JP4804874B2 - Cassette type injection mold - Google Patents

Description

  The present invention is a mold for molding a substantially cylindrical member, such as a lens barrel, by injection molding means, and in particular, a plurality of types of members by attaching a cassette to the mother mold in a detachable manner. The present invention relates to a cassette type injection molding mold in which a part of the mold can be shared when molding the mold.

  The injection mold is composed of a fixed-side mold member provided with a sprue bush and a runner, and a movable-side mold component member joined and separated from the fixed-side mold component member, By joining these two mold component members, a product forming portion for injecting resin is formed. After molding, the movable mold component member is separated from the fixed mold component member. Thus, the molded product is taken out.

Different molds are used each time a member of various shapes is molded, but instead of providing all the parts that make up the mold for each molded part, some parts that make up the mold are shared. For example, Patent Document 1 discloses a configuration in which only parts related to the product forming unit are configured as cassette-type replacement parts. In this known cassette type mold, a movable side mold plate in which a product forming portion is formed and a fixed side mold plate in which a runner is formed are provided inside a base mold, and guide pins protruding from the fixed mold plate side are provided. The relative positions of both mold plates are positioned by inserting them into guide holes formed in the movable mold plate, and both mold plates are joined at the time of mold clamping.
Japanese Patent Laid-Open No. 2001-30310

  In Patent Document 1, the two mold plates are positioned by fitting the guide pin and the guide hole, and in order to smoothly fit the guide pin and the guide hole, Will occur. If the product forming part is formed only on the movable side of the template, this level of problem will not be a particular problem, but the product forming part is fitted with male and female by a cassette member between the fixed side and the movable side. When formed in the joint, there is a problem that an accurate product cannot be formed due to the influence of the positional deviation between the fixed side and the movable side due to the above-described structure.

  The present invention has been made in view of the above points, and an object of the present invention is to detachably connect each of the movable side and fixed side cassettes to each mother die in a cassette mold. In this case, it is intended to ensure accurate alignment.

  In order to achieve the above-described object, the present invention is arranged such that a fixed-side matrix in which a fixed-side cassette is detachably connected and a movable-side matrix in which a movable-side cassette is detachably connected are arranged on the same axis. A cassette-type injection molding die in which the movable cassette and the fixed cassette are clamped so as to be fitted into a male and female, and a product forming portion is formed between which the substantially cylindrical member is molded. A cassette side reference surface comprising a taper surface portion and a flat surface portion is formed on each of the fixed side and movable side cassettes, and each of the fixed side and movable side master dies is provided with each of the cassette side reference surfaces. Forming a master-side reference surface composed of a tapered surface portion and a flat surface portion in contact with the surface, each taper surface portion being inclined with respect to the axis, and each flat surface portion being in a direction perpendicular to the axis, the fixed Side cassette and The fixed side matrix and the movable side cassette and the movable side matrix are connected with bolts directed in the axial direction, respectively, and the respective tapered surface portions and the planar portions are in pressure contact with each other. It is characterized by that.

  Thus, the relative position is fixed between the master die and the cassette in the axial direction by abutting so that the plane portion comes into surface contact. However, it is not positioned in the direction orthogonal to the axis line simply by contacting the flat portion. Therefore, the taper surface portion is provided and the taper is fitted to adjust the position in the direction perpendicular to the axis of the mother die and the cassette. It is possible to completely adjust the position of both members by fitting the tapered surfaces, but if so, it is necessary to apply a strong pressing force to the tapered surfaces. It becomes extremely difficult to pull out the taper protrusion inserted into the hole, and if it is loosely fitted to facilitate this insertion / removal, the relative positioning cannot be performed. As described above, by performing alignment by the cooperative action of the tapered surface portion and the flat surface portion, it is easy to attach and detach the cassette while ensuring strict position adjustment.

  The product forming part is of a substantially cylindrical shape, but when the product has an undercut part, the movable side cassette is provided with a split mold divided into a plurality, and when joined to the fixed side cassette, Each split mold is configured to have a cylindrical shape. In this case, the mold must be clamped so that each split mold accurately follows the fixed cassette. For this purpose, a tapered surface portion that is inclined in the axial direction is formed on the outer peripheral surface of each split mold, and the end surface portion is formed to form a flat portion in a direction perpendicular to the axial line. It is desirable to form a taper surface portion and a flat surface portion that come into contact with the split taper surface portion and the flat surface portion.

  By aligning the axes of the fixed side mold and the movable side mold so that they coincide with each other accurately, the fixed side and the movable side which are detachably mounted on the fixed side mold and the movable side mold By fixing each cassette on the side with bolts, the two cassettes are assembled so that they are reliably aligned, and an accurate product forming part is formed when the mold is clamped. Can be formed.

    Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, FIG. 1 shows a cross-section in a state where the fixed side and movable side dies and the cassette are separated, and FIG. 2 shows a state where the cassette type mold is clamped.

  First, in FIG. 1, which is shown in an exploded state, 10 is a fixed side matrix and 20 is a movable side matrix. Further, 30 is a fixed side cassette, and 40 is a movable side cassette. The fixed-side cassette 30 is detachably fixed to the fixed-side base 10, and the movable-side cassette 40 is detachably fixed to the movable-side base 20. 2, L indicates a fixed side, P indicates a movable side, the mother die 20 and the cassette 40 are members of the movable side P, and the mother die 10 and the cassette 30 become the fixed side L. . The fixed-side mother die 10 is fixedly held, and the movable-side mother die 20 reciprocates in the direction of the axis A of the mold. The holding means for the fixed-side mother die 10 and the movable-side mother die The illustration and detailed description of the 20 driving means are omitted.

  The stationary side mold 10 includes a mounting plate 12 provided with a locating ring 11 in which a nozzle (not shown) of an injection molding machine is positioned and held, a support plate 13 fixedly connected to the mounting plate 12 and a positioning block 14. It has composition which has.

  The movable side mold 20 includes a receiving plate 21 and a positioning block 22 connected to the receiving plate 21. A spacer 23 is connected to the positioning block 22, and a mounting plate 24 is fixed to the spacer 23. The spacer 23 is an annular member, and an ejector block 25 is provided therein. An ejector plate 26 is mounted on the ejector block 25, and an ejector pin 27 is erected on the ejector plate 26, and the ejector pin 27 extends to a position facing a product forming portion 50 described later. Yes. In the figure, reference numeral 28 denotes a key for fixing the ejector plate 26 to the ejector block 25.

  The fixed side cassette 30 has a sprue bush 31, and a sprue 32 is formed in the sprue bush 31. The sprue bush 31 is inserted into the bush receiver 33, and the sprue bush 31 and the bush receiver 33 are fixed in a mutually connected state. Further, a fixed mold plate member 34 is provided in contact with the bush receiver 33, and a runner 35 communicating with the spru 32 is formed in the fixed mold plate member 34. The fixed mold plate member 34 is provided with a retainer member 36 formed in a ring shape, and a skirt member 37 is further fixed to the retainer member 36. Is attached with an angular pin 38.

  Furthermore, the movable side cassette 40 has a split mold 41 and a core 42 which are divided into three as movable mold members, and the split mold 41 is provided in three slide grooves 44 provided in the radial direction on the slide table 43. The slider 45 is connected and fixed. Each slider 45 is provided with an insertion hole 45a through which the angular pin 38 is inserted. The slide table 43 is fixed to the base member 46. An insertion hole 47 is formed in the center portion of the slide table 43, and the core 42 penetrates through the insertion hole 47 in a state where the core 42 is inserted through the annular movable plate member 48 to the base member 46. The core 42 and the movable mold plate member 48 are fixed to the base member 46.

  The fixed side cassette 30 is detachably attached to the fixed side mother die 10, and the movable side cassette 40 is detachably attached to the movable side mother die 20. Then, as shown in FIG. 2, the product forming part 50 is formed at a predetermined position between the fixed side cassette 30 and the movable side cassette 40 by joining the movable side master 20 to the fixed side master 10. As a result, the mold is clamped.

  The sprue bush 31 constituting the fixed side cassette 30 is fixed to the mounting plate 12 of the fixed side mother die 10 with bolts. The mounting plate 12 is provided with an introduction hole 15 for connecting the nozzle of the molding machine to the sprue 32 when the nozzle of the molding machine is connected to the locating ring 11. Further, the bush receiver 33 is bolted to the support plate 13. Further, the skirt member 37 is fitted to the positioning block 14. A tapered surface portion 37a is formed on the outer peripheral surface of the skirt member 37 so as to be reduced in diameter toward the connecting side to the fixed mold plate member 34, that is, inclined with respect to the axis A. A flat portion 37b is formed in a direction extending in a flange shape so as to be continuous with the diameter portion, that is, in a direction orthogonal to the axis A. On the other hand, a taper surface portion 14a having a taper angle coincident with the taper surface portion 37a of the skirt member 37 is formed on the inner peripheral surface of the positioning block 14, and is connected to the most widened portion of the taper surface portion 14a. A flat surface portion 14 b that abuts on the flat surface portion 37 b of the skirt member 37 is formed. One or more (preferably about three or four) bolts 39 are attached to the flat portion 37b, and the bolts 39 are screw holes provided in the portion where the flat portion 14b of the positioning block 14 is formed. 16 to be screwed.

  Therefore, the taper surface portion 37a is the cassette side reference taper surface portion, the taper surface portion 14a is the master die side reference taper surface portion, the flat surface portion 37b is the cassette side reference flat surface portion, and the flat surface portion 14b is the mother die side reference flat surface portion. Is formed to have extremely high surface accuracy.

  On the other hand, a movable cassette 40 is assembled to the movable mold 20, and in the movable cassette 40, the core 42 and the movable mold plate member 48 are attached to the base member 46. For this purpose, the base member 46 is assembled so that the position of the base member 46 is strictly adjusted with respect to the movable side mold 20. For this reason, the base member 46 projects in an annular shape, and in this projecting portion, a tapered surface portion 46a is formed on the outer peripheral surface with a diameter decreasing toward the side opposite to the mounting portion of the core 42 on the axis A. In addition, a flat surface portion 46b extending inward from the most reduced diameter portion of the tapered surface portion 46a so as to be orthogonal to the axis A is formed. On the other hand, the positioning block 22 in the movable side mold 20 is formed with a taper surface portion 22a that coincides with the taper angle of the taper surface portion 46a of the base member 46, and is connected to the taper surface portion 22a. An annular flat surface portion 22b to which the flat surface portion 46b is joined is formed. And the inside of this plane part 22b is a through-hole. The base member 46 has one or more (preferably about three or four) bolts 49 attached to the flat surface portion 46 b, and the bolts 49 are screw holes 29 provided in the flat surface portion 22 b of the positioning block 22. It is fixed to. Further, the slide table 43 on which the split mold 41 is mounted is fixed to the receiving plate 21 independently of the base member 46.

  Therefore, the taper surface portion 46a is the cassette side reference taper surface portion, the taper surface portion 22a is the master die side reference taper surface portion, the flat surface portion 46b is the cassette side reference flat surface portion, and the flat surface portion 22b is the mother die side reference flat surface portion. Is formed to have extremely high surface accuracy.

  Further, when the mold clamping is performed, the leading end portion 42a of the core 42 is fitted into the fitting recess 34a provided in the fixed mold plate member 34, and the fixed cassette 30 and the movable cassette 40 are not connected to each other. They are joined so as to be aligned. As shown in FIG. 3, the split mold 41 is divided into three parts. By entering the skirt member 37 and displacing them in the direction of the arrow, they are joined to each other in a circular state. become.

  For this reason, a tapered surface portion 41a whose diameter increases as it goes toward the slide table 43 is formed on the outer peripheral surface of each split mold 41, and a drop-down portion is formed on the center side of these distal surface portions. Thus, the drop-in portion is a flat portion 41b. On the other hand, the inner peripheral surface of the skirt member 37 in the fixed-side cassette 30 is a tapered surface portion 37c that expands away from the fixed mold plate member 34. The taper angle of the tapered surface portion 37c is that of the split mold 41. It coincides with the tapered surface portion 41a. Further, the end face of the fixed mold plate member 34 is a flat portion 34b. Therefore, when the mold is clamped between the fixed cassette 30 and the movable cassette 40, the leading end 42a of the core 42 is fitted into the fitting recess 34a of the fixed mold plate member 34, and the fitting recess 34a The flat portion 34 b formed around the surface abuts on the flat portion 41 b of the split mold 41 in the movable cassette 40. At the same time, the tapered surface portion 41 a comes into contact with the tapered surface portion 37 c of the skirt member 37. As a result, the movable side cassette 40 is configured, and at least each member related to the product molding unit 50 follows the fixed side cassette 30 side.

  As described above, the fixed side cassette 30 can be assembled to the fixed side mold 10, and the movable side cassette 40 can be assembled to the movable side mold 20. Here, different cassettes 30 and 40 are used according to the shape and size of the molded product. However, if the master dies 10 and 20 are accurately aligned in the direction of the axis A, these fixed and movable cassettes are used. 30 and 40 are assembled in a state in which the above-described reference surfaces are brought into contact with the mother dies 10 and 20, respectively, so that the respective parts constituting the mold are accurately aligned in the direction of the axis A. Then, the movable side mother die 20 is joined to the fixed side mother die 10 so that the angular pin 38 is inserted into the insertion hole 45 a of the slider 45 connected to the split die 41. As a result, mold clamping is performed, and the split mold 41 divided into three parts is joined, and the product molding part 50 is formed on the outer peripheral part of the core 42.

  Therefore, by connecting a nozzle of an injection molding machine to the locating ring 11 and supplying a molding resin, the resin flows into the product molding portion 50 from the gate provided in the runner 35 and molding is performed. When the molded resin is cooled, the movable side die 20 is separated from the fixed side die 10. At the same time, the movable-side cassette 40 is separated from the fixed-side cassette 30. At this time, the split mold 41 is displaced in a direction away from each other by the slider 45 through which the angular pin 38 is inserted. The entire circumference of the outer periphery of the molded product with the cut is opened. When the ejector pin 27 is pushed up from this state, the molded product is released from the mold and taken out.

  Thus, the fixed-side cassette 30 and the movable-side cassette 40 are detachably attached to the fixed-side and movable-side master dies 10,20. Accordingly, when the shape or the like of the product forming part 50 is changed, the fixed side and movable side cassettes 30 and 40 can be exchanged, and the fixed side and movable side master dies 10 and 20 can be used as they are.

  Between the fixed side mold 10 and the fixed side cassette 30, a bolt 39 is used so that the tapered surface portion 37 a and the flat surface portion 37 b formed on the skirt member 37 are joined to the tapered surface portion 14 a and the flat surface portion 14 b of the positioning block 14. By being fastened, it can be assembled in a state in which the positions are accurately adjusted to each other. Further, between the movable side mold 20 and the movable side cassette 40, the taper surface portion 46 a and the flat surface portion 46 b formed on the base member 46 are joined to the taper surface portion 22 a and the flat surface portion 22 b of the positioning block 22, and the bolt 49. By fixing the two, they are assembled in a state where the positions are accurately adjusted with respect to each other. Here, the positioning of the fixed and movable cassettes 30 and 40 in the axial direction with respect to the fixed and movable masters 10 and 20 is performed between the plane portions 14b and 37b and between the plane portions 22b and 46b. Positioning in the direction perpendicular to the axial direction and in the tilt direction is performed at the joint surfaces between the tapered surface portions 14a and 37a and between the tapered surfaces 22a and 46a.

  When the cassettes 30 and 40 are replaced, the skirt member 37 and the base member 46 are separated from the positioning blocks 14 and 22 by detaching the bolts 39 and 49 from the positioning blocks 14 and 22, respectively. At this time, if the pressing force at the tapered surface portion is large, it becomes difficult to separate the skirt member 37 and the base member 46. As already described, since the mutual alignment is performed not only by the taper surface portion but also by the cooperative action with the flat surface portion, it is possible to align the taper surface portions so that they are not so strongly pressed against each other. .

  The product molding unit 50 includes a fixed mold plate member 34, a split mold 41, a core 42, and a movable mold plate member 48. The fixed mold plate member 34 is connected to the skirt member 37. The skirt member 37 is directly fixed to the fixed base plate 10, and the member constituting the cassette 30 other than the fixed mold plate member 34, that is, the sprue bush. 31 and the bush receiver 33 are not connected to the skirt member 37. Therefore, the influence of the error due to the sprue bush 31 and the bush receiver 33 does not reach the fixed mold plate member 34, and the assembly is performed with high accuracy. The core 42 and the movable plate member 48 are also attached to a base member 46 that is directly fixed to the movable side mold 20, and the base member 46 is not connected to the members constituting the cassette 40. Therefore, the core 42 and the movable mold member 48 can be assembled with high accuracy. Moreover, since the core 42 and the fixed mold plate member 34 are in the male-female fitting state, the relative position adjustment between the cassettes 30 and 40 is accurately performed. For this reason, since the split mold 41 follows the skirt member 37 that is accurately positioned in the cassette 30 on the fixed side, the split mold 41 is also positioned with high accuracy.

It is sectional drawing which decomposes | disassembles and shows the injection die which shows one Embodiment of this invention. It is sectional drawing which shows the metal mold | die of FIG. It is a top view which shows the operation | movement of a split mold.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Fixed side mother die 14 Positioning block 14a Tapered surface part 14b Flat surface part 16 Screw hole 20 Movable side mother die 22 Positioning block 22a Tapered surface part 22b Flat surface part 29 Screw hole 30 Fixed side cassette 31 Sprue bush 32 Sprue 33 Bush receiver 34 Fixed mold plate Member 34a Fitting recess 34b Planar portion 35 Runner 37 Skirt member 37a, 37c Tapered surface portion 37b Planar portion 39 Bolt 40 Movable cassette 41 Split mold 41a Tapered surface portion 41b Planar portion 46 Base member 46a Tapered surface portion 46b Planar portion 48 Movable mold plate member 49 Bolt 50 Molding part

Claims (2)

A fixed-side master block in which a fixed-side cassette is detachably connected and a movable-side master block in which a movable-side cassette is detachably connected are arranged on the same axis, and the movable-side cassette and the fixed-side cassette are connected to male and female. In a cassette-type injection mold in which a product forming part is formed that is clamped so as to be fitted and a substantially cylindrical member is formed between both cassettes.
Forming a cassette side reference surface comprising a taper surface portion and a flat surface portion on each of the fixed side and movable side cassettes,
In each of the fixed side and movable side master dies, a master die side reference surface comprising a tapered surface portion and a flat surface portion in contact with each cassette side reference surface is formed,
Each taper surface portion is inclined with respect to the axis, and each plane portion is formed in a direction orthogonal to the axis, between the fixed cassette and the fixed matrix, and between the movable cassette and the movable side. A cassette type injection molding die characterized in that each of the taper surface portions and the flat surface portions are press-contacted with each other by a bolt oriented in the axial direction between the mother die. The movable cassette is provided with a plurality of split molds, and each split mold has a cylindrical shape when joined to the fixed cassette, and the outer peripheral surface of each split mold has the axial direction The end surface portion is formed with a flat portion in a direction perpendicular to the axis, and the fixed cassette is contacted with the split taper surface portion and the flat portion. 2. The cassette type injection molding die according to claim 1, wherein the taper surface portion and the flat surface portion are in contact with each other.

Images