JP2004170389A - Sensor apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sensor apparatus capable of electrostatically shielding a detection circuit easily. <P>SOLUTION: The coated electric wire for shielding electrostatically is wound around the detection circuit in plane-shape. For instance, the coated electric wire is wound spirally and singly. When the sensor is further provided with a detection circuit board on which the detection circuit is arranged and a cylindrical case, the coated electric wire is wound in a cylindrical surface shape around the detection circuit board. The direction of the axis of the cylindrical surface coincides with the direction of the axis of the case. <P>COPYRIGHT: (C)2004,JPO

Description

  The present invention relates to a sensor device in which a detection circuit is electrostatically shielded.

  In an inductive proximity sensor, an insulating flexible film having a conductor pattern is wrapped around the printed circuit board on which the circuit is mounted to electrostatically shield the printed circuit board and the conductor pattern is deposited on the back of the core. It is known to solder to a film (see Patent Document 1).

Also, in a coil device in which a coil winding is applied to a magnetic core, it is known that a thin wire of a metal magnetic material such as permalloy or silicon steel is wound around the coil winding to magnetically shield the coil winding. (See Patent Document 2).
JP-A-56-1436 JP-A-11-195542

  In the proximity sensor adopting the electrostatic shield structure described in Patent Document 1, it is necessary to provide a high cost copper foil film for each model in which a complicated shape is subjected to secondary processing for each model. It takes much time and effort to assemble a copper foil film with a shape around the circuit board by hand, and it is difficult to automate the winding of the copper foil film with a complicated shape around the circuit board. That the man-hour for soldering the copper foil part of the attached film to the GND pattern of the circuit board is large, that it is difficult to automate the soldering of the copper foil part of the film with the copper foil to the GND pattern of the circuit board, The need for a more complicated film with an electrostatic shielded copper foil provided with leads and joints for electrically joining the metal deposition portion of the core and the GND pattern of the circuit board, and the metal deposition portion of the core and the circuit It is difficult to automate the soldering of the board to the GND pattern using a lead wire or a film with a copper foil, and the surface of the film with a copper foil is used to secure insulation between electronic components and an outer case. It is necessary to apply an insulating layer, which requires a film with a high cost of copper foil, and the insulating layer is relatively thin. And short-circuits with circuit patterns are likely to occur.

  The shield structure described in Patent Document 2 has a structure in which the object to be shielded is not a circuit board but a coil, and a magnetic material wire is thickly wound for the purpose of magnetic shielding. It was not suitable for electrostatic shielding purposes.

  The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a sensor device that can easily perform electrostatic shielding of a detection circuit.

  Still other objects and operational effects of the present invention will be easily understood by those skilled in the art by referring to the following description in the specification.

  In the sensor device according to the present invention, a covered electric wire is wound in a planar shape around a detection circuit for electrostatic shielding.

  According to such a configuration, a conductor layer formed by winding a covered wire in a sheet shape is generally formed around a detection circuit which is generally susceptible to noise in a sensor device. , The detection circuit can be electrostatically shielded. For the purpose of electrostatic shielding, the core wire of the coated electric wire is preferably made of a material having a small electric resistance such as copper, and does not need to contain a magnetic material. The detection circuit may be provided on a circuit board, or may be a simple lead-out path of an output signal of a transducer for converting a physical quantity into an electric signal, for example, a metal lead frame.

  For the purpose of electrostatic shielding, it is sufficient that the coated electric wire is wound thinly. For example, the insulated wire may be spirally and unitarily wound around the sensing circuit. With this configuration, the thickness of the shield layer can be minimized while obtaining the effect of the electrostatic shield, so that the size of the sensor device can be easily reduced.

  The sensor device may include a detection circuit board provided with a detection circuit and a cylindrical case. In one embodiment of the present invention in such a case, the coated electric wire is wound in a cylindrical shape around the detection circuit board, and the direction of the axis of the cylindrical surface matches the direction of the axis of the case. With such a configuration, the space in the case can be effectively used.

  One embodiment of the sensor device according to the present invention is a proximity sensor device including a detection coil having a core, and the detection circuit including an oscillation circuit having the detection coil as a resonance element. The proximity sensor device includes a product called a proximity switch.

  In the proximity sensor device which is one embodiment of the sensor device according to the present invention, a metal film for electrostatically shielding the detection coil is provided on the outer surface of the core, and the covered electric wire is electrically connected to the metal film of the core. Is also good. By doing so, the detection coil can also be electrostatically shielded.

  In this case, a detection circuit board provided with a detection circuit is provided, and the covered electric wire is electrically connected to the metal film of the core at both ends, and is electrically connected to the ground pattern of the detection circuit board at an intermediate portion thereof. You may make it so. The connection between the insulated wire and the metal film of the core is a part where stress due to filling resin etc. is likely to be applied, but if both ends of the insulated wire are connected, even if one of the connections is cut off, the detection coil An electrostatic shield is maintained.

  The winding of the detection coil of the proximity sensor device is required to have a high core wire density when wound, but does not require a high covering strength. On the other hand, the coated electric wire wound around the detection circuit is not required to have a high core wire density when wound, but it is necessary to prevent an unintended electrical short circuit with the detection circuit. For this purpose, it is preferable that the covering strength of the covered electric wire used for the shield be higher than the covering strength of the covered electric wire used as the winding of the detection coil.

  However, if there is no risk of a short circuit between the covered wire and the detection circuit, the covered wire used for shielding and the covered wire used as the winding of the detection coil may be of the same type. In this way, the manufacturing process can be simplified.

  Another embodiment of the sensor device according to the present invention is a photoelectric sensor including a light receiving element that receives light from a detection target area and converts the light into an electric signal, and outputs a signal related to a state of the detection target area based on an output of the light receiving element. Device. Photoelectric sensor devices include photoelectric switches and products called photomicrosensors and photomicroswitches. The detection circuit in the photoelectric sensor device may be simply a path for deriving the output signal of the light receiving element, but often includes a light receiving circuit that amplifies the output signal of the light receiving element. In the case where a discriminating circuit for discriminating the detection target based on the output of the light receiving circuit is provided, the portion of the discriminating circuit can be included in the subject of the electrostatic shield. A light-emitting element, a light-emitting circuit that causes the light-emitting element to emit light, and a photoelectric processing apparatus further including a central processing circuit that controls the light-emitting circuit and determines a detection target based on the output of the light-receiving circuit. Can be included in the object of the electrostatic shielding, including the part of the central processing circuit.

  In the photoelectric sensor device according to the present invention, the covered electric wire can be wound in a plane around the light receiving element. By doing so, not only the detection circuit but also the light receiving element can be electrostatically shielded by the step of winding the covered electric wire.

  One embodiment of the photoelectric sensor device according to the present invention includes a detection circuit board provided with a detection circuit, a cylindrical case, and a substantially half-cylindrical substrate holder that supports the detection circuit board and is housed in the case. In addition, the covered electric wire is wound around the detection circuit board and the board holder in a planar manner. The covered electric wire may be wound around the light receiving element in a planar manner.

  According to the present invention, the electrostatic shield of the detection circuit of the sensor device can be easily performed.

  Hereinafter, a proximity sensor according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows an exploded perspective view of a proximity sensor to which the winding shield structure of the present invention is applied. This proximity sensor has been previously proposed by the present applicant (WO 02/075763 pamphlet), and is obtained by integrating all components constituting the proximity sensor into several modules. In addition, the number of assembling steps can be reduced, and the cost can be reduced.

  That is, the components of the proximity sensor are integrated into a detection end module SMJ (details will be described later), a connection member module CMJ (details will be described later), and an output circuit module OMJ (details will be described later).

  The detection end module (SMJ) will be described. The detection end module (SMJ) includes a detection coil 4 wound around a resin spool 3, a ferrite core 5 on which the detection coil 4 is mounted, a resin coil case 1 accommodating the detection coil 4 and the ferrite core 5, And a detection circuit board 6 on which a detection circuit including an oscillation circuit having the detection coil 4 as a resonance element is mounted. The connection between the detection coil 4 and the detection circuit board 6 is performed by soldering the coil terminal pins 39 and 40 on the detection coil 4 side to the connection pads 61 and 62 on the detection circuit board 6 side. An assembly in which the spool 3, around which the detection coil 4 is wound, the ferrite core 5, and the detection circuit board 6 are integrated, is housed in the resin coil case 1, and then the primary injection is performed in the coil case 1. The mold resin is filled. Reference numeral 2 denotes a ring-shaped mask conductor fitted on the outer periphery of the distal end portion of the coil case 1. As proposed by the present applicant, the presence of this mask conductor 2 causes the detection end to be detected. The module (SMJ) is self-contained so that the characteristics are constant regardless of the presence or absence of the outer shell case 13 and the difference in the material.

  Next, the connection member module (CMJ) will be described. The connection member module (CMJ) includes a harness 7 which is a film-shaped wiring board. A plurality of wiring patterns are formed on the harness 7 in parallel along the longitudinal direction. The harness 7 is in a state where its middle portion is folded into a V-shape, so that it is easy to cope with the outer shell cases 13 having various lengths.

  Next, the output circuit module (OMJ) will be described. The output circuit module (OMJ) mainly includes an output circuit board 8 on which an output circuit IC 9, a light emitting diode 10, and the like are mounted. Terminal pads 11a and 11b are provided on the rear end 12 of the output circuit board 8.

  The above-described detection end module (including the coil case 1, the mask conductor 2, the spool 3, the detection coil 4, the ferrite core 5, and the detection circuit board 6) and the output circuit module (including the output circuit board 8) are connected. They are connected to each other via a member module (including the harness 7) and are housed in a cylindrical outer shell case 13 whose both ends are open. At this time, the opening of the distal end of the outer shell case 13 is closed by press-fitting the coil case 1. The rear end opening of the outer shell case 13 is closed by the end plug 15. The rear end of the end plug 15 has a slit 16 from which the rear end 12 of the output circuit board 8 projects, an injection port 17 used for injecting the second casting resin, and an internal air when the resin is injected. An exhaust port 18 for exhausting the cord protector 20 is provided, and a fold 19 for promoting fusion with the resin constituting the cord protector 20 is formed on the outer periphery of the rear end.

  The detection end module (SMJ), the connection member module (CMJ), and the output circuit module (OMJ) are housed in the outer shell case 13, and the rear opening of the outer shell case 13 is closed with the end plug 15. By injecting the pressurized molten resin from the inlet 17, the gap in the outer shell case 13 is filled with the secondary casting resin to seal out water and oil from the outside. Thereafter, the electric cord 21 is soldered to the terminal pads 11a and 11b of the rear end portion 12 of the output circuit board 8 protruding from the slit 16 of the end plug 15 and subsequently introduced into a predetermined molding die to thereby obtain the cord. The protector 20 is insert-molded. As a result, a cord-fixed proximity sensor is completed.

  FIG. 2 schematically shows a longitudinal sectional view of the proximity sensor thus completed. In the figure, 27 is a primary casting resin, 28 is a sealing resin for sealing the detection circuit board 6, and 29 is a secondary casting resin for sealing a gap in the outer shell case 13. Further, 21 is an electric cord, 22 is an outer cover, 23 and 24 are core wires, and 25 and 26 are conductors.

  As described above, the inside of the outer case 13 of the proximity sensor which is a completed product is filled with the primary casting resin 27 and the secondary casting resin 29.

  Next, a partial cross-sectional perspective view of the proximity sensor in a state where the primary casting resin 27 and the secondary casting resin 29 are removed is shown in FIG. The reference numeral 31 in the drawing indicates a planar winding portion of the covered electric wire. As will be described in detail later, the planar winding portion 31 is formed by winding the covered electric wire 30 around the wide portion of the detection circuit board 6 in a planar manner. Has been realized.

  Next, a procedure for creating the planar winding unit 31 will be described with reference to FIGS.

  FIG. 4 is an explanatory view showing the coating removing step. First, a preparation operation for starting winding of the covered electric wire will be described. In this preparatory stage, as shown in FIG. 4, by irradiating a laser beam to two places on the insulated wire 30, the coating is melted and removed, and the exposed conductor portions 32 and 33 are formed. . On the other hand, as shown in FIG. 5, on the side of the ferrite core 5 and the detection circuit board 6, an operation of attaching the overlaid solders 34, 35, 36 is performed. Here, the attachment position of the build-up solder 34 is the beginning of the winding of the covered electric wire 30, the attachment position of the build-up solder 35 is the end of the winding of the covered electric wire 30, and the attachment position of the build-up solder 36 is the terminal on the detection circuit board 6. It corresponds to the pad 61. This terminal pad 61 functions as a GND pattern. The ferrite core 5 has a thin cylindrical shape having an end surface 5a and a core peripheral surface 5b, and a metal deposition film is formed on the core end surface 5a and the core peripheral surface 5b. Overlay solders 34 and 35 are attached to this metallized film.

  Subsequently, as shown in FIG. 6, the conductor exposed portion 32 on the insulated wire 30 is joined to the build-up solder 34 on the core end face 5 a of the ferrite core 5 by irradiating a laser beam, thereby joining the joint solder 34 a. Then, the winding start end of the insulated wire 30 is electrically connected to the core end surface of the ferrite core 5.

  Subsequently, as shown in FIG. 7, by winding the insulated wire 30 around the detection circuit board 6 for one turn, the conductor exposed portion 33 on the insulated wire 30 is positioned on the overlay solder 36 on the detection circuit board 6. Then, the joint solder 36a is formed by irradiating this with a laser beam. As described above, since the terminal pad 61 to which the build-up solder 36 is attached functions as a GND pattern, the covered electric wire 30 is grounded to the GND pattern at the solder joint 36a.

  By the way, the terminal pad 62 on the detection circuit board 6 is on the side opposite to GND and directly connected to the oscillation circuit. As shown in FIG. 6, after the insulated wire 30 is fixed to the core end face 5a by the bonding solder 34, the insulated wire 30 is started to be wound from the board edge on the terminal pad 62 side. This is because the part to be protected from noise is the “leading wire of the detection coil” of the “spool on the connection side to the oscillation circuit”, and it is desired to wind the part around the part as little as possible. The positioning at the time of winding the covered electric wire 30 while hooking it on the edge of the substrate 6 is preferably such that the hooking portion is flat because the hooking portion is preferably flat.

  The reason why the insulated wire 30 was joined at the terminal pad 61 is that the insulated wire 30 and the detection circuit board 6 could be short-circuited (the sheath of the insulated wire 30 was peeled off with a laser or the like, but the stripping length was several millimeters) (Which may occur). Specifically, the coil terminal pin 39 connected to the back side of the terminal pad 61 is a GND terminal, and even if the coil terminal pin 39 and the insulated wire 30 are short-circuited, they are both at the GND potential, and This is because no trouble occurs in operation.

  Subsequently, as shown in FIG. 8, the covered electric wire 30 fixed to the detection circuit board 6 with the bonding solder 36a is pulled up to the shoulder 38, which is the upper end in the drawing of the wide portion 6a of the detection circuit board 6, and thereafter. As shown in FIG. 9, the covered electric wire 30 is sequentially wound down from the top to the bottom. As shown in FIGS. 8 and 9, the reason why the insulated wire 30 was pulled up from the position of the bonding solder 36 a to the shoulder portion 38 and then rolled down was that the shield layer formed by the winding was “1”. Layer) only. That is, since the clearance between the coil case 1 and the detection circuit board 6 is considerably small, if two or three layers of the winding are wound, there is a possibility that the winding shield layer may interfere at the time of insertion into the coil case 1. Because there is.

  Although a method of sequentially winding up from the bottom to the top is also conceivable, at the positions of the coil terminal pins 39 and 40, as shown in FIG. 9, swelling occurs due to the entanglement of the coil wires and the solder. Therefore, when winding the insulated wire 30 at this portion, it may slide down due to the inclination of the built-up portion, and it may be difficult to wind the wire at a uniform pitch. Actually, as shown by arrows A and B in FIG. 9, as a result of winding up from the bottom to the top, the windings are shifted down from the top of the mountain to the hem along the slope, resulting in uniform winding. It was relatively difficult. On the other hand, as shown in FIGS. 9 and 10, when sequentially rolling down from top to bottom, it was relatively easy to wind at a uniform pitch.

  Thereafter, as shown in FIG. 10, the planar winding portion 31 is formed around the wide portion 6 a by winding down the coated electric wire 30 by one layer in order from top to bottom. Since the planar winding portion 31 has a layered shape made of a conductor, it is effectively grounded to a GND pattern at the bonding solder 36a, thereby effectively functioning as an electrostatic shielding member. In addition, the planar winding portion 31 thus formed is insulated by the insulating coating in the direction of the adjacent covered electric wire, that is, in the direction crossing the covered electric wire, and no current flows. Then, even if the high-frequency magnetic field generated from the detection coil 4 crosses the planar winding portion 31 to generate an eddy current electromotive force, the eddy current does not flow in the direction crossing the winding, so that eddy current loss hardly occurs. Thus, it is possible to avoid harming the characteristics of the proximity sensor.

  Finally, as shown in FIGS. 11 and 12, the conductor exposed portion 43 is formed by irradiating the insulated wire 30 with a laser beam, and the exposed conductor portion 43 is positioned on the overlaid solder 35 on the core end surface 5a. If the exposed conductor 43 is joined to the core end face 5a by irradiation, as shown in FIG. 12, the coated electric wire forming the shield layer at the two places on the core end face 5a, namely, the joint solder 34a and the joint solder 35a is ferrite. It is electrically connected to the core. In addition, since the covered electric wire 30 is electrically connected to the GND potential at the terminal pad 61, the potential of the metal deposition film of the ferrite core 5 is also stabilized at the GND potential.

  Thereafter, as shown in FIG. 12, if the covered electric wire 30 following the conductor exposed portion 43 is cut, the covered electric wire is tightly wound around the wide portion 6 a of the detection circuit board 6 in a planar manner. The part 31 is completed and is connected to the GND potential, thereby completing the electrostatic shield structure. Moreover, at this time, since the coated electric wire 30 is also connected to the ferrite core 5 at two points, the potential of the metal deposition film of the ferrite core 5 also becomes the GND potential, which contributes to stabilization of operation. The joint between the insulated wire 30 and the metal-deposited film of the ferrite core 5 may be disconnected due to stress applied during the injection of the primary casting resin 29, during curing, and during expansion and contraction after curing. In this case, since the connection is made at two places, the effect of the electrostatic shield by the metal deposition film is maintained even if the connection at one place is cut off.

  In addition, since the operation of winding the covered electric wire around the wide portion 6a of the detection circuit board 6 can be easily automated using a coil winding machine or the like, the electrostatic shield structure in this type of proximity sensor is inexpensive. Can be provided.

  Next, FIG. 13 shows a diagram illustrating an example of an electric wire applicable to the shielded structure by winding according to the present invention. 1A shows a single-layer covered electric wire, FIG. 2B shows a two-layer covered electric wire (No. 1), FIG. 2C shows a two-layer covered electric wire (No. 2), and FIG.

  As shown in FIG. 1A, the single-layer coated electric wire has a single copper wire 44 serving as a conductor and a polyurethane coating 45. This covered electric wire can also be used as a winding of the detection coil in the above-described embodiment of the proximity sensor. The approximate thickness of the polyurethane film is 0.01 mm, and the outer diameter of the entire covered wire is 0.02 mm to 0.60 mm. Such a single-layer coated electric wire is a coil wire widely used in general. Used for relay coils, transformers, small motors, communication coils, etc. Very high versatility and low material cost. However, when wound directly on the substrate, there is a risk that the edge of the substrate may be damaged. Therefore, it may be preferable to cover the edge of the substrate with an insulating tape or the like, apply a radius, and then wind the substrate. Alternatively, an insulating layer may be provided in advance on the surface of the substrate. As the insulating layer, silicon potting, a cylindrical resin member, a heat-shrinkable tube, or the like can be used.

  The two-layer coated electric wire (No. 1) shown in FIG. 1B has a single copper wire 46 serving as a conductor, a first polyurethane film 47, and a second polyester film 48 of polyester. The first layer coating 47 and the second layer coating 48 are both extrusion coatings. When the thinnest one is selected, the conductor diameter is 0.11 mm, and the outer diameter of the polyester film is about 0.18 mm. When the conductor diameter is 0.11 mm, the approximate thickness of each film is about 0.01 mm of a polyurethane film and about 0.025 mm of a polyester film.

  Characteristically, the two-layer insulation film is superior in processing resistance and has high insulation properties. The insulation resistance is somewhat lower than that of the three-layer insulation film, but the space is small and the space efficiency is good because the outer sheath diameter is small. Material cost is lower than that.

  The two-layer coated electric wire (No. 2) of FIG. 3C has a single copper wire 49 serving as a conductor, a first polyurethane film 50, and a second nylon film 51. The second layer nylon coating is obtained by baking a nylon resin. The outer diameter is about 0.02 mm to 0.55 mm. The approximate thickness of each coating is about 0.01 mm for the polyurethane coating and about 0.005 mm for the nylon coating.

  As a feature, it can be said that it is a generally used coil wire, is a coated wire having a low material cost, and generally being excellent in processing resistance and deterioration characteristics. However, when wound directly on a substrate, the edge may not be tolerated. In that case, it would be necessary to wind the tape from above with its edges covered with insulating tape or the like.

  The three-layer coated electric wire shown in FIG. 3D is composed of a single copper wire 52 serving as a conductor, a first polyurethane film 53, a second polyester film 54, and a third polyamide film 55. Have. The conductor diameter is 0.11 mm, and the outer diameter of the polyamide film is 0.24 mm. When the conductor diameter is 0.11 mm, the approximate thickness of each coating is about 0.01 mm for the polyurethane coating, about 0.028 mm for the polyester coating, and about 0.028 mm for the polyamide coating.

  Characteristically, since it is a three-layer insulating film, it is durable even at the edge of the substrate and has sufficient insulation resistance.

According to the above embodiment, the following effects can be obtained.
(1) A large cost reduction is expected because the shield part can be constituted by a covered electric wire having a low material cost.
(2) Since the shield portion is formed by winding the covered electric wire around the circuit board, one type of covered electric wire can be used for each type of each size. Therefore, it is not necessary to arrange the shield members for each type, and the member management becomes easy.
(3) Since the shielded portion is formed by winding the covered electric wire around the circuit board, the assembly can be easily automated using a winding machine.
(4) Lead wires or copper foil for joining the coil core metal deposition portion and the GND of the circuit board are not required, and the cost of members can be reduced.
(5) The electrical connection of the shield to the circuit board GND can be easily automated.
(6) The electrical bonding of the coil core metal deposition section to the circuit board GND can be easily automated.
(7) Since the coated electric wire is wound over the electronic component mounted on the circuit board, the electronic component is protected from the outside. Therefore, it is possible to reduce the stress of the casting resin applied to the electronic component, and it is possible to prevent the electronic component from peeling and cracking.
(8) When the detection coil is used in common with a double track, the same wire and the same shield member can be used for the detection coil, so that the members can be integrated, and inventory management and cost reduction can be achieved.
(9) When the same material is used in common with the detection coil, the same equipment can be used for the winding step of the detection coil and the winding step of the shield, thereby reducing equipment costs and the number of steps. It is.
(10) Since a shield portion fitted to a circuit board or an electronic component for winding a covered electric wire can be configured, it is not necessary to provide an extra space in advance and mounting efficiency is higher than in the conventional case of winding a film with a copper foil. Excellent in

  By the way, a detection circuit board provided with a detection circuit, a core, and a detection coil are integrated, and a detection circuit board that does not include an output circuit is particularly called a detection end module of a proximity sensor. If a substrate provided with an output circuit is prepared separately from the detection circuit substrate, and a plurality of types of detection end modules and output circuit substrates are prepared, many types of proximity sensor devices can be manufactured by their combination. . The detection end module can be distributed as a single product as an intermediate product of the proximity sensor device. By winding the covered electric wire around the detection circuit board of the detection end module to form an electrostatic shield layer, the shield layer is almost in close contact with and integrated with the detection circuit board. The volume of the module is increased only slightly, and the shielding layer is not easily broken during handling. Therefore, it is easy to handle the detection end module as an intermediate product.

  Next, a circuit block diagram of a photoelectric sensor to which the present invention is applied is shown in FIG. The light emitting and receiving system of this photoelectric sensor includes a light emitting element 201 formed of an LED, a light receiving element 202 formed of a photodiode, a light emitting circuit section 203 for causing the light emitting element 201 to emit light, and a current of the light receiving element 202. A light receiving circuit unit 204 that converts an output signal into a voltage signal and amplifies the voltage signal. Then, in the present embodiment, the light receiving circuit unit 204 corresponds to the detection circuit of the present invention.

  The central processing circuit 205 is formed of an ASIC, controls the light emitting circuit unit 203 so that the light emitting element 201 performs pulse lighting at a predetermined cycle, and outputs an output signal of the light receiving circuit unit 204 in synchronization with the lighting timing of the light emitting element 201. (Light receiving signal). Also, the central processing circuit 205 has a threshold value for the light receiving signal, and if the magnitude of the light receiving signal continuously exceeds the threshold value for a predetermined number of times, the central processing circuit 205 determines that the light is incident. The threshold value is adjustable by the sensitivity volume 206. The indicator 207 includes two indicators, an operation indicator and a stability indicator. The operation indicator lights up when it is determined that the light is on. The stability indicator lights up when a light receiving signal greater than a threshold by a certain percentage or more is obtained. The output circuit unit 208 converts the determination result signal into an electric signal of a predetermined specification and outputs the signal to the outside. The power supply circuit unit 209 receives a DC power input within a predetermined voltage range from the outside, converts the input into a voltage required inside the sensor, and supplies power to each circuit unit.

  In this embodiment, the covered electric wire 217 is wound around the light emitting element 201, the light receiving element 202, the light emitting circuit 203, the light receiving circuit 204, the central processing circuit 205, the output circuit 208, and the power supply circuit 209. Electrostatic shielded. The object of the electrostatic shield may be at least a part of the light receiving circuit unit 204 at least.

  FIG. 15 is a partial cross-sectional perspective view of the photoelectric sensor assembly from which the case has been removed. In this figure, the optical holder 210 is shown in cross section with the upper half removed. In the figure, a board holder 211 is made of resin and holds a main circuit board 212. On the main circuit board 212, the respective circuit units in FIG. 14 other than the light emitting element 201 and the light receiving element 202 are mounted. As described above, the light receiving circuit unit 204 as the detection circuit and the other circuit units are provided on the main circuit board 212, but the main circuit board 212 corresponds to the detection circuit board in relation to the present invention. Signals between the light emitting element 201 and the light receiving element 202 and the main circuit board 212 are transmitted via the light emitting and receiving element board 213. In addition, in the figure, 214 is a light projecting lens, 215 is a light receiving lens, 216 is a lens cover, 217 is a covered electric wire, 218 is a connection part, and 207a and 207b are indicator lights constituting an indicator light part.

  FIG. 16 shows a state of the photoelectric sensor assembly when the end of the covered electric wire is viewed from a different angle from FIG. An area indicated by reference numeral 219 is a winding shield area. As is clear from the figure, the covered electric wire 217 is also wound around the optical holder 210 containing the light receiving element 202. The terminal end of the insulated wire 217 is bonded and fixed to the optical holder 210. Note that a locking portion may be provided on the optical holder 210, and the coated wire 217 may be fixed by hooking the locking portion.

  FIG. 17 shows a state in which the photoelectric sensor assembly is housed in the case 220. In this example, the case 220 is displayed in cross section. The material of the case 220 is a resin or a metal. The case 220 is provided with a hole 221 for operating the sensitivity volume 206. A relay member (not shown) for transmitting the rotation of the driver held by the operator to the sensitivity volume 206 is fitted into the hole 221. The case 220 is provided with a hole 222 for visually recognizing the indicator lights 207a and 207b. A transparent window member (not shown) is fitted into the hole 222.

  The ridge on the side surface of the substrate holder 211 contacts the inner surface of the case 220. The substrate holder 211 is not exactly a half-cylindrical cylinder, but a C-shaped cylindrical section having an angle of more than 180 degrees around the central axis. Therefore, when the substrate holder 211 is inserted into the case 220, there is no play in the case 220. Further, a groove is provided on the lower surface of the substrate holder 211 in parallel with the central axis. Since the groove fits into the convex portion on the inner surface of the case, the rotation of the substrate holder 211 with respect to the case 220 is prevented. With such a structure, the substrate holder 211 can be positioned with respect to the case 220 simply by inserting the substrate holder 211 into the case 220 from the front of the case 220. Further, according to the shape of the substrate holder 211, the shape is substantially half-cylindrical and there are few irregular portions, so that the coated electric wires 217 can be easily aligned and wound. If components are mounted only on the surface of the substrate holder 211 on the part of the main circuit board 212 where the covered electric wire 217 is wound, the surface of the main circuit board 212 on the side in contact with the covered electric wire 217 will be covered. Since there are no obstacles that disturb the winding of the insulated wire, the insulated wire 217 is more easily aligned and wound, and the possibility of short circuit between the insulated wire 217 and the circuit is further reduced. Although this photoelectric sensor further has a cap structure at the rear end of the case and a cable lead-out structure, illustration and description are omitted.

It is an exploded perspective view of a proximity sensor. It is a longitudinal cross-sectional view of a proximity sensor. It is a partial cross section perspective view of a proximity sensor. It is explanatory drawing which shows a coating removal process. It is explanatory drawing which shows a solder attachment process. It is explanatory drawing which shows the joining process with the core at the time of a winding start. It is explanatory drawing which shows the joining process with the board | substrate at the time of one-turn winding. It is explanatory drawing which shows the shift process to a board | substrate upper end. It is explanatory drawing which shows a unwinding start process. It is explanatory drawing which shows a winding-down completion process. It is explanatory drawing which shows the coating removal process of a winding end. It is explanatory drawing which shows the joining process with the core at the time of the end of winding. It is a figure showing the example of an applicable electric wire. It is a circuit block diagram of a photoelectric sensor. It is a partially broken perspective view of the photoelectric sensor assembly from which the case was removed. It is a perspective view of the photoelectric sensor assembly which shows the winding end state of a covered electric wire. It is a partially broken perspective view showing the state where the photoelectric sensor assembly was housed in a case.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Coil case 2 Mask conductor 3 Spool 4 Detector coil 5 Ferrite core 6 Detector circuit board 7 Harness 8 Output circuit board 9 Output circuit IC
DESCRIPTION OF SYMBOLS 10 Light emitting diode 11 Terminal pad 12 Rear end 13 Outer shell case 14 Operation display window 15 End plug 16 Slit 17 Injection port 18 Exhaust port 19 Hidder part 20 Code protector 21 Electric cord 22 Outer skin 23, 24 Core wire 25, 26 Conductor 27 1 Next casting resin 28 Sealing resin 29 Secondary casting resin 30 Covered electric wire 31 Planar winding part 32, 33 Conductor exposed part 34, 35, 36 Overlay solder 37 Detection circuit IC
38 Shoulder 39,40 Coil terminal pin 34a, 35a, 36a Bonding solder 44 Conductor 45 Film 46 Conductor 47 First layer film 48 Second layer film 49 Conductor 50 First layer film 51 Second layer film 52 Conductor 53 First layer Film 54 Second layer film 55 Third layer film 61, 62 Terminal pad 100 Proximity sensor 200 Photoelectric sensor 201 Light emitting element 202 Light receiving element 203 Light emitting circuit section 204 Light receiving circuit section 205 Central processing section 206 Sensitivity volume 207 Indicator lamp section 208 Output circuit section 209 Power supply circuit section 210 Optical holder 211 Substrate holder 212 Main circuit board 213 Light emitting and receiving element board 214 Light emitting lens 215 Light receiving lens 216 Lens cover 217 Covered electric wire 218 Connection section 219 Winding shield section 220 Case 221 hole 222 hole

Claims (11)

  A sensor device in which a covered electric wire is wrapped around the detection circuit in a planar manner for electrostatic shielding.   The sensor device according to claim 1, wherein the covered electric wire is spirally and unitarily wound around the detection circuit.   A detection circuit board provided with a detection circuit and a cylindrical case are further provided, and the covered electric wire is wound around the detection circuit board in a cylindrical shape, and the direction of the axis of the cylindrical surface is the direction of the axis of the case. 3. The sensor device according to claim 1, wherein:   The sensor device according to claim 1, further comprising a detection coil having a core, wherein the detection circuit is a proximity sensor device including an oscillation circuit having the detection coil as a resonance element.   The proximity sensor according to claim 4, wherein a metal film for electrostatically shielding the detection coil is provided on an outer surface of the core, and the covered electric wire is electrically connected to the metal film of the core. apparatus.   The detection circuit is provided with a detection circuit board provided, the coated electric wire, both ends thereof are electrically connected to the metal film of the core, and electrically connected to the ground pattern of the detection circuit board at an intermediate portion thereof. The proximity sensor device according to claim 5, wherein   The proximity sensor device according to claim 4, wherein the covering strength of the covered electric wire used for the shield is higher than the covering strength of the covered electric wire used as the winding of the detection coil.   The proximity sensor device according to claim 4, wherein the covered electric wire used for the shield and the covered electric wire used as the winding of the detection coil are of the same type.   The sensor device according to claim 1, further comprising a light receiving element that receives light from the detection target area and converts the light into an electric signal, and outputs a signal related to a state of the detection target area based on an output of the light receiving element.   The photoelectric sensor device according to claim 9, wherein the covered electric wire is also wound around the light receiving element in a planar shape.   A detection circuit board provided with the detection circuit, a cylindrical case, and a substantially half-cylindrical substrate holder that supports the detection circuit board and is housed in the case; The photoelectric sensor device according to claim 9, wherein the photoelectric sensor device is wound around the substrate holder in a planar manner.

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