JP2006078448A

JP2006078448A - Pressure sensitive sensor

Info

Publication number: JP2006078448A
Application number: JP2004265750A
Authority: JP
Inventors: Hiroshi Mizawa; 博史見澤; Hiroshi Masuko; 浩史増子
Original assignee: Mitsuba Corp
Current assignee: Mitsuba Corp
Priority date: 2004-09-13
Filing date: 2004-09-13
Publication date: 2006-03-23

Abstract

<P>PROBLEM TO BE SOLVED: To prevent erroneous detection when attached to a curve part, and to surely detect a load. <P>SOLUTION: Pressure sensitive conductive rubber 4 is filled in a tube-like skin 3, a pair of electrode wires 5a, 5b are arranged inside the pressure sensitive conductive rubber, and a cavity 6 is provided between the both electrode wires to bring one part of a conductive route into an insulated condition. An increase of the load onto the pressure sensitive sensor is detected by a high level of change in a resistance value, since an conductive elastic member reducing the resistance value in response to the increase of compression deformation is used, and since the resistance value is reduced remarkably in a prescribed compression deformation area, and the presence of the applied load is thereby detected quickly and surely. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は、感圧センサに関するものである。 The present invention relates to a pressure sensitive sensor.

従来、開閉体の挟み込みを感圧センサにより検出するものとして、例えば自動車のドアに設けられたパワーウィンドウ装置に用いたものがある。そのものでは、ウィンドウの全閉時における挟み込みを検出するべくドアサッシュに感圧センサを設け、ウィンドウの閉側端とドアサッシュとの間に物体が挟まれた場合に生じる圧力を検出して挟み込みを判定している。感圧センサは、ウェザーストリップに中空部を設け、その中空部内に一対の電極と、両電極間に介装した感圧導電性ゴムシートとにより構成されている。
実願昭５８−１８３１２５号のマイクロフィルム 2. Description of the Related Art Conventionally, there is one used for a power window device provided at a door of an automobile, for example, to detect the sandwiching of an opening / closing body by a pressure sensor. In itself, a pressure-sensitive sensor is provided in the door sash to detect pinching when the window is fully closed, and the pressure generated when an object is pinched between the closed side end of the window and the door sash is detected and pinched. Judgment. The pressure-sensitive sensor has a weather strip provided with a hollow portion, and is constituted by a pair of electrodes in the hollow portion and a pressure-sensitive conductive rubber sheet interposed between both electrodes.
Microfilm of No.58-183125

上記した感圧センサにあっては、導電性ゴムシートに絶縁突起が一体成形されており、外部圧力が加わっていない通常状態では突起により導電性ゴムシートと電極との間に絶縁空間が存在し、物体を挟み込んで外部圧力が加わると突起が潰されて導電性ゴムシートと電極とが互いに接触する。その接触により両電極同士が電気的導通状態になり、その信号により挟み込みを検出することができる。挟み込み検出に対してはウィンドウを停止して開動作に移すという制御をすることができる。 In the pressure sensor described above, the insulating protrusion is integrally formed on the conductive rubber sheet, and in the normal state where no external pressure is applied, there is an insulating space between the conductive rubber sheet and the electrode due to the protrusion. When an external pressure is applied while sandwiching an object, the protrusion is crushed and the conductive rubber sheet and the electrode come into contact with each other. Due to the contact, the two electrodes are brought into an electrically conductive state, and pinching can be detected by the signal. For pinching detection, it is possible to control to stop the window and shift to the opening operation.

開閉体には、自動車では上記ウィンドウに限らずドアやサンルーフなど種々のものがあり、また建築物ではドアなどがある。特に自動車の場合には流線型のボディ形状に合わせて開閉体の開口部の枠が直線形状ではないものがある。そのような部位に上記感圧センサを設けた場合には、曲線形状の部位に対しては感圧センサの電極がその曲線形状に沿って曲げられるため、その曲率が大きい場合には取り付け状態で電極と導電性ゴムシートとが接触してしまう虞がある。また、完全に接触していない場合でも極めて近接した状態の場合には振動などで誤検出してしまうことが考えられる。 The opening / closing body is not limited to the above window in automobiles, and includes various doors and sunroofs, and there are doors in buildings. In particular, in the case of an automobile, the frame of the opening of the opening / closing body is not a linear shape in accordance with the streamlined body shape. When the pressure sensor is provided in such a part, the electrode of the pressure sensor is bent along the curved part for a curved part. There is a possibility that the electrode and the conductive rubber sheet come into contact with each other. Further, even when the contact is not complete, it may be erroneously detected due to vibration or the like in a very close state.

上記構造の感圧センサにあっても、絶縁突起の大きさや形状を調整することにより曲率の大きな部位に対しても取り付け状態で電極と導電性ゴムシートとの接触を回避することが可能である。しかしながら、例えば絶縁突起を大きく形成した場合には物体の挟み込み時に突起が潰れにくくなり、挟み込み検出感度が鈍るという問題が生じる。 Even in the pressure-sensitive sensor having the above structure, it is possible to avoid contact between the electrode and the conductive rubber sheet in an attached state even for a portion having a large curvature by adjusting the size and shape of the insulating protrusion. . However, for example, when the insulating protrusion is formed large, the protrusion is not easily crushed when the object is sandwiched, and there is a problem that the sandwiching detection sensitivity is lowered.

このような課題を解決して、曲線部への取り付けにおいて誤検出を防止すると共に荷重を確実に検出可能とする感圧センサを実現するために本発明に於いては、互いに離間しかつ平行状態に設けられた一対の長尺の電極と、少なくとも前記両電極間に充填されかつ弾性変形する導電性弾性部材とを有し、前記導電性弾性部材は、前記導電性弾性部材に加わる荷重による圧縮変形に伴って抵抗値が増減するものであり、前記導電性弾性部材内に、所定の圧縮変形域に至るまでは抵抗値の変化が小さく、かつ当該所定の圧縮変形域にて抵抗値の変化が大きくなる抵抗変化手段が設けられているものとした。 In order to solve such a problem and to realize a pressure-sensitive sensor that can detect a load reliably while preventing erroneous detection in mounting on a curved portion, in the present invention, it is separated from each other and in a parallel state. And a conductive elastic member that is filled between and at least elastically deforms between the electrodes, and the conductive elastic member is compressed by a load applied to the conductive elastic member. The resistance value increases or decreases with deformation, and the change in resistance value is small until reaching a predetermined compression deformation region in the conductive elastic member, and the resistance value change in the predetermined compression deformation region. It is assumed that resistance changing means for increasing the resistance is provided.

特に、前記抵抗変化手段が、前記所定の圧縮変形域に至るまでは前記両電極間の導電経路の一部を遮断し得る絶縁状態であり、前記所定の圧縮変形域にて前記絶縁状態が消滅する絶縁領域を前記導電性弾性部材内に設けたものであると良く、さらに前記絶縁領域が空隙であると良い。また、絶縁領域は複数箇所設けられていると良い。さらに、開閉体による物体の挟み込みを検出するべく、前記開閉体の開閉方向端に前記一対の電極を当該開閉方向に並べるように設けて使用されると良い。 In particular, the resistance changing means is in an insulating state capable of blocking a part of the conductive path between the electrodes until reaching the predetermined compression deformation region, and the insulation state disappears in the predetermined compression deformation region. It is preferable that an insulating region to be provided is provided in the conductive elastic member, and the insulating region is preferably a gap. In addition, a plurality of insulating regions are preferably provided. Further, in order to detect the object being caught by the opening / closing body, the pair of electrodes may be provided at the opening / closing direction end of the opening / closing body so as to be arranged in the opening / closing direction.

このように本発明によれば、圧縮変形の増大に応じて抵抗値が減少する導電性弾性部材を用い、所定の圧縮変形域に至るまでは抵抗値の変化が小さく、かつ所定の圧縮変形域にて抵抗値の変化が大きくなる抵抗変化手段を設けたことから、感圧センサに対する荷重の増大を抵抗値の変化量によって検出することができるため、感圧センサの取り付け時の誤検出を防止できる上、荷重が加わったことを確実に検出することができる。 As described above, according to the present invention, the conductive elastic member whose resistance value decreases as the compression deformation increases is used, and the change in the resistance value is small until the predetermined compression deformation range is reached. Since the resistance change means that increases the resistance value at 1 is provided, an increase in the load on the pressure sensor can be detected by the amount of change in the resistance value, thus preventing erroneous detection when the pressure sensor is installed. In addition, it is possible to reliably detect that a load has been applied.

特に、導電性弾性部材内に絶縁領域を設け、圧縮変形により絶縁状態が消滅することにより、その絶縁状態消滅時に抵抗値が一気に低減するため、導電性弾性部材内に絶縁領域を設けるという簡単な構造で速やかにかつ確実な検出を行い得る感圧センサを構成し得る。さらに、絶縁領域としては空隙であって良く、導電性弾性部材内に空隙を設けるだけで上記構造を達成し得る。また、絶縁領域を任意の数だけ設定することで、所定の圧縮変形域までの抵抗値の変化率をより細かく制御することができる。 In particular, since an insulating region is provided in the conductive elastic member and the insulation state disappears due to compression deformation, the resistance value is reduced at a stroke when the insulating state disappears. Therefore, the insulating region is provided in the conductive elastic member. A pressure-sensitive sensor capable of prompt and reliable detection with the structure can be configured. Furthermore, the insulating region may be a gap, and the above structure can be achieved only by providing a gap in the conductive elastic member. In addition, by setting an arbitrary number of insulating regions, the rate of change in resistance value up to a predetermined compression deformation region can be controlled more finely.

また、一対の電極を開閉体の開閉方向に並べることにより、開閉体による挟み込み発生時には導電性弾性部材が両電極の並び方向に圧縮変形するため、両電極間の抵抗値の変化を検出することにより圧縮変形状態を監視することができ、開閉体の挟み込み検出に好適に用いることができる。 In addition, by arranging the pair of electrodes in the opening / closing direction of the opening / closing body, the conductive elastic member is compressed and deformed in the alignment direction of both electrodes when pinching occurs by the opening / closing body, so that a change in resistance value between both electrodes can be detected. Thus, the compression deformation state can be monitored, and it can be suitably used for detecting pinching of the opening / closing body.

以下、本発明の実施の形態を、図面を参照しながら説明する。図１は本発明が適用された自動車用スライドドアの閉側縁部を示す要部側面図である。図において、開閉体としてのスライドドア１の閉側端の縁部に、その縁部に沿って上下方向に延在する感圧センサ２が取り付けられている。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a side view of an essential part showing a closed side edge part of an automobile sliding door to which the present invention is applied. In the figure, a pressure sensitive sensor 2 extending in the vertical direction along the edge is attached to the edge of the closed side end of the slide door 1 as an opening / closing body.

感圧センサ２は、図２に示されるように、弾性材からなるチューブ状の外皮３と、その中に内蔵された導電性弾性部材としての感圧導電性ゴム４と、感圧導電性ゴム４の中に埋設されかつドア１の開閉方向に互いに所定の間隔をあけて配置された一対の電極としての各電極線５ａ・５ｂと、両電極線５ａ・５ｂ間の導通経路の一部を絶縁状態にするべく感圧導電性ゴム４内に発泡状態に形成した絶縁領域としての２つの空隙６とにより構成されている。なお、感圧センサ２のドア１への取り付けは、上記弾性材からなる外皮３に一体的に成形したドア係止部によって行ったり、接着やねじ等の固定手段によって行われたりする。 As shown in FIG. 2, the pressure-sensitive sensor 2 includes a tube-shaped outer skin 3 made of an elastic material, a pressure-sensitive conductive rubber 4 as a conductive elastic member incorporated therein, and a pressure-sensitive conductive rubber. 4 and a part of the conduction path between the electrode lines 5a and 5b as a pair of electrodes embedded in the opening and closing direction of the door 1 with a predetermined interval between them. The pressure-sensitive conductive rubber 4 is composed of two voids 6 as insulating regions formed in a foamed state so as to be in an insulating state. The pressure sensor 2 is attached to the door 1 by a door locking portion formed integrally with the outer skin 3 made of the elastic material, or by fixing means such as adhesion or screws.

感圧導電性ゴム４は、ゴムの中に導電粒子を均一に分布させて、圧力により圧縮すると導電粒子同士の接触数が増えて抵抗値が下がるものである。空隙６は、各電極線５ａ・５ｂの導電経路の一部を絶縁状態にするように、図２の断面図において両電極線５ａ・５ｂ間を結ぶ直線の導電経路となる部分の両脇に、すなわちドア開閉方向に直交する方向に並んで２つ配設され手いる。空隙６の形状は、図示例ではドア開閉方向を短軸とする楕円状に形成されている。なお、空隙６の位置や形状、数は図示例に限定されるものではなく、位置は外皮３の内側で感圧導電性ゴム４に設けられていれば良く、また、形状は円形やその他の断面形状であって良く、さらに、その数は感圧センサ２の太さや取り付け位置の形状等に合わせて任意に設定可能である。 In the pressure-sensitive conductive rubber 4, when conductive particles are uniformly distributed in the rubber and compressed by pressure, the number of contacts between the conductive particles increases and the resistance value decreases. The gap 6 is formed on both sides of a portion that becomes a straight conductive path connecting the electrode lines 5a and 5b in the cross-sectional view of FIG. 2 so that a part of the conductive path of the electrode lines 5a and 5b is insulated. That is, two are arranged side by side in a direction orthogonal to the door opening / closing direction. In the illustrated example, the gap 6 is formed in an elliptical shape with the door opening / closing direction as the short axis. Note that the position, shape, and number of the gaps 6 are not limited to the illustrated example, and the position may be provided on the pressure-sensitive conductive rubber 4 inside the outer skin 3, and the shape may be circular or other It may be a cross-sectional shape, and the number thereof can be arbitrarily set according to the thickness of the pressure-sensitive sensor 2 or the shape of the mounting position.

図３に上記感圧センサ２を用いた挟み込み判定回路７のブロック図を示す。図において、各電極５ａ・５ｂが抵抗−電圧変換回路８に接続されており、抵抗−電圧変換回路８の出力ポートが比較器９の信号電圧入力ポートに接続されている。比較器９の基準電圧ポートには閾値設定回路１０から出力される閾値電圧Ｖｄが入力する。比較器９では、抵抗−電圧変換回路８からのセンサ信号電圧Ｖｓと閾値電圧Ｖｄとを比較し、センサ信号電圧Ｖｓが閾値電圧Ｖｄ以上になったら所定の電圧を出力する。比較器９からの出力電圧に応じてスイッチ回路１１からスイッチング信号（オン／オフ）が制御回路１２（図１参照）に出力される。制御回路１２は、通常の自動開閉や挟み込み回避などの制御をドア１に連結された駆動モータ１３に対して行う。 FIG. 3 shows a block diagram of the pinching determination circuit 7 using the pressure sensor 2. In the figure, the electrodes 5 a and 5 b are connected to the resistance-voltage conversion circuit 8, and the output port of the resistance-voltage conversion circuit 8 is connected to the signal voltage input port of the comparator 9. The threshold voltage Vd output from the threshold setting circuit 10 is input to the reference voltage port of the comparator 9. The comparator 9 compares the sensor signal voltage Vs from the resistance-voltage conversion circuit 8 with the threshold voltage Vd, and outputs a predetermined voltage when the sensor signal voltage Vs becomes equal to or higher than the threshold voltage Vd. A switching signal (ON / OFF) is output from the switch circuit 11 to the control circuit 12 (see FIG. 1) in accordance with the output voltage from the comparator 9. The control circuit 12 performs control such as normal automatic opening / closing and avoiding pinching on the drive motor 13 connected to the door 1.

次に、上記感圧センサ２を用いた挟み込み判定要領について図４を参照して以下に示す。物体による荷重を受けていない（非挟み込み状態）場合には感圧センサ２は図２に示されるように内部の感圧導電性ゴム４の弾性復元力により円形断面形状に保持されている。その状態での両電極線５ａ・５ｂ間の導電率は、両者間に存在する感圧導電性ゴム４の導電経路の抵抗値により決まる。 Next, the pinching determination procedure using the pressure sensor 2 will be described below with reference to FIG. When no load is applied by the object (non-pinching state), the pressure-sensitive sensor 2 is held in a circular cross-sectional shape by the elastic restoring force of the pressure-sensitive conductive rubber 4 inside as shown in FIG. The electrical conductivity between the electrode lines 5a and 5b in this state is determined by the resistance value of the conductive path of the pressure-sensitive conductive rubber 4 existing between them.

非挟み込み状態では感圧導電性ゴム４が最も膨張している状態であり、図２に示されるように両電極線５ａ・５ｂ間に２つの空隙６による大きな絶縁領域が存在している。その状態での両電極線５ａ・５ｂ間の導電経路は、両電極線５ａ，５ｂとを最短距離で結んだ経路上に導電性ゴムが存在する両空隙６間の直線的な部分と、各空隙６を迂回する２ヶ所の各湾曲的な部分とになる。したがって、空隙６のないもの（外皮３内に感圧導電性ゴムが完全に充填されているもの）に比べて両電極線５ａ・５ｂ間の抵抗値が大きく、図５に示される第１の変化域Ａ側に示されるように抵抗値が高く保持される。 In the unpinched state, the pressure-sensitive conductive rubber 4 is in the most expanded state, and there is a large insulating region due to the two gaps 6 between the electrode wires 5a and 5b as shown in FIG. In this state, the conductive path between the electrode lines 5a and 5b includes a linear portion between the gaps 6 where the conductive rubber exists on the path connecting the electrode lines 5a and 5b at the shortest distance, The two curved portions that bypass the gap 6 are formed. Accordingly, the resistance value between the electrode wires 5a and 5b is larger than that without the gap 6 (the pressure-sensitive conductive rubber is completely filled in the outer skin 3), and the first resistance shown in FIG. As shown on the change area A side, the resistance value is kept high.

挟み込み初期など挟み込み方向に物体１４による弱い荷重を感圧センサ２が受けると、空隙６は図２に示される円形断面形状の状態から図４に示されるような空隙６が潰された状態の範囲で変化する。図４の状態では空隙６による絶縁状態が消滅するため感圧導電性ゴム４の空隙６部分も導通状態となり、所定の圧縮変形域としての図５に示される第２の変化域Ｂにて両電極線５ａ・５ｂ間の導通抵抗値が一気に減少する。なお、挟み込み方向へ感圧導電性ゴム４が圧縮変形するため、その変形量に応じても導通抵抗値が減少する。 When the pressure-sensitive sensor 2 receives a weak load from the object 14 in the clamping direction such as in the initial stage of clamping, the gap 6 ranges from the circular cross-sectional shape shown in FIG. 2 to the state where the gap 6 is crushed as shown in FIG. It changes with. In the state of FIG. 4, the insulating state due to the gap 6 disappears, so that the gap 6 portion of the pressure-sensitive conductive rubber 4 is also in a conductive state, and both the two change areas B shown in FIG. The conduction resistance value between the electrode wires 5a and 5b decreases at a stretch. In addition, since the pressure-sensitive conductive rubber 4 is compressively deformed in the sandwiching direction, the conduction resistance value is reduced even in accordance with the amount of deformation.

さらに挟み込み（荷重）が増していくと、図６に示されるように感圧センサ２がより一層潰される。その挟み込み方向の荷重の増大に応じて感圧導電性ゴム４がより大きく圧縮変形するため、その変形量（荷重）に応じて図５の第３の変化域Ｃに示されるように抵抗値が漸減する。 As the pinching (load) further increases, the pressure-sensitive sensor 2 is further crushed as shown in FIG. Since the pressure-sensitive conductive rubber 4 is further compressed and deformed as the load in the sandwiching direction increases, the resistance value is changed according to the deformation amount (load) as shown in the third change region C in FIG. Decrease gradually.

このように感圧センサ２に加わる荷重に応じて第２の変化域Ｂで抵抗値が大きく変化するため、その変化を検出するための閾値Ｒｄを第２の変化域Ｂ内の任意の所に設定することにより、第２の変化域Ｂを通過する抵抗変化を検出することができる。特に空隙６が潰れて両電極線５ａ・５ｂ間に空隙６による絶縁空間が存在しなくなった状態を判別し得るように閾値Ｒｄを設定することにより、空隙６が押し潰されていない状態（図２）から潰された状態に感圧センサ２が圧縮変形した（図４）ことを検出し得る。 As described above, since the resistance value greatly changes in the second change region B according to the load applied to the pressure-sensitive sensor 2, the threshold value Rd for detecting the change is set at an arbitrary place in the second change region B. By setting, it is possible to detect a resistance change passing through the second change region B. In particular, the gap 6 is not crushed by setting the threshold value Rd so that it is possible to determine the state in which the gap 6 is crushed and the insulating space due to the gap 6 no longer exists between the electrode lines 5a and 5b (see FIG. It is possible to detect that the pressure-sensitive sensor 2 has been compressed and deformed in the state crushed from 2) (FIG. 4).

両電極線５ａ・５ｂ間の抵抗値が上記閾値Ｒｄになった時の抵抗−電圧変換回路８の出力Ｖｓが閾値電圧Ｖｄとなるように閾値設定回路１０の出力を設定する。それにより、抵抗−電圧変換回路８の出力Ｖｓと閾値電圧Ｖｄとを比較器９で比較し、その結果をスイッチ回路１１のオン／オフ信号で出力する。すなわち、両電極５ａ・５ｂ間の抵抗値が閾値Ｒｄよりも低下したら、挟み込み判定出力としてのスイッチ回路１１の出力がオフからオンに切り替わり、スイッチ回路１１の出力がオンになったら挟み込みが生じたと判定することができる。 The output of the threshold setting circuit 10 is set so that the output Vs of the resistance-voltage conversion circuit 8 becomes the threshold voltage Vd when the resistance value between the electrode lines 5a and 5b becomes the threshold Rd. Thereby, the output Vs of the resistance-voltage conversion circuit 8 and the threshold voltage Vd are compared by the comparator 9, and the result is output by the on / off signal of the switch circuit 11. That is, when the resistance value between the electrodes 5a and 5b is lower than the threshold value Rd, the output of the switch circuit 11 as the pinch determination output is switched from OFF to ON, and pinch occurs when the output of the switch circuit 11 is ON. Can be determined.

なお、スイッチ回路１１のオン出力を制御回路１２で受信したら、制御回路１２ではドア１を停止して反転させるようにモータ１３に対する制御を行う。この反転制御は、上記したように空隙６が潰れた時点で行うことができる。空隙６が完全に潰れた後における感圧導電性ゴム４の圧縮変形による反発力は圧縮変形の進行に伴って増大することになるが、それに対して空隙６が潰れるまでは感圧センサ２の圧縮変形による反発力はそれ程大きくないため、挟み込み判定において感圧センサ２の大きな反発力が生じた状態で挟み込みを判定することになることを回避できる。また、上記閾値Ｒｄを横切る場合には荷重のわずかな増加に対して抵抗値が大きく変化するため、荷重が大きくなる前に素早く挟み込み判定を行うことができるなど、挟み込まれた物体１４が柔らかい場合に挟み込み判定までに荷重が増大し過ぎて物体１４を傷付けてしまうことを防止し得る。 When the control circuit 12 receives the ON output of the switch circuit 11, the control circuit 12 controls the motor 13 so that the door 1 is stopped and reversed. This inversion control can be performed when the gap 6 is crushed as described above. The repulsive force due to the compression deformation of the pressure-sensitive conductive rubber 4 after the gap 6 is completely crushed increases with the progress of the compression deformation. On the other hand, until the gap 6 is crushed, the pressure sensor 2 Since the repulsive force due to the compression deformation is not so large, it is possible to avoid pinching being determined in a state where a large repulsive force of the pressure-sensitive sensor 2 is generated in the pinching determination. In addition, when the threshold Rd is crossed, the resistance value greatly changes with a slight increase in the load. Therefore, when the object 14 is soft, for example, it is possible to quickly determine the object before the load increases. It is possible to prevent the load from being increased excessively until the object is caught and the object 14 is damaged.

また、本発明による感圧センサ２にあっては、感圧導電性ゴム４の中に空隙６を設けたことから、空隙６が潰れて空隙６の内面同士が接触するまで空隙６による絶縁状態が保持される。図示例のように感圧センサ２をひも状に形成してドア１の縁部の形状に沿わせて取り付けた場合に、その縁部の形状がボディの流線型などの影響を受けて湾曲状となっている場合、その湾曲部において感圧センサ２が大きく曲げられることになる。そのような場合でも、例えば図７（ａ）・（ｃ）に示されるように、湾曲部の曲率が小さい位置（VIIc−VIIc線の部分）では空隙６が初期状態に近い状態で保たれているが、図７（ａ）・（ｂ）に示すように中央の曲率が大きい位置（VIIb−VIIb線の部分）では、空隙６が変形しているものの隙間の存在によってその部分の絶縁性が保持されるため、その状態から空隙６が潰れて感圧導電性ゴム４がその圧縮変形量が大きくなるような荷重を受けた場合に両電極５ａ・５ｂ間の抵抗減少によりその荷重を検出することができる。 Further, in the pressure-sensitive sensor 2 according to the present invention, since the gap 6 is provided in the pressure-sensitive conductive rubber 4, the insulation state by the gap 6 is maintained until the gap 6 is crushed and the inner surfaces of the gap 6 are in contact with each other. Is retained. When the pressure-sensitive sensor 2 is formed in a string shape and attached along the shape of the edge of the door 1 as in the illustrated example, the shape of the edge is curved due to the influence of the streamline shape of the body. If so, the pressure-sensitive sensor 2 is greatly bent at the curved portion. Even in such a case, for example, as shown in FIGS. 7A and 7C, at the position where the curvature of the bending portion is small (the portion of the line VIIc-VIIc), the gap 6 is maintained in a state close to the initial state. However, as shown in FIGS. 7A and 7B, at the position where the curvature at the center is large (portion VIIb-VIIb), although the gap 6 is deformed, the insulation of that portion is caused by the presence of a gap. Therefore, when the pressure-sensitive conductive rubber 4 receives a load from which the pressure-sensitive conductive rubber 4 is compressed and the amount of compressive deformation increases, the load is detected by reducing the resistance between the electrodes 5a and 5b. be able to.

上記したように感圧導電性ゴム４内に空隙６が部分的に配置されていることから、残りの部分により空隙６が潰されるようになる曲げに対してある程度の強度が得られる。図示例のように感圧導電性ゴム４の空隙６を設けられた部分が両電極線５ａ・５ｂ間を直線的に結ぶ部分を含む橋脚状に形成されていることにより、上記曲線部に取り付けただけで空隙６が潰されることを好適に防止し得る。また、空隙６の存在により感圧センサ２が曲がり易くなると共に、上記したように空隙６が潰されるまでにある程度の強度が得られるため、曲線部に対する追従性が良くなって取り付け許容度が大となり、種々の形状に取り付け可能になる。 Since the gap 6 is partially disposed in the pressure-sensitive conductive rubber 4 as described above, a certain degree of strength can be obtained with respect to the bending in which the gap 6 is crushed by the remaining part. As shown in the example, the portion provided with the gap 6 of the pressure-sensitive conductive rubber 4 is formed in a bridge pier shape including a portion that linearly connects the two electrode wires 5a and 5b, so that it is attached to the curved portion. It can prevent suitably that the space | gap 6 is crushed only by. Further, the presence of the gap 6 makes the pressure-sensitive sensor 2 easy to bend, and as described above, a certain degree of strength is obtained before the gap 6 is crushed. It becomes possible to attach to various shapes.

なお、図示例では絶縁領域として空隙６を設けたが、空気による絶縁に限定されず、何らかの電気的な抵抗体を空隙６に相当する孔内に受容するようにしても良い。例えば、荷重が加わったときに抵抗率が変化するような液体を孔内に封入しても良い。また、荷重が加わったときにその部位に存在する抵抗体が荷重の加わっていない部位に移動するように構成することもできる。さらに、孔内に絶縁材を受容する場合には、孔が潰れた場合に孔の内面の少なくとも一部が接触し抵抗値の大きな変化が生じるようにするべく、絶縁材の断面積を孔よりは小さくしておいても良い。 In the illustrated example, the gap 6 is provided as the insulating region. However, the present invention is not limited to the insulation by air, and any electrical resistor may be received in the hole corresponding to the gap 6. For example, a liquid whose resistivity changes when a load is applied may be enclosed in the hole. In addition, when a load is applied, the resistor present in the part can be moved to a part where the load is not applied. In addition, when an insulating material is received in the hole, the cross-sectional area of the insulating material should be less than that of the hole so that when the hole is crushed, at least a part of the inner surface of the hole comes into contact and a large change in resistance occurs. Can be kept small.

本発明にかかる感圧センサは、荷重を受けた場合の圧縮変形を両電極間の大きな抵抗変化により検出することができ、物体の接触を検出するもの、特に開閉体の挟み込み検出装置等として有用である。 The pressure-sensitive sensor according to the present invention can detect compressive deformation when subjected to a load by a large resistance change between both electrodes, and is useful as a device for detecting contact of an object, in particular, a pinch detection device for an opening / closing body. It is.

本発明が適用された自動車用スライドドアの閉側縁部を示す要部側面図である。It is a principal part side view which shows the closed side edge part of the sliding door for motor vehicles to which this invention was applied. 図１の矢印II−II線に沿って見た感圧センサの断面図である。It is sectional drawing of the pressure-sensitive sensor seen along the arrow II-II line | wire of FIG. 感圧センサによる検出回路を示すブロック図である。It is a block diagram which shows the detection circuit by a pressure sensor. 感圧センサの変形初期の状態を示す図２に対応する図である。It is a figure corresponding to FIG. 2 which shows the state of a deformation | transformation initial stage of a pressure sensor. 荷重に対する抵抗値変化及びスイッチ回路の出力波形を示す図である。It is a figure which shows the resistance value change with respect to a load, and the output waveform of a switch circuit. 挟み込み検出状態を示す図２に対応する図である。FIG. 3 is a diagram corresponding to FIG. 2 showing a pinching detection state. （ａ）は図１の矢印VII−VII線付近を拡大して示す感圧センサの断面図であり、（ｂ）は（ａ）のVIIb−VIIb線に沿ってみた感圧センサの断面図であり、（ｃ）は（ａ）のVIIc−VIIc線に沿って見た感圧センサの断面図である。(A) is sectional drawing of the pressure-sensitive sensor which expands and shows the arrow VII-VII line vicinity of FIG. 1, (b) is sectional drawing of the pressure-sensitive sensor seen along the VIIb-VIIb line of (a). FIG. 6C is a cross-sectional view of the pressure-sensitive sensor viewed along the line VIIc-VIIc in FIG.

符号の説明Explanation of symbols

１ドア
２感圧センサ
４感圧導電性ゴム
５ａ・５ｂ電極線
６空隙
７判定回路
１２制御回路
DESCRIPTION OF SYMBOLS 1 Door 2 Pressure sensor 4 Pressure sensitive conductive rubber 5a * 5b Electrode wire 6 Air gap 7 Judgment circuit 12 Control circuit

Claims

互いに離間しかつ平行状態に設けられた一対の長尺の電極と、少なくとも前記両電極間に充填されかつ弾性変形する導電性弾性部材とを有し、
前記導電性弾性部材は、前記導電性弾性部材に加わる荷重による圧縮変形に伴って抵抗値が増減するものであり、
前記導電性弾性部材内に、所定の圧縮変形域に至るまでは抵抗値の変化が小さく、かつ当該所定の圧縮変形域にて抵抗値の変化が大きくなる抵抗変化手段が設けられていることを特徴とする感圧センサ。 A pair of long electrodes that are spaced apart from each other and provided in parallel, and a conductive elastic member that is at least filled between the electrodes and elastically deformed;
The conductive elastic member has a resistance value that increases or decreases with compressive deformation due to a load applied to the conductive elastic member.
Resistance change means is provided in the conductive elastic member so that the change of the resistance value is small until reaching the predetermined compression deformation region and the change of the resistance value is large in the predetermined compression deformation region. Characteristic pressure sensor.

前記抵抗変化手段が、前記所定の圧縮変形域に至るまでは前記両電極間の導電経路の一部を遮断し得る絶縁状態であり、前記所定の圧縮変形域にて前記絶縁状態が消滅する絶縁領域を前記導電性弾性部材内に設けたものであることを特徴とする請求項１に記載の感圧センサ。 Insulation state in which the resistance changing means can block a part of the conductive path between the two electrodes until reaching the predetermined compression deformation region, and the insulation state disappears in the predetermined compression deformation region. The pressure-sensitive sensor according to claim 1, wherein a region is provided in the conductive elastic member.

前記絶縁領域が空隙であることを特徴とする請求項２に記載の感圧センサ。 The pressure-sensitive sensor according to claim 2, wherein the insulating region is a gap.

前記絶縁領域は複数箇所に設けられていることを特徴とする請求項１乃至請求項３のいずれかに記載の感圧センサ。 The pressure-sensitive sensor according to claim 1, wherein the insulating region is provided at a plurality of locations.

開閉体による物体の挟み込みを検出するべく、前記開閉体の開閉方向端に前記一対の電極を当該開閉方向に並べるように設けて使用されることを特徴とする請求項１乃至請求項４のいずれかに記載の感圧センサ。
5. The device according to claim 1, wherein the pair of electrodes are provided so as to be arranged in the opening / closing direction at an end of the opening / closing body in order to detect the object being caught by the opening / closing body. A pressure-sensitive sensor according to claim 1.