JP5628623B2 - Mold - Google Patents

Description

  The present invention relates to a molding die for obtaining a molded body having an undercut portion.

  Conventionally, most of the resin moldings have been manufactured by an injection molding machine, but what has a so-called undercut portion that protrudes in a direction perpendicular to the mold clamping direction of the mold cannot be removed as it is. For this reason, various methods have been proposed in which the undercut portion is removed without difficulty by combining split molds or by moving part of the molds forward and backward.

  For example, as shown in FIG. 7 (a), in a mold composed of a combination of an upper mold 1 and a lower mold 2, a slide core 3 extending obliquely is provided inside the mold, as shown in FIG. 7 (b). After the mold is opened, a method is widely known in which the ejector plate 4 provided on the lower side of the lower mold 2 is raised to push the slide core 3 together with the molded body 5 obliquely upward and to remove the molded body 5 from the slide core 3. (See, for example, Patent Document 1).

JP 2003-231160 A

  By the way, as shown in FIG. 8, the applicant of the present application integrally forms rotating shafts 9, 9 ′ on the left and right end surfaces of the hinge coupling portion 8 of the lid body 7 in the hinge coupling portion 8 between the container body 6 and the lid body 7. Then, by inserting this into the vertical holes 10 and 10 'on the container body 6 side, a compact container that does not require a metal hinge pin (so-called jagged pin) is devised, and a utility model right has already been obtained (registered) (See Utility Model No. 2536726).

  This has the advantage that the assembling process of the container body 6 and the lid 7 can be simplified. However, when the lid 7 is obtained integrally by injection molding, as shown by the arrow, it faces downward in the figure. Since the concave shape (arrow P) and the protruding shape (arrows Q and Q ') protruding in the left-right direction are provided close to each other, for example, the structure like the slide core 3 will be used. However, not only does the number of slide cores 3 increase and the mechanism becomes complicated, but there is a problem that the arrangement of each of them is difficult. In addition, it is conceivable that the rotary shafts 9 and 9 'are formed integrally with the concave shape of the hinge connecting portion 8 by using a split mold that is divided into two parts. There is a problem that a split-type burr is formed on the peripheral surface of ′, and the lid body 7 may be difficult to open and close smoothly. Note that the hook 11 for engaging the lid body 7 with the container body 6 also has a protrusion at its tip, but this protrusion is easily removed from the mold due to the flexibility of the hook 11 itself, so that the mold is removed. There is no problem.

  Therefore, for such a molded body having a plurality of undercut portions with different concave and convex directions, it is strongly desired to provide an excellent molding die that can be handled with a simple structure. Such a mold has not been put into practical use yet.

  The present invention has been made in view of such circumstances, and is an excellent molding die that can be easily removed even if it is a molded body having a plurality of undercut portions having different concave and convex directions. The purpose is to provide

In order to achieve the above-mentioned object, the present invention has a first undercut portion having an unevenness in the front-rear direction, and unevenness in the left-right direction on both left and right end surfaces of the portion where the first undercut portion is formed. A molding die for obtaining molded bodies each having a second undercut portion, and a cavity mold for mainly shaping the upper surface of the molded body and a lower surface of the molded body. And a base stand disposed below the core mold, the core mold penetrating the retractable mold in the advance and retreat direction, wherein the core mold penetrates the cavity mold. And a first guide hole inclined in the front-rear direction, a pair of left and right second guide holes inclined in the left- right direction with the first guide hole penetrating the advance / retreat type in the advance / retreat direction, and the first Inserted through the guide hole First inclined and, the first in the right and left sides of the slanted are respectively inserted into the second guide hole of the pair left and right direction which is slidably disposed along the inner peripheral surface inclined backward And a pair of left and right second inclined molds slidably disposed along the inner peripheral surface inclined to each other, and the lower ends of the first and second inclined molds are attached to the base table on its mounting surface. And the upper end portion of the first inclined mold has a concave portion for shaping the first undercut portion, and the second inclined mold. Each upper end of each has a concave portion for shaping the second undercut portion, and at the time of clamping, the advance / retreat die advances toward the cavity die, and the cavity die, advance / retreat die, and the above The upper ends of the first and second inclined molds are closed together. A molded body shaping space is formed, and when the mold is opened, the advance / retreat mold retracts from the cavity mold or the base stand rises, and the first and second inclined molds are inclined inner peripheral surfaces of the guide holes. , The upper end portions of the first and second inclined molds are detached from the molded body shaping surface, and the first and second undercut portions of the molded body can be simultaneously punched. The molding die set so as to be the first gist.

  In addition, among the first and second inclined molds, at least one of the inclined molds slides along the inclined surface forming a predetermined angle with respect to the base table. A molding die that is locked in a movable state and that maintains the inclined posture of the inclined mold at the time of mold opening operation is a second gist.

  In the present invention, the “front-rear direction” and “left-right direction” are provisional in order to specify the direction of unevenness of two undercut portions formed in a single molded body and having different directions at right angles to each other. The direction of unevenness in one undercut portion is defined as “front-rear direction”, and the direction of unevenness in the other undercut portion is defined as “left-right direction”.

That is, in the molding die of the present invention, the lower end portions of the molded body are locked in a slidable state with the base stand, and the upper end portions of the molded body are closed to each other . A first inclined mold that forms a space for shaping the undercut portion and a pair of left and right second inclined molds are inserted into guide holes provided in the forward and backward types, and the guide It is configured to be slidably arranged along the inner peripheral surface where the hole is inclined. Then, the advancing / retracting type that holds the inclined mold slidably moves forward and closes toward the cavity mold when the mold is clamped, and the inclined molds are also closed to form a molded body shaping space as a whole. On the other hand, when the mold is opened, the first and second inclined molds protrude upward from the advance / retract type guide holes due to the advance / retreat mold retreating from the cavity mold or the base stand rises, and the first tilt The upper end of the mold is displaced in the front-rear direction, and the upper ends of the pair of left and right second inclined molds are displaced from each other in the left-right direction so that the first and second undercut portions of the molded body can be simultaneously die-cut. It is set to be.

Therefore, according to this configuration, the first inclined type and the pair of left and right second inclined types are moved forward and backward, or along the inclined surfaces inclined in the front-rear direction and the left-right direction. since that is with the base table of the lifting operation to move in the direction that different from each other, as in the conventional product shown in FIG. 7, there is no need to provide a complicated mechanism for each inclined, low part count With a simple configuration, two types of undercut portions with different directions can be efficiently removed.

Then, in particular, the upper Symbol second slanted right pair, the left and right sides of the first inclined, since the provided in an arrangement in which opposed to each other, the rotary shaft as shown in FIG. 8, a hinge connecting portion And can be easily shaped.

  In the present invention, in particular, at least one of the pair of inclined molds is locked in a state in which a lower end portion of at least one inclined mold can slide along an inclined surface having a predetermined angle with respect to the base table. In the mold opening operation, when the tilted posture of the tilted mold is kept constant, the molded product can be removed more smoothly.

It is a perspective view which shows the shape of the molded object in one embodiment of this invention. It is AA 'sectional drawing of FIG. It is principal part sectional drawing of the front-back direction of the shaping die of the said embodiment. It is principal part sectional drawing of the left-right direction of the said shaping | molding die. It is explanatory drawing of arrangement | positioning of the molded object obtained by the said shaping die, and a metal mold | die. It is a partial explanatory view of the compact shown in FIG. (A), (b) is explanatory drawing of the conventional shaping die. It is explanatory drawing of the compact container using the molded object which has an undercut part.

  Next, an embodiment for carrying out the present invention will be described. However, the present invention is not limited to this embodiment.

  FIG. 1 shows a molded body 20 molded using a molding die according to an embodiment of the present invention. The molded body 20 is used as a lid body of a compact container. Like the lid body 7 of FIG. 8, the hinge connecting portion 22 having a concave portion 21 on the inner side and a rotating shaft protruding in the left-right direction from the left and right end surfaces thereof. 23 is integrally formed. And as shown in FIG. 2 which is AA 'sectional drawing of FIG. 1, the protruding item | line 24 for mirror attachment is provided in the inner surface.

  In addition, the direction of the unevenness | corrugation in which the said recessed part 21 was formed (it shows by the arrow X in FIG. 1) is called the front-back direction, and the direction with the hinge connection part 22 is made into the back side. Further, the direction in which the rotating shaft 23 protrudes (indicated by an arrow Y in FIG. 1) is referred to as the left-right direction, and the left and right sides when the molded body 20 is viewed as indicated by the arrow Z in FIG. The standard.

  FIG. 3 shows a state in which a molding die used for molding the molded body 20 is cut along a cross section extending in the left-right direction and viewed from the front side, and a plan view of the molded body 20 is shown. 5 corresponds to the BB ′ cross section. 4 shows a state in which the molding die is cut along a cross section extending in the front-rear direction and viewed from the left side to the right side, and corresponds to the CC ′ cross section of FIG.

  In these drawings, 30 is a cavity mold for mainly shaping the upper surface of the molded body 20, and 31 is a core mold for mainly shaping the lower surface of the molded body 20. In addition, a set of two base stands 32 and 33 are disposed below the core mold 31, and a fixed base 34 is disposed further below.

  The core mold 31 includes an advancing / retracting mold 35 provided so as to be able to advance and retract toward the cavity mold 30, a first guide hole 36 that penetrates the advancing / retreating mold 35 in the advancing / retreating direction and is inclined in the front-rear direction, And a pair of left and right second guide holes 37a and 37b inclined in the left and right direction with the first guide hole 36 interposed therebetween, and an inclined type inserted through each of the guide holes 36, 37a and 37b. 40, 41a, 41b.

  The advancing / retracting type 35 has a structure in which a core element 42 and a guide element 43 that supports the core element 42 are combined, and various tool steels having excellent wear resistance (for example, carbon tool upper, Speed steel, alloy tool steel, etc.). In addition, the three inclined molds 40, 41a, 41b are also made of various tool steels having excellent wear resistance. The first and second guide holes 36, 37a, 37b are all formed in the core element 42, and the guide element 43 below is inserted into the guide holes 36, 37a, 37b. Holes 44, 45a, 45b are provided for guiding the sliding movement of the inclined molds 40, 41a, 41b. Further, around the lower end opening of each hole 44, 45a, 45b, in order to smoothly receive the sliding movement of the inclined molds 40, 41a, 41b, it is formed of various tool steels having excellent smoothness and wear resistance. Slide guides 44 ', 45a', 45b 'are fitted.

  As shown in FIGS. 3 and 4, the first inclined mold 40 inserted through the first guide hole 36 has a hinge connecting portion 22 of the target molded body 20 (see FIGS. 1 and 2). A mold for forming an undercut portion having irregularities in the front-rear direction, which is T-shaped when viewed from the front, and is inclined toward the front side along the inclined inner peripheral surface of the first guide hole 36. The protrusion 50 for shaping the recessed part 21 inside the hinge connection part 22 is formed in a protruding manner on the T-shaped lateral side which is the upper end part. In addition, in the T-shaped lateral side portion, the corners of the portions surrounded by the circles W at both ends are tapered, so that the portion of the core element 42 that enters this portion becomes too thin. Therefore, the strength is not considered to be weakened.

  And the lower end part of the said 1st inclination type | mold 40 is latched to the guide block 51 attached to the lower base stand 33 among 2 sets of base stands 32 and 33 in a slidable state. Has been. That is, the guide block 51 has an inclined surface 52 formed with a downward inclination (an inclination angle of 30 °) toward the front side and side walls 53 standing on both the left and right sides. A groove portion 54 that is inclined along the inclined surface 52 is formed. A guide pin 56 protruding in the left-right direction via a shaft 55 is provided at the lower end of the first inclined mold 40, and the guide pin 56 is engaged with the left and right groove portions 54 of the guide block 51. As a result, the lower end surface of the first inclined mold 40 comes into contact with the inclined surface 52 of the guide block 51 and is slidably locked.

  It should be noted that the surface of the guide block 51 on which the first inclined mold 40 slides is inclined downward by 30 ° toward the front side, as will be described later. When sliding along the first guide hole 36, the inclined mold 40 slides in an oblique direction while maintaining a 30 ° inclination angle as shown by the arrow R in FIG. It is a thing considered to do.

  Further, the pair of left and right inclined molds 41a and 41b inserted through the second guide holes 37a and 37b protrude in the left and right direction of the hinge connecting portion 22 in the target molded body 20 (see FIGS. 1 and 2). As shown in FIG. 3, a concave portion 57 for shaping the rotary shaft 23 is formed as seen from the front. The shaping surfaces are arranged so as to face each other and the horizontal side portion of the first inclined mold 40 is sandwiched from the left and right directions. In accordance with the direction of inclination of the second guide holes 37a and 37b, the inclined positions are closer to each other as they go downward.

  The lower end portions of the second inclined molds 41a and 41b are provided between the base bases 32 and 33 on both the left and right sides of the guide block 51 that locks the lower end portion of the first inclined mold 40. The sliding blocks 58a and 58b are engaged with each other, and are slidably contacted along the upper surface of the lower base 33 through the sliding blocks 58a and 58b. In FIG. 3, 59 is a shaft that connects the lower ends of the second inclined molds 41a and 41b and the sliding blocks 58a and 58b.

  In addition, the part which contact | abuts the said sliding blocks 58a and 58b among the said lower base stand 33 is formed with various tool steels excellent in abrasion resistance.

  A molded body 20 shown in FIG. 1 can be obtained by using the molding die as described below, for example. That is, first, this mold is attached to an injection molding machine and clamped to close the cavity mold 30 and the core mold 31 to each other as shown in FIGS. At this time, the advancing / retracting die 35 is positioned at the most elevated position, and the first and second inclined dies 40, 41a, 41b inserted into the first and second guide holes 36, 37a, 37b are respectively By the inclined surfaces of the guide holes 36, 37a, 37b, they are closed together while pressed against each other. Thereby, the cavity mold 30, the advance / retreat mold 35, and the inclined molds 40, 41a, 41b form a space for shaping the molded body 20.

  Therefore, the target molded body 20 can be obtained by injecting the resin material at a high pressure into the molded body shaping space via a predetermined path (not shown) and cooling it.

  When the cavity mold 30 is opened upward by mold opening and the molded body 20 is taken out, the base stands 32 and 33 are raised as shown by arrows in FIGS. With this operation, the upper ends of the first and second inclined molds 40, 41a, 41b protrude upward from the first and second guide holes 36, 37a, 37b of the advance / retreat mold 35, and each inclined mold The side surfaces of 40, 41a and 41b slide along the inclined inner peripheral surfaces of the guide holes 36, 37a and 37b, and the first inclined mold 40 is located on the near side as indicated by an arrow R in FIG. The second inclined molds 41a and 41b move so as to open in the left-right direction as indicated by an arrow S in FIG. As a result, the two undercut portions (the concave and convex portions including the concave portion 21 of the hinge connecting portion 22 and the convex portion of the rotating shaft 23) that form an angle of 90 ° with each other are in a state where the mold can be removed. It can be taken out from the molding die.

  As already described, when the first inclined mold 40 is opened forward, the inclined mold 40 slides along the inclined surface 52 of the guide block 51 so that the inclined attitude of the inclined mold 40 is It is designed to open while maintaining a posture inclined 30 ° toward the front side. For this reason, the undercut portion can be smoothly cut in a stable state in a diagonally downward direction of 30 °.

  By the way, in consideration of die-cutting in a 30 ° diagonally downward direction, the structure of the undercut portion of the molded body 20 is such that the lower surface 21a of the recess 21 inside the hinge connecting portion 22 is 31 ° as shown in FIG. It is an inclined surface.

  Further, for the same purpose, as shown in FIG. 4, a concave strip 24 a for shaping the convex strip 24 (see FIG. 2) of the molded body 20 on the upper end surface of the first inclined mold 40 is also provided. The groove surface is formed as a 29 ° inclined surface, and one surface of the ridge 24 is shaped into the inclined surface.

  Thus, according to the molding die, the first and second inclined molds 40, 41a, 41b that form the space for shaping the undercut portion of the molded body 20 in a closed state are moved forward and backward. The first and second guide holes 36, 37a, 37b formed in the mold 35 are slidably disposed along the inclined surfaces. When the mold is clamped, the advance / retreat mold 35 moves forward toward the cavity mold 30. In the closed state, the first and second inclined molds 40, 41a, 41b are also closed to form a molded body shaping space as a whole. Conversely, when the mold is opened, the upper side of the molded body 20 is When the base stands 32 and 33 are raised in the opened state, the first and second inclined molds 40, 41a and 41b protrude upward from the guide holes 36, 37a and 37b of the advance / retreat mold 35, respectively. The first inclined mold 40 is a hand Open on the side, a second slanted 41a, 41b is opened in the lateral direction, the undercut portion of the molded body 20 is adapted to be stamped.

  And according to the said structure, the 1st inclination type | mold 40 inclined in the front-back direction and the 2nd inclination type | molds 41a and 41b inclined in the left-right direction are mutually 90 degrees with the raising / lowering operation | movement of the base stands 32 and 33. Since they are closed and opened in different directions, the undercut portions provided in the two directions can be efficiently removed with a simple configuration with a small number of parts.

  In addition, according to the above configuration, the second inclined molds 41a and 41b are provided so as to face each other so that they can be opened horizontally in opposite directions. The shaft 23 can be easily formed integrally with the hinge connecting portion 22. And since the side peripheral surface of the obtained rotating shaft 23 is shaped by the mold | die (2nd type | mold 41a, 41b) of all the circumferences, like the case where a split type is used, a side peripheral surface is used. There is an advantage that no burrs are generated on the way and the surface is beautiful.

  In the molding die of the present invention, the opening / closing operation to the first and second inclined molds 40, 41a, 41b for shaping the undercut portion is performed by the first and second provided on the advancing / retracting mold 35 side. As long as the inclined surfaces of the two guide holes 36, 37a, 37b are used, any configuration may be used.

  In the above example, in order to give the first and second inclined molds 40, 41a, and 41b an opening / closing operation, the base tables 32 and 33 are raised when the mold is opened, and the inclined mold 40 and the like are moved forward and backward. However, instead of this, the inclined die 40 or the like may be opened by retracting (ie, lowering) the advance / retreat die 35 from the cavity die 30 side.

  Further, the molding die of the present invention is not limited to the type in which the mold clamping mold is opened in the vertical direction as in the above example, but may be of the type in which the mold clamping mold is opened in the left-right direction. In that case, the advancing / retracting die 35 and the base bases 32, 33 are set so as to advance / retreat in the left / right direction, and the inclined dies 40, 41a, 41b only have a shape extending in the left / right direction. There is no difference.

  Depending on the shape of the undercut portion, as in the above example, it is necessary to open at least one of the inclined mold 40 and the like while sliding in an oblique direction while maintaining the inclined posture. In such a case, it is preferable to slide the lower end portion of the inclined mold 40 or the like along the inclined surface of a predetermined angle as in the above example. However, if this is not necessary, the lower end of the inclined mold 40 or the like may be locked so as to slide horizontally on the base table 32 side.

  The present invention can be used for a molding die for obtaining a molded body having two undercut portions having different directions.

30 Cavity type 31 Core type 32, 33 Base base 35 Advance / Retreat type 36, 37a, 37b Guide hole 40, 41a, 41b Inclined type

Claims (2)

Has a first undercut portion having irregularities in the front-rear direction, the left and right end surface of the first part undercut portion is formed, a second undercut portions in the lateral direction of irregularities each molding A mold for obtaining a body, a cavity mold for mainly shaping the upper surface of the molded body, a core mold for shaping mainly a lower surface of the molded body, and a lower part of the core mold An advancing / retreating type in which the core mold is provided so as to be able to advance and retract toward the cavity mold, and a first guide hole that penetrates the advancing / retreating direction in the advancing / retreating direction and is inclined in the front-rear direction Similarly, a pair of left and right second guide holes that penetrate the advance / retreat type in the advance / retreat direction and incline in the left / right direction with the first guide hole interposed therebetween, and are inserted into the first guide hole and inclined in the front / rear direction. Along the inner surface A first inclined to be de freely arranged, freely the first in the right and left sides of the slanted are respectively inserted into the second guide hole of the pair slide along the inner circumferential surface inclined in the lateral direction consists of the second slanted pair of left and right and which is arranged, the first, lower end of the second inclined type, to the base platform, each engaging in a state capable of sliding along the mounting surface The upper end portion of the first inclined mold has a concave portion for shaping the first undercut portion, and each upper end portion of the second inclined mold is provided with the second undercut portion. Each has a concave part for shaping the cut part, and at the time of clamping, the advance / retreat mold advances toward the cavity mold, and the upper ends of the cavity mold, the advance / retreat mold, and the first and second inclined molds Are closed together to form a shaped body shaping space. The first and second inclined molds slide along the inclined inner peripheral surface of each guide hole by moving the advance / retreat mold backward from the cavity mold or raising the base table. The upper end portion of the second inclined mold is separated from the molded body shaping surface, and the first and second undercut portions of the molded body are set so that they can be simultaneously punched. Molding mold.   The lower end portion of at least one of the inclined molds of the first and second inclined molds is locked so as to be slidable along an inclined surface having a predetermined angle with respect to the base table, and the mold opening operation is performed. 2. The molding die according to claim 1, wherein the inclined posture of the inclined mold is kept constant.

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