CN102152442A

CN102152442A - Injection molding method and injection molding device

Info

Publication number: CN102152442A
Application number: CN2010106232860A
Authority: CN
Inventors: 横山胜助; 金子光雄
Original assignee: FUJI SEIKOU Co Ltd
Current assignee: FUJI SEIKOU Co Ltd
Priority date: 2009-12-28
Filing date: 2010-12-27
Publication date: 2011-08-17
Also published as: JP2011136515A; KR101242991B1; JP5496649B2; KR20110076799A

Abstract

Disclosed is an injection molding method and an injection molding device, capable of compressing synthetic resin in a die cavity without generating burrs, thereby producing synthetic resin products with excellent appearance. The producing of the die is easy, low in cost and higher in durability. The method includes feeding heating media to a heating medium path of a sleeve sheet of a fixed die portion and a mobile die portion for heating to a temperature higher than the softening point of the synthetic resin; injecting and filling the molten synthetic resin into a die cavity and pressurizing; feeding heating media to a heating medium path of a sleeve sheet installation body of a fixed die portion and a mobile die portion for heating so as to make the sleeve sheet installation body undergo thermal expansion before or after pressurizing, supplying coolant to the heating medium path of the sleeve sheet to cool after the thermal expansion and compressing the synthetic resin with a pressure higher than injection pressure of the synthetic resin and at the same time curing the synthetic resin.

Description

Ejection forming method and injection molding device for molding

Technical field

The present invention relates to a kind of ejection forming method and injection molding device for molding, fixed mould and moveable die are being given under the closing state, the injection of the synthetic resin of fusion is filled in the die cavity (cavity), and in mould, this synthetic resin is compressed.

Background technology

For the ejection forming method of synthetic resin, for example, disclose as institutes such as patent documentations 1, following technology has been proposed, that is, and before the synthetic resin of injection fusion, the face side shaped surface side form chamber formation face that makes formed products is heated, thereby make the transfer printing raising.

The prior art document

Patent documentation

Patent documentation 1 Japanese patent laid-open 6-254924 communique

But, for the ejection forming method that attaches the pressing function that in injecting molding die, synthetic resin is compressed, with the degree that the synthetic resin of being filled is suppressed, extraly the merging face of the formation die cavity of fixed mould and moveable die is opened, inject after the synthetic resin of fusion, the merging face of two moulds is closed, carry out mold closing, then synthetic resin is suppressed, therefore, there is following problem, promptly, the forming synthetic resin product are easy to generate burr (burr), can't increase decrement (compacting amount) in order to suppress these burr.

Therefore, for thin-wall product and Yan Shangke, but for the big product of heavy wall and decrement, must significantly the merging face of two moulds be opened in advance,, then can on merging face, be produced a large amount of burr if under this state, suppress.

Certainly, in order to solve described problem, need can not produce the mold structure of burr, in the case, the making difficulty of mould increases, and cost (cost) raises, and the durability of mould is reduced.Can produce following problem in addition: owing to suppress with the temperature below the softening point of synthetic resin, therefore, synthetic resin injection portion with away from the position of this injection portion, the synthetic resin temperature produces difference, when suppressing, the pressed density of synthetic resin produces difference, thereby causes the exterior quality of forming synthetic resin product to produce difference.

Summary of the invention

Therefore, in view of described aspect, the objective of the invention is to: can in mould, compress the synthetic resin in the die cavity, can not produce burr, can make the good forming synthetic resin product of exterior quality, the making difficulty of mould not high also can, cost also is suppressed, and the durability of mould is improved.

Therefore, first invention is a kind of ejection forming method, and fixed mould and moveable die are being given under the closing state, the synthetic resin of fusion is injected be filled in the die cavity and be shaped, and this ejection forming method is characterised in that:

Nesting piece at least one mould in described fixed mould or the moveable die heats, described fixed mould or moveable die comprise the nesting piece that forms described die cavity and are arranged on the outside of described nesting piece and by the high metal nesting piece fixing body of thermal coefficient of expansion

Heat and after being warming up to more than the softening point of synthetic resin at nesting piece, the synthetic resin of fusion is injected be filled in the described die cavity and pressurize at least one mould in described fixed mould or the moveable die,

In the front and back that this pressurize finishes, described nesting piece fixing body to described at least one mould heats, make the thermal expansion of described nesting piece fixing body, and the nesting piece to described at least one mould cools off, come described synthetic resin is compressed with the pressure more than the injection pressure of described synthetic resin, make described synthetic resin sclerosis simultaneously.

In addition, second invention is a kind of injection molding device for molding, and fixed mould and moveable die are being given under the closing state, the synthetic resin of fusion is injected be filled in the die cavity and be shaped, and this injection molding device for molding is characterised in that:

At least one mould in described fixed mould or the moveable die comprises the nesting piece that forms described die cavity, and is arranged on the outside of described nesting piece across heat-barrier material and by the high metal nesting piece fixing body of thermal coefficient of expansion,

In the nesting piece of described at least one mould and nesting piece fixing body, be provided with heating unit and cooling unit,

Coming nesting piece at least one mould in described fixed mould or the moveable die to heat by described heating unit and after being warming up to more than the softening point of synthetic resin, be filled in the described die cavity synthetic resin injection of fusion and pressurize, in the front and back that this pressurize finishes, come the described nesting piece fixing body of described at least one mould is heated by described heating unit, make the thermal expansion of described nesting piece fixing body, and come the nesting piece of described at least one mould is cooled off by described cooling unit, come described synthetic resin is compressed with the pressure more than the injection pressure of described synthetic resin, make described synthetic resin sclerosis simultaneously.

The effect of invention

According to the present invention, can in mould, compress the synthetic resin in the die cavity, can not produce burr, can make the good forming synthetic resin product of exterior quality, the making difficulty of mould not high also can, cost also is suppressed, and the durability of mould is improved.

Description of drawings

Fig. 1 is vertical orthogonal view of injection moulding mould.

Fig. 2 be in order to the phase I to ejection forming method describe want portion's profile.

Fig. 3 wants portion's profile in order to what second stage was described.

Fig. 4 wants portion's profile in order to what the phase III was described.

Fig. 5 wants portion's profile in order to what the quadravalence section was described.

The explanation of symbol

1: the fixation side assembly

2: fixation side first base plate

3: fixation side second base plate

4: fixation side the 3rd base plate

6: fixed mould portion

6A, 26A: nesting piece

6B, 26B: nesting piece fixing body

7: locating ring

8: sprue bush

9: the first running channels

10: first flow

11: the second running channels

12: the second runners

13: cast gate (side gate)

20: movable side assembly

21: movable side first base plate

22: movable side second base plate (liftout plate)

23: movable side the 3rd base plate

24: movable side the 4th base plate

26: moveable die portion

27,28: heat-barrier material

29,30,31,32,34,35: the hot media path

31A, 32A, 34A, 35A: hot media inlet

31B, 32B, 34B, 35B: hot media outlet

33,36: divide plate

G1, G2: gap

J: injection-molded article

S: die cavity

The specific embodiment

Below, come embodiments of the present invention are described based on Fig. 1 to Fig. 5.At first, coming integral body to the injection moulding mould of first embodiment of the present invention to constitute based on Fig. 1 describes.The 1st, be installed on the fixation side assembly of not shown fixed disk (fixed platen) by screw (bolt), this fixation side assembly 1 comprises: fixation side first base plate (base plate) 2, be fixed in fixation side second base plate 3 of this fixation side first base plate 2 by screw, be fixed in fixation side the 3rd base plate 4 of this fixation side second base plate 3 by screw, be provided in the recess of this fixation side the 3rd base plate 4 and the fixed mould portion 6 of being fixed in this fixation side the 3rd base plate 4 by screw, be arranged on the position of being partial to described fixed disk of described fixation side first base plate 2 and fixation side first base plate 2 be positioned the locating ring (locating ring) 7 of fixed disk, and be adjacent to this locating ring 7 and sprue bush (sprue bush) 8 of setting etc.

And, be formed with first running channel 9 at the center of described sprue bush 8, these first running channel, 9 usefulness so that the synthetic resin of the fusion of never illustrated injection nozzle (nozzle) injection pass through, be formed with first flow (runner) 10 in the bottom of this first running channel 9, and be formed with second running channel 11 of the outlet that is equivalent to this first flow 10, the bottom of this external this second running channel 11 is formed with second runner 12, and is formed with the cast gate (side gate (side gate)) 13 of the outlet that is equivalent to this second runner 12.This cast gate 13 is communicated with from the peristome that side and die cavity S end in described fixed mould portion 6 are opened in this die cavity S end.

On the other hand, the 20th, be installed on the movable side assembly of not shown movable plate by screw, this movable side assembly 20 comprises: movable side first base plate 21, be fixed in movable side second base plate 22 (liftout plate (ejector plate)) of this movable side first base plate 21 by screw, be fixed in movable side the 3rd base plate 23 of described movable side first base plate 21 by screw in the mode of surrounding this movable side second base plate 22, be fixed in movable side the 4th base plate 24 of this movable side the 3rd base plate 23 by screw, and the moveable die portion 26 etc. that is entrenched in the recess of this movable side the 4th base plate 24 and is fixed in this movable side the 4th base plate 24.

And, the upright guide bar (not shown) of being located at described movable side the 3rd base plate 23 is inserted into the bullport that is arranged at fixation side the 3rd base plate 4, described guide bar is guided by this bullport, thus movable side assembly 20 can move up and down.

Utilize the upper surface of described moveable die portion 26 and the lower surface of described fixed mould portion 6 to form die cavity S, the synthetic resin of fusion is injected in this die cavity S, make the forming synthetic resin product.

Fixed mould portion 6 comprises nesting piece 6A and the nesting piece fixing body 6B that is configured in the outside (upside) of nesting piece 6A across heat-barrier material 27, and moveable die portion 26 comprises nesting piece 26A and the nesting piece fixing body 26B that is configured in the outside (downside) of nesting piece 26A across heat-barrier material 28.Nesting piece 6A and nesting piece 26A are made by the steel of the special steel that is suitable for the forming synthetic resin mould (for example, the CENA1 of Hitachi Metals limited company).In addition, nesting piece fixing body 6B and nesting piece fixing body 26B are made by high for example aluminium (aluminum) alloy of thermal coefficient of expansion, and are being coated by heat-

barrier material

27,28 respectively.That is, nesting piece fixing body 6B utilize between heat-barrier material 27 and described fixation side the 3rd base plate 4 and and nesting piece 6A between heat insulation.In addition, nesting piece fixing body 26B utilize between heat-barrier material 28 and described movable side the 4th base plate 24 and and nesting piece 26A between heat insulation.

In described fixation side the 3rd base plate 4 and movable side the 4th base plate 24, be provided with the temperature adjustment unit, thereby always described fixation side the 3rd base plate 4 and movable side the 4th base plate 24 maintained set point of temperature.Promptly, 29 are formed in the hot media path in described fixation side the 3rd base plate 4 of being partial to fixed

mould portion

6,30 are formed in the hot media path in movable side the 4th base plate 24 of being partial to moveable die portion 26, according to the temperature that is suitable for being injected into the synthetic resin in the die cavity S, suitable hot media is supplied to described hot media path 29,30, and described fixation side the 3rd base plate 4, fixed mould portion 6, movable side the 4th base plate 24 and moveable die portion 26 are always maintained at set point of temperature.

In the nesting piece 6A of the close die cavity S of described fixed mould portion 6, be provided with heating unit and cooling unit.Promptly, the 31st, in the nesting piece 6A of the close die cavity S of described fixed mould portion 6, the hot media path that forms along this die cavity S, make the heating that flows into via hot media inlet 31A from each supply source be steam, various oil with medium or add hot water or the cooling water or the cold air of conduct cooling usefulness medium, flow in this hot media path 31, the die cavity of fixed mould portion 6 is formed the face side heats or cool off, the heating that flows into hot media path 31 from hot media inlet 31A with medium or cooling with medium from hot media outlet 31B outflow.

In addition, the 32nd, following hot media path, this hot media path comprises the path that extends along horizontal direction in the whole nesting piece fixing body 6B that is formed at described fixed mould portion 6, and the path that is communicated with this path along the vertical direction extension, making the heating that flows into from hot media inlet 32A is steam with medium, various oil or add hot water, or as cold air or the cooling water of cooling with medium, flow in this hot media path 32, whole nesting piece fixing body 6B is heated or cools off, and the heating that flows into hot media path 32 from hot media inlet 32A is flowed out from hot media outlet 32B with medium with medium or cooling.In the described hot media path 32 that longitudinally extends, be provided with the division plate 33 that forms stream.

In addition, the 34th, in the nesting piece 26A of the close die cavity S of described moveable die portion 26, the hot media path that forms along this die cavity S, to make the heating that flows into from hot media inlet 34A be steam, various oil with medium or add hot water or as cooling water or the cold air of cooling with medium, flow in this hot media path 34, the die cavity of moveable die portion 26 is formed the face side heats or cool off, the heating that flows into hot media path 34 from hot media inlet 34A with medium or cooling with medium from hot media outlet 34B outflow.

In addition, the 35th, following hot media path, this hot media path comprises the path that extends along horizontal direction in the whole nesting piece fixing body 26B that is formed at described moveable die portion 26, and the path that is communicated with this path along the vertical direction extension, making the heating that flows into from hot media inlet 35A is steam with medium, various oil or add hot water, or as cold air or the cooling water of cooling with medium, flow in this hot media path 35, whole nesting piece fixing body 26B is heated or cools off, and the heating that flows into hot media path 35 from hot media inlet 35A is flowed out from hot media outlet 35B with medium with medium or cooling.In the described hot media path 35 that longitudinally extends, be provided with the division plate 36 that forms stream.

Moreover, the heating unit, the cooling unit that are arranged at described nesting piece 6A, nesting piece fixing body 6B, nesting piece 26A and nesting piece fixing body 26B are not limited to hot media path, heating medium, cooling medium, also can be other unit, heating unit for example also can be electric heater (electric heater).

Then, come the action that is shaped is described based on Fig. 2 to Fig. 5 especially.At first, hot media is supplied to described hot media path 29,30, fixed mould portion 6 and moveable die portion 26 are always maintained at set point of temperature.Then, carry out under the state of mold closing, as shown in Figure 2, between the upper surface of the nesting piece 26A of the lower surface of the nesting piece 6A of fixed mould portion 6 and moveable die portion 26, be formed with the die cavity S that is filling synthetic resin in fixed mould portion 6 and moveable die portion 26.

Under described state, in order to make the transfer printing raising, make heating flow into hot media path 31 and the hot media path 34 of nesting piece 6A and nesting piece 26A respectively with medium, nesting piece 6A and nesting piece 26A are heated, be warming up to the above temperature of softening point of the synthetic resin that is injected among the die cavity S.

Then, injection nozzle is fed to sprue bush 8, the synthetic resin of fusion is injected into via first running channel 9, first flow 10, second running channel 11, second runner 12 and cast gate 13 in the die cavity S between moveable die portion 26 and the fixed mould portion 6, keeps injection pressure and pressurize for the pressed density that is filled to the synthetic resin in the die cavity S is improved.

In addition, as shown in Figure 3, (can be when pressurize finishes in the front and back that the pressurize for synthetic resin finishes, perhaps also can be before pressurize finishes slightly or after a while), make heating flow into hot media path 32 and the hot media path 35 of nesting piece fixing body 6B and nesting piece fixing body 26B, hastily to nesting piece fixing body 6B and nesting piece fixing body 26B heats and this nesting piece fixing body 6B and nesting piece fixing body 26B are heated up and thermal expansion with medium.In addition, if the thermal expansion of nesting piece fixing body 6B and nesting piece fixing body 26B begins, then after the hot media path 31 of nesting piece 6A and nesting piece 26A and the heating in the hot media path 34 are discharged with medium, cooling is flowed into medium, nesting piece 6A and nesting piece 26A are cooled off.In the case, make nesting piece fixing body 6B and nesting piece fixing body 26B thermal expansion,, nesting piece 6A and nesting piece 26A are begun to cool down if the pressed density of synthetic resin is increased to certain density.

The result, as shown in Figure 4, in fixed mould portion 6, thermal expansion takes place and pushes nesting piece 6A downwards in nesting piece fixing body 6B, in moveable die portion 26, thermal expansion takes place and upwards pushes nesting piece 26A in nesting piece fixing body 26B, die cavity S is narrowed down, and the nesting piece 6A and the nesting piece 26A that form die cavity S cooled off, therefore, the synthetic resin one side that is filled to die cavity S is compressed the sclerosis of (compacting) one side by the pressure more than the injection pressure, thereby becomes forming synthetic resin product J.

So, synthetic resin compression in the die cavity S, sclerosis, form after the forming synthetic resin product J, the hot media path 32 of nesting piece fixing body 6B and nesting piece fixing body 26B and the heating in the hot media path 35 are discharged with medium, replace cooling is flowed in hot media path 32 and the hot media path 35 with medium, whereby, thermal contraction takes place in nesting piece fixing body 6B and nesting piece fixing body 26B, thereby removes described pressurize.Therefore, as shown in Figure 5, in die cavity S, be formed with small clearance G 1 and clearance G 2 up and down at forming synthetic resin product J.Then, fixed mould portion 6 and moveable die portion 26 are carried out die sinking, forming synthetic resin product J is taken out.

According to above present embodiment, under the state of mold closing, can utilize the thermal expansion of nesting piece fixing body 6B and nesting piece fixing body 26B to come easily and moderately the synthetic resin in the die cavity S is compressed, make this synthetic resin sclerosis, when die sinking, between the surface of forming synthetic resin product J and nesting piece 6A and nesting piece 26A, form clearance G 1 and clearance G 2, thereby can successfully carry out die sinking.

Therefore, in order in injecting molding die, synthetic resin to be suppressed compression, make this synthetic resin sclerosis, thereby making formed products, needed can not produce the mold structure of burr in the past, in the case, the making difficulty of mould increases, cost raises, and the durability of mould is reduced, and can produce following problem: owing to suppress with the temperature below the softening point of synthetic resin, therefore, synthetic resin injection portion with away from the position of this injection portion, resin temperature produces difference, and when suppressing, the pressed density of synthetic resin produces difference, thereby cause the exterior quality of forming synthetic resin product to produce difference, but can eliminate the problems referred to above point.

That is, can not make the forming synthetic resin product produce burr, and can not influence outward appearance on the whole, can constitute mould at an easy rate and the durability of mould is improved.

Moreover, as mentioned above, in the present embodiment, in order in mould, the synthetic resin that is filled to die cavity S to be compressed, and in order to form space G1 and space G2, nesting piece fixing body 6B and nesting piece fixing body 26B to two

mold

6,26 heat, and nesting piece 6A and nesting piece 26A are cooled off, make nesting piece fixing body 6B and nesting piece fixing body 26B thermal expansion, come this synthetic resin is compressed with the pressure more than the injection pressure of described synthetic resin, make this synthetic resin sclerosis simultaneously.But, be not limited thereto, also can be only any the nesting piece fixing body at least among the nesting piece fixing body 26B of the nesting piece fixing body 6B of fixed mould portion 6 or moveable die portion 26 be heated, and only any nesting piece at least among nesting piece 6A or the nesting piece 26A is cooled off.

As mentioned above, embodiments of the present invention are illustrated, but to those skilled in the art, can take various replacement examples, revise or distortion based on described explanation, the present invention comprises described various replacement example, revises or distortion in the scope that does not break away from its aim.

Claims

1. an ejection forming method is giving fixed mould and moveable die under the closing state, the injection of the synthetic resin of fusion is filled in the die cavity and is shaped, and this ejection forming method is characterised in that:

2. an injection molding device for molding is giving fixed mould and moveable die under the closing state, the injection of the synthetic resin of fusion is filled in the die cavity and is shaped, and this injection molding device for molding is characterised in that: