WO2017033501A1 - Liquid sensor - Google Patents

Liquid sensor Download PDF

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Publication number
WO2017033501A1
WO2017033501A1 PCT/JP2016/063607 JP2016063607W WO2017033501A1 WO 2017033501 A1 WO2017033501 A1 WO 2017033501A1 JP 2016063607 W JP2016063607 W JP 2016063607W WO 2017033501 A1 WO2017033501 A1 WO 2017033501A1
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WO
WIPO (PCT)
Prior art keywords
light
elastic pieces
pair
tube
liquid sensor
Prior art date
Application number
PCT/JP2016/063607
Other languages
French (fr)
Japanese (ja)
Inventor
功 寺澤
Original Assignee
パナソニック デバイスＳｕｎｘ 株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by パナソニック デバイスＳｕｎｘ 株式会社 filed Critical パナソニック デバイスＳｕｎｘ 株式会社
Priority to CN201690001112.1U priority Critical patent/CN208173494U/en
Priority to DE112016003886.0T priority patent/DE112016003886T5/en
Publication of WO2017033501A1 publication Critical patent/WO2017033501A1/en

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
    • G01F23/22—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water
    • G01F23/28—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring the variations of parameters of electromagnetic or acoustic waves applied directly to the liquid or fluent solid material
    • G01F23/284—Electromagnetic waves
    • G01F23/292—Light, e.g. infrared or ultraviolet
    • G01F23/2921—Light, e.g. infrared or ultraviolet for discrete levels
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/41—Refractivity; Phase-affecting properties, e.g. optical path length
    • G01N21/4133—Refractometers, e.g. differential
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/85—Investigating moving fluids or granular solids
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/41—Refractivity; Phase-affecting properties, e.g. optical path length
    • G01N2021/416—Visualising flow by index measurement

Definitions

  • the present invention relates to a liquid sensor that optically detects the presence or absence of a liquid in a translucent tube.
  • a liquid sensor described in Patent Document 1 is known as this type of liquid sensor.
  • this liquid sensor light is emitted from the light emitting element toward the tube while the translucent tube is sandwiched inside the large arc-shaped main body, and the light passing through the tube is received by the light receiving element. Since the light refraction mode in the tube varies depending on the presence or absence of the liquid in the tube, the presence or absence of the liquid in the tube can be optically detected based on the amount of light received by the light receiving element.
  • the present invention has been made in view of such a situation, and an object thereof is to improve the holding force with respect to the tube.
  • One aspect of the present invention is a liquid sensor that detects whether or not a liquid is present in a light-transmitting tube, the light projecting unit that irradiates detection light, the light projecting unit that faces the light projecting unit, and the detection A light receiving portion that receives light, and a holding member that is provided between the light projecting portion and the light receiving portion and has a pair of elastic pieces for sandwiching the tube, and each of the pair of elastic pieces Is a direction that intersects the longitudinal direction of the elastic piece and extends in a direction different from the irradiation direction, and each of the slits of the pair of elastic pieces includes the light projecting unit and A light-shielding part that is disposed on the optical axis of the detection light between the light-receiving part and shields a part of the detection light emitted from the light-projecting part in a direction intersecting the longitudinal direction of the elastic piece;
  • the light-shielding part includes the detection light emitted from the light projecting part.
  • the holding force for the tube can be improved.
  • FIG. 4 is a sectional view taken along line 4-4 in FIG.
  • (A) (b) is explanatory drawing which shows the state of detection light.
  • A) is explanatory drawing which shows the state of the detection light in a tube
  • the exterior of the liquid sensor of the present embodiment includes a main body case 10 and a cover member 20.
  • the main body case 10 is made of, for example, a hard resin.
  • the main body case 10 has a flat plate portion 11 and a cylindrical portion 12 protruding from the flat plate portion 11.
  • Two bolt holes 13 penetrating in the thickness direction are formed in the flat plate portion 11 at two locations.
  • the main body case 10 is fixed to an object S such as a wall surface by fixing bolts (not shown) inserted through these bolt holes 13.
  • the bolt hole 13 functions as an attachment portion.
  • the cover member 20 is attached to the open end of the cylindrical portion 12 of the main body case 10.
  • the light-transmitting tube T to be measured by the liquid sensor is held by the portion of the cover member 20 exposed to the outside of the liquid sensor.
  • the direction in which the tube T is held by the cover member 20 is the holding direction of the tube T.
  • the direction in which the liquid sensor (main body case 10) is attached to the object S, and the direction perpendicular to the surface of the object S to which the main body case 10 is attached are the attachment direction of the liquid sensor (main body case 10).
  • the holding direction of the tube T and the mounting direction of the liquid sensor are the same direction, that is, the holding direction and the mounting direction are the same direction.
  • a sensor unit 30 that detects the presence or absence of liquid in the tube T is accommodated in the cylindrical portion 12 of the main body case 10.
  • the sensor unit 30 includes a substrate frame 31, a light projecting frame 32, and a light receiving frame 33.
  • the substrate frame 31 is elongated in one direction.
  • the light projecting frame 32 and the light receiving frame 33 are erected vertically from one end and the other end of the substrate frame 31 in the same direction.
  • the substrate frame 31 includes a bottom frame portion 31A, a side frame portion 31B, and a cover frame portion 31C.
  • a circuit element 34 for controlling various operations in the liquid sensor is mounted on the bottom frame portion 31A.
  • the side frame portion 31 ⁇ / b> B has a rectangular frame shape and surrounds the circuit element 34.
  • the cover frame portion 31C closes the mounting space of the circuit element 34 surrounded by the bottom frame portion 31A and the side frame portion 31B.
  • the cover frame portion 31C is elongated in one direction, and a first fitting portion 35 and a second fitting portion 36 are provided at one end and the other end in the longitudinal direction, respectively.
  • the light projecting frame 32 and the light receiving frame 33 are respectively fitted to the first fitting portion 35 and the second fitting portion 36. Thereby, the light projecting frame 32 and the light receiving frame 33 are fixed to the substrate frame 31.
  • the cover member 20 is fitted to the main body case 10 so as to close the opening of the cylindrical portion 12 of the main body case 10 in a state where the sensor unit 30 is accommodated in the cylindrical portion 12 of the main body case 10.
  • the insertion hole 40 formed in the cover member 20 and the insertion hole 41 formed in the main body case 10 overlap.
  • a positioning pin 43 is inserted into the overlapping insertion holes 40 and 41 from the outside of the main body case 10.
  • the positioning pins 43 play a role of positioning the housing position of the sensor unit 30 in the cylindrical portion 12 of the main body case 10 by contacting the cover frame portion 31C of the substrate frame 31 in the sensor unit 30 from above. .
  • the cover member 20 is integrally formed of, for example, black soft resin.
  • the cover member 20 includes a top surface P having a substantially rectangular shape. At the center position in the longitudinal direction of the top surface P, a concave groove 50 is formed that extends linearly from one end to the other end of the top surface P in the short direction.
  • a pair of elastic pieces 51 ⁇ / b> A and 51 ⁇ / b> B are formed on the bottom surface of the concave groove 50, which are curved in an arc shape and extend over the entire length of the concave groove 50.
  • the pair of elastic pieces 51A and 51B plays a role of holding and holding the tube T.
  • the tip edges 56A and 56B of the pair of elastic pieces 51A and 51B have open ends into which the tube T is inserted and removed.
  • the distal end edges 56A and 56B of the pair of elastic pieces 51A and 51B are provided with a first tapered surface P1 that gradually becomes narrower in the insertion direction of the tube T, which is the direction from the distal end to the proximal end of the elastic pieces 51A and 51B. Is formed. Due to the first tapered surface P1 at the tip edge, the width between the tip portions of the pair of elastic pieces 51A and 51B becomes gradually narrower in the insertion direction.
  • each elastic piece 51A, 51B includes a tip edge 56A or 56B that intersects the optical axis of the detection light and into which the tube T is inserted and removed.
  • the distal edge 56A of the elastic piece 51A includes an inclined surface that faces the elastic piece 51B and moves away from the elastic piece 51B toward the distal end of the distal edge 56A.
  • the tip edge 56B of the elastic piece 51B includes an inclined surface that faces the elastic piece 51A and moves away from the elastic piece 51A toward the tip of the tip edge 56B.
  • the longitudinal ends of the concave groove 50 at the end edges 56A and 56B of the pair of elastic pieces 51A and 51B are gradually narrowed from both longitudinal ends of the concave groove 50 toward the center.
  • a second taper surface P2 is formed. That is, the tip edge 56A of the elastic piece 51A includes two inclined surfaces that are formed at both ends in the longitudinal direction of the tip edge 56A and approach each other toward the tip of the tip edge 56A.
  • the leading edge 56B of the elastic piece 51B includes two inclined surfaces that are formed at both ends in the longitudinal direction of the leading edge 56B and approach each other toward the tip of the leading edge 56B.
  • a slit 52 extending from the proximal end to the distal end of the pair of elastic pieces 51A, 51B is formed at the center position in the longitudinal direction of the pair of elastic pieces 51A, 51B.
  • the slit 52 passes through the pair of elastic pieces 51 ⁇ / b> A and 51 ⁇ / b> B along a direction orthogonal to the bottom surface of the groove 50. Further, the slit 52 communicates with a concave portion 54 formed on the bottom surface of the concave groove 50.
  • each elastic piece 51A, 51B has a slit 52 formed on the optical axis of the detection light between the light projecting element 37 and the light receiving element 38 and dividing the elastic piece 51A or 51B.
  • the light projecting element 37 and the light receiving element 38 are disposed so as to face each other through the slit 52.
  • the light projecting element 37 functions as a light projecting unit
  • the light receiving element 38 functions as a light receiving unit.
  • the detection light emitted from the light projecting element 37 in the direction intersecting with the extending direction of the slit 52 enters the concave groove 50 from the passage hole 55 ⁇ / b> A formed in the cover member 20.
  • the detection light incident in the concave groove 50 passes through the space between the pair of elastic pieces 51A and 51B via the slits 52 formed in each of the pair of elastic pieces 51A and 51B.
  • the detection light that has passed through the elastic piece 51B is received by the light receiving element 38 through the passage hole 55B formed in the cover member 20. That is, the slit 52 is disposed on the optical axis AX of the detection light formed between the light projecting element 37 and the light receiving element 38.
  • the refractive mode of the detection light SL changes according to the difference between the refractive index of the material of the tube T and the refractive index of the medium inside the tube T.
  • the refractive index of the liquid L is larger than the refractive index of the air A. Therefore, the difference in refractive index is relatively small. Therefore, of the detection light SL irradiated from the light projecting element 37, the ratio of the detection light SL that does not reach the light receiving element 38 due to refraction at the interface between the tube T and the liquid L is relatively small.
  • the amount of light received by the light receiving element 38 is compared with a predetermined threshold, and when the amount of received light is less than the predetermined threshold, it is determined that the inside of the tube T is filled with air A. Is possible.
  • the light receiving element 38 outputs a signal having a level corresponding to the amount of received light.
  • the detection circuit composed of the circuit elements 34 mounted on the substrate frame 31 shown in FIG. 2 compares the level (for example, voltage value) of the signal output from the light receiving element 38 with a threshold value, and a detection signal corresponding to the comparison result. Is generated. This detection signal makes it possible to determine whether the medium inside the tube T is the liquid L or the air A.
  • the pair of elastic pieces 51A and 51B is divided into a plurality of pieces in the same direction by forming a slit 52 at the center position in the longitudinal direction. Therefore, the pair of elastic pieces 51A and 51B are easily elastically deformed as compared with the configuration in which the pair of elastic pieces 51A and 51B continuously extend over the entire region in the longitudinal direction, and the adhesion of the pair of elastic pieces 51A and 51B to the tube T is improved. Will be.
  • the slit 52 formed for the purpose of holding the tube T also functions as an optical path of the detection light SL necessary for optically detecting the liquid in the tube T. Therefore, the strength of the pair of elastic pieces 51A and 51B is compared with a case where a slit 52 and a through hole are newly provided in the pair of elastic pieces 51A and 51B for the purpose of forming such an optical path of the detection light SL. It will also improve.
  • the following effects can be obtained.
  • the pair of elastic pieces 51A and 51B in the cover member 20 are divided in the longitudinal direction of the tube T by the slits 52 so as to be in close contact with the tube T, the tube T can be easily fitted. The holding force with respect to the tube T can be improved.
  • the slit 52 formed to divide the elastic pieces 51A and 51B also functions as an optical path of the detection light SL. For this reason, it is not necessary to separately form a through-hole or the like in order to secure the optical path of the detection light SL, and the strength of the elastic pieces 51A and 51B is not reduced. can do.
  • a second taper surface that gradually narrows from both ends in the longitudinal direction of the tube T toward the center at both ends in the longitudinal direction of the tube T of the tip edges 56A and 56B of the pair of elastic pieces 51A and 51B. P2 is formed. Therefore, when the tube T is sandwiched between the pair of elastic pieces 51A and 51B in the order from one end side to the other end side in the longitudinal direction, the tube T is sandwiched while being guided by the second tapered surface P2. Can be held on the cover member 20 more simply.
  • the slit 52 penetrates the pair of elastic pieces 51A and 51B in the insertion / extraction direction of the tube T, and a concave portion 54 communicating with the slit 52 is formed on the surface of the cover member 20 where the pair of elastic pieces 51A and 51B is formed. Is formed. Therefore, even if a part of the detection light that has passed through the slit 52 is emitted from the slit 52 so as to deviate from the optical axis AX, such detection light is scattered and reflected in the concave portion 54 of the cover member 20 after passing through the slit 52. Therefore, it is possible to prevent such detection light from entering the light receiving element 38 by mistake.
  • the cover member 20 is attached to the main body case 10 having the bolt holes 13 for attaching the liquid sensor to the object S.
  • the material of the main body case 10 is more rigid than the material of the cover member 20. high. Therefore, since the main body case 10 is made of a material having a relatively high rigidity, the liquid sensor can be stably attached to the object S.
  • the holding direction of the tube T with respect to the cover member 20 is the same as the mounting direction of the main body case 10 with respect to the object S. Therefore, for example, when the tube T that is the target of the liquid sensor is drawn along the wall surface of the room, the main body case 10 can be directly attached to the wall surface of the room that is the object S or the like. Moreover, since the attachment operation
  • the cover member 20 may be made of a black resin material. Therefore, since the detection light SL that has passed through the slit 52 is reduced from being scattered and reflected by the cover member 20, it is possible to prevent such detection light SL from entering the light receiving element 38 by mistake.
  • the exterior of the liquid sensor of the present embodiment is constituted by a main body case 10 and a cover member 70.
  • the cover member 70 functions as a holding member.
  • the cover member 70 is attached to the open end of the cylindrical portion 12 of the main body case 10.
  • the cover member 70 is made of a black resin material, like the cover member 20 of the first embodiment.
  • the sensor unit 30 is accommodated in the cylindrical portion 12 of the main body case 10.
  • the sensor unit 30 includes a substrate frame 31, a light projecting frame 32, and a light receiving frame 33.
  • the substrate frame 31 includes a bottom frame portion 31A, a side frame portion 31B, and a cover frame portion 31C.
  • the cover member 70 and the sensor unit 30 are fixed to the main body case 10 by positioning pins 43 inserted into the insertion holes 41 of the main body case 10.
  • An insertion hole 40 is formed in the cover member 70.
  • the cover member 70 is inserted into the main body case 10 so that the insertion hole 40 overlaps the insertion hole 41 of the main body case 10.
  • the positioning pin 43 is inserted through the insertion hole 41 of the main body case 10 and the insertion hole 40 of the cover member 70.
  • the top surface P of the cover member 70 is formed in a substantially rectangular shape.
  • a groove 50 is formed in the cover member 70 from the top surface P toward the main body case 10.
  • the concave groove 50 extends linearly from one end to the other end of the top surface P at the center position in the longitudinal direction of the top surface P.
  • a pair of elastic pieces 71 ⁇ / b> A and 71 ⁇ / b> B is disposed in the concave groove 50.
  • the pair of elastic pieces 71 ⁇ / b> A and 71 ⁇ / b> B extends from the bottom surface of the groove 50 toward the open end of the groove 50, that is, the top surface P.
  • the pair of elastic pieces 71A and 71B extend from the entire longitudinal direction of the concave groove 50, that is, from one end to the other end in the longitudinal direction.
  • the pair of elastic pieces 71A and 71B are curved in an arc shape.
  • the pair of elastic pieces 71A and 71B have curved inner peripheral surfaces facing each other.
  • the pair of elastic pieces 71A, 71B are curved according to the outer diameter of the tube T held by these elastic pieces 71A, 71B.
  • open ends into which the tube T is inserted and removed are formed at the tip edges 76A and 76B of the pair of elastic pieces 71A and 71B.
  • the distal end edges 76A and 76B of the pair of elastic pieces 71A and 71B are provided with a first tapered surface P1 that gradually becomes narrower in the insertion direction of the tube T, which is a direction from the distal end to the proximal end of the elastic pieces 71A and 71B. Is formed. Due to the first tapered surface P1 at the tip edge, the width between the tip portions of the pair of elastic pieces 71A and 71B becomes gradually narrower in the insertion direction.
  • the distal ends of the pair of elastic pieces 71A and 71B are arranged at the distal ends of the pair of elastic pieces 71A and 71B from the outer side to the inner side of the space between the pair of elastic pieces 71A and 71B.
  • a first taper surface P ⁇ b> 1 is formed in which the width between is gradually narrowed.
  • a slit 52 extending from the proximal end to the distal end of the pair of elastic pieces 71A, 71B is formed at the center position in the longitudinal direction of the pair of elastic pieces 71A, 71B.
  • the slit 52 passes through the pair of elastic pieces 71 ⁇ / b> A and 71 ⁇ / b> B along a direction orthogonal to the bottom surface of the groove 50. Further, the slit 52 communicates with a concave portion 54 formed on the bottom surface of the concave groove 50.
  • the light projecting element 37 and the light receiving element 38 are disposed so as to face each other.
  • a straight line (one-dot chain line) connecting the light projecting element 37 and the light receiving element 38 is defined as an optical axis AX.
  • the slit 52 is disposed on the optical axis AX.
  • the cover member 70 has passage holes 55A and 55B arranged on the optical axis AX.
  • the passage holes 55A and 55B are formed by, for example, slits 57A and 57B of the side walls 56A and 56B that form the concave groove 50.
  • Slits 57A and 57B extending along the same direction as the slit 52 are formed in the longitudinal center of the side walls 56A and 56B forming the inner side surfaces 50A and 50B of the concave groove 50.
  • the slit 57 ⁇ / b> A penetrates the side wall 56 ⁇ / b> A and forms a passage hole 55 ⁇ / b> A that communicates the space 58 ⁇ / b> A in which the light projecting element 37 (see FIG. 11) is disposed with the inside of the groove 50.
  • the slit 57B penetrates the side wall 56B and forms a passage hole 55B that communicates the space 58B in which the light receiving element 38 (see FIG. 11) is disposed with the inside of the groove 50.
  • the slit 52 is formed with light shielding portions 72A and 72B.
  • the light shielding part 72 ⁇ / b> A is formed between two elastic pieces 71 ⁇ / b> A divided by the slit 52.
  • the light shielding portion 72B is formed between two elastic pieces 71B divided by the slit 52. That is, the light shielding portions 72A and 72B are arranged in the vicinity of the pair of elastic pieces 51A and 51B in the slit 52.
  • Each of the light shielding portions 72A and 72B is disposed adjacent to the corresponding elastic piece 51A and 51B in the longitudinal direction of the elastic piece 51A and 51B.
  • the light shielding portions 72A and 72B include two side surfaces for sandwiching the tube at a position different from the pair of elastic pieces 51A and 51B.
  • the light shielding portions 72A and 72B are formed in a straight line extending from the bottom surface of the groove 50 toward the tips of the pair of elastic pieces 71A and 71B.
  • the light shielding portions 72A and 72B are formed such that the tips of the light shielding portions 72A and 72B are in contact with the outer peripheral surface of a tube T (not shown) held by the pair of elastic pieces 71A and 71B.
  • the light shielding portions 72A and 72B are in the slit 52 and are formed integrally with the pair of elastic pieces 71A and 71B.
  • Shield portions 73A and 73B are disposed on the side walls 56A and 56B, respectively. As shown in FIG. 8, the light shielding part 73A is formed so as to straddle the slit 57A formed in the side wall 56A. Similarly, the light shielding part 73B is formed so as to straddle the slit 57B formed in the side wall 56B (see FIG. 10).
  • the light blocking portions 72A, 72B, 73A, 73B block a part of the light emitted from the light projecting element 37.
  • the region through which the liquid L passes in the tube T changes depending on the presence or absence of the liquid L. Accordingly, the amount of detection light SL received by the light receiving element 38 through the region inside the tube T changes.
  • the liquid sensor determines whether the inside of the tube T is filled with the liquid L or the air A according to the amount of light received by the light receiving element 38. That is, the liquid sensor determines the presence or absence of the liquid L according to the amount of light received by the light receiving element 38. Accordingly, light that does not pass through the region through which the liquid L passes is not necessary for detection.
  • the light shielding portions 72A, 72B, 73A, and 73B are light (unnecessary light) other than light that passes through the region where the liquid L passes through the tube T, that is, the region inside the tube T, among the light emitted from the light projecting element 37. It is provided so as to block.
  • the detection light SL passes through the boundary (interface) between the two media, the detection light SL is bent according to the difference in refractive index between the two media.
  • FIG. 12A and 12B schematically show the light projecting element 37, the light receiving element 38, the tube T, and the light shielding portions 72A, 72B, 73A, and 73B.
  • the inside of the tube T is filled with the liquid L.
  • the inside of the tube T is filled with air A such as bubbles.
  • the difference between the refractive index of the tube T and the refractive index of the liquid L is smaller than the difference between the refractive index of the tube T and the refractive index of the air A.
  • the detection light SL emitted from the light projecting element 37 passes through the tube T and the liquid L substantially linearly.
  • the detection light SL is not received by the light receiving element 38.
  • the detection light SL emitted from the light projecting element 37 is refracted on the inner peripheral surface Ta of the tube T and travels inside the tube T substantially parallel to the optical axis AX. Then, the light is refracted on the inner peripheral surface Ta and the outer peripheral surface Tb of the tube T and received by the light receiving element 38.
  • the light receiving element 38 outputs a signal having a level corresponding to the amount of light received.
  • the level for example, voltage value
  • the level of this signal is compared with a predetermined threshold value, and a detection signal having a level corresponding to the comparison result is generated.
  • the level of this detection signal corresponds to the medium inside the tube T. Therefore, the medium inside the tube T (region through which the detection light SL is transmitted) can be determined based on the level of the detection signal.
  • the detection light SL emitted from the light projecting element 37 is diffused radially from the light projecting element 37.
  • the detection light SL may be reflected according to the refractive index difference and the incident angle to the boundary (interface).
  • the light Sa indicated by the alternate long and short dash line is unnecessary light, and is reflected by the inner peripheral surface Ta and the outer peripheral surface Tb of the tube T and reaches the light receiving element 38. That is, the unnecessary light Sa passes through the bottom surface side of the concave groove 50 from the inner peripheral surface Ta of the tube T, that is, the base end side of the pair of elastic pieces 71A and 71B, and does not pass through the medium (air A in the drawing).
  • the light Sb indicated by the two-dot chain line is unnecessary light, and passes through the distal end side of the pair of elastic pieces 71A and 71B from the inner peripheral surface Ta in the tube T and reaches the light receiving element 38. That is, the unnecessary light Sb does not pass through the medium (air A).
  • These unnecessary lights Sa and Sb are not affected by the medium inside the tube T. That is, it is unnecessary light (unnecessary light) for detecting the medium.
  • the light blocking portions 72A and 73A of the present embodiment block unnecessary light Sa and Sb. Therefore, unnecessary light Sa and Sb do not reach the light receiving element 38. For this reason, the amount of light received by the light receiving element 38 changes according to the medium (liquid L or air A) inside the tube T. For this reason, the difference in the amount of received light is large, and erroneous determination can be suppressed. Further, since the difference in the amount of received light is large, the threshold value can be easily set.
  • the broken lines indicate the optical paths of unnecessary light Sa and Sb that are unnecessary light.
  • the light shielding parts 72B and 73B are arranged in these optical paths. Therefore, stray light (light due to irregular reflection or the like) may pass through an optical path indicated by a broken line. Such stray light causes fluctuations in the amount of light received by the light receiving element 38, that is, disturbance.
  • the light blocking portions 72B and 73B block stray light and suppress fluctuations in the amount of received light. For this reason, erroneous determination due to stray light or the like can be suppressed.
  • the light blocking portions 72A, 72B, 73A, 73B block a part of the light emitted from the light projecting element 37.
  • the light shielding portions 72A, 72B, 73A, and 73B are light (unnecessary light) other than light that passes through the region where the liquid L passes through the tube T, that is, the region inside the tube T, among the light emitted from the light projecting element 37. It is provided so as to block. Therefore, unnecessary light Sa and Sb do not reach the light receiving element 38. For this reason, the amount of light received by the light receiving element 38 changes according to the medium (liquid L or air A) inside the tube T. For this reason, the difference in the amount of received light is large, and erroneous determination can be suppressed.
  • the light shielding portions 72A and 72B are disposed in the slit 52 that divides the pair of elastic pieces 71A and 71B.
  • the detection light SL emitted from the light projecting element 37 passes through the slit 52. Therefore, the light shielding portions 72A and 72B disposed in the slit 52 easily shield a part of the detection light SL.
  • the light shielding portions 72A and 72B are disposed in the slit 52 that divides the pair of elastic pieces 71A and 71B.
  • the light (emitted light) emitted from the light projecting element 37 spreads radially.
  • the emitted light includes detection light SL that passes through the inside of the tube T through which the liquid L passes and unnecessary light Sa that does not pass through the inside of the tube T. Therefore, by disposing the light shielding portions 72A and 72B so as to be in contact with the tube T, unnecessary light Sa can be shielded, and the amount of the detection light SL blocked by the light shielding portions 72A and 72B can be reduced. That is, a decrease in the amount of the detection light SL can be suppressed.
  • each said embodiment can also be implemented with the following forms. -In the said embodiment, you may employ
  • FIG. 1 In the said embodiment, you may employ
  • the attachment direction of the main body case 10 with respect to the object S and the holding direction of the tube T with respect to the pair of elastic pieces 51A, 51B, 71A, 71B may be different from each other.
  • the recess 54 formed on the bottom surface of the groove 50 may be omitted.
  • the tip edges of the pair of elastic pieces 51 ⁇ / b> A and 51 ⁇ / b> B may be configured to have end faces that have a constant width over the entire region in the longitudinal direction of the tube T.
  • the light projecting element 37 and the light receiving element 38 are not necessarily arranged to face each other.
  • the irradiation direction of the detection light from the light projecting element 37 and the incident direction of the detection light to the light receiving element 38 And may be configured to cross each other diagonally.
  • the light shielding parts 73A and 73B may be omitted.
  • the detection light SL output from the light projecting element 37 decreases in amount as the angle increases from the center of the emitted light. Therefore, in the tube T, the amount of detection light passing through the distal ends of the pair of elastic pieces 51A and 51B may have less influence on the result of determining the presence or absence of the liquid L than the inner peripheral surface Ta. For this reason, in the liquid sensor using the light projecting element 37 that emits the detection light SL with less influence, the light shielding portions 73A and 73B can be omitted.
  • the light shielding portions 72B and 73B on the light receiving element 38 side may be omitted. Further, the light shielding portions 72A and 73A on the light projecting element 37 side may be omitted. In the second embodiment, unnecessary light is shielded by the light shielding portions 72A, 72B, 73A, 73B disposed in the vicinity of the tube T. Therefore, in the cover member 70, the size and shape of the passage holes 55A and 55B may be changed as appropriate.
  • the pair of elastic pieces 51A and 51B may have the second tapered surface P2 at the end.

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Abstract

This liquid sensor for detecting whether or not a liquid is present inside a translucent tube (T) comprises: a lighting unit (37) emitting a detection light; a light receiving unit (38) facing the lighting unit (37) and receiving the detection light; and a holding member (70) provided between the lighting unit (37) and the light receiving unit (38), having a pair of elastic pieces (71A, 71B) for sandwiching the tube (T). Each of the elastic pieces (71A, 71B) has a slit (52) extending in a direction intersecting with the length direction of the elastic pieces (71A, 71B) in a different direction from the illumination direction, the slit (52) of each of the elastic pieces (71A, 71B) being disposed on the optical axis of the detection light between the lighting unit (37) and the light receiving unit (38). In addition, light blocking portions (72A, 72B, 73A, 73B) are provided for blocking a portion of the detection light exiting from the lighting unit (37) in a direction intersecting with the length direction of each of the elastic pieces (71A, 71B). The light blocking portions (72A, 72B, 73A, 73B) are provided in such a manner as to block, from among the detection light exiting from the lighting unit (37), light other than the light passing through a region in the tube (T) where the liquid passes.

Description

液体センサLiquid sensor
　本発明は、透光性を有するチューブ内の液体の有無を光学的に検出する液体センサに関する。 The present invention relates to a liquid sensor that optically detects the presence or absence of a liquid in a translucent tube.
　従来から、この種の液体センサとしては、特許文献１に記載の液体センサが知られている。この液体センサでは、大弧状の本体部の内側において透光性のチューブが挟持された状態で、発光素子からチューブに向けて光が照射され、チューブを通じた光が受光素子によって受光される。チューブにおける光の屈折態様がチューブ内の液体の有無に応じて異なるため、チューブ内の液体の有無を受光素子の受光量に基づいて光学的に検出することが可能である。 Conventionally, a liquid sensor described in Patent Document 1 is known as this type of liquid sensor. In this liquid sensor, light is emitted from the light emitting element toward the tube while the translucent tube is sandwiched inside the large arc-shaped main body, and the light passing through the tube is received by the light receiving element. Since the light refraction mode in the tube varies depending on the presence or absence of the liquid in the tube, the presence or absence of the liquid in the tube can be optically detected based on the amount of light received by the light receiving element.
特開平８－２９３２３４号公報JP-A-8-293234
　ところで、上記文献に記載の液体センサでは、チューブにおいて挟持の対象とする部分の長さが長いことから本体部とチューブとの間に隙間が生じやすく、チューブに対する十分な保持力が得られにくいという問題があった。 By the way, in the liquid sensor described in the above document, since the length of the portion to be clamped in the tube is long, a gap is easily generated between the main body and the tube, and it is difficult to obtain a sufficient holding force for the tube. There was a problem.
　本発明は、このような実情に鑑みてなされたものであり、その目的は、チューブに対する保持力を向上することにある。 The present invention has been made in view of such a situation, and an object thereof is to improve the holding force with respect to the tube.
　本発明の一側面は、透光性を有するチューブ内に液体が存在するかどうかを検知する液体センサであって、検出光を照射する投光部と、前記投光部と対向し、前記検出光を受光する受光部と、前記投光部と前記受光部との間に設けられ、前記チューブを挟持するための一対の弾性片を有する保持部材と、を備え、前記一対の弾性片の各々は、前記弾性片の長手方向と交差する方向であって、かつ、前記照射方向とは異なる方向に延在するスリットを有し、前記一対の弾性片の各々のスリットは、前記投光部と前記受光部との間の前記検出光の光軸上に配置され、前記投光部から出射された検出光の一部を前記弾性片の長手方向と交差する方向において遮光する遮光部をさらに備え、前記遮光部は、前記投光部から出射された検出光のうち、前記チューブにおいて液体が通る領域を通過する光以外の光を遮光するように設けられている。 One aspect of the present invention is a liquid sensor that detects whether or not a liquid is present in a light-transmitting tube, the light projecting unit that irradiates detection light, the light projecting unit that faces the light projecting unit, and the detection A light receiving portion that receives light, and a holding member that is provided between the light projecting portion and the light receiving portion and has a pair of elastic pieces for sandwiching the tube, and each of the pair of elastic pieces Is a direction that intersects the longitudinal direction of the elastic piece and extends in a direction different from the irradiation direction, and each of the slits of the pair of elastic pieces includes the light projecting unit and A light-shielding part that is disposed on the optical axis of the detection light between the light-receiving part and shields a part of the detection light emitted from the light-projecting part in a direction intersecting the longitudinal direction of the elastic piece; The light-shielding part includes the detection light emitted from the light projecting part. Serial is provided so as to block light other than light passing through a region through which the liquid in the tube.
　本発明によれば、チューブに対する保持力を向上することができる。 According to the present invention, the holding force for the tube can be improved.
第一実施形態の液体センサの斜視図。The perspective view of the liquid sensor of 1st embodiment. 液体センサの分解斜視図。The disassembled perspective view of a liquid sensor. カバー部材の斜視図。The perspective view of a cover member. 図３の４－４線矢視断面図。FIG. 4 is a sectional view taken along line 4-4 in FIG. カバー部材の平面図。The top view of a cover member. 液体センサの断面図。Sectional drawing of a liquid sensor. 液体センサの要部拡大断面図であって、（ａ）は、チューブ内が液体で満たされているときの検出光の屈折態様を示し、（ｂ）は、チューブ内が空気で満たされているときの検出光の屈折態様を示す。It is principal part expanded sectional drawing of a liquid sensor, Comprising: (a) shows the refraction | bending aspect of the detection light when the inside of a tube is satisfy | filled with the liquid, (b) is the inside of the tube being filled with air. The refraction mode of the detection light is shown. 第二実施形態の液体センサの斜視図。The perspective view of the liquid sensor of 2nd embodiment. 液体センサの分解斜視図。The disassembled perspective view of a liquid sensor. カバー部材の断面を示す斜視図。The perspective view which shows the cross section of a cover member. 液体センサの断面図。Sectional drawing of a liquid sensor. （ａ）（ｂ）は検出光の状態を示す説明図。(A) (b) is explanatory drawing which shows the state of detection light. （ａ）はチューブにおける検出光の状態を示す説明図、（ｂ）は不要光の遮光状態を示す説明図。(A) is explanatory drawing which shows the state of the detection light in a tube, (b) is explanatory drawing which shows the light-shielding state of unnecessary light.
　（第一実施形態）
　以下、第一実施形態の液体センサを説明する。
　図１に示すように、本実施形態の液体センサの外装は、本体ケース１０とカバー部材２０とにより構成されている。 (First embodiment)
Hereinafter, the liquid sensor of the first embodiment will be described.
As shown in FIG. 1, the exterior of the liquid sensor of the present embodiment includes a main body case 10 and a cover member 20.
　本体ケース１０は、例えば硬質樹脂等からなる。本体ケース１０は、平板部１１と、平板部１１から突出した筒部１２とを有している。平板部１１には、その厚み方向に貫通する２つのボルト孔１３が二箇所に形成されている。本体ケース１０は、これらのボルト孔１３に挿通された固定ボルト等（図示略）により、例えば壁面等の対象物Ｓに固定される。ボルト孔１３は、取付部として機能する。 The main body case 10 is made of, for example, a hard resin. The main body case 10 has a flat plate portion 11 and a cylindrical portion 12 protruding from the flat plate portion 11. Two bolt holes 13 penetrating in the thickness direction are formed in the flat plate portion 11 at two locations. The main body case 10 is fixed to an object S such as a wall surface by fixing bolts (not shown) inserted through these bolt holes 13. The bolt hole 13 functions as an attachment portion.
　カバー部材２０は、本体ケース１０の筒部１２の開口端に取り付けられている。カバー部材２０において液体センサの外側に露出する部分によって、液体センサの測定対象となる透光性のチューブＴが保持される。なお、カバー部材２０にチューブＴを保持する方向をチューブＴの保持方向とする。液体センサ（本体ケース１０）を対象物Ｓに取り付ける方向、対象物Ｓにおいて本体ケース１０の取付られる面に垂直な方向を液体センサ（本体ケース１０）の取付方向とする。これら、チューブＴの保持方向と液体センサの取付方向は互いに同じ方向、つまり保持方向と取付方向とは同一方向である。 The cover member 20 is attached to the open end of the cylindrical portion 12 of the main body case 10. The light-transmitting tube T to be measured by the liquid sensor is held by the portion of the cover member 20 exposed to the outside of the liquid sensor. The direction in which the tube T is held by the cover member 20 is the holding direction of the tube T. The direction in which the liquid sensor (main body case 10) is attached to the object S, and the direction perpendicular to the surface of the object S to which the main body case 10 is attached are the attachment direction of the liquid sensor (main body case 10). The holding direction of the tube T and the mounting direction of the liquid sensor are the same direction, that is, the holding direction and the mounting direction are the same direction.
　図２に示すように、本体ケース１０の筒部１２には、チューブＴ内の液体の有無を検知するセンサユニット３０が収容されている。センサユニット３０は、基板フレーム３１と、投光フレーム３２と、受光フレーム３３とを有している。基板フレーム３１は、一方向に細長く延びている。投光フレーム３２と受光フレーム３３は、基板フレーム３１の長手方向の一端及び他端から、それぞれ同一方向に垂直に立設されている。 As shown in FIG. 2, a sensor unit 30 that detects the presence or absence of liquid in the tube T is accommodated in the cylindrical portion 12 of the main body case 10. The sensor unit 30 includes a substrate frame 31, a light projecting frame 32, and a light receiving frame 33. The substrate frame 31 is elongated in one direction. The light projecting frame 32 and the light receiving frame 33 are erected vertically from one end and the other end of the substrate frame 31 in the same direction.
　基板フレーム３１は、ボトムフレーム部３１Ａ、サイドフレーム部３１Ｂ、カバーフレーム部３１Ｃを含む。ボトムフレーム部３１Ａには液体センサにおける各種の動作を制御する回路素子３４が実装されている。サイドフレーム部３１Ｂは四角枠状をなし、回路素子３４を囲む。カバーフレーム部３１Ｃは、ボトムフレーム部３１Ａとサイドフレーム部３１Ｂとにより囲まれた回路素子３４の実装空間を閉塞する。なお、カバーフレーム部３１Ｃは、一方向に細長く延びており、その長手方向の一端及び他端には第１の嵌合部３５及び第２の嵌合部３６がそれぞれ設けられている。第１の嵌合部３５及び第２の嵌合部３６には、投光フレーム３２及び受光フレーム３３がそれぞれ嵌合される。これにより、基板フレーム３１に投光フレーム３２と受光フレーム３３が固定される。 The substrate frame 31 includes a bottom frame portion 31A, a side frame portion 31B, and a cover frame portion 31C. A circuit element 34 for controlling various operations in the liquid sensor is mounted on the bottom frame portion 31A. The side frame portion 31 </ b> B has a rectangular frame shape and surrounds the circuit element 34. The cover frame portion 31C closes the mounting space of the circuit element 34 surrounded by the bottom frame portion 31A and the side frame portion 31B. The cover frame portion 31C is elongated in one direction, and a first fitting portion 35 and a second fitting portion 36 are provided at one end and the other end in the longitudinal direction, respectively. The light projecting frame 32 and the light receiving frame 33 are respectively fitted to the first fitting portion 35 and the second fitting portion 36. Thereby, the light projecting frame 32 and the light receiving frame 33 are fixed to the substrate frame 31.
　また、カバー部材２０は、本体ケース１０の筒部１２にセンサユニット３０が収容された状態で、本体ケース１０の筒部１２の開口を閉塞するように本体ケース１０に嵌合されている。このとき、カバー部材２０に形成された挿通孔４０と本体ケース１０に形成された挿通孔４１とが重なる。これら重なり合った挿通孔４０，４１に対して本体ケース１０の外側から位置決めピン４３が挿入されている。この位置決めピン４３は、センサユニット３０における基板フレーム３１のカバーフレーム部３１Ｃに対して上方から接触することで、本体ケース１０の筒部１２内でのセンサユニット３０の収容位置を位置決めする役割を果たす。 Further, the cover member 20 is fitted to the main body case 10 so as to close the opening of the cylindrical portion 12 of the main body case 10 in a state where the sensor unit 30 is accommodated in the cylindrical portion 12 of the main body case 10. At this time, the insertion hole 40 formed in the cover member 20 and the insertion hole 41 formed in the main body case 10 overlap. A positioning pin 43 is inserted into the overlapping insertion holes 40 and 41 from the outside of the main body case 10. The positioning pins 43 play a role of positioning the housing position of the sensor unit 30 in the cylindrical portion 12 of the main body case 10 by contacting the cover frame portion 31C of the substrate frame 31 in the sensor unit 30 from above. .
　次に、カバー部材２０の構成について詳細に説明する。
　図３に示すように、カバー部材２０は、例えば黒色の軟質樹脂等により一体成形されている。カバー部材２０は、略矩形状をなす天面Ｐを含む。天面Ｐの長手方向の中央位置には、天面Ｐの短手方向の一端から他端に亘って直線状に延びる凹溝５０が形成されている。凹溝５０の底面には、円弧状に湾曲して凹溝５０の長手方向の全域に亘って延びる一対の弾性片５１Ａ，５１Ｂが形成されている。この一対の弾性片５１Ａ，５１Ｂは、チューブＴを挟持して保持する役割を果たす。 Next, the configuration of the cover member 20 will be described in detail.
As shown in FIG. 3, the cover member 20 is integrally formed of, for example, black soft resin. The cover member 20 includes a top surface P having a substantially rectangular shape. At the center position in the longitudinal direction of the top surface P, a concave groove 50 is formed that extends linearly from one end to the other end of the top surface P in the short direction. A pair of elastic pieces 51 </ b> A and 51 </ b> B are formed on the bottom surface of the concave groove 50, which are curved in an arc shape and extend over the entire length of the concave groove 50. The pair of elastic pieces 51A and 51B plays a role of holding and holding the tube T.
　図４に示すように、一対の弾性片５１Ａ，５１Ｂの先端縁５６Ａ，５６Ｂは、チューブＴが挿抜される開口端を有する。この一対の弾性片５１Ａ，５１Ｂの先端縁５６Ａ，５６Ｂには、弾性片５１Ａ，５１Ｂの先端から基端に向かう方向であるチューブＴの挿入方向において、次第に幅狭となる第１のテーパ面Ｐ１が形成されている。先端縁の第１のテーパ面Ｐ１により、一対の弾性片５１Ａ，５１Ｂの先端部の間の幅は、挿入方向において、次第に幅狭となる。つまり、一対の弾性片５１Ａ，５１ＢにおいてチューブＴが挿抜される先端縁には、一対の弾性片５１Ａ，５１Ｂの間の空間の外側から内側に向けて、一対の弾性片５１Ａ，５１Ｂの先端部の間の幅が、次第に幅狭となる第１のテーパ面Ｐ１が形成されている。すなわち、各弾性片５１Ａ，５１Ｂは、検出光の光軸と交差し且つチューブＴが挿抜される先端縁５６Ａまたは５６Ｂを含む。弾性片５１Ａの先端縁５６Ａは、弾性片５１Ｂと対向し且つ先端縁５６Ａの先端に向かうにつれて弾性片５１Ｂから遠ざかる傾斜面を含む。同様に、弾性片５１Ｂの先端縁５６Ｂは、弾性片５１Ａと対向し且つ先端縁５６Ｂの先端に向かうにつれて弾性片５１Ａから遠ざかる傾斜面を含む。 As shown in FIG. 4, the tip edges 56A and 56B of the pair of elastic pieces 51A and 51B have open ends into which the tube T is inserted and removed. The distal end edges 56A and 56B of the pair of elastic pieces 51A and 51B are provided with a first tapered surface P1 that gradually becomes narrower in the insertion direction of the tube T, which is the direction from the distal end to the proximal end of the elastic pieces 51A and 51B. Is formed. Due to the first tapered surface P1 at the tip edge, the width between the tip portions of the pair of elastic pieces 51A and 51B becomes gradually narrower in the insertion direction. In other words, the distal ends of the pair of elastic pieces 51A and 51B are arranged at the distal ends of the pair of elastic pieces 51A and 51B from the outer side to the inner side of the space between the pair of elastic pieces 51A and 51B. A first taper surface P <b> 1 is formed in which the width between is gradually narrowed. That is, each elastic piece 51A, 51B includes a tip edge 56A or 56B that intersects the optical axis of the detection light and into which the tube T is inserted and removed. The distal edge 56A of the elastic piece 51A includes an inclined surface that faces the elastic piece 51B and moves away from the elastic piece 51B toward the distal end of the distal edge 56A. Similarly, the tip edge 56B of the elastic piece 51B includes an inclined surface that faces the elastic piece 51A and moves away from the elastic piece 51A toward the tip of the tip edge 56B.
　図５に示すように、一対の弾性片５１Ａ，５１Ｂの先端縁５６Ａ，５６Ｂにおける凹溝５０の長手方向の両端には、凹溝５０の長手方向の両端から中央に向けて次第に幅狭となる第２のテーパ面Ｐ２が形成されている。つまり、弾性片５１Ａの先端縁５６Ａは、当該先端縁５６Ａの長手方向における両端にそれぞれ形成され且つ先端縁５６Ａの先端に向かうにつれて互いに近づく２つの傾斜面を含む。同様に、弾性片５１Ｂの先端縁５６Ｂは、先端縁５６Ｂの長手方向における両端にそれぞれ形成され且つ先端縁５６Ｂの先端に向かうにつれて互いに近づく２つの傾斜面を含む。 As shown in FIG. 5, the longitudinal ends of the concave groove 50 at the end edges 56A and 56B of the pair of elastic pieces 51A and 51B are gradually narrowed from both longitudinal ends of the concave groove 50 toward the center. A second taper surface P2 is formed. That is, the tip edge 56A of the elastic piece 51A includes two inclined surfaces that are formed at both ends in the longitudinal direction of the tip edge 56A and approach each other toward the tip of the tip edge 56A. Similarly, the leading edge 56B of the elastic piece 51B includes two inclined surfaces that are formed at both ends in the longitudinal direction of the leading edge 56B and approach each other toward the tip of the leading edge 56B.
　一対の弾性片５１Ａ，５１Ｂにおける長手方向の中央位置には、一対の弾性片５１Ａ，５１Ｂの基端から先端まで延びるスリット５２が形成されている。スリット５２は、凹溝５０の底面と直交する方向に沿って、一対の弾性片５１Ａ，５１Ｂを貫通している。さらに、スリット５２は、凹溝５０の底面に形成された凹部５４に連通している。換言すると、各弾性片５１Ａ，５１Ｂは、投光素子３７と受光素子３８との間の検出光の光軸上に形成され且つ当該弾性片５１Ａまたは５１Ｂを分割するスリット５２を有する。 A slit 52 extending from the proximal end to the distal end of the pair of elastic pieces 51A, 51B is formed at the center position in the longitudinal direction of the pair of elastic pieces 51A, 51B. The slit 52 passes through the pair of elastic pieces 51 </ b> A and 51 </ b> B along a direction orthogonal to the bottom surface of the groove 50. Further, the slit 52 communicates with a concave portion 54 formed on the bottom surface of the concave groove 50. In other words, each elastic piece 51A, 51B has a slit 52 formed on the optical axis of the detection light between the light projecting element 37 and the light receiving element 38 and dividing the elastic piece 51A or 51B.
　図６に示すように、カバー部材２０が本体ケース１０に嵌合された状態では、投光素子３７と受光素子３８とがスリット５２を介して互いに対向するように配置される。投光素子３７は、投光部として機能し、受光素子３８は、受光部として機能する。そして、投光素子３７からスリット５２の延在方向と交差する方向に照射される検出光は、カバー部材２０に形成された通過孔５５Ａから凹溝５０内に入射される。凹溝５０内に入射された検出光は、一対の弾性片５１Ａ，５１Ｂの各々に形成されたスリット５２を介して一対の弾性片５１Ａ，５１Ｂの間の空間を通過する。弾性片５１Ｂを通過した検出光は、カバー部材２０に形成された通過孔５５Ｂを介して受光素子３８に受光される。すなわち、スリット５２は、投光素子３７と受光素子３８との間に形成される検出光の光軸ＡＸに配置されている。 As shown in FIG. 6, in a state where the cover member 20 is fitted to the main body case 10, the light projecting element 37 and the light receiving element 38 are disposed so as to face each other through the slit 52. The light projecting element 37 functions as a light projecting unit, and the light receiving element 38 functions as a light receiving unit. Then, the detection light emitted from the light projecting element 37 in the direction intersecting with the extending direction of the slit 52 enters the concave groove 50 from the passage hole 55 </ b> A formed in the cover member 20. The detection light incident in the concave groove 50 passes through the space between the pair of elastic pieces 51A and 51B via the slits 52 formed in each of the pair of elastic pieces 51A and 51B. The detection light that has passed through the elastic piece 51B is received by the light receiving element 38 through the passage hole 55B formed in the cover member 20. That is, the slit 52 is disposed on the optical axis AX of the detection light formed between the light projecting element 37 and the light receiving element 38.
　図７（ａ）及び図７（ｂ）に示すように、一対の弾性片５１Ａ，５１Ｂに透光性のチューブＴが保持された状態で投光素子３７から検出光が照射されると、その照射された検出光がスリット５２を介してチューブＴの外表面に到達し、更にはチューブＴの内部を横切るようにチューブＴを透過した後に受光素子３８に受光される。 As shown in FIG. 7A and FIG. 7B, when detection light is irradiated from the light projecting element 37 in a state where the pair of elastic pieces 51A and 51B hold the translucent tube T, The irradiated detection light reaches the outer surface of the tube T through the slit 52, and further passes through the tube T so as to cross the inside of the tube T, and then is received by the light receiving element 38.
　このとき、検出光ＳＬの屈折態様は、チューブＴの材質の屈折率と、チューブＴの内部の媒質の屈折率との差に応じて変化する。
　図７（ａ）に示すように、チューブＴの内部が液体Ｌで満たされているとき、液体Ｌの屈折率は、空気Ａの屈折率よりも大きい。したがって、屈折率の差が比較的小さくなる。そのため、投光素子３７から照射された検出光ＳＬのうち、チューブＴと液体Ｌとの界面で屈折したことにより受光素子３８に到達しない検出光ＳＬの比率が比較的少なくなる。 At this time, the refractive mode of the detection light SL changes according to the difference between the refractive index of the material of the tube T and the refractive index of the medium inside the tube T.
As shown in FIG. 7A, when the inside of the tube T is filled with the liquid L, the refractive index of the liquid L is larger than the refractive index of the air A. Therefore, the difference in refractive index is relatively small. Therefore, of the detection light SL irradiated from the light projecting element 37, the ratio of the detection light SL that does not reach the light receiving element 38 due to refraction at the interface between the tube T and the liquid L is relatively small.
　図７（ｂ）に示すように、チューブＴの内部が気泡等により空気Ａで満たされているとき、液体Ｌの屈折率は、空気Ａの屈折率よりも小さい。したがって、屈折率の差が比較的大きくなる。そのため、投光素子３７から照射された検出光ＳＬのうち、チューブＴと空気Ａとの界面で屈折したことにより受光素子３８に到達しない検出光の比率が比較的多くなる。 7B, when the inside of the tube T is filled with air A with bubbles or the like, the refractive index of the liquid L is smaller than the refractive index of the air A. Therefore, the difference in refractive index becomes relatively large. Therefore, in the detection light SL irradiated from the light projecting element 37, the ratio of the detection light that does not reach the light receiving element 38 due to refraction at the interface between the tube T and the air A is relatively large.
　そこで、本実施形態では、受光素子３８における受光量を所定の閾値と比較し、その受光量が所定の閾値未満であるときに、チューブＴの内部が空気Ａで満たされていると判定することを可能とする。具体的には、受光素子３８は受光量に応じたレベルの信号を出力する。図２に示す基板フレーム３１に実装された回路素子３４からなる検出回路は、受光素子３８から出力される信号のレベル（たとえば電圧値）と閾値とを比較し、その比較結果に応じた検出信号を生成する。この検出信号により、チューブＴの内部の媒体が液体Ｌか空気Ａかを判定することを可能とする。 Therefore, in the present embodiment, the amount of light received by the light receiving element 38 is compared with a predetermined threshold, and when the amount of received light is less than the predetermined threshold, it is determined that the inside of the tube T is filled with air A. Is possible. Specifically, the light receiving element 38 outputs a signal having a level corresponding to the amount of received light. The detection circuit composed of the circuit elements 34 mounted on the substrate frame 31 shown in FIG. 2 compares the level (for example, voltage value) of the signal output from the light receiving element 38 with a threshold value, and a detection signal corresponding to the comparison result. Is generated. This detection signal makes it possible to determine whether the medium inside the tube T is the liquid L or the air A.
　次に、本実施形態の液体センサの作用について説明する。
　一対の弾性片５１Ａ，５１Ｂは、その長手方向の中央位置にスリット５２が形成されることにより、同一方向において複数に分割されている。そのため、一対の弾性片５１Ａ，５１Ｂがその長手方向の全域に亘って連続して延びる構成と比較して弾性的に変形しやすくなり、一対の弾性片５１Ａ，５１ＢのチューブＴに対する密着性も向上することとなる。 Next, the operation of the liquid sensor of this embodiment will be described.
The pair of elastic pieces 51A and 51B is divided into a plurality of pieces in the same direction by forming a slit 52 at the center position in the longitudinal direction. Therefore, the pair of elastic pieces 51A and 51B are easily elastically deformed as compared with the configuration in which the pair of elastic pieces 51A and 51B continuously extend over the entire region in the longitudinal direction, and the adhesion of the pair of elastic pieces 51A and 51B to the tube T is improved. Will be.
　また、本実施形態では、チューブＴの保持を目的として形成したスリット５２が、チューブＴ内の液体を光学的に検出するのに必要となる検出光ＳＬの光路としても機能する。そのため、このような検出光ＳＬの光路を形成することを目的として、一対の弾性片５１Ａ，５１Ｂにスリット５２や貫通孔を新たに設ける場合と比較して、一対の弾性片５１Ａ，５１Ｂの強度を向上することにもなる。 In this embodiment, the slit 52 formed for the purpose of holding the tube T also functions as an optical path of the detection light SL necessary for optically detecting the liquid in the tube T. Therefore, the strength of the pair of elastic pieces 51A and 51B is compared with a case where a slit 52 and a through hole are newly provided in the pair of elastic pieces 51A and 51B for the purpose of forming such an optical path of the detection light SL. It will also improve.
　したがって、上記実施形態によれば、以下に示す効果を得ることができる。
　（１）カバー部材２０における一対の弾性片５１Ａ，５１Ｂをスリット５２によってチューブＴの長手方向にそれぞれ分割してチューブＴに対して密着させやすくすることで、チューブＴを嵌めやすくすることができるとともに、チューブＴに対する保持力を向上することができる。また、弾性片５１Ａ，５１Ｂをそれぞれ分割するために形成したスリット５２が検出光ＳＬの光路としても機能する。このため、検出光ＳＬの光路を確保するために貫通孔等を別途形成する必要が無く、弾性片５１Ａ，５１Ｂの強度を低下することがないため、この点においてもチューブＴに対する保持力を向上することができる。 Therefore, according to the above embodiment, the following effects can be obtained.
(1) While the pair of elastic pieces 51A and 51B in the cover member 20 are divided in the longitudinal direction of the tube T by the slits 52 so as to be in close contact with the tube T, the tube T can be easily fitted. The holding force with respect to the tube T can be improved. Further, the slit 52 formed to divide the elastic pieces 51A and 51B also functions as an optical path of the detection light SL. For this reason, it is not necessary to separately form a through-hole or the like in order to secure the optical path of the detection light SL, and the strength of the elastic pieces 51A and 51B is not reduced. can do.
　（２）一対の弾性片５１Ａ，５１ＢにおいてチューブＴが挿抜される先端縁５６Ａ，５６Ｂには、一対の弾性片５１Ａ，５１Ｂの間の空間の外側から内側に向けて次第に幅狭となる第１のテーパ面Ｐ１が形成されている。そのため、チューブＴが第１のテーパ面Ｐ１にガイドされつつ一対の弾性片５１Ａ，５１Ｂに挟持されるため、チューブＴを簡便にカバー部材２０に保持させることができる。 (2) First end edges 56A and 56B into which the tube T is inserted and removed from the pair of elastic pieces 51A and 51B are gradually narrowed from the outside to the inside of the space between the pair of elastic pieces 51A and 51B. The taper surface P1 is formed. Therefore, since the tube T is held between the pair of elastic pieces 51A and 51B while being guided by the first tapered surface P1, the tube T can be easily held by the cover member 20.
　（３）一対の弾性片５１Ａ，５１Ｂの先端縁５６Ａ，５６ＢのうちチューブＴの長手方向の両端には、チューブＴの長手方向の両端から中央に向けて次第に幅狭となる第２のテーパ面Ｐ２が形成されている。そのため、チューブＴをその長手方向の一端側から他端側の順に一対の弾性片５１Ａ，５１Ｂに挟持させる際に、チューブＴが第２のテーパ面Ｐ２にガイドされつつ挟持されるため、チューブＴを更に簡便にカバー部材２０に保持させることができる。 (3) A second taper surface that gradually narrows from both ends in the longitudinal direction of the tube T toward the center at both ends in the longitudinal direction of the tube T of the tip edges 56A and 56B of the pair of elastic pieces 51A and 51B. P2 is formed. Therefore, when the tube T is sandwiched between the pair of elastic pieces 51A and 51B in the order from one end side to the other end side in the longitudinal direction, the tube T is sandwiched while being guided by the second tapered surface P2. Can be held on the cover member 20 more simply.
　（４）スリット５２は、一対の弾性片５１Ａ，５１ＢをチューブＴの挿抜方向に貫通しており、カバー部材２０における一対の弾性片５１Ａ，５１Ｂの形成面には、スリット５２に連通する凹部５４が形成されている。そのため、スリット５２を通過した検出光の一部が光軸ＡＸから外れるようにスリット５２から射出されたとしても、こうした検出光はスリット５２を通過した後にカバー部材２０の凹部５４内で散乱・反射されることとなるため、こうした検出光が受光素子３８に誤って入光することを抑制できる。 (4) The slit 52 penetrates the pair of elastic pieces 51A and 51B in the insertion / extraction direction of the tube T, and a concave portion 54 communicating with the slit 52 is formed on the surface of the cover member 20 where the pair of elastic pieces 51A and 51B is formed. Is formed. Therefore, even if a part of the detection light that has passed through the slit 52 is emitted from the slit 52 so as to deviate from the optical axis AX, such detection light is scattered and reflected in the concave portion 54 of the cover member 20 after passing through the slit 52. Therefore, it is possible to prevent such detection light from entering the light receiving element 38 by mistake.
　（５）カバー部材２０は、液体センサを対象物Ｓに取り付けるためのボルト孔１３を有する本体ケース１０に装着されるものであり、本体ケース１０の材質は、カバー部材２０の材質よりも剛性が高い。そのため、本体ケース１０が比較的剛性の高い材質により構成されるため、液体センサを対象物Ｓに対して安定して取り付けることができる。 (5) The cover member 20 is attached to the main body case 10 having the bolt holes 13 for attaching the liquid sensor to the object S. The material of the main body case 10 is more rigid than the material of the cover member 20. high. Therefore, since the main body case 10 is made of a material having a relatively high rigidity, the liquid sensor can be stably attached to the object S.
　（６）カバー部材２０に対するチューブＴの保持方向は、対象物Ｓに対する本体ケース１０の取付方向と同一方向である。そのため、例えば液体センサの対象とするチューブＴが室内の壁面に沿って引き回されているとき等に、本体ケース１０を対象物Ｓとなる室内の壁面等に対して直接取り付けることが可能となる。また、本体ケース１０の取付動作とチューブＴの保持動作が同一方向から行われるため、それらの動作を簡便に行うことも可能となる。 (6) The holding direction of the tube T with respect to the cover member 20 is the same as the mounting direction of the main body case 10 with respect to the object S. Therefore, for example, when the tube T that is the target of the liquid sensor is drawn along the wall surface of the room, the main body case 10 can be directly attached to the wall surface of the room that is the object S or the like. . Moreover, since the attachment operation | movement of the main body case 10 and the holding operation of the tube T are performed from the same direction, those operation | movement can also be performed simply.
　（７）カバー部材２０は、黒色の樹脂材料により構成されてもよい。そのため、スリット５２を通過した検出光ＳＬがカバー部材２０で散乱・反射することが低減されるため、こうした検出光ＳＬが受光素子３８に誤って入光することを抑制できる。 (7) The cover member 20 may be made of a black resin material. Therefore, since the detection light SL that has passed through the slit 52 is reduced from being scattered and reflected by the cover member 20, it is possible to prevent such detection light SL from entering the light receiving element 38 by mistake.
　（第二実施形態）
　次に、第二実施形態の液体センサを説明する。
　なお、第一実施形態と同じ部材については同じ符号を付し、説明の一部または全てを省略する。 (Second embodiment)
Next, the liquid sensor of the second embodiment will be described.
In addition, the same code | symbol is attached | subjected about the same member as 1st embodiment, and a part or all of description is abbreviate | omitted.
　図８に示すように、本実施形態の液体センサの外装は、本体ケース１０とカバー部材７０とにより構成されている。カバー部材７０は、保持部材として機能する。カバー部材７０は、本体ケース１０の筒部１２の開口端に取り付けられている。例えば、カバー部材７０は、第一実施形態のカバー部材２０と同様に、黒色の樹脂材料により構成されている。 As shown in FIG. 8, the exterior of the liquid sensor of the present embodiment is constituted by a main body case 10 and a cover member 70. The cover member 70 functions as a holding member. The cover member 70 is attached to the open end of the cylindrical portion 12 of the main body case 10. For example, the cover member 70 is made of a black resin material, like the cover member 20 of the first embodiment.
　図９に示すように、本体ケース１０の筒部１２には、センサユニット３０が収容される。センサユニット３０は、基板フレーム３１と、投光フレーム３２と、受光フレーム３３とを有している。基板フレーム３１は、ボトムフレーム部３１Ａ、サイドフレーム部３１Ｂ、カバーフレーム部３１Ｃを含む。 As shown in FIG. 9, the sensor unit 30 is accommodated in the cylindrical portion 12 of the main body case 10. The sensor unit 30 includes a substrate frame 31, a light projecting frame 32, and a light receiving frame 33. The substrate frame 31 includes a bottom frame portion 31A, a side frame portion 31B, and a cover frame portion 31C.
　カバー部材７０及びセンサユニット３０は、本体ケース１０の挿通孔４１に挿通された位置決めピン４３により、本体ケース１０に対して固定されている。カバー部材７０には挿通孔４０が形成されている。カバー部材７０は、挿通孔４０を本体ケース１０の挿通孔４１と重なるように、本体ケース１０に挿入される。位置決めピン４３は、本体ケース１０の挿通孔４１とカバー部材７０の挿通孔４０に挿通される。 The cover member 70 and the sensor unit 30 are fixed to the main body case 10 by positioning pins 43 inserted into the insertion holes 41 of the main body case 10. An insertion hole 40 is formed in the cover member 70. The cover member 70 is inserted into the main body case 10 so that the insertion hole 40 overlaps the insertion hole 41 of the main body case 10. The positioning pin 43 is inserted through the insertion hole 41 of the main body case 10 and the insertion hole 40 of the cover member 70.
　図８に示すように、カバー部材７０の天面Ｐは略矩形状に形成されている。カバー部材７０には、天面Ｐから本体ケース１０に向かって凹溝５０が形成されている。凹溝５０は、天面Ｐの長手方向の中央位置に、天面Ｐの短手方向の一端から他端まで直線状に延びている。凹溝５０には、一対の弾性片７１Ａ，７１Ｂが配設ざれている。一対の弾性片７１Ａ，７１Ｂは、凹溝５０の底面から凹溝５０の開口端、つまり天面Ｐに向かって延びている。また、一対の弾性片７１Ａ，７１Ｂは、凹溝５０の長手方向の全域、つまり長手方向の一端から他端まで延びている。一対の弾性片７１Ａ，７１Ｂは、円弧状に湾曲している。そして、一対の弾性片７１Ａ，７１Ｂは、互いに対向する湾曲している内周面を有する。一対の弾性片７１Ａ，７１Ｂは、これらの弾性片７１Ａ，７１Ｂにより保持するチューブＴの外径に応じて湾曲している。 As shown in FIG. 8, the top surface P of the cover member 70 is formed in a substantially rectangular shape. A groove 50 is formed in the cover member 70 from the top surface P toward the main body case 10. The concave groove 50 extends linearly from one end to the other end of the top surface P at the center position in the longitudinal direction of the top surface P. A pair of elastic pieces 71 </ b> A and 71 </ b> B is disposed in the concave groove 50. The pair of elastic pieces 71 </ b> A and 71 </ b> B extends from the bottom surface of the groove 50 toward the open end of the groove 50, that is, the top surface P. Further, the pair of elastic pieces 71A and 71B extend from the entire longitudinal direction of the concave groove 50, that is, from one end to the other end in the longitudinal direction. The pair of elastic pieces 71A and 71B are curved in an arc shape. The pair of elastic pieces 71A and 71B have curved inner peripheral surfaces facing each other. The pair of elastic pieces 71A, 71B are curved according to the outer diameter of the tube T held by these elastic pieces 71A, 71B.
　図１１に示すように、一対の弾性片７１Ａ，７１Ｂの先端縁７６Ａ，７６Ｂには、チューブＴが挿抜される開口端が形成されている。この一対の弾性片７１Ａ，７１Ｂの先端縁７６Ａ，７６Ｂには、弾性片７１Ａ，７１Ｂの先端から基端に向かう方向であるチューブＴの挿入方向において、次第に幅狭となる第１のテーパ面Ｐ１が形成されている。先端縁の第１のテーパ面Ｐ１により、一対の弾性片７１Ａ，７１Ｂの先端部の間の幅は、挿入方向において、次第に幅狭となる。つまり、一対の弾性片７１Ａ，７１ＢにおいてチューブＴが挿抜される先端縁には、一対の弾性片７１Ａ，７１Ｂの間の空間の外側から内側に向けて、一対の弾性片７１Ａ，７１Ｂの先端部の間の幅が、次第に幅狭となる第１のテーパ面Ｐ１が形成されている。 As shown in FIG. 11, open ends into which the tube T is inserted and removed are formed at the tip edges 76A and 76B of the pair of elastic pieces 71A and 71B. The distal end edges 76A and 76B of the pair of elastic pieces 71A and 71B are provided with a first tapered surface P1 that gradually becomes narrower in the insertion direction of the tube T, which is a direction from the distal end to the proximal end of the elastic pieces 71A and 71B. Is formed. Due to the first tapered surface P1 at the tip edge, the width between the tip portions of the pair of elastic pieces 71A and 71B becomes gradually narrower in the insertion direction. In other words, the distal ends of the pair of elastic pieces 71A and 71B are arranged at the distal ends of the pair of elastic pieces 71A and 71B from the outer side to the inner side of the space between the pair of elastic pieces 71A and 71B. A first taper surface P <b> 1 is formed in which the width between is gradually narrowed.
　一対の弾性片７１Ａ，７１Ｂにおける長手方向の中央位置には、一対の弾性片７１Ａ，７１Ｂの基端から先端までの延びるスリット５２が形成されている。スリット５２は、凹溝５０の底面と直交する方向に沿って、一対の弾性片７１Ａ，７１Ｂを貫通している。さらに、スリット５２は、凹溝５０の底面に形成された凹部５４に連通している。 A slit 52 extending from the proximal end to the distal end of the pair of elastic pieces 71A, 71B is formed at the center position in the longitudinal direction of the pair of elastic pieces 71A, 71B. The slit 52 passes through the pair of elastic pieces 71 </ b> A and 71 </ b> B along a direction orthogonal to the bottom surface of the groove 50. Further, the slit 52 communicates with a concave portion 54 formed on the bottom surface of the concave groove 50.
　図１１に示すように、投光素子３７と受光素子３８は、互いに対向するように配置されている。投光素子３７と受光素子３８とを結ぶ直線（一点鎖線）を光軸ＡＸとする。スリット５２は、光軸ＡＸ上に配設されている。 As shown in FIG. 11, the light projecting element 37 and the light receiving element 38 are disposed so as to face each other. A straight line (one-dot chain line) connecting the light projecting element 37 and the light receiving element 38 is defined as an optical axis AX. The slit 52 is disposed on the optical axis AX.
　図１１に示すように、カバー部材７０には、光軸ＡＸ上に配設された通過孔５５Ａ，５５Ｂを有している。通過孔５５Ａ，５５Ｂは、たとえば凹溝５０を形成する側壁５６Ａ，５６Ｂのスリット５７Ａ，５７Ｂにより形成される。凹溝５０の内側面５０Ａ，５０Ｂを形成する側壁５６Ａ，５６Ｂには、長手方向中央に、上記のスリット５２と同じ方向に沿って延びるスリット５７Ａ，５７Ｂが形成されている。 As shown in FIG. 11, the cover member 70 has passage holes 55A and 55B arranged on the optical axis AX. The passage holes 55A and 55B are formed by, for example, slits 57A and 57B of the side walls 56A and 56B that form the concave groove 50. Slits 57A and 57B extending along the same direction as the slit 52 are formed in the longitudinal center of the side walls 56A and 56B forming the inner side surfaces 50A and 50B of the concave groove 50.
　図１０に示すように、スリット５７Ａは、側壁５６Ａを貫通し、投光素子３７（図１１参照）が配置される空間５８Ａと凹溝５０内とを連通する通過孔５５Ａを形成する。同様に、スリット５７Ｂは、側壁５６Ｂを貫通し、受光素子３８（図１１参照）が配置される空間５８Ｂと凹溝５０内とを連通する通過孔５５Ｂを形成する。 As shown in FIG. 10, the slit 57 </ b> A penetrates the side wall 56 </ b> A and forms a passage hole 55 </ b> A that communicates the space 58 </ b> A in which the light projecting element 37 (see FIG. 11) is disposed with the inside of the groove 50. Similarly, the slit 57B penetrates the side wall 56B and forms a passage hole 55B that communicates the space 58B in which the light receiving element 38 (see FIG. 11) is disposed with the inside of the groove 50.
　図１０に示すように、スリット５２には、遮光部７２Ａ，７２Ｂが形成されている。遮光部７２Ａは、スリット５２により分割された２つの弾性片７１Ａの間に形成されている。同様に、遮光部７２Ｂは、スリット５２により分割された２つの弾性片７１Ｂの間に形成されている。すなわち、遮光部７２Ａ，７２Ｂは、スリット５２内において一対の弾性片５１Ａ，５１Ｂの近傍に配置されている。遮光部７２Ａ，７２Ｂの各々は、弾性片５１Ａ，５１Ｂの長手方向において対応する弾性片５１Ａ，５１Ｂと隣接するように配置されている。遮光部７２Ａ，７２Ｂは、一対の弾性片５１Ａ，５１Ｂとは異なる位置でチューブを挟持するための２つの側面を含む。 As shown in FIG. 10, the slit 52 is formed with light shielding portions 72A and 72B. The light shielding part 72 </ b> A is formed between two elastic pieces 71 </ b> A divided by the slit 52. Similarly, the light shielding portion 72B is formed between two elastic pieces 71B divided by the slit 52. That is, the light shielding portions 72A and 72B are arranged in the vicinity of the pair of elastic pieces 51A and 51B in the slit 52. Each of the light shielding portions 72A and 72B is disposed adjacent to the corresponding elastic piece 51A and 51B in the longitudinal direction of the elastic piece 51A and 51B. The light shielding portions 72A and 72B include two side surfaces for sandwiching the tube at a position different from the pair of elastic pieces 51A and 51B.
　遮光部７２Ａ，７２Ｂは、凹溝５０の底面から、一対の弾性片７１Ａ，７１Ｂの先端に向かって延びる直線状に形成されている。また、遮光部７２Ａ，７２Ｂは、該遮光部７２Ａ，７２Ｂの先端が、一対の弾性片７１Ａ，７１Ｂにより保持されるチューブＴ（図示略）の外周面と当接するように形成されている。例えば、遮光部７２Ａ，７２Ｂは、スリット５２内にあって、一対の弾性片７１Ａ，７１Ｂと一体的に形成されている。 The light shielding portions 72A and 72B are formed in a straight line extending from the bottom surface of the groove 50 toward the tips of the pair of elastic pieces 71A and 71B. The light shielding portions 72A and 72B are formed such that the tips of the light shielding portions 72A and 72B are in contact with the outer peripheral surface of a tube T (not shown) held by the pair of elastic pieces 71A and 71B. For example, the light shielding portions 72A and 72B are in the slit 52 and are formed integrally with the pair of elastic pieces 71A and 71B.
　側壁５６Ａ，５６Ｂ上には、それぞれ遮光部７３Ａ，７３Ｂが配設されている。図８に示すように、遮光部７３Ａは、側壁５６Ａに形成されたスリット５７Ａを跨ぐように形成されている。同様に、遮光部７３Ｂは、側壁５６Ｂに形成されたスリット５７Ｂを跨ぐように形成されている（図１０参照）。 Shield portions 73A and 73B are disposed on the side walls 56A and 56B, respectively. As shown in FIG. 8, the light shielding part 73A is formed so as to straddle the slit 57A formed in the side wall 56A. Similarly, the light shielding part 73B is formed so as to straddle the slit 57B formed in the side wall 56B (see FIG. 10).
　遮光部７２Ａ，７２Ｂ，７３Ａ，７３Ｂは、投光素子３７から出射される光の一部を遮る。この液体センサにおいて、液体Ｌの有無に応じて、チューブＴにおいて液体Ｌが通る領域が変化する。これにより、チューブＴの内側の領域を通過して受光素子３８により受光される検出光ＳＬの受光量が変化する。液体センサは、受光素子３８の受光量に応じて、チューブＴの内部が液体Ｌで満たされているか空気Ａで満たされているかを判定する。つまり、液体センサは、受光素子３８の受光量に応じて液体Ｌの有無を判定する。したがって、液体Ｌが通る領域を通過しない光は、検出に対して不要となる。遮光部７２Ａ，７２Ｂ，７３Ａ，７３Ｂは、投光素子３７から出射される光のうち、チューブＴにおいて液体Ｌが通る領域、つまりチューブＴの内側の領域を通過する光以外の光（不要光）を遮るように設けられている。 The light blocking portions 72A, 72B, 73A, 73B block a part of the light emitted from the light projecting element 37. In this liquid sensor, the region through which the liquid L passes in the tube T changes depending on the presence or absence of the liquid L. Accordingly, the amount of detection light SL received by the light receiving element 38 through the region inside the tube T changes. The liquid sensor determines whether the inside of the tube T is filled with the liquid L or the air A according to the amount of light received by the light receiving element 38. That is, the liquid sensor determines the presence or absence of the liquid L according to the amount of light received by the light receiving element 38. Accordingly, light that does not pass through the region through which the liquid L passes is not necessary for detection. The light shielding portions 72A, 72B, 73A, and 73B are light (unnecessary light) other than light that passes through the region where the liquid L passes through the tube T, that is, the region inside the tube T, among the light emitted from the light projecting element 37. It is provided so as to block.
　次に、本実施形態の液体センサの作用について説明する。
　検出光ＳＬは、２つの媒質の境界（界面）を通過するとき、２つの媒質の屈折率の差に応じて、屈曲する。 Next, the operation of the liquid sensor of this embodiment will be described.
When the detection light SL passes through the boundary (interface) between the two media, the detection light SL is bent according to the difference in refractive index between the two media.
　図１２（ａ）及び図１２（ｂ）には、投光素子３７、受光素子３８、チューブＴ、遮光部７２Ａ，７２Ｂ，７３Ａ，７３Ｂの模式的に示されている。図１２（ａ）において、チューブＴの内部は液体Ｌで満たされている。一方、図１２（ｂ）において、チューブＴの内部は気泡等による空気Ａで満たされている。 12A and 12B schematically show the light projecting element 37, the light receiving element 38, the tube T, and the light shielding portions 72A, 72B, 73A, and 73B. In FIG. 12A, the inside of the tube T is filled with the liquid L. On the other hand, in FIG. 12B, the inside of the tube T is filled with air A such as bubbles.
　チューブＴの屈折率と液体Ｌの屈折率との差は、チューブＴの屈折率と空気Ａの屈折率の差よりも小さい。このため、図１２（ａ）に示す場合、投光素子３７から出射された検出光ＳＬは、チューブＴと液体Ｌとをほぼ直線状に通過する。このため、検出光ＳＬは受光素子３８により受光されない。一方、図１２（ｂ）に示す場合、投光素子３７から出射された検出光ＳＬは、チューブＴの内周面Ｔａにおいて屈折し、光軸ＡＸとほぼ平行にチューブＴの内部を進む。そして、チューブＴの内周面Ｔａ及び外周面Ｔｂにおいて屈折し、受光素子３８により受光される。 The difference between the refractive index of the tube T and the refractive index of the liquid L is smaller than the difference between the refractive index of the tube T and the refractive index of the air A. For this reason, in the case shown in FIG. 12A, the detection light SL emitted from the light projecting element 37 passes through the tube T and the liquid L substantially linearly. For this reason, the detection light SL is not received by the light receiving element 38. On the other hand, in the case shown in FIG. 12B, the detection light SL emitted from the light projecting element 37 is refracted on the inner peripheral surface Ta of the tube T and travels inside the tube T substantially parallel to the optical axis AX. Then, the light is refracted on the inner peripheral surface Ta and the outer peripheral surface Tb of the tube T and received by the light receiving element 38.
　受光素子３８は、受光量に応じたレベルの信号を出力する。この信号のレベル（たとえば電圧値）を所定のしきい値と比較し、比較結果に応じたレベルの検出信号が生成される。この検出信号のレベルは、チューブＴ内部の媒質に対応する。したがって、検出信号のレベルにより、チューブＴの内部（検出光ＳＬが透過する領域）の媒質を判定することが可能となる。 The light receiving element 38 outputs a signal having a level corresponding to the amount of light received. The level (for example, voltage value) of this signal is compared with a predetermined threshold value, and a detection signal having a level corresponding to the comparison result is generated. The level of this detection signal corresponds to the medium inside the tube T. Therefore, the medium inside the tube T (region through which the detection light SL is transmitted) can be determined based on the level of the detection signal.
　ところで、投光素子３７から出射される検出光ＳＬは、投光素子３７から放射状に拡散される。検出光ＳＬは、屈折率差と境界（界面）への入射角度に応じて反射する場合がある。 Incidentally, the detection light SL emitted from the light projecting element 37 is diffused radially from the light projecting element 37. The detection light SL may be reflected according to the refractive index difference and the incident angle to the boundary (interface).
　図１３（ａ）において、一点鎖線にて示す光Ｓａは不要光であり、チューブＴの内周面Ｔａと外周面Ｔｂにおいて反射し、受光素子３８に到達する。つまり、不要光Ｓａは、チューブＴの内周面Ｔａよりも凹溝５０の底面側、つまり一対の弾性片７１Ａ，７１Ｂの基端側を通過し、媒質（図では空気Ａ）を通過しない。二点鎖線にて示す光Ｓｂは不要光であり、チューブＴにおいて、内周面Ｔａより一対の弾性片７１Ａ，７１Ｂの先端側を通過し、受光素子３８に到達する。つまり、不要光Ｓｂは、媒質（空気Ａ）を通過しない。これらの不要光Ｓａ，Ｓｂは、チューブＴの内部の媒質に影響されない。つまり、媒質の検出に対して不要な光（不要光）である。 13A, the light Sa indicated by the alternate long and short dash line is unnecessary light, and is reflected by the inner peripheral surface Ta and the outer peripheral surface Tb of the tube T and reaches the light receiving element 38. That is, the unnecessary light Sa passes through the bottom surface side of the concave groove 50 from the inner peripheral surface Ta of the tube T, that is, the base end side of the pair of elastic pieces 71A and 71B, and does not pass through the medium (air A in the drawing). The light Sb indicated by the two-dot chain line is unnecessary light, and passes through the distal end side of the pair of elastic pieces 71A and 71B from the inner peripheral surface Ta in the tube T and reaches the light receiving element 38. That is, the unnecessary light Sb does not pass through the medium (air A). These unnecessary lights Sa and Sb are not affected by the medium inside the tube T. That is, it is unnecessary light (unnecessary light) for detecting the medium.
　そして、これらの不要光は、図１２（ａ）に示すように、チューブＴの内部が液体Ｌにより満たされているときにも、受光素子３８にて受光される。このため、図１２（ｂ）に示すように、チューブＴの内部が空気Ａにより満たされたときとの受光量の差が少なくなり、しきい値の設定を難しくする。また、しきい値の設定によっては、誤判定を招く虞がある。 And these unnecessary lights are received by the light receiving element 38 even when the inside of the tube T is filled with the liquid L as shown in FIG. For this reason, as shown in FIG. 12B, the difference in the amount of received light with respect to when the inside of the tube T is filled with the air A is reduced, making it difficult to set the threshold value. Further, depending on the setting of the threshold value, there is a risk of erroneous determination.
　図１３（ｂ）に示すように、本実施形態の遮光部７２Ａ，７３Ａは、不要光Ｓａ，Ｓｂを遮る。したがって、不要光Ｓａ，Ｓｂは、受光素子３８に到達しない。このため、受光素子３８における受光量は、チューブＴの内部の媒質（液体Ｌまたは空気Ａ）に応じて変化する。このため、受光量の差が大きく、誤判定を抑制することができる。また、受光量の差が大きいため、しきい値を容易に設定することができる。 As shown in FIG. 13B, the light blocking portions 72A and 73A of the present embodiment block unnecessary light Sa and Sb. Therefore, unnecessary light Sa and Sb do not reach the light receiving element 38. For this reason, the amount of light received by the light receiving element 38 changes according to the medium (liquid L or air A) inside the tube T. For this reason, the difference in the amount of received light is large, and erroneous determination can be suppressed. Further, since the difference in the amount of received light is large, the threshold value can be easily set.
　なお、図１３（ｂ）において破線は不要光である不要光Ｓａ，Ｓｂの光路を示す。遮光部７２Ｂ，７３Ｂは、これらの光路に配置されている。したがって、迷光（乱反射等による光）が破線にて示す光路を通る場合がある。このような迷光は、受光素子３８における受光量の変動を招く、つまり外乱となる。遮光部７２Ｂ，７３Ｂは、迷光を遮り、受光量の変動を抑制する。このため、迷光等による誤判定を抑制することができる。 In FIG. 13B, the broken lines indicate the optical paths of unnecessary light Sa and Sb that are unnecessary light. The light shielding parts 72B and 73B are arranged in these optical paths. Therefore, stray light (light due to irregular reflection or the like) may pass through an optical path indicated by a broken line. Such stray light causes fluctuations in the amount of light received by the light receiving element 38, that is, disturbance. The light blocking portions 72B and 73B block stray light and suppress fluctuations in the amount of received light. For this reason, erroneous determination due to stray light or the like can be suppressed.
　本実施形態によれば、以下に示す効果を得ることができる。
　（１１）第一実施形態に示した（１），（２），（４）～（７）と同様の効果を得ることができる。 According to the present embodiment, the following effects can be obtained.
(11) The same effects as (1), (2), (4) to (7) shown in the first embodiment can be obtained.
　（１２）遮光部７２Ａ，７２Ｂ，７３Ａ，７３Ｂは、投光素子３７から出射される光の一部を遮る。遮光部７２Ａ，７２Ｂ，７３Ａ，７３Ｂは、投光素子３７から出射される光のうち、チューブＴにおいて液体Ｌが通る領域、つまりチューブＴの内側の領域を通過する光以外の光（不要光）を遮るように設けられている。したがって、不要光Ｓａ，Ｓｂは、受光素子３８に到達しない。このため、受光素子３８における受光量は、チューブＴの内部の媒質（液体Ｌまたは空気Ａ）に応じて変化する。このため、受光量の差が大きく、誤判定を抑制することができる。 (12) The light blocking portions 72A, 72B, 73A, 73B block a part of the light emitted from the light projecting element 37. The light shielding portions 72A, 72B, 73A, and 73B are light (unnecessary light) other than light that passes through the region where the liquid L passes through the tube T, that is, the region inside the tube T, among the light emitted from the light projecting element 37. It is provided so as to block. Therefore, unnecessary light Sa and Sb do not reach the light receiving element 38. For this reason, the amount of light received by the light receiving element 38 changes according to the medium (liquid L or air A) inside the tube T. For this reason, the difference in the amount of received light is large, and erroneous determination can be suppressed.
　（１３）遮光部７２Ａ，７２Ｂは、一対の弾性片７１Ａ，７１Ｂを分割するスリット５２内に配設されている。スリット５２は、投光素子３７から出射される検出光ＳＬが通過する。したがって、スリット５２内に配設された遮光部７２Ａ，７２Ｂは、検出光ＳＬの一部を容易に遮光する。 (13) The light shielding portions 72A and 72B are disposed in the slit 52 that divides the pair of elastic pieces 71A and 71B. The detection light SL emitted from the light projecting element 37 passes through the slit 52. Therefore, the light shielding portions 72A and 72B disposed in the slit 52 easily shield a part of the detection light SL.
　（１４）遮光部７２Ａ，７２Ｂは、一対の弾性片７１Ａ，７１Ｂを分割するスリット５２内に配設されている。投光素子３７から出射される光（出射光）は、放射状に広がる。この出射光は、液体Ｌが通るチューブＴの内部を通過する検出光ＳＬと、チューブＴの内部を通過しない不要光Ｓａを含む。したがって、遮光部７２Ａ，７２ＢをチューブＴに接するように配設することにより、不要光Ｓａを遮光し、遮光部７２Ａ，７２Ｂにより検出光ＳＬを遮る量を少なくすることができる。つまり、検出光ＳＬの光量の低下を抑制することができる。 (14) The light shielding portions 72A and 72B are disposed in the slit 52 that divides the pair of elastic pieces 71A and 71B. The light (emitted light) emitted from the light projecting element 37 spreads radially. The emitted light includes detection light SL that passes through the inside of the tube T through which the liquid L passes and unnecessary light Sa that does not pass through the inside of the tube T. Therefore, by disposing the light shielding portions 72A and 72B so as to be in contact with the tube T, unnecessary light Sa can be shielded, and the amount of the detection light SL blocked by the light shielding portions 72A and 72B can be reduced. That is, a decrease in the amount of the detection light SL can be suppressed.
　なお、上記各実施形態は、以下のような形態にて実施することもできる。
　・上記実施形態において、カバー部材２０の材質の色として、黒色以外の色を採用してもよい。 In addition, each said embodiment can also be implemented with the following forms.
-In the said embodiment, you may employ | adopt colors other than black as a color of the material of the cover member 20. FIG.
　・上記実施形態において、対象物Ｓに対する本体ケース１０の取付方向と、一対の弾性片５１Ａ，５１Ｂ，７１Ａ，７１Ｂに対するチューブＴの保持方向とが互いに異なる方向であってもよい。 In the above embodiment, the attachment direction of the main body case 10 with respect to the object S and the holding direction of the tube T with respect to the pair of elastic pieces 51A, 51B, 71A, 71B may be different from each other.
　・上記実施形態において、凹溝５０の底面に形成された凹部５４を省略してもよい。
　・上記実施形態において、一対の弾性片５１Ａ，５１Ｂの先端縁は、チューブＴの長手方向の全域に亘って一定幅となる端面を有するように構成してもよい。 In the above embodiment, the recess 54 formed on the bottom surface of the groove 50 may be omitted.
In the above embodiment, the tip edges of the pair of elastic pieces 51 </ b> A and 51 </ b> B may be configured to have end faces that have a constant width over the entire region in the longitudinal direction of the tube T.
　・上記実施形態において、一対の弾性片５１Ａ，５１Ｂ，７１Ａ，７１Ｂの先端縁は、チューブＴの挿抜方向に沿って直線状に延びる端面を有するように構成してもよい。
　・上記実施形態において、投光素子３７と受光素子３８とは必ずしも互いに対向して配置される必要はなく、投光素子３７からの検出光の照射方向と受光素子３８への検出光の入射方向とが斜めに交差するように構成してもよい。 -In above-mentioned embodiment, you may comprise so that the front-end edge of a pair of elastic piece 51A, 51B, 71A, 71B may have an end surface extended linearly along the insertion / extraction direction of the tube T. FIG.
In the above-described embodiment, the light projecting element 37 and the light receiving element 38 are not necessarily arranged to face each other. The irradiation direction of the detection light from the light projecting element 37 and the incident direction of the detection light to the light receiving element 38 And may be configured to cross each other diagonally.
　・第二実施形態において、遮光部７３Ａ，７３Ｂを省略してもよい。投光素子３７から出力される検出光ＳＬは、出射される光の中心から角度が大きくなるほど光量が少なくなる。したがって、チューブＴにおいて、内周面Ｔａよりも一対の弾性片５１Ａ，５１Ｂの先端側を通る検出光の光量が、液体Ｌの有無を判定する結果に対する影響が少ない場合がある。このため、影響が少ない検出光ＳＬを出射する投光素子３７を用いた液体センサでは、遮光部７３Ａ，７３Ｂの省略が可能となる。 In the second embodiment, the light shielding parts 73A and 73B may be omitted. The detection light SL output from the light projecting element 37 decreases in amount as the angle increases from the center of the emitted light. Therefore, in the tube T, the amount of detection light passing through the distal ends of the pair of elastic pieces 51A and 51B may have less influence on the result of determining the presence or absence of the liquid L than the inner peripheral surface Ta. For this reason, in the liquid sensor using the light projecting element 37 that emits the detection light SL with less influence, the light shielding portions 73A and 73B can be omitted.
　・第二実施形態において、受光素子３８側の遮光部７２Ｂ，７３Ｂを省略してもよい。また、投光素子３７側の遮光部７２Ａ，７３Ａを省略してもよい。
　・第二実施形態では、チューブＴの近傍に配設された遮光部７２Ａ，７２Ｂ，７３Ａ，７３Ｂにより不要光を遮光する。したがって、カバー部材７０において、通過孔５５Ａ，５５Ｂの大きさや形状を適宜変更してもよい。 In the second embodiment, the light shielding portions 72B and 73B on the light receiving element 38 side may be omitted. Further, the light shielding portions 72A and 73A on the light projecting element 37 side may be omitted.
In the second embodiment, unnecessary light is shielded by the light shielding portions 72A, 72B, 73A, 73B disposed in the vicinity of the tube T. Therefore, in the cover member 70, the size and shape of the passage holes 55A and 55B may be changed as appropriate.
　・第二実施形態において、第一実施形態と同様に、一対の弾性片５１Ａ，５１Ｂは端部に第２のテーパ面Ｐ２を有するものとしてもよい。 In the second embodiment, as in the first embodiment, the pair of elastic pieces 51A and 51B may have the second tapered surface P2 at the end.

Claims (14)

  1. 　透光性を有するチューブ内に液体が存在するかどうかを検知する液体センサであって、
    　検出光を照射する投光部と、
    　前記投光部と対向し、前記検出光を受光する受光部と、
    　前記投光部と前記受光部との間に設けられ、前記チューブを挟持するための一対の弾性片を有する保持部材と、を備え、
    　前記一対の弾性片の各々は、
    　前記弾性片の長手方向と交差する方向であって、かつ、前記照射方向とは異なる方向に延在するスリットを有し、
    　前記一対の弾性片の各々のスリットは、前記投光部と前記受光部との間の前記検出光の光軸上に配置され、
    　前記投光部から出射された検出光の一部を前記弾性片の長手方向と交差する方向において遮光する遮光部をさらに備え、
    　前記遮光部は、前記投光部から出射された検出光のうち、前記チューブにおいて液体が通る領域を通過する光以外の光を遮光するように設けられている、液体センサ。     A liquid sensor for detecting whether or not liquid is present in a translucent tube,
    A light projecting unit that emits detection light;
    A light receiving portion facing the light projecting portion and receiving the detection light;
    A holding member provided between the light projecting unit and the light receiving unit and having a pair of elastic pieces for sandwiching the tube;
    Each of the pair of elastic pieces is
    A slit that extends in a direction that intersects the longitudinal direction of the elastic piece and that is different from the irradiation direction;
    Each slit of the pair of elastic pieces is disposed on the optical axis of the detection light between the light projecting unit and the light receiving unit,
    A light-shielding part that shields a part of the detection light emitted from the light projecting part in a direction intersecting the longitudinal direction of the elastic piece;
    The said light shielding part is a liquid sensor provided so that light other than the light which passes the area | region where a liquid passes in the said tube among the detection lights radiate | emitted from the said light projection part may be shielded.
  2. 　前記一対の弾性片の各々は、
    　前記検出光の光軸と交差し、前記チューブが挿抜される先端縁を含み、
    　前記一対の弾性片の先端縁は、
    　前記一対の弾性片の間の空間の外側から内側に向けて次第に狭くなる幅を有する第１のテーパ面を含む、請求項１に記載の液体センサ。     Each of the pair of elastic pieces is
    Crossing the optical axis of the detection light, including a tip edge into which the tube is inserted and removed,
    The tip edges of the pair of elastic pieces are
    2. The liquid sensor according to claim 1, further comprising a first tapered surface having a width that gradually decreases from the outside to the inside of the space between the pair of elastic pieces.
  3. 　前記一対の弾性片の各々の先端縁は、
    　当該先端縁の長手方向における両端に形成され、前記先端縁の長手方向の両端から中央に向けて次第に狭くなる幅を有する第２のテーパ面を含む、請求項２に記載の液体センサ。     The leading edge of each of the pair of elastic pieces is
    3. The liquid sensor according to claim 2, comprising a second tapered surface formed at both ends in the longitudinal direction of the tip edge and having a width that gradually narrows from both ends in the longitudinal direction of the tip edge toward the center.
  4. 　前記一対の弾性片の各々の前記スリットは、前記検出光の光軸上において対応する弾性片を分割し、
    　前記保持部材は、
    　前記一対の弾性片の各々の前記先端縁とは反対側の基端縁と結合する形成面と、
    　前記形成面に形成され、前記一対の弾性片の各々のスリットに連通する凹部とを含む、請求項２または３に記載の液体センサ。     The slit of each of the pair of elastic pieces divides the corresponding elastic piece on the optical axis of the detection light,
    The holding member is
    A forming surface coupled to a base edge opposite to the tip edge of each of the pair of elastic pieces;
    The liquid sensor according to claim 2, further comprising a recess formed on the forming surface and communicating with each slit of the pair of elastic pieces.
  5. 　前記保持部材を装着する本体ケースをさらに備え、
    　前記本体ケースは、
    　前記液体センサを対象物に取り付けるための取付部を含み、
    　前記本体ケースの材質は、前記保持部材の材質よりも高い剛性を有する、請求項１～４の何れか一項に記載の液体センサ。     Further comprising a body case for mounting the holding member;
    The body case is
    An attachment portion for attaching the liquid sensor to an object;
    The liquid sensor according to any one of claims 1 to 4, wherein a material of the main body case has higher rigidity than a material of the holding member.
  6. 　前記保持部材が前記チューブを保持する方向は、前記対象物に前記本体ケースを取付ける方向と同一である、請求項５に記載の液体センサ。 The liquid sensor according to claim 5, wherein a direction in which the holding member holds the tube is the same as a direction in which the main body case is attached to the object.
  7. 　前記保持部材は、黒色の材質により構成されている、請求項１～６の何れか一項に記載の液体センサ。 The liquid sensor according to any one of claims 1 to 6, wherein the holding member is made of a black material.
  8. 　前記遮光部は、
    　前記チューブにおいて、内周面より前記一対の弾性片の基端側を通過する光を遮断する第１の遮光部を含む、請求項１に記載の液体センサ。     The shading part is
    2. The liquid sensor according to claim 1, wherein the tube includes a first light-blocking portion that blocks light that passes through a base end side of the pair of elastic pieces from an inner peripheral surface.
  9. 　前記第１の遮光部は、前記スリット内に設けられた、請求項８に記載の液体センサ。 The liquid sensor according to claim 8, wherein the first light-shielding portion is provided in the slit.
  10. 　前記遮光部は、
    　前記チューブにおいて、内周面より前記一対の弾性片の先端側を通過する前記検出光を遮断する第２の遮光部を含む、請求項８または９に記載の液体センサ。     The shading part is
    10. The liquid sensor according to claim 8, wherein the tube includes a second light-shielding portion that blocks the detection light passing through the distal ends of the pair of elastic pieces from the inner peripheral surface.
  11. 　前記第１の遮光部は、前記スリット内において前記一対の弾性片の近傍に配置されている、請求項８～１０の何れか１項に記載の液体センサ。 The liquid sensor according to any one of claims 8 to 10, wherein the first light shielding portion is disposed in the vicinity of the pair of elastic pieces in the slit.
  12. 　前記第１の遮光部は、２つの第１の遮光部のうちの１つであり、
    　前記２つの第１の遮光部の各々は、前記弾性片の長手方向において対応する弾性片と隣接するように配置されている、請求項１１に記載の液体センサ。     The first light-shielding part is one of two first light-shielding parts,
    12. The liquid sensor according to claim 11, wherein each of the two first light shielding parts is disposed adjacent to a corresponding elastic piece in a longitudinal direction of the elastic piece.
  13. 　前記２つの第１の遮光部の各々は、対応する弾性片と一体的に形成されている、請求項１２に記載の液体センサ。 The liquid sensor according to claim 12, wherein each of the two first light shielding portions is integrally formed with a corresponding elastic piece.
  14. 　前記２つの第１の遮光部は、前記一対の弾性片とは異なる位置で前記チューブを挟持するための２つの側面を含む、請求項１２または１３に記載の液体センサ。 14. The liquid sensor according to claim 12, wherein the two first light shielding portions include two side surfaces for sandwiching the tube at a position different from the pair of elastic pieces.
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH08293234A (en) * 1995-04-20 1996-11-05 Omron Corp Level gage
JPH10253425A (en) * 1997-03-12 1998-09-25 Toa Medical Electronics Co Ltd Liquid sensor for tube
JPH11276576A (en) * 1998-03-26 1999-10-12 Sanyo Electric Works Ltd Tube holding structure of detector
JP2009133747A (en) * 2007-11-30 2009-06-18 Horiba Ltd Channel sensor
JP2012063328A (en) * 2010-09-17 2012-03-29 Welco Co Ltd Liquid sensor

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5752412Y2 (en) * 1978-04-18 1982-11-15
JPH0388553U (en) * 1989-12-25 1991-09-10

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH08293234A (en) * 1995-04-20 1996-11-05 Omron Corp Level gage
JPH10253425A (en) * 1997-03-12 1998-09-25 Toa Medical Electronics Co Ltd Liquid sensor for tube
JPH11276576A (en) * 1998-03-26 1999-10-12 Sanyo Electric Works Ltd Tube holding structure of detector
JP2009133747A (en) * 2007-11-30 2009-06-18 Horiba Ltd Channel sensor
JP2012063328A (en) * 2010-09-17 2012-03-29 Welco Co Ltd Liquid sensor

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