JP2000280260A - Mold apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance molding accuracy, to shorten a molding cycle and to also enhance maintenance properties in a mold apparatus equipped with an inclined core for forming an undercut part. SOLUTION: An inclined core 54 is not directly supported on an ejection plate 51 but supported on an inclined core base stand 52 fixed to the ejection plate 51 so as to be protruded toward a fixed mold 31. By this constitution, the inclined core 54 is shortened. The inclined core 54 is held to the inclined core base stand 52 on the side of the fixed mold 31 in a detachable manner by a bolt 56. A closure plate 45 covering the bolt 56 to form a product cavity 33 is fixed to a movable receiving plate 42 on the side of the fixed mold 31 in a detachable manner by a bolt 46.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding die device used for injection molding of a resin and the like, and more particularly to a structure for treating an undercut portion.

[0002]

FIGS. 4 and 5 show an example of a conventional molding die apparatus. The product 1 molded by the molding apparatus has a side wall 3 bent substantially perpendicularly from a side edge of the main plate 2 and a projection 4 on the inner surface of the side wall 3. I have.

[0003] The molding die has a fixed die 11 and a movable die 12. The fixed mold 12 and the movable mold 12 move up and down in the figure (mold opening and closing direction A) to open and close each other, and form a product cavity 13 having the shape of the product 1 therebetween when the mold is closed. The mold opening and closing direction A is the main plate 2 of the product 1.
The movable mold 12 forms the inner surface of the product 1. Therefore, the convex portion 4 of the product 1 is an undercut portion that forms an undercut shape in the mold opening / closing direction A on the movable mold 12 side.

[0004] A movable mold 12 on the lower side of the figure is a movable side mounting plate which is mounted on a movable side platen of a molding machine (not shown).
14, a movable-side receiving plate 15 fixed via a spacer block (not shown) to the upper surface of the movable-side mounting plate 14 in FIG.
And a movable mold plate 16 fixed to the upper surface in FIG. The movable mold plate 16 forms the product cavity 13. A projecting plate 17 is provided between the movable mounting plate 14 and the movable receiving plate 15 in the mold opening / closing direction A.
Is supported movably within a predetermined range. This protruding plate 17
Is composed of a first protruding plate member 17a and a second protruding plate member 17b which are stacked and fixed in the mold opening / closing direction A.

[0005] The protruding plate 17 is provided with an inclined core 18 for protruding the molded product 1 when the mold is opened and releasing the product 1 from the movable mold 12. This inclined core 18
The product 1 has a concave portion 18a which forms the convex portion 4. The inclined core 18 has a flange portion 19 provided at the end on the side opposite to the fixed die 11 between the first protruding plate member 17a and the counterbore portion 20 formed on the second protruding plate member 17b. By being slidably sandwiched, it is movable in the direction B orthogonal to the mold opening / closing direction A with respect to the protruding plate 17. The direction B is a direction substantially orthogonal to the side wall 3 having the protrusion 4 in the product 1. And, the inclined core 18 freely passes through the through hole 21 formed in the movable-side receiving plate 15, and
An inclined hole 22 formed in the movable mold plate 16 is slidably penetrated. The inclined hole 22 and the inclined core 18 are inclined with respect to the mold opening / closing direction A. The direction of the inclination is a direction away from the protrusion 4 toward the fixed mold 11 side.

At the time of molding, as shown in FIG.
The mold 11 and the movable mold 12 are closed, and the fixed mold 11 and the movable mold 12 are closed.
A product cavity 13 is formed between 12. In this state, the product cavity 13 is filled with a molten thermoplastic resin as a molding material from a gate (not shown). When the resin in the product cavity 13 is solidified, the fixed mold 11 and the movable mold 12 are opened as shown in FIG. Upon opening the mold,
Due to the difference in mold release resistance between the fixed mold 11 forming the outer surface of the product 1 and the movable mold 12 forming the inner surface of the product 1, the resin solidified in the product cavity 13, that is, the molded product 1,
First, it separates from the fixed mold 11 and stays on the movable mold 12 side. Next,
For example, the protruding plate 17 moves toward the fixed mold 11 by driving of a driving source provided in the molding machine. With the movement of the protruding plate 17, the inclined core 18 also moves toward the fixed mold 11, whereby the product 1 is protruded and separated from the movable mold 12. Since the inclined core 18 is fitted in the inclined hole 22 of the movable mold plate 16 which is inclined and has the same inclination, the inclined core 18 is orthogonal to the mold opening / closing direction A as it moves toward the fixed mold 1. Also moves in the direction B. As a result, the inclined core 18 is
And the molded product 1 can be taken out without any trouble. After the product 1 is taken out, the mold is closed again, and the above molding steps are repeated.

However, in the conventional mold apparatus, since the inclined core 18 is directly supported on the protruding plate 17, there are the following problems. First, for example, the inclined core 18 and the movable mold plate
If resin enters the gap between the side surfaces of the 16 inclined holes 22, molding becomes impossible, so maintenance work such as cleaning or replacing the worn inclined core 18 is necessary, but to remove the inclined core 18 The movable mold 12 must be removed from the molding machine and the entire movable mold 12 must be disassembled. This disassembly and reassembly take time and effort, resulting in poor maintainability.

Further, since the inclined core 18 is long, the influence of dimensional errors is apt to occur, and it is difficult to increase the molding accuracy. For example, on the inner surface of the product 1, a step may be generated in the portion 5 between the inclined core 18 and the movable mold plate 16. Further, since the inclined core 18 is long and the sliding part a between the movable core plate 16 and the sliding part b between the protruding plate 17 in the inclined core 18 is separated, the inclined core 18 is inclined. A large moment is generated in the core 18, and the inclined core 18 is easily inclined from a regular position. For this reason, there is a possibility that so-called galling occurs in the sliding portions a and b, resulting in an operation failure or a reduction in molding accuracy. Also, the mold opening / closing speed cannot be increased, and it is difficult to shorten the molding cycle.

On the other hand, Japanese Patent Application Laid-Open No. Hei 6-262629 describes that an inclined core is shortened by interposing a joint rod fixed to the projecting plate between the inclined core and the projecting plate. ing. By shortening the inclined core in this way, it is possible to improve the molding accuracy and shorten the molding cycle. However, in the mold device described in the above publication, the inclined core is movable with respect to the joint rod by the connection pin and the long hole, but since the connection pin has a directionality perpendicular to the mold opening and closing direction, The inclined core cannot be disassembled and assembled from the parting line side of the movable mold with the fixed mold. To disassemble the inclined core, the entire movable mold must also be disassembled. Therefore, the maintainability has room for improvement.

[0010] The present invention is intended to solve such a problem, and in a molding die apparatus having an inclined core, it is possible to improve the molding accuracy, shorten the molding cycle, and further maintain the mold. The purpose is to improve the performance.

[0011]

According to a first aspect of the present invention, there is provided a first mold and a second mold which are opened and closed with each other to form a product cavity therebetween when the mold is closed. In a molding die apparatus for molding a product having an undercut portion having an undercut shape with respect to the opening and closing direction of these molds, the second mold moves in the opening and closing direction of both molds. And a projecting plate for releasing the product molded in the product cavity from the second mold, forming an undercut portion of the product, and opening and closing the two molds in conjunction with the projecting operation of the projecting plate. An inclined core which moves in a direction intersecting with the inclined core and which comes off from the undercut portion when the mold is opened. The inclined core base protruding toward the second mold body is fixed to the projecting plate. Second type In which the inclined core and removably supported from said and in movable in a direction crossing the opening and closing direction of both mold elements second mold side to the end side.

In molding, the first mold and the second mold are closed, and a molding material is filled in a product cavity formed between these molds. In particular, the undercut portion of the product is formed by the inclined core on the first mold body side. Then, after the molding material filled in the product cavity is solidified, both molds are opened, and the molding material solidified in the product cavity, that is, the product is taken out. Upon opening the mold, the product first leaves the second mold and remains on the first mold side.
Next, the ejection plate moves toward the second mold, and the inclined core moves together with the inclined core base fixed to the ejection plate toward the second mold to eject the product and separate from the first mold. Type. At this time, the inclined core also moves in a direction intersecting the opening and closing direction of the two mold bodies, and comes off the undercut portion. Thus, the product can be taken out without the obstruction of the undercut portion. After the product is taken out, the mold is closed again, and the above molding process is repeated. At the time of maintenance, the first mold is removed from the molding machine,
The inclined core can be removed from the second mold body in a state where the mold is opened without disassembling the entire first mold body.

According to a second aspect of the present invention, in the molding die apparatus of the first aspect, an elongated hole is formed at an end of the inclined core on the inclined core base side, and the second hole is formed in the elongated hole. By detachably attaching the inclined core fixture penetrated from the mold side to the second mold side end surface of the inclined core base, the inclined core is slidably supported on the end surface of the inclined core base, In the first mold, an end of the inclined core on the inclined core base side is covered from a second mold side, and a mold component forming the product cavity is protruded from the mold component. It is attached to a mold component located on the plate side by a mold component fixing fixture that is removable from the second mold side.

At the time of maintenance, with the mold opened, the mold component fixing fixture is removed from the second mold side, and the mold component forming the product cavity is removed from the mold component on the protruding plate side. By removing the inclined core fixture from the second mold side, the inclined core can be detached from the inclined core base. Reassembly may be performed in the reverse order.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the molding die apparatus of the present invention will be described below with reference to FIGS. The molded product 1 is the same as that shown in FIGS. 4 and 5 described above, and has a convex portion 4 on the inner surface of the side wall portion 3 which is bent substantially perpendicularly from the side edge of the main plate portion 2. ing. The molding apparatus of this embodiment is for injection molding of a thermoplastic resin.

Reference numeral 31 denotes a fixed mold as a second mold, and 32 denotes a first mold.
The fixed type and the movable type
Reference numeral 32 denotes a product cavity 33 having the shape of the product 1 formed therebetween when the mold is closed by moving in the vertical direction in the figure (the mold opening / closing direction A) and opening and closing each other. In the figure, PL indicates a parting line between the fixed mold 31 and the movable mold 32. The mold opening and closing direction A is set in a direction orthogonal to the main plate portion 2 of the product 1, and the inner side of the product 1 is formed by the movable mold 32. Therefore, the convex portion 4 of the product 1
The movable mold 32 has an undercut portion having an undercut shape in the mold opening / closing direction A.

Although the fixed die 31 on the upper side of the figure shows only the fixed mold plate 36 forming the product cavity 33, it is attached to the fixed platen of the injection molding machine, and the nozzle of the injection molding machine is Has a material passage 37 connected thereto. The material passage 37 communicates with the product cavity 33 at the gate 38.

The movable mold 32 has a movable mounting plate 41 attached to a movable platen of a molding machine and a spacer block (not shown) on the upper surface of the movable mounting plate 41, that is, on the surface of the fixed mold 31 side. The movable-side receiving plate 42 as a mold component fixed to the movable side, and a movable-side mold plate 43 as a mold component fixed to the upper surface of the movable-side receiving plate 42 in the drawing. The movable mold plate 43 forms the product cavity 33. A through-hole 44 is formed in the movable mold plate 43 at a position corresponding to the vicinity of the convex portion 4 of the product 1, and the through-hole 44 serves as a mold component forming a part of the product cavity 33. Is embedded and fixed. The cover plate 45 is fixed to the movable receiving plate 42 by a bolt 46 serving as a mold component fixing member detachable from the fixed mold 31 side, that is, the parting line PL side.
It is detachably attached to.

The movable-side mounting plate 41 and the movable-side receiving plate 42
A protruding plate 51 is supported movably within a predetermined range in the mold opening / closing direction A. The protruding plate 51 is provided with a first protruding plate member 51 that is stacked and fixed in the mold opening / closing direction A.
a and a second protruding plate member 51b. The inclined core base 52 is fixed to the protruding plate 51 so as to protrude toward the fixed mold 31. The inclined core base 52 has a flange portion 53 formed at an end on the side opposite to the fixed die 31 and is fixed by being sandwiched between both protruding plate members 51a and 51b. On the end surface of the inclined core base 52 on the fixed mold 31 side, an inclined core 54 for projecting the molded product 1 and releasing it from the movable mold 32 is movably supported in a direction B orthogonal to the mold opening and closing direction A. Have been. This direction (inclination core shift movement direction) B
Is a direction substantially orthogonal to the side wall 3 having the convex portion 4 in the product 1. And, the inclined core 54 is provided with the convex portion 4 of the product 1.
Has a concave portion 54a that forms Here, the inclined core 54
Will be described in more detail. An elongated hole 55 penetrating in the mold opening / closing direction A and extending in the inclined core shift movement direction B is formed at an end of the inclined core 54 on the inclined core base 52 side. Further, a bolt 56 as an inclined core fixture is penetrated through the elongated hole 55 from the fixed mold 31 side, and is detachably attached to the inclined core base 52. further,
The cover plate 45 detachable from the fixed mold 31 side is an inclined core.
The end of the inclined core base 52 at 54 is covered from the fixed mold 31 side. Thereby, the fixed type in the inclined core base 52
An inclined core 54 is slidably supported on the end surface on the 31 side, and the inclined core 54 is detachable from the fixed mold 31 side.

The inclined core base 52 and the inclined core 54
Has a through hole 57 formed in the movable-side receiving plate 42, and the inclined core 54 is slidable in an inclined hole 58 formed between the movable-side mold plate 43 and the lid plate 45. Penetrates. This inclined hole
58 and the inclined core 54 are inclined with respect to the mold opening / closing direction A. The direction of the inclination is a direction away from the protrusion 4 toward the fixed mold 31 side. As a result, the protruding plate 51
When the mold is opened, the inclined core 54 projects the molded product 1 and comes off the projection 4 when the mold is opened.

Next, the operation of the above configuration will be described. In molding, first, as shown in FIG. 1, the fixed mold 31 and the movable mold 32 are closed, and a product cavity 33 is formed between the fixed mold 31 and the movable mold 32. And fixed type
The product cavity 33 is filled with a molten thermoplastic resin as a molding material from the gate 38 through the material passage 37 in the material 31. As a result, the product 1 is formed in the product cavity 33. In particular, the convex portion 4 which is an undercut portion is formed by the inclined core.
52 formed.

After the resin filled in the product cavity 33 is solidified, the fixed mold 31 and the movable mold 32 are opened as shown in FIG. Take out. At the time of opening the mold, the product 1 is first separated from the fixed mold 31 and moves due to the difference in release resistance between the fixed mold 31 forming the outer surface of the product 1 and the movable mold 32 forming the inner surface of the product 1. Stay on the mold 32 side. Next, the protruding plate 51 moves toward the fixed mold 31 by, for example, driving of a driving source provided in the molding machine. Along with this, the inclined core 54 is fixed together with the inclined core base 52 fixed to the protrusion plate 51.
The product 1 is moved to the side 31 to protrude and is released from the movable mold 32. At this time, since the inclined core 54 is fitted in the inclined hole 58 of the movable mold 32 which is inclined and has the same inclination, the inclined core 54 is orthogonal to the mold opening / closing direction A as it moves toward the fixed mold 31. It also moves in direction B. As a result, the inclined core 54 is
And the molded product 1 can be taken out without obstructing the inclined core 54. After the product 1 is taken out, the mold is closed again, and the above molding steps are repeated.

When it is necessary to remove the inclined core 54 for cleaning or replacement of the worn-out inclined core 54, the fixed mold 31 and the movable mold 32 remain attached to the molding machine.
Then, as shown in FIG. 3, the bolt 46 is removed from the fixed mold 31 side, that is, the parting line PL side, and the cover plate 45 is removed. Further, the bolts 56 that are exposed with the lid 45 removed are removed, and the inclined core 54 is detached from the inclined core base 52. Inclined core
Reassembly of the cover 54 and the cover plate 45 may be performed in the reverse order.

Thus, the inclined core 54 can be removed without removing the movable mold 32 from the molding machine and without disassembling the movable mold 32 as a whole. Therefore, the labor and time required for the maintenance work around the inclined core 54 can be reduced, and the maintainability is improved. Moreover, movable type 32
Is relatively simple.

Then, the inclined core base 52 is fixed to the projecting plate 51 by protruding toward the fixed mold 31 side.
And an inclined core moving in a direction B orthogonal to the mold opening / closing direction A
Since the 54 is supported, the inclined core 54 can be shortened. The entire length of the inclined core 54 can be reduced to about 1/2 to 1/3 as compared with the conventional case where the inclined core 18 is directly supported on the protruding plate 17. Thereby, the influence of the dimensional error is less likely to occur, and the molding accuracy can be improved. In addition, the reliability of the operation of the inclined core 54 is improved, and the inclined core base 52 and the movable mold plate 43 are improved.
Also, the sliding portions c, d, and e between the cover plate 45 and the cover plate 45 are less likely to be galled. As a result, the molding accuracy can be further improved, and the opening / closing speed of the fixed mold 31 and the movable mold 32 can be increased, so that the molding cycle can be shortened.

It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made. For example,
The shape of the product to be molded is not limited to that of the embodiment,
An undercut portion may be formed by the hole instead of the convex portion 4. Further, the configuration of the molding die apparatus of the present invention can also be used for molding die apparatuses other than injection molding of a thermoplastic resin.

[0027]

According to the first aspect of the present invention, in a molding die apparatus in which an undercut portion of a product is formed by an inclined core, a second mold is provided on a protruding plate on a first mold side having an inclined core. The inclined core base protruding toward the body side is fixed, and the inclined core is movably supported on the inclined core base in a direction intersecting the opening and closing directions of the first mold body and the second mold body. When the length is shortened, the molding accuracy can be improved, and the reliability of the operation of the inclined core is improved, so that the molding cycle can be shortened. In addition, since the inclined core can be removed from the second mold side, it is not necessary to remove the second mold from the molding machine or disassemble the entire second mold during maintenance of the inclined core. The required labor and time can be reduced.

Further, according to the molding die apparatus of the second aspect of the present invention, a long hole is formed at an end of the inclined core, and the inclined core fixing tool penetrated from the second mold side into the long hole. The inclined core base is detachably attached to an end face of the inclined core base on the side of the second mold, and the end of the inclined core is attached to the second mold in the second mold.
Since the mold component forming the product cavity and covering the mold cavity from the mold body side is attached to the mold component located on the protruding plate side by the mold component fixing fixture detachable from the second mold side, With a simple configuration, the inclined core can be
Can be removable from the side of the mold.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of a molding die apparatus of the present invention, showing a mold closed state.

FIG. 2 is a sectional view of the same, showing a mold open state.

FIG. 3 is a sectional view of the same, showing a state in which the inclined core is disassembled.

FIG. 4 is a cross-sectional view showing an example of a conventional molding die apparatus;
This shows the mold closed state.

FIG. 5 is a sectional view of the same, showing a mold open state.

[Explanation of symbols]

 1 Product 4 Convex part (undercut part) 31 Fixed mold (second mold) 32 Movable mold (first mold) 33 Product cavity 42 Movable side receiving plate (mold component) 45 Lid plate (mold) Components) 46 Bolt (Fixed component fixing member) 51 Extruded plate 52 Inclined core base 54 Inclined core 55 Slot 56 Bolt (inclined core fixture)

Claims (2)

[Claims] 1. An undercut comprising a first mold and a second mold which are mutually opened and closed to form a product cavity therebetween when the mold is closed, and which have an undercut shape in the opening and closing directions of these molds. In the molding die apparatus for molding a product having a part, the second mold moves in the opening and closing directions of both molds to release the product molded in the product cavity from the second mold. A projecting plate, and an inclined core that forms an undercut portion of the product and moves in a direction intersecting the opening and closing direction of the two mold bodies in conjunction with the projecting operation of the projecting plate, and comes off the undercut portion when the mold is opened. And fixing an inclined core base projecting toward the second mold side to the protruding plate, and opening and closing the inclined core at an end of the inclined core base on the second mold side. Direction crossing the direction A molding die device supported movably and detachably from a second mold side. 2. An oblong core is formed at an end of the oblique core on the oblique core base side, and an oblique core fixing tool penetrated from the second mold body side into the oblong hole is provided on a second end of the oblique core base.
The inclined core base is slidably supported on the end surface of the inclined core base by being removably attached to the end surface of the inclined core base. The end of the side is covered from the second mold side, and the mold forming material forming the product cavity is detachable from the second mold side to the mold forming material located closer to the protruding plate than this mold forming material. The molding die apparatus according to claim 1, wherein the molding die apparatus is attached by a suitable mold component fixing member.