JPH01320122A - Injection mold of cylindrical synthetic resin molded item - Google Patents
Injection mold of cylindrical synthetic resin molded itemInfo
- Publication number
- JPH01320122A JPH01320122A JP15360588A JP15360588A JPH01320122A JP H01320122 A JPH01320122 A JP H01320122A JP 15360588 A JP15360588 A JP 15360588A JP 15360588 A JP15360588 A JP 15360588A JP H01320122 A JPH01320122 A JP H01320122A
- Authority
- JP
- Japan
- Prior art keywords
- synthetic resin
- resin molded
- cylindrical
- molded item
- mold
- 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
Links
- 229920003002 synthetic resin Polymers 0.000 title claims abstract description 58
- 239000000057 synthetic resin Substances 0.000 title claims abstract description 58
- 238000002347 injection Methods 0.000 title description 6
- 239000007924 injection Substances 0.000 title description 6
- 239000000463 material Substances 0.000 claims abstract description 26
- 238000001746 injection moulding Methods 0.000 claims description 13
- 229910010293 ceramic material Inorganic materials 0.000 claims description 3
- 229920001721 polyimide Polymers 0.000 abstract description 9
- 239000009719 polyimide resin Substances 0.000 abstract description 9
- 239000002184 metal Substances 0.000 abstract description 5
- 230000002093 peripheral effect Effects 0.000 abstract description 5
- 239000004734 Polyphenylene sulfide Substances 0.000 abstract description 3
- 239000003365 glass fiber Substances 0.000 abstract description 3
- 238000004519 manufacturing process Methods 0.000 abstract description 3
- 238000000034 method Methods 0.000 abstract description 3
- 229920000069 polyphenylene sulfide Polymers 0.000 abstract description 3
- 229920005989 resin Polymers 0.000 abstract description 3
- 239000011347 resin Substances 0.000 abstract description 3
- 229910000831 Steel Inorganic materials 0.000 description 8
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 8
- 239000002826 coolant Substances 0.000 description 8
- 239000010959 steel Substances 0.000 description 8
- 238000010586 diagram Methods 0.000 description 6
- 238000000465 moulding Methods 0.000 description 5
- 238000001816 cooling Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000012805 post-processing Methods 0.000 description 2
- 229910000975 Carbon steel Inorganic materials 0.000 description 1
- 239000010962 carbon steel Substances 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000009760 electrical discharge machining Methods 0.000 description 1
- 238000005323 electroforming Methods 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 229920001187 thermosetting polymer Polymers 0.000 description 1
Landscapes
- Moulds For Moulding Plastics Or The Like (AREA)
- Injection Moulding Of Plastics Or The Like (AREA)
Abstract
Description
【発明の詳細な説明】
(産業上の利用分野)
本発明はギヤ、カム、シロッコファンのロータ、ねじポ
ンプのねじロータ、スクリュー型圧縮機又はポンプのス
クリューロータ等に用いられる円筒状合成樹脂成形品の
射出成形用型に関する。Detailed Description of the Invention (Industrial Application Field) The present invention relates to a cylindrical synthetic resin molding used for gears, cams, rotors of sirocco fans, screw rotors of screw pumps, screw rotors of screw compressors or pumps, etc. Regarding injection molds for products.
(従来の技術及びその課題)
従来、スクリュー型圧縮機のスクリューロータは機械構
造用炭素鋼等の高強度鉄鋼材料を機械加工することによ
って製造されており、特に、そのスクリューは専用の加
工機械によりシングルカッタ又はホブ等を用いて精密に
加工されている。(Prior art and its problems) Conventionally, the screw rotor of a screw compressor has been manufactured by machining high-strength steel materials such as carbon steel for machine structures. Precisely processed using a single cutter or hob.
従って、このスクリューロータはスクリューの加工に多
大の工数を必要とするのみならず切削誤差による精度の
ばらつきが大きい。Therefore, this screw rotor not only requires a large number of man-hours to process the screw, but also has large variations in accuracy due to cutting errors.
また、このスクリューロータはその全体が鉄鋼材料から
なるので、その重量は大きく、従って、その回転時の慣
性が大きいのみならずスクリューロータの駆動のために
大きな動力を必要とする。Furthermore, since this screw rotor is entirely made of steel, it is heavy, and therefore not only has a large inertia during rotation, but also requires a large amount of power to drive the screw rotor.
そこで、スクリューロータの重量を低減するため、例え
ば、特開昭59−32688号公軸に示されるように、
合成樹脂を射出成形することによってスクリューロータ
を製造することが提案された。Therefore, in order to reduce the weight of the screw rotor, for example, as shown in the public shaft of JP-A No. 59-32688,
It has been proposed to manufacture screw rotors by injection molding synthetic resin.
しかしながら、このスクリューロータは射出成形時の成
形収縮が大きいのみならず両端部の外径寸法が中央部の
それに比して大きくなり、スクリューロータに要求され
る寸法精度を得ることが困難なため、後加工が必要とな
り、その結果、工数低減には限度があった。However, this screw rotor not only has a large molding shrinkage during injection molding, but also has an outer diameter larger at both ends than the center, making it difficult to obtain the dimensional accuracy required for a screw rotor. Post-processing is required, and as a result, there is a limit to the reduction in man-hours.
(課題を解決するための手段)
本発明は上記課題を解決するために発明されたものであ
って、軽量で寸法精度が高い円筒状合成樹脂成形品を成
形しうる射出成形用型を捉供することを目的とする。(Means for Solving the Problems) The present invention was invented to solve the above problems, and provides an injection molding mold capable of molding a cylindrical synthetic resin molded product that is lightweight and has high dimensional accuracy. The purpose is to
この目的を達成するため、本発明の射出成形用型は円筒
状合成樹脂成形品の端面を限界する型部材の全部又は一
部を上記円筒状合成樹脂成形品の円筒面を限界する型部
材よりも熱伝導率が小さい材料で構成している。In order to achieve this object, the injection mold of the present invention replaces all or part of the mold member that limits the end face of the cylindrical synthetic resin molded product with the mold member that limits the cylindrical surface of the cylindrical synthetic resin molded product. It is also made of a material with low thermal conductivity.
円筒状合成樹脂成形品の端面を限界する型部材の全部又
は一部は合成樹脂材料やセラミック材料で構成するのが
望ましい。It is desirable that all or part of the mold member that limits the end face of the cylindrical synthetic resin molded product be made of a synthetic resin material or a ceramic material.
(作用)
本発明においては、上記構成を具えているため、円筒状
合成樹脂成形品の射出成形時、成形品の端面からの熱の
移動を抑制することにより円筒状合成樹脂成形品の径方
向の成形収縮量を軸線方向に沿って均一化する。(Function) Since the present invention has the above configuration, during injection molding of a cylindrical synthetic resin molded product, by suppressing heat transfer from the end face of the molded product, the radial direction of the cylindrical synthetic resin molded product is suppressed. The amount of molding shrinkage is made uniform along the axial direction.
(実施例)
以下、本発明をスクリュー型圧縮機の雌スクリユーロー
タの成形用型に適用したl実施例について図面を参照し
ながら具体的に説明する。(Example) Hereinafter, an example in which the present invention is applied to a mold for forming a female screw rotor of a screw compressor will be specifically described with reference to the drawings.
第2図及び第3図に雌スクリユーロータが示され、この
スクリューロータIは鉄鋼等からなる金属製シャフト2
とこれを被覆する合成樹脂層3からなる。A female screw rotor is shown in FIGS. 2 and 3, and this screw rotor I has a metal shaft 2 made of steel or the like.
and a synthetic resin layer 3 covering this.
合成樹脂層3は全体としてほぼ円筒状をなし、その両端
面はシャフト2に直交する平面とされ、外周面には6条
のスクリューが形成されている。The synthetic resin layer 3 has a generally cylindrical shape as a whole, both end surfaces thereof are planes perpendicular to the shaft 2, and six screws are formed on the outer peripheral surface.
この合成樹脂層3はスクリューロータ1に要求される機
械的強度、耐熱性等を満足する材料、例えば、40%w
tガラス繊維強化ポリフェニレンサルファイド樹脂から
なる。また、シャフト2と合成樹脂層3との接合強度を
増大させるため、シャフト3の外周面が合成樹脂層3で
被覆される部分はローレフト加工を施し又は螺旋溝等を
設けておくのが望ましい。This synthetic resin layer 3 is made of a material that satisfies the mechanical strength, heat resistance, etc. required for the screw rotor 1, for example, 40%w.
Made of glass fiber reinforced polyphenylene sulfide resin. Furthermore, in order to increase the bonding strength between the shaft 2 and the synthetic resin layer 3, it is desirable that the portion of the outer circumferential surface of the shaft 3 covered with the synthetic resin layer 3 is subjected to a low left processing or provided with a spiral groove or the like.
第1図にはこの雌スクリユーロータ1を射出成形するた
めの成形型の略示的断面図が示されている。FIG. 1 shows a schematic cross-sectional view of a mold for injection molding this female screw rotor 1. As shown in FIG.
成形型は合成樹脂層3の外周面を限界するキャビティ1
1とこの両端に組み合わされる端面リング13.14に
よって構成されている。キャビティ11の内面の輪郭は
Ni−Co電気鋳造法又は放電加工等によって加工され
、その外周面は可動側型板10に固定されている。The mold has a cavity 1 that limits the outer peripheral surface of the synthetic resin layer 3.
1 and end rings 13 and 14 assembled to both ends thereof. The contour of the inner surface of the cavity 11 is processed by Ni--Co electroforming or electrical discharge machining, and the outer peripheral surface thereof is fixed to the movable template 10.
端面リング13の中心部にはポリイミド樹脂等からなる
インサートリング13aが組み込まれ、また、端面リン
グ14の中心部内面にはポリイミド樹脂からなる内張材
14aが張り付けられ、これらインサートリング13a
及び内張材14aは合成樹脂層3の両端面を限界する。An insert ring 13a made of polyimide resin or the like is incorporated in the center of the end ring 13, and a lining material 14a made of polyimide resin is attached to the inner surface of the center of the end ring 14.
And the lining material 14a limits both end surfaces of the synthetic resin layer 3.
キャビティilの外周面には環状の冷却媒体流路20.
21.22が軸線方向に所定の間隔を隔てて形成されて
いる。また、端面リング14の外面には円形の冷却媒体
流路23が形成されている。冷却媒体流路20.21.
22.23にはそれぞれ独立して温度又はfi!iを変
更することができる図示しない温調器からの冷却媒体が
循環する。なお、15はエジェクタシャフト、16はス
トッパ、17はコイルスプリング、18は溶融状態の合
成樹脂を供給するノズル、19は供給路、24は冷却媒
体流路20.21.22.23内を流れる冷却媒体の漏
洩を防止するためのソールリングである。An annular cooling medium flow path 20 is provided on the outer peripheral surface of the cavity il.
21 and 22 are formed at predetermined intervals in the axial direction. Further, a circular cooling medium flow path 23 is formed on the outer surface of the end ring 14 . Coolant flow path 20.21.
22.23 each independently has temperature or fi! A cooling medium from a temperature regulator (not shown) that can change i is circulated. In addition, 15 is an ejector shaft, 16 is a stopper, 17 is a coil spring, 18 is a nozzle for supplying molten synthetic resin, 19 is a supply path, and 24 is a cooling medium flowing in the cooling medium flow path 20.21.22.23. This is a sole ring to prevent media leakage.
しかして、スクリューロータ1の製造時、金属製シャフ
ト2が成形型内に配置され、その一端は端面リング14
の中心を貫通してエジェクタシャフト15に接合され、
他端はインサートリング+3aの中心を貫通してストッ
パ16に嵌合される。そして、可動側型板IOを図示し
ない手段によって約150℃に維持すると同時に冷却媒
体流路20.21.22.23のそれぞれに約150℃
の冷却媒体をを流してキャビティ11及び端面リング1
3.14を約150℃に維持する。Therefore, when manufacturing the screw rotor 1, the metal shaft 2 is placed in a mold, and one end thereof is connected to the end face ring 14.
is connected to the ejector shaft 15 through the center of the
The other end passes through the center of the insert ring +3a and is fitted into the stopper 16. The movable template IO is maintained at approximately 150°C by means not shown, and at the same time, each of the cooling medium flow paths 20, 21, 22, and 23 is maintained at approximately 150°C.
A cooling medium is passed through the cavity 11 and the end ring 1.
3.14 is maintained at approximately 150°C.
そこで、高温で溶融状態の40%−Lガラス繊維強化ポ
リフェニレンサルファイド樹脂をノズル18から供給路
19を経て成形型内に射出することによって金属製シャ
フト2を被覆する合成樹脂N3が形成される。Therefore, the synthetic resin N3 covering the metal shaft 2 is formed by injecting 40%-L glass fiber reinforced polyphenylene sulfide resin in a molten state at a high temperature from the nozzle 18 through the supply path 19 into the mold.
このようにして射出成形された合成樹脂層3の外径寸法
の軸線方向に沿う変化が第4図に示され、また、成形型
をモデル化してその1/4モデルについて有限要素法を
用いて温度解析を行った結果が第6図に示されている。Figure 4 shows the change in the outer diameter dimension of the synthetic resin layer 3 injection-molded in this way along the axial direction. The results of temperature analysis are shown in FIG.
インサートリング13a及び内張材14aを具えず、端
面リング13及び14をキャビティ11と同し鉄鋼材料
で構成した成形型を用いて上記と同様の条件で射出成形
して得られた合成樹脂層3の外径寸法の軸線方向に沿う
変化が第5図に示され、温度解析の結果が第7図に示さ
れている。第4図と第5図を比較すれば明らかなように
本発明によれば合成樹脂層3の外径寸法が長手方向中央
部で小さくなる中低現象は著しく軽減され、また、第6
図と第7図を比較すれば明らかなように第7図に示すも
のにおいては等1線が合成樹脂層3の長手方向中央部で
は軸線と平行に並んでいるが両端部では軸線に垂直に並
ぶのに対し、本発明によれば、第6図に明らかなように
等1線は合成樹脂層3の全長に亘って軸線に平行に並ん
でいる。Synthetic resin layer 3 obtained by injection molding under the same conditions as above using a mold in which the end rings 13 and 14 are made of the same steel material as the cavity 11 without the insert ring 13a and the lining material 14a. FIG. 5 shows the change in the outer diameter dimension along the axial direction, and FIG. 7 shows the results of temperature analysis. As is clear from a comparison of FIG. 4 and FIG. 5, according to the present invention, the phenomenon of mid-low diameter in which the outer diameter of the synthetic resin layer 3 becomes smaller at the center in the longitudinal direction is significantly reduced.
As is clear from a comparison between the figure and FIG. 7, in the case shown in FIG. 7, the equal lines are aligned parallel to the axis in the longitudinal center of the synthetic resin layer 3, but perpendicular to the axis at both ends. In contrast, according to the present invention, as is clear from FIG. 6, the equal lines are arranged parallel to the axis over the entire length of the synthetic resin layer 3.
以上から推測すれば、端面リング13及び14をキャビ
ティ11と同様の鉄鋼材料で構成した場合には、成形型
内の合成樹脂層3はその端部において端面リング13.
14への熱移動が大きいためキャビティ11への熱移動
のみに依存している中央部より冷却速度が速く、この結
果、端部は早い時期に冷却固化して外径寸法が決まって
しまうのに対し、インサートリング13a及び内張材1
4aをポリイミド樹脂材料で構成した場合にはポリイミ
ド樹脂材料の熱伝導率が0.26Kcal/m、hr、
℃で鉄鋼材料の熱伝導率より大巾に小さく、合成樹脂
層3の端部からインサートリング13a及び内張材14
aへの熱移動が抑制され、この結果、合成樹脂層3の全
長に亘り径方向の冷却速度がほぼ均一になったためと考
えられる。Judging from the above, if the end rings 13 and 14 are made of the same steel material as the cavity 11, the synthetic resin layer 3 in the mold will be formed at the ends of the end rings 13 and 14.
Since the heat transfer to cavity 14 is large, the cooling rate is faster than that of the center part, which relies only on heat transfer to cavity 11. As a result, the end part cools and solidifies earlier, and the outer diameter dimension is determined. On the other hand, the insert ring 13a and the lining material 1
When 4a is made of a polyimide resin material, the thermal conductivity of the polyimide resin material is 0.26 Kcal/m, hr,
℃, the thermal conductivity of the insert ring 13a and the lining material 14 is much lower than that of steel material.
This is thought to be because the heat transfer to a was suppressed, and as a result, the cooling rate in the radial direction became almost uniform over the entire length of the synthetic resin layer 3.
上記実施例においては、インサートリング13a及び内
張材14aとして、熱伝導率が小さく、かつ、300℃
程度の溶融状態の合成樹脂に接し、かつ、その射出圧力
に耐える必要があるため、熱硬化製ポリイミド樹脂を用
いたが、同等の性質を持つ他の合成樹脂材料を用いるこ
とができ、また、端面リング13及び14の全体をポリ
イミド樹脂又はこれと同効の合成樹脂材料で構成するこ
とができる。In the above embodiment, the insert ring 13a and the lining material 14a have a low thermal conductivity and a temperature of 300°C.
Thermosetting polyimide resin was used because it needed to be in contact with a synthetic resin in a molten state and withstand its injection pressure, but other synthetic resin materials with similar properties could be used. The end rings 13 and 14 can be entirely made of polyimide resin or a synthetic resin material having the same effect.
また、合成樹脂層3の外径寸法の精度を向上するため溶
融合成樹脂の射出圧力を高くする必要がある場合には合
成樹脂層3の端面を限界する型部材としてジルコニア等
のセラミック材料を用いることができる。In addition, if it is necessary to increase the injection pressure of the molten synthetic resin in order to improve the accuracy of the outer diameter dimension of the synthetic resin layer 3, a ceramic material such as zirconia is used as a mold member that limits the end surface of the synthetic resin layer 3. be able to.
ジルコニアを用いた場合の温度解析の結果が第8図に示
され、ジルコニアはポリイミド樹脂に比べて熱伝導率が
一桁程高く、従って、断熱効果は劣るが鉄鋼材料に比べ
れば冷却速度は半分程度となり合成樹脂層3の寸法精度
はかなり改善される。The results of temperature analysis when using zirconia are shown in Figure 8. Zirconia has a thermal conductivity that is about an order of magnitude higher than that of polyimide resin. Therefore, although its insulation effect is inferior, the cooling rate is half that of steel materials. As a result, the dimensional accuracy of the synthetic resin layer 3 is considerably improved.
(発明の効果)
本発明においては、円筒状合成樹脂成形品の端面を限界
する型部材の全部又は一部を上記円筒状合成樹脂成形品
の円筒面を限界する型部材よりも熱伝導率が小さい材料
で構成したため、円筒状合成樹脂成形品の射出成形時、
成形品の端面からの熱の移動を抑制することにより円筒
状合成樹脂成形品の径方向の成形数hillを軸線方向
に沿って均一化することができる。(Effects of the Invention) In the present invention, all or part of the mold member that limits the end face of the cylindrical synthetic resin molded product has a thermal conductivity higher than that of the mold member that limits the cylindrical surface of the cylindrical synthetic resin molded product. Because it is made of small material, it is difficult to injection mold a cylindrical synthetic resin molded product.
By suppressing the transfer of heat from the end surface of the molded product, the number of moldings in the radial direction of the cylindrical synthetic resin molded product can be made uniform along the axial direction.
従って、射出成形のみによって寸法精度が高い円筒状合
成樹脂成形品を得ることができるので後加工を要せず、
従って、寸法精度の高い円筒状合成樹脂成形品を安価に
製造できる。Therefore, a cylindrical synthetic resin molded product with high dimensional accuracy can be obtained only by injection molding, and no post-processing is required.
Therefore, a cylindrical synthetic resin molded product with high dimensional accuracy can be manufactured at low cost.
第1図は本発明の1実施例を示す成形型の略示的断面図
、第2図は雌スクリユーロータの部分的に断面とした側
面図、第3図は第2図のm−m線に沿う断面図、第4図
は本発明によって得られた合成樹脂成形品の径方向寸法
の軸線方向に沿う変化を示す線図、第5図及び第6図は
合成樹脂成形品の端面を限界する型部材を外周面を限界
する型部材と同し鉄鋼材料で構成した場合を示し、第5
図は射出成形時における温度解析の結果を示す線図、第
6図は合成樹脂成形品の径方向寸法の軸線に沿う変化を
示す線図である。第7図は本発明による合成樹脂成形品
の射出成形時における温度解析の結果を示す線図である
。第8図は合成樹脂成形品の端面を限界する型部材をジ
ルコニアで構成した場合の射出成形時における温度解析
の結果を示す線図である。
円筒状合成樹脂成形品−3、円筒面を限界する型手続補
正書印発)
昭和/;多年11 月し一日FIG. 1 is a schematic cross-sectional view of a mold showing one embodiment of the present invention, FIG. 2 is a partially cross-sectional side view of a female screw rotor, and FIG. 3 is taken along m-m in FIG. 4 is a line diagram showing changes along the axial direction in the radial dimension of the synthetic resin molded product obtained by the present invention, and FIGS. 5 and 6 are diagrams showing the end face of the synthetic resin molded product. This shows the case where the limiting mold member is made of the same steel material as the limiting mold member, and the fifth
The figure is a diagram showing the results of temperature analysis during injection molding, and FIG. 6 is a diagram showing changes in the radial dimension of a synthetic resin molded product along the axis. FIG. 7 is a diagram showing the results of temperature analysis during injection molding of the synthetic resin molded product according to the present invention. FIG. 8 is a diagram showing the results of temperature analysis during injection molding when the mold member that limits the end face of the synthetic resin molded product is made of zirconia. Cylindrical synthetic resin molded product - 3, stamped mold procedure amendment that limits the cylindrical surface) Showa/; November 1st, many years
Claims (3)
全部又は一部を上記円筒状合成樹脂成形品の円筒面を限
界する型部材よりも熱伝導率が小さい材料で構成したこ
とを特徴とする円筒状合成樹脂成形品の射出成形用型。(1) All or part of the mold member that limits the end face of the cylindrical synthetic resin molded product is made of a material that has a lower thermal conductivity than the mold member that limits the cylindrical surface of the cylindrical synthetic resin molded product. A mold for injection molding of cylindrical synthetic resin molded products.
全部又は一部を合成樹脂材料で構成したことを特徴とす
る請求項(1)記載の円筒状合成樹脂成形品の射出成形
用型。(2) For injection molding of a cylindrical synthetic resin molded product according to claim (1), wherein all or part of the mold member that limits the end face of the cylindrical synthetic resin molded product is made of a synthetic resin material. Type.
全部又は一部をセラミック材料で構成したことを特徴と
する請求項(1)記載の円筒状合成樹脂成形品の射出成
形用型。(3) A mold for injection molding a cylindrical synthetic resin molded product according to claim (1), wherein all or part of the mold member that limits the end face of the cylindrical synthetic resin molded product is made of a ceramic material. .
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP63153605A JP2642952B2 (en) | 1988-06-23 | 1988-06-23 | Mold for injection molding of cylindrical synthetic resin molded products |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP63153605A JP2642952B2 (en) | 1988-06-23 | 1988-06-23 | Mold for injection molding of cylindrical synthetic resin molded products |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH01320122A true JPH01320122A (en) | 1989-12-26 |
JP2642952B2 JP2642952B2 (en) | 1997-08-20 |
Family
ID=15566138
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP63153605A Expired - Lifetime JP2642952B2 (en) | 1988-06-23 | 1988-06-23 | Mold for injection molding of cylindrical synthetic resin molded products |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP2642952B2 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2007083535A (en) * | 2005-09-22 | 2007-04-05 | Noboru Naoi | Mold for worm gear |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6485724A (en) * | 1987-09-28 | 1989-03-30 | Polyplastics Co | Method for injection molding cylindrical molded item |
-
1988
- 1988-06-23 JP JP63153605A patent/JP2642952B2/en not_active Expired - Lifetime
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6485724A (en) * | 1987-09-28 | 1989-03-30 | Polyplastics Co | Method for injection molding cylindrical molded item |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2007083535A (en) * | 2005-09-22 | 2007-04-05 | Noboru Naoi | Mold for worm gear |
Also Published As
Publication number | Publication date |
---|---|
JP2642952B2 (en) | 1997-08-20 |
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