JPS61122981A - Molding method of reel flange - Google Patents

Molding method of reel flange

Info

Publication number
JPS61122981A
JPS61122981A JP24286884A JP24286884A JPS61122981A JP S61122981 A JPS61122981 A JP S61122981A JP 24286884 A JP24286884 A JP 24286884A JP 24286884 A JP24286884 A JP 24286884A JP S61122981 A JPS61122981 A JP S61122981A
Authority
JP
Japan
Prior art keywords
reel flange
pin
gate
mold
flange
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.)
Granted
Application number
JP24286884A
Other languages
Japanese (ja)
Other versions
JPH0532836B2 (en
Inventor
Kenji Iwano
賢二 岩野
Kazuyoshi Shinohara
篠原　和芳
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP24286884A priority Critical patent/JPS61122981A/en
Publication of JPS61122981A publication Critical patent/JPS61122981A/en
Publication of JPH0532836B2 publication Critical patent/JPH0532836B2/ja
Granted legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17—Component parts, details or accessories; Auxiliary operations
    • B29C45/26—Moulds
    • B29C45/34—Moulds having venting means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/0025—Preventing defects on the moulded article, e.g. weld lines, shrinkage marks
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17—Component parts, details or accessories; Auxiliary operations
    • B29C45/26—Moulds
    • B29C45/2628—Moulds with mould parts forming holes in or through the moulded article, e.g. for bearing cages
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17—Component parts, details or accessories; Auxiliary operations
    • B29C45/46—Means for plasticising or homogenising the moulding material or forcing it into the mould
    • B29C45/56—Means for plasticising or homogenising the moulding material or forcing it into the mould using mould parts movable during or after injection, e.g. injection-compression moulding

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Mechanical Engineering (AREA)

Abstract

PURPOSE:To prevent a generation of cracks in a welding section by injecting a thermoplastic resin from a gate into a metal mold, forming a disk shape reel flange having a through-hole in a center part, and disposing a protruding pin except for a welding section produced at a side opposing to the gate seeing from the through-hole. CONSTITUTION:On a mold of a reel flange 3 of a tape cassette for a video tape recorder, a thermoplastic resin is injected from a gate 10 of an upper metal mold 8 to provide a protruding pin 7b for separating the flange 3 from a lower metal mold 9 at a position except for a welding part 6 generated at an opposite side to the gate 10 seeing from the hole 11 of the flange 3. At a position corresponding to the weld 6, a protruding pin 7c is disposed, and the pin 7c is moved more slowly than the pin 7b, and during injecting the resin, gas remaining in the metal mold is discharged from a spacing A between the pin 7c and the metal mold 8. In this manner, the welding section 6 is made small, an external force applied to the welding section is decreased to prevent the generation of cracks, and obtain the reel flange 3 excellent in strength.

Description

【発明の詳細な説明】 産業上の利用分野 本発明は、ビデオテープレコーダ用テープカセットの磁
気テープを巻取る中心部分に貫通した孔ｔ−モったリー
ルフランジの成形法に関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for forming a reel flange having a T-shaped hole extending through the central portion of a tape cassette for a video tape recorder for winding a magnetic tape.

従来例の構成とその問題点 従来から、テープカセットのリール機構は第１図に示す
ようなものが用いられている。第１図はリール機構の断
面図であって、１は磁気テープを巻取るリール本体、ネ
はリールバネ（図示せず）で繰返し荷重を受けるピボッ
ト、３は透明の熱可塑性樹脂で成形されたリールフラン
ジである。第２図はリールフランジ３の斜視図であって
、４は前記熱可塑性樹脂を注入するゲートの跡、Ｓ＆は
リールフランジ３を金型から離型する際の突き出しピン
の跡、６はリールフランジ３成形の際に発生するウェル
ド部である。１１はピボット２の先端を突出させるだめ
の孔である。Conventional Structure and Problems Conventionally, a tape cassette reel mechanism as shown in FIG. 1 has been used. Figure 1 is a cross-sectional view of the reel mechanism, where 1 is the reel body that winds the magnetic tape, 2 is the pivot that receives repeated loads from a reel spring (not shown), and 3 is the reel molded from transparent thermoplastic resin. It is a flange. FIG. 2 is a perspective view of the reel flange 3, where 4 is the mark of the gate for injecting the thermoplastic resin, S& is the mark of the ejection pin when releasing the reel flange 3 from the mold, and 6 is the reel flange. 3. This is a weld part that occurs during molding. 11 is a hole from which the tip of the pivot 2 protrudes.

第３図は、リールフランジ３の成形時の金型の断面図で
あって、７２Ｌは成形されたリールフランジ３を下金型
９から離型する突き出しピン、８は上金型、人は突き出
しピン７ａと下金型９間の隙間、１０は前記熱可塑性樹
脂を金型に注入するゲ−トである。FIG. 3 is a cross-sectional view of the mold during molding of the reel flange 3, in which 72L is an ejection pin for releasing the molded reel flange 3 from the lower mold 9, 8 is an upper mold, and 72L is an ejection pin for releasing the molded reel flange 3 from the lower mold 9; A gap 10 between the pin 7a and the lower mold 9 is a gate for injecting the thermoplastic resin into the mold.

ところで従来のリールフランジ３の成形の場合、前記リ
ールフランジ３の中央にある孔１１のため、孔１１から
みてゲートの跡４０反対側に、ウェルド部６が発生する
。これを複数の突き出しピン７＆で離型する際に、突き
出しピンＴ＆の一個がウェルド部ｅ上に位置しているた
め、他の場所と比べ強度の弱いウェルド部６から割れが
発生するという欠点があった。By the way, in the case of conventional molding of the reel flange 3, because the hole 11 is located at the center of the reel flange 3, a weld portion 6 is generated on the opposite side of the gate mark 40 when viewed from the hole 11. When this is released from the mold using a plurality of ejector pins 7&, one of the ejector pins T& is located on the weld part e, so there is a drawback that cracks occur from the weld part 6, which is weaker than other places. there were.

発明の目的 本発明は、このような従来の欠点を解決するもので、中
心部に孔を持つ円形部品であるリールフランジの成形時
の割れを防止することを目的とするものである。OBJECTS OF THE INVENTION The present invention solves these conventional drawbacks, and aims to prevent cracking during molding of a reel flange, which is a circular part having a hole in the center.

発明の構成 上記目的を達成するために本発明は、中心部に板厚を貫
通した孔を有する円板状のリールフランジを透明の熱可
塑性樹脂でゲートから射出成形して、複数の突出しピン
で前記金型から突き呂す時に、前記孔から見てゲートの
反対側に発生するウェルド部を避けて、前記突出しピン
を配置した、リールフランジの成形法に関するものであ
る。Structure of the Invention In order to achieve the above object, the present invention has a disc-shaped reel flange having a hole penetrating the thickness of the plate in the center by injection molding from a gate using transparent thermoplastic resin, and a plurality of protruding pins. The present invention relates to a method of forming a reel flange, in which the ejecting pin is arranged to avoid a weld portion that occurs on the opposite side of the gate when viewed from the hole when the reel flange is pierced from the mold.

また、前記ウェルド部金避けて前記突出しピンを配置し
た、リールフランジの成形法であって。Moreover, the method for forming a reel flange includes arranging the protruding pin to avoid the weld part metal.

金型の前記ウェルド部に対応する位置に突出しピンと同
様の動きをする可動ビンを設け、前記可動ピンは突出し
ピンよりも遅れて動くようにしたリールフランジの成形
法に関するものである。This invention relates to a reel flange molding method in which a movable pin that moves in the same way as an ejector pin is provided at a position corresponding to the weld portion of the mold, and the movable pin moves later than the ejector pin.

実施例の説明 以下、本発明の一実施例を示す第４図、第６図。Description of examples 4 and 6 showing an embodiment of the present invention.

第６図の図面を用いて説明する。なお従来例と同一箇所
については、同一番号を付している。This will be explained using the drawing of FIG. Note that the same numbers are given to the same parts as in the conventional example.

第４図はリールフランジ成形時の金型の断面図である。FIG. 4 is a sectional view of a mold during reel flange molding.

７ｂは中心部の孔１１から見てゲートの反対側に発生す
るウェルド部６を避けたところに設置した突き出しピン
、また７Ｃは金型のウェルド部に対応する位置で突き出
しピン７ｂと同様の動きをするが突き出しピン７ｂより
も遅れて動く可動ビンである。第６図、第６図は成形後
のリールフランジの斜視図である。５ｂは突き出しピン
７ｂの跡、６Ｇは可動ビン７Ｃの跡である。7b is an ejector pin installed in a place avoiding the weld part 6 that occurs on the opposite side of the gate when viewed from the center hole 11, and 7C is a position corresponding to the weld part of the mold and moves in the same way as the ejector pin 7b. However, it is a movable bottle that moves later than the ejector pin 7b. 6 and 6 are perspective views of the reel flange after molding. 5b is the mark of the ejector pin 7b, and 6G is the mark of the movable bottle 7C.

以上のように構成されたリールフランジの成形法につい
て、以下その動作を説明する。The operation of the method for forming the reel flange constructed as described above will be described below.

まず金型８，９に熱可塑性樹脂を注入する訳であるが可
動ビン７Ｃが突き出しピン７ｂより遅れて動くため注入
時に可動ビン７Ｃと金型８の隙間ムから金型内の残留ガ
スが排出する。したがって通常ウェルド部６に残る残留
ガスを少なくすることができ、ウェルド部６を小さくで
きる。また中心の孔１１からみてゲートの反対側に発生
するウェルド部ｅを避けたところに突き出しピン７ｂを
設置することで、ウェルド部６に加わる力を低減し、リ
ールフランジの割れを防止できる。First, thermoplastic resin is injected into the molds 8 and 9, but since the movable bottle 7C moves later than the ejector pin 7b, residual gas in the mold is discharged from the gap between the movable bottle 7C and the mold 8 during injection. do. Therefore, the residual gas that normally remains in the weld portion 6 can be reduced, and the weld portion 6 can be made smaller. Furthermore, by installing the ejecting pin 7b in a location away from the weld portion e that occurs on the opposite side of the gate when viewed from the center hole 11, the force applied to the weld portion 6 can be reduced and cracking of the reel flange can be prevented.

発明の効果 以上のように本発明によると、中心部に孔を持つリール
フランジの成形法において、前記孔から見てゲートの反
対側に発生するウェルド部を避けたところに突き品しピ
ンを設置することで、前記ウェルド部に加わる力を低減
してリールフランジの割れを防止することが可能となる
。Effects of the Invention As described above, according to the present invention, in the method of forming a reel flange having a hole in the center, the pin is installed in a place that avoids the weld part that occurs on the opposite side of the gate when viewed from the hole. By doing so, it is possible to reduce the force applied to the weld portion and prevent the reel flange from cracking.

また、金型のウェルド部に対応する位置に突き出しピン
と同様の動きをする可動ビンを設け、前記可動ビンを前
記突き出しピンよりも遅らせて突出動作させることで、
熱可塑性樹脂を金型中に注入する際のウェルド部の原因
となる残留ガスを、樹脂注入時の圧力で前記可動ビンと
金型との隙間から排出し、ウェルド部を小さくすること
ができ。Further, by providing a movable bottle that moves in the same manner as the ejector pin at a position corresponding to the weld part of the mold, and causing the movable bottle to eject at a slower rate than the ejector pin,
Residual gas that causes a weld when thermoplastic resin is injected into a mold can be discharged from the gap between the movable bottle and the mold using the pressure at the time of resin injection, making it possible to reduce the size of the weld.

リールフランジの強度を向上させることができ本発明は
実用的効果が大である。The present invention has great practical effects because it can improve the strength of the reel flange.

【図面の簡単な説明】[Brief explanation of drawings]

第１図はリール機構の断面図、第２図は従来のリールフ
ランジの成形法により成形されたリールフランジの斜視
図、第３図は従来のリールフランジ成形時の金型の断面
図、第４図は本発明のリールフランジ成形時の金型の断
面図、第５図、第６図は本発明のリールフランジの成形
法により成形されたリールフランジの斜視図である。 １・・・・・・リール本体、２・・・・・・ピボット、
３・・・・・・リールフランジ、４・・・・・・ゲート
の跡、６ａ・・・・・・突出しピンの跡、５ｂ・・・・
・・突出しピンの跡、５ｃ・・・・・・可動ビンの跡、
６・・・・・・ウェルド部、７＆、７ｂ・−・・・・突
出しビン、７Ｇ・・・・・・可動ビン、８・・・・・・
上金型、９・思・下金型、１０・・・・・・ゲート、１
１・・・・・・孔、ム・・・・・・ビンと金型間の隙間
。 代理人の氏名　弁理士　中　尾　敏　男　ほか１名第１
図 第２図 第３図 第５図 第６図 ｔｔ　　　　　４−Fig. 1 is a sectional view of the reel mechanism, Fig. 2 is a perspective view of a reel flange formed by a conventional reel flange forming method, Fig. 3 is a sectional view of a mold for forming a conventional reel flange, and Fig. 4 is a sectional view of the reel flange forming method. The figure is a sectional view of a mold for molding the reel flange of the present invention, and FIGS. 5 and 6 are perspective views of the reel flange molded by the reel flange molding method of the present invention. 1... Reel body, 2... Pivot,
3... Reel flange, 4... Gate mark, 6a... Ejection pin mark, 5b...
・・Eject pin mark, 5c・・・・・・Movable bottle mark,
6...Weld part, 7&, 7b...Protruding bottle, 7G...Movable bottle, 8...
Upper mold, 9, lower mold, 10...gate, 1
1...hole, gap...gap between the bottle and the mold. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 Figure 5 Figure 6 tt 4-

Claims (2)

【特許請求の範囲】[Claims] （１）熱可塑性樹脂材料をゲートから金型内に射出し、
中心部に板厚を貫通した孔を有する円板状のリールフラ
ンジを成形して、複数の突出しピンによって前記金型か
ら突出するようにし、前記孔から見て前記ゲートの反対
側に発生するウェルド部を避けて前記突出しピンを配置
したことを特徴とするリールフランジの成形法。(1) Inject thermoplastic resin material into the mold from the gate,
A disc-shaped reel flange having a hole penetrating through the plate thickness in the center is molded so that it protrudes from the mold by a plurality of ejecting pins, and a weld occurs on the opposite side of the gate when viewed from the hole. 1. A method for forming a reel flange, characterized in that the protruding pin is arranged so as to avoid a portion of the reel flange. （２）金型のウェルド部に対応する位置に突出しピンと
同様の動きをする可動ピンを設け、前記可動ピンは突出
しピンよりも遅れて動くようにしたことを特徴とする特
許請求の範囲第１項記載のリールフランジの成形法。(2) A movable pin that moves in the same way as the ejector pin is provided at a position corresponding to the weld portion of the mold, and the movable pin moves later than the ejector pin. Forming method of reel flange described in section.
JP24286884A 1984-11-16 1984-11-16 Molding method of reel flange Granted JPS61122981A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP24286884A JPS61122981A (en) 1984-11-16 1984-11-16 Molding method of reel flange

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP24286884A JPS61122981A (en) 1984-11-16 1984-11-16 Molding method of reel flange

Publications (2)

Publication Number Publication Date
JPS61122981A true JPS61122981A (en) 1986-06-10
JPH0532836B2 JPH0532836B2 (en) 1993-05-18

Family

ID=17095435

Family Applications (1)

Application Number Title Priority Date Filing Date
JP24286884A Granted JPS61122981A (en) 1984-11-16 1984-11-16 Molding method of reel flange

Country Status (1)

Country Link
JP (1) JPS61122981A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0466186A2 (en) * 1990-07-13 1992-01-15 Canon Kabushiki Kaisha Ink sheet cartridge for a recording apparatus

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0466186A2 (en) * 1990-07-13 1992-01-15 Canon Kabushiki Kaisha Ink sheet cartridge for a recording apparatus
US5536093A (en) * 1990-07-13 1996-07-16 Canon Kabushiki Kaisha Supply and take-up reels in an ink sheet cartridge and recording apparatus using said ink sheet cartridge

Also Published As

Publication number Publication date
JPH0532836B2 (en) 1993-05-18

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