JP2005031067A - Load detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a load detection device using an optical fiber which is small in size and high in sensitivity. <P>SOLUTION: A pressure sensing sensor 10 of the load detection device is constituted by being provided with the optical fiber 12 having a predetermined length; a light emitting element 18 which is located at one end 12A side of the optical fiber 12 in a lengthwise direction emits, and is incident a light on one end 12A of the optical fiber 12; a light receiving element 20 which is located at the other end 12B side of the optical fiber 12 in the lengthwise direction receives the light transmitted through the optical fiber 12, and outputs a signal corresponding to a received light quantity; a power source wire 22A for use in the light emission which is connected to the light emitting element 18 and is wound spirally around a periphery of the optical fiber 12; and the wire 24A for use in the light emission. The power source wire 22A for use in the light emission which is wound spirally in the periphery of the optical fiber 12 performs as an indentor, and enhances the sensitivity of the pressure sensing sensor 10. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a load detection device using an optical fiber.

  In vehicles such as automobiles, for example, a pinch detection sensor is used to detect foreign object pinching between a side window glass driven by a power window device and a window frame, and between an electric slide door or back door and a vehicle body. It has. In addition, as the pinching sensor, a pressure-sensitive sensor that detects a pressurizing force (a reaction force received from a foreign object) accompanying the pinching is used.

  As such a pressure sensitive sensor, it is considered to use an optical fiber sensor (for example, refer to Patent Document 1). This optical fiber sensor includes an optical fiber having elasticity, light incident means including a light source that emits light and enters a certain amount of light into the optical fiber, and a light receiving body that receives the light transmitted through the optical fiber. Has been. In this optical fiber sensor, an external force (pressing force) that deforms the optical fiber is detected based on a change in the amount of light transmitted by the deformation of the optical fiber, that is, a change in the amount of light received by the photoreceptor.

  Further, a push button device using an optical fiber is known (for example, see Patent Document 2). In this push button device, one of a pair of optical fibers that are divided into two in the longitudinal direction and normally transmit light from one to the other is deformed by the operation of the push button, and the light transmission to the other is blocked, thereby pushing the push button A signal (ON / OFF signal) corresponding to the presence / absence of an operation is output. That is, this push button device is used as a switch.

  Furthermore, a linear external pressure sensor using an optical fiber is considered as a submarine cable accident detection application (see, for example, Patent Document 3). The sensor core that constitutes the linear external pressure sensor is configured by forming protrusions or protrusions on the outer peripheral surface of the outer layer coating of the optical fiber core wire, and when the external pressure is applied at any position in the longitudinal direction, the position Further, local lateral pressure is applied to the internal optical fiber by the protrusions or protrusions. Thereby, it is possible to detect that an external force is applied to the linear external pressure sensor and the position in the longitudinal direction where the external force is applied.

A configuration in which a pressure-sensitive sensor using a leaky optical fiber is incorporated in a bumper of an automobile as a collision sensor is also known (see, for example, Patent Document 4).
Japanese Patent Laid-Open No. 7-151615 Japanese Utility Model Publication No. 7-025527 Japanese Utility Model Publication No. 5-073604 JP-A-7-190732

  However, in the conventional optical fiber sensor as described above, the load per unit area (unit length) is small when the load (pressing force) is applied substantially uniformly over a wide range in the longitudinal direction, so that the sensitivity is low. There was a problem. In particular, it is desired to improve detection sensitivity in applications that are applied to vehicles and detect the pinching of relatively large objects such as human hands and arms.

  Further, in the conventional push button device as described above, one of the optical fibers has a free end that is displaceable with respect to the other, and a push button that displaces the free end is necessary. The device was large overall as a result of the space needed to place the ends and push buttons and allow these strokes.

  Further, the conventional linear external pressure sensor as described above has a problem that the number of parts or the amount of material used increases because the protrusions or protrusions are formed on the outer peripheral surface of the coating, resulting in an increase in cost. Moreover, this linear external pressure sensor is used for detecting an accident in a submarine cable, and for example, no consideration has been given to handling properties, assembling properties, and the like required for automotive applications and the like.

  In view of the above facts, an object of the present invention is to obtain a load detection device that is small and has good sensitivity.

  In order to achieve the above object, a load detection device according to a first aspect of the present invention includes an optical fiber having a predetermined length and a longitudinal end of the optical fiber, and emits light from one end of the optical fiber. A light-emitting means that is incident on the other end in the longitudinal direction of the optical fiber, and a light-receiving means that receives light transmitted through the optical fiber and outputs a signal corresponding to the amount of received light, and an outer periphery of the optical fiber And a connection line for conducting to the light emitting means or the light receiving means.

  In the load detection device according to the first aspect, the light incident on the optical fiber from the one end by the light emitting means is received by the light receiving means disposed on the other end side through the optical fiber. When the optical fiber is deformed by an external force, the amount of light transmitted through the optical fiber, that is, the amount of light received by the light receiving means changes (for example, the amount of transmission decreases due to a transmission loss due to deformation). This light receiving means outputs a signal corresponding to the amount of received light, that is, the magnitude of the external force. As a result, the load acting on the optical fiber is detected. The output signal of the light receiving means may be a signal (for example, an analog signal) that changes according to the magnitude of the amount of received light, and a binary signal that switches depending on whether the amount of received light exceeds a predetermined threshold ( For example, an ON / OFF signal) may be used.

  Here, since the connection line is formed in a spiral shape along the outer periphery of the optical fiber, in other words, the spiral inner periphery formed by the connection line is in contact with or in close proximity to the outer periphery of the optical fiber. When the load detecting device (load receiving portion thereof) is pressed by a relatively large one and the like and an external force is applied, the external force is transmitted to the optical fiber via a connecting line partially located in the longitudinal direction. That is, the optical fiber is greatly recessed (deformed) locally at a portion where the connecting line functioning as an indenter transmits an external force. Thereby, the sensitivity of load detection due to deformation of the optical fiber is improved. In addition, the load detection device is small in size because it does not include a movable part with respect to the optical fiber.

  Note that the spiral connection line along the outer periphery of the optical fiber may be configured by, for example, winding directly around the outer periphery of the optical fiber in a spiral manner, and inserting (fitting) the optical fiber into a previously formed spiral. May be configured.

  Thus, the load detection device according to claim 1 is small and has good sensitivity. Since the connection line for conducting to the light emitting means or the light receiving means functions as an indenter, the sensitivity can be improved without increasing the number of parts and the materials used, compared to the configuration in which the connection line and the indenter are provided separately. It is. In addition, the connection wire that is spirally wound around the outer periphery of the optical fiber does not hinder the bending of the optical fiber. Furthermore, since the connection line for continuity is wound around the optical fiber, the connection line is prevented from becoming an obstacle when installing the load detection device, and the electrical connection between the load detection device and the outside is connected to the optical fiber. It becomes possible to concentrate on one end side in the longitudinal direction.

  A load detection device according to a second aspect of the present invention is the load detection device according to the first aspect, wherein the load detection device includes a plurality of the connection lines, and each connection line is formed in a spiral shape along the outer periphery of the optical fiber. It is a feature.

  In the load detection device according to claim 2, the plurality of connection lines are each formed in a spiral shape along the outer periphery of the optical fiber. That is, the indenter is formed by a spiral having two or more connecting wires. For this reason, for example, the light emitting means or the light receiving means can be electrically connected to the power supply side and the ground side connection line so that power can be supplied, or a signal line or the like can be connected (conductive) in addition to the power supply line. Further, the indenter is disposed relatively uniformly on the outer peripheral portion of the optical fiber, and sensitivity variations in each direction (particularly in the circumferential direction) are suppressed.

  A load detection device according to a third aspect of the invention is characterized in that, in the load detection device according to the first or second aspect, the connection line is bonded to the outer peripheral surface of the optical fiber.

  In the load detection device according to the third aspect, since the connection line is bonded to the outer peripheral surface of the optical fiber, the spiral pitch of the connection line is maintained at a predetermined pitch. For this reason, for example, when the external force is applied or when the applied external force is eliminated, the connecting line is prevented from being displaced in the longitudinal direction of the optical fiber.

  A load detection device according to a fourth aspect of the present invention is the load detection device according to any one of the first to third aspects, wherein the load detection device is formed in a tubular shape, and the light is in contact with the connection line on an inner surface. A cover member for covering the fiber is further provided.

  In the load detection device according to the fourth aspect, the connection line is disposed between the optical fiber and the cover member while being sandwiched between the optical fiber and the cover member. The external force is transmitted to the optical fiber through the cover member and the connecting line, and deforms the optical fiber. As described above, since the cover member is provided, the optical fiber or the connection line does not directly contact the load detection object or the foreign object. That is, the optical fiber or the connection line is protected and the reliability is improved.

  A load detection device according to a fifth aspect of the invention is characterized in that, in the load detection device according to the fourth aspect, the connection line is held on an inner peripheral portion of the cover member.

  In the load detection device according to the fifth aspect, the connecting wire is held on the inner peripheral portion of the cover member in a spiral state. For this reason, by inserting the optical fiber into the spiral formed by the connection line held by the cover member, it is possible to easily obtain a state in which the spiral connection line is along the inner peripheral surface of the optical fiber.

  A load detection device according to a sixth aspect of the present invention is the load detection device according to the first or second aspect, wherein the connection line wound spirally around the outer peripheral surface of the optical fiber is connected to the connection line and The optical fiber is held by a coating layer that is in close contact with the optical fiber.

  In the load detection device according to claim 6, the connection line is spirally wound around the outer periphery of the optical fiber and is coated in close contact with the optical fiber along with the coating layer. It is held on the outer periphery. For this reason, for example, when the external force is applied or when the applied external force is eliminated, the connecting line is prevented from being displaced in the longitudinal direction of the optical fiber. The coating layer can be, for example, a coating layer formed by coating or dipping, a heat-shrinkable tube after heat-shrinking, or the like.

  A load detection device according to a seventh aspect of the present invention is the load detection device according to any one of the first to sixth aspects, wherein the light emitting means or the light receiving means is attached to a longitudinal end portion of the optical fiber. It is characterized by that.

  In the load detection device according to the seventh aspect, since the light emitting means or the light receiving means is directly or indirectly attached to the optical fiber, it is easy to handle. Moreover, component management and assembly are facilitated by attaching the light emitting means or the light receiving means to the optical fiber. In particular, in the configuration in which the light emitting means and the light receiving means are respectively attached to different end portions in the longitudinal direction of the optical fiber, it is possible to handle the load detection device as a whole as a whole, handling, component management, assembly Improve.

  The load detection device according to an eighth aspect of the present invention is the load detection device according to the seventh aspect, wherein the light emitting means or the light receiving means is connected to the optical fiber via a support member provided at a longitudinal end portion of the optical fiber. It is attached to the longitudinal direction edge part of this.

  In the load detection device according to the eighth aspect, the light emitting device or the light receiving device is attached to the longitudinal end portion of the optical fiber via the support member. That is, the end portion of the optical fiber, the light emitting means, or the light receiving means are respectively held by the support members. With this support member, the position, posture, and the like of the light emitting means or the light receiving means with respect to the optical fiber can be maintained in an appropriate state. For this reason, the position (posture) of the light emitting means or the light receiving means with respect to the longitudinal end of the optical fiber, that is, the amount of incident light or the amount of received light is stabilized, and the reliability is improved.

  A load detection device according to a ninth aspect of the present invention is the load detection device according to the eighth aspect, wherein the light emitting means or the light receiving means is connected to the connection line via a connection portion disposed on the support member. It is characterized by that.

  In the load detection device according to the ninth aspect, the connection line and the light emitting means or the light receiving means are connected to each other through a connection portion arranged on the support member. For this reason, the connection line and the light emitting means or the light receiving means can be easily connected. Further, it is possible to prevent the connection line from being unnecessarily lengthened for connection with the light emitting means or the light receiving means. In particular, this configuration is suitably applied when the connection line and the light emitting means or the light receiving means are connected in a state where the light emitting means or the light receiving means and the optical fiber are respectively held by the support members.

  A load detection device according to a tenth aspect of the present invention is the load detection device according to the eighth or ninth aspect, wherein the support member sandwiches and holds a longitudinal end portion of the optical fiber via the connection line. It has the holding part to perform.

  In the load detection device according to the tenth aspect, the end portion in the longitudinal direction of the optical fiber is sandwiched by the grip portion from the outer peripheral side via the connection line and is held by the support member. Thereby, it is possible to reliably hold the optical fiber in which the spiral connection line is located on the outer peripheral side with a simple structure on the support member.

  A load detection device according to an eleventh aspect of the present invention is the load detection device according to any one of the first to tenth aspects, wherein the light emitting means or the light receiving means and a lengthwise end surface of the optical fiber are interposed. It is characterized by being sealed with a light-transmitting sealing agent.

  In the load detection device according to the eleventh aspect, since the sealant seals between the light emitting means or the light receiving means and the end face of the optical fiber, there is no light between the light emitting means or the light receiving means and the end face of the optical fiber. Intrusion of foreign matter, moisture and the like is prevented while permeability is maintained.

  A pressure-sensitive sensor 10 as a load detection device according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 3.

  FIG. 1 shows a schematic overall configuration of the pressure-sensitive sensor 10 in a side view. FIG. 2A shows a partially enlarged side sectional view of the internal structure of the pressure-sensitive sensor 10, and FIG. 2B shows the internal structure of the pressure-sensitive sensor 10 orthogonal to the longitudinal direction. Is shown in a cross-sectional view. As shown in these drawings, the pressure-sensitive sensor 10 includes an optical fiber 12.

  The optical fiber 12 includes a long cylindrical core 14 and a clad 16 that covers the outer periphery of the core 14, and is formed in a cylindrical shape having a predetermined length (long) as a whole. In the first embodiment, the core 14 is made of an elastic (flexible) material such as silicone rubber, and the clad 16 is made of a flexible material such as fluororesin. Thereby, the optical fiber 12 has flexibility as a whole, and local elastic deformation (deformable deformation) is possible.

  In this optical fiber 12, the refractive index of the clad 16 is lower than the refractive index of the core 14, and the light introduced from one end 12A in the longitudinal direction is refracted at the boundary between the core 14 and the clad 16 and the other. The light is transmitted toward the end portion 12B and led out from the other end portion 12B. In addition, as a fluororesin which comprises the clad 16, polytetrafluoroethylene etc. can be used, for example.

  The optical fiber 12 described above has a configuration in which the light transmission amount from the one end portion 12A to the other end portion 12B changes according to the deformation amount. Specifically, the optical fiber 12 is configured such that the greater the amount of deformation, that is, the external force required for deformation, the greater the light transmission loss and the light transmission amount from the one end portion 12A to the other end portion 12B. In addition, even when the optical fiber 12 receives a load of the same magnitude, the load acts locally and deforms greatly (depresses) locally than when the load acts over a wide range and undergoes bending deformation. However, transmission loss increases.

  The pressure sensitive sensor 10 includes a light emitting element 18 that is a light source as a light emitting means. The light emitting element 18 is a light emitting diode (LED) in the first embodiment, and is disposed in the vicinity of the outer side in the axial direction of the one end 12 </ b> A of the optical fiber 12. Thereby, the light emitting element 18 is disposed so that light emitted from the light emitting element 18 can be incident on the core 14 exposed at the one end 12 </ b> A of the optical fiber 12. The light emitting element 18 is configured to emit light when energized, and a wiring for energizing the light emitting element 18 will be described later.

  Further, the pressure-sensitive sensor 10 includes a light receiving element 20 as a light receiving means that is a photoelectric conversion element that converts received light into an electrical signal. The light receiving element 20 is disposed near the outside in the axial direction of the other end portion 12B of the optical fiber 12 so as to receive the light emitted from the light emitting element 18 and transmitted through the optical fiber 12. The light receiving element 20 is a photodiode or phototransistor that generates or amplifies current according to the amount of received light, or a CdS cell (cadmium sulfide cell) that changes its electric resistance value according to the amount of received light.

  The light emitting element 18 and the light receiving element 20 described above are electrically connected as shown in FIG. FIG. 3 shows an example in which a phototransistor is used as the light receiving element 20. As shown in this figure, the pressure-sensitive sensor 10 includes a power supply wiring 22 connected to an external power supply (not shown) and a ground wiring 24 grounded externally. The power supply wiring 22 and the ground wiring 24 are covered conductive wires.

  The power supply wiring 22 is branched into a light emitting power supply line 22 </ b> A connected to the light emitting element 18 and a light receiving power supply line 22 </ b> B connected to the light receiving element 20. Similarly, the ground wiring 24 is branched into a light emitting ground line 24 </ b> A connected to the light emitting element 18 and a light receiving ground line 24 </ b> B connected to the light receiving element 20. The light emitting power supply line 22A and the light receiving power supply line 22B are connected to the light emitting element 18 and the light receiving element 20 via a resistor R having a predetermined electric resistance value, respectively.

  Thus, when a switch (not shown) between the power supply wiring 22 and the power supply is closed, the light emitting element 18 and the light receiving element 20 are energized (powered), the light emitting element 18 emits light, and the light receiving element 20 that is a phototransistor is The light transmitted through the optical fiber 12 is received, and the current is amplified according to the amount of received light.

  In the first embodiment, the signal wiring 26 is led out from the resistor R in the light receiving power supply line 22B and the light receiving element 20, and the potential difference between the signal wiring 26 and the ground is output. Signal (sensor signal). This output signal is inversely proportional to the amount of light received by the light receiving element 20, that is, the amount of deformation of the optical fiber 12 or the external force required for the deformation. The signal wiring 26 is a coated conductor.

  As shown in FIG. 1, the power supply wiring 22, the ground wiring 24, and the signal wiring 26 are covered in a bundled state on the light receiving element 20 side (the other end 12 </ b> B side of the optical fiber 12) to form a wire harness 28. ing. The end of the wire harness 28 is connected to a connector or the like (not shown).

  Then, the light-emitting power supply line 22A led out from the wire harness 28 is spirally wound around the optical fiber 12 (outside of the clad 16), reaches the one end 12A from the other end 12B of the optical fiber 12, and has a resistance. It is connected to the light emitting element 18 via R (not shown in FIG. 1). Similarly, the light emitting ground wire 24A led out from the wire harness 28 is spirally wound around the outer peripheral portion of the optical fiber 12 to reach the one end portion 12A from the other end portion 12B of the optical fiber 12, and the light emitting element 18 is reached. It is connected to the.

  The light emitting power supply line 22A and the light emitting ground line 24A are wound around the optical fiber 12 in parallel with each other. That is, on the outer peripheral portion of the optical fiber 12, two spiral protrusions functioning as an indenter as described later are formed by the light emission power line 22A and the light emission ground line 24A.

  The helical pitch between the light emitting power line 22A and the light emitting ground line 24A forming the indenter (the distance between the axial centers of the adjacent light emitting power line 22A and the light emitting ground line 24A in the longitudinal direction of the optical fiber 12) is: It is desirable to set it within the range of 2 mm to 30 mm, and specifically, it is determined according to the application of the pressure-sensitive sensor 10 and the wiring diameter. Further, it is desirable that the outer diameters of the light emitting power supply line 22A and the light emitting ground line 24A are equal (substantially equal) and within a range of 0.1 to 50 times the outer diameter of the core 14. Specifically, it is determined according to the application of the pressure-sensitive sensor 10.

  The light emission power line 22A and the light emission ground line 24A correspond to the “connection line” in the present invention. The sensor main body is constituted by the light-emitting power supply line 22A and the light-emitting ground line 24A and the optical fiber 12 in which they are spirally wound (partially in contact or in close proximity to each other in the longitudinal direction). 30.

  Further, the light-emitting power supply line 22A and the light-emitting ground line 24A may have a slight gap between the light-emitting power line 22A and the light-emitting ground line 24A. It is fixed to. As this fixing method, for example, adhesion or welding can be employed, and in the first embodiment, adhesion that facilitates the fixing operation is employed.

  Although not shown, the pressure sensor 10 described above is applied to a foreign object pinching detection device of a power window device, an electric slide door device, and an electric back door device in a vehicle such as an automobile, and the sensor main body 30 (optical fiber). The output signal corresponding to the deformation of 12), that is, the external force acting on the optical fiber 12, is output from the signal wiring 26 to the foreign object pinching detection device as a diagnostic signal.

  The foreign object pinching detection device determines that no pinching has occurred when the diagnostic signal input from the pressure sensor 10 is equal to or less than a preset threshold value. On the other hand, in the foreign object pinching detection device, when the diagnosis signal input from the pressure sensor 10 exceeds the above threshold, that is, the amount of light transmitted through the optical fiber 12 due to transmission loss due to the deformation of the optical fiber 12 exceeds a predetermined range. When it decreases, it is judged that pinching has occurred.

  Such a foreign object pinching detection device (a pinching determination function) may be incorporated into, for example, each control device (ECU) of a power window device, an electric slide door device, or an electric back door device. It may be incorporated in the sensor 10 side or in an abnormality detection ECU that integrates vehicle abnormality detection.

  In the foreign object pinching detection device, the diagnosis signal input from the pressure sensor 10 rises to the power supply voltage (value dropped by the resistance R) or falls to 0 voltage, that is, exceeds the second threshold value. It is also possible to detect that a failure such as disconnection has occurred in the pressure-sensitive sensor 10 by detecting whether it is below the threshold value.

  When the foreign object pinching detection device detects foreign object pinching between the side window glass that opens and closes the side window by the power window device and the side window sash, the sensor body 30 of the pressure sensor 10 is, for example, near the weather strip. The garnish is disposed at the lower end along the longitudinal direction of the garnish. Moreover, when detecting the foreign object pinching between the slide door driven by the electric slide door device and the B pillar, the sensor main body 30 is, for example, elongated in the vertical direction at the end facing the B pillar side of the slide door. To be placed. Furthermore, in the case of detecting foreign object pinching between the back door and the rear gate driven by the electric back door device, the sensor body 30 is elongated in the vertical direction on both side portions of the back door facing the rear gate, for example. Arranged.

  Next, the operation of the first embodiment will be described.

  When the pressure-sensitive sensor 10 having the above configuration is supplied with power through the power supply wiring 22, the light emitting element 18 emits light, and the light enters the optical fiber 12 from one end portion 12 </ b> A thereof. The light passes through the core 14 while being refracted at the boundary between the core 14 and the clad 16, exits from the other end 12 </ b> B, and is received by the light receiving element 20. The light receiving element 20 that has received the light outputs an output signal corresponding to (in inverse proportion to) the amount of received light from the signal wiring 26. The above operation is always performed while power is being supplied.

  An output signal from the signal wiring 26 is input to the foreign object pinching detection device, and the foreign object pinching detection device compares the magnitude of the output signal with a preset threshold value.

  When there is no pinching between the side window glass and the side window sash, between the sliding door and the B pillar, or between the back door and the rear gate, the output signal of the pressure sensor 10 is set in the foreign object pinching detection device. The foreign object pinching detection device determines that no pinching has occurred.

  On the other hand, when pinching occurs between the side window glass and the side window sash (garnish), between the slide door and the B pillar, or between the back door and the rear gate, the pressure applied by the pinching is garnished and slides. It acts on the sensor main body 30 attached to the door or the back door. Due to this applied pressure, the optical fiber 12 constituting the sensor body 30 is deformed. Then, in the pressure-sensitive sensor 10, the transmission loss of light in the optical fiber 12 increases, and the amount of light received by the light receiving element 20 decreases rapidly (in a short time). For this reason, the output signal output from the signal wiring 26 increases rapidly.

  The foreign object pinching detection apparatus to which the output signal (diag signal) is input determines that pinching has occurred when the magnitude of the output signal exceeds the threshold value. In this case, the foreign object pinching detection device is, for example, a pinching release command signal for stopping or reversing the drive motor constituting the applied power window device, power slide door device, or electric back door device. Is output to a power window device, a power slide door device, or an electric back door device.

  Here, since the light emitting power supply line 22A and the light emitting grounding wire 24A are each spirally wound around the outer periphery of the optical fiber 12, the sensor main body 30 is configured. When an external force is applied by being pressed by a relatively large (long in the longitudinal direction), the optical fiber 12 is connected to the light emitting power line 22A or the light emitting ground line 24A partially located in the longitudinal direction. Thus, the applied pressure is transmitted.

  As a result, the optical fiber 12 does not act substantially uniformly over a certain range in the longitudinal direction, and the portion pressed through the light emission power line 22A or the light emission ground line 24A is locally greatly deformed. To do. Since the transmission loss of the optical fiber 12 is more likely to cause local deformation than deformation over a wide range, the light-emitting power line 22A or the light-emitting ground line 24A functions as an indenter to locally By greatly deforming, the detection sensitivity of deformation, that is, load is improved.

  For this reason, when the pressure sensor 10 is applied to a foreign object pinching detection device, the pinching can be detected at a stage where the applied pressure acting on the sensor body 30 is small, that is, at the initial stage of pinching. It is also possible to improve the protection of unpinched objects such as hands and arms.

  As described above, the pressure-sensitive sensor 10 according to the first embodiment is small in size because it has good sensitivity and does not include any parts that move with respect to the optical fiber 12.

  In the pressure-sensitive sensor 10, since the light emitting power supply line 22A and the light emitting ground line 24A for conduction to the light emitting element 18 function as indenters, the above-described sensitivity is improved without increasing the number of components. Yes.

  Further, the light emitting power supply line 22 </ b> A and the light emitting ground line 24 </ b> A that are spirally wound around the outer periphery of the optical fiber 12 do not hinder the bending of the optical fiber 12. For this reason, the sensor body 30 is attached to a curved portion (for example, the edge portion of the garnish or the like) while being deformed along the curved shape, or an external force that bends and deforms the sensor body 30 is detected. Is also possible.

  Furthermore, both the light-emitting power supply line 22A and the light-emitting ground line 24A necessary for causing the light-emitting element 18 to emit light are both wound around the optical fiber 12 and reach from the one end 12A to the other end 12B. Connection wiring with the outside of the pressure-sensitive sensor 10 is concentrated on one side in the longitudinal direction of the sensor body 30. That is, the pressure-sensitive sensor 10 having the wire harness 28 provided only on one side in the longitudinal direction and excellent in handling and installation is realized.

  Furthermore, since the spiral protrusions functioning as an indenter are formed in two lines by the light emitting power supply line 22A and the light emitting ground line 24A, the indenter is formed in the longitudinal direction and the circumferential direction in the outer peripheral part of the optical fiber 12. Can be arranged at substantially equal intervals, and the sensitivity can be made substantially uniform with respect to the load acting direction. Further, since the light emitting power supply line 22A and the light emitting ground line 24A have substantially the same length, the electrical characteristics are also stabilized.

  Further, since the light emitting power supply line 22A and the light emitting ground line 24A are respectively bonded to the outer peripheral portion of the optical fiber 12, the pitch of each spiral of the light emitting power supply line 22A and the light emitting ground line 24A and the interval between them are predetermined. Held at the value of. For this reason, for example, the positional deviation in the longitudinal direction of the optical fiber 12 of the light emitting power supply line 22A and the light emitting ground line 24A is prevented when an external force is applied or when the applied external force is eliminated.

  Next, a modified example of the sensor main body constituting the pressure-sensitive sensor 10 according to the first embodiment of the present invention will be described. Note that components / portions that are basically the same as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and description thereof is omitted.

  FIG. 4 shows a partially enlarged side sectional view of a sensor main body 40 according to a modification. As shown in this figure, the sensor body 40 is different from the sensor body 30 in that it includes a cover member 42 that covers the optical fiber 12 from the outer peripheral side.

  The cover member 42 is formed into a long flexible tube with a soft material such as rubber or elastomer. Two spiral grooves 42 </ b> A and 42 </ b> B are formed in the inner peripheral portion of the cover member 42 over the entire length. A part of the light emitting power supply line 22A in the radial direction is fitted (embedded) in the spiral groove 42A, and a part of the light emitting ground line 24A in the radial direction is fitted in the spiral groove 42B.

  Thus, the light emitting power supply line 22A and the light emitting ground line 24A are held by the cover member 42 while having a coaxial spiral shape. The optical fiber 12 is inserted (fitted) into two spirals formed by the light emission power line 22A and the light emission ground line 24A.

  In manufacturing the sensor body 40, the cover member 42 holding the light emitting power supply line 22 </ b> A and the light emitting grounding line 24 </ b> A having a spiral shape is manufactured by a known method so that the sensor body 40 has a length that constitutes the sensor body 40. Disconnect. Thereafter, the optical fiber 12 having substantially the same length is inserted into the spiral formed by the light emitting power supply line 22A and the light emitting ground line 24A held in the cut cover member 42, and is prevented from coming off as necessary. (Adhesion similar to the sensor body 30 may be used).

  The light emitting element 18 and the light receiving element 20 are attached to the sensor body 40 thus manufactured, and electrical connection as shown in FIG. 3 is performed. Thereby, the pressure-sensitive sensor 10 provided with the sensor main body 40 which concerns on a modification is manufactured easily.

  Even with the configuration including the sensor main body 40 according to this modification, the same effects as those of the first embodiment can be obtained. Further, in the pressure-sensitive sensor 10 including the sensor body 40, the cover member 42 is provided, so that the light emitting power supply line 22A, the light emitting ground line 24A, and the optical fiber 12 are protected by the cover member 42. That is, the light-emitting power supply line 22A, the light-emitting ground line 24A, and the optical fiber 12 are covered with the cover member 42 and directly to a foreign object, an object to be sandwiched, a partner to be sandwiched (for example, a B-pillar for a sliding door), and the like. It is protected from damage and disconnection. Thereby, the reliability of the pressure sensitive sensor 10 provided with the sensor main body 40 improves.

  In addition, since the light emitting power supply line 22A and the light emitting ground line 24A that are spirally wound around the outer periphery of the optical fiber 12 are covered with the cover member 42 and cannot be seen from the outside, the sensor body 40, that is, the pressure sensor 10 is The appearance is clean and looks great.

  Since the light emitting power supply line 22A and the light emitting grounding line 24A are formed in a spiral shape while being held by the cover member 42, the light emitting power line 22A and the light emitting grounding line 24A have light in the spiral formed. By inserting or fitting the fiber 12, it is possible to easily obtain the sensor body 40 that exhibits the above effects.

(Second Embodiment)
Next, a pressure-sensitive sensor 50 as a load detection device according to a second embodiment of the present invention will be described with reference to FIGS. Note that components / portions that are basically the same as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and description thereof is omitted.

  FIG. 5 shows a schematic overall configuration of the pressure-sensitive sensor 50 in a sectional view, and FIG. 6 shows the pressure-sensitive sensor 50 in a side view. As shown in these drawings, the pressure-sensitive sensor 50 includes an optical fiber 12, a light emitting element 18, and a light receiving element 20 in which a light emitting power supply line 22A and a light emitting ground line 24A are spirally wound. Yes. The pressure-sensitive sensor 50 is electrically configured in exactly the same manner as the pressure-sensitive sensor 10 (as shown in FIG. 3), and the light-emitting power supply line 22A and the light-receiving power supply line 22B are loaded by deformation of the optical fiber 12. It is the same as the pressure sensor 10 in that the detection sensitivity is improved.

  The pressure sensor 50 includes a sensor body 52 instead of the sensor body 30. In the sensor main body 52, the light-emitting power supply line 22A and the light-emitting ground line 24A that are spirally wound around the outer periphery of the optical fiber 12 are coated with a surface coating layer 54 as a coating layer together with the optical fiber 12. It is configured. The surface coating layer 54 is formed so as to adhere to and cover the outer peripheral side exposed surfaces of the optical fiber 12, the light emitting power supply line 22 </ b> A, and the light emitting ground line 24 </ b> A by coating, dipping, and the like, and protects them from damage and disconnection. And the function of holding the light emitting power supply line 22A and the light emitting ground line 24A on the outer periphery of the optical fiber 12.

  The pressure-sensitive sensor 50 includes a light-emitting unit 56 and a light-receiving unit 58 provided at the longitudinal end of the sensor body 52, respectively, and can be handled as a single unit (module) as a whole. . In the following, first, the light emitting unit 56 will be described, and the light receiving unit 58 is basically the same as the light emitting unit 56, the same reference numerals as those of the light emitting unit 56 are omitted, and the description is omitted. Is mainly explained.

  The light emitting unit 56 includes a terminal holder 60 as a support member. The terminal holder 60 is made of, for example, a resin material such as phenol resin or polybutylene terephthalate (PBT), and has electrical insulation. The terminal holder 60 includes a bottom plate portion 62 having a substantially rectangular flat plate shape, and a sensor clamp 64 is erected along the plate thickness direction from one longitudinal end side of the bottom plate portion 62.

  As shown in FIG. 7A and FIG. 7B, the sensor clamp 64 has an end portion in the longitudinal direction of the sensor main body 52 sandwiched between the pair of clamp pieces 64A so that the end portion of the sensor main body 52 is elastic. Is gripped (held). That is, the sensor clamp 64 is configured to hold the optical fiber 12 between the pair of clamp pieces 64A via the surface coating layer 54, the light emitting power supply line 22A, and the light emitting ground line 24A.

  An element clamp 66 protrudes from the bottom plate portion 62 of the terminal holder 60, and the element clamp 66 holds the light emitting element 18 between a pair of clamp pieces 66A. In the state held by the element clamp 66, the light emitting element 18 is configured so that light emitted from the light emitting element 18 can enter the core 14 exposed at the one end 12 </ b> A of the optical fiber 12. In this state, the tip of the sensor main body 52 protrudes to the light emitting element 18 side from the sensor clamp 64, and between the light emitting element 18 and the end face on the one end 12A side of the optical fiber 12 (the core 14 exposed at the end), A slight gap C is set. Further, a stopper wall 68 protrudes from the side opposite to the sensor body 52 with respect to the light emitting element 18 in the bottom plate portion 62, and the stopper wall 68 regulates the separation of the light emitting element 18 from the sensor body 52. ing.

  Further, the terminal holder 60 holds a pair of power supply terminals 70 and 72 as connection portions. The power supply terminals 70 and 72 are formed in a flat plate shape from a material having good conductivity and welding (including soldering or other soldering) such as a metal plate obtained by plating tin on a copper plate. The power supply terminals 70 and 72 are mainly wiring connection portions 70A and 72A positioned on the sensor body 52 side of the light emitting element 18 and element connection portions 70B mainly positioned on the opposite side of the light emitting element 18 from the wiring connection portion 70A. 72B, and connecting portions 70C and 72C for connecting the wiring connecting portion 70A and the element connecting portion 70B on the side of the light emitting element 18, respectively.

  These power supply terminals 70 and 72 are arranged so as not to contact each other inside a vertical wall 74 erected along the longitudinal direction from both sides of the terminal holder 60. In the second embodiment, each of the power supply terminals 70 and 72 is engaged between a pair of clamp pieces 66A and element connection portions 70B and 72B, which are positioned so as to be able to engage with each other on the inner side in the width direction of the coupling portions 70C and 72C. The stopper walls 68 are positioned so as to be in non-contact with each other. The power supply terminals 70 and 72 may be held by the terminal holder 60 by caulking or bonding, or may be integrally formed with the terminal holder 60 by insert molding.

  As shown in FIG. 5, the power supply terminal 70 is connected to the wiring connection portion 70 </ b> A with the end portion of the light emitting power supply line 22 </ b> A connected in a conductive state by welding (welding portion W <b> 1), and the element connection portion 70 </ b> B. The power supply side terminal 18A of the light emitting element 18 is joined in a conductive state by welding (welded portion W2). In addition, the power supply terminal 72 is joined to the wiring connection portion 72A in a conductive state at the end of the light emitting ground wire 24A by welding (welding portion W3), and to the element connection portion 72B on the ground side of the light emitting element 18. Terminal 18B is joined in a conductive state by welding (welded portion W4). The resistor R on the light emitting power supply line 22 </ b> A side is built in the light emitting element 18. Thereby, the light emitting element 18 is connected to the light emitting power supply line 22A and the light emitting ground line 24A via the pair of power supply terminals 70 and 72 so as to be able to supply power.

  Each welded portion W1 to W4 may be configured to bear (or share) the mounting strength of the sensor main body 52 and the light emitting element 18 with respect to the terminal holder 60 via the power supply terminals 70 and 72. Even in this case, it is preferable to provide the terminal holder 60 with the sensor clamp 64 and the element clamp 66 that perform the function of maintaining the posture of the sensor main body 52 and the light emitting element 18 with respect to the terminal holder 60 (that is, maintaining the mutual positional relationship). Further, as the power supply terminals 70 and 72, for example, a printed board can be used. In this case, the resistor R may be mounted on the power supply terminal 70.

  In the light emitting unit 56, the gap C between the light emitting element 18 and the longitudinal end surface of the sensor main body 52 (the end surface of the core 14 exposed to the surface) is sealed with a sealant 76. The sealant 76 is made of a light-transmitting material such as a transparent synthetic resin having a UV cut function, for example, and is arranged on the sensor body 52 side of the light emitting element 18 from the end of the sensor body 52 (a part of the sensor clamp 64). It is applied over a portion and filled in the gap C. The sealing agent 76 prevents entry of foreign matter, moisture, or the like into the gap C while maintaining the light transmittance of the gap C. In the second embodiment in which the light emitting unit 56 has a coating portion 78 described later, the sealing agent 76 functions to prevent a watertight agent described later from entering the gap C and impairing light transmittance. It has become.

  Furthermore, the light emitting unit 56 is configured to be covered in a sealed state by a covering unit 78 as a whole. In the second embodiment, the covering portion 78 includes an inner layer 78A made of a watertight agent such as a polyamide resin and an outer skin 78B made of an olefin resin or the like and covering the inner layer 78A. The inner layer 78A encloses the end of the sensor main body 52 covered with the covering portion 78, the light emitting element 18, the terminal holder 60, and each of the power supply terminals 70 and 72 in a close contact state to prevent water and the like from entering the light emitting portion 56. It is supposed to be.

  The covering portion 78 as described above can be constituted by, for example, a two-layer heat shrinkable tube. Note that the covering portion 78 is not limited to a configuration having a two-layer structure, and may be configured as a single layer with a thermoplastic resin material formed by hot melt molding such as polyamide, polypropylene, or silicone. .

  On the other hand, the light receiving unit 58 is configured such that the sensor clamp 64 of the terminal holder 60 holds the end of the optical fiber 12 in the sensor body 52 on the other end 12B side and the element clamp 66 holds the light receiving element 20. ing. The light receiving element 20 has a signal terminal 20C in addition to the power supply terminals 20A and 20B connected to the power supply terminals 70 and 72, respectively.

  In the light receiving unit 58, the power supply wiring 22 and the ground wiring 24 are connected to the power supply terminals 70 and 72, respectively, and the signal wiring 26 is connected to the signal terminal 20C. In the light receiving unit 58, a wire harness 28 in which the power supply wiring 22, the ground wiring 24, and the signal wiring 26 are bundled is led out of the covering unit 78 from the side opposite to the sensor main body 52.

  Other configurations of the light receiving unit 58 are basically the same as the corresponding configurations in the light emitting unit 56. Therefore, in the pressure-sensitive sensor 50 according to the second embodiment, the same effects as those of the pressure-sensitive sensor 10 except for the effects of the light-emitting side power supply line 22A and the light-emitting side ground line 24A being bonded to the optical fiber 12. Is obtained. The pressure sensor 50 can provide the following effects.

  First, since the outer periphery of the optical fiber 12 is held by the surface coating layer 54 for the light emitting side power supply line 22A and the light emitting side grounding line 24A, the pitch of each spiral of the light emitting power supply line 22A and the light emitting grounding line 24A and each other The interval is held at a predetermined value. For this reason, for example, the positional deviation in the longitudinal direction of the optical fiber 12 of the light emitting power supply line 22A and the light emitting ground line 24A is prevented when an external force is applied or when the applied external force is eliminated. Further, since the light emitting power supply line 22A, the light emitting ground line 24A, and the optical fiber 12 are covered with the surface coating layer 54, they are protected from damage or disconnection due to contact of foreign matter or the like. Thereby, the reliability of the pressure-sensitive sensor 50 provided with the sensor main body 52 improves.

  The pressure sensor 50 has the light emitting element 18 and the light receiving element 20 attached to both ends of the optical fiber 12 in the longitudinal direction. That is, the light emitting part 56 and the light receiving part 58 are respectively attached to both ends of the sensor body 52 in the longitudinal direction. Since it is provided, it can be handled as one sensor unit (assembly) as a whole. For this reason, parts management and the assembly | attachment property to a vehicle are favorable.

  And since the light emitting element 18 and the light receiving element 20 are each attached to the longitudinal direction edge part of the optical fiber 12 via the terminal holder 60, it is maintained at an appropriate position, posture, etc. with respect to the optical fiber 12. As a result, the position (posture) of the light emitting element 18 or the light receiving element 20 relative to the longitudinal end of the optical fiber 12, that is, the amount of incident light or the amount of received light is stabilized, and the reliability of the pressure sensor 50 is improved. In particular, the terminal holder 60 has a simple structure of the sensor body 52 in which a spiral indenter is formed on the outer periphery of the optical fiber 12 because the sensor clamp 64 including the pair of clamp pieces 64A sandwiches and grips the sensor body 52. Thus, the terminal holder 60 can be securely held.

  Further, the light emitting side power supply line 22A and the light emitting side ground line 24A are connected to the light emitting element 18 and the light receiving element 20 via the power supply terminals 70 and 72 held by the terminal holder 60. In the configuration in which the light emitting unit 56 and the light receiving unit 58 are provided at the ends, the light emitting side power supply line 22A and the light emitting side ground line 24A can be easily connected to the light emitting element 18 and the light receiving element 20.

  Furthermore, in the pressure sensor 50, the gaps C between the light emitting element 18 and the light receiving element 20 and the end face of the optical fiber 12 are respectively sealed with the sealant 76. The structure which prevents intrusion of a foreign substance, water or the like while maintaining the above is realized. As a result, it is possible to prevent the amount of light received by the light receiving element 20 from being reduced by foreign matter or the like entering the gap C.

  Next, an application example of the pressure-sensitive sensors 10 and 50 other than the foreign object pinching detection device will be described based on FIG. 8A or FIG. In this example, the pressure-sensitive sensor 50 is attached to a front bumper 80 of a vehicle such as an automobile and applied as a collision sensor to detect a vehicle collision. This will be specifically described below.

  The front bumper 80 includes a bumper skeleton member 80A that is coupled to the vehicle body side structure 82 and is long in the vehicle width direction, a bumper cover 80B that covers the bumper skeleton member 80A from the front side (arrow A side shown in FIG. 8), and a bumper skeleton member. The foam material 80C is filled between 80A and the bumper cover 80B. Both ends in the longitudinal direction of the bumper skeleton member 80A are curved so as to go around to the sides. The space between the bumper skeleton member 80A and the bumper cover 80B may be a hollow structure without filling the foam material 80C.

  The sensor body 52 of the pressure-sensitive sensor 50 is fixed to the front surface of the bumper skeleton member 80A. The light emitting unit 56 and the light receiving unit 58 are attached to opposite longitudinal ends (curved portions that wrap around the side) of the bumper skeleton member 80A. The signal line 26 of the pressure sensor 50 is connected to the collision detection ECU 84 of the vehicle, and an output signal corresponding to the amount of light received by the light receiving element 20 is sent from the signal line 26 to the collision detection ECU 84 as a diagnostic signal. It is designed to output.

  The collision detection ECU 84 determines that no collision has occurred when the diagnosis signal input from the pressure sensor 50 is equal to or less than a preset threshold value. On the other hand, the collision detection ECU 84 causes the optical fiber 12 (sensor main body 52) to be deformed by a vehicle collision (front collision) when the diagnostic signal input from the pressure sensor 50 exceeds the threshold value, that is, due to transmission loss. It is determined that a front collision has occurred when the amount of light that has passed through has decreased beyond a predetermined range.

  The collision detection ECU 84 that has determined that a front collision has occurred outputs a collision signal to, for example, an airbag device, a seat belt device, a brake device, or the like. The collision detection ECU 84 may be incorporated in each control device (ECU) that controls each of the above devices, or may be incorporated in a control device that integrally controls the safety of the vehicle. Further, in the collision detection ECU 84, as in the case of the pressure sensor 10, it is also possible to detect that a failure such as disconnection has occurred in the pressure sensor 50 based on a signal from the signal wiring 26.

  In the pressure-sensitive sensor 50, the light-emitting side power supply line 22 </ b> A and the light-emitting side grounding line 24 </ b> A are spirally wound around the outer periphery of the optical fiber 12, thereby forming a spiral indenter on the outer periphery of the optical fiber 12. Therefore, the impact caused by the collision with the bumper cover 80B is locally input to the optical fiber 12 via the foam 80C, the light-emitting side power supply line 22A or the light-emitting side grounding line 24A, and the vehicle collision is reliably detected. Can do. In particular, the relatively light collision detection accuracy is good.

  Therefore, the same effect can be obtained even when the pressure sensor 10 including the sensor body 30 or the sensor body 40 is applied to the collision sensor. Further, as a collision sensor applied to a vehicle such as an automobile, for example, the pressure sensor 10, 50 is attached to a rear bumper and applied as a rear collision sensor, or the pressure sensor 10, 50 is attached to a door or a side sill of the vehicle. Needless to say, it can be applied as a side collision sensor.

  In each of the above-described embodiments or modifications, the light-emitting power supply line 22A and the light-emitting ground line 24A have a preferable configuration in which two spiral protrusions are formed on the outer peripheral portion of the optical fiber 12. However, for example, the spiral protrusion may be formed on the outer peripheral portion of the optical fiber 12 by only one of the light-emitting power supply line 22A and the light-emitting ground line 24A. As shown in FIG. 28, three spiral protrusions may be formed on the outer periphery of the optical fiber 12 by the light receiving power supply line 22 </ b> B, the light receiving ground line 24 </ b> B, and the signal wiring 26. Further, as shown in FIG. 9A, a single spiral protrusion is formed on the outer periphery of the optical fiber 12 by the light emitting power supply line 22A and the light emitting grounding wire 24A using the two-wire coated conductor 44. As shown in FIG. 9B, a single spiral protrusion is formed by the light receiving power supply line 22B, the light receiving ground line 24B, and the signal wiring 26 by using a three-wire covered conductor 46. It may be formed. Furthermore, the connection line (wiring) that forms the spiral protrusion that functions as an indenter is not limited to a circular shape in cross section, and the portion covered by the cover member 42 may be a bare conductor. good.

  Further, in each of the above-described embodiments or modifications, an analog signal corresponding to (in inverse proportion to) the deformation of the optical fiber 12 is output from the light receiving element 20, but the present invention is not limited to this, for example, By incorporating a comparator (comparator) or CPU (arithmetic unit) in the light receiving element 20, an ON / OFF signal with a predetermined deformation amount of the optical fiber 12 as a boundary may be output. That is, the pressure-sensitive sensor 10 may be configured to have (part of) the function of the foreign object pinching detection device.

  Further, in each of the above embodiments or modifications, the light emitting element 18 is configured by a light emitting diode and the light receiving element 20 is configured by a phototransistor (photodiode or CdS). It is not limited and is not limited by each structure and combination of a light emission means and a light reception means.

  Furthermore, in each of the above-described embodiments or modifications, the optical fiber 12 is composed of a core 14 made of silicone rubber and a clad 16 made of a flexible material such as a fluororesin. However, the present invention is not limited by the material or combination of the core or clad constituting the optical fiber 12, and the optical fiber 12 is deformed by an external force. Any change in the amount of transmission is sufficient.

  Further, in the above-described embodiment or modification, the indenter (spiral ridge) is formed over the substantially entire length of the optical fiber 12 by the light-emitting power supply line 22A and the light-emitting ground line 24A. The invention is not limited to this, and for example, an indenter may be formed only by a part of the optical fiber 12 in the longitudinal direction (a part where sensitivity is desired to be improved) by the light-emitting power supply line 22A or the like.

  Furthermore, in the above modification, the light emitting power supply line 22A and the light emitting ground line 24A are preferably held by the cover member 42 before the assembly of the optical fiber 12, but the present invention is not limited thereto. For example, the cover member 42 may be attached in a state where the light-emitting power supply line 22A and the light-emitting ground line 24A are wound around the outer periphery of the optical fiber 12.

  Furthermore, in each of the above-described embodiments or modifications, the load detection device in the present invention is exemplified as the pressure-sensitive sensor 10 applied to the vehicle foreign object pinching detection device. However, the load detection device in the present invention is not limited to this. However, the present invention can be applied to any application for detecting a load. In particular, the load detection device according to the present invention is suitably applied to applications where the required detection range is relatively long.

  Moreover, in the said 2nd Embodiment, although the light emitting element 18 and the light receiving element 20 showed the preferable structure attached to the longitudinal direction edge part of the optical fiber 12, this invention is not limited to this, The light emitting element 18 In addition, any one of the light receiving elements 20 may be attached to the end of the optical fiber 12. Further, the attachment structure and the wiring connection structure of the light emitting elements 18 and 20 to the optical fiber 12 are not limited to the preferred structure by the terminal holder 60 and the power supply terminals 70 and 72, and any attachment structure or wiring connection structure is possible. May be adopted. Furthermore, it goes without saying that the present invention is not limited by the presence or absence of the sealant 76 and the covering portion 78 and the structure.

  Furthermore, in the second embodiment, the light emitting side power supply line 22A and the light emitting side ground line 24A are fixed to the outer peripheral surface of the optical fiber 12 by the surface coating layer 54, and the light emitting portions 56 and the light receiving portions are disposed at both ends in the longitudinal direction of the sensor body 52. However, the present invention is not limited to this. For example, the light emitting element 18 and the light receiving element 20 are connected to the longitudinal ends of the sensor body 30 or the sensor body 40 via the terminal holder 60, for example. It may be attached. In addition, the present invention is not limited to the configuration in which the light emitting unit 56 and the light receiving unit 58 are provided at both ends of the optical fiber 12, and only one of the light emitting element 18 and the light receiving element 20 is attached to the sensor bodies 30, 40, 52 may be provided at one end in the longitudinal direction. Furthermore, the present invention is not limited by the holding structure of the light emission side power supply line 22A and the light emission side ground line 24A with respect to the optical fiber 12.

1 is a side view showing a schematic overall configuration of a pressure-sensitive sensor according to a first embodiment of the present invention. (A) is a sectional side view which expands and shows a part of sensor main body which comprises the pressure-sensitive sensor which concerns on the 1st Embodiment of this invention, (B) is a cross section orthogonal to an axial direction. 1 is a schematic circuit diagram illustrating an electrical configuration of a pressure-sensitive sensor according to a first embodiment of the present invention. It is a sectional side view corresponding to FIG. 2 which shows the modification of the sensor main body which comprises the pressure-sensitive sensor which concerns on the 1st Embodiment of this invention. It is a sectional side view which shows the schematic whole structure of the pressure-sensitive sensor which concerns on the 2nd Embodiment of this invention. It is a side view of the pressure-sensitive sensor which concerns on the 2nd Embodiment of this invention. It is a figure which expands and shows a part of pressure-sensitive sensor which concerns on the 2nd Embodiment of this invention, Comprising: (A) is a sectional side view, (B) is a cross section in alignment with 7B-7B of FIG. 7 (A). FIG. It is a figure which shows the application example as a collision sensor of the pressure sensor which concerns on embodiment of this invention, Comprising: (A) is a top view, (B) is sectional drawing which follows 8B-8B of FIG. 8 (A). . It is a figure which shows the modification of the connection wiring which comprises the pressure sensitive sensor which concerns on embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Pressure-sensitive sensor (load detection apparatus), 12 ... Optical fiber, 18 ... Light emitting element (light emitting means), 20 ... Light receiving element (light receiving means), 22A ... Light emitting power supply line (connection line), 24A ... Light emitting ground Wire (connection line), 42 ... cover member, 50 ... pressure sensor (load detection device), 54 ... surface coating layer (covering layer), 60 ... terminal holder (support member), 64 ... sensor clamp (gripping part), 70 ... 72 ... Feed terminal (connection part), 76 ... Sealing material

Claims (11)

A predetermined length of optical fiber;
A light emitting means disposed on one end side in the longitudinal direction of the optical fiber and emitting light to enter light from one end of the optical fiber;
A light receiving means arranged on the other end side in the longitudinal direction of the optical fiber, receiving light transmitted through the optical fiber and outputting a signal corresponding to the amount of received light;
Formed in a spiral shape along the outer periphery of the optical fiber, and a connection line for conducting to the light emitting means or the light receiving means;
A load detection device.   The load detection device according to claim 1, wherein a plurality of the connection lines are provided, and each connection line is formed in a spiral shape along the outer periphery of the optical fiber.   The load detection device according to claim 1, wherein the connection line is bonded to an outer peripheral surface of the optical fiber.   4. The load detection according to claim 1, further comprising a cover member that is formed in a tubular shape and covers the optical fiber in a state where the connection line is in contact with an inner surface thereof. 5. apparatus.   The load detection device according to claim 4, wherein the connection line is held on an inner peripheral portion of the cover member.   3. The optical fiber, wherein the connection line wound spirally around the outer peripheral surface of the optical fiber is held on the optical fiber by a coating layer that is in close contact with the connection line and the optical fiber. The load detection apparatus described.   The load detecting device according to any one of claims 1 to 6, wherein the light emitting means or the light receiving means is attached to a longitudinal end portion of the optical fiber.   8. The load detection according to claim 7, wherein the light emitting means or the light receiving means is attached to the longitudinal end of the optical fiber via a support member provided at the longitudinal end of the optical fiber. apparatus.   The load detecting device according to claim 8, wherein the light emitting unit or the light receiving unit is connected to the connection line via a connection portion disposed on the support member.   10. The load detection device according to claim 8, wherein the support member includes a grip portion that sandwiches and holds a longitudinal end portion of the optical fiber via the connection line. 11.   The space between the light emitting means or the light receiving means and the longitudinal end face of the optical fiber is sealed with a light-transmitting sealing agent. Load detection device.

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