JP4411634B2 - Flame detection device - Google Patents

Description

The present invention relates to a flame detection apparatus having a simple structure in which an ultraviolet ray detection discharge tube for detecting ultraviolet rays contained in a flame is detachably provided and the replacement work is facilitated .

As one type of flame detection device, there is a flame detection device that detects ultraviolet rays contained in a flame using an ultraviolet ray detection discharge tube (UV tube) . In this UV tube, a pair of discharge electrodes that generate ultraviolet rays upon receiving ultraviolet rays are enclosed in a cylindrical glass tube. A pair of rod-like electrodes (electrode pins) connected to the pair of discharge electrodes of the UV tube is led out from one end portion in the axial direction. The UV tube having such a structure is used, for example, as a sensor of a flame detection device that monitors a combustion state in a boiler (see, for example, Patent Document 1).

  In this type of flame detection device, as shown in FIG. 7A, sockets 1 that are respectively fitted to a pair of rod-like electrodes (electrode pins) 12 provided at one end of the UV tube 10 are provided. . This UV tube is attached to a unit holder (not shown) as shown in FIG. When the UV tube 10 breaks down or is regularly replaced, for example, an operator who performs maintenance or the like removes the UV tube 10 from the socket 1.

Further, there is known a flame detection device that can be securely attached to a unit holder with its orientation aligned without reverse connection of a pair of external connection terminals provided at the rear end of the flame detection unit (for example, Patent Documents). 2).
In the flame detection unit used in this flame detection device, a pair of external connection terminals connected to the ultraviolet sensor are arranged side by side at the rear end of the casing containing the ultraviolet sensor. On the other hand, the unit holder is provided with a pair of press contact terminals. The flame detection unit is attached to the unit holder by the operator. At this time, the external connection terminal of the flame detection unit is brought into pressure contact with the pressure contact terminal of the unit holder.
Japanese Patent Laid-Open No. 5-12581 JP 2004-37091 A

  As shown in FIG. 7, the unit holder described above cannot accommodate the UV tube 10 and the socket 1 unless it is longer than the axial length obtained by combining the length of the body portion of the UV tube 10 and the length of the socket 1. Further, the unit holder needs to have a margin for the operator to attach and detach the UV tube 10. That is, the unit holder needs a tolerance in the axial length direction in addition to the axial length described above. For this reason, there exists a problem that a unit holder becomes long. Therefore, there is a problem that the flame detection device becomes long and hinders downsizing.

  Further, the electrode pins 12 of the UV tube 10 are usually provided symmetrically around the axial center of one end of the UV tube 10 in the longitudinal direction. For this reason, there also exists a problem that the polarity of the electrode pin 12 may be misidentified. That is, when the worker attaches the UV tube 10 to the socket 1, there is a concern that the UV tube 10 is rotated around the axis and attached to the socket 1 in the opposite direction. That is, the connection (polarity) of the UV tube 10 may be reversed.

  The present invention has been made in view of such circumstances, and the object thereof is to downsize the flame detection device and to reliably attach the UV tube housed in the unit holder, and to be easily detached. It is another object of the present invention to provide a flame detection device that can also be used.

In order to achieve the above-described object, the flame detection apparatus according to the present invention has a pair of rod-like electrodes respectively connected to a pair of discharge electrodes enclosed in a cylindrical tube protruding outside from the rear end of the tube. It comprises a unit holder that detachably holds a parallel ultraviolet sensor,
The unit holder includes a receiving portion into which a front end portion of the ultraviolet sensor is fitted, a placement portion on which the rear end portion of the ultraviolet sensor with the front end portion fitted into the receiving portion is placed, and a mounting portion A pair of connection terminals provided side by side and sandwiching the pair of rod-shaped electrodes of the ultraviolet sensor ,
Each of the pair of connection terminals includes a pair of flat plate electrodes provided to face each other and sandwiching the rod-shaped electrode,
Each of the pair of flat plate electrodes is provided with a gap gradually narrowed from the mounting surface of the mounting portion to a predetermined height position, and a bent portion bent outward at the predetermined height position. The rod-shaped electrode fitted below the bent portion is pressed toward the mounting portion and sandwiched between the mounting portion .

  According to the above-described flame detection apparatus, the rod-shaped electrode (pin) of the ultraviolet sensor can be reliably held by the connection terminal constituted by the electrode that is opposed to the flat conductor provided in the unit holder. That is, this connection terminal is provided with a bent portion that is bent at different heights from the mounting surface of the unit holder on which the ultraviolet sensor is mounted to narrow the gap between the opposed flat plate electrodes. And the electrode pin of an ultraviolet sensor is reliably hold | gripped between the said bending part and said mounting surface of a pair of said flat plate electrode.

The flame detection apparatus according to the present invention, between the receiving portion and the mounting portion in said unit holder, in place of the ultraviolet sensor in contact with the two positions in the circumferential direction on the peripheral surface of the ultraviolet sensor It is characterized by including a position fixing portion for positioning.
That is, the above-described flame detection device includes, for example, a position fixing portion in which two slope portions different from each other are arranged in a V shape (for example, like a V block), and each of the two slope portions includes the UV sensor. The ultraviolet sensor is positioned at a predetermined position in contact with two locations on the pipe circumferential surface . Accordingly, the V-shaped slope portion of the position fixing portion contacts the wall portion of the ultraviolet sensor, and the ultraviolet sensor is securely positioned and fixed at a predetermined position.

Preferably, the unit holder includes an arc-shaped holding body that holds a peripheral wall of the ultraviolet sensor that is mounted by inserting a tip portion into the receiving portion, and the ultraviolet sensor is installed on the position fixing portion by the holding body. It is desirable to configure as follows.
The above-described flame detection device fixes the ultraviolet sensor at a predetermined position so as to sandwich the ultraviolet sensor between the holding body and the position fixing unit.

In addition, you may comprise the above-mentioned holding body as a cylindrical shape which has the bottom part which sealed the end part which has an internal diameter substantially larger than the outer diameter of a cylindrical ultraviolet sensor. Incidentally, a hole (insertion hole) through which an electrode pin of the ultraviolet sensor protrudes when the ultraviolet sensor is attached to the holder is provided at the bottom of the holder.
Further, the ultraviolet sensor is provided with the pair of rod-shaped electrodes around the axis thereof, and projects in an axial direction of the ultraviolet sensor so as to be eccentric from the axis to define the direction of the pair of rod-shaped electrodes. When the holding body is provided with a positioning pin, it is desirable that the holding body has a through hole through which the pair of rod-shaped electrodes are inserted at the bottom, and a pin holding portion that houses the positioning pin inside and is insulated from the outside. .
Further, the unit holder is positioned between the pair of connection terminals and prevents the insertion of the positioning pin between the pair of connection terminals, so that the pair of rod-shaped electrodes in the ultraviolet sensor mounted on the unit holder It is desirable to have a wall part that defines the direction of the arrangement of the.

  In the above-described flame detection device, for example, when the worker attaches the ultraviolet sensor to the unit holder, the mounting position of the positioning pin protruding in the same direction as the electrode pin is regulated by a wall portion that spatially partitions the electrode pins of the ultraviolet sensor. To do. For this reason, the operator can attach the ultraviolet sensor to the unit holder without reversing the polarity of the electrode pins of the ultraviolet sensor.

  As described above, in the flame detection device of the present invention, the pair of flat plate electrodes arranged on the placement surface of the unit holder on which the ultraviolet sensor is placed are bent at different heights from the placement surface, A bent portion is provided to narrow the gap between the opposed flat plate electrodes. In the flame detection device of the present invention, the electrode pin is sandwiched between the bent portion of the pair of flat plate electrodes and the mounting surface. For this reason, the electrode pin is gripped with a strong contact force from each of the two electrode plates constituting the connection terminal. Therefore, the flame detection device of the present invention can reliably bring the electrode pin into contact with the connection terminal, and can constitute a highly reliable flame detection device.

  In the flame detection device of the present invention, a position fixing unit is provided between the receiving part of the unit holder and the pair of terminals so as to contact at least two places on the peripheral wall of the UV tube and position the ultraviolet sensor at a predetermined position. . Specifically, a V-shaped position fixing part is provided at the UV tube mounting position of the unit holder. Further, the UV tube is gripped by an arc-shaped holding frame (clamp) that holds the peripheral wall of the UV tube so as not to be displaced from a predetermined position. For this reason, the flame detection device of the present invention can be reliably installed at a predetermined position of the unit holder by the guide of the position fixing unit while gripping the UV tube by the clamp.

  Furthermore, the flame detection device of the present invention is provided with a wall portion that spatially partitions the electrodes of the unit holder. This wall portion plays a role of hindering the mounting when the operator tries to mount the UV tube with the polarity reversed. Therefore, the operator can attach the UV tube to the unit holder without making a mistake in the polarity of the UV tube.

Hereinafter, a flame detection apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a schematic configuration of a flame detection apparatus according to an embodiment of the present invention. In addition, the flame detection apparatus shown in this figure is a figure which shows one Embodiment which concerns on this invention, Comprising: This invention is not limited by this figure.
Now, this flame detection apparatus is roughly composed of, for example, a flange unit 20 attached to a viewing window (not shown) such as a gas burner by an operator or the like, a unit holder 30 attached to the flange unit 20, and the unit. A shutter unit 40 incorporated in the lower part of the holder 30 is provided. In this flame detection device, an operator or the like attaches the UV tube 10 to the unit holder 30 via the holder 11 that holds the ultraviolet sensor (UV tube) 10 on the upper surface (mounting surface 36) of the unit holder 30. It is configured to be detachable. In the flame detection device, the unit holder 30 and the shutter unit 40 are collectively covered with a cover 50. The shutter unit 40 is provided opposite to the tip of the UV tube 10 attached to the unit holder 30. The shutter unit 40 includes a shutter 41 made of a leaf spring body that blocks ultraviolet rays from entering the UV tube 10 and a drive mechanism (not shown) of the shutter 41 made of an electromagnetic coil.

Incidentally, in the UV tube 10, a pair of discharge electrodes that generate an electric discharge upon receiving ultraviolet rays are enclosed in a cylindrical glass tube 10a. The UV tube 10 seals the glass tube 10a and symmetrically positions a pair of rod-like electrodes (electrode pins) 12 respectively connected to the pair of discharge electrodes from one axial end thereof. A cylindrical sealing portion 10b is provided.
On the other hand, as shown in FIGS. 2 and 3, the unit holder 30 has a tip holding portion in which an operator or the like fits the tip of the UV tube 10 on the mounting surface side (mounting surface 36) of the flange unit 20. A part (receiving part) 31 is provided. The shutter 41 described above is selectively positioned inside the tip holding portion 31. The sealing portion 10b of the UV tube 10 is provided with a positioning pin 13 in a direction that matches the protruding direction of the electrode pin 12 described above.

  The positioning pin 13 is electrically insulated from the detection element in the UV tube 10. It is provided so that the polarity of the other two electrode pins 12 can be easily distinguished from the position of the positioning pin 13. For example, when the UV tube 10 faces the rear end of the UV tube 10 in the axial direction, the polarity of the left electrode 12 is positive and the polarity of the right electrode 12 is negative when the positioning pin 13 is positioned in the center. The arrangement of each electrode pin 12 is determined so as to be. The positioning pin 13 is slightly longer than the two electrode pins 12. For this reason, an operator etc. can distinguish the positioning pin 13 and the two electrode pins 12 easily.

The UV tube 10 is attached and fixed to the holding body 11 of the unit holder 30 by an operator or the like. The holding body 11 is made of, for example, an insulating heat-resistant plastic. The holder 11 has an inner diameter substantially larger than the outer diameter of the sealing portion 10b of the UV tube 10, and has a cylindrical shape having a bottom portion sealed at one end.
This will be specifically described with reference to FIGS. A through hole 11 a is provided on one end surface of the holding body 11. When the UV tube 10 is inserted inside the holding body 11 by an operator or the like, the through hole 11a allows the electrode pin 12 of the UV tube 10 to pass through the sealing surface of the holding body 11. A pin holding portion 11 b is provided on the sealing surface of the holding body 11. When the UV tube 10 is inserted inside the holding body 11 by an operator or the like, the pin holding portion 11b stores and holds the positioning pin 13 of the UV tube 10 inside the pin holding portion 11b.

  Incidentally, the pin holding portion 11b is made of the same material as that for forming the holding body 11. When the UV tube 10 is mounted on the unit holder 30 by an operator or the like, the pin holding portion 11b plays a role of maintaining insulation even when the positioning pin 13 touches a conductive portion or the like (not shown). The pin holding portion 11b is provided with a sealing lid 11d that seals each connection terminal 32 when an operator or the like attaches the UV tube 10 to the unit holder 30. Further, a tab 11 c for fixing the holding body 11 to the unit holder 30 is provided on the outer peripheral surface of the holding body 11. Incidentally, the tab 11 c includes a screw through hole 11 e that penetrates the screw 14.

  On the other hand, on the unit holder 30 side, a screw groove 37 for receiving the screw 14 penetrating the screw through hole 11e is provided. Incidentally, when an operator or the like attaches the UV tube 10 to the unit holder 30, a slight gap is formed between the holder 11 and the unit holder 30. As will be described in detail later, this gap contributes to improving the positioning accuracy of the UV tube 10 when an operator or the like fixes the holder 11 to the unit holder 30 with the screw 14 via the screw through hole 11e. Yes.

Further, on the upper surface side (mounting surface 36) of the unit holder 30, a positioning portion 34 for positioning the UV tube 10 at a predetermined site is provided. The positioning portion 34 is provided between the screw grooves 37 and 37 described above. The positioning unit 34 plays a role of positioning the UV tube 10 at a predetermined position in combination with the holding of the UV tube 10 by the holding body 11.
Incidentally, the positioning portion 34 has a slope portion 34a having a V-shape on two surfaces. Specifically, the positioning unit 34 has a form similar to, for example, a V block. When the UV tube 10 is attached to the unit holder 30 by an operator or the like, the wall surface of the sealing portion 10b of the UV tube 10 moves so as to be in contact with each inclined surface portion 34a. Then, the UV tube 10 is positioned at a predetermined position. Specifically, when a worker or the like attaches the UV tube 10 to the holding body 11 and attaches it to the unit holder 30 on the mounting surface 36 side, a slight gap is formed between the holding body 11 and the unit holder 30. it can. Then, when an operator or the like fixes the holding body 11 to the unit holder 30 with the screws 14, the operator moves so that the cylindrical outer wall surface of the sealing portion 10 b is in contact with the slope portion 34 a of the positioning portion 34. For this reason, the UV tube 10 moves to a predetermined axial position and is positioned on the placement surface 36 side.

A pair of connection terminals 32 are provided at the rear end of the unit holder 30. The connection terminal 32 includes a pair of flat plate electrodes 33 whose electrode surfaces face each other. The electrode pins 12 of the UV tube 10 are sandwiched between the flat plate electrodes 33.
Further, the flat plate electrode 33 constituting the connection terminal 32 has bent portions 33a bent at different heights from the placement surface 36 of the unit holder 30 on which the UV tube 10 is mounted. The bent portion 33a is configured to narrow the gap between the flat plate electrodes 33. That is, the pair of flat plate electrodes 33 are arranged so that the top portions (one side) of the bent portions 33a are close to each other. When each electrode pin 12 of the UV tube 10 is inserted between the flat plate electrodes 33 facing each other by an operator or the like, the flat plate electrodes 33 are slightly bent so that the respective electrode gaps are widened. In other words, the electrode pin 12 is always placed in a state where it receives a contact force from both plate electrodes 33 due to the elastic force of both plate electrodes 33. Thus, each electrode pin 12 is sandwiched between the bent portion 33 a of the pair of flat plate electrodes 33 and the mounting surface 36.

  Now, the flame detection device of the present invention configured as described above is characterized in that the connection terminals 32 formed of a pair of opposed flat plate electrodes 33 are different in height from the mounting surface 36 of the unit holder 30. The bent portion 33a is bent at a portion, the gap between the flat plate electrodes 33 is narrowed by the bent portion 33a, and each electrode pin 12 provided in the UV tube 10 is connected to the bent portion 33a of the pair of flat plate electrodes 33. It is in a point of being sandwiched between the mounting surface 36.

Further, another feature of the flame detection apparatus according to the present invention is that a positioning portion 34 for positioning the UV tube 10 at a predetermined position of the unit holder 30 is provided. Furthermore, another feature of the flame detection apparatus according to the present invention is that a holding body 11 that securely fixes the UV tube 10 to the unit holder 30 is provided.
The flame detection device of the present invention having such a feature is obtained by bending the connection terminal 32 provided on the unit holder 30 at different heights from the placement surface 36 of the unit holder 30 on which the UV tube 10 is mounted. It has a portion 33a. The bent portion 33 a is configured to narrow the gap between the flat plate electrodes 33. For this reason, the flame detection device of the present invention can prevent a decrease in contact force between the electrode pin 12 and the connection terminal 32 due to an assembly error when the UV tube 10 is mounted on the unit holder 30. In particular, the plate electrode 33 has an electrode structure that narrows the gap between the plate electrodes 33. For this reason, when an operator or the like attaches the UV tube 10 to the unit holder 30, the electrode pin 12 of the UV tube 10 is locked by the top portion. Therefore, even if vibration or the like is applied to the flame detection device, the UV tube 10 is not detached from the connection terminal 32, and of course, contact failure does not occur. For this reason, it becomes possible to comprise a highly reliable flame detection apparatus.

Further, the connection terminal 32 is configured to sandwich the electrode pin 12 of the UV tube 10 with the plate electrode 33. For this reason, the axial direction of the UV tube 10 attached to the unit holder 30 can be short. Therefore, the flame detection device can be reduced in size.
Further, the unit holder 30 is provided with a positioning portion 34. The positioning portion 34 has a form similar to a V block that positions the UV tube 10 at a predetermined position. Then, when the worker or the like assembles the UV tube 10 to the unit holder 30, the wall surface of the UV tube 10 comes into contact with the slope portion 34 a of the positioning portion 34 at two sides. At this time, the UV tube 10 is positioned at a predetermined portion while being in contact with the inclined surface portion 34a. Therefore, it is possible to reduce assembly errors when assembled to the unit holder 30. For this reason, the electrode pin 12 of the UV tube 10 is more securely held between the connection terminals 32. For this reason, it is possible to configure a highly reliable flame detection device.

Furthermore, the flame detection apparatus of the present invention includes a holding body 11 that holds the UV tube 10. The holding body 11 is provided with a pin holding portion 11b. This pin holding part 11b accommodates and holds the positioning pin 13 provided at the rear end part of the UV tube 10 therein.
Specifically, when an operator or the like tries to attach the UV tube 10 to the unit holder 30 in the reverse direction with the UV tube 10 held by the holder 11, a wall provided between the connection terminals 32 and 32. The part 35 prevents the pin holding part 11b from entering. For this reason, the UV tube 10 is not sandwiched between the connection terminals 32. That is, the UV tube 10 is correctly attached to the unit holder 30 by an operator or the like only when the condition that the wall portion 35 provided between the connection terminals 32 and 32 does not become an obstacle is satisfied. For this reason, the malfunction which connects the electrode pin 12 of the UV tube 10 in reverse direction (reverse polarity) is not caused. The pin holding portion 11b also plays a role of maintaining insulation so that the positioning pin 13 does not touch the conductive portion or the like (not shown) when the UV tube 10 is attached to the unit holder 30 by an operator or the like. .

The tab 11 c provided on the outer peripheral surface of the holding body 11 is provided with a screw through hole 11 e that penetrates the screw 14. For this reason, an operator or the like can fix the UV tube 10 to the unit holder 30 by attaching the holding body 11 to the unit holder 30 through the screw through hole 11e.
Further, when the worker or the like attaches the UV tube 10 to the unit holder 30 via the holding body 11, the worker or the like screws the holding body 11 with the screw 14, and between the holding body 11 and the unit holder 30. The gaps are eliminated. For this reason, combined with the positioning effect of the UV tube 10 by the positioning portion 34, the UV tube 10 can be more reliably positioned at a predetermined site. Further, since the holding body 11 is screwed to the unit holder 30, the UV tube 10 is not detached from the connection terminal 32 even if vibration or the like is applied to the flame detection device. For this reason, it becomes possible to comprise a highly reliable flame detection apparatus.

  In addition, although the apparatus using a UV tube was illustrated here, when using a semiconductor optical sensor, it can implement similarly. In addition, the present invention can be variously modified and implemented without departing from the scope of the invention.

The disassembled perspective view which shows the schematic whole structure of the flame detection apparatus which concerns on one Embodiment of this invention. The perspective view which shows the schematic external appearance shape of the unit holder in the flame detection apparatus shown in FIG. The top view which shows the schematic external appearance shape of the unit holder in the flame detection apparatus shown in FIG. The perspective view which shows the schematic external appearance shape of the holding body with which the flame detection apparatus shown in FIG. 1 is mounted | worn. The top view which looked at the unit holder with which the holding body shown in FIG. 4 is mounted | worn from the rear-end part. The figure for demonstrating the rough external appearance shape and its mounting state of UV tube with which the holding body shown in FIG. 4 is mounted | worn. The figure for demonstrating the mounting state of UV tube and a socket in the conventional flame detection apparatus.

Explanation of symbols

10 UV tube 11 Holder 12 Electrode pin (bar electrode)
13 Positioning Pin 20 Flange Unit 30 Unit Holder 32 Connection Terminal 34 Positioning Part

Claims (4)

A unit holder for detachably holding a UV sensor provided in parallel with a pair of rod-like electrodes connected to a pair of discharge electrodes enclosed in a cylindrical tube projecting from the rear end of the tube to the outside. A flame detection device,
The unit holder includes a receiving portion into which a front end portion of the ultraviolet sensor is fitted, a placement portion on which the rear end portion of the ultraviolet sensor with the front end portion fitted into the receiving portion is placed, and a mounting portion A pair of connection terminals provided side by side and sandwiching the pair of rod-shaped electrodes of the ultraviolet sensor ,
Each of the pair of connection terminals includes a pair of flat plate electrodes provided to face each other and sandwiching the rod-shaped electrode,
Each of the pair of flat plate electrodes is provided with a gap gradually narrowed from the mounting surface of the mounting portion to a predetermined height position, and a bent portion bent outward at the predetermined height position. A flame detecting device , wherein the rod-like electrode fitted below the bent portion is pressed toward the mounting portion and sandwiched between the mounting portion and the mounting portion. . The unit holder is provided with a position fixing portion that is in contact with two circumferential positions on the circumferential surface of the ultraviolet sensor and defines the placement position of the ultraviolet sensor with respect to the placement portion, and the receiving portion and the placement portion. The flame detection device according to claim 1, wherein the flame detection device is provided in between . The ultraviolet sensor is provided with the pair of rod-shaped electrodes symmetrically about the axis thereof, and is positioned in the axial direction of the ultraviolet sensor so as to be eccentrically projected from the axis to define the alignment direction of the pair of rod-shaped electrodes. With pins,
The unit holder has a cylindrical shape having a bottom portion sealed at one end , and includes a holding body that is attached to the rear end portion of the ultraviolet sensor and is detachably provided on the mounting portion.
The said holding body is provided with the through-hole which each penetrates a pair of said rod-shaped electrode in the bottom part, and the pin holding part which accommodates the said positioning pin inside and insulates from the outside. The flame detection apparatus described in 1. The ultraviolet sensor is provided with the pair of rod-shaped electrodes symmetrically about the axis thereof, and is positioned in the axial direction of the ultraviolet sensor so as to be eccentrically projected from the axis to define the alignment direction of the pair of rod-shaped electrodes. With pins,
The unit holder is positioned between the pair of connection terminals and prevents the insertion of the positioning pins between the pair of connection terminals , and the array of the pair of rod-shaped electrodes in the ultraviolet sensor mounted on the unit holder. flame detector according to claim 1 or 2 characterized by having a wall portion defining the orientation.

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