JP2007013526A - Detection sensor and detection sensor system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a detection sensor and a detection sensor system capable of more easily comprehending the operating state of the detection sensor. <P>SOLUTION: When a display relative threshold value -50 digit (negative value input) is inputted and a reference level 100 digit is acquired, in the case that a current light requirement level is 20 digit, -80 digit is displayed on an LCD 56 as a relative light requirement level and the display relative threshold value -50 digit is displayed on an LCD 57. On the other hand, when the reference level 102 digit is acquired, for instance, -82 digit is displayed on the LCD 56 as the relative light requirement level and on the LCD 57, the display relative threshold value -50 digit is displayed in the same way as the time when the reference level 100 digit is acquired. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a detection sensor and a detection sensor system.

Patent Document 1 below discloses a technique related to a detection sensor including a detection switch and a display device. This is because the detection value at the detection switch at that time is stored as a zero reset reference value by performing a predetermined operation, and thereafter, the detection value obtained by subtracting the zero reset reference value from the current detection value at the detection switch (Hereinafter referred to as “detected value after subtraction”) and a threshold value obtained by subtracting a zero reset reference value from a preset threshold value (hereinafter referred to as a threshold value after subtraction) are respectively displayed on two display units. According to such a configuration, the operator can visually recognize the current detection value and the threshold value as relative values with respect to the zero reset reference value by displaying on the display unit, and the detection switch compared to the case where each is displayed as an absolute value. There is an advantage that the operating state in can be grasped at a glance.
Japanese Patent No. 3255229

  By the way, the thing of the structure of patent document 1 arranges a some detection switch along with a manufacturing line, for example, arrange | positions it so that the to-be-detected object which flows through the manufacturing line may be detected one by one, and it continues to each of these some detection switches. There are cases where display devices are arranged and arranged in one place. In this case, since each detection sensor detects the same detected object, it is grasped by comparing the operation state between each detection sensor that the threshold value after subtraction displayed on all the display devices is displayed with the same value. May be desirable because it can.

  However, in the configuration of the above-mentioned Patent Document 1, since the detection value varies when a predetermined operation is performed on each detection sensor, the zero reset reference value varies. If it does so, even if the threshold value preset in each detection sensor is the same value, for example, the threshold value after subtraction will vary. This makes it difficult to compare and grasp the operating state between the detection sensors, and eventually it is necessary to individually adjust the setting thresholds so that the threshold values after subtraction at the detection sensors become the same value.

  The present invention has been completed based on the above circumstances, and an object thereof is to provide a detection sensor and a detection sensor system that can more easily grasp the operation state of the detection sensor. .

As means for achieving the above object, a detection sensor according to the invention of claim 1 includes a detection means for detecting a detection level of an object to be detected in a detection region, a detection level at the detection means, and a detection threshold value. A determination means for determining the presence or absence of the object to be detected by comparison, an operation means, an acquisition means for acquiring a detection level at the detection means as a reference level based on an operation at the operation means, and a display threshold value is changed. Setting means for enabling setting, calculation means for calculating a relative detection level based on a difference between the current detection level in the detection means and the reference level acquired in the acquisition means, display means, and the display means Display control means for controlling the display operation, and the determination means determines, as the detection threshold, a level corresponding to the reference level and the display threshold set by the setting means. Performs an operation, the display control means, said display means, the said threshold value for display with the relative detection level, characterized in that to simultaneously or selectively displayed.
Note that “the level according to the reference level and the display threshold set by the setting unit” is obtained, for example, by using the lower detection level as the reference level when there is no object to be detected in the detection region. In this configuration, the display threshold (in the case of positive value input) is added to the reference level. In the configuration in which the higher one is acquired as the reference level, the display threshold (in the case of positive value input) is subtracted from the reference level. Level.

  According to a second aspect of the present invention, in the detection sensor according to the first aspect, the setting means includes an input means for inputting the display threshold, and the display threshold is input to the input means. When the operation means is operated, the detection level at that time is acquired as a reference level, and the reference level is added based on the display threshold value to set the level as the detection threshold value in the determination means. .

  According to a third aspect of the present invention, in the detection sensor according to the first or second aspect, the display means includes at least two display units, the display threshold is displayed on one display unit, and another display is performed. The relative detection level is displayed on the part.

  According to a fourth aspect of the present invention, in the detection sensor according to any one of the first to third aspects, the acquisition unit acquires, as a reference level, a detection level when the detected object is not present in the detection region. It is characterized by doing.

  A detection sensor system according to a fifth aspect of the present invention comprises a plurality of the detection sensors according to any one of the first to fourth aspects, wherein display means of the plurality of detection sensors can be arranged adjacent to each other. It is characterized by.

  According to a sixth aspect of the present invention, in the detection sensor system according to the fifth aspect, each of the detection sensors receives data from another detection sensor and transmits the data to a detection sensor different from the other detection sensor. The display threshold data set by one detection sensor is sequentially transmitted to other detection sensors.

  According to a seventh aspect of the present invention, in the detection sensor system according to the sixth aspect, based on the operation of the operation means in the one detection sensor, the operation command is sequentially transmitted to the other detection sensors by the communication means. The acquisition unit performs an acquisition operation based on an operation command transmitted from each of the detection sensors.

<Invention of Claim 1>
According to this configuration, it is possible to display the display threshold as it is by setting the display threshold to be displayed on the display means in advance. Therefore, it becomes easy to grasp the operating state of the detection sensor based on the relative detection level corresponding to the reference level that is also displayed on the display means.

<Invention of Claim 2>
According to this configuration, the reference level can be acquired and the detection threshold can be determined collectively by inputting the display threshold and operating the operation unit.

<Invention of Claim 3>
According to this configuration, the display threshold value and the relative detection level can be displayed on the two display units, respectively, so that it becomes easier to grasp the operating state.

<Invention of Claim 4>
According to this configuration, the detection level in a relatively stable state where there is no object to be detected in the detection region can be set as the reference level, and variations in the reference level can be suppressed.

<Invention of Claim 5>
In the detection sensor system comprising a plurality of detection sensors as described above, the present invention arranges the display means of the plurality of detection sensors adjacent to each other, and sees them to collectively indicate the operating states of the plurality of detection sensors. This is especially useful when you want to understand with

<Invention of Claim 6>
According to this configuration, if a display threshold is set in one detection sensor, the display threshold data is sequentially transmitted to the other detection sensors and set in each detection sensor. Therefore, it is not necessary to individually set display threshold values for each detection sensor.

<Invention of Claim 7>
According to this configuration, an operation for acquiring the reference level may be performed on one detection sensor, and workability can be improved.

An embodiment of the present invention will be described with reference to FIGS.
<Overall configuration>
The sensor system 1 (corresponding to “detection sensor system” in the claims) of the present embodiment is configured by, for example, three optical fiber sensors 2 (corresponding to “detection sensors” in the claims) having the same structure. For example, it is used for detecting a workpiece W (corresponding to “object to be detected” in the claims) that sequentially flows on the production line at each position. In each figure, there is a portion in which one of the three optical fiber sensors 2 is provided with a reference numeral and the other reference numerals are omitted.

  As shown in FIG. 1, each optical fiber sensor 2 includes a light projector 10, a light receiver 20, and an amplifier unit 30, and the parallel light emitted from the front surface of the light projector 10 is received by the light receiver 20. A detection region X is formed by a parallel light path, and the presence or absence of the workpiece W is detected by the amplifier unit 30 based on the received light level at the light receiver 20 that changes according to the advance position of the workpiece W in the detection region. It is.

  The housing 11 of each projector 10 has a substantially rectangular box shape, and a translucent window member 12 through which parallel light is emitted is provided on the front surface of the housing 11 (the surface facing the light receiver 21). An optical fiber cable 40 is led out from the signal line outlet on the upper surface of the housing 11, and an end of the optical fiber cable 40 is introduced into the amplifier unit 30. Light from the light projecting element 31 provided in the amplifier unit 30 is guided into the light projector 10 via the optical fiber cable 40 and is converted into parallel light by a collimator lens (not shown) provided in the light projector 10. After that, the light is emitted from the translucent window member 12.

  The housing 21 of each light receiver 20 also has a substantially rectangular box shape, and a translucent window into which the parallel light emitted from the light projector 10 enters the front surface of the housing 21 (the surface facing the light projector 10). A member 22 is provided. An optical fiber cable 40 is led out from the signal line outlet on the upper surface of the housing 21, and an end portion of the optical fiber cable 40 is introduced into the amplifier unit 30. The light that has entered the translucent window member 22 is collected by a condenser lens (not shown) provided in the light receiver 20 and is provided in the amplifier unit 30 via the optical fiber cable 40. Light is received at 32.

  Each amplifier unit 30 is provided so as to be movable with respect to the DIN rail 42 by passing the clamping unit through a known DIN rail 42. Both ends of the amplifier unit 30 group are sandwiched by fixing members 43, and the fixing members 43 are screwed. Each amplifier unit 30 is fixed to the DIN rail 42 by being fixed to the DIN rail 42 by fastening.

  Further, on the upper surface of each amplifier unit 30, a plurality of lighting units 50 that are turned on according to the operating state of the optical fiber sensor 2, a display unit 51, and a so-called jog switch (registered trademark) (“input means” in the claims) And a mode change-over switch 53 are arranged.

  Of these, the jog switch 52 gives a signal to the CPU 37 from the switch input circuit 54 (see FIG. 2) in accordance with the operation. The contents set according to the operation are displayed on the display unit 51 driven by the display circuit 55 (corresponding to “display control means” in the claims). The display unit 51 includes two 7-segment four-digit liquid crystal displays (corresponding to “display means” in the claims, hereinafter referred to as “LCDs 56 and 57”) arranged side by side. With this jog switch 52, it is possible to input a display relative threshold value (corresponding to “display threshold value” in claims), a determination operation thereof, and the like. The jog switch 52 includes an operation wheel that is rotated by a finger, although the structural details are not shown, and by rotating the operation wheel, each digit of the LCDs 56 and 57 has 0-9. Each number or letter can be displayed, and the number displayed on the LCDs 56 and 57 can be confirmed by pressing the operation wheel at a desired position.

<Internal configuration of amplifier section>
The electrical configuration of each amplifier unit 30 is as shown in FIG. The light projecting element 31 emits light to the incident end of the optical fiber cable 40 connected to the projector 10, while the light receiving element 32 receives light from the optical fiber cable 40 led out from the light receiver 20.

  Further, a communication light receiving element 33 is provided on the left side surface of the housing of the amplifier unit 30 and is connected to a light receiving circuit 34 provided therein to receive light as light from another adjacent optical fiber sensor 2. An analog signal corresponding to the communication signal is output. The light receiving circuit 34 converts the analog signal received from the communication light receiving element 33 into a digital signal and transmits it to a CPU 37 described later.

  Further, a communication light projecting element 35 is provided on the right side surface of the housing, and is connected to a light projecting circuit 36 provided inside to perform a light projecting operation according to a drive signal from the light projecting circuit 36. Then, a communication signal is output as light and transmitted to another optical fiber sensor 2 disposed adjacent to the communication signal. The light projecting circuit 36 receives a control signal from the CPU 37 and transmits a drive signal to the light projecting element 35 in accordance with the control signal.

  With such a configuration, communication signals are transmitted by optical communication from one end side of the three optical fiber sensors 2 (the leftmost optical fiber sensor 2 in FIG. 2) to the other end side (the rightmost optical fiber sensor 2 in FIG. 2). Sequential transmission can be performed by the bucket relay system. Therefore, the communication light receiving element 33, the light receiving circuit 34, the communication light projecting element 35, and the light projecting circuit 36 correspond to “communication means” in the claims.

<Setting of zero adjustment function and relative threshold for display>
Now, each optical fiber sensor 2 of the present embodiment causes the projector 10 and the light receiver 20 to perform a light projecting / receiving operation by a predetermined operation of the jog switch 52 or the like, and stores the received light amount level at that time as a reference level. And a so-called zero adjustment function for displaying on the LCD 56 a relative received light amount level obtained by subtracting the reference level from the received light amount level detected in each light projecting / receiving operation thereafter.

  Specifically, the mode changeover switch 53 is operated to switch to the zero adjustment mode, and the jog switch 52 performs the confirmation operation. Then, the CPU 37 projects the light projecting element 31, receives the light reception signal from the light receiving element 32 in synchronization with this, acquires the light reception level, and stores this light reception level in the memory 58 as a reference level. . At this time, the CPU 37, the light projecting element 31, and the light receiving element 32 function as “acquiring means” in the claims.

  Here, in the present embodiment, the determination operation in the zero adjustment mode is executed in a state where there is no work W between the projector 10 and the light receiver 20. That is, the acquired reference level is a received light amount level in a state where there is no workpiece W between the projector 10 and the light receiver 20 (corresponding to “detection level when there is no object to be detected” in the claims). . The received light amount level when the workpiece W is present may vary depending on, for example, the direction of the workpiece W, but basically a stable received light amount level can be obtained as long as the received light amount level is obtained when there is no workpiece W. It is.

  Further, in the present embodiment, when switching to the zero adjustment mode is set, the display relative threshold value currently set is displayed on the LCD 57, and the display value can be changed by rotating the jog switch 52.

  Then, the display value currently displayed on the LCD 57 by the determination operation with the jog switch 52 is stored in the memory 58 as a display relative threshold value. The display relative threshold value is determined according to the detection sensitivity of the workpiece W required by the operator, and is a detection threshold value (absolute value with respect to the received light amount level) with respect to the reference level acquired during the zero adjustment mode setting operation. Is a value (= detection threshold−reference level) indicating a margin amount. Then, the CPU 37 adds the reference level currently stored in the memory 58 and the display relative threshold value to calculate a detection threshold value (= reference level + display relative threshold value) and stores it in the memory 58.

  Thereafter, when switching to the detection mode is performed by operating the mode selector switch 53, the CPU 37 causes the light projecting element 31 and the light receiving element 32 to perform a light projecting / receiving operation at a predetermined cycle, and the received light amount level in each light projecting operation, The detection threshold value (= reference level + display relative threshold value) is compared. And the presence or absence of the workpiece | work W is detected based on the comparison result which reverses with when the workpiece | work W exists in the said detection area X, and when there is no workpiece | work W, and makes the said lighting part 50 perform lighting operation.

  Further, in the detection mode, the CPU 37 subtracts the reference light level from the current light receiving light level acquired for each light projecting / receiving operation (= the current light receiving light level−the reference level). Level)) is displayed on the LCD 56, and the display relative threshold is displayed on the LCD 57 as it is. In short, the relative received light amount level is a relative value of the current received light amount level with respect to the received light amount level (reference level) when there is no workpiece W, and varies depending on the detection state of the workpiece W during each light projecting / receiving operation.

  Here, the reference level acquired in the setting operation of the zero adjustment mode is the light receiving amount level in the state where there is no workpiece W, and is basically always stable. Fluctuates somewhat depending on the peripheral state at the position (incident state of disturbance light from the periphery). Accordingly, in a configuration in which a value obtained by subtracting the reference level from the detection threshold value is displayed on the display unit as a relative threshold value as in the conventional case, the relative threshold value varies depending on the peripheral state. Some users want to display a relative threshold value as a desired margin amount determined by the user on the display unit.

  In the configuration of the present embodiment, the display threshold value as a desired margin determined by the user is displayed on the LCD 57 as it is, and a value obtained by adding the display threshold value to the reference level is used to detect the presence / absence of the workpiece W in the detection mode. It was used as a threshold for detection. Specifically, as shown in FIG. 3, when a display relative threshold value of -50 digits (negative value input) is input and a reference level of 100 digits is acquired, if the current received light amount level is 20 digits, the relative received light amount is displayed on the LCD 56. The level is displayed as −80 digits, and the display relative threshold value −50 digits is displayed on the LCD 57. On the other hand, for example, when the reference level 102 digits is acquired, −82 digits is displayed as the relative light receiving amount level on the LCD 56, and the display relative threshold value −50 digits is displayed on the LCD 57 as in the case of acquiring the reference level 100 digits. . That is, regardless of the value of the reference level, it is possible to always display the display relative threshold value indicating the margin amount determined by the user.

  In this embodiment, as described above, optical communication is possible between the three optical fiber sensors 2. For example, when the setting operation in the zero adjustment mode is performed in the first optical fiber sensor 2 in the foreground in FIG. 1, the “display relative threshold data” and the “reference level” that are set and input at the time of the setting operation. An “acquisition command command” (corresponding to the “operation command” in the claims) is transmitted from the first optical fiber sensor 2 to the second optical fiber sensor 2 disposed adjacent thereto, and further two It is transmitted from the eye to the third optical fiber sensor 2 by the bucket relay system.

  The CPU 37 of each of the second and third optical fiber sensors 2 stores the received “display relative threshold data” in the memory 58 and executes the light projecting / receiving operation based on the “reference level acquisition command”. Get the reference level. Here, for example, the first optical fiber sensor 2 sets and inputs a display relative threshold of -50 digits, the first reference level is 100 digits, the second reference level is 102 digits, and the first reference level is 105 digits. A case will be described where the detection mode is in the state shown in FIG. In this case, since there is a workpiece W in the detection region X of the first optical fiber sensor 2, the current received light amount level is reduced to 20 digits, and as a result, the LCD 56 displays -80 digits as the relative received light amount level. Is done. For the second and third optical fiber sensors 2, since there is no workpiece W, the current received light level is 102 digits and 105 digits as in the reference level. As a result, each LCD 56 displays 0 digit. become. The display relative threshold value -50 digits is displayed on the LCD 57 of each optical fiber sensor 2. Therefore, the user can grasp the operation state (detection state) of each optical fiber sensor 2 based on the common margin (display relative threshold) determined by the user. The detection threshold is set to 50 digits for the first unit, 52 digits for the second unit, and 55 digits for the third unit.

  As described above, in the present embodiment, only the first optical fiber sensor 2 is subjected to the zero adjustment setting operation, and the second and third optical fiber sensors 2 are collectively set to zero adjustment. Can do.

<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, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.
(1) In the above-described embodiment, an example in which the detection sensor is applied to a photoelectric optical fiber sensor has been described. If there is, it can be applied to various sensors such as a magnetic sensor and a contact sensor.

  (2) In the above-described embodiment, an example of application to a so-called transmission type optical fiber sensor has been described. However, the present invention can also be applied to a so-called reflection type optical fiber sensor. In this case, the received light amount level indicates the minimum value in the state where there is no workpiece W, and this is acquired as the reference level. Then, if the display relative threshold value is inputted as a positive value, the same processing as in the above embodiment is executed.

  (3) In the above embodiment, the wireless optical communication method is adopted as the communication means. However, the communication method is not limited to this, and a wired optical communication method through a fiber may be used. It may be.

  (4) Although the example applied to the three optical fiber sensors 2 has been described in the above embodiment, the present invention is not limited to this, and the present invention can also be applied to two, four or more.

  (5) In the above embodiment, both the “display relative threshold data” and the “reference level acquisition command command” are transmitted to each optical fiber sensor 2 by optical communication. Only the “display relative threshold data” is transmitted, and the operation for acquiring the reference level is individually performed by each optical fiber sensor 2 or only the “reference level acquisition command command” is transmitted, and the display relative threshold is set. The input may be performed individually by each optical fiber sensor 2.

The perspective view which shows the whole sensor system which concerns on one Embodiment of this invention. Diagram showing the electrical configuration of the amplifier section Explanatory drawing for demonstrating the display value of the display part in one optical fiber sensor Explanatory drawing for demonstrating the display value of the display part in three optical fiber sensors

Explanation of symbols

1. Sensor system (detection sensor system)
2. Optical fiber sensor (detection sensor)
10. Projector (detection means, acquisition means)
20. Light receiver (detection means, acquisition means)
33. Light receiving element for communication (communication means)
34. Light receiving circuit (communication means)
35 .. Projecting element for communication (communication means)
36 ... Light emitting circuit (communication means)
37 ... CPU (acquisition means, determination means, calculation means)
52 ... Jog switch (operating means, setting means, input means)
55. Display circuit (display control means)
56, 57 ... LCD (display means)
W: Workpiece (object to be detected)
X: Detection area

Claims (7)

Detection means for detecting the detection level of the detection object in the detection region;
Determination means for determining the presence or absence of the detected object by comparing the detection level of the detection means and a detection threshold;
Operation means;
An acquisition means for acquiring a detection level at the detection means as a reference level based on an operation at the operation means;
Setting means for setting the display threshold to be changeable;
A calculation means for calculating a relative detection level by a difference between a current detection level in the detection means and the reference level acquired by the acquisition means;
Display means;
Display control means for controlling the display operation of the display means,
The determination means performs a determination operation using the level according to the reference level and the display threshold set by the setting means as the detection threshold,
The display control unit causes the display unit to display the display threshold and the relative detection level simultaneously or selectively. The setting means includes input means for inputting the display threshold value,
When the operation means is operated in a state where the display threshold value is input to the input means, the detection level at that time is acquired as a reference level, and the reference level is added based on the display threshold value. The detection sensor according to claim 1, wherein: is a threshold value for detection in the determination unit. The display means includes at least two display units,
The detection sensor according to claim 1, wherein the display threshold is displayed on one display unit, and the relative detection level is displayed on another display unit. The detection sensor according to any one of claims 1 to 3, wherein the acquisition unit acquires a detection level when the detection object is not present in the detection region as a reference level. A detection sensor system comprising a plurality of the detection sensors according to any one of claims 1 to 4, wherein display means of the plurality of detection sensors can be arranged adjacent to each other. Each of the detection sensors includes a communication unit that receives data from another detection sensor and transmits the data to a detection sensor different from the other detection sensor,
6. The detection sensor system according to claim 5, wherein display threshold data set by one detection sensor is sequentially transmitted to another detection sensor. Based on the operation of the operation means in the one detection sensor, the operation command is sequentially transmitted to the other detection sensors by the communication unit, and acquired by the acquisition unit based on the operation command transmitted in each of the detection sensors. The detection sensor system according to claim 6, wherein each operation is executed.

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