JP5663224B2 - 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. 11 (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. 11 (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. 12, the applicant of the present application integrally forms rotating shafts 9 and 9 ′ on the left and right end surfaces of the hinge connecting portion 8 of the lid body 7 in the hinge connecting 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, there is a problem that the number of the slide cores 3 is increased and the arrangement of the slide cores 3 is difficult. Also, it must be equipped with a cylinder for raising and lowering the ejector plate, and the mold becomes very large as a whole, takes up space, and the assembly work becomes complicated, increasing the burden of equipment costs and production costs. found. 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 object, the present invention provides a molding die for obtaining a molded body having an undercut portion, a cavity mold for mainly shaping the upper surface of the molded body, and the molded body. A core mold mainly for shaping the lower surface, and a base stand disposed below the core mold, wherein the core mold is provided so as to be movable back and forth toward the cavity mold, and the advance / retract mold A guide hole penetrating in the advancing and retracting direction, a pair of inclined surfaces formed on the inner peripheral surface of the guide hole so that the distance between them increases, and a side surface of the guide hole inserted into the guide hole becomes the inclined surface. A pair of inclined molds slidably disposed along the pair of inclined molds, and the lower ends of the pair of inclined molds are locked to the base table so that they can slide along the mounting surface. , The upper end of each Adapted to form a space for shaping the undercut portion of the molded body in a closed state, the above undercut portion includes a first undercut portion that projects in a direction in which the gradient type is opened A second undercut portion projecting in a direction perpendicular to a direction in which the inclined mold opens, and at the time of clamping, the advance / retreat mold advances toward the cavity mold, and the cavity mold, the advance / retreat mold, and the pair of The tip portions of the inclined molds are closed together to form a molded body shaping space. When the mold is opened, the advance / retreat mold retracts from the cavity mold, and the upper ends of the pair of inclined molds protrude upward from the guide holes. by side while slides along the inclined surface of the guide hole, open to the rear the inclined each other, and the first undercut portion of the molded body and the second undercut portion The molding die is configured so as to be capable vent the first aspect.

  In addition, the present invention particularly relates to a state in which at least one of the pair of inclined molds can slide along an inclined surface having a predetermined angle with respect to the base table. A molding die that is stopped and is configured so that the inclined posture of the inclined mold is kept constant during the mold opening operation is a second gist.

That is, in the molding die of the present invention, each lower end portion is locked in a slidable state with the base stand, and each upper end portion is shaped to form an undercut portion of the molded body in a closed state. A pair of inclined molds designed to form a space for sliding is freely slidable along the inclined surfaces formed so that the distance between the inner circumferential surfaces of the guide holes provided in the advance and retract type increases. It has a configuration arranged in. And the said undercut part is equipped with the 1st undercut part which protrudes in the direction which the said inclination type opens, and the 2nd undercut part which protrudes in the orthogonal | vertical direction with respect to the direction where the said inclination type opens, In a state in which the forward and backward molds that hold the inclined molds slidably move forward toward the cavity molds at the time of clamping, the inclined molds are also closed to each other, and a molded body shaping space is formed as a whole, On the other hand, when the mold is opened, when the advance / retreat mold retreats from the cavity mold, the upper part of the molded body is opened, and the inclined molds protrude upward from the advance / retract type guide holes and open to the rear, thereby the first of the molded body The second undercut portion is set so that it can be punched.

Therefore, according to this configuration, the pair of inclined molds arranged in a so-called V shape in a side view along the inclined surfaces extending upward from each other closes or opens with the advance / retreat operation. Therefore, unlike the conventional product shown in FIG. 11, there is no need to provide an ejector plate or a cylinder for raising and lowering the slide core, and the first and second can be efficiently performed with a simple configuration with a small number of parts . The undercut portion can be removed.

Moreover, not only the first undercut portion which is punched in a direction inclined this opens, also the second undercut protruding perpendicularly against the direction in which the inclined open, to shape simultaneously be Therefore, it is possible to cope with a molded body having more complicated unevenness.

  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 side surface direction of the shaping die of the said embodiment. It is principal part sectional drawing of the front direction of the said shaping | molding die. (A) is principal part explanatory drawing of the planar direction of the said shaping | molding die, (b) is a partial explanatory drawing of the molded object shown in FIG. It is operation | movement explanatory drawing of the said shaping die. It is principal part sectional drawing of the side surface direction of the shaping die of other embodiment of this invention. It is principal part sectional drawing of the front direction of the said shaping | molding die. It is operation | movement explanatory drawing of the said shaping die. It is operation | movement explanatory drawing of the said shaping die. (A), (b) is explanatory drawing of the conventional shaping die. It is explanatory drawing of the compact container in which the molded object which has an undercut part was used.

  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. 12, the molded body 20 has a hinge connecting portion 22 having a recess 21 on the inside, and a rotating shaft projecting in the left-right direction from the left and right end faces. 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.

  FIG. 3 shows a cross section of a main part of a molding die used for molding the molded body 20 from the side surface direction, and is a cross-sectional view taken along the line BB ′ of FIG. Equivalent to. FIG. 4 shows a cross section of the main part of the molding die from the front direction, 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. A base table 32 is disposed below the core mold 31. However, in FIG. 5, the cavity mold 30 is not shown, and only the outline of the recess opening for shaping the upper surface of the molded body 20 is indicated by a chain line 15.

  The core mold 31 is spaced apart from each other on an advancing / retracting mold 33 provided so as to be movable back and forth toward the cavity mold 30, a guide hole 34 penetrating the advancing / retreating mold 33 in the advancing / retreating direction, and an inner peripheral surface of the guide hole 34. A pair of inclined surfaces 35 and 36 formed so as to expand upward, and a pair of inclined molds 37 inserted through the guide holes 34 and slidably disposed along the inclined surfaces 35 and 36. 38.

  The advancing / retracting type 33 has a structure in which a core element 39 and a guide element 40 that supports the core element 39 are combined, and various tool steels having excellent wear resistance (for example, carbon tool upper steel, high-speed steel). , Alloy tool steel, etc.). The pair of inclined dies 37 and 38 are also made of various tool steels having excellent wear resistance.

  Of the inclined molds 37 and 38, the inclined mold 37 whose upper part is disposed on the back side (left side in FIG. 3) is substantially T-shaped when viewed from the front as shown in FIG. The inclined mold 38 arranged on the front side (right side in FIG. 3) is substantially L-shaped when viewed from the front (the upper outline of the inclined mold 38 omitted to show the inclined mold 37 in FIG. The upper ends of the two extending in the left-right direction are relatively inconsistent with each other. The opposing surfaces 37a, 38a of the inclined molds 37, 38 are both formed vertically, and a part of the lower surface of the molded body 20 is formed by closing the both surfaces to the opposing surfaces 37a, 38a. And the unevenness | corrugation is formed so that the space for shaping the hinge connection part 22 grade | etc., (Refer FIG. 1) used as an undercut part may be formed.

  That is, as shown in FIG. 4, an upper protrusion 40 ′ for shaping a part of the lower surface of the molded body 20 and an inner side of the hinge connecting portion 22 are formed on the facing surface 37 a of the inclined mold 37. A front projecting portion 41 for shaping the concave portion 21 and a concave portion 42 for shaping the inner half of the hinge connecting portion 22 and the rotating shaft 23 are formed. Further, as shown by a broken line in FIG. 3, a concave portion 43 for shaping the outer half of the hinge connecting portion 22 and the rotating shaft 23 is formed on the facing surface 38 a of the inclined mold 38.

  On the other hand, the lower end portions of the inclined molds 37 and 38 are arranged in a substantially straight line in the left-right direction (the direction perpendicular to the paper surface in FIG. 3), and sliding guide spaces 51 and 52 provided on the base table 32. And is slidably locked. More specifically, a pair of guide pins 53 and 54 projecting in the left-right direction are provided at the lower ends of the inclined dies 37 and 38, respectively. The guide pins 53 and 54 are provided on the base base 32. The guide spaces 51 and 52 are engaged with the ceiling surfaces 51a and 52a. The lower end surfaces of the inclined dies 37 and 38 are slidably in contact with the bottom surfaces 51b and 52b of the guide spaces 51 and 52, respectively.

  The base table 32 has a structure in which two upper and lower base plates 55 and 56 are combined in order to provide the guide spaces 51 and 52, and portions constituting the bottom surfaces 51b and 52b of the guide spaces 51 and 52 are provided. It is made of various tool steels with excellent wear resistance.

  Of the guide spaces 51 and 52, the bottom 51b of the guide space 51 that locks the lower end of the inclined mold 38 whose upper portion is disposed on the front side (right side in FIG. 3) extends horizontally. When the inclined mold 38 slides along the inclined surface 36 of the guide hole 34, the lower end surface of the inclined mold 38 slides in the horizontal direction along with the operation.

  Of the guide spaces 51 and 52, the guide space 52 that locks the lower end portion of the inclined mold 37 whose upper portion is disposed on the back side (left side in FIG. 3) has a bottom surface 52b on the front side. When the inclined mold 37 slides along the inclined surface 35 of the guide hole 34 as will be described later, the lower end surface of the inclined mold 37 is 30 with the operation. The robot slides in an oblique direction while maintaining a posture maintaining an inclination angle of °.

  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 together as shown in FIG. At this time, the advancing / retracting mold 33 is positioned at the most elevated position, and the inclined molds 37 and 38 inserted into the guide hole 34 are pressed toward each other by the inclined surfaces 35 and 36 of the guide hole 34. It becomes a state and is closed. Thereby, a space for shaping the molded body 20 is formed by the cavity mold 30, the advance / retreat mold 33, and the inclined molds 37 and 38.

  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.

And when taking out the molded object 20 by mold opening, as shown in FIG. 6, the said advance / retreat type | mold 33 descend | falls from the cavity type | mold 30 side to the base stand 32 side. With this operation, the upper ends of the inclined molds 37 and 38 protrude upward from the guide hole 34 of the advance / retreat mold 33, and the side surfaces of both inclined molds 37 and 38 become inclined surfaces 35 and 36 of the guide hole 34. And the inclined molds 37 and 38 open rearward as shown by thick arrows. Thereby, the undercut part ( the 1st undercut part: the recessed part 21 inside the hinge connection part 22, the 2nd undercut part: rotating shaft 23 ) of the said molded object 20 will be in the state which can be die-released, The molded body 20 can be taken out from the molding die.

  When the inclined mold 37 is opened rearward, the inclined mold 37 slides along the inclined bottom surface 52b of the guide space 52, so that the inclined attitude is inclined 30 ° rearward. It is designed to open backwards while keeping it. For this reason, the undercut portion can be smoothly cut in a stable state in a diagonally downward direction of 30 °.

  Incidentally, in consideration of die-cutting 30 ° diagonally downward, 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 as shown in FIG. The inclined surface is 31 °, and a part 23a of the peripheral surface of the rotating shaft 23 is chamfered at 31 °. The chain line 25 indicates the boundary between the shaping surface by the inclined mold 37 and the shaping surface by the inclined mold 38.

  Further, for the same purpose, as shown in FIG. 6, the concave strip for shaping the convex strip 24 of the molded body 20 on the upper end surface of the inclined mold 37 is also an inclined surface having one groove surface of 29 °. The one surface of the ridge 24 is shaped into an inclined surface.

  Thus, according to the molding die, the pair of inclined dies 37 and 38 that form a space for shaping the undercut portion of the molded body 20 in the closed state are formed in the advance / retreat die 33. The tilting molds 37 and 38 are arranged so as to be slidable along the inclined surface in the guide hole 34, and when the mold is clamped, the advancing / retracting mold 33 is advanced toward the cavity mold 30 and closed. Closed to form a molded body shaping space as a whole. Conversely, when the mold is opened, the advance / retreat mold 33 is retracted from the cavity mold 30 and the upper side of the molded body 20 is opened, and the inclined molds 37 and 38 are advanced / retracted. The undercut portion of the molded body 20 can be punched out by projecting upward from the 33 guide holes 34 and opening backward.

  And according to the said structure, a pair of inclination type | molds 37 and 38 arrange | positioned in the side view so-called V shape along the inclined surfaces 35 and 36 which are formed in the guide hole 34 and spread toward the upper side, Since the advancing / retracting type 33 is closed and opened with each other, it is not necessary to provide an ejector plate or a cylinder for raising and lowering the slide core as in the conventional product of FIG. The undercut portion can be efficiently removed with a simple configuration with a small amount.

  In addition, as in the above example, the concave portion 21 that is the first undercut portion is formed between the inclined dies 37 and 38 by devising the arrangement of the undercut portion shaping space of the inclined dies 37 and 38. Since the rotary shaft 23, which is the second undercut portion extending in the direction perpendicular to the second undercut portion, can be shaped at the same time, the molded body having more complicated irregularities can be handled. There is an excellent effect of being able to.

  In the molding die of the present invention, the opening / closing operation to the pair of inclined molds 37 and 38 for shaping the undercut portion is performed by using the inclined surfaces 35 and 36 of the guide hole 34 provided on the advancing / retracting mold 33 side. Any configuration may be used as long as it is used.

  For example, as shown in FIG. 7 (a cross-sectional view of the main part when the molding die is viewed from the side) and FIG. 8 (a cross-sectional view of the main part when the molding die is viewed from the front), the upper end is disposed on the front side. The inclined mold 38 may be provided with a more complicated shape, and the inclined mold 38 may be opened rearward stepwise by using the inclination of the inner peripheral surface of the guide hole 34. In this molding die, the inclined mold 38 on the front side (right side in FIG. 7) slides along the inclined surface 36 of the guide hole 34 on the surface of the upper end opposite to the side facing the inclined mold 37. In addition, the surface on the side facing the inclined mold 37 also slides along the inner peripheral surface of the guide hole 34 sequentially, so that the opening operation is performed in two stages. Yes. The rest of the basic configuration is the same as that of the embodiment shown in FIGS. 3 to 6, and the same parts are denoted by the same reference numerals and description thereof is omitted.

  The molding die will be described in more detail. Among the inclined dies 37 and 38, the inclined die 38 on the near side has a relatively long surface facing the inclined die 37 and extends vertically downward. At the time of tightening, as shown in this figure, among the vertical surfaces 61 of the inclined mold 37, the upper part contacts the upper part of the inclined mold 37 and the lower part contacts the vertical surface 62 formed on the inner peripheral surface of the guide hole 34. A space for shaping the molded body 20 is formed by the cavity mold 30, the advancing / retracting mold 33, and the inclined molds 37 and 38 in the contact state. An inclined slide surface 63 having a relatively short distance is formed below the vertical surface 61 of the inclined mold 38, and on the inner peripheral surface side of the guide hole 34, below the vertical surface 62, A second inclined surface 64 is formed along the slide surface 63.

  When opening the mold, first, as shown in FIG. 9, when the advancing / retracting mold 33 is slightly lowered, the inclined molds 37 and 38 slide along the inclined surfaces 35 and 36 of the guide hole 34 to guide the guide. As a result of projecting upward from the hole 34, the inclined mold 38 is slightly opened rearward as indicated by a thick arrow. On the other hand, the inclined die 37 has only a vertical surface 61 that slides along the vertical surface 62 on the guide hole 34 side, and maintains an upright posture.

  Then, as shown in FIG. 10, the advancing / retracting die 33 is further lowered from the state where the slide surface 63 of the inclined mold 38 and the second inclined surface 64 on the guide hole 34 side are in contact with each other. As described above, the inclined mold 37 is further opened rearward, and the inclined mold 38 is opened largely rearward so that the undercut portion can be removed smoothly. This molding die also has the same effect as the above example.

  Note that 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 two examples, 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 33 is set so as to advance / retreat in the left / right direction and open / close with the cavity die 30, and the inclined dies 37, 38, etc. only have a shape extending in the left / right direction. There is no difference.

Further, the molding die of the present invention, as described above two examples, the undercut portion with a trouble in mold release is a plurality, but that apply to molding of the case projecting in different directions, the undercut portion Of course, even if there is only one, the undercut portion can be easily removed from the mold, which is preferable.

  Depending on the shape of the undercut portion, it is necessary to open at least one of the inclined dies 37 and 38 backward while sliding in an oblique direction while maintaining the inclined posture as in the above example. If not, the lower ends of the inclined molds 37 and 38 may be slid horizontally on the base table 32 side.

INDUSTRIAL APPLICATION This invention can be utilized for the shaping | molding die for obtaining the molded object which has several undercut parts from which the direction of an unevenness | corrugation differs .

30 Cavity type 31 Core type 32 Base stand 33 Advance / Retreat type 34 Guide hole 35, 36 Inclined surface 37, 38 Inclined type

Claims (2)

A molding die for obtaining a molded body having an undercut portion, a cavity mold for mainly shaping the upper surface of the molded body, and a core mold for mainly shaping the lower surface of the molded body, A base stand disposed below the core mold, wherein the core mold is provided so as to be movable forward and backward toward the cavity mold, a guide hole penetrating the advance / retract mold in the forward and backward direction, and the guide hole A pair of inclined surfaces formed on the inner peripheral surface of the guide hole so that the distance between them increases, and a pair of inclined surfaces that are inserted through the guide holes and slidably disposed along the inclined surface. In the pair of inclined molds, the lower end portions of the pair of inclined molds are locked to the base table in a state of being slidable along the mounting surface, and the upper end portions are closed with each other. Under the above molded body Tsu DOO portion adapted to form a space for shaping the said undercut section includes a first undercut portion that projects in a direction which the inclined open, with respect to the direction of the gradient type is opened A second undercut portion projecting in the vertical direction, and at the time of clamping, the advance / retreat die advances toward the cavity die, and the cavity die, the advance / retreat die and the pair of inclined die tips close to each other When the mold is opened, the advance / retreat mold retracts from the cavity mold, the upper ends of the pair of inclined molds protrude upward from the guide holes, and the side faces are inclined surfaces of the guide holes. by sliding along, this by opening the rear the inclined each other, the first undercut portion of the molded body and the second undercut portion is set to be enable demolding Molding die according to claim.   Of the pair of inclined molds, at least one of the inclined molds is locked in such a manner that the lower end portion of the inclined molds can slide along an inclined surface that forms a predetermined angle with respect to the base table. The molding die according to claim 1, wherein the inclined posture of the die is kept constant.

Images