain period of time. Extrusion of 200 to the cavity 2 side (FIG. 7 → 8) occurs. Then, during the fixed period (during the period of the previous extrusion), separation / cutting (gate cut) of the resin molded body 100 and the resin residue 200 occurs. It is a structure in which the urging shaft portion 51 and the rotating shaft portion 71 are arranged at a distance d (see FIG. 4) from the extrusion plate 41 to cause the delay / delay for a certain period of time. The delay mechanism 53 (see FIG. 4) configured in this way is a delay means included in the second extrusion means 50, whereby the pressing by the first extrusion means 40 generated based on the movement of the extrusion plate 41. -It is possible to delay the pressing / extrusion by the second extrusion means 50, which is generated based on the movement of the same extrusion plate 41, with respect to the extrusion.

As shown in FIG. 8, the rotating means 70 pushes the resin residue 200 extruded to the cavity 2 side by a predetermined second distance e (predetermined distance) by the second extrusion means 50 to open the molds of the cavity 2 and the core 3. It is rotated in a predetermined rotation direction around a predetermined rotation axis Z extending in a direction. The rotating means 70 here includes a rotating shaft portion 71, a third extrusion means 60, and rotating guide portions 79 and 39 provided in the rotating shaft portion 71 and the rotating shaft portion insertion hole 37. The third extrusion means 60 includes an extrusion plate 41 and a drive source 43 (see FIG. 4), and the extrusion plate 41 can be moved to the cavity 2 side based on the drive force of the drive source 43. ..

Specifically, the rotating means 70 further pushes (moves) the extrusion plate 41, which has been moved to the cavity 2 side by the second extrusion means 50 by the second distance e, to the cavity 2 side by the third extrusion means 60. With the further pushing (movement), the rotation guide portions 79 and 39 rotate the rotation shaft portion 71 around the rotation axis Z by a predetermined angle in the predetermined rotation direction R (see FIGS. 12 and 13). As shown in FIG. 4, the rotation guide portion 79 here is a guide groove 79 formed on the outer periphery of the columnar rotation shaft portion 71 so as to extend in the mold opening direction, and the rotation guide portion 39 is a guide thereof. A guide pin 39 provided at a fixed position of the core 3 (here, the core main body 30) so as to be arranged so as to enter the groove 79.

The guide pin 39 moves along the guide groove 79 as the rotary shaft portion 71 is pushed out toward the cavity 2. The guide groove 79 formed on the outer peripheral surface of the rotary shaft portion 71 starts at a position where the guide pin 39 enters in a state immediately before the resin molded body 100 is extruded toward the cavity 2 by the first extrusion means 40 (FIG. (Refer to 6), the resin residue 200 is pushed out to the cavity 2 side by the second extrusion means 50 from the start position, moves the second distance e, and the resin residue 200 exceeds the PL surface at an intermediate position (see 6). (See FIG. 8), the mold opening direction is formed linearly toward the core 3 side. As a result, the resin molded body 100 is extruded to the cavity 2 side, and the guide groove 79 is formed with respect to the core 3 (core body 30) on which the guide pin 39 is provided until the resin residue 200 exceeds the PL surface. The rotating shaft portion 71 is maintained in a non-rotating state.

However, the guide groove 79 is provided so as to bend in the circumferential direction toward the core 3 side in the mold opening direction beyond the intermediate position (see FIG. 8). As a result, after the resin residue 200 exceeds the PL surface, the rotating shaft portion 71 in which the guide groove 79 is formed rotates with respect to the core 3 (core main body 30) provided with the guide pin 39. The rotation direction R is determined by the bending direction of the guide groove 79, and the rotation angle is determined by the circumferential position of the bent end. The guide groove 79 here is formed so that the resin residue 200 rotates in a predetermined rotation direction R shown in FIG. 11 by a predetermined angle (here, 90 degrees) beyond the PL surface. The guide groove 79 here is formed so as to reach the end position in a form that slightly extends linearly toward the core 3 side in the mold opening direction after the bending is completed.

Hereinafter, the injection molding method in this embodiment will be specifically described.

First, the molten resin is injected into the molding space 9 of the molded mold 10 shown in FIG. 4 via the runner L and the gate G, and is cooled and solidified. As a result, as shown in FIG. 5, the resin molded body 100 is molded in the molding space 9 (molding step). At the same time as this molding, the resin residue 200 is also molded in the resin flow path including the runner L and the gate G (molding step). The molded resin residue 200 is integrally connected to the resin molded body 100.

After these moldings, as shown in FIG. 6, mold opening for separating the cavity 2 and the core 3 is executed (mold opening step). As a result, the resin molded body 100 is exposed on the core 3.

Next, as shown in FIGS. 6 to 7, the resin molded body 100 is extruded and extruded. Here, with the cavity 2 and the core 3 opened, the first extrusion means 40 extrudes the pressing portion 4 toward the cavity 2 (mold extrusion step).

Specifically, the first extrusion means 40 extrudes the extrusion plate 41 toward the cavity 2 by the driving force of the drive source 43 (see FIG. 4) by the first distance d (see FIG. 4). As a result, the extrusion shaft portion 42 is extruded toward the cavity 2, and by the extrusion, the pressing portion 4 at the tip of the extrusion shaft portion 42 extrudes the resin molded body 100 toward the cavity 2. However, the resin molded body 100 is integrally connected to the resin residue 200, and the resin residue 200 is prevented from being extruded to the cavity 2 side by the extrusion blocking portion 5. Therefore, cutting (gate cut) occurs at the connection portion (near the opening of the gate G) between the resin molded body 100 and the resin residue 200, and only the separated resin molded body 100 is pushed out to the cavity 2 side. The pressing portion 4 for pushing out the resin molded body 100 is a portion close to the opening of the gate G forming the inner wall of the gate G, and the pressing portion 4 pushes out the resin molded body 100, as in the conventional case. , Distortion, deformation, cracking, etc. are unlikely to occur at the connection portion of the resin molded body 100 with the gate G.

Along with this cutting (gate cutting), the resin molded body 100 is released from the core 3 as shown in FIGS. 7 to 8. After the mold is released, the second extrusion means 50 simultaneously extrudes the resin residue 200 separated from the resin molded body 100 and the extrusion blocking portion 5 toward the cavity 2 (residue pressing step).

Specifically, the second extrusion means 50 is extruded by the first extrusion means 40 toward the cavity 2 by the first distance d by the driving force of the drive source 43 (see FIG. 4) (see FIG. 7). ) Is further pushed out to the cavity 2 side by a second distance e (see FIG. 8). As shown in FIG. 7, the extrusion plate 41 extruded to the cavity 2 side by the first extrusion means 40 by the first distance d (see FIG. 4) is in contact with the base ends of the urging shaft portion 51 and the rotary shaft portion 71. It has reached the position where it touches. The extruded plate 41 that has reached this contact position is further extruded toward the cavity 2 to extrude the urging shaft portion 51 and the rotary shaft portion 71 toward the cavity 2 side (along with the extruded shaft portion 42), and by their extruding. The tips (reference numerals 5, 71A) of the urging shaft portion 51 and the rotating shaft portion 71 push the resin residue 200 toward the cavity 2 (see FIG. 8).

The second distance e is set so as to be a position where the resin residue 200 does not interfere with the core 3 when the resin residue 200 undergoes rotation described later. The second distance e here is set so that the entire resin residue 200 is pushed out toward the cavity 2 from the split surface PL of the cavity 2 and the core 3.

The resin residue 200 extruded to the cavity 2 side by the second extrusion means 50 by a predetermined distance is the resin residue 200 from the extrusion blocking portion 5 as shown in FIGS. 8 to 9 and 12 to 13. Is separated and the rotating means 70 is rotated around the rotation axis Z by a predetermined angle in the rotation direction R so that the cavity 2 can be removed (rotation step).

Specifically, the rotating means 70 has a second extrusion plate 41 extruded to the cavity 2 side by the second extrusion means 50 by a second distance e (see FIG. 8), as shown in FIGS. 8 to 9. (3) The urging shaft portion 51 and the rotary shaft portion 71 are pushed out to the cavity 2 side (along with the extrusion shaft portion 42) by further pushing toward the cavity 2 side by the extrusion means 60. The rotary shaft portion 71 is a guide provided with a guide pin 39 protruding from the core 3 (core main body 30) linearly on the outer peripheral surface when extruded to the cavity 2 side by the first and second extrusion means 40 and 50. It moves in the pushing direction while maintaining the state of entering the groove 79. Therefore, the rotation shaft portion 71 was maintained non-rotating around the rotation axis Z (FIG. 6 → FIG. 7 → FIG. 8). However, at the time of extrusion by the third extrusion means 60 (FIG. 8 → 9), the guide groove 79 forms a curved shape in which the outer peripheral surface bends in a predetermined circumferential direction as the guide groove 79 is directed toward the extrusion direction. As shown in FIGS. 12 to 13, the unit 71 rotates by a predetermined angle (90 degrees) in a predetermined rotation direction around the rotation axis Z.

By this rotation, as shown in FIGS. 9 and 13, the resin residue 200 is separated from the extrusion blocking portion 5 that has prevented the resin residue 200 from moving toward the cavity 2. As shown in FIG. 10, the resin residue 200 separated from the extrusion blocking portion 5 can move to the cavity 2 side and can be removed from the tip end (71A) of the rotating shaft portion 71. Therefore, after this rotation, it is collected by a well-known method such as free fall or collection by a robot arm (recovery step).

Finally, the shape of the extrusion blocking portion 5 will be specifically described. As shown in FIG. 15B, the extrusion blocking portion 5 has a wedge shape that wraps around the cavity 2 side (upper side of the figure) with respect to a part 201 of the resin residue 200, and the wedge-shaped portion 201 makes the resin residue. It prevents the 200 from moving / pushing out to the cavity 2 side. As shown in FIG. 4, the wedge-shaped portion 201 here is located directly below the gate G, and the extrusion blocking portion 5 that locks adjacent to the wedge-shaped portion 201 opposes the pushing force of the resin molded body 100. ing. On the other hand, as shown in FIG. 14, the extrusion blocking portion 5 has a shape that allows the resin residue 200 to be detached by rotating around the rotation axis Z in the rotation direction R.

As shown in FIG. 15B, the extrusion blocking portion 5 here has a wedge-shaped portion 201 formed on the R side in the rotation direction. As shown in FIGS. 15A and 15B, in the locking surface 201f of the wedge-shaped portion 201, the upper end position f1 is located on the rotation direction R side and the lower end position f2 is located on the opposite side to the rotation direction R. It is formed as a flat surface that is inclined and spreads toward the rotation direction R side from the upper end position f1 to the lower end position f2. Therefore, the resin residue 200 has a shape that allows rotation in one direction, in which rotation in the direction opposite to the rotation direction R is prohibited.

Although the embodiments of the present invention have been described above, this is merely an example, and the present invention is not limited thereto. For example, in the above embodiment, various changes can be made based on the knowledge of those skilled in the art, such as omitting some constituents or adding other constituents.

Hereinafter, a modified example of the above-described embodiment will be described. The parts having the same functions as those in the above embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. Further, the above-mentioned example and the following modified example and another embodiment can be appropriately combined and carried out within a range that does not cause a technical contradiction.

In the above embodiment, the resin residue 200 is an integral resin body including the inside of the gate G and the runner L, but the resin residue 200 may be an integral resin body including the inside of the gate G, the runner L, and the sprue (not shown). good.

In the above embodiment, the tip (71A) of the rotary shaft portion 71 is arranged so as to enter the LM in the runner intermediate portion, and the resin residue 200 is formed so as to surround the periphery thereof, whereby the resin residue 200 is formed. Although it is in an engaged state in which it can rotate integrally with the resin residue, the tip (71A) bites into the molded resin residue 200 when the rotary shaft portion 71 is extruded by the second extrusion means 50, and the resin residue. It may be in an engaged state that can rotate integrally with 200.

In the above embodiment, the first extrusion means 40, the second extrusion means 50, and the third extrusion means 60 all have a single extrusion means with a delay function (main extrusion) utilizing a common mechanism for moving the extrusion plate 41. Means). Furthermore, since the rotating means 70 includes the third extrusion means 60, it can be said that the rotating means 70 is formed as an extrusion mechanism (main extrusion means) having a delay function and a rotation function. However, the extrusion means 40, 50, 60 and the rotation means 70 may be formed as different mechanisms, and each object may be extruded or rotated at each timing.

In the above embodiment, the rotating means 70 is a mechanical mechanism that rotates in conjunction with the extrusion of the rotating shaft portion 71 to the cavity 2 side by the guide structure by the groove and the pin, but the rotating means 70 is extruded by the second extrusion means 50. An electric type may be used in which the rotating shaft portion 71 is rotated in a predetermined direction by a predetermined angle by a motor or the like after completion. At the time of this rotation, it is not necessary to involve extrusion / movement by the third extrusion means 60 of the above embodiment, and a configuration may be made in which the rotation is performed without extrusion / movement.

In the above embodiment, the extrusion blocking portion 5 prevents the resin residue 200 from moving / pushing out to the cavity 2 side, but the resin residue 200 can be detached by the rotation of the resin residue 200 by the rotating means 70. If it is a shape, the shape may be different from the above embodiment.

For example, the extrusion blocking portion 5 can be formed as shown in FIGS. 16 and 17. As shown in FIG. 17C, the extrusion blocking portion 5 is outside or inside the wedge-shaped portion 201 which is a part of the resin residue 200 in the radial direction of rotation (here, inside: FIG. 17C). It is on the left side) and forms a wedge shape that wraps around the cavity 2 side (upper side in the figure). As shown in FIG. 17A, the wedge-shaped portion 201 here has an upper end position r1 outside in the radial direction of rotation (right side in the figure) and a lower end position r2 inside in the radial direction of rotation (left side in the figure). It has a spherical shape centered on a predetermined position on the rotation axis Z (see FIG. 16). As a result, the resin residue 200 rotates around the rotation axis Z, and is separated from the extrusion blocking portion 5 so that the resin residue 200 can escape to the cavity 2 side. In this embodiment, the resin residue 200 can be separated from the extrusion blocking portion 5 even if the resin residue 200 is rotated in the direction opposite to the predetermined rotation direction R.

1 Injection molding device 2 Cavity 3 Core 30 Core body 37 Rotating shaft part insertion hole (through part)
39 Guide pin (rotation guide part)
4 Pushing part 40 First extrusion means 41 Extrusion plate 42 Extrusion shaft part 5 Extrusion prevention part 50 Second extrusion means 51 Erasing shaft part 52 Erasing means 53 Delay mechanism (delay means)
60 Third extrusion means 70 Rotating means 71 Rotating shaft part 71A Tip part of rotating shaft part 79 Guide groove (rotating guide part)
100 Resin molded body 200 Resin residue G Gate L Runner PL Divided surface Z Rotating axis

Claims (4)

An injection molding device that molds a resin molded body by injecting molten resin into the molding space formed between the core and the cavity and cooling and solidifying it.
A part of the inner wall surface of the gate that opens from the core side to the cavity side with respect to the molding space, and a pressing portion located around the opening so as to face the resin molded body on the core side.
The first extrusion means for extruding the resin molded body toward the cavity side by pressing the pressing portion against the cavity side with the cavity and the core opened.
An extrusion blocking portion having a shape that prevents the resin residue that remains in the resin flow path including the gate leading to the molding space and is cooled and solidified by molding the resin molded body to the cavity side.
By extruding the resin molded product toward the cavity side by the first extrusion means, the resin molded body is separated from the resin residue whose extrusion to the cavity side is blocked by the extrusion blocking portion, and is released from the core. With
After the mold release, the second extrusion means for extruding the resin residue separated from the resin molded body together with the extrusion blocking portion toward the cavity side.
A rotating means for rotating the resin residue extruded to the cavity side by a predetermined distance by the second extrusion means in a predetermined rotation direction around a predetermined rotation axis extending in the mold opening direction of the cavity and the core.
The injection molding apparatus comprising the above, wherein the extrusion blocking portion has a shape that can be separated from the resin residue by the rotation. The injection molding apparatus according to claim 1, wherein the rotating means rotates a rotating shaft portion that is integrally rotatably engaged with the resin residue around the rotating axis. When the second extrusion means extrudes the resin residue by the predetermined distance and then further extrudes the resin residue into the rotating shaft portion and the penetrating portion of the core to which the rotating shaft portion penetrates, the resin residue is extruded to each other. Is provided with a rotation guide portion for relative rotation in a predetermined rotation direction around the rotation axis.
The injection molding apparatus according to claim 2, wherein the rotating means includes the second extrusion means and the rotation guide portion provided on the rotating shaft portion and the penetrating portion. When the resin molded body is extruded by the first extrusion means, the extrusion blocking portion is urged to the side opposite to the cavity so that the resin residue is not extruded to the cavity side together with the resin molded body. The injection molding apparatus according to any one of claims 1 to 3, further comprising an urging means.

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