JP2009109422A - Detection sensor, and amplifier body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a detection sensor allowing investigation of a failure. <P>SOLUTION: The detection sensor 1 includes a detecting means 15 for performing detecting operation based on the existence of a detection object, a storing means 32 for storing past detection distance information in the detecting operation, and an output means 15 to output the detection distance information stored in the storing means 32 in response to a trigger signal from the outside. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a detection sensor and an amplifier body.

As an example of the detection sensor, there is an optical fiber sensor (see Patent Document 1 below). The light emitted from the light projecting element is emitted to the detection area via the optical fiber cable, and the light from the detection area is received by the light receiving element via the optical fiber cable and output from the light receiving element. Based on the received light signal, it is detected whether or not a detection target exists in the detection region.
JP 2003-14984 A

  By the way, for example, when a problem occurs during the use of the optical fiber sensor by the user, this is a problem that occurred before shipment, such as the time of manufacture of the optical fiber sensor, or a new problem occurred due to the user's usage method, etc. It is necessary to investigate whether it is a malfunction. However, the conventional detection sensor has nothing to investigate it.

  The present invention has been completed based on the above circumstances, and an object thereof is to provide a detection sensor capable of investigating a problem.

As means for achieving the above object, the detection sensor according to the first aspect of the invention is a detection that performs a detection operation in accordance with a physical quantity of a detection target (for example, a change in physical quantity depending on the presence / absence of the detection target or a state such as a distance). Means, storage means for storing past detection distance information in the detection operation, and output means for outputting the detection distance information stored in the storage means in response to an external trigger signal.
According to the present invention, if the detection distance information when the detection operation is executed in the past (for example, at the time of manufacture) is stored in the storage unit, the past detection distance and the current detection distance are compared, It is possible to know whether a malfunction that has occurred has occurred from the past or has newly occurred, and it becomes possible to investigate the malfunction.

According to a second aspect of the present invention, there is provided an amplifier body of a detection sensor in which a detection head is detachably provided, a detection means for performing a detection operation according to a physical quantity of a detection target based on a signal from the detection head, and the detection operation Storage means for storing past detection distance information and output means for outputting the detection distance information stored in the storage means in response to an external trigger signal.
According to the present invention, if the detection distance information when the detection head is attached and the detection operation is executed in the past (for example, at the time of manufacture or when the user starts using) is stored in the storage means, the past detection is performed. By comparing the distance with the current detection distance, it is possible to know whether the presently occurring defect has occurred from the past or newly, and it is possible to investigate the defect.

  According to the present invention, it is possible to investigate a defect in a detection sensor.

<Embodiment 1>
A first embodiment of the present invention will be described with reference to FIGS.
In FIG. 1, the direction of arrow A is the forward direction, and the direction of arrow B is the right direction.

1. Schematic Configuration of Entire Sensor System The sensor system of the present embodiment is configured to include, for example, 16 optical fiber sensors 1 (only four of which are shown in FIGS. 1 and 2) having the same structure, and each optical fiber sensor. 1 are arranged adjacent to each other with the leading ends of the optical fibers 19 derived therefrom facing the detection region, and perform a detection operation according to the presence or absence of the detection target in the detection region. Then, the sensor system reflects, for example, the detection result of each optical fiber sensor 1 in the transmission signal transmitted from the communication unit 2, while the light positioned on the other end side from the optical fiber sensor 1 positioned on the one end side. Data transmission (serial transmission) is performed by a so-called bucket relay system that sequentially transfers to the fiber sensor 1.

  In the following description, when referring to the entire optical fiber sensor 1, it is referred to as a sensor 1, and when referring to individual optical fiber sensors 1, the first optical fiber sensor 1 to the second optical fiber sensor 1 are referred to as the second optical fiber sensor 1. These are referred to as sensor 1, third sensor 1, and fourth sensor 1. In the present embodiment, the first sensor 1 provided on the left side in FIG. 2 is a parent device, and the right second sensor 1 is a child device. These are also referred to as a parent device sensor 1A and a child device sensor 1B.

2. External Configuration of Each Device (1) Optical Fiber Sensor As shown in FIG. 1, each sensor 1 has a configuration in which an optical fiber 19 is led out from the front surface of the amplifier body 40. Specifically, the amplifier main body 40 has a box shape, and the tip of the optical fiber 19 is inserted into a fiber insertion hole provided on the front surface, while a cable connector C connected to a control unit (not shown) is provided on the rear surface. It is connected. Further, a light projecting element 12 corresponding to the output side coupler is provided on the right side surface of the sensor 1, and a light receiving element 11 corresponding to the input side coupler is provided on the left side surface. A square-shaped through-hole 13 penetrating is formed. Further, a pinching portion (hidden by the terminal unit 4 in FIG. 1) is formed by forming dovetail grooves (grooves whose opening side is narrower than the bottom surface side) along the alignment direction of the sensors 1 on the lower surface. (Not shown) is provided.

  The sensor 1 is mounted by passing the clamping portion through a groove of a well-known DIN rail 3 corresponding to a mounting rail, and the light projecting element 12 and the light receiving element 11 of the sensor 1 which are closely adjacent to each other face each other. It has become a state. The light projecting element 12 and the light receiving element 11 are driven by a light projecting circuit 16 and a light receiving circuit 14, respectively. Each sensor 1 is also provided with a memory 32 (see FIG. 3).

(2) Communication Unit and Termination Unit A communication unit 2 and a termination unit 4 that are similarly box-shaped are arranged on the sides of the first and fourth sensors 1. The communication unit 2 is provided with a holding part (not shown) having the same shape as the holding part of the sensor 1, and is attached to the holding part through the DIN rail 3. In addition, two screw holes 21 formed so as to penetrate between the upper and lower surfaces are provided, and a screw 22 that is screwed into the screw hole 21 is provided. 3 can be inserted and fixed to the DIN rail 3. The end unit 4 is similarly provided with a clamping part 41, a screw hole 42 and a screw 43, and can be fixed to the DIN rail 3 by tightening the screw 43.

  The light projecting element 23 corresponding to the output side coupler provided on the right side surface of the communication unit 2 is disposed at a position facing the light receiving element 11 of the first sensor 1, and is positioned at the position facing the through hole 13 at the input side. A light receiving element 24 corresponding to a coupler is provided. Further, the light receiving element 44 corresponding to the relay input portion provided on the left side surface of the termination unit 4 is arranged at a position facing the light projecting element 12 of the fourth sensor 1, and at a position facing the through hole 13. A light projecting element 45 corresponding to the relay output unit is provided. An optical axis can be formed between the light projecting element 45 of the termination unit 4 and the light receiving element 24 of the communication unit 2 through the through hole 13 of the sensor 1.

3. Next, the electrical configuration of the sensor system will be described with reference to FIG.
(1) Communication unit First, a setting operation unit 20 is provided in the housing of the communication unit 2, and an input of an address for specifying the communication partner sensor 1 by operating a setting switch provided therein, and the sensor A command to be executed by 1 (an example of an external trigger signal) can be input. In addition, by connecting a personal computer (not shown) to the communication unit 2, an address and a command to each sensor 1 can be input via the communication unit 2 by an operation on this computer, or from each sensor 1. Data can be acquired by a computer.

  The switch state of this setting switch is taken into the CPU 25, where a transmission signal is generated and given to the light projecting circuit 26 which constitutes the communication unit side transmitting means together with the light projecting element 23. The light projecting circuit 26 supplies a drive current to the light projecting element 23 based on the transmission signal, and sequentially transmits the transmission signal as an optical signal to the first sensor 1 at a predetermined cycle (for example, 50 μS). On the other hand, the light incident on the light receiving element 24 is input to the CPU 25 via the light receiving circuit 27 corresponding to the communication unit side receiving means.

(2) Optical fiber sensor In each sensor 1, a transmission signal received as an optical signal by the light receiving element 11 is converted into an electric signal, and converted into a digital signal by a light receiving circuit 14 that constitutes an inter-sensor receiving means together with the light receiving element 11. And given to the CPU 15. The CPU 15 executes detection operation, transmission error determination, and the like based on a synchronization signal included in the transmission signal, and executes various processes based on command data. Then, a transmission signal reflecting its own detection result is sent to the light projecting circuit 16 that constitutes the sensor-to-sensor transmission means together with the light projecting element 12, and a drive current is supplied from the light projecting circuit 16 to the light projecting element 12 for light projection. Light up.

  As shown in FIG. 3, each sensor 1 is provided with a power supply terminal P <b> 1 and a ground terminal P <b> 2 for supplying power to the sensor 1. A switch element 50 (for example, a transistor) and a resistor 51 are connected between the power supply terminal P1 and the ground terminal P2. Further, an output terminal P3 is connected to a connection point between the switch element 50 and the resistor 51.

  The CPU 15 performs a light projecting / receiving operation during the detection operation. In other words, the light projecting unit 17 emits light, and is projected onto the detection region through the optical fiber 19. At this time, the amount of light received by the light receiving unit 18 that receives the reflected light from the detection region through the optical fiber 19 is acquired. Then, the received light amount is compared with a threshold value, and an on / off signal corresponding to the comparison result is given to the control terminal (for example, base) of the switch element 50. Thereby, the switch element 50 is turned on and off. At this time, the CPU 15 functions as detection means. The terminals P1 to P3 are provided on the connector C.

(3) Termination unit The light incident on the light receiving element 44 corresponding to the relay input section of the termination unit 4 is converted into a digital signal by the light receiving circuit 46 and then passed through a relay amplifier 48 having a signal amplification function. The light is sent to the light projecting circuit 47. Based on the signal, the light projecting circuit 47 supplies a drive current to the light projecting element 45 corresponding to the relay output unit to project light from the light projecting element 45. As a result, the transmission signal transmitted between the sensors 1 is returned from the termination unit 4 to the communication unit 2. The output of the light projecting element 45 is set to be stronger than the light projecting element 12 of the sensor 1.

4). Regarding storage of test result information When the user uses the sensor 1, a malfunction may occur. Specifically, the detection distance that is the limit distance from which the presence or absence of the detection target can be determined, the power consumption of the sensor 1, the detection sensitivity, the output level of the output terminal P3, and the like satisfy the specifications of the sensor 1 (for example, catalog specifications). There may not be. And if you can grasp whether such a defect has occurred from the time of manufacture (before the product is shipped) or a new one after the product has been shipped, for example, depending on the user's usage environment, It can be used for future measures.

  Therefore, various inspections are performed on each sensor 1 at the manufacturing stage, and the inspection results can be stored in the memory 32 (an example of a storage unit). However, since various setting information and the like are also stored in the memory 32, not much test result information should be stored in the memory 32. In the present embodiment, only the detection distance information (an example of past detection distance information) and power consumption information at the manufacturing stage are stored in the memory 32. This is because these tend to occur frequently and are particularly important inspection items.

  The detection distance is measured by first disposing the detection object in the detection region and displacing the distance between the sensor 1 and the detection object while causing the sensor 1 to perform the light projecting / receiving operation. If the distance between the sensor 1 and the detection object at the time when the on / off of the switch element is switched (when the level of the output terminal P3 is inverted), the detection distance can be obtained. In the method of measuring power consumption, first, a shunt resistor (not shown) is connected between the power supply terminal P1 and the output terminal P3, and the switch element is turned on. The current consumption between the power supply terminal P1 and the ground terminal P2 at this time is measured with a multimeter (not shown).

  Next, using the serial transmission by the communication unit 2 and the termination unit 4, the respective detection distance information and power consumption information are transmitted to each sensor 1 and stored in each memory 32. As a result, each sensor 1 stores detection distance information and power consumption information at the time of manufacture in the memory 32. Note that the detection distance information and the power consumption information are not necessarily the detection distance data and the power consumption data themselves, and may be stored in the memory 32 after being encoded or encrypted, for example.

  When the manufacturer receives a consultation from the user that the above problem has occurred, the manufacturer performs the following operation. First, the current detection distance and current consumption are measured by the above measuring method. Next, by inputting a command (an example of a trigger signal) in the communication unit 2, the detection distance information and the power consumption information at the time of manufacture of each sensor 1 stored in the memory 32 are extracted using the serial transmission. . At this time, the CPU 15, the light projecting element 12, the light projecting circuit 16, and the like function as output means.

  If both the detection distance and the power consumption value are the same at the time of manufacture and the current time, it is understood that the problem has occurred from the time of manufacture, and it is understood that the manufacturing process and the transport process should be reviewed. On the other hand, if the value of at least one of the detection distance and the power consumption differs between the time of manufacture and the current time, there is a possibility of a malfunction due to the user's usage environment / method, so the user is notified of the correct usage environment / method.

  For example, the current detection distance information and power consumption information are transmitted to the memory 32 of each sensor 1 by the serial transmission, and the CPU 15 of each sensor 1 determines the values of the detection distance and power consumption at the time of manufacture and the current time. It may be determined whether or not they are the same, and a signal corresponding to the determination result is returned to the communication unit 2. Moreover, the structure which makes the display means 38 perform the display pattern according to the said determination result may be sufficient.

<Embodiment 2>
FIG. 4 shows a second embodiment. In the first embodiment, the light projecting element and the light receiving element are integrally provided in the amplifier main body 40. However, the detection sensor of the present embodiment is a detection in which the light projecting element and the light receiving element are derived from the amplifier main body. This is a so-called head-separated photoelectric sensor provided on the head side.

  The head-separated photoelectric sensor according to the present embodiment (hereinafter referred to as “photoelectric sensor 60”) includes a light projecting element 62 (for example, a light emitting diode) and encloses a signal line L connected to the light projecting element 62 (not shown). A light projecting head unit 61 (an example of a detection head) formed by deriving a cable and a light receiving element 64 (for example, a photodiode), and a light receiving head unit 63 formed by deriving a signal line L connected to the light receiving element 64. (An example of a detection head) and an amplifier main body 70 including two connection terminal portions 66 and 67 for light projection and light reception to which signal lines L from both head portions 61 and 63 are connected, respectively. ing.

  The light projecting head unit 61 and the light receiving head unit 63 are arranged in parallel toward a predetermined detection region, for example, and receive light signals (from the light receiving element 64 that change due to reflection by the detection target W existing in front of them) ( An example of a signal from the detection head) The presence or absence of the detection object W is detected based on the level. Both head portions 61 and 63 are detachably attached to the amplifier main body 70.

  The amplifier main body 70 includes a CPU 69 that functions as detection means. Among the above-mentioned light projecting connection terminal portions 66, one connection terminal 66A is a transistor whose collector side is connected to the DC power source Vcc through a biasing resistor and receives a drive pulse P from the CPU 69 to perform a switching operation. 68 is connected to the emitter side, and the other connection terminal 66B is connected to the ground line.

  Of the light receiving connection terminal portion 67, one connection terminal 67A is connected to the DC power source Vcc via a bias resistor and connected to the CPU 69 via a capacitor 65, and the other connection terminal 67B. Is connected to the ground line. Capacitor 65 serves as DC voltage removal.

  Further, the CPU 69 gives a driving pulse P to the transistor 68 at a predetermined timing. Thereby, the light projecting element 62 of the light projecting head portion 61 connected to the light projecting connection terminal portion 66 emits light and performs a light projecting operation. Further, the CPU 69 reads the potential at the connection point with the capacitor 65 in synchronization with the output timing of the drive pulse P and compares it with a predetermined threshold value. Here, the threshold value is set to, for example, an intermediate level between the potential level when the detection target W is not present in the detection region and the potential level when the detection target W is present. Then, the CPU 69 outputs a detection signal via, for example, an output circuit (not shown) when the potential level exceeds the threshold value.

The photoelectric sensor 60 is also provided with a memory 32, three terminals P1 to P3, a switch element 50, and a resistor 51, as in the first embodiment.
By the way, as described above, the photoelectric sensor 60 of the present embodiment is a head separation type, and the light projecting head unit 61 and the light receiving head unit 63 are mounted on the amplifier main body 70 in a replaceable manner. Accordingly, the light projecting head unit 61 and the light receiving head unit 63 that are connected to the amplifier main body 70 may differ between when the photoelectric sensor 60 is manufactured and when it is used by the user.

  Therefore, for example, at the manufacturing stage, a standard head for inspection (the light projection head unit 61 and the light receiving head unit 63 have the same configuration and are prepared for inspection) is connected to the amplifier main body 70, and at the manufacturing stage, Detection distance information (an example of past detection distance information) and power consumption information are stored in the memory 32. When a problem occurs during user use, the detection distance and current consumption at that time are measured.

  However, in this configuration, the detection distance and the like stored in the memory 32 are those when the standard head is mounted, while the currently measured detection distance and the like are not the standard head but are actually used by the user. The projection head unit 61 and the light receiving head unit 63 are mounted.

  Therefore, for example, when the user attaches the light projecting head unit 61 and the light receiving head unit 63 to the amplifier main body 70, it is preferable to measure the detection distance at that time and store it in the memory 32. Then, when a malfunction occurs after that, the detected distance information (an example of past detected distance information) stored in the memory 32 and the detected distance information measured at the time of the malfunction are the same. Since the head portion 61 and the light receiving head portion 63 are mounted, the problem can be investigated with high accuracy.

  The memory 32 may be configured to store both the information at the time of manufacture and the information at the time of initial mounting as detection distance information or the like, or when the detection distance information at the time of initial mounting is captured, A configuration may be used in which rewriting and updating is performed on the one.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) In the above embodiment, both the detection distance information and the power consumption information are stored in the memory 32 or measured, but only one of these may be stored and measured. .
(2) In the above embodiment, the detection sensor is a reflective photoelectric sensor or fiber sensor, but is not limited thereto, and may be a transmission type. Further, as long as the presence / absence of the detection target can be detected, the sensor is not limited to the optical type but may be a magnetic type, ultrasonic type, pressure type or the like.
(3) Although “past detection distance information” is the information at the time of manufacture or at the beginning of mounting in the above-described embodiment, the present invention is not limited to this, and may be another time point as long as it is a detection distance measured in the past.

The perspective view which shows the external appearance of the sensor system which concerns on Embodiment 1 of this invention. Block diagram showing the internal configuration of the sensor system Block diagram showing the internal configuration of the amplifier body of the optical fiber sensor The block diagram which shows the internal structure of the photoelectric sensor of Embodiment 2.

Explanation of symbols

1 ... sensor (detection sensor)
15, 23 ... CPU (detection means, output means)
32 ... Memory (storage means)
60 ... Photoelectric sensor (detection sensor)
61: Light projecting head (detection head)
63. Light receiving head section (detection head)
70 ... Amplifier body W ... Object to be detected

Claims (2)

Detection means for performing a detection operation according to the physical quantity of the detection object;
Storage means for storing past detection distance information in the detection operation;
A detection sensor comprising: output means for outputting the detection distance information stored in the storage means in response to an external trigger signal. An amplifier body of a detection sensor in which a detection head is detachably provided,
Detection means for performing a detection operation in accordance with a physical quantity of a detection object based on a signal from the detection head;
Storage means for storing past detection distance information in the detection operation;
An amplifier body of a detection sensor, comprising: output means for outputting the detection distance information stored in the storage means in response to an external trigger signal.

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