JP5527565B2 - Fiber photoelectric sensor - Google Patents

Description

  The present invention relates to a fiber-type photoelectric sensor that can be closely connected to each other via a mounting rail such as a DIN rail, and more particularly to a fiber-type photoelectric sensor that is suitable for mounting in a small space.

  A fiber-type photoelectric sensor that can be connected in large numbers via a DIN rail and has one set of light emitting / receiving fibers, one set of light emitting / receiving circuits, and one output line is already known (Patent Document 1). reference).

  In addition, a sensing system circuit for realizing a desired sensing function in connection with a fiber head, and a light emitting / receiving element for performing bidirectional optical communication with a sensor on one side in a state of being connected in a plurality of adjacent positions A first optical communication system circuit including the second optical communication system circuit including a light projecting / receiving element for performing bidirectional optical communication with the adjacent sensor on the other side in a state of being connected in a plurality of adjacent fashion. There is already known a fiber-type photoelectric sensor that is housed in a housing that can be connected in a large number through the optical fiber, and that enables two-way optical communication with adjacent sensors in the connected state (see Patent Document 2). .

  Also, using the first and second side communication system circuits, try handshaking with both adjacent sensors, learn its own position in the sensor array, and assign and set the learned unique address. , A sensing operation timing specific to the position is generated, and the sensing system circuit is driven according to the operation timing to realize the sensing operation, and is received from an adjacent sensor on one side between the sensing operations. A fiber equipped with a data selective transfer function that transfers data to the adjacent sensor on the other side, except for data that is applied only to itself, and a function that executes a command included in the received data addressed to itself A type photoelectric sensor is already known (see Patent Document 3).

  In addition, a single unit is provided with a plurality of detection channels, and the front and rear optical fiber insertion ports corresponding to one detection channel are arranged vertically, and the number of such optical fiber insertion ports is equal to the number of detection channels. A multi-channel fiber photoelectric sensor arranged in the lateral direction is already known (see Patent Document 4).

JP 2002-279871 A International Publication No. 01/31607 Pamphlet JP 2001-222786 A JP 7-301733 A

  In recent years, with the increasing sophistication of control at industrial sites, there is a need to control a large number of detection objects with a single control device. When a large number of objects to be detected exist at high density, a fiber-type photoelectric sensor tends to be frequently used because of the small size of the sensor head and ease of handling. In particular, a continuous fiber type photoelectric sensor that can be connected in large numbers via a DIN rail is preferable in that a large number of sensors can be mounted in a narrow space.

  However, since the conventional fiber photoelectric sensors described in Patent Documents 1 to 3 can only cover the detection operation for one channel, for example, 8 channels (8 locations), 16 channels (16 locations) When there are a plurality of detection objects such as 32 channels (32 locations), it is necessary to arrange a large number of fiber photoelectric sensors such as 8, 16, 32 according to the number of channels. Of course, with regard to the width or thickness of these sensors in the connecting direction, as a result of studies by each manufacturer to reduce the thickness, for example, a reduction to a width of about 10 mm has been achieved. However, since these efforts to reduce the thickness are limited, as the number of channels increases, the continuous length of the sensor group along the DIN rail becomes difficult to ignore. In particular, in the case where it is unavoidable to be incorporated in a control device such as a machine tool, there are more space restrictions than in the case of being incorporated in a general control panel.

  In addition, since the sensor is an independent product for each channel, the use of many sensors increases the cost. Since the case of the sensor may be large, it may be possible to reduce costs by handling multiple detection channels in a single product, but the number of channels required by the user varies, so any user In order to satisfy these needs, many models with different numbers of channels are required, and a sufficient cost reduction effect cannot be obtained after all. In addition, when the number of channels is increased, it is not clear what kind of consideration should be given to the configuration from the viewpoints of performance such as output responsiveness, the function of cooperating with other fiber-type photoelectric sensors connected, and ease of use. Further, if the optical fiber insertion ports of a plurality of detection channels are arranged in the horizontal direction as in the fiber type photoelectric sensor described in Patent Document 4, the space saving effect due to the increase in the number of channels cannot be obtained sufficiently.

  The present invention has been made paying attention to such conventional problems, and the object of the present invention is to provide a fiber capable of reducing the actual occupied width per channel when a plurality of units are connected. It is to provide a type photoelectric sensor.

  Another object of the present invention is to provide a fiber-type photoelectric sensor capable of maintaining the operation and display function for each channel as much as possible while reducing the substantial occupied width per channel. It is in.

  Another object of the present invention is to perform output operation and display operation by effectively using detection information between adjacent channels while substantially reducing the occupied width per channel. An object of the present invention is to provide a fiber-type photoelectric sensor that can be used.

  Still another object of the present invention is to provide a highly compatible fiber photoelectric sensor that can be directly applied to a conventional one-channel continuous sensor system.

  Still another object of the present invention is to reduce costs regardless of whether a relatively small number of detection channels are used or a relatively large number of detection channels are required. The object is to provide a fiber-type photoelectric sensor.

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

  The fiber-type photoelectric sensor of the present invention has a rail mounting portion on the bottom surface, a display portion and an operation portion on the top surface, a fiber insertion opening on the front surface, a cord lead-out type or connector-type output portion on the rear surface, and dimensions in the rail longitudinal direction. Is assumed to be 15 mm or less.

  Here, the “rail mounting portion” is mainly conscious of a DIN rail or the like, but the meaning of “rail” does not mean a specific physical shape. For this reason, it goes without saying that this type of fiber-type photoelectric sensor includes a wide variety of rails or fixtures of any shape that are used when mounting the inside of a control panel or control device. In addition, the “upper surface” on which the “display unit and the operation unit” are provided means the upper surface when mounted on a horizontal mounting surface, and is a surface that is positioned vertically upward in an arbitrary mounting state. It goes without saying that it is not. Here, the upper surface may be a transparent cover or the like on the upper surface. Furthermore, the upper surface does not necessarily need to be a flat surface, and all the surfaces that are inclined or have a gently curved surface for easy visual recognition are also included in the upper surface.

  The “front surface” provided with the fiber insertion port also means the front surface when attached to a horizontal surface, and does not mean the front surface in an arbitrary posture. If the sensor housing and fiber clamper housing are separable, the surface of the clamper into which the fiber is inserted corresponds to the “front” here. The meaning of “front” should be understood from comparison with “rear” described later.

  Needless to say, the “rear surface” on which the output unit is provided is the “rear surface” with respect to the “front surface” when mounted on a horizontal plane. Note that the “cord drawing method” is a method in which the tip of an electric cord corresponding to a power supply line or signal line is permanently fixed inside the sensor housing with solder, screws, etc., and is not removable in normal operation. In other words, the connector system is one in which the power supply line and the signal line are detachably attached to the sensor body case via the connector as disclosed in Japanese Patent Application Laid-Open No. 2001-196127 by the present applicant. At this time, there is also known one in which adjacent connectors are connected to share a power line.

  Furthermore, the reason why the length in the longitudinal direction of the rail is set to 15 mm or less is an invention applied to a thin product having a size comparable to a size that has been achieved by the current product and is expected to be standard in the future. This is to make it clear. Note that if this size of the fiber photoelectric sensor is too small, the display unit and the operation switch become small and difficult to use. Therefore, it is considered that there is a suitable size instead of thinning anywhere. The preferable dimension is about 5 to 15 mm, and more preferably 7 to 12 mm.

  Based on the above premise, in the present invention, two sets of light projecting circuits and light receiving circuits corresponding to the first and second detection channels are provided. Here, the light receiving circuit does not include an A / D converter provided in the subsequent stage. Therefore, it is not necessary to have a separate A / D converter for each of the two sets of light receiving circuits. That is, the “two sets of light receiving circuits” mentioned here satisfy the requirement if there are two sets of light receiving elements and analog amplifier circuits. In particular, when the CPU is configured using a microprocessor, the A / D converter with a built-in microprocessor does not have a large number of bits, which imposes restrictions on high accuracy of measurement and display. In such a case, although it is somewhat expensive, if an external A / D converter is used and this is switched to the first channel and the second channel by the selector, the cost is not increased so much. A high number of data bits can be ensured, and high accuracy in detection and display can be realized.

  Next, in the present invention, a single detection operation of two detection channels (controlling the timing of obtaining the light projection timing and the amount of received light, and determining the amount of received light based on the threshold value) is performed in a time division manner. It has a CPU. As means for realizing such a CPU, not only a microprocessor but also hardware such as a programmable gate array may be used. In addition, the time division referred to here is not limited to “alternating a series of processes from light projection and reception to determination,” and may include various time division methods. As a result, the space factor occupied by the circuit components can be reduced and the cost can be reduced as compared with the case where two CPUs are provided for each detection channel.

  In the present invention, two output lines corresponding to the two detection channels are provided. Here, “two output lines” means to exclude one corresponding to two detection channels in a time division manner using one output line. With such a configuration, since a dedicated output line exists for each channel, the output responsiveness is not impaired as compared with the time division configuration.

  Moreover, in this invention, it has four fiber insertion openings located in a line up and down on the front surface. Here, the lower two are a light emitting / receiving pair corresponding to the first channel, and the upper two are a light emitting / receiving pair corresponding to the second detection channel. When such a configuration is adopted, when a one-channel type fiber type photoelectric sensor is manufactured, if the light emitting / receiving pair constituting the detection channel is present at a position corresponding to the lower two of the housing, the one-channel type The basic structure is the same between the housing structure of the present invention and the two-channel type housing structure of the present invention, and the parts can be shared. In addition, since there are light projecting fibers and light receiving fibers used in this type of fiber-type photoelectric sensor in close contact with each other in parallel, fiber insertion ports corresponding to one channel are adjacent to each other vertically. When arranged, it becomes easy to attach the close-integrated light projecting fiber and the light receiving fiber, in which only a portion to be inserted into the sensor body is branched, to the sensor body.

  In the present invention, the first and second numerical display units are provided on the upper surface. Each of these numerical value display parts is arranged with numbers in the case longitudinal direction. In addition, the first and second numerical display units themselves are also arranged at regular intervals in the longitudinal direction of the case. As a result, the longitudinal direction of the case and the vertical direction of each numerical value are orthogonal to each other, and the numerical values can be arranged in the longitudinal direction of the case with a minimum space, thereby increasing the number of numerical digits that can be arranged. .

  Further, according to the present invention, the first numerical value display unit can display the received light amount of the first detection channel, and the second numerical display unit can display the received light amount of the second detection channel. That is, instead of switching one numerical value display section and displaying the first detection channel and the second detection channel alternatively, it is possible to simultaneously confirm the received light amount of both channels. As a result, although the detection function and display function for two channels are contained in one housing, these functions are not different from those of the conventional two one-channel type sensors. The space factor in the continuous state can be improved without deteriorating.

  According to the fiber-type photoelectric sensor of the present invention described above, it is possible to install photoelectric sensors having two functions (two channels) in the width of about one unit, and confirm the operation status of both channels simultaneously. There is an effect that can be done. Furthermore, since two detection channels are included in a single sensor product, a case and a CPU can be shared between the channels, so that the cost can be reduced. In addition, a user who needs any number of channels can satisfy the requirements by combining the sensor of the present invention having two detection channels with the sensor having one conventional detection channel. An increase in cost due to the provision of the sensor can be avoided. When a large number of detection channels are used, even if the number of channels is more than one, the waste of cost becomes a relatively small ratio, so that only the sensor of the present invention may be used.

  In a preferred embodiment of the present invention, a first operation indicator lamp is provided adjacent to the first numerical display section, and a second operation indicator lamp is provided adjacent to the second numerical display section. Either of the first and second operation indicator lamps is sandwiched between the first and second numerical display units.

  According to such a configuration, since the operation indicator lamp is provided adjacent to each channel, the relationship between the operation state and the amount of received light in each detection channel can be easily understood, and the usability is good. Become.

  According to a preferred embodiment of the present invention, the display contents of the first numerical value display unit and the second numerical value display unit are changed according to the selection operation, and the received light amount of the first detection channel and the received light amount of the second detection channel. It is possible to switch between the received light amount and threshold value of the first detection channel and the received light amount and threshold value of the second detection channel.

  According to such a configuration, each of the received light amounts or the received light amount and the threshold value for each channel can be appropriately and selectively displayed on two numerical display units provided in advance. While the functions for the channels are covered by a single sensor, the display function for each channel is not impaired.

  In a preferred embodiment of the present invention, a logical operation means for performing a logical operation between the detection result of the first detection channel and the detection result of the second detection channel, and the logical operation result by the logical operation means Is provided. “Logical operation means” includes both a logic circuit configured by wired logic and software executed by a microprocessor. In addition, regarding the “output line for outputting a logical operation result”, one of the two output lines described above can also be used, or a dedicated output line can be provided separately.

  According to such a configuration, in addition to being able to output the logical operation results of two adjacent channels, the inter-sensor communication is unnecessary compared to the conventional logical operation between adjacent sensors. High logic operation output can be obtained. In addition, since communication between adjacent sensors is unnecessary, the time can be omitted and more complicated logical operations can be performed.

  In a preferred embodiment of the present invention, a difference calculation means for calculating a difference between the light reception amount of the first detection channel and the light reception amount of the second detection channel, and a difference calculation by the difference calculation means Discriminating means for discriminating the result by the threshold value and an output line for outputting the discrimination result by the discriminating means are provided. Here, the “difference calculating means” can include both the case where an analog difference calculating circuit is used and the case where software is executed by a microprocessor. In addition, regarding the “output line for outputting the determination result”, one of the two output lines described above may be used, or a dedicated output line may be provided separately from them.

  In a preferred embodiment of the present invention, there is provided a fiber lock mechanism that simultaneously locks four fibers inserted into four fiber insertion ports arranged vertically by operating a single clamp operator. Provided. Conventionally, when a pair of optical fibers is locked, the two optical fibers are integrally clamped by a single movable block. If there are two pairs of light projecting / receiving optical fibers as in the present invention, there may be cases where attachment / detachment is required for each fiber pair. However, if two optical fiber pairs arranged vertically are locked and unlocked separately, two clamp operators (also called clamp levers, lock buttons, etc.) are required as a result. Then, for example, when the clamp operation element is a clamp lever, the two levers are rotated in order to allow the two clamp levers to coexist in a narrow space of the sensor housing and to be operated independently. Either the shaft is shifted back and forth or the lever is narrowed and arranged in parallel in the width direction of the sensor housing, and in any case, an extremely complicated structure must be adopted. As in the present invention, when the main purpose is to reduce the occupied space in the continuous state, rather than making it possible to detach and attach two pairs of fibers separately, the structure can be simplified to accommodate the case. Priority should be given to ease. From this point of view, it can be said that a fiber lock mechanism that simultaneously locks four fibers by operating a single clamp operator is optimal for the purpose of space saving. Here, the fiber lock mechanism includes a base block in which four fiber insertion holes for receiving the tip of the fiber are arranged at appropriate intervals in the vertical direction (the interval may or may not be constant), and a base block 4 flexible C-rings fixed to the base block so as to correspond to the respective inlets of the 4 fiber insertion ports, and 4 on the front side of the base block and supported slidably in the vertical direction. A common slide actuator that engages with each of the C-rings to expand or contract its diameter, and a clamp lever that is rotatably supported by the base block and slides the slide actuator by the rotation. It may be included.

  Furthermore, in a preferred embodiment of the present invention, each time the detection operation timing generated based on the external synchronization signal arrives, the detection channel to be detected is set as the first detection channel and the second detection channel. Switching means for alternately switching to the detection channel is provided.

  In general, in this type of sensor system, a plurality of slave units are connected to a single master unit (the master unit and the slave units have the same configuration and are either self-configured or set by an external device. The master unit periodically sends a synchronization signal to the adjacent sensor by a timer, while each slave unit connected to the master unit sends the synchronization signal by, for example, a bucket relay method. Each handset sensor performs the detection operation after receiving the synchronization signal from the adjacent sensor and transmits the synchronization signal to the adjacent sensor with a slight delay time. . As a result, while the master unit manages the synchronization of the entire system, the slave unit performs light projection and reception with a slight time difference, thereby preventing interference between adjacent sensors. On the other hand, in each master unit or slave unit, a certain amount of time is required for processing the received light data after the light transmission / reception, and during these cycles, the operation of all the sensors constituting the system is completed. The reception processing operation in the last sensor must be completed. However, if the conventional one-channel built-in sensor and the two-channel built-in sensor of the present invention are mixed, or all the sensors constituting the sensor system are the two-channel built-in sensor of the present invention, the same When detection operation is performed with a slight delay time between adjacent channels in the sensor, especially when two receiving circuits are mounted on the same circuit board, noise is mixed between channels or voltage fluctuation of the power supply line. It is assumed that the detection operation is hindered by the influence of the above.

  In addition, if the detection operation for two channels is continuously performed in one sensor, naturally, the time to complete the operation occupied by the one sensor becomes longer. Even if the assumed maximum number of channels is mounted, such as 16 channels and 32 channels, the operation in the last channel should be completed within a predetermined cycle, but there are sensors with 2 channels in the system. By doing so, one cycle may be exceeded (so-called cycle time over), and there is a possibility that the operation of the entire sensor system may be hindered.

  On the other hand, as in this embodiment of the present invention, although there are two channels in the sensor housing, adjacent two channels in one sensor are not operated continuously, that is, each time the operation of the sensor system is completed. If the adjacent sensors perform detection operations alternately, the time required for the detection operation is the same as that of a sensor with one channel even if a two-channel function is installed in one sensor. Even in the sensor system that performs the synchronization management, the detection operation can be performed normally without any trouble in the entire sensor system.

  In this embodiment, a plurality of slave units exist with respect to the single master unit described above, and not only a sensor system of a type that sequentially transfers synchronization signals, but also each sensor in which a common synchronization line constitutes the system in parallel. Even in a sensor that is synchronized as a whole with a unique delay time on each sensor side, it functions effectively. That is, even in a sensor system using such a common synchronization line, the maximum cycle time corresponding to the most planned number of connected units such as 8, 16, and 32 is determined, so two channels can be used for a specific sensor. If the occupancy time per unit increases due to the mounting, the same inconvenience should occur in the entire system.

  Therefore, as in this embodiment, every time the detection operation timing generated based on the external synchronization signal arrives, the detection channel on which the detection operation should be performed is alternated between the first detection channel and the second detection channel. Even if the sensor system has a predetermined cycle (cycle time) in advance, even if a sensor having two channels is incorporated in one or all of the sensors constituting the sensor system, There is an advantage that it does not adversely affect.

  The fiber type photoelectric sensor of the present invention defined from other viewpoints has a rail mounting portion on the bottom surface, a display portion and an operation portion on the top surface, a fiber insertion port on the front surface, and an output portion composed of a cord drawing method or a connector method on the rear surface, respectively. 2 sets of light projecting circuits and light receiving circuits corresponding to the first and second detection channels, a single CPU for performing the detection operation of the two detection channels in a time-sharing manner, and two detection channels The two output lines corresponding to, four fiber insertion ports arranged on the front surface, and the upper surface of the case, can display a number of digits arranged in the longitudinal direction of the case, the first detection And a display configured to be able to display the received light amount of the channel and the received light amount of the second detection channel by means of numerical values. According to this fiber-type photoelectric sensor, as described above, it can be manufactured at a lower cost than the two sensors corresponding to one channel. In addition, since the amount of light received by each channel can be confirmed numerically, it is easy to use.

  According to a preferred embodiment of this fiber type photoelectric sensor, the indicator can display a plurality of digits arranged in the longitudinal direction of the case, and the first, A second numerical value display unit is provided, and the first numerical value display unit can display the amount of light received by the first detection channel, and the second numerical value display unit can display the amount of light received by the second detection channel. It is said. As a result, the amount of light received by both channels can be confirmed simultaneously. As another embodiment of the display, the received light amount of each channel may be switched to one numerical value display unit and displayed.

  This fiber type photoelectric sensor can adopt various arrangements of four fiber insertion openings. For example, two fiber insertion openings of one channel are arranged vertically, and fiber insertion openings of different channels are arranged in the horizontal direction. Two fiber insertion openings of one channel are arranged in the horizontal direction, and fiber insertions of different channels are inserted. An arrangement in which the mouths are arranged one above the other, an arrangement including these oblique positional relationships, and the like. According to another preferred embodiment of the fiber photoelectric sensor, the length in the rail longitudinal direction is 15 mm or less, and the four fiber insertion openings are arranged vertically on the front surface. As a result, the four fiber insertion openings can be easily arranged on the front surface of the narrow sensor, and the function (two channels) photoelectric sensor for two units can be arranged in the width of about one unit. .

  The four fiber insertion openings can be arranged so that the lower two are a light emitting / receiving pair corresponding to the first detection channel and the upper two are a light emitting / receiving pair corresponding to the second detection channel.

  As is apparent from the above description, according to the photoelectric sensor of the present invention, the detection operation for two channels can be performed with one unit, and the received light amount of each channel can be confirmed by a numerical value. It can be manufactured at a lower cost than the corresponding two sensors.

It is a perspective view which shows the continuous attachment state of a photoelectric sensor. It is a disassembled perspective view which shows the internal structure of a photoelectric sensor. It is a disassembled perspective view which shows the internal structure of a clamp assembly. It is a perspective view which shows the unclamped state of a clamp assembly. It is a perspective view which shows the clamp state of a clamp assembly. It is the perspective view which looked at the fiber gripper from diagonally forward. It is a figure which shows the front and back surface of a fiber gripper. It is a figure which shows the left side surface and right side surface of a fiber gripper. It is explanatory drawing of the external dimension of a photoelectric sensor. It is a block diagram which shows the electrical hardware constitutions of a photoelectric sensor. It is a general flowchart which shows the whole software structure of a photoelectric sensor. It is a flowchart which shows the whole SET mode process. It is a flowchart which shows the whole RUN mode process. It is a flowchart which shows a measurement interruption process. It is explanatory drawing which expands and shows the detail of the whole display part. It is explanatory drawing which shows the display mode of a 1st, 2nd numerical value display part. It is a time chart for demonstrating the operation timing of the two channels allocated to each sensor U1, U2, U3. It is explanatory drawing which shows each processing content of the general flowchart of FIG. 11 in a table format. It is explanatory drawing which shows each process content of the SET mode process of FIG. 12 in a table format. It is explanatory drawing which shows the relationship between the function number F and the function content, and the channel individual setting possibility in a table format. It is explanatory drawing which shows each processing content of the RUN mode process of FIG. 13 in a table format. It is explanatory drawing which shows each process content of the measurement interruption process of FIG. 14 in a table format.

  Hereinafter, a preferred embodiment of a fiber photoelectric sensor according to the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are merely examples of the present invention, and needless to say, the gist of the present invention is defined only by the claims.

  FIG. 1 is a perspective view showing a connected state of photoelectric sensors according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view showing the internal structure of the photoelectric sensor.

  As shown in the drawings, the photoelectric sensor 1 of this embodiment includes a case body 10 having an upper surface opened, a body assembly 20 that is inserted into the case body 10 and closes the opening 106 of the case body 10, and And a clamper assembly (corresponding to the lock mechanism of the present invention) 30 accommodated and held in a clamper holder portion 210 provided at the front of the main assembly 20. The case body 10 is a synthetic resin integrated molded product and has a hexahedral structure including a front plate 101, a rear plate 102, a right side plate 103, a left side plate 104, and a lower plate (bottom plate) 105. The front plate 101 has a first channel light emitting fiber insertion port 107, a first channel light receiving fiber insertion port 108, a second channel light emitting fiber insertion port 109, and a second channel light receiving light. A fiber insertion port 110 is provided. That is, the front plate 101 is provided with four fiber insertion openings arranged vertically, and the two lower fiber insertion openings 107 and 108 are for inserting a light projecting / receiving pair corresponding to the first detection channel. The upper two fiber insertion ports 109 and 110 are for inserting a light projecting / receiving pair corresponding to the second detection channel.

  As shown in FIG. 1, the electric cord 5 is drawn from the rear plate 102 of the case body 10. This electric cord 5 is of a fixed type, and includes a first channel output core wire 51, a second channel output core wire 52, a Vcc core wire 53, and a GND core wire 54. It is. As described above, when pulling out a connector connection type electric cord, as shown in Japanese Patent Laid-Open No. 2001-196127, when exchanging power between adjacent connectors, the connected endmost device is used. The Vcc core wire 53 is not included except for the electrical cord output from the sensor of the part.

  The right side plate 103 and the left side plate 104 of the case body 10 are provided with light projecting / receiving windows 112 for optical communication with adjacent sensors at the same left and right positions. Therefore, when a plurality of sensors are connected via the DIN rail 2, the light projecting / receiving windows 112 face each other between adjacent sensors. In the figure, Lt is transmission infrared light, and Lr is reception infrared light.

  A DIN rail fitting groove 111 for attaching to the DIN rail 2 is formed in the lower surface plate 105 of the case body 10. Although not shown, each DIN rail fitting groove 111 is provided with an engagement mechanism for facilitating attachment / detachment with the DIN rail 2.

  An upper surface of the case body 10 is an opening 106, and the body assembly 20 is inserted into the opening, and the opening 106 is closed by the upper panel 20 </ b> A of the body assembly 20.

  As shown in FIG. 2, the main assembly 20 is configured by integrally assembling a component mounting board 20 </ b> B housed inside the case main body 10 and an upper panel 20 </ b> A that closes the upper opening 106 of the case main body 10. The upper panel 20A is provided with a “display unit” that occupies approximately 2/3 of the left side in FIG. 2 and an “operation unit” that occupies approximately 1/3 of the right side of FIG.

  The display unit includes a first numerical display unit 201, a second numerical display unit 202, a first operation indicator lamp 203, and a second operation indicator lamp 204. In other words, the first operation indicator lamp 203 is provided adjacent to the left side of the first numerical display unit 201, and the second operation indicator lamp 204 is provided adjacent to the left side of the second numerical display unit 202. As a result, the second operation indicator lamp 204 is disposed in a state of being sandwiched between the first numerical display unit 201 and the second numerical display unit 202. Each of the first numerical value display unit 201 and the second numerical value display unit 202 is configured by a 4-digit 7-segment LED display, and the numbers of each digit are arranged along the longitudinal direction of the main body case 10. Yes. In other words, the numbers of each digit are directed so that the vertical direction is orthogonal to the longitudinal direction of the case body 10. Therefore, a 4-digit numerical indicator and two operation indicator lamps are efficiently arranged in a limited space on the top panel 20A. In the present embodiment, as described later, the received light amount of the first channel can be displayed on the first numerical display unit 201 and the received light amount of the second channel can be displayed on the second numerical display unit 202. The received light amount of the two channels may be displayed in 202, and the received light amount of the first channel may be displayed in 202. In this case, 201 can be referred to as a second numerical value display unit, and 202 can be referred to as a first numerical value display unit.

  On the other hand, the operation unit occupying approximately 1/3 of the right side of the top panel 20A includes a push button 205 functioning as an UP switch operation unit, a push button 206 functioning as a DOWN switch operation unit, and a MODE switch operation unit. A push button 207 that functions, a slide operator 208 that functions as an operation unit of a SET / RUN changeover switch, and a slide operator 209 that functions as an operation unit of a channel changeover switch are provided. Hereinafter, the push button 205 is referred to as an UP button, the push button 206 is referred to as a DOWN button, and the push button 207 is referred to as a MODE button.

  A clamper holder portion 210 is provided at the front portion of the main body assembly 20, and the clamper assembly 30 is accommodated and fixed in the clamper holder portion 210.

  FIG. 3 is an exploded perspective view showing the internal structure of the clamper assembly, FIG. 4 is an exploded perspective view showing the clamper assembly in an unclamped state, FIG. 5 is an exploded perspective view showing the clamped state of the clamper assembly, and FIG. A perspective view of the fiber gripper is shown in FIG. 6, a front view and a back view of the fiber gripper are shown in FIG. 7, and a left side view and a right side view of the fiber gripper are shown in FIG.

  As shown in FIG. 3, the clamper assembly 30 includes a base block 310, a lower fiber gripper 320, an upper fiber gripper 330, a clamp lever 340, and a slide actuator 350.

  Four fiber insertion holes 310a, 310b, 310c, and 310d are provided on the front surface of the base block 310. The insertion hole 310a is for inserting the tip of the first channel light projecting optical fiber 31, and the insertion hole 310b is for receiving the tip of the light receiving optical fiber 32 of the first channel. is there. Similarly, the insertion hole 310c is for receiving the distal end portion of the light projecting optical fiber 41 of the second channel, and the insertion hole 310d is for receiving the distal end portion of the light receiving optical fiber 42 of the second channel. Is. In addition to the insertion holes, positioning holes 310e and 310f for the lower fiber gripper 320 and a mounting stage 310i are provided on the front surface of the base block 310. Similarly, positioning holes 310g and 310h for the upper fiber gripper 330 and a mounting stage 310j are provided on the front surface of the base block 310. In addition, guide protrusions 310 n, 310 o, and 310 p that engage with the slide actuator 350 are provided on the left and right edge portions on the front side of the base block 310. A bracket 310l is provided on the upper portion of the base block 310, and a shaft hole 310m is provided in the bracket 310l. A clamper lever 340 is rotatably attached to the shaft hole 310m via a pin 310k.

  As shown in FIGS. 6 to 8, the lower fiber gripper 320 has a shape in which an upper C ring portion 320a and a lower C ring portion 320b are connected, and is integrally formed using plastic. As shown in FIG. 6, the gap portion 320f of the upper C ring portion 320a is located on the left side, and the gap portion 320g of the lower C ring portion 320b is located on the right side. An ear part 320c is provided at the free end of the upper C ring part 320a, and an ear part 320d is provided at the free end of the lower C ring part 320b. By pushing down these ears 320c and 320d downward, the inner diameters of the upper C-ring part 320a and the lower C-ring part 320b are reduced. Conversely, when the downward force on the ears 320c and 320d is released, the C-ring parts 320a and 320b are restored to their original shapes by elasticity, and the inner diameter is expanded. As will be described in detail later, when the slide actuator 350 slides up and down, a downward force is applied to the ear portions 320c and 320d, and the upper C-ring portion 320a and the lower C-ring portion 320b are bent to have an inner diameter. Is reduced, and the fibers inserted in the ring portions are firmly gripped.

  As shown in FIGS. 7 and 8, a round bar-like protrusion 320 h and a flat protrusion 320 i are formed on the back surface of the lower fiber gripper 320. As described above, the protrusion 320h is inserted into the positioning hole 310e of the base block 310, and the protrusion 320i is inserted into the positioning hole 310f. Further, the bottom surface of the lower fiber gripper 320 abuts on the stage 310i, whereby the entire lower fiber gripper 320 is placed on the stage 310i and is firmly fixed to the base block 310 via the positioning holes 310e and 310f. Is done. The upper fiber gripper 330 has the same structure, and is placed on the stage 310j and fixed to the base block 310 through the positioning holes 310g and 310h. As a result, the four C-ring portions 320a, 320b, 330a, and 330b are positioned at the inlet portions of the four fiber insertion holes 310a, 310b, 310c, and 310d provided in the base block 310.

  The slide actuator 350 has a U-shaped cross section when viewed from above. A lower window 350a and an upper window 350b are formed in the front side. In addition, three guide slits 350c, 350d, and 350e are provided on the left and right side surfaces. When these guide slits 350c, 350d, and 350e are engaged with the guide protrusions 310n, 310o, and 310p on the base block 310 side, the slide actuator 350 is held on the base block 310 side, and with a slight stroke in the vertical direction. It is slidable. Four protrusions 350 f, 350 g, 350 h, and 350 i are provided on the left and right side walls in the slide actuator 350. When the slide actuator 350 slides downward, a protrusion 350f formed on the left side surface of the slide actuator 350 comes into contact with the ear portion 320c of the upper C ring portion 320a of the lower fiber gripper 320. At the same time, the protrusion 350 g formed on the right side surface inside the slide actuator 350 abuts on the ear portion 320 d of the lower C-ring portion 320 b of the lower fiber gripper 320. Therefore, when the slide actuator 350 slides further downward, the ear part 320c and the ear part 320d of the lower fiber gripper 320 are pushed downward, and the C-ring part is bent, so that the respective inner diameters are reduced. Thereby, the fibers inserted through the ring portions 320a and 320b are firmly gripped. The same operation is performed in the upper fiber gripper 330, and the protrusions 350h and 350i of the slide actuator 350 are brought into contact with the corresponding ear portions of the upper C ring portion 330a and the lower C ring portion 330b of the upper fiber gripper 330. The inner diameters of the ring portions are reduced, and the inserted fibers are gripped firmly.

  A clamp lever 340 is rotatably attached to the shaft hole 310m of the bracket 330l of the base block 310 via a pin 310k. That is, in a state where the shaft hole 310m of the bracket 310l and the shaft hole 340a of the clamp lever 340 are aligned with each other, the clamp lever 340 rotates with respect to the bracket 310l by passing the pins 310k through the shaft holes. Fixed to move freely. In such a state, the cam portion 340 b formed on the lower surface of the clamp lever 340 contacts the upper end surface 350 j of the slide actuator 350. Therefore, as shown in FIG. 4, when the clamp lever 340 is lifted, the slide actuator 350 is lifted upward by the restoring force of the C-ring portion. On the other hand, as shown in FIG. 5, when the clamp lever 340 is pushed down, the cam portion 340b presses the upper end surface 350j of the slide actuator 350 downward, causing the slide actuator 350 to slide downward. As described, the protrusions 350f to 350i hit the corresponding ears of the upper and lower fiber grippers 320 and 330, and push down the corresponding ears, so that the corresponding ears of the C ring portions 320a, 320b, 330a and 330b are lowered. When pushed down, the fiber is gripped firmly.

  As described above, according to the clamper assembly of the present embodiment, the base block 310 in which the four fiber insertion holes 310a to 310d for receiving the tip portions of the fibers are arranged at appropriate intervals in the vertical direction, and the base block 310 4 Four flexible C-rings 320a, 320b, 330a, 330b fixed to the base block corresponding to the respective inlets of the fiber insertion holes 310a-310d, and in the vertical direction on the front side of the base block 310 And a single slide actuator 350 that engages with each of the four C-rings 320a, 320b, 330a, and 330b to enlarge or reduce the diameter thereof, and is rotatable to the base block 310. The slide actuator 350 is slid by the rotation. That is one having a clamp lever 340. Therefore, by operating one clamp lever 340, the four fibers of the first channel and the second channel can be locked simultaneously. In addition, although the clamp lever 340 and the slide actuator 350 are common, the four C-ring portions are integrated two by two and separated into the lower fiber gripper 320 and the upper fiber gripper 330, and the fibers Since the grippers 320 and 330 are independent of each other and do not cooperate with each other, if the sensor is configured for one channel instead of two, only one of the fiber grippers need be removed, and most components It is also possible to selectively produce one channel and two channels for sharing. In addition, the slide actuator 350 has a U-shaped cross section when viewed from above, so that it is structurally strong and can maintain strength even when it is thinned. This is suitable for transmitting the force from the clamp lever 340 to the upper and lower fiber grippers 320 and 330. Further, in both the upper and lower fiber grippers 320 and 330, the upper and lower C-ring portions 320a and 320b are arranged so that the gap portions 320f and 320g are different from each other on the left and right sides, and the side of the slide actuator 350 engaged therewith. Since the protrusions 350f and 350g are also separated on the left and right sides, the force from above can be applied equally to the upper C-ring part 320a and the lower C-ring part 320b, and the fiber can be gripped with a good balance.

  Returning to FIGS. 1 and 2, a hinge 211 is provided at the rear of the top panel 20A, and the transparent top cover 6 that opens and closes the top panel 20A is rotatably attached by the hinge 211. In FIG. 4, the protrusion 322 is a guide pin when the clamper assembly 30 is attached to the clamper holder part 210.

  Next, an explanatory diagram of the external dimensions of the photoelectric sensor described in FIGS. 1 to 8 is shown in FIG. As shown in the figure, the photoelectric sensor 1 shown in FIGS. 1 to 8 has a width W, a height H, and a depth L. Here, the width W corresponds to the dimension in the longitudinal direction of the DIN rail, as shown in FIG. The depth L corresponds to a dimension in a direction orthogonal to the longitudinal direction of the DIN rail. Further, the height H corresponds to a dimension in a direction perpendicular to the mounting surface of the DIN rail 2. In particular, in the photoelectric sensor 1 in this embodiment, the width W is set to a range of 7 mm to 12 mm, the height H is set to 25 mm to 40 mm, and the depth L is set to a range of 60 mm to 80 mm. As a more specific example, the width W is 10 mm, the height H is 32 mm, and the depth L is 70 mm. According to the two-channel mounting type photoelectric sensor having such a width W, the continuous mounting width when 8 units are connected is 80 mm, the capacity for 16 channels, and the connecting width when 16 units are connected is 160 mm and 32 channels. When the capacity is 32 minutes, the continuous width is 320 mm and the capacity for 64 channels can be covered. Therefore, as compared with the conventional one-channel mounting type photoelectric sensor, the channel capacity can be doubled with the same number of consecutively mounted photoelectric sensors, which is more suitable for high-density mounting.

  Next, FIG. 10 shows a block diagram showing an electrical hardware configuration of the photoelectric sensor of the same embodiment. In the figure, reference numeral 700 denotes a board mounting circuit included in the component mounting board 20B shown in FIG. The board-mounted circuit 700 is mainly composed of a control unit (CPU) 701. In this embodiment, the control unit (CPU) 701 is realized by a microprocessor that functions as a one-chip microcomputer.

  The entire substrate mounting circuit 700 is divided into a detection system circuit and a communication system circuit. First, the detection system circuit will be described in detail. The detection system circuit is divided into a first channel side and a second channel side. Both configurations are almost the same.

  That is, the first channel side includes a light projecting system circuit, a light receiving system circuit, and an APC system circuit. The light projecting circuit includes a light projecting circuit 701a that operates in response to a signal S11 from a control unit (CPU) 701, and an LED 702a that is driven by the light projecting circuit 701a. The light emitted from the LED 702a constituting the light projecting circuit is introduced into the light projecting optical fiber 31 and sent to a fiber head (not shown). The light receiving system circuit includes a main light receiving PD 703a that receives light coming from the light receiving fiber 32, and an amplifier circuit 704a that amplifies the output signal of the main light receiving PD 703a. The APC circuit includes an APC light receiving PD 705a that receives light from the LED 702a constituting the light projecting circuit, and an APC light receiving circuit 706a that amplifies the output signal of the APC light receiving PD. The output signal S13 of the APC light receiving circuit 706a is taken into the CPU 701 through an A / D converter with a built-in CPU (not shown). As a result, the CPU 701 executes auto power control related to the LED 702a constituting the light projecting circuit.

  Similarly, the light emitting system circuit, the light receiving system circuit, and the APC system circuit are also included on the second channel side. The light projecting circuit includes a light projecting circuit 701b that operates in response to a signal S21 from the control unit (CPU) 701, and an LED 702b that is driven by the light projecting circuit 701b. Light emitted from the LED 702b is introduced into the light projecting fiber 41 and sent to a fiber head (not shown). The light receiving system circuit includes a main light receiving PD 703b that receives light from the light receiving fiber 42, and an amplification circuit 704b that amplifies the output of the main light receiving PD 703b. The APC system circuit includes an APC light receiving PD 705b that receives light from the LED 702b constituting the light projecting circuit, and an APC light receiving circuit 706b that amplifies the output of the APC system circuit 705b. The output signal S23 of the APC light receiving circuit 706b is taken into the control unit (CPU) 701 via a CPU built-in A / D converter (not shown) and used for auto power control of the LED 702b constituting the light projecting system circuit.

  On the other hand, an output signal S12 of the first channel amplifier circuit 704a and an output signal S22 of the second channel amplifier circuit 704b are input in parallel to the input side of the channel switching circuit 707. The channel switching circuit 707 performs a switching operation under the control of the CPU 701. Further, an external A / D converter 708 provided separately from the CPU 701 is provided on the output side of the channel switching circuit 707. The number of output bits of the converter 708 is set sufficiently larger than that of the A / D converter built in the control unit (CPU) 701. As an example, the A / D converter with a built-in CPU currently has about 10 bits, whereas the external A / D converter 708 has 12 bits. Therefore, the CPU 701 controls the channel switching circuit 707 as appropriate so that the light reception output of the main light reception PD 703a for the first channel or the output of the main light reception PD 703b for the second channel can be accurately detected via the external A / D converter 708. Can be detected.

  Next, a communication system circuit will be described. This communication system circuit is also divided into a left side and a right side. That is, as described above with reference to FIGS. 1 and 2, the left and right side plates of the case body 10 of the photoelectric sensor 1 are provided with the light projecting and receiving windows 112. By performing optical communication, individual photoelectric sensors connected adjacent to each other can perform optical communication with the left and right adjacent photoelectric sensors. The optical communication system circuit is divided into a right side and a left side.

  The left communication system circuit includes a transmission system circuit and a reception system circuit. The transmission system circuit includes a communication projection drive circuit 709a that operates in response to a signal S41 from the CPU 701, and a communication LED 710a that is driven by the communication projection drive circuit 709a. Here, the communication LED 710a is set to emit infrared light. The reception system circuit includes a communication PD 711a that receives infrared light from an adjacent sensor, and a communication amplification circuit 712a that amplifies the output of the communication PD 711a. The output signal S42 of the communication amplifier circuit 712a is taken into the CPU 701. Transmission data is included in signal S41, and reception data is included in signal S42.

  The communication system circuit on the right side includes a transmission system circuit and a reception system circuit. The transmission system circuit includes a communication light projecting drive circuit 709b that operates in response to a signal S51 from the CPU 701, and a communication LED 710b that is driven by the communication light projecting drive circuit 709b. Here, the communication LED 710b is set to emit infrared light. The reception system circuit includes a communication PD 711b that receives infrared light emitted from an adjacent sensor, and a communication amplification circuit 712b that amplifies the output of the communication PD 711b. The output signal S52 of the communication amplifier circuit 712b is taken into the CPU 701. Transmission data is included in signal S51, and reception data is included in signal S52.

  The output system circuit includes a control output circuit 715 for the first channel and a control output circuit 716 for the second channel. The control output circuit 715 for the first channel generates a detection output of the first channel system, and the detection output obtained in this way is sent to the core wire 51 for the first channel output included in the electrical cord 5. The control output circuit 716 for the second channel generates a control output for the second channel system, and the signal from the control output circuit 716 for the second channel is the second channel included in the electrical code 5. It is sent out to the core wire 52 for output. Thus, this photoelectric sensor has separate control output circuits 715 and 716 for the first channel and the second channel. Therefore, when a detection output is generated asynchronously in either the first channel or the second channel, this signal can be sent immediately to the core wire 51 or 52 included in the electric cord 5 at any time. That is, if one control output circuit common to the first channel and the second channel is provided, and this is switched appropriately in time division, the response of the detection output is impaired. Since each channel has a dedicated control output circuit 715, 716, the response speed is not impaired.

  The power supply circuit 718 stabilizes the power obtained from the Vcc core wire 53 and the GND core wire 54 and supplies the stabilized power to the substrate mounting circuit 700. Further, the CPU reset circuit 717 has an action of resetting the microprocessor constituting the control unit (CPU) 701 in response to a predetermined operation by the user.

  Next, the configuration of the display system will be described. A display drive circuit 719 is provided as a display system element. As described above with reference to FIGS. 1 and 2, the display drive circuit 719 includes a 7-segment display constituting the first numerical value display unit 201 and a 7-segment display constituting the second numerical value display unit 202. The operation indicator lamp 203 of the first channel and the operation indicator lamp 204 of the second channel are driven. The data to be driven is generated by the arithmetic processing of the CPU 701.

  Next, the configuration of the operation system will be described. An operation circuit 720 is included as the operation system. As described above with reference to FIGS. 1 and 2, the operation circuit 720 includes an UP switch 205a corresponding to the UP button 205, a DOWN switch 206a corresponding to the DOWN button 206, and a MODE switch corresponding to the MODE button 207. 207a, the SET / RUN switch 208a corresponding to the SET / RUN slide operator 208, and the channel switch 209a corresponding to the channel switch slide operator 209, by processing signals, these switches were operated. This is transmitted to the control unit (CPU) 701 and the corresponding control program is activated.

  In FIG. 10, reference numeral 714 denotes an EEPROM for storing various setting data necessary for the control unit (CPU) 701, and reference numeral 713 denotes a clock necessary for the operation of the control unit (CPU) 701. It is a crystal oscillator for generating.

  Next, FIG. 11 shows a general flowchart showing the entire software configuration of the photoelectric sensor, and FIG. 18 shows an explanatory diagram showing the processing contents of the flowchart in the form of a table. The operation of the photoelectric sensor shown in the embodiment will be described in detail below with reference to these drawings.

  When the process is started in FIG. 11, an initial setting process (step 1101) is first executed. As shown in FIG. 18, in this initial setting process (step 1101), initialization of various memories, indicator lamps, and control output, and processing for calling essential items from the EEPROM 714 and checking data are executed. Thereafter, the state of the SET / RUN changeover switch 208a shown in FIG. 10 is referred to (step 1102).

  As a result of referring to the state of the SET / RUN changeover switch 208a, if it is set to the SET side (step 1102 SET), then the SET mode initial setting process (step 1103) is executed. As shown in FIG. 18, in the SET mode initial setting process (step 1103), the SET mode setting value is initialized and the function number F is initialized (F = 0). As will be described in detail later, FIG. 20 is an explanatory diagram showing the relationship between the function number F and the function contents, and whether individual channels can be set, in a table format. Here, teaching (F = 0), operation mode setting (F = 1), detection function setting (F = 2), timer function setting (F = 3), display content setting (F = 4), key function assignment setting (F = 5), power tuning target value setting (F = 6), display direction setting (F = 7), and output content setting (F = 8). When the SET mode initial setting process (step 1103) ends, the SET mode process (step 1104) is subsequently executed according to the contents of the SET mode designated at that time. Thereafter, as long as the content of the SET / RUN changeover switch 208a is determined to be “SET” (YES in step 1105), the SET mode processing (step 1104) is continuously executed, and the content of the SET / RUN changeover switch 208a becomes “RUN”. Is determined (NO in step 1105), the process returns to step 1102.

  FIG. 12 is a flowchart showing the entire SET mode processing, and FIG. 19 is an explanatory diagram showing the processing contents of the SET mode processing of FIG. 12 in a table format. As shown in these figures, when the SET mode process is started, a function-specific display process (step 1201) is executed to control the indicator lamp and display according to the set function number (F). Is done.

  After that, a key input detection process (step 1202) is executed to detect a key input at regular intervals. When an input is detected, a setting is made so that the corresponding process can be executed. Here, the key input is detected through operations of the UP button 205, the DOWN button 206, the MODE button 207, the slide operator 208, and the slide operator 209. Thereafter, a state of waiting for key input is entered (NO in step 1203).

  In this state, it is determined that there is a key input (YES in step 1203), and if it is determined that it is a function switching command (YES in step 1204), the value of the function number (F) is incremented by +1 each time. The value is increased until reaching the value (NO in step 1206) (step 1205), and is reset to zero each time the maximum value is reached (YES in step 1206) (step 1207). Thus, the operator can select a desired function while changing the function number (F) by operating the UP button 205 shown in FIG.

  On the other hand, after the operator selects the function number (F), for example, when the MODE button 207 is operated to instruct the execution of the function (NO in steps 1204 and 1208), the function-specific execution process is performed (step 1209). In this function-specific execution processing (step 1209), processing according to the set function number (F) is executed, and in the case of a function capable of individual channel setting, the state of the channel selector switch 209a is detected and Processing for the channel to be performed is performed.

  FIG. 20 is an explanatory diagram showing the relationship between the function number (F) and the function contents and whether individual channel setting is possible in a table format.

  That is, as shown in FIG. 20, if the function number (F) is “0”, the teaching function is selected. In this teaching function, various teachings are performed in accordance with key inputs to determine a threshold value. As teaching methods, teaching without work, teaching without work, maximum sensitivity setting, and the like can be employed as already various methods. In this example, individual setting for each channel regarding the teaching function is possible. Therefore, while performing teaching without workpiece for the first channel, you can freely use teaching without workpiece for the second channel or changing the threshold value between the first channel and the second channel. Can be done. For this reason, one sensor can cover two channels, but adopts different types of teaching for each channel, realizing the same function as if using two sensors with one channel built in. can do.

  When the function number (F) is “1”, the operation mode setting function is selected. In this operation mode setting function, it is possible to set operation modes such as an ON mode when light is incident and an ON mode when light is blocked. Even in this operation mode setting function, individual setting is possible for each channel. Therefore, even if two channels are included in one sensor, different operation modes are set for each channel, such as setting the first channel to the ON mode when light enters and the second channel to the ON mode when light is blocked. Can be performed. This also realizes the same function as if two sensors built in one channel are used, while two channels are covered by one sensor.

  When the function number (F) is “2”, the detection function setting function is selected. With this detection function setting function, the detection function can be selected. Depending on the selection of this function, the detection algorithm at the time of ON / OFF determination differs. Here, a standard mode, a fastest mode, a high accuracy mode, and the like are prepared as detection functions. In this embodiment, regarding this detection function setting function, individual setting for each channel is denied.

  When the function number (F) is “3”, the timer function setting function is selected. In this timer function setting function, the timer mode and the timer time are set. With this setting, the output timing for ON / OFF determination is set. Here, timer mode includes timer off, off delay, on delay, one shot, and the like. In addition, a specification is set such that the timer time is set within a possible range except when the timer is off. In this timer function setting function, individual setting for each channel is possible. Therefore, various setting contents can be selected such that the timer mode is set to off-delay for the first channel while the on-delay is set for the second channel. Even from this point, although one sensor has a function for two channels, a timer function can be set for each channel, so that it is easy to use.

  When the function number (F) is “4”, the display content setting function is selected. In this display content setting function, display content is selected. Here, as the display contents, a received light amount, a threshold value, a bar display, and the like are prepared. In addition, the display contents can be combined and displayed, and hold values (peak, bottom, etc.) of the contents can be displayed. However, regarding this display content setting function, individual setting for each channel is denied.

  When the function number (F) is “5”, the key function assignment setting function is selected. In this key function assignment setting function, the role of the key in the RUN mode is selected. Here, power tuning, zero reset, and the like are prepared as key assignments. Regarding this key function assignment setting function, individual setting for each channel is denied.

  When the function number (F) is “6”, the power tuning target value setting function is selected. In this power tuning target value setting function, a target value at the time of power tuning execution is set. Regarding the power tuning target value setting function, individual setting for each channel is denied.

  When the function number (F) is “7”, the display direction setting function is selected. In this display direction setting function, the display direction is selected. Here, if “normal” is set, display in the normal direction is performed, and if “reverse” is selected, display in the reverse direction is performed. Regarding this display direction setting function, individual setting for each channel is denied.

  When the function number (F) is “8”, the output content setting function is selected. In this output content setting function, the output content of the second channel is set in the 2-output type model. Here, as output contents, normally independent output, AND output, OR output, and differential output are prepared. Normally, there is no need to explain the independent output. However, when the AND output is selected, the logical product of the detection output of the first channel and the detection output of the second channel is calculated and this is output to a specific output line. Is output. When the OR output is set, the logical sum of the detection output of the first channel and the detection output of the second channel is obtained by calculation, and this logical sum output is sent to a specific output line. When the difference output is further set, the difference calculation between the light reception amount of the first channel and the light reception amount of the second channel is performed, and the result obtained by comparing the obtained difference output with a predetermined threshold is as follows: Sent to a specific output line. That is, the determination result is sent out to a specific output line depending on whether or not the deviation between the received light amount of the first channel and the received light amount of the second channel exceeds a predetermined threshold value. This difference calculation is performed by a microprocessor constituting the control unit (CPU) 701, as will be described later when the RUN mode is executed. However, a similar function can be achieved even if an analog operation circuit such as an OP amplifier is separately provided, the operation is performed outside the control unit (CPU) 701, and the operation result is further discriminated by an analog comparator. It goes without saying that it can be realized. In particular, regarding this differential output, what was previously performed by two adjacent photoelectric sensors is taken into one of the sensors via communication between the adjacent sensors, and then logical determination is performed. Compared with the configuration of this type, the two-channel built-in sensor according to the present invention eliminates the need for communication between adjacent sensors, thereby improving output response and communication. By not interposing, it is possible to realize a more advanced determination output with sufficient time margin. Returning to the flowchart of FIG. 12, even if a key input is detected (1203 YES), if it is not related to the SET mode processing, the SET mode processing is skipped (1204 NO, 1208 NO), and other processing is executed. .

  Returning to FIG. 11, if it is determined that the state of the SET / RUN selector switch 208a is "RUN" (step 1102RUN), then the RUN mode initial setting process (step 1106) is executed. In this RUN mode initial setting process (step 1106), as shown in FIG. 18, initialization of indicator lamps and control output, initialization of threshold values and various RUN mode setting values, and projection / reception channel numbers are performed. C is initialized (C = 1). Here, the value of the light emitting / receiving channel number C is used to control which detection channel should be operated in the RUN mode described later. That is, in this embodiment, since the first channel system and the second channel system are alternately executed in a time division manner by one CPU, which one of them is executed is determined by this light emitting / receiving channel number C. It is determined according to the value of.

  Thereafter, as long as the content of the SET / RUN changeover switch 208a is determined to be “RUN” (YES in step 1108), the RUN mode process (step 1107) is continuously executed.

  FIG. 13 is a flowchart showing the entire RUN mode processing, and FIG. 21 is an explanatory diagram showing each processing content of the RUN mode processing in a table format. In FIG. 13, when the process is started, an indicator light control process is first executed (step 1301). In this indicator light control process (step 1301), lighting control of the 7-segment display is performed according to the designated display content. Here, “designated display content” is determined by selecting the display content setting function by setting the function number (F) to “4” in the SET mode processing (step 1104). The amount of light received, threshold value, and bar display.

  Subsequently, communication command execution processing (step 1302) is executed. In this communication command execution process (step 1302), when a communication command is received in a measurement interrupt process (step 1350) described later, this means that the process of the corresponding command is executed. As previously disclosed by the present applicant in Japanese Patent Application Laid-Open No. 2001-222788, a data setting command, an operation disable command, a hidden function execution command, and the like are prepared. Subsequently, in the APC process (step 1303), the monitor light reception amount acquired in the measurement interrupt process (step 1350) described later is monitored, and the power of the APC (auto power control) light projecting current is set at regular intervals. Control ') Perform correction. At this time, since APC correction is performed for each channel, even when the characteristics of the light projecting element, the light receiving element, the light projecting circuit, and the light receiving circuit are different for each channel, appropriate automatic power control is always performed for each channel. Is done.

  Subsequently, in the key input detection process (step 1304), the key input is detected at regular intervals, and when an input is detected, setting is performed so that the corresponding process can be executed. Thereafter, based on the detected key input state, the contents instructed by the key input are the channel switching command (step 1306), the threshold adjustment command (step 1307), the power tuning command (step 1308), and the zero reset command. (Step 1309) and the key lock command (Step 1310) are determined. Here, according to those determination results, channel switching processing (step 1311), threshold adjustment processing (step 1312), power tuning processing (step 1313), zero reset processing (step 1314), key lock processing (step 13) 1315) is executed.

  Here, when the channel switching process (step 1311) is executed, the designated channel is switched according to the key input. That is, in FIG. 1 and FIG. 2, when the slide operator 209 is set to either the first channel or the second channel, the setting state is read via the channel changeover switch 209a and the designated channel is read. Is switched.

  When the threshold adjustment process (step 1312) is executed, the threshold is changed according to the key input, and the threshold adjustment process corresponding to the designated channel is performed. Done. That is, the threshold value is changed in accordance with a predetermined key operation for the designated channel depending on whether the slide operator 209 is set to the first channel or the second channel at that time.

  Further, when the power tuning process (step 1313) is executed, optimal adjustment of the light projecting power and the light receiving gain is performed so as to obtain a target detection value (execution of power tuning). On the other hand, when “power tuning cancellation” is requested, the default light emission power and light reception gain state are restored (power tuning cancellation). Further, execution of power tuning and cancellation of power tuning are performed for a designated channel in accordance with the setting state of the channel changeover switch 209. As a result, it is possible to perform separate power tuning for the first channel or the second channel individually, so even if the characteristics of the light projecting / receiving system differ between the first channel and the second channel, Optimal power tuning is performed, and the same usability as using two sensors with one channel built-in can be obtained.

  Further, when the zero reset process (step 1314) is executed, the starting light reception amount is determined so that the current light reception amount display becomes “0”. Thereafter, the received light amount is displayed from the starting received light amount. Similarly, the threshold value is also shifted and displayed according to the above-mentioned received light amount of the starting point (execute zero reset). On the other hand, when “zero reset release” is requested, a return to the default received light amount display state is performed (zero reset release). Since these zero reset execution and zero reset release can be performed individually for the designated channel as in the previous case, the operation is exactly the same as using two sensors with one channel built-in. Zero reset can be executed for each channel at intervals. The zero reset process has been previously disclosed in detail in Japanese Patent Laid-Open No. 2001-124594 by the applicant of the present application, and thus the description thereof is omitted here.

  When the key lock process (step 1315) is executed, “key lock” is set. When this “key lock” is set, it operates so as not to accept an input other than a specific key. On the other hand, when “key lock release” is requested, the lock state is released.

  Subsequently, the measurement interrupt process (step 1350) executed by the scheduled interrupt will be described in detail. FIG. 14 is a flowchart showing the measurement interrupt process, and FIG. 22 is an explanatory diagram showing the processing contents of the measurement interrupt process in a table format.

  When the process is started in FIG. 14, a synchronous communication process (step 1401) is first executed. In this synchronous communication process, as shown in FIG. 22, a light projection synchronization signal is transmitted to the adjacent sensor. As described above with reference to FIGS. 1 and 2, the left and right side plates 103 and 104 of the main body case 10 of the photoelectric sensor 1 have the light emitting / receiving windows 112 formed therein. As described above with reference to FIG. 10, the left communication LED 710a, the left communication PD 711a or the right communication LED 710b, and the right communication PD 711b are arranged. Then, by appropriately driving these LEDs and PD, information can be transmitted and received between adjacent sensors via optical communication. The details of the transmission and reception of such information have been disclosed in detail in Japanese Patent Laid-Open No. 2001-222786 by the present applicant. That is, in this synchronous communication process (step 1401), a light emission synchronization signal is transmitted to an adjacent slave unit at regular intervals by a scheduled timer process from a master unit located at the end of a series of sensors connected in series. . Then, each slave unit connected to the slave unit sequentially transfers the projection synchronization signal to the adjacent slave unit with a certain delay time. As a result, in the parent device and each child device adjacent thereto, the operation timing at which the device itself should operate can be acquired with a slight phase delay, for example, at a cycle of 100 μsec.

  Thus, when it is determined that the operation timing has come as a result of the execution of the synchronous communication process (step 1401), the contents of the set channel at that time are determined based on the contents of the channel setting register C. If “C = 1”, it is determined that the first channel is set, and if “C = 2”, the second channel is determined.

  As a result of referring to the contents of the channel designation register C, if the contents are determined to be “1”, the processing of the first channel system is subsequently performed, whereas if it is determined to be “2”, the second Channel system processing is executed.

  Assuming that it is determined that the value of the channel designation register C is “1” (step 1402 C = 1), a light projecting / receiving process (step 1403) for the first channel is subsequently executed. In the light projection / reception process (step 1403) relating to the first channel, lighting control of the first channel light projection LED 702a is performed in accordance with the set detection mode, and the received light amount obtained through the main light reception PD 703a in that state. Is converted into an electrical signal and then A / D conversion is performed via the A / D converter 708 to obtain a detection value. The detected value detected here is used for ON / OFF determination processing relating to the first channel, display in the RUN mode processing, and the like.

  Subsequently, an ON / OFF determination process (step 1404) regarding the first channel is executed. In the ON / OFF determination process (step 1404) for the first channel, the set detection function, timer mode, and operation mode (L.ON / D.ON) are compared by comparing the acquired detection value with the threshold level. ) To determine ON / OFF of the first channel.

  Subsequently, output control processing (step 1405) regarding the first channel is executed. In the output control process for the first channel (step 1405), output control of the first channel control output and lighting control of the operation indicator lamp are performed according to the ON / OFF state of the first channel. At this time, the control output of the first channel is transmitted to the outside via the first channel control output circuit 715 shown in FIG. 10, and the lighting control of the operation indicator lamp 203 is performed via the display drive circuit 719. Done.

  In this way, after the output control processing for the first channel (step 1405) is completed, the value of the channel designation register is rewritten from “1” to “2” (step 1406). Thereafter, when command communication processing (step 1413) is executed and command communication is received by communication, the received content is saved and command transfer to the adjacent sensor is performed.

  Next, when the next interruption process is executed, the content of the channel designation register C is determined after waiting for the arrival of the operation timing in the synchronous communication process (step 1401) (step 1402). At this time, since the value of the channel designation register C has been rewritten from “1” to “2” in the previous interrupt processing (step 1406), C = 2 in the current determination processing (step 1402). As a result, a light projecting / receiving process (step 1407) relating to the second channel is executed.

  In the light projection / reception process (step 1407) regarding the second channel, the lighting control of the light projection LED 702b of the second channel is performed in accordance with the set detection mode, and the received light amount obtained via the main light reception PD 703b is converted into an electric signal. Then, the detection value is obtained by performing A / D conversion via the A / D converter 708. The detection value acquired here is used for the ON / OFF determination processing related to the second channel, the display in the RUN mode processing, and the like.

  When the execution of the light projection / reception processing (step 1407) relating to the second channel is completed in this way, it is subsequently determined whether or not the difference detection output is set (step 1408). As described above, the difference detection output can be specified by setting “8” as the function number (F) and selecting the output content setting function in the SET mode process (step 1104). . If it is determined that there is no difference detection output designation (NO in step 1408), then an ON / OFF determination process (step 1409) relating to the second channel is executed.

  In the ON / OFF determination process (step 1409) regarding the second channel, the set detection function, timer mode, and operation mode (L.ON / D.ON) are compared by comparing the acquired detection value with the threshold level. ) To determine ON / OFF of the second channel.

  On the other hand, if it is determined that there is a difference detection output designation (step 1408 YES), then a difference determination process (step 1410) is executed. In this difference determination process (step 1410), the timer mode and the operation mode (L. ON./L) are compared by comparing the threshold level with a value obtained by subtracting the light reception amount of the second channel from the light reception amount of the first channel. D. ON), ON / OFF determination of the second channel is performed. That is, by this difference determination process, a difference between both received light amounts is obtained between two channels incorporated in one sensor, and a determination output is output depending on whether or not the difference exceeds a predetermined threshold value. It can be generated.

  Subsequently, an output control process (step 1411) regarding the second channel is executed. In this output control process (step 1411), output control of the second channel control output and lighting control of the operation indicator lamp are performed according to the output content setting in the SET mode. As described above with reference to FIG. 20, as the output content setting, a normal independent output, an AND output, an OR output, and a differential output are prepared. In “normally independent output”, the ON / OFF determination result for the second channel is output. In the “AND output”, the AND output of the ON / OFF determination result of the first channel and the second channel is transmitted. In the case of “OR output”, an OR output of ON / OFF determination results of the first channel and the second channel is generated and sent to the outside. Further, in “difference output”, the determination result obtained in the difference determination process (step 1410) is output.

  In this way, when the output control process for the second channel (step 1411) is completed, the value of the channel designation register C is rewritten from “2” to “1” (step 1412). After that, when the command communication process (step 1413) is executed and the command communication is received by communication, the received content is held and the command is transferred to the adjacent sensor. Transition to measurement interrupt processing.

  As a result, as a result of the reference processing of the channel specification register C in step 1402 and the channel specification register rewrite processing performed in steps 1406 and 1412, the value of the channel specification register C is alternately “1” and “ 2 ”, the first channel system processing (steps 1403 to 1405) and the second channel system processing (steps 1407 to 1411) are alternately executed.

  Then, as shown in FIG. 17, in the sensor system in which a large number of sensors are connected via the DIN rail, the first channel and the second channel are the main units in the individual 2-channel built-in sensors. It is executed alternately with the determined light projection period in between, and each sensor operates normally without disturbing the synchronization management in the same manner as the conventional photoelectric sensor with a built-in one channel.

  That is, although two channels are incorporated in one sensor, only one channel in each sensor is activated every one operation cycle, so 8 points according to the operation cycle determined by the master unit, Even in a model in which the maximum number of connections is limited, such as 16 points or 32 points, even if one of those sensors or all of them are the two-channel built-in type sensors according to the present invention, There is a risk that the operation period of the final sensor will exceed the predetermined period and the entire system will be hindered by the simultaneous operation of two channels within a single sensor within a short time. It can be prevented in advance.

  That is, the example of FIG. 17 takes three sensors (sensors U1, U2, U3) as an example, and when each is a two-channel built-in type sensor, the operation cycle (cycle) of the conventional one-channel built-in type is shown. This indicates that this operates normally while maintaining (time).

  1CH and 2CH are assigned to the sensor U1 which is the parent device, 3CH and 4CH are assigned to the sensor U2 which is the child device, and 5CH and 6CH are assigned to U3 which is the child device. In this state, if the sensor U1 as the master unit takes the initiative and transmits a synchronization signal to the sensor U2 as the adjacent sensor at a constant period, the sensor U2 performs the detection operation for 3CH, and then further detects the sensor from the sensor U2. A synchronization signal is transmitted by optical communication toward U3. Then, in the subsequent sensor U3, the detection operation regarding 5CH is performed. Thereafter, when the synchronization period elapses, the sensor U1 performs a detection operation for 2CH by timer management, and a synchronization signal is transmitted to the sensor U2 that continues slightly later than this. Then, in the sensor U2, a detection operation related to 4CH is performed, and thereafter, a synchronization signal is transmitted by optical communication with respect to the sensor U3 with a slight delay. Then, the detection operation related to 6CH is performed in the sensor U3, and then the detection operation related to 1CH is performed in the sensor U1 which is the master unit after waiting for the elapse of the light projection cycle by the internal timer management. . Thereafter, a synchronization signal is sent to the sensor U2 as an optical signal with a slight delay. Then, the detection operation related to 3CH is performed in the sensor U2, and a synchronization signal is transmitted to the sensor U3 by optical communication with a slight delay thereafter. Then, the sensor U3 performs a detection operation on 5CH, and thereafter, in each of the sensors U1, U2, and U3, two adjacent channels are alternately executed. As a result, even though two channels are built in each sensor, the dedicated time in each sensor is the same as that of a one-channel built-in sensor, so as long as the maximum number of sensors can be connected. By increasing the number of connected sensors to the maximum specified number, it is possible to double the number of channels that can be handled while maintaining a certain sensor exclusive width.

  Finally, FIG. 15 is an explanatory diagram showing an enlarged detail of the entire display unit, and FIG. 16 is an explanatory diagram showing a display mode of the first and second numerical value display units.

  That is, in the present invention, various display modes related to the first channel and the second channel can be obtained by skillfully using the first numerical value display unit 201 and the second numerical value display unit 202.

  As shown in FIG. 16A, if the <light reception amount + light reception amount> display is selected, the light reception amount of the first channel is set to “1000” in the first numerical value display portion 201, and the second numerical value display portion. In 202, the received light amount of the second channel is displayed as "3000".

  Also, as shown in FIG. 16 (b), if the <light reception amount + threshold value> display is selected in a state where the channel changeover switch 209a is set to the first channel, the first numerical value display unit 201 is displayed. The received light amount of the first channel is displayed as “4000”, and at the same time, the threshold value of the first channel is displayed as “1800” on the second numerical value display unit 202.

  Further, as shown in FIG. 16C, in the state where the channel changeover switch 209a is set to the second channel side, if <light reception amount + threshold> display is selected, the first numerical value display unit 201 is displayed. , The received light amount of the second channel is displayed as “3000”, and the threshold value of the second channel is displayed as “700” on the second numerical value display unit 202.

  Further, as shown in FIG. 16D, when the <bar> display is selected, the light quantity on the light incident side of each channel is displayed on the first numerical value display unit 201 by dividing the area vertically and simultaneously. On the second numerical value display section 202, the light-shielding side light quantity of each channel is similarly displayed as a bar with the area divided vertically.

  Furthermore, as shown in FIG. 16 (e), for example, in a state where the channel changeover switch 209a is set to the second channel side, if the <light reception amount difference value + threshold> display is selected, the first The numerical value display unit 201 displays the difference between the received light amount of the first channel and the received light amount of the second channel as “+300”, and the second numerical value display unit 202 displays the difference threshold value as “−500”. The

  As described above, as shown in FIGS. 16A to 16E, according to the present invention, the two numeric display units 201 and 202 are incorporated while incorporating the functions of two channels in one sensor. Can be used to display various data such as the amount of received light, threshold value, and difference in an easy-to-understand manner for the operator, and not only the numerical display but also the input of each channel as shown in FIG. It is also possible to display the light side or light shielding side light amount as a bar.

  As described above in detail, according to the two-channel built-in fiber photoelectric sensor of the present embodiment, the same channel capacity can be provided in half the space compared to the conventional one-channel built-in photoelectric sensor. On the other hand, if the same amount of space as in the previous system is secured, twice the channel capacity can be obtained. In addition, since the two channels incorporated in each sensor operate only one by one alternately for each synchronization period, the synchronization period is disturbed even when applied to a conventional one-channel embedded system. In addition, there is no adverse effect on other sensors, and the two channels do not operate at the same time with a slight time difference within one sensor. It is possible to provide a highly reliable and user-friendly sensor system without causing a problem that the potential fluctuation affects the operation of the other channel.

  In addition, by skillfully utilizing the two numerical display units and two operation indicator lamps provided on both sides of the sensor case, the received light amount of both channels can be viewed simultaneously, and the received light amount and threshold value for each channel can be determined. It is possible to provide the operator with good usability by observing the images while comparing them, or by further displaying the light quantity data of the two channels in two columns on the upper and lower sides of the numerical display.

DESCRIPTION OF SYMBOLS 1 Photoelectric sensor 2 DIN rail 5 Electrical cord 6 Upper surface cover 10 Case main body 20 Main body assembly 20A Upper surface panel 20B Component mounting board 30 Clamp assembly 31 Optical fiber for 1st channel light emission 32 Optical fiber for 1st channel light reception 41 2nd Optical fiber for channel light emission 42 Optical fiber for light reception of second channel 51 Core wire for first channel output 52 Core wire for second channel output 53 Core wire for Vcc 54 Core wire for GND 101 Front plate 102 Rear plate 103 Right side plate 104 Left side plate 105 Bottom plate (bottom plate)
106 opening 107 fiber insertion port for first channel projection 108 fiber insertion port for first channel reception 109 fiber insertion port for second channel projection 110 fiber insertion port for second channel reception 111 DIN rail fitting groove 112 Projector / Receiver Window 201 First Numerical Display Unit 202 Second Numerical Display Unit 203 First Operation Indicator Light 204 Second Operation Indicator Light 205, 206, 207 Push Button 205a UP Switch 206a DOWN Switch 207a MODE Switch 208, 209 Slide Operator 208a SET / RUN changeover switch 209a Channel changeover switch 210 Clamper holder part 211 Hinge part 310 Base block 310a-310d Fiber insertion hole 310e, 310g Positioning hole 310f, 310h Positioning hole 3 0i, 310j Stage 310n, 310o, 310p Guide projection 310l Bracket 310m Shaft hole 310k Pin 320 Lower fiber gripper 320a Lower fiber gripper upper C ring portion 320b Lower fiber gripper lower C ring portion 320h Round rod projection 320i Flat plate 320f, 320g Gap part 330 Upper fiber gripper 330a Upper C ring part of upper fiber gripper 330b Lower C ring part of upper fiber gripper 340 Clamp lever 340a Shaft hole 340b Clamp lever cam part 350 Slide actuator 350a Lower window 350b Upper window 350c, 350d, 350e Guide slit 350f, 350g, 350h, 350i Protrusion 350j for sliding the fiber gripper Upper surface 700 substrate mounting the circuit 701 the control unit of the Chueta (CPU)
701a First channel light projection circuit 701b Second channel light projection circuit 702a First channel LED
702b Second channel LED
703a Main light receiving PD of the first channel
703b Main light receiving PD of the second channel
704a First channel amplifier circuit 704b Second channel amplifier circuit 705a First channel light receiving PD for APC
705b 2nd channel light receiving PD for APC
706a APC light receiving circuit for the first channel 706b APC light receiving circuit for the second channel 707 Channel switching circuit 708 External A / D converter 709a Communication light projecting drive circuit on the left side 710a Communication LED on the left side
710b Right communication LED
711a PD for communication on the left side
711b PD for communication on the right side
712a Communication amplifier circuit on the left side 712b Communication amplifier circuit on the right side 713 Oscillator 714 EEPROM
715 1-channel control output circuit 716 2-channel control output circuit 717 CPU reset circuit 718 power supply circuit 719 display drive circuit 720 operation circuit W sensor width H sensor height L sensor depth

Claims (2)

A fiber-type photoelectric sensor having a rail mounting portion on the bottom surface, a display portion and an operation portion on the top surface, a fiber insertion port on the front surface, and an output portion consisting of a cord drawing method or a connector method on the rear surface,
Two sets of light projecting circuits and light receiving circuits corresponding to the first and second detection channels;
A single CPU that performs time-division detection operation of two detection channels;
Two output lines corresponding to the two detection channels;
And four fiber insertion ports arranged on the front surface,
A SET processing mode in which the function contents of the setting items provided in each detection channel can be set;
The RUN processing mode in which the detection operation by the two sets of the light projecting circuit and the light receiving circuit is switchable according to the function contents of the setting items set in the two detection channels is characterized in that it can be switched. Fiber photoelectric sensor. Channel switching means capable of switching which one of the first and second detection channels is designated;
The fiber type photoelectric sensor according to claim 1, wherein the detection channel in the SET processing mode is designated by the channel switching means.

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