JP2979238B2 - Method and apparatus for simultaneous molding of multiple molded products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a case where a large number of thin plate-like molded products are simultaneously molded or a case where a resin in a molten state is hardened and hardly shrinks when molded. Also, the present invention relates to a method of forming a thin plate-shaped molded product that cannot have a draft angle, and an apparatus used for the method.

[Conventional technology]

For example, it is necessary to improve the color purity of a color CRT, eliminate color unevenness on the surface of the CRT, and reproduce a uniform color. When the adjustment of the color purity is incomplete, the entire screen is not uniformly whitened but partially colored, and an image having a complete color cannot be reproduced. Therefore, in order to prevent the disadvantage of color unevenness in a color cathode ray tube, multiple purity magnets are provided behind the deflection yoke at the neck of the cathode ray tube, and by changing the position of this deflection yoke and the purity magnet in the circumferential direction. Adjusted to eliminate color unevenness.

The purity magnet M is a kind of magnetic ring made of synthetic resin, and includes a ring portion a and an operation portion b projecting outward from the ring portion a as shown in FIGS. 8 (A) and 8 (B). (Arm), and is injection-molded into a thin plate using a synthetic resin mixed with a magnetic material.

The purity magnet M having such a shape generally adopts a method in which cavities are arranged in a plane on both sides of a runner portion provided on a mating surface of a mold (mold frame) and a molten resin is injected into the cavity. is there. With this arrangement of cavities, if the upper mold (one mold) is separated from the lower mold (the other mold), the surface of the lower mold will be in an open state, and the molded product can be easily removed. On the other hand, it requires a large mold with a large area. As a result, the manufacturing cost of the mold increases,
It is difficult to control the temperature of the mold, and it is difficult to form a molded product having less distortion and excellent dimensional accuracy.

In order to solve the problem in the molding process, as shown in FIGS. 9 and 10, the purity magnet M is erected on the connecting rod d via the connecting part c to form a comb-shaped assembly as a whole. After forming and magnetizing this assembly through a magnetizing step, the individual purity magnets M
The present inventor has developed a method of completing the separation.

[Problems to be solved by the invention]

The method of forming the assembly of the purity magnet M of this new method can be formed in a remarkably dense state as compared with the conventional forming method in which the cavity is formed in a plane on the mating surface of the mold. Although this is a much more efficient method since the size is reduced, the following problems have occurred.

That is, the resin used for this purity magnet is heat-resistant, and its melting temperature and injection pressure are remarkably higher than those used for molding a normal molded product. Further, the heat-resistant resin has a property that its volume expands or hardly shrinks with solidification.

As an example of the resin, as a component for forming a molded body, 6-nylon is 12 to 25% by volume, preferably 15%, and magnetic powder is similarly 88 to 75%, preferably 85% by volume. Mix and mold using an injection molding machine.

Therefore, this flat molded product is strongly adhered to the cavity dug in the mold, and it is substantially difficult to push out the molded product from the mold by pushing it out in the thickness direction of the molded product.

In a general molding method, a "draft angle" is provided in a direction in which the molded product is removed in order to facilitate removal of the molded product. However, as in the case of the purity magnet M, the plate thickness is thin. Therefore, it is difficult to substantially form a draft in a molded product having a large diameter, a wide width and a large flat surface area, and even if it is provided, it is considerably large due to a large area. Become.

However, since the purity magnet M is required to have a small thickness and to have a uniform thickness, it is difficult to make the thickness such that the inclined surface has a draft.

As another problem, in order to improve molding efficiency, it is necessary to reduce the interval (pitch) between the purity magnets M implanted on the connecting rod 4.

If the pitch is reduced, it becomes extremely difficult for the molded product, which is difficult to pull out even as described above, to come out of the mold, and therefore, in order to avoid the above-mentioned drawbacks, it is usually necessary to make the interval too small. Was substantially difficult, and productivity could not be improved from a certain range.

Furthermore, plate-like molded products with a large area compared to the thickness,
It easily adheres to the cavity of the mold at the time of molding. Therefore, it is easy to remove it from the larger area, but it is difficult to remove it with a protruding pin in the thickness direction, and the molded product is damaged. In such a case, the mold must be designed in consideration of the removal of the molded product rather than the molding efficiency, so that a large mold having the cavities arranged in a plane must be used.

SUMMARY OF THE INVENTION The present invention provides a molding method capable of easily extracting a molded product, particularly a plate-shaped molded product, which is harder to remove than the conventional mold, even in a dense state, and an apparatus for performing the method.

[Means for solving the problem]

In order to achieve the above object, the present invention provides (1) a method for simultaneously molding a large number of molded articles in a parallel arrangement, wherein the molded product is orthogonal to the mating surface of the fixed mold portion and the movable mold portion and has a width of 2 mm at the mating surface. The two pieces of laminated plate layers in which the divided piece layers are laminated are arranged on the fixed mold part side and the movable mold part side, respectively, and a two-part cavity is formed in the mating surface of the piece board, and at least the fixed mold part side is formed. In the state where the pieces are fastened and the two pieces are brought together, a predetermined cavity is completed and a molten resin is injected to form a molded product.Then, the tightening pressure of the pieces is released to remove a gap between the pieces. This is a method for simultaneous molding of a large number of molded products that can be formed and molded products can be taken out.

Further, (2) two mold plates, a concave groove formed on one or both of the mating surfaces of the mold plates, and are accommodated in the concave groove in a stacked state, and A simultaneous molding apparatus for a large number of molded articles, comprising: a group of plate members each having a number of cavity plates formed with cavities; and a lock block for moving forward and backward between the end portions of the group of plate members or between the plate plates to pressurize and depressurize the group of plate members. It is.

In the case of a normal mold, the cavity is a fixed hole or recess, and a part of the side wall is configured to move, and the molded product is extracted from the hole or recess. On the other hand, the present invention is characterized in that the side wall forming the cavity is positively moved in a direction different from the direction in which the molded product is pulled out, and the molded product is peeled off from the mold. .

(Operation)

In a method of molding a large number of molded products in a laminated state, a cavity is formed in a mating surface of a plurality of pieces, a predetermined cavity is formed in a state where the pieces are assembled, and after a resin is injected into the cavity. In addition, since the pressing force between the pieces is loosened to easily separate the molded product from the cavity, it is possible to efficiently produce a thin molded product or a molded product using a resin that does not significantly shrink.

〔Example〕

 Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a conceptual diagram of a molding apparatus, which comprises a fixed mold section 1 and a movable mold section 2.

The fixed mold part 1 includes a base 3, a protruding plate 4 having protruding pins protruding in accordance with the number of molded products, a spacer 4a for securing a motion range of the protruding plate 4, a movable mold plate 5 (form frame), It comprises a slide core 6 and the like moving along the surface of the template 5.

The movable mold part 2 includes a fixed mold plate 7 (mold) and the fixed mold plate 7.
And a mounting plate 8 approaching and moving away from the mounting plate 8.
The mounting plate 8 has a guide rod 13 and a lock block 14.
Are protruded toward the movable mold plate 5 on the fixed mold portion 1 side.

The slide core 6 is provided with a plurality of core members 9 (members forming holes of the ring portions a) protruding in the surface direction of the movable mold plate 5. To
A large number of piece plates 11 (cavity cores) each having a cavity provided on the mating surface are fitted in a state of being aligned and stacked, and press plates 12 and 12a are fitted into ends of the group of pieces 11.

Then, the lock block 14 provided on the movable mold part 2 side is fitted into the groove 16 provided on the mating surface of the pressing plates 12 and 12a, and the rear of the end of the group of pieces 11 is pressed via the pressing plate 12. ,
The block 11 is configured to be tightened into one block.

FIG. 2 is a plan view of the movable mold plate 5 constituting the fixed mold portion 2. In the central portion of the movable mold plate 5, a concave groove 10 is formed. That is, "cavity core"
Are arranged, and a cavity 18 is provided on the mating surface of the piece plate 11. A pressing plate 11a and a pressing plate 12, 12a are provided at the extreme end of this group of plate plates 11, and a groove is formed on the mating surface of the pressing plates 12, 12a.
16 are open.

FIG. 3 shows a cross section in a state where the fixed mold part 2 and the movable mold part 1 are joined, and a piece plate 11 housed in the fixed mold part 2,
A pair of molds is formed by the piece plate 11b housed in the movable mold part 1,
A cavity 18 is formed at the mating surface. Also,
A protruding plate 4 is provided along the movable mold plate 5 so that a protruding pin 19 is operated to remove a molded product. Note that a 'is for the ring section a, b' is for the operation section b,
c 'indicates the cavity of the connecting portion c, and d' indicates the cavity of the connecting rod d.

FIG. 4 shows a state in which pressing plates 12 and 12a are arranged at the end of a piece plate 11, and a lock block 14 is moved in the direction of arrow A in a groove 16 formed between the pressing plates 12 and 12a. This shows a state in which the piece plate 11 is pressed in the direction of the arrow B via 12 to integrate the piece plate 11 into one block to form a predetermined cavity 18.

Next, the opening operation of the molding apparatus according to the present invention will be described.

In FIG. 1, the movable cavity 2 is pressed against the stationary mold 1 by a cylinder device (not shown), and a predetermined cavity 18 is closed as shown in FIG. It is formed. This state is the state shown in FIG. 5, and in this state, the molten resin
8) Injected inside.

When the molding of the target molded product is completed in this way, the mounting plate 8 is slightly moved in the direction of arrow C as shown in FIG. 6 to lock the lock block 14 with the groove 16 between the pressing plates 12 and 12a.
Extract more. By removing the lock block 14 in this manner, the pressing force that has pressed many piece plates 11 in one direction is released.

Next, as shown in FIG. 7, the gap D is formed between the fixed mold plate 7 and the movable mold plate 5 by moving the fixed mold plate 7 (mold frame) together with the mounting plate 8 in the direction of arrow C. In the step shown in FIG. 6, since the pressing force between the pieces 11 is released together with the retraction of the lock block 14, the clamping force of the pieces 11 is released across the molded product, and the molded product is released from the cavity 18. It is in a state where it can be easily peeled off.

Next, by operating the projecting plate 4 shown in FIG. 1 and FIG.
By protruding inward, the molded product can be extracted from the gap D.

Although the lock block 14 is used as a means for pressing a large number of pieces 11 to integrate them into a block shape, the point is that any means for generating a force for integrally pressing the pieces 11 may be used. Means may be used, and this means can be applied not only at the end of the group of pieces 11 but also at the center, and can be applied not only at one place but also at a plurality of places.

In the present invention, the means for pressing the piece plate 11 is
Although the lock block 14 that moves together is advantageous in terms of the configuration of the device, a cylinder device can be used instead.

〔The invention's effect〕

The present invention relates to 1.) a method of simultaneously molding a large number of molded articles in a parallel arrangement in a state where a piece plate which is orthogonal to a mating surface of a fixed mold portion and a movable mold portion and is bisected by the mating surface is laminated. The two piece plate groups are disposed on the fixed mold part side and the movable mold part side, respectively, and a two-part cavity is formed in the mating surface of the piece plates. After completing the predetermined cavity by abutting the group of pieces and injecting a molten resin to form a molded product, the clamping pressure of the group of pieces is released to form a gap between the pieces, and the molded product can be taken out. 2.) a method of simultaneously molding a large number of molded articles; 2.) two mold plates, a groove formed on one or both of the mating surfaces of the mold plates, and a stacked state accommodated in the groove. From the large number of pieces with a cavity formed on the mating surface That the Komaita group, a simultaneous forming apparatus of multiple molded article having a locking block for pressurizing the pressure-dividing the Komaita group as forward and backward to the end or frame plates of 該駒 plate group.

Accordingly, two pieces of plate groups, which are orthogonal to the mating surface of the fixed mold portion and the movable mold portion and are divided into two pieces at the mating surface, are disposed on the fixed mold portion side and the movable mold portion side, respectively. A cavity divided into two is formed in the mating surface of the two pieces, and the two pieces of plate groups are abutted to complete a predetermined cavity, and a molded product is molded by injecting a molten resin.
Molding can be performed in a densely arranged state in parallel, and the size of the mold can be reduced, thereby significantly improving productivity and efficiency in the molding process.

Further, after molding the molded product by injecting the molten resin in a state where at least the fixed die group side is tightened, the clamping pressure of the die plate group is released to form a punch gap between the die plates, and the molded product is formed. Can be taken out, so use a resin with high adhesiveness that cannot be taken out of the mold with a normal molding method or a resin that shrinks less during solidification, and a large number of thin plate-like molded products are arranged in parallel. Even in a densely packed state, the molded product can be easily peeled from the mold and taken out.

[Brief description of the drawings]

1 is a perspective view showing an outline of a molding apparatus according to an embodiment of the present invention, FIG. 2 is a plan view showing a mold part of the molding apparatus, FIG. 3 is a sectional view of the mold part, and FIG. FIG. 3 is a perspective view showing a fastening means for a piece plate (cavity core) constituting a main part of the present invention. FIG. 5 to FIG. 7 are explanatory views of the opening state of the mold. 8 (A) and 8 (B) are a front view and a side view of the purity magnet, FIG. 9 is a side view of a molded product of the assembly of the purity magnet, and FIG. 10 is a front view. DESCRIPTION OF SYMBOLS 1 ... Fixed mold part (lower mold part) 2 ... Movable mold part (upper mold part) 3 ... Base 4, Projection plate 5 ... Movable mold plate, 6 ... Slide core 7 ... Fixed mold plate , 8 mounting plate 9 core member 10 groove 11 core plate (cavity core) 12 pressing plate 13 guide rod 14 lock block 15 guide hole 16 Groove, 18 ... Cavity 19 ... Protruding pin.

Continuation of front page (56) References JP-A-61-249722 (JP, A) JP-A-63-166506 (JP, A) JP-A-56-77109 (JP, A) , U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B29C 33/00-33/76 B29C 45/26-45/44 B29C 45/64

Claims (2)

(57) [Claims] 1. A method for simultaneously molding a large number of molded articles in a parallel arrangement, wherein two pieces of plates are stacked perpendicularly to a mating surface of a fixed mold portion and a movable mold portion and bisected by the mating surface. The groups are arranged on the fixed mold part side and the movable mold part side, respectively, and a cavity divided into two is formed in the mating surface of the piece plates, and at least the piece groups on the fixed mold part side are fastened and both piece groups are set. After a predetermined cavity is completed by injecting a molten resin to form a molded product, the clamping pressure of the group of plate members is released to form a gap between the pieces, and
A method for simultaneous molding of many molded products that allows removal of molded products. 2. A mold plate, a groove formed on one or both of the mating surfaces of the form plates, a cavity accommodated in the groove in a stacked state, and a cavity formed in the mating surface. And a lock block for advancing and retreating between the end portions or between the pieces of the plate group to pressurize and decompress the group of plate pieces.