JPH0451326B2 - - Google Patents
Info
- Publication number
- JPH0451326B2 JPH0451326B2 JP1239482A JP23948289A JPH0451326B2 JP H0451326 B2 JPH0451326 B2 JP H0451326B2 JP 1239482 A JP1239482 A JP 1239482A JP 23948289 A JP23948289 A JP 23948289A JP H0451326 B2 JPH0451326 B2 JP H0451326B2
- Authority
- JP
- Japan
- Prior art keywords
- mold
- pressure
- resin
- filling
- molten resin
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000011347 resin Substances 0.000 claims description 56
- 229920005989 resin Polymers 0.000 claims description 56
- 238000000465 moulding Methods 0.000 claims description 25
- 238000001746 injection moulding Methods 0.000 claims description 8
- 238000000034 method Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 238000005429 filling process Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 125000006850 spacer group Chemical group 0.000 description 2
- 230000007423 decrease Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
Description
【発明の詳細な説明】 〔産業上の利用分野〕 この発明は、射出成形方法に関する。[Detailed description of the invention] [Industrial application field] The present invention relates to an injection molding method.
第６図に従来の射出成形方法における射出時の
成形機のラム圧および金型内の溶融樹脂圧（以
下、型内樹脂圧という）の変化を示す。この図に
示すように、成形機のラム圧は、溶融樹脂を充填
する時（充填時）には高く、保圧時にはこれより
低いが、従来の成形方法においては、型内樹脂圧
が充填時にはラム圧にほぼ追随して上昇し、保圧
時には、充填された溶融状態の樹脂が次第に冷却
固化する際に収縮することに伴い、充填時型内樹
脂圧より圧力が次第に低下していく、という圧力
変化のパターンをとるものであつた。このような
圧力変化は、例えば油圧により生じるラム圧、金
型内のキヤビテイの容積、成形機のノズルからキ
ヤビテイへ到る通路における溶融樹脂の流れの抵
抗、キヤビテイに臨むゲートの径等種々の要因に
帰因すると思われる。
FIG. 6 shows changes in the ram pressure of the molding machine and the molten resin pressure in the mold (hereinafter referred to as in-mold resin pressure) during injection in a conventional injection molding method. As shown in this figure, the ram pressure of the molding machine is high when filling with molten resin (during filling) and lower when holding pressure, but in conventional molding methods, the resin pressure in the mold is high during filling. The ram pressure rises almost in line with the ram pressure, and during pressure holding, the molten resin filled in the mold contracts as it gradually cools and solidifies, and the pressure gradually decreases compared to the resin pressure inside the mold during filling. It followed a pattern of pressure changes. Such pressure changes are caused by various factors such as the ram pressure generated by hydraulic pressure, the volume of the cavity in the mold, the resistance to the flow of molten resin in the path from the nozzle of the molding machine to the cavity, and the diameter of the gate facing the cavity. This seems to be due to.
ところで、固定された型締め能力（型締め力）
を持つ成形機で成形できる成形品の投影面積は、
投影面積×型内樹脂圧＝型締め力
で決まる大きさが上限であり、投影面積×型内樹
脂圧が成形機の型締め能力を越えると、雄型と雌
型との間の分割面が開き（開き量ｈ）、結果とし
て、第５図に示す如く、雄型１と雌型２との分割
面１ａ，２ａに生じた〓間３に溶融樹脂Ｍが入り
込み、成形品にバリMaが生じることとなり、製
品不良となり、時には成形が中断される。一方、
成形品の充填密度を所期の大きさ以上にするため
には、型内樹脂圧を一定の値以上にする必要があ
るので、結局、成形可能な成形品の投影面積は、
成形機の型締め力により制限される。
By the way, fixed mold clamping capacity (mold clamping force)
The upper limit of the projected area of a molded product that can be molded with a molding machine is the size determined by projected area x resin pressure in the mold = mold clamping force, and the projected area x resin pressure in the mold exceeds the mold clamping capacity of the molding machine. Then, the dividing surface between the male mold and the female mold opens (opening amount h), and as a result, as shown in FIG. The molten resin M enters into the molded product, causing burrs Ma to occur in the molded product, resulting in product defects and sometimes leading to discontinuation of molding. on the other hand,
In order to increase the filling density of the molded product to the desired size or higher, the resin pressure within the mold must be greater than a certain value, so in the end, the projected area of the moldable molded product is
Limited by the clamping force of the molding machine.
本発明は上記事情に鑑み、固定された型締め能
力を持つ射出成形機において、バリを発生させる
ことはなく、従来の上限以上の大きさの投影面積
の成形を可能にすることを目的とする。 In view of the above circumstances, an object of the present invention is to enable molding of a projected area larger than the conventional upper limit without generating burrs in an injection molding machine having a fixed mold clamping capacity. .
本発明は、上記問題点を解決するために、キヤ
ビテイへの溶融樹脂充填時に、充填後の保圧時に
必要な最大型内樹脂圧より低い範囲内で型内樹脂
圧を漸次増大させて、雄型および雌型に接する部
分に溶融樹脂が冷却固化されたスキン硬化層を形
成させつつ溶融樹脂の充填を行つた後、これから
さらに型内樹脂圧を増大させて成形機の型締め能
力（＝投影面積×型内樹脂圧）を超える圧力で保
圧を行うこととした。
In order to solve the above problems, the present invention gradually increases the resin pressure in the mold within a range lower than the maximum resin pressure in the mold required for holding pressure after filling when filling the cavity with molten resin. After filling the molten resin while forming a hardened skin layer where the molten resin is cooled and solidified in the area in contact with the mold and female mold, the resin pressure inside the mold is further increased to increase the mold clamping capacity (= projection) of the molding machine. It was decided to hold pressure at a pressure exceeding (area x resin pressure in the mold).
充填時の型内樹脂圧が低くかつ当該型内樹脂圧
を漸次増大させているので、溶融樹脂のキヤビテ
イ内での移動速度（つまり充填速度）が遅くな
り、したがつて、溶融樹脂のキヤビテイ奥部に達
する時間が長くなり、したがつて、その間に金型
に接する薄い層がよく冷却固化されてスキン硬化
層となる。このスキン硬化層の内部は溶融状態で
あり、保持圧力がその内部溶融層を伝わつて全体
に作用する。したがつて、この状態からさらに型
内樹脂圧を増大させることにより成形機の型締め
能力を越える投影面積×型内樹脂圧が加わつて、
金型の分割面が開いても、スキン硬化層の存在の
ため、その〓間に溶融樹脂が入り込むことはな
く、したがつて成形品にバリは生じない。次い
で、内部溶融層も冷却固化される。
Since the resin pressure in the mold during filling is low and the resin pressure in the mold is gradually increased, the moving speed of the molten resin within the cavity (in other words, the filling speed) is slowed down, and therefore the molten resin is moved deep into the cavity. During this time, the thin layer in contact with the mold is well cooled and solidified to become a hardened skin layer. The inside of this hardened skin layer is in a molten state, and the holding pressure is transmitted through the internal molten layer and acts on the entire surface. Therefore, by further increasing the resin pressure in the mold from this state, the projected area x the resin pressure in the mold exceeds the mold clamping capacity of the molding machine.
Even if the dividing surfaces of the mold are opened, due to the presence of the hardened skin layer, molten resin will not enter between them, and therefore no burrs will form on the molded product. Then, the internal molten layer is also cooled and solidified.
第１図〜第４図に従つて本発明の一実施例を説
明する。
An embodiment of the present invention will be described with reference to FIGS. 1 to 4.
第２図は、金型Ａ、および成形機Ｂの断面図で
ある。 FIG. 2 is a sectional view of the mold A and the molding machine B.
金型Ａの詳細を説明すると、１は雄型、２は雌
型、４は固定側取付け板、５は固定側スペーサ、
６は可動側スペーサ、７は可動側取付け板、８は
突出板（上）、９は突出板（下）、１０はロケート
リング、１１はマニホールド、１２はトーピー
ド、１３はランナーブツシユ、１４は突出ピン、
１５はランナーである。また、１６は雄型１と雌
型２との間に形成されるキヤビテイ、つまり成形
品部分であり、実施例では、第５図で示した特性
を示す従来の金型でのキヤビテイの数の２倍を有
しており（つまり、投影面積が２倍である）、成
形機Ｂからの溶融樹脂は各キヤビテイに共通に射
出される。そして、キヤビテイ１６に臨むゲート
１７の径は、従来の金型におけるゲートの径より
大きく、例えば1.6倍の径としている。なお、実
施例の成形品は浅いコツプ状である。 To explain the details of the mold A, 1 is a male mold, 2 is a female mold, 4 is a fixed side mounting plate, 5 is a fixed side spacer,
6 is a movable side spacer, 7 is a movable side mounting plate, 8 is a protrusion plate (top), 9 is a protrusion plate (bottom), 10 is a locate ring, 11 is a manifold, 12 is a torpedo, 13 is a runner bush, 14 is a protruding pin,
15 is a runner. Further, 16 is a cavity formed between the male die 1 and the female die 2, that is, a molded product part. (that is, the projected area is twice as large), and the molten resin from molding machine B is commonly injected into each cavity. The diameter of the gate 17 facing the cavity 16 is larger than the diameter of the gate in a conventional mold, for example, 1.6 times the diameter. Note that the molded product of the example has a shallow cup shape.
成形機Ｂについて説明すると、油圧シリンダ１
８により往復駆動されるラム１９がヒータ２０で
加熱される加熱筒２１内に摺動自在に収容され、
加熱筒２１の後方上部にホツパ２２を備え、先端
にノズル２３を備えた構造である。 To explain about molding machine B, hydraulic cylinder 1
A ram 19 reciprocally driven by a ram 8 is slidably housed in a heating cylinder 21 heated by a heater 20.
It has a structure in which a hopper 22 is provided at the rear upper part of the heating cylinder 21, and a nozzle 23 is provided at the tip.
上記の金型Ａ、成形機Ｂで射出成形を行うが、
この場合、ラム圧、すなわちラム１９が加熱筒２
１内の溶融樹脂に作用する圧力を従来の金型にお
けるラム圧と同じとする（従つて油圧シリンダ１
８の油圧が従来と同じ）と、第１図に示す如き圧
力変化のパターンで射出成形が行われる。すなわ
ち、型内樹脂圧は、充填時には充分低い圧力が漸
次増大し、保圧時には充填時の圧力より高い型内
樹脂圧が保持される。この保圧時の型内樹脂圧
は、成形品の充填密度を上げるために必要な圧力
以上であつて、しかも成形機の型締め能力を超え
る圧力にする。 Injection molding is performed using the above mold A and molding machine B.
In this case, the ram pressure, that is, the ram 19
The pressure acting on the molten resin in hydraulic cylinder 1 is the same as the ram pressure in a conventional mold (therefore, the pressure acting on the molten resin in hydraulic cylinder 1
8), injection molding is performed with a pressure change pattern as shown in FIG. That is, the resin pressure in the mold is a sufficiently low pressure during filling and gradually increases, and during pressure holding, the resin pressure in the mold is maintained at a higher pressure than the pressure during filling. The resin pressure in the mold during this pressure holding is set to be higher than the pressure necessary to increase the filling density of the molded product, and moreover to a pressure that exceeds the mold clamping capacity of the molding machine.
このような圧力変化のパターンにより成形が行
われると、第３図に示す充填過程を経てキヤビテ
イの末端まで達する。この時、充填時の型内樹脂
圧を低くかつ当該樹脂圧を漸次増大させて、溶融
樹脂Ｍの充填速度を遅くさせることにより、第４
図に示すように、雄型１、雌型２に接する薄い層
をよく冷却固化させてスキン硬化層M2を形成さ
せる。このスキン硬化層M1の内部は溶融状態で
あり、保持圧力がその内部溶融層M2を伝つて全
体に作用する。このように、スキン硬化層M1を
形成させているため、そのまま型内樹脂圧を増大
させて成形機の型締め能力を超える圧力で保圧を
行う際に金型の分割面１ａ，２ａが開いても、そ
の〓間３に溶融樹脂が入り込むことはなく、した
がつて成形品にバリは生じない。また、低い型内
樹脂圧で漸次キヤビテイ全体に樹脂を充填させる
ため、内部応力発生の少ない成形品を得ることが
できる。 When molding is performed using such a pattern of pressure changes, the mold reaches the end of the cavity through the filling process shown in FIG. At this time, the resin pressure in the mold during filling is kept low and the resin pressure is gradually increased to slow down the filling speed of the molten resin M.
As shown in the figure, the thin layer in contact with the male mold 1 and the female mold 2 is thoroughly cooled and solidified to form a hardened skin layer M2 . The inside of this hardened skin layer M 1 is in a molten state, and the holding pressure acts on the entire surface through the internal molten layer M 2 . In this way, since the skin hardening layer M 1 is formed, when the resin pressure in the mold is increased and holding pressure is performed at a pressure that exceeds the mold clamping capacity of the molding machine, the dividing surfaces 1a and 2a of the mold are Even when opened, molten resin will not enter the gap 3, and therefore no burrs will form on the molded product. Furthermore, since the entire cavity is gradually filled with resin at a low resin pressure within the mold, a molded product with less internal stress generation can be obtained.
なお、実施例は、従来の成形方法に比し、成形
品の個数を２倍とし、ゲート径を約1.6倍とした
が、第１図に示す如く充填時に、充填後の保圧時
に必要な最大型内樹脂圧より低い範囲内で径内樹
脂圧を漸次増大させて、雄型および雌型に接する
部分に溶融樹脂が冷却固化されたスキン硬化層を
形成させつつ成形するものであればよい。したが
つて、多数個取りでより多い多数個取りとするも
のに限らず、成形しようとする成形品自体の投影
面積を大きくする場合でもよい。さらに、成形品
の投影面積自体は従来と変えずに、ラムの送り速
度を遅くすることによつてもよい。 In addition, compared to the conventional molding method, in this example, the number of molded products was doubled and the gate diameter was approximately 1.6 times, but as shown in Fig. It is sufficient that molding is performed by gradually increasing the resin pressure within the diameter within a range lower than the maximum resin pressure within the mold, and forming a hardened skin layer in which the molten resin is cooled and solidified in the areas in contact with the male and female molds. . Therefore, the molded product to be molded is not limited to a molded product having a larger number of molded parts, but may have a larger projected area. Furthermore, the projected area of the molded product itself may be unchanged from the conventional one by slowing down the feeding speed of the ram.
以上説明したように本発明によれば、充填時
に、充填後の保圧時の型内樹脂圧より低い範囲内
で型内樹脂圧を漸次増大させて、雄型および雌型
に接する部分に溶融樹脂が冷却固化されたスキン
硬化層を形成させつつ溶融樹脂の充填を行つた
後、これからさらに型内樹脂圧を増大させて成形
機の型締め能力（＝投影面積×型内樹脂圧）を超
える圧力で保圧を行うので、溶融樹脂の充填速度
が遅くなつて、金型に接する薄い層がスキン硬化
層となり、したがつて、成形機の型締め能力を越
える力により金型が開いても、成形品にバリは発
生しない。したがつて、来の成形方法と比し、操
作の複雑化を招くことなく同じ型締め能力の成形
機を用いても、より大きな投影面積の成形が可能
となる。また、スキン硬化層ができるので、金型
の寸法精度が多少悪くて分割面にもともと〓間が
ある場合でも、バリが生じない。
As explained above, according to the present invention, during filling, the in-mold resin pressure is gradually increased within a range lower than the in-mold resin pressure during pressure holding after filling, and melting occurs in the parts in contact with the male and female molds. After filling with molten resin while forming a hardened skin layer where the resin is cooled and solidified, the resin pressure in the mold is further increased to exceed the molding machine's mold clamping capacity (= projected area x resin pressure in the mold). Since pressure is used to hold the pressure, the filling speed of the molten resin is slowed down, and the thin layer in contact with the mold becomes a hardened skin layer, which prevents the mold from opening due to force exceeding the mold clamping capacity of the molding machine. , no burrs occur on the molded product. Therefore, compared to conventional molding methods, it is possible to mold a larger projected area without complicating operations and using a molding machine with the same mold clamping capacity. In addition, since a hardened skin layer is formed, burrs do not occur even if the dimensional accuracy of the mold is somewhat poor and there is a gap in the dividing surface.
第１図〜第４図は本発明の一実施例を示すもの
で、第１図はラム圧および型内樹脂圧についての
圧力−時間グラフ、第２図は金型および射出成形
機の断面図、第３図はキヤビテイ部分要部（第２
図のイ部）の充填過程における状態の拡大図、第
４図は同充填直後における状態の拡大図、第５〜
６図は従来の射出成形方法を示すもので、第５図
は圧力−時間グラフ、第６図はキヤビテイ部分要
部の充填直後の状態図である。
Figures 1 to 4 show an embodiment of the present invention, with Figure 1 being a pressure-time graph for ram pressure and resin pressure in the mold, and Figure 2 being a cross-sectional view of the mold and injection molding machine. , Figure 3 shows the main part of the cavity (second
Figure 4 is an enlarged view of the state during the filling process in part A) of the figure, Figure 4 is an enlarged view of the state immediately after filling, and Figures 5-
6 shows a conventional injection molding method, FIG. 5 is a pressure-time graph, and FIG. 6 is a state diagram immediately after filling of the main part of the cavity.
Claims (1)
保圧時に必要な最大型内樹脂圧より低い範囲内で
型内樹脂圧を漸次増大させて、雄型および雌型に
接する部分に溶融樹脂が冷却固化されたスキン硬
化層を形成させつつ溶融樹脂の充填を行つた後、
これからさらに型内樹脂圧を増大させて成形機の
型締め能力（＝投影面積×型内樹脂圧）を超える
圧力で上記保圧を行うことを特徴とする射出成形
方法。1. When filling the cavity with molten resin, the resin pressure in the mold is gradually increased within a range lower than the maximum resin pressure in the mold required for holding pressure after filling, so that the molten resin cools down in the parts that contact the male and female molds. After filling with molten resin while forming a solidified skin hardening layer,
An injection molding method characterized by further increasing the resin pressure in the mold and performing the above-mentioned holding pressure at a pressure exceeding the mold clamping capacity of the molding machine (=projected area x resin pressure in the mold).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23948289A JPH02125711A (en) | 1989-09-14 | 1989-09-14 | Injection molding method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23948289A JPH02125711A (en) | 1989-09-14 | 1989-09-14 | Injection molding method |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59170705A Division JPH0684031B2 (en) | 1984-08-16 | 1984-08-16 | Injection molding method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02125711A JPH02125711A (en) | 1990-05-14 |
| JPH0451326B2 true JPH0451326B2 (en) | 1992-08-18 |
Family
ID=17045433
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23948289A Granted JPH02125711A (en) | 1989-09-14 | 1989-09-14 | Injection molding method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02125711A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09300171A (en) * | 1996-05-17 | 1997-11-25 | Shisuto:Kk | Filtering device and filtering system |
| US5849183A (en) * | 1996-08-30 | 1998-12-15 | Kabushiki Kaisha Syst | Filtration apparatus |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5390371A (en) * | 1977-01-20 | 1978-08-09 | Toshiba Machine Co Ltd | Injection and compression molding process |
-
1989
- 1989-09-14 JP JP23948289A patent/JPH02125711A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5390371A (en) * | 1977-01-20 | 1978-08-09 | Toshiba Machine Co Ltd | Injection and compression molding process |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02125711A (en) | 1990-05-14 |
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