JP3779139B2

JP3779139B2 - Injection mold

Info

Publication number: JP3779139B2
Application number: JP2000260079A
Authority: JP
Inventors: 豊蔵中島
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2000-08-30
Filing date: 2000-08-30
Publication date: 2006-05-24
Anticipated expiration: 2020-08-30
Also published as: JP2002067101A

Description

【０００１】
【発明の属する技術分野】
本発明は型開閉方向に対して傾斜するスプルーを備えた射出成形金型に関する。
【０００２】
【従来の技術】
従来、ノズルからスプルー、ゲート等の湯道を介して製品キャビティ内に溶融樹脂を注入するような射出成形金型において、ノズルの位置は、金型のバランスや多機種対応等のため固定型の略中央部に設置されることが多い反面、ゲートの位置は、製品形状等の関係により中央部から離れた位置に設定されることがあり、このためノズルとゲート等を結ぶスプルー部が型開き方向に対して斜めに傾斜して配設されることがある。
このとき、成形品を成形した後、型開きする際、スプルーが傾斜していると成形品がスプルー部から抜け出る時の抵抗が増大して、固定型側に付着しやすくなり、成形品が固定型に付着するとその後の取出しが困難になるため、可動型側にアンダーカット部を設け、型開きの段階では可動型から離脱しにくいようにし、型開きが終了した後、押出しピンや押出しプレート等により押出すような技術が一般的である。（スプルーが傾斜していない例については、例えば実開昭５６−１２０２２０号等）
【０００３】
【発明が解決しようとする課題】
ところが、このように可動型側にアンダーカット部を設け、押出しピンや押出しプレート等で成形品を押出す方式は、押出しプレートや押出しピンやこれらの駆動装置を金型の内部に設ける必要があり、構造が大掛かりになるとともに、設備コストがかかるという問題がある。
【０００４】
そこで本発明は、スプルーが型開き方向に対して傾斜する射出成形金型において、成形品の離型構造を簡素化するとともに、設備コストの低減を図ることを目的とする。
【０００５】
【課題を解決するための手段】
上記目的を達成するため本発明は、型の開閉方向に対して傾斜するスプルー部を備えた固定型に対し、可動型が型締め、型開き自在にされる射出成形金型において、可動型の型合わせ面には、スプルー部の開口位置に対応してアンダーカット形状部を設けるようにし、このアンダーカット形状部を、スプルー部の傾斜方向と逆方向に傾斜して突出する突起形状にした。
【０００６】
そしてこのようなアンダーカット形状部により、型開きの時点で成形品が可動型から抜け出しにくいようにし、傾斜スプルーの引抜抵抗の増大を打ち消すとともにこれを若干上回るようにする。そして、ノズルとスプルーの境目の部分で分断されて成形品が固定型から離脱するようにする。
この際、アンダーカット形状として、スプルー部の傾斜方向と逆方向に傾斜して突出する突起形状にすることで、傾斜スプルー部の引抜き抵抗に対抗する力を有効に生じさせることが出来る。
【０００７】
また請求項２では、この金型に、成形された成形品を離型させる押出し機構を設けるようにし、この押出し機構として、固定型に突出自在に設けられ且つ付勢部材で付勢される固定側押出し部材と、可動型に突出自在に設けられ且つ付勢部材で付勢される可動側押出し部材から構成するとともに、固定側押出し部材と可動側押出し部材の一部同士がお互いに当接し、また他の部分が成形品を押圧出来るようにし、更に固定型側の付勢部材の付勢力が可動型側の付勢部材の付勢力より強くなるように設定した。
【０００８】
そして型締め状態では、固定側押出し部材と可動側押出し部材の当接部同士が、お互いに押圧して、両者とも付勢部材の付勢力に抗して金型内に没入するようにし、型開きの初期段階では、付勢力の大きい固定側押出し部材が可動側押出し部材を押圧して、成形品が可動型側に押し付けられるようにする。そして更に型開きして、固定側押出し部材と可動側押出し部材の当接が離れると、可動側押出し部材により成形品が押出されて可動型から離脱するようにする。
【００９】
因みに、このような押出し機構は、従来の押出しピンや押出しプレート等の大掛かりな装置を使用しなくても良い簡素な構成であり、本出願人が既に提案している特願平１１−３４００３２号に示される技術である。
【００１０】
また請求項３では、型の開閉方向に対して傾斜するスプルー部を備えた固定型と可動型が型締め、型開き自在にされる射出成形金型において、スプルー部の開口位置には、型開きの初期段階で成形体を可動型に押付け、型開きの最終段階で可動型から成形体を押出す押出し機構が設けるようにし、この押出し機構は、固定型に突出自在に設けられ且つ付勢部材で付勢される固定側押出し部材と、可動型に突出自在に設けられ且つ付勢部材で付勢される可動側押出し部材から構成するとともに、固定側押出し部材と可動側押出し部材の一部同士がお互いに当接し、他の部分が成形品を押圧出来るようにし、また固定型側の付勢部材の付勢力が可動型側の付勢部材の付勢力より強くなるように設定した。
【００１１】
このように、スプルー部の開口位置に押出し機構を設け、型開きの初期段階で成形体が可動型に押し付けられるようにすることにより、型開き時に、スプルー部の開口位置での可動型への付着度を高めることが出来、固定型のスプルー部の引抜き抵抗の増大に対して有効に対抗できる。
【００１２】
【発明の実施の形態】
本発明の実施の形態について添付した図面に基づき説明する。
ここで図１は本発明に係る射出成形金型の型合わせ面の説明図、図２は金型の押出し機構を示す縦断面図、図３は金型のスプルー部を示す縦断面図、図４は押出し機構の説明図、図５は型開きに伴う成形品の押出し状態を説明する説明図、図６はアンダーカット形状部の作用を示す説明図、図７はランナ部に押出し機構を設ける構成例の型合わせ面の説明図、図８はランナ部の押出し機構の説明図、図９は同作用図である。
【００１３】
本発明に係る射出成形金型１は、スプルーが傾斜する金型において、成形品を取出す押出し機構を簡素化して設備費用の削減等を図ることが出来るようにされ、図１乃至図３に示すように、固定型２に対して開閉自在な可動型３を備えるとともに、図３に示すように、固定型２にはノズル４に連通するスプルー部５が設けられ、このスプルー部５は型の開閉方向に対して斜めに傾斜している。
【００１４】
そしてこのスプルー部５の下流側開口部は、ランナ部６やゲート部７を介して製品キャビティ部８に連通している。
【００１５】
また、固定型２と可動型３には、製品キャビティ部８から成形品を取出すための押出し機構９が設けられており、この押出し機構９は、図１、図２に示すように、製品キャビティ部８の周縁に沿って複数配設されるとともに、各押出し機構９は、それぞれ固定型２に設けられる固定側押出し部材としての固定側押出しピン１１と、可動型３に設けられる可動側押出し部材としての可動側押出しピン１２を備え、これら固定側押出しピン１１と可動側押出しピン１２は、それぞれのスプリング１３、１４により前方に付勢されている。
そして、固定側押出しピン１１側のスプリング１３の付勢力は、可動側押出しピン１２のスプリング１４の付勢力より大きくされている。
【００１６】
また、前記固定側押出しピン１１と可動側押出しピン１２には、図５、図６に示すように、カット面１１ｃ、１２ｃと段部１１ｄ、１２ｄが形成されて、各ストッパ１５により前方への突出量が規制されるとともに、先端部等の一部が直接当接し合う当接面１１ｔ、１２ｔとされ、また他の一部が製品キャビティ部８を形成するキャビティ面１１ｐ、１２ｐとされている。
【００１７】
以上のような押出し機構９の作用について図５に基づき説明すると、型開きが開始された初期段階では、図５（ａ）に示すように、固定型２側のスプリング１３が強いため、型開きストロークに応じて固定側押出しピン１１だけが前進し、成形品Ｓを可動型３側に押し付け、そのうち固定側押出しピン１１の段部１１ｄがストッパ１５に当接する。
【００１８】
更に型開きが進行すると、図５（ｂ）に示すように、可動側押出しピン１２が前進を始め、成形品Ｓを可動型３から押出す。
すなわち、この押出し機構９は、型開きの初期段階で成形品Ｓを可動型３に押し付け、型開きの最終段階で成形品Ｓを可動型３から離型させ、従来のような大掛かりな押出し機構や駆動装置等を必要としない。
【００１９】
ところで、図３に示すように、前記ランナ部６に対応する可動型３側には、アンダーカット形状部１６が形成されており、このアンダーカット形状部１６は、スプルー部５の傾斜方向と逆方向に傾斜して突出する突起形状にされている。
これは、型開き時に、傾斜したスプルー部５により引抜き抵抗が増加し、成形品Ｓが固定型２側に付着しやすくなるのを打ち消して、確実に可動型３側に付着させ且つスプルー部５とノズル４の境目の部分を確実に分断させるためのものである。
【００２０】
以上のような射出成形金型１の作用等について、図６に基づき説明する。
図６（ａ）に示すように、ノズル４から注入した溶融樹脂はスプルー部５、ランナ部６、ゲート部７を通して製品キャビティ部８に充填される。そして溶融樹脂が凝固して成形品Ｓが成形された後、型開きが開始されると、型開きの初期段階では図６（ｂ）に示すように、成形品Ｓの周縁部は複数の押出し機構９により可動型３に押し付けられ、またランナ部６ではアンダカット形状部１６によりスプルー部５の引抜き抵抗が打ち消されて、成形品Ｓは確実に可動型３に付着する。
【００２１】
そして更に型開きが進行すると、図６（ｃ）に示すように、押出し機構９の作用により成形品Ｓは可動型３から押出され、その後、図６（ｄ）、（ｅ）のようにスプルー部５から成形品Ｓが抜き出される。
【００２２】
以上のような射出成形金型１において、ノズル部４のアンダーカット形状部１６の作用により、傾斜スプルーの引抜き抵抗に拘わらず、ノズル４とスプルー部５の境目部分で確実に分断し、成形品Ｓを可動型３に付着させた状態で型開きすることが出来る。
【００２３】
次に、ランナ部６に押出し機構１７を設ける別構成例について、図７乃至図９に基づき説明する。
この構成例では、ランナ部６にアンダーカット形状部を設ける代わりに、一対の押出しピンで構成される押出し機構１７を設けるようにしたものであり、この押出し機構１７の基本的構成は、前記成形品Ｓ周縁部の押出し機構９と同一である。
【００２４】
すなわち、図８に示すように、この押出し機構１７は、固定型２に設けられる固定側押出しピン１８と、可動型３に設けられる可動側押出しピン１９を備え、これら固定側押出しピン１８と可動側押出しピン１９は、それぞれのスプリング２０、２１により前方に付勢されている。
そして、固定側押出しピン１８側のスプリング２０の付勢力は、可動側押出しピン１９側のスプリング２１の付勢力より大きくされている。
【００２５】
また、固定側押出しピン１８と可動側押出しピン１９は、カット面１８ｃ、１９ｃと段部１８ｄ、１９ｄが形成されて、ストッパ２２（図９）により突出量が規制されるとともに、先端部の一部が直接当接し合う当接面１８ｔ、１９ｔとされ、また他の一部がランナ部６を形成する円弧状部１８ｐ、１９ｐとされている。
尚、成形品Ｓの周縁部の押出し機構９については、前記例と同一である。
【００２６】
以上のような射出成形金型１において、図９（ａ）に示すように、溶融樹脂を注入して成形品Ｓが成形されると型開きが開始され、型開きの初期段階では、図９（ｂ）に示すように、付勢力の強い固定側押出しピン１８が突出してランナ部６を可動型３に押し付け、固定側押出しピン１８の段部１８ｄがストッパ２２に当接した後は、図９（ｃ）に示すように、可動側押出しピン１９が突出し始め、最後に図９（ｄ）に示すように、成形品Ｓを可動型３から押出す。
【００２７】
この構成例の場合も、従来のような大掛かりな押出し機構や駆動装置等を必要とせず、簡素な構成にすることが出来、設備費用の削減が図られる。
【００２８】
尚、本発明は以上のような実施形態に限定されるものではない。本発明の特許請求の範囲に記載した事項と実質的に同一の構成を有し、同一の作用効果を奏するものは本発明の技術的範囲に属する。
例えば成形品の形状や、押出しピン１１、１２、１８、１９の具体的構成等は任意であり、また金型１のタイプは縦型でも横型でも良い。
【００２９】
【発明の効果】
以上のように本発明に係る射出成形金型は、傾斜スプルー部を備えた射出成形金型の可動型の型合わせ面に、スプルー部の開口位置に対応してアンダーカット形状部を設けるようにし、このアンダーカット形状部を、スプルー部の傾斜方向と逆方向に傾斜して突出する突起形状にしたため、スプルー部の引抜き抵抗の増大に拘わらず、成形品を固定型から離脱させて可動型に付着させることが出来、その後、成形品を押出す機構を簡素に且つ安価に構成することが出来る。
そして請求項２のような押出し機構を設ければ好適である。
また請求項３のように、ランナ部に押出し機構を設けるようにしても同様の効果が得られる。
【図面の簡単な説明】
【図１】本発明に係る射出成形金型の型合わせ面の説明図
【図２】金型の押出し機構を示す縦断面図
【図３】金型のスプルー部を示す縦断面図
【図４】押出し機構の説明図
【図５】型開きに伴う成形品の押出し状態を説明する説明図
【図６】アンダーカット形状部の作用を示す説明図
【図７】ランナ部に押出し機構を設ける構成例の型合わせ面の説明図
【図８】ランナ部の押出し機構の説明図
【図９】同作用図
【符号の説明】
１…射出成形金型、２…固定型、３…可動型、５…スプルー部、６…ランナ部、８…製品キャビティ、９…押出し機構、１１…固定側押出しピン、１２…可動側押出しピン、１３…スプリング、１４…スプリング、１６…アンダーカット形状部、１７…押出し機構、１８…固定側押出しピン、１９…可動側押出しピン、２０…スプリング、２１…スプリング、Ｓ…成形品。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an injection mold having a sprue inclined with respect to a mold opening / closing direction.
[0002]
[Prior art]
Conventionally, in an injection mold where molten resin is injected into a product cavity from a nozzle through a runway such as a sprue or gate, the position of the nozzle is fixed so as to balance the mold and handle multiple models. Although it is often installed at the approximate center, the gate position may be set away from the center due to the shape of the product, etc. In some cases, it is disposed obliquely with respect to the direction.
At this time, when the mold is opened after molding the molded product, if the sprue is inclined, the resistance when the molded product comes out of the sprue portion increases, and it becomes easier to adhere to the fixed mold side, and the molded product is fixed. Since it will be difficult to take out after adhering to the mold, an undercut part will be provided on the movable mold side so that it will not be easily detached from the movable mold at the stage of mold opening. A technique such as extrusion is generally used. (For examples where the sprue is not inclined, for example, Japanese Utility Model Publication No. 56-120220)
[0003]
[Problems to be solved by the invention]
However, the method of providing an undercut portion on the movable mold side and extruding a molded product with an extrusion pin, an extrusion plate, or the like as described above requires that an extrusion plate, an extrusion pin, or a driving device thereof be provided inside the mold. There is a problem that the structure becomes large and the equipment cost is high.
[0004]
Therefore, an object of the present invention is to simplify the mold release structure of a molded product and reduce the equipment cost in an injection mold in which a sprue is inclined with respect to the mold opening direction.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides an injection mold in which a movable mold is clamped and mold-opened with respect to a fixed mold having a sprue portion inclined with respect to the mold opening / closing direction. An undercut shape portion was provided on the mold matching surface corresponding to the opening position of the sprue portion, and the undercut shape portion was formed into a protrusion shape that was inclined and projected in the direction opposite to the inclination direction of the sprue portion.
[0006]
Such an undercut shape portion makes it difficult for the molded product to come out of the movable die at the time of mold opening, negating the increase in the pulling resistance of the inclined sprue and slightly exceeding it. Then, it is divided at the boundary between the nozzle and the sprue so that the molded product is detached from the fixed mold.
At this time, as the undercut shape, a projection shape that protrudes in a direction opposite to the inclination direction of the sprue portion can be used to effectively generate a force that opposes the pulling resistance of the inclined sprue portion.
[0007]
According to a second aspect of the present invention, the mold is provided with an extrusion mechanism for releasing the molded product, and the extrusion mechanism is fixedly provided so as to protrude from the fixed mold and urged by the urging member. A side extruding member and a movable extruding member that is provided in a movable mold so as to protrude freely and are energized by an energizing member, and a part of the fixed extruding member and the movable extruding member abut each other, Further, the other parts can press the molded product, and the urging force of the urging member on the fixed mold side is set to be stronger than the urging force of the urging member on the movable mold side.
[0008]
In the mold clamping state, the abutting portions of the fixed side extruding member and the movable side extruding member are pressed against each other so that both of them are immersed in the mold against the urging force of the urging member, In the initial stage of opening, the fixed-side pushing member having a large urging force presses the movable-side pushing member so that the molded product is pressed against the movable mold side. Then, the mold is further opened, and when the fixed side pushing member and the movable side pushing member are separated from each other, the molded product is pushed out by the movable side pushing member and detached from the movable die.
[009]
Incidentally, such an extruding mechanism has a simple configuration that does not require the use of a large-scale apparatus such as a conventional extruding pin or extruding plate, and Japanese Patent Application No. 11-340032 already proposed by the present applicant. It is a technique shown in
[0010]
According to a third aspect of the present invention, there is provided an injection mold in which a fixed mold and a movable mold each having a sprue portion inclined with respect to the mold opening / closing direction are clamped and opened freely. An extrusion mechanism is provided that pushes the molded body against the movable mold at the initial stage of opening, and extrudes the molded body from the movable mold at the final stage of mold opening. The fixed-side extrusion member that is urged by the member and the movable-side extrusion member that is provided in the movable mold so as to protrude freely and is urged by the urging member, and the fixed-side extrusion member and a part of the movable-side extrusion member They were set to contact each other so that the other part could press the molded product, and the urging force of the urging member on the fixed mold side was stronger than the urging force of the urging member on the movable mold side.
[0011]
In this way, by providing an extrusion mechanism at the opening position of the sprue part and by allowing the molded body to be pressed against the movable mold at the initial stage of mold opening, the mold can be opened to the movable mold at the opening position of the sprue part. The degree of adhesion can be increased, and this can effectively counter the increase in the pull-out resistance of the fixed sprue portion.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the accompanying drawings.
Here, FIG. 1 is an explanatory view of a die-mating surface of an injection mold according to the present invention, FIG. 2 is a longitudinal sectional view showing a mold extrusion mechanism, and FIG. 3 is a longitudinal sectional view showing a sprue portion of the mold. 4 is an explanatory diagram of an extrusion mechanism, FIG. 5 is an explanatory diagram illustrating an extruded state of a molded product accompanying mold opening, FIG. 6 is an explanatory diagram illustrating an operation of an undercut shape portion, and FIG. 7 is provided with an extrusion mechanism in a runner portion. FIG. 8 is an explanatory diagram of a push-out mechanism of a runner part, and FIG.
[0013]
The injection mold 1 according to the present invention can reduce the equipment cost by simplifying an extrusion mechanism for taking out a molded product in a mold having an inclined sprue, and is shown in FIGS. 1 to 3. As shown in FIG. 3, the fixed die 2 is provided with a sprue portion 5 that communicates with the nozzle 4 as shown in FIG. It is inclined obliquely with respect to the opening and closing direction.
[0014]
The downstream opening of the sprue portion 5 communicates with the product cavity portion 8 via the runner portion 6 and the gate portion 7.
[0015]
Further, the fixed mold 2 and the movable mold 3 are provided with an extruding mechanism 9 for taking out a molded product from the product cavity portion 8, and the extruding mechanism 9 has a product cavity as shown in FIGS. A plurality of push-out mechanisms 9 are arranged along the periphery of the portion 8, and each push-out mechanism 9 includes a fixed-side push pin 11 as a fixed-side push member provided in the fixed die 2 and a movable-side push member provided in the movable die 3. The fixed-side push pin 11 and the movable-side push pin 12 are urged forward by springs 13 and 14, respectively.
The urging force of the spring 13 on the fixed side pushing pin 11 side is made larger than the urging force of the spring 14 on the movable side pushing pin 12.
[0016]
Further, as shown in FIGS. 5 and 6, cut surfaces 11 c and 12 c and stepped portions 11 d and 12 d are formed on the fixed side push pin 11 and the movable side push pin 12, and each stopper 15 moves forward. The protruding amount is restricted, and contact surfaces 11t and 12t with which a part such as a tip part abuts directly are formed, and the other parts are cavity surfaces 11p and 12p that form the product cavity part 8. .
[0017]
The operation of the extrusion mechanism 9 as described above will be described with reference to FIG. 5. At the initial stage when the mold opening is started, as shown in FIG. 5 (a), the spring 13 on the fixed mold 2 side is strong. Only the fixed-side extrusion pin 11 moves forward according to the stroke, and the molded product S is pressed against the movable mold 3, and the step portion 11 d of the fixed-side extrusion pin 11 comes into contact with the stopper 15.
[0018]
When the mold opening further proceeds, as shown in FIG. 5 (b), the movable side push pin 12 starts to advance, and the molded product S is pushed out from the movable mold 3.
In other words, the extrusion mechanism 9 presses the molded product S against the movable mold 3 at the initial stage of mold opening, and releases the molded product S from the movable mold 3 at the final stage of mold opening. No drive device is required.
[0019]
Incidentally, as shown in FIG. 3, an undercut shape portion 16 is formed on the movable mold 3 side corresponding to the runner portion 6, and this undercut shape portion 16 is opposite to the inclination direction of the sprue portion 5. It has a protruding shape that inclines and protrudes in the direction.
This is because, when the mold is opened, the pulling resistance is increased by the inclined sprue portion 5 and cancels out that the molded product S tends to adhere to the fixed die 2 side. This is for surely dividing the boundary between the nozzle 4 and the nozzle 4.
[0020]
The operation of the injection mold 1 as described above will be described with reference to FIG.
As shown in FIG. 6A, the molten resin injected from the nozzle 4 is filled into the product cavity portion 8 through the sprue portion 5, runner portion 6, and gate portion 7. When the mold opening is started after the molten resin is solidified and the molded product S is molded, the peripheral portion of the molded product S is extruded at the initial stage of mold opening as shown in FIG. The mechanism 9 is pressed against the movable mold 3, and the pull-out resistance of the sprue section 5 is canceled by the undercut shape section 16 at the runner section 6, so that the molded product S is securely attached to the movable mold 3.
[0021]
When the mold opening further proceeds, as shown in FIG. 6 (c), the molded product S is pushed out of the movable mold 3 by the action of the extrusion mechanism 9, and then sprue as shown in FIGS. 6 (d) and 6 (e). The molded product S is extracted from the portion 5.
[0022]
In the injection mold 1 as described above, due to the action of the undercut shape portion 16 of the nozzle portion 4, regardless of the pulling resistance of the inclined sprue, it is surely divided at the boundary between the nozzle 4 and the sprue portion 5, and the molded product The mold can be opened with S attached to the movable mold 3.
[0023]
Next, another configuration example in which the extrusion mechanism 17 is provided in the runner portion 6 will be described with reference to FIGS.
In this configuration example, instead of providing the undercut shape portion in the runner portion 6, an extrusion mechanism 17 constituted by a pair of extrusion pins is provided. The basic configuration of the extrusion mechanism 17 is the above-described molding. This is the same as the extrusion mechanism 9 at the peripheral edge of the product S.
[0024]
That is, as shown in FIG. 8, the push-out mechanism 17 includes a fixed-side push pin 18 provided in the fixed mold 2 and a movable-side push pin 19 provided in the movable mold 3, and is movable with the fixed-side push pin 18. The side push pin 19 is urged forward by the respective springs 20 and 21.
The biasing force of the spring 20 on the fixed side push pin 18 side is made larger than the bias force of the spring 21 on the movable side push pin 19 side.
[0025]
The fixed-side push pin 18 and the movable-side push pin 19 have cut surfaces 18c and 19c and stepped portions 18d and 19d, and the amount of protrusion is restricted by the stopper 22 (FIG. 9). The contact surfaces 18t and 19t are in direct contact with each other, and the other portions are arc-shaped portions 18p and 19p forming the runner portion 6.
In addition, about the extrusion mechanism 9 of the peripheral part of the molded article S, it is the same as the said example.
[0026]
In the injection mold 1 as described above, as shown in FIG. 9A, mold opening is started when the molded product S is molded by injecting molten resin, and in the initial stage of mold opening, FIG. As shown in (b), after the fixed side push pin 18 having a strong biasing force protrudes and presses the runner portion 6 against the movable mold 3, and the step portion 18d of the fixed side push pin 18 contacts the stopper 22, As shown in FIG. 9 (c), the movable side push pin 19 starts to protrude, and finally, as shown in FIG. 9 (d), the molded product S is pushed out from the movable die 3.
[0027]
Also in the case of this configuration example, a conventional large-scale extrusion mechanism, a driving device, and the like are not required, and a simple configuration can be achieved, thereby reducing equipment costs.
[0028]
The present invention is not limited to the above embodiment. What has substantially the same configuration as the matters described in the claims of the present invention and exhibits the same operational effects belongs to the technical scope of the present invention.
For example, the shape of the molded product, the specific configuration of the extrusion pins 11, 12, 18, and 19 are arbitrary, and the type of the mold 1 may be vertical or horizontal.
[0029]
【The invention's effect】
As described above, the injection mold according to the present invention is provided with the undercut shape portion corresponding to the opening position of the sprue portion on the mold matching surface of the movable mold of the injection mold having the inclined sprue portion. Since the undercut shape part has a projection shape that protrudes in a direction opposite to the inclination direction of the sprue part, the molded product is detached from the fixed mold and made movable, regardless of the increase in the pull-out resistance of the sprue part. Then, the mechanism for extruding the molded product can be configured simply and inexpensively.
It is preferable to provide an extrusion mechanism as in claim 2.
Further, the same effect can be obtained by providing an extrusion mechanism in the runner as in the third aspect.
[Brief description of the drawings]
FIG. 1 is an explanatory view of a die-mating surface of an injection mold according to the present invention. FIG. 2 is a longitudinal sectional view showing a mold extrusion mechanism. FIG. 3 is a longitudinal sectional view showing a sprue portion of the mold. Explanatory view of the extrusion mechanism FIG. 5 Explanatory view explaining the extruded state of the molded product as the mold is opened FIG. 6 Explanatory view showing the action of the undercut shape portion FIG. 7 shows a configuration in which an extrusion mechanism is provided in the runner portion Explanatory drawing of example die-matching surface [Fig. 8] Explanatory drawing of runner part push-out mechanism [Fig. 9] Operation diagram [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Injection mold, 2 ... Fixed mold, 3 ... Movable mold, 5 ... Sprue part, 6 ... Runner part, 8 ... Product cavity, 9 ... Extrusion mechanism, 11 ... Fixed side extrusion pin, 12 ... Movable side extrusion pin , 13 ... Spring, 14 ... Spring, 16 ... Undercut shape part, 17 ... Extrusion mechanism, 18 ... Fixed side push pin, 19 ... Movable side push pin, 20 ... Spring, 21 ... Spring, S ... Molded article.

Claims

An injection mold in which a movable mold is clamped and mold-opened with respect to a fixed mold having a sprue portion inclined with respect to the opening and closing direction of the mold. An undercut shape portion is provided corresponding to the opening position of the portion, and this undercut shape portion is an injection mold that is formed into a protrusion shape that is inclined and protrudes in a direction opposite to the inclination direction of the sprue portion . The mold is provided with an extruding mechanism for releasing the molded product, and the extruding mechanism is provided on a fixed-side extruding member that is provided so as to protrude from the fixed mold and is urged by an urging member. A movable-side pushing member that is provided in a movable mold so as to protrude freely and is urged by a urging member, a part of the fixed-side pushing member and a movable-side pushing member abut each other, and the other part is To be able to press the molded product Further, the urging force of the urging member on the fixed mold side is set to be stronger than the urging force of the urging member on the movable mold side, and a plurality of the extruding mechanisms are provided at the peripheral edge of the molded product. injection mold, characterized in that.

In contrast to a fixed mold having a sprue portion that is inclined with respect to the opening and closing direction of the mold, the movable mold is an injection mold that can be clamped and freely opened. An extrusion mechanism is provided that pushes the molded body against the movable mold at the initial stage of the mold and extrudes the molded body from the movable mold at the final stage of mold opening. A fixed-side extrusion member that is urged by the member and a movable-side extrusion member that is provided in a movable mold so as to protrude freely and are urged by the urging member, and a part of the fixed-side extrusion member and the movable-side extrusion member Are in contact with each other, and other parts can press the molded product, and the urging force of the urging member on the fixed mold side is set stronger than the urging force of the urging member on the movable mold side. , said pushing mechanism is double the periphery of the molded article Injection mold, characterized in that are provided.