Method for manufacturing a sensor supporting member

An opening and closing apparatus is disclosed. The opening and closing apparatus includes an opening and closing body, a capacitance sensor, and a sensor support member. The dynamic capacitance sensor has a conductive sensor electrode, and outputs a detection signal that corresponds to the capacitance between the sensor electrode and a conductive object located close to the sensor electrode. The sensor support member includes a guard electrode, a holding portion, an attaching portion, and a conductive reinforcing member. The reinforcing member is embedded in the main body. At least a part of the reinforcing member is embedded in the guard electrode such that the reinforcing member is integrated with the guard electrode.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from Japanese application 2008-141472, filed on May 29, 2008, incorporated by reference herein in its entirety.

FIELD OF THE INVENTION

The present invention relates to an opening and closing apparatus that opens and closes an opening with an opening and closing body actuated by drive force, for example, of a motor, and to a method for manufacturing a sensor supporting member for fixing a capacitance sensor that detects whether an object exists between the opening and closing body and the edge of the door opening.

BACKGROUND OF THE INVENTION

Conventionally, some vehicles such as automobiles are equipped with a power sliding door apparatus (opening and closing apparatus), which opens and closes a door opening on a side on a side with a door panel (an opening and closing body) slid by drive force, for example, of a motor. Such a power sliding door apparatus has a function for preventing an object from being caught between the door panel and the edge of the door opening.

For example, Japanese Laid-Open Patent Publication No. 2006-300924 discloses a power sliding door apparatus that includes a capacitance sensor (sensor body) with a sensor electrode. The capacitance sensor is fixed to the front end of the door panel with a sensor support member. The capacitance sensor is electrically connected to a capacitance detector. The capacitance detector detects changes in the capacitance of the capacitance sensor using the sensor electrode. In this power sliding door apparatus, changes of the capacitance of the capacitance sensor is detected by using the sensor electrode. When an object it is detected that an object is close to the front end of the door panel based on the detected capacitance changes, the motor is controlled to stop the sliding of the door panel.

Changes in the capacitance of the capacitance sensor detected by using the sensor electrode is subtle when an object has approached the front end of the door panel. Therefore, when the capacitance of the capacitance sensor detected by using the sensor electrode is changed due to disturbance, the existence of an object can be erroneously detected. Factors of disturbance include changes in the stray capacity caused by wiring in the vehicle, changes in the impedance of the door panel, and changes in the electrical potential of the door panel caused by electrification. Therefore, to prevent erroneous detection caused by disturbance, the sensor support member of the power sliding door apparatus of the above publication includes a guard electrode, which is maintained at the same voltage as the sensor electrode. The guard electrode is made of conductive resin material, and is integrally formed with insulating resin material forming the sensor support member. The guard electrode is in contact with a reinforcing member that is made of a conductive metal plate embedded in the insulating resin material.

Although the above publication describes that the sensor support member is formed by extrusion molding, no specific method for manufacturing is disclosed. When manufacturing the sensor support member having the guard electrode by the extrusion molding, two different resin materials, which are insulating resin material and conductive resin material, need to be integrated and formed into desired shapes. This is expected to complicate the manufacture of the sensor support member. Thus, there is a demand for a method that facilitates the manufacture of sensor support members.

SUMMARY OF THE INVENTION

Accordingly, it is an objective of the present invention to provide an opening and closing apparatus having a sensor support member, which has a guard electrode made of a conductive resin material and is easy to manufacture, and a method for manufacturing the sensor support member.

To achieve the foregoing objective and in accordance with a first aspect of the present invention, an opening and closing apparatus including an opening and closing body, a drive portion, a capacitance sensor, a sensor support member, and a detection section is provided. The opening and closing body is used for opening and closing an opening formed in an opened and closed body. The drive portion actuates the opening and closing body. The capacitance sensor has a conductive sensor electrode, and outputs a detection signal that corresponds to the capacitance between the sensor electrode and a conductive object located close to the sensor electrode. The sensor support member fixes the capacitance sensor either to a closing end of the opening and closing body that is on the leading side when the opening and closing body is being closed or to an edge of the opening. The sensor support member includes a guard electrode, a holding portion, an attaching portion, and a conductive reinforcing member. The guard electrode is made of conductive resin material. The voltage of the guard electrode is maintained either at the same level as the voltage of the sensor electrode or at a level of a constant ratio relative to the voltage of the sensor electrode. The holding portion holds the capacitance sensor. The attaching portion has a main body made of insulating resin material, and fixes the holding portion either to the closing end or to the edge of the opening. The conductive reinforcing member is embedded in the main body. At least a part of the reinforcing member is embedded in the guard electrode such that the reinforcing member is integrated with the guard electrode. The detecting section detects the object located close to the capacitance sensor based on the detection signal output from the capacitance sensor.

In accordance with a second aspect of the present invention, a method for manufacturing a sensor support member is provided. The sensor support member fixes a capacitance sensor, which detects a conductive object existing between an opening and closing body actuated by a drive portion and an edge of an opening, either to a closing end of the opening and closing body that is on the leading side when the opening and closing body is being closed or to the edge of the opening. The capacitance sensor includes a conductive sensor electrode, and outputs a detection signal that corresponds to the capacitance between the sensor electrode and a conductive object located close to the sensor electrode. The sensor support member includes a guard electrode made of conductive resin material. The voltage of the guard electrode is maintained either at the same level as the voltage of the sensor electrode or at a level of a constant ratio relative to the voltage of the sensor electrode. The manufacturing method includes: embedding at least a part of a conductive reinforcing member in the guard electrode, thereby integrating the reinforcing member with the guard electrode; and embedding the reinforcing member in insulating resin material that forms the sensor support member.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Hereinafter, a preferred embodiment according to the present invention will be described.

FIG. 1illustrates a vehicle2equipped with an opening and closing apparatus, which is a power sliding door apparatus1. As shown inFIG. 1, the vehicle2includes an opened and closed body made of a conductive metal material, which is a vehicle body3. A rectangular opening, which is a door opening4, is formed in the left side of the vehicle body3. The door opening4is opened and closed with a rear door panel5(opening and closing body) formed of conductive metal material. The rear door panel5has a rectangular shape in accordance with the shape of the door opening4.

The rear door panel5is attached to the vehicle body3with a drive portion, which is an actuating mechanism11, so as to be movable substantially in the front-rear direction relative to the vehicle body3. A lock mechanism (not shown), for example, a latch is provided in the rear door panel5. The lock mechanism immovably locks the rear door panel5with respect to the vehicle body3when the rear door panel5closes the door opening4, that is, when the rear door panel5is at the fully closed position. A half latch detecting portion (not shown), which is composed, for example, of a limit switch, is provided in the vicinity of the lock mechanism. The half latch detecting portion outputs a half latch detection signal to a control circuit device91(seeFIG. 2) of the power sliding door apparatus1if the lock mechanism is in a half latched state.

The actuating mechanism11is composed of an upper rail12, a lower rail13, and a center rail14provided in the vehicle body3, and an upper arm15, a lower arm16, and a center arm17provided in the rear door panel5.

The upper rail12and the lower rail13are respectively provided in an upper portion and a lower portion of the door opening4in the vehicle2, and extend along front-rear direction of the vehicle2. The center rail14is provided in a substantially center in the up-down direction of a part rearward of the door opening4in the vehicle2, and extends along the front-rear direction of the vehicle2. Each of the rails12to14is formed in such a manner as to extend linearly along the front-rear direction of the vehicle2. A front end of each of the rails12to14is curved toward the interior of the passenger compartment.

The arms15to17are respectively fixed to positions of an upper portion, a lower portion, and a center portion in a side surface facing the interior of the passenger compartment of the rear door panel5. The upper arm15is coupled to the upper rail12. The lower arm16is coupled to the lower rail13. The center arm17is coupled to the center rail14. The arms15to17are respectively guided by the rails12to14so as to be movable along the front-rear direction of the vehicle2.

The lower arm16is moved forward and rearward by a drive mechanism21. More specifically, the drive mechanism21includes a drive pulley22and a plurality of driven pulleys23at positions closer to the passenger compartment than the lower rail13. The pulleys22,23are each rotatable about a shaft extending in the up-down direction of the vehicle2. An endless belt24is wound around the drive pulley22and the driven pulleys23. A distal end portion of the lower arm16is fixed to the endless belt24. As shown inFIGS. 1 and 2, the drive mechanism21includes a slide actuator25connected to the drive pulley22. The slide actuator25is located in the passenger compartment. The slide actuator25is provided with a slide motor26and a transmission mechanism (not shown), which reduces the speed of rotation of the slide motor26and transmits the rotation to the drive pulley22. When the slide motor26is driven, the drive pulley22is rotated. Then, the endless belt24is rotated to move the lower arm forward and rearward. The rear door panel5is thus slid forward and rearward.

A position detector27for detecting rotation of the slide motor26is located in the slide actuator25. The position detector27includes, for example, a permanent magnet and a Hall IC (not shown). The permanent magnet rotates integrally with the rotary shaft (not shown) of the slide motor26or with the reducing gear (not shown) of the speed reducing mechanism, and the Hall IC is arranged to face the permanent magnet. The Hall IC outputs, as position detection signals, pulse signals in accordance with changes in the magnetic field of the permanent magnet caused by rotation of the permanent magnet.

The drive mechanism21includes a closure actuator28located in the rear door panel5. The closure actuator28is provided with a closure motor29and a speed reducing mechanism (not shown), which reduces the speed of rotation of the closure motor29. When the closure motor29is driven, the rear door panel5is moved to a position where the rear door panel5is lockable by the lock mechanism.

The power sliding door apparatus1also includes an operation switch31electrically connected to the control circuit device91. When an occupant of the vehicle2operates the operation switch31to open the door opening4, the operation switch31outputs to the control circuit device91an open signal, which is a command for sliding the rear door panel5so as to open the door opening4. On the other hand, when the occupant of the vehicle2operates the operation switch31to close the door opening4, the operation switch31outputs to the control circuit device91a close signal, which is a command for sliding the rear door panel5so as to close the door opening4. The operation switch31is provided in a predetermined portion (for example, in the dashboard) within the passenger compartment, on a side of the rear door panel5inside the passenger compartment, or in a portable item (not shown) carried together with the ignition key.

The power sliding door apparatus1has an object detecting section41(detecting section) for detecting an object that is close to or contacts a front end5aof the rear door panel5. The object detecting section41includes a sensor portion42(capacitance sensor), an ON-OFF detector43, and a capacitance detecting circuit44.

The sensor portion42is provided along the leading end of the rear door panel5when the rear door panel5is being closed, that is, along the front end5aof the rear door panel5. As shown inFIG. 3A, the sensor portion42includes a cable-like sensor body45and a sensor support member46for fixing the sensor body45to the door panel5.

As shown inFIG. 3B, the sensor body45has an elongated shape. An insulating layer51is proved at a center portion of the sensor body45. The insulating layer51is substantially cylindrical. The insulating layer51is formed of insulating material that has insulation properties and restoring characteristics and can be elastically deformed. The insulating layer51is formed, for example, of soft synthetic resin or rubber. A separation hole51ais formed in a radially center portion of the insulating layer51. The separation hole51aextends in the longitudinal direction of the insulating layer51. The separation hole51ahas four separation recesses51bto51e, which form a cross in the cross section along the direction perpendicular to the longitudinal direction of the insulating layer51are arranged at equal angular intervals. The separation recesses51bto51eare connected at a radial center of the insulating layer51and extend radially outward. In the separation hole51a,the four separation recesses51bto51eeach extend helically along the longitudinal direction of the insulating layer51.

Inside the insulating layer51, first to fourth electrode wires52ato52dare supported by the insulating layer51. The electrode wires52ato52deach include a flexible core electrode53and a cylindrical conductive coating layer54. The core electrode53is formed by twining conductive fine lines, and coated by the conductive coating layer54. The conductive coating layer54has conductivity and elasticity. Each of the electrode wires52ato52dis located between an adjacent pair of the separation recesses51bto51e, and extends helically along the separation recesses51bto51e. More than half the circumferential surface of each of the electrode wires52ato52dis embedded in the insulating layer51.

A conductive sensor electrode56is provided on the outer circumference of the insulating layer51. The sensor electrode56is cylindrical and coats the insulating layer51from one end to the other end in the longitudinal direction. For example, the sensor electrode56is formed to be cylindrical by winding metallic lines about the outer circumference of the insulating layer51. The outer circumference of the sensor electrode56is coated by a cylindrical outer layer57. The outer layer57is formed of insulating material and can be elastically deformed. The length of the outer layer57in the longitudinal direction is equal to the length of the insulating layer51in the longitudinal direction.

As shown inFIG. 2, the first electrode wire52aand the third electrode wire52care electrically connected to each other at first ends in the longitudinal direction (the right ends as viewed inFIG. 3). The second electrode wire52band the fourth electrode wire52dare electrically connected to each other at first ends in the longitudinal direction (the right ends as viewed inFIG. 2). The third electrode wire52cand the fourth electrode wire52dare electrically connected to each other at a second end in the longitudinal direction (the left end as viewed inFIG. 2) with a resistor58in between. A second end of the second electrode wire52b(the left end as viewed inFIG. 2) is connected to a ground GND, or grounded to the vehicle body3. A second end of the first electrode wire52a(the left end as viewed inFIG. 2) is electrically connected to the ON-OFF detector43. The first electrode wire52areceives electricity through the control circuit device91and the ON-OFF detector43.

As shown inFIG. 3A, the sensor support member46is formed by integrally forming an attaching portion61for fixing the sensor support member46to the rear door panel5and a holding portion62for holding the sensor body45.

The attaching portion61has an attaching portion main body65, which is made of elastic insulating resin material. A reinforcing member63and a guard electrode64are embedded in the main body65. The reinforcing member63is formed of conductive metal plate. The guard electrode64is formed of conductive rubber. The insulating resin material forming the main body65includes rubber and elastomer. In the present embodiment, the main body65is formed of elastomer.

The reinforcing member63is used for reinforcing the sensor support member46. As shown inFIG. 4, the reinforcing member63includes a belt-like reinforcing core63aand a plurality of reinforcing extensions63b, which are arranged along the longitudinal direction of the reinforcing core63a.The reinforcing extensions63bextend from both of the widthwise sides of the reinforcing core63a. The length of the reinforcing core63ain the longitudinal direction is substantially equal to the length of the sensor body45(refer toFIG. 3A) in the axial direction. The reinforcing extensions63bare formed at equal intervals along the longitudinal direction of the reinforcing core63a. The width of a gap63cbetween each pair of the reinforcing extensions63bthat are adjacent to each other in the longitudinal direction of the reinforcing core63a(the width in the same direction as the longitudinal direction of the reinforcing core63a) is substantially equal to the width of each reinforcing extension63b(the width in the same direction as the longitudinal direction of the reinforcing core63a) in the present embodiment. The reinforcing extensions63bare bent at proximal portions such that the distal ends of the reinforcing extensions63bon one side in the widthwise direction of the reinforcing core63aand the ends of the reinforcing extensions63bon the other side approach each other. When viewed from longitudinal direction of the reinforcing core63a, each reinforcing extension63bis substantially L-shaped. Since the reinforcing extensions63bare bent at proximal portions, the reinforcing member63is shaped like a channel when viewed in the longitudinal direction.

The guard electrode64is arranged to coat the reinforcing core63aand the proximal portions of the reinforcing extensions63b, so as to be integrated with the reinforcing member63. Thus, the outer surface of the reinforcing core63aand the outer surface of the proximal portions of the reinforcing extensions63bare coated with the guard electrode64, and a proximal part of a gap63cbetween each adjacent pair of the reinforcing extensions63b, which are arranged in the longitudinal direction of the reinforcing core63a, is filled with the conductive resin forming the guard electrode64. The guard electrode64closely contacts the reinforcing member63.

As shown inFIG. 3A, the reinforcing member63is embedded in the main body65of the attaching portion61. The main body65has a channel-like cross section perpendicular to the longitudinal direction of the sensor support member46. The main body65has an attaching groove65abetween the reinforcing extensions63bfacing each other through the reinforcing core63a. The attaching groove65aopens at an opposite side to the reinforcing core63a. The attaching groove65aextends along the longitudinal direction of the sensor support member46from one end to the other end of the attaching portion61. Two pairs of pressing projections65bproject toward each other from opposite inner surfaces of the attaching groove65a. Each pressing projection65bis integrally formed with the main body65.

The cylindrical holding portion62is formed of the same insulating resin material as the main body65and has elasticity. The holding portion62is formed integrally with the attaching portion61and is located on the side opposite to the attaching groove65awhen viewed along the axial direction. The length of the holding portion62in the axial direction is substantially equal to the length of the sensor body45in the axial direction. A retaining hole62ais formed in the holding portion62. The retaining hole62aextends in the axial direction of the holding portion62. The inner diameter of the retaining hole62ais slightly greater than the outer diameter of the sensor body45. The sensor body45is inserted into the retaining hole62a.

The sensor support member46is fixed to the front end5aof the rear door panel5with the sensor body45inserted in the retaining hole62a. The rear door panel5includes an inner plate71located on the inner side of the vehicle and an outer plate72located on the outer side of the vehicle. At the front end of the inner plate71(at an end in the advancing direction of the vehicle2), a fixed portion71aand an extended portion71bare formed. The fixed portion71aextends substantially parallel with the widthwise direction of the vehicle, and the extended portion71bextends from the outer end of the fixed portion71atoward the front of the vehicle2. The distal end of the extended portion71bis covered by the outer plate72. A bracket73having a press-fitted portion73aextending toward the front of the vehicle2is fixed to a front surface of the fixed portion71ain the vehicle2. The bracket73extends along the up-down direction of the vehicle2. The bracket73is formed such that its length in the longitudinal direction (the same as the up-down direction of the vehicle2) is substantially the same as the length of the sensor support member46in the longitudinal direction. By press fitting the press-fitted portion73ainto the attaching groove65a, the sensor support member46is fixed to the bracket73. As a result, the sensor body45is fixed to the front end5aof the rear door panel5. In a state where the sensor support member46is fixed to the front end5aof the rear door panel5, the guard electrode64is located rearward of the sensor body45.

As shown inFIG. 2, the guard electrode64is electrically connected to the sensor electrode56through a buffer amplifier81, and the reinforcing member63is grounded. That is, the guard electrode64is grounded through the reinforcing member63. The guard electrode64is maintained to the same voltage as the sensor electrode56by the buffer amplifier81.

The ON-OFF detector43, together with the sensor body45, forms a touch type pressure sensitive sensor that detects an object (not shown) present between the rear door panel5and the edge of the door opening4when the rear door panel5is being closed. The ON-OFF detector43is arranged in the rear door panel5and is connected to the ground GND.

As shown inFIGS. 2 and 3B, when no pressing force is applied to the sensor body45, current supplied to the first electrode wire52aflows through the third electrode wire52c,the resistor58, and the fourth electrode wire52din this order. On the other hand, when a pressing force is applied to the sensor body45from the direction of arrow a as shown inFIGS. 2 and 3C, the outer layer57, the sensor electrode56, and the insulating layer51are elastically deformed. As a result, one of the first electrode wire52aand the third electrode wire52ccontacts and is electrically connected to one of the second electrode wire52band the fourth electrode wire52d. Then, the current supplied to the first electrode wire52aflows to the fourth electrode wire52dwithout flowing through the resistor58. Accordingly, the voltage value between the first electrode wire52aand the ground GND when no pressing force is applied to the sensor body45is different from that when a pressing force is applied to the sensor body45. The ON-OFF detector43detects changes in the voltage value between the first electrode wire52aand the ground GND, and outputs a signal indicating a change in the voltage value, that is, an object contact signal, to the control circuit device91. For example, the ON-OFF detector43has a threshold value that has been determined based on the voltage value between the first electrode wire52aand the ground GND in a state where no pressing force is being applied to the sensor body45. When the voltage value between the first electrode wire52aand the ground GND exceeds the threshold value, the ON-OFF detector43outputs an object contact signal. When the pressing force applied to the sensor body45is removed, the shapes of the outer layer57, the sensor electrode56, and the insulating layer51are restored, and the shapes of the first to fourth electrode wires52ato52dare restored.

As shown inFIG. 2, the capacitance detecting circuit44is electrically connected to the sensor electrode56. The capacitance detecting circuit44and the sensor body45form a capacitance type proximity sensor that detects without any physical contact the presence of a conductive object existing between the rear door panel5and the edge of the door opening4when the rear door panel5is being closed.

The capacitance detecting circuit44is arranged in the rear door panel5. The capacitance detecting circuit44is electrically connected to the control circuit device91. The capacitance detecting circuit44detects the capacitance between the sensor electrode56and an object in the proximity of the sensor electrode56(for example, the ground surface, a part of a human body, and a conductive foreign object). That is, based on an electrical signal that is sent from the sensor electrode56of the sensor body45and indicates the distance between the sensor electrode56and an object, the capacitance detecting circuit44detects the capacitance of the sensor electrode56. The capacitance detecting circuit44outputs the detected capacitance of the sensor electrode56(detection value) to the control circuit device91.

The power sliding door apparatus1in the present embodiment is controlled by the control circuit device91. The control circuit device91functions as a microcomputer that includes a ROM (Read Only Memory) and a RAM (Random Access Memory). The control circuit device91is located, for example, in the vicinity of the slide motor26, and supplied with drive electricity from a battery92of the vehicle2. The control circuit device91controls the slide actuator25and the closure actuator28based on various types of signals sent from the half latch detecting portion, the position detector27, the operation switch31, the ON-OFF detector43, and the capacitance detecting circuit44.

The control circuit device91includes a determination circuit91a. The determination circuit91ahas a threshold value for determining that a conductive object is in the proximity of the sensor portion42. When the rear door panel5is being closed, the determination circuit91acompares the threshold value output by the capacitance detecting circuit44with the threshold value. Based on the comparison result, the determination circuit91adetermines whether there is an object in the proximity of the sensor portion42, that is, whether there is a conductive object in the vicinity of the front end5aof the rear door panel5. In the present embodiment, when the detection value output from the capacitance detecting circuit44is greater than the threshold, the determination circuit91adetermines that there is an object in the proximity of the sensor portion42, and outputs an object proximity signal indicating that the object is in the proximity of the sensor portion42. The threshold value is set based on the capacitance that is actually detected by the capacitance detecting circuit44when the rear door panel5is being closed with no object between the edge of the door opening4and the front end5aof the rear door panel5.

The operation of the power sliding door apparatus1will now be described.

When receiving an open signal from the operation switch31, the control circuit device91outputs a drive signal to the slide motor26to open the rear door panel5. When the rear door panel5reaches a position where the door opening4is fully open, the control circuit device91stops the slide motor26. Based on the rotation detection signals sent from the position detector27, the control circuit device91monitors the position of the rear door panel5.

When receiving a close signal from the operation switch31, the control circuit device91activates the ON-OFF detector43and the capacitance detecting circuit44, and controls the slide motor26to close the rear door panel5. When receiving a half latch detection signal from the half latch detecting portion while the rear door panel5is being closed, the control circuit device91controls the closure motor29such that the rear door panel5is moved to a position where the rear door panel5can be locked by the lock mechanism. When the rear door panel5closes the door opening4, the control circuit device91stops the slide motor26and the closure motor29.

If a conductive object exists between the door opening4and the rear door panel5when the rear door panel5is being closed, the distance between the sensor portion42(the sensor electrode56) and the object decreases as the rear door panel5moves. Accordingly, the detection value output from the capacitance detecting circuit44exceeds the threshold value output from the determination circuit91a. When the detection value output by the capacitance detecting circuit44exceeds the threshold value, the determination circuit91aoutputs an object proximity signal. When the determination circuit91aoutputs an object proximity signal, the control circuit device91reverses the slide motor26, thereby opening the rear door panel5by a predetermined amount.

The voltage of the guard electrode64located in the sensor support member46supporting the sensor body45is maintained at the same level as that of the sensor electrode56by the buffer amplifier81. Therefore, the capacitance detected by using the sensor electrode56is prevented from being influenced by disturbance. Also, when a conductive object approaches the sensor body45, the capacitance of the sensor electrode56is prevented from being changed due to the approach of the object since the voltage of the guard electrode64is maintained at the same level as that of the sensor electrode56. That is, when there is a conductive object approaches the sensor body45from behind in the vehicle, the guard electrode64prevents the capacitance detected by the capacitance detecting circuit44from being changed. Therefore, objects that are unlikely to get caught between the rear door panel5and the edge of the door opening4are not detected. On the other hand, when a conductive object in front of the rear door panel5, that is, an object that is likely to get caught between the rear door panel5and the edge of the door opening4, approaches the sensor body45, the capacitance detected by the capacitance detecting circuit44is changed, so that the object is detected.

When receiving an object contact signal from the ON-OFF detector43while the rear door panel5is being closed, the control circuit device91reverses the slide motor26, thereby opening the rear door panel5by a predetermined amount.

The method for manufacturing the sensor support member46will now be described. The method for manufacturing the sensor support member46of the present embodiment includes a step for forming a reinforcing plate, a step for forming a guard electrode, a step for bending, and a step for embedding.

First, in the reinforcing plate forming step, a reinforcing plate101, which will be formed into the reinforcing member63through the bending step discussed below, is formed as shown inFIG. 5A. The reinforcing plate101includes a belt-like reinforcing core63aand a plurality of reinforcing extensions63b, which are arranged at equal intervals along the longitudinal direction of the reinforcing core63a. The reinforcing extensions63bextend in the widthwise direction of the reinforcing core63afrom both of the widthwise sides of the reinforcing core63a. That is, each reinforcing extension63bextends in a direction perpendicular to the longitudinal direction of the reinforcing core63a. The reinforcing plate101is formed as a flat plate so that the reinforcing core63aand the reinforcing extensions63bare in the same plane. The reinforcing plate101is formed by punching a conductive metal plate through press work.

Next, in the guard electrode forming step, the guard electrode64is formed integrally with the reinforcing plate101. As shown inFIG. 5B, conductive resin material in a liquid state is applied to the reinforcing plate101such that the reinforcing core63aand the proximal portions of the reinforcing extensions63bare embedded. The conductive resin material is then hardened to form the guard electrode64. In the present embodiment, the guard electrode64is formed by extrusion molding, and the conductive resin material of the guard electrode64is molded simultaneously when being applied to the reinforcing plate101. The guard electrode64integrated with the reinforcing plate101coats the reinforcing core63aand the proximal portions of the reinforcing extensions63b, and fills a proximal part of the gap63cbetween each adjacent pair of the reinforcing extensions63b, which are arranged in the longitudinal direction of the reinforcing core63a.

Subsequently, the reinforcing extensions63bof the reinforcing plate101is bent in the bending step. The reinforcing extensions63bare bent at proximal portions such that the distal ends of the reinforcing extensions63bon one side in the widthwise direction of the reinforcing core63aand the ends of the reinforcing extensions63bon the other side approach each other. Therefore, when viewed from longitudinal direction of the reinforcing core63a, each reinforcing extension63bis substantially L-shaped. As a result, the reinforcing member63is shaped like a channel when viewed in the longitudinal direction. That is, the proximal portions of the reinforcing extensions63bare bent in the bending step, so that the reinforcing plate101is formed into the reinforcing member63having a shape conforming to the attaching portion61.

Next, in the embedding step, the reinforcing member63having the guard electrode64is embedded in the main body65. In the embedding step, insulating resin material is subjected to extrusion molding to form the main body65and the holding portion62. The extrusion molding is performed while embedding the reinforcing member63, with which the guard electrode64is integrally formed, in the main body65. The sensor support member46, which is completed through the embedding step, is fixed to the front end5aof the rear door panel5after the sensor body45is inserted in the retaining hole62a.

The present embodiment has the following advantages.

(1) The guard electrode64made of conductive rubber is integrally formed with the reinforcing member63, which reinforces the sensor support member46. The attaching portion61of the sensor support member46is formed by embedding the reinforcing member63integrally formed with the guard electrode64in the main body65. Therefore, compared to the case where a guard electrode made of conductive rubber and insulating resin material forming a sensor supporting member are molded simultaneously to form the sensor support member, the sensor support member46is more easily formed. Since the guard electrode64is integrally formed with the reinforcing member63before a portion of the sensor support member46that is made of insulating resin material (that is, the holding portion62and the main body65) are formed, the guard electrode64is firmly secured to the reinforcing member63compared to the case where a portion of a sensor support member that is made of insulating resin material and a guard electrode are formed integrally. Further, since the guard electrode64and the reinforcing member63are embedded in the insulating resin material forming the sensor support member46, the guard electrode64and the reinforcing member63are not inadvertently short-circuited.

(2) In the embedding step, the reinforcing member63integrally formed with the guard electrode64is embedded in the main body65, which is made of insulating resin material forming the attaching portion61. Since the reinforcing member63reinforces the attaching portion61, the manufactured sensor support member46is firmly secured to the front end5aof the rear door panel5.

(3) In the guard electrode forming step, the guard electrode64is formed integrally with the flat reinforcing plate101. This facilitates the formation of the guard electrode64. Since the reinforcing plate101is formed as a flat plate, the apparatus for forming the guard electrode64is unlikely to be complicated. Thus, the manufacturing costs can be reduced.

(4) Since the guard electrode64is integrally formed with the reinforcing member63formed by a conductive plate, the current through the guard electrode64is stable compared to the case where a guard electrode made of conductive rubber is formed separately from the reinforcing member63. If only the reinforcing member63is used as a guard electrode, that is, if the sensor support member46has no guard electrode made of conductive rubber, the gap63cbetween each adjacent pair of the reinforcing extensions63bneeds to be narrow to reduce the part that does not face the door panel5, so that the guard electrode sufficiently exerts its function. However, in the present embodiment, since the guard electrode64made of conductive rubber is integrally formed with the reinforcing member63, the capacitance detected by the capacitance detecting circuit44is effectively inhibited from being unnecessarily changed by disturbance regardless of the shape of the reinforcing member63.

(5) The reinforcing member63includes the belt-like reinforcing core63aand the reinforcing extensions63b, which are arranged along the longitudinal direction of the reinforcing core63a. The reinforcing extensions63bextend from both of the widthwise sides of the reinforcing core63a.Since the cross-sectional shape of the reinforcing member63is not constant along the longitudinal direction, the reinforcing member63is easy to bend in the longitudinal direction of the reinforcing core compared to a reinforcing member having a constant cross-sectional shape along the longitudinal direction of the reinforcing core. Therefore, the sensor support member46having the reinforcing member63is easily attached to the front end5aof the rear door panel5even if the front end5ais curved. Also, since the reinforcing member63is formed by bending the reinforcing plate101, which is formed by pressing, the reinforcing member63is easy to form.

(6) The guard electrode64is formed integrally with the reinforcing member63so as to coat a part of the reinforcing member63(in the present embodiment, the reinforcing core63aand the proximal portions of the reinforcing extensions63b). Thus, even if the reinforcing member63is curved, the guard electrode64hardly comes off the reinforcing member63. Therefore, even if the sensor support member46is fixed to the front end5aof the rear door panel5in a curved state, the current through the guard electrode64is prevented from being unstable.

The above embodiment of the present invention may be modified as follows.

In the embedding step of the above embodiment, after the reinforcing member63integrally formed with the guard electrode64is embedded in the main body65to complete the sensor support member46, the sensor body45is inserted in the retaining hole62aof the holding portion62. However, extrusion molding may be performed such that the sensor body45is retained in the holding portion62at the same time as the holding portion62and the main body65are formed of insulating resin material. If the embedding of the reinforcing member63in the main body65and the holding of the sensor body45by the holding portion62are performed simultaneously, the number of steps is reduced, which improves the productivity. Also, the space between the guard electrode64and the sensor body45is easily made constant along the longitudinal direction the sensor support member46.

In the guard electrode forming step of the above embodiment, after the guard electrode64is formed integrally with the flat reinforcing plate101, the bending step is performed to bending the reinforcing extensions63bto complete the reinforcing member63. However, the reinforcing extensions63bmay be bent to complete the reinforcing member63before the guard electrode64is formed, and thereafter, the guard electrode forming step may be performed to form the guard electrode64integrally with the reinforcing member63.

In the above embodiment, the reinforcing plate101is formed by pressing. However, the reinforcing plate101may be formed by a method other than pressing.

In the above embodiment, the guard electrode64is provided in the attaching portion61. However, the guard electrode64may be provided on the holding portion62as long as it is integrally formed with the reinforcing member63. The reinforcing member63is embedded in the main body65, which forms the attaching portion61. However, the reinforcing member63may be embedded in other part as long as it is embedded in the insulating resin material forming the sensor support member46. For example, the reinforcing member63may be embedded in the holding portion62.

In the above embodiment, the sensor support member46has the attaching portion61and the holding portion62, which are formed integrally by extrusion molding. However, the attaching portion61and the holding portion62may be separately formed, and then the holding portion62may be fixed to the attaching portion61with adhesive to form the sensor support member46. The sensor support member46may be formed solely by the attaching portion61. In this case, the sensor body45is directly fixed to the attaching portion61with adhesive.

The shapes of the reinforcing member63and the reinforcing plate101are not limited to those in the above embodiment. For example, as shown inFIG. 6, a reinforcing member111includes a belt-like reinforcing core111alike the reinforcing core63aof the above embodiment, and a plurality of reinforcing extensions111b, which are arranged along the longitudinal direction of the reinforcing core111a. The reinforcing extensions111bextend in the widthwise direction (the transverse direction) of the reinforcing core111afrom both of the widthwise sides (in the transverse direction) of the reinforcing core111a. Each reinforcing extension111bis formed like a rectangular plate that extends in a direction perpendicular to the longitudinal direction of the reinforcing core111a. The reinforcing extensions111bare formed at equal intervals along the longitudinal direction of the reinforcing core111a. The reinforcing extensions111bon one side in the widthwise direction of the reinforcing core111aare each located between two of the reinforcing extensions111bon the other side in the widthwise direction of the reinforcing core111a. The thus configured reinforcing plate111is bent at proximal portions of the reinforcing extensions111b(at parts shown by broken lines inFIG. 6).

In a reinforcing plate121shown inFIG. 7, a reinforcing core121ais shaped such that, when viewed in the direction along the thickness, rectangular recesses and projections are repetitively formed along the longitudinal direction of the reinforcing core121a. The reinforcing extensions121bare formed like rectangular plates that extend in the widthwise direction of the reinforcing core121afrom both of the widthwise sides of the reinforcing core121a. The reinforcing extensions121bare integrally formed with the reinforcing core121a. The flat-plate like reinforcing plate121is bent at proximal portions of the reinforcing extensions121b(at parts shown by broken lines inFIG. 7).

In a reinforcing plate131shown inFIG. 8, a reinforcing core131ais shaped so as to extend zigzag in the longitudinal direction when viewed in the direction along the thickness. The reinforcing extensions131bare formed like rectangular plates that extend in the widthwise direction of the reinforcing core131afrom both of the widthwise sides of the reinforcing core131a. The reinforcing extensions131bare integrally formed with the reinforcing core131a. Each reinforcing extension131bextends from a bent portion of the reinforcing core131a. The flat-plate like reinforcing plate131is bent at proximal portions of the reinforcing extensions131b(at parts shown by broken lines inFIG. 8).

A reinforcing plate141shown inFIG. 9Ahas a reinforcing core141aand a plurality of recesses141bon both sides of the reinforcing core141ain the widthwise direction. Each recess141bis dented toward the center in the widthwise direction of the reinforcing core141a. The recesses141bare formed at equal intervals along the longitudinal direction of the reinforcing core141a. The recesses141bare formed between the reinforcing extensions63b. When viewed from the direction of the thickness of the reinforcing plate141, each recess141bhas a triangular shape. A reinforcing plate142shown inFIG. 9Bhas a reinforcing core142aand a plurality of recesses142bon both sides of the reinforcing core142ain the widthwise direction. When viewed from the direction of the thickness of the reinforcing plate142, each recess142bhas an arcuate shape. The recesses141bare formed between the reinforcing extensions63b. A reinforcing plate143shown inFIG. 9Chas a reinforcing core143a, of which each side in the widthwise direction is saw-toothed. These reinforcing plates141to143are bent at proximal portions of the reinforcing extensions63b(at parts shown by broken lines in the drawings).

A reinforcing plate151shown inFIG. 10extends in a rectangular meander line along the longitudinal line when viewed in the direction of the thickness. The reinforcing plate151is bent at two parts in the widthwise direction (at parts shown by broken lines inFIG. 10) along the longitudinal direction.

A reinforcing plate161shown inFIG. 11Ais different from the reinforcing plate101(the reinforcing member63) of the above embodiment in the shape of reinforcing extensions. Reinforcing extensions161bof the reinforcing plate161extend in the widthwise direction of a reinforcing core161afrom both of the widthwise sides of the reinforcing core161a.Each reinforcing extension161bis shaped as a trapezoid, the width of which decreases from the proximal end toward the distal end. Also, the reinforcing extensions161bare arranged at equal intervals along the longitudinal direction of the reinforcing core161a. In a reinforcing plate162shown inFIG. 11B, trapezoidal reinforcing extensions162bon one side in the widthwise direction of a reinforcing core162aare each located between two of trapezoidal reinforcing extensions162bon the other side in the widthwise direction of the reinforcing core162a. These reinforcing plates161,162are bent at proximal portions of the reinforcing extensions161b,162b(at parts shown by broken lines inFIGS. 11A and 11B). The shape of the reinforcing extensions is not limited to trapezoidal, but may be triangular, polygonal, or semicircular. Also, the reinforcing extensions do not need to be formed at equal internals along the longitudinal direction of the reinforcing core.

A reinforcing member171shown inFIG. 12Ais formed by bending a metallic line (for example, wire) having circular cross section into a wavy shape. After the entire reinforcing member171is embedded in a guard electrode172made of conductive resin material, the reinforcing member171is bent along the longitudinal direction at two positions in the widthwise direction such that the reinforcing member171has a channel-like shape when viewed from the longitudinal direction. Although coatings the entire reinforcing member171in the example shown inFIG. 12A, the guard electrode172may partly coat the reinforcing member171. For example, a guard electrode shown inFIG. 12Bis integrally formed with the reinforcing member171so as to coat a center portion in the widthwise direction of the reinforcing member171, and expose both widthwise ends of reinforcing member171, that is, bent portions from the guard electrode173. In the examples ofFIGS. 12A and 12B, the reinforcing member171is formed by a metallic line. However, a reinforcing member formed by knitting a plurality of metallic lines may be used.

If a reinforcing core is used that does not have a straight form as the reinforcing core63aof the above embodiment, but has a complicated shape as the reinforcing cores121a,131a,141a,142a, and143aof the reinforcing plates121,131,141,142, and143, the guard electrode64is less likely to come off the reinforcing member when the reinforcing member is curved. Further, the reinforcing member is easier to bend in the widthwise direction of the reinforcing core. Therefore, even in the case where the front end5aof the rear door panel5is curved, the sensor support member46is easily attached to the door panel5, and the guard electrode64is easily electrically stabilized.

In the sensor support member46of the above embodiment, the reinforcing core63aof the reinforcing member63has a straight shape when viewed from the longitudinal direction, but may be curved in accordance with the outer surface of the sensor body45.

In the embedding step of the above embodiment, the main body65and the holding portion62are formed by extrusion molding. However, the main body65and the holding portion62may be formed, for example, by injection molding.

The position of the guard electrode64in relation to the reinforcing member63is not limited to that in the above embodiment. As long as the guard electrode64is attached to a side surface of the reinforcing member63and embed at least a part of the reinforcing member63, the guard electrode64may be formed in any part of the reinforcing member63. For example, a guard electrode181shown inFIG. 13coats the entire surface of the reinforcing member63. A guard electrode182shown inFIG. 14Acoats the outer part of the surface of the reinforcing member63. In the example shown inFIG. 14B, conductive rubber forming a guard electrode182fills spaces between each adjacent pair of the reinforcing extensions63b, which are arranged along the longitudinal direction of the reinforcing member63(the direction perpendicular to the sheet ofFIG. 14B). A guard electrode183shown inFIG. 15Acoats the inner part of the surface of the reinforcing member63. In the example shown inFIG. 15B, conductive rubber forming a guard electrode183fills spaces between each adjacent pair of the reinforcing extensions63b,which are arranged along the longitudinal direction of the reinforcing member63(the direction perpendicular to the sheet ofFIG. 15B). This structure has the same advantages as the above embodiment.

The guard electrode64may have in it a carrier line formed of a conductive metallic line. In the example ofFIG. 16, a guard electrode191made of conductive rubber is formed between the facing reinforcing extensions63b, and a plurality of carrier lines192are embedded in the guard electrode191. The carrier lines192extend in the longitudinal direction of guard electrode191. The carrier lines192are embedded in the guard electrode191when the guard electrode191is integrally formed with the reinforcing member63. The guard electrode191is therefore further electrically stabilized by the carrier lines192.

In the guard electrode forming step, the guard electrode64may be formed by a method other by extrusion molding. The guard electrode64may be formed by, for example, injection molding.

In the above embodiment, the guard electrode64is formed of conductive rubber, but may be formed of material other than conductive rubber as long as it is formed of conductive resin material.

In the above embodiment, the capacitance detecting circuit44outputs the capacitance detected by using the sensor electrode56. However, the capacitance detecting circuit44may output an amount of change of the capacitance of the sensor electrode56. In this case, the determination circuit91adetermines whether there is an object in the proximity of the front end5aof the rear door panel5based on the amount of change of capacitance output by the capacitance detecting circuit44.

In the above embodiment, the guard electrode64is maintained to the same voltage as the sensor electrode56by the buffer amplifier81. However, the guard electrode64may be maintained at the same voltage as the sensor electrode56by a structure other than the buffer amplifier81. Alternatively, instead of being maintained at the same voltage as the sensor electrode56, the guard electrode64may be maintained at a voltage of a constant ratio relative to the voltage of the sensor electrode56.

In the above embodiment, the sensor portion42is fixed to the front end5aof the rear door panel5. However, the sensor portion42may be fixed to the edge of the door opening4. In this case, the sensor portion42is fixed, for example, to a part of the edge of the door opening4that faces the front end5aof the rear door panel5in the front-rear direction of the vehicle2.

In the above embodiments, the present invention is applied to the power sliding door apparatus1, in which the rear door panel5is slid in the front-rear direction of the vehicle2, thereby opening or closing the door opening4provided on a side of the vehicle2. However, the present invention may be applied to an opening and closing apparatus other than the power sliding door apparatus1as long as the apparatus uses the drive power of a drive motor to open and close an opening. For example, the present invention may be applied to a power window apparatus that raises and lowers a vehicle window glass using the drive power of a motor. In this case, the sensor portion42is arranged at the upper edge of the window glass or at an edge of an opening that is opened and closed by the window glass. For example, the present invention may be applied to an opening and closing apparatus that opens and closes a tail opening of a vehicle using a flip-up backdoor or to an opening and closing apparatus that opens and closes a train door.