JP2005122436A - Flame sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a flame sensor whose operation can be confirmed even before the product is completed and to obtain a flame sensor eliminating the need to specially provide a protection member for protecting a light receiving element against wind etc. <P>SOLUTION: The flame sensor 1 which senses a flame by receiving infrared rays from the flame by the light receiving element 8 through a light reception window 7 is provided with a light receiving element storage part 13 comprising a light receiving element holder 15 which is mounted on a circuit board 5 to house the light receiving element 8, the light reception window 7 which is disposed in front of the light receiving element holder 15, and a light receiving element cover 16 which houses the light receiving element holder 15 while fixing the light reception window 7 to the light receiving element holder 15. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a flame detector for detecting a flame by detecting infrared rays or the like emitted from a flame with a light receiving element.

As a conventional example of a flame detector, for example, there is one described in JP-A-2002-123875 (Patent Document 1). In the fire detector described in the publication, an infrared sensor 9 for detecting infrared rays from a flame is provided inside a casing composed of a main body case 1 and a cover case 2, and the infrared sensor 9 is provided at a relative position thereof. The infrared rays from the flame are received through the sapphire glass 12 mounted in the opening 11 of the cover case 2 so that the flame can be detected.
JP 2002-123875 A

  In the conventional flame detector, a light receiving window for protecting the light receiving element (infrared sensor 9 in the conventional example) provided in the sensor so that the light receiving element can receive infrared rays from the flame. (Sapphire glass 12 in the conventional example) is provided, and the light receiving window is provided by being attached to an opening of a main body cover of the fire detector (cover case 2 in the conventional example).

  For this reason, the conventional flame detector has the following problems.

1) The operation cannot be confirmed without completing the product.
2) Check the operation after the product is completed, and if a defect is found, the main body cover must be removed before adjustment.
3) In order to protect the light receiving element from wind or the like, a protective member (protective packing 19 in the conventional example) covering the light receiving element is separately required.

  SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to obtain a flame detector that can confirm operation even before a product is completed.

  Another object of the present invention is to provide a flame detector that can eliminate the need to separately provide a protective member for protecting the light receiving element from wind or the like.

  The present invention for achieving the above object will be described as follows.

  The present invention relates to a case composed of a main body and a main body cover, a circuit board accommodated in the case, and an infrared ray received from a flame through an opening formed in the main body cover and mounted on the circuit board. A flame detector comprising: a light receiving element that is mounted on the circuit board and accommodates the light receiving element; a light receiving window positioned in front of the light receiving element holder; and A flame detector, characterized in that a light receiving element housing portion including a light receiving element cover for housing the light receiving element holder is provided while being fixed to the element holder.

  In the present invention, the light receiving window for protecting the light receiving element and allowing the light receiving element to receive the infrared rays from the flame is fixed to the light receiving element housing portion. Even so, the operation can be confirmed.

  In other words, according to the present invention, it is possible to obtain a flame detector that can confirm operation even before the product is completed.

  In the present invention, since the light receiving element is covered by the light receiving element housing portion including the light receiving element holder, the light receiving window, and the light receiving element cover, the light receiving element can be protected from wind and the like.

  That is, according to the present invention, it is possible to obtain a flame detector that can eliminate the need to separately provide a protective member for protecting the light receiving element from wind or the like.

  An embodiment of a flame detector according to the present invention will be described first with reference to FIGS. 1 is a schematic cross-sectional view taken along the line II of FIG. 2, FIG. 2 is a plan view, and FIG. 3 is a side view.

  1 to 3, the flame detector 1 includes a case 4 composed of a main body 2 and a main body cover 3, and is attached to a mounting base (not shown) by a blade fitting 27 and attached to a ceiling surface or the like ( The illustration of the blade fitting 27 is omitted in FIG.

  A light receiving element 8 is mounted on the circuit board 5 accommodated in the case 4, and an operation check lamp 9 and a contamination degree measuring light emitting element 10 that emits near infrared light are mounted close to each other.

  The main body cover 3 is formed in a frustoconical shape, and an opening 6 is formed in a concave center portion. Further, the body cover 3 is formed with a cap fitting portion 3a. The body cover 3 is made of a methacrylic resin material which is fitted into the cap fitting portion 3a and accommodates the operation check lamp 9 and the pollution degree measuring light emitting element 10. A transparent translucent cap 11 is provided.

The light receiving element 8 is housed in the light receiving element housing portion 13, and is mounted on the circuit board 5 so that the light receiving portion 8 a is positioned relative to the opening 6 of the main body cover 3. The light receiving element accommodating portion 13 surrounds the periphery of the light receiving element 8 and fixes the band pass filter 14 to the relative position with respect to the light receiving portion 8a of the light receiving element 8 by three locking claws 15b (FIGS. 2 and 4). A light receiving element holder 15 and a light receiving element holder 15 are accommodated. A light receiving window 7 made of sapphire glass is fixed to the front surface of the light receiving element holder 15 at a relative position to the light receiving portion 8a of the light receiving element 8. It consists of a transparent cylindrical light receiving element cover 16 made of a resin material. The light receiving element accommodating portion 13 is engaged 17 by a plurality of locking pieces 16b and protrusions 15c (only one set shown in FIG. 1) corresponding to the light receiving element cover 16 and the light receiving element holder 15, and the light receiving element holder 15 And the circuit board 5 are attached to the circuit board 5 by being engaged by a plurality of corresponding locking pieces 15d and locking holes 5a (only one set is shown in FIG. 4). The bandpass filter 14 has a property of transmitting only light within a specific wavelength band, and in the present embodiment, only the infrared light in the wavelength band of the CO ₂ resonance radiation emitted from the flame is used. Used for transmission.

  As a result, in the flame detector 1, infrared rays from the flame pass through the light receiving window 7 and the band pass filter 14 from the opening 6 of the main body cover 3 and are received by the light receiving portion 8 a of the light receiving element 8. The element 8 can detect the flame by detecting the infrared rays.

  The translucent cap 11 accommodates the operation confirmation lamp 9, and accommodates the first accommodation chamber 19 having the first translucent window 18 for the operation confirmation lamp 9 and the light emitting element 10 for measuring the contamination degree. And a second storage chamber 21 having a second light transmission window 20 for the measurement light emitting element 10. The first storage chamber 19 has a substantially box shape having no surface on the circuit board 5 side, and the second storage chamber 21 has a substantially box shape having no surface on the circuit board 5 side and the surface side of the main body cover 3. Is.

  In the translucent cap 11, the first translucent window 18 is formed in a quadrangular pyramid shape and the surface is formed in a satin shape, and is provided to protrude outward from the surface of the main body cover 3. The translucent window 20 is formed on the side wall 21 b of the second storage chamber 21 and is provided facing the opening 6 of the main body cover 3.

  The operation check lamp 9 is mounted with its lead wire portion 9 b directly attached to the circuit board 5, its light emitting portion 9 a is located in the first housing chamber 19 of the translucent cap 11, and the degree of contamination The light emitting element for measurement 10 is mounted on the circuit board 5 via the socket 10c, and the light emitting portion 10a is located in the second storage chamber 21 in the vicinity of the lowermost back side of the main body cover 3, Further, by bending the lead wire portion 10b, the light emitting portion 10a is bent at a predetermined bending angle and directed to the light receiving window 7, and the optical axis of the contamination degree measuring light receiving element 22 and the optical axis of each other are described later. It is oriented in the opposite direction.

  The second storage chamber 21 in which the contamination degree measuring light emitting element 10 is accommodated is provided with a light emitting part holder 21a for accommodating the light emitting part 10a of the contamination degree measuring light emitting element 10 at the tip thereof. The part holder 21 a is formed by a side wall 21 b and an inclined surface 21 c that is provided on the back side of the lowermost surface of the main body cover 3 and extends along a predetermined bending angle of the light emitting part 10 a. And the position of the light emission part 10a is controlled because the side wall 21b is located in the front side of the light emission part 10a, and the inclined surface 21c is located in the back side of the light emission part 10a.

  The contamination degree measuring light receiving element 22 that receives light from the contamination degree measuring light emitting element 10 is directly attached to the circuit board 5 and is mounted on the circuit board 5 via the element accommodating portion 13. Located on the opposite side of the light emitting element 10, the lead wire portion 22 b is bent, the light receiving portion 22 a is bent at a predetermined bending angle, and the contamination measuring light emitting element 10 and the optical axis of each other face each other. It is directed in the direction to do.

  Incidentally, the predetermined bending angle of the light emitting portion 10a of the light emitting element 10 for contamination degree measurement may be defined by bending the lead wire portion 10b by jig bending, or without depending on the jig bending. At the time of assembly, the light emitting unit 10a may be defined by being accommodated in the light emitting unit holder 21a while sliding the inclined surface 21c of the light emitting unit holder 21a, that is, the inclined surface along the predetermined bending angle of the light emitting unit 10a. In addition, when the lead wire portion 10b is bent by jig bending to define the bending angle of the light emitting portion 10a, a reaction force is generated, so it is conceivable that the bending angle becomes shallow due to a change with time, but the light emitting portion 10a. The change from the predetermined bending angle can be prevented by the inclined surface 21c along the predetermined bending angle. Here, the inclined surface 21 c of the light emitting unit holder 21 a is provided on the back side of the lowermost surface of the main body cover 3, but it may be formed in the second storage chamber 21 of the translucent cap 11.

  Furthermore, the installation position of the contamination degree measuring light emitting element 10 and the contamination degree measuring light receiving element 22 may be interchanged.

  In the flame detector 1 configured as described above, a light receiving window 7 is attached to the circuit board 5 so that the light receiving element 8 can receive infrared rays from the flame while protecting the light receiving element 8. Since the light receiving element accommodating portion 13 is provided, even before the main body cover 3 is attached, the test light as a simulated flame of a test apparatus (not shown) is made incident by using the assembly of the circuit board 5. The operation can be confirmed.

  Therefore, according to the flame detector 1, the operation can be confirmed even before the product is completed.

  In the flame detector 1, the light receiving element is covered by the light receiving element housing portion including the light receiving element holder, the light receiving window, and the light receiving element cover, so that the light receiving element can be protected from wind and the like. It is not necessary to separately provide a protective member for protecting the light receiving element from wind or the like.

  Further, in the flame detector 1, the light from the contamination measuring light emitting element 10 is formed in the second light transmitting window 20, the light receiving window 7, the notch 15 a formed in the element holder 15, and the light receiving element cover 16. Then, the light passes through the third light transmission window 16a and is received by the contamination measuring light-receiving element 22. Thereby, the light transmittance of the light receiving window 7 can be measured, and the degree of contamination of the light receiving window 7 can be known.

  Next, FIG. 4 is a schematic cross-sectional view taken along the line IV-IV in FIG. 2 and shows a sensitivity test LED 25 which is an example of a sensitivity test light emitting element for performing a sensitivity test of the light receiving element 8.

  As shown in FIG. 4, the sensitivity test LED 25 mounted on the circuit board 5 is accommodated in the light receiving element cover 16, and is attached to the light receiving element holder 15 by the sensitivity test LED support portion 26 formed on the light receiving element holder 15. It is fixed. In the sensitivity test LED 25, the light emitting portion 25a is directed to the bandpass filter 14. Specifically, the near-infrared rays emitted from the light emitting portion 25a toward the bandpass filter 14 are bandpass. The light is reflected by the filter 14 and reaches the light receiving element 8, but is directed in such a direction. The bandpass filter 14 has the property of transmitting light in the same wavelength band as the infrared rays from the flame as described above, but not transmitting light in the other wavelength bands. If the light does not pass through the filter 14, the light beam is reflected by the band pass filter 14 and reaches the light receiving element 8.

  Therefore, according to the flame detector 1, the sensitivity test of the light receiving element 8 can be performed in the light receiving element accommodating portion 13.

It is a schematic sectional drawing (II line part of FIG. 2) of the flame detector in embodiment of this invention. It is a top view of a flame detector same as the above. It is a side view of a flame detector same as the above. It is a schematic sectional drawing of a flame detector same as the above (IV-IV line part of FIG. 2).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Flame detector 2 Main body 3 Main body cover 3a Cap fitting part 4 Case 5 Circuit board 5a Locking hole 6 Concave opening 7 Light receiving window 8 Light receiving element 8a Light receiving part 9 Operation check lamp 9a Light emitting part 9b Lead wire part 10 Pollution degree Light emitting element for measurement 10a Light emitting part 10b Lead wire part 10c Socket 11 Light transmitting cap 13 Light receiving element accommodating part 14 Band pass filter 15 Light receiving element holder 15a Notch 15b Locking claw 15c Projection 15d Locking piece 16 Light receiving element cover 16a First 3 translucent window 16b Locking hole 18 1st translucent window 19 1st accommodating chamber 20 2nd translucent window 21 2nd accommodating chamber 21a Light emission part holder 21b Side wall 21c Inclined surface 22 Light reception for contamination degree measurement Element 22a Light receiving portion 22b Lead wire portion 25 LED for sensitivity test
25a Light emitting part 26 Sensitivity test LED support part

Claims (4)

A case composed of a main body and a main body cover, a circuit board housed in the case, a light receiving element mounted on the circuit board and receiving infrared rays from a flame through an opening formed in the main body cover; In a flame detector comprising:
A light receiving element holder that is mounted on the circuit board and accommodates the light receiving element, a light receiving window positioned in front of the light receiving element holder, and the light receiving window is fixed to the light receiving element holder while the light receiving element holder is accommodated. A flame detector characterized by comprising a light receiving element housing portion comprising a light receiving element cover.   The light receiving element accommodating portion is engaged with the circuit board by engaging the light receiving element holder with the circuit board and engaging the light receiving element cover with the light receiving element holder. The flame detector according to claim 1.   3. The flame detection according to claim 1, wherein a light-emitting element for sensitivity test of the light-receiving element mounted on the circuit board is housed in the light-receiving element housing portion and fixed to the light-receiving element holder. vessel. A pair of light-emitting elements and a light-receiving element for measuring the degree of contamination of the light-receiving window are mounted on the circuit board with the light-receiving element housing portion interposed therebetween,
In the light receiving element holder, a notch portion is formed on the optical axis of the light emitting element for measuring the degree of contamination and the light receiving element,
4. The flame detector according to claim 1, wherein the light receiving element cover is made of a material that transmits light from the light emitting element for measuring the degree of contamination.

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