JPS5945203B2 - Structure of pressure sensitive contact - Google Patents

Description

【発明の詳細な説明】 本発明は感圧接点の構造に関し、更に詳細に述べれば導
電性粒子を内部に均一に分散して成る導電性弾性体を用
いる感圧接点の構造に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a pressure sensitive contact, and more particularly to the structure of a pressure sensitive contact using a conductive elastic body having conductive particles uniformly dispersed therein.

従来の感圧接点の構造は、感圧導電性弾性体を直接に金
属などの電極板上に焼付け（加硫接着）するか、或は導
電性の接着剤によって接着し、一体化して構成されてい
た。The structure of conventional pressure-sensitive contacts is such that a pressure-sensitive conductive elastic body is directly baked (vulcanized adhesive) onto an electrode plate made of metal or the like, or is bonded and integrated with a conductive adhesive. was.

しかしながら、このような感圧接点の構造ではスイッチ
としての感度（導通するに要する力）が鈍くなると共に
、感度が一定しない欠点を有し、実用上大きな問題とな
っていた。However, such a pressure-sensitive contact structure has the disadvantage that the sensitivity as a switch (the force required for conduction) is low and the sensitivity is not constant, which has been a major problem in practical use.

このような欠点を改良するために、各種の工夫が行われ
た。Various efforts have been made to improve these drawbacks.

例えば、電極板の面をターレット加工などで凹凸にした
り、電極板上に細い金属線を並べたり、金網或いは金属
布を配置したものが考えられた。For example, it has been considered to make the surface of the electrode plate uneven by turret processing or the like, to arrange thin metal wires on the electrode plate, or to arrange wire mesh or metal cloth on the electrode plate.

しかしながら、このような構造の感圧接点はいずれも電
極と感圧導電性体とが電気的に充分に一体化されている
とは言いがたかった。However, in all pressure-sensitive contacts having such a structure, it cannot be said that the electrode and the pressure-sensitive conductive body are sufficiently electrically integrated.

また、付随的に、前述したような構造の従来の感圧接点
は、構造が複雑になるばかりでなく、繰返し動作によっ
て各部が摩耗して耐久性が悪いなどの欠点があった。Additionally, the conventional pressure-sensitive contacts having the structure described above not only have a complicated structure, but also have drawbacks such as poor durability due to wear of various parts due to repeated operations.

このような、従来の欠点である感圧接点における感度の
鈍化と不安定性は各種の実験および解析の結果次のよう
な原因に基づいていることが判明した。As a result of various experiments and analyses, it has been found that the conventional drawbacks of decreased sensitivity and instability in pressure sensitive contacts are due to the following causes.

一般に、感圧導電性弾性体は、第１図に示されるように
加圧力Ｐによって該弾性体中に歪が生じ、その部分が導
電性を示し、この導電化の現象には静水圧或は圧縮など
の体積歪の寄与はほとんどない。Generally, in a pressure-sensitive conductive elastic body, as shown in FIG. There is almost no contribution from volumetric strain such as compression.

従って、感圧導電性弾性体が歪んだ領域（第１図におい
て斜線で示された部分）１が導電化する。Therefore, the region 1 where the pressure-sensitive conductive elastic body is distorted (the shaded area in FIG. 1) becomes electrically conductive.

しかし、第１図に示されるような、電極板２上に感圧導
電性弾性体３が直接接着配置された従来の感圧接点では
、例えば鋼球４で感圧導電性弾性体３に力を繰返し掛け
て行（と、感圧導電性弾性体３の電極面への接着部近傍
における感圧導電性弾性体中の歪が防害され、その結果
導電化しない部分５が生じる。However, in a conventional pressure-sensitive contact in which a pressure-sensitive conductive elastic body 3 is directly bonded and arranged on an electrode plate 2 as shown in FIG. is repeatedly applied (and the strain in the pressure-sensitive conductive elastic body in the vicinity of the bonded portion of the pressure-sensitive conductive elastic body 3 to the electrode surface is prevented, and as a result, a portion 5 that does not become conductive is generated).

このような部分５が生じると加圧力Ｐを相当太き（しな
ければ導電化しないため全体としての感度（導通するに
要する力）が鈍（なる。If such a portion 5 occurs, the pressing force P must be increased considerably, otherwise conductivity will not occur, and the overall sensitivity (force required for conduction) will become dull.

これにより、前述したような感圧接点の感度の鈍化と不
安定さが発生する。This causes the pressure sensitive contact to become less sensitive and unstable as described above.

従って、本発明の目的は、従来の感圧接点の構造におけ
る導電化に要する過大化と再現性の悪さを改良した感圧
接点の構造を提供することにある。SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a pressure-sensitive contact structure that improves the conventional pressure-sensitive contact structure in which the excessive conductivity required and the poor reproducibility are overcome.

本発明の感圧接点の構造は、電極面との接着による拘束
の影響する範囲の感圧導電性弾性体の部分を、加圧力の
有無にかかわらず導電性を有する導電性弾性体で置き代
えることによって電極面近傍における感圧導電性弾性体
中の歪の発生しない部分での不導電化部分を取り除（こ
とができ、そのために、感圧導電弾性との間に導電性の
弾性体を配置したことに特徴を有する。In the structure of the pressure-sensitive contact of the present invention, the portion of the pressure-sensitive conductive elastic body in the range affected by restraint due to adhesion to the electrode surface is replaced with a conductive elastic body that has conductivity regardless of the presence or absence of pressurizing force. By doing this, it is possible to remove the non-conductive part of the pressure-sensitive conductive elastic body in the vicinity of the electrode surface where no strain occurs. It is characterized by its placement.

本発明の感圧接点の構造は本発明の好適な実施例および
図面を参照して説明する以下の記載より一層理解されよ
う。The structure of the pressure sensitive contact of the present invention will be better understood from the following description with reference to preferred embodiments of the invention and the drawings.

第２図には、本発明に係る感圧接点の構造が断片的に示
されており、本発明の感圧接点１０の構造によれば感圧
導電性弾性体１１と電極面１２との間に導電性弾性体１
３が配置されて層構成されている。FIG. 2 shows a fragmentary structure of the pressure-sensitive contact according to the present invention, and according to the structure of the pressure-sensitive contact 10 of the present invention, the gap between the pressure-sensitive conductive elastic body 11 and the electrode surface 12 is Conductive elastic body 1
3 are arranged to form a layered structure.

前記感圧導電性弾性体１１は、該弾性体に何等の力を掛
けていない時には高抵抗の絶縁性を示し、力を加えた時
にはその力を加えた部分の抵抗値が低下して導通する材
料である。The pressure-sensitive conductive elastic body 11 exhibits high-resistance insulation when no force is applied to the elastic body, and when force is applied, the resistance value of the part to which the force is applied decreases and conduction occurs. It is the material.

このような感圧導電性弾性体１１は絶縁性のゴム弾性体
又は弾性を有する合成樹脂に、銅、ニッケル、クローム
、ステンレススチール、金、銀、アルミ、ニクロム或は
炭素などの導電性粒子を均一に分散させて形成されたも
の、又は特開昭４９−１１４７９８号に開示された感圧
抵抗素などが用いられる。Such a pressure-sensitive conductive elastic body 11 is made by adding conductive particles such as copper, nickel, chrome, stainless steel, gold, silver, aluminum, nichrome, or carbon to an insulating rubber elastic body or an elastic synthetic resin. A uniformly dispersed resistor element or a pressure sensitive resistor element disclosed in JP-A-49-114798 can be used.

電極面１２は、一般に金属物体の表面であるが、特に接
点バネに用いられる燐青銅板、銅板、ステンレススチー
ル板、或はニッケル板のような板材又は印刷回路板上の
導体面であってもよ（、さらに目的によっては抵抗塗料
の塗膜面であってもよい。The electrode surface 12 is generally the surface of a metal object, but may also be a conductive surface on a printed circuit board or a plate material, such as a phosphor bronze plate, a copper plate, a stainless steel plate, or a nickel plate, used in particular for contact springs. Furthermore, depending on the purpose, it may be the surface coated with a resistive paint.

また、導電性弾性体１３は、ゴム弾性体又は弾性を有す
る合成樹脂にアセチレンブラック、エレクトロ・コンダ
クティブ・ファーネス（ＥＣＦ）、などの導電性カーボ
ンブランク、又は銀粉、ラネーニッケルなどの金属微粉
末、或いはこれらの混合物を混入した一般に周知の導電
性弾性体材料である。The conductive elastic body 13 is made of a rubber elastic body or a synthetic resin having elasticity, a conductive carbon blank such as acetylene black or electro conductive furnace (ECF), or a metal fine powder such as silver powder or Raney nickel, or a metal powder such as silver powder or Raney nickel. This is a generally known conductive elastomer material mixed with a mixture of

本発明は、第３図に示される如（、対向する電極面１２
，１２’間に導電性弾性体１３−感圧導電性弾性体１１
一導電性弾性体１３′を配置した構成でもよい。As shown in FIG.
, 12' between the conductive elastic body 13 and the pressure-sensitive conductive elastic body 11.
A structure in which one conductive elastic body 13' is arranged may also be used.

この第３図は感圧接点の構造を理解し易くするために各
層を部分的に剥離した状態で示している。In FIG. 3, each layer is shown partially peeled off to make it easier to understand the structure of the pressure sensitive contact.

本発明における感圧接点の構造は何等の接着剤を用いる
ことな（作ることができ、またその方が好ましい。The structure of the pressure sensitive contact in the present invention can be made without using any adhesive, and it is preferable to do so.

特に感圧導電性弾性体１１の層と導電性弾性体１３の層
とは加硫接着或いは加熱による相互の融着を用いること
が良く、このことは両層のゴム弾性体或いは弾性合成樹
脂の組合せを選べばほとんどの場合可能となる。In particular, the layer of pressure-sensitive conductive elastic body 11 and the layer of conductive elastic body 13 are preferably bonded together by vulcanization or heating, and this means that the rubber elastic body or elastic synthetic resin of both layers This is possible in most cases if you choose a combination.

また、導電性弾性体１３の電極面１２への接着は一般の
導電性接着剤を使用してもほとんど悪影響はない。Further, even if a general conductive adhesive is used to adhere the conductive elastic body 13 to the electrode surface 12, there is almost no adverse effect.

更に、前記感圧導電性弾性体層１１と前記導電性弾性体
層１３とは、完成後（加硫するタイプの材料にあっては
加硫後）の硬度或いは弾性率が似かよった組合せが好ま
しい。Further, it is preferable that the pressure-sensitive conductive elastic layer 11 and the conductive elastic layer 13 have similar hardness or elastic modulus after completion (after vulcanization in the case of vulcanized type materials). .

しかし、この条件は必須のものではなく、後述するよう
に各層の厚さの変化で補償することができる。However, this condition is not essential, and can be compensated for by changing the thickness of each layer, as described below.

一般には両層の厚さはほぼ同一にすると多くの場合良い
結果が得られた。In general, good results have been obtained in many cases when the thicknesses of both layers are approximately the same.

次に本発明の感圧接点の構造における実施例について説
明する。Next, embodiments of the structure of the pressure sensitive contact of the present invention will be described.

実施例 電極板として、厚さ１００μｍのステンレス板を準備し
、次いでシリコンゴムＫＥ７０１Ｂ−ｕ（信越化学製）
１００重量部にカルボニルニッケル粉（＃２５５、イン
タナショナルニッケル社製）４５０重量部と加硫剤とか
ら成る導電性弾性体組成物と、シリコンゴムＫＥ６６０
−ｕ（信越化学製）１００重量部に対し１００から２５
０メソシユの粒度のマイクロホンカーボン８０重量部と
加硫剤とから成る感圧導電性弾性体組成物とをカレンダ
ーにより２層ラミネートシートとした上、先に準備した
ステンレス板に更にラミネートして、常法により加熱加
硫した。As an example electrode plate, a stainless steel plate with a thickness of 100 μm was prepared, and then silicone rubber KE701B-u (manufactured by Shin-Etsu Chemical) was prepared.
A conductive elastic body composition consisting of 100 parts by weight, 450 parts by weight of carbonyl nickel powder (#255, manufactured by International Nickel Co., Ltd.) and a vulcanizing agent, and silicone rubber KE660.
-u (manufactured by Shin-Etsu Chemical) 100 to 25 per 100 parts by weight
A pressure-sensitive conductive elastomer composition consisting of 80 parts by weight of microphone carbon having a particle size of 0.0 mS. It was heated and vulcanized by the method.

このようにして完成された接点構造全体の厚さは０．７
ｍｍで、２種のゴム層の厚さはほぼ等しくした。The thickness of the entire contact structure completed in this way is 0.7
The thicknesses of the two rubber layers were approximately equal in mm.

次いで、前記構造の感圧接点について、ステンレス板の
面にベークライト板を貼り付けて全体を支持し、感圧導
電性ゴム弾性体の面から直径４ｍｍのステンレス球を繰
り返えし押し付けてその球とステンレス板との間の抵抗
値を測定した処、第４図に示されるような特性を得た。Next, regarding the pressure-sensitive contact having the above structure, a Bakelite plate is attached to the surface of the stainless steel plate to support the entire body, and a stainless steel ball with a diameter of 4 mm is repeatedly pressed against the surface of the pressure-sensitive conductive rubber elastic body. When the resistance value between the steel plate and the stainless steel plate was measured, the characteristics shown in FIG. 4 were obtained.

これによれば、第４図から明らかなように、感圧接点に
おける感度の鈍化が起らず、しかも不安定性が生じない
。According to this, as is clear from FIG. 4, the sensitivity of the pressure sensitive contact does not decrease, and furthermore, instability does not occur.

これを、第５図に示された特性と比較してみると、第５
図に示されたグラフは、前述の実施例において使用され
た感圧導電性弾性体を厚さ０．４ｍｍのシートに形成し
、これをニッケル板上に接着剤を用いて接着し、直径４
朋のステンレススチール球を前記感圧導電性弾性体層を
その上面から繰返し押し付け、その加圧力と、ニッケル
板−ステンレス球間の抵抗値との関係を示している。Comparing this with the characteristics shown in Figure 5, we find that
The graph shown in the figure was obtained by forming the pressure-sensitive conductive elastic body used in the above-mentioned example into a sheet with a thickness of 0.4 mm, which was adhered to a nickel plate using an adhesive, and with a diameter of 4 mm.
My friend's stainless steel ball is repeatedly pressed against the pressure-sensitive conductive elastic layer from above, and the relationship between the pressing force and the resistance value between the nickel plate and the stainless steel ball is shown.

この第５図に示されたグラフによれば、繰返し加圧によ
り感度が鈍くなり、大きな力を加えないと抵抗が下がら
ない状態が明瞭に示される。According to the graph shown in FIG. 5, it is clearly shown that the sensitivity becomes dull due to repeated pressurization and the resistance does not decrease unless a large force is applied.

このようなことから、本発明の感圧接点の構造によれば
、金属板などの電極面と感圧導電性弾性体層との間に導
電性弾性体層を配し一体化した感圧接点は感圧導電性弾
性体の弾性をそこなわず、従って感度が良（、且つ安定
した抵抗および長寿命の効果を奏する。Therefore, according to the structure of the pressure-sensitive contact of the present invention, a pressure-sensitive contact in which a conductive elastic layer is arranged between an electrode surface such as a metal plate and a pressure-sensitive conductive elastic layer is integrated. does not impair the elasticity of the pressure-sensitive conductive elastic body, thus providing good sensitivity (and stable resistance and long life).

第６図には、本発明の感圧接点の構造を可変抵抗器に用
いた場合の該抵抗器が断片的に示されている。FIG. 6 partially shows a variable resistor in which the structure of the pressure-sensitive contact of the present invention is used.

この可変抵抗器２０は、基板２１、抵抗体２２、感圧導
電性弾性体２３、導電性弾性体２４、および導電体２５
を層構成して一体化し、加圧手段２６で加圧される。This variable resistor 20 includes a substrate 21, a resistor 22, a pressure-sensitive conductive elastic body 23, a conductive elastic body 24, and a conductor 25.
are formed into layers and integrated, and then pressurized by the pressurizing means 26.

このように、感圧導電性弾性体２３と導電体２５との間
に導電性弾性体２４を配したことにより、この抵抗器の
特性が極めて良くなる。By arranging the conductive elastic body 24 between the pressure-sensitive conductive elastic body 23 and the conductor 25 in this way, the characteristics of this resistor are extremely improved.

また、感圧導電性弾性体と電極との間、或いは感圧導電
性と引出線との間に導電性弾性体を配置することもでき
る。Further, a conductive elastic body can be disposed between the pressure-sensitive conductive elastic body and the electrode, or between the pressure-sensitive conductive body and the lead wire.

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

第１図は従来の感圧接点において感圧導電性弾性体の上
面から鋼球を押し行けてその導電化の状態を示す断面図
、第２図は本発明の感圧接点の構造を示す斜視図、第３
図は本発明の別の実施例を示す感圧接点であって各層を
一部剥離して示す感圧接点の斜視図、第４図は本発明の
実施例における加圧力と抵抗値の関往を示すグラフ、第
５図は従来の感圧接点における加圧力と抵抗値の関係を
示すグラフ、第６図は本発明の感圧接点の構造を可変抵
抗器に適用した際の該可変抵抗器を断片的に示す断面図
である。 １０・・・・・・感圧接点、１１・・・・・・感圧導電
性弾性体、１２・・・・・・電極板、１３・・・・・・
導電性弾性体。Fig. 1 is a cross-sectional view showing the state of conductivity when a steel ball is pushed from the top surface of a pressure-sensitive conductive elastic body in a conventional pressure-sensitive contact, and Fig. 2 is a perspective view showing the structure of the pressure-sensitive contact of the present invention. Figure, 3rd
The figure is a perspective view of a pressure-sensitive contact showing another embodiment of the present invention, with each layer partially peeled off, and Fig. 4 shows the relationship between pressing force and resistance value in the embodiment of the present invention. FIG. 5 is a graph showing the relationship between pressing force and resistance value in a conventional pressure-sensitive contact, and FIG. 6 is a graph showing a variable resistor when the structure of the pressure-sensitive contact of the present invention is applied to the variable resistor. FIG. 10...Pressure sensitive contact, 11...Pressure sensitive conductive elastic body, 12...Electrode plate, 13...
Conductive elastic body.

Claims (1)

【特許請求の範囲】[Claims] １ 電極面と感圧導電性弾性体との間に導電性弾性体を
配置して成る感圧接点の構造。1. A pressure-sensitive contact structure in which a conductive elastic body is arranged between an electrode surface and a pressure-sensitive conductive elastic body.