JPH0698643B2 - Molding machine for synthetic resin moldings - Google Patents
Molding machine for synthetic resin moldingsInfo
- Publication number
- JPH0698643B2 JPH0698643B2 JP27425891A JP27425891A JPH0698643B2 JP H0698643 B2 JPH0698643 B2 JP H0698643B2 JP 27425891 A JP27425891 A JP 27425891A JP 27425891 A JP27425891 A JP 27425891A JP H0698643 B2 JPH0698643 B2 JP H0698643B2
- Authority
- JP
- Japan
- Prior art keywords
- synthetic resin
- cavity
- molded body
- molding
- pressure
- 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 - Fee Related
Links
Landscapes
- Moulds For Moulding Plastics Or The Like (AREA)
- Injection Moulding Of Plastics Or The Like (AREA)
- Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)
Description
【0001】[0001]
【産業上の利用分野】本発明は合成樹脂製成形体用成形
装置、特に射出成形法を用いる成形装置の改良に関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding apparatus for molded articles made of synthetic resin, and more particularly to an improvement of a molding apparatus using an injection molding method.
【0002】[0002]
【従来の技術】射出成形法の適用下では、成形用キャビ
ティに溶融合成樹脂を射出して成形体を成形した後、そ
の成形体に収縮を補うための圧力、即ち保圧を付与しな
ければならない。2. Description of the Related Art Under the application of an injection molding method, after a molten synthetic resin is injected into a molding cavity to mold a molded body, a pressure for compensating for shrinkage, that is, a holding pressure must be applied to the molded body. I won't.
【0003】従来は、溶融合成樹脂の射出圧を高く設定
することによって前記保圧を得ている。Conventionally, the holding pressure is obtained by setting a high injection pressure of the molten synthetic resin.
【0004】[0004]
【発明が解決しようとする課題】しかしながら従来装置
によると、成形体が大型である場合、それに伴い射出圧
を増加させることになるので、ばりの発生を抑制するた
めには、型締め力を増大させなければならず、そのため
の設備費が上昇する、という問題がある。However, according to the conventional apparatus, when the molded body is large, the injection pressure is increased accordingly. Therefore, in order to suppress the occurrence of flash, the mold clamping force is increased. There is a problem that the equipment cost for that purpose must be increased.
【0005】本発明は、前記に鑑み、溶融合成樹脂の射
出圧を高めることなく十分な保圧を得ることを可能に
し、これによりばりの発生を抑制し得る設備費の安価な
前記成形装置を提供することを目的とする。In view of the above, the present invention provides the above-mentioned molding apparatus which makes it possible to obtain a sufficient holding pressure without increasing the injection pressure of the molten synthetic resin, thereby suppressing the occurrence of burrs and having a low equipment cost. The purpose is to provide.
【0006】[0006]
【課題を解決するための手段】本発明に係る合成樹脂製
成形体用成形装置は、成形用キャビティ、その成形用キ
ャビティに連通するゲートおよび前記成形用キャビティ
に連通するオーバフロー室を有する成形型と、前記ゲー
トを通じて前記成形用キャビティに射出された溶融合成
樹脂に空洞部を形成して中空成形体を成形すべく、前記
溶融合成樹脂内にガスを吹込むガス吹込み機構と、前記
中空成形体に保圧を付与すべく、前記オーバフロー室内
にガスを吹込む保圧付与機構とを備えていることを特徴
とする。A molding apparatus for a synthetic resin molded body according to the present invention comprises a molding die having a molding cavity, a gate communicating with the molding cavity, and an overflow chamber communicating with the molding cavity. A gas blowing mechanism for blowing gas into the molten synthetic resin to form a hollow portion in the molten synthetic resin injected into the molding cavity through the gate to form a hollow molded body; In order to apply a holding pressure to the pressure chamber, a holding pressure applying mechanism for blowing gas into the overflow chamber is provided.
【0007】また本発明に係る合成樹脂製成形体用成形
装置は、成形用キャビティ、その成形用キャビティに連
通するゲートおよび前記成形用キャビティに連通するオ
ーバフロー室を有する成形型と、前記ゲートを通じて前
記成形用キャビティに射出された溶融合成樹脂よりなる
中実成形体に保圧を付与すべく、前記オーバフロー室内
にガスを吹込む保圧付与機構とを備えていることを特徴
とする。Further, the molding apparatus for a synthetic resin molded body according to the present invention includes a molding die having a molding cavity, a gate communicating with the molding cavity and an overflow chamber communicating with the molding cavity, and the molding die through the gate. In order to apply a holding pressure to the solid molded body made of the molten synthetic resin injected into the molding cavity, a holding pressure applying mechanism for injecting gas into the overflow chamber is provided.
【0008】[0008]
【実施例】図1〜図3は成形装置の一実施例を示し、そ
の成形装置は中空成形体の成形に用いられる。1 to 3 show an embodiment of a molding apparatus, which is used for molding a hollow molded body.
【0009】図1において、成形型1は固定型2と可動
型3とよりなり、両型2,3によって、円筒状をなす成
形用キャビティ4、そのキャビティ4の一端に連通する
ゲート5およびキャビティ4の他端に流出路6を介して
連通するオーバフロー室7が形成される。ゲート5は図
示しない射出ノズルに連通する。また流出路6の断面積
はキャビティ4の断面積よりも小さくなるように設定さ
れる。In FIG. 1, a molding die 1 is composed of a fixed die 2 and a movable die 3, and a molding cavity 4 having a cylindrical shape, a gate 5 and a cavity communicating with one end of the cavity 4 by the dies 2 and 3. An overflow chamber 7 that communicates with the other end of 4 via the outflow passage 6 is formed. The gate 5 communicates with an injection nozzle (not shown). The cross-sectional area of the outflow passage 6 is set to be smaller than the cross-sectional area of the cavity 4.
【0010】可動型3に、ゲート5を通じて成形用キャ
ビティ4に射出された溶融合成樹脂に空洞部を形成すべ
く、その溶融合成樹脂内に高圧ガスを吹込むガス吹込み
機構8が設けられている。そのガス吹込み機構8は次の
ように構成される。The movable mold 3 is provided with a gas blowing mechanism 8 for blowing a high pressure gas into the molten synthetic resin so as to form a cavity in the molten synthetic resin injected into the molding cavity 4 through the gate 5. There is. The gas blowing mechanism 8 is configured as follows.
【0011】可動型3のゲート5近傍にガス用吹込み孔
9が形成され、その吹込み孔9を開閉する第1油圧シリ
ンダ10が可動型3に付設される。第1油圧シリンダ1
0のシリンダ本体11は、吹込み孔9側より可動型3外
部に向って順次配列された小径孔a1 ,中径孔a2 およ
び大径孔a3 を有する。大径孔a3 にピストン12が摺
動自在に嵌合され、そのピストン12により大径孔a 3
内は中径孔a2 側の第1油圧室13とそれと反対側の第
2油圧室14とに区画される。また小径孔a1にピスト
ン12と一体のピストンロッド15が摺動自在に嵌合さ
れ、そのピストンロッド15によって小径孔a1 内に、
吹込み孔9に連通するガス用流通室16が形成される。
ピストンロッド15先端に、それよりも小径のロッド状
弁体17が一体に設けられ、その弁体17は吹込み孔9
に挿脱される。中径孔a2 および大径孔a3 間の段部b
は、ピストン12のストッパとして機能し、ピストン1
2が段部bに衝合した状態では弁体17が吹込み孔9に
挿入されてそれを閉鎖する。A gas blowing hole 9 is formed near the gate 5 of the movable die 3, and a first hydraulic cylinder 10 for opening and closing the blowing hole 9 is attached to the movable die 3. First hydraulic cylinder 1
The cylinder body 11 of 0 has a small diameter hole a 1 , a medium diameter hole a 2 and a large diameter hole a 3 which are sequentially arranged from the side of the blow hole 9 toward the outside of the movable mold 3 . Piston 12 is slidably fitted in the large diameter hole a 3, the large diameter hole a 3 by its piston 12
The inside is partitioned into a first hydraulic chamber 13 on the side of the medium diameter hole a 2 and a second hydraulic chamber 14 on the opposite side . The piston 12 integral with the piston rod 15 is slidably fitted in the small diameter hole a 1, the small-diameter hole a 1 by the piston rod 15,
A gas flow chamber 16 communicating with the blow hole 9 is formed.
A rod-shaped valve body 17 having a smaller diameter than that of the piston rod 15 is integrally provided at the tip of the piston rod 15.
Be inserted and removed. Step b between the medium diameter hole a 2 and the large diameter hole a 3
Acts as a stopper for the piston 12, and the piston 1
When 2 abuts against the stepped portion b, the valve body 17 is inserted into the blowing hole 9 and closes it.
【0012】第1,第2油圧室13,14は油路18,
19を介して第1切換弁20の第1,第2ポートにそれ
ぞれ接続され、その第1切換弁20の圧力ポートは油圧
源21に、また戻りポートは油タンク22にそれぞれ接
続される。流通室16は遮断弁23を持つガス路24を
介して窒素ガス等の第1高圧ガス供給源25に接続され
る。The first and second hydraulic chambers 13 and 14 include oil passages 18,
The first switching valve 20 is connected to the first and second ports via 19, and the pressure port of the first switching valve 20 is connected to the hydraulic pressure source 21 and the return port is connected to the oil tank 22. The flow chamber 16 is connected to a first high pressure gas supply source 25 such as nitrogen gas via a gas passage 24 having a shutoff valve 23.
【0013】さらに、可動型3に、流出路6を開閉する
流出路開閉機構26が設けられている。その流出路開閉
機構26は次のように構成される。Further, the movable mold 3 is provided with an outflow passage opening / closing mechanism 26 for opening / closing the outflow passage 6. The outflow passage opening / closing mechanism 26 is configured as follows.
【0014】可動型3に流出路6に交差するガイド孔2
7が形成され、そのガイド孔27を介して流出路6を開
閉する第2油圧シリンダ28が可動型3に付設される。
第2油圧シリンダ28のシリンダ本体29は、ガイド孔
27側より可動型3外部に向って順次配列された小径孔
c1 、中径孔c2 および大径孔c3 を有する。大径孔c
3 にピストン30が摺動自在に嵌合され、そのピストン
30により大径孔c 3 内は中径孔c2 側の第1油圧室3
1とそれと反対側の第2油圧室32とに区画される。ま
た小径孔c1 およびガイド孔27にピストン30と一体
のロッド状弁体33が摺動自在に嵌合され、その弁体3
3が流出路6と交差するようになっている。中径孔c2
および大径孔c3 間の段部dは、ピストン30のストッ
パとして機能し、ピストン30が段部dに衝合した状態
では弁体33が流出路6を閉鎖する。A guide hole 2 that intersects the outflow passage 6 in the movable mold 3.
The movable die 3 is provided with a second hydraulic cylinder 28 which is formed with the guide hole 27 and which opens and closes the outflow passage 6 through the guide hole 27.
The cylinder body 29 of the second hydraulic cylinder 28 has a small diameter hole c 1 , a medium diameter hole c 2 and a large diameter hole c 3 which are sequentially arranged from the guide hole 27 side toward the outside of the movable mold 3 . Large diameter hole c
A piston 30 is slidably fitted into the third hydraulic pressure chamber 3, and the piston 30 causes the inside of the large-diameter hole c 3 to have the first hydraulic chamber 3 on the side of the medium-diameter hole c 2.
1 and therewith is partitioned into a second hydraulic chamber 32 on the opposite side. A rod-shaped valve element 33 integral with the piston 30 is slidably fitted in the small-diameter hole c 1 and the guide hole 27.
3 intersects with the outflow passage 6. Medium diameter hole c 2
The step portion d between the large diameter hole c 3 and the large hole c 3 functions as a stopper of the piston 30, and the valve body 33 closes the outflow passage 6 when the piston 30 collides with the step portion d.
【0015】弁体33は熱伝導性の低い材料、例えばス
テンレス材より構成され、これにより弁体33に接触す
る溶融合成樹脂の固化を防止することができる。弁体3
3に加熱用ヒータを内蔵させてもよい。The valve element 33 is made of a material having a low thermal conductivity, for example, a stainless material, which prevents the molten synthetic resin coming into contact with the valve element 33 from solidifying. Disc 3
A heater for heating may be built in 3.
【0016】第1油圧室31は、油路34を介してガス
吹込み機構8の第1油圧室13側の油路18に接続され
る。また第2油圧室32は、油路35を介してガス吹込
み機構8の第2油圧室14側の油路19に接続される。The first hydraulic chamber 31 is connected to the oil passage 18 on the first hydraulic chamber 13 side of the gas blowing mechanism 8 via an oil passage 34. The second hydraulic chamber 32 is connected to the oil passage 19 on the side of the second hydraulic chamber 14 of the gas blowing mechanism 8 via the oil passage 35.
【0017】また可動型3に、オーバフロー室7内、図
示例では流出路6の開放に伴いオーバフロー室7内に流
出した過剰樹脂にガスを吹込んで成形用キャビティ4内
の中空成形体に保圧を付与する保圧付与機構36が設け
られている。その保圧付与機構36は次のように構成さ
れる。Gas is blown into the movable mold 3 in the overflow chamber 7, in the illustrated example, the excess resin flowing into the overflow chamber 7 when the outflow passage 6 is opened, so that the hollow molded body in the molding cavity 4 is maintained in pressure. A holding pressure applying mechanism 36 for applying the pressure is provided. The holding pressure applying mechanism 36 is configured as follows.
【0018】可動型3にオーバフロー室7に連通するガ
ス用吹込み孔37が形成され、その吹込み孔37を開閉
する第3油圧シリンダ38が可動型3に付設される。第
3油圧シリンダ38のシリンダ本体39は、吹込み孔3
7側より可動型3外部に向って順次配列された小径孔e
1 、中径孔e2 および大径孔e3 を有する。その大径孔
e3 にピストン40が摺動自在に嵌合され、そのピスト
ン40により大径孔e 3 内は中径孔e2 側の第1油圧室
41とそれと反対側の第2油圧室42とに区画される。
また小径孔e 1 にピストン40と一体のピストンロッド
43が摺動自在に嵌合され、そのピストンロッド43に
よって小径孔e 1 内に、吹込み孔37に連通するガス用
流通室44が形成される。ピストンロッド43先端に、
それよりも小径のロッド状弁体45が一体に設けられ、
その弁体45は吹込み孔37に挿脱される。中径孔e2
および大径孔e3 間の段部fは、ピストン40のストッ
パとして機能し、ピストン40が段部fに衝合した状態
では弁体45が吹込み孔37に挿入されてそれを閉鎖す
る。A gas blowing hole 37 communicating with the overflow chamber 7 is formed in the movable die 3, and a third hydraulic cylinder 38 for opening and closing the blowing hole 37 is attached to the movable die 3. The cylinder body 39 of the third hydraulic cylinder 38 has the blow hole 3
Small diameter holes e sequentially arranged from the 7 side toward the outside of the movable mold 3
1 , having a medium diameter hole e 2 and a large diameter hole e 3 . Its large diameter e 3 the piston 40 is slidably fitted, the piston 40 by the large diameter e 3 in the first hydraulic chamber 41 of the middle diameter hole e 2 side at the same side opposite the second hydraulic chamber 42 is divided into a.
The piston 40 integral with the piston rod 43 to the small-diameter hole e 1 is slidably fitted, by its piston rod 43 to the small-diameter hole e 1, gas distribution chamber 44 which communicates with the blow holes 37 are formed It At the tip of the piston rod 43,
A rod-shaped valve body 45 having a smaller diameter than that is integrally provided,
The valve body 45 is inserted into and removed from the blow hole 37. Medium diameter hole e 2
And the stepped portion f between the large diameter hole e 3 functions as a stopper of the piston 40, and when the piston 40 abuts the stepped portion f, the valve element 45 is inserted into the blow hole 37 and closes it.
【0019】第1,第2油圧室41,42は油路46,
47を介して第2切換弁48の第1,第2ポートにそれ
ぞれ接続され、その第2切換弁48の圧力ポートは前記
油圧源21に、また戻りポートは前記油タンク22にそ
れぞれ接続される。流通室44は遮断弁49を持つガス
路50を介して窒素ガス等の第2高圧ガス供給源51に
接続される。第2高圧ガス供給源51のガス吹込み圧
は、第1高圧ガス供給源25のガス吹込み圧よりも高く
なるように設定されている。The first and second hydraulic chambers 41 and 42 include oil passages 46,
The second switching valve 48 is connected to the first and second ports of the second switching valve 48 via 47, the pressure port of the second switching valve 48 is connected to the hydraulic pressure source 21, and the return port of the second switching valve 48 is connected to the oil tank 22. . The flow chamber 44 is connected to a second high pressure gas supply source 51 such as nitrogen gas via a gas passage 50 having a shutoff valve 49. The gas injection pressure of the second high pressure gas supply source 51 is set to be higher than the gas injection pressure of the first high pressure gas supply source 25.
【0020】次に、中空成形体の成形作業について説明
する。 (a) 図1に示すように、成形型1を閉じた状態にお
いて、第1,第2切換弁20,48を第1切換位置Gに
保持して第1,第2,第3油圧シリンダ10,28,3
8の第1油圧室13,31,41を油タンク22に、ま
た第2油圧室14,32,42を油圧源21にそれぞれ
接続し、各ピストン12,30,40を作動させて第1
油圧シリンダ10の弁体17の前進により吹込み孔9を
閉鎖し、また第2油圧シリンダ28の弁体33の前進に
より流出路6を閉鎖し、さらに第3油圧シリンダ38の
弁体45の前進により吹込み孔37を閉鎖する。 (b) 両遮断弁23,49を開放し、第1,第2高圧
ガス供給源25,51を作動して高圧ガスを両流通室1
6,44に導入する。 (c) 射出ノズルよりゲート5を通じてキャビティ4
に溶融合成樹脂Rを射出して充填する。この場合、キャ
ビティ4に溶融合成樹脂Rが充填されるまでは流出路6
が閉鎖されているので、溶融合成樹脂Rに射出圧が十分
に作用してその溶融合成樹脂Rのキャビティ4内面との
接触面側が平滑化される。その接触面側は、成形型1に
より冷却されて流動しにくくなり、結果的に中空成形体
のスキン層を形成する。Next, the molding operation of the hollow molded body will be described. (A) As shown in FIG. 1, with the mold 1 closed, the first, second switching valves 20, 48 are held at the first switching position G, and the first, second, and third hydraulic cylinders 10 are held. , 28, 3
The first hydraulic chambers 13, 31, 41 of No. 8 are connected to the oil tank 22, and the second hydraulic chambers 14, 32, 42 are connected to the hydraulic power source 21, respectively, and the pistons 12, 30, 40 are operated to operate the first hydraulic chambers.
By advancing the valve body 17 of the hydraulic cylinder 10, the blowing hole 9 is closed, by advancing the valve body 33 of the second hydraulic cylinder 28, the outflow passage 6 is closed, and further advancing the valve body 45 of the third hydraulic cylinder 38. The blowing hole 37 is closed by. (B) Both the shutoff valves 23 and 49 are opened, the first and second high pressure gas supply sources 25 and 51 are operated, and the high pressure gas is supplied to both flow chambers 1.
6,44. (C) Cavity 4 through the gate 5 from the injection nozzle
Then, the molten synthetic resin R is injected and filled. In this case, the outflow passage 6 is not filled until the cavity 4 is filled with the molten synthetic resin R.
Is closed, the injection pressure sufficiently acts on the molten synthetic resin R, and the contact surface side of the molten synthetic resin R with the inner surface of the cavity 4 is smoothed. The contact surface side is cooled by the molding die 1 and becomes hard to flow, and consequently forms the skin layer of the hollow molded body.
【0021】また溶融合成樹脂Rの射出圧は、保圧を兼
ねていないので、比較的低く設定され、これによりばり
の発生が抑制される。 (d) 図2に示すように、第1切換弁20を第2切換
位置Hに切換えて第1,第2油圧シリンダ10,28の
第1油圧室13,31を油圧源21に、また第2油圧室
14,32を油タンク22にそれぞれ接続し、両ピスト
ン12,30を作動させて第1油圧シリンダ10の弁体
17の後退により吹込み孔9を開放し、また第2油圧シ
リンダ28の弁体33の後退により流出路6を開放す
る。Further, the injection pressure of the molten synthetic resin R does not also serve as a holding pressure, so that it is set to a relatively low value, which suppresses the occurrence of burrs. (D) As shown in FIG. 2, the first switching valve 20 is switched to the second switching position H so that the first hydraulic chambers 13 and 31 of the first and second hydraulic cylinders 10 and 28 serve as the hydraulic power source 21, and The two hydraulic chambers 14 and 32 are connected to the oil tank 22, respectively, and the pistons 12 and 30 are actuated to retract the valve body 17 of the first hydraulic cylinder 10 to open the blow hole 9 and to open the second hydraulic cylinder 28. The outflow passage 6 is opened by retreating the valve body 33.
【0022】同時に溶融合成樹脂R内に吹込み孔9を通
じて高圧ガスが吹込まれ、これにより溶融合成樹脂R内
に空洞部v1 が形成されると共に過剰樹脂rが流出路6
を通じオーバフロー室7に流出して中空成形体M1 が成
形される。At the same time, high-pressure gas is blown into the molten synthetic resin R through the blowing holes 9, whereby a cavity v 1 is formed in the molten synthetic resin R and the excess resin r is discharged from the outflow passage 6.
Through to the overflow chamber 7 and the hollow molded body M 1 is molded.
【0023】溶融合成樹脂Rにおいて、オーバフロー室
7に流出する過剰樹脂rは、キャビティ4内面との接触
面側が成形型1により冷却されて流動しにくくなってい
ることから、内側に存する樹脂であり、したがって前記
流出によって中空成形体M1 の表面が荒されることはな
い。また中空成形体M1 の空洞部v1 内には高いガス圧
が均等に作用しているので、肉厚の均一化が図られる。 (e) 図3に示すように、オーバフロー室7内に過剰
樹脂rが略充填された後第2切換弁48を第2切換位置
Hに切換えて第3油圧シリンダ38の第1油圧室41を
油圧源21に、また第2油圧室42を油タンク22にそ
れぞれ接続し、ピストン40を作動させて弁体45の後
退により吹込み孔37を開放する。In the molten synthetic resin R, the excess resin r flowing out into the overflow chamber 7 is a resin existing inside because the contact surface side with the inner surface of the cavity 4 is cooled by the molding die 1 and becomes hard to flow. Therefore, the outflow does not roughen the surface of the hollow molded body M 1 . Since high gas pressure in the hollow molded body M 1 of the cavity v 1 is acting equally, uniform wall thickness can be achieved. (E) As shown in FIG. 3, after the excess resin r is substantially filled in the overflow chamber 7, the second switching valve 48 is switched to the second switching position H to set the first hydraulic chamber 41 of the third hydraulic cylinder 38. The oil pressure source 21 and the second oil pressure chamber 42 are connected to the oil tank 22, respectively, and the piston 40 is operated to retract the valve body 45 to open the blowing hole 37.
【0024】同時に過剰樹脂r内、図示例では空洞部v
1 に連通する小空洞部v2 内に吹込み孔37を通じて高
圧ガスが吹込まれ、その小空洞部v2 の容積が拡大され
る。そして、小空洞部v2 の容積拡大に伴い中空成形体
M1 に保圧が付与されるので、その保圧によって中空成
形体M1 におけるひけが大幅に抑制される。At the same time, in the excess resin r, a cavity v in the illustrated example.
High-pressure gas is blown into the small cavity v 2 communicating with 1 through the blowing hole 37, and the volume of the small cavity v 2 is expanded. Then, since the holding pressure is applied to the hollow molded body M 1 as the volume of the small hollow portion v 2 increases, sink marks in the hollow molded body M 1 are significantly suppressed by the holding pressure.
【0025】このようにして、表面性が良好で、肉厚の
均一な中空成形体M1 を得ることができる。In this way, it is possible to obtain a hollow molded article M 1 having a good surface property and a uniform wall thickness.
【0026】図4,図5は成形装置の他の実施例を示
し、その成形装置は中実成形体の成形に用いられる。4 and 5 show another embodiment of the molding apparatus, which is used for molding a solid molded body.
【0027】図4において、成形型52は固定型53と
可動型54とよりなり、両型53,54によって成形用
キャビティ55、そのキャビティ55の一端に連通する
ゲート56およびキャビティ55の他端に流出路57を
介して連通するオーバフロー室58が形成される。固定
型53にホットランナブロック59およびそのブロック
59に接続された射出ノズル60が設けられ、その射出
ノズル60はゲート56に連通する。可動型54にはノ
ックアウトピン61が設けられる。In FIG. 4, a molding die 52 is composed of a fixed die 53 and a movable die 54, and a molding cavity 55, a gate 56 communicating with one end of the cavity 55 and the other end of the cavity 55 by the two dies 53, 54. An overflow chamber 58 communicating with the outflow passage 57 is formed. The fixed die 53 is provided with a hot runner block 59 and an injection nozzle 60 connected to the block 59, and the injection nozzle 60 communicates with the gate 56. The movable mold 54 is provided with a knockout pin 61.
【0028】可動型54において、そのオーバフロー室
58近傍に保圧付与機構36が設けられている。その機
構36は前記と同一構造であるから、同一部分には同一
符号を付して構造の説明は省略する。ただし、第2高圧
ガス供給源51のガス吹込み圧は、前記実施例の場合よ
りも低くてよい。In the movable die 54, a pressure holding mechanism 36 is provided near the overflow chamber 58. Since the mechanism 36 has the same structure as that described above, the same parts are designated by the same reference numerals and the description of the structure will be omitted. However, the gas injection pressure of the second high-pressure gas supply source 51 may be lower than that in the above embodiment.
【0029】次に、中実成形体の成形作業について説明
する。 (a) 図4に示すように、成形型52を閉じた状態に
おいて、第2切換弁48を第1切換位置Gに保持して第
3油圧シリンダ38の第1油圧室41を油タンク22
に、また第2油圧室42を油圧源21にそれぞれ接続
し、ピストン40を作動させて第3油圧シリンダ38の
弁体45の前進によって吹込み孔37を閉鎖する。 (b) 遮断弁49を開放し、第2高圧ガス供給源51
を作動して高圧ガスを流通室44に導入する。 (c) 射出ノズル60よりゲート56を通じてキャビ
ティ55に溶融合成樹脂Rを射出する。その樹脂Rはキ
ャビティ55に充填されて中実成形体M2 が成形され、
その過剰樹脂rは流出路57を通じてオーバフロー室5
8に流出する。Next, the molding operation of the solid molded body will be described. (A) As shown in FIG. 4, in a state where the molding die 52 is closed, the second switching valve 48 is held at the first switching position G and the first hydraulic chamber 41 of the third hydraulic cylinder 38 is moved to the oil tank 22.
Further, the second hydraulic chamber 42 is connected to the hydraulic power source 21, respectively, and the piston 40 is operated to advance the valve body 45 of the third hydraulic cylinder 38 to close the blowing hole 37. (B) The shutoff valve 49 is opened, and the second high-pressure gas supply source 51
Is operated to introduce high-pressure gas into the flow chamber 44. (C) The injection nozzle 60 injects the molten synthetic resin R into the cavity 55 through the gate 56. The resin R is filled in the cavity 55 and a solid molded body M 2 is molded,
The excess resin r passes through the outflow passage 57 to the overflow chamber 5
Runs out to 8.
【0030】この場合、溶融合成樹脂Rの射出圧は、過
剰樹脂rとオーバフロー室58との間に所定の空間が残
置される程度に比較的低く設定され、これによりばりの
発生が抑制される。 (d) 図5に示すように、第2切換弁48を第2切換
位置Hに切換えて第3油圧シリンダ38の第1油圧室4
1を油圧源21に、また第2油圧室42を油タンク22
にそれぞれ接続し、ピストン40を作動させて弁体45
の後退により吹込み孔37を開放する。In this case, the injection pressure of the molten synthetic resin R is set relatively low to the extent that a predetermined space is left between the excess resin r and the overflow chamber 58, which suppresses the occurrence of flash. . (D) As shown in FIG. 5, the second switching valve 48 is switched to the second switching position H to move the first hydraulic chamber 4 of the third hydraulic cylinder 38.
1 to the hydraulic source 21 and the second hydraulic chamber 42 to the oil tank 22.
To the valve element 45 by operating the piston 40.
The blow hole 37 is opened by retreating.
【0031】同時にオーバフロー室58の過剰樹脂r内
に吹込み孔37を通じて高圧ガスが吹込まれ、これによ
り過剰樹脂r内に小空洞部v2 が形成され、その小空洞
部v 2 の容積の拡大に伴い中実成形体M2 に保圧が付与
される。At the same time, in the excess resin r in the overflow chamber 58.
High-pressure gas is blown into the blowhole 37 through the
Small cavity v in excess resin r2Is formed and its small cavities
Part v 2With the expansion of the volume of2Holding pressure is applied to
To be done.
【0032】この保圧により、中実成形体M2 における
ひけが大幅に抑制されるので、その中実成形体M2 の表
面性が良好となり、また肉厚が均一化される。By this holding pressure, sink marks in the solid molded body M 2 are significantly suppressed, so that the surface property of the solid molded body M 2 is improved and the wall thickness is made uniform.
【0033】図6は、図4の成形型52の変形例を示
し、流出路57の入口に、小空洞部v 2 がキャビティ5
5へ延出するのを阻止する突出部62を設けたものであ
る。この突出部62の阻止作用により中実成形体M2 に
おける気泡の形成を確実に防止することができる。FIG. 6 shows a modification of the molding die 52 of FIG.
Then, at the entrance of the outflow passage 57, a small cavity v 2Is cavity 5
5 is provided with a protrusion 62 for preventing the extension of
It Due to the blocking action of the protruding portion 62, the solid molded body M is2To
It is possible to reliably prevent the formation of bubbles in the air.
【0034】[0034]
【発明の効果】本発明によれば、前記のようにガスの吹
込みによる保圧付与機構を備えることによって、溶融合
成樹脂の射出圧を比較的低く設定することが可能とな
り、これにより、型締め力を増大させることなくばりの
発生を抑制し得る設備費の安価な成形装置を提供するこ
とができる。According to the present invention, by providing the holding pressure imparting mechanism by blowing gas as described above, it becomes possible to set the injection pressure of the molten synthetic resin to a relatively low level, which allows the mold It is possible to provide a molding apparatus that can suppress the occurrence of flash without increasing the tightening force and has a low equipment cost.
【図1】キャビティに溶融合成樹脂を充填した状態を示
す中空成形体用成形装置の縦断面図である。FIG. 1 is a vertical cross-sectional view of a hollow molded body molding apparatus showing a state where a cavity is filled with a molten synthetic resin.
【図2】キャビティに充填された溶融合成樹脂にガスを
吹込んだ状態を示す中空成形体用成形装置の縦断面図で
ある。FIG. 2 is a vertical cross-sectional view of a hollow molding body molding apparatus showing a state in which a gas is blown into a molten synthetic resin filled in a cavity.
【図3】中空成形体に保圧を付与した状態を示す中空成
形体用成形装置の縦断面図である。FIG. 3 is a vertical cross-sectional view of a hollow molded body molding apparatus showing a state in which a holding pressure is applied to the hollow molded body.
【図4】キャビティに溶融合成樹脂を充填した状態を示
す中実成形体用成形装置の縦断面図である。FIG. 4 is a vertical cross-sectional view of a molding apparatus for a solid molded body, showing a state in which a cavity is filled with molten synthetic resin.
【図5】中実成形体に保圧を付与した状態を示す中実成
形体用成形装置の要部縦断面図である。FIG. 5 is a vertical cross-sectional view of a main part of a molding device for a solid molded body, showing a state where a holding pressure is applied to the solid molded body.
【図6】中実成形体に保圧を付与した状態を示す他の中
実成形体用成形装置の要部縦断面図である。FIG. 6 is a vertical cross-sectional view of a main part of another solid-state molded product forming apparatus showing a state where a holding pressure is applied to the solid molded product.
1,52 成形型 4,55 キャビティ 5,56 ゲート 7,58 オーバフロー室 8 ガス吹込み機構 36 保圧付与機構 M1 中空成形体 M2 中実成形体 R 溶融合成樹脂 r 過剰樹脂 v1 空洞部1,52 Mold 4,55 Cavity 5,56 Gate 7,58 Overflow chamber 8 Gas injection mechanism 36 Pressure holding mechanism M 1 Hollow molded body M 2 Solid molded body R Melted synthetic resin r Excess resin v 1 Cavity part
Claims (2)
ャビティ(4)に連通するゲート(5)および前記成形
用キャビティ(4)に連通するオーバフロー室(7)を
有する成形型(1)と、前記ゲート(5)を通じて前記
成形用キャビティ(4)に射出された溶融合成樹脂
(R)に空洞部(v1 )を形成して中空成形体(M1 )
を成形すべく、前記溶融合成樹脂(R)内にガスを吹込
むガス吹込み機構(8)と、前記中空成形体(M1 )に
保圧を付与すべく、前記オーバフロー室(7)内にガス
を吹込む保圧付与機構(36)とを備えていることを特
徴とする合成樹脂製成形体用成形装置。1. A mold (1) having a molding cavity (4), a gate (5) communicating with the molding cavity (4) and an overflow chamber (7) communicating with the molding cavity (4). A hollow molded body (M 1 ) by forming a cavity (v 1 ) in the molten synthetic resin (R) injected into the molding cavity (4) through the gate (5)
In order to shape the said and blow the molten synthetic resin (R) gas into the free gas blow mechanism (8), the hollow molded body (M 1) in order to impart holding pressure, said overflow chamber (7) in 1. A molding apparatus for a synthetic resin molded body, comprising: a holding pressure imparting mechanism (36) for blowing gas into the chamber.
キャビティ(55)に連通するゲート(56)および前
記成形用キャビティ(55)に連通するオーバフロー室
(58)を有する成形型(52)と、前記ゲート(5
6)を通じて前記成形用キャビティ(55)に射出され
た溶融合成樹脂(R)よりなる中実成形体(M2 )に保
圧を付与すべく、前記オーバフロー室(58)内にガス
を吹込む保圧付与機構(36)とを備えていることを特
徴とする合成樹脂製成形体用成形装置。2. A mold (52) having a molding cavity (55), a gate (56) communicating with the molding cavity (55), and an overflow chamber (58) communicating with the molding cavity (55). , The gate (5
Gas is blown into the overflow chamber (58) in order to apply a holding pressure to the solid molded body (M 2 ) made of the molten synthetic resin (R) injected into the molding cavity (55) through 6). A molding device for a synthetic resin molded body, which is provided with a pressure holding mechanism (36).
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP27425891A JPH0698643B2 (en) | 1991-10-22 | 1991-10-22 | Molding machine for synthetic resin moldings |
GB9222153A GB2260932B (en) | 1991-10-22 | 1992-10-21 | Molding apparatus for producing synthetic resin molded product |
DE4235673A DE4235673C2 (en) | 1991-10-22 | 1992-10-22 | Method of manufacturing an injection molded hollow resin part and apparatus for carrying out the method |
US08/234,606 US5612067A (en) | 1991-10-22 | 1994-04-28 | Molding apparatus for producing synthetic resin molded product |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP27425891A JPH0698643B2 (en) | 1991-10-22 | 1991-10-22 | Molding machine for synthetic resin moldings |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH05111938A JPH05111938A (en) | 1993-05-07 |
JPH0698643B2 true JPH0698643B2 (en) | 1994-12-07 |
Family
ID=17539184
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP27425891A Expired - Fee Related JPH0698643B2 (en) | 1991-10-22 | 1991-10-22 | Molding machine for synthetic resin moldings |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0698643B2 (en) |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR20010113253A (en) * | 2000-06-17 | 2001-12-28 | 김성동 | Forming mold construction |
JP5303363B2 (en) * | 2009-05-28 | 2013-10-02 | 三菱エンジニアリングプラスチックス株式会社 | Injection molding method and mold assembly of molded product having hollow part |
CN108834407B (en) * | 2016-01-06 | 2021-05-18 | 铃木康公 | Mold device, injection molding system, and method for manufacturing molded product |
-
1991
- 1991-10-22 JP JP27425891A patent/JPH0698643B2/en not_active Expired - Fee Related
Also Published As
Publication number | Publication date |
---|---|
JPH05111938A (en) | 1993-05-07 |
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