JPS5962773A - Plastic piston - Google Patents

Abstract

PURPOSE:To prevent a piston from breakage even though it is assempled with an heat insulating plate having a large coefficient of thermal expansion, by fitting an asbestos insulating plate in a recess formed at the foremost part. CONSTITUTION:A recess 7 is formed in the opening provided at the tip of a plastic piston 3 on its pad pressing side, and therein an asbestos insulating plate 8 is fitted to allow it to make contact with the backing plate 6a for the pad. This heat insulating plate 8 is made of a composite consisting by weight of 25- 45% asbestos and 55-75% cement, and has a small coefficient of thermal expansion. Thereby breakage of the plastic piston can be prevented which is likely to occur due to thermal expansion of the heat insulating plate.

Description

【発明の詳細な説明】 本発明は熱硬化性樹脂に硝子繊維等の無機質を含イイし
たディスクブレーキ用樹脂ピストンに関するものである
。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resin piston for a disc brake in which a thermosetting resin contains an inorganic material such as glass fiber.

最近フェノール樹脂等の熱硬化性樹脂に硝子繊維、雲母
、カーボン繊維、銅等の無機質を添加したピストンがデ
ィスクブレーキに用いられているが、これに膨張係数の
大きい断熱板を組付けるとピストンが破損するおそれが
生じる。Recently, pistons made by adding inorganic materials such as glass fiber, mica, carbon fiber, and copper to thermosetting resins such as phenolic resins have been used in disc brakes, but when a heat insulating plate with a large expansion coefficient is attached to these pistons, the pistons become There is a risk of damage.

そこで本発明はこの点に鑑み、樹脂ピストン先端に嵌合
口部を形成し、該凹部にアスベスト系断熱板を嵌合した
ことに、ｌ：ｔ’ｓ　ピストンの破損を防止することに
ある。In view of this, the present invention aims to prevent damage to the l:t's piston by forming a fitting opening at the tip of the resin piston and fitting an asbestos-based heat insulating plate into the recess.

以下第１図に示す一実施例について説明すると、キャリ
パボディ１に形成されシリンダ２に摺動可能に設けられ
る樹脂ピストン３Ｆｉ、熱硬化性樹脂をマトリックスと
し、これに無機質を添加したものである。An embodiment shown in FIG. 1 will be described below. A resin piston 3Fi formed in a caliper body 1 and slidably provided in a cylinder 2 has a thermosetting resin as a matrix and an inorganic substance is added thereto.

熱硬化性樹脂としては一般にフェノール樹脂が用いられ
ているがポリアミド樹脂、その他適宜のものを用いるこ
とができる。また無機質として幻１、硝子繊維、謀母、
カーボン繊維、銅等の適宜のものを用いることができる
が、硝子繊維を３５チ〜５０俤含有させるとピストンの
膨張を抑えることができる。Phenol resin is generally used as the thermosetting resin, but polyamide resin and other appropriate resins can also be used. In addition, as inorganic substances, phantom 1, glass fiber, conspiracy mother,
An appropriate material such as carbon fiber or copper can be used, but if 35 to 50 pieces of glass fiber are included, expansion of the piston can be suppressed.

この樹脂ピストン３は、その表面にマトリックスとして
用いた熱硬化性樹脂の硬化層４を形成し、無機質による
角シールの損傷や、ブレーキ液による樹脂ピストンの侵
食を防止している。This resin piston 3 has a hardened layer 4 of thermosetting resin used as a matrix formed on its surface to prevent damage to the corner seals caused by inorganic substances and corrosion of the resin piston caused by brake fluid.

樹脂ピストン３のパッド６押圧側の先端開口部に°は嵌
合凹部７ｆ！ｃ形成し、該凹部７にアスベスト系の断熱
板８が嵌合され、これをパッド裏板６ａに当接させてい
る。The end opening of the resin piston 3 on the pressing side of the pad 6 has a fitting recess 7f! An asbestos-based heat insulating plate 8 is fitted into the recess 7 and brought into contact with the pad back plate 6a.

この断熱板８は、ｎｉｌ：比にして石綿２５％〜４５％
およびセメント５５％〜７５％から組成された成形体に
て構成されていて、断熱効果が高く、しかも膨張係数が
小さい。This heat insulating board 8 has a nil ratio of 25% to 45% asbestos.
It is composed of a molded body composed of 55% to 75% of cement, has a high heat insulating effect, and has a small coefficient of expansion.

、＠２図に示す実が１１例は、ピストン６の先端開口部
に環状の嵌合凹部７′を形成し、該凹部７′にアスベス
ト系断熱板８を嵌合したものである。In the 11th example shown in Figure 2, an annular fitting recess 7' is formed in the opening at the tip of the piston 6, and an asbestos-based heat insulating plate 8 is fitted into the recess 7'.

本発明は以上のように、樹脂ピストンの先９８１ｉ凹部
にアスベスト系の断熱板を嵌合したから、耐熱性に優れ
るとともに、断熱板の熱膨張による樹脂ピストンの破損
を防止している。As described above, in the present invention, since an asbestos-based heat insulating plate is fitted into the recessed portion 981i at the tip of the resin piston, it has excellent heat resistance and prevents damage to the resin piston due to thermal expansion of the heat insulating plate.

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

第１図は本発明の一実施例を示す断面正面図、第２図は
他の実施例を示す要部断面図である。 ３は樹脂ピストン、４は硬化層、７．７’は嵌合四部、
８は断熱板である。 崩１図 命２図 手続補正書 昭和５７年１１月　５日 特許庁長官若杉４（１大　　殿 １、事件の表示 昭和５フイＩ１１寺　♂「　願第１７０７５６５２、発
　明の名称 樹脂ピストン 事件との関係　　　　／）Ｊ許出願人 ４、代理人 ５、補正命令の日付 別紙の通り 同量の第１（￥Ｉ及び第２図を別紙の通ｐ言Ｊ正するＯ
以　　上 手続補正書 昭和５８年　６月　２「１ 特許庁長官若　杉和夫　殿 ■、事件の表示 昭和５７　４１　　ｆｔ’！ｒ　　許＋９ｉ第１７０７
５６！；事件との関係　　ｌ庁許出願人 ４、代理人 ６、補正により増加する発明の数 別紙の通り 明細書第３頁第７行の［角シール１を「角シール５」と
訂正する。 以上FIG. 1 is a sectional front view showing one embodiment of the present invention, and FIG. 2 is a sectional view of main parts showing another embodiment. 3 is a resin piston, 4 is a hardened layer, 7.7' is a fitting four part,
8 is a heat insulating board. Amendment 1, Figure 2, Procedural Amendment, November 5, 1980, Commissioner of the Japan Patent Office Wakasugi 4 (1 Daiden 1, Indication of the case Showa 5 Fui I 11 Temple ♂ ' Application No. 17075652, Name of the invention Resin Piston Incident) Relationship /) Applicant 4, agent 5, date of amendment order.
Written amendment to the above procedure June 2, 1980 1 Mr. Kazuo Wakasugi, Director General of the Patent Office■, Indication of the case 1982 41 ft'!r +9i No. 1707
56! ;Relationship with the case l Office patent applicant 4, attorney 6, number of inventions increased by amendment As shown in the attached sheet, corner seal 1 in line 7 of page 3 of the specification is corrected to ``corner seal 5.''that's all

Claims (1)

【特許請求の範囲】[Claims] 工、　硝子繊維、翼辺、カーボン＃ｉ！！紐、銅等の無
機質を熱硬化性樹脂に含有した樹脂ピストンにおいて、
該ピストン先端に嵌合凹部を形成し、該凹部にアスベス
ト系断熱板を嵌合したことを％徴とする樹脂ピストン。Engineering, glass fiber, wing edge, carbon #i! ! In resin pistons containing inorganic materials such as string and copper in thermosetting resin,
A resin piston characterized in that a fitting recess is formed at the tip of the piston, and an asbestos-based heat insulating plate is fitted into the recess.