JP2011104939A - Injection molding mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an injection molding mold which is easily fabricated and is suited as the mold for relatively small amount production of a molded product having an undercut. <P>SOLUTION: An undercut forming means 4 includes: slide cores 41, 42 which are movable in the direction vertical to the opening and closing direction of the movable side mold plate 26; operation members 43 which are attached to the slide cores 41, 42 and are extended to the outer side of the direction vertical to the opening and closing direction of the movable side mold plate 26; and guide members 44 which are disposed on the movable side mold plate 26 and guide the operation members 43. The operation members 43 is manually moved and, thereby, slide cores 41, 42 can be moved. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an injection mold, and more particularly to an injection mold suitable for manufacturing a molded product having an undercut.

  The injection mold includes a fixed mold and a movable mold for clamping and opening the mold, and at the time of mold clamping, the fixed mold and the movable mold of the fixed mold are used. A cavity corresponding to the shape of a molded product to be molded is formed between the movable side template. For example, when the molded product is a cylindrical body, the fixed-side mold plate and the movable-side mold plate form the outer peripheral surface of the molded product, and the inner peripheral surface of the molded product has an undercut forming means having a slide core. Formed by.

  As an undercut forming means, it has an angular pin provided on the fixed side mold plate and a slide core that is movably provided on the movable side mold plate and through which the angular pin is passed. Along with this, the slide core slides along the angular pin to release the slide core from the molded product in conjunction with the release of the movable side mold plate from the molded product ( Patent Document 1). An undercut forming means for moving a slide core using a hydraulic cylinder mechanism is also known.

JP 2002-205324 A

  An injection mold having an undercut forming means for moving a slide core using a hydraulic cylinder mechanism has a problem that the apparatus becomes large and costly. By having an undercut forming means that performs the release of the slide core from the molded product in conjunction with the release of the movable side mold plate from the molded product, as in Patent Document 1 above, Although this problem is improved, although such injection molds are suitable for mass automatic production, they are still difficult to manufacture as molds for relatively small volume production for shape confirmation and performance evaluation. There is a demand for an injection mold that can easily produce a molded product having an undercut.

  An object of the present invention is to provide an injection mold that is easy to manufacture and suitable as a mold for relatively small-scale production of a molded product having an undercut.

  An injection mold according to the present invention is an injection mold including a fixed mold plate and a movable mold plate that form a cavity of a predetermined shape, and an undercut forming means that forms an undercut of a predetermined shape. The undercut forming means includes a slide core movable in a direction orthogonal to the opening / closing direction of the movable side mold plate, an operation member attached to the slide core and extending outward in a direction orthogonal to the opening / closing direction of the movable side mold plate, A guide member provided on the movable side mold plate or the fixed side mold plate for guiding the operation member, and the slide core can be moved by manually moving the operation member. To do.

  The injection mold includes a fixed mold and a movable mold for clamping and opening the mold, and at the time of mold clamping, the fixed mold and the movable mold of the fixed mold are used. A cavity corresponding to the shape of a molded product to be molded is formed between the movable side template. The undercut that cannot be formed only by the fixed side mold plate and the movable side mold plate is formed by an undercut forming means having a slide core.

  As the slide core, one that is slidably inserted into an angular pin provided on the fixed side template and slides in a direction perpendicular to the mold opening direction in conjunction with the movement of the movable template is well known. However, in the injection mold according to the present invention, the slide core is moved manually. The slide core may be disposed on the movable side or may be disposed on the fixed side. Accordingly, the guide member is provided on either the movable side template or the fixed side template. Thus, at the initial stage of mold opening, the slide core moves together with the movable side mold plate or remains on the fixed side mold plate side together with the molded product. After the movement of the movable side template is stopped, the operation member is moved manually in a direction orthogonal to the mold opening direction. Therefore, in the case of using an angular pin, if the movement amount of the slide core in the mold release direction is large, it is necessary to increase the movement amount of the movable side mold, and there is a problem that the entire apparatus becomes large. The amount of movement of the side mold and the amount of movement of the slide core can be set separately from each other, thereby making it possible to reduce the size of the apparatus.

  The fixed-side mold is composed of a fixed-side mounting plate and a fixed-side mold plate, and the movable-side mold is composed of a movable-side mounting plate, a spacer block, a receiving plate, a protruding plate, a movable-side mold plate, and the like. . The fixed side mold plate and the movable side mold plate are preferably composed of a cavity insert for forming a cavity and a mold plate main body that detachably supports the cavity insert.

  The guide member includes a pair of support blocks arranged at a predetermined interval, and a guide block provided between the pair of support blocks and provided with a guide hole, and the pair of support blocks is fixed. It is preferable that an operation member moving space is formed between the fixed-side mold plate and the movable-side mold plate by being interposed at the abutting portion between the template plate and the movable-side template plate. That is, the fixed side mold plate and the movable side mold plate are usually directly abutted with each other, whereas in the injection mold according to the present invention, the fixed side mold plate and the movable side mold plate support the guide member. It is faced through a block.

  The operation member includes, for example, a slide pin that is slidably passed through a guide hole of the guide member and has a distal end portion fixed to the slide core, and a handle provided on the proximal end side of the slide pin.

  The slide core includes a base portion that is movably supported by the movable side template, and a cavity forming portion that is integrally provided on the base portion so as to correspond to the shape of the molded product. The base portion is the same as the support block of the guide member. The mold is clamped in a movable core part that is always in contact with the movable mold plate and protrudes from the fixed mold plate during clamping, and a slide core storage recess provided in the mold body of the fixed mold plate. It consists of a fixed part that is sometimes fitted. The surfaces on which the slide core, the fixed mold plate and the movable mold plate are in contact with each other are preferably inclined surfaces or tapered surfaces so that the contact surfaces can be easily positioned. Specifically, the fixed-side template is provided with a slide-core storage recess capable of storing the fixed-side portion of the slide core, and the peripheral surface of the slide-core storage recess is an inclined surface. Correspondingly, an inclined surface is also provided on the fixed side portion of the base of the slide core. Thereby, at the time of mold clamping, the slide core is positioned with high accuracy by the inclined surface being pushed by the inclined surface of the slide core housing recess.

  To obtain a molded product using this injection mold, the molten thermoplastic resin is injected into the cavity, and after the injected thermoplastic resin is solidified, the fixed mold and the movable mold are opened. To do. When the fixed side mold and the movable side mold are opened, the slide core does not move in conjunction, and when the mold is opened, the molded product with the slide core inserted is mounted on the movable side mold plate. Appears. In this state, when the slide core is extracted from the molded product by manual operation, the molded product remains in a state of being mounted on the movable side mold plate. Can be removed from the movable side template.

  According to the present invention, the undercut forming means includes a slide core that is movable in a direction orthogonal to the opening / closing direction of the movable side mold plate, and an outer side that is attached to the slide core and orthogonal to the opening / closing direction of the movable side mold plate. And a guide member provided on the movable side mold plate or the fixed side mold plate for guiding the operation member. The slide core can be moved by manually moving the operation member. Therefore, the configuration for performing the release of the slide core from the molded product in conjunction with the release of the movable side mold plate from the molded product is not required, and the manufacture becomes easy. Therefore, it is possible to obtain an injection mold suitable as a mold for producing a relatively small amount of a molded product having an undercut.

FIG. 1 is a partially cutaway front view showing a clamping state of an embodiment of an injection mold according to the present invention. FIG. 2 is a front view in which a part showing the mold open state of the injection mold (before the slide core is retracted) is cut away. FIG. 3 is a front view in which a part showing the mold opening state of the injection mold (after the slide core is retracted) is cut out. FIG. 4 is an enlarged view of FIG. 1 showing the cavity shape in the mold clamping state.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, up and down and left and right refer to up and down and left and right in each figure. Also, the front side of the paper surface is the front and the back side is the back. The upper side is the fixed side, the lower side is the movable side, the vertical direction is the opening / closing direction of the movable side mold, and the left / right direction is the moving direction of the slide core. The upper and lower sides are convenient, and for example, the fixed side can be arranged on the right and the movable side can be arranged on the left.

  As shown in FIG. 1 to FIG. 4, the injection mold (1) according to the present invention has a fixed mold (2) having a fixed mold (12) and a fixed mold (12). A movable side mold (3) having a movable side mold plate (22) that moves up and down to clamp and open the mold, and a pair of slide cores (41) and (42). An undercut forming means (4) for forming an undercut having a predetermined shape in a cavity having a predetermined shape formed by the plate (12) and the movable side mold plate (22).

  The fixed-side mold (2) includes a fixed-side mounting plate (11) and a fixed-side mold plate (12) integrally connected to the lower surface of the fixed-side mounting plate (11).

  The stationary-side template (12) includes a cavity insert (13) for forming a cavity and a template body (14) that detachably supports the cavity insert (13). The template body (14) is provided on the bottom of the slide core storage recess (14a) and the slide core storage recess (14a) that can accommodate the upper half of each slide core (41) (42). The cavity insert (13) is provided with a bottom surface of the slide core storage recess (14a) that is shaped to correspond to the molded product (P). It is attached to the template body (14) by protruding downward from the bottom surface (upper surface) and being fitted into the recess (14b) for nest storage.

  The movable side mold (3) includes a movable side mounting plate (21) which is moved in the vertical direction by an actuator (not shown), and a spacer block (22) fixed to the left and right of the upper surface of the movable side mounting plate (21). The receiving plate (23) integrally connected to the upper surfaces of the left and right spacer blocks (22), and the upper and lower protruding plates (24) (25) arranged so as to be movable in the vertical direction between the left and right spacer blocks (22) And a movable mold plate (26) integrally connected to the upper surface of the receiving plate (23).

  The movable side mold plate (26) includes a cavity insert (27) for forming a cavity and a template body (28) that detachably supports the cavity insert (27). The template body (28) is provided with a through hole (28a) for accommodating the insert, and the cavity insert (27) has an upper surface shaped to correspond to the molded product (P) for accommodating the insert. It protrudes upward from the upper surface of the through hole (28a) and is attached to the template body (28).

  A locating ring (15) for positioning the fixed side mold (2) is provided on the fixed side mounting plate (11). A sprue bushing (16) as a resin supply port is provided over the fixed side mounting plate (11) and the fixed side mold plate (12). The fixed side mold plate (12) is provided with a guide pin (17), and the guide pin (17) avoids interference with the slide core (41) (42) to the movable side mold (3). It is designed to be inserted into the provided guide hole (3a).

  The movable mounting plate (21) is provided with a projecting rod (29) for moving the upper and lower projecting plates (24), (25) upward. On the upper surface of the lower protruding plate (25), a protruding pin (30) for pushing the molded product (P) upward is provided. A return pin (31) is further provided on the upper surface of the lower protruding plate (25) in parallel with the protruding pin (30), and the upper surface of the return pin (31) faces the upper surface of the template body (28). It is assumed to be one. A compression coil spring (32) is fitted on the return pin (31), and the lower surface of the compression coil spring (32) is received by the upper surface of the upper protruding plate (24), and the compression coil spring (32) The upper surface is received by the lower surface of the template body (28) of the movable template (26).

  The undercut forming means (4) is movable in the left-right direction (a direction perpendicular to the opening / closing direction of the movable side mold plate (22)), and the left and right slide cores (41), (42) that face each other at the time of clamping, Left and right operation members (43) attached to each slide core (41) (42) and extending outward in the left-right direction, and guides provided on the movable side template (26) to guide each operation member (43) It consists of a member (44).

  Each slide core (41) (42) is in a forward state (a state where the left and right slide cores (41), (42) are abutted with each other) shown in FIGS. 1 and 2, and a reverse state (a left and right slide core) shown in FIG. (41) and (42) are separated from each other) by manual operation.

  Each slide core (41) has a base (51) (53) whose lower end is movably supported by the template body (28) of the movable side template (22), and the base (51) (53) integrally. The cavity forming section (52) (54) is provided.

  The operation member (43) includes a slide pin (45) whose tip is provided on each slide core (41) (42), and a bottomed cylindrical handle provided on the proximal end side of the slide pin (45) ( 46). The slide pin (45) is formed of a hexagonal bolt, and the tip thereof is fixed to the slide core (41) (42) by being screwed into a screw hole provided in each slide core (41) (42). The handle (46) is slidable with respect to the slide pin (45), and is arranged so that the bottom wall through which the slide pin (45) passes is directed inward in the left-right direction. The bottom wall of the handle (46) through which the slide pin (45) passes is provided with a shock reducing washer (47) during sliding for protecting the handle (46).

  The guide member (44) includes a rectangular parallelepiped support block (48) fixed at a predetermined interval in the front and rear directions on the left and right ends of the upper surface of the template body (28) of the movable side template (26), and the front and rear And an L-shaped guide block (49) secured between the support blocks (48). The guide block (49) is provided with a guide hole (49a) for sliding the slide pin (45).

  In the mold clamping state shown in FIG. 1, the lower surface of the mold body (14), which serves as the reference surface for the fixed-side mold (12), is at the same position (the same height) as the axis of the molded product (P). In addition, the upper surface of the template body (28), which serves as the reference surface for the movable template (22), extends from the reference surface of the fixed template (12) by the same distance as the depth of the slide core storage recess (14a). It is in a distant position (not the same position as the axis of the molded product (P), but a position below this). The support block (48) of the guide member (44) is disposed between the template body (14) of the fixed side template (12) and the template body (28) of the movable side template (22). ing. That is, the template body (14) of the fixed side template (12) and the template body (28) of the movable side template (22) are not directly abutted but support the guide member (44). It is faced through a block (48). As a result, the slide pin (45) of the operating member (43) and the base portions (51) (53) of the left and right slide cores (41) (42) above the template body (28) of the movable side template (22). A space (operation member moving space) for moving the movable side portions (51a) and (53a) is secured.

  As shown in an enlarged view in FIG. 4, the molded product (P) manufactured by the injection mold (1) of this embodiment has both ends composed of a large diameter portion and a small diameter portion connected to the large diameter portion via a stepped portion. It is an open stepped cylinder. Then, a stepped cylindrical molded product is formed by the cavity insert (13) of the fixed side mold plate (12), the cavity insert (27) of the movable side mold plate (26) and the left and right slide cores (41) (42). A cavity for forming (P) is formed.

  The cavity forming portion (52) of the left slide core (41) has an outer diameter that is intermediate between the outer diameter and inner diameter of the large diameter portion of the molded product (P), and is on the large diameter side of the molded product (P). The base side disk part (52a) that forms the end face, the inner peripheral surface of the large diameter part of the molded product (P) having an outer diameter equal to the inner diameter of the large diameter part of the molded product (P), and the inner step connected thereto The intermediate disk part (52b) that forms the surface and the butted end side disk part that forms the inner peripheral surface of the small diameter part of the molded product (P) having an outer diameter equal to the inner diameter of the small diameter part of the molded product (P) ( 52c). Further, the cavity forming portion (54) of the right slide core (42) has a larger outer diameter than the outer diameter of the small diameter portion of the molded product (P), and forms a small diameter side end surface of the molded product (P). Part (54a) and an outer diameter equal to the inner diameter of the small-diameter part of the molded product (P), and is abutted against the butted end disk part (52c) of the left slide core (41) when moving forward. It consists of a butted end side disk part (54b) which forms the inner peripheral surface of the small diameter part.

  Also, the bases (51) and (53) of the left and right slide cores (41) and (42) have the same height as the support block (48) of the guide member (44) and are always in contact with the movable side template (26). And the movable side part (51a) (53a) which protrudes from the fixed side template (12) at the time of mold clamping, and the slide core storage recess provided in the template body (14) of the fixed side template (12) (14a) includes fixed side portions (51b) and (53b) that are fitted during mold clamping.

  Corresponding to the fact that the vertical cross-sectional shape of the slide core storage recess (14a) is trapezoidal and the peripheral surface is an inclined surface, as shown in FIG. 4, each slide core (41) The fixed sides (51b) (53b) of the base (51) (53) of (42) are also provided with inclined surfaces (51c) (53c), so that when the mold is clamped, the left and right slide cores (41 ) (42) is positioned with high accuracy by the inclined surfaces (51c) and (53c) being pushed by the inclined surfaces of the slide core housing recess (14a). Further, the outer peripheral surface (52d) of the base side disk part (52a) of the cavity forming part (52) of the left slide core (41) and the disk part (54a) of the cavity forming part (54) of the right slide core (42) ) Outer peripheral surface (54c) is a tapered surface whose diameter decreases in the direction in which each slide core (41) (42) advances, and correspondingly, the fixed side template (12) Each slide core abutment surface (13a) (27a) (13b) (27b) of the cavity insert (13) and the cavity insert (27) of the movable side mold plate (26) is also each slide core (41) (42) The slide cores (41) (42) at the time of mold clamping have these tapered surfaces (52d) (54c) (13a) ( 27a), (13b), and (27b) are positioned with high precision by pressing each other.

  According to the present invention, the cavity formed by the cavity insert (13) of the fixed mold (12), the cavity insert (27) of the movable mold (26), and the left and right slide cores (41) (42). A molded article (P) is formed by injecting and filling the molten resin and solidifying it (see FIG. 1). Thereafter, the movable side mold plate (21) is moved to open the movable side mold (3), whereby the movable side mold plate (26) is separated from the fixed side mold plate (12). When the movable mold (3) is opened relative to the fixed mold (2), the left and right slide cores (41) and (42) do not move in conjunction with the movable mold plate (26). When opened, the molded product (P) in which the left and right slide cores (41) and (42) are inserted appears in a state of being mounted on the movable side template (26) (see FIG. 2). In this state, by manually moving the operating member (43), the left and right slide cores (41) and (42) are moved backward (the left slide core (41) is moved to the left and the right slide core (42) is moved to the left). When the left and right slide cores (41) and (42) are pulled out from the molded product (P), the molded product (P) remains attached to the movable side mold plate (26) (see Fig. 2). 3). In this state, it is possible to take out the same as in the past, and by moving the upper and lower protruding plates (24) and (25) and protruding the protruding pins (30), the molded product (P) is moved to the movable side mold plate (26). Taken from.

  In the above, since the slide core (41) (42) can be moved by manually moving the operating member (43), the slide core (41) (42) is separated from the molded product (P). A structure for performing the mold in conjunction with the release of the movable side mold plate (26) from the molded product (P) is not required, and the production of the injection mold (1) is facilitated. Also, the amount of movement of the movable mold plate (26) from the state of FIG. 1 to the state of FIG. 2 and the amount of movement of the slide cores (41) (42) from the state of FIG. 2 to the state of FIG. Can be set separately, and in order to increase the amount of movement of the slide core (41) (42), such as the movement of the slide core linked to the movement of the movable side template, There is no need to increase the amount of movement of the template (26). Accordingly, the apparatus can be downsized, and the injection mold (1) of the present invention is suitable as a mold for producing a relatively small amount of a molded product having an undercut.

  In the above description, a cylindrical body is exemplified as the molded product (P), and the slide cores (41) and (42) have been described as having a pair of left and right. However, the molded product (P) has a square cross section, a star cross section, It can be set as the arbitrary shapes which have an undercut, such as the shape which has various cylinders, such as elliptical cross section, and a hollow part. Also, only one slide core may be provided on either the left or right side, and the cavity insert (13) of the fixed side mold plate (12) and the cavity insert (27) of the movable side mold plate (26) are divided. In some cases, the number may be 3 or more (for example, an 8-way slide).

  As described above, the case where the slide core (41) (42) is provided on the movable side template (26) has been described, but the slide core (41) (42) is operated by reversing the fixed side and the movable side. The member (43) and the guide member (44) may be provided on the fixed side. In this case, the slide core remains on the fixed mold plate side together with the molded product (P), but the basic operation is the same as that shown in FIGS. To do.

(1) Injection mold
(4) Undercut forming means
(12) Fixed side template
(26) Movable side template
(41) (42) Slide core
(43) Operation member
(44) Guide member
(48) Support block
(49) Information block
(49a) Guide hole

Claims (2)

  In an injection mold having a fixed mold plate and a movable mold plate for forming a cavity having a predetermined shape and an undercut forming device for forming an undercut having a predetermined shape, the undercut forming means is a movable mold. A slide core movable in a direction perpendicular to the opening / closing direction of the plate, an operation member attached to the slide core and extending outward in a direction perpendicular to the opening / closing direction of the movable side plate, and a movable side plate or a fixed side die An injection mold comprising a guide member provided on a plate for guiding an operation member, wherein the slide core can be moved by manually moving the operation member.   The guide member includes a pair of support blocks arranged at a predetermined interval, and a guide block provided between the pair of support blocks and provided with a guide hole, and the pair of support blocks is fixed. The operation member moving space is formed between the fixed-side mold plate and the movable-side mold plate by being interposed in the abutting portion between the template plate and the movable-side template plate. Injection mold.

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