JPH02255243A - Gypsum mold for casting metallic mold for forming tire - Google Patents

Gypsum mold for casting metallic mold for forming tire

Info

Publication number
JPH02255243A
JPH02255243A JP1074378A JP7437889A JPH02255243A JP H02255243 A JPH02255243 A JP H02255243A JP 1074378 A JP1074378 A JP 1074378A JP 7437889 A JP7437889 A JP 7437889A JP H02255243 A JPH02255243 A JP H02255243A
Authority
JP
Japan
Prior art keywords
mold
sipe
plaster
casting
metal piece
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.)
Pending
Application number
JP1074378A
Other languages
Japanese (ja)
Inventor
Shigeo Sawada
澤田 重生
Toshiaki Ishihara
敏明 石原
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.)
NGK Insulators Ltd
Original Assignee
NGK Insulators 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 NGK Insulators Ltd filed Critical NGK Insulators Ltd
Priority to JP1074378A priority Critical patent/JPH02255243A/en
Publication of JPH02255243A publication Critical patent/JPH02255243A/en
Pending legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29DPRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
    • B29D30/00Producing pneumatic or solid tyres or parts thereof
    • B29D30/06Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
    • B29D30/0601Vulcanising tyres; Vulcanising presses for tyres
    • B29D30/0606Vulcanising moulds not integral with vulcanising presses
    • B29D2030/0607Constructional features of the moulds
    • B29D2030/0613Means, e.g. sipes or blade-like elements, for forming narrow recesses in the tyres, e.g. cuts or incisions for winter tyres

Landscapes

  • Tyre Moulding (AREA)
  • Mold Materials And Core Materials (AREA)
  • Molds, Cores, And Manufacturing Methods Thereof (AREA)
  • Moulds For Moulding Plastics Or The Like (AREA)

Abstract

PURPOSE:To cast a metallic mold for forming tire without detachment at circumference of a metal piece at the time of casting even in the case of the total length of the metal piece exceeds 20mm by forming a hole to a mold body at end part of the metal piece. CONSTITUTION:In the gypsum mold 1 for casting the metallic mold for forming tire, difference of thermal expansion between the gypsum mold 1 and metal piece 2 developed caused by coming into contact with hot temp. of molten metal at time of casting, is absorbed with the hole 3 formed at end part of the metal piece 2. Therefore, the gypsum 1 at circumference of the metal piece 2 is not detached by expansion of the metal piece 2. Therefore, correction of recessing defect on the forming surface in the metallic mold needing much labor is unnecessary and the perfect metallic mold for forming the tire can be easily manufactured.

Description

【発明の詳細な説明】 (産業上の利用分野) 本発明はタイヤ成形用金型を鋳造するための石膏型に関
するものである。
DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a plaster mold for casting a tire mold.

(従来の技術) タイヤの表面に幅がIM程度の細いスリットを形成した
い場合には、内表面にこれに対応するサイプと呼ばれる
金属片を突設したタイヤ成形用金型が使用されている。
(Prior Art) When it is desired to form a narrow slit with a width of about IM on the surface of a tire, a tire molding die is used which has a corresponding metal piece called a sipe protruding from the inner surface.

タイヤ成形用金型はアルミニウム合金を石膏型に鋳込ん
で製造する方法が知られており、このようなサイプ付の
タイヤ成形用金型を製造するには、予めこの石膏型の表
面にサイプを植え込んでおき、鋳造時に石膏型の表面形
状とともにサイプをタイヤ成形用金型の表面に反転させ
る方法が取られている。
It is known that tire molding molds are manufactured by casting an aluminum alloy into a plaster mold.In order to manufacture such a tire molding mold with sipes, sipes are first placed on the surface of the plaster mold. A method is used in which the sipes are implanted, and the surface shape of the plaster mold and the sipes are inverted onto the surface of the tire mold during casting.

ところがサイプ材としては、通常ステンレス鋼が用いら
れるため、石膏型との間の熱膨張差が大きく、特にサイ
プの長さが20閣以上の場合には鋳造時にサイプの周囲
の石膏型が剥離することがあった。この剥離した部分は
凝固途中の溶湯側へ移動することにより、最終的にはタ
イヤ成形用金型の成形面において凹状欠陥となって現れ
る。この凹状欠陥を修正するにはサイプの数が極めて多
いこともあり、多大は工数を要し、程度によっては修正
不可能となる場合があった。
However, since stainless steel is usually used as the sipe material, there is a large difference in thermal expansion between it and the plaster mold, and especially when the length of the sipe is 20 mm or more, the plaster mold around the sipe will peel off during casting. Something happened. This peeled portion moves toward the molten metal that is in the middle of solidification, and eventually appears as a concave defect on the molding surface of the tire molding die. Correcting this concave defect requires a large number of man-hours because the number of sipes is extremely large, and depending on the extent, it may not be possible to correct the defect.

(発明が解決しようとする課題) 本発明はこのような従来の問題点を解決して、サイプの
全長が20ff1)1を越える場合にも鋳造時にサイプ
の周囲が剥離するおそれのないタイヤ成形用金型を鋳造
するための石膏型を提供するために完成されたものであ
る。
(Problems to be Solved by the Invention) The present invention solves these conventional problems and provides a tire molding device that does not cause the periphery of the sipe to peel off during casting even when the total length of the sipe exceeds 20ff1). It was completed to provide a plaster mold for casting molds.

(課題を解決するための手段) 上記の課題は、石膏製の鋳型本体にサイプを植え込んだ
石膏型であって、サイプの端部の鋳型本体に穴を形成し
たことを特徴とするタイヤ成形用金型を鋳造するための
石膏型によって解決することができる。また上記の課題
は、石膏製の鋳型本体(1)に45度以上の角度で屈曲
したサイプを植込んだ石膏型であって、サイプの屈曲部
の外側の鋳型本体に穴を形成したことを特徴とするタイ
ヤ成形用金型をSR造するだめの石膏型によって解決す
ることができる。なおサイプの厚みが0.8間を超える
場合には、サイプの端部の鋳型本体に穴を形成する方法
では、鋳型の剥離を完全には防止できず、穴の代わりに
サイプの周囲に溝を形成しておくものとする。
(Means for solving the problem) The above problem is a gypsum mold in which sipes are implanted in a gypsum mold body, and a hole is formed in the mold body at the end of the sipe for tire molding. Can be solved by plaster molds for casting molds. Furthermore, the above problem is related to a plaster mold in which a sipe bent at an angle of 45 degrees or more is implanted in the gypsum mold body (1), and a hole is formed in the mold body outside the bent part of the sipe. This problem can be solved by using a plaster mold that is characterized by SR construction of a tire mold. If the thickness of the sipe exceeds 0.8 mm, forming a hole in the mold body at the end of the sipe will not completely prevent the mold from peeling, and instead of a hole, a groove will be formed around the sipe. shall be formed.

(作用) このように構成された本発明のタイヤ成形用金型を鋳造
するための石膏型は、鋳造時に高温の溶湯との接触によ
り発生する石膏型とサイプとの間の熱腫脹差がサイプの
端部または周囲に形成された穴や溝によって吸収される
ため、サイプの腫脹によりサイプの周囲の石膏型が剥離
することがない。従って多大な工数を要する金型の成形
面の凹状欠陥の修正が不要となり、完全なタイヤ成形用
金型を容易に製造することが可能となる。
(Function) The plaster mold for casting the tire molding die of the present invention configured as described above is such that the difference in thermal swelling between the plaster mold and the sipes, which occurs due to contact with high-temperature molten metal during casting, is reduced by the sipes. The swelling of the sipe will not cause the plaster mold around the sipe to peel off because it is absorbed by the holes and grooves formed at or around the edges of the sipe. Therefore, it becomes unnecessary to correct concave defects on the molding surface of the mold, which requires a large number of man-hours, and it becomes possible to easily manufacture a complete tire molding mold.

以下に本発明を図示の実施例によって詳細に説明する。The present invention will be explained in detail below with reference to illustrated embodiments.

(実施例) 第1図はサイプの形状がストレートである実施例を示し
、(1)はタイヤ成形用金型を鋳造するための石膏製の
鋳型本体、(2)はその表面に植え込まれたサイプであ
る。本実施例のサイプ(2)はステンレス系合金からな
るもので、その厚みは0.8閤以下、その長さは20m
5+以上のものである。このようなサイプ(2)の端部
の鋳型本体(1) 丘は、穴(3)が形成されている。
(Example) Figure 1 shows an example in which the shape of the sipe is straight. It is a sipe. The sipe (2) in this example is made of stainless steel alloy, has a thickness of 0.8 mm or less, and a length of 20 m.
5+ or higher. The mold body (1) at the end of such a sipe (2) has a hole (3) formed therein.

穴(3)の大きさは、幅がサイプ(2)の厚みより大き
く、長さ方向には0.3mm以上でサイプの熱腫脹量を
考慮すると、サイプの長さに対し0.015を乗じた寸
法以上とする必要がある。また穴(3)の深さはサイプ
(2)の植え込み深さ以1とされている。なお、穴(3
)は鋳造時における溶湯の進入方向とは逆の方向、即ち
サイプ(2)が熱膨張する方向のサイプ(2)の端部に
形成しておくものとする。
The size of the hole (3) is larger than the thickness of the sipe (2) in width and 0.3 mm or more in the length direction. Considering the amount of heat swelling of the sipe, multiply the length of the sipe by 0.015. The dimensions must be at least the same. Further, the depth of the hole (3) is set to be 1 greater than the planting depth of the sipe (2). In addition, the hole (3
) shall be formed at the end of the sipe (2) in the direction opposite to the direction in which the molten metal enters during casting, that is, in the direction in which the sipe (2) thermally expands.

第1図のサイプ(2)は溶湯が進入してくる方向、即ち
縦方向に長く延びているが、サイプ(2)が横方法に延
びている場合には、水平面に対する角度が30度以下で
あればその両端に穴(3)を形成しておくことが好まし
い。
The sipe (2) in Figure 1 extends long in the direction in which the molten metal enters, that is, in the vertical direction, but if the sipe (2) extends horizontally, the angle with the horizontal plane is 30 degrees or less. It is preferable to form holes (3) at both ends, if any.

第2図はサイプ(2)が45度以上の角度で屈曲した形
状を持つ場合の実施例を示している。この場合にはサイ
プ(2)はへ方自とB方向に熱膨張することとなるので
、サイプ(2)の端部の鋳型本体(1)に穴(3)を形
成するほかに、サイプ(2)の屈曲部の外側の鋳型本体
(1)に穴(4)を形成しておくものとする。なおサイ
プ(2)のストレート部の長さが20胴未満であれば、
そのストレート部の熱膨張を吸収するための穴(3)又
は(4)は省略することができる。
FIG. 2 shows an embodiment in which the sipe (2) has a shape bent at an angle of 45 degrees or more. In this case, the sipe (2) will thermally expand in the direction B, so in addition to forming the hole (3) in the mold body (1) at the end of the sipe (2), A hole (4) shall be formed in the mold body (1) outside the bent portion of 2). In addition, if the length of the straight part of the sipe (2) is less than 20 mm,
The hole (3) or (4) for absorbing thermal expansion of the straight portion can be omitted.

第3図は厚みが0.8 mを越えたサイプ(2)の周囲
の鋳型本体(1)に溝(5)を形成した実施例を示す。
FIG. 3 shows an embodiment in which a groove (5) is formed in the mold body (1) around a sipe (2) with a thickness exceeding 0.8 m.

この実施例では溝(5)の幅はサイプの17みに対し、
片側で0.1〜0.3鵬広くしてあり、また長さ方向に
はサイプの全長に0.015を乗じた寸法以−ヒの間隔
があくようにしてあり、溝(5)とサイプ(2)の直線
部との間に部分的に石膏を充填して両者を固定している
。この石膏充填部(6)は1個のサイプ(2)に対して
2〜6個程度とすればよ(、サイプ(2)を鋳型本体(
1)に確実に保持させるためのものである。
In this embodiment, the width of the groove (5) is 17 mm compared to the width of the sipe.
It is made 0.1 to 0.3 mm wider on one side, and in the length direction there is a gap equal to the total length of the sipe multiplied by 0.015, so that the groove (5) and the sipe are Plaster is partially filled between the straight line part (2) and the two are fixed. The number of plaster filling portions (6) should be approximately 2 to 6 for each sipe (2).
1) is to be held securely.

以上に説明した各実施例の石膏型を用いてアルミニウム
合金を鋳造すると、前述のようにサイブ(2)の熱腫脹
が吸収されてサイプ(2)の周囲の石膏型が剥離するこ
とがない。またサイプ(2)と鋳型本体(1)との間等
に穴(3)、(4)、溝(5)に対応する溶湯の挿し込
み部ができるが、これらの挿し込み部の形状は棒状ある
いはTA jIi状であるため、冷却して型ばらし後に
容易に折取ることができる。
When an aluminum alloy is cast using the plaster molds of the examples described above, the thermal swelling of the sipes (2) is absorbed and the plaster molds around the sipes (2) do not peel off, as described above. In addition, there are insertion parts for the molten metal corresponding to the holes (3), (4), and grooves (5) between the sipe (2) and the mold body (1), but the shape of these insertion parts is rod-shaped. Alternatively, since it has a TA jIi shape, it can be easily broken off after being cooled and demolded.

(発明の効果) 本発明は以上に説明したように、サイプの端部もしくは
周囲の鋳型本体に穴や溝を形成することにより、サイプ
の全長が20++uaを越えサイプと石膏との熱腫脹差
が大きくなるような場合にも、鋳造時にサイプの周囲の
石膏が剥離するおそれをなくすることができる。従って
本発明によれば従来のように剥離部が溶湯側へ移動する
ことによるタイヤ成形用金型の成形面の凹状欠陥の発生
がなくなり、修正工数を大幅に低減することができる。
(Effects of the Invention) As explained above, the present invention has a structure in which the total length of the sipe exceeds 20++ ua and the thermal swelling difference between the sipe and the plaster is reduced by forming holes and grooves in the end of the sipe or the surrounding mold body. Even if the size of the sipe becomes large, it is possible to eliminate the risk that the plaster around the sipe will peel off during casting. Therefore, according to the present invention, it is possible to eliminate concave defects on the molding surface of a tire molding die due to the movement of the peeled portion toward the molten metal, as in the prior art, and it is possible to significantly reduce the number of repair steps.

よって本発明は従来の問題点を解決したタイヤ成形用金
型を鋳造するための石膏型として、産業の発展に寄与す
るところは極めて大きいものである。
Therefore, the present invention greatly contributes to the development of industry as a plaster mold for casting a tire mold that solves the conventional problems.

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

第1図は本発明の第1の実施例を示す斜視図、第2図は
第2の実施例を示す斜視図、第3図は第3の実施例を示
す一部切欠斜視図である。 (1);石膏製の鋳型本体、(2):サイプ、(3)、
(4):穴、(5):溝。
FIG. 1 is a perspective view showing a first embodiment of the present invention, FIG. 2 is a perspective view showing a second embodiment, and FIG. 3 is a partially cutaway perspective view showing a third embodiment. (1): Gypsum mold body, (2): Sipe, (3),
(4): Hole, (5): Groove.

Claims (1)

【特許請求の範囲】 1、石膏製の鋳型本体(1)にサイプ(2)を植え込ん
だ石膏型であって、サイプ(2)の端部の鋳型本体(1
)に穴(3)を形成したことを特徴とするタイヤ成形用
金型を鋳造するための石膏型。 2、石膏製の鋳型本体(1)に45度以上の角度で屈曲
したサイプ(2)を植込んだ石膏型であって、サイプ(
2)の屈曲部の外側の鋳型本体(1)に穴(4)を形成
したことを特徴とするタイヤ成形用金型を鋳造するため
の石膏型。 3、石膏製の鋳型本体(1)にサイプ(2)を植込んだ
石膏型であって、サイプ(2)の周囲の鋳型本体(1)
に溝(5)を形成したことを特徴とするタイヤ成形用金
型を鋳造するための石膏型。 4、溝(5)とサイプ(2)の直線部との間に部分的に
石膏を充填して両者を固定した請求項3記載のタイヤ成
形用金型を鋳造するための石膏型。
[Scope of Claims] 1. A plaster mold in which a sipe (2) is embedded in a mold body (1) made of plaster, the mold body (1) at the end of the sipe (2).
) A plaster mold for casting a tire molding die, characterized in that a hole (3) is formed in the hole (3). 2. A plaster mold in which a sipe (2) bent at an angle of 45 degrees or more is embedded in a gypsum mold body (1).
2) A plaster mold for casting a tire mold, characterized in that a hole (4) is formed in the mold body (1) outside the bent part. 3. A plaster mold in which sipes (2) are implanted in a plaster mold body (1), and the mold body (1) around the sipes (2).
A plaster mold for casting a tire molding die, characterized in that a groove (5) is formed in the gypsum mold. 4. A plaster mold for casting a tire mold according to claim 3, wherein plaster is partially filled between the groove (5) and the straight part of the sipe (2) to fix both.
JP1074378A 1989-03-27 1989-03-27 Gypsum mold for casting metallic mold for forming tire Pending JPH02255243A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP1074378A JPH02255243A (en) 1989-03-27 1989-03-27 Gypsum mold for casting metallic mold for forming tire

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1074378A JPH02255243A (en) 1989-03-27 1989-03-27 Gypsum mold for casting metallic mold for forming tire

Publications (1)

Publication Number Publication Date
JPH02255243A true JPH02255243A (en) 1990-10-16

Family

ID=13545448

Family Applications (1)

Application Number Title Priority Date Filing Date
JP1074378A Pending JPH02255243A (en) 1989-03-27 1989-03-27 Gypsum mold for casting metallic mold for forming tire

Country Status (1)

Country Link
JP (1) JPH02255243A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011212966A (en) * 2010-03-31 2011-10-27 Bridgestone Corp Production process of tire mold
JP2015107589A (en) * 2013-12-04 2015-06-11 株式会社ブリヂストン Production method of tire vulcanization mold tool

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011212966A (en) * 2010-03-31 2011-10-27 Bridgestone Corp Production process of tire mold
JP2015107589A (en) * 2013-12-04 2015-06-11 株式会社ブリヂストン Production method of tire vulcanization mold tool

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