JPH03292116A - Molding method of resin molded product and mold - Google Patents

Abstract

PURPOSE:To enable easy and smooth molding without forming gate marks on the outside, by a method wherein at the time of the primary molding, a moving mold body provided on a female mold of a movable retainer plate is ejected in the direction of a male mold of a retainer plate and secondary casting material filling space is blocked and at the time of the secondary molding, the moving mold body is restored in the direction of a female mold, the secondary casting material filling space is formed and two-layer molding is performed. CONSTITUTION:Under a mold clamping state, a moving mold body 34 is made to approach to a retainer plate 1 side, the tip surface is stuck to a product surface of a male mold 2 of a retainer plate 1, the primary casting material is cast into a cavity 5 obtained by blocking a secondary casting material filling space and the primary molding is performed. Then the tip surface of the moving mold body 34 is separated from the product surface of the male mold 2, made into almost the same as the product surface of a female mold 4 of a movable retainer plate 3, the secondary casting material filling space is formed and the secondary molding is performed by casting the secondary casting material into the cavity 5. A mold is broken after cooling and solidification of a product within the cavity 5 and the product stuck to the female mold 4 is taken out by ejecting the same. Since gate marks are formed on the inside of a transparent part 100, an outward appearance of an obtained two-colored molded product C becomes favorable.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for injecting a primary injection material and a secondary injection material into a cavity formed between a fixed mold plate and a movable mold plate that face each other. The present invention relates to a method for molding a resin molded product and a mold for molding a two-color (two-layer) molded product (for example, an audio player) by sequentially filling the product.

[Conventional technology]

Generally, when injection molding an audio cassette case, for example, a cavity is inserted between a cavity mold forming the outer surface of the cassette top and a core mold forming the inner surface of the cassette half. The product is molded by supplying the molten resin flowing through the mold through the gate.

[Problem to be solved by the invention]

By the way, in this case, if a normal type gate is provided in the cavity mold corresponding to the outer surface of the cassette half, uneven gate marks will remain on the outer surface of the molded cassette half, resulting in poor appearance. In particular, it is desired that the gate position for injecting the secondary injection material (transparent resin) for window molding of the cassette half, which is a two-color molded product, has no problems in terms of appearance and two functions.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to prevent gate marks from being formed on the outer surface of a molded product, to cause no problems in appearance, and to easily and smoothly create a molded product. The object of the present invention is to provide a method for molding a resin molded product and a mold for molding it.

[Means to solve the problem]

In order to achieve the above object, claim 1 of the present invention provides resin injection by sequentially filling a gap formed between a fixed mold plate and a movable mold plate facing each other with a primary injection material and a secondary injection material. In a molding method for molding a molded article, the fixed mold plate is provided with a male mold, the movable mold plate is provided with a female mold, and the female mold is provided with a movable mold body movable in the mold opening/closing direction, and - During molding, the female movable mold body is made to protrude toward the male mold, and the remaining cavity is filled with the primary injection material while the secondary injection material filling space is closed, and then, during the secondary molding, The movable mold body is moved back to form a secondary injection material filling space, and the secondary injection material is filled into this space to form a resin molded product.

In addition, claim 2 of the present invention provides a method for forming a resin molded product by sequentially filling a primary injection material and a secondary injection material into a gap formed between a fixed mold plate and a movable mold plate that face each other. In the mold, the fixed mold plate is provided with a male mold, the movable mold plate is provided with a female mold, and the female mold is provided with a movable mold body movable in the mold opening/closing direction, and the male mold A mold release mechanism is provided in the gap to release the molded resin product.

[Effect]

In the method for molding a resin molded product of the present invention, during primary molding, a movable mold body provided in the female mold of the movable mold plate protrudes toward the male mold of the fixed mold plate to close the secondary injection material filling space. During secondary molding, the mold is returned to the female mold direction to form a secondary injection material filling space to form a two-color (two-layer) molded product.

In addition, in the mold for molding resin molded products of the present invention, by moving the position of the movable mold body provided in the female mold of the movable mold plate between the second molding and the secondary molding, After a two-color (two-layer) molded product is molded, the resin molded product attached to the male mold of the fixed mold body is released from the mold by a mold release mechanism when the mold is opened.

〔Example〕

Hereinafter, the present invention will be explained in detail based on FIGS. 1 to 4.

FIG. 1 shows a first embodiment of the present invention, and this figure shows a cross section cut at right angles to the left and right sides of the center line Q. In FIG. 1, reference numeral 1 denotes a fixed mold plate, and a male mold 2 is attached to this fixed mold plate 1. Further, a movable mold plate 3 is provided so as to be able to approach and move away from the fixed mold plate 1, and a female mold 4 is attached to this movable mold plate 3. A cavity (gap) 5 for molding the audio cassette half C is formed between the male mold 2 and the female mold 4.

As shown in FIG.
colored portions 101102 formed on both sides of the colored portions 101102, and a pair of connecting portions 103 that connect these colored portions 101 and 102.
It is composed of.

Submarine gate marks 105 from the primary molding are formed on the pair of vertical edges 104 on the front surface of the colored part 102, and gate marks from the secondary molding are formed on the inner surface of the transparent part l○0. It is formed.

The fixed mold plate 1 includes a first. A second fixed receiving plate 67 is attached to each of the second fixed receiving plates 7, and a third fixed receiving plate 9 is attached to the second fixed receiving plate 7 via a spacer 8. And between the second fixed receiving plate 7 and the third fixed receiving plate 9, there is a first. Second. A third projecting plate 10, 11, 12 is provided movably in the mold opening/closing direction, and these third projecting plates 10, 11, 12 are movable in the mold opening and closing direction. Second.
A protruding bottle 13 having a base attached to the third protruding plates 10 to 12 is attached to the second protruding plate 13. It penetrates the first fixed receiving plates 7, 6 and the fixed mold plate 1 and enters and retracts into the cavity 5. Further, the third projecting plate 12 includes first and second fixed receiving plates 6 and 7.
A piston rod of a hydraulic protruding cylinder 14 fixed to is connected to the piston rod.

A fixed mounting plate 16 is attached to the third fixed receiving plate 9 via a spacer 15, and this fixed mounting plate 16 includes:
A pair of locate rings 17, 18 are attached.

In correspondence with these locate rings 17 and 18, sprue bushes 19 and 20 for injecting the secondary injection material (colored resin) and the secondary injection material (transparent resin) are fitted into the fixed mounting plate 16. The nozzles of a pair of injection molding machines come into contact with these sprue bushes 19 and 20. Further, a manifold 22 is arranged between the third fixed receiving plate 9 and the fixed mounting plate 16 via a distance piece 21, and this manifold 22
For each of the above blueprints 1. 19 and 20 are connected. Further, a pair of first bushes 23 and 24 are connected to the manifold 22 in a state that passes through the third fixed receiving plate 9 and the third and 21st protruding plates 12 to 10. .24, the second. A pair of heating bodies (spears) 25 and 26 passing through the first fixed receiving plates 7 and 6 and the fixed mold plate 1 have a second bar on their outer periphery.

They are connected with shoes 27 and 28 arranged.

And the above-mentioned Spruptsushi, 19.20. , manifold 22, first pusher, inside of 23.24 and heating element 2
5.26 and the second bushing 27.28, a pair of resin passages 29.30 for the molten resin (for the secondary injection material and the secondary injection material) are formed, respectively. The resin passage 29 for this purpose is communicated with the cavity 5 via a runner and a submarine gate formed between the fixed mold plate 1 and the movable mold plate 3. Furthermore, the resin passage 30 for the secondary injection material is in direct communication with the cavity 5.

A movable receiving plate 31 is attached to the movable mold plate 3,
A movable mounting plate 33 is attached to the movable receiving plate 31 via a spacer 32. A movable mold body 34 is provided penetrating the movable mold plate 3 and the movable receiving plate 31 so as to be movable in the mold opening/closing direction, and a movable receiving plate 35 is attached to the base of the movable mold body 34. ing. In addition, the movable receiving plate 3
5 is connected to a piston rod of a hydraulic moving cylinder 37 attached to a movable mounting plate 33 and a support plate 36 fixed to the movable mounting plate 33. By operating this moving cylinder 37, The distal end surface of the movable mold body 34 comes into close contact with the product surface of the male mold 2 of the fixed mold plate 1 during secondary molding, and contacts the product surface of the female mold 4 of the movable mold plate 3 during secondary molding. It is supposed to be between -. Furthermore, a rectangular wave-like uneven surface 38 is formed on the surface of the movable mounting plate 33 side of the movable receiving plate 35, and an uneven surface 39 that engages with the uneven surface 38 is formed opposite to this uneven surface 38. Sliding plate 4 equipped with
0 is provided so as to be movable along a guide member 41 fixed to the support plate 36 in a direction perpendicular to the mold opening/closing direction. A piston rod of a hydraulic sliding cylinder 42 installed on the movable mounting plate 33 is connected to the sliding plate 40 .

Furthermore, a fixed rod 43 having a base attached between the movable mounting plate 33 and the support receiving plate 36 is connected to the sliding plate 40. The fixed rod 43 and the protruding pin 13 are loosely fitted into the movable receiving plate 35 and are provided through the movable body 34.
A pair of mounting holes 106 of the cassette nozzle C are formed by this.

When performing two-color molding of the cassette half C using the injection mold configured as described above, first, the piston rod of the movable sill 37 is advanced in the mold clamped state as shown in FIG. , the movable receiving plate 35 and the movable mold body 3
4 approaches the fixed mold plate 1 side, and the tip surface of the movable mold body 34 comes into close contact with the product surface of the male mold 2 of the fixed mold plate l. In this case, as the movable receiving plate 35 moves, the uneven surface 38 of the movable receiving plate 35
Then, the meshing state of the uneven surface 39 of the sliding plate 40 is released,
The convex portions of the two concave and convex surfaces 38 and 39 are on the same plane. Next, when the piston rod of the sliding cylinder 42 is moved backward, the convex portions of the concavo-convex surfaces 38 and 39 come into close contact with each other, so that the movable mold body 34 is moved against the movable receiving plate 3.
5, sliding plate 40, support plate 36. It will be reliably supported by the movable mounting plate 33.

In this state, the sprue handle, 19. Manifold 22. 1st Bush 23. The primary injection material supplied through the resin passage 29 inside the second bush 27 is injected into the cavity 5 with the secondary injection material filling space closed by the movable mold body 34 via the runner and the submarine gate. -Blow molding is carried out.

Next, moving to secondary forming, first, by advancing the piston rod of the sliding cylinder 42, the movable receiving plate 35 and the sliding plate 40, which have been in a state in which the convex portions of the two uneven surfaces 38 and 39 have been in close contact with each other, are removed. In this relationship, the sliding plate 40 is guided by the guide member 41 and slides along the support plate 36 in a direction perpendicular to the mold opening/closing direction, and the convex part of the uneven surface 38 and the concave part of the uneven surface 39 The positions of match. Therefore, in this state, when the piston mouth/throat of the movable cylinder 37 is moved backward, the movable receiving plate 35 moves toward the movable mounting plate 33, and the uneven surface 38 of the movable receiving plate 35 and the uneven surface of the sliding plate 40 are moved. 39
As a result, the convex part of the uneven surface 38 and the concave part of the uneven surface 39 come into close contact with each other, and the tip surface of the movable mold body 34 is separated from the product surface of the male mold 2 of the fixed mold plate 1. The product surface of the female mold 4 of the movable mold plate 3 is aligned with the product surface, and a secondary injection material filling space is formed.

Next, sprue bush 20. Manifold 22, first bushing 24. The secondary injection material supplied through the resin passage 30 inside the second bulb 28 is fed into the cavity 5.
The secondary injection material is injected into the filling space inside, and secondary molding is performed.

Further, after the secondary molding is completed and the product in the cavity 5 is cooled and solidified, a mold opening step is started, in which the movable mold plate 3 is separated from the fixed mold plate 1. In this case, the product is fixed template 1
The mold is opened while it is attached to the male mold 2. Next, by retracting the piston rod of the protruding cylinder/cylinder 14, the first, second, . The third protrusion plates 10 to 12 are moved to the movable mold plate 3 side, and the tip of the protrusion pin 13 protrudes the product attached to the male mold 2 to smoothly release it from the mold.
Take it out.

Two-color molded product (cassette half) obtained in this way
In C, transparent part (window part) 1 formed by secondary molding
No gate marks are found on the outer surface of 00, and gate marks for secondary molding are formed on the inner surface of transparent part 100.
When looking at the cassette half from the outside, the gate marks for secondary molding are noticeable.The appearance is good, and the uneven surface of the gate marks is formed on the outer surface of the cassette half, as in the past. never be done.

3 and 4 show an injection mold for a two-layer cassette half according to a second embodiment of the present invention. In this embodiment, the same parts as those in the first embodiment are shown. The same reference numerals will be given to the same reference numerals and the explanation will be omitted. Note that the fixed mold side is the same as the configuration shown in FIG. 1, so the drawing is omitted.

A first movable receiving plate 50 is attached to the movable mold plate 3, and a second movable receiving plate 51 is attached to the first movable receiving plate 50. The second movable receiving plate 51 has a third
A movable receiving plate 52 is attached, and this third movable receiving plate 5
A movable mounting plate 53 is attached to 2. Further, a first movable mold body 54 that passes through the movable mold plate 3 and the first movable receiving plate 50 and forms a window portion of the cassette half is provided so as to be movable in the mold opening/closing direction. A first movable receiving plate 55 that can move a predetermined distance within the second movable receiving plate 51 is connected to the base of the movable body 54 . A piston rod of a hydraulic moving cylinder 56 installed in the third movable receiving plate 52 is connected to the first movable receiving plate 55 so as to pass through the second movable receiving plate 51. . Furthermore, movable template 3. 1st. A second movable mold body 57 that penetrates the second movable receiving plate 50, 51 and forms the periphery of the window of the cassette half into two layers is provided so as to be movable in the mold opening/closing direction. A second movable receiving plate 58 is connected to the base of the mold body 57. Then, this second moving receiving plate 58
A connecting pin 59 is installed between the movable receiving plate 55 and the first movable receiving plate 55 with a play of a predetermined interval maintained, and when the piston rod of the movable cylinder 56 is advanced, the first movable receiving plate 55 The distal end surface of the first movable mold body 54 comes into close contact with the product surface of the male mold 2 of the fixed mold plate 1 via the plate 55, and the second movable receiving plate 58 moves via the connecting pin 59 to The distal end surface of the movable mold body 57 approaches the product surface of the male mold 2 to maintain a predetermined distance, while the movable cylinder 5
When the piston rod 6 is moved backward, the tip end surface of the first movable mold body 54 is brought into contact with the movable mold plate 3 via the first movable receiving plate 55.
substantially coincides with the product surface of the female mold 4, and the connecting pin 59.
The distal end surface of the second movable mold body 57 is made to substantially coincide with the product surface of the female mold 4 (the distal end surface of the first movable mold body 54) via the second movable receiving plate 58.

Further, a sliding plate 60 is provided between the second movable receiving plate 58 and the third movable receiving plate 52, and the surface between the second moving receiving plate 58 and the sliding plate 60 is mutually Engaging rectangular wave-like uneven surfaces 61 and 62 are formed. A piston rod of a hydraulic sliding cylinder 63 installed on the third driving receiving plate 52 is connected to the sliding plate 60.

When molding a two-layer cassette half using the injection mold according to the second embodiment of the present invention configured as described above, first, in the mold clamping state shown in FIG. The piston rod 56 is advanced to move the first movable receiving plate 55 toward the fixed mold plate 1 side. This allows the first
The first movable mold body 54 approaches the male mold 2 side of the fixed mold plate 1 together with the movable receiving plate 55 . Next, the first movable receiving plate 55 and the second
When the play of the connecting pin 59 connecting the movable receiving plate 58 is eliminated, the second movable receiving plate 58 and the second movable mold plate 57 start moving toward the fixed mold plate 1 side. As a result, the distal end surface of the first movable mold body 54 comes into close contact with the product surface of the male die 2 of the fixed mold plate 1, and there is a gap between the distal end surface of the second movable mold body 57 and the product surface of the male mold 2. The second movable body 57 stops while maintaining a predetermined interval.

At this time, the convex surface portion of the concave-convex surface 61 of the second movable receiving plate 58 and the convex surface portion of the concave-convex surface 62 of the sliding plate 60 are located on the same plane. Next, when the piston rod of the sliding cylinder 63 is retreated, the convex portions of the two uneven surfaces 61 and 62 come into close contact with each other, so that the second movable body 57 Moving plate 60. Third movable receiving plate 52. It will be reliably supported by the movable mounting plate 53.

In this way, the first. With the secondary injection material filling space closed by the second movable mold body 54, 57, the secondary injection material is injected into the cavity 5 and one-blow molding is performed.

Next, the process moves to secondary forming, and first, the piston rod of the sliding cylinder 63 is advanced. In this case, the second movable body 5
7 and the product surface of the male mold 2 of the fixed mold plate 1, the second movable mold body 57 and the second movable receiving plate 58 are placed on the sliding plate 60 side. is pressed, but by the moving cylinder 56, the first. Second moving receiving plate 55.5
8 is pressed toward the fixed mold plate l side, and the primary injection material between the tip surface of the second movable mold body 57 and the product surface of the male mold 2 contracts due to cooling and solidification, thereby causing the second movement. The receiving plate 58 smoothly moves along the sliding plate 60 or the third movable receiving plate 52 without strongly pressing the sliding plate 60. Then, when the piston rod of the movable sill 56 is retracted in a state where the convex surface portion of the concavo-convex surface 61 of the second movable receiving plate 58 and the concave surface portion of the concave-convex surface 62 of the sliding plate 60 are aligned, the first The movable receiving plate 55 moves toward the movable mounting plate 53, the first movable mold body 54 separates from the product surface of the male die 2, and the first movable receiving plate 55 and the second movable receiving plate 58 are connected. When the play of the connecting pin 59 is eliminated, the second movable receiving plate 58 and the second movable mold body 57 move toward the movable mounting plate 53. Subsequently, the first movable receiving plate 55 comes into contact with the second movable receiving plate 51 and stops, and the convex surface portion of the uneven surface 61 of the second movable receiving plate 58 and the concave surface portion of the uneven surface 62 of the sliding plate 60 come into contact with. At this time, the distal end surface of the first movable mold body 54 and the distal end surface of the second movable mold body 57 form approximately the same surface as the product surface of the female mold 4 of the movable mold plate 2, and thereby, A secondary injection material filling space is formed. In this state, secondary molding is performed by injecting the secondary injection material into the secondary injection material filling space.

Further, after the secondary molding is completed and the product in the cavity 5 is cooled and solidified, a mold opening step is started, in which the movable mold plate 3 is separated from the fixed mold plate 1. In this case, the mold is opened while the product is attached to the male mold 2 of the fixed mold plate 1, so the mold release mechanism on the fixed mold side is activated to project the product from the male mold 2 and release it from the mold. .

Two-layer molded product (cassette half) obtained in this way
In this case, no gate marks are found on the outer surface of the transparent part formed by secondary molding, and the gate marks for secondary molding are formed on the inner surface of the transparent part, so it is difficult to see the cassette half from the outside. In this case, the gate marks for secondary molding are noticeable and the appearance is good.

〔Effect of the invention〕

As explained above, claim 1 of the present invention provides a resin molded product by sequentially filling a primary injection material and a secondary injection material into a gap formed between a fixed mold plate and a movable mold plate that face each other. In a molding method for molding, the fixed mold plate is provided with a male mold, the movable mold plate is provided with a female mold, and the female mold is provided with a movable mold body movable in the mold opening/closing direction; , the moving mold body of the female mold is made to protrude toward the male mold, and the remaining cavity is filled with the primary injection material while the secondary injection material filling space is closed, and then, during secondary molding, the moving mold body is The mold body is retreated to form a space for filling the secondary injection material, and this space is filled with the secondary injection material to mold the resin molded product, so the movement provided in the female die of the movable template is During blow molding, the mold body protrudes toward the male mold of the stationary mold plate to close the secondary injection material filling space, and during secondary molding, returns to the female mold direction to form a secondary injection material filling space. By molding a colored (two-layer) molded product, a product that does not cause problems in appearance can be easily and smoothly molded.

In addition, claim 2 of the present invention provides a molding process in which a resin molded product is formed by sequentially filling a primary injection material and a secondary injection material into a gap formed between a fixed mold plate and a movable mold plate that face each other. In the mold, the fixed mold plate is provided with a male mold, the movable mold plate is provided with a female mold, and the female mold is provided with a movable mold body movable in the mold opening/closing direction, and the male mold Since a mold release mechanism is provided to release the resin molded product molded in the gap, the position of the movable mold body provided in the female mold of the movable mold plate is set at the same time as during blow molding. After forming a two-color (two-layer) fffl-shaped product by moving it during the next molding, the resin molded product attached to the male mold of the fixed mold body is released by the mold release mechanism when the mold is opened. To mold a product without forming gate marks on the outer surface of the product and having an extremely good appearance when viewed from the outside.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention, and FIG. 2 is a sectional view showing a first embodiment of the present invention.
FIG. 1 is a perspective view showing an example of a cassette half molded by the injection mold, FIGS. 3 and 4 show a second embodiment of the present invention, and FIG. 3 is a sectional view, and FIG. FIG. 4 is a sectional view of the cavity portion during secondary molding. 1... Fixed mold plate, 2... Male mold, 3... Movable mold plate,
4... Female mold, 5... Cavity (void), 10 ・
1st protrusion plate, 11...2nd protrusion plate, 12...3rd protrusion plate, 13...protrusion pin (mold release mechanism), 14...protrusion cylinder, 34...movable mold body, 54...First moving body, 57... Second moving body.

Claims (1)

[Claims] 1) In a molding method for molding a resin molded product by sequentially filling a primary injection material and a secondary injection material into a gap formed between a fixed template and a movable template that face each other. , the fixed mold plate is provided with a male mold, the movable mold plate is provided with a female mold, and the female mold is provided with a movable mold body movable in the mold opening/closing direction, and during primary molding, the movable mold body of the female mold is provided. The body is made to protrude in the direction of the male mold, and the remaining cavity is filled with the primary injection material while the secondary injection material filling space is closed. Then, during secondary molding, the movable mold body is retreated and the second injection material is filled. 1. A method for molding a resin molded product, comprising forming a space for filling a secondary injection material, and filling this space with the secondary injection material to mold the resin molded product. 2) In a molding die for molding a resin molded product by sequentially filling a primary injection material and a secondary injection material into a gap formed between a fixed mold plate and a movable mold plate that face each other, the fixed mold mentioned above A male mold is provided on the plate, a female mold is provided on the movable mold plate, a movable mold body is provided on the female mold so as to be movable in the mold opening/closing direction, and the male mold is molded in the void. A mold for molding a resin molded product, characterized in that a mold release mechanism is provided for releasing the resin molded product.