JP3932418B2 - Photoelectric sensor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a photoelectric separation type sensor in which a light transmitter and a light receiver are separated.
[0002]
[Prior art]
FIG. 6 is a right side view showing an optical axis adjustment mechanism of a conventional photoelectric separation type smoke detector, and FIG. 7 is an explanatory view showing a method of adjusting the optical axis, which was published in JP-A-6-131574. A part of the drawing is shown.
In FIGS. 6 and 7, S is a photoelectric separation type sensor, which is composed of a light transmitter 101 and a light receiver 102 which are separated from each other. The light transmitter 101 and the light receiver 102 have a main body 100 having a similar structure, and the following mechanism is housed in the main body 100.
[0003]
Reference numeral 103 is a circuit cover, 104 is a printed circuit board, 105 is a base fixed to the main body 100, 106 is a separator, 107 and 108 are springs, 109 is a support member formed of a U-shaped metal plate, and 110 is a lens holder. is there. Further, 111 is a mirror, 112 and 113 are aiming holes, 114 and 115 are two adjustment screws for vertical and horizontal directions provided in the optical axis direction, 116 and 117 are knobs for adjustment screws, and 118 is a light receiver. A plurality of LEDs attached to the printed circuit board 104 on the 102 side and color-coded according to the level.
[0004]
The lens holder 110 is supported by the left and right open ends of the support member 109 so as to be rotatable in the vertical direction, and the support member 109 is mounted on the separator 106 so as to be rotatable in the horizontal direction. Although not shown in detail, the two adjustment screws 114 and 115 are both connected to holes and screws provided at positions deviated from the respective rotation axes of the lens holder 110 and the support member 109 to adjust the adjustment screws. The lens holder 110 and the support member 109 are rotated while rotating 114 and 115 forward and backward.
[0005]
Such adjustment of the optical axis of the photoelectric separation type sensor S is roughly performed first by the aiming holes 112 and 113 in a state where the light transmitter 101 and the light receiver 102 are arranged opposite to each other as shown in FIG. That is, the knobs 116 and 117 are turned while looking through the aiming hole 113 of the light transmitter 101 from an oblique direction so that the light receiver 102 enters the field of view through the reflecting mirror 111 and the aiming hole 112. When the adjusting screw 114 is turned with one knob 116, the lower part of the lens holder 110 is directly rotated in the vertical direction about the support shaft with the left and right support members 109 (C to D in FIG. 6).
[0006]
Further, when the adjustment screw 115 side is rotated by the other knob 117, the lens holder 110 rotates in the horizontal direction integrally with the support member 109, with the vertical rotation axis of the separator 106 as a fulcrum. Next, while turning on the plurality of LEDs 118 provided in the light receiver 102, the knobs 116 and 117 are similarly turned to adjust the output level. That is, the linear displacement in the optical axis direction accompanying the screwing of the two adjusting screws 114 and 115 is directly or indirectly converted into the vertical and horizontal rotation angles of the lens holder 110 to adjust the optical axis. It can be done.
[0007]
[Problems to be solved by the invention]
In the conventional smoke detector, as described above, the optical axis is adjusted by converting the linear displacement accompanying the screwing of the two adjusting screws into the vertical and horizontal rotation angles of the lens holder. It has become. For this reason, when the amount of linear displacement increases, the screw shaft deviates from the optical axis direction and tilts δ according to the amount of displacement [FIG. 5 (b)]. As a result, the vicinity of the head of the adjustment screw may be caught in the insertion hole of the base or the lens holder, and rotation may become unsmooth, resulting in a problem in the adjustment of the optical axis. In addition, since the lens holder constituting the optical system such as a lens is supported by the open end of the U-shaped support member, there is a problem that the support member is deformed and the strength is difficult. there were.
[0008]
The present invention has been made to solve the above-mentioned problems of the conventional apparatus, and improves the problem of the adjustment operation of the optical axis due to the linear / rotation angle displacement conversion action caused by the operation of the adjustment screw. A simple process was applied to the frame (support member) to increase the strength while suppressing an increase in production costs, and a robust and trouble-free apparatus was constructed. In addition, the rotation angle of the optical system at the time of optical axis adjustment is displayed on an enlarged scale to realize a photoelectric separation type sensor that is convenient for handling.
[0010]
[Means for Solving the Problems]
The present invention relates to a photoelectric separation type sensor having a U-shaped support frame on a table and an optical table that accommodates a light receiving and receiving element supported by an open end of the support frame, and is opposed to each other in a monitoring space. A photoelectric separation type sensor is constructed in which the support frame is formed of a rectangular plate material subjected to bead processing in the longitudinal direction, and the protruding surface of the support frame bead processing is brought into contact with the sliding surface of the instrument base. .
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
1 is a front view showing a configuration of a light receiver according to Embodiment 1 of the present invention, FIG. 2 is an explanatory plan view of FIG. 1, and FIG. 3 is an explanatory view of a right side of FIG. In the embodiment of the present invention, different names and symbols are used for some of the functional members common to the conventional ones.
1 to 3, reference numeral 1 denotes a transmitter / receiver, which shows a receiver 1b. Reference numeral 2 denotes a case of the transmitter / receiver 1, and 20 denotes a case cover. Reference numeral 21 denotes a front plate having an arc shape having the same horizontal cross section, and 22 denotes a lower cover.
[0013]
Reference numeral 3 denotes a table that constitutes a frame portion of the main body 2. 31 is a sliding surface in the horizontal direction of the table 3, 32 is a holding part standing on the front surface of the table 3 from the sliding surface 31, 33 is an insertion hole provided in the holding part 32 in a groove shape in the lateral direction, 34 Is a suspension plate that serves as a mounting base on the back side of the instrument base 3, 35 is a suspension piece of a suspension board 34 that is screwed into a box (not shown), and 36 is an extension of the instrument base 3 having a plurality of dharma holes. Reference numeral 37 denotes an attachment screw, and reference numeral 38 denotes an attachment screw for fixing the lower portion of the case cover 20 to the attachment projection 39 of the instrument base 3 when the case cover 20 is hooked on the upper portion of the suspension plate 34. Reference numeral 4 denotes a metal support frame having a substantially “U-shaped” longitudinal cross section at the front. The U-shaped portion of the support frame 4 is subjected to reinforcing bead processing by a press, and two parallel protrusions 40 along the length direction are continuously formed. 41 is a bearing hole drilled in the horizontal direction at the open ends of the left and right protrusions, 42 and 43 are connecting pieces bent vertically from the support frame 4, and 44 and 45 are screws provided on the connecting pieces 42 and 43. A hole 46 is a central fixing screw. The support frame 4 formed in this way is fixed on the sliding surface 31 of the table 3 so that the protruding side of the two ridges 40 is in contact with the sliding surface 31 and can be rotated around the fixing screw 46. The
[0014]
Reference numeral 5 denotes an optical bench, which is molded into a bowl shape with dark resin. 51 is a rotating shaft on the left and right sides of the optical bench 5, 52 and 53 are aiming holes and peeping holes, 54 is an inclined mirror, and a sighting device that can be adjusted from left and right diagonally in a paired structure. Yes. Further, 55 is a Fresnel lens fitted on the front surface, 56 is a holding part in which a longitudinal insertion hole 57 is formed, and 58 is a light receiving element such as a photodiode provided on the inner axis. The optical bench 5 configured as described above is supported by the support frame 4 so as to be rotatable in the vertical direction by fitting the rotation shaft 51 into the bearing holes 41 on both the left and right sides. L is the optical axis of the optical system including the optical bench 5.
[0015]
61 and 62 are two adjusting screws provided in parallel along the optical axis L, 63 and 64 are washers, and 65 and 66 are helical springs for applying an expansion force in the assembled state. In particular, here, as the two washers 63 and 64 that receive the screw pressure of the adjusting screws 61 and 62, a decorative washer in which the receiving surface of the screw head is formed in a concave curved surface as shown in FIG. 5 is used. . In addition, the two adjusting screws 61 and 62 of the first embodiment are provided so as to be displaced from the apparent center of rotation of the optical bench 5 as in the conventional case. One adjustment screw 61 is threaded through the insertion hole 33 of the table 3 through the decorative washer 63 and the spiral spring 65, and the tip is screwed into the screw hole 44 of the support frame 4. The other adjustment screw 62 is passed through the insertion hole 57 of the optical bench 5 through the decorative washer 64 and the like, and then the screw tip is screwed into the screw hole 45 of the support frame 4.
[0016]
Reference numeral 7 denotes an operation unit provided at the lower part of the main body 2. Reference numeral 70 denotes a panel of the operation unit 7, and 71 and 72 denote printed circuit boards. 73 and 74 are fire confirmation lamps and trouble indicator lamps using LEDs, 75 is a mode selector switch, 76 and 77 are distance selector switches and setting volumes, 78 is a light emission period selector switch, and 79 is a battery terminal. The fire confirmation lamp 73 and the trouble display lamp 74 are exposed from the lower cover 22. 81 is a seal type nameplate (see also FIG. 4 below) pasted on the side of the table 3, 82 is a display such as a model name displayed on the nameplate 81, and 83 is a guide for the rotation angle when adjusting the level. It is a scale to be done. 85 is a terminal block, 86 is a power supply or signal conductor, and 87 is a connector connected to the conductor. Reference numeral 9 denotes a heater for preventing fogging.
[0017]
Although the light receiver 1b is illustrated in FIGS. 1 to 3 described above, the same shape housing 2 is commonly used for the transmitter / receiver 1. The difference between the light transmitter 1a (not shown) and the light receiver 1b is mainly the printed circuit boards 71, 72 and the like mounted on the inside of the optical bench 5 on which the light transmission / reception elements and signal processing circuits and LEDs are mounted. It is limited to the structural members due to functional differences between transmission and reception. And the main body 2 of the light transmitter 1a and the light receiver 1b having a common housing is covered with a case cover 20 at the periphery, and both sides of the ceiling, side walls, etc. in the building via a mounting plate (not shown) And are attached to face each other in a straight line.
[0018]
Next, the operation of the first embodiment of the present invention having such a configuration will be described with reference to FIG. The above-described suspension plate 34 is installed in advance in a box (not shown) provided in the vicinity of the ceiling of the opposite side wall in the building using a suspension piece 35 or the like and screwed. An unillustrated electric wire drawn out from the wall is connected to the terminal block 85 through the installed suspension plate 34, and the printed circuit boards 71 and 72 of the operation unit 7 and the connector 87 for the heater 9 are also connected. . When the wiring is completed, it is fixed to the dharma hole of the mounting piece 36 protruding in a J shape on the back side of the table 3 with a plurality of mounting screws 37. The case cover 20 of the light receiver 1 is hooked on the upper part of the suspension plate 34 and the lower part thereof is fixed to the mounting projection 39 of the table 3 with the mounting screw 38, but before that, The optical axis L is adjusted in the following procedure.
[0019]
With the case cover 20 of the light receiver 1b attached to the side wall removed, the light source 1a on the opposite side wall surface is passed through the aiming hole 52 and the mirror 54 by looking through the viewing hole 53 from the front oblique direction of the main body 2. See through. While seeing through, the right adjustment screw 61 is turned to rotate the support frame 4. Then, the center of the horizontal width of the projection image of the light transmitter 1 a on the mirror 54 is made to coincide with the center of the aiming hole 52 in the horizontal direction. By this operation, the horizontal (left and right) direction of the optical axis L using the sighting device is adjusted.
[0020]
In this case, as described above, an inclination δ is generated in the screw shaft in accordance with the linear / rotation angle displacement converting action by the adjusting screw 61, and the head of the adjusting screw 61 is relatively moved to the left and right. However, since the adjustment screw 61 is provided with the decorative washer 63 having a concave curved surface, the bearing surface follows the inclination of the screw shaft, and the inside of the long hole-shaped insertion hole 33 is freely changed. The bearing operation of the adjusting screw 61 (62) is shown in FIG. In addition, the contact surface of the support frame 4 that is rotated based on the screwing of the adjusting screw 61 is performed by line contact between the two protrusions 40 and the sliding surface 31, and the contact friction is extremely small. Therefore, the screwing of the adjusting screw 61 and the rotation of the support frame 4 are smooth, and as a result, the optical axis can be adjusted smoothly. On the other hand, the mechanical strength of the support frame 4 is enhanced by the beaded protrusions 40, and the vicinity of the open end provided with the bearing hole 41 is not deformed by an impact or the like, so that the optical axis adjustment is accurately maintained. FIG. 5C shows another embodiment of the adjusting screw. The adjusting screw 68 has a head 69 with a spherical shape matching the receiving surface of the washer 63, and there is no possibility of being caught when the adjusting screw 68 is screwed. Needless to say, the opposite side of the receiving surface of the washer 63 is flat and easily moves through the insertion hole 33.
[0021]
Following the horizontal adjustment of the optical axis L, the optical axis adjustment in the vertical direction is then performed using the sighting device. The left adjustment screw 62 is used for adjusting the optical axis in the vertical direction. When the adjustment screw 62 in which the tip screw portion is screwed into the screw hole 45 is rotated forward and backward, the holding portion 56 is pushed and pulled, and the optical bench 5 having the Fresnel lens 55 fitted on the front surface moves the left and right rotation shafts 51. Rotates up and down in a vertical plane around the center. Then, when the center of the projected image of the front light transmitter 1 a projected onto the mirror 54 through the aiming hole 52 is confirmed at the center position of the aiming hole 52, the optical axes of the light transmitter 1 a and the light receiver 1 b. L matches and the optical axis adjustment of the optical system is completed. When the optical bench 5 is rotated up and down, the insertion hole 57 in which the head of the adjustment screw 62 is elongated in the vertical direction moves in the vertical direction. However, the decorative washer 64 can move the insertion screw 57 smoothly without being caught.
[0022]
In general, a light transmitting element used in this type of sensor has directivity. When the peak value of the received light output deviates from the optical axis L based on the directivity of the light transmitting element, it is necessary to compensate for the deviation by adjusting the optical axis. For this reason, after the apparent optical axis adjustment of the optical system using the sighting device is finished, final adjustment for compensating directivity is performed using a level meter (not shown). For optical axis adjustment to compensate for directivity, a level meter (DVM) for measuring the light reception output of the light receiving element 58 is connected to the light receiver 1b side. The light receiving output corresponding to the rotational position of the adjusting screws 61 and 62 on the light transmitter 1a side is measured by the level meter connected to the light receiver 1b.
[0023]
In the first embodiment, a scale 83 displayed on the nameplate 81 on the side surface of the light receiver 1b is utilized in order to perform the optical axis adjustment easily and quickly. First, on the side surface of the device base 3 of the main body 2, instruction lines D1 and D2 (reference positions) are set in order to indicate the scale 83 as a guide for the operator. The two indication lines D1 and D2 may be anywhere within the same vertical plane of the rotating portion of the scale 83, the support frame 4 and the optical bench 5 so that the movement amount can be grasped with respect to the horizontal scale 83. . In the first embodiment, as shown in FIG. 4, the vertical line of the right protrusion 40 is set to the instruction line D <b> 1 on the support frame 4 side when moving in the horizontal direction. In addition, the vertical line on the left edge of the rectangular holding portion 56 formed so as to protrude to the outer periphery near the front surface is selected as the instruction line D2 on the optical bench 5 side when moving in the up-and-down direction.
[0024]
After the instruction lines D1 and D2 are set, the adjustment screw 61 on the light transmitter 1a side is turned to check the rotational direction in which the light reception output of the level meter rises. That is, after confirming the rotation direction, the adjustment screw 61 is turned to approach the peak value, and the output value and the scale 83 at that time are read when the inclination of the received light output is somewhat relaxed. Subsequently, the adjustment screw 61 is rotated in the same direction, and the scale when the peak value is reached and the same value as that at the time of ascent is read. Similarly, the left adjustment screw 62 reads the “scale” at the same output when the output rises and falls. Then, the instruction lines D1 and D2 are made to coincide with the intermediate scale 83 between the increase value and the decrease value, respectively.
[0025]
For example, when the adjusting screws 61 and 62 are individually turned clockwise and counterclockwise in the first embodiment shown in FIG. 5, the indications of the scale 83 are “4-6” and “2-1”, respectively. ”. At this time, “5” and “1.5” corresponding to intermediate values of “4 to 6” and “2 to 1” are regarded as approximate peak values of the received light output. Thus, the final optical axis adjustment for compensating the directivity of the light transmitting element is completed by matching the intermediate values “5” and “1.5” of the movement range of the instruction lines D1 and D2. After the completion, the support frame 4 and the optical bench 5 on the light transmitter 1a side are fixed, and the detector is set so that the fire can be detected when the light reception output exceeds a certain value.
[0026]
On the other hand, according to the design specifications of the implementation product of the first embodiment, the full width A of the support frame 4 (the distance between the left and right protrusions 40 ... FIG. 2) is configured to be 95 mm. Further, the actual distance B from the rotation axis of the optical bench 5 shown in FIG. 4 to the lower end of the holding portion 56 is 42 mm. Therefore, the horizontal distance a when the support frame 4 is rotated by 1 ° in the horizontal direction can be calculated from the equation tan θ = [a / (A / 2)]. However, θ is an arbitrary angle. Similarly, the horizontal distance b when the optical bench 5 is rotated by 1 ° in the vertical direction can be calculated from the equation tan θ = (b / B).
[0027]
Using the first formula,
a = (95/2) × tan 1 ° ≈0.8 mm (1)
In addition, b is also calculated from the following equation.
b = 42 × tan1 ° ≈0.7 mm (2)
As a result, when the scale 83 is moved from 4 to 5 and 2-1 as described above in the first embodiment, the rotation angles are rotated by approximately 5 ° and 5.5 °. That is, the unit for adjustment in the horizontal direction and the vertical direction can be expressed by the power of an approximate angle. According to the above adjustment example, the optical axis L of the light transmitter 1a that was on the origin in the two-dimensional coordinates in the vertical direction moves to the second quadrant. By this final adjustment operation, the directivity of the light transmitter 1 whose optical axis has been adjusted in the optical system is compensated.
[0028]
In the first embodiment, a scale 83 is displayed on the name plate 81 attached to the side surface of the table 3 below the main body 2, and the lines of the ridges 40 and the holding portions 56 at the lower part of the main body 2 are indicated on the scale 83. Instead, it was configured to adjust the level while reading the rotation angle. Therefore, the scale 83 is enlarged to make it easy to read, and the engraving of the scale 83 and the production of the name plate 81 can be achieved at once. Further, since both the instruction lines D1 and D2 need only coincide with the intermediate value of the scale 83 corresponding to the increase value and the decrease value, the level adjustment operation can be performed easily and quickly.
[0029]
In particular, if the scale 83 is recorded as a tangent function scale, it is possible to express the scale 83 with an accurate angle. The level-adjusted transmitter / receiver 1 is installed on the opposing wall surface in the building. Then, pulsed infrared light is projected from the light transmitter side, and the generation of smoke in the monitoring space is monitored. When smoke accompanying a fire enters the optical path, the amount of light received by the light receiving element 58 on the side of the light receiver 1b is attenuated to a predetermined value or less so that a fire is detected.
[0030]
In the above-described embodiment of the present invention, the case where the common scale 83 is provided on the name plate 81 on the left side of the table 3 has been described as an example, but the scale 83 may be provided separately from the left and right. It may be separated. Moreover, although the case where an operator set both the instruction lines D1 and D2 with vertical lines such as the protrusion 40 and the holding portion 56 has been described as an example, if necessary, an instruction is given with a colored triangular index or the like. You can also. In the first embodiment, the fixing screw 46 is used for both the rotation and fixing of the support frame 4. However, the support frame 4 may be fixed at a position different from the rotation axis, and the arc-shaped front plate 21 may be fixed. Also, the shape of the optical bench 5 is not necessarily limited to the embodiment.
Further, in the present embodiment, the adjusting screws 61 and 62 are respectively screwed into the screw holes 44 of the connecting pieces 42 of the support frame 4 through the insertion holes 33 of the holding part 32 of the device base 3 or the holding of the optical stand 5. Although it is screwed into the screw hole 45 of the connecting piece 43 of the support frame 4 through the insertion hole 57 of the part 56, it is sufficient that the optical axis depending on the direction of the optical table 5 can be adjusted with respect to the table 3 fixed to the installation surface. Adjustment screws 61 and 62 used for a mechanism for rotating the optical bench 5 with respect to a horizontal or vertical axis may be used. The support frame 4 and the optical bench 5 are horizontal and the instrument 3 and the support frame 4 are vertical. You may make it rotate in a direction.
[0032]
【The invention's effect】
The present invention relates to a photoelectric separation type sensor having a U-shaped support frame on a table and an optical table which is supported by an open end of the support frame and which is disposed opposite to each other in a monitoring space. Then, a photoelectric separation type sensor was constructed in which the support frame was molded with a rectangular plate material subjected to bead processing in the longitudinal direction, and the bead processing protruding surface of the support frame was brought into contact with the sliding surface of the instrument base.
As a result, since the entire U-shaped support frame is reinforced and the support of the optical bench is stabilized, the optical axis is not tilted and smoke detection is not hindered. Further, since the contact surface of the support frame with the instrument base is in line contact and the frictional resistance is small, optical adjustment with the adjusting screw can be smoothly performed.
[0034]
Therefore, according to the present invention, it is possible to provide a photoelectric separation type sensor that can be manufactured at low cost, is inexpensive, has no trouble, and is easy to handle.
[Brief description of the drawings]
FIG. 1 is a front view showing a configuration of a first embodiment of the present invention.
FIG. 2 is an explanatory diagram of the plane of FIG.
FIG. 3 is an explanatory diagram of the right side surface of FIG. 1;
4 is an explanatory diagram of a holder according to Embodiment 1. FIG.
FIG. 5 is an operation explanatory view of an adjusting screw.
FIG. 6 is a right side view showing an optical axis adjustment mechanism of a conventional photoelectric separation type smoke detector.
FIG. 7 is an explanatory diagram showing a conventional optical axis adjustment method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Sending and receiving device 1a Transmitting device 1b Receiving device 2 Case body 3 Device stand 4 Support frame 5 Optical stand 9 Heater 20 Case cover 31 Sliding surface 32 Holding part 33 Insertion hole 40 Projection line 41 Bearing holes 42 and 43 Connection piece 44, 45 Screw hole 46 Fixing screw 51 Rotating shaft 52 Aiming hole 53 Peep hole 54 Mirror 56 Holding part 57 Insertion hole 61, 62 Adjustment screw 63, 64 Washer 65, 66 Spiral spring 81 Name plate 83 Scale A, B Distance D1 , D2 Indicator line L Optical axis

Claims (1)

In the photoelectric separation type sensor having an U-shaped support frame on the table and an optical table supported by the open end of the support frame and having an optical table that accommodates the light receiving element and arranged oppositely in the monitoring space,
Said support frame is molded in a rectangular plate subjected to beading in the longitudinal direction, and the support frame of the beading of the projecting surface the device table of the sliding surface contacted photoelectric separated you wherein the allowed Type sensor.

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